This document summarizes research on scaling limits of CMOS devices and proposed structures to overcome these limits. It first discusses how quantum mechanical effects and short channel effects become problematic as devices are scaled down, limiting further scaling. It then reviews various structures proposed by other researchers, including fully depleted SOI MOSFETs with strained silicon channels, dual material gates, and gate-all-around structures. Finally, it proposes a new structure combining these elements: a fully depleted SOI gate-all-around MOSFET using a strained silicon channel and dual material gate to address scaling challenges while improving performance.
Microelectronic technology
This report briefly discusses the need for Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs), their structure and principle of operation. Then it details the fabrication and characterization of the MOSFETs fabricated at the microelectronic lab at University of Malaya
shows the simulation and analysis of a MOSFET device using the MOSFet tool. Several powerful analytic features of this tool are demonstrated, including the following:
calculation of Id-Vg curves
potential contour plots along the device at equilibrium and at the final applied bias
electron density contour plots along the device at equilibrium and at the final applied bias
spatial doping profile along the device
1D spatial potential profile along the device
Dual Metal Gate and Conventional MOSFET at Sub nm for Analog ApplicationVLSICS Design
This document summarizes a study comparing a conventional MOSFET and dual metal gate (DMG) MOSFET at the 30nm technology node. Simulations were performed using Silvaco TCAD tools. Key results include:
1) The DMG MOSFET has a lower subthreshold slope and significantly lower gate leakage current compared to the conventional MOSFET.
2) Mobility and transconductance are higher in the DMG MOSFET, indicating better performance for analog applications that require high gain.
3) The DMG MOSFET has a higher intrinsic delay, making it more suitable for applications operated at lower voltages such as filters and sample-and-hold circuits, where gate
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
This document discusses how different gate dielectric materials affect the threshold voltage of nanoscale MOSFETs. Simulations were conducted using MATLAB and SCHRED software to obtain C-V characteristics for MOSCAP structures with different dielectric materials (PTFE, Polyethylene, SiO2) and thicknesses. Threshold voltages were extracted from the C-V curves using classical, semi-classical, and quantum mechanical models. The results show that lower dielectric constant materials like PTFE reduce threshold voltage more than higher k materials like SiO2. PTFE is suggested as a suitable low-k material for developing MOSFETs and interconnects at the nanoscale.
Threshold Voltage Roll-off by Structural Parameters for Sub-10 nm Asymmetric ...TELKOMNIKA JOURNAL
This study is to analyze threshold voltage roll-off according to structural parameters of sub-10 nm
asymmetric double gate MOSFET. In case of sub-10nm channel length, because of short channel effects
resulting from the rapid increase of tunneling current, even asymmetric double gate (DG) MOSFET, which
has been developed for reducing short channel effects, will increase threshold voltage roll-off, and this is
an obstacle against the miniaturization of asymmetric DGMOSFET. Especially, since asymmetric
DGMOSFET can be produced differently in top and bottom oxide thickness, top/bottom oxide thickness will
affect the threshold voltage roll-off. To analyze this, thermal emission current and tunneling current model
have been calculated, and threshold voltage roll-off in accordance with the reduction of channel length has
been analyzed by using channel thickness and top/bottom oxide thickness as parameters. As a result, it is
found that, in short channel asymmetric double gate MOSFET, threshold voltage roll-off is changed greatly
according to top/bottom gate oxide thickness, and that threshold voltage roll-off, in particular, is generated
more greatly according to silicon thickness. In addition, it is found that top and bottom oxide thickness have
a relation of inverse proportion mutually for maintaining identical threshold voltage.
SPICE model of drain induced barrier lowering in sub-10 nm junctionless cylin...IJECEIAES
We propose a SPICE Drain Induced Barrier Lowering (DIBL) model for sub10 nm Junctionless Cylindrical Surrounding Gate (JLCSG) MOSFETs. The DIBL shows the proportionl relation to the -3 power of the channel length L g and the 2 power of silicon thickness in MOSFET having a rectangular channel, but this relation cannot be used in cylindrical channel because of the difference in channel structure. The subthreshold currents, including the tunneling current from the WKB (Wentzel-Kramers-Brillouin) approximation as well as the diffusion-drift current, are used in the model. The constant current method is used to define the threshold voltage as the gate voltage at a constant current, (2πR/L g ) 10 -7 A for channel length and channel radius R. The central potential of the JLCSG MOSFET is determined by the Poisson equation. As a result, it can be seen that the DIBL of the JLCSG MOSFET is proportional to the –2.76 power of the channel length, to the 1.76 power of the channel radius, and linearly to the oxide film thickness. At this time, we observe that the SPICE parameter, the static feedback coefficient, has a value less than 1, and this model can be used to analyze the DIBL of the JLCSG MOSFET.
The document provides an overview of the history and scaling of transistors and integrated circuits. It discusses how vacuum tubes were replaced by transistors, with the first transistor invented in 1947 and the first integrated circuit in 1958. It describes how continuous scaling and improvements in silicon manufacturing have led to billions of transistors being integrated onto a single chip today. The document then discusses different transistor technologies, including MOSFETs, and how scaling to smaller sizes introduced challenges like short channel effects that new transistor designs like FinFETs help address.
Microelectronic technology
This report briefly discusses the need for Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs), their structure and principle of operation. Then it details the fabrication and characterization of the MOSFETs fabricated at the microelectronic lab at University of Malaya
shows the simulation and analysis of a MOSFET device using the MOSFet tool. Several powerful analytic features of this tool are demonstrated, including the following:
calculation of Id-Vg curves
potential contour plots along the device at equilibrium and at the final applied bias
electron density contour plots along the device at equilibrium and at the final applied bias
spatial doping profile along the device
1D spatial potential profile along the device
Dual Metal Gate and Conventional MOSFET at Sub nm for Analog ApplicationVLSICS Design
This document summarizes a study comparing a conventional MOSFET and dual metal gate (DMG) MOSFET at the 30nm technology node. Simulations were performed using Silvaco TCAD tools. Key results include:
1) The DMG MOSFET has a lower subthreshold slope and significantly lower gate leakage current compared to the conventional MOSFET.
2) Mobility and transconductance are higher in the DMG MOSFET, indicating better performance for analog applications that require high gain.
3) The DMG MOSFET has a higher intrinsic delay, making it more suitable for applications operated at lower voltages such as filters and sample-and-hold circuits, where gate
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
This document discusses how different gate dielectric materials affect the threshold voltage of nanoscale MOSFETs. Simulations were conducted using MATLAB and SCHRED software to obtain C-V characteristics for MOSCAP structures with different dielectric materials (PTFE, Polyethylene, SiO2) and thicknesses. Threshold voltages were extracted from the C-V curves using classical, semi-classical, and quantum mechanical models. The results show that lower dielectric constant materials like PTFE reduce threshold voltage more than higher k materials like SiO2. PTFE is suggested as a suitable low-k material for developing MOSFETs and interconnects at the nanoscale.
Threshold Voltage Roll-off by Structural Parameters for Sub-10 nm Asymmetric ...TELKOMNIKA JOURNAL
This study is to analyze threshold voltage roll-off according to structural parameters of sub-10 nm
asymmetric double gate MOSFET. In case of sub-10nm channel length, because of short channel effects
resulting from the rapid increase of tunneling current, even asymmetric double gate (DG) MOSFET, which
has been developed for reducing short channel effects, will increase threshold voltage roll-off, and this is
an obstacle against the miniaturization of asymmetric DGMOSFET. Especially, since asymmetric
DGMOSFET can be produced differently in top and bottom oxide thickness, top/bottom oxide thickness will
affect the threshold voltage roll-off. To analyze this, thermal emission current and tunneling current model
have been calculated, and threshold voltage roll-off in accordance with the reduction of channel length has
been analyzed by using channel thickness and top/bottom oxide thickness as parameters. As a result, it is
found that, in short channel asymmetric double gate MOSFET, threshold voltage roll-off is changed greatly
according to top/bottom gate oxide thickness, and that threshold voltage roll-off, in particular, is generated
more greatly according to silicon thickness. In addition, it is found that top and bottom oxide thickness have
a relation of inverse proportion mutually for maintaining identical threshold voltage.
SPICE model of drain induced barrier lowering in sub-10 nm junctionless cylin...IJECEIAES
We propose a SPICE Drain Induced Barrier Lowering (DIBL) model for sub10 nm Junctionless Cylindrical Surrounding Gate (JLCSG) MOSFETs. The DIBL shows the proportionl relation to the -3 power of the channel length L g and the 2 power of silicon thickness in MOSFET having a rectangular channel, but this relation cannot be used in cylindrical channel because of the difference in channel structure. The subthreshold currents, including the tunneling current from the WKB (Wentzel-Kramers-Brillouin) approximation as well as the diffusion-drift current, are used in the model. The constant current method is used to define the threshold voltage as the gate voltage at a constant current, (2πR/L g ) 10 -7 A for channel length and channel radius R. The central potential of the JLCSG MOSFET is determined by the Poisson equation. As a result, it can be seen that the DIBL of the JLCSG MOSFET is proportional to the –2.76 power of the channel length, to the 1.76 power of the channel radius, and linearly to the oxide film thickness. At this time, we observe that the SPICE parameter, the static feedback coefficient, has a value less than 1, and this model can be used to analyze the DIBL of the JLCSG MOSFET.
The document provides an overview of the history and scaling of transistors and integrated circuits. It discusses how vacuum tubes were replaced by transistors, with the first transistor invented in 1947 and the first integrated circuit in 1958. It describes how continuous scaling and improvements in silicon manufacturing have led to billions of transistors being integrated onto a single chip today. The document then discusses different transistor technologies, including MOSFETs, and how scaling to smaller sizes introduced challenges like short channel effects that new transistor designs like FinFETs help address.
This paper analyzes the reliability of MOSFETs that use indium-tin oxide as the gate oxide instead of silicon dioxide. Interface trap charges at the oxide-silicon interface can degrade MOSFET performance by changing the threshold voltage over time. The paper finds that MOSFETs using indium-tin oxide exhibit improved immunity to the effects of interface trap charges compared to those using silicon dioxide. Specifically, indium-tin oxide MOSFETs show enhanced static, linearity, and intermodulation performance metrics when subjected to both positive and negative interface trap charges. Thus, indium-tin oxide has potential to improve MOSFET reliability by reducing sensitivity to interface trap charge effects.
Design of carbon nanotube field effect transistor (CNTFET) small signal model IJECEIAES
The progress of Carbon Nanotube Field Effect Transistor (CNTFET) devices has facilitated the trimness of mobile phones, computers and all other electronic devices. CNTFET devices contribute to model these electronics instruments that require designing the devices. This research consists of the design and verification of the CNTFET device's small signal model. Scattering parameters (S-parameters) is extracted from the CNTFET model to construct equivalent small model circuit. Current sources, capacitors and resistors are involved to evaluate this equivalent circuit. S-parameters and small signal models are elaborated to analyze using a technique to form the small signal equivalent circuit model. In this design modeling process, at first intrinsic device's Y-parameters are determined. After that series of impedances are calculated. At last, Y-parameters model are transformed to add parasitic capacitances. The analysis result shows the acquiring high frequency performances are obtained from this equivalent circuit.
This document summarizes the design and performance analysis of 20nm silicon/germanium channel pentagonal and trapezoidal nanowire transistors. It presents the objectives of designing these nanowire transistors with different process parameters like diameter and height. The methodology involves using TCAD software to simulate the transfer characteristics, output characteristics, and short channel effects for different cross-sectional shapes and materials. The results show that pentagonal and trapezoidal nanowire transistors with germanium channels exhibit higher on-currents and on/off current ratios than triangular nanowire transistors. Key performance metrics like subthreshold swing and DIBL are also better for the pentagonal and trapezoidal nanowire transistors.
Clad metals are composite metal containing two or more layers that have been bonded together. The bonding may have been accomplished by rolling, extrusion, welding, diffusion bonding, casting, heavy chemical deposition, or heavy electroplating. Clad metals offer the opportunity to combine desirable properties and/or characteristics of individual metals and alloys into a material "system" that provides improved characteristics over the individual metals. In the event the bond quality is compromised, these materials will not meet their original purpose. Disbond in clad layers is very similar to an internal void in single layer materials such as steel strip material.
Design of Nanoscale 3-T DRAM using FinFETIOSR Journals
This document describes the design of a 3-transistor (3T) dynamic random access memory (DRAM) cell using both CMOS and FinFET technologies at the 32nm node. Simulation results show that the FinFET-based DRAM cell has lower average power (9.5136uW vs 10.869uW), lower power dissipation (144.7353uW vs 235.2313uW), and much lower leakage power (2.4303nW vs 1.8781uW) compared to the CMOS-based cell. FinFET devices are able to better control short channel effects at small scales compared to planar CMOS, enabling lower power DRAM designs. The document provides
This document discusses carbon nanotube field-effect transistors (CNTFETs) as a potential substitute for MOSFETs. CNTFETs could help overcome limitations of MOSFET scaling by providing higher carrier mobility, excellent electrostatics, and gate control. CNTFETs exhibit advantages like better threshold voltage and subthreshold slope control as well as higher current density and transconductance compared to MOSFETs. However, mass production of CNTFETs faces challenges related to defects, failure rates, and production costs that are higher than for traditional CMOS.
Performance analysis of cntfet and mosfet focusing channel length, carrier mo...IJAMSE Journal
Enhancement of switching in nanoelectronics, Carbon Nano Tube (CNT) could be utilized in nanoscaled Metal Oxide Semiconductor Field Effect Transistor (MOSFET). In this review, we present an in depth discussion of performances Carbon Nanotube Field Effect Transistor (CNTFET) and its significance in nanoelectronic circuitry in comparison with Metal Oxide Semiconductor Field Effect Transistor(MOSFET). At first, we have discussed the structural unit of Carbon Nanotube and characteristic electrical behaviors beteween CNTFET and MOSFET. Short channel effect and effects of scattering and electric field on mobility of CNTFET and MOSFET have also been discussed. Besides, the nature of ballistic transport
and profound impact of gate capacitance along with dielectric constant on transconductance have also
have been overviewed. Electron ballistic transport would be the key in short channel regime for high speed
switching devices. Finally, a comparative study on the characteristics of contact resistance over switching
capacity between CNTFET and MOSFET has been addressed.
This document discusses MOSFET scaling and emerging nanoelectronic devices. It begins by outlining the objectives and introducing MOSFET scaling and its limits. It then describes techniques used for continued MOSFET scaling like strained silicon and high-k dielectrics. Emerging devices like FinFETs, organic field-effect transistors, and single electron transistors are also summarized. Fabrication processes for devices like TiOx single electron transistors using STM oxidation are briefly outlined.
The document summarizes a presentation on modeling and simulating ballistic transport in carbon nanotube field effect transistors (CNTFETs). It compares the performance of Schottky-barrier and doped-contact CNTFET structures. Key findings from simulations using the non-equilibrium Green's function formalism include that doped-contact CNTFETs provide higher drive currents. Thinner gate oxides and higher dielectric constants improve device electrostatics and increase on/off current ratios for both device types. Smaller nanotube diameters also increase performance by providing a larger bandgap and better electrostatic control.
The document presents a study of ballistic transport in carbon nanotube field effect transistors (CNTFETs) using numerical modeling and simulation. It compares the performance of Schottky-barrier CNTFETs and MOSFET-like CNTFETs. Key findings include that thinner oxides and higher dielectric constant materials provide better electrostatic gate control and higher on-off current ratios, and that doped contact CNTFETs generally exhibit better performance than Schottky-barrier CNTFETs. The study provides insights into scaling effects and quantum phenomena in CNTFET devices.
ULTRA HIGH SPEED FACTORIAL DESIGN IN SUB-NANOMETER TECHNOLOGYcscpconf
This work proposes a high speed and low power factorial design in 22nm technology and also it counts the effect of sub nano-meter constraints on this circuit. A comparative study for this
design has been done for 90nm, 45nm and 22nm technology. The rise in circuit complexity and speed is accompanied by the scaling of MOSFET’s. The transistor saturation current Idsat is an important parameter because the transistor current determines the time needed to charge and discharge the capacitive loads on chip, and thus impacts the product speed more than any other transistor parameter. The efficient implementation of a factorial number is carried out by using
a decremented and multipliers which has been lucidly discussed in this paper. Normally in a factorial module a number is calculated as the iterative multiplication of the given number to
the decremented value of the given number. A Parallel adder based decremented has been proposed for calculating the factorial of any number that also includes 0 and 1. The
performances are calculated by using the existing 90-nm CMOS technology and scaling down the existing technology to 45-nm and 22-nm.
Impact of multiple channels on the Characteristics of Rectangular GAA MOSFET IJECEIAES
Square gate all around MOSFETs are a very promising device structures allowing to continue scaling due to their superior control over the short channel effects. In this work a numerical study of a square structure with single channel is compared to a structure with 4 channels in order to highlight the impact of channels number on the device’s DC parameters (drain current and threshold voltage). Our single channel rectangular GAA MOSFET showed reasonable ratio Ion/Ioff of 10 4 , while our four channels GAA MOSFET showed a value of 10 3 . In addition, a low value of drain induced barrier lowering (DIBL) of 60mV/V was obtained for our single channel GAA and a lower value of with 40mv/v has been obtained for our four channel one. Also, an extrinsic transconductance of 88ms/µm have been obtained for our four channels GAA compared to the single channel that is equal to 7ms/µm.
IMPACT OF STRAIN AND CHANNEL THICKNESS ON PERFORMANCE OF BIAXIAL STRAINED SIL...VLSICS Design
In this paper the impact of strain and channel thickness on the performance of biaxial strained silicon MOSFET with 40 nm channel length has been analyzed by simulation in TCAD Sentaurus Simulator. With the increase in the mole fraction of germanium at the interface of the channel region, the strain in the silicon channel increases and with it the mobility of the carriers increases and thus the drain current increases. The mole fraction in this paper is varied from 0 to 0.3. Other than mobility, the increase in strain also shows improvement in other performance parameters. The impact of variation in channel thickness on the functionality parameters of the MOSFET has also been analyzed. The channel thickness cannot be increased more than the critical thickness and therefore, in this paper the thickness is varied from 2nm to 20 nm. It is observed that beyond 10nm the performance improvement gets saturated and therefore the critical thickness for the channel of this structure is 10nm..
Carbon nanotube field-effect transistors (CNTFETs) have advantages over traditional MOSFETs by avoiding issues like short channel effects and high leakage currents that arise from continuous MOSFET scaling. CNTFETs use carbon nanotubes that can be metallic or semiconducting depending on their structure. They have a similar structure to MOSFETs but current flow depends on ballistic transport and electron confinement in the CNT. CNTFETs also have lower quantum capacitance than MOSFETs, resulting in lower propagation delay. Neural networks are well-suited for modeling CNTFETs with their simple, continuous equations that can account for channel length variations. However, precisely controlling CNT
Design, Construction and Implementation of a Bradbury-Nielsen Gate for Time-o...David Torre
The document describes the design, construction, and testing of a Bradbury-Nielsen Gate (BNG) for use in time-of-flight calculations of an electrospray thruster. A 50-wire BNG was constructed with a 3"x3" frame and 2"x2" inner window using Delrin. Experimental testing confirmed the BNG could deflect the ion beam as expected, reducing current by up to 94% when powered on. However, issues with thermal expansion, noise, and the thruster prevented reliable time-of-flight measurements. Future work is needed to address these issues and obtain more precise experimental hardware.
Deterioration of short channel effectsijistjournal
This document presents an analytical model for surface potential and electric field in a novel dual halo triple material surrounding gate (DH-TMSG) MOSFET structure. The DH-TMSG incorporates symmetrical dual halo regions near the source and drain, and a triple material gate. The analytical model uses a parabolic approximation method and boundary conditions to derive expressions for surface potential. Simulation results show that the DH-TMSG design significantly reduces short channel effects by producing peaks and steps in the surface potential and electric field profiles through the channel. This improves carrier transport and device performance compared to other multi-gate structures.
SUB TEN MICRON CHANNEL DEVICES ACHIEVED BY VERTICAL ORGANIC THIN FILM TRANSI...VLSICS Design
The channel lengths of the top contact organic thin film transistors are usually defined during their fabrication by optical lithography or by shadow masking during the metal deposition process. Realizing short channel (sub-ten micron channel length) transistors by lithography will require costly lithography equipment. On the other hand, it is extremely challenging to achieve short channel transistors using the low cost shadow mask process. One low cost method of achieving short channel devices is to build vertical transistors with the transistor, where the channel gets defined in the vertical part of the device. This paper shows that vertical channel top contact organic thin film transistor has been successfullyrealized on the vertical edge of trench. This helped in creating the device with channel lengths less than ten microns, much smaller than what could be typically achieved with the use of shadow masks.
DESIGN OF DIFFERENT DIGITAL CIRCUITS USING SINGLE ELECTRON DEVICESmsejjournal
Single Electron transistor (SET) is foreseen as an excellently growing technology. The aim of this paper is
to present in short the fundamentals of SET as well as to realize its application in the design of single
electron device based novel digital logic circuits with the help of a Monte Carlo based simulator. A Single
Electron Transistors (SET) is characterized by two most substantial determinants. One is very low power
dissipation while the other is its small stature that makes it a favorable suitor for the future generation of
very high level integration. With the utilization of SET, technology is moving past CMOS age resulting in
power efficient, high integrity, handy and high speed devices. Conducting a check on the transport of single
electrons is one of the most stirring aspects of SET technologies. Apparently, Monte Carlo technique is in
vogue in terms of simulating SED based circuits. Hence, a MC based tool called SIMON 2.0 is exercised
upon for the design and simulation of these digital logic circuits. Further, an efficient functioning of the
logic circuits such as multiplexers, decoders, adders and converters are illustrated and established by
means of circuit simulation using SIMON 2.0 simulator.
This document summarizes a study that used finite element analysis and Monte Carlo simulation to analyze the probabilistic design and random optimization of an aerofoil wing made of composite materials. The study modeled an NACA0012 aerofoil composite structure in ANSYS and varied design parameters like chord length, ply angle, elastic modulus, and loading conditions randomly to analyze uncertainty in bending stress. Over 1000 simulations were run. Optimization was also performed to find a set of design variables that reduced the bending stress objective function. The best set reduced bending stress from 1131.79 N/mm2 to 180.58 N/mm2. The study concluded there was significant uncertainty when chord length and ply angle varied and provided correlations between design variables and bending
This document discusses optimization of boiler blowdown and blowdown heat recovery in the textile industry. It finds that 1.3% of total fuel is typically wasted through boiler blowdown. By installing an automatic blowdown system and a heat recovery system, up to 85% of the wasted fuel can be recovered. This reduces fuel costs and increases boiler efficiency. Recovering blowdown heat helps raise the temperature of feedwater entering the boiler, allowing up to a 1% reduction in fuel consumption. Proper optimization of blowdown and use of heat recovery systems can significantly improve energy efficiency in textile industry boiler operations.
This paper analyzes the reliability of MOSFETs that use indium-tin oxide as the gate oxide instead of silicon dioxide. Interface trap charges at the oxide-silicon interface can degrade MOSFET performance by changing the threshold voltage over time. The paper finds that MOSFETs using indium-tin oxide exhibit improved immunity to the effects of interface trap charges compared to those using silicon dioxide. Specifically, indium-tin oxide MOSFETs show enhanced static, linearity, and intermodulation performance metrics when subjected to both positive and negative interface trap charges. Thus, indium-tin oxide has potential to improve MOSFET reliability by reducing sensitivity to interface trap charge effects.
Design of carbon nanotube field effect transistor (CNTFET) small signal model IJECEIAES
The progress of Carbon Nanotube Field Effect Transistor (CNTFET) devices has facilitated the trimness of mobile phones, computers and all other electronic devices. CNTFET devices contribute to model these electronics instruments that require designing the devices. This research consists of the design and verification of the CNTFET device's small signal model. Scattering parameters (S-parameters) is extracted from the CNTFET model to construct equivalent small model circuit. Current sources, capacitors and resistors are involved to evaluate this equivalent circuit. S-parameters and small signal models are elaborated to analyze using a technique to form the small signal equivalent circuit model. In this design modeling process, at first intrinsic device's Y-parameters are determined. After that series of impedances are calculated. At last, Y-parameters model are transformed to add parasitic capacitances. The analysis result shows the acquiring high frequency performances are obtained from this equivalent circuit.
This document summarizes the design and performance analysis of 20nm silicon/germanium channel pentagonal and trapezoidal nanowire transistors. It presents the objectives of designing these nanowire transistors with different process parameters like diameter and height. The methodology involves using TCAD software to simulate the transfer characteristics, output characteristics, and short channel effects for different cross-sectional shapes and materials. The results show that pentagonal and trapezoidal nanowire transistors with germanium channels exhibit higher on-currents and on/off current ratios than triangular nanowire transistors. Key performance metrics like subthreshold swing and DIBL are also better for the pentagonal and trapezoidal nanowire transistors.
Clad metals are composite metal containing two or more layers that have been bonded together. The bonding may have been accomplished by rolling, extrusion, welding, diffusion bonding, casting, heavy chemical deposition, or heavy electroplating. Clad metals offer the opportunity to combine desirable properties and/or characteristics of individual metals and alloys into a material "system" that provides improved characteristics over the individual metals. In the event the bond quality is compromised, these materials will not meet their original purpose. Disbond in clad layers is very similar to an internal void in single layer materials such as steel strip material.
Design of Nanoscale 3-T DRAM using FinFETIOSR Journals
This document describes the design of a 3-transistor (3T) dynamic random access memory (DRAM) cell using both CMOS and FinFET technologies at the 32nm node. Simulation results show that the FinFET-based DRAM cell has lower average power (9.5136uW vs 10.869uW), lower power dissipation (144.7353uW vs 235.2313uW), and much lower leakage power (2.4303nW vs 1.8781uW) compared to the CMOS-based cell. FinFET devices are able to better control short channel effects at small scales compared to planar CMOS, enabling lower power DRAM designs. The document provides
This document discusses carbon nanotube field-effect transistors (CNTFETs) as a potential substitute for MOSFETs. CNTFETs could help overcome limitations of MOSFET scaling by providing higher carrier mobility, excellent electrostatics, and gate control. CNTFETs exhibit advantages like better threshold voltage and subthreshold slope control as well as higher current density and transconductance compared to MOSFETs. However, mass production of CNTFETs faces challenges related to defects, failure rates, and production costs that are higher than for traditional CMOS.
Performance analysis of cntfet and mosfet focusing channel length, carrier mo...IJAMSE Journal
Enhancement of switching in nanoelectronics, Carbon Nano Tube (CNT) could be utilized in nanoscaled Metal Oxide Semiconductor Field Effect Transistor (MOSFET). In this review, we present an in depth discussion of performances Carbon Nanotube Field Effect Transistor (CNTFET) and its significance in nanoelectronic circuitry in comparison with Metal Oxide Semiconductor Field Effect Transistor(MOSFET). At first, we have discussed the structural unit of Carbon Nanotube and characteristic electrical behaviors beteween CNTFET and MOSFET. Short channel effect and effects of scattering and electric field on mobility of CNTFET and MOSFET have also been discussed. Besides, the nature of ballistic transport
and profound impact of gate capacitance along with dielectric constant on transconductance have also
have been overviewed. Electron ballistic transport would be the key in short channel regime for high speed
switching devices. Finally, a comparative study on the characteristics of contact resistance over switching
capacity between CNTFET and MOSFET has been addressed.
This document discusses MOSFET scaling and emerging nanoelectronic devices. It begins by outlining the objectives and introducing MOSFET scaling and its limits. It then describes techniques used for continued MOSFET scaling like strained silicon and high-k dielectrics. Emerging devices like FinFETs, organic field-effect transistors, and single electron transistors are also summarized. Fabrication processes for devices like TiOx single electron transistors using STM oxidation are briefly outlined.
The document summarizes a presentation on modeling and simulating ballistic transport in carbon nanotube field effect transistors (CNTFETs). It compares the performance of Schottky-barrier and doped-contact CNTFET structures. Key findings from simulations using the non-equilibrium Green's function formalism include that doped-contact CNTFETs provide higher drive currents. Thinner gate oxides and higher dielectric constants improve device electrostatics and increase on/off current ratios for both device types. Smaller nanotube diameters also increase performance by providing a larger bandgap and better electrostatic control.
The document presents a study of ballistic transport in carbon nanotube field effect transistors (CNTFETs) using numerical modeling and simulation. It compares the performance of Schottky-barrier CNTFETs and MOSFET-like CNTFETs. Key findings include that thinner oxides and higher dielectric constant materials provide better electrostatic gate control and higher on-off current ratios, and that doped contact CNTFETs generally exhibit better performance than Schottky-barrier CNTFETs. The study provides insights into scaling effects and quantum phenomena in CNTFET devices.
ULTRA HIGH SPEED FACTORIAL DESIGN IN SUB-NANOMETER TECHNOLOGYcscpconf
This work proposes a high speed and low power factorial design in 22nm technology and also it counts the effect of sub nano-meter constraints on this circuit. A comparative study for this
design has been done for 90nm, 45nm and 22nm technology. The rise in circuit complexity and speed is accompanied by the scaling of MOSFET’s. The transistor saturation current Idsat is an important parameter because the transistor current determines the time needed to charge and discharge the capacitive loads on chip, and thus impacts the product speed more than any other transistor parameter. The efficient implementation of a factorial number is carried out by using
a decremented and multipliers which has been lucidly discussed in this paper. Normally in a factorial module a number is calculated as the iterative multiplication of the given number to
the decremented value of the given number. A Parallel adder based decremented has been proposed for calculating the factorial of any number that also includes 0 and 1. The
performances are calculated by using the existing 90-nm CMOS technology and scaling down the existing technology to 45-nm and 22-nm.
Impact of multiple channels on the Characteristics of Rectangular GAA MOSFET IJECEIAES
Square gate all around MOSFETs are a very promising device structures allowing to continue scaling due to their superior control over the short channel effects. In this work a numerical study of a square structure with single channel is compared to a structure with 4 channels in order to highlight the impact of channels number on the device’s DC parameters (drain current and threshold voltage). Our single channel rectangular GAA MOSFET showed reasonable ratio Ion/Ioff of 10 4 , while our four channels GAA MOSFET showed a value of 10 3 . In addition, a low value of drain induced barrier lowering (DIBL) of 60mV/V was obtained for our single channel GAA and a lower value of with 40mv/v has been obtained for our four channel one. Also, an extrinsic transconductance of 88ms/µm have been obtained for our four channels GAA compared to the single channel that is equal to 7ms/µm.
IMPACT OF STRAIN AND CHANNEL THICKNESS ON PERFORMANCE OF BIAXIAL STRAINED SIL...VLSICS Design
In this paper the impact of strain and channel thickness on the performance of biaxial strained silicon MOSFET with 40 nm channel length has been analyzed by simulation in TCAD Sentaurus Simulator. With the increase in the mole fraction of germanium at the interface of the channel region, the strain in the silicon channel increases and with it the mobility of the carriers increases and thus the drain current increases. The mole fraction in this paper is varied from 0 to 0.3. Other than mobility, the increase in strain also shows improvement in other performance parameters. The impact of variation in channel thickness on the functionality parameters of the MOSFET has also been analyzed. The channel thickness cannot be increased more than the critical thickness and therefore, in this paper the thickness is varied from 2nm to 20 nm. It is observed that beyond 10nm the performance improvement gets saturated and therefore the critical thickness for the channel of this structure is 10nm..
Carbon nanotube field-effect transistors (CNTFETs) have advantages over traditional MOSFETs by avoiding issues like short channel effects and high leakage currents that arise from continuous MOSFET scaling. CNTFETs use carbon nanotubes that can be metallic or semiconducting depending on their structure. They have a similar structure to MOSFETs but current flow depends on ballistic transport and electron confinement in the CNT. CNTFETs also have lower quantum capacitance than MOSFETs, resulting in lower propagation delay. Neural networks are well-suited for modeling CNTFETs with their simple, continuous equations that can account for channel length variations. However, precisely controlling CNT
Design, Construction and Implementation of a Bradbury-Nielsen Gate for Time-o...David Torre
The document describes the design, construction, and testing of a Bradbury-Nielsen Gate (BNG) for use in time-of-flight calculations of an electrospray thruster. A 50-wire BNG was constructed with a 3"x3" frame and 2"x2" inner window using Delrin. Experimental testing confirmed the BNG could deflect the ion beam as expected, reducing current by up to 94% when powered on. However, issues with thermal expansion, noise, and the thruster prevented reliable time-of-flight measurements. Future work is needed to address these issues and obtain more precise experimental hardware.
Deterioration of short channel effectsijistjournal
This document presents an analytical model for surface potential and electric field in a novel dual halo triple material surrounding gate (DH-TMSG) MOSFET structure. The DH-TMSG incorporates symmetrical dual halo regions near the source and drain, and a triple material gate. The analytical model uses a parabolic approximation method and boundary conditions to derive expressions for surface potential. Simulation results show that the DH-TMSG design significantly reduces short channel effects by producing peaks and steps in the surface potential and electric field profiles through the channel. This improves carrier transport and device performance compared to other multi-gate structures.
SUB TEN MICRON CHANNEL DEVICES ACHIEVED BY VERTICAL ORGANIC THIN FILM TRANSI...VLSICS Design
The channel lengths of the top contact organic thin film transistors are usually defined during their fabrication by optical lithography or by shadow masking during the metal deposition process. Realizing short channel (sub-ten micron channel length) transistors by lithography will require costly lithography equipment. On the other hand, it is extremely challenging to achieve short channel transistors using the low cost shadow mask process. One low cost method of achieving short channel devices is to build vertical transistors with the transistor, where the channel gets defined in the vertical part of the device. This paper shows that vertical channel top contact organic thin film transistor has been successfullyrealized on the vertical edge of trench. This helped in creating the device with channel lengths less than ten microns, much smaller than what could be typically achieved with the use of shadow masks.
DESIGN OF DIFFERENT DIGITAL CIRCUITS USING SINGLE ELECTRON DEVICESmsejjournal
Single Electron transistor (SET) is foreseen as an excellently growing technology. The aim of this paper is
to present in short the fundamentals of SET as well as to realize its application in the design of single
electron device based novel digital logic circuits with the help of a Monte Carlo based simulator. A Single
Electron Transistors (SET) is characterized by two most substantial determinants. One is very low power
dissipation while the other is its small stature that makes it a favorable suitor for the future generation of
very high level integration. With the utilization of SET, technology is moving past CMOS age resulting in
power efficient, high integrity, handy and high speed devices. Conducting a check on the transport of single
electrons is one of the most stirring aspects of SET technologies. Apparently, Monte Carlo technique is in
vogue in terms of simulating SED based circuits. Hence, a MC based tool called SIMON 2.0 is exercised
upon for the design and simulation of these digital logic circuits. Further, an efficient functioning of the
logic circuits such as multiplexers, decoders, adders and converters are illustrated and established by
means of circuit simulation using SIMON 2.0 simulator.
This document summarizes a study that used finite element analysis and Monte Carlo simulation to analyze the probabilistic design and random optimization of an aerofoil wing made of composite materials. The study modeled an NACA0012 aerofoil composite structure in ANSYS and varied design parameters like chord length, ply angle, elastic modulus, and loading conditions randomly to analyze uncertainty in bending stress. Over 1000 simulations were run. Optimization was also performed to find a set of design variables that reduced the bending stress objective function. The best set reduced bending stress from 1131.79 N/mm2 to 180.58 N/mm2. The study concluded there was significant uncertainty when chord length and ply angle varied and provided correlations between design variables and bending
This document discusses optimization of boiler blowdown and blowdown heat recovery in the textile industry. It finds that 1.3% of total fuel is typically wasted through boiler blowdown. By installing an automatic blowdown system and a heat recovery system, up to 85% of the wasted fuel can be recovered. This reduces fuel costs and increases boiler efficiency. Recovering blowdown heat helps raise the temperature of feedwater entering the boiler, allowing up to a 1% reduction in fuel consumption. Proper optimization of blowdown and use of heat recovery systems can significantly improve energy efficiency in textile industry boiler operations.
This document summarizes a finite element analysis of spur gear teeth. It describes building FE models in ANSYS to analyze how varying the tip radius and tooth width affects stresses at the root and mating surfaces of gear teeth. Results from the FE models are compared to stresses calculated using Lewis's bending stress equation and the AGMA gear design standard. Stress concentrations are highest at the root of gear teeth. Varying the number of teeth changes the diametral pitch and impacts the bending stresses.
This document summarizes a research paper that proposes an intelligent Bloom join filter approach for query optimization. The approach uses sets of Bloom filters to represent relations and joining attributes, with the goal of minimizing collisions and maximizing data reduction. Experiments show that applying multiple filters increases the percentage of data reduction for relations when processing queries. The approach constructs filters for each joining attribute and applies existing or new filters to relations to reduce their size. This helps optimize query execution by reducing processing costs, data transmission costs, and collisions during joins.
The document proposes and evaluates energy recovery flip-flops that operate with a single-phase sinusoidal clock to reduce power consumption. A resonant clock generator is designed to produce the sinusoidal clock signal. Simulations show the proposed flip-flops achieve over 80% delay reduction and 47% power reduction compared to conventional designs. An H-tree clock network distributes the sinusoidal clock signal. Total power savings of up to 80% are achieved compared to square wave clocking schemes. Clock gating is also proposed to further reduce power when the flip-flops are inactive.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Este documento discute la importancia de la interactividad en las aplicaciones, donde el usuario siente que controla y navega libremente la aplicación a través de enlaces entre pantallas. También menciona que más personas se están sumergiendo en el mundo virtual de forma continua a través de la web y dispositivos, con consecuencias impredecibles a medida que más usuarios pasan tiempo en el mundo digital. Además, define la usabilidad como la facilidad con que las personas pueden usar una herramienta o sitio web de forma clara y elegante.
El SEO consiste en optimizar un sitio web para aumentar el tráfico orgánico mediante mejoras internas y externas. Requiere conocimiento técnico y es un proceso a largo plazo orientado a los buscadores que mejora la posición y relevancia de una página en los resultados de búsqueda.
Slide li análise de contexto de ensino e aprendizado na escola pública 2Myrian Conor
O documento analisa os desafios do ensino de inglês na escola pública brasileira, identificando falta de estrutura, materiais e motivação entre professores e alunos. Questionários com alunos mostraram interesse em atividades dinâmicas, mas dificuldades com interpretação de texto devido à falta de recursos. Melhorias no ensino de inglês requerem mudanças na educação e novas abordagens dos professores.
The document outlines a development framework with connectivity in Iskandar and establishing a healthcare hub as key initiatives to drive growth. It discusses Iskandar's experience in establishing a green hospital as part of developing a healthcare hub in the region.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive function. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
El documento describe diferentes métodos de investigación en psicología como estudios de casos, observación natural, pruebas, estudios de correlación e investigación experimental. Explica que la investigación experimental involucra formular una hipótesis, recabar nueva información, y determinar si los resultados apoyan u oponen la hipótesis original.
Las instrucciones describen cómo hacer velas de colores usando sal teñida y tizas de cera. Se instruye rayar las tizas de cera y mezclarlas con sal teñida de colores, luego derretir la mezcla y verterla en moldes para que se endurezca en velas de colores personalizadas.
Este documento describe cómo usar variables y disfraces en Scratch para transformar objetos. Explica que las variables permiten crear cadenas de caracteres que pueden usarse como herramientas en un programa Scratch, y que los disfraces permiten editar un objeto para darle diferentes apariencias como números en un dado. Luego detalla cómo crear una variable llamada "valor" y copiar un objeto dado seis veces para editar cada copia con un número diferente usando disfraces.
Desenvolvimento de sites para empresa de automação e suas submarcas, incluindo análise da concorrência, wireframes e direcionamento de conteúdo para três sites.
Este documento presenta una colección de fórmulas y ejercicios resueltos para prepararse para la Prueba de Selección Universitaria (PSU) en Chile. Incluye fórmulas y ejemplos de porcentajes, interés, proporcionalidad, probabilidad, ecuaciones, funciones cuadráticas y más. El autor espera que este material sirva como último repaso antes de rendir la PSU.
Structural and Electrical Analysis of Various MOSFET DesignsIJERA Editor
Invention of Transistor is the foundation of electronics industry. Metal Oxide Semiconductor Field Effect Transistor (MOSFET) has been the key to the development of nano electronics technology. This paper offers a brief review of some of the most popular MOSFET structure designs. The scaling down of planar bulk MOSFET proposed by the Moore’s Law has been saturated due to short channel effects and DIBL. Due to this alternative approaches has been considered to overcome the problems at lower node technology. SOI and FinFET technologies are promising candidates in this area.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Threshold voltage roll-off for sub-10 nm asymmetric double gate MOSFETIJECEIAES
Threshold voltage roll-off is analyzed for sub-10 nm asymmetric double gate (DG) MOSFET. Even asymmetric DGMOSFET will increase threshold voltage roll-off in sub-10 nm channel length because of short channel effects due to the increase of tunneling current, and this is an obstacle against the miniaturization of asymmetric DGMOSFET. Since asymmetric DGMOSFET can be produced differently in top and bottom oxide thickness, top and bottom oxide thicknesses will affect the threshold voltage roll-off. To analyze this, thermal emission current and tunneling current have been calculated, and threshold voltage roll-off by the reduction of channel length has been analyzed by using channel thickness and top/bottom oxide thickness as parameters. As a result, it is found that, in short channel asymmetric double gate MOSFET, threshold voltage roll-off is changed greatly according to top/bottom gate oxide thickness, and that threshold voltage roll-off is more influenced by silicon thickness. In addition, it is found that top and bottom oxide thickness have a relation of inverse proportion mutually for maintaining identical threshold voltage. Therefore, it is possible to reduce the leakage current of the top gate related with threshold voltage by increasing the thickness of the top gate oxide while maintaining the same threshold voltage.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Analytical modeling of electric field distribution in dual material junctionl...VLSICS Design
In this paper, electric field distribution of the junctionless dual material surrounding gate MOSFETs
(JLDMSG) is developed. Junctionless is a device that has similar characteristics like junction based
devices, but junctionless has a positive flatband voltage with zero electric field. In Surrounding gate
MOSFETs gate material surrounds the channel in all direction , therefore it can overcome the short
channel effects effectively than other devices. In this paper, surface potential and electric field distribution
is modelled. The proposed surface potential model is compared with the existing central potential model. It
is observed that the short channel effects (SCE) is reduced and the performance is better than the existing
method.
Introduction gadgets have gained a lot of attention.pdfbkbk37
The document discusses the increasing need for ultra-low power electronic devices due to advances in mobile technology and the internet of things. It covers limitations in further reducing power consumption and scaling transistors according to Moore's Law. Transition metal dichalcogenides are discussed as a potential channel material for ultra-low power transistors due to their ability to achieve high ON/OFF ratios even at the monolayer level. The document also mentions using technology computer-aided design (TCAD) tools like the Quantum Transport Simulator to model and optimize new materials and device geometries.
ECE 6030 Device Electronics discusses advances in low-power electronics and internet-connected devices. As transistors continue to shrink according to Moore's law, new challenges have emerged like increased OFF current. The document discusses approaches to overcoming these challenges, including new materials like transition metal dichalcogenides and their use in ultra-low power transistors. Device and circuit simulation tools are also discussed as important for optimizing new device designs without costly fabrication.
Performance analysis of ultrathin junctionless double gate vertical MOSFETsjournalBEEI
This document summarizes a study that analyzes the performance of ultrathin junctionless double gate vertical MOSFETs (JLDGVM) and compares them to conventional junctioned double gate vertical MOSFETs (JDGVM) through process and device simulation. The simulation results show that the drain current (ID) of n-type and p-type JLDGVM is enhanced by 57% and 60% respectively compared to JDGVM. Additionally, JLDGVM exhibit a larger ION/IOFF ratio and smaller subthreshold slope, implying better power consumption and faster switching capability than JDGVM. The junctionless configuration eliminates challenges associated with forming ultra-shallow junctions between the source/
Comparative analysis of technology advancement from single gate to multi gate...eSAT Journals
Abstract
Among the entire contender in modern microelectronics,DG-MOSFET is a front line runner in planar technology. Itsunique
structure allows scaling the device at sub-nanometer region and mimicking the electrical characteristics of a MOSFET.Here
simulation of NMOS, SOI-NMOS, and DG-NMOS is presentedand relative comparison among short channel characteristics
ispresented.It has been seen that among all the above stated device, DG-MOSFET possess better immune to leakage current with
betterDIBL, whereas SOI MOSFET have better driving capacity.
KeyWords:SOI-MOSFET, DG-MOSFET, UTB, DIBL,SCEs
High Performance Germanium Double Gate N-MOSFETIJMER
The current MOSFET technology supports scaling down to nanometer. To achieve
enhanced transistor switching, it is difficult to keep the equivalent driver current at the same level
since it changes by the certain restrictions like effective masses, density of states, uniaxial- and
biaxial- strain; band structure, channel orientation, channel mobility, off-state leakage, switching
delay in nano-scale and parasitic latch up. Current strained-Si is the ruling technology for
intensifying the performance of MOSFET and development of strain can provide a better solution to
the scaling. The future of nano-scale MOSFETs relies on exploration of novel higher mobility channel
materials such as stained-Ge and strained III-V groups that might perform even better than very
highly strained-Si. In addition, parameters such as injection velocity, short channel length effect and
Band-to-Band Tunneling (BTBT) result in reduction of inversion charge, increase in leakage current,
resulting in decrease in the drive current. While developing accurate model of MOSFETs all these
complex effects should be captured. It is proposed to
1. Design high performance double gate n-MOSFET with channel material Ge.
2. Benchmarked & stimulate high performance double gate n-MOSFET by using the simulation
techniques.
The document discusses the history and development of transistors from their invention in 1947 to modern 3D transistors. It describes how Moore's Law of transistor scaling led to the development of 3D tri-gate transistors to overcome limitations of planar transistors. The document explains how 3D transistors provide better performance than planar transistors through conducting channels on three sides of a vertical fin structure. It discusses the construction, operation, benefits and challenges of integrating 3D transistors into mainstream manufacturing.
Electrical characterization of si nanowire GAA-TFET based on dimensions downs...IJECEIAES
This research paper explains the effect of the dimensions of Gate-all-around Si nanowire tunneling field effect transistor (GAA Si-NW TFET) on ON/OFF current ratio, drain induces barrier lowering (DIBL), sub-threshold swing (SS), and threshold voltage (V T ). These parameters are critical factors of the characteristics of tunnel field effect transistors. The Silvaco TCAD has been used to study the electrical characteristics of Si-NW TFET. Output (gate voltage-drain current) characteristics with channel dimensions were simulated. Results show that 50nm long nanowires with 9nm-18nm diameter and 3nm oxide thickness tend to have the best nanowire tunnel field effect transistor (Si-NW TFET) characteristics.
Geometric and process design of ultra-thin junctionless double gate vertical ...IJECEIAES
The junctionless MOSFET architectures appear to be attractive in realizing the Moore’s law prediction. In this paper, a comprehensive 2-D simulation on junctionless vertical double-gate MOSFET (JLDGVM) under geometric and process consideration was introduced in order to obtain excellent electrical characteristics. Geometrical designs such as channel length (Lch) and pillar thickness (Tp) were considered and the impact on the electrical performance was analyzed. The influence of doping concentration and metal gate work function (WF) were further investigated for achieving better performance. The results show that the shorter Lch can boost the drain current (ID) of n-JLDGVM and p-JLDGVM by approximately 68% and 70% respectively. The ID of the n-JLVDGM and p-JLVDGM could possibly boost up to 42% and 78% respectively as the Tp is scaled down from 11nm to 8nm. The channel doping (Nch) is also a critical parameter, affecting the electrical performance of both n-JLDGVM and p-JLDGVM in which 15% and 39% improvements are observed in their respective ID as the concentration level is increased from 1E18 to 9E18 atom/cm3. In addition, the adjustment of threshold voltage can be realized by varying the metal WF.
Leakage Power Reduction Techniques Revisited in a CMOS Inverter Circuit at De...idescitation
As CMOS Technology is aiming at miniaturization
of MOS devices, a trend of increase in the static power
consumption is being observed. The main sources of static
power consumption are sub-threshold current and gate oxide
leakage current. In this work, we discuss the major sources of
power consumption, various techniques to reduce leakage
power and their trade-offs in a CMOS inverter logic circuit at
90nm. Three most popular leakage current reduction
techniques are studied with respect to a conventional inverter
circuit. It is seen that the main trade-off is between the area
and the static leakage current. This paper aims to reduce the
static power dissipation with a small compromise in area.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
small geometry effect and working of solar cellShivank Rastogi
The document discusses MOSFET theory and operation, including:
- MOSFET device structure and types (depletion and enhancement mode).
- Regions of operation depending on gate-source and drain-source voltages.
- Effects that occur at small device geometries including short channel effects like drain-induced barrier lowering, velocity saturation, and hot carriers.
- Operation and efficiency of solar cells made from semiconductor materials, and how efficiency depends on the material bandgap. Design improvements like PERL cells are also discussed.
Accurate leakage current models for MOSFET nanoscale devices IJECEIAES
This paper underlines a closed form of MOSFET transistor’s leakage current mechanisms in the sub 100nmparadigm.The incorporation of drain induced barrier lowering (DIBL), Gate Induced Drain Lowering (GIDL) and body effect (m) on the sub-threshold leakage (I sub ) was investigated in detail. The Band-To-Band Tunneling (I BTBT ) due to the source and Drain PN reverse junction were also modeled with a close and accurate model using a rectangular approximation method (RJA). The three types of gate leakage (I G ) were also modeled and analyzed for parasitic (I GO ), inversion channel (I GC ), and gate substrate (I GB ). In addition, the leakage resources due to the aggressive reduction in the oxide thickness (<5nm) have been investigated. Simulation results using HSPICE exhibits a tremendous agreement with the BSIM4 model. The dominant value of the sub-threshold leakage was due to the DIBL and GIDL effects. Various recommendations regarding minimizing the leakage current at both device level and the circuit level were suggested at the end of this paper.
Investigation and design of ion-implanted MOSFET based on (18 nm) channel lengthTELKOMNIKA JOURNAL
The aim of this study is to invistgate the characteristics of Si-MOSFET with 18 nm length of ion implemented channel. Technology computer aided design (TCAD) tool from Silvaco was used to simulate the MOSFET’s designed structure in this research. The results indicate that the MOSFET with 18 nm channel length has cut-off frequency of 548 GHz and transconductance of 967 μS, which are the most important factors in calculating the efficiency and improving the performance of the device. Also, it has threshold voltage of (-0.17 V) in addition obtaining a relatively small DIBL (55.11 mV/V). The subthreshold slope was in high value of 307.5 mV/dec. and this is one of the undesirable factors for the device results by short channel effect, but it does not reduce its performance and efficiency in general.
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/how-axelera-ai-uses-digital-compute-in-memory-to-deliver-fast-and-energy-efficient-computer-vision-a-presentation-from-axelera-ai/
Bram Verhoef, Head of Machine Learning at Axelera AI, presents the “How Axelera AI Uses Digital Compute-in-memory to Deliver Fast and Energy-efficient Computer Vision” tutorial at the May 2024 Embedded Vision Summit.
As artificial intelligence inference transitions from cloud environments to edge locations, computer vision applications achieve heightened responsiveness, reliability and privacy. This migration, however, introduces the challenge of operating within the stringent confines of resource constraints typical at the edge, including small form factors, low energy budgets and diminished memory and computational capacities. Axelera AI addresses these challenges through an innovative approach of performing digital computations within memory itself. This technique facilitates the realization of high-performance, energy-efficient and cost-effective computer vision capabilities at the thin and thick edge, extending the frontier of what is achievable with current technologies.
In this presentation, Verhoef unveils his company’s pioneering chip technology and demonstrates its capacity to deliver exceptional frames-per-second performance across a range of standard computer vision networks typical of applications in security, surveillance and the industrial sector. This shows that advanced computer vision can be accessible and efficient, even at the very edge of our technological ecosystem.
Ivanti’s Patch Tuesday breakdown goes beyond patching your applications and brings you the intelligence and guidance needed to prioritize where to focus your attention first. Catch early analysis on our Ivanti blog, then join industry expert Chris Goettl for the Patch Tuesday Webinar Event. There we’ll do a deep dive into each of the bulletins and give guidance on the risks associated with the newly-identified vulnerabilities.
Fueling AI with Great Data with Airbyte WebinarZilliz
This talk will focus on how to collect data from a variety of sources, leveraging this data for RAG and other GenAI use cases, and finally charting your course to productionalization.
Skybuffer SAM4U tool for SAP license adoptionTatiana Kojar
Manage and optimize your license adoption and consumption with SAM4U, an SAP free customer software asset management tool.
SAM4U, an SAP complimentary software asset management tool for customers, delivers a detailed and well-structured overview of license inventory and usage with a user-friendly interface. We offer a hosted, cost-effective, and performance-optimized SAM4U setup in the Skybuffer Cloud environment. You retain ownership of the system and data, while we manage the ABAP 7.58 infrastructure, ensuring fixed Total Cost of Ownership (TCO) and exceptional services through the SAP Fiori interface.
Generating privacy-protected synthetic data using Secludy and MilvusZilliz
During this demo, the founders of Secludy will demonstrate how their system utilizes Milvus to store and manipulate embeddings for generating privacy-protected synthetic data. Their approach not only maintains the confidentiality of the original data but also enhances the utility and scalability of LLMs under privacy constraints. Attendees, including machine learning engineers, data scientists, and data managers, will witness first-hand how Secludy's integration with Milvus empowers organizations to harness the power of LLMs securely and efficiently.
zkStudyClub - LatticeFold: A Lattice-based Folding Scheme and its Application...Alex Pruden
Folding is a recent technique for building efficient recursive SNARKs. Several elegant folding protocols have been proposed, such as Nova, Supernova, Hypernova, Protostar, and others. However, all of them rely on an additively homomorphic commitment scheme based on discrete log, and are therefore not post-quantum secure. In this work we present LatticeFold, the first lattice-based folding protocol based on the Module SIS problem. This folding protocol naturally leads to an efficient recursive lattice-based SNARK and an efficient PCD scheme. LatticeFold supports folding low-degree relations, such as R1CS, as well as high-degree relations, such as CCS. The key challenge is to construct a secure folding protocol that works with the Ajtai commitment scheme. The difficulty, is ensuring that extracted witnesses are low norm through many rounds of folding. We present a novel technique using the sumcheck protocol to ensure that extracted witnesses are always low norm no matter how many rounds of folding are used. Our evaluation of the final proof system suggests that it is as performant as Hypernova, while providing post-quantum security.
Paper Link: https://eprint.iacr.org/2024/257
Main news related to the CCS TSI 2023 (2023/1695)Jakub Marek
An English 🇬🇧 translation of a presentation to the speech I gave about the main changes brought by CCS TSI 2023 at the biggest Czech conference on Communications and signalling systems on Railways, which was held in Clarion Hotel Olomouc from 7th to 9th November 2023 (konferenceszt.cz). Attended by around 500 participants and 200 on-line followers.
The original Czech 🇨🇿 version of the presentation can be found here: https://www.slideshare.net/slideshow/hlavni-novinky-souvisejici-s-ccs-tsi-2023-2023-1695/269688092 .
The videorecording (in Czech) from the presentation is available here: https://youtu.be/WzjJWm4IyPk?si=SImb06tuXGb30BEH .
How information systems are built or acquired puts information, which is what they should be about, in a secondary place. Our language adapted accordingly, and we no longer talk about information systems but applications. Applications evolved in a way to break data into diverse fragments, tightly coupled with applications and expensive to integrate. The result is technical debt, which is re-paid by taking even bigger "loans", resulting in an ever-increasing technical debt. Software engineering and procurement practices work in sync with market forces to maintain this trend. This talk demonstrates how natural this situation is. The question is: can something be done to reverse the trend?
The Microsoft 365 Migration Tutorial For Beginner.pptxoperationspcvita
This presentation will help you understand the power of Microsoft 365. However, we have mentioned every productivity app included in Office 365. Additionally, we have suggested the migration situation related to Office 365 and how we can help you.
You can also read: https://www.systoolsgroup.com/updates/office-365-tenant-to-tenant-migration-step-by-step-complete-guide/
What is an RPA CoE? Session 1 – CoE VisionDianaGray10
In the first session, we will review the organization's vision and how this has an impact on the COE Structure.
Topics covered:
• The role of a steering committee
• How do the organization’s priorities determine CoE Structure?
Speaker:
Chris Bolin, Senior Intelligent Automation Architect Anika Systems
Discover top-tier mobile app development services, offering innovative solutions for iOS and Android. Enhance your business with custom, user-friendly mobile applications.
Monitoring and Managing Anomaly Detection on OpenShift.pdfTosin Akinosho
Monitoring and Managing Anomaly Detection on OpenShift
Overview
Dive into the world of anomaly detection on edge devices with our comprehensive hands-on tutorial. This SlideShare presentation will guide you through the entire process, from data collection and model training to edge deployment and real-time monitoring. Perfect for those looking to implement robust anomaly detection systems on resource-constrained IoT/edge devices.
Key Topics Covered
1. Introduction to Anomaly Detection
- Understand the fundamentals of anomaly detection and its importance in identifying unusual behavior or failures in systems.
2. Understanding Edge (IoT)
- Learn about edge computing and IoT, and how they enable real-time data processing and decision-making at the source.
3. What is ArgoCD?
- Discover ArgoCD, a declarative, GitOps continuous delivery tool for Kubernetes, and its role in deploying applications on edge devices.
4. Deployment Using ArgoCD for Edge Devices
- Step-by-step guide on deploying anomaly detection models on edge devices using ArgoCD.
5. Introduction to Apache Kafka and S3
- Explore Apache Kafka for real-time data streaming and Amazon S3 for scalable storage solutions.
6. Viewing Kafka Messages in the Data Lake
- Learn how to view and analyze Kafka messages stored in a data lake for better insights.
7. What is Prometheus?
- Get to know Prometheus, an open-source monitoring and alerting toolkit, and its application in monitoring edge devices.
8. Monitoring Application Metrics with Prometheus
- Detailed instructions on setting up Prometheus to monitor the performance and health of your anomaly detection system.
9. What is Camel K?
- Introduction to Camel K, a lightweight integration framework built on Apache Camel, designed for Kubernetes.
10. Configuring Camel K Integrations for Data Pipelines
- Learn how to configure Camel K for seamless data pipeline integrations in your anomaly detection workflow.
11. What is a Jupyter Notebook?
- Overview of Jupyter Notebooks, an open-source web application for creating and sharing documents with live code, equations, visualizations, and narrative text.
12. Jupyter Notebooks with Code Examples
- Hands-on examples and code snippets in Jupyter Notebooks to help you implement and test anomaly detection models.
Monitoring and Managing Anomaly Detection on OpenShift.pdf
Nc342352340
1. Sabina, Alok K. Kushwaha / International Journal of Engineering Research and Applications
(IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 3, Issue 4, Jul-Aug 2013, pp 2335-2340
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Dual material gate-all-around Fully Depleted SOI MOSFET with
Strained Si/Ge Channel
Sabina*, Alok K. Kushwaha**
*(Assistant professor, School of Engg. & Technology,Ansal University, Gurgaon, Haryana
** (Dean, School of Engg. & Technology,Ansal University, Gurgaon, Haryana
ABSTRACT
After a lot of efforts to scale down the
devices, now the scaling limits of device have
reached i.e. it’s not possible to scale down the
CMOS further. For further scaling of device we
need to change the materials used for the gate and
channel. In this paper different structures
suggested by different authors are covered along
with their benefits and limitations. A structure
based on the Fully Depleted SOI Gate All around
(FD SOI GAA) MOSFET with strained Si Channel
has been suggested to overcome the scaling limits
along with the QME consideration in modeling.
Keywords-CMOS, FD, Gate-All-Around, Quantum
Mechanical Effect, Scaling Effects, SOI, Strained Si.
I. INTRODUCTION
CMOS technology has contributed signifi-
cantly for the development of almost all the coun-
tries. This is due to the vast applications used in
every sphere and industry. With the fast pace of tech-
nological changes, consumer electronic device re-
quirements are also growing. Hence, the need for
large scale, complex integrated circuits increases at
the same pace. With the scaling of the device or with
the increase in the device count in an IC, area de-
creases, but power dissipation and the speed becomes
most important issues. Keeping in mind all these is-
sues, now the device dimensions have reached a limit
that cannot be further scaled down. With further scal-
ing of the device, the effects like Short-Channel-
Effects (SCE), Quantum Mechanical Effects (QME)
becomes dominating. So while designing, the most
fundamental challenge is the trade-off between short-
channel effects and the impact of Source-drain resis-
tance (due to change in channel length).
With the scaling, the devices trends from
microelectronics to nanoelectronics regime following
the moore’s law. This movement starts with the bulk
CMOS transistor followed by SOI CMOS with dif-
ferent gate structures like single gate, double gate,
trigate and then gate all around, with different gate
materials like single material, dual material. In a con-
ventional, bulk-silicon microcircuit, the active ele-
ments are isolated from the silicon body with a deple-
tion layer of a p-n junction. The leakage current of
this p-n junction exponentially increases with tem-
perature and limit the operation of microcircuits at
high temperatures. Bulk CMOS transistor as dis-
cussed by Kang [1] aces a very serious problem of
Latch-up due to the formation of parasitic bipolar
transistors. As discussed by Ulicki [2], Silicon-on-
insulator (SOI) offers superior CMOS devices with
higher speed, higher density, excellent radiation
hardness and reduced second order effects for submi-
cron VLSI applications. Dual-Material Gate (DMG)
structure offers an alternative way of simultaneous
SCE suppression and improved device performance
by careful control of the material work function and
length of the laterally amalgamated gate materials
explained by Chaudhary [3]. With the change in the
no of gates i.e. from single gate to multigate the con-
trol of the gate voltage on the channel surface poten-
tial increases. By combining the benefits of Dual
material with the dual gate, Kushwaha [4] concluded
that the DMDG SOI MOSFET is the option that can
limit the SCE to a very large extend. Choudhary [5]
suggested the stressed Si structure for improving the
carrier mobility.
In this review paper, there are four sections.
Section I includes the introduction. In Section 2, var-
ious problems, encountered during scaling of
MOSFET, are explained. In Section 3, various struc-
tures, suggested of different authors to overcome
those problems, are explained. Section 4 includes the
proposed work on the basis of section III suggestions.
II. SCALING EFFECTS
In 1965, Gordon Moore wrote a paper enti-
tled “Cramming more Components onto Integrated
Circuits” where he first proposed that transistor den-
sity on chips would grow exponentially [6]. Follow-
ing this law, various MOSFET models designed. This
law was followed for more than forty-five years. But
now with further scaling of the devices, the various
problems are encountered Quantum Tunneling of
carriers, Short Channel Effects Like Edge potential
effects, Punchthrough, Drain Induced Barrier Lower-
ing (DIBL), Hot Carrier Effect and subthreshold
Swing. So, there is a large need of considering the
new structures with new materials that can be proven
suitable to follow the law with suppressed problems.
2.1. Quantum Mechanical Effect
With the scaling of the device, the model
used to describe the behavior of MOS faces difficul-
ties to achieve the accurate description. As more
complicated phenomena starts arising out of down-
2. Sabina, Alok K. Kushwaha / International Journal of Engineering Research and Applications
(IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 3, Issue 4, Jul-Aug 2013, pp 2335-2340
2336 | P a g e
scaling of MOSFET, we need to consider those entire
phenomenon before the modeling of MOSFET. One
such phenomenon is the failure of classical physics.
At this classical physics limit, quantum mechanics
need to be taken into account. The major issue is the
increase in quantum effects near the Si/SiO2 interface
that affects the charge carrier distribution in the
channel inversion layer. The thermal wavelength of
an electron is given by 𝜋ℎ 2 𝑚 𝐾𝐵 𝑇, which is about
8nm at room temperature when m is the free electron
mass. This wavelength is very smaller than the gate
length in the foreseen future described by ITRS [7],
oxide thickness, and channel depth for current devic-
es. So the quantum plays a very important role in
modeling the MOSFET that can be used as a simula-
tion model.
Fig.1 Tunneling currents Igs, Igd, Igc of
MOSFET by WANG [8]
In case of ultra thin gate oxide, the electric
field will be very high, which in turn pushes the
charge carriers through the channel to account for the
gate direct tunneling current, demonstrated by Wang
[8] shown in the fig.1. Other Quantum mechanical
effects are energy quantization, displacement of
energy charge density of the bulk, Quantum mechan-
ical tunneling from source to drain, threshold voltage
and drain saturation voltage shift described by
Choudhary & ROY [9] and Abebe [10]. Hence to
best describe the characteristics of a device the model
approach should include the QME.
2.2. Short Channel Effects
2.2.1 End effects and channel length
modulation
The voltage applied on the gate, drain and
the source induces the depletion region in the body.
Hence there are three depletion regions i.e. under the
gate which is balanced by gate voltage and other two
regions are balanced by the source and drain voltages
as shown in the fig.2 below. But as the channel
length decreases then the effect of drain to source
voltage as well as the gate voltage affects the deple-
tion region under the gate. And the control of gate
starts decreasing over the effect introduced under the
gate and hence the operation of MOSFET gets dis-
turbed. One more factor i.e. drain voltage also affects
the channel length. When the effect of the drain vol-
tage is more as compared to the gate voltage, then
channel length modulates and the transistor starts
conducting a constant value current i.e. saturation
region current. This effect is more dominating in case
of short channel.
Fig.2 Depletion charge region in long channel
(left) and Short channel (right)
2.2.2 DIBL-Drain Induced Barrier Lowering
Due to the reduction of gate control over the
drain current, DIBL effect comes into the picture. In
short channel devices, drain biased depletion region
has the effect of lowering the barrier potential at the
source end and hence there is a current flow even
when the device is OFF. This effect is also more do-
minating in Short channel devices and can be alle-
viated by increasing the doping concentration of the
channel region.
2.2.3 Punchthrough
Punchthrough is an extreme version of the
DIBL and occurs when due to the increase in drain
voltage the depletion region of source and drain over-
laps. When the depletion region of drain and source
overlaps, then a substantial current flows through the
channel, even with no bias at the gate terminal. In-
creasing the doping of channel region can alleviate
this problem.
As discussed, the solution to overcome this problem
of SCE is to increase the doping level in the channel
region. But with the increase of doping level in the
channel region, the scattering at the ionized impuri-
ties also increases and the elevated vertical electrical
field due to the impurities also increases which in
turn degrade the device performance. Also suggested
by Subrahmanyam & Kumar [11] Vertical gate struc-
ture can be used to mitigate the SCEs.
III. MOSFET STRUCTURES
Different authors suggested different struc-
tures, from time to time, with various improvements.
Some of the models using planar technology are:
3.1. Structure with different Channel doping:
Partially Depleted, Fully Depleted MOSFET.
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3.2. Structure with different Substrate: Bulk Si
MOSFET, SOI MOSFET.
3.3. Structure with different gate structures i.e.
single gate, Double gate, Gate-all-Around.
3.4. Structure with different gate materials: Sin-
gle material, dual material Gate.
3.5. Structure with strained and unstrained
Channel: Strained Si Channel, Unstrained Si Channel
MOSFET.
3.1. Partially Depleted Vs Fully Depleted
MOSFET
In Partially Depleted MOSFET, a part of the body
region remains undepleted while in Fully Depleted
MOSFET; the depletion region extends in the whole
body. The various Characteristics of the two models
are as follows:
3.1.1. Kink in the drain current
In PD, the current kink is observed at a par-
ticular drain voltage due to the electron-hole pair
generated by impact-ionization. In FD, there is lower
potential barrier for the minority carriers as whole of
the body is depleted of carriers. So there is no accu-
mulation of holes in the body region and consequent
kink in the drain characteristics.
3.1.2. Floating Body Effect
PD devices are significantly sensitive to dy-
namic body effect due to the presence of different
doping structures available in the body and require
the body to be connected to a constant potential. FD
devices are unaffected by the dynamic body effects
and are more stable.
Floating body PD SOI MOSFETs biased above the
kink voltage have a drain current higher than tied
body devices, but dependent on switching frequency.
Perron et Al. [12] showed the results that in MHz
range the on current increases, but the leakage current
in Off-state also increases.
3.1.3. Parasitic bipolar effects
Parasitic bipolar transitors are formed in the
MOSFET where Source, body and drain act as emit-
ter, base and collector respectively. As the body is
more depleted in FD devices, parasitic transistor is
more effective in FD devices. These parasitic transis-
tor leads to the latch-up problem.
3.2. Bulk Si Vs SOI MOSFET
The SOI employs a thin layer of Si isolated
from the Si substrate by a thick layer of silicon oxide.
Insulator layer provides dielectrically isolation and
reduces various circuit parasitic capacitances and
hence reduces the latch-up problem and also increas-
es the speed of the device.
The SOI layer also provides some protection
against the radiation hardness, as the electron-hole
pair generated in the SI substrate due to the radiations
cannot affect the channel. But in case of Bulk Si, as
there is no isolation between the Si substrate and the
channel, so the electron-hole pair generated affects
the channel and ultimately the device performance is
degraded. Also the Short-channel-effects are reduced
to a very large extend in SOI MOSFETS due to the
presence of thin Si film.
Fig.3 shows the performance of SOI MOSFETs. The
low resistivity substrate that is used in bulk silicon
CMOS processes limits the integration of high-
quality passive components and gives rise to sub-
strate coupling issues.
Fig.3 Performance improved in SOI MOSFETS
Tinella et al. [13] explained that the HRSOI (high
resistive SOI) improves the RF circuit performance
and reduces the substrate coupling issues.
3.3. Single Gate Vs Multigate
Gate terminal is the input terminal whose
potential creates an effect in the channel to control
the flow of current inside the channel. Colinge [14]
demonstrated the reasons for evolving from single
gate to multi-gate structures. The fig.4 shows the
Source and drain terminals, which are connected by a
channel. L is the length of the channel and E is the
electric field induced in the channel due to the gate
voltage. This Electric field has different components
along different axes.
Fig.4 Electric field lines from source to drain
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When there are two gates as shown in fig.5
(middle), then there are voltages from two sides gate
to control the current flow in the channel i.e. much
better control over the charge flow in the channel.
Fig.5 MOSFET with single gate (top), double
gate ( middle) and gate all-arround (bottom)
So in case of double gate, when the channel is even
shortened, the flow of current can be better controlled
in comparison to the single gate. Similarly in the case
of Gate-all –around, the best control over the channel
in comparison to double gate and tri-gate. The
relation of the Electrostatic control effect with no of
gates was best described by Colinge [15] in the
equation form as:
Electrostatic Control α
𝑛 𝜀 𝑜𝑥
𝜀𝑆𝑖 𝑡 𝑆𝑖 𝑡 𝑜𝑥
Where n is the no of gates.
Jingbin et al. [16] explained that the explosive growth
of power consumption and sensitivity to size varia-
tions limits the single-gate scalability below 6 nm
gate length. Jimenez [17] explained the use of bene-
fits of GAA MOSFET in various applications i.e.
Nanowire.
3.4. Single Material Vs Dual Material Gate
Proposed by Long et al. [18] dual material
gate MOSFET induces the step potential at the inter-
face between the different gate materials and make
the much higher field in the channel region that im-
proves the carrier transit speed and hence increases
the device driving capability. Due to the screen ef-
fects from the gate with low work function of DMG
MOSFET, the high electric field near the drain end is
effectively reduced, which suppresses the hot carrier
effects and reduces the substrate current leakage.
As predicted by Choudhary [3] Dual materi-
al when used in Single gate SOI MOSFET gives the
much better performance in terms of SCEs. Kumar &
Chaudhary [19] developed the threshold voltage
model for dual material surrounding gate MOSFET
using Quasi potential approach (QPA). Chiang [20]
developed the exact two-dimensional subthreshold
behavior model, which comprises two-dimensional
potential, threshold voltage, subthreshold current, and
subthreshold swing and found that DMSG MOSFET
exhibits superiority over single material for lowering
SCEs.
3.5. Strained Vs Unstrained Si Channel
By appling the stress on the Si the lattice
constant of Si changes and so we have to use SiGe
below the strained Si as shown in fig.6, so that there
are no dislocations in the structure explained by Kim
et al. [21] and Batwani et al. [22].
Fig.6 Unstrained Si (top) and Strained Si
(bottom)
The stress applied to Si channel lifts band
degeneracies, causes band warping and hence results
in carrier effective mass change.
From the mass-mobility relation we have:
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μ=
𝑒 𝜏
𝑚∗ 𝜇
Where m* is the effective mass, is the relaxation
time and μ is the mobility. So as the effective mass
reduces the mobility increases. In this way by using
stressed Si, the mobility in the channel can be in-
creased.
Fig.7 Dual-material Gate-all-around strained Si
MOSFET
Nuo [25] suggested the Strained Si MOSFET as the
next generation MOSFET by simulating the results
for different gate structures.Gate-all-around
MOSFET along with the benefits of dual-material
and the strained Si model is the proposed one and is
shown in fig.7.
IV. CONCLUSION AND FUTURE WORK
The scaling of CMOS transistors has driven
the tremendous growth of the semiconductor indus-
try. As described by various authors CMOS is reach-
ing its limits. In this review paper all models derived
till now has been discussed along with their limits. A
work can be proposed for modeling of a SOI
MOSFET using DM Gate-All-Around Structure with
stressed III-V group materials for channel including
the QME. This proposed model could replace the
CMOS when the limit is reached.
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