The near-surface damage which was introduced into heterostructures during H-plasma exposure was investigated by means of photoluminescence spectroscopy and transmission electron microscopy. Multiple quantum well structures were used to monitor the depth of plasma- and/or H-related defects. It was shown that H plasma-exposure introduced defects at depths which exceeded the ion ranges, in implanted solids, by more than an order of magnitude. The introduction of {111} H platelets into GaAs during plasma exposure was also demonstrated for the first time. A correlation was found between the depth distributions of these platelets and the extent of induced defects. However, it was shown that these extended defects were not responsible for the reduction in optical efficiency of the near-surface material. It was instead suggested that point-like defects which resulted from ion bombardment and/or H itself were the cause of the optical deterioration.

Near-Surface Defects in H-Plasma Exposed InGaAs/GaAs Quantum Well Structures J.R.Botha, J.H.Neethling, A.W.R.Leitch: Semiconductor Science and Technology, 1999, 14[12], 1147-53