Enhanced Sensitivity Pt/AlGaN/GaN Heterostructure NO Sensor Using a Two-Step Gate Recess Technique

Journal article (2021)

Authors

J. Sun Tsinghua University, Electronic Components, Technology and Materials - EEMCS
Teng Zhan Chinese Academy of Sciences
R. Sokolovskij Southern University of Science and Technology
Zewen Liu Tsinghua University
Pasqualina M Sarro Electronic Components, Technology and Materials - EEMCS
Kouchi Zhang Electronic Components, Technology and Materials - EEMCS
Research Group
Electronic Components, Technology and Materials (EEMCS) (TU Delft)
Copyright: © 2021 J. Sun, Teng Zhan, R. Sokolovskij, Zewen Liu, Pasqualina M Sarro, Kouchi Zhang
DOI
help_outline
https://doi.org/10.1109/JSEN.2021.3082205
Gas sensor AlGaN/GaN Gate recess NO
More Info
expand_more

Published Date

2021

Language

English

Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Faculty

Electrical Engineering, Mathematics and Computer Science

Department

Microelectronics

Research Group

Electronic Components, Technology and Materials

Abstract

Based on our proposed precision two-step gate recess technique, a suspended gate-recessed Pt/AlGaN/GaN heterostructure gas sensor integrated with a micro-heater is fabricated and characterized. The controllable two-step gate recess etching method, which includes O2 plasma oxidation of nitride and wet etching, improves gas sensing performance. The sensitivity and current change of the AlGaN/GaN heterostructure to 1-200 ppm NO2/air are increased up to about 20 and 12 times compared to conventional gate device, respectively. The response time is also reduced to only about 25 % of value for conventional device. The sensor has a suspended circular membrane structure and an integrated micro-hotplate for adjusting the optimum working temperature. The sensitivity (response time) increases from 0.75 % (1250 s) to 3.5 % (75 s) toward 40 ppm NO2/air when temperature increase from 60°C to 300°C. The repeatability and cross-sensitivity of the sensor are also demonstrated. These results support the practicability of a high accuracy and fast response gas sensor based on the suspended gate recessed AlGaN/GaN heterostructure with an integrated micro-heater.