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

摘要

Diode 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 mu m x 35 mu m. The sensor is sensitive to the vacuum pressure range from 10(-1) Pa to 10(4) Pa when driven by a constant current as small as 10 mu A, and the power consumption is low at 50 mu W. (C) 2019 Elsevier B.V. All rights reserved.