Method for manufacturing a single crystal diamond
A method for manufacturing a single crystal diamond in which vapor phase synthetic single crystal diamond is additionally deposited on a single crystal diamond seed substrate obtained by vapor phase synthesis, includes a step of measuring flatness of the seed substrate, a step of determining whether or not to flatten the seed substrate based on the measurement result of the flatness, and any one of the following two steps of a step of additionally depositing the vapor phase synthetic single crystal diamond after flattening the seed substrate for which the flattening is necessary based on the determination and a step of additionally depositing the vapor phase synthetic single crystal diamond without flattening the seed substrate for which the flattening is not necessary based on the determination.
1. A method for manufacturing a single crystal diamond in which a single crystal diamond seed substrate obtained by vapor phase synthesis is placed on a stage and vapor phase synthetic single crystal diamond is additionally deposited thereon, the method comprising:
a step of flattening a single crystal diamond seed substrate having a flatness greater than 20 μm by forming a flattening layer on a surface or a rear surface of the single crystal diamond seed substrate, wherein the flattening layer is formed by depositing vapor phase synthetic single crystal diamond at a certain power to produce a single crystal diamond seed substrate having a flatness of 20 μm or less, and
a step of additionally depositing the vapor phase synthetic single crystal diamond on the single crystal diamond seed substrate having the flatness of 20 μm or less at a power higher than the certain power when forming the flattening layer.
2. The method for manufacturing a single crystal diamond according to claim 1 , wherein the single crystal diamond seed substrate is placed on the stage, a pressure is reduced from an adsorption hole formed on the stage to thereby make the single crystal diamond seed substrate adsorbed on the stage by a difference between a gas pressure inside a chamber and a reduced gas pressure inside the adsorption hole of the stage, and thereby, the single crystal diamond seed substrate is flattened.
3. The method for manufacturing a single crystal diamond according to claim 1 , wherein the power for forming the flattening layer is 1,000 W.