H2-O2混合气氛刻蚀制备金刚石纳米晶薄膜

提供了在镜面抛光Si衬底上沉积平滑的纳米金刚石（NCD）薄膜的方法。采用微波等离子体化学气相沉积（CVD）系统，利用H2、CH4和O2为前驱气体，在镜面抛光的Si基片上制备了直径为5cm的NCD薄膜，用扫描电镜（SME）和共焦显微拉曼光谱分析其表面形貌和结构特点。分析表明，利用这种方法可以制备出高sp^3含量的NCD薄膜。通过与沉积时间加长而沉积条件相同情况下合成的金刚石微晶薄膜形貌相对比，分析了H2-O2混合气氛刻蚀制备NCD薄膜的机理。分析表明，基底的平滑度对O2的刻蚀作用起到重要的影响；在平滑的基底上，含量较少的O2的刻蚀作用也很明显；随着基底的平滑度下降，混合气氛中O2的刻蚀作用逐渐减弱。     

衬底表面处理对燃烧焰法沉积金刚石膜成核密度的影响

研究了衬底表面不同处理对燃烧焰法沉积金刚石成核密度的影响，发现用硬微粉（金刚石，碳化硅）对衬底的刻划，能明显地提高成核密度，在衬底表面涂覆机械泵油或先沉积薄类金刚石层也能显著提高成核密度。成核密度的提高有利于生长出连续金刚石膜。     

低压气相生长金刚石薄膜成核机理的研究

本文论述了低压气相生长金刚石薄膜中活性原子团ＣＨ＿３和原子态氢在金刚石成核运动中的作用以及衬底材料性能对成核的影响，认为活性基ＣＨ＿３是生长金刚石的主要活性物质，它们在衬底表面的吸附、碰撞、聚集等构成了成核运动，原子氢在成核运动中的主要作用是参与ＣＨ＿３的脱氢反应和石墨相碳原子团的刻蚀反应，并且还有稳定ＣＨ＿３中ＳＰ￣３杂化轨道的作用。衬底材料性能对成核的影响在于晶格失配而导致的错配位错和晶格畸变所引起的界面势垒和晶核弹性能的增加。最后讨论了金刚石薄膜与衬底之间是否存在过渡层问题，认为过渡层不是金刚石唯一的成核区，它的存在与生长条件密切相关，并且解释了关于过渡层实验研究中遇到的相互矛盾的结论。     

军用纳米金刚石膜的研究与应用综述

对金刚石膜(及类金刚石膜)与传统光学材料的特性作了比较，分析了美军对于金刚石膜军用光学应用的需求以及金刚石膜在现有高科技武器装备中的应用前景，介绍了研制纳米金刚石膜的关键技术问题(主要是CVD和PLD方法)以及国内外研究和应用现状。     

外延纳米金刚石膜及其场发射特性

研究了纳米金刚石外延薄膜的制备方法及其场发射特性。采用电泳方法将粒径20nm以下的纳米金刚石微品沉积到Ti电极衬底上，用热丝CVD方法在纳米金刚石微晶薄膜上再外延生长一层含非晶碳金刚石薄膜。用Raman光谱研究了外延纳米金刚石薄膜的结构并在高真空条件下研究了其场发射特性。     

C60薄层作为CVD金刚石成核区的研究

本文研究了在微波等离子体ＣＶＤ系统中，金刚石在Ｃ６０蒸发膜表面的成核行为，观察到金刚石晶核聚集现象，并且讨论了这种成核行为的产生机理。     

氮掺杂金刚石膜的生长特性

采用电子辅助化学气相沉积法(EA-CVD),在含氮气氛中制备出金刚石膜,利用SEM、Raman光谱、EPR测试手段研究了氮气对金刚石膜品质的影响及氮掺杂特性.结果表明,在950℃基片温度下,沉积气氛中掺入氮气后,金刚石膜晶形变为"菜花状", 非金刚石碳的含量增加,膜的品质下降.在800℃基片温度下,沉积气氛中掺入氮气后,孪晶和二次成核减少,金刚石膜的结晶形貌得到改善.通过Raman光谱和EPR分析发现,在金刚石膜中氮杂质主要以Ns0,[N-V]0和[N-v]-1的形式存在,而且随着氮气流量的增加,Ns0的含量增加,[N-V]0含量减少,[N-V]-1含量变化不明显.     

氮掺杂金刚石膜的生长特性

采用电子辅助化学气相沉积法(EA-CVD),在含氮气氛中制备出金刚石膜,利用SEM、Raman光谱、EPR测试手段研究了氮气对金刚石膜品质的影响及氮掺杂特性.结果表明,在950℃基片温度下,沉积气氛中掺入氮气后,金刚石膜晶形变为"菜花状", 非金刚石碳的含量增加,膜的品质下降.在800℃基片温度下,沉积气氛中掺入氮气后,孪晶和二次成核减少,金刚石膜的结晶形貌得到改善.通过Raman光谱和EPR分析发现,在金刚石膜中氮杂质主要以Ns0,[N-V]0和[N-v]-1的形式存在,而且随着氮气流量的增加,Ns0的含量增加,[N-V]0含量减少,[N-V]-1含量变化不明显.     

Si衬底气相生长金刚石薄膜的成核机制

本文根据热力学成核理论，研究了Ｓｉ衬底表面气相生长金刚石薄膜的成核机理，提出了与实验相符的理论分析。     

金刚石电子材料生长的研究进展

简述了金刚石兼具物理的和化学的优良性质,尤其是金刚石的半导体电气性质,即宽带隙、高击穿电场、高载流子迁移率和高热导率,成为固态功率器件最有前途的半导体材料之一。介绍了金刚石基的电子器件及其材料生长的研究进展,分析了金刚石膜的导电机理以及材料生长的新技术。重点介绍了采用包括微波等离子体化学汽相淀积(MPCVD)等方法制备金刚石膜、本征单晶生长、硼掺杂等技术。目前在直径为100~200 mm的硅衬底上,可以淀积均匀的超纳米结晶金刚石(UNCD)膜。此外,对金刚石电子学和光电子学的未来进行了展望。     

C60与金刚石薄膜成核关系的研究

采用热丝化学气相沉积法在覆盖C60膜的硅基片上沉积金刚石膜,研究了金刚石膜的成核与生长.实验结果表明,金刚石的成核密度可达1×106Cm-2,利用这种方法可实现衬底无损淀积金刚石膜.C60之所以能够促进金刚石成核,我们认为主要与C60分子本身独特的结构及H原子的激活作用有关.同时,高温下C60分解后残留的石墨等碳碎片以及C原子与衬底Si反应生成的SiC都可作为金刚石的成核位.     

CVD金刚石膜制备方法及其应用

介绍了金刚石膜的应用和低压下化学汽相沉积金刚石膜的主要方法及其最新进展,并对各种方法的优缺点作了简要评述。     

硫掺杂纳米金刚石薄膜的图形化生长

利用电子增强热丝化学气相沉积(EACVD)技术,以CH4/H2/H2S/Ar为工作气体,SiO2/Si为衬底,制备了硫掺杂金刚石薄膜。研究了利用光刻技术实现薄膜的图形化生长。结果表明:以SiO2作掩模的光刻技术能够使得硫掺杂金刚石薄膜在光滑SiO2/Si基片上很好地图形化生长。Hall效应检测表明硫掺杂金刚石薄膜为n型,给出了n型金刚石/p-Si异质结的反向I-V特性曲线。     

Electrical property dependence on thickness and morphology of nanocrystalline diamond thin films

In this study, we investigate the influence of nanocrystalline diamond (NCD) thin film morphology and thickness on their electrical properties. NCD films are grown on p-type Si substrates with varied thicknesses from 250 to 788 nm. Electrical contacts are formed from combination of Ti/Au metal layers (100 nm thick each). The I-V and breakdown field measurements are used to analyze the electrical properties of metal/NCD/Si sandwich structure. In addition, NCD films are analyzed by scanning electron microscopy and Raman spectroscopy for better interpretation of the I-V measurements.     

Growth of oriented diamond film on single crystalline 6H-SiC substrates

The bias-enhanced nucleation (BEN) technique in hot-filament chemical vapor deposition (HF-CVD) has been applied to single crystalline 6H-SiC substrates for the deposition of oriented diamond. The results of scanning electron microscopy (SEM) showed that on (000 ) face not only oriented diamond with relationship (111) Dia.//(000 )6H-SiC and 〈110〉Dia.//(11 0)6H-SiC, but also high nucleation density (>10⁹ cm⁻²) have been achieved. In the case of deposition on (0001) face of 6H-SiC under the same experimental conditions, although the nucleation density of diamond was enhanced, however, oriented diamond was not found. Diamond nucleation density is higher on (0001) face than that on (000 ) face. The differences in diamond oriented nucleation and nucleation density on these two faces are attributed to the difference of their specific free surface energy. The experimental results have shown that the 6H-SiC substrate surfaces are etched by the accelerated H-ions during BEN process, and many micro-triangular crystals with the faces of the kind {01 4} are formed on the substrate surface. Diamonds nucleate on the top of the micro-triangular crystals. Micro-Raman spectrum shows a strong feature of diamond crystals at 1334 cm⁻¹.     

快速热退火温度对纳米晶氢-硅薄膜及其p-n结性能的影响

采用快速热退火(RTA)对热丝化学气相沉积HWCVD制 备的非晶氢-硅(a-Si:H)薄膜进行晶化处理,并在此基础上制备了 纳米晶氢-硅(nc-Si:H)薄膜p-n结。利用拉曼(Raman)光谱、X射线衍射(XRD)、 扫描电子显微镜(SEM)和分光光 度计研究了所制备(nc-Si:H)薄膜的结构、光学性能与退火温度的关系;同时, 研究了不同RTA条 件下制备p-n结的整流特性随温度变化的规律。研究发现,随RTA温度由700℃升高至 1100℃,薄膜的晶化率由46.3%提高到96%,拉曼峰半高宽(FWHM)由19.7cm－1降低至7. 1cm－1。当退火 温度为700℃时,薄膜的XRD谱中只有一个较弱的Si(111)峰;当退火 温度高于900 ℃时,薄膜 的XRD谱中除Si(111)峰外,还出现了Si(220)、Si(311)峰。同时,随退火温度的升高,薄膜 的禁 带宽度由1.68eV升高至2.05eV。由于禁带宽 度的增加,相应的p-n结最高工作温度也由180℃升高至300℃。     

Molecular view of diamond CVD growth

In this paper, we discuss the simulation of the chemical vapor deposition (CVD) of diamond films on the molecular scale. These simulations are performed using a kinetic Monte Carlo method that combines the surface chemistry that is important to diamond growth with an atomic-scale picture of the diamond surface and its evolving atomic structure and morphology. We address the determination of surface reaction kinetics and growth conditions from experiments and reactor-scale models, and the prediction of polycrystalline film texture and morphology from the molecular-scale results. The growth rates and the concentrations of incorporated point defects as a function of substrate temperature for {100}- and {111}-oriented diamond films are obtained from the molecular-scale growth simulations. The {100} growth rates increase with temperature up to 1200K and then decrease above this value. The {111} growth rates increase with temperature at all of the temperatures studied. The concentrations of point defects in the {100} and {111} films are low at substrate temperatures below 1200K, but increase substantially at higher temperatures. The growth efficiency, measured as the ratio of film growth rate to defect concentration, is maximum between 1100–1200K for both film orientations, suggesting that this temperature range is ideal for CVD diamond growth under the simulated growth conditions.     

修饰掺硼金刚石电极循环伏安法检测尿酸

用直流等离子体喷射化学气相沉积(CVD)法制备掺 硼金刚石(BDD)薄膜电极。通过扫描电镜(SEM)观察到薄膜表面分布均匀致密;霍尔测 试仪检测薄膜的电阻率为0.023Ω·cm,载流子浓度为6.423×10¹⁹ cm－3;循环伏安法(CVa)测得其电极电势窗为 3.4V;分析了浓度为10μmol/L的 尿酸(UA)溶液在BDD电极表面的电化学响应,表明扫描速率的平方根与氧化峰电流呈线性关 系。通过对比茜素黄、牛磺酸和L-半胱氨酸3种物质对BDD电极进行修饰,表明由L-半胱氨 酸修饰BDD电极的电催化氧化能力最强;在浓度为1×10－7～1×10－4 mol/L范围内,浓度的对数与氧化峰电流呈线性关系,且检测限为 1×10－8 mol/L。实验结果表明,20倍浓度的葡萄糖和抗坏血酸对UA的 检测不构成影响。     

基于电感耦合氧等离子体金刚石膜表面修饰的功率优化

采用电感耦合等离子体（ICP）氧等离子体刻蚀金刚石膜,探寻金刚石膜表面处理的方法。通过分析不同ICP射频源功率和不同偏压源功率下的刻蚀速率,研究了金刚石膜刻蚀的机理作用;通过拉曼光谱进行表征,分析刻蚀前后sp2与sp3的含量。结果表明,在ICP氧等离子体刻蚀的过程中,sp3键部分转化为sp2键;刻蚀后表面粗糙度降低;当...     

Processing and properties of CVD diamond for thermal management

One of the many remarkable properties of diamond is its thermal conductivity, about five times that of copper and the highest of all known materials. The high thermal conductivity in combination with the relative ease of diamond film growth by chemical vapor deposition process makes the material suitable for many applications such as thermal management in high power electronic circuits. For thermal managements applications, various processing steps are needed for the diamond films, such as the metallization for reliable solder bonding, metallurgical processes for planarizing of the faceted growth surface and removal of fine-grained diamond regions with poor thermal conductivity. This paper will review the properties and processing of diamond films for thermal management applications.