US 12,188,880 B2
Method of calibrating coordinate position identification accuracy of laser surface inspection apparatus and method of evaluating semiconductor wafer
Keiichiro Mori, Saga (JP); and Takahiro Nagasawa, Saga (JP)
Assigned to SUMCO CORPORATION, Tokyo (JP)
Appl. No. 17/774,761
Filed by SUMCO CORPORATION, Tokyo (JP)
PCT Filed Oct. 6, 2020, PCT No. PCT/JP2020/037787
§ 371(c)(1), (2) Date May 5, 2022,
PCT Pub. No. WO2021/090624, PCT Pub. Date May 14, 2021.
Claims priority of application No. 2019-202182 (JP), filed on Nov. 7, 2019.
Prior Publication US 2022/0373478 A1, Nov. 24, 2022
Int. Cl. G01N 21/95 (2006.01); G01N 21/956 (2006.01); H01L 21/66 (2006.01)
CPC G01N 21/9501 (2013.01) [G01N 21/95684 (2013.01); H01L 22/12 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A method of calibrating a coordinate position identification accuracy of a laser surface inspection apparatus that detects LPDs of a semiconductor wafer surface by scanning the wafer surface with incident laser light while rotating the semiconductor wafer,
which comprises:
detecting a COP in a surface of a reference wafer with each of a laser surface inspection apparatus to be calibrated and an apparatus for calibration that obtains an X coordinate position and a Y coordinate position of the COP with a two-dimensional Cartesian coordinate system;
determining a COP that is detected as the same COP by the laser surface inspection apparatus to be calibrated and the apparatus for calibration with a determination criterion that a positional difference between a detected position obtained by the laser surface inspection apparatus to be calibrated and a detected position obtained by the apparatus for calibration on the reference wafer surface is within a threshold range for determining whether the COP detected respectively by the apparatuses is the same COP; and
calibrating the coordinate position identification accuracy of the laser surface inspection apparatus to be calibrated by adopting the X coordinate position and the Y coordinate position obtained by the apparatus for calibration as true values of the X coordinate position and the Y coordinate position of the COP that is determined to be the same COP,
wherein the calibration of the coordinate position identification accuracy includes determining correction values for the X coordinate position and the Y coordinate position of the detected position detected by the laser surface inspection apparatus to be calibrated,
wherein, for each of a plurality of COPs, each of which is determined to be the same COP, the coordinate position deviation distance is obtained from the X coordinate position X1 and the Y coordinate position Y1 obtained by the apparatus for calibration, and the X coordinate position X2 and the Y coordinate position Y2 obtained by the laser surface inspection apparatus to be calibrated using the following expressions:
X coordinate position deviation distance=(X2−X1),
Y coordinate position deviation distance=(Y2−Y1), and
wherein the X coordinate position deviation distances and the Y coordinate position deviation distances are obtained for the plurality of COPs, and at least one of their respective average values, mode values, or median values is utilized as the correction values.