Title :
Superconducting TiN Films Sputtered Over a Large Range of Substrate DC Bias
Author :
Iftekhar Jaim, H.M. ; Aguilar, J.A. ; Sarabi, B. ; Rosen, Y.J. ; Ramanayaka, A.N. ; Lock, E.H. ; Richardson, C.J.K. ; Osborn, K.D.
Author_Institution :
Lab. for Phys. Sci., Univ. of Maryland, College Park, MD, USA
Abstract :
We have investigated properties of superconducting titanium nitride (TiN) films that were sputtered over a large range of RF-induced DC bias voltage applied to the substrate. Films grown with the largest bias voltages contained cubic TiN phases with a large fraction of the (200) crystalline growth orientation. These films also contained the smallest concentrations of oxygen impurities, resulting in stoichiometric TiN. Over the range of bias, variations of the stress from slightly tensile to highly compressive were measured and correlated to crystallinity of the (200) growth. The films exhibited highly uniform thickness and resistivity, and show the potential for yielding reproducible low-temperature devices. Finally, coplanar resonators fabricated with the films exhibited high kinetic inductance and quality factor, where the latter was obtained in part from temperature-dependent frequency shifts.
Keywords :
electrical resistivity; impurities; sputter deposition; stoichiometry; superconducting thin films; tensile strength; titanium compounds; (200) crystalline growth orientation; RF-induced DC bias voltage; TiN; compressive strength; coplanar resonator; cubic TiN phase; electrical resistivity; film thickness; kinetic inductance; low-temperature device; oxygen impurities; quality factor; stoichiometry; stress variation; substrate DC bias voltage; superconducting titanium nitride film sputtering; temperature-dependent frequency shift; tensile strength; Conductivity; Films; Inductance; Kinetic theory; Substrates; Temperature measurement; Tin; Kinetic inductance; MKIDs; Q-factor; Titanium nitride (TiN); kinetic inductance; quantum computing; titanium nitride (TiN); two-level systems;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2014.2366036