Atomic Layer Deposition of Titanium Nitride for Quantum Circuits*

High kinetic inductance thin films are of great interest for superconducting detectors, coupling to hybrid systems, and novel superconducting qubits. We demonstrate that titanium nitride thin films grown via plasma-enhanced atomic layer deposition support superconducting microwave resonators with internal quality factors up to 1.0 million at single photon powers, and find that the dominant loss mechanism in these resonators is likely due to two-level systems. Utilizing nanowire geometries, we realize characteristic impedances greater than a resistance quantum with Z ~ 28 kΩ while maintaining low losses and a compact device footprint (8×8 μm²). The corresponding increase in zero point voltage fluctuations makes this material an excellent candidate for integration into hybrid quantum systems and quantum sensing.