Photo-reflectance, Raman scattering and photoluminescence methods were used to characterize In0.52Al0.48As surfaces which had been exposed to a CH4-H plasma. The photo-reflectance spectra indicated that reactive ion etching produced non-radiative recombination centers, scattering centers, and defects which led to a decrease in the signal intensity, a broadened line-width and a red-shift of transitions upon increasing the radio-frequency power. In Raman scattering studies, as the radio-frequency power was increased, the greater of 2 longitudinal optical modes shifted towards lower frequencies and the line-shape became increasingly asymmetrical. Corresponding photoluminescence measurements showed that the transition energies red-shifted with increasing radio-frequency power. It was concluded that the present methods were sensitive means for the study of near-surface damage of epilayers.

G.C.Jiang: Japanese Journal of Applied Physics, 1996, 35[1-2A], 533-6