Abstract: The object of the present invention is to prevent the single crystal during pulling operation from turning to polycrystal when the single crystal under pulling operation is gripped by a gripper and to achieve the gripping automatically. When a wire 1 is moved down to immerse a seed crystal 3 into surface of a Si melt 11 in a quartz crucible 10, arms 12 and 13 wait at such positions that tips do not come into contact with the Si melt 11, and tips of the gripping arm 12 are opened so that the tips are not brought into contact with a portion with larger diameter 5 during pulling operation. By pulling up the wire 1, a neck portion 4, a portion with larger diameter 5, a constricted portion 6, and a crystal main portion 7 are formed under the seed crystal 3. When a sensor 14 detects that upper surface of the portion with larger diameter 5 has come into contact with the tips of the contact/detecting arm 13 during pulling operation, tips of the gripping arm 12 are closed and grip the constricted portion 6.

Abstract: A wafer 1 has a chamfered edge 2 polished to specular glossiness, and a laser mark for indication of crystal orientation is put on the chamfered edge 2. Another laser mark 4 for indication of specification, production number, identification, etc. may be carved as a bar code on the chamfered edge 2. These marks 3, 4 are carved on the chamfered edge 2 by laser marking which does not put any harmful influences on the wafer 1.

Abstract: A shallow notch 1 as a tentative mark is engraved on a periphery of an ingot at a position corresponding to a predetermined crystal orientation in the step of grinding the periphery of the ingot. After the ingot is sliced to wafers, a mark 2 for indication of a crystal orientation is carved on a sliced wafer at a position determined on the basis of the notch 1 by laser marking. Thereafter, the wafer is chamfered to a round shape, and the notch 1 is removed by the chamfering. Since a part where the mark 2 shall be carved is determined on the basis of the notch 1, the mark 2 is efficiently carved on the wafer without the necessity of subjecting each wafer to an X-ray analyzer.

Abstract: A pair of ring-shaped lapping plates 13, 23 are faced to both surfaces of a wafer 1. Each lapping plate 13, 23 has an outer diameter approximately equal to a radius of the wafer 1 and a lapping surface 14, 24 sliding in contact with the wafer 1. Each lapping plate 13, 23 is rotated along a direction reverse from the other, while an abrasion slurry A is fed into cavities 15, 25 of the lapping plates 13, 23 and discharged together with dusts separated from the wafer 1 through grooves engraved in the lapping surfaces 14, 24 and gaps between the wafer 1 and the lapping surfaces 14, 24. The lapping plate 23 is carried toward the stationary lapping plate 13 at a rate corresponding to abrasion of the lapping surfaces 14, 24. During lapping, the wafer 1 is rotated by drive rollers 31 and supported by guide rollers 32. In this way, both surfaces of the wafer 1 are simultaneously lapped.