LONG-TIME AIR OXIDATION AND OXIDE SUBSTRATE REACTIONS ON GASB, GAAS AND GAP AT ROOM-TEMPERATURE STUDIED BY X-RAY PHOTOELECTRON-SPECTROSCOPY

The room temperature oxidation behaviour of GaSb, GaAs and GaP has been monitored for a period of 3 years using X-ray photoelectron spectroscopy. By comparisons of the compositions of the growing oxide and the depth profiles of the 3-year oxide, information on the oxide-substrate interfacial reactions is obtained. The growing oxide surface consists of Ga//2O//3 and Sb//2O//3 (Sb:Ga approximately equals 1) for GaSb, a metastable Ga-O-As complex (As:Ga approximately equals 0. 5) for GaAs, and P//2O//5 and Ga//2O//3 plus GaPO//4 (P:Ga approximately equals 3) for GaP. The oxide-substrate reaction occurs for GaSb and GaAs, and the resulting interface shows three features: (1) increase in gallium oxide; (2) decrease in the B**v oxide; (3) deposition of elemental B**v, even at room temperature, although a very long period of time is necessary. For GaP, no such reaction occurs.