Optical properties of low temperature grown GaAs - the influence of a hydrogen plasma treatment

Defects generated during the growth process in low temperature grown GaAs are studied by infrared (IR) absorption and low temperature photoluminescence. The growth temperature and As4-pressure during growth determine critically the density of antisite related defects. Annealing the layers well above the growth temperature reduces the defect density. Hydrogen plasma treatment has only a minor effect on the defect density. However, hydrogen plasma treatment at temperatures below the growth temperature of the layers reveal a new photoluminescence (PL) band which is tentatively assigned to a complex involving hydrogen and an instrinsic defect.