共查询到20条相似文献,搜索用时 234 毫秒
1.
Chang Young KimR. Navamathavan Heang Seuk LeeJong-Kwan Woo Myung Taek HyunKwang-Man Lee Won Young JeungChi Kyu Choi 《Thin solid films》2011,519(20):6732-6736
Low-dielectric constant SiOC(H) films were deposited on p-type Si(100) substrates by plasma-enhanced chemical-vapor deposition (PECVD) using dimethyldimethoxy silane (DMDMS, C4H12O2Si) and oxygen gas as precursors. To improve the physicochemical properties of the SiOC(H) films, the deposited SiOC(H) films were exposed to ultraviolet (UV) irradiation in a vacuum. The bonding structure of the SiOC(H) films was investigated by Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The electrical characterization of SiOC(H) films were carried out through I-V measurements using the comb-like patterns of the TiN/Al/Ti/SiOC(H)/TiN/Al/Ti metal-insulator-metal (MIM) structure. Excessive UV treatment adversely affected the SiOC(H) film, which resulted in an increased dielectric constant. Our results provide insight into the UV irradiation of low-k SiOC(H) films. 相似文献
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P.S. Hoffmann N.I. FainerO. Baake M.L. KosinovaY.M. Rumyantsev V.A. TrunovaA. Klein B. PollakowskiB. Beckhoff W. Ensinger 《Thin solid films》2012,520(18):5906-5913
SiCxNy thin films were produced by plasma-enhanced chemical vapor deposition and characterized by ellipsometry, Fourier transform infrared and Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, as well as, by near-edge X-ray absorption fine structure measurements in total-reflection X-ray fluorescence geometry. The temperature of synthesis was varied between 100 °C and 800 °C, the precursors hexamethyldisilazane or hexamethylcyclotrisilazane were used with an addition of N2, He, and NH3, respectively. The composition of the products was determined to be constant in Si with about 20 at.%, whereas the sum of C and N results in 80 at.% (each varying between 20 and 60 at.%). Consequently, it can be stated, that in the produced silicon carbonitride a network of Si is built with SiCSi, SiCCSi, and SiNSi bridges. The comparison of the chemical composition and of the physical properties shows for the samples produced with He or N2, respectively (without NH3) that the refractive index and the absorption coefficient are increasing with an increasing content of carbon in the final formula SiC4 − nNn (with n = 1, 2, or 3). 相似文献
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Doping of AsSSe amorphous films by silver photo-dissolution leads to a decrease of the optical gap and to an increase of the refractive index in forming AgAsSSe films. The difference of the optical gap and refractive index between undoped and doped films has been found in case of Ag15As26S29Se30 film up to 0.37 eV and 0.26, respectively. Transreflectance in far infrared spectral region indicates formation of AgAsS2 and AgAsSe2 entities in Ag15As26S29Se30 film. Scanning probe microscopy, namely atomic force microscopy, atomic force acoustic microscopy (AFAM) and Kelvin probe force microscopy (KPFM) was used for studying AgAsSSe films. It was found that silver growth is rather three dimensional and it is reminiscent of the Stranski-Krastanov growth mode. Observed silver protuberances represent silver reservoirs responsible for a local increase of silver content. Hence, the silver growth mode enhances formation of nano/meso inhomogeneities of the surface and near surface density/stiffness, seen in AFAM, and in the surface electric potential, seen in KPFM. 相似文献
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Perovskite structure-based ceramic precursors have a characteristic property of substitution in the ‘A’ site of the ABO3 structure. This makes them a potential material for nuclear waste management in synthetic rock (Synroc) technology. In order to simulate the mechanism of rare earth fixation in perovskite, PrxCa1−xTiO3 (where x = 0.1) has been synthesized through ceramic route by taking calculated quantities of oxides of Ca, Ti and Pr as starting materials. The ceramic phase has been characterized by its powder diffraction pattern. The Rietveld analysis of the X-ray diffraction data has been carried out using GSAS software to achieve the convergence which gives the Rp = 5.74% and Rwp = 8.17%. The (h, k, l) values for different lattice planes have been calculated. The praseodymium substituted perovskite crystallizes in orthorhombic symmetry with space group: Pbnm, Z = 4. The unit cell parameters at room temperature are a = 5.39609(31) Å, b = 5.44869(30) Å and c = 7.6565(5) Å. The calculated and observed values of the corresponding intensities, 2θ and density of the polycrystalline powder show good agreement. GSAS-based calculation for bond distances TiO, CaO and bond angles OTiO, OCaO has been reported. 相似文献
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Fengzhen HuangXiaomei Lu TingTing XuYaoyang Liu Weining SuYaming Jin Yi KanJinsong Zhu 《Thin solid films》2012,520(21):6489-6492
Co and Nd co-substituted Bi5Ti3FeO15 thin films were prepared on Pt/Ti/SiO2/Si substrates via metal organic decomposition method. The structural and multiferroic properties of the films were investigated. It was found that Co ions enter into the lattice and occupy the Fe site. The Bi4.15Nd0.85Ti3Fe0.5Co0.5O15 films simultaneously exhibit ferroelectric and ferromagnetic properties at room temperature, and its 2Pr and 2Mr are 38 μC/cm2 and 3 kA/m, respectively. Moreover, substitutions create local ferromagnetic order and antiferromagnetic order depending on whether the local bonding is FeOCo or FeOFe/CoOCo, respectively. The competing interaction of the ferromagnetic and antiferromagnetic phases results in an interesting magnetic behavior of the films. 相似文献
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Malgorzata AdamkiewiczTony O'Hara David O'HaganGeorg Hähner 《Thin solid films》2012,520(22):6719-6723
Vinyl-terminated self-assembled monolayers (SAMs) offer significant flexibility for further chemical modification and can serve as a versatile starting point for a tailoring of surface properties. A vapor phase deposition of such films would offer advantages in cases where the preparation from solution is not an option or not desired, for example in connection with silicon microstructures such as micro-electromechanical systems. We show that SAMs of 9-decenyltrichlorosilane (CH2CH(CH2)8SiCl3), 10-undecenyltrichlorosilane (CH2CH(CH2)9SiCl3), 14-pentadecenyltrichlorosilane (CH2CH(CH2)13SiCl3), decyltrichlorosilane (CH3(CH2)9SiCl3), and octadecanetrichlorosilane (CH3(CH2)17SiCl3) can be prepared both from solution and from the vapor phase. The resulting layers were compared by static contact angle measurements, ellipsometry, X-ray photoelectron spectroscopy, and atomic force microscopy to determine their surface wettability, the film thickness, the smoothness and homogeneity of the respective films, and their chemical composition and each method gave films of comparable quality. Deposition of functionalized SAMs from the vapor phase is rare. Here we report the parameters for the preparation of well-ordered vinyl-terminated SAMs from the vapor phase. 相似文献
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To go further in the comprehension of hydrogen desorption mechanisms from PECVD (Plasma Enhanced Chemical Vapour Deposited) silicon nitride, a method to determine the chemical composition of amorphous silicon nitride films using fast and non destructive characterization techniques has been developed. In particular, SiH, NH, SiSi and SiN bond concentrations are calculated from Fourier transform infra red spectroscopy, ellipsometry and mass measurement. Next, different PECVD silicon nitride films were annealed at 600 °C during 2 min. Results show that hydrogen desorption from PECVD silicon nitride depends on film mass density and main chemical reactions leading to hydrogen desorption are identified thanks to the determination of SiSi and SiN bond concentrations. 相似文献
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Pascal Maillard 《Materials Research Bulletin》2008,43(1):30-37
The synthesis of reactive nitridation precursors prepared using citrate complexation/calcination route has shown interest in the study of the system R2TaON. Novel fluorite-type phases have been evidenced in the oxide series R2TaO5.5 (R = NdYb, Y) and oxynitride series R2.67Ta1.33(O,N,□)8. Chemical and optical analyses were performed to characterize these phases, as well as structural analogies with R2WO6 and R2MoO5 oxide families. 相似文献
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Effects of photoirradiation in UV and VUV regions during plasma exposure to polymers 总被引:1,自引:0,他引:1
Ken Cho Yuichi Setsuhara Kosuke Takenaka Masaharu Shiratani Makoto Sekine Masaru Hori 《Thin solid films》2011,519(20):6810-6814
Interactions between photons irradiated from Ar-O2 mixture plasmas and polymer surfaces were investigated on the basis of depth analyses of chemical bonding states in the nano-surface layer of polyethylene terephthalate (PET) films via hard X-ray photoelectron spectroscopy (HXPES) and conventional X-ray photoelectron spectroscopy (XPS). The PET films were exposed to photons from the Ar-O2 mixture plasmas by covering the PET samples with MgF2 and quartz windows as optical filters for evaluation of photoirradiation effects in ultraviolet (UV) and vacuum ultraviolet (VUV) regions. The HXPES results indicated that the degradation of the chemical bonding states due to photoirradiation in regions was insignificant in deeper regions up to about 50 nm from the surface. Whereas, conventional XPS analysis showed that CO bond, OCO bond and CO bond increased after photoirradiation in UV and VUV regions. These results suggest that the increase in oxygen functionalities (CO bond, OCO bond and CO bond) may be attributed to chemical reactions and/or terminations of scissed bonds via photodecompositions of the polymer with oxygen and/or OH species (oxygen molecules and radicals during plasma exposure and/or oxygen molecules and moisture after taking the PET samples out of the plasma reactor to the ambient air) in the vicinity of the sample surface. 相似文献
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Alex Lemes Marçal Emerson Henrique de FariaJane Karla de Faria Borges Machado Eduardo José NassarKatia Jorge Ciuffi Paulo Sergio Calefi 《Thin solid films》2012,520(21):6541-6546
Films consisting of Eu3+ β-diketonate complexes were deposited onto glassy substrates by means of the spin- and dip-coating techniques, using different ion/ligand ratios. Absorption spectroscopy in the infrared region revealed the typical stretching bands of the SiOSi and SiOH bonds of the inorganic matrix as well as bands relative to the CO and CH symmetric vibration of β-diketone (dibenzoylmethane). The films displayed UV-visible absorption band at 350 nm, attributed to the organic ligand. Luminescence properties were studied by photoluminescence spectroscopy. Upon ligand excitation, the emission spectra exhibited the characteristic bands of the Eu3+ ion corresponding to the transition from the excited state 5D0 to the ground state 7FJ. Scanning electron microscopy confirmed the formation of a film with average thickness ranging from 80 to 100 nm. The sol-gel process and the deposition techniques resulted in the effective formation of nanofilms, which opens up perspectives for their application in photonics. 相似文献
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A new phase diagram is reported for the CaOAl2O3SiO2H2O (CASH) system at 200 °C. This system is rare in nature but has applications in cementing geothermal and deep oil wells. The phase diagram was constructed by synthesising a range of hydroceramics with CASH assemblages from oilwell cement, silica flour (quartz) and alumina (corundum). A hydroceramic is defined as any ceramic material incorporating water as H2O or OH. At 200 °C, gyrolite, hillebrandite, jaffeite, portlandite, quartz, 11 Å tobermorite, xonotlite, hibschite and katoite were observed as product phases. The mineral assemblages produced the following three-phase triangles in the CaOAl2O3SiO2 diagram: Gyr + Qtz + Xon; Crn + Tob + Xon; Crn + Hib + Xon; Crn + Hib + Jaf; Crn + Jaf + Kat; Hib + Jaf + Por; Hib + Jaf + Xon; and two reactions are found to be in progress at 200 °C. When alumina is present in the reaction mixture, the thermal stability of tobermorite is extended to higher temperature, and the crystallinity of tobermorite and xonotlite enhanced. 相似文献
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This paper reports on the preparation and characterization of CrBN nanocomposite coatings for low friction, low wear and high thermostability applications. Sputtered CrBN thin films were prepared in order to obtain a composite structure consisting of hard CrB2 and CrN crystallites as well as hexagonal BN lubricant phase by unbalanced magnetron sputtering (UBM) of a CrB2 target in an Ar/N2 gas discharge. Coatings, with a total thickness of 4.5-5.5 μm, were deposited at 450 °C on silicon single-crystal substrates. A nanocomposite structure was obtained by increasing the nitrogen content of the sputtering gas. The coating microstructure was investigated on selected samples by high-resolution transmission electron microscopy. The films were generally found to consist of crystallites of a 1-4 nm size embedded in amorphous matrix. This crystalline phase was identified by electron diffraction as hexagonal CrB2 for low nitrogen content and cubic CrN for high nitrogen content. In the medium composition range, the structure was amorphous, still keeping the two-phase morphology. The use of high-resolution imaging mode helped to reveal the composition of the amorphous phase which seems predominantly to consist of boron nitride. 相似文献
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Glasses with the nominal compositions of xWO325La2O3(75 − x)B2O3 (mol%) with x = 15, 25, and 50 were prepared using a conventional melt quenching method, and their structure and crystallization behavior were examined from Raman scattering spectra and X-ray diffraction analyses. The glasses are colorless in the visible light region and give the optical band gap energy of 3.49-3.61 eV. The glass transition and crystallization temperatures and the thermal stability against crystallization decrease with increasing WO3 content. The strong Raman bands at 840 and 940-960 cm−1 suggest that the main coordination state of W6+ ions in the glasses is isolated (WO4)2− tetrahedral units. The formation of WO6 octahedral units is also suggested in the glasses with high WO3 contents. The main crystallization mechanism in the glasses is the surface crystallization, and the glass of 50WO325La2O325B2O3 shows the crystallization of LaBWO6 single phase. The present study proposes that WO3La2O3B2O3 glasses and crystallized glasses are very interesting as optical functional materials. 相似文献
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S. Benmokhtar A. El Jazouli J.P. Chaminade M. Menetrier 《Materials Research Bulletin》2007,42(5):892-903
A new titanium oxyphosphate Mg0.50TiO(PO4) has been synthesized and characterized by several physical techniques: X-ray diffraction, 31P MAS-NMR, Raman diffusion, infrared absorption and diffuse reflectance spectroscopy. It crystallizes in the monoclinic system with unit cell parameters: a = 7.367(9), b = 7.385(8), c = 7.373(9) Å, β = 120.23(1), with the space group P21/c (no. 14), Z = 4. The crystal structure has been refined by the Rietveld method using X-ray powder diffraction. The conventional R indices obtained are Rwp = 0.138, Rp = 0.096 and RB = 0.0459. The structure of Mg0.50TiO(PO4) consists of infinite chains of corner-shared [TiO6] octahedra parallel to the c-axis, crosslinked by corner-shared [PO4] tetrahedra. These infinite chains have alternating short (1.74 Å) and long (2.26 Å) TiO bonds and are similar to those found in titanium oxyphosphate MII0.50TiO(PO4) (M2+ = Fe2+, Co2+, Ni2+, Cu2+, Zn2+). The magnesium atom is located in an antiprism between two [TiO6] octahedra. 31P MAS NMR showed only a single 31P resonance line, in a good agreement with the crystal structure. Raman and IR spectra show strong bands respectively at 765 and 815 cm−1, attributed to the vibration of TiOTiO bonds in the infinite chains. The gap due to the Oxygen-Titanium(IV) charge transfer is 3.37 eV. 相似文献
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The phase composition and chemical bonding of ZrC and ZrSiC films deposited by magnetron sputtering has been studied. The results show that the binary Zr-C films at higher carbon contents form nanocrystallites of ZrC in an amorphous carbon matrix. The addition of Si induces a complete amorphization of the films above a critical concentration of about 15 at.%. X-ray diffraction and transmission electron microscopy confirm that the amorphous films contain no nanocrystallites and therefore can be described as truly amorphous carbides. The amorphous films are thermally stable but start to crystallize above 500 °C. Analysis of the chemical bonding with X-ray photoelectron spectroscopy suggests that the amorphous films exhibit a mixture of different chemical bonds such as ZrC, ZrSi and SiC and that the electrical and mechanical properties are dependent on the distribution of these bonds. For higher carbon contents, strong SiC bonds are formed in the amorphous Zr-Si-C films making them harder than the corresponding binary Zr-C films. 相似文献
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S.C. Ray T.I.T. Okpalugo H.M. Tsai J.C. Jan P. Papakonstantinou W.J. Wang 《Materials Research Bulletin》2005,40(10):1757-1764
We have investigated the electronic and bonding structure using Fourier-transform infra-red (FT-IR) spectra and studied photoluminescence (PL) from micro-Raman spectra analysis of a-C:H:Si (Si:DLC) thin films deposited by plasma enhanced chemical vapour deposition (PECVD) method. Tetramethylsilane [Si(CH3)4, TMS] vapour was used as Silicon precursor and a bias voltage of 400 V was applied during deposition. It is observed from FT-IR spectra that with increasing TMS flow rate, the intensity of SiHn and CHn modes is increased significantly. PL study indicates that the PL is increased and that the PL peak position is shifted towards lower energy when the TMS flow rate increases gradually during deposition. 相似文献
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NaSm9(SiO4)6O2 powders were synthesized by mild hydrothermal method at 180 °C for 24 h. The infrared optical properties and structure of the obtained powders were characterized. There existed two narrow and sharp absorptive bands near 943 cm− 1 (10.6 μm). The band at 938 cm− 1 was assigned to the stretching vibrations of SiOSm groups connecting to Q1 species and the band at 989 cm− 1 was attributed to the stretching vibrations of SiOSm groups linking with Q0 species. The reflectivity was lower than 1% from 900 to 1200 nm and reached the minimum of 0.46% at 1073 nm. The prepared powders exhibit potential to act as a new kind of absorptive material for the infrared light of 10.6 μm and 1.06 μm. 相似文献