Patent ID: 7248349
Filing Date: 2007-07-24
Classification: G03F

Abstract:
1. An exposure method for correcting a focal point, comprising: illuminating a mask a single time, said mask being a mask in which a mask-pattern including at least a set of a first mask-pattern and a second mask-pattern mutually different in shape is formed, from a direction in which a point located off an optical axis of an exposure apparatus is a center of illumination, using an asymmetric illumination light to the optical axis, and exposing and projecting an image of said mask-pattern toward an image-receiving element, said asymmetric illumination light having a single chief ray incidence direction; measuring a mutual relative distance between images of said first and second mask-patterns exposed and projected on said image-receiving element, thereby measuring a focal point of a projecting optical system of said exposure apparatus; and moving said image-receiving element along a direction of said optical axis of said exposure apparatus on a basis of a result of said measurement, and disposing said image-receiving element at an appropriate focal point of said projecting optical system.