Intro -- Abstract -- Populärvetenskaplig sammanfattning -- Preface -- Acknowledgements -- Introduction -- Purpose and outline -- Silicon nitride and silicon nitride-based materials -- Silicon nitride -- Silicon oxynitride -- Silicon carbonitride -- Thin film deposition and process characterization -- Magnetron sputtering -- High power impulse magnetron sputtering -- Reactive sputtering -- Sputtering with different reactive gases -- Plasma characterization -- Langmuir probe measurements -- Mass spectrometry -- Experimental details of thin film deposition -- Thin film characterization -- X-ray photoelectron spectroscopy -- Elastic recoil detection analysis -- X-ray reflectivity -- Raman spectroscopy -- Transmission electron microscopy -- Residual stress measurement -- Nanoindentation -- Spectroscopic ellipsometry -- Summary of included publications -- Bibliography -- Included publications and author's contribution.