Introduction to ICs and Transistor Fundamentals Brief History Transistor Types Moore’s Law Design vs Fabrication

First Programmable Electronic Computer Electrical Numerical Integrator and Calculator (ENIAC) is created by the US army in 1947 Build out of 18,000 vacuum tubes, ENIAC consumed 200kW and suffered a failure on average every 6 hours

A Brief History 1958: First integrated circuit 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) 2006 Intel Duo Core mprocessor (151 million transistors) 55% compound annual growth rate over 48 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

Annual Sales transistors manufactured in million for every human on the planet

VLSI Applications VLSI is an implementation technology for electronic circuitry - analogue or digital It is concerned with forming a pattern of interconnected switches and gates on the surface of a crystal of semiconductor Microprocessors personal computers Microcontrollers Memory - DRAM / SRAM Special Purpose Processors - ASICS (CD players, DSP applications) Optical Switches Has made highly sophisticated control systems mass-producable and therefore cheap

Invention of the Transistor Vacuum tubes ruled in first half of 20 th century. Large, expensive, power-hungry, unreliable 1947: first point contact transistor

First Transistor and Integrated Circuit The first transistor used germanium and was created by a team lead by William Shockley at Bell Labs in 1947 Shockley later shared the Noble prize in physic for his work on the transistor Shockley semiconductor was founded in Palo Alto in Bob Noyce and Gordon Moore were hired by Shockley to being work on a silicon transistor In 1957, Noyce, Moore and 6 others leave to found Fairchild semiconductor The first IC proposed independently by Bob Noyce at Fairchild and Jack Kilby at Texas Instruments in 1959 TI used germanium while Fairchild used silicon with incorporated wires In 1968 Noyce and Moore leave Fairchild to found Intel. Intel is short for INTegrated ELectronics

Transistor Types Bipolar junction transistors (BJT) npn or pnp silicon structure Small current into very thin base layer controls large currents between emitter and collector Base currents limit integration density

Cont.. Field Effect Transistors (FET) n-channel FET and p-channel FET Also known as unipolar transistor Operates on the principle that semiconductor conductivity can be increased or decreased by the presence of electric field

Cont… MOS transistor Metal Oxide Semiconductor Field Effect Transistors (MOSFET) Complementary Metal Oxide Semiconductor (CMOS)

Cont… MOSFET nMOS and pMOS MOSFETS Voltage applied to insulated gate controls current between source and drain Low power allows very high integration

Cont… CMOS Uses complementary and symmetrical pairs of p-type and n-type MOSFETs for logic functions Extremely useful for digital circuitry design (act as a simple switches w/o having pull-up resistors) Main advantage : much smaller power dissipation

Cont… CMOS operation (NMOS)

Cont… CMOS operation (PMOS)

Cont… Complementary MOS (CMOS) D G G S D D S NMOSPMOS BG D S G S D B NMOS with bulk contactPMOS with bulk contact G = Gate D = Drain S = Source B = Bulk

CMOS inverter circuit

1970’s processes usually had only nMOS transistors Inexpensive, but consume power while idle 1980s-present: CMOS processes for low idle power MOS Integrated Circuits Intel bit SRAM Intel bit  Proc

The integrated circuit from an Intel 8742, an 8-bit microcontroller that includes a CPU running at 12 MHz, 128 bytes of RAM, 2048 bytes of EPROM, and I/O in the same chip.Intel microcontrollerCPU RAM EPROMI/O Intel Duo Core processor, CPU speed max 3 GHz with almost 2 billion transistors

Moore’s Law 1965: Gordon Moore plotted transistor on each chip Transistor counts have doubled every months As of 2006, chip areas range from a few square mm to around 350 mm 2, with up to 1 million transistors per mm 2.mm transistors mm Integration Levels SSI : 10 gates MSI : 1000 gates LSI : 10,000 gates VLSI : > 10k gates

Fit straight line on semilog scale Moore's Law Intel 4004 (1971) 108 KHz 2300 Transistors 10um Technology Pentium 4 2 GHz >40,000,000 Transistors 0.18um Technology

Empirical Evidence of Moore’s Law Integrated Processor: Starting with Intel's 486 processor series, cache memory is included Increase in the number of transistors Integrated processor chips - L1 cache + L2 cache. Multi-chip package: Pentium Pro and Pentium II L2 added in the same silicon from 2 nd Gen Celeron processors. Computer clock frequency and the number of instructions per second (MIPS) keep increasing but have become very inaccurate indicators of processor power. parallel processing is used in many alternative forms. Two important numbers in wafer fabrication: wafer size and feature size Wafer size increase to enable higher volume capacity Features size reduced to enable more die/chip per wafer Advantage of integration's economies of scale more and more of the circuit's components onto one die cost/integration curve begins to drop as integration increases. at some point the effects of defect density kick in and drive costs up more transistors increase the power density of the chip. Add more functionality (or complexity) to the die Reduce the size of the die while keeping the same functionality/complexity. Shrinking of features size improve the processor's clock speed or lower its power dissipation

Corollaries Many other factors grow exponentially Ex: clock frequency, processor performance

Design versus Fabrication Design Inexpensive Software based Small setup area Related with design skill Fabrication Costly Hardware and software based Huge setup area Related with chemical process