Browsing by Author "Chao, Kuo-Yi"

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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.
A novel technique for measuring pico-scale flow rate of a liquid solution using a microchannel
(2008-03-28)
Chang, Kow-Ming
;
Chao, Kuo-Yi
;
Lin, Kun-Feng
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
As micrototal analysis system (mu-TAS) becoming more extensively used, techniques for fabricating microchannels, microactuators, and measuring systems are becoming increasingly important. This study describes a novel method for fabricating a closed microchannel that can be used to measure the pico-scale flow rate of a liquid solution with an accuracy of better than 1 pL/s. The flow rate of 9 pL/s is calculated from the measurements. Without any high temperature or high-voltage processing, the microchannel can be integrated in the complementary metal-oxide-semiconductor (CMOS) microfluidic system and the fabricating process involves only some standard CMOS processes and common materials. The batch fabrication of a single integrated circuit (IC) chip is essential to reaching the goal of a system in one chip. (C) 2007 Elsevier B.V. All rights reserved.
Characteristics of zirconium oxide gate ion-sensitive field-effect transistors
(2007-07-01)
Chang, Kow-Ming
;
Chao, Kuo-Yi
;
Chou, Ting-Wei
;
Chang, Chin-Tien
;
電子工程學系及電子研究所
In this study. the zirconium oxide (ZrO2) membrane has been successfully applied as a pH-sensitive layer for ion-sensitive field-effect transistors (ISFETs). It exhibited an excellent response range of 56.7-58.3 mV/pH from the fixed current measurement using HP4156A. The ZrO2 membrane prepared by direct current (DC) sputtering was used as a pH-sensitive film that showed good surface adsorption with oxide and silicon. The pH sensitivities slightly decreased in 1 M NaCl solution; however. the device showed a perfect linear response of 52.5 mV/pH. The linear pH sensitivity response was measured between pH 1 to 13 in a buffer solution that was provided by Riedel-deHan.
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.