ECE467: Introduction to VLSI Design Lecture-1 Introduction to Integrated Circuits: Historical Developments Basic Concepts and Definition Metrics of Design

Igor Paprotny paprotny@uic.edu

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ENIAC - The first Electronic Computer (1946)

Dimension:

80 Feet Long 8.5 Feet High Several Feet Wide Parts:

18000 Vacuum Tubes

Technological Revolution Fueled by

Integrated Circuits A tiny tablet PC with less than 1 thickness can be give you million times higher computing power than the earliest computer

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Telephone- Communicate Greater Distances

Johnson 6 (1875): The Gallows Frame Telephone was one of the earliest phones Designed by Alexander Graham Bell and built by Thomas A. Watson

The first generation telephone sets were wall mounted, magneto and battery type, with a crank on the side to generate current for ringing

In the station an operator must be present in front of a switch board to connect the callers phone line to the receivers phone line

The overall operation was mechanical and involved manual operators

Early Days of

Telephone

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Todays Telephone

Units

Digital Cellular Market (Phones Shipped) 1996 1997 1998 1999 2000 48M 86M 162M 260M 435M

Small Power Signal RF RF Power Management Analog Baseband Digital Baseband (DSP + MCU)

(data from Texas Instruments)

Regular Phone

Personal Organizer

Text and Graphical

Communication

Audio/Video Entertainment

Image Capturing

Internet Browsing

Gaming Device

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Todays Telephone

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Early Days of Television An Announcement - July 1928 of the British magazine, called Television. "Baird Televisors ("seeing-in instruments") will be on sale in the country [England] at the annual Radio Exhibition to be held at Olympia, September 22nd to 29th,

1928" Announcement Caption: "One of the several designs of the new Baird Televisor, which will be marketed here

and in America in September."

Seeing instruments: Seeing from distance From Wikipedia

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Television: Past and Present

Dimension: Size of a standard breakfast table

Screen: Diagonally 7 Viewable

Colors and Shades: 2 (black and white)

Dimension: 58 x 35 x 4

Screen: Diagonally 61 Viewable

Colors and Shades: 16.9 Million Different Shades

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Which Color You Like?

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What is the common Platform for all of these

Remarkable Developments?

Integrated Circuit (IC)

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Electrical Circuit and its Classification Electrical Circuit:

An electrical circuit is a closed loop formed by a power source, and a set of active and passive elements to process and deliver an electrical signal (voltage or current).

Active element: The electrical characteristics of active elements vary depending on applied excitation force. These elements have the ability to act as electrical switches (ON-OFF characteristics). These elements can amplify electrical signals.

Examples of:

pn-junction Diode Transistors: BJT, MOSFET, JFET etc

vacuum tube

Passive element: Electrical characteristics of passive elements mainly depend on the physical properties and the geometrical shapes of the elements. These elements can not act as switch or amplifier.

Example:

Resistor, Inductor,

Capacitor,

Wire

Insulator

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Electrical Circuit and its Classification

Classification of Electrical Circuit: Discrete Circuit

Each circuit element (active or passive) comes as an individual components to be placed and connected on a PCB board.

Integrated circuit:

Integrated circuit (IC) is referred to a circuit, where all the active and

passive components are fabricated on a single semiconductor substrate,

known as a chip

The components of IC are:

Transistors and Diodes.

Wires and Insulators.

Resistor, Inductor and Capacitors.

The principal element or the main working device in IC is the transistor.

All other components in IC play supporting role for the transistors.

Paprotny et al. Sensors and Actuators (A: Physical), 2013

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Invention of Transistor Transistor Definition:

Transistors are electronically controlled switches with a control terminal and two other terminals that are connected or disconnected depending on the voltage applied to the control terminal. Pre-Transistor Era: Vacuum tube was the technology for most of the electronic circuits before transistors were invented.

Vacuum tubes ruled in the first half of the 20th century

Vacuum tubes are large, expensive, power-hungry, and unreliable

Excessive power consumption made vacuum tubes obsolete Point contact transistor: John Bardeen and Walter Brattain

of Bell Lab invented point contact

transistor in 1947

It was nearly declared military secret

Bell Lab made it public

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Technology Selection for Integrated Circuits The beginning of Integrated Circuit (IC):

The concept of IC was introduced by Jack Kilby of Texas Instrument in 1958 to miniaturize electronic circuits by building multiple transistors on a

single substrate. A two transistors (BJTs) flip-flop had been the first Integrated Circuit

implementation, which was built from germanium slice and gold wires

Bipolar Junction Transistor (BJT):

BJT, invented in 1949 by Schockley, comes in npn or pnp silicon structure It requires a small current into the base layer that controls large currents between the emitter and the collector

BJT was more reliable, less noisy, and more power-efficient than first version of point contact transistor

Invention of BJT and inception of the idea of building IC lead to the introduction of first set of commercial IC logic gates, called Fairchild Micrologic Family (1958)

Transistor-Transistor Logic (TTL), pioneered in 1962, became very successful IC logic family. TTL had the advantage of offering higher integration density, which made TTL the most popular logic design approach until 1980s.

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Bipolar Junction Transistor

n p n E

B

C

p n p E C

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Technology Selection for Integrated Circuits Emitter Coupled Logic:

Other logic families were also developed keeping higher performance in mind.

For example, Emitter Coupled Logic (ECL), which is capable of producing subnanosecond gates.

ECL 3-input Gate Motorola 1966

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Technology Selection for Integrated Circuits Metal Oxide Semiconductor Field Effect Transistors (MOSFET):

The idea of Field Effects devices was originally proposed by German

scientist Julius Lilienfield in 1925 and British scientist Oskar Heil in 1935

Material problems foiled early attempts to make functioning device

MOSFET has three functional terminals: Gate, Source and Drain

In MOSFET, which comes in two flavors NMOS and PMOS, a voltage

applied to the insulated gate controls current between the source and the drain

n+

p

Gate Source Drain

bulk Si

SiO2

Polysilicon

n+

n

Gate Source Drain

bulk Si

p+ p+

NMOS PMOS

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Technology Selection for Integrated Circuits MOSFET largely replaced BJT Technology:

The quiescent power dissipated by the base current of BJT limited the integration density as IC became more complex

Power consumption was the reason that haunted vacuum tube approach. For the same reason BJT started loosing favor as compared more power- efficient MOSFET technology

MOSFETs offer the advantage of almost zero control current while idle.

Low power consumption of MOSFETs allows very high integration

Improvement of silicon processes made MOSFETs more popular due to simpler fabrication process, and lower cost and area per device

First generations of MOSFET ICs used PMOS-only technology. But PMOS-only processes suffered from poor performance, yield, and reliability

NMOS-only processes became dominant in the 1970s. NMOS transistor has the advantage of implementing faster gate for the same area compared to PMOS transistor

But soon Complementary MOS (CMOS) technology replaced every technology in more than 80% of IC applications

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Technology Selection for Integrated Circuits Complementary Metal Oxide Semiconductor (CMOS):

In 1963 Frank Wanlass at Fairchild described the first logic gates using both NMOS and PMOS transistors, earning the name CMOS

Wanlass used discrete transistors, but soon improvement of silicon technology made CMOS integrated circuits possible

While NMOS process is less expensive than CMOS, NMOS logic gates still consumes power while idle.

CMOS logic gates consumes almost zero static power

Even the discrete CMOS circuit built by Wanlass consumed only nano- watts of power, six orders of magnitude less than their bipolar counterparts

Power consumption became the major issue in 1980s as hundreds of thousands of transistors were integrated onto a single chip

CMOS process has become the most widely adopted technology and replaced most of NMOS and bipolar processes for nearly all digital applications

Currently CMOS technology holds more than 80% of the market share

CMOS Technology

inverter gate

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More of Historical Developments First 4 Kbits memory: First memory IC was built in 1970 using MOSFET

Intel later pioneered NMOS technology with its 1101 256-bit static random access

memory First Microprocessor: First 4-bit Microprocessor (Intel 4004) came in 1972

1970s processes usually had only nMOS transistors

Intel Pentium 4 came in 2003: Contained 55 million transistors

512-Mbit dynamic memory (DRAM): Contained half a billion transistors

Intel 1101 256-bit SRAM Intel 4004 4-bit mProc Intel Pentium 4 mProc

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Historical Growth Rate Growth Rate:

Number of transistors increased from 2 in the first IC (1958) to 55 millions in Intel Pentium 4 (2003). A growth corresponds to a compound rate of 53% annually over 45 years No other technology or industry in human history has sustained such a high growth rate for so long. Most other fields involve tradeoffs between performance, power and price. However, as transistors become smaller, they also become faster and cheaper Steady miniaturization of transistors and improvement of process and manufacturing technologies made it possible

Moores Law:

Gordon Moore the founder of Intel observed in 1965 that plotting the number of transistors that can be most economically integrated on a chip gives a straight line on a semi-logarithmic scale. At that time he found that transistor count doubling every 18 months. This observation has been called Moores Law

In 2013 semiconductor industry manufactured more than one quintillion (1018)

transistors, or 100 million for every human being on this planet

Not only the transistor count, but also the clock frequency or the speed of

integrated circuits have seen an unprecedented rise over the last few decades

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Historical Growth Rate

Semiconductor Industry

1994: IC industry has become a $100B/year business

Annual 20% growth

2.5 x salary for average U.S. worker

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Level of Integration SSI: Small-scale Integration (SSI) circuits has been classified as those with roughly fewer than 10 gates and about a dozen transistors per gate, such as, 7400 series logic ICs.

MSI: Medium-scale Integration (MSI) circuits are those with up to 1000 gates per chip, such as, 74000 series counters

LSI: Large-scale Integration (LSI) circuits have up to 10,000 gates per chip, such as, 8- bit microprocessor It soon became apparent that new names would have to be created every five years if this naming trend continued and thus the term VLSI is used to describe all ICs from 1980s onward

VLSI: Very Large Scale Integration (VLSI) circuits can now contain hundreds of thousands of gates with billions of transistors per chip In some literature the term ULSI (Ultra Large Scale Integration) is used for current and upcoming integrated circuits, but this term has not yet become

popular. Integration Levels

SSI: MSI: LSI: VLSI:

10 gates 1000 gates 10,000 gates > 10k gates

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Transistor Scaling Transistor Sizes:

Intel 4004 in 1971 used transistors with minimum dimensions of 10 micrometer, whereas Pentium 4 in 2003 used 130 nanometer transistors. This corresponds to two orders of magnitude in reduction over three decades

IC industry has now entered into the Nanometer Regime

As predicted this downward scaling of transistors will continue for at least a decade

Dramatic scaling of all physical and electrical parameters is going on simultaneously

Why Scaling:

Technology shrinks by 0.7/generation

With every generation can integrate 2x more functions per chip; chip cost does not

increase significantly

Cost of a function decreases by 2x

But

How to design chips with more and more functions?

Design engineering population and efficiency does not double every two years

Hence, a need for more efficient design methods

Resolve numerous challenges that arise at every design step in every generation

Exploit different levels of abstraction

Scale Perspective of Integrated Circuits

~ 10 000 km = 1 x 108 m 1 m

1/107

300 mm = 3 x 10-1 m

1/107

~ IBM 20 nm process = 2 x 10-8 m