公开(公告)号：JPH04186716A

公开(公告)日：1992-07-03

申请号：JP31684290

申请日：1990-11-20

Applicant: CANON KK

Inventor： MATSUTANI SHIGEKI ,  UZAWA SHIGEYUKI

IPC: G03F9/00 ,  H01L21/027 ,  H01L21/30

Abstract: PURPOSE:To detect a position of an alignment mark highly accurately while unnecessary noise light is eliminated by correcting an adjustable allowance based on an uneven shape on a resist surface in the vicinity of the alignment mark on a wafer surface by using Moire fringes obtained by two grating patterns different in pitch. CONSTITUTION:Grating patterns G1, G2 different in pitch from each other in a conjugation relation with a wafer W through an optical system are arranged so that their grating directions coincide with an alignment direction, while the pattern G1 is illuminated by a lighting system. Accordingly a light flux from the pattern G1 is incident to an alignment mark face Wa on the wafer surface perpendicularly to the wafer W surface on a plane parallel to a grating direction of the pattern G1 and slantly with a predetermined angle in a plane perpendicular to the grating direction of the pattern G1 to form an image of the pattern G1. The image is projected onto the pattern G2 surface, a signal from an image sensing device 110 is used to calculate a surface of a resist on the alignment mark Wa region by an arithmetic means and relative alignment of the wafer W and the image sending device 110 is performed.

公开(公告)号：JPH0423421A

公开(公告)日：1992-01-27

申请号：JP12700590

申请日：1990-05-18

Applicant: CANON KK

Inventor： MATSUTANI SHIGEKI ,  UZAWA SHIGEYUKI ,  TAKAKURA SHIN ,  TANAKA HIROSHI

IPC: G03F9/00 ,  H01L21/027 ,  H01L21/30

Abstract: PURPOSE:To make it possible to perform stabilized and highly accurate alignment by minimizing the difference between an estimation signal to be matched based on a minimum root approximation method and a temperature and then setting a point having the highest value of correlation degree to the center of alignment. CONSTITUTION:After having minimized the difference between as estimation signal to be matched based on the minimum root approximately method and a template, a product between an inverse number of a sum of an absolute value which represents the difference between the estimation signal and the template in its unidimensional window and geometric information which is used to approximate the template and the estimation signal is set to the degree of correlation where a point having the highest degree of correlation is detected as the center of mark alignment, thereby performing alignment. This construction makes it possible to adjust the condition of water alignment mark light, that is, perform stabilized alignment independent of the type of estimation waves. Furthermore, pattern matching is carried out after the functions are approximated based on the minimum root method, which strengthen S/S and hence improves the accuracy.

公开(公告)号：JPH03287001A

公开(公告)日：1991-12-17

申请号：JP8746090

申请日：1990-04-03

Applicant: CANON KK

Inventor： SATO MAKOTO ,  MURAKI MASATO ,  TAKAKURA SHIN ,  MATSUTANI SHIGEKI ,  UZAWA SHIGEYUKI

IPC: G01B11/00 ,  H01L21/027 ,  H01L21/30

Abstract: PURPOSE:To enable positioning which is hardly affect by a noise by determining the position of the whole mark according to mark element position detection information which is weighted as determined according to the position. CONSTITUTION:Mark elements Mw of a wafer W on an XY stage 15 are detected through a lighting device 2, a half-mirror 3, an image pickup optical system 5, etc., and converted by an A/D converting device 6 into a two-dimensional signal corresponding to the X and Y directions of the image pickup surface, and the signal is passed through a binary-coding device 8 and matched by a matching device 9 with the output of a template generating device 7 to detect the position of each element Mw roughly. This position information is interpolated with the primary discrete signal generated by an integrator 10 and a mark position detecting device 11 detects mark element positions. Then weight coefficients based upon the mark element positions from an evaluation arithmetic unit 12 are calculated and a position detecting device 13 determines the position of the whole mark; and the influence of a noise due to interference fringes depending upon the mark element positions, resist thickness variation, etc., is reduced to improve the mark position detection accuracy, thereby positioning the wafer with high accuracy.