Plasma-Assisted Hybrid Vapour Deposition Technology for Thin Film Fabrication

Continuous development of thin film deposition technologies is essential for the fabrication of films that meet the specific requirements of their target applications and working conditions. Therefore, it is necessary to increase the number of accessible and tuneable process parameters, which can be achieved by venturing into the field of hybrid techniques. Among a variety of available deposition techniques, the focus of this work is on physical vapour deposition magnetron sputtering (PVD MS) methods, with the addition of microwave (MW) plasma. The main advantage of this work is its generalised approach to examining the "big picture" not only of film deposition itself, but also of the phenomena occurring at the material source, how they affect the deposition environment and the nature of the decoupled effects, and how they relate to film characteristics. With this in mind, the reader is first guided through selected plasma physics concepts necessary to follow the proposed hybrid vapour deposition (HVD) processes. The validity of this methodology is examined on the example of three material case studies, namely diamond-like carbon (DLC), indium nitride (InN) and zinc tin nitride (ZTN). Each case study explores the influencing factors of MS, starting with pulsed direct current magnetron sputtering (p-DCMS) through high power impulse magnetron sputtering (HiPIMS) and reactive HiPIMS (R-HiPIMS). Furthermore, the effects of incorporating the volume MW plasma (which fills the entire vacuum chamber) are investigated in the context of improving process control through tailored phenomenological decoupling, i.e. separation of otherwise interdependent effects. A range of in situ diagnostic techniques are used, including studying the obtained HiPIMS I(V,t) curves, time-resolved optical emission spectroscopy (OES), time-of-flight mass spectrometry (ToF-MS) and Langmuir probe measurements. The fabricated films were characterised in terms of the material's structure, micro- and nanostructure, as well as application properties. The obtained results highlight the significant contribution of MW plasma for enhancing phenomenon control during sputtering for all studied material cases.