Hfcvd Diamond Polycrystalline Film Morphology, Texture And Twinning

For many industrial applications such as cutting tools, optical components and microelectronic devices, the control of film structure and morphology of Diamond is of critical importance. The effect of substrate temperature, ambient pressure and nitrogen on the growth morphology and texture of diamond film has been studied in a hot-filament chemical vapor deposition reactor. The morphology and structure of deposited film have been characterized by means of Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). By analyzing the results, conclusions were drawn as following:1. The parameters in the HFCVD have evident effect on the morphology and texture of diamond film.(1) In a pressure range of 20-60Torr, the higher the temperature of the substrate (TS) is, the lower the growth parameter (F ) is.(2) In a pressure range of 60-100Torr, the lower the pressure is, the better the crystallinity is.(3) With the addition of nitrogen, a polycrystalline film with a declined quality was deposited at low TS, a polycrystalline film with {111} morphology was deposited at high TS.2. The film texture characterized by XRD is found to be in good agreement with predication of selection growth model. In the conditions that F > V3,the shape of the isolated particles of the film becomes octahedral the polycrystalline film exhibits <100>-oriented texture. In the conditions that F~ V3/2, the shape of the isolated particles of the film nearly becomes cubo-octahedron. In the conditions thalF < I/ V3,the shape of the isolated particles of the film becomes cubic the polycrystalline film exhibits -oriented texture.3. An explanation for the high probability of <110>-oriented texture is given from the view of twin .For the condition =1 /A/3,penetration twins play an important role in the morphology of diamond film. Geometrical configurations which have been simulated using the penetration model fit very well to the film morphology.