Low power AlGaN/GaN MEMS pressure sensor for high vacuum application

Abstract

A micro-scale pressure sensor based on suspended AlGaN/GaN heterostructure is reported with nonlinear sensitivity. By sealing the cavity, vacuum sensing at various temperatures was demonstrated. To validate the proposed concept of the AlGaN/GaN vacuum sensor, a 700 m diameter circular membrane was electrically characterized under applied static and dynamic pressures at various temperatures ranging from 25 • C to 100 • C. The current change of the AlGaN/GaN heterostructure increased as the vacuum and temperature increases due to the increase of 2DEG density by tensile strain. The dynamic current change from 96 kPa down to 10 Pa of AlGaN/GaN heterostructure pressure sensor was 18.75 % at 100 • C. The maximum sensitivity reached 22.8 %/kPa with a power consumption of 1.8 W. These results suggest that suspended AlGaN/GaN heterostructures are promising for high vacuum and high-temperature sensing applications.

Ultrahigh-Sensitivity Pressure Sensor With Graphene Aerogel Electrodes

“…The recent literature contains numerous references that describe innovative pressure sensors . Those sensors usually use either the principle of piezoresistivity [3,4,5,6,7,8,9,10,12,14,15,17,21] (see Appendix A for performance parameters), or capacitance variation [11,13,16,18,19,20,22,23] (see Appendix A). The advantage of the new sensor introduced in this paper is the excellent sensitivity to very low pressures (0.1 Pa to 10 Pa).…”

Study on the GaN/AlGaN Piezotronic Effect Applied in Pressure Sensors

“…Up to now, most studies on the pressure sensors have addressed the abrupt AlGaN/GaN heterostructure in which electrons are confined in a quantum well. [15][16][17][18] There is another type called graded AlGaN/GaN heterostructure with linear change of Al mole fraction, which was shown to have good performance for microwave power devices. 19,20 However, this graded heterostructure has not been studied to be applied in pressure sensors.…”