Synthesis of nanocomposite thin films based on the Mo-Si-C ternary system and compositional tailoring through controlled ion bombardment

A major advantage of sputtering processes compared to evaporation processes is the possibility of synthesizing films that replicate the composition of the source (target) material,particularly in the case of alloy targets. This is related to the unique feature of sputtering, viz, formation of an “altered layer” which facilitates reproduction of the target composition in the thin film. An exciting and novel area of research deals with the synthesis of nanocomposite thin films by sputtering composite targets. In this article, the feasibility of depositing a composite thin film based on the Mo-Si-C temary system through RF magnetron sputtering of a MoSi₂+XSiC target, and the possibility of modifying the film composition by controlled ion bombardment (i.e., “ion plating” or “bias sputtering”), will be discussed. In this context, the role of the sputter yields for Mo, Si, and C will be examined with respect to the ability to vary the composition of as-deposited films. In addition, the modifications which were required to sputter a 58.4-mm-diameter composite target (produced inhouse, by different synthesis reactions) using a 127×381-mm Vac Tec cathode will be discussed. Details of Auger electron spectroscopy (AES) scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses of the as-deposited films will be presented.