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Brunke, Lyle Brent

Publications and source records attributed to Brunke, Lyle Brent.

13 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

SNS Josephson Junctions With Tunable Ta–N Barriers

In this paper, we report on the fabrication and characterization of Nb/Ta-N/Nb Josephson junctions grown by room temperature magnetron sputtering on 150-mm diameter Si wafers. Junction characteristics depend upon the Ta-N barrier composition, which was varied by adjusting the N 2 flow during film deposition. Higher N 2 flow rates raise the barrier resistance and increase the junction critical current. This work demonstrates the viability of Ta-N as an alternative barrier to aluminum oxide, with the potential for large scale integration.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Tunable Nitride Josephson Junctions.

We have developed an ambient temperature, SiO 2 /Si wafer - scale process for Josephson junctions based on Nb electrodes and Ta x N barriers with tunable electronic properties. The films are fabricated by magnetron sputtering. The electronic properties of the Ta x N barriers are controlled by adjusting the nitrogen flow during sputtering. This technology offers a scalable alternative to the more traditional junctions based on AlO x barriers for low - power, high - performance computing.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Degradation of superconducting Nb/NbN films by atmospheric oxidation

Niobium and niobium nitride thin films are transitioning from fundamental research toward wafer scale manufacturing with technology drivers that include superconducting circuits and electronics, optical single photon detectors, logic, and memory. Successful microfabrication requires precise control over the properties of sputtered superconducting films, including oxidation. Previous work has demonstrated the mechanism in oxidation of Nb and how film structure could have deleterious effects upon the superconducting properties. This study provides an examination of atmospheric oxidation of NbN films. By examination of the room temperature sheet resistance of NbN bulk oxidation was identified and confirmed by secondary ion mass spectrometry. As a result, Meissner magnetic measurements confirmed the bulk oxidation not observed with simple cryogenic resistivity measurements.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗