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Carrier mobility, threshold voltage and drain leakage current are investigated for MOS devices fabricated on (001)Si on (1̄012) sapphire substrates with special emphasis on crystalline defects and residual stress in silicon films. Mobility anisotropies which are ascribed to electron mass anisotropies caused by lateral compressive stress in SOS are observed in E-type and D-type MOS devices in the temperature range from 1.4 to 300 K. Moreover, mobility humps which resulted from marked changes in the electron configuration among energy valleys are found on <µH-VG> curves at 1.4 and 4.2 K in the devices with a certain combination of silicon film thickness and channel directions. This can be explained by changes in conductivity-effective-mass and surface roughness scattering. In deep D-type MOS devices, the scattering due to space charge regions around dislocations is found to be predominant over other carrier scattering processes from results on the in-depth distribution of Hall mobility and carrier concentration.

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The scattering of transverse electromagnetic waves by density fluctuations in a magnetized plasma is found to be significantly dependent upon the presence of paramagnetic decay instabilities driven by a lower-hybrid pump wave. This possibility offers interesting new approaches to plasma diagnostics.

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