Fabrication and characterization of Al-Mn superconducting films for applications in TES bolometers*
Qing Yu, Yifei Zhang, Changhao Zhao, Kaiyong He, Rutian Huang, Yongcheng He, Xinyu Wu, Jianshe Liu, Wei Chen
Abstract
Superconducting transition edge sensor (TES) bolometers require superconducting films to have controllable transition temperatures T c in different practical applications. The value of T c strongly affects thermal conductivity and thermal noise performance of TES detectors. Al films doped with Mn (Al–Mn) of different concentrations can accomplish tunable T c . A magnetron sputtering machine is used to deposit the Al–Mn films in this study. Fabrication parameters including sputtering pressure and annealing process are studied and their influences on T c and superconducting transition width Δ T c are optimized. The Al–Mn films with Δ T c below 1.0 mK for T c in a range of 520 mK–580 mK are successfully fabricated.