Substrate-dependent structural evolution during the oxidation of SiNx thin films

SiN x thin films have garnered attention as promising barrier films, primarily due to their low impurity diffusion rates, making them suitable for various technological applications. Despite their potential, these films face challenges because they are prone to degradation in hostile environments. This study investigated the oxidation behavior of SiN x thin films, particularly when deposited on two different types of substrates: rigid silicon (Si) and flexible polyethylene terephthalate (PET) films. A thorough microstructural analysis of the SiN x films reveals their detailed morphological and compositional characteristics, enabling a comparison between the SiN x /Si and SiN x /PET films. This study further investigates the impacts of high-temperature and humidity exposure on SiN x thin films, systematically elucidating the degradation behaviors and underlying mechanisms. The structural evolution during SiN x film oxidation is illustrated at the nanoscale, and the factors contributing to the oxidation were analyzed. This study deepens our understanding of the interplay between oxidation processes and the unique environmental conditions of substrates, offering insights into enhancing the stability and reliability of these materials. Graphical abstract