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

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 p-n 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.