Browsing by Author "Tsai, CP"

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An acoustic echo canceller using lapped orthogonal transform
(1997)
Wei, CH
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Tsai, CP
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交大名義發表
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電子工程學系及電子研究所
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National Chiao Tung University
In the teleconference system or the hands-free telephone, the speech broadcasted from the loudspeaker can be transformed back to the talker as a far-end talker-echo. The far-end talker-echo can be eliminated by an acoustic echo canceller. An acoustic echo canceller based on the lapped orthogonal transform (LOT) using discrete Walsh-Hadamard transform (DWHT) as the building block for the fast algorithm is presented. The new structure can provide better ERLE and tracking capability than the structure using the LOT presented by Malver [6]. The computation complexity of the new structure is much lower than the orthogonal transform LMS structure.
Electrical characteristics of low temperature polysilicon TFT with a novel TEOS/oxynitride stack gate dielectric
(2003-08-01)
Chang, KM
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Yang, WC
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Tsai, CP
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電子工程學系及電子研究所
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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.
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
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Yang, WC
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Tsai, CP
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電子工程學系及電子研究所
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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.
Syntheses of nano-sized cubic phase early transition metal carbides from metal chlorides and n-butyllithiurn
(2002-08-01)
Chang, YH
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Chin, CW
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Chen, YC
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Wu, CC
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Tsai, CP
Nano-sized early transition metal carbides, including TiC, ZrC, HfC, V4C3, NbC and TaC, were synthesized from colloidal precursors generated by reducing the metal chlorides, TiCl4, ZrCl4, HfCl4, VCl3, NbCl5, and TaCl5, respectively, with n-C4H9Li in hexane. The colloids were formed from the reduction of the metal centers, which then nucleated into nano-scaled metal clusters. The major byproducts were LiCl, C4H10, and C4H8, indicating that the butyl groups probably underwent beta-hydrogen elimination and reductive elimination. This suggests that C-C bond activation of the butyl groups was in operation, leaving residual carbon atoms in the metal colloids. The colloids were further heated at 873-1273 K to crystallize into cubic phase TIC, ZrC, HfC, V4C3, NbC and TaC nanoparticles.
Tetrahydrofuran activation assisted synthesis of nanosized lithium niobate and lithium tantalate
(2006-04-01)
Chien, CH
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Chang, YH
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Tsai, CP
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Peng, CW
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Wang, LS
Black solid precursors obtained from reactions between MCl5 (M = Nb, Ta) and alkyllithiums, n-butyllithium ((BuLi)-Bu-n) and ethyllithium (EtLi), in tetrahydrofuran (THF) were heat treated under vacuum at 673-973 K to form nano-sized particles (20-100 nm in diameter) of lithium niobate (LiNbO3) and lithium tantalate (LiTaO3). Stoichiometry of the reactants is critical and affects the phases of the products. Based on the volatile byproducts detected, a reaction pathway involving the activation of THF by alkyllithiums is proposed to be important for the formation of LiNbO3 and LiTaO3 precursors.