... pieces,VRRM>1200V , Generally it is to point to by monocrystalline silicon wafer cut into slices, has a diameter of 6 inches ... 12 inches, etc,the main production specifications for integrated circuits. Silicon wafer just raw material,chip is finished products.Semiconductor is ... between insulators substance.At present the most used is silicon, and early germanium, and the compound gallium arsenide, etc ...