Silicon Wafers
Silicon is a gray, brittle, tetravalent, nonmetallic chemical element. It makes up 27.8% of the earth’s crust and next to Oxygen, it is the most abundant element in nature. Silicon can be found in materials such as quartz, agate, flint and common beach sand amongst many others. It is the main component in building materials like cement, brick and glass. Silicon is also the material that the majority of semiconductors and micro chips are built on. Ironically, silicon by itself does not conduct electricity very well. However, it can take on dopants precisely in order to control resistivity to an exact specification.
Before a semiconductor can be built, silicon must be transformed into a wafer. This begins with the growth of a silicon ingot. A single silicon crystal is a solid composed of atoms arranged in a three dimensional periodic pattern that extends throughout the material. A polysilicon crystal is formed by many small single crystals with different orientations and alone, cannot be used for semiconductor devices. Polycrystalline silicon must be melted into one single crystal in order to manufacture wafers that can be used for semiconductor applications.
