Browsing by Author "Chang, Chih-Pang"

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Amorphous Titanium Oxide Semiconductors on Quasi-Crystal-Like InGaZnO Channels for Thin Film Transistor Applications
(2015-06)
Hsu, Hsiao-Hsuan
;
Chiou, Ping
;
Cheng, Chun-Hu
;
Yen, Shiang-Shiou
;
Tung, Chien-Hung
This paper reports an InGaZnO thin-film transistor with titanium-oxide semiconductor as channel capping layer. Based on the experimental results, the titanium-oxide semiconductor has the function of not only a surface passivation layer to reduce the defect states localized at grain boundaries near source/drain contacts, but also a mobility booster to enhance electric field across channel. Compared to control IGZO TFT, the crystalline IGZO TFTs with titanium-oxide semiconductor exhibits an improved performance of a low drive voltage of <5 V, a low threshold voltage of 1.9 V, a low sub-threshold swing of 244 mV/decade, and a high mobility of 13.7 cm(2)/V s. The simple titanium-oxide capping process have been demonstrated in this work, which provides considerable potential for further display applications requiring a low power operation and a low-temperature fabrication.
Correlation of thermal annealing effect, crystallinity and electrical characteristics in c-axis crystallized InGaZnO thin-film transistors
(2015-09-15)
Hsu, Hsiao-Hsuan
;
Yen, Shiang-Shiou
;
Chiu, Yu-Chien
;
Chiou, Ping
;
Chang, Chun-Yen
A low off-state current of 1.6 x 10(-14) A/mu m and a small subthreshold gate swing of 152 mV/decade were achieved in a novel thin film transistor using a c-axis crystallized InGaZnO semiconductor that could be obtained at a low substrate temperature range of 150 degrees C. From experimental results, we found that the lowered off-state current is mainly attributed to the formation of rich Ga-O bonds to reduce oxygen vacancies, and the c-axis crystallized structure of IGZO to increase the potential barrier on the source side due to the increase of local trap states at the grain boundary. (C) 2015 Elsevier B.V. All rights reserved.
Effect of CF(4) Plasma on Properties and Reliability of Metal-Induced Lateral Crystallization Silicon Transistors
(2010-01-01)
Chang, Chih-Pang
;
Wu, YewChung Sermon
;
材料科學與工程學系
;
Department of Materials Science and Engineering
In this study, a CF(4) plasma etching treatment was applied to metal-induced lateral crystallization (MILC) polycrystalline silicon thin film transistors (poly-Si TFTs). It was found that the electrical properties and reliability of the MILC poly-Si TFTs were improved by the treatment. The minimum off-state currents were also reduced. This is because this etching method involves not only passivating the trap states but also etching away the Ni-related defects on the top surface of MILC poly-Si.
Effect of CF4 Plasma on Properties and Reliability of Metal-Induced Lateral Crystallization Silicon Transistors
(2010-01-01)
Chang, Chih-Pang
;
Wu, YewChung Sermon
;
材料科學與工程學系
;
Department of Materials Science and Engineering
In this study, a CF4 plasma etching treatment was applied to metal-induced lateral crystallization (MILC) polycrystalline silicon thin film transistors (poly-Si TFTs). It was found that the electrical properties and reliability of the MILC poly-Si TFTs were improved by the treatment. The minimum off-state currents were also reduced. This is because this etching method involves not only passivating the trap states but also etching away the Ni-related defects on the top surface of MILC poly-Si.
Electrical performance and thermal stability of MIC poly-Si TFTs improved using drive-in nickel induced crystallization
(2011-03-15)
Lai, Ming-Hui
;
Wu, Yew Chung Sermon
;
Chang, Chih-Pang
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Ni-metal-induced crystallization (MIC) of amorphous Si (alpha-Si) has been used to fabricate low-temperature polycrystalline silicon (poly-Si) thin-film transistors (TFTs). The current crystallization technology, however, often leads to trap Ni and NiSi(2) precipitates, which degrade the device performance. In this study, a new manufacturing method for poly-Si TFTs using drive-in Ni induced crystallization (DIC) was proposed. In DIC, F(+) implantation was used to drive Ni in the alpha-Si layer. It was found that the electrical performance (especially leakage current) and thermal stability of DIC-TFTs were improved due to the reduction of Ni concentration and passivation of trap states near the SiO(2)/poly-Si interface. (C) 2010 Elsevier B.V. All rights reserved.
Enhanced performance and reliability of NILC-TFTs using FSG buffer layer
(2012-02-15)
Chen, Chien-Chih
;
Wu, YewChung Sermon
;
Chang, Chih-Pang
;
材料科學與工程學系
;
Department of Materials Science and Engineering
A new manufacturing method for Ni-metal-induced lateral crystallization thin film transistors (NILC-TFTs) using fluorine-silicate-glass (FSG) was proposed. In FSG-TFTs, fluorine ion was implanted into the buffer oxide layer to form FSG before NILC processes. It was found FSG-TFTs exhibit high field-effect mobility, low threshold voltage, low subthreshold slope, high ON/OFF current ratio, low trap state density, low interface trap state density, and good reliability compared with typical NILC-TFTs. (c) 2011 Elsevier B.V. All rights reserved.
High Performance and Reliability of Poly-Si Thin-Film Transistors Using Nickel Drive-In Induced Laterally Crystallization
(2010)
Wu, YewChung Sermon
;
Chang, Chih-Pang
;
材料科學與工程學系
;
Department of Materials Science and Engineering
In this study, polycrystalline silicon thin film transistors using drive-in Ni induced lateral crystallization (DILC) was proposed. In DILC, F+ implantation was used to drive Ni in the alpha-Si layer. To reduce the Ni contamination, the remained Ni film was then removed, and subsequently annealed at 590 degrees C. It was found DILC TFTs exhibit high field-effect mobility, low threshold voltage, low subthreshold slope, high on-state current, lower trap state density, smaller standard deviations, and low off-state leakage current compared with conventional Ni-metal-induced lateral crystallization (MILC) TFTs.
Improved electrical characteristics and reliability of MILC poly-Si TFTs using fluorine-ion implantation
(2007-11-01)
Chang, Chih-Pang
;
Wu, YewChung Sermon
;
材料科學與工程學系
;
Department of Materials Science and Engineering
In this letter, fluorine-ion (F+) implantation was employed to improve the electrical performance of metal-induced lateral-crystallization (MILC) polycrystalline-silicon thin-film transistors (poly-Si TFTs). It was found that fluorine ions minimize effectively the trap-state density, leading to superior electrical characteristics such as high field-effect mobility, low threshold voltage, low subthreshold slope, and high ON/OFF-current ratio. F+-implanted MILC TFTs also possess high immunity against the hot-carrier stress and, thereby, exhibit better reliability than that of typical MILC TFTs. Moreover, the manufacturing processes are simple (without any additional thermal-annealing step), and compatible with typical MILC poly-Si TFT fabrication processes.
Improved Electrical Performance and Reliability of Poly-Si TFTs Fabricated by Drive-In Nickel-Induced Crystallization with Chemical Oxide Layer
(2011-06-01)
Lai, Ming-Hui
;
Wu, Yewchung Sermon
;
Chang, Chih-Pang
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Ni-metal-induced crystallization (MIC) of amorphous Si (alpha-Si) has been employed to fabricate low-temperature polycrystalline silicon thin-film transistors (TFTs). However, the Ni residues degrade the device performance. In this study, a new method for manufacturing MIC-TFTs using drive-in Ni-induced crystallization with a chemical oxide layer (DICC) is proposed. Compared with that of MIC-TFTs, the on/off current ratio (I (on)/I (off)) of DICC-TFTs was increased by a factor of 9.7 from 9.21 x 10(4) to 8.94 x 10(5). The leakage current (I (off)) of DICC-TFTs was 4.06 pA/mu m, which was much lower than that of the MIC-TFTs (19.20 pA/mu m). DICC-TFTs also possess high immunity against hot-carrier stress and thereby exhibit good reliability.
Improved Electrical Performance and Uniformity of MILC Poly-Si TFTs Manufactured Using Drive-In Nickel-Induced Lateral Crystallization
(2009-11-01)
Chang, Chih-Pang
;
Wu, YewChung Sermon
;
材料科學與工程學系
;
Department of Materials Science and Engineering
A new manufacturing method for polycrystalline silicon (poly-Si) thin-film transistors (TFTs) using drive-in nickel-induced lateral crystallization (DILC) was proposed. In DILC, a F(+) implantation was used to drive Ni in the alpha-Si layer. To reduce Ni contamination, the remained Ni film was then removed and subsequently annealed at 590 degrees C. It was found that DILC TFTs exhibit high field-effect mobility, low threshold voltage, low subthreshold slope, high ON-state current, lower trap-state density, smaller standard deviations, and low OFF-state leakage current compared with conventional Ni-metal-induced lateral crystallization TFTs.
Improved Electrical Performance of MILC Poly-Si TFTs Using CF(4) Plasma by Etching Surface of Channel
(2009-02-01)
Chang, Chih-Pang
;
Wu, YewChung Sermon
;
材料科學與工程學系
;
Department of Materials Science and Engineering
In this letter, a new manufacturing method for metal-induced lateral crystallization (MILC) polycrystalline silicon thin-film transistors (poly-Si TFTs) using CF(4) plasma was proposed. It was found that CF(4) plasma effectively minimizes the trap-state density by etching away the top surface of MILC and passivating the trap states, leading to superior electrical characteristics such as high field-effect mobility, low threshold voltage, low subthreshold slope, low leakage current, and high ON-/OFF-current ratio. CF(4)-Plasma MILC TFTs also possess high immunity against the hot-carrier stress and thereby exhibit better reliability than that of conventional MILC TFTs. Moreover, the manufacturing processes are simple (without any additional thermal annealing step) and compatible with MILC TFT processes.
Improved Electrical Performance of MILC Poly-Si TFTs Using CF4 Plasma by Etching Surface of Channel
(2009-02-01)
Chang, Chih-Pang
;
Wu, YewChung Sermon
;
材料科學與工程學系
;
Department of Materials Science and Engineering
In this letter, a new manufacturing method for metal-induced lateral crystallization (MILC) polycrystalline silicon thin-film transistors (poly-Si TFTs) using CF4 plasma was proposed. It was found that CF4 plasma effectively minimizes the trap-state density by etching away the top surface of MILC and passivating the trap states, leading to superior electrical characteristics such as high field-effect mobility, low threshold voltage, low subthreshold slope, low leakage current, and high ON-/OFF-current ratio. CF4-Plasma MILC TFTs also possess high immunity against the hot-carrier stress and thereby exhibit better reliability than that of conventional MILC TFTs. Moreover, the manufacturing processes are simple (without any additional thermal annealing step) and compatible with MILC TFT processes.
Improved uniformity and electrical performance of continuous-wave laser-crystallized TFTs using metal-induced laterally crystallized si film
(2008-11-01)
Chang, Chih-Pang
;
Wu, Yewchung Sermon
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Continuous-wave (CW) laser crystallization (CLC) of amorphous Si (alpha-Si) has previously been employed to fabricate high-performance low-temperature polycrystalline silicon (poly-Si) thin-film transistors (TFTs). Unfortunately, their uniformity was poor because the shape of the beam profiles was Gaussian. In this study, alpha-Si film was replaced by Ni-metal-induced laterally crystallized Si (MILC-Si). MILCLC-Si was MILC-Si irradiated by a CW laser (lambda approximate to 532 nm and power approximate to 3.8 W). It was found that the performance and uniformity of the metal-induced laterally crystallized continuous-wave laser crystallization - thin film transistors (MILCLC-TFTs) were much better than those of the CLC-TFTs. Therefore, the MILCLC-TFT is suitable for application in systems on panels.
Structural and electrical characteristics of thin film transistor employing an oriented crystalline InGaZnO channel
(2015-04-01)
Yen, Shiang-Shiou
;
Hsu, Hsiao-Hsuan
;
Chiou, Ping
;
Cheng, Chun-Hu
;
Tung, Chien-Hung
In this study, we investigate the impact of orientated crystalline InGaZnO (IGZO) thin film transistor. To evaluate interface thermodynamic stability of temperature-sensitive IGZO film, the film-structural stabilities of high-and low-indium-content InGaZnO were studied. With increasing annealing temperature up to 700 degrees C, the crystallinity becomes more pronounced while device electrical characteristics are further improved. We find that the apparently reduced off-state current can be attributed to the formation of c-axis-orientated crystalline located at the X-ray diffraction peak of (0, 0, 16). The performance improvements include a very low turn-on voltage close to zero voltage, a small subthreshold swing of 130mV/dec, and a low off-state current of 2.4 x 10(-14)A/mu m at a low operating voltage of 4V. (C) 2015 The Japan Society of Applied Physics