A study was made of the chemical vapor deposition of SiGeC layers onto <100> Si substrates. At a growth temperature of 550C, concentrations of C which were as high as 2% could be incorporated into SiGe with a Ge content of about 25%. This led to the formation of monocrystalline random alloys by using low flow rates of methylsilane (C precursor) in a dichlorosilane and germane mixture. At intermediate methylsilane flow rates, Fourier transform infra-red spectroscopic absorption spectra indicated the growth of amorphous layers. In the case of layers which had been grown by using a high flow rate of methylsilane, there were SiC-like peaks in the Fourier transform infra-red spectra. This indicated the precipitation of SiC. The films were also characterized by means of X-ray diffraction, high-resolution transmission electron microscopy, secondary ion mass spectroscopy, and Rutherford back-scattering spectroscopy. A defect-free band-edge photoluminescence, at both 30 and 77K, was observed in Si/SiGeC/Si quantum wells; even at power densities which were as low as 0.5 and 1W/cm2, respectively. A deep photoluminescence at about 0.8eV, and a luminescence at 0.94eV that was due to D3 dislocations, were not observed under any excitation conditions.

C.W.Liu, A.S.Amour, J.C.Sturm, Y.R.J.Lacroix, M.L.W.Thewalt, C.W.Magee, D.Eaglesham: Journal of Applied Physics, 1996, 80[5], 3043-7