Metallic air-bridges fabricated by multiple acceleration voltage electron beam lithography

Abstract

We present a new method of fabricating metallic air-bridge microstructures that is based on a single layer resist and a variation of the electron energy used during the electron beam lithography process. Electrons in the range of 3–30 keV cause radiation-induced reactions in the resists to depths adjustable from fractions of a micrometer up to several micrometers. By varying the energy at which the lithography process is carried out, we obtain three-dimensional profiles in the electron beam resist after exposure and development. Air-bridge structures can then be created by metal evaporation and lift-off.