HF-CVD中辉光等离子体对硅(100)基底上金刚石高密度外延形核的作用

在典型的热丝化学气相沉积（HF-CVD）设备中利用辉光放电等离子体实现了镜面抛光的单晶硅（100）基底上金刚石高密度异质外延形核．实验中以硅基底作为阴极，其表面的放电电流密度高达80mA／cm2。利用原子力显微镜（AFM）、扫描电子显微镜（SEM）、俄歇电子谱（AES）等测试手段对所得样品进行了分析。结果发现，经过10min的生长之后，在硅（100）表面上实现了金刚石（D）均匀外延形核，取向关系为D（110）／／Si（110）及D（100）／／Si（100），形核密度高达5x109／cm2。根据放电参数对阴极鞘层的等离子体参数的计算结果与AMF及SEM分析一致，表明了阴极鞘层对于金刚石异质外延形核具有决定作用，并据此讨论了进一步改善异质外延形核均匀性的途径。     

脉冲负偏压增强的高质量金刚石薄膜的沉积

由于直流偏压方法沉积金刚石薄膜易出现电荷积聚现象，从而影响了薄膜的均匀性。本文采用脉冲负偏压增强热丝化学气相沉积(HFCVD)法，以WC—Co硬质合金为衬底制备金刚石薄膜，探讨了在不同频率脉冲直流偏压(500∽5000Hz)T，脉冲偏压对金刚石薄膜的均匀性、致密性和晶粒度的影响，并且讨论了脉冲偏压作用的机理。对沉积的金刚石薄膜进行SEM、XRD和Raman分析。结果表明，采用500Hz脉冲偏压可获得高质量的金刚石薄膜，薄膜的晶粒度小，均匀性和致密性较好。     

高取向低粗糙度金刚石薄膜生长的研究

目的研究热丝化学气相沉积(HFCVD)工艺对金刚石薄膜生长的影响,确定影响金刚石薄膜生长的因素。方法采用热丝CVD法,以丙酮为碳源,在不同晶面的Si衬底上沉积金刚石薄膜,通过金相显微镜、X射线衍射仪分析薄膜生长特性。结果不同沉积温度下生长的金刚石薄膜表面形貌差异很大。在高、低碳源浓度下分别获得了(400)和(111)晶面取向的金刚石薄膜。采用分步沉积法,改善了成膜的效率。结论气源浓度和生长温度是影响金刚石薄膜生长的重要因素,分步沉积法对于金刚石薄膜的生长有较大影响。     

碳化硅衬底沉积高取向金刚石薄膜

采用直流辉光放电等离子体设备在单晶碳化硅表面沉积高晶取向金刚石薄膜,研究了预处理方法、基片温度以及甲烷浓度(甲烷与氢气的体积比)对金刚石薄膜晶粒取向的影响。用SEM、Raman等测试方法对金刚石薄膜进行表征。结果表明:研磨处理可以提高金刚石形核密度,高的形核密度有利于金刚石薄膜的沉积;过高或过低的基片温度会使得金刚石薄膜表现出(111)面生长的趋势;高甲烷浓度和低甲烷浓度也会使得金刚石薄膜晶粒取向发生改变。最终采用850℃以及5%甲烷浓度这一沉积参数进行金刚石薄膜的沉积,制备出了取向度非常好的(100)面金刚石薄膜。     

纳米金刚石TiV色心的实验制备与性能研究

目的 利用磁控溅射辅助微波等离子体化学气相沉积技术制备钛掺杂纳米金刚石薄膜.方法 预先通过磁控溅射在石英玻璃基底上沉积纳米钛颗粒,然后使用微波等离子体化学气相沉积(MPCVD)设备在其表面沉积金刚石薄膜,通过活性氢原子将钛带入含碳生长基团中,从而将钛掺入纳米金刚石薄膜内.使用X射线光电子能谱(XPS)、拉曼光谱(Ram...     

C60作为石英衬底过渡层气相生长金刚石薄膜

本文采用微波等离子体化学气相沉积方法，以Ｃ６０膜作为过渡层，在石英衬底表面，首次在等离子体预处理中无衬底负偏压条件下的生长出金刚石晶粒。通过扫描电镜观察到金刚石晶粒呈菜花状，生长表现为（１００）晶界。     

热丝法气相沉积金刚石薄膜的影响因素

由于热丝法气相沉积金刚石薄膜成膜质量好、设备简单、成本低而得到广泛应用。本文探求了工具上应用最广泛的硬质合金上利用热丝法沉积金刚石薄膜的原理,并着重讨论了在该系统中影响金刚石薄膜质量的几个因素：预处理技术、碳源浓度、温度和气压,在金刚石的形核时期和生长时期这些因素的作用是不同的,同时这些因素又相互影响。根据影响因素制定出了最优的工艺参数,最后在硬质合金上得到了均匀而致密的金刚石薄膜,经XRD分析,由（111)和(220)晶面组成,主要是(111)面,晶粒尺寸平均为113．5nm,这些探索为金刚石沉积技术在工具上的大规模应用打下了基础。     

HF-CVD中辉光等离子体对硅（100）基底上金刚石高密度外延形核的作用

在典型的热丝化学气相沉积(HF-CVD)设备中利用辉光放电等离子体实现了镜面抛光的单晶硅(100)基底上金刚石高密度异质外延形核．实验中以硅基底作为阴极．其表面的放电电流密度高达80mA／cm^2．利用原子力显微镜(AFM)、扫描电子显微镜(SEM)，俄歇电子谱(AES)等测试手段对所得样品进行了分析．结果发现、经过10min的生长之后，在硅(100)表面上实现了金刚石(D)均匀外延形棱，取向关系为D(110)∥Si(110)及D(100)∥Si(100)，形核密度高达5×10°/cm^2、根据放电参数对阴极鞘层的等离子体参数的计算结果与AMF歧SEM分析一致，表明了阴极鞘层对于金刚石异质外蜒形桉具有决定作用．并据此讨论了进一步改善异质外延形核均匀性的途径。     

梯度基体温度法和反应溅射TiC过渡层对钛合金基体沉积金刚石薄膜的影响

以H2和CH4作为反应气体,采用热丝化学气相沉积法(HFCVD)在钛合金(Ti6Al4V)平板基体上制备金刚石薄膜,利用扫描电镜(SEM)、X射线衍射仪(XRD)、激光拉曼光谱(Raman)和洛氏硬度仪分析薄膜的表面形貌、结构、成分和附着性能,研究了高温形核-低温生长的梯度降温法对原始钛合金和反应磁控溅射TiC过渡层的钛合金表面沉积金刚石薄膜的影响。结果表明:原始基体区和TiC过渡层区沉积的金刚石薄膜平均尺寸分别为0.77μm和0.75μm,薄膜内应力分别为-5.85GPa和-4.14GPa,TiC层的引入可以有效提高金刚石的形核密度和晶粒尺寸的均匀性,并减少薄膜残余应力;高温形核-低温生长的梯度降温法可以有效提高金刚石的形核密度和质量,并提高原始基体上沉积金刚石薄膜的附着性能。     

化学气相沉积的金刚石膜标准制定中应考虑的问题

静压法合成的单晶人造金刚石和人造金刚石微粉，就品种，技术条件，包装，杂质检验，抗压强度测定方法，粒度组成等有关问题，已经建立了国家标准。化学气相沉积法制取的金刚石膜因出现的时间短还未建立起有关标准。化学气相沉积金刚石膜的方法有热丝法，微波法和直流电弧等离子体喷射法三类，本就直流电弧等离子体喷射化学气相沉积的自支撑人造金刚石膜标准的制定中应考虑到的一些问题提出了我们的看法。     

氩气流量对等离子体喷射法制备的金刚石膜形核的影响

采用100kW级直流电弧等离子喷射法进行金刚石膜沉积,阐述了氩气对维持电弧稳定的重要作用,讨论了氩气流量对衬底表面轰击的影响,氩气流量和不同电弧分区对形核期金刚石表面形貌和晶粒尺寸的影响,以及时间和不同预处理方式对金刚石形核密度的影响。结果表明:随着氩气流量的增加,氩气对衬底表面的轰击作用增强,金刚石膜表面形貌呈现从(111)到(100)的变化规律,金刚石晶粒尺寸减小,晶形变得不完整;弧边位置(100)取向更明显;使用金刚石微粒对衬底进行研磨预处理能显著提高金刚石的形核密度。     

Nucleation of highly oriented diamond on silicon

Highly oriented diamond particles were deposited on the mirror-polished (100) silicon substrates in the belljar type microwave plasma deposition system. The diamond films were deposited by a three-step process consisting of carburization, bias-enhanced nucleation and growth. The bias-enhanced nucleation was performed under the deposition conditions such as 2-3% of methane concentration in hydrogen, 1333-2666 Pa of total pressure, the negative bias voltage below 200V and the substrate temperature of 1073 K. By adjusting the geometry of the substrate and substrate holder, very dense disc-shaped plasma was formed on the substrate when the bias voltage was below 200V. As characterized by transmission electron microscopy (TEM), almost perfectly oriented diamond particles were obtained only in this dense plasma. From the results of the optical emission spectra of disc-shaped dense plasma, it was found that the concentrations of atomic hydrogen and hydrocarbon radicals were increased with negative bias voltage. As a result, it was suggested that the highly oriented diamonds were obtained by the combination of the high dose of hydrocarbon radicals and the increased hydrogen etching effects.     

化学气相沉积金刚石微球的生长机制研究

采用微波等离子体化学气相沉积法,在过饱和碳离子浓度条件下,在单晶硅衬底上制备了球形结构的多晶金刚石微球,通过控制沉积气压与温度的变化,研究了金刚石由石墨生长区向纳米晶的球形结构、再到具有良好结晶性的金刚石生长区的过渡过程。结果表明:沉积气压与温度的升高导致微球的粒径增大,微球由sp3、sp2键共存相转变为较纯的金刚石相;在一定的碳离子过饱和度和气压、温度范围内,微球的形成主要受二次形核过程的控制。气压和温度升高后,微球呈<110>取向生长,微球的形成主要受（111）面高密度孪晶和层错缺陷的控制,揭示了化学气相沉积金刚石不同生长区内二次形核机制与孪晶层错机制诱导的金刚石微球的生长过程。      

Characterization of （100）-orientated diamond film grown by HFCVD method with a positive DC bias voltage

The （100）-orientated diamond film was deposited by hot-filament chemical vapor deposition （HFCVD） technology with a positive DC bias voltage. The morphology, X-ray diffraction （XRD）, RMAN spectrum and dark current versus applied voltage characteristics analysis show that the positive dc bias can increase the nucleation density and （100）-orientated growth, making the growth of the high quality diamond film easier and cheaper than using other methods.     

Nucleation studies of pulsed bias enhanced CVD of diamond on biomaterials

The effects of bias voltage, bias time, frequency, and duty cycle on the nucleation of diamond were investigated. Pulsed duty cycles were 0.4 μs, and the frequency varied between 0 and 100 kHz. The substrates were pretreated by a direct current (dc) bias using 3 vol. % CH₄ in Ar/H₂ plasma. Growth and surface roughness were controlled using pulsed frequencies, with mean R _a values of 20 nm. Films were characterized in terms of orientation and surface roughness using transmission electron microscopy and atomic force microscopy. Bias-enhanced nucleation is shown to profoundly increase the nucleation densities by promoting ion bombardment of the substrate surface, thus creating nucleation sites for subsequent growth on substrates such as titanium alloys and steel. This technology promotes smooth diamond facets without abrasive surface damage. Controlling the surface roughness and morphology is of critical importance for many new biomedical and electronic devices. This paper was presented at the fourth International Surface Engineering Congress and Exposition held August 1–3, 2005 in St. Paul, MN.     

Effects of pre-treatments and interlayers on the nucleation and growth of diamond coatings on titanium substrates

During diamond deposition on titanium substrates, two processes exist: (1) diffusion of hydrogen into a titanium substrate and the formation of hydride thereby degrading the mechanical properties of the substrate; and (2) competition among the rapid diffusion of carbon atoms into substrates, the formation of carbide and the nucleation of diamond crystals (thereby affecting the nucleation and growth rate of the diamond coating). To increase the diamond nucleation rate and prevent the rapid diffusion of hydrogen and carbon into the substrate, different surface treatments and interlayers were studied in this paper. Results showed that polishing with diamond pastes and ultrasonic pre-treatment in diamond suspensions will significantly increase the nuclei density of diamond crystals. However, the diffusion of hydrogen into the substrate could not be prevented. Pre-etching of the titanium substrate using hydrogen plasma for a short time significantly increased the nuclei density of diamond crystals. Results showed that on a TiN interlayer, there was no significant improvement in diamond nucleation and growth, and the deposited diamond coatings showed poor adhesion. New diamond crystals were formed on the DLC interlayer in which DLC acted as the precursor for diamond nucleation. However, the so-formed diamond coating showed spallation. The plasma nitrided layer could prevent the rapid diffusion of hydrogen and carbon into the titanium substrate, but results showed a relatively low nucleation density of diamond crystals and poor adhesion. A graded interlayer combining plasma nitriding followed by plasma carbonitriding was effective in preventing the rapid diffusion of hydrogen and carbon into the substrate and improving the nucleation rate and adhesion of diamond coating.     

Effect of negative substrate bias voltage on the nucleation and growth of Cu films during the initial stage of ion beam deposition

We focused the effect of a negative substrate bias voltage on the nucleation and growth of Cu films during the initial stage of ion beam deposition. The resultant microstructure of Cu films was observed by atomic force microscopy (AFM). It was found that Cu films with or without a negative substrate bias voltage have a different dependence of nucleation and growth. It was established that the mechanism of nucleation and growth of Cu films is changed to a progressive nucleation and lateral growth by a sufficient migration of adatoms accelerated by applying a negative substrate bias voltage.     

Effect of substrate bias voltage on the texture and microstructure of Cu thin films deposited by ion beam deposition

Cu thin films deposited by non-mass separated ion beam deposition under various substrate bias voltages were investigated. The film textures and microstructure were analyzed by X-ray diffraction and field emission scanning electron microscopy, and the resistivity of the film was measured with the Van der Pauw method. It was found that the optimum negative substrate bias voltage for Cu films was −50 V. The Cu films deposited without substrate bias voltage showed a columnar grain structure with small grains and random orientation. However, when a substrate bias voltage of −50 V was applied, the Cu films had a non-columnar structure with a strong (111) texture and large grains. The electrical resistivity of the Cu films decreased remarkably with increasing negative substrate bias voltage, and reaching a minimum value of 1.8±0.13 μΩ cm at the substrate bias voltage of −50V.     

CVD金刚石薄膜及膜-基界面形态

采用直流等离子体财流CVD法在硬质合金基体上沉积了多晶金刚石薄膜,借助XRD、Raman光谱、SEM和EPMA等对金刚石薄膜及膜-基界面的结构、形貌和成分进行了研究.结果表明,结晶度高的刻面型金刚石薄膜质量、纯度较好,膜-基界面处较致密,机械锚固作用明显,结合性能较好沉积前后基体表面形貌变化很大,存在数十微米厚的脱钴-等离子体刻蚀层,等离子体刻蚀导致脱钻表面更加凹凸不平,为金刚石形核提供了有利条件.     

CVD金属石薄膜及膜——基界面形态

采用直流等离子体射流ＣＶＤ法在硬质合金基体上沉积了多晶金刚石薄膜,借助ＸＲＤ,Ｒａｍａｎ,光谱、ＳＥＭ和ＥＰＭＡ等对金刚石薄膜及膜－基界面的结构、形貌和成分进行了研究,结果表明,结晶度高的刻面型金刚石薄膜质量、纯主较好,膜－基界面处较致密,机械锚固作用明显,结合性能较好,沉积前后基体表面形貌变化很大,存在数十数米厚的脱钴－等离子体刻蚀层,等离子体刻蚀导致脱钴表面更加凹凸不平,为金刚石形核提供了有利