In this work we report on the growth of Si-Ge-C hetero-epitaxial layers on silicon in a MOCVD reactor. A major obstacle in realizing a high Ge-content in the cubic 3C-SiC lattice is the strong trend towards segregation and phase separation in the ternary system. In terms of the atomic diameter, Ge should be more likely to substitute Si in the SiC lattice. However, concerning the excess energy the bond between Ge and C is not supposed to be stable.
We will present several growth runs at different precursor flow-rates and different temperatures in the range of 1090 °C - 1330 °C and discuss the appearance of a SiGe phase. In order to detect the different bonds in the layers, especially Ge-C bonds, the samples were investigated by means of Raman-spectroscopy and x-ray diffraction. The Ge concentration was investigated by EDX measurements. No proof for the formation of Ge-C was found so far.