SURFACE MODIFICATION OF N-GAAS BY 50 MEV SILICON IONS

An effective passivation of the surface states in n-GaAs has been achi eved by high energy (50 MeV) silicon ion irradiation at a fluence of 1 x 10(13) ions cm(-2). The effect of passivation on the nature of defe cts has been studied by the technique of thermally stimulated exoelect ron emission (TSEE) measurements. Consequently an enhancement in the i ntensity of the band edge, photoluminescence (PL) has also been notice d. The results of TSEE and PL measurements are augmented by surface an alysis using x-ray photoelectron spectroscopy. An effective migration of silicon was observed from the buried layer towards the surface by r adiation enhanced outdiffusion process. A stable passivating layer of silicon dioxide was found on GaAs surface which has been accounted for the enhancement in the PL intensity. (C) 1998 American Institute of P hysics.