Plassys SA Multichamber Evaporation System UHV” is a state-of-the-art thin film deposition tool that we use to make our Josephson junctions, the nonlinear inductors that are at the heart of all our quantum circuits. With its purchase we have been able to significantly improve reproducibility in the fabrication of these junctions. This was made possible by the features of the new evaporation system, in particular, the UHV capability and the presence of an additional, dedicated chamber for the oxidation of film surfaces.
The “AJA sputterer” is a state of the art machine for deposition of normal metal or superconducting thin ultra-high purity films on a substrate or wafer. In the field of superconducting circuits the coherence time of a quantum bit which can be used for information processing is strongly reduced by impurities in and at the boundary between materials. The AJA sputtering machine is currently one of the best products on the market that features tools for surface cleaning and the ultra-high quality material deposition. In addition, a large number of target materials and several process gasses allow us to produce more advanced multi-layer structures such as Nb tri-layer Josephson junctions. Having a larger collection of non-dissipative non-linear elements on a chip will vastly extend the area of our research.