Orientation dependence of oxygen adsorption on a cylindrical GaAs crystal

The orientation dependence of oxygen adsorption was studied by AES using a cylindrically shaped GaAs single crystal prepared by ion bombardment and annealing. The cylinder axis was [110] so that the cylinder surface exposed all the main low index surfaces and all transitions between them. The adsorption behavior in the range (001)–(111)Ga–(110)–(111)As can basically be understood in terms of enhanced adsorption on edge adjacent sites. A thorough analysis in the range (111)Ga–(110) reveals a transition from steps one (110) layer high near (110) to steps two (110) layers high at (331) between the two low index faces.