Browsing by Author "Chang, Chih-Tien"

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A Novel pH-dependent Drift Improvement Method for Zirconium Dioxide Gated pH-Ion Sensitive Field Effect Transistors
(2010-05-01)
Chang, Kow-Ming
;
Chang, Chih-Tien
;
Chao, Kuo-Yi
;
Lin, Chia-Hung
;
電子工程學系及電子研究所
A novel compensation method for Zirconium dioxide gated Ion Sensitive Field Effect Transistors (ISFETs) to improve pH-dependent drift was demonstrated. Through the sequential measurements for both the n-channel and p-channel ISFETs, 75-100% pH-dependent drift could be successfully suppressed for the first seven hours. As a result, a nearly constant drift rate versus pH value was obtained, which increases the accuracy of pH measurements. Meanwhile, the drawback of the hyperbolic-like change with time of the common drift behavior for ISFETs was improved. A state-of-the-art integrated scheme adopting this method was also illustrated.
Development of an Ion Sensitive Field Effect Transistor Based Urea Biosensor with Solid State Reference Systems
(2010-06-01)
Chang, Kow-Ming
;
Chang, Chih-Tien
;
Chan, Kun-Mou
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Development of FET-Type Reference Electrodes for pH-ISFET Applications
(2010)
Chang, Kow-Ming
;
Chang, Chih-Tien
;
Chao, Kuo-Yi
;
Chen, Jin-Li
;
電子工程學系及電子研究所
A reference field effect transistor (FET) fabrication method by using a perfluorosulfonated proton exchange membrane associated with ion-insensitive polymers is proposed. The single-layer film of the perfluorosulfonated polymer/photoresist composite among the eight films tested demonstrated the best performance of 5.8 mV/pH and 11.27 mV/pNa sensitivities. Meanwhile, the drift performances were 3.5 mV/h and less than 1 mV/h for the first and second 4 h tests. A high sensitivity of 52.1 mV/pH and a low interference of 4.61 mV/pNa were obtained in the range of pH 1-13 through the differential arrangement with ZrO(2) gate ion-sensitive field-effect transistors (ISFETs). Meanwhile, the transconductance match of the proposed reference FET/ISFET pair would simplify the differential readout circuits.