SPUTTER-INDUCED FORMATION OF AN ELECTRON ACCUMULATION LAYER IN IN0.52AL0.48AS

Ar-sputtering of In0.52Al0.48As was investigated with room-temperature Raman and photoluminescence spectroscopy. A clear increase of carrier density in the near-surface region was observed in the Raman spectra. The PL intensity was found to depend in a complex way on plasma self- bias potential, incident laser irradiance, and InAlAs doping level, in dicating that the recombination mechanisms dominating the PL response differ with changing experimental conditions. The observed trends can be explained by sputter-induced formation of an electron accumulation layer in the near-surface region.