Essay by Anonymous UserHigh School, 12th gradeA, February 1996

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Whipped this out in a matter of hours for the english teacher well written

Silicon is the raw material most often used in integrated circuit (IC)

fabrication. It is the second most abundant substance on the earth. It is

extracted from rocks and common beach sand and put through an exhaustive

purification process. In this form, silicon is the purist industrial

substance that man produces, with impurities comprising less than one part in

a billion. That is the equivalent of one tennis ball in a string of golf

balls stretching from the earth to the moon.

Semiconductors are usually materials which have energy-band gaps smaller

than 2eV. An important property of semiconductors is the ability to change

their resistivity over several orders of magnitude by doping. Semiconductors

have electrical resistivities between 10-5 and 107 ohms.

Semiconductors can be crystalline or amorphous. Elemental semiconductors

are simple-element semiconductor materials such as silicon or germanium.

Silicon is the most common semiconductor material used today. It is

used for diodes, transistors, integrated circuits, memories, infrared

detection and lenses, light-emitting diodes (LED), photosensors, strain

gages, solar cells, charge transfer devices, radiation detectors and a

variety of other devices. Silicon belongs to the group IV in the periodic

table. It is a grey brittle material with a diamond cubic structure.

Silicon is conventionally doped with Phosphorus, Arsenic and Antimony and

Boron, Aluminum, and Gallium acceptors. The energy gap of silicon is 1.1

eV. This value permits the operation of silicon semiconductors devices at

higher temperatures than germanium.

Now I will give you some brief history of the evolution of electronics

which will help you understand more about semiconductors and the silicon

chip. In the early 1900's before integrated circuits and silicon chips

were invented, computers and radios were made with vacuum tubes. The

vacuum tube was...