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Introduction Handout

Books:- The Science and Engineering of Microelectronic

Fabrication by Stephen A Campbell

-Microelectronics - An Integrated approach byHowe and Sodini

- Additional materials / Source materials for thelectures

Attendance Policy Homework Assignments Quizzes Office Hours / Appointments / Contact

routes

QuickTime and aPhoto - JPEG decompressor

are needed to see this picture.

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Lecture Time!

Hard course? Naah! Not if you study!I am involved in the learning process with you guysI am not an expert. Just a few steps ahead of you. So

catch up with me. Fast. Ill essentially be givingcrashers as per my limited knowledge and

understandingInteract Interact Interact - positively though..

Be creative.

Ask questions (even if you fear I wont know theanswers!)

There are no stupid or wrong questions! (if its aboutscience or the art - we dont do anything else in

class)6 hours of prep / 1 credit hour for me

Should be at least 3 to 6 hours of prep / credit hourfor you

Once again. Questions ENCOURAGED. Moreover,correct me and get extra credit!!

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Introduction to the Course

An uncommon course... Survey of topics. With no linearprogression

Each topic in itself can be made into acourse in it self, so you can imagine howdeep can we go

Topics: Industrial in nature + thoughdrenched in pure sciences =Microelectronics

Sciences/Engineering fields used: Physics,Electronics, Materials Science, Chemistry

and Industrial Design

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e ore we s ar ..

...let me

scare you...let me scare youThis course can become vitally important to

your career if you plan to go on about makingchips - not the potato kind!

The stuff we study can be used in a numberof other courses and fields (Buzzzz. Nano?)

Since we have to cover a lot of topics, we will

have to go really fast in the lectures.Therefore, you must read a lot on your own.Study a lot on your own.

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You should be a master of this by the end ofthe course

So what is this?How is it made?

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You should be a master of this by the end ofthe course

Schematic of MOS Transistor (MetalOxide Semiconductor) on left, and a

SEM image of an actual made in Si

one on the right.

The processes used to make it:- Deposition- Doping- Photolithography-Etching

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Another Example

A simple resistor voltage divider, at left is the circuit

representation (A) ; in the middle a physical layout of thedevice (B), and on the right most is the technology flow for

fabricating the resistor

- Notice the steps from 1 to 8

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Multidisciplinary NatureMicroelectronics

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Very Brief History ofMicroelectronics

First working transistor was invented in 1947 atBell Labs, by William Shockley, John Bardeen, and

Walter Brattain.

Notice the size?

This was a point-contact transistor

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Brief History...

Originally all the devices were discrete devices existingas separate units in their own package, examplescapacitors, vacuum tubes, or like the transistor you saw inprevious slide

However, two separate inventors unaware of each other,invented the first integrated circuit, independently.

1958 Jack Kilby at Texas Instruments, and Robert Noyceco-founder of Fairchild Semiconductor Corp. created thefirst integrated circuits.

Kilby used Ge, and Noyce used Si.

1961 First commercially available integrated circuit wasmade available by Fairchild Semiconductor Crop. and therest is history as they say.

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microelectronics Modern electronicsconsists of severalextremely small devicesintegrated in onecircuit, made usingmicroelectronic

fabrication techniques ona suitable substrate

Number of devices orcomponents now goes up

to billions

Feature sizes can nowbe as small as 22nm

...any one got a laptop with an Intel Core i3, i5, or i7980x processors? - that was 32nm technology..

SEM image of an IC circuit circa mid

1980s, which has transistors that areonly only a few microns (1 m = 1e-6meters) on a side.

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Named after Gordon E. Moore, Intels co-founder who described the process

in a1965 paper

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More about the course...

At first glance these mere numbers, orincredible component / device densities seemextremely daunting

However, in this course we will focus on howthese circuits are built rather than how they aredesigned or even how these transistors work

You will study those topics in other classes. Like inthe next semester you will study something onthe lines of micro design

So we will mainly study the basic operationsrequired to build these ICs. These steps will becalled Unit Processes following Campbellschapters division.

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more... The collection and ordering of these several unitprocesses for making a useful product (a chip)

will be called a technology

Another interesting fact is that based on thelimitations of these unit processes, and onwhat can be or cannot be made, the design partwill hence follow the fabrication part.

In other words, the designer must have someinput from the fabricator

In microelectronics a document called designrules or layout rules is something the designerhas to follow to design a chip or IC or anynumber of electronic circuits.

These layout rules specify how small or largethese features can be made or how close twodifferent features can be when using a

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Reading Assignment

Chapter 1 of Campbells The Scienceand Engineering of Microelectronic

Fabrication

First page of Chapter 1 ofHowe andSodinis Microelectionics - AnIntegrated Approach

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Materials (Review)

In microelectronics we use specifictype of materials often calledelectronic materials

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Survey

Fabrication? Yes, Device Design? No. Basic electronics? No. I expect you have

studied that already.

Designing of electric circuits atmicrolevel? Not really.

Nanotechnology? Pretty close, but notexactly. Electronics at nano level? No actually

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Electronic Materials

The main purpose of electronic materials is togenerate and control the flow an electriccurrent

Electronic Materials include:- Conductors; have low resistance, which allows

electrical current flow

- Insulators; have high resistance, which suppressesthe flow of electric current

- Semiconductors; can allow or restrict the flow ofelectric current

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Conductors and Insulators

Why are conductors conducting andinsulators non-conducting?

- Valence Electrons

- Easily strips away from the atom,floating freely, causing electricalcurrent

- In insulators atoms are tightlybound and electrons are not freeto flow

- Insulators are mostly compoundsof several elements

Copper Atom

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Semiconductor

Semiconductor is a class of material whereconductivity can be controlled to vary a largeorders of magnitude

- Elemental Semiconductors: Si, Ge

- Compound Semiconductors (fixed composition): SiC,GaN, GaAs, InP

- Alloy: Si1-XGeX, Al1-XGaXAs, Hg1-XCdXTe

Purity: Semiconductor devices are made of ultra puresemiconductor materials, which means impurity(unintentional doping) should be

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Structure of Solids (3D)

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Unit Cells

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Simple Cubic Lattice

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Body Centered Cubic (BCC)Lattice

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Face Centered Cubic (FCC)Lattice

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Diamond Lattice

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Silicon Lattice Cell

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Zincblend Lattice

- Similar to diamondlattice except that it has

two different types ofatoms- Each atom has 4covalent bonds, but

bonds with atoms ofother type

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GaAs Lattice Cell

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Lecture 2 - Packing Density

Assume that atoms are like closely packedhard spheres, so then what is the packingdensity for the Simple Cubic Lattice?

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Miller Indices

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Miller Indices of a Plane

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Miller Indices : Example

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Miller Indices : Special

Cases

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Miller Indices of a Vector

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Miller Indices : Notations

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Crystal Planes

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Quick Exercise

Draw a FCC Structure?

Draw a direction [111] on it?

Draw another direction [101] on it?

Draw a plane (111) and (101) on it?

Updated at the end of

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Updated at the end ofLecture 2 Reading

AssignmentRead Chapter 2, parts 2.2 and 2.3from Campbells The Science andEngineering of Microelectronic

Fabrication

Basically develop an understandingof crystal structures, miller indices

for points and planes and theirimportance with regard tosemiconductors