Patent ID: 11926923
Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
Field: Surface technology, coating (Chemistry)
Classification: CPC C | IPC C

Claim 6:
7. An indium phosphide single crystal substrate, wherein
a residual strain in a tangential direction in an outer circumferential portion is a compressive strain, the outer circumferential portion extending between an inner circumference located 10 mm inward from an outer circumference toward a center and a location located 5 mm inward from the outer circumference, and
an average value of the magnitude of the residual strain in the outer circumferential portion is not less than 2.5×10−6 and not more than 1.5×10−5, the magnitude of the residual strain being represented by an absolute value |Sr−St| of a difference between a radial strain component Sr and a tangential strain component St.