Selective Growth of GaAs by Molecular Beam Epitaxy

Abstract

Selective epitaxial growth of GaAs on patterned GaAs substrates covered with SiNx have been demonstrated at 580°C by using atomic hydrogen irradiation in molecular beam epitaxy. The mechanism of the selective growth is mainly due to the re-evaporation of GaAs from the mask, SiNx. Re-evaporation rate of GaAs from the SiNx surface is larger than that from the SiO2 surface, and hence the selective growth of GaAs can be more easily achieved using SiNx mask. The epitaxial patterns of GaAs have clear crystal facets. In the line and space patterns along [110], (11̄0), (111)B and (211)B faces appear and in the [11̄0] line, (311)A and (111)A faces appear. There are no edge peaking and the side wall definitely reflects the mask edge boundary.