US 11,894,271 B2
Method of processing wafer
Karl Heinz Priewasser, Munich (DE); and Hideyuki Sandoh, Tokyo (JP)
Assigned to DISCO CORPORATION, Tokyo (JP)
Filed by DISCO CORPORATION, Tokyo (JP)
Filed on Jul. 20, 2021, as Appl. No. 17/380,606.
Claims priority of application No. 2020-125480 (JP), filed on Jul. 22, 2020.
Prior Publication US 2022/0028742 A1, Jan. 27, 2022
Int. Cl. H01L 21/78 (2006.01); H01L 21/66 (2006.01); H01L 21/3065 (2006.01)
CPC H01L 21/78 (2013.01) [H01L 21/3065 (2013.01); H01L 22/12 (2013.01); H01L 22/20 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A method of processing a wafer, comprising:
a wafer preparing step of preparing a measurement wafer and a product wafer each including a first surface that has a plurality of areas demarcated by a plurality of streets thereon and a second surface that is opposite the first surface;
a measurement etching step of forming a first mask on the first surface or the second surface of the measurement wafer and supplying a gas in a plasma state to first areas of the measurement wafer that are exposed through the first mask and that correspond to the streets to etch the first areas under predetermined conditions to form grooves in the measurement wafer;
after the measurement etching step, a measuring step of demarcating a plurality of concentric areas in an array from a center to an outer circumference of the measurement wafer and measuring depths of the grooves in the respective concentric areas;
after the measuring step, a thickness adjusting step of adjusting a thickness of the product wafer such that the product wafer is progressively thinner in areas thereof that correspond to the areas of the measurement wafer where the grooves are shallower; and,
after the thickness adjusting step, an etching step of forming a second mask on the first surface or the second surface of the product wafer and supplying a gas in a plasma state to second areas of the product wafer that are exposed through the second mask and that correspond to the streets to etch the second areas under predetermined conditions.