Improving contact and via process latitude through selective upsizing

摘要

This paper describes a simple technique to improve the process latitude for contact and via printing. The techniqueapplies a selective upsizing algorithm to the mask data during the mask preparation step. For each contact or via, thealgorithm looks for available spaces by checking relevant layers near it. When spaces are available, selective edges of acontact or via will be sized to improve the process latitude. This paper describes algorithms used to implement thistechnique. Multiple designs of various design styles are used to demonstrate the effectiveness of the algorithms. Theimplications on mask preparation, mask making and wafer processing are also discussed.