Canyon lithography

We describe a simple resist structure for implementing brushfire lithography (BFL) in electron-beam writing. The outlines of the pattern features are written as narrow deep openings formed in a single layer of positive electron resist. An oblique evaporation of a metal film onto the surface yields outlined electrically isolated metal copies of the features. These can be toned by selective electrically controlled etching. Transfer of the metal pattern to the underlying resist completes the structure.