Browsing by Author "Lin, Je-Wei"

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Enhancement of Open-Circuit Voltage Using CF4 Plasma Treatment on Nitric Acid Oxides
(2013-05-01)
Lin, Je-Wei
;
Wu, Chien-Hung
;
Wu, Sheng-Wei
;
Hseih, Wei-Ping
;
Du, Chen-Hsu
Surface passivation of solar cells is investigated using CF4 plasma treatment on low-temperature oxides to enhance the open-circuit voltage of the solar cells. Low-temperature oxides grown by a nitric acid solution are treated with the CF4 plasma. Solar cells undergoing this scheme show an improved performance, including low-saturation current density and good quantum efficiency at short wavelengths. Experimental results demonstrate that the CF4 plasma pretreatment on low-temperature oxides can significantly improve the open-circuit voltage, short-circuit current, and fill factor for silicon wafer-based solar cells. This technique is very promising for in-line solar cell manufacturing.
Formation of inverted-pyramid structure by modifying laser processing parameters and acid etching time
(2011)
Lin, Je-Wei
;
Liu, En-Ting
;
Wu, Chien-Hung
;
Hsieh, Ing-Jar
;
Chao, Tien-Sheng
This paper is to investigate the possibility to fabricate the inverted-pyramid structure on silicon wafer base solar cell by using laser scribing technology. The UV spectrometer and SEM had also been used to observe the reflectance and microstructure of the wafer surface. In this experiment, a Q-switched Nd:YAG laser operating at wavelength of 1064nm is used to scribe on the p-type wafer surface to produce inverted-pyramid structure. In order to remove the laser damage, we used acid etching and Alkaline etching solutions to smooth the damage region and inverted pyramid structure formed, simultaneously.
High-Performance Poly-Si Thin-Film Transistors With L-Fin Channels
(2012-02-01)
Lu, Yi-Hsien
;
Kuo, Po-Yi
;
Lin, Je-Wei
;
Wu, Yi-Hong
;
Chen, Yi-Hsuan
For the first time, we construct poly-Si thin-film transistors (TFTs) with novel L-shaped poly-Si fin channels (poly-Si TFTs with L-fin channels, called LFin-TFTs). The L-fin channels of LFin-TFTs are similar to the multiple-gated fin channels of FinFETs. The LFin-TFTs exhibit a low supply gate voltage (3 V), a good subthreshold swing (SS) similar to 190 mV/dec, and a high on/off current ratio (I-ON/I-OFF) > 10(6) (V-D = 1 V) without hydrogen-related plasma treatments. After Ni salicidation, the devices exhibit steep SS similar to 148 mV/dec and I-ON/I-OFF similar to 10(7). After NH3 plasma treatment, the characteristics of the devices are further improved. The LFin-TFTs have steeper SS similar to 132 mV/dec, higher I-ON/I-OFF > 10(7), and threshold voltage (V-TH) similar to 0.036 V.
Improved Rear-Side Passivation by Atomic Layer Deposition Al2O3/SiNx Stack Layers for High V-OC Industrial p-Type Silicon Solar Cells
(2013-09-01)
Lin, Je-Wei
;
Chen, Yi-Yang
;
Gan, Jon-Yiew
;
Hseih, Wei-Ping
;
Du, Chen-Hsu
This research develops high open-circuit voltage (V-OC) p-type industrial screen-printed silicon solar cells using improved rear surface passivation. It shows a significant improvement in the minority carrier lifetime by low temperature (<450 degrees C) thermal atomic layer deposition of Al2O3 layers and plasma-enhanced chemical vapor deposition of SiNx passivation layers. An increase in the V-OC and the short-circuit current (J(SC)) due to an improved long-wavelength response are also demonstrated. With the optimized stack layers, a high efficiency of 19.2% across a large area (156 cm(2)) is seen. Furthermore, the rear-side passivation scheme can be easily integrated into the conventional screen-printed process. This is very promising for in-line solar cell manufacturing.
Oxide Thinning and Structure Scaling Down Effect of Low-Temperature Poly-Si Thin-Film Transistors
(2012-01-01)
Ma, William Cheng-Yu
;
Chiang, Tsung-Yu
;
Lin, Je-Wei
;
Chao, Tien-Sheng
;
電子物理學系
In this paper, the gate oxide thickness, and the channel length and width of low-temperature poly-Si thin-film transistors (LTPS-TFTs) have been comprehensively studied. The scaling down of gate oxide thickness from 50 to 20 nm significantly improves the subthreshold swing (S. S.) of LTPS-TFTs from 1.797 V/decade to 0.780 V/ decade and the threshold voltage V(TH) from 10.87 V to 5.00 V. Moreover, the threshold voltage V(TH) roll-off is also improved with the scaling down of gate oxide thickness due to gate capacitance density enhancement. The channel length scaling down also shows significant subthreshold swing S. S. improvement due to a decreasing of the channel grain boundary trap density. However, the scaling down of channel length also increases the series resistance effect, resulting in the degradation of the field-effect mobility mu(FE). Therefore, the channel length dependence of field-effect mobility mu(FE) is slightly different with different channel width due to the competition of channel grain boundary trap density effect and series resistance effect.
Reliability Analysis of Symmetric Vertical-Channel Nickel-Salicided Poly-Si Thin-Film Transistors
(2012-08-01)
Wu, Yi-Hong
;
Lin, Je-Wei
;
Lu, Yi-Hsien
;
Kuo, Rou-Han
;
Yen, Li-Chen
"In this paper, a reliability analysis of symmetric Vertical-channel Ni-SAlicided poly-Si thin-film transistors (VSA-TFTs) is performed for the first time. First, we compare the drain-induced barrier-lowering effect (DIBL) of VSA-TFTs. The VSA-TFTs with thinner gate oxide thickness, an offset structure, and a longer floating n(+) region have better immunity to DIBL. Second, VSA-TFTs with a longer floating n(+) region also have better immunity under hot-carrier (HC) stress and self-heating (SH) stress. However, VSA-TFTs with a shorter floating n(+) region also have better immunity to positive gate bias (PGB) stress. Consequently, in order to optimize reliability characteristics, including SH stress, HC stress, and PGB stress, it is necessary to modulate the length of the floating n(+) region. Third, the PGB stress, rather than SH stress or HC stress, becomes a major issue for VSA-TFTs under the stress bias below 4 V. In other words, PGB stress will dominate the degradation behaviors when the stress bias is not high enough to achieve SH stress and HC stress. Finally, the worst degradation condition of VSA-TFTs under HC stress, similar to that of most TFT devices, occurs when the stress of V-G is less than half of V-D"
The Effect of Different Carrier Gases and Channel Thicknesses on the Characteristics of ZnO TFTs Prepared by Atmospheric Pressure Plasma Jet
(2011)
Chang, Kow-Ming
;
Huang, Sung-Hung
;
Chi, Chia-Wei
;
Wu, Chin-Jyi
;
Lin, Je-Wei
Thin film transistors (TFTs) with a ZnO channel layer deposited by atmospheric pressure plasma jet (APPJ) were demonstrated. ZnO channel layers were fabricated with a non-vacuum and low-temperature process (100 degrees C). The effects of different carrier gases (nitrogen gas and compressed dry air) and channel thickness on the characteristics of ZnO TFTs were investigated. Reactive oxygen species can effectively repair the oxygen vacancies result in a low leakage current. By reducing the channel thickness, the undesired source to drain current flow can be eliminated. By using CDA as a carrier gas and reducing the channel thickness, a subthreshold swing of 3.75 V/decade, a field-effect mobility of 3.49 cm(2)/Vs and a Ion/Ioff current ratio of 4.08x10(7) were obtained.
The effect of thermal annealing on the properties of IGZO TFT prepared by atmospheric pressure plasma jet
(2012)
Wu, Chien-Hung
;
Chang, Kow-Ming
;
Huang, Sung-Hung
;
Deng, I-Chung
;
Wu, Chin-Jyi
We fabricated bottom gate TFTs with IGZO channel layer deposited by atmospheric pressure plasma jet (APPJ). The effect of thermal annealing on the properties of IGZO TFTs was studied. After post annealing, the IGZO thin films showed a smooth and dense structure. The transistors annealed at 300 degrees C showed clear switching behavior with a negative threshold voltage of -0.571 V and a mobility of 2.6 cm(2)/V-s. After 500 degrees C post annealing, IGZO thin film showed an amorphous-like phase and the average transmittance is more than 80% in the visible range. Good electrical characteristics were achieved, including a threshold voltage of 6.74V, a subthreshold swing of 1.54 V/dec, a mobility of 10.31 cm(2)/V-s and a large I-on/I-off ratio of 3.28x10(8).
Transparent conductive indium-doped zinc oxide films prepared by atmospheric pressure plasma jet
(2011-05-31)
Chang, Kow-Ming
;
Huang, Sung-Hung
;
Wu, Chin-Jyi
;
Lin, Wei-Li
;
Chen, Wei-Chiang
Atmospheric-pressure plasma processing has attracted much interest for industrial applications due to its low cost, high processing speed and simple system. In this study, atmospheric-pressure plasma jet technique was developed to deposit indium-doped zinc oxide films. The inorganic metal salts of zinc nitrate and indium nitrate were used as precursors for Zn ions and In ions, respectively. The effect of different indium doping concentration on the morphological, structural, electrical and optical properties of the films was investigated. Grazing incidence X-ray diffraction results show that the deposited films with a preferred (002) orientation. The lowest resistivity of 1.8 x 10(-3) Omega cm was achieved with the 8 at.% indium-doped solution at the substrate temperature of 200 degrees C in open air, and average transmittance in the visible region was more than 80%. (C) 2011 Elsevier B.V. All rights reserved.