The selective epitaxial growth (SEG) rate of silicon for wafers with various oxide coverages (OCs) (the ratio of oxide area to silicon area on a silicon wafer) and oxide thicknesses, ranging from 0% to 90% and 0 to 500 nm, respectively, in a rf heated cold-wall reduced-pressure chemical vapor deposition (RPCVD) pancake reactor, using the SiH2Cl2-HCl-H-2 gas system, was investigated at a chamber pressure of 40 Torr and a temperature of 970 degrees C. The highest growth rate is about 175 nm/min, occurred at the oxide coverage of 90% and oxide thickness of 200 nm; the lowest growth rate is about 112 nm/min, occurred at the oxide coverage of 30% and oxide thickness of 500 nm. The growth rate of a control sample (a bare silicon wafer) is 110 nm/min. According to these data, a semiempirical expression for the SEG rate of undoped wafers in an RPCVD pancake reactor system is developed. The growth rate is exponentially dependent on the oxide coverage and a function of oxide thickness. This expression is suitable for the in situ p-type doped wafer with 60% OC and the boron concentration of 1.0x10(17) cm(-3) as well. (C) 2008 American Vacuum Society.