Silicon wafer is a very thin round disk cut from high-purity silicon. A round silicon ingot is sliced to thicknesses of approximately 1mm. The surfaces of the resulting disk are polished carefully, then it is cleaned, resulting in the completed wafer. Silicon wafers are made from high-purity silicon and are the material of semiconductor devices. These wafers can also be fabricated with a SEMI notch or one or two SEMI flats.