Nanoscale fabrication by intrinsic suppression of proximity-electron exposures and general considerations for easy and effective top–down fabrication

We present results of a planar process development based on the combination of electron-beam lithography and dry etching for fabricating high-quality superconducting photosensitive structures in the sub-100 nm regime. The devices were fabricated by the application of an intrinsic proximity-effect suppression procedure which makes the need for an elaborated correction algorithm redundant for planar design layouts which are orders of magnitude smaller than the backscattering length. In addition, we discuss the necessary considerations for extending the fabrication spatial scale of optical contact-lithography with a mercury arc-discharge photon source down to the order of the exposure photon's wavelength (sub-μm), thereby minimizing the writing time on the electron-beam lithograph. Finally we developed a unique and novel technique for controlling the undercut during a planar lift-off fabrication procedure without cleaving the wafer.