Low hydrogen content silicon oxycarbonitride (SiOCN) thin films were grown by plasma-enhanced chemical vapor deposition exploiting hydrogen dilution with silane/methane/nitrous oxide or tetramethylsilane/nitrous oxide precursors. The effects of deposition temperature were compared by investigating the compositional, optical, mechanical, and electrical properties of films grown at 100 °C, 250 °C, and 400 °C at thicknesses ranging from 50 nm to 10 μm. The dielectric constant and high breakdown strength of the films remain relatively constant at between 4–5 and 6.8 ± 0.2 MV cm−1 to 9.1 ± 0.3 MV cm−1, respectively, despite the differences in deposition temperature. Other properties of the films include excellent transparency in the visible regime, high nanoindentation hardness (4 to 12 GPa), and relatively low measured stress on Si (−20 to −300 MPa). Overall, the results of this work show that these SiOCN films can be used in a wide variety of applications, including as a dielectric within high voltage capacitors, transparent abrasion-resistant coatings for plastic windows, coatings on flexible substrates, a metal diffusion barrier for low-k dielectrics and polymer films, or within various microelectronic fabrication steps or systems.