PEALD deposited TaC_xN_1-x, a low loss High Kinetic Inductance platform for quantum applications

Superconducting nitrides are critical materials for high kinetic inductance films in quantum sensing and computing. While physical vapor deposition (PVD) remains the standard, atomic layer deposition (ALD) offers superior uniformity and thickness control. However, ALD faces materials challenges such as issues related to direct nucleation on silicon substrates and controlling film purity.

We present a study of plasma-enhanced (PE)-ALD tantalum carbonitride (TaC_xN_1-x) synthesis on silicon substrates and the utility of this material system for quantum device applications. Specifically, we investigate the influence of the nucleation layer on the structural and superconducting properties of the films. The crystalline structure is examined using transmission electron microscopy (TEM). Furthermore, resonator test structures are fabricated and characterized to quantify superconducting device metrics in the microwave regime, including kinetic inductance and microwave loss. Our study provides critical insights into the prospects of ALD-grown thin film superconducting materials for quantum device applications.