| 摘要 |
<p>A colourless, transparent low defect density, synthetic type IIa diamond single crystal, in which the etch pits due to needle-shaped defects are at most 3 x 10<5> pieces/cm<2>, and which can be applied to uses requiring high crystallinity of diamond, for example, monochromators, semiconductor substrates, spectroscopic crystals in X-ray range, electronic materials, etc., is provided by a process for the production of the colourless, transparent, low defect density, synthetic diamond single crystal by growing new diamond crystal on a seed crystal of diamond by the temperature gradient method which comprises using a crystal defect free diamond single crystal, as a seed crystal of diamond, and optionally subjecting to a heat treatment in a non-oxidizing atmosphere at a low pressure and a temperature of 1100 to 1600 DEG C.</p> |
