Wafer testing is a step performed during semiconductor device fabrication. Monocrystalline silicon is used to produce wafers used in the semiconductor and electronics industry. Usually the semiconductor of choice is silicon. BCl is also used in plasma etching in semiconductor manufacturing. Electrodes of metal, graphite and semiconductor material are widely used. KOH is also used for semiconductor chip fabrication. It is the basis for modern nanoelectronic semiconductor device fabrication. These integrated circuits were supplied by Fairchild Semiconductor and Motorola. Impurity atoms are atoms of a different element than the atoms of the intrinsic semiconductor. Since then, Samsung has been a leader in semiconductor device fabrication. Doping is the process of adding dopants to a semiconductor material. Usually, capacitance in semiconductor devices is positive. The wavelength emission is tuneable by adjusting the material of the semiconductor. Research continues on creating insulators with acceptable electrical characteristics on other semiconductor materials. The idea of thermal resistance of a semiconductor heat sink is an approximation.