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

Abstract

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

References in corpus (22)

• Superconducting Qubits: Current State of Play
• Decoherence in Josephson Qubits from Dielectric Loss
• Towards understanding two-level-systems in amorphous solids -- Insights from quantum circuits
• Planar Superconducting Resonators with Internal Quality Factors above One Million
• Surface participation and dielectric loss in superconducting qubits
• Improved superconducting qubit coherence using titanium nitride
• Materials loss measurements using superconducting microwave resonators
• Reducing intrinsic loss in superconducting resonators by surface treatment and deep etching of silicon substrates
• X-ray diffraction peak profiles from threading dislocations in GaN epitaxial films
• Study of loss in superconducting coplanar waveguide resonators
• Low Loss Superconducting Titanium Nitride Coplanar Waveguide Resonators
• Analysis and mitigation of interface losses in trenched superconducting coplanar waveguide resonators
• Strongly disordered TiN and NbTiN s-wave superconductors probed by microwave electrodynamics
• Characterization and Reduction of Capacitive Loss Induced by Sub-Micron Josephson Junction Fabrication in Superconducting Qubits
• Investigation of microwave loss induced by oxide regrowth in high-Q Nb resonators
• Investigating surface loss effects in superconducting transmon qubits
• Etch Induced Microwave Losses in Titanium Nitride Superconducting Resonators
• Comparison of Dielectric Loss in Titanium Nitride and Aluminum Superconducting Resonators
• Superconductivity behavior in epitaxial TiN films points at surface magnetic disorder
• Charge Berezinskii-Kosterlitz-Thouless transition in superconducting NbTiN films
• Millikelvin temperature cryo-CMOS multiplexer for scalable quantum device characterisation
• Design and Testing of Kinetic Inductance Detectors Made of Titanium Nitride