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OES study of the gas phase during diamond films deposition in high power DC arc plasma jet CVD system 下载免费PDF全文
This paper used optical emission spectroscopy (OES) to study the gas
phase in high
power DC arc plasma jet chemical vapour deposition (CVD) during diamond films growth processes. The
results show that all the deposition parameters (methane concentration,
substrate temperature, gas flow rate and ratio of H2/Ar) could strongly
influence the gas phase. C2 is found to be the most sensitive radical
to deposition parameters among the radicals in gas phase. Spatially resolved
OES implies that a relative high concentration of atomic H exists near the
substrate surface, which is beneficial for diamond film growth. The
relatively high concentrations of C2 and CH are correlated with high
deposition rate of diamond. In our high deposition rate system, C2 is
presumed to be the main growth radical, and CH is also believed to
contribute the diamond deposition. 相似文献
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Microcrystalline boron-doped diamond (BDD) films are synthesized on the silicon substrate by the hot-filament chemical vapor deposition method under the gas mixture of hydrogen and methane in the presence of boron carbide (B4C) placed in front of filaments. The observed results of scanning electron microscopy, Raman spectroscopy and X-ray diffraction show the morphologies. Microstructures for various deposition pressures of as-grown diamond films are found to be dependent on the change of deposition pressure. These results reveal that with the increase of deposition pressure, resistivity decreases and increase in the grain size is noted in the presence of B4C. Resistivity shows a sudden fall of about three orders of magnitude by the addition of boron in the diamond films. This is due to the crystal integrity induced by B-atoms in the structure of diamond in the presence of B4C. These results are also significant for the conventional applications of BDD materials. The effects of deposition pressure on the overall films morphology and the doping level dependence of the diamond films have also been discussed. 相似文献
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Abstract In the present paper, diamond films have been synthesized on tungsten carbide, sintered diamond and high pressure diamond by hot filament chemical vapour deposition method from the mixture gas of methane and hydrogen, and growth features of diamond were studied. 相似文献
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M.G. Donato G. Faggio M. Marinelli G. Messina E. Milani A. Paoletti S. Santangelo A. Tucciarone G. Verona Rinati 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,20(1):133-139
High quality synthetic diamonds were grown on single-crystal silicon by microwave plasma enhanced chemical vapour deposition
(CVD). A careful optimisation of both the experimental setup and the growth parameters was necessary before that the achievement
of the best results was made possible. The films were deposited using a CH4-H2 gas mixture at methane concentrations variable in the range 0.6-2.2%, while the substrate temperature was fixed at 750 °C. Raman spectroscopy and photoluminescence (PL) were utilised to monitor the quality of the deposited films and to study
the spatial distribution of defects, respectively. Micro-Raman analysis shows that linewidths of the diamond peak lower than
2.4 cm-1 can be easily measured at the growth surface, indicating that the crystalline quality of individual grains is comparable
to that of the best natural diamonds. The excellent phase purity of the diamond microcrystals at the growth surface is witnessed
by the complete absence of any non-diamond carbon feature and by a very weak luminescence background in the 1.6-2.4 eV spectral
range. A worsening of the quality of the diamond particles is found moving from the growth surface towards the film-substrate
interface. A photoluminescence feature at about 1.68 eV, commonly associated to Si impurities, is distinctly observed as the
exciting laser beam is focused close to the interface. A progressive degradation of the global quality of the films is found
with increasing methane concentration in the gas mixture, as witnessed by an increased PL background in the films grown at
higher methane concentrations.
Received 24 November 2000 相似文献
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Technical Physics - With the aim of developing a gas-jet technique for depositing diamond structures, the flow of a hydrogen–methane mixture through hot coaxial tungsten cylindrical channels... 相似文献
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采用蒙特卡罗方法,对源料气体为CH4/H2混合气的电子助进化学气相沉积(EACVD)中 的氢原子(H)、碳原子(C)以及CH基团的发射过程进行了模拟.研究了CH4浓度、反应室气压 和衬底偏压等工艺参数对发射光谱及成膜的影响.研究发现,CH基团可能是有利于金刚石薄 膜生长的活性基团,而碳原子不是;偏压的升高可提高电子平均温度及衬底表面附近氢原子 的相对浓度;通过氢原子谱线可测定电子平均温度并找到最佳成膜实验条件.该结果对EACVD 生长金刚石薄膜过程中实时监测电子平均温度,有效控制工艺条件,生长出高质量的金刚石 薄膜具有重要的意义.
关键词:
蒙特卡罗模拟
金刚石薄膜
发射光谱 相似文献
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R. Bogdanowicz Lukasz Golunski Michal Sobaszek 《The European physical journal. Special topics》2013,222(9):2223-2232
Spatially resolved optical emission spectroscopy (SR-OES) was used to investigate microwave activated H2/Ar/CH4 plasma under conditions of the electron cyclotron resonance (ECR). The chemistry and composition of the gas phase were studied using self-designed fibre-optic system with echelle type spectrometer during CVD deposition of polycrystalline diamond. One-dimensional intensity profiles of the main species were collected along the vertical axis of chamber. The dominant species in the flux, originating from excited hydrogen and hydrocarbons, were identified as H, H+, CH and CH+; they are crucial for the diamond deposition process. The effect of ECR on the spatial distribution of H2 and CH4 dissociation profiles was studied in depth. The influence of processing parameters (gas flow rates, input power, pressure and magnetic field level) on species excitation as a function of the distance above substrate was asessed. The obtained data can be used for the ECR system optimization. 相似文献
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Gopi K. Samudrala Georgiy Tsoi Andrei V. Stanishevsky Jeffrey M. Montgomery Samuel T. Weir 《高压研究》2013,33(3):388-398
Epitaxial boron-doped diamond films were grown by microwave plasma chemical vapor deposition for application as heating elements in high pressure diamond anvil cell devices. To a mixture of hydrogen, methane and oxygen, diborane concentrations of 240–1200 parts per million were added to prepare five diamond thin-film samples. Surface morphology has been observed to change depending on the amount of diborane added to the feed gas mixture. Single-crystal diamond film with a lowest room temperature resistivity of 18 mΩ cm was fabricated and temperature variation of resistivity was studied to a low temperature of 12 K. The observed minima in resistivity values with temperature for these samples have been attributed to a change in conduction mechanism from band conduction to hopping conduction. We also present a novel fabrication methodology for monocrystalline electrically conducting channels in diamond and present preliminary heating data with a boron-doped designer diamond anvil to 620 K at ambient pressure. 相似文献
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A.R. Sobia S. AdnanA. Mukhtiar A.A. KhurramA.A. Turab A. AwaisA. Naveed Q.J. FaisalH. Javaid G.J. Yu 《Current Applied Physics》2012,12(3):712-717
The effect of nitrogen addition in the feed gas on the finally incorporated amount of hydrogen in the diamond nanorods (DNRs) thin films has been investigated. The Raman spectroscopy measurements helped to understand the structural and quality changes with increasing nitrogen gas flow rate during CVD deposition. The hydrogen concentration was measured with 3.0 MeV He2+ beam using elastic recoil detection analysis technique and it was found that with the addition of nitrogen, the hydrogen concentration was increased. The results of non-Rutherford backscattering spectroscopy (NRBS) used to measure the amount of nitrogen in the DNRs thin films have shown that the incorporated nitrogen is below the detection limit of NRBS technique. Our results suggested that the addition of nitrogen has affected the overall quality of diamond films in two ways; increasing the thickness of diamond films by increasing the non-diamond carbon content and increasing the hydrogen impurity incorporation. The role of nitrogen additive on diamond growth and hydrogen incorporation is discussed. 相似文献
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《Current Applied Physics》2009,9(3):698-702
Diamond films consist of crystallites having nanometer grains were deposited using low methane concentration by hot filament chemical vapor deposition (HFCVD). The results show that films consist of nanodiamond grains with grain sizes ranging from 20 nm to 200 nm having thickness dependent size. Increasing the deposition time, the grain size increases and hence the thickness of the film increases. The diamond nucleation (nucleation density 1010 cm−2) is comparable to that obtained by biasing the substrate. The use of low methane concentration for the formation of nano crystallites improves the quality of the film as indicated by Raman spectroscopy. The distance between the filament and substrate is increased while maintaining the substrate temperature. The effects of this large separation on the gas phase chemistry are discussed which helps to understand the reduced size of the crystallites under input gas ratios when microcrystallines are obtained. 相似文献
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利用介质阻挡放电等离子体化学气相沉积技术,在蒸镀有25nm Ni催化剂层的Si基片上,以CH4和H2作为反应气体,在973K下制备了碳纳米管,并研究了微量水的引入对碳纳米管形貌的影响.场发射扫描电子显微镜结果表明,不加水时,制备出的碳纳米管直径不均匀,分布在40—90nm之间,呈链节状的结构;加入少量水时,制备出的碳纳米管直径比较均匀,集中在70nm左右,表面为瘤状结构;当水的流量进一步增加时,得到的碳纳米管表面光滑,出现了枝状结构.原位测量了加水前后等离子体区的发射光谱,分析了微量水的引入对于碳纳米管形貌变化的影响机理.
关键词:
碳纳米管
介质阻挡放电
水
发射光谱 相似文献
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J. Larjo H. Koivikko K. Lahtonen R. Hernberg 《Applied physics. B, Lasers and optics》2002,74(6):583-587
This paper reports the two-dimensional mapping of atomic hydrogen concentration with two-photon excited laser induced fluorescence
in a multi-wire grid hot-filament chemical vapor deposition reactor. The measurements were made in a diamond film deposition
environment under different filament temperatures and wire configurations. The measurement was calibrated with a titration
reaction using NO2 as a titrant. The kinetic gas temperature in the reactor was measured from the Doppler broadening of the Lyman-β transition
excited in the fluorescence. The filament temperature was found to have a significant effect on atomic hydrogen production
and transfer to the substrate. The axial concentration distributions were compared to a one-dimensional kinetic gas–surface
chemistry model with good agreement. The model produced a reasonable estimate for the bulk diamond film growth rate.
Received: 25 June 2001 / Revised version: 15 February 2002 / Published online: 2 May 2002 相似文献
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以NiO和8%(摩尔分数)氧化钇稳定的氧化锆为原料,采用注凝成型工艺制备了管状固体氧化物燃料电池阳极支撑体.用离子浸渍法对阳极支撑体进行表面修饰.用电化学工作站测单电池交流阻抗和输出性能并且用化学气相色谱仪对电池尾气进行分析.测试结果表明修饰后的阳极在通甲烷的情况下出现了一定程度的积炭,但是积炭现象在一定的测试时间内达到平衡,没有对电池造成破坏,并且显著地提高了电池阳极的电化学性能.单电池在通入氢气和甲烷的情况下最大输出功率密度分别达到了225和400 mW/cm2. 相似文献
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《Current Applied Physics》2002,2(3):201-204
WC–6%Co cutting tool inserts were coated with diamond films using a double bias-assisted hot-filament chemical vapor deposition method. Coating of the cutting tools with chemical vapor deposition diamond is taken as a three-step process in which the growth of diamond follows the pretreatment and nucleation of the substrate. The presented operating parameters allow to substantially suppress the presence of amorphous carbon and/or graphite phases in the diamond films deposited on WC/Co tools. The substrate temperature of ∼700 °C, and a low methane concentration result in a sharp diamond Raman peak centered at 1333–34 cm−1 with FWHM of 6–7 cm−1 as detected by micro-Raman spectroscopy. The diamond morphology is characterized by scanning electron microscopy, optical microscopy, and micro-Raman spectroscopy. 相似文献
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Diamond-like carbon (DLC) films were deposited on Si (1 0 0) substrate using a low energy (219 J) repetitive (1 Hz) miniature plasma focus device. DLC thin film samples were deposited using 10, 20, 50, 100 and 200 focus shots with hydrogen as filling gas at 0.25 mbar. The deposited samples were analyzed by XRD, Raman Spectroscopy, SEM and XPS. XRD results exhibited the diffraction peaks related to SiO2, carbon and SiC. Raman studies verified the formation amorphous carbon with D and G peaks. Corresponding variation in the line width (FWHM) of the D and G positions along with change in intensity ratio (ID/IG) in DLC films was investigated as a function of number of deposition shots. XPS confirmed the formation sp2 (graphite like) and sp3 (diamond like) carbon. The cross-sectional SEM images establish the 220 W repetitive miniature plasma focus device as the high deposition rate facility for DLC with average deposition rate of about 250 nm/min. 相似文献
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A. von Keudell M. Meier T. Schwarz-Selinger 《Applied Physics A: Materials Science & Processing》2001,72(5):551-556
Methyl radicals (CH3) and atomic hydrogen (H) are dominant radicals in low-temperature plasmas from methane. The surface reactions of these radicals
are believed to be key steps leading to deposition of amorphous hydrogenated carbon (a-C:H) films or polycrystalline diamond
in these discharges. The underlying growth mechanism is studied, by exposing an a-C:H film to quantified radical beams of
H and CH3. The deposition or etching rate is monitored via ellipsometry and the variation of the stoichiometry is monitored via isotope
labeling and infrared spectroscopy. It was shown recently that, at 320 K, methyl radicals have a sticking coefficient of 10-4 on a-C:H films, which rises to 10-2 if an additional flux of atomic hydrogen is present. This represents a synergistic growth mechanism between H and CH3. From the interpretation of the infrared data, a reaction scheme for this type of film growth is developed: atomic hydrogen
creates dangling bonds by abstraction of bonded hydrogen within a surface layer corresponding to the range of H in a-C:H films.
These dangling bonds serve at the physical surface as adsorption sites for incoming methyl radicals and beneath the surface
as radicalic centers for polymerization reactions leading to carbon–carbon bonds and to the formation of a dense a-C:H film.
Received: 18 July 2000 / Accepted: 12 December 2000 / Published online: 3 April 2001 相似文献