ARXPS Analysis on As-Passivated GaAs Surfaces by HF Dipping Method

Undoped (001)GaAs surfaces have been analyzed with angular-resolve X-ray photoemission spectroscopy (ARXPS). The ARXPS analysis was performed on the GaAs surfaces which had been exposed to air for about 3 weeks after chemical etching or HF dipping. Both Ga 2 O 3 and As 2 O 3 signals were detected on the etched surface, whereas the Ga 2 O 3 signal was not detected on the HF-dipped surface. This implies that the HF-dipped surface can be cleaned in vacuum by a thermal treatment at ∼500°C.