GROWTH OF GAAS EPITAXIAL MICROCRYSTALS ON AN S-TERMINATED GAAS SUBSTRATE BY SUCCESSIVE IRRADIATION OF GA AND AS MOLECULAR-BEAMS

Numerous GaAs epitaxial microcrystals with an average base size of 250 angstrom x 430 angstrom with (111) facets were fabricated on a sulfur-terminated (S-terminated) GaAs (001) substrate with successive irradiation of Ga and As molecular beams. The growth of GaAs microcrystals on the S-terminated substrate was caused by a vapor-liquid-solid (VLS) mechanism. This phenomenon originated in the inertness for the adhesion of Ga and As molecules and nearly equal lattice constants of the S-terminated GaAs surface and GaAs surface. This method, called droplet epitaxy, is thought to show promise as a growth method for fabricating GaAs quantum well boxes.