Metal diffusion and surface pattern formation on GaAs and As/sub 2/S/sub 3/ semiconductors

The possible changes of composition, phase transformations at the surface were investigated in GaAs samples, covered with 50 nm thick Au layer and annealed at different temperatures. Diffusion processes at metal-semiconductor interface determine the surface pattern formation, which has fractal structure. Comparison was made with interdiffusion processes in Au-amorphous As/sub 2/S/sub 3/ and Bi-As/sub 2/S/sub 3/ structures, which were found as useful for micro and macroscopic surface relief formation, optical recording due to the additional photo-stimulated diffusion.