EFFECT OF RTCVD GROWTH-CONDITIONS ON THE CRYSTAL QUALITY OF PSEUDOMORPHIC SI1-X-YGEXCY FILMS

High-quality pseudomorphic Si1-x-yGexCy alloy layers were grown on (10 0) silicon substrates by rapid thermal chemical vapor deposition in th e SiH4/GeH4/SiCH6/H-2 system between 530 and 600 degrees C. A Ge conte nt of up to 30 at% and a C content of up to 2.2 at% were achieved, The effect of the partial pressures of the reactive gases on substitution al C incorporation and crystal quality was investigated. A process win dow of partial pressures of SiH4 and SiCH6 was found for obtaining goo d films. This process window is independent of the partial pressure of GeH4 and growth temperature. A relatively high SiH4 partial pressure is needed to freeze C atoms into substitutional lattice sites and obta in good crystal quality.