系统压强对微波等离子体化学气相沉积金刚石成核的影响

为了在氧化铝上制备（100）定向织构的金刚石薄膜,必须先提高金刚石的成核密度,在微波等离子体化学气相沉积（MPCVD）系统中,采用低压成核的方法,在氧化铝陶瓷上沉积出高成核密度的金刚石薄膜,扫描电镜显示其成核密度可达10^8cm^-2。在此基础上,沉积出（100）织构的金刚石薄膜。     

用MPCVD法在WC—Co刀具上沉积金刚石薄膜

研究了硬质合金基体的预处理对金刚石沉积的影响,并确定了用MPCVD法在WC-Co刀具上沉积金刚石薄膜的工艺参数。采用了一些提高成核密度和沉积速率的方法,用SEM、XRD和Raman对金刚石薄膜的性质进行了分析。结果表明,合适的预处理可以有效的抑制钴的溢出并提高薄膜的质量。     

用MPCVD法在WC-Co刀具上沉积金刚石薄膜(英文)

研究了硬质合金基体的预处理对金刚石沉积的影响,并确定了用 MPCVD法在 WC－ Co刀具 上沉积金刚石薄膜的工艺参数。采用了一些提高成核密度和沉积速率的方法, 用 SEM、 XRD和 Raman对金刚石薄膜的性质进行了分析。结果表明,合适的预处理可以有效的抑制钴的溢出并提 高薄膜的质量。     

高品质金刚石膜微波等离子体CVD技术的发展现状

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。     

偏压对金刚石薄膜选择性成核和生长影响的研究

利用偏压增强MPCVD法成功地实现了金刚石薄膜在附有SiO2掩膜图形的镜面抛光的Si(100)上的选择性织构生长,列举了最佳偏压成核与选择性生长条件,SEM和Raman光谱对所得样品进行了表征,并对偏压对选择性成核和生长的影响机制进行了探讨.     

MPCVD制备金刚石膜的形核与生长过程

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。     

纳米粉预处理的CVD金刚石薄膜成核与生长研究

研究了纳米金刚石粉预处理的光滑硅衬底上CVD金刚石薄膜的成核与生长．通过与研磨处理样品相比较,纳米金刚石的预处理极大地提高了成核密度（可达10⁹／cm²）、成核速度与成膜质量,并能方便地进行成核密度的控制,是一种经济实用、简单有效的预处理方法．     

金刚石晶粒和薄膜的侧向沉积

将传统的灯丝热解化学气相沉积系统改装成侧向沉积系统，并在其中进行了金刚石薄膜的正、侧向沉积。研究表明，侧向沉积的成核密度和生长度与正向沉积的情况基本相同，崦侧向沉积系统中金刚石颗粒和薄膜的沉积速率要比传统的沉积系统的高，但结构更趋复杂。讨论服基底对金刚石成核和生长过程的影响，深化了厂金刚石沉积机理的理解。     

圆柱谐振腔式微波等离子体金刚石膜CVD沉积室的FDTD模拟与优化

微波等离子体化学气相沉积(MPCVD)技术被认为是制备高质量金刚石膜的一种最重要的技术手段。对微波等离子体金刚石膜沉积装置进行模拟与优化,可大大减少设计和改进MPCVD装置时所需要的时间与成本。本文在结合使用谐振腔质量因子和沉积台上方等离子体的密度与分布两个优化判据的基础上,采用Matlab语言和时域有限差分方法,模拟了圆柱谐振腔式微波等离子体金刚石膜沉积装置,并对其主要尺寸进行了优化。     

CVD生长金刚石薄膜衬底负偏压增强成核效应

基于已经得到的实验结果的分析，本文较详细地讨论了低压化学气相沉积（ＣＶＤ）金刚石薄膜过程中，衬底负偏压对金刚石成核的增强效应，明确阐述了负偏压增强成核的作用机理，并且讨论了这种效应作为提高金刚石在非金刚石衬底表面成核密度的一种方法所具有的优点以及存在的不足。     

采用正交法研究金刚石偏压形核

在微波等离子体化学气相沉积装置中 ,采用正交试验法研究金刚石在镜面抛光的Si( 1 0 0 )面上的偏压形核过程中 ,形核时间、偏压电压、气压及甲烷浓度对形核密度的影响 ,研究结果表明 :形核密度随形核时间的增加而增加 ,适中的偏压电压和沉积气压有利于金刚石的形核 ,而甲烷浓度的影响很小。正交试验所得的最佳形核条件为偏压 -1 5 0V ;时间 1 2min ;气压 4kPa;CH4 比率 5 % ,在该条件下金刚石的形核密度达到 1 0 1 0 个 cm2 。     

微波等离子体化学气相沉积法在硅片上同时生长碳化硅和金刚石

研究了衬底温度、核化密度、衬底表而预处理等工艺参数对微波等离子体化学气相沉积法在硅片上同时生长碳化硅和金刚石的影响.采用扫描电镜、X-射线衍射、喇曼光谱和红外光谱对样品进行了表征.结果表明:从高核化密度生长的金刚石膜中探测不到碳化硅;不论对硅衬底进行抛光预处理还是未抛光预处理,从低核化密度牛长的金刚石厚膜中总能探测到碳化硅.碳化硅生长在硅衬底上未被金刚石覆盖的地方,或者是在金刚石晶核之间的空洞处.碳化硅形成和金刚石生长是同时发生的两个竞争过程.此研究结果为制备金刚石和碳化砟复合材料提供了一种新的方法.     

Diamond deposition on copper: studies on nucleation, growth, and adhesion behaviours

This paper presents a systematic study on diamond growth on copper by microwave plasma chemical vapour deposition (MPCVD). It includes the following four main parts. 1. Effect of substrate pre-treatment on diamond nucleation. 2. Effect of deposition conditions on diamond nucleation and growth. 3.Preparation of free-standing diamond films using copper substrate. 4. Adherent diamond coating on copper using an interlayer. In the first part we show that diamond nucleation on copper is strongly affected by the substrate pre-treatment. The residues of abrasives left in the surface of the copper substrate play an important role in the diamond nucleation. In the second part we show that the diamond growth rate increases with microwave power and gas pressure. The effect of the microwave power is mainly an effect of substrate temperature. Increasing methane concentration results in a higher nucleation density and higher growth rate, but at the cost of a lower film quality. Gas flow rate has little influence on the diamond nucleation density and growth rate. In the third part we demonstrate the possibility of preparing large area free-standing diamond films using copper substrate, which has nearly no carbon affinity and usually leads to weak adhesion of the diamond films. The normally observed film cracking phenomenon is discussed and a two-step growth method is proposed for stress release. In the fourth part we show that adherent diamond coating on copper can be obtained using a titanium interlayer. Residual stress in the films is evaluated by Raman spectroscopy. It is found that with increase in the film thickness, the diamond Raman line shifts from higher wave numbers to lower, approaching 1332 cm–1. The stress variation along the depth of the film is also analysed using Airy stress theory.     

温度场对金刚石薄膜质量的影响

在引进的韩国微波等离子化学气相沉积（MPCVD）设备中,利用氢气和甲烷作为气源,在单面抛光的（100）单晶硅片上研究了不同的形核温度和生长温度条件下制备出金刚石薄膜。通过Raman光谱、XRD光谱和扫描电子显微镜（SEM）对制备的金刚石膜的质量进行表征。研究结果表明,形核温度和生长温度对金刚石膜的生长均有影响。形核温度过低会增大薄膜中的非金刚石相的含量,促使二次形核增加,降低了金刚石薄膜质量。随着生长温度的升高,金刚石中非金刚石相含量越少,金刚石的质量提高,但金刚石的晶面同时也被大量刻蚀。     

采用MPCVD法在硅衬底上选择性生长金刚石膜

采用微波等离子体化学气相沉积（MPCVD）法在附有SiO2掩摸的硅衬底上选择性沉积出了金刚石膜。采用扫描电子显微镜（SEM）和Raman光谱仪对金刚石膜的表面形貌和结构进行了表征。并讨论了衬底温度对金刚石薄膜选择性沉积的影响。得出了较佳的沉积条件。     

MPCVD法在氧化铝陶瓷上的金刚石膜沉积及其成核分析

用微波等离子体化学气相沉积（ＭＰＣＶＤ）法在氧化铝陶瓷基片上沉积了金刚石薄膜。实验表明，对基片进行适当的预处理，包括用金刚石研磨膏仔细研磨和沉积前原位沉积一层无定形碳层，可显著提高成核密度；对硅衬底和氧化铝基片上金刚石膜的成核过程进行了对比分析，并提出了提高氧化铝基片上沉积金刚石的成核的措施。     

Deposition of diamond coating on pure titanium using micro-wave plasma assisted chemical vapor deposition

The nucleation and growth of diamond coatings on pure Ti substrate were investigated using microwave plasma assisted chemical vapor deposition (MW-PACVD) method. The effects of hydrogen plasma, plasma power, gas pressure and gas ratio of CH₄ and H₂ on the microstructure and mechanical properties of the deposited diamond coatings were evaluated. Results indicated that the nucleation and growth of diamond crystals on Ti substrate could be separated into different stages: (1) surface etching by hydrogen plasma and the formation of hydride; (2) competition between the formation of carbide, diffusion of carbon atoms and diamond nucleation; (3) growth of diamond crystals and coatings on TiC layer. During the deposition of diamond coatings, hydrogen diffused into Ti substrate forming titanium hydride and led to a profound microstructure change and a severe loss in impact strength. Results also showed that pre-etching of titanium substrate with hydrogen plasma for a short time significantly increased the nuclei density of diamond crystals. Plasma power had a significant effect on the surface morphology and the mechanical properties of the deposited diamond coatings. The effects of gas pressure and gas ratio of CH₄ and H₂ on the nucleation, growth and properties of diamond coatings were also studied. A higher ratio of CH₄ during deposition increased the nuclei density of diamond crystals but resulted in a poor and cauliflower coating morphology. A lower ratio of CH₄ in the gas mixture produced a high quality diamond crystals, however, the nuclei density and the growth rate decreased dramatically.