Method for producing diamond thin film and apparatus for producing diamond thin film

An apparatus for producing a diamond thin film, which is an apparatus for producing a diamond thin film for synthesizing a diamond thin film on a base material by a plasma CVD method using inductively coupled plasma, comprising:

• a vacuum vessel in which the base material is disposed and to which a raw material gas containing C, H, and O is supplied;
• an antenna disposed inside or outside the vacuum vessel and comprising a conductor element and a capacitive element electrically connected to each other in series;
• and
• a high-frequency power source for applying high frequency to the antenna to generate inductively coupled plasma in the vacuum vessel,
• wherein plasma characteristics in the vacuum vessel when synthesizing the diamond thin film comprise:
• an electron temperature of 1.0 eV or more and 2.0 eV or less,
• an electron density of 1.0×1011 cm−3 or more and 1.0×1012 cm−3 or less, and an ion saturation current of 1.0×10−4 A or more and 1.0×10−2 A or less.