Patent ID: 9708732
Date: 2017-07-18
CPC Classifications: C23C,C30B,H01L

Claim:
1. A susceptor for supporting a semiconductor substrate at the time of performing vapor-phase epitaxy of an epitaxial layer, wherein a pocket in which the semiconductor substrate is to be placed is formed on an upper surface of the susceptor, the pocket has a two-stage structure having an upper-stage-pocket portion for supporting an outer peripheral edge portion of the semiconductor substrate and a lower-stage-pocket portion that is formed on a central side of the pocket below the upper-stage-pocket portion, through holes that penetrate to a back surface of the susceptor and are opened at the time of performing the vapor-phase epitaxy are formed in the lower-stage-pocket portion, and a groove is provided entirely upon the back surface of the susceptor at a position corresponding to that of the upper-stage-pocket portion, the groove being elongate in a direction parallel to the back surface of the susceptor, wherein: the groove is provided at least along the entire region corresponding to the position of the upper-stage-pocket portion; the groove includes a plurality of grooves arranged along an entire periphery of the susceptor, each of the plurality of grooves being arranged radially; each of the plurality of grooves arranged radially has a length that is ¼ or less of a radius of the substrate in the radial direction of the substrate to be placed on the susceptor, a width of 5 mm or less, and a depth that is 75% or less of a thickness of the susceptor at a position corresponding to that of the upper-stage-pocket portion; and the plurality of grooves causes the surface area of the susceptor back surface at a position corresponding to the upper-stage-pocket portion to be at least three times more than that of a susceptor having no grooves.