Plasma-enhanced atomic layer deposition of titanium nitride for superconducting devices

This study examines the superconducting properties of titanium nitride (TiN) deposited via plasma-enhanced atomic layer deposition on both planar and three-dimensional (3D) structures. Our deposition method achieves consistent uniformity, maintaining sheet resistance (R□) > 95% across a 6-in. wafer, crucial for large-scale superconducting device fabrication and yield optimization. The planar films, akin to reactive-sputtered TiN, reached a critical temperature (Tc) of 4.35 K at a thickness of ≈40 nm. For aspect ratios (ARs) between 2 and 40, we observed a single transition of ≈2 K at ARs between 2 and 10.5, and multiple transitions at ARs > 10.5. We discuss mechanisms influencing superconducting properties in the 3D structures, aligning with current and future superconducting technologies.