Improved Air Gap Error Using Frequency Estimation and Peak Filter in Solid Immersion Lens-Based Plasmonic Lithography System

The performance of plasmonic lithography depends on how small the air gap is. In this paper, we focus on rejecting the dominant frequency of disturbance. In order to do this, frequency estimation and peak filter are used in this paper. We achieve about 12% and 10% reduction in the standard deviation and maximum peak to peak of Gap Error Signal (GES) respectively. This work will improve the quality of plasmonic lithography in the size and stability of patterns.