Multimode hydrogen depassivation lithography: A method for optimizing atomically precise write times

Abstract

A method to enhance the speed of scanning tunneling microscope based hydrogen depassivation lithography is presented. In order to maximize patterning speed while maintaining the capability to retain atomic precision with respect to line edges and feature positions, a multimode technique is used where the modes are characterized either by large or small spot sizes. For areas where atomically precise lithography is required, a tip sample bias of 4–4.5 V is used. In other areas, such as in the center of a large solid pattern, large (∼7 nm) linewidth field emission lithography with a tip sample bias of 8 V is used. A method to generate an optimized set of writing vectors for each mode is described and applied to a fundamental square pattern on the Si(100) surface with an experimental 78% write time reduction. An analysis of the optimal vectors indicates that patterning times may be reduced by up to 95%.