Heteroepitaxial Silicon Growth Using SiH4 in Helium‐Hydrogen Atmospheres

Abstract

The use of H2-He growth atmospheres has been studied for the growth of Si on spinel and sapphire. It was found that film growth rates are carriergas composition dependent and, in general, show an increase with increased H2 concentrations. At low concentrations of H2 in He, only slight changes in growth rate occur, if any, and growth rates become very temperature dependent, decreasing with increasing temperature. At a growth temperature of I025~ film doping levels do not change appreciably with growth rate for a constant dopant gas (ASH3) flow rate and high growth rates (up to about 10 #m/min). Film properties are also affected by the Sill4 source, growth temperature, the condition of the spinel surface, and the orientation of the substrate. Mobilities up to 925 cm2/V-sec have been measured in 2 ~m thick (lll)Si films grown on spinel. The growth of (100)Si on (l10)MgA1204 has been observed. The quality of Si films grown in H2-He and pure H2 atmospheres on (01]'2)A1~O8 and ,~(1120)A1208 does not seem to be influenced by the growth atmosphere, but growth on (101-4)A1~O~ has produced higher quality films in a Ha-in-He carrier gas than in pure Ha. * Electrochemical Society Active Member.