Title: Mask pattern for estimating amplitude aberrations, method of estimating the quantity of amplitude aberration, and amplitude-aberration estimating filter
Application Number: 200310117906 Application Date: 1998.02.19
Publication Number: 1542914 Publication Date: 2004.11.03
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: G03F1/00;G03F7/20;H01L21/027;H01L21/66
Applicant(s) Name: Mitsubishi Electric Corp. Address:
Inventor(s) Name: Kamon Kazuya
Attorney & Agent: liang yong
Abstract:
    In a projection printing apparatus, illumination light from a lamp housing illuminates a photomask, and a diffracted light beam from the photomask is focused on an exposed substrate via a projection optical system to project a circuit pattern, the projection optical system including first and second halfmirrors and first and second concave mirrors. The first and second halfmirrors are arranged in symmetry or similar symmetry with respect to a normal to an optical axis of a diffracted light beam directed from the first halfmirror to the second halfmirror. Thus, a projection printing apparatus and a projection printing method are obtained in which unevenness in transmissivity in the projection optical system can be compensated for and steric hindrance or degradation of image characteristics is not caused.
Time: 8