US 12,191,152 B2
Method of helical chamfer machining silicon wafer
Kentarou Ishida, Tokyo (JP)
Assigned to SUMCO CORPORATION, Tokyo (JP)
Appl. No. 17/290,861
Filed by SUMCO Corporation, Tokyo (JP)
PCT Filed Oct. 4, 2019, PCT No. PCT/JP2019/039403
§ 371(c)(1), (2) Date May 3, 2021,
PCT Pub. No. WO2020/105298, PCT Pub. Date May 28, 2020.
Claims priority of application No. 2018-216585 (JP), filed on Nov. 19, 2018.
Prior Publication US 2021/0327718 A1, Oct. 21, 2021
Int. Cl. H01L 21/304 (2006.01); B24B 9/06 (2006.01); B24B 47/25 (2006.01); B24B 49/02 (2006.01); B24B 49/05 (2006.01); B24B 49/18 (2006.01); B24B 53/06 (2006.01); B24B 53/07 (2006.01); H01L 21/687 (2006.01)
CPC H01L 21/304 (2013.01) [B24B 9/065 (2013.01); B24B 47/25 (2013.01); B24B 49/02 (2013.01); B24B 49/05 (2013.01); B24B 49/183 (2013.01); B24B 53/06 (2013.01); B24B 53/062 (2013.01); B24B 53/07 (2013.01); H01L 21/68764 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method of helical chamfer machining silicon wafers, comprising performing helical chamfer machining on a plurality of silicon wafers in succession, the helical chamfer machining being performed by, while rotating a chamfering wheel provided with a fine grinding grindstone portion with a rotation angle being inclined with respect to the vertical direction, pressing one silicon wafer being rotated against the fine grinding grindstone portion so that a finished wafer taper angle of an edge portion in the one silicon wafer is within an allowable angle range of a target wafer taper angle, the method further comprising:
firstly truing the fine grinding grindstone portion of the chamfering wheel using a first truer having a first truer taper angle;
firstly helical chamfer machining a first silicon wafer of the plurality of silicon wafers using the fine grinding grindstone portion having been subjected to the firstly truing so that a finished wafer taper angle of the machined first silicon wafer is within the allowable angle range of the target wafer taper angle;
directly measuring a groove bottom diameter of the fine grinding grindstone portion after the firstly helical chamfer machining;
secondly truing the fine grinding grindstone portion of the chamfering wheel using a second truer having a second truer taper angle when the groove bottom diameter is smaller than a predetermined threshold value; and
secondly helical chamfer machining a second silicon wafer of the plurality of silicon wafers using the fine grinding grindstone portion having been subjected to the secondly truing so that a finished wafer taper angle of the machined second silicon wafer is within the allowable angle range of the target wafer taper angle,
wherein the second truer taper angle is larger than the first truer taper angle.