US 12,394,723 B2
Alignment device and alignment method
Shohei Hamada, Tokyo (JP); Hidetoshi Nishiyama, Tokyo (JP); and Atsushi Miki, Tokyo (JP)
Assigned to Hitachi High-Tech Corporation, Tokyo (JP)
Appl. No. 18/020,675
Filed by Hitachi High-Tech Corporation, Tokyo (JP)
PCT Filed Aug. 31, 2020, PCT No. PCT/JP2020/032803
§ 371(c)(1), (2) Date Feb. 10, 2023,
PCT Pub. No. WO2022/044307, PCT Pub. Date Mar. 3, 2022.
Prior Publication US 2023/0326870 A1, Oct. 12, 2023
Int. Cl. H01L 23/544 (2006.01); H01L 21/68 (2006.01)
CPC H01L 23/544 (2013.01) [H01L 21/681 (2013.01); H01L 2223/54426 (2013.01)] 12 Claims
OG exemplary drawing
 
1. An alignment device for comparing alignment images, each of which includes an alignment mark with each other and which are captured at at least two chips of a wafer held on a stage, to align the stage and the wafer, the alignment device comprising:
the stage configured to hold the wafer;
an alignment illumination light source configured to irradiate the wafer held on the stage with light;
an alignment image processing unit configured to receive light from the wafer and acquire the alignment images of the wafer;
an information input and output unit configured to input and output information to and from a user; and
an alignment processing unit configured to process information from the alignment image processing unit and the information input and output unit, wherein
the alignment processing unit sets an alignment image captured on a first wafer as a reference image, quantifies, on the basis of a difference obtained by comparing the reference image with an alignment image captured on a second wafer, information on a change of a wafer surface state with passage of time from a time when the alignment image of the first wafer is captured to a time when the alignment image of the second wafer is captured, and displays, on the information input and output unit, the quantified information on the change of the wafer surface state with the passage of time.