Browsing by Author "Yang, WC"

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1.0 nm oxynitride dielectrics prepared by RTP in mixtures of N-2 and O-2 ambient
(2004)
Chang, KM
;
Yang, WC
;
Chen, CF
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This work presents a reliable method of growing aggressively scaled, 1.0 nm thick, gate dielectric in mixtures of N-2 and O-2 ambient at 900degreesC for 15 s by rapid thermal processing (RTP). These oxynitride films have excellent interface properties, 100 times lower leakage current density, and better charge trapping properties than rapid thermal oxidation SiO2 of identical thickness prepared in pure O-2 ambient. The effect of interfacial nitrogen concentration on the device characteristics with gate oxynitride films grown in various N-2/O-2 gas flow ratios was also investigated. The results demonstrate that the uniform nitrogen content increases with the N-2/O-2 gas flow ratio and that high-quality oxynitride films can be obtained by RTP in an optimum gas flow ratio of N-2/O-2 = 5/1 (slm). (C) 2004 The Electrochemical Society.
Electrical and reliability characteristics of 1nm ultrathin oxynitride gate dielectric prepared by RTP
(2003)
Yang, WC
;
Chen, CF
;
Chang, KM
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Ultra low leakage and highly reliable 1 nm gate oxynitride films were successfully developed. Ultrathin oxynitride films were prepared by RTP in N-2/O-2 = 5/1 (slm) optimum mixed gas ambient These films show excellent interface properties, significantly low gate leakage current, and superior enhanced reliability. Moreover, interface trap generation under higher field stressing was also investigated.
Electrical characteristics of low temperature polysilicon TFT with a novel TEOS/oxynitride stack gate dielectric
(2003-08-01)
Chang, KM
;
Yang, WC
;
Tsai, CP
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This investigation is the first to demonstrate a novel tetraethylorthosilicate. (TEOS)/oxynitride stack gate dielectric for low-temperature poly-Si (LTPS) thin film transistors (TFTs), composed, of a plasma-enhanced chemical vapor deposition (PECVD) thick TEOS oxide/ultrathin oxynitride grown by. PECVD N2O-plasma. The stack oxide shows a very high electrical breakdown field of 8.4 MV/cm, which is approximately 3 MV/cm larger than traditional PECVD TEOS oxide. The field effective mobility of stack oxide UPS TFTs is over 4 times than that of traditional TEOS oxide UPS TFTs. these. improvements are attributed to the high quality N2O-plasma grown ultrathin oxynitride forming strong Si drop N bonds, as well as to reduce the trap density in the dxynitride/poly-Si interface.
High-performance RSD poly-Si TFTs with a new ONO gate dielectric
(2004-06-01)
Chang, KM
;
Yang, WC
;
Hung, BF
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This paper developed a novel polycrystalline silicon (poly-Si) thin-film transistor (TFT) structure with the special features: 1) a new oxide-nitride-oxynitride (ONO) multilayer gate dielectric to reduce leakage current, improved breakdown characteristics, and enhanced reliability; and 2) raised source/drain (RSD) structure to reduce series resistance. These features were used to fabricate high-performance RSD-TFTs with ONO gate dielectric. The ONO gate dielectric on poly-Si films shows a very high breakdown field of 9.4 MV/cm, a longer time dependent dielectric breakdown, larger QBD, and a lower charge-trapping rate than single-layer plasma-enhanced chemical vapor deposition tetraethooxysilane oxide or nitride. The fabricated RSD-TFTs with ONO gate dielectric exhibited excellent transfer characteristics, high field-effect mobility of 320 cm(2) /V . s, and an on/off current ratio exceeding 10(8).
High-performance RSD poly-Si TFTs with a new ONO gate dielectric
(2004-06-01)
Chang, KM
;
Yang, WC
;
Hung, BF
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This paper developed a novel polycrystalline silicon (poly-Si) thin-film transistor (TFT) structure with the special features: 1) a new oxide-nitride-oxynitride (ONO) multilayer gate dielectric to reduce leakage current, improved breakdown characteristics, and enhanced reliability; and 2) raised source/drain (RSD) structure to reduce series resistance. These features were used to fabricate high-performance RSD-TFTs with ONO gate dielectric. The ONO gate dielectric on poly-Si films shows a very high breakdown field of 9.4 MV/cm, a longer time dependent dielectric breakdown, larger QBD, and a lower charge-trapping rate than single-layer plasma-enhanced chemical vapor deposition tetraethooxysilane oxide or nitride. The fabricated RSD-TFTs with ONO gate dielectric exhibited excellent transfer characteristics, high field-effect mobility of 320 cm(2) /V . s, and an on/off current ratio exceeding 10(8).
Low-temperature poly-Si thin-film transistor with a N2O-plasma ONO multilayer gate dielectric
(2004)
Chang, KM
;
Yang, WC
;
Hung, BF
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
High-performance polycrystalline silicon (poly-Si) thin-film transistors (TFTs) with oxide/nitride/oxynitride (ONO) multilayer gate dielectrics were fabricated. The low-temperature (less than or equal to300degreesC) ONO multilayer dielectric uses three stacked layers: the bottom layer is a very thin N2O-plasma oxynitride deposited by plasma-enhanced chemical vapor deposition (PECVD), the middle layer is PECVD Si3N4, and the top layer is tetraethoxysilane (TEOS) oxide. The ONO gate dielectric on poly-Si films shows a very high breakdown field of 9.4 MV/cm, a longer time-dependent dielectric breakdown lifetime and a lower charge trapping rate than single-layer PECVD TEOS oxide or nitride. The fabricated poly-Si TFTs with ONO gate dielectric exhibited excellent transfer characteristics, high field-effect mobility of 213 cm(2)/V s, and an ON/OFF current ratio of over 10(8). (C) 2004 The Electrochemical Society.
Performance and reliability of low-temperature polysilicon TFT with a novel stack gate dielectric and stack optimization using PECVD nitrous oxide plasma
(2004-01-01)
Chang, KM
;
Yang, WC
;
Tsai, CP
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This paper proposes a novel tetraethylorthosilicate (TEOS)/oxynitride stack gate dielectric for low-temperature poly-Si thin-film transistors, composed of a plasma-enhanced chemical vapor deposition (PECVD) thick TEOS oxide/ultrathin, oxynitride grown by PECVD N2O plasma. The novel stack gate dielectric exhibits a very high electrical breakdown field of 8.5 MV/cm, which is approximately 3 MV/cm higher than traditional PECVD TEOS oxide. The novel stack oxide also has better interface quality, lower bulk-trap density, and higher long-term reliability than PECVD TEOS dielectrics. These improvements are attributed to the formation of strong Si drop N bonds of high quality ultra-thin oxynitride grown by PEVCD N2O plasma, and the reduction in the trap density at the oxynitride/poly-Si interface.
Polyacetylenic compounds and butanol fraction from Bidens pilosa can modulate the differentiation of helper T cells and prevent autoimmune diabetes in non-obese diabetic mice
(2004-11-01)
Chang, SL
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Chang, CLT
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Chiang, YM
;
Hsieh, RH
;
Tzeng, CR
\Compelling evidence suggests that infiltrating CD4(+) type I helper T (Th1) cells in the pancreatic islets play a pivotal role in the progression of diabetes in non-obese diabetic (NOD) mice. We demonstrate in the present report that a butanol fraction of B. pilosa suppressed the development of diabetes, helped maintain levels of blood sugar and insulin in NOD mice in a dose-dependent manner and elevated the serum IgE levels regulated by Th2 cytokines in NOD mice. Moreover, the butanol fraction inhibited the differentiation of naive helper T (Th0) cells into Th1 cells but enhanced their transition into type II helper T (Th2) cells using an in vitro T cell differentiation assay. Two polyacetylenic compounds, 2-beta-D-glucopyranosyloxy-1-hydroxy-5(E)-tridecene-7,9,11-triyne and 3-beta-D-glucopyranosyloxy-1-hydroxy-6(E)-tetradecene-8,10,12-triyne, identified from the butanol fraction also prevented the onset of diabetes like the butanol fraction. The latter compound showed a stronger activity for T cell differentiation than the former. In summary, the butanol fraction of B. pilosa and its polyacetylenes can prevent diabetes plausibly via suppressing the differentiation of Th0 cells into Th1 cells and promoting that of Th0 cells into Th2 cells.
The changing effect of N-2/O-2 gas flow rate ratios on ultrathin nitrogen-enriched oxynitride gate dielectrics
(2004)
Chang, KM
;
Yang, WC
;
Chen, CF
;
Hung, BF
;
電子工程學系及電子研究所
We report the growth of an ultrathin 1.0 nm (equivalent oxide thickness = 0.86 nm) oxynitride gate dielectric by rapid thermal processing (RTP) in high-N-2 but low-O-2 gas flow ambient. The effect of the changing N-2/O-2 gas flow ratio on the characteristics of oxynitride films was investigated. High-quality oxynitride film could be formed by RTP in an optimum N-2/O-2 gas flow ratio of 5/1. Detailed characterization (transmission electron microscopy, J-E capacitance-voltage, stress-induced leakage current, charge-trapping properties! demonstrated the high quality of the oxynitride dielectric and showed that low leakage current density J(g) = 0.1 A/cm(2) at 1 V, was 1.85 orders of magnitude lower than that of SiO2. These improvements are attributed to the presence of nitrogen at the interface and in the bulk of the oxynitride. (C) 2004 The Electrochemical Society.
The design of a bionic sensory chip based on the CNN model derived from the mammalian retina
(2003)
Yang, WC
;
Lin, LJ
;
Wu, CY
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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 work, a bionic sensory chip based on the CNN model derived from the mammalian retina is proposed. A CMOS compatible sensory chip is designed based on the CNN model to mimic functions of photoreceptor and horizontal cell of the mammalian retina. The sensory chip contains a focal plane array of 32x32 similar pixels that perform functions of photoreceptor and horizontal cell. Spatial and temporal characteristics of a one-dimensional array are verified via HSPICE simulations in this paper, while a two-dimensional array of 32x32 cells is to be fabricated to investigate real-time images obtained by this bionic sensory chip.
The distinct effects of a butanol fraction of Bidens pilosa plant extract on the development of Th1-mediated diabetes and Th2-mediated airway inflammation in mice
(2005)
Chang, CLT
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Kuo, HK
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Chang, SL
;
Chiang, YM
;
Lee, TH
Bidens pilosa is claimed to be useful for immune or anti-inflammatory disorders; however, little scientific evidence has been published concerning its function. In this paper., immune disease mouse models were used to study the function of a butanol fraction of B. pilosa. We demonstrated treatment with the butanol fraction of B. pilosa ameliorated Th1 cell-mediated autoimmune diabetes in nonobese diabetic (NOD) mice but caused deterioration of Th2 cell-mediated airway inflammation induced by ovalbumin (OVA) in BALB/c mice. We next showed that Th2 cytokines (IL-4 and/or IL-5) increased but Th1 cytokine (IFN-gamma) decreased following injections with the butanol fraction of B. pilosa in both mouse strains. Accordingly, Th2 cytokine-regulated IgE production in mouse serum increased following treatment with this fraction. Finally, we found that the butanol fraction of B. pilosa inhibited Th1 cell differentiation but promoted Th2 cell differentiation. Taken together, the butanol fraction of B. pilosa has a dichotomous effect on helper T cell-mediated immune disorders, plausibly via modulation of T cell differentiation.