Effects of Surface Treatments on Optical Properties of GaN

摘要

Removing artificial oxide layer is important for fabrication process of semiconductor devices. We employed photoluminescence for optical, reflection high energy electron diffraction, atomic force microscope, and Nomarski microscope for surface analysis. We found that it is more difficult to remove the oxide layer made by O-plasma such as in O-plasma asher than that of native one. Our result reached that HF etching is effective for removal of the artificial oxide layer without changing surface morphology. In addition, (NH{sub}4){sub}2S{sub}x treatment after HF etching reduces donor bound exciton drastically which is dominant luminescence near the band edge at low temperature.