English

Critical Temperature tuning of Ti/TiN multilayer films suitable for low temperature detectors

Superconductivity 2014-01-17 v2 Instrumentation and Detectors

Abstract

We present our current progress on the design and test of Ti/TiN Multilayer for use in Kinetic Inductance Detectors (KIDs). Sensors based on sub-stoichiometric TiN film are commonly used in several applications. However, it is difficult to control the targeted critical temperature TCT_C, to maintain precise control of the nitrogen incorporation process and to obtain a production uniformity. To avoid these problems we investigated multilayer Ti/TiN films that show a high uniformity coupled with high quality factor, kinetic inductance and inertness of TiN. These features are ideal to realize superconductive microresonator detectors for astronomical instruments application but also for the field of neutrino physics. Using pure Ti and stoichiometric TiN, we developed and tested different multilayer configuration, in term of number of Ti/TiN layers and in term of different interlayer thicknesses. The target was to reach a critical temperature TCT_C around (1÷1.5)(1\div 1.5) K in order to have a low energy gap and slower recombination time (i.e. low generation-recombination noise). The results prove that the superconductive transition can be tuned in the (0.5÷4.6)(0.5\div 4.6) K temperature range properly choosing the Ti thickness in the (0÷15)(0\div 15) nm range, and the TiN thickness in the (5÷100)(5\div 100) nm range

Keywords

Cite

@article{arxiv.1307.3781,
  title  = {Critical Temperature tuning of Ti/TiN multilayer films suitable for low temperature detectors},
  author = {A. Giachero and P. Day and P. Falferi and M. Faverzani and E. Ferri and C. Giordano and B. Marghesin and F. Mattedi and R. Mezzena and R. Nizzolo and A. Nucciotti},
  journal= {arXiv preprint arXiv:1307.3781},
  year   = {2014}
}