Nb-AlOx-Nb SNAP Technology for 125 mm Wafers Developed in Partnership with Silicon Technology
We have demonstrated a 4-mask-level selective niobium anodization process (SNAP) technology for 125 mm wafers. With the exception of the initial Nb-AlOx-Nb trilayer preparation, this process is carried out almost exclusively within a VLSI fabrication area and utilizes existing 1x lithography, Cl-based reactive ion etching, and materials deposition capability developed for Si technology. Our design consists of a personalized wafer layout with a number of 6 × 6 mm diagnostic chips and a wide variety of SQUIDs, magnetometers (as large as 12 × 12 mm), gradiometers (as large as 12 × 24 mm), soliton oscillators, and other Josephson devices at minimum design rules of 2 μm. We have used this process to produce high quality Josephson junctions with the figure of merit Vm > 60 mV for a Josephson critical current density Jc of 500–1000 A/cm2. Resistors were fabricated with 35-nm-thick e-beam evaporated Pt having a sheet resistance of about 4Ω/□. This approach to Josephson fabrication provides a low overhead, fast turn-around process particularly well suited for trilayer development and for production of many physically large, application specific integrated Josephson devices.
KeywordsSheet Resistance Critical Current Density Josephson Junction Anodization Current Density Wafer Temperature
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- M.B. Ketchen, D. Pearson, A. Kleinsasser, C.-K. Hu, M. Smyth, J. Logan, K. Stawiasz, E. Baran, M. Jaso, T. Ross, K. Petrillo, M. Manny, S. Basavaiah, S. Brodsky, S.B. Kaplan, W.J. Gallagher, and M. Bhushan, accepted for publication in Appl. Phys. Lett., 1991.Google Scholar
- C.-K. Hu, N. Mazzeo, S.J. Wind, D.J. Pearson, and M.B. Ketchen, to be published in the Proceedings of the International Conference on Metallurgical Coatings and Thin Films held in San Diego, California, 1991.Google Scholar