Oxide removal from GaAs(100) by atomic hydrogen
Juergen A. Schaefer, V. Persch, Stuart R. Stock, Thomas Allinger, Albrecht Goldmann · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1991
We used molecular hydrogen in the presence of a hot tungsten filament to clean GaAs(100) wafers after inserton into an UHV4 chamber. The H2-pressure was varied between lxlO torr and 5x10 torr. During exposure the sample remained either at room temperature or at elevated temperatures up to 600 K. The mechanism we suggest for the removal of oxygen and carbon is the formation of chemical products like H90 and CH4 and their subsequent desorption. Also a build-up of gaflium- and arsenic-hydrides and their desorption is possible. After cleaning a clear ixi-LEED pattern indicates a rather well-ordered surface.