Wafer group, wafer manufacturing device, and wafer manufacturing method

A wafer manufacturing method, for a wafer having two opposed lower and upper surfaces and an orientation flat (OF) formed by cleavage, comprising the steps of:

• putting a scribe on the lower surface for forming OF, at least as a part of a planned cleavage line, by a scriber disposed in a belt-like gap at a joint of the double-open stage which can be freely double-opened, with a lower surface side of the wafer fixed to the stage;
• and
• double-opening the stage downward in conjunction with a downward movement of the pressing part by moving the pressing part including an indenter having a long portion, which is freely swingable along the gap in a pendulum manner, from an upper side to a lower side of the stage after release of a fixture of the wafer, and cleaving the wafer by pressing the planned cleavage line on the upper surface opposed to the scribe put on the lower surface, by the long portion of the indenter.

A wafer group constituted by a plurality of wafers, with all of them having an orientation flat (OF),

• wherein the wafer group is constituted by 30 or more wafers, and
• for each wafer constituting the wafer group, a plot is formed in which the number of each wafer sequentially given from the side close to one end of an ingot is taken as X axis, and a concentration of a predetermined element in each wafer is taken as Y axis, and in this plot, the number of portions where continuity of the plot is lost, is a number equal to or less than 10% of a value obtained by adding the number of portions wherein continuity of the plot is lost to a total number of the wafers in the wafer group, and an increase/decrease value of the concentration of the predetermined element in a wafer of the next number is three times or less than the increase/decrease value assumed from the continuity of the plot, as compared with the wafer of an arbitrary number, and
• in an OF orientation accuracy of the wafer group represented by an angle, the OF orientation accuracy in each wafer is within ±0.010°.