Patent ID: 6858445
Filing Date: 2005-02-22
Classification: G03F

Abstract:
1. A method for adjusting the overlay of two mask planes in a photolithographic process for the production of an integrated circuit, the method comprising the steps of: providing a substrate with at least one first mask plane, which has been patterned by exposure of a first mask using a first exposure device; orientating a second mask, which is provided for patterning a second mask plane using a second exposure device, with respect to the first mask plane; measuring an overlay between the first mask plane and the second mask plane; providing error data, which are stored in a database, regarding errors of the first and second masks and/or errors of the first and second exposure devices by a measurement by means of a common reference grid; analyzing the measured overlay taking account of the error data provided in advance regarding the errors of the first and second masks and/or errors of the first and second exposure devices; comparing a result of said analyzing with a predetermined specification; and performing a correction step for correcting the orientation of the second mask depending on a result of said comparing.