Method for detecting positions of photomask and substrate

Abstract

A photomask having a pattern area having plurality of patterns to be transferred onto a transfer member generally regularly arranged thereon comprises a non-pattern area of a size no smaller than a size of at least one said pattern and provided at a predetermined position in said pattern area.

What is claimed is: 
     
       1. A photomask having formed thereon a pattern area having a plurality of thin film head patterns to be transferred onto a local area of a transfer member, said photomask being used in a projection exposure device having a position detection mechanism for detecting a position of at least one predetermined detection area in said local area on said transfer member having said thin film head patterns transferred thereon, along an optical axis of a projection optical system, said photomask comprising: a non-pattern area of a size substantially equal to or larger than a size corresponding to a size of said detection area and provided at a portion in said pattern area corresponding to said local area;   said non-pattern area being transferred as a flat area on said transfer member.   
     
     
       2. A photomask according to claim 1, wherein said non-pattern area has no said thin film pattern.   
     
     
       3. A photomask according to claim 1 having a reference mark in said non-pattern area for two-dimensionally and relatively positioning said photomask and said transfer member. 
     
     
       4. A method for detecting a position, along an optical axis of a projection optical system, of a detection area on a transfer member in projecting an image of a photomask repeatedly onto said transfer material through said projection optical system, comprising the steps of: exposing the image of said photomask including a pattern area having unit patterns formed thereon and a non-pattern area having no said unit pattern onto said transfer member through said projection optical system;   processing said transfer member to form a step relative to a surface of said transfer member at a position on said exposed transfer member corresponding to said pattern area and not to form the step at a position on said exposed transfer member corresponding to said non-pattern area; and   detecting the position along the optical axis by using the position on said transfer member corresponding to said non-pattern area as said detection area.