Diffusion in semiconductors
This chapter discusses diffusion phenomena in the semiconductors Si, Ge, and GaAs. Silicon and GaAs are the two main materials used in fabricating electronic and optoelectronic devices. Diffusion in Ge will also be mentioned for the reason that it is the simplest case among semiconductors. Diffusion processes are used in doping a semiconductor with n-type and p-type dopant atoms to produce pn-junctions for device operations. The n- and p-type dopants are specific kinds of substitutional impurity species producing the electric carriers electrons (e) and holes (h), respectively, in a semiconductor. Diffusion processes are also involved in the removal of detrimental metallic impurities, in silicide formation and in thermal SiO2 growth in fabricating devices using Si.