Design, fabrication and characterization of Ti/Au TES with different dimensions of suspended beams

For photon detection, superconducting transition-edge sensor (TES) micro-calorimeters are excellent energy-resolving devices. In this study, we report our recent work in developing Ti-/Au-based TES. The Ti/Au TES devices were designed and implemented with a thickness ratio of 1:1 and different suspended structures using micromachining technology. The characteristics were evaluated and analyzed, including surface morphology, 3D deformation of suspended Ti/Au TES device structure, I–V characteristics, and low-temperature superconductivity. The results show that the surface of Ti/Au have good homogeneity and the surface roughness of Ti/Au is significantly increased compared with the substrate. The structure of Ti/Au bilayer film significantly affects the deformation of suspended devices, but the deformation does not affect the I–V characteristics of the devices. For devices with the Ti/Au bilayer (150×150 μm) and beams (100×25 μm), the transition temperature (Tc) is 253 mK with a width of 6 mK, and the value of the temperature sensitivity α is 95.1.