| SiC is a promising semiconductor with wide band gap, however its insensitivity to visible or near infrared light greatly limits its application in optoelectronics. A lattice matched SiCGe epilayer on SiC substrate may make up this disadvantage by change of its band gap with composition ratio and make SiC-based devices to meet the needs in optoelectronic applications. The method to hetero-epitaxially grow the SiCGe alloy films on SiC substrates in a hot-wall low pressure chemical vapor deposition (LPCVD) system and basic properties of the samples prepared in the pilot study are presented in this thesis.The main contributions in the work done for preparation of this thesis are as follows:1. Improving the homemade hot wall CVD system to make its background vacuum and the highest substrate temperature reach to the levels of 3.0X 10-3Pa and 1000℃ with a deviation of 1 ℃, respectively, to meet a basic demand of growing SiCGe on SiC.2. It is proposed from a study on the lattice mismatch between SiCGe and SiC that the SiCGe with proper composition ratio of Ge in a certain range should rather well lattice-match to SiC and the lattice-match is independent to the polytypes.3. SiCGe samples were prepared under different growth conditions and characterized by XPS XRD SEM AFM, Ellipsometer and Four-Probe Resistivity Meters. The results indicate that the ratios of Si and Ge in the epilayer increase as the growth temperature increases, meanwhile the ration of C decreases. The samples prepared at lower temperature exhibit a good morphology and a sharp interface, while they are polycrystalline. As the growth temperature increases, the epilayers begin to grow under 3D-mode and the quality degrades as well. A remarkable photoelectric effect is confirmed by the sheet resistance tests of some typical samples under illumination with a normal light source in comparison with the tests in dark.
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