A MEMS Thermopile Pirani Sensor Integrated With Composite Nanoforests for Vacuum Monitoring in Semiconductor Equipment

In this work, a novel MEMS thermopile Pirani sensor integrated with composite nanoforests (CNFs) is presented. As the CNFs have high porosity and a large surface area to volume ratio (SVR), such a sensor possesses enlarged gas heat conduction. Besides, the surface plasmon resonance (SPR) introduced by the CNFs increases light absorption of the sensor, and the enhanced electromagnetic field of the SPR can effectively convert optical energy into heat energy. Compared with the pristine Pirani sensor without such CNFs, the output voltage of this novel sensor is increased by up to 70.9%, the low detection limit (LDL) of pressure is extended by 300%, and its maximum sensitivity is improved by 68.1%. With these superiorities, the as-prepared Pirani sensor can successfully monitor the vacuum information of different semiconductor manufacturing equipments. Backed up by the CMOS-compatible preparation process of the device, a promising future with diverse scenarios for practical applications is expected.