A research team led by Profs. CHEN Deyong and WANG Junbo from the Aerospace Information Research Institute (AIR) of the Chinese Academy of Sciences has developed a novel microsensor that enhances both the accuracy and measurement range of vacuum pressure detection. Their findings were published in the journal Microsystems & Nanoengineering.

Wide-range vacuum sensors play a vital role in various high-tech fields. In the semiconductor industry, for instance, precise pressure control is crucial for processes such as chemical vapor deposition and plasma etching. However, existing sensor technologies face a trade-off between measurement range and accuracy: Pirani gauges offer a wide measurement range but lack precision, while capacitance diaphragm gauges (CDGs) boast high accuracy but have limited range. Composite sensors, which combine the two technologies, are large, complex, and sensitive to gas types.

To tackle these issues, the team created a micro-electromechanical systems (MEMS) pressure sensor. It can operate smoothly across six orders of magnitude (from 0.3 Pa to 100,000 Pa) using a single sensing element, integrating two resonator operating modes into one chip. At low pressures (0.3 Pa–1,000 Pa), it adopts a "mode-localization" mode that amplifies tiny pressure changes into easily detectable signals. At higher pressures (1,000 Pa–100,000 Pa), it automatically switches to a traditional resonance mode, which is highly accurate and stable.

This dual-mode design delivers exceptional performance. The sensor achieves a resolution of approximately 0.1 Pa in low-pressure environments and 2.0 Pa in high-pressure settings. Calibration errors are minimal: a relative deviation of 1.99% at 120°C under low pressure, and as low as 0.01% of full scale under high pressure. It also performs reliably over a broad temperature range from –20°C to 120°C and is unaffected by different gas types.

All these functionalities are integrated into a compact MEMS chip with a volume of just 27.2 mm³—significantly smaller than conventional commercial sensor chips, which can be over 200 times larger. 

The study provides insights into applications in semiconductor manufacturing, space missions, and high-precision engineering.