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...