| 摘要 |
PURPOSE:To reduce the generation of a displacement largely from a circumferential edge, and to decrease defects in a photoetching process by each forming rectilinear tapers from the surface and the back extending over the whole circumference of a wafer and forming the ends of both tapers in arcuate circumferential ends. CONSTITUTION:A semiconductor base body 40 has a circumferential surface as the surface 11, the back 12, an arcuate circumferential end surface 20 and rectilinear tapered surfaces 21, 21'. A circumferential end angle alpha at a section 22 formed by the surface 11 and the inclined plane 21 and an angle alpha' at a section 22' formed by the back 12 and the inclined plate 21' are brought to obtuse angles of 90 deg. or more. Circumferential end angles beta and beta' each formed by the arcuate circumferential end surface 20 and both inclined planes 21 and 21' are also brought to 90 deg. or more. |
