06-06-2012, 11:13 AM
Fabrication of MOSFETs
Fabrication of MOSFETs.ppt (Size: 4.8 MB / Downloads: 0)
Introduction
Integrated circuits: many transistors on one chip.
Very Large Scale Integration (VLSI): millions of logic gates + many Mbits of memroy
Complementary Metal Oxide Semiconductor
Fast, cheap, low power transistors
Today: How to build your own simple CMOS chip
CMOS transistors
Building logic gates from transistors
Transistor layout
Rest of the course: How to build a good CMOS chip
Invention of the Transistor
Vacuum tubes ruled in first half of 20th century Large, expensive, power-hungry, unreliable
1947: first point contact transistor
John Bardeen and Walter Brattain at Bell Labs
Transistor Types
Bipolar transistors
npn or pnp silicon structure
Small current into very thin base layer controls large currents between emitter and collector
Base currents limit integration density (power dissipation issue)
Metal Oxide Semiconductor Field Effect Transistors
nMOS and pMOS MOSFETS
Voltage applied to insulated gate controls current between source and drain
Low power allows very high integration (ideally zero static power).
Summary
MOS Transistors are stack of gate, oxide, silicon
Can be viewed as electrically controlled switches
Build logic gates out of switches
Draw masks to specify layout of transistors
Now you know everything necessary to start designing schematics and layout for a simple chip!