Computer chips start out as ordinary sand, which is silicon dioxide. However, the silicon must be made very, very pure. The first step is to melt the sand, in a furnace that reaches about 3200^o F, and mix with carbon. This first purification process creates 99% pure Silicon, a common output is Silicon Carbide. The Silicon Carbide is processed in a trichlorosilane distillation method to create 99.9999% pure silicon called polycrystalline silicon. The polysilicon is broken up into chunks. These chunks are melted in a crucible at about 2500^o F. A silicon crystal seed is dipped in molten silicon and slowly drawn out to create a cylinder of silicon. These silicon cylinders are some of the purest crystals on the planet. Once the silicon cylinder is grown to the desired diameter, it is sawed into wafers. These wafers are polished to achieve a very flat mirror surface. Transistors, and other micro-electronic parts, are built on the polished wafer in layers in a process called etching. The wafer is then sawed into its individual chips. Each chip is mounted in an electronic package that serves to protect it and connect it to the outside world. It has been said that computer chips are the greatest value added product in the world. We essentially take a pile of sand and change it into thousands of dollars worth of computer chips.

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