Characterization of SOS Films Grown with Amorphous Si Buffer Layers by MOS FET's

Electrical properties of Si films grown epitaxially on sapphire substrates with amorphous Si buffer layers (less than 40 Å) have been studied by fabricating n-channel MOS FET's. The effective mobility of the MOS FET's fabricated on SOS with the buffer layer was 1.36 to 1.5 times as large as the one without the buffer layer, at V G-V T=4V. The SOS film was grown at a slow growth rate (550 Å/min) and thickness was 0.55 µm. This result indicates that the present growth method is useful for thinning Si films as VLSI devices.