Advancements in superconducting cavities for 3D CQED systems*

High coherence 3D cavities have allowed for the creation of single and multimode quantum memories and the creation of non-trivial bosonic states that can be stabilized against decay. Scaling the number of accessible modes in these systems will require the creation of cavities with very long coherence times. In this talk we will discuss the adaptation of niobium superconducting RF accelerator cavity processes to cavity designs common to CQED research. This will include outlining our in-house surface treatment processes and their efficacy in reducing dissipative loss. This includes techniques such as UHV annealing, nitrogen surface doping, and surface oxide diffusion to lower conductive and two-level system loss to ensure high coherence at single-photon powers. We will also discuss a pathway for using these cavities to study loss in qubit-cavity systems.