ABSTRACT
The development of using Mn as a p-type dopant in GaAs- and/or InP-based compound semiconductors grown by molecular beam epitaxy (MBE) has been hindered by the inability to obtain a smooth surface with a high doping. The diffusion runs of Mn in GaAs using separate Mn granules in the sealed ampoules resemble to MBE incorporation of Mn doping under As-deficient conditions, while the diffusion runs using contact Mn films on the GaAs substrates are actually identical to Seltzer’s diffusion experiments. The surface of the GaAs substrate after Mn diffusion using MnAs as the source remains smooth and shiny, and further transmission electron microscopy (TEM) analysis shows no surface reaction and no apparent dislocation generation. The enhanced Al and Ga interdiffusion, together with the fast/slow interstitial/substitutional diffusion mechanism, suggest that point defects of charged interstitial Ga ions rather than Ga vacancies may also be responsible for the layer disordering, as in the case for Zn.
