29-11-2012, 11:55 AM
TRIGATE TRANSISTORS
TRIGATE TRANSISTOR.pptx (Size: 2.22 MB / Downloads: 32)
Introduction
Tri-gate or 3-D are terms used by Intel corporation.
Is a non-planar transistor architecture.
Some basics
Ideally a transistor needs to do three things:
1) Allow as much current to flow when it's on
(performance)2) Allow as little current to flow when it's off
(power wastage)3) Switch between on and off states as quickly as
possible (performance)
What is fet..
Is a voltage-controlled device.
Fabricated on a p-type substrate.
Heavily doped n-type Source and Drain.
A thin layer of SiO2.
Metal connection to insulator to form the Gate.
Basic operation of fet
Apply a voltage vGS.
VGS repels the holes in the body near the gate region.
Lowers the concentration of the holes.
The inversion layer is where the current flow actually happens.
MOORE’S LAW(1965)
It states that the number of transistors on integrated circuits doubles approximately every 24 months, resulting in higher performance at lower cost.
Foundation of semiconductor and computing industries.
Need of 3D transistor
Traditional 2-D transistors become impossible on further reduction of size
Increased gate oxide leakage.
Short-channel effect increases (DIBL, velocity saturation)
Increased junction leakage
"on" and "off" effectively become indistinguishable
Fin
Rises up vertically from the silicon substrate into the gate area.
Single gate stacked on top of two other gates
The gate wraps around silicon fin
“Fin” and the “gate” are separated by high k dielectric material.
The inversion layer forms into this fin in three of its sides.
Total device width Ztotal=2*HSi+WSi.
More features
3D transistor measures about 22nm.
Could fit more than 4,000 of them across the width of a human hair
This fin enables the provision of three gate on each side.
Control of current is accomplished by these gates.
Gate switching
Both 22nm and 32nm transistors consume more power at high frequency
At low power levels – 37% faster
At high power level – 18% faster
Unprecedented combination of improved performance and energy efficiency
advantages
Further scaling possible – More compact
Maximum current when on- Performance
Almost zero current when off-Power consumption
Reduced leakage current
Faster operation – Increased performance
Unprecedented combination of both speed and power consumption
Only 2-3% increase in cost
Technological advances
Continuation of Moore’s law
Multiple fins
3D transistors can have multiple fins connected together
Increase in the amount of current flowing through a single transistor increase power usage
All controlled by single gate
Applications and present Advancement
Intel is launched family of processors Ivy Bridge - the first one to use "3D transistor“
More than 300 mobile products and more than 270 different desktops in development
Already built three factories to fabricate the new chips
Finds application from supercomputers to small handheld devices
Increasing height of fins performance can be further increased
conclusion
With a small increase in cost there is a large improvement in speed and performance
Hopes that more advancements can be made