The Fabrication and Indentation of Cubic Silicon Carbide Diaphragm for Acoustic Sensing

In this study, 550 nm thick cubic silicon carbide square diaphragms were back etched from Si substrate. Then, indentation was carried out to samples with varying dimensions, indentation locations, and loads. The influence of three parameters is documented by analyzing load-displacement curves. It was found that diaphragms with bigger area, indented at the edge, and low load demonstrated almost elastic behaviour. Furthermore, two samples burst and one of them displayed pop-in behaviour, which we determine is due to plastic deformation. Based on optimum dimension and load, we calculate maximum pressure for elastic diaphragms. This pressure is sufficient for cubic silicon carbide diaphragms to be used as acoustic sensors to detect poisonous gasses.