Patent ID: 8826854
Filing Date: 2014-09-09
Classification: C23C

Abstract:
1. A direct-current plasma CVD apparatus for growing a diamond, comprising: a fixed electrode having a rounded portion, and a substrate stage having a top flat face and combined with an electrode for placing a substrate, wherein, the substrate stage top face is located to avoid a vertical line from a center of the fixed electrode so that the substrate during growth is located to avoid the vertical line from the center of the fixed electrode, an angle formed between a line of a length R connecting a center of the substrate stage top face with the center of the fixed electrode and the line extended in vertical direction from the center of the fixed electrode is 90° or less, the substrate stage top face is disposed at a position that is tangent to a circle having a radius R, a center of the circle being located at the center of the fixed electrode, and the top face of the substrate stage is circular and has a radius of r, and the angle θ(°) formed between the line connecting the center of the substrate stage top face with the center of the fixed electrode and the line extended in vertical direction from the center of the fixed electrode satisfies the following relation: the fixed electrode and the substrate stage are made of any one of tantalum (Ta), molybdenum (Mo), and tungsten (W).