1. Introduction to VLSI CMPE/ELEE 4375 Introduction

2. Outline Syllabus Introduction to VLSI
Logistics (time, place, instructor, website, textbook)
Grading
Topics
Outcomes
Introduction to VLSI
A brief history
MOS transistors
CMOS logic gates
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3. Course Information (1) Time and Place Instructor
Class: 8:45 am - 9:35 am
MWF Engineering Building 1.262
Instructor
Hasina Huq
ENGR 3.278,
Office hours: MTW 1.00 pm pm or walk in or by appointment
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4. Course Information (2) Prerequisites
Digital logic (ELEE 2330) and Electronic 1(ELEE 3301), or equivalent
I assume you know the following topics
Boolean algebra, logic gates, etc.
MOSFET characteristics
Undergraduate physics: Ohm’s law, resistors, capacitors, etc.
Undergraduate math: calculus
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5. Course Information (3)
Text Ken Martin, Digital Integrated Circuits design, Oxford,
Reference Class handouts
Cadence manual set
H.Craig Casey, Jr., Devices for Integrated Circuits, John-Wiley,
Baker, Li, & Boyce, CMOS Circuit Design, Layout, and Simulation, IEEE Press, 1998.
Account UNIX (lab access)
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6. Course Information (4) Grading 60% project 5% homework
15% mid-term exam
20% final exam
Laboratory Based Projects (3) 60% (10%, 20%, 30%)
Final project include design, report and presentation
Total 100%
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7. Course Information (5) Topics NMOS,PMOS CMOS logic gate
fabrication and layout
MOS transistor characteristics
Performance analysis for VLSI circuits
digital circuits design
Integrated Circuit (IC) design
Compact & cost effective design
System on chip
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8. Course Information (6)
Use the Electric CAD tool to design a chip including (depending on tool availability)
Schematic entry
Layout
Transistor-level cell design
Gate-level logic design
Hierarchical design
Switch-level simulation (IRSIM)
Design rule checking (DRC)
Electrical rule checking (ERC)
Network consistency checking (NCC)
HDL design (Verilog)
Place and route
Pad frame generation and routing
Pretapeout verification
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9. Course Information (7) Outcomes
Estimate and optimize combinational circuit delay using RC delay models and logical effort
Design high speed and low power logic circuits
Understand interconnect and reliability issues
Design functional units including adders, multipliers, DFF, ROMs, SRAMs, and PLAs
Beware of the VLSI trends and challenges
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10. Introduction Integrated circuits: many transistors on one chip.
Very Large Scale Integration (VLSI): very many
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 and fabrication
Rest of the course: How to build a good CMOS chip
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11. A Brief History 1958: First integrated circuit 2003
Flip-flop using two transistors
Built by Jack Kilby at Texas Instruments
2003
Intel Pentium 4 mprocessor (55 million transistors)
512 Mbit DRAM (> 0.5 billion transistors)
53% compound annual growth rate over 45 years
No other technology has grown so fast so long
Driven by miniaturization of transistors
Smaller is cheaper, faster, lower in power!
Revolutionary effects on society
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12. The impact of ICs on modern society has been pervasive.
Without them current computer, electronics systems and
information-technology revolution would not exist.
Immense amount of signal and computer processing is realized in a single IC.
Most of the students of Computer/ Electrical Engineering are exposed to Integrated Circuits (IC's) at a very basic level, involving circuits like multiplexers, Flip flop, encoders etc.
But there is a lot bigger world out there involving miniaturization, that a micrometer and a microsecond are literally considered huge! This is the world of VLSI - Very Large Scale Integration.
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13. The course will help you to understand why you need to learn the Chip / Integrated Circuit (IC) Design technologies. This involves packing more and more logic devices into smaller areas and smaller areas. This has opened up a big opportunity to do things that were not possible before. VLSI circuits are everywhere ... your computer, your car, your brand new state-of-the-art digital camera, the cell-phones, and what have you. All this involves a lot of expertise on many fronts within the same field, which we will look at in the course. At UTPA we use Cadence simulation tool which is an industry standard simulator
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14. Modern ICs are enormously complicated
Modern ICs are enormously complicated. A large chip may have more transistors than there are people on Earth i.e. may contain millions of transistors. The rules for what can and cannot be manufactured are also extremely complex. An IC process may well have more than 600 rules. CAREER:
 Design Engineer: Takes specifications, defines architecture, does circuit design, runs simulations, supervises layout, tapes out the chip to the foundry, evaluates the prototype once the chip comes back from the fab.
TYPICAL COMPANIES AND JOBS? Intel, IBM, Texas Instruments, Motorola, National Semiconductor, Maxim, Linear Technology, Siemens, Qualcomm
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15. University: Most of the universities in USA are offering VLSI course at undergraduate level because of reality, demand. Dept: Electrical and Computer Engineering: University of Texas at Austin, Rice University, Department of Electrical and Computer Engineering at Texas A&M University, Dept. of Electr. Eng. & Comput. Sci., Univ of Michigan. Ann Arbor, MI, Department of Electrical and Computer Engineering UC Berkeley
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20. Invention of the Transistor
Vacuum tubes ruled in first half of 20th century Large, expensive, power-hungry, unreliable
1947: first point contact transistor at Bell Labs
John Bardeen and Walter Brattain at Bell Labs
Read Crystal Fire
by Riordan, Hoddeson
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21. 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
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
Simpler fabrication process
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22. MOS Integrated Circuits
1970’s processes usually had only nMOS transistors
Inexpensive, but consume power while idle
1980s-present: CMOS processes for low idle power
Intel bit SRAM
Intel bit mProc
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23. 1965: Gordon Moore plotted the number of transistors on each chip
Moore’s Law
1965: Gordon Moore plotted the number of transistors on each chip
Fit straight line on semilog scale
Transistor counts have doubled every 26 months
Integration Levels
SSI: 10 gates
MSI: gates
LSI: 10,000 gates
VLSI: > 10k gates
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24. Corollaries Many other factors grow exponentially
Ex: clock frequency, processor performance
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25. Scaling Down: a Mystery
In 1971, minimum dimensions of 10 um in 4004.
In 2003, minimum dimensions of 130 ns in Pentium4.
Scaling down forever ? (No, transistors cannot be less than atoms)
Many predictions of fundamental limits to scaling have already proven wrong
We believe that scaling will continue for at least another decade.
What is the future?
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26. Periodic Table
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27. Dopants Silicon is a semiconductor
Pure silicon has no free carriers and conducts poorly
Adding dopants increases the conductivity
Group V (Arsenic): extra electron (n-type)
Group III (Boron): missing electron, called hole (p-type)
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