Investigation of AlGaN/GaN Ion-Sensitive Heterostructure Field-Effect Transistors-Based pH Sensors with Al2O3 Surface Passivation and Sensing Membrane

Han Yin Liu, Wei Chou Hsu, Wei Fan Chen, Chih Wei Lin, Yi Ying Li, Ching Sung Lee, Wen Ching Sun, Sung Yen Wei, Sheng Min Yu

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)

Abstract

This paper demonstrates an AlGaN/GaN ion-sensitive heterostructure field-effect transistors (ISHFETs)-based pH sensors with an aluminum oxide (Al2O3) to serve as a passivation layer and a sensing membrane at the same time. Al2O3 was deposited by the ultrasonic spray pyrolysis deposition (USPD) method. It was found that the ISHFET with Al2O3 showed a higher pH sensitivity of 55.6 mV/pH, a faster response speed of 3 s (from pH 4 to pH 7) and 7 s (from pH 7 to pH 10), a lower hysteresis voltage of 4.3 mV, and a smaller drift rate of 1.25 mV/h (at pH 7) compared with the ISHFET without passivation. In addition, the ISHFET with an Al2O3 passivation layer exhibited significant surface potential variation and low degradation rate. These results suggest that the performance of ISHFET improved using USPD-grown Al2O3.

Original languageEnglish
Article number7409941
Pages (from-to)3514-3522
Number of pages9
JournalIEEE Sensors Journal
Volume16
Issue number10
DOIs
Publication statusPublished - 2016 May 15

All Science Journal Classification (ASJC) codes

  • Instrumentation
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Investigation of AlGaN/GaN Ion-Sensitive Heterostructure Field-Effect Transistors-Based pH Sensors with Al<sub>2</sub>O<sub>3</sub> Surface Passivation and Sensing Membrane'. Together they form a unique fingerprint.

Cite this