A new technique was developed in order to study atomic movements during ultra-violet laser-enhanced and low-temperature (below 400C) thermal oxidation. This method combined a classical marker technique with low-energy ion-scattering spectroscopy. During the formation of thin (about 1nm) oxide layers, the marker remained on the oxide surface. This indicated that oxidation occurred, at the GaAs/oxide interface, via the diffusion of an O species. This differed from the oxidation of metals such as Ni and Cu, where the use of the same technique confirmed earlier observations that oxidation occurred at the oxide/ambient interface. The diffusion of a metal species resulted in the marker being buried during oxidation of the metal surfaces.

M.T.Schmidt, Z.Wu, C.F.Yu, R.M.Osgood: Surface Science, 1990, 226[1-2], 199-205