Overlay measurement method

摘要

An overlay measurement method includes providing three predetermined patterns, including a first predetermined pattern, a second predetermined pattern and a third predetermined pattern. An inspection process is then performed on said three predetermined patterns, to obtain three image points, including a first image point, a second image point and a third image point respectively. Next, a defining process is performed to define a default position, and a calculating process is performed to obtain a real offset value x=(p−q)*(c−a)/(a−b)+p.

主权项

1. A overlay measurement method, comprising:
providing three predetermined patterns: a first predetermined pattern, a second predetermined pattern and a third predetermined pattern; performing an inspection process on said three predetermined patterns, to obtain three image points: a first image point, a second image point and a third image point respectively; performing a defining process to define a default position; and performing a calculating process to obtain a real offset value x=(p−q)*(c−a)/(a−b)+p, wherein:
p is the distance between the first predetermined pattern and the third predetermined pattern;q is the distance between the second predetermined pattern and the third predetermined pattern;a is the offset value between the default position and the first image point;b is the offset value between the default position and the second image point; andc is the offset value between the default position and the third image point; wherein said inspection process, said defining process and said calculating process are performed through a computer system.