Arrangement for projection copying masks on to a work piece

US4357100A · kind A · utility

Assignee

• Censor Patent- und Versuchs-Anstalt · LI

Inventors

• Herbert E. Mayer · Abensberg, DE
• Ernst Lobach · Eschen, LI

Key dates

• Filing date: Jan 2, 1980
• Grant date: Nov 2, 1982
• Expiry date: Jan 2, 2000

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F9/7076
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An arrangement for projection copying of masks onto a workpiece, in particular onto a semiconductor substrate for producing integrated circuits, wherein the images of the patterns of the masks are formed by a projection lens on a photosensitive layer on the workpiece. The projection lens is completely corrected at the exposure wavelength used, and alignment patterns of the mask are aligned relative to adjustment marks on the workpiece, after images of the alignment pattern and the adjustment mark have been formed in the same plane, with adjustment exposure, by the projection lens and possibly an auxiliary optical means. The formation of the images of the adjustment marks in the plane of the alignment pattern or the alignment pattern in the plane of the adjustment marks is effected by means of the projection lens and possibly the auxiliary optical means, with an image defect which changes points to lines extending sagittally or meridionally with respect to the optical axis, and that the adjustment marks and the alignment pattern include lines which correspondingly extend sagittally and meridionally respectively with respect to the optical axis.