  Silicon-based dielectric is crucial for many superconducting devices,
including high-frequency transmission lines, filters, and resonators. Defects
and contaminants in the amorphous dielectric and at the interfaces between the
dielectric and metal layers can cause microwave losses and degrade device
performance. Optimization of the dielectric fabrication, device structure, and
surface morphology can help mitigate this problem. We present the fabrication
of silicon oxide and nitride thin film dielectrics. We then characterized them
using Scanning Electron Microscopy, Atomic Force Microscopy, and
spectrophotometry techniques. The samples were synthesized using various
deposition methods, including Plasma-Enhanced Chemical Vapor Deposition and
magnetron sputtering. The films morphology and structure were modified by
adjusting the deposition pressure and gas flow. The resulting films were used
in superconducting resonant systems consisting of planar inductors and
capacitors. Measurements of the resonator properties, including their quality
factor, were performed.
