Suspended AlGaN/GaN HEMT NO₂ Gas Sensor Integrated With Micro-heater

Abstract

We developed an AlGaN/GaN high electron mobility transistor (HEMT) sensor with a tungsten trioxide (WO 3 ) nano-film modified gate for nitrogen dioxide (NO 2 ) detection. The device has a suspended circular membrane structure and an integrated micro-heater. The thermal characteristic of the Platinum (Pt) micro-heater and the HEMT self-heating are studied and modeled. A significant detection is observed for exposure to a low concentration of 100 ppb NO 2 /N 2 at ∼300 • C. For a 1 ppm NO 2 gas, a high sensitivity of 1.1% with a response (recovery) time of 88 second (132 second) is obtained. The effects of relative humidity and temperature on the gas sensor response properties in air are also studied. Based on the excellent sensing performance and inherent advantages of low power consumption, the investigated sensor provides a viable alternative high performance NO 2 sensing applications. It is suitable for continuous environmental monitoring system or high temperature applications.

A computational study of a chemical gas sensor utilizing Pd–rGO composite on SnO2 thin film for the detection of NOx

“…Also this sensor exposed to 1 ppb, which gives high sensitivity of 1.1% is obtained. This type of sensor is suitable for continuous monitoring of environmental pollutant at high temperature 5 . In this paper, a design of Tin dioxide with/without a Pd/rGO active layer for the NO x gas sensor with IDE is presented.…”

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

“…The temperature was controlled by the microprobe station used and the integrated microheater was used to modulate the membrane temperature to improve sensitivity. More details about the process of GaN-based sensors can be found in earlier publications [17,20,29].…”

“…Lots of research has been done focusing on microwave [11] and power [12] devices thanks to the robust performance in high temperature or high radiation environment. Additionally, thanks to the wide bandgap semiconductor properties, AlGaN/GaN heterostructure based sensors have been reported for various sensing applications such as pressure [13][14][15][16], gases [17][18][19] and optical [20][21][22]. Compared to silicon carbide (SiC), the piezoresistive gauge factor of AlGaN/GaN heterostructures is approximately three times higher than the highest gauge factor reported for SiC [23], which represents the potential of AlGaN/GaN heterostructures in high-temperature pressure sensing applications.…”

Performance Optimization of Nitrogen Dioxide Gas Sensor Based on Pd-AlGaN/GaN HEMTs by Gate Bias Modulation

“…Currently, NO 2 gas sensors based on AlGaN/GaN high electron mobility transistors (HEMTs) have been the subject of intense research [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. The large variation of the sensitivity of these sensors was explained by the trade-off between the sensitivity ( S ) and the base drain current ( I 0 ).…”