A combined MEMS thermal vacuum sensor with a wide pressure range

MEMS thermal vacuum sensors have been widely applied in many academic and industry fields, and pressure range is a key performance of MEMS thermal vacuum sensors. To extend the pressure range, a combined MEMS thermal vacuum sensor that consists of two diode-type MEMS thermal vacuum sensors in series is proposed in this work. The two diode-type sensors are designed to have different areas of sensitive region and distances between sensitive region and heat sink, and their responses to the pressure are from 3.0 x 10-3 to 3 x 104 Pa and from 1.7 x 10-2 to 4.4 x 105 Pa, respectively. By series-connecting them, the combined sensor achieves a pressure range of 1.3 x 10-3 to 6.9 x 105 Pa without any additional control circuit. In addition, it possesses a relatively small size of 400 x 300 mu m2. These indicate that the combined MEMS thermal vacuum sensor has the characteristics of wide pressure range, high sensitivity and small size.