Reduction of Second Order Alignment Error
Original Publication Date: 1989-Mar-01
Included in the Prior Art Database: 2005-Jan-29
By printing a first portion of a standard alignment aid on one mask level and a second portion of the aid on a next mask level, mask alignment of the mask for the third level and all following levels is a best fit to the two previous levels of alignment. By this means, second order alignment error (misalignment to images made prior to images last formed) are reduced.