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Recently, sputter-deposited MoSi2 films have been successfully used as a barrier material in Nb/MoSi2/Nb Josephson junctions. In this report, we present our study on the deposition conditions of MoSi2 film for electronics application. We investigated the film stress and sheet resistance as a function of deposition conditions. We also studied the micro-structural change in the film according to the deposition conditions using electron microscopes. We suggest that the thermal strain need to be considered in order to get a reliable junction.

Developed a new fabrication process for 10-V Josephson junction series arrays (JJAs). A plasma nitridation process is employed for reducing the microwave attenuation in the Josephson microstripline. Improvements of microwave attenuation are about 2 dB for test arrays of 2000, 3000, and 4000 Josephson junctions in a single stripline. We obtained stable quantized voltage steps up to 12 V at 76.4 and 86.8 GHz with step amplitudes of more than 5 /spl mu/A and stability times of more than 5 min. The circuits used 14 648 junctions arranged in 8 parallel paths.

A planar Bi-Sb multijunction thermal converter was fabricated on the LPCVD Si/sub 3/N/sub 4//SiO/sub 2//Si/sub 3/N/sub 4/-diaphragm, prepared by silicon bulk micromachining, which thermally isolated a bifilar Pt- or NiCr-heater and the hot junctions of a Bi-Sb thermopile from the silicon substrate. The voltage responsivity, the ac-dc transfer difference, and the fluctuations of the output thermoelectric voltage and heater resistance were discussed to investigate the design factors of a thermal converter. The respective voltage responsivities in air and in a vacuum of the thermal converter with a built-in NiCr-heater were about 14.0 mV/mW and 54.0 mV/mW. The ac-dc voltage and the current transfer differences in air were about /spl plusmn/0.60 ppm and /spl plusmn/0.11 ppm in the dc reversing frequency range from 10 Hz to 10 kHz. They are sufficiently small to be used as practical ac standards. Compared to the thermal converter with a built-in Pt-heater, the thermal converter with a built-in NiCr-heater demonstrated a higher voltage responsivity and smaller ac-dc transfer differences, while exhibiting slightly larger fluctuations in output thermoelectric voltage and in heater resistance.

We have developed a new fabrication process for integrated Nb/Al/sub 2/O/sub 3//Nb Josephson series arrays using the selective niobium anodization process (SNAP), the image reversal technique (IRT) and lift-off. To avoid chaotic behavior, the critical current of the array was decreased by post-fabrication annealing or the in situ multilayer oxidation process. In the frequency range 70-100 GHz, the array containing 2520 junctions produced stable quantized voltage steps up to 2 V with step widths of 40-100 /spl mu/A and stability times of more than 4 h. >