Patent ID: 8455367

Claim:
A method of manufacturing a nitride semiconductor substrate of minimal bow, the method comprising: a nitride-semiconductor deposition step of vapor-phase depositing nitride semiconductor crystal onto a base heterosubstrate; a nitride-semiconductor substrate preparation step of removing the base heterosubstrate from the nitride semiconductor crystal grown in said deposition step to thereby obtain a freestanding as-grown nitride semiconductor substrate of from 20 mm to 50 mm diameter, the as-grown substrate thereby intrinsically having a bow of ±40 μm to ±100 μm; a bow-reduction step of carrying out, on at least either the front side or the back side of the freestanding as-grown nitride semiconductor substrate, at least grinding and etching operations so as to create a bow-reducing damage layer, in which the crystalline structure of the nitride-semiconductor crystal is transformed, on at least either the front side or the back side of the nitride-semiconductor substrate, and so as to remove the damage layer from at least either the front side or the back side of the nitride-semiconductor substrate to an extent such as to minimize the intrinsic bow in the nitride-semiconductor substrate to be within a range of from 30 μm to −20 μm.