Silicon‐on‐Sapphire Crystalline Perfection and MOS Transistor Mobility

Experimental data show that there is a correlation between the crystalline perfection of a (100) silicon‐on‐sapphire epitaxial film and the magnitude and direction of misorientation of the sapphire substrate from the {1 02} normal. The perfection is ascertained by measuring the half‐width of Si {400} θ:2θ x‐ray diffraction profiles. Data obtained from SOS/MOS transistors show a direct relationship between epitaxial perfection and FET mobility. Other factors which influence the perfection of the SOS film are growth temperature and film thickness.