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 (100) silicon substrates by rapid thermal chemical vapor deposition in the SiH4/GeH4/SiCH6/H-2 system between 530 and 600 degrees C. A Ge content 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 substitutional C incorporation and crystal quality was investigated. A process window of partial pressures of SiH4 and SiCH6 was found for obtaining good 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 obtain good crystal quality.