TEXTURE FORMATION OF DIAMOND FILM SYNTHESIZED IN THE C-H-O SYSTEM

The texture formation mechanism in diamond films in the C-H-0 system was investigated from the viewpoint of the evolutionary selection rule. In order to know the dependence of growth rate on the crystal orientation accurately, isolated particles and films were deposited simultaneously using the tungsten-filament chemical vapor deposition method. The methane and oxygen content in hydrogen ranged up to 3.0% and 1.2% respectively. Substrate temperature was between 750-degrees-C and 1100-degrees-C, but the filament temperature was fixed at 2100-degrees-C. The pressure and flow rate were 40 mbar and 100 sccm respectively. For the isolated particles with octahedral and cubic shapes, the texture orientation was [100] and [111] respectively. The texture orientation varied continuously from [100] to [111] as the octahedral particle changed to a cube in the sequence truncated octahedron, cubo-octahedron and truncated cube. This result was in good agreement with the evolutionary selection rule. Texture maps at several deposition temperatures are presented as a function of the methane and oxygen concentration.