Browsing by Author "Wang, JL"

Now showing 1 - 5 of 5

Characteristics of (Pb, Sr)TiO3 films post treated by low temperature technologies
(2004)
Wang, JL
;
Jan, CK
;
Shye, DC
;
Kuo, MW
;
Cheng, HC
The novel annealing technologies, rapid thermal annealing (RTA) and excimer laser annealing (ELA) at low substrate temperature (300degreesC), were applied on the (Pb, Sr)TiO3 (PSrT) films. The PSrT film post treated by ELA only exhibits ferroelectric property and lager dielectric constant than as-deposited PSrT film. The PSrT film post treated by RTA only shows poor P-E curve and large leakage current. Interesting, the electrical properties of the PSrT film can be greatly enhanced by both of the ELA and the succeeding RTA treatments, so ferroelectric properties and dielectric constant can be reached as high as 15 muC/cm(2) of P-s and 574 of dielectric constant. In this work, excellent electrical properties of PSrT film post treated by both of ELA and succeeding RTA at low substrate temperature were systematically studied.
Correlation between N 1s XPS binding energy and bond distance in metal amido, imido, and nitrido complexes
(2003-07-28)
Wu, JB
;
Lin, YF
;
Wang, JL
;
Chang, PJ
;
Tasi, CP
Synchrotron-based X-ray photoelectron spectroscopy is used to measure N 1s binding energies of several metal amido, imido, and nitrido complexes of group 5 and 6 metals. The N 1s binding energy decreases as the formal M-N bond order increases. A simple correlation between the contraction of the M-N bond and the lowering of binding energy is also observed. This correlation supports a notion that the bonding character of a linear metal-imido linkage resembles that of a metal-nitrido linkage closely.
Interlayer growth and electrical behavior of Ta2O5/SiOxNy/Si gate stacks
(2004)
Lai, YS
;
Chen, JS
;
Wang, JL
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Growth and reaction of the interlayer (IL) between ultrathin Ta2O5 films and bare, and N2O or NH3 plasma-nitrided Si substrate, before and after rapid thermal oxidation (RTO), is examined by X-ray photoelectron spectroscopy. The IL thickness extracted from the attenuated Si 2p photoelectron signal shows that the thermal instability between Ta2O5 and Si causes the IL to grow further after RTO annealing. The SiOxNy layer formed on the N2O plasma-nitrided Si appears to provide better barrier efficiency in retarding the growth of IL. For current-voltage measurements, an anomalous saturated current is observed for as-deposited Ta2O5 films when stressed positive bias, presumably due to the film/substrate stress-induced Si bandgap widening. After RTO annealing, the leakage current through Ta2O5/IL stacks is higher under positive bias than under negative bias. Ta2O5 deposited on N2O-nitrided Si also exhibits the best leakage behavior among the three systems with the current of 1.7 x 10(-8) A/cm(2) at E = 2.0 MV/cm and 1.9 x 10(-7) A/cm(2) at E = +2.0 MV/cm. The correlation between leakage current as well as IL growth is also discussed. (C) 2004 The Electrochemical Society.
Syntheses of nano-sized cubic phase early transition metal carbides from metal chlorides and n-butyllithiurn
(2002-08-01)
Chang, YH
;
Chin, CW
;
Chen, YC
;
Wu, CC
;
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.
Thermal decomposition mechanisms of tungsten nitride CVD precursors on Cu(111)
(2006-02-01)
Yang, YW
;
Wu, JB
;
Wang, JL
;
Lin, YF
;
Chiu, HT
Chemisorption and thermal decomposition of metallorganic chemical vapor deposition precursors, (t-BuN)(2)W(NHBu-t)(2), bis(tertbutyl imido) bis(tert-butylamido) tungsten (BTBTT) and (t-BuN)(2)W(NEt2)(2), bis(tert-butylimido)bis(diethylamido)tungsten (BTBDT), on Cu(111) have been investigated by means of thermal desorption spectroscopy (TDS) and synchrotron-based X-ray photoelectron spectroscopy (SR-XPS) under ultrahigh vacuum conditions. The precursors remain intact upon chemisorption on Cu(111) at 100 K, and at 300 K both precursors decompose readily via the characteristic hydride abstraction/elimination pathways to produce two stable surface intermediates for each precursor. For BTBTT, one species is W(=NBu-t)(3) and the other is proposed to be a bridged amido complex, [(t-BuN)(2)W(mu-NBu-t)](2). In comparison, a W-imine complex and a W-N-C metallacycle are two intermediates produced from BTBDT, Annealing toward 800 K further decomposes the intermediates and the detectable desorption species are completely derived from the ligands. The desorption products from BTBTT include t-butylamine generated from alpha-H abstraction, isobutylene from gamma-H elimination, acetonitrile from beta-methyl elimination.. and molecular hydrogen. In addition to these desorption species, BTBDT produces hydrogen cyanide and imine (EtN = CHMe) via beta-H elimination, not possible with BTBTT due to the absence of beta-H in the ligands. Eventually, tungsten nitrides incorporating oxygen atoms and a small amount of graphitic carbons are formed and the stoichiometry is approximated as WN1.5O0.1. Oxygen incorporation, driven by a large oxide formation enthalpy, is sensitively dependent on the moisture exposure in UHV environment. (c) 2005 Elsevier B.V. All rights reserved.