Epitaxial titanium nitride microwave resonators: Structural, chemical, electrical, and microwave properties

Titanium nitride is an attractive material for a range of superconducting quantum-circuit applications owing to its low microwave losses, high surface inductance, and chemical stability. The physical properties device performance, nevertheless, depend strongly on the quality materials. Here we focus highly crystalline epitaxial titanium thin films deposited sapphire substrates using magnetron sputtering at intermediate temperature (300$^{\circ}$C). We perform set systematic comprehensive characterization thoroughly understand structural, chemical, transport properties. Microwave losses temperatures are studied patterned resonators, where best internal factor in single-photon regime measured be $3.3\times 10^6$, $> 1.0\times 10^7$ high-power regime. Adjusted with filling loss-tangent here compares well previously reported values resonators. This work lays foundation low-loss quantum circuits.