Compact micro-Pirani vacuum sensor based on series diodes without heating structure

Publication date: Available online 14 February 2019Source: Sensors and Actuators A: PhysicalAuthor(s): Debo Wei, Jianyu Fu, Ruiwen Liu, Ying Hou, Chao Liu, Weibing Wang, Dapeng ChenAbstractDiode based micro-Pirani vacuum sensors attract considerable attention because they do not require special materials and are compatible with complementary metal oxide semiconductors (CMOS). However, their complex heating structure makes it difficult to reduce the sensor size. This paper reports a novel compact micro-Pirani vacuum sensor based on series diodes. The self-heating effect of the series diodes helps simplify the structural design by avoiding a dedicated heating structure. Moreover, the small size of the series diodes ensures high temperature coefficient. The proposed design reduces the sensor size without sacrificing the performance. In fact, simulation results indicate that the series diodes help enhance the device performance. A sensor was fabricated by a CMOS compatible process. The sensor size was reduced significantly to 35 μm × 35 μm. The sensor is sensitive to the vacuum pressure range from 10-1 Pa to 104 Pa when driven by a constant current as small as 10 μA, and the power consumption is low at 50 μW.Graphical Abstract

Source: Sensors and Actuators A: Physical - February 15, 2019 Category: Physics Source Type: research