First Demonstration of Silicon Carbide Microphone

In this work, we demonstrate the first prototype of silicon carbide microphone. A cubic silicon carbide (3C-SiC) on Si (111) wafer is back-etched to make acoustic diaphragm, which is then bonded with back plate that has acoustic holes. A custom-made package is used to test it. We characterize the responses of silicon carbide microphone in term of capacitance-voltage plot, capacitance-frequency plot, and sensitivity. These performances are then compared with four published prototypes that employ other materials as the acoustic diaphragm. The successful fabrication and testing of silicon carbide microphone pave way for future designs for operation in harsh environments.