Growth Optimization of MoSi Thin Film and Measurement of Transport Critical Current Density of its Meander Structure

Amorphous thin film superconductors are promising alternatives for the development of superconducting radiation detectors, especially superconducting nanowire single‐photon detectors and superconducting microwire single‐photon detectors, due to their homogeneous nature, ease of deposition, and superconducting parameters comparable to the materials currently being used. A study on the optimization of the growth technology and superconducting transition temperature ( T C ) of MoSi thin films grown on SiO 2 ‐coated Si substrate is reported here. These films have been synthesized by cosputtering of Mo and Si targets with varying compositions and thicknesses to achieve optimized T C values close to that of the bulk. Mo 80 Si 20 and Mo 83 Si 17 compositions of the film, each with a thickness of 17 nm, exhibit the highest T C of 6.4 and 5.9 K, respectively. Additionally, a meander structure with a 17 μm wire width is patterned to estimate the transport critical current density ( J C ), which is measured to be 1.4 × 10 9 A m −2 at 4 K. Variation of the T C with film thickness and deposition pressure has been studied. Electrical resistance as a function of temperature of the film before and after meandering is also studied. These properties are compatible with the fabrication of superconducting nanowire, microwire, and wide strip single‐photon detectors.