A Computer Simulation of the Recombination Process at Semiconductor Surfaces

A rigorous computer simulation of the recombination process through surface or interface states is made. It is shown that the surface recombination velocity is not a characteristic constant of the surface as is usually assumed, but depends strongly on the charge neutrality level of surface states, sign and amount of the fixed charge, the substrate doping level and profile, and the light intensity. It is also shown that S can be reduced by introducing a suitable amount of a fixed charge or by forming a highly doped surface layer. The effect of the device doping profile on S is also discussed.