Various impurities are used in VLSI processes. The key factors for the selection
of the impurities are their solid solubility and diffusion coefficient. B, As, P are commonly
used as doping impurities due to their high solid solubility. In and Sb are sometimes used to
realize shallow junctions due to their low diffusion coefficients. We briefly showwhere
various impurities are used in two distinguished devices of bipolar transistors and MOS
FET’s.
Keywords: Solid solubility, diffusioncoefficient, boron, arsenic, phosphorous,
antimony, indium, bipolar, MOS, emitter, base, collector, source, drain, gate,
extension, pocket.
