A versatile pattern generator for high-resolution electron-beam lithography

Abstract

A versatile, PC-based pattern generator for nanometer structure research applications has been developed. The pattern generator interprets data produced by a computer-aided design software package and controls the scanning and beam-blanking coils of a scanning electron microscope. The patterns are written using a vector scanning mode with each vector being written as a series of point exposures. By synchronizing the beam-blanking and the beam-scanning signals, a pattern is written in the steady state of the microscope and the pattern generator. This technique affords a high degree of accuracy and pattern perfection over a wide range of field sizes. At low magnification, patterns may be written over a large area (0.5×0.5 mm2 ), while at high magnification, delineation of nanometer scale circular arcs and straight lines of arbitrary angle is possible. We also demonstrate how the pattern generator can be used for registration to a resolution of better than 150 nm.