Browsing by Author "Lin, Chan Yu"

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Comparison of ZnO and Ti-doped ZnO sensing membrane applied in electrolyte-insulator-semiconductor structure
(2018-04-15)
Lee, Ming Ling
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Wang, Jer Chyi
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Kao, Chyuan Haur
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Chen, Hsiang
;
Lin, Chan Yu
In this paper, we demonstrate electrolyte-insulator-semiconductor devices for biochemical sensing applications prepared from ZnO and Ti-doped ZnO sensing membranes deposited on Si substrates by radio frequency sputtering. The structural, morphological, and compositional features of these deposited films with multitemperature annealing were studied using X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy, respectively. Sensitivity, linearity, hysteresis, and drift rate were measured to determine the sensing and reliability performance of all fabricated devices. Compared to the ZnO electrolyte-insulator-semiconductor (EIS), the Ti-doped ZnO EIS sensor annealed at 700 degrees C exhibits a higher sensitivity of 57.56 mV/pH, lower hysteresis of 2.79 mV, and lower drift rate of 0.29 mV/h. For Ti-doped ZnO, sensitivities of 3.62 mV/mM and 6.42 mV/mM were obtained for urea and glucose sensing, respectively. The improvements are owing to Ti-doping, which produces a rougher sensing surface, a well-crystallized grain structure, and thinner silicate and SiO2 at the silicon-oxide interface.
Physical and electrical properties of flash memory devices with nickel oxide(NiO2) charge trapping layer
(2017-06-01)
Lee, Ming Ling
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Chen, Hsiang
;
Kao, Chyuan Haur
;
Mahanty, Rama Krushna
;
Sung, Wei Kung
In this study, we proposed a metal-oxide high-k-oxide-silicon (MOHOS) memory device using a nickel oxide film as the charge trapping layer, and studied the effect of post-deposition rapid thermal annealing (RTA) on the physical and electrical properties. The physical properties were investigated via multiple material analysis techniques such as X-ray diffraction and atomic force microscopy. The optimal annealing temperature for depositing the charge trapping layer was determined through a thorough investigation of the memory window, program/erase (P/E) cycle, crystalline structure, and material composition. Compared to the as-deposited NiO2 film, a MOHOS-type memory device annealed at 900 degrees C in a nitrogen atmosphere exhibited improved memory characteristics, in terms of a larger window in the capacitance-voltage hysteresis, better data retention (lower charge loss of 11%), faster program and erase cycles, and endurance characteristics (104 P/E cycles) without any significant drift in the flat band voltage. Therefore, the MOHOS memory device with a NiO2 trapping layer is a very promising candidate for future memory device applications. (C) 2017 Elsevier Ltd. All rights reserved.
Sensing and structural properties of Ti-doped tin oxide (SnO2) membrane for bio-sensor applications
(2017-09-01)
Isabel, A. Panimaya Selvi
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Kao, Chyuan Haur
;
Mahanty, Rama Krushna
;
Wu, Yew Chung Sermon
;
Li, Chung Yi
We investigated the effect of rapid thermal annealing (RTA) on the sensing and structural characteristics of Ti-doped SnO2 based electrolyte-insulator-semiconductor (EIS) pH sensors. The Ti-doped Tin oxide (SnO2) EIS sensor annealed at 700 degrees C post deposition annealing, exhibits the best sensing characteristics in terms of sensitivity, linearity, hysteresis and drift rate. This derives from Ti incorporation that improves the thin-film stoichiometry by reducing dangling bonds on the dielectric surface and improves the temperature stability. We further studied the structural, compositional, and morphological characteristics of the deposited thin-film. RTA treatment increases the sensitivity and linearity by creating larger grain size and higher number of surface sites. Sodium (Na+) and potassium (K+) sensing performance was also measured using the fabricated EIS sensors.
The structural and electrical comparison of Y2O3 and Ti-doped Y2O3 dielectrics
(2017-02-15)
Lee, Ming Ling
;
Kao, Chyuan Haur
;
Chen, Hsiang
;
Lin, Chan Yu
;
Chung, Yu Teng
A Ti-doped Y2O3(Y2Ti2O5) dielectric on polycrystalline silicon followed by rapid thermal annealing results in improved characteristics including a higher effective dielectric constant, higher breakdown electric field, lower electron trapping rate, and larger charge-to-breakdown when compared with Y2O3. The performance of high-k Y2O3 and Y2Ti2O5 dielectrics were investigated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), capacitance-voltage, and current density-voltage. Incorporating Ti into the Y2O3 dielectric imparts improvements in the structural and electrical performance of the material. The Y2Ti2O5 dielectric with 800 degrees C annealing treatment has the best performance among all the samples tested.