Low Temperature Scanning Electron Microscope for Fabrication and Characterization of High-Tc Josephson Junctions and Circuits

摘要

Liquid helium cooled TEM/STEM sample holder with electrical access to thin film samples is developed. The cryogenic sample holder was used together with a Nabity Nanometer Pattern Generation System to investigate important issues, such as the threshold energy and amount of exposure, in the fabrication of electron beam modified planar Hg-1212 Josephson junctions. The results indicate that for beam energy less than about 80 keV the changes in the superconducting properties of Hg-1212 thin films are temporary. In addition, the amount of exposure required to make junctions with stable properties makes the technique useful only for circuits of a few junctions.