- Chen, C.-H. and Gosele, U. and Tan, T.Y., Simulation of under- and supersaturation of gallium vacancies in gallium arsenide during silicon in- and outdiffusion,
Semiconductor Process and Device Performance Modelling. Symposium
pp. 99 - 104 .
(last updated on 2007/04/10)
Si diffusivity in GaAs shows a dependence on the cubic power of its concentration or the concentration of electrons n under both in- and outdiffusion conditions. Hence, Si diffusion in GaAs is consistent with the Fermi-level effect model invoking the triply-negatively-charged Ga vacancies, VGa3- as the point defect species responsible for diffusion to occur on the Ga sublattice under n-doping conditions. However, the Si diffusivity values of the indiffusion cases are several orders of magnitude smaller than those of the outdiffusion cases at the same Si concentrations. This means that the two apparent Si diffusivity values under intrinsic conditions also contain the same discrepancy, which has been previously assessed to be due to a VGa3- undersaturation in indiffusion cases and a VGa3- supersaturation in outdiffusion cases. In this study we have calculated the VGa3- under- and supersaturation values using known Si diffusivities. We found that the GaAs surface states play a key role in the development of the VGa3- under- and supersaturations
diffusion;doping profiles;Fermi level;gallium arsenide;III-V semiconductors;semiconductor doping;semiconductor process modelling;silicon;surface states;vacancies (crystal);