Halogenation of gallium arsenide(100) and (111) surfaces using atomic beams

Abstract

GaAs (100) and (111) gallium-rich surfaces (Ga/As≃1.4) have been halogenated using beams of atomic chlorine and fluorine under ultrahigh-vacuum conditions. XPS and LEED analyses of the resulting thin films indicate that chlorine atoms produce a disordered highly arsenic-defficient GaCl x reaction product layer whose thickness decreases as temperature increases from 110 to 271 K. At 121 K and above, a stable reaction layer is not observed but an ordered, stoichiometric to As-rich GaAs surface is formed; a residual submonolayer of chlorine is present at temperatures up to 571 K