Nano-crystalline Si films were deposited on different substrates (silicon single crystal, Quartz glass, and ITO film) by using ultra-vacuum conventional plasma enhances chemical vapor deposition (PEVD) method. The microstructure of the films were studied by means of cross-sectional high resolution electrom icroscopy (XHREM) technique. It was foudn that nano-sized Si particles can grown directly on the single Si crystal substrate, while for glass and ITo film substrates, an amorphous buffer layer was always formed before the formation of the nano-Si crystals. The average grain size of the nano-crystals is about 5 nm. There is no a preferred growth direction, that is to say, no texture structure was observed. The grain boundaries between the nano-grains have extended to boundary regions which are full of amorphous matter. Lattice distortion, compared with the bulk Si crystal, is a general feature inside the nano-grains. A large number of various kinds of structure defects, such the convenience formation of the nano-crystal. These nano-crystalline Si films were foudn to show quantum dot effect under liquid N_2 temperature.
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