Patent ID: 6162412
Filing Date: 2000-12-19
Classification: C23C

Abstract:
A method for producing diamond by a CVD method comprising:decomposing and reacting a reaction gas containing carbon atoms, hydrogen atoms, oxygen atoms, and nitrogen gas, a concentration of carbon atoms in relation to hydrogen atoms being (A %), a concentration of nitrogen gas in relation to the whole reaction gas being (B ppm), and a concentration of oxygen atoms in relation to hydrogen atoms being (C %), the amounts of A, B and C satisfying the equation:.alpha.=(B).sup.1/2 .times.(A-1.2C)wherein a is not larger than 13 or B is not larger than 20 and said carbon atoms comprise at least 99.9% of .sup.12 C or .sup.13 C, and further wherein synthesized diamond contains 20 ppm or less of nitrogen atoms.