Current Progress of Pressure Sensors for Harsh Environments Based on Wide-Bandgap Semiconductors

To perform pressure measuring or monitoring under harsh environments, robust materials are in demand. The outstanding properties of wide-bandgap semiconductors (WBGS) such as silicon carbide, III-V nitrides, and diamond offer great potential for these materials as micro-electro-mechanical-system (MEMS) pressure sensors toward such purpose. The variations in materials growth and surface/bulk machining technologies lead to the development of pressure sensors using these materials stays at different stages. The technologies for MEMS pressure sensors based on silicon carbide are established, and those of III-V nitrides are still under development. In contrast, the application of diamond in pressure sensors is far behind other wide-bandgap semiconductors. By using WBGS materials, the MEMS pressure sensors can operate at 600°C or higher for more than one hundred hours. In this paper, the recent patents on the progress of micro-machined pressure sensors based on the wide-bandgap semiconductors will be reviewed.