Title :
Microwave Properties of Superconducting Atomic-Layer Deposited TiN Films
Author :
Coumou, P.C.J.J. ; Zuiddam, M.R. ; Driessen, E.F.C. ; de Visser, P.J. ; Baselmans, J.J.A. ; Klapwijk, Teunis M.
Author_Institution :
Kavli Inst. of Nanosci., Delft Univ. of Technol., Delft, Netherlands
Abstract :
We have grown superconducting TiN films by atomic layer deposition with thicknesses ranging from 6 to 89 nm. This deposition method allows us to tune the resistivity and critical temperature by controlling the film thickness. The microwave properties are measured, using a coplanar-waveguide resonator, and we find internal quality factors above a million, high sheet inductances (5.2-620 pH), and pulse response times up to 100 μs. The high normal state resistivity of the films (>; 100 μΩ · cm) affects the superconducting state and thereby the electrodynamic response. The microwave response is modeled using a quasiparticle density of states modified with an effective pair-breaker, consistently describing the measured temperature dependence of the quality factor and the resonant frequency.
Keywords :
Q-factor; atomic layer deposition; coplanar waveguides; resonators; superconducting thin films; superconducting transition temperature; titanium compounds; TiN; atomic layer deposition; coplanar-waveguide resonator; critical temperature; electrodynamic response; film thickness; microwave properties; microwave response; quality factors; resistivity; resonant frequency; size 6 nm to 89 nm; superconducting atomic-layer deposited films; superconducting state; temperature dependence; Microwave measurements; Microwave theory and techniques; Q factor; Resonant frequency; Superconducting microwave devices; Temperature measurement; Tin; ALD; TiN; microwave resonator; thin films;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2012.2236603
