Formation and etching of thin nitride layers on GaAs using atomic nitrogen and hydrogen

This paper reports on the nitridation of (001) GaAs using atomic nitrogen and the etching characteristics of the nitride layers formed using atomic hydrogen. Nitrogen and hydrogen molecules were cracked by a hot W filament to produce atomic nitrogen and hydrogen. After nitridation and etching, GaAs cap layers were grown by molecular beam epitaxy to form GaAs/GaN/GaAs structures. We determine the sheet nitrogen atom concentration for these structures by secondary ion mass spectrometry analysis. As the nitridation temperature decreases, the etched nitrogen atom concentration increases. The N-As bonds might be responsible for this increased concentration. The etching rate also depends on the substrate temperature.