Electron beam lithography using fixed beam moving stage

Abstract

Large area patterns with small submicron features are difficult to write using conventional electron beam lithography (EBL) methods. This would be more challenging especially if the patterns have large lateral aspect ratios such as waveguide tapers. Conventionally, the patterning area is divided into smaller write fields and the stage moves in between various write fields. Precise stage movement is necessary to reduce stitching errors. However, even the most accurate laser interferometer based control systems are prone to stochastic thermal drifts. In this paper, new methods of EBL patterning are explored using the stitch free method of writing and overcoming the conventional time constraints for writing large area patterns. Further, the methods presented are suited for writing structures with micron and nanosized features in the same pattern.