SOI (silicon-on-insulator) is a fabrication technique where transistors are built on a thin silicon layer resting on an insulating layer, allowing for higher speed, lower power consumption, and easier fabrication compared to traditional bulk silicon. The main types of SOI are partially depleted SOI (PD-SOI) and fully depleted SOI (FD-SOI). SOI offers advantages like reduced parasitic capacitance but also faces limitations such as higher manufacturing costs and floating body effects. SOI is increasingly being used in applications like smartphones, tablets, and automotive systems.

1. SILICONE ON INSULATOR
PRESENTED BY,
Mutharasi . A

2. Introduction
Invention
What is SOI ?
Why is SOI ?
Fabrication of SOI
Types of SOI
Floating body effect and History effect in PD-SOI
Advantages of SOI
Limitations of SOI
Applications of SOI
Conclusion and Future work
CONTENT

3. Latest fabrication technology.
Chip in a Blanket.
Silicon-on-Silicon.
Increasing demand for high performance, low power & low area
among micro-electronic device led to its invention.
INTRODUCTION

4. SOI (silicon-on-insulator) has been known for ~ 20 years.
In 1993 Honeywell started product development of SOI to support commercial aircraft
electronic engine controls.
First it was used for military purposes in U.S.A.
INVENTION

5. It is the latest fabrication technique.
It is easier & cheaper.
Transistors are build on a silicon layer resting on insulating layer of silicon-di-
oxide known as BOX (burried oxide).
Only a thin layer from a face of the wafer used for making electronic
components, the rest essentially serves as mechanical support. S.O.I.
WHAT IS SOI ?

6. To enhance the performance.
Higher speed.
Less power consumption.
Easier fabrication.
Cheaper etching process.
More electronic devices can be fabricated on same chip (30% more than bulk).
It reduces parasitic capacitance when compared to bulk or epi-wafers. S.O.I.
WHY SOI ?

7. Fewer mask and ion implementation steps (because of the elimination of well & field
isolation implements).
Less complex (costly) lithography and etching required to achieve next-generation
performance.
Some fabrication process:
SIMOX – Separation by Implantation of Oxygen
Smart-cut SOI Technology
BESOI – Bond and Etch-back SOI
SOS – Silicon-on-Sapphire S.O.I.
FABRICATION OF SOI ?

8. 1.PD-SOI ,
2.FD-SOI .
1.Partially Depleted SOI(PD-SOI):
Silicon dioxide layer is thicker.
History dependent.
The exact voltage depends on the history of source, gate, and drain
voltages leading up to the current time (the “history effect”).
TYPES OF SOI
2.Planer fully Depleted SOI:
FD-SOI technology relies on an ultra- thin layer of silicon over a Buried Oxide
(commonly called BOX).
History independent.

9. Usually seen in Partially-Depleted S.O.I.
The MOS structure is accompanied by a parasitic bipolar device in parallel.
The base of this device is ‘floating’.
FLOATING BODY EFFECT:
HISTORY EFFECT IN PD-SOI:
In PD—SOI the next switching time marginally depends on previous
switching time.
The second switch is seen to be faster than the first switch. This is
known as ‘History Effect’.

10. ADVANTAGES Of S.O.I. :
Suitable for high-energy radiation environments.
Parasitic capacitances of SOI devices are much smaller.
Elemination of Substrate Noise .
Less Temperature SensitivitY.
Easier scale-down of threshold voltage.
Higher transconductance (especially of FD) implies higher gain.
Lower power consumption compared to bulk devices at low current
level.

11. LIMITATIONS OF S.O.I. :
Self-heating
Major bottleneck is high manufacturing costs of the wafer.
Floating-body effects impede extensive usage of SOI.
Floating body causes the History Effect

12. APPLICATION :
Daily use product such as markets such as :
Mobile Internet Devices (Smartphones, Tablets, Netbooks …),
Imaging (Digital Camera, Camcorders…),
Cellular Telecom,
Mobile Multimedia
Home Multimedia (Set Top Box, TV, Blu-Ray),
Automotive Infotainment,
etc.

13. CONCLUSION AND FUTURE WORK :
We have investigated the SOI technology and its application to next
generation low power, high performance DRAM systems by intensive
simulations.
Due to its characteristics, SOI is fast becoming a standard in IC fabrication.
Several companies have taken up SOI manufacturing.
High-volume production of SOI is yet to become common.

14. REFERENCE :
J.P. Colinge, “Silicon-On-Insulator Technology: Materials to VLSI, Second Edition” ,
D. K. Sadana and M. Current, “Fabrication of Silicon-On- Insulator (SOI) Wafers Using
Ion Implantation”.
J. Kuo, Low- Voltage SOI CMOS VLSI Devices and Circuits.
http://www.jpl.nasa.gov
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