An absolute MEMS capacitance vacuum sensor with a full range of (1-1000) Pa has been designed, fabricated and tested. The working principle of the capacitance vacuum sensor is explained and its fabrication process is introduced. For obtaining high sensitivity, the sensor’s pressure-sensing diaphragm with large width-to-thickness ratio is manufactured using the silicon-on-insulator (SOI). A silicon buffer block is adopted to improve the linearity of the sensor and prevent the pressure-sensing diaphragm from being damaged due to overload. The sensor is packaged by anodic bonding process in a certain high vacuum environment to form a sealed cavity, in which the vacuum degree is maintained by the non-evaporable getter (NEG) film deposited on the buffer block surface. The absolute pressure measurement of the packaged sensor has been performed with a vacuum measurement system. The tests results show that the capacitance-pressure curve is piecewise linear in the full range (1-1000) Pa. And the sensor exhibits high stability and reproducibility. The maximum sensitivity of the sensor is 33.03 fF/Pa, while the resolution can reach 0.5 Pa. Moreover, the temperature characteristic of the sensor has been evaluated, and it turns out that the effect of temperature on the sensor is quite small in a certain temperature range. [2020-0276]

中文翻译：

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基于硅缓冲块的MEMS电容真空传感器的设计与制作

已经设计、制造和测试了全范围 (1-1000) Pa 的绝对 MEMS 电容真空传感器。阐述了电容式真空传感器的工作原理，介绍了其制作工艺。为了获得高灵敏度，传感器的宽厚比压力传感膜片采用绝缘体上硅 (SOI) 制造。采用硅缓冲块，提高传感器的线性度，防止压力传感膜片因过载而损坏。传感器在一定的高真空环境下通过阳极键合工艺封装形成密封腔，其中真空度由沉积在缓冲块表面的非蒸发性吸气剂（NEG）膜维持。封装传感器的绝对压力测量已使用真空测量系统进行。测试结果表明，电容-压力曲线在整个范围（1-1000）Pa内呈分段线性。该传感器具有较高的稳定性和重现性。传感器的最大灵敏度为33.03 fF/Pa，分辨率可达0.5 Pa。另外，对传感器的温度特性进行了评估，结果表明温度对传感器的影响在一定范围内是很小的。温度范围。[2020-0276] 此外，还对传感器的温度特性进行了评估，发现在一定温度范围内，温度对传感器的影响很小。[2020-0276] 此外，还对传感器的温度特性进行了评估，发现在一定温度范围内，温度对传感器的影响很小。[2020-0276]