INDIUM DIFFUSION IN N-TYPE GALLIUM-ARSENIDE

Diffusion of indium markers at T=900 degrees C have been measured in u ndoped and Te-doped GaAs epilayers grown by organometallic vapor phase epitaxy. The diffusivity was found to be a linear function of electro n concentration over the range n=2x10(17)-1.5x10(19) cm(-3). The resul ts are consistent with the interdiffusion of AlAs-GaAs superlattices, and the diffusivities of In and Al in GaAs at 900 degrees C are found to be essentially identical within experimental noise. The results str ongly suggest that group III interdiffusion in GaAs is controlled by a Ga vacancy with a charge of -1. (C) 1997 American Institute of Physic s.