Nanoscale Based Digital Very Large Scale Integration Circuit.

1. Nanoscale Based Digital VLSI
Device
The Future Of Semiconductor Technology
Presented by:
Neha Patel(23904136)
Priyanka Kumari(23204116)

2. Content
• Introduction
• Nanoscale devices are crucial for advanced VLSI circuits
• Nanoscale Devices
• Application
• Challenges in Nanoscale Device Integration
• Future Trends
• Reference

3. Introduction
• Nanoscale Device-Based Digital VLSI Circuits refer to the design and
fabrication of integrated circuits at the nanoscale level, where the key
building blocks are nanoscale devices such as transistors and other
components.
• The term "nanoscale" generally refers to dimensions on the order of
nanometers (1 nm = 10^-9 meters).
• Nanoscale technology has become increasingly important in the field of
digital circuits due to the demand for smaller, faster, and more
energy-efficient electronic devices.

4. Nanoscale devices are crucial for
advanced VLSI circuits
• Miniaturization and Integration: Miniaturization is the process of
making something smaller, often without significantly compromising its
functionality. This allows the integration of a significantly higher number
of transistors and components on a single chip, which is essential for
creating advanced and complex VLSI circuits.
• Higher Performance: Nanoscale circuits can operate at extremely
high speeds, making them suitable for a wide range of applications,
including high-performance computing, artificial intelligence, and digital
signal processing.
• Low Power Consumption:The smaller transistors typically consume
less power, extending battery life in portable devices and reducing heat
generation.
• Greater Functionality:More transistors and components integrated
onto a chip, VLSI circuits can perform more complex functions and
handle a wider range of tasks. Applications like artificial intelligence, data
processing, and communication systems.

5. • Advanced Materials and Properties:Materials are chosen for their
unique properties that can enhance the performance, reliability, and
energy efficiency of electronic devices. Materials are Graphene, Carbon
Nanotubes(CNTs),2D materials.
• Reliability and Precision

6. Nanoscale Devices
• FinFET
• Nanowire Transistor
• Corbon nanotube
• Memristors
• Quantum Dots
• Nenoelectromechanical System

7. FinFET
Introduction:
• It is a type of multi gate MOSFET.
• It is widely used over planer CMOS FET.
• Fin is a channel in between source and drain.
• FinFET can have two or four or more Fin in same structure.
Structure of FinFET:

8. V-I Characteristics of FinFET: The drain current increases when the drain
source voltage is applied. Initially it increases linearly and after that it
enters into saturation region.

9. Advantage:
• Lower power consumption
• Operates at lower voltage
• Operating speed is higher
• Static leakage current is reduced up to 90%.
Disadvantage:
• Fabrication cost is high.
• Controlling the Fin depth is difficult.
Application:
• Used in the microprocessor & smart phones.

10. Carbon Nanotube
Nanotubes are formed by rolling two-dimensional graphite into a cylindrical
shape structure. Nanotubes are hollow from inside. The diameter of the nanotube is
around 1-3 nanometers. The length of the carbon nanotube is much higher than its
diameter. Nanotube length generally goes to a few micrometers.
Structure and typs of CNT: The crystalline structure of carbon nanotubes
exists in the form of regular hexagons .

11. Properties of carbon nanotubes:
• Electrical Conductivity – Carbon nanotubes (CNTs) are electrically and
thermally conductive and have a high mechanical strength.
• Strength And Elasticity – In terms of tensile strength and elastic
modulus, carbon nanotubes are the strongest and stiffest materials yet
found.
• Carbon nanotubes are good conductors of heat.
• Carbon nanotubes are chemically neutral. So, they are chemically stable.
Therefore, carbon nanotubes resist corrosion.
Applications:
• Carbon nanotubes are utilized in energy storage, device modelling,
automotive parts, sporting goods, water filters, thin-film electronics,
coatings, actuators, and electromagnetic shields.

12. Nanowire Transistor
• A significant limitation of CNTs is the inability to control, during
manufacturing, whether the CNT is metallic or semiconducting. This poses
a considerable difficulty for large-scale fabrication. Single-crystal silicon
nanowires have been fabricated, with diameters ranging from 6 nm to 20
nm, and with lengths from 1micron to 10microns.
• Nanowire transistors are extremely small transistors with a wire-like
structure. They provide better control over the flow of current and are
commonly used in digital logic circuits.
• Metallic and semiconductor nanowires have been manufactured to build
wires, diodes, and FETs.
• Homogeneous nanowires can be doped using phosphorous and boron to
have either p- or n-type properties.

13. Structure of nanowire Transistor

14. Memristor
• Memristor is a two terminal non linear resistor and it is a passive element
and it does not store energy.
• It remembers the last amount of current passed through it or the last
value of voltage applied to it.
• It is a resistor with memory.
• Memristors are nanoscale devices with the unique ability to change their
resistance based on the history of the voltage applied to it.
Structure of Memristor:

15. Memristive system:

16. Fundamental Concept:
Resistor --- It relates Voltage & Current (dv=R.di).
Capacitor--- It relates Voltage & Charge (dq=C.dv).
Inductor --- It relates Current & Magnetic Flux (d Φ =L. di).
Memristor --- It relates Charge and Magnetic Flux by relation
d Φ =M. dq

17. Quantum Dots
• It is a zero dimension nano structure in which there is confinement of the
particle along all direction. The charge carrier is not free to move in any
direction.
• Quantum Dots (QDs) are semiconducting nanocrystalline materials with
the diameters usually 2 to 10 nm. Example - Si,cadmium selenide,
cadmium sulfide or indium arsenide.
• QDs can produce distinct colors determined by the size of the particles.

18. Energy level
• In quantum dots the energy level become discrete and the energy gap
become large compared to a bulk made of same material.
• As the nanomaterial become large the energy gap become smaller and
the quantum dot change his colour.

19. Application
1. Electronics
Advanced Transistors
Quantum Computing
2. Memory Devices
3. Sensors
4. Photonics
5. Medicine
6. Defense and Security
7. Environmental Remediation

20. Challenges in Nanoscale Device
Integration
Manufacturing Precision: Even tiny variations or defects at the
nanoscale can have a significant impact on device
performance.
Variability: Nanoscale devices are more susceptible to
manufacturing variations and defects, resulting in variations in
device properties.
Reliability: Nanoscale devices are more susceptible to wear and
tear, which can affect their long-term reliability.
Materials Compatibility: Selecting appropriate materials for
nanoscale devices is crucial.

21. Future Trends
• Miniaturization: Shrinking feature sizes for more compact and powerful
circuits.
• Post-CMOS Technologies: Exploring alternatives to traditional CMOS
transistors as we approach physical limits.
• 3D Integration: Stacking chips to boost performance and reduce power
consumption.
• Energy Efficiency: Green computing with an emphasis on low-power
circuits.
• Biologically Inspired Circuits: Circuit designs inspired by nature.
• Secure Hardware: Hardware security features for safer computing.
• Photonics Integration: On-chip optical communication for faster data
transfer.

22. Refrences
• M. Lundstrom, ‘‘Is Nanoelectronics the Future of Microelectronics?’’ Proc. Int’l Symp.
Low Power Electronics and Design (ISLPED 02), IEEE Press, 2002, pp. 172-177.
• D. Whang et al., ‘‘Large Scale Hierarchical Organization of Nanowire Arrays for
Integrated Nanosystems,’’ Nano Letters, vol. 3, no. 9, Sept. 2003, pp. 1255-1259.
• A. Bachtold et al., ‘‘Logic Circuits with Carbon Nanotube Transistors,’’ Science, vol.
294, no. 5545, 9 Nov. 2001, pp. 1317-1320.
• S. Rosenblatt et al., ‘‘Mixing at 50 GHz Using a Single-Walled Carbon Nanotube
Transistor,’’ Applied Physics Letters, vol. 87, no. 15, 10 Oct. 2005, pp. 153111.1-
153111.3.
• T. Rueckes et al., ‘‘Carbon Nanotube-Based Nonvolatile Random Access Memory for
Molecular Computing,’’ Science, vol. 289, no. 5476, 7 July 2000, pp. 94-97.
• G. Zhang et al., ‘‘Selective Etching of Metallic Carbon Nanotubes by Gas-Phase
Reaction,’’ Science, vol. 314, no. 5801, 10 Nov. 2006, pp. 974-977.