Proximity error correction method for continuous moving stage electron beam writing

Abstract

Fabrication of high density waveguide-like structures using electron-beam lithography is challenging due to concerns such as stitching errors and proximity issues, which lead to irregularities in the fabricated structure. Continuous moving stage writing method is used to avoid the stitching errors for the long waveguide-like structures, but conventional proximity error correction methods cannot be applied in such cases. The authors propose a simple theoretical method to proximity correct such structures and experimentally demonstrate it in the case of high density millimeter long waveguide-like or grating structures. This method is ideal for high aspect ratio writing, which involves structures that have elements that are much longer than the separation between them. Also, in this method, every element can be assigned a single dose and thus does not need fracturing of individual elements. Experimental results agree well with the theoretically obtained corrections.