Wafer with patterned Nb film
Wafer with patterned Nb film
Nb/Ta resonators and qubit electrodes
VTT-Technical Research Centre of Finland Ltd
Qu-Pilot
This process is suitable for fabrication of extremely low-loss electrodes for capacitors, co-planar waveguides, and other similar structures used on, e.g., qubit chips. VTT has fabricated a large number of superconducting high-Qi resonators on these films, consistently reaching low-power Qi values of 0.5 to 1.5 million co-planar resonators with center frequencies in the range of 4 to 7 GHz and center pin (gap) width of 20 µm (10 µm). Specifications: Standard chip sizes: 2.5 mm x 2.5 mm, 2.5 mm x 5.0 mm, 5.0 mm x 5.0 mm, 10 mm x 5.0 mm, 10 mm x 10 mm (others on case-by-case basis) Non-metallized area at chip perimeter: ≥ 50 µm Metallization line width: ≥ 1.0 µm Slit width: ≥ 0.8 µm Metallization line width reproducibility: ± 0.075 µm Metallization sheet resistance (at room temperature): ca. 1.1 Ω
CPW test resonators
Photograph of VTT’s typical CPW resonator test chip, with eight 4 to 8 GHz resonator coupled weakly to a common feedline.
Lumped element resonator Qi
Qi values vs number of photons in Nb-based lumped-element resonators, fabricated and characterized by VTT.
Sensing Computing Communication
7
Superconducting 
Prototyping  Mass production Fabrication