A technical paper titled “Ultra-thin TaN Damascene Nanowire Structures on 300 mm Si Wafers for Quantum Applications” was published by researchers at NY CREATES, United States Air Force Research Laboratory and SUNY Polytechnic Institute.
“We report on the development and characterization of superconducting damascene tantalum nitride (TaN) nanowires, 100 nm to 3 μm wide, with TaN thicknesses varying from 5 nm to 35 nm, using 193 nm optical lithography and chemical mechanical planarization among other 300 mm wafer-scale processes. The TaN film composition chosen for nanowire fabrication was informed by a detailed study of unpatterned TaN films with varying nitrogen to tantalum ratios, formed by reactive sputtering. We also discuss the influence of encapsulation by copper and disordered atomic layer deposited TaN on the critical current of superconducting nanowires. Superconducting critical current density (measured at 12 mK) ranges from 0.12 MA/cm2 to 0.85 MA/cm2 depending on nanowire width and film thickness. The potential of ultra-thin TaN nanowires at 300 mm scale is discussed in the context of applications such as on-chip integration for readout of superconducting qubits, in single photon detection for quantum computing, as well as in large single photon detecting focal plane arrays for cosmology in a broader range of wavelengths.”
Find the technical paper here. Published: June 2023.
E. Bhatia et al., “Ultra-thin TaN Damascene Nanowire Structures on 300 mm Si Wafers for Quantum Applications,” in IEEE Transactions on Quantum Engineering, doi: 10.1109/TQE.2023.3289257.