Microsecond carrier lifetimes in Si films prepared on SiO2-coated Si substrates by zone-melting recrystallization and by subsequent epitaxial growth

Abstract
The generation lifetimes in zone‐melting‐recrystallized Si films on SiO2‐coated Si substrates and in epitaxial Si layers grown by chemical vapor deposition on the recrystallized films have been determined by pulsed metal‐oxide‐semiconductor (MOS) capacitor and pn junction leakage current measurements. For recrystallized Si films that are 1×1017 cm−3 n type and 1×1016 cm−3 p type, respectively, the lifetimes are 0.2–0.5 μs and ∼1 μs. For epitaxial Si layers that are 2×1015 cm−3 n type, lifetimes are 0.8–1.3 μs, compared to ∼2 μs for control layers grown on single‐ crystal Si 〈100〉 wafers. The relatively high lifetimes suggest the possibility of fabricating bipolar devices utilizing Si‐on‐insulator structures prepared by the present techniques.