Electrical properties of epitaxial silicon films on α-alumina

Single-crystal films of silicon have been deposited on the (1l02) plane of α-alumina by the pyrolysis of silane. Carrier concentration and mobility have been studied in the films as functions of growth temperature and substrate preparation. The effects of initial and overall growth rate have also been examined. Undoped layers are p-type with carrier concentrations from 1015 to 1017 holes/cm3 depending on growth temperature. Hole mobilities up to 174 cm2 v-1 sec-1 have been obtained. Diodes, MOST's and low-gain bipolar transistors have been formed in the material and minority carrier lifetime in the nanosecond range has been estimated from device characteristics.