3C-SiC-on-Si based MEMS packaged capacitive pressure sensor operating up to 500 ºC and 5 MPa

Abstract

This paper reports a packaged MEMS capacitive pressure sensor based 3C-SiC using bulk-micromachining technology that operates on the pressure up to 5.0 MPa and temperature up to 500 oC. The diaphragm employs a single-crystal 3C-SiC thin film that is back-etched from its Si substrate. A photosensitive ProTEK PSB is used as a protection mask layer to reduce the process steps. We compare our results with similar work that also employs a single-crystal 3C-SiC-on-Si capacitive pressure sensor with ceramic package. The MEMS capacitive pressure sensor is employed with 3C-SiC that was performed using hot wall low pressure chemical vapor deposition (LPCVD) reactors at the Queensland Micro and Nanotechnology Center (QMNC), Griffith University. This paper also focuses on comparing those two highest efficiency distributions in MEMS capacitive pressure sensor device to other types of MEMS capacitive pressure sensor. Different temperature, hysteresis and repeatability tests are presented to demonstrate the functionality of the packaged MEMS capacitive pressure sensor. As expected, the output hysteresis has low hysteresis (less than 0.05%) which has inflexibility greater than traditional silicon. By utilizing this low hysteresis was revealed the packaged MEMS capacitive pressure sensor has high repeatability and stability of the sensor.