An electro-optical component comprising an erbium and oxygen implanted silicon waveguide and a superconducting microwave resonator. A blocking layer of opaque material arranged between the waveguide and microwave resonator. The microwave resonator coherently coupled to spin states of the erbium.

Disclosed herein are approaches for forming a uniform film with reduced surface roughness for photonic applications. One method includes providing a workpiece including a contact etch stop layer (CESL) over a device layer, patterning the CESL to expose an upper surface of the device layer in a waveguide target area, and patterning a waveguide from a dielectric film formed over the waveguide target area. The method may further include directing ions into an upper surface of the waveguide using a high-temperature ion implant to decrease a surface roughness of the upper surface of the waveguide.