Effective corner rounding correction in the data preparation for electron beam lithography

Abstract

A new correction technique has been developed not only to reduce the corner rounding, but also to restrain the building up of shot counts that is able to increase the exposure time in electron beam (e-beam) lithography. It is able to prove the developed corner rounding correction technique is useful with high accuracies throughout the simulation of several different types of correction in the data preparation software, Inscale® from Aselta Nanographics, and its comparisons with exposure images. The developed one is helpful to suppress the accumulation of shot counts either. Furthermore, it shows the general limit of corner rounding correction in a conventional variable shaped beam exposure tool with current resist process. Firstly, we are demonstrating the new method for correcting the corner rounding that either can avoid the extension of exposure shot counts, called writing time. Secondly, this study reveals the current bounds of corner rounding correction, especially the lithography employing the shaped beam tool. Finally, we propose the criteria of data preparation for the corner rounding in e-beam lithography, specifically upcoming 18nm technology node and practical applications.