US 12,205,855 B2
Process tool for analyzing bonded workpiece interface
Hau-Yi Hsiao, Chiayi (TW); Kuo-Ming Wu, Zhubei (TW); Chun Liang Chen, Tainan (TW); and Sheng-Chau Chen, Tainan (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on Aug. 26, 2021, as Appl. No. 17/412,330.
Prior Publication US 2023/0069432 A1, Mar. 2, 2023
Int. Cl. H01L 21/66 (2006.01); G01N 21/95 (2006.01); H01L 21/56 (2006.01)
CPC H01L 22/26 (2013.01) [G01N 21/9501 (2013.01); H01L 21/563 (2013.01); H01L 22/12 (2013.01); H01L 22/34 (2013.01); G01N 2201/11 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
generating electromagnetic radiation that is directed toward a perimeter of a pair of bonded workpieces and toward a radiation sensor that is arranged behind the perimeter of the pair of bonded workpieces;
scanning the electromagnetic radiation along a vertical axis that extends from below the pair of bonded workpieces to above the pair of bonded workpieces;
measuring an intensity of the electromagnetic radiation that impinges on the radiation sensor throughout the scanning, wherein measuring the intensity comprises recording a plurality of intensity values of the electromagnetic radiation at a plurality of different positions along the vertical axis extending past top and bottom surfaces of the pair of bonded workpieces; and
determining a position of an interface between the pair of bonded workpieces based on a maximum measured intensity value of the plurality of intensity values.