ABSTRACT
We found that one of the difficulties in growing (110) AlGaAs/GaAs hetero-structures with a high-quality interface is the lack of steps to stabilize Ga atom migration during growth. Insertion of an InAs buffer layer introduces a high density of misfit dislocations which provide equivalent steps at the growing surface. We found, however, that the hetero-interface of the structures grown by this method is very poor and neither quantum wells nor modulation doped hetero-interfaces can be grown.
We have shown that by lowering the growth temperature down to 400°C and using a high As4 to Ga ratio (30), atomically flat (110) interface can be obtained. The FWHMs of photo luminescence spectra from quantum wells with different well widths are as narrow as those of the best (100) hetero-interface and the fluctuation of the interface roughness is less than one monolayer.
