Papers

ICMCTF2006 Session FP: FP Poster

Thursday, May 4, 2006 5:00 PM in Room Town & Country

Thursday Afternoon

Time Period ThP Sessions | Topic F Sessions | Time Periods | Topics | ICMCTF2006 Schedule

FP-1 Vacuum Electron Field Emission from SnO₂ Nanowhiskers Annealed in Oxygen and Nitrogen S.H. Luo (Shanghai Institute of Microsystem and Information Technology/Chinese Academy of Sciences, PR China); W. Liu, M. Zhang, Z. Di, C. Lin (Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, PR China); P.K. Chu (City University of Hong Kong, PR China) Tin oxide is known for its application in gas sensors, transparent conducting electrodes and dye-based solar cells. Our previous work has shown SnO₂ nanowhiskers are good electron emitters. However, the effects of surface states on the field emission properties have not been investigated. In this study OSnO₂ nanowhiskers are intentionally subjected to O₂ and N₂ annealing and the field emission properties of the annealed SnO₂ nanowhiskers are investigated. The current generated by the emission of electrons is observed to drastically increase and the threshold field defined as the emission current density at 1 µA/cm² is reduced from 3.17 of the as-grown sample to 2.59 V/µm of the sample annealed in N₂. The threshold field is increased to 3.63 V/µm after annealing in O₂. Analysis of the slope and intercept of the Fowler Nordheim plot reveals that the dependence of the threshold field on the surface treatment is due to the different work functions. Four transfer infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) results show that the amount of Sn-O bonds is reduced as N is introduced into the materials during annealing in N₂. High-resolution XPS results indicate that the binding energy of Sn 3d and O1s shift towards higher binding energies. For the sample annealed in O₂, the Sn-O bond i enhanced and the surface crystalline quality is improved. The binding energies of Sn 3d and O1s shift slightly towards lower binding energies. Our study shows that annealing in N₂ yields a surface that is locally terminated by N-O bonds. This increases field emission by raising the bands towards the vacuum level and lowering the emission barrier. Our results also show that annealing in O₂ can make the surface more chemically uniform and increase the emission barrier.
FP-6 Raman Spectra and Structural Analysis in ZrN_xO_y Thin Films P. Carvalho, C. Moura, L. Cunha, F. Vaz, L. Rebouta (Universidade do Minho, Portugal); E. Alves (Instituto Tecnológico Nuclear, Portugal) Raman spectroscopy has been used as a local probe to characterize the evolution of phases on the preparation and annealing of decorative zirconium oxynitride (ZrN_xO_y) thin films produced by dc reactive magnetron sputtering. The lines shapes, the frequency position and widths of the Raman bands show a systematic change as function of the reactive gas flow. The as-deposited zirconium nitride film presents a Raman spectrum with the typical broaden bands, due to the disordered induced by N vacancies. The recorded Raman spectrum of the zirconium oxide film is also typical of the monoclinic phase of ZrO₂. Raman spectra of zirconium oxyniride thin films present changes related with the oxygen content in films composition. These changes are confirmed by XPS analysis. XPS spectra reveal that the N 1s, O 1s and Zr 3d peaks evolution are well correlated with the structural changes of the coatings. The N1s peak is composed of two components, which are related with the two existing zirconium nitride phases (ZrN and Zr₃N₄). On the other hand, the Zr 3d peak shows a complex structure that can be ascribe as revealing the presence of nitride, oxynitride, and oxide phases.
FP-8 Asymmetric Synthesis of Terminal Epoxides and Diols in the Zeolite Membrane System using New Chiral Salen Catalyst Y.-H Lee, C.-K Shin, G.-J Kim (INHA University, Korea) The unsupported self-standing films of zeolite were obtained by in situ traditional wet hydrothermal synthesis.¹ The most zeolite crystals were grown in the form of aggregates. In order to obtain a high productivity, thin mesoporous layer was coated on zeolite membrane with a high catalyst volume fraction.² The enantioseletive hydrolytic resolution of racemic epoxides was performed in the ZSM-5/MCM-41 membrane system containing chiral salen complexes.³ The chiral salen complexes immobilized on the membrane showed a very high enantioselectivity in the hydrolysis of terminal epoxides such as epichlorohydrine, epoxybutane, styrene oxide and 1,2-epoxyhexane. The catalyst in membrane could be recycled again by filling the reactants in the separated reactor. The catalytic activity and selectivity of Co(salen) complexes have not changed more or less after four times of reusing. The catalytic membrane system allows to separate the reagents with markedly different polarities without the need for a mutual solvent and to increase the conversion of reactant. ¹T. Sano, Y. Kiyozumi, F. Mizukami, H. Takaya, T. Mouri and M. Watanabe, Zeolites, 12 (1992) 131 ² H.S. Roh, J. S. Chang, and S. E. Park, Korean J. Chem. Eng., 16 (1999) 331. ³ M.Tokunaga, J.F.Larrow, F. Kakiuchi and E. N. Jacobsen, SCIENCE, 277 (1997) 936. .
FP-9 Measurements and Modelling of the DC Temperature Dependence of Electrical Conductivity in Thin Films of Lead Phthalocyanine T.S. Shafai (Staffordshire University, United Kingdom); R.D. Gould (Keele University, United Kingdom) Many of the phthalocyanines exhibit p-type conductivity, and electrical conductivity through thin films of these materials having ohmic contacts show space-charge-limited conductivity (SCLC) dominated by trap levels located within the bandgap. In the present work evaporated thin films of lead phthalocyanine with ohmic gold electrodes were prepared, which showed two distinct regions in the dependence of current density J on applied voltage V. At low voltages sample conductivity was ohmic, changing at higher voltages to a square-law dependence of J on V, which is indicative of SCLC dominated by trap levels located at a single discrete energy level. The results of temperature measurements indicate three distinct regions, in each of which the hole concentrations are controlled by different activation energies. A simple model is proposed in which a single trap level is located at the same energy spacing E_t from the valence band edge as a single acceptor level. This predicts three different temperature ranges, two of which correspond to those covered by the experimental results. The experimental results indicate a trap level located at an energy E_t = 0.36 eV above the valence band edge and a thermal band gap E_g = 1.51 eV. Using the proposed model together with data from the experimental J-V characteristics, an acceptor concentration of 4.85 x 10¹⁹ m ^-3 and a trap concentration of 5.18 x 10²⁵ m^-3 are indicated. Measurements of mobility based on this model yield a value of 2.6 x 10^-4 m² V^-1 s^-1, which is in close agreement with previous work.
FP-10 Study of the Structure of BaTiO₃ Thin Films by Raman Spectroscopy J. Xu, D.P. Durisin, G.W. Auner (Wayne State University) Raman spectra of BaTiO₃ thin films grown on Si (100) substrate by pulsed laser deposition have been studied at room temperature. The films were deposited at different substrate temperature and oxygen pressure to investigate their influence on the film structure, and hence the Raman spectra. The Raman peaks attributed to the tetragonal ferroelectric phase of BaTiO₃ were identified. The peaks of impurity (non BaTiO₃) phases were observed. The films were also examined by several characterization methods. The polycrystalline structure of the films was determined by x-ray diffraction (XRD). The stoichiometric analysis was carried out by x-ray photoelectron spectroscopy (XPS). The variation of Raman spectra of the BaTiO₃ films grown at different deposition parameters was qualitatively consistent with XRD and XPS measurements performed on the same films. Results indicate that Raman spectroscopy has particular advantage for detecting low-concentration impurity phases of BaTiO₃ films.
FP-11 A Study of the Surface of Copper Phthalocyanine Thin Films Using Atomic Force Microscopy R.D. Gould, Q. Zhou, A. Milling (Keele University, United Kingdom) Copper phthalocyanine is an organic semiconductor whose surface conductivity varies in the presence of adsorbed gases. As a toxic gas sensor it has been successful in detecting NO₂ at a level of less than 1 ppm. To further characterise this material the surface morphology was investigated using atomic force microscopy (AFM). Twice-purified material was deposited by thermal evaporation onto glass substrates maintained at room temperature. The films were of typical thickness 100 nm and were deposited at rates of 0.3 - 0.5 nm s^-1. The samples were annealed for a period of 1 hour in nitrogen at various temperatures in the range 373 - 558 K and were characterised by X-ray diffraction (XRD) and AFM. There was a transition from the α-phase to the β-phase when annealed at 523 K and above, and the mean grain size progressively increased from about 20 nm to over 50 nm for annealing at 558 K. AFM images showed that the as-deposited films were composed of fine granules. When annealed above 423 K there was a clear increase in granular size which reflects the growth of crystallites. The topography of the films annealed at 523 K, where the XRD results showed an α-to-β phase transition, differed drastically from the others and showed a fine needle-like structure. Granular size exceeded the corresponding XRD crystallite size and it was concluded that each granule is composed of several crystallites. Higher magnification surface lattice images were obtained from β-phase single crystals and compared with those from β-phase films. Both showed the characteristic "herring-bone" molecular structure, with a distance between parallel stacks of 1.93 nm on the (001) surface. The surface lattice of the films had a disordered structure, with a higher concentration of defects, which it was concluded may act as a suitable site for gaseous adsorption.
FP-13 Fabrication of CoSi₂ Nanocrystals Embedded in SiO₂ with Memory Effect P.-H. Yeh, L.J. Chen (National Tsing Hua University, Taiwan); P.-T. Liu (National Chiao Tung University, Taiwan); T.-C. Chang (National Sun Yat- Sen University, Taiwan) CoSi₂ nanocrystals embedded in the SiO₂ layer exhibiting memory effect have been formed by dry oxidation of amorphous Si/Co/SiO₂ structure at 800°C. A pronounced capacitance-voltage hysteresis was observed with a memory window of 1.1 V under the 3-V programming voltage. The programming voltages of CoSi₂ nanocrystals are lower than the semiconductor nanocrystals (~7V). The processing of the structure is compatible with the current manufacturing technology of semiconductor industry.
FP-14 Comparison of Microstructure and Surface Evolutions for Nanolayered CrN/AlN and TiN/AlN Coatings at Elevated Temperatures S.-K. Tien, J.G. Duh (National Tsing Hua Univerisity, Taiwan) CrN/AlN and TiN/AlN multilayer coatings with modulation period of 4 nm and thickness ratio equal to 1.0 were manufactured by RF magnetron sputtering. Both films were annealed at temperatures of 800°C and 900°C in air and maintained for 1, 9, and 16 hrs. The microstructure evolutions of both coatings at as-deposited and heat treated conditions were identified by transmission electron microscope (TEM) and X-ray diffraction (XRD). The variation of surface roughness was measured by atomic force microscope (AFM). After heat treatment at 800°C for 1hr, the thick oxide layer around 200 nm was formed on the surface on TiN/AlN coating. The oxide layer of TiN/AlN coating was composed of two different regimes, including Al₂O₃ doped Ti on the top surface and crystalline TiO₂ layer between Al₂O₃ layer and nitride coating. On the other hand, an oxide layer smaller than 50 nm was revealed in CrN/AlN coating and was identified by EDX as the metal-deficient oxide layer. As a result, the CrN/AlN coating exhibited superior stability to TiN/AlN coating with the same modulation period.
FP-15 Structural Characterization of Sputter-Deposited Ba_{0.48√sub0.52}TiO₃/LaNiO₃ Artificial Superlattice Structure by X-Ray Reflectivity and Diffraction H.-Y. Lee, H.-J. Liu (National Synchrotron Radiation Research Center, Taiwan); K.-F. Wu, C.-H. Lee (National Tsing Hua University, Taiwan) Ba_{0.48√sub0.52}TiO₃/LaNiO₃ artificial superlattices with a symmetric sublayer structure were successfully fabricated on an Nb-doped SrTiO₃ (001) single-crystalline substrate with rf magnetron sputtering. X-ray reflectivity and high-resolution diffraction measurements were employed to characterize the microstructure of these films. Formation of a superlattice structure was confirmed from the appearance of Bragg peaks separated by Kiessig fringes in x-ray reflectivity curves and a diffraction pattern. The fitted result from x-ray reflectivity curves shows that the densities of the Ba_{0.48√sub0.52}TiO₃ and LaNiO₃ sublayers are slightly less than their bulk values. A proper conformal roughness between Ba_{0.48√sub0.52}TiO₃ and LaNiO₃ layers was observed through off-specular scattering. The appearance of discernible satellite peaks beside the main peak of the crystal truncation rod observed for deposited films clearly demonstrates that a well defined superlattice structure can be formed with rf sputtering. The artificial Ba_{0.48√sub0.52}TiO₃/LaNiO₃ superlattices exhibit a large dielectric constant and a small dielectric loss.
FP-17 Self-Assembled Epitaxial CoSi₂ Nanowires S.Y. Chen, L.J. Chen (National Tsing Hua University, Taiwan) Self-assembled sililicide nanowires have been widely investigated in rare-earth metal/Si and Ti/Si systems in the past. In these systems, the anisotropic lattice mismatch dominated the wire growth. However, similar investigations on some practical metal silicides, such as Co/Si and Ni/Si systems, have been scarce. In this work, we report the results of formation of self-assembled CoSi₂ nanowires on (001)Si. TEM was utilized to observe the morphology and probe the mechanisms of nanowire formation. The reactive deposition epitaxy (RDE) method was utilized to promote the formation of CoSi₂ nanowires. The presence of type-B silicide/Si interfaces could break the 4-fold symmetry of the (001) surface and lead to the wire-shaped growth of silicide islands. The deposition temperature, deposition rate, and thickness of metal films were found to greatly influence the morphology of the wires. The typical wires grown at 750°C have 10 nm in diameter and 200-300 nm in length.
FP-18 The Formation of Pb Nanowires on Zn Foil by Galvanic Displacement Using Zn as Reducing Agent C.Y. Wang, M.Y. Lu, L.J. Chen (National Tsing Hua University, Taiwan) A solution-phase method has been developed for the high yield synthesis of single crystalline nanowires of lead with ~10 µm and ~100 nm in length and width, respectively. The Pb nanowires formed via galvanic displacement reaction on the zinc foil using Zn as a reducing agent at room temperature. The length and width of such nanowires could be easily adjusted by the reaction time and lead nitrate concentration. Transmission electron microscopy and energy dispersive X-ray spectrometer analysis showed that the nanowires were single crystalline and the outer surface was covered with a thin amorphous layer composed of Pb, Zn and N. The morphology of Pb nanostructures is significantly influenced by the concentration and reaction time. Field-emission scanning electron microscopy showed that with increasing lead nitrate concentration, the morphology of Pb nanoplate converted to nanowire. For short reaction time, needlelike nanowires are dominant products as compared with long reaction time. The Pb nanowires may have interesting superconducting properties, which are currently under investigation.
FP-19 Characterization of Pd-Free Electroless Co Cap Selectively Deposited on Cu Surface via Borane-Based Reducing Agent S.-Y. Chang, C.-C. Wan, Y.-Y. Wang (Tsing-Hua University, Taiwan); C.-H. Shih (TSMC, Taiwan); M.-H. Tsai (Taiwan); S.-L. Shue, C.-H. Yu, M.-S. Liang (TSMC, Taiwan) Highly selective and self-activated (Pd-free) electroless Co-based deposition for copper-lines capping has been developed. The effects of incorporation of P, W and B in particular into Co deposit on its structure, film composition and effectiveness as capping layer were investigated. TEM image of its cross-section shows no extraneous deposition was observed, which translates to selective and direct deposition of the film on Cu surface. Results from GIXRD analysis on as-deposited Co-based films reveal that the introduction of B led to the formation of deposits with nanocrystalline or amorphous structure as indicated by the broadening of the diffraction peak. Such structure change very little after annealing over 400°C for 30 min. AES depth profiles also reveal uniform distribution of the elemental components and extremely low B content with incorporation of P. Additionally, Cu was not detected on Co film, indicating such films could serve as capping layer to inhibit copper diffusion.
FP-20 High-Performance Polycrystalline Silicon Thin Film Transistor with ONO Gate Dielectric and Multiple Nanowire Channels S.C. Chen (National Tsing Hua University, Taiwan); T.-C. Chang (National Sun Yat- Sen University, Taiwan); P.-T. Liu, Y.C. Wu, C.C. Tsai (National Chiao Tung University, Taiwan); T.S. Chang, C.H. Lien (National Tsing Hua University, Taiwan) This study first proposes a novel higher dielectric constant thin-film transistors (TFT's) structure with multiple nanowire channels which uses oxide/nitride/oxide (ONO) as gate dielectric. By using ONO-TFT's, On-current could be enhanced dramatically. Experimental results appear that the ONO structure increases the ON-current because of its higher effective capacitance. On the other hand, the width would be increased by increased the muti-channel numbers. Thus, the ON-current could be enhanced further more. The high performance of proposed ONO-TFT structure with muti-channel provides a good driving capability for AM-LCD technology.
FP-21 Applicaion of the Low Dielectric Methyl-silsesquiazane (MSZ) as Passivation Layer on TFT-LCD T.S. Chang (National Tsing Hua University, Taiwan); T.-C. Chang (National Sun Yat- Sen University, Taiwan); P.-T. Liu (National Chiao Tung University, Taiwan); C.Y. Chiang, S.C. Chen, F.S. Yeh (National Tsing Hua University, Taiwan) In this work, a low-k material, methylsilsesquiazane (MSZ) has been investigated as passivation dielectric layer on thin-film transistor (TFT) arrays. The characteristics of low-k film have been also studied, especially under visible light illumination and electric operation. Compared with the conventional nitride film (k~7), the MSZ passivation layer shows low residual stress and low dielectric constant (k~2.6) which lowers the RC delay in device. On the other hand, the high transmittance and good planarization characteristics of low-k MSZ film could enhance the brightness and aperture of thin-film transistors liquid crystal displays (TFT-LCDs).
FP-22 Oxygen Doping on the Structure and Properties of Nanocrystalline TiN_xO_y Thin Film S. Chiu, J.-H. Huang, G-.P. Yu (National Tsing Hua University, Taiwan) Nano-crystalline Ti N_xO_y films were deposited on AISI 304 stainless steel substrate using unbalanced magnetron sputtering (UBM) system. The effect of oxygen flow rate was investigated on the composition, structure, mechanical properties, and corrosion resistance of Ti N_xO_y films which based on the pervious optimum conditions of TiN film. The residual stress and preferred orientation of Ti N_xO_y films were determined using X-ray diffraction (XRD). Hardness of the films was measured using nano-indentation, and surface roughness observed by atomic force microscopy (AFM). The total residual stress of the film was measured by both optical method and modified sin method. The ratio of Ti/N/O and composition depth profiles in Ti N_xO_y thin film was obtained by X-ray photoelectron spectroscopy (XPS). The grain size of Ti N_xO_y films was ranged from 27 to 12 nm. The oxygen content of the thin film observed by XPS increased with the oxygen flow rate from 0.9% to 44 at % . As the oxygen content increased, the color of Ti N_xO_y films changed from golden yellow to blue and then to pink .The XRD results showed that preferred orientation of Ti N_xO_y films changed from (111) to (200) for the oxygen flow rate up to 0.5sccm; when oxygen flow rate was up to 1sccm, titanium oxide was observed. As the oxygen content in films increased, hardness and residual stress of films decreased. The corrosion resistance of Ti N_xO_y films was evaluated by salt spray test and potentiodynamic scan. Icorr decreased with increasing of oxygen content in Ti N_xO_y films. Electrical conductivity may be the major factor to affect corrosion resistance. The series of films exhibit a consistent relationship among structure, composition, hardness, and corrosion resistance for Ti N_xO_y.
FP-23 Growth of Parallel Erbium Silicide Nanowire Arrays on Flat Si(001) W.-C. Tsai, L.J. Chen (National Tsing Hua University, Taiwan) Rare-earth silicide nanowires grown on flat Si(001) surface at 500°C were studied by scanning tunneling microscopy. The wire-like structures were found to grow from single-row, double-row to three-row of Er atoms. Eventually, widen nanowires were found. The appearance of the shift in Si dimer rows is attributed to the formation of an ordered vacancy superstructure in the NWs. From studying STM images, the period of vacancy ordering structure of ErSi_2-x along c-axis was 2c.
FP-24 Fabrication of ZnO Nanoneedles by a Simple Solution Route Y.-C. Chang, H.-Y. Hsieh, L.J. Chen (National Tsing Hua University, Taiwan) ZnO nanostructures have been grown on ZnO-coated silicon substrate by a solution-phase approach at low temperature. The substrate was formed by spin coated zinc acetate and annealed at 300°C to provide nucleation sites for the growth of nanostructures. The ZnO nanostructure has a taper-like morphology. The diameters of the needle tips normally range from 10 to 50 nm and the lengths were about 1 - 2 µm. The morphologies and microstructures of ZnO nanoneedles are characterized by field-emission scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The present study achieved the control of ZnO morphologies from nanorods to nanoneedles in a sample hydrothermal process.
FP-25 The Study of Mg-Doped GaN Using Synchrotron X-ray Diffraction Anomalous Fine Structure and Traditional X-ray Diffraction Techniques C.-P. Chuang (National Tsing Hua University, Taiwan); H.-H. Hung, L.-Y. Jang (National Synchrotron Radiation Research Center, Taiwan); J.-H. Huang (National Tsing Hua University, Taiwan) Epitaxial GaN:Mg films grown by MOVPE were studied using synchrotron x-ray. Magnesium can change the stacking fault energy of either wurtzite or zinc-blende structures so as to make coexistence of two phases. The d-spacing difference between Z(111) and W(0001) was clearly resolved as 0.02 Å using high-resolution X-ray diffraction. With much increasing flow rate of Cp₂Mg, Mg ions plays an important role as nucleation center to generate prismatic step fronts and thus inverse domain boundaries. These Mg-rich defect phases of 8.4° tilted (10-11) orientation are coherent to the substitutional-interstitial model of Mg-complexes and well correlate to the prevailing of yellow band in the photoluminescence spectrum. In addition, according to DAFS results, apparent tensile strain and interstitial Mg have been observed only in these orientation-tilted structures.
FP-26 Study on Low Temperature SONOS Nonvolatile Memory Technology Using HDPCVD N₂O Plasma Oxidation C.-H. Chen (National Tsing Hua University, Taiwan); T.-C. Chang (National Sun Yat- Sen University, Taiwan); P.-T. Liu (National Chiao Tung University, Taiwan); J.-R. Chen (National Tsing Hua University, Taiwan) We proposed novel low temperature silicon-oxide-nitride-oxide-silicon (SONOS) nonvolatile memory technology. The tunneling oxide was formed by N₂O plasma oxidation using high density plasma chemical vapor deposition (HDPCVD). The thickness of oxidized film was found about 12nm after the N₂O plasma treatment with power 600w at 350⁰C for 5minutes. By Electron Spectroscopy for Chemical Analysis (ESCA), peak of Si-N bond was detected in N₂O plasma tunneling oxide layer. In addition, the oxide-nitride-oxide (ONO) stacked structure was also fabricated by HDPCVD system. By capacitance-voltage (C-V) measurement, the threshold voltage shift of ONO stacked structure was observed about 1.5V. It is more potential to integration nonvolatile memory into poly-Si thin film transistor circuits.
FP-27 Formation of Porous Structure of ZnO with the Nanosphere Pattern Template H.-Y. Hsieh, Y.-C. Chang, L.J. Chen (National Tsing Hua University, Taiwan) ZnO is a wide band gap material with potential application as photonic crystals and gas sensors. Larger-area ZnO pore arrays were prepared on the Si substrate. The precursor of the Zn(CH₃COO)₂ solution was dipped on the nanosphere pattern template. The precursor was deposited around the nanospheres to form the hexagonal networks. The morphology of the structure changed with the concentration of the precursor and the size of the nanosphere. For Zn(OH)₂ deposited in the space between the nanospheres and annealed at 300°C in the air, Zn(OH)₂ transferred to regular network ZnO. The corresponding cathodoluminescence is in the UV region.
FP-28 Characterization of Activation Processes of Porous Ti and Ti-Zr-V Getter Films by Synchrotron Radiation Photoemission Spectroscopy (SRPES) C.-C. Li, J.-L. Huang (National Cheng-Kung University, Taiwan); R.-J. Lin (Intellectual Property Exchange Limited, Taiwan) The essential requirements for the non-evaporable getter (NEG) material are the low activation temperature, short activation time and high pumping speed (high surface area, high solubility and diffusion rate for the absorbed molecules). It is known that a ternary alloy of titanium, zirconium and vanadium can be fully activated at low temperature. The activation conditions and activation mechanism are strongly related to the composition of the getters. Therefore, we try to study the activation condition and mechanism of porous Ti and TiZrV films. The highly porous Ti and TiZrV film getters on (100) silicon substrates have been successfully grown by the glancing angle deposition of dc magnetron sputtering method. The glancing angle is defined as the angle between the surface normal of the substrate and the surface normal of the target. The porous Ti and TiZrV films are composed of isolated nano-columnar crystalline crystals. The typical size and inter-distance of the columnar crystals of porous Ti and TiZrV films are (100 nm and 120 nm), and (30 nm and 15 nm), respectively. The thermal activation temperature of the porous Ti and TiZrV films were investigated by synchrotron radiation photoemission spectroscopy (SRPES) with different excitation energy to vary the surface sensitivity. The results show that the superficial oxide layer covering the air-exposed finally disappears via its progressive reduction during the thermal activation. The detailed results about the effects of activation temperature on the core level and valence band spectra of porous Ti, TiZrV films and their activation temperature will be presented.
FP-29 Synthesis and Characteristics of Polyimide/Titania Nano Hybrid Films M.-H. Tsai, S.-J. Lion, P.-H. Chang (National Chin Yi Institute of Technology, Taiwan) Polyimide/Titania nano hybrid films are synthesized by sol-gel technology. [4,4’-(4,4’-Isopropylidene diphenoxy) bis (phthalic anhydride)] (IDPA), 4,4’-Diaminodiphenyl ether (ODA) and 3-Aminopropyltrimethoxysilane (APrTMOS) mixed thoroughly and reacted. APrTMOS is a monofunctional amine monomer and used for controlling the block chain length of 5000-10000 g/mole for IDPA-ODA oligomer. And then tetraethyl orthotitanate (Ti(OEt)₄) and actylacetone, the latter is as chelating agent, are added and then polyamic acid are formed through sol-gel reaction. After imidization reaction at high temperature, cross-linked structure of Polyimide/Titania nano hybrid films are formed. Effect of composition, titania content and size, PI block chain length and cross-link density are studied on the dynamical mechanical strength, thermal property, surface property and adhesion strength to copper system. TiO₂ has been successfully introduced to the PI matrix by the FTIR measurement. Surface energy decreases as the block chain length and TiO₂ content increased, while Tg and storage modulus increased. The size of TiO₂ dispersed in PI matrix, which is shown by TEM, decreased as the APrTOMS content increased. And the adhesion strength to copper system will promoted also.
FP-32 Oxidation of Macroparticles in Chromium Nitride Films H.-Y. Chen (Asia University, Taiwan) The oxidation of macroparticles in chromium nitride films has examined by field emission scanning electron microscope. The films were prepared by catholic arc plasma deposition technique. After that, the films were annealed at 600 and 800°C for 2h in air. A very thin and dense oxide overlayer adhered to the macroparticle at 600°C. The macroparticle became porous structure and the radial equaxial grain oxide structure surrounded the macroparticle with a gap at 800°C, meanwhile the coarse grain oxide structure covered the surface. A possible oxidation processing of the macroparticle is also proposed.

Time Period ThP Sessions | Topic F Sessions | Time Periods | Topics | ICMCTF2006 Schedule