Title :
pH-sensing characteristics and hysteresis effect of AZO/Glass extended-gate field-effect transistor
Author :
Chiang, Jung-Lung ; Kuo, Chia- Yu
Author_Institution :
Dept. of Electron. Eng., Chung Chou Inst. of Technol., Yuanlin, Taiwan
Abstract :
In this study, the AZO/Glass pH sensing structure was fabricated using r.f. sputtering at 10 mTorr and the power was set 100W. The thickness of AZO thin film was 204nm and the grain size was 40-50nm. Afterwards, the sensing structure connected with a standard metal-oxide-semiconductor field-effect transistor (MOSFET) as an extended-gate field-effect transistor (EGFET). The semiconductor parameter analysis measurement (Keithley 4200) was utilized to measure the current-voltage (I-V) characteristics curves to analysis the pH sensing properties in the different concentration between pH=7 to pH=11 buffer solutions. In addition, the hysteresis effect of AZO pH-EGFET was investigated in the pH=9→10→11→10→9→8→7→8→9 loop cycle using the constant voltage constant current (CVCC) readout circuit. According to the experimental results, the pH sensitivity was obtained 30.52 mV/pH and the magnitude of hysteresis is 3.41 mV, respectively.
Keywords :
II-VI semiconductors; MOSFET; aluminium; chemical sensors; glass; grain size; ion sensitive field effect transistors; pH measurement; thin films; wide band gap semiconductors; zinc compounds; MOSFET; constant voltage constant current readout circuit; current-voltage characteristics curves; glass extended-gate field-effect transistor; grain size; hysteresis effect; metal-oxide-semiconductor field-effect transistor; pH-sensing; power 100 W; pressure 10 mtorr; rf sputtering; semiconductor parameter analysis; size 204 nm; size 40 nm to 50 nm; thin film thickness; Glass; Hysteresis; Logic gates; MOSFET circuits; Sensors; Sputtering; Transistors; AZO; EGFET; hysteresis effect; pH sensitivity;
Conference_Titel :
Electric Information and Control Engineering (ICEICE), 2011 International Conference on
Conference_Location :
Wuhan
Print_ISBN :
978-1-4244-8036-4
DOI :
10.1109/ICEICE.2011.5777817
