Preparation and Characterization of SiC Thin Films for 3H2O Steam Sensing

Abstract

The objective of this study is to elaborate SiC thin film as a humidity sensing element and study its behavior towards tritiated water vapor, to apply it for radiation protection purposes. Silicon carbide was chosen as a material because of its remarkable properties and its capacity to be applied in harsh environments. The thin layers of SiC were deposited on the Si substrate by the magnetron sputtering technique. Their morphological, structural, and optical properties were examined by scanning electron microscopy, X-ray diffraction, and UV visible spectroscopy, respectively. The obtained thin films were examined by X-ray fluorescence and Auger electron spectrometry to get the elemental and chemical state information. The film's sensitivity was carried out by current–voltage measurements of SiC/pSi(100)/Cu Schottky diode structure before and after exposure to tritiated water steam for 10 and 38 days in an airtight container. The impedance measurements were performed in air, at room temperature,  with  frequencies  ranging  from 10^-5 Hz to 0.1 Hz. The current showed an increase in forward bias after exposure to the super-heavy water vapor, which implies that the obtained amorphous SiC thin films could have an application as a tritiated water vapor sensing element at room temperature.