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<正>(接2023年第6期88页)微波等离子体CVD法是制备优质金刚石薄膜的好方法。在微波CVD装置中,极高频率的微波电场将使气体放电产生等离子体。等离子体中电子的快速往复运动进一步撞击气体分子,使得气体分子分解为H*和各种活性基团。这些大量的原子氢和活性的含碳基团是用低温低压的CVD方法沉积金刚石所必需的。 相似文献
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在金刚石膜的化学气相沉积过程中,使用脉冲电源激励的微波等离子体可以提高金刚石膜的沉积速率或金刚石膜的质量。本文使用Langmuir探针研究了在工频脉冲电源激励条件下形成的线形微波H2等离子体的状态和开关特性。实验测量了在使用一支磁控管单独激励和两支磁控管共同激励情况下的H2等离子体的状态参量,包括等离子体的空间电位‰、探针悬浮电位Vf、电子温度Te和电子密度ne随时间的变化,特别是讨论了H2等离子体参量在激励电源开启与关断瞬间的过渡特征。 相似文献
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在自行设计的直接耦合石英管式微波等离子体化学气相沉积(Chemical Vapor Deposition,CVD)金刚石膜装置的石英管反应腔加上磁镜场来约束等离子体,使等离子体球成为“碟盘”状,提高了等离子体球的密度,在基本参数为反应压力2.5kPa、基片温度450℃、Ar、CH4、H2气体流量分别为40sccm、4sccm、60sccm,则沉积面积可由30mm增长到50mm,沉积速率由3.3μm/h增长到3.8μm/h,反射电流由15μA减小到5μA。从而大大减少了薄膜在石英管壁和观察窗上的沉积,更好地利用微波能量,有效利用电离的活性基团沉积出高质量的金刚石薄膜。 相似文献
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利用微波等离子体化学气相沉积(MPCVD)法分别在CH4/H2/Ar体系、CH4/H2/O2体系和C2H5OH/H2体系中进行纳米金刚石(NCD)薄膜的制备研究。采用原子力显微镜(AFM)和激光拉曼光谱(Raman)等方法对不同体系中制备得到的NCD薄膜的表面形貌及其质量进行了检测。结果表明:在CH4/H2体系中添加O2对于促进高平整度NCD薄膜的效果明显优于添加At;C2H5OH/H2体系更有利于制备颗粒更细、金刚石相含量更高的NCD薄膜。利用等离子体CVD技术的相关理论对上述结论进行了理论分析。 相似文献
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《真空科学与技术学报》2017,(6)
本文介绍了一种具有双侧波导同轴线耦合结构的新型微波等离子体源。通过电磁场模拟计算和等离子体发射光谱测量对同轴线耦合反应腔内部结构进行了优化,研究了线形等离子体源腔体结构对等离子体均匀性和长度的影响,并且在杆状样品表面进行了金刚石薄膜的沉积实验。实验结果表明:双侧波导同轴线耦合式新型线形等离子体源可以在引导天线表面产生圆柱状的线形等离子体,其等离子体的均匀性和长度受腔体内部结构的影响,在引导天线外径为4 mm,单侧模式匹配棒伸入量为10 mm的腔体结构下,等离子体的均匀性大于90%。通过对杆状样品表面不同位置处金刚石膜质量和等离子体沉积环境的测量,进一步验证了等离子体的均匀性。此外,线形等离子体的长度受引导天线长度和工作气压影响,这主要与反应腔内电磁场分布以及微波传输衰减有关。 相似文献
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在自行设计出的直接耦合石英管式微波等离子体化学气相沉积fchemical Vapor Deposition,CVD)金刚石膜装置的石英管反应腔加上磁镜场,以更好地约束等离子体,使等离子体球成为“碟盘”状,提高了等离子体球的密度,在基本参数不变的情况下,沉积面积可由ψ30mm增长到50mm,沉积速度由每小时3.3μm增长到3.8μm,反射电流减小,从而减少了在石英管壁和观察窗的沉积,更好地利用微波能量,有效利用电离的活性基团沉积出高质量的(类)金刚石薄膜。 相似文献
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微波等离子体刻蚀处理对金刚石薄膜涂层刀具附着力和切削性能的影响 总被引:1,自引:0,他引:1
用HFCVD法在硬质合金(YG6)刀具衬底上沉积金刚石薄膜,用氢微波等离子体刻蚀的方法对衬底进行表面预处理,研究了该预处理技术对WC硬质合金衬底表面成分的影响,进一步探讨了所沉积金刚石薄膜的表面形貌和附着力,并通过难加工材料实际切削试验。研究了所制备的金刚石薄膜涂层刀具的切削性能。试验结果表明,Ar-H2微波等离子体刻蚀脱碳处理是提高金刚石薄膜附着力和改善涂层刀具切削性能的有效预处理方法。 相似文献
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《Materials Chemistry and Physics》1998,57(1):41-46
The polycrystalline diamond films in this research were deposited using a methane/hydrogen gas mixture in a microwave plasma assisted chemical vapor deposition system. Large-grain, several μm size crystallite, diamond films and small-grain, sub-micron size crystallite, diamond films were prepared by diamond paste and diamond powder nucleation method, respectively. It is found that there is no oxygen incorporated into the diamond films during the microwave plasma chemical vapor deposition process at the synthesis temperature between 900°C and 1000°C. However, the oxygenated phenomena did appear for both of the large-grain and the small-grain polycrystalline diamond films after the films were exposed to air for a period of time. It was shown that the large-grain diamond films are oxygenated more than the small-grain diamond films as the samples were exposed to air for a period of time and also after the chemical cleaning treatment. It is indicated that the oxygenated phenomena of the diamond films come from two contributors, the diamond crystallite surfaces and the diamond grain boundaries. The reaction between the diamond grain boundaries and the air is fast and the oxidized dangling bonds are hard to remove. However, the oxidized dangling bonds on the diamond crystallite surfaces are gradually formed and are easily etched away by the hydrogen plasma. 相似文献
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非晶金刚石薄膜的制备及其性能研究 总被引:3,自引:0,他引:3
本文利用一种新的等离子体沉积技术-真空磁过滤弧沉积制备得到一种无氢的非晶碳膜。EELS分析表明,这种非晶碳膜几乎不含有s0^2和sp杂化键,呈现出高度的金刚石特征,以致可以被称为非晶金刚石膜。 相似文献
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MPCVD制备金刚石膜的形核与生长过程 总被引:1,自引:1,他引:0
简要介绍了金刚石膜的物理化学特性及应用领域。对比分析了主要化学气相沉积方法的优缺点,并指出MPCVD所面临的技术瓶颈。总结了反应腔体内压强、基片温度、基体材料及增强形核技术对金刚石膜形核过程的影响。较低腔体内压力、基片温度,高碳源浓度及等离子体预处理能有效提高形核密度。阐述了各过程参数对金刚石膜生长的影响和微米、纳米、超纳米金刚石膜的技术特点及应用。指出各类金刚石膜制备所面临的技术难题,并综述了解决该技术瓶颈的最新研究工作。 相似文献
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Discontinuous and continuous diamond films with different morphologies and qualities were deposited on n2+-type Si(100) substrates, using the hot-filament chemical vapor deposition (CVD) technique from CH4–H2 gas mixtures. The field-emission characteristics of these diamond films were investigated. The turn-on fields at a 0.01mA/cm2 current density were recorded for all the tested CVD-diamond films. It was found that discontinuous diamond films showed a much lower turn-on field (1.2 V/μm) than continuous ones (20 V/μm). The effective working function of continuous diamond films was around 0.1 eV, while that for discontinuous diamond films is about 0.03 eV. O2 plasma post-deposition sharpening of thick diamond films indicated that the geometrical-field enhancement, caused by the surface topographic changes, has no significant influence on the turn-on field. 相似文献
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金刚石膜拥有许多优异的性能。在制备金刚石膜的各种方法之中,高功率微波等离子体化学气相沉积(MPCVD)法因其产生的等离子体密度高,同时金刚石膜沉积过程的可控性和洁净性好,因而一直是制备高品质金刚石膜的首选方法。在世界范围内,美、英、德、日、法等先进国家均已掌握了以高功率MPCVD法沉积高品质金刚石膜的技术。但在我国国内,高功率MPCVD装备落后一直是困扰我国高品质金刚石膜制备技术发展的主要障碍。首先综述国际上高功率MPCVD装备和高品质金刚石膜制备技术的发展现状,包括各种高功率MPCVD装置的特点。其后,回顾了我国金刚石膜MPCVD技术的发展历史,并介绍北京科技大学近年来在发展高功率MPCVD装备和高品质金刚石膜制备技术方面取得的新进展。 相似文献
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A CN/diamond composite structure on silicon substrate was obtained by a two-step technique in preparing polycrystalline diamond layers by microwave plasma assisted chemical vapor deposition and then CN films by reactive rf magnetron sputtering. The samples were annealed at different temperatures in the range of 200 to 800 °C, respectively. All the as-grown and annealed CN films, which fully covered the diamond underlayer with the formation of a rather adhesive interface, exhibited amorphous nature uniquely. X-ray photoelectron spectroscopy and energy-dispersive x-ray studies both revealed that the nitrogen concentration of the films decreases after annealed at high temperature. Infrared spectra also suggested the thermal modifications on the content and structure of the CN films. The electric resistivity varies in a large range as the annealing temperature increasing, and confirmed the bonding configuration in favor of a graphite-like structure at high temperature. 相似文献
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Characterization of hypervelocity impact craters on chemical vapour-deposited diamond and diamond-like carbon films 总被引:2,自引:0,他引:2
Microwave plasma chemical vapour-deposited (CVD) process has been used to grow polycrystalline diamond films over silicon
substrates. Diamond-like carbon (DLC) thin films were grown over silicon substrates using a microwave plasma disc reactor.
Reactant gases of CH4 and H2 were used in both CVD processes. Some preliminary feasibility tests were performed on the possible
applicability of diamond and diamond-like carbon thin films for space-protective applications against artificially simulated
electrically actuated plasma drag hypervelocity impact of olivine particles. As-deposited films were analysed by Raman for
their chemical nature. The morphology and dimensions of hypervelocity impact craters in diamond and DLC films was also studied
by scanning electron microscopy (SEM) and optical microscopy. The velocity of debris particles was determined by high-speed
photography using a streak camera. The size of the impact particles was determined by measuring the size of the holes formed
in the mylar sheet mounted just above the target diamond and DLC film/silicon and coordinates of the impact sites were determined
using the same apparatus.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
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In order to investigate the effects of argon and oxygen on diamond synthesis, the behaviors of diamond deposition using microwave plasma chemical vapor deposition method have been studied by varying the concentrations of argon and oxygen in the methane-hydrogen gas mixture. Diamond films were deposited on silicon wafer under the conditions of substrate temperatures: 1073 1173 K, total reaction pressure: 5333 Pa (40 Torr), methane concentrations: 0.5 5.0%, and they were characterized by scanning electron microscopy, Raman spectroscopy and optical emission spectroscopy. The deposition rates of diamond films were enhanced by adding argon into the methane-hydrogen system, but nondiamond carbon phases in the films also increased. It resulted from the increase of hydrocarbon radicals in the plasma. As oxygen was added, the quality of deposited diamond films was improved due to the decrease of C2 radicals and increase of OH radicals in the plasma. Simultaneous addition of 0.3% oxygen and 20% argon has been able to effectively suppress the formation of nondiamond carbon components and increase the deposition rate of diamond films. It appears that the ionized argon (Ar+) and excited argon atoms (Ar*) may activate the various chemical species and promote the reactions between the gas phase species and oxygen in the plasma. 相似文献