Growth And Characterization Of Si And SiGe Epitaxial Films By UHV/CVD

This thesis work mainly involves the deposition by UHV/CVD and characterization of undoped epitaxial SiGe single-layer and multi-layer as well as studies of SiGe growth kinetics. The deposition of relaxed Si_1-xGe_x buffer used for high Ge content virtual substrate is also included in the article.In the research we use high resolution X-ray diffractometry, Raman scattering spectroscopy, secondary ion mass spectrometry, TEM and atomic force microscopy to characterize the deposited films.In the experiments we utilize UHV/CVD-II growth system of our laboratory. At first, we accomplished growth of high quality layers of Si_1-xGe_x single layer with germanium contents of 0.127660℃, and the growth parameters are optimized in the growth. We analyse systematically the relation of growth temperature, source gas flux ratio, germane incorporation and growth rate, and research on their influence on the quality of the film. Secondly, upon that ground, we finish the growth of multi-quantum well and super lattice multi-layers. The measurement results indicate that the multi-layers acquired have high periodicity with clear Si/SiGe dividing lines and abrupt interfaces, the content and thickness of each layer are uniform. The atomic interdiffusion at Si/SiGe interfaces is suppressed efficiently. At last, Graded Si_1-xGe_x buffer used for high Ge content virtual substrate is investigated which makes ground for Si-based device development.