Browsing by Author "Wang, Bau-Ming"

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Effect of Ni residues on the performance and the uniformity of nickel-induced lateral crystallization polycrystalline silicon nanowire thin-film transistors
(2010-11-01)
Wang, Bau-Ming
;
Yang, Tzu-Ming
;
Wu, YewChung Sermon
;
Su, Chun-Jung
;
Lin, Horng-Chih
High performance nickel-induced lateral crystallization (NILC) polycrystalline silicon (poly-Si) nanowire (NW) thin-film transistors (TFTs) were fabricated. The phosphorous-doped amorphous silicon (alpha-Si)/chem-SiO(2) films were employed as Ni-gettering layers to investigate effect of Ni residues on the performance and the uniformity of NILC poly-Si NW TFTs. It was found that the performance and the uniformity of NW TFTs were greatly improved after Ni-gettering process. (C) 2010 Elsevier B.V. All rights reserved.
Effect of Ni residues on the performance and the uniformity of nickel-induced lateral crystallization polycrystalline silicon nanowire thin-film transistors
(2010-11-01)
Wang, Bau-Ming
;
Yang, Tzu-Ming
;
Wu, YewChung Sermon
;
Su, Chun-Jung
;
Lin, Horng-Chih
High performance nickel-induced lateral crystallization (NILC) polycrystalline silicon (poly-Si) nanowire (NW) thin-film transistors (TFTs) were fabricated. The phosphorous-doped amorphous silicon (alpha-Si)/chem-SiO(2) films were employed as Ni-gettering layers to investigate effect of Ni residues on the performance and the uniformity of NILC poly-Si NW TFTs. It was found that the performance and the uniformity of NW TFTs were greatly improved after Ni-gettering process. (C) 2010 Elsevier B.V. All rights reserved.
Enhanced Performance of LEDs Using Periodic Tent-Like Post Patterns on A-plane Sapphire Substrates
(2011-12-01)
Lin, Bo-Wen
;
Chang, Chung-Cheng
;
Hsieh, Cheng-Yu
;
Wang, Bau-Ming
;
Wu, YewChung Sermon
Periodic tent-like post patterns on a-plane sapphire substrates were fabricated using a two-step etching process. They were denoted as a-plane dot pattern sapphire substrate (ADPSS). Compared with the GaN-based light-emitting diode (LED) grown on a-plane sapphire without any pattern (AFlat), the ADPSS-LED has higher output power, light extraction efficiency (LEE), and external quantum efficiency (EQE), and better crystal quality. The output power of ADPSS-LED was 9.6 mW, which was 68.4% larger than the AFlat-LED. In addition, the blue shift of ADPSS-LED was found to be less than that of AFlat-LED.
Gettering of Ni from Nickel-Induced Lateral Crystallization Silicon Using Amorphous Silicon and Chemical Oxide
(2009)
Wang, Bau-Ming
;
Wu, YewChung Sermon
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Nickel contamination inside nickel-metal-induced lateral crystallization (NILC) polycrystalline silicon poses a problem in the fabrication of high-performance thin-film transistors. In this study, amorphous Si (alpha-Si) and chemical oxide (chem-SiO(2)) films were employed to reduce the impurity of Ni-metal within the NILC film. The top 100 nm thick alpha-Si layer served as a gettering layer, while the middle 5 nm thick chem-SiO(2) layer served as an etching stop layer. It was found that nickel contamination was greatly reduced after annealing at 550 degrees C for only 12 h.
Improved Gettering Efficiency of Ni from Nickel-Mediated Crystallization Silicon Using Phosphorus-Doped Amorphous Silicon
(2009-06-01)
Wang, Bau-Ming
;
Wu, Yewchung Sermon
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Ni-metal-induced lateral crystallization (NILC) has been utilized to fabricate polycrystalline silicon thin-film transistors. However, the NILC process often leads to Ni and NiSi(2) precipitates being trapped. In this study, two kinds of films were used as gettering layers: (1) amorphous Si and (2) phosphorus-doped amorphous Si. After annealing at 550A degrees C for 12 h, it was found that phosphorous dopant did improve the gettering efficiency of amorphous Si.
Improved Performance of NILC Poly-Si Nanowire TFTs by Using Ni-Gettering
(2010)
Wang, Bau-Ming
;
Yang, Tzu-Ming
;
Wu, YewChung Sermon
;
Su, Chun-Jung
;
Lin, Horng-Chih
Nickel contamination inside nickel-metal induced lateral crystallization polycrystalline silicon is an issue to fabricate high performance nanowire thin film transistors. The phosphorous-doped alpha-Si/chem-SiO2 films were employed as Ni-gettering layers to investigate effect of Ni residues on the performance of NILC poly-Si NW TFTs. It was found that the performance of NW TFTs was greatly improved after Ni-gettering process.
Improvement of Epitaxy GaN Quality Using Liquid-Phase Deposited Nano-Patterned Sapphire Substrates
(2012-12-15)
Hsieh, Cheng-Yu
;
Lin, Bo-Wen
;
Cho, Hsin-Ju
;
Wang, Bau-Ming
;
Chang, Nancy
A relatively simple and easy and inexpensive liquid-phase deposition (LPD) method is employed to introduce nanoscale silica hemispheres on sapphire substrates for fabricating a nano-patterned sapphire substrate (NPSS). Compared with GaN grown on sapphire without any pattern, the NPSS-GaN film is of much better quality as observed by scanning electron microscopy, transmission electron-microscopy, X-ray diffraction, cathodoluminescence, and photoluminescence. This is because GaN is initiated from the c-plane instead of the LPD-silica surface. In addition, many dislocations within the NPSS-GaN bend toward the patterns, or end at the GaN/void interfaces.
Investigation of GaN Films Grown on Liquid-Phase Deposited SiO2 Nanopatterned Sapphire Substrates
(2012)
Hsieh, Cheng-Yu
;
Lin, Bo-Wen
;
Cho, Hsin-Ju
;
Wang, Bau-Ming
;
Wu, YewChung Sermon
A simple, easy and relatively inexpensive liquid phase deposition (LPD) method was used to introduce nano SiO2 on sapphire substrates to fabricate nanoscale patterned sapphire substrates (PSS). Two kinds of nanoscale PSS were used to grow GaN, namely "NPOS" which is nano-pattern oxide on sapphire substrate and "NPSS" which is nano-patterned sapphire substrate. It was found that upper region of NPSS-GaN had the best quality. This is because as the growth time increased, laterally-grown GaN caused the threading dislocations to bend toward the patterns. Besides, voids formed on the NPSS pattern sidewalls caused more threading dislocation bending toward these voids. (C) 2012 The Electrochemical Society. All rights reserved.
Semipolar GaN Films on Prism Stripe Patterned a-Plane Sapphire Substrates
(2012)
Hsieh, Cheng-Yu
;
Lin, Bo-Wen
;
Cheng, Wen-Hao
;
Wang, Bau-Ming
;
Chang, Li
A (10 (1) over bar4) semipolar GaN layer was grown on periodic stripe patterned a-plane sapphire substrate fabricated by using two-steps etching process. The stripes in prism shape were inclined with sapphire c-axis in 60 degrees. The orientation relationship between semipolar GaN and sapphire is (0002)(GaN)//(2 (1) over bar(1) over bar(3) over bar)(sapphire) and [2 (1) over bar(1) over bar0](GaN)//[23 (5) over bar2](sapphire) as defined by selected area diffraction in transmission electron microscopy (TEM). Growth of semipolar GaN on the sidewalls of the prism stripes is evidenced from TEM and X-ray phi scan. The quality of semipolar GaN film is reasonably good as examined with X-ray rocking curves. In addition, TEM and cathodoluminescence results show that the dislocation density in the semipolar GaN is significantly reduced near the film surface. (C) 2012 The Electrochemical Society. All rights reserved.
The Formation and the Plane Indices of Etched Facets of Wet Etching Patterned Sapphire Substrate
(2012)
Chen, Yu-Chung
;
Hsiao, Feng-Ching
;
Lin, Bo-Wen
;
Wang, Bau-Ming
;
Wu, YewChung Sermon
A two-step chemical wet etching processes were used to investigated the formation and the plane indexes of exposed etched facets of wet etching patterned sapphire substrate (PSS). It was found when SiO2 mask still remained on the top c-plane, the structure of PSS comprised of a hexagonal pyramid covered with six facets {3 (4) over bar 17} with a flat top c-plane. When SiO2 mask were etched away, beside six facets on the bottom, there were 3 extra facets {1 (1) over bar 05} exposed on the top. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.095206jes] All rights reserved.
Using BCl3-Based Plasma to Modify Wet-Etching Pattern Sapphire Substrate for Improving the Growth of GaN-Based LEDs
(2013-02-15)
Lin, Bo-Wen
;
Niu, Chen-Yi
;
Hsieh, Cheng-Yu
;
Wang, Bau-Ming
;
Hsu, Wen-Ching
Wet-etching pattern sapphire substrates (PSS) have been used to grow GaN-based light-emitting diodes (LEDs). However, after wet etching, several sidewall facets are exposed on the patterns of PSS. These sidewall facets would grow zincblende GaN and form irregular voids. In this letter, BCl3-based plasma is used to solve this problem and improve the performance of GaN-based LEDs.
Using Phosphorus-Doped alpha-Si Gettering Layers to Improve NILC Poly-Si TFT Performance
(2010-02-01)
Wang, Bau-Ming
;
Wu, YewChung Sermon
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Ni-metal-induced lateral crystallization (NILC) has been utilized to fabricate polycrystalline silicon (poly-Si) thin-film transistors (TFTs). However, the current crystallization technology often leads to trapped Ni and NiSi(2) precipitates, thus degrading device performance. In this study, phosphorus-doped amorphous silicon (p-alpha-Si) and chemical oxide (chem-SiO(2)) films were used as Ni-gettering layers. After a gettering process, the Ni impurity within the NILC poly-Si film and the leakage current were both reduced, while the on/off current ratio was increased. This gettering process is compatible with NILC TFT processes and suitable for large-area NILC poly-Si films.