Lithography using electron beam induced etching of a carbon film

A focused electron beam was found, in the presence of oxygen gas, to induce the etching of a plasma enhanced chemical vapor deposited amorphous hydrogenated carbon (PECVD a-C:H) film. This reaction was used to pattern the film directly, eliminating the need for subsequent development of the exposed areas (as required for conventional resists). Pattern transfer from the film into gold and into silicon was investigated. Submicrometer patterns have been transferred from a 50-nm-thick PECVD a-C:H film into a gold film by wet chemical etching. With a silicon substrate, the exposure process produced an etch-resistant layer on the surface.