Browsing by Author "Pan, Tung-Ming"

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Al-SiO2-Y2O3-SiO2-poly-Si Thin-Film Transistor Nonvolatile Memory Incorporating a Y2O3 Charge Trapping Layer
(2013)
Pan, Tung-Ming
;
Yen, Li-Chen
;
Mondal, Somnath
;
Lo, Chieh-Ting
;
Chao, Tien-Sheng
In this letter, we investigate the structural properties and electrical characteristics of the Al-SiO2-Y2O3-SiO2-poly-Si (AOYOP) thin-film transistor (TFT) nonvolatile memory device. The composition of Y2O3 charge-trapping layer was analyzed using X-ray photoelectron spectroscopy. The Y2O3 AOYOP TFT memory device exhibited a large memory window of 2.5 V, a long charge retention time of ten years with a minimal charge loss of similar to 15%, and a better endurance performance for P/E cycles up to 10(5). (c) 2013 The Electrochemical Society. All rights reserved.
Development of High-kappa Eu2Ti2O7 EIS Devices Using Poly-N-isopropylacrylamide as an Enzyme Encapsulation Material for pH Detection and Uric Acid Biosensing
(2012-01-01)
Pan, Tung-Ming
;
Chang, Kung-Yuan
;
Wu, Min-Hsien
;
Tsai, Shiao-Wen
;
Ko, Fu-Hsiang
In this study, we proposed an electrolyte-insulator-semiconductor (EIS) device fabricating a high-kappa Eu2Ti2O7 sensing membrane deposited on Si substrates through cosputtering for pH detection and uric acid biosensing applications. The EIS device incorporating a high-kappa Eu2Ti2O7 sensing membrane annealed at 900 degrees C exhibited a higher sensitivity of 59.03 mV/pH, a smaller hysteresis voltage of 2.8 mV, and a lower drift rate of 0.586 mV/h compared to those of the other annealing temperatures. These results are attributed to the small number of crystal defects and the large surface roughness. Furthermore, for high-kappa Eu2Ti2O7 EIS-based biosensing application, a phase tunable poly-N-isopropylacrylamide (PNIPAAm) was used as an enzyme encapsulating material, making the loading and removal of a biological recognition element on a biosensor easily. In this study, a hybrid configuration of the high-kappa Eu2Ti2O7 EIS biosensor with an unease-immobilizing PNIPAAm film attached was established and was demonstrated for uric acid biosensing. The sensitivity of a Eu2Ti2O7 EIS biosensor was 17.6 mV/mM for uric acid concentrations ranging from 2 to 8 mM.
Effect of Sensing Film Thickness on Sensing Characteristics of Dual-Gate Poly-Si Ion-Sensitive Field-Effect-Transistors
(2014-12-01)
Yen, Li-Chen
;
Tang, Ming-Tsyr
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Tan, Chia-Ying
;
Pan, Tung-Ming
;
Chao, Tien-Sheng
We investigate the effect of sensing film thickness on the sensing characteristics of dual-gate (DG) poly-Si ion-sensitive field-effect transistors (ISFETs). The pH sensitivity (from 37.57 to 9.32 mV/pH) of the DG poly-Si ISFET device degrades with the increase in the sensing film thickness (from 20 to 120 nm), whereas hysteresis voltage (from 6.7 to 1.12 mV for a neutral to acid to alkaline to neural loop) and drift rate (from 13.47 to <3 mV/h at pH 7) improve accordingly. An improved hysteresis and drift phenomena are attributed to the reduction in top-gate capacitance of the sensing membrane, causing a smaller capacitive-coupling ratio (top-gate capacitance of sensing membrane to bottom-gate capacitance of tetraethylorthosilicate oxide).
Effect of Ti doping concentration on resistive switching behaviors of Yb2O3 memory cell
(2012-08-20)
Mondal, Somnath
;
Chen, Hung-Yu
;
Her, Jim-Long
;
Ko, Fu-Hsiang
;
Pan, Tung-Ming
We investigate the resistive memory switching behaviors of Yb2O3 thin films for different Ti-dopant concentrations. A higher doping concentration of 9.4% of Ti atom into Yb2O3 thin film causes the switching mechanism to change from bipolar to unipolar behavior. This is ascribed to different chemical compositions of the filament through the oxide film. The reset mechanism is associated with the annihilation of oxygen vacancies and other ionic and electronic defects within or near the interface area of oxide film for bipolar switching, while it is believed to be due to rupture of the conducting filament by local Joule heating effect for unipolar resistive switching. Furthermore, the incorporation of Ti atom into the Yb2O3 memory device exhibits improved electrical performances including low set/reset voltages and good endurance and retention characteristics. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4747695]
Effects of CF(4) Plasma Treatment on the Electrical Characteristics of Poly-Silicon TFTs Using a Tb(2)O(3) Gate Dielectric
(2010-07-01)
Pan, Tung-Ming
;
Li, Zhi-Hong
;
Deng, Chih-Kang
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this paper, we developed high-k Tb(2)O(3) poly-Si thin-film transistors (TFTs) using different CF(4) plasma power treatments. The high-k Tb(2)O(3) poly-Si TFT device with a 20-W plasma power exhibited better electrical characteristics in terms of a highly effective carrier mobility, a high-driving current, a low-threshold voltage, a small subthreshold slope, and a high I(ON)/I(OFF) current ratio. This result is attributed to the incorporation of fluorine atoms into the Tb(2)O(3)/poly-Si interface to reduce the trap-state density. The high-k Tb(2)O(3) poly-Si TFT prepared under a 20-W CF(4) plasma power also enhanced electrical reliabilities, including hot carrier and positive bias temperature instability. All of these results suggest that the CF(4) plasma-treated poly-Si Tb(2)O(3) TFT is a good candidate for high-performance low-temperature poly-Si TFTs.
Effects of CF4 Plasma Treatment on the Electrical Characteristics of Poly-Silicon TFTs Using a Tb2O3 Gate Dielectric
(2010-07-01)
Pan, Tung-Ming
;
Li, Zhi-Hong
;
Deng, Chih-Kang
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this paper, we developed high-k Tb2O3 poly-Si thin-film transistors (TFTs) using different CF4 plasma power treatments. The high-k Tb2O3 poly-Si TFT device with a 20-W plasma power exhibited better electrical characteristics in terms of a highly effective carrier mobility, a high-driving current, a low-threshold voltage, a small subthreshold slope, and a high I-ON/I-OFF current ratio. This result is attributed to the incorporation of fluorine atoms into the Tb2O3/poly-Si interface to reduce the trap-state density. The high-k Tb2O3 poly-Si TFT prepared under a 20-W CF4 plasma power also enhanced electrical reliabilities, including hot carrier and positive bias temperature instability. All of these results suggest that the CF4 plasma-treated poly-Si Tb2O3 TFT is a good candidate for high-performance low-temperature poly-Si TFTs.
Electrical and reliability characteristics of polycrystalline silicon thin-film transistors with high-kappa Eu2O3 gate dielectrics
(2012-04-23)
Yen, Li-Chen
;
Hu, Chia-Wei
;
Chiang, Tsung-Yu
;
Chao, Tien-Sheng
;
Pan, Tung-Ming
In this study, we developed a high-performance low-temperature polycrystalline silicon thin-film transistor (LTPS-TFT) incorporating an ultra thin Eu2O3 gate dielectric. High-kappa Eu2O3 LTPS-TFT annealed at 500 degrees C exhibits a low threshold voltage of 0.16 V, a high effective carrier mobility of 44 cm(2)/V-s, a small subthreshold swing of 142 mV/decade, and a high I-on/I-off current ratio of 1.34 x 10(7). These significant improvements are attributed to the high gate-capacitance density due to the adequate quality of Eu2O3 gate dielectric with small interfacial layer of effective oxide thickness of 2.5 nm. Furthermore, the degradation mechanism of positive bias temperature instability was studied for a high-k Eu2O3 LTPS-TFT device. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4705472]
High-kappa Eu2O3 and Y2O3 Poly-Si Thin-Film Transistor Nonvolatile Memory Devices
(2013-07-01)
Pan, Tung-Ming
;
Yen, Li-Chen
;
Huang, Sheng-Hao
;
Lo, Chieh-Ting
;
Chao, Tien-Sheng
In this paper, we have successfully fabricated low-temperature polycrystalline silicon thin-film transistor (LTPS-TFT) nonvolatile memory devices employing high-kappa Eu2O3 and Y2O3 films as the charge trapping layer. The LTPS-TFT memory device uses band-to-band tunneling-induced hot hole injection and gate Fowler-Nordheim injection as the program and erase methods, respectively. Compared with the Y2O3 film, the LTPS-TFT memory device using an Eu2O3 charge-trapping layer exhibited a lower subthreshold swing and a larger memory window, a smaller charge loss, and a better endurance performance, presumably because of the higher charge-trapping efficiency of the Eu2O3 film.
High-Performance Double-Gate alpha-InGaZnO ISFET pH Sensor Using a HfO2 Gate Dielectric
(2018-01-01)
Lu, Chih-Hung
;
Hou, Tuo-Hung
;
Pan, Tung-Ming
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this paper, we present a high-performance double-gate (DG) amorphous indium-gallium-zinc-oxide (alpha-InGaZnO) ion-sensitive field-effect transistor (ISFET) using three HfO2 gate dielectric thicknesses as a top gate (TG). The DG structure alpha-InGaZnO TFTs with a 40-nm TG HfO2 dielectric exhibited a small threshold voltage of 50 mV, a low subthreshold swing of 144.1 mV/decade, and a high ION/IOFF current ratio of 4.5x107. The alpha-InGaZnO ISFET prepared at the 40-nm HfO2 sensing membrane in the DG mode showed a pH sensitivity of 937 mV/pH, which is far more than the Nernst limit. The hysteresis and drift behaviors of DG ISFET fabricated with the 40-nm condition also showed relatively better chemical stability compared with other conditions.
Improvement in pH Sensitivity of Low-Temperature Polycrystalline-Silicon Thin-Film Transistor Sensors Using H-2 Sintering
(2014-03-01)
Yen, Li-Chen
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Tang, Ming-Tsyr
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Chang, Fang-Yu
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Pan, Tung-Ming
;
Chao, Tien-Sheng
In this article, we report an improvement in the pH sensitivity of low-temperature polycrystalline-silicon (poly-Si) thin-film transistor (TFT) sensors using an H-2 sintering process. The low-temperature polycrystalline-silicon (LTPS) TFT sensor with H-2 sintering exhibited a high sensitivity than that without H-2 sintering. This result may be due to the resulting increase in the number of Si-OH2+ and Si-O- bonds due to the incorporation of H in the gate oxide to reduce the dangling silicon bonds and hence create the surface active sites and the resulting increase in the number of chemical reactions at these surface active sites. Moreover, the LTPS TFT sensor device not only offers low cost and a simple fabrication processes, but the technique also can be extended to integrate the sensor into other systems.
Influence of Postdeposition Annealing on Physical and Electrical Properties of High-k Yb2TiO5 Gate Dielectrics
(2010)
Pan, Tung-Ming
;
Yen, Li-Chen
;
Chiang, Chien-Hung
;
Chao, Tien-Sheng
;
電子物理學系
The structure and electrical properties of a high-k Yb2TiO5 gate dielectric deposited on Si(100) substrates through reactive cosputtering were investigated. X-ray diffraction, X-ray photoelectron spectroscopy and atomic force microscopy were used to study the morphological and chemical features of these films as functions of the growth conditions. The Yb2TiO5 dielectrics annealed at 800 degrees C exhibited a thinner capacitance equivalent thickness, a lower gate leakage current, a smaller density of interface state, and a relatively lower hysteresis voltage compared to those at other annealing temperatures. These results are attributed to the formation of a rather well-crystallized Yb2TiO5 structure and composition.
Label-free and real-time detection of ferritin using a horn-like polycrystalline-silicon nanowire field-effect transistor biosensor
(2016-07)
Yen, Li-Chen
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Pan, Tung-Ming
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Lee, Chiang-Hsuan
;
Chao, Tien-Sheng
;
電子物理學系
In this paper, we used the horn-like polycrystalline-silicon nanowire field-effect transistor (poly-Si NW FET) biosensors to detect ferritin. It employs the trapezoidal-shape dummy gate structure fabricated at the spacer wire process to form the shape of horn-like nanowires. The horn-like poly-Si NW FET using a channel length of 2 mu m exhibited better electrical characteristics, such as a smaller threshold voltage of 1.1 V and a higher I-on/I-off of 3.47 x 10(5), compared to other channel lengths. In addition, the horn-like poly-Si NW FET sensor exhibited a high sensitivity of 133.47 mV/pH exceeding the Nernst limit. This result is attributed to the higher capacitive-coupling ratio (top-gate capacitance to bottom-gate capacitance). Moreover, we used a horn-like poly-Si NW FET biosensor to detect the ferritin in buffer solution due to its label-free, real-time, and high-sensitive. We modified 3-aminopropyltriethoxysilane on the SiO2/Si3N4/SiO2 stacked surface followed by glutaraldehyde functionalized, and the ferritin antibodies were immobilized on the aldehyde terminal. While the serum ferritin antigen was prepared in the buffer, the results indicated that the sensor could detect serum ferritin below 50 pg/mL in a micro-fluidic channel. (C) 2016 Elsevier B.V. All rights reserved.
Label-free Detection of Prostate Specific Antigen Using a Silicon Nanobelt Field-effect Transistor
(2012-05-01)
Wu, Chi-Chang
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Pan, Tung-Ming
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Wu, Chung-Shu
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Yen, Li-Chen
;
Chuang, Cheng-Keng
In this study, we proposed a silicon nanobelt field-effect transistor (FET) to detect prostate specific antigen (PSA). The nanobelt FET device displayed n-channel depletion characteristics. The immobilization of prostate specific antibody (anti-PSA) molecules was attached onto the nanobelt FET surface by using the aldehyde groups of glutaraldehyde linked to the amino groups of 3-aminopropyltriethoxysilane (APTES). The shift in the drain current vs time curves of a nanobelt FET biosensor revealed that the electrical signal had a logarithmic relationship with respect to the concentration of the PSA, and detection capability was estimated in the 5 pg/mL level. To enhance the sensitivity of a nanobelt FET biosensor, this biosensor was designed by inserting arginine molecules between glutaraldehyde and APTES. Therefore, the detection capability of the developed sensor was extended to 50 fg/mL. Also, the relationship between the current shift and the logarithm of PSA concentration was exhibited linearity in the range 50 fg/mL - 500 pg/mL. The excellent electrical results of this label-free PSA nanobelt FET biosensor suggested that such biosensor might be potentially useful tools for biological research and future prostate cancer screening.
Low-Voltage InGaZnO Ion-Sensitive Thin-Film Transistors Fabricated by Low-Temperature Process
(2016-12)
Lu, Chih-Hung
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Hou, Tuo-Hung
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Pan, Tung-Ming
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this brief, we developed a low-voltage (V-DS = 0.5 V and V-GS = 0.8 V) InGaZnO ion-sensitive thin-film transistor (ISTFT) sensor using a high-kappa HfO2 sensing membrane grown by low-temperature atomic layer deposition. The InGaZnO TFT exhibited a low threshold voltage of 0.2 V, a high field-effect mobility of 5.9 cm(2)/V-s, a small subthreshold swing of 90 mV/decade, and high I-ON/I-OFF ratio of 2.4x10(7). The pH sensor based on an InGaZnO ISTFT device exhibits a high sensitivity of 60.5 mV/pH and good linearity in the pH range from 3 to 11. Moreover, such a pH ISTFT sensor presents a hysteresis width of 8 mV after a pH loop of 7 -> 4 -> 7 -> 10 -> 7 and a low drift rate of 2.5 mV/h at pH 7.
Metal-Semiconductor-Metal Photocurrent Chip for Hydrogen Peroxide and Biomolecular Sensing with Chemiluminescence
(2014-01-01)
Ko, Fu-Hsiang
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Lin, Ching-Chang
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Sun, Da-Shiuan
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Pan, Tung-Ming
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材料科學與工程學系
Photodetectors are generally the most promising, representative and widely-used type of detectors, and the applications of photodetectors are quite extensively. Photodetectors are made of photosensitive elements which are able to turn the light signal into electrical signal. Owing to the nature of fast responding speed and capability of large volume manufacturing, it provides photodetectors an advantageous future in biomedical sensing territory. This study focuses on fabrication method of the flexible photodetectors and application to biomolecule sensing through luminescence. The photosensitive element is based on silicon wafer which is treated with chemical etching process to achieve pliable characteristic. Then, the metal-semiconductor- metal structural flexible photodetectors are achieved after integrated with simple fabricating processes. The accomplished devices are handled with immobilization steps to fix the target enzyme which is able to catalyze the luminescent reaction. We provide a portable biomolecule sensor with outstanding flexible characteristic and high sensitivity and it exhibits illustrious stable consequence in various situations.
Real-Time and Label-Free Detection of the Prostate-Specific Antigen in Human Serum by a Polycrystalline Silicon Nanowire Field-Effect Transistor Biosensor
(2013-08-20)
Huang, Yu-Wen
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Wu, Chung-Shu
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Chuang, Cheng-Keng
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Pang, See-Tong
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Pan, Tung-Ming
In this research, we used a polycrystalline silicon nanowire field-effect transistor (poly-Si NWFET) as a biosensor that employs the sidewall spacer technique instead of an expensive electron beam lithography method. When compared with commercial semiconductor processes, the sidewall spacer technique has the advantages of simplicity and low cost. hi this study, we employed a novel poly-Si NWFET device for real-time, label-free, and ultrahigh-sensitivity detection of prostate-specific antigen (PSA) in human serum. Since serum proteome is very complex containing high levels of salts and other interfering compounds, we hereby developed a standard operating procedure for real-sample pretreatment to keep a proper pH value and ionic strength of the desalted serum and also utilized Tween 20 to serve as the passivation agent by surface modification on the NWFET to reduce nonspecific binding for medical diagnostic applications. We first modified 3-aminopropyltriethoxysilane on the surface of a poly-Si nanowire device followed by glutaraldehyde functionalization, and the PSA antibodies were immobilized on the aldehyde terminal. While PSA was prepared in the buffers to maintain an appropriate pH value and ionic strength, the results indicated that the sensor could detect trace PSA at less than 5 fg/mL in a microfluidic channel. The novel poly-Si NWFET is developed as a diagnostic platform for monitoring prostate cancer and predicting the risk of early biochemical relapse.
Resistive Switching Characteristics of Tm2O3, Yb2O3, and Lu2O3-Based Metal-Insulator-Metal Memory Devices
(2012-09-01)
Pan, Tung-Ming
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Lu, Chih-Hung
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Mondal, Somnath
;
Ko, Fu-Hsiang
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生物科技學系
In this paper, we investigated the electroforming-free resistive switching (RS) behavior in the Ru/RE2O3/TaN (rare-earth, RE, RE = Tm, Yb, and Lu) memory device fabricated with full room temperature process. The conduction mechanism of RE2O3 - based memory devices in the low-resistance state is ohmic emission, whereas Tm2O3, Yb2O3, and Lu2O3 memory devices in the high-resistance state are space charge limited conduction (SCLC), ohmic behavior, and SCLC, respectively. The Ru/Lu2O3/TaN device showed a high-resistance ratio of similar to 10(4), a high device yield of similar to 70%, a good data retention as long as 10(5) s measured at 85 degrees C, and a reliable endurance for up to 100 cycles, suggesting the optimal chemical defects (metallic Lu and nonlattice oxygen ion) in Lu2O3 film. All of these results suggest that Ru/Lu2O3/TaN structure memory is a good candidate for future nonvolatile RS memory applications.
Structural and Electrical Properties of High-k HoTiO3 Gate Dielectrics
(2010)
Pan, Tung-Ming
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Yen, Li-Chen
;
Hu, Chia-Wei
;
Chao, Tien-Sheng
;
電子物理學系
We developed a high-k HoTiO3 gate dielectric deposited on Si (100) through reactive cosputtering. They found that the HoTiO3 dielectrics annealed at 800 degrees C exhibited excellent electrical properties such as high capacitance value, small density of interface state, almost no hysteresis voltage, and low leakage current. This phenomenon is attributed to the decrease in intrinsic defect due to the formation of well-crystallized HoTiO3 structure and composition.
Surface Cleaning of the Nanowire Field-Effect Transistor for Gene Detection
(2011-12-01)
Wu, Chi-Chang
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Liu, Fu-Ken
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Lin, Ling-Hung
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Pang, See-Tong
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Chuang, Cheng-Keng
The efficiency of DNA immobilization by using various surface cleaning methods is studied in this work. The degree of surface cleaning is evaluated by the surface tension measurement to reveal the contribution from the polar and apolar terms. The observation from the fluorescent microscope images indicates the effectiveness of surface clean by the acetone and ethanol mixtures, as well as the sulphuric acid and hydrogen peroxide mixtures. We also fabricate a series of back-gated, 60-nm nanowired (NW) field-effect transistor (FET) sensors for mutation gene detection by following the developed acetone and ethanol mixtures. Electrical properties of the NWFET sensor demonstrate the n-channel depletion characteristics. The current of the sensor is reduced once the attachment of negative charge molecules. The single-stranded capture DNA is chemically immobilized onto the surface of silicon NWFET by three-step reactions. The sensor surface demonstrates the great performance of current shift after the suitable cleaning. The NWFET sensor is successfully applied to detect the BRAF(V599E) mutation genes from the hybridized processes. The sensing behaviour estimated from the electrical signal reaches the femtomolar level.
Surface Effect of Assembling Enzyme and Modulation of Surface Enzyme Activity with Electric Potential Stress
(2012-06-01)
Chao, Cheng-Han
;
Li, Kun-Lin
;
Wu, Chung-Shu
;
Lee, Cheng-Che
;
Chiang, Han-Ping
The fluorescent marker of rhodamine B amine is successfully used to evaluate the immobilization capability onto silicon-based patterns fabricated by semiconductor manufacturing. Only the silicon dioxide surface, by means of fluorescent observation, can immobilize the rhodamine molecule by the sequential linkage of (3-aminopropyl) triethoxysilane (APTES) and glutaraldehyde. The phenol sulfotransferase enzyme is also successfully immobilized onto the silicon dioxide surface by the linking molecules of APTES and sulfosuccinimidyl 4-(N-maleimidomethyl)-cyclohezane-1-carboxylate in the home-made apparatus. The enzyme activity of the sulfotransferase is determined from the absorbance of 4-nitrophenol at 400 nm wavelength. The surface immobilized enzyme remains its activity for catalytic reaction at least 120-min duration. The surface saturation effect on the activity of immobilized enzyme is explained and ascribed to the surface diffusion effect of electric double layers. We can success control the surface immobilized enzyme by electric potential stress. The activity of enzyme is reduced under negative potential, while is enhanced under positive potential. The electric potential can induce the enzyme structure variation and modulate the enzyme activity due to the electrostatic effect.