Si-homoepitaxy by electron cyclotron resonance CVD

摘要

Low-temperature homoepitaxy of silicon has been achieved at T=450/spl deg/C by using electron cyclotron resonance CVD (2.45 GHz, up to 1.5 kW). H/sub 2/ and H/sub 2//Ar were used as excitation gases and either SiH/sub 4/ or mixtures of SiH/sub 4/ with PH/sub 3//H/sub 2/ or B/sub 2/H/sub 6//H/sub 2/ served as process gas. The epitaxial layers were grown with a thickness of up to 3 /spl mu/m at a rate of up to 25 nm/min. Highly phosphorus-doped epitaxial layers were used as emitters in 2/spl times/2 cm/sup 2/ solar cell structures on p-type FZ- and SILSO-wafers as base material. These cells had AM1.5 efficiencies of up to 15% and 11%, respectively. The results suggest that recombination at the base-emitter interface is a limiting factor.