Chapter 1 - Introduction To Ic Design 1r3g3v

IC DESIGN AND PROCESS BENM 3133

Learning Outcomes • At the end of this subject, student should be able to: ▫ ▫ ▫ ▫

Discover the IC design technology, structure of CMOS devices, fabrication and packaging process. [PO1,C3] Analyze a CMOS operation and characteristics. [PO2,C4] Design transistor-level logic and layout design for CMOS technology. [PO3,C5] Demonstrate a report on a digital circuit design project to recognize the needs for, and ability to engage in independent and life-long learning as well as identify entrepreneurial and business opportunities in related area. [PO11,A3]

Week

Session

Syllabus

1

Lecture 1 17/2-21/2 Introduction

2

Lecture 2 24/2-28/2 Tutorial 1

Chapter 2: CMOS Characteristics and Analysis Review of MOS transistors pn-junction MOS Transistors : nMOS and pMOS

3

Lecture 3 3/3-7/3

Chapter 2: CMOS Characteristics and Analysis MOS modes and regions of operations MOS enhancement transistors

4

Lecture 4 10/3-14/3 Tutorial 2

Chapter 2: CMOS Characteristics and Analysis IV characteristics Non ideal IV CV characteristics

Chapter 1: Introduction to IC Design History of microelectronics Components for logic A brief history of MOST Introduction to IC Classification of IC IC design Why design IC IC design hierarchy IC technologies (CMOS, Bipolar & BiCMOS)

Week

Session

Syllabus

5

Lecture 5 17/3-21/3 Lab 1

Chapter 2: CMOS Characteristics and Analysis DC response : CMOS inverter, voltage transfer characteristic, operating regions, beta ratio, threshold voltage.

6

Lecture 6 24/3-28/3 Tutorial 3

Chapter 3: CMOS Circuits and Logic Design Design representations Complementary CMOS MOS transistors switches CMOS logic

7

Lecture 7 31/3-4/4 Test 1

Chapter 3: CMOS Circuits and Logic Design Inverter Combinational logic NAND gate NOR gate Compound gate

8 9

MID TERM BREAK (7/4-11/4) Lecture 8 14/4-18/4 Tutorial 4

Chapter 4: IC Layout and Design Introduction Layout design rules and layout considerations nMOS transistor layout CMOS inverter layout

Week

Session

Syllabus

10

Lecture 9 21/4-25/4 Lab 2

Chapter 4: IC Layout and Design Stick diagram: stick diagram color code, transistor, implied connections and crossovers, s and taps. Practice of stick diagram

11

Lecture 10 28/4-2/5 Assignment

Chapter 4: IC Layout and Design Layout design Mask layout Complex logic gates layout

12

Lecture 11 5/5-9/5 Lab 3

Chapter 4: IC Layout and Design Euler path Multiple gates Multi-cell layout

13

Lecture 12 12/5-16/5

Chapter 5: IC Fabrication & Process Technology Introduction Silicon semiconductor manufacturing technology Semiconductor device fabrication Fabrication process: silicon wafer preparation, epitaxial growth, oxidation.

Week

Session

Syllabus

14

Lecture 13 19/5-23/5 Industrial Talk Tutorial 5

Chapter 5: IC Fabrication & Process Technology Fabrication process (cont) : photolithography, diffusion, ion implantation, etching, isolation, metallization, packaging.

15

Lecture 14 26/5-30/5 Test 2

Chapter 5: IC Fabrication & Process Technology SiO2 patterning LOCOS/STI Basic CMOS technology Cross -section

16

REVISION WEEK

17, 18

EXAMINATION WEEK

References • Sung-Mo Kang, Yusuf Leblebici, CMOS Digital Integrated Circuits, McGraw Hill, 2009. • B. L. Anderson, R. L. Anderson, Fundamentals of Semiconductor Devices, McGraw Hill, 2008. • J. M. Rabaey, Digital Integrated Circuits: A Design Perspective, Prentice Hall, 2009. • Muhammad H. Rashid, Microelectronic Circuit: Analysis and Design, Cengage Learning, 2010. • Behzad Razavi, Design of Analog CMOS Integrated Circuits, Mc Graw Hill, 2010.

Evaluation

Introduction to IC Design CHAPTER 1

HISTORY OF MICROELECTRONICS  Science of electronics began in 1895 – Lorentz postulated existence of electrons  By 1897, Braun built simple cathode-ray tube (the 1st electron valve)  Beginning of century, Fleming invented Diode he called a valve  In 1907, Lee De Forest made a triode & can amplify signals

 By 1940’s several scientist in Bell Labs start investigating material called semiconductors  Then they made a diode from it that have many advantages – No Vacuum, Much smaller, Operate well in Room temperature & No warm-up time  The start of Microelectronics !!!

HISTORY OF MICROELECTRONICS (cont..)  In 1948, William Shockley at Bell Lab invented Transistor act as amplifier & Received Nobel Price in 1956

 By 1953, Transistors were small enough to be fitted in ear & can operate in higher freq within larger temperature ranges, then it became so small that many can be placed in single piece of silicon – Microchips & They started the Microelectronics Industry !!  By 1960’s, several transistors put on single IC, further refined into SSI (Small-scale integration : < than 100 transistors), 1966 evolved to MSI (Medium-scale integration : > than 100 but < than 1000 transistor), Next to LSI (Large-scale integration : > than 1000), then VLSI ( > than 100 000 transistors) & now ULSI ( > than 1 mil transistors)

Components for Logic Diode

p n E

Bipolar Transistors

MOS Transistors Enhancement

n p n

B

p n p

C Depletion

Silicon Oxide Insulator

G N-channel

S P-channel

n

p

n

D

SUB Field Induced N-channel

A Brief History of MOST • Basic principles proposed by J. Lilienfeld as early as 1925 !!! • In 1935, O. Heil resembling closely structure of modern MOS transistor • Materials problem foiled these early attempts & led to invention of Bipolar transistor • MOS remained oddity till invention of Si planar process in 1960 led to MOS calculator in 1965 using single-polarity p-type transistor • Used of both polarity transistor on the same substrate was invented in early 1960’s by 2 people: • P.K. Weimer issued on May 22, 1965 that featured elements of modern CMOS flipflops – led to TFT technology • Frank Wanlass Fairchild S/C R&D granted on 5 Dec 1967 that covered CMOS concept & three ccts : Inverter, NOR & NAND using MOS Devices • Hallmark of CMOS – LOW POWER DISSIPATION – has overcome bipolar popularity – Initially used for low power application such as watches • CMOS technology has increased in level and now it clearly holds the center stage as the dominant of VLSI technology

Introduction to IC • In electronics, an integrated circuit: ▫ Also known as IC, microcircuit, microchip, silicon chip or chip. ▫ Is a miniaturized electronic circuit:  Consist of semiconductor active devices (diode, BJT, MOS, CMOS inverter) and ive components (resistor, capacitor, inductor).  Manufactured in the surface of a thin substrate of semiconductor material.

Basic Definition of IC • Is a miniature, low cost electronic circuit consisting of active and ive components that are ed together on a single crystal chip of silicon. • Advantages of IC ▫ ▫ ▫ ▫ ▫

miniaturization leads to increased equipment density. system reliability is increased because soldering is avoided. the cost is low because ICs are manufactured in a batch process. operating speed is increased. power consumption is decreased.

History of Integrated Circuits • Integrated circuits, i.e., devices with multiple electronic devices on the same substrate, ▫ were invented in late 1950s, by Jack St. Clair Kilby at Texas Instruments,Inc.

• In 1970s, Gordon Moore, on of the founders of Intel ,

▫ predicted that the number of transistors per chip doubles every ones and a half years.

• The minimum channel length of MOS transistors dropped from 25μm in 1960s to 90nm in the year 2002,

▫ with benefit of much higher complexity, smaller volume and higher speed.

Integrated Circuits of Ten or Twenty Years Ago • A signal processing system required multiple: ▫ analog IC chips (amplifiers, filters and A/D and D/A converters) ▫ digital IC chips (memory, DSP and interfacing logic) and plenty of ive discrete components.

• Analog and digital IC chips were traditionally designed and fabricated in different technologies. ▫ analog circuits use bipolar technologies ▫ digital circuits are in MOS technologies.

• A system which consists of a large number of integrated and discrete components is power hungry, huge and expensive.

Integrated Circuits of Today • Most of the integrated chips have both analog and digital circuits. ▫ is called mixed-signal integration.

• Penetrating into every corner of our everyday life, from supercomputers, space probes, medical diagnostic equipments and etc. • Digital circuit design is mostly automated from logic synthesis to placement and routing ▫ while analog circuit design remains as an almost all handcrafted art.

Integrated Circuits of Today (cont..)

Figure 1.0: Mixed-signal system-on-a-chip (SoC) integration

Classification of IC • ICs can be classified into different types depending on: ▫ Linearity ▫ type of transistor used

or ▫ manufacturing process.

Classification of IC (cont..) • Linearity. ▫ can be classified as either linear or digital.  linear ICs:  have any output voltage and will follow linearity principle inside the specified range.  is the operational amplifier or op amp, which consists of resistors, diodes, and transistors in a conventional analog circuit.

 digital ICs :  have only two possible output levels. Example: Logic gates and flip-flop

Classification of IC (cont..) • Transistor ▫ BJT ICs use Bipolar Junction Transistors and FET ICs use Field Effect Transistor.

• Manufacturing ▫ can be classified as either hybrid or monolithic.

Classification of IC (cont..) • Manufacturing ▫ Hybrid IC:

 electronic circuit integrated on the ceramic substrate using various components and then enclosed in the single package  are combinations of monolithic, film and discrete components.

 is often encapsulated in epoxy, as shown in the Fig. 1. 1.  is used for high frequency and high power(e.g communication system, voltage regulator, etc).

Figure 1.1

Classification of IC (cont..) • Manufacturing ▫ Monolithic IC:  called a chip or die, contains both active and ive elements.  entire circuit is built into a single piece of semiconductor.

 the most common integrated circuits such as microprocessors, memories, etc.

IC Design • Integrated circuit design:

▫ Is a subset of electrical engineering. ▫ encomes the specialized design techniques required to build miniaturized electronic components into an electrical network on a monolithic semiconductor substrate.

▫ involves the creation of electronic components such as transistors, resistors, capacitors and the metallic interconnect of these components onto a piece of semiconductor (silicon).

IC Design (cont..) • A method to isolate the individual components formed in the substrate is necessary since the substrate silicon is conductive and often forms an active region of the individual components. • The two common methods are: ▫ p-n junction isolation ▫ dielectric isolation. • Attention must be given to: since ICs contain very ▫ power dissipation of transistors and interconnect resistances ▫ current density of the interconnection, s and vias.

tiny devices compared to discrete components

IC Design (cont..) • the physical layout of certain circuit sub blocks is typically critical: ▫ in order to segregate noisy portions of an IC from quiet portions ▫ to balance the effects of heat generation across the IC OR ▫ to facilitate the placement of connections to circuitry outside the IC.

IC Design (cont..) • IC design falls into two broad categories design techniques : ▫ digital IC ▫ analog IC

IC Design (cont..) • Digital IC Design:

▫ focuses on maximizing circuit density and placing circuits so that clock and timing signals are routed efficiently. ▫ Increasing the switching speed and minimizing capacitance of the interconnection. ▫ maximizes the performance of microprocessors, FPGAs, RAM, ROM, flash memories and digital ASICs.

IC Design (cont..) • Analog IC Design:

▫ is more concerned with the physics of the semiconductor devices such as gain, matching, power dissipation, resistance, etc. ▫ Fidelity of analog signal amplification and filtering is usually critical and as a result, analog ICs use larger area active devices than digital designs and are usually less dense in circuit. ▫ has specializations in power IC design and RF IC design. ▫ is used in the design of op-amps, linear regulators, phase locked loops, oscillators and active filters.

A typical IC design cycle involves several steps:

Why Design Integrated Circuits • Size

▫ ICs are much smaller  both transistors and wires are shrunk to micrometer/nanometer sizes, compared to the millimeter or centimeter scales of discrete components.

▫ Small size leads to advantages in speed and power consumption,

 since smaller components have smaller parasitic resistances, capacitances and inductances.

• Speed

▫ Signals can be switched between logic 0 and 1 much quicker within a chip than they can between chips. ▫ Communication within a chip can occur hundreds of times faster than communication between chips on the PCB. ▫ The high speed of circuits on-chip is due to their small size  smaller components and wires have smaller parasitic capacitances that slow down the signal.

Why Design Integrated Circuits (cont…) • Power Consumption ▫ Logic operations within a chip also take much less power. ▫ Once again, lower power consumption is largely due to the small size of circuits on the chip  smaller parasitic capacitances and resistances require less power to drive them.

Integrated Circuits Design Hierarchy • ICs are microscopic electronic network that are created in a special type of material called a semiconductor. • Silicon is a semiconductor and is used as the base material for the vast majority of modern electronic systems. • ICs are quite complex, and a complete understanding of every aspect of chip design and fabrication requires several years of study and practical experience. • Design task is made easier by breaking the problem into design hierarchies where the problem is viewed at several different levels.

Integrated Circuits Design Hierarchy (cont…) • System Design

▫ Main operations of the chip are determined. Block diagrams are used to illustrate the main sections that make up the system. Only the input / output characteristics are important, and there are no details about what actually is inside each block.

• Logic Design

▫ Design the logic networks that are required inside each block to obtain the input/output characteristics used at the system design level. The output is generally in the form of a netlist, which is just a description of the logic gates and wiring needed to implement the design.

Integrated Circuits Design Hierarchy (cont…) • Circuit Design

▫ Logic network is transformed into an electronic network using transistors as switching devices. Digital variables are represented by voltage levels that change in time. Transistors allow the designer to create logic circuits that steer signals into different paths using switching mechanisms.

• Physical Design

▫ Electronic circuits are transformed into on-screen colored geometrical patterns using computer graphics and analysis tools. Each color or shading represents a material, such as a metal, and the patterns indicate how to form 3-D transistor structures and wire them together.

• Chip Fabrication

▫ The physical design is transformed into a finished silicon chip that can be put into a package for eventual wiring into a product.

CMOS, Bipolar and BiCMOS technologies • CMOS and Bipolar in silicon are the two mainstream semiconductor technologies. • BiCMOS is the combination of the above two, which has both CMOS and bipolar transistors. BiCMOS = CMOS + Bipolar

CMOS, Bipolar and BiCMOS technologies (cont..) • CMOS technologies have the advantages of: ▫ Low cost for very large scale integration of both high-density digital circuits ( DSP and memory) and analog circuits (amplifiers, filters, A/D & D/A converters). ▫ High accuracy sample data circuits for ideal properties of MOS switches such as switched-capacitor filters and A/D & D/A converters. ▫ new CMOS technologies with smaller feature sizes can operate at increasingly high speed, comparable to some bipolar technologies. ▫ More efficient in power consumption

CMOS, Bipolar and BiCMOS technologies (cont..) • Bipolar silicon technologies:

▫ bipolar transistors can operate at higher frequencies than CMOS with relatively smaller consumption. ▫ suitable for pure anategration with relatively high operating speed (RF circuits) or relatively high power applications. ▫ digital circuits in bipolar are power hungry, prohibiting very large scale integration.

CMOS, Bipolar and BiCMOS technologies (cont..) • BiCMOS technologies have most advantages of both CMOS and bipolar technologies ▫ but at the expense of higher manufacturing cost due to required extra processing steps.

• The performance of bipolar transistors in BiCMOS are usually inferior to that of pure bipolar technologies. ▫ Thus CMOS technologies become mainstream technologies for mix signal integration due to the advantages of low cost and high integration density.