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Q & A: better computing through silicon

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Most recent answer: 10/22/2007
Q:
Why is Silicon used to make computer chips?
- kengfoo (age 13)
Anglican High, Singapore
A:
Kengfoo,

Great question!
Silicon is used to make computer chips because it is used in transistors, which are a major component of the chips. The reason it is used in transistors is because of its semiconducting properties. If something is a semiconductor, that just means that it conducts more electricity than an insulator (like plastic) but less than a metal (like copper). Also, if you add other materials to Silicon (this is called doping), you can change how conductive it is. Another great thing about silicon is that it's a fairly abundant, and therefore inexpensive, material. It can be found in sand!

~Ann

Also, the key feature of semiconductors that lets us make transistors out of them is that how conductive they are can be rapidly switched. Transistors are like little valves, in which one electrical current or voltage is used to control another current. In semiconductors, there are several ways in which one electrical signal can change how easy it is for another electrical current to flow through. In effect, the signal from one transistor changes the next one almost as if it changed the 'doping' that Ann describes. That's how complicated logic machines can be built out of transistors.
Mike W.

(published on 10/22/2007)

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