Calibration and Optimization of Near-Field Scanning Microwave Microscope

Abstract

The focus in this master thesis project was to calibrate the near field scanning microwave microscope (NSMM) and find its sensitivity to dissipation. For this purpose NSMM performance was modeled and flat gold samples embedded with superconductive niobium films were fabricated, first with e- beam lithography and then with photolithography. Atomic Force Microscope (AFM) characterization showed that our fabrication method of flat gold allows to get RMS roughness of less than 1nm, essential factor to eliminate topography effect from microwave contrast. NSMM scanning of the sample fabricated with e-beam lithography showed microwave contrast after cooling down due to proximity effect, while the sample fabricated with photolithography did not show same kind of contrast. After making sure that this sample is superconductive with DC measurement, a test setup was prepared to enhance NSMM sensitivity.