Process and arrangement for copying masks on a workpiece with arrangement for correction of alignment errors

Claim 1

In a method of copying a pattern of a mask member upon a semiconductor substrate member in the production of integrated circuits, whereby a semiconductor substrate member is disposed in an image plane of an objective having an optical axis and an image of said mask pattern is cast upon a first predetermined area of said substrate member during an exposure interval, said substrate member is then shifted in said image plane, a second predetermined area of substrate member is positioned along said optical axis and another image of said mask member is cast upon said substrate member, and the sequence is repeated until a multiplicity of predetermined areas of said substrate member have been exposed, the improvement wherein: (a) initiating prior to the conclusion of one of said exposure intervals a determination of the alignment error between the mask pattern and the respective predetermined area, said determination being carried out at least in part during one of said exposure intervals; and (b) adjusting the position of one of said members prior to a subsequent exposure to correct the relative positions of said members after the respective shift for said subsequent exposure by a value corresponding to said alignment error.