Tantalum Damascene Coplanar Waveguide Resonators Fabricated Using 300 mm Scale Processes

TL;DR

This paper investigates a damascene fabrication process to reduce surface oxides in superconducting resonators, aiming to improve device performance by lowering surface-related losses.

Contribution

It demonstrates a novel damascene process for superconducting devices that potentially reduces surface oxides and associated losses, using 300 mm scale fabrication.

Findings

Modest performance improvement observed with damascene process

Simulation suggests reduced surface participation ratio

Process compatible with large-scale fabrication

Abstract

Surface oxides contribute to losses in superconducting transmon devices resulting in degraded performance. We explore the use of the damascene process to replace the sidewall native oxide of a device with a metal/substrate interface. We simulate sidewall oxidation by burying an oxide layer during fabrication. We observe a modest improvement between the two types of devices, which is suggestive of a reduction in the surface participation ratio.