Effects of Deuterium on Low-Temperature Si Epitaxy by Photo-Chemical Vapor Deposition

Epitaxial Si films have been successfully grown by the photochemical vapor deposition process using the mixture of SiH4, SiH2F2 and D2 gases at temperatures from 200 to 475°C. Using H2 as diluting gas, the epitaxial Si films were obtained at temperatures from 200 to 350°C. However, the upper limit of the growth temperature was raised about 100°C (from 350 to 475°C) by substituting D2 for H2 as the diluting gas. Surface morphology and crystallinity were also improved with D2. Furthermore, we carried out heavy phosphorous doping with D2 and obtained a film with an electron concentration of 1×1021 cm-3.