Optimization of Urea-EnFET Based on Ta2O5 Layer with Post Annealing

Sensors

Cheng-En Lue¹  Ting-Chun Yu¹  Chia-Ming Yang²  Dorota G. Pijanowska³ 

[1] Department of Electronic Engineering, Chang Gung University, 259 Wen-Hwa 1 st road, Kwei-Shan, Tao-Yuan, 333, Taiwan; E-Mail:;Device Section, Department of WAT and Devices, Inotera Memories Inc., 667 Fuhsing 3 rd Road, Hwa-Ya Technology Park, Kwei-Shan, Tao-Yuan, 333, Taiwan; E-Mail:;Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ul. Ks. Trojdena 4, 02-109 Warsaw, Poland; E-Mail:

关键词: urea;    enzymatic field effect transistor (EnFET);    ion sensitive field effect transistor (ISFET);    tantalum pentoxide (Ta₂O₅);    post N₂ annealing;   

DOI  :  10.3390/s110504562

来源: mdpi

【 摘 要 】

In this study, the urea-enzymatic field effect transistors (EnFETs) were investigated based on pH-ion sensitive field effect transistors (ISFETs) with tantalum pentoxide (Ta₂O₅) sensing membranes. In addition, a post N₂ annealing was used to improve the sensing properties. At first, the pH sensitivity, hysteresis, drift, and light induced drift of the ISFETs were evaluated. After the covalent bonding process and urease immobilization, the urea sensitivity of the EnFETs were also investigated and compared with the conventional Si₃N₄ sensing layer. The ISFETs and EnFETs with annealed Ta₂O₅ sensing membranes showed the best responses, including the highest pH sensitivity (56.9 mV/pH, from pH 2 to pH 12) and also corresponded to the highest urea sensitivity (61 mV/pC_urea, from 1 mM to 7.5 mM). Besides, the non-ideal factors of pH hysteresis, time drift, and light induced drift of the annealed samples were also lower than the controlled Ta₂O₅ and Si₃N₄ sensing membranes.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.