Preparation and Corrosion Resistance of Amorphous SiN _<i>x</i> Films from Hexamethyldisiloxane Solution by PECVD

Abstract

SiN x films were deposited on Si wafer and SUS steel (Fe–18Cr–8Ni) substrate from a hexamethyldisiloxane solution by N 2 plasma‐enhanced chemical vapor deposition equipped with a liquid injection device. The SiN x films with dense columnar structures were identified to be amorphous by means of X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and X‐ray photoelectron spectroscopy. An enhancement of deposition rate, in combination with a large amount of oxygen contaminant, was obtained after modifying the nozzle position from a top injection to a side injection method by providing a greater liquid supply. The corrosion performance of SiN x film‐coated SUS steel was evaluated by exposure test in KCl vapor atmosphere at 650°C, indicating that the high purity SiN x film demonstrated a significantly improved resistance, while an increased remanent oxygen content inside the films produced a deleterious effect on the anti‐corrosion behavior.