Laterally seeded regrowth of silicon over SiO2 through strip electron beam irradiation

Abstract

We have studied the laterally seeded regrowth of polycrystalline Si film over SiO2 islands through the use of a very narrow strip electron beam of a high-energy density. A 0.5-μm polycrystalline Si film was deposited over the entire surface of wafers on which SiO2 islands, 30–100 μm wide and 2 cm long, had been formed. A stationary electron beam 60 μm×3 cm was focused on the wafer surface with an average energy density of 0.7 MW/cm2 at 10 kV. The wafers were irradiated for 0.1–2 ms while moving at a speed of up to 500 cm/s past the beam. A transmission electron microscopic analysis showed that the laterally seeded regrowth of Si films over SiO2 islands were realized successfully and that the regrowth film which covered the SiO2 islands resulted in a quasi-single-crystal film with small-angle boundaries. The average speed of the front of the lateral regrowth over the SiO2 was estimated to be about 200 cm/s.