Browsing by Author "Huang, Yu-Xiang"

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A study of heat transfer enhancement via corona discharge by using a plate corona electrode
(2017-06-01)
Tsui, Yeng-Yung
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Huang, Yu-Xiang
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Lan, Chao-Cheng
;
Wang, Chi-Chuan
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機械工程學系
This paper is concerned with the corona discharge used to enhance heat transfer. Both theoretical and experimental procedures are employed. To examine the heat transfer resulting from corona discharge, a thin plate is employed as the corona electrode and a heated plate is grounded to form the collecting electrode. Experiments show that the heat transfer coefficient at the center of the heated plate is increased by a factor in the range 2.6-4.8 times comparing with natural convection. Optical images reveal that corona discharge occurs at the two side corners of the plate electrode when the corona voltage is low and a bluish sheet of discharge issuing from the front edge of the electrode is visible at sufficiently high voltages. Comparison between predicted temperatures and measurements indicates that significant differences exist at low corona voltages and good agreement is obtained when the voltage is high enough. This result is mainly attributed to the 2-D assumption employed in the simulation and the heat loss appearing in the experiment. The corona discharge is stronger for small electrode gaps. However, the corona voltage allowed before formation of the electrical spark is higher for large electrode gaps, leading to better heat transfer. (C) 2017 Elsevier B.V. All rights reserved.
An Au-free GaN High Electron Mobility Transistor with Ti/Al/W Ohmic Metal Structure
(2015)
Yao, Jing-Neng
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Lin, Yueh-Chin
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Chuang, Yu-Lin
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Huang, Yu-Xiang
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Shih, Wang-Cheng
We demonstrate the Au-free GaN HEMT device with the Ti/Al/W Ohmic metal structure. Excellent surface roughness 4.88nm for Ti/Al/W Ohmic stucture was achieved after metallization. The DC characteristics is comparable with conventional HEMTs and the stress performance with high voltage is better than conventional HEMTs.
Au-Free GaN High-Electron-Mobility Transistor with Ti/Al/W Ohmic and WN (X) Schottky Metal Structures for High-Power Applications
(2016-07)
Hsieh, Ting-En
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Lin, Yueh-Chin
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Chu, Chung-Ming
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Chuang, Yu-Lin
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Huang, Yu-Xiang
In this study, an Au-free AlGaN/GaN high-electron-mobility transistor (HEMT) with Ti/Al/W ohmic and WNx Schottky metal structures is fabricated and characterized. The device exhibits smooth surface morphology after metallization and shows excellent direct-current (DC) characteristics. The device also demonstrates better performance than the conventional HEMTs under high voltage stress. Furthermore, the Au-free AlGaN/GaN HEMT shows stable device performance after annealing at 400A degrees C. Thus, the Ti/Al/W ohmic and WN (X) Schottky metals can be applied in the manufacturing of GaN HEMT to replace the Au based contacts to reduce the manufacturing costs of the GaN HEMT devices with comparable device performance.
GaN High-Electron-Mobility Transistor with WNx/Cu Gate for High-Power Applications
(2015-12-01)
Hsieh, Ting-En
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Lin, Yueh-Chin
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Li, Fang-Ming
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Shi, Wang-Cheng
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Huang, Yu-Xiang
A GaN high-electron-mobility transistor (HEMT) with WN (x) /Cu gate for high-power applications has been investigated. The direct-current (DC) characteristics of the device are comparable to those of conventional Ni/Au-gated GaN HEMTs. The results of high-voltage stress testing indicate that the device is stable after application of 200 V stress for 42 h. The WN (x) /Cu-gated GaN HEMT exhibited no obvious changes in the DC characteristics or Schottky barrier height before and after annealing at 250A degrees C for 1 h. These results demonstrate that the WN (x) /Cu gate structure can be used in a GaN HEMT for high-power applications with good thermal stability.
Improved linearity and reliability in GaN metal-oxide-semiconductor high-electron-mobility transistors using nanolaminate La2O3/SiO2 gate dielectric
(2016-04)
Hsu, Ching-Hsiang
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Shih, Wang-Cheng
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Lin, Yueh-Chin
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Hsu, Heng-Tung
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Hsu, Hisang-Hua
Improved device performance to enable high-linearity power applications has been discussed in this study. We have compared the La2O3/SiO2 AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors (MOS-HEMTs) with other La2O3-based (La2O3/HfO2, La2O3/CeO2 and single La2O3) MOS-HEMTs. It was found that forming lanthanum silicate films can not only improve the dielectric quality but also can improve the device characteristics. The improved gate insulation, reliability, and linearity of the 8 nm La2O3/SiO2 MOS-HEMT were demonstrated. (C) 2016 The Japan Society of Applied Physics
Improved linearity and reliability in GaN metal-oxide-semiconductor high-electron-mobility transistors using nanolaminate La2O3/SiO2 gate dielectric
(2016-04-01)
Hsu, Ching-Hsiang
;
Shih, Wang-Cheng
;
Lin, Yueh-Chin
;
Hsu, Heng-Tung
;
Hsu, Hisang-Hua
Improved device performance to enable high-linearity power applications has been discussed in this study. We have compared the La2O3/SiO2 AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors (MOS-HEMTs) with other La2O3-based (La2O3/HfO2, La2O3/CeO2 and single La2O3) MOS-HEMTs. It was found that forming lanthanum silicate films can not only improve the dielectric quality but also can improve the device characteristics. The improved gate insulation, reliability, and linearity of the 8 nm La2O3/SiO2 MOS-HEMT were demonstrated. (C) 2016 The Japan Society of Applied Physics