Writing strategy and electron-beam system with an arbitrarily shaped beam

Abstract

Articles you may be interested inFacile fabrication of high-resolution extreme ultraviolet interference lithography grating masks using footing strategy during electron beam writing J. Vac. Sci. Technol. B 31, 06F602 (2013); 10.1116/1.4822016Variable cell projection as an advance in electron-beam cell projection system Development of an electron-beam lithography system for high accuracy masks Proximity effect correction using pattern shape modification and area density map for electron-beam projection lithography J.Chrome on glass mask writing at 75 kV with the IBM EL4+electron-beam systemThe greatly increased complexity of modern masks has in turn led to increased write times and cost of the masks. Any opportunity to decrease write time while providing the required accuracy of the fabricated pattern is highly beneficial. A writing strategy using an arbitrarily shaped beam (ASB) results in a considerably smaller number of flashes to write a complex pattern compared to other strategies. The design of an ASB system is proposed. The ASB electron-beam column is similar to that of a variable-shaped beam system, except for a modified beam-shaping block. This suggests the relatively easy integration of an ASB column. The throughput of an ASB system is higher than the throughput of other systems, except for patterns with low coverage or simple geometries. In addition to the throughput advantages, an ASB system enables higher accuracy, including the feasibility of writing features according to "ideal" optical proximity correction.

Generalization of shot definition for variable shaped e-beam machines for write time reduction

“…Babin [1] proposed multiple deflector/aperture stages, with each aperture a circle (or approximation thereto) to form "arbitrarily shaped" shots. His objective was to match the curvilinear target shapes of an "ideal" optical proximity corrected (OPC) mask.…”