VTT Aluminum Junction Process (VTT)
https://www.cmc.ca/vtt-aluminum-junction-process/
CMC Microsystems offers access to the VTT Aluminum Junction process on high-resistivity silicon substrate via a multi-projects wafer (MPW) service that provides 20 copies of the design. The process allows for fabrication of Niobium side-wall passivated junctions via a Nb-Al-AlOx-Nb trilayer, with junction sizes as low as 0.6 um, alongside a single wiring layer on top. The process offers a current density ranging from 30 to 3000 A/cm^2.
This technology has applications in superconducting tunnel junction circuits such as SQUID magnetometers and Josephson parametric amplifiers among others as well as low temperature electronics