A novel high-performance wide-range vacuum sensor based on a weak-coupling resonator.

Abstract

Wide-range vacuum sensors (0.1-10⁵ Pa) are crucial for a variety of applications, particularly in semiconductor equipment. However, existing sensors often face a trade-off between measurement range and accuracy, with some offering a wide range at the expense of low accuracy, and others providing high accuracy within a limited range. This restricts their applicability in advanced technologies. The primary challenge lies in the sensitivity constraints at medium vacuum, the accuracy limitations at low vacuum, and the dependence of gas types. In this study, a new paradigm of high-performance wide-range MEMS diaphragm-based vacuum sensor is proposed, which is inherently small volume and independent of gas types. The sensor measures the vacuum pressure based on a two degree of freedom weak-coupling resonator, which operates in two distinct modes. In the range from 0.3 Pa to 10³ Pa, it works in mode-localized mode, where amplitude ratio serves as the output to enhance sensitivity and resolution. For pressure ranging from 10³ Pa to 10⁵ Pa, it works in traditional resonance mode, with frequency serving as the output to achieve high accuracy. Experimental results demonstrate that the proposed sensor outperforms conventional vacuum sensors.