A Comparative Study of Various Analytical Techniques to Investigate Ni-Si Thin Film Characteristics

Abstract

Thin film characterization is fundamental across materials science, engineering, and beyond, providing crucial insights into film composition, morphology, crystallinity, and optical properties. This understanding optimizes thin film performance in various applications, enhances fabrication processes, and ultimately advances technology and innovation in diverse industries. Thus, in this study, we aim to systematically investigate the nanoscale structure and chemistry of the Ni-Si layer formed at high temperature using Transmission Electron Microscopy (TEM), Energy Dispersive X- Ray Spectroscopy (EDS), X-ray Photoelectron Spectroscopy (XPS), and Auger Electron Spectroscopy. The evolution of various phases within the Ni-Si layer at high temperatures exhibits critical implications for its structural integrity and functional properties. Initially, during the annealing process, the formation of Ni-Si phases undergoes a sequential transformation, starting with the formation of NiSi, progressing to NiSi2, and ultimately reaching Ni2Si. Each phase transition is accompanied by distinct changes in microstructure and chemical composition, significantly impacting the layer's mechanical and electrical properties [1]. Our TEM results in conjunction with EDS elemental analysis revealed significant microstructural changes and a mixture of various Ni-Si phases, namely, NiSi, NiSi2, and Ni2Si. Subsequently, XPS provided chemical information by probing the surface composition and oxidation states of elements within the Ni-Si layer, facilitating the identification of surface species and the monitoring of chemical reactions occurring at elevated temperatures. Finally, AES analysis, with its higher lateral resolution, and enhanced sensitivity to surface elemental compositions, as well as its depth profiling capabilities, confirmed EDS findings and enabled a comprehensive characterization of elemental distribution and diffusion phenomena within the Ni-Si layer. Selected references [1] A. M. Thron, P. K. Green, K. Liu, K. van Benthem, “Structural changes during the reaction of Ni thin films with (100) silicon substrates” , Acta Materialia 60 (2012) 2668–2678, doi: 10.1016/j.actamat.2012.01.033