原位氮掺杂对CVD金刚石薄膜生长和结构的影响

以氮气为杂质源 ,采用微波等离子体化学气相沉积技术进行了金刚石薄膜的原位掺杂 ,研究了氮掺杂对CVD金刚石薄膜的形貌结构和生长行为的影响。运用SEM ,Raman ,XRD和FTIR等手段对样品进行了分析表征。实验结果表明 ,原位氮掺杂的CVD金刚石薄膜的晶面显露、晶粒尺寸、致密性、生长速率以及薄膜的微结构特征等均强烈地依赖于反应气体中氮源浓度比 ;如果氮源气体流量适当 ,杂质氮不仅能进入金刚石薄膜晶格中 ,还能与薄膜中碳原子形成化学键结合     

原位氮掺杂对CVD金刚石薄膜生长和结构的影响

以氮气为杂质源，采用微波等离子体化学气相沉积技术进行了金刚石薄膜的原位掺杂，研究了氮掺杂对CVD金刚石薄膜的形貌结构和生长行为的影响。运用SEM，Raman，XRD和FTIR等手段对样品进行了分析表征。实验结构表明，原位氮掺发的CVD金刚石薄膜的晶面显露、晶粒尺寸、致密性、生长速率以及薄膜的微结构特征等均强烈的地依赖于反应气体中氮源浓度比；如果氮源气体流量适当，杂质氮不仅能进入金刚石薄膜晶格中，还能与薄膜中碳原子形成化学键结合。     

原位光发射谱研究横向偏压金刚石薄膜生长过程

利用热丝ＣＶＤ方法研究了横向偏压对金刚石薄膜成核和生长的影响．实验表明,随着偏流的增加,金刚石在光滑硅衬底上的成核密度得到显著提高,最高可达 １．１×１０^８ｃｍ^－２,但是横向偏压不利于金刚石薄膜的生长．原位光发射谱研究发现,横向偏流的增加提高了原子氢和ＣＨ基团的浓度,导致衬底表面非晶碳层的形成,这可能是造成横向偏压促进金刚石成核却不利于金刚石薄膜生长的主要原因．     

沉积参数对化学气相沉积纳米金刚石薄膜的影响

用强电流直流伸展电弧化学气相沉积金刚石薄膜装置,在CH4-Ar和CH4-H2-Ar气氛中沉积了纳米金刚石薄膜,研究了沉积气氛中H2加入量和沉积压力对金刚石薄膜显微组织和生长机制的影响.沉积气氛中H2含量对金刚石薄膜的表面形貌、晶粒尺寸和生长速度有显著影响,随着H2含量增加,金刚石晶粒尺寸增大,薄膜生长速度提高.在1%CH4-Ar气氛中沉积的纳米金刚石薄膜,晶粒尺寸细小,薄膜表面形貌光滑平整.在1%CH4-少量H2-Ar气氛中沉积的金刚石薄膜,晶粒尺寸小于100nm,薄膜表面形貌较平整.随着沉积压力提高,金刚石薄膜的生长速度增大.用激光Ram an对金刚石薄膜进行了表征.     

化学汽相沉积金刚石薄膜的生长

利用热丝化学汽相沉积法生长出优异的金刚石薄膜，研究表明，金刚石的成核依赖于沉积点的尖锐度，薄膜的生长包括晶粒长大和薄膜上的二次成核及其生长，可用分层生长来描述，金刚石晶粒的生长由外延生长和二次成核及其生长组成。也是分层进行的，结果导致了金刚石晶体和薄膜的层状结构。     

直流热阴极CVD金刚石薄膜生长特性研究

为了获得高质量的金刚石薄膜,采用直流热阴极化学气相沉积系统分别在不同基片温度和不同碳源气体含量条件下生长金刚石薄膜,利用Raman光谱、SEM和XRD检测方法研究了基片温度和碳源气体含量对金刚石薄膜生长特性的影响.结果表明,金刚石薄膜与基片Mo之间有Mo2C的过渡层存在;1000℃的温度能够促进金刚石晶体的生长,抑制其他碳杂质的形成,CH4体积分数为2%适于快速生长高纯度的金刚石薄膜.     

氮气氛下金刚石薄膜生长过程中的光发射谱研究

利用原位光发射谱对衬底附近的化学气相性质进行了研究．研究表明,氮气的引入使得金刚石生长的气相化学和表面化学性质发生了很大变化．含氮基团的萃取作用提高了金刚石表面氢原子的脱附速率,从而提高了金刚石膜的生长速率．而含氮基团的选择吸附使金刚石（１００）取向变得化学糙化,这种化学糙化使得（１００）晶面生长速率远大于其它晶面,最终使金刚石薄膜呈现（１００）织构．还利用化学气相沉积方法研究了氮气浓度对金刚石生长的影响,结果与光发射谱分析是一致的．     

生长温度对CVD金刚石薄膜的影响

系统研究了ＣＶＤ金刚石薄膜成膜过程中生长温度对薄膜质量、生长率和力学性能的影响。研究结果表明：在典型沉积条件下，生长温度愈高、薄膜的晶体质量愈好；但薄膜的应力状况和附着性能变坏；在８００℃时，金刚石薄膜的生长速率最大。讨论了ＣＶＤ金刚石薄膜作为机械工具涂层的最佳生长温度。     

面向薄膜材料光热特性参数的FPTR检测技术研究

该文提出采用频域光热辐射测量技术(FPTR)对金刚石薄膜的光热特性进行检测。首先,建立调制激光作用于一维有限厚度试件的热波频域响应模型,并搭建光热辐射测量检测系统;其次,采用该试验系统对厚度为200μm、直径为1.5 mm的金刚石薄膜进行频域光热辐射测量技术检测试验研究,得到了调制激光作用于金刚石薄膜的光热动态响应特性;最后,采用反问题求解方法获取金刚石薄膜的光热特性参数。试验结果表明,频域光热辐射测量技术可以对金刚石薄膜进行高精度检测。     

激光器全反射介质膜的制作原理与光学厚度测定

阐述了光学薄膜的镀制原理、反射率推算,阐述了镀制全反射介质薄膜过程中光学厚度的测定方法-极值法测量的原理和所用光线的波长,阐述了得到高反射率的条件,给出了测量膜厚的实验系统装置,并叙述了镀制17层全反射介质薄膜的过程和测量的方法,最后给出了17层全反射介质薄膜的反射率测量结果。     

Theoretical analysis of SAW propagation characteristics in (100) oriented AlN/diamond structure

In this study, the finite element method is employed to calculate SAW characteristics in (100) AlN/diamond based structures with different electrical interfaces; i.e., IDT/ AlN/diamond, AlN/IDT/diamond, IDT/AlN/thin metal film/ diamond, and thin metal film/AlN/IDT/diamond. The effects of Cu and Al electrodes as well as the thickness of electrode on phase velocity, coupling coefficient, and reflectivity of SAWs are illustrated. Propagation characteristics of SAWs in (002) AlN/diamond-based structures are also presented for comparison. Simulation results show that to retain a large reflectivity for the design of RF filters and duplexers, the Cu IDT/(100) AlN/diamond structure possesses the highest phase velocity and largest coupling coefficient at the smallest AlN film thickness- to-wavelength ratio.     

Investigation into polishing process of CVD diamond films

A new technique used for polishing chemical vapor deposition (CVD) diamond films has been investigated, by which rough polishing of the CVD diamond films can be achieved efficiently. A CVD diamond film is coated with a thin layer of electrically conductive material in advance, and then electro-discharge machining (EDM) is used to machine the coated surface. As a result, peaks on the surface of the diamond film are removed rapidly. During machining, graphitization of diamond enables the EDM process to continue. The single pulse discharge shows that the material of the coated layer evidently affects removal behavior of the CVD diamond films. Compared with the machining of ordinary metal materials, the process of EDM CVD diamond films possesses a quite different characteristic. The removal mechanism of the CVD diamond films is discussed.     

Thermal Diffusivity Measurement of Diamond Films1

This paper discusses the short-pulse-flash method developed for thermal diffusivity measurements on thin films. Two kinds of CVD diamond film have been prepared, and their thermal diffusivity in the perpendicular direction has been measured with this method. The measurement errors caused by the surface coating are discussed.     

金刚石薄膜涂层硬质合金刀具的界面表征

采用SEM对金刚石薄膜涂层硬质合金刀具的金刚石薄膜表面、背面及金刚石薄膜剥落后的硬质合金刀片表面的典型形貌进行了观察,并采用TEM对金刚石薄膜／硬质合金刀片横截面的微观组织进行了研究,还采用FT—Raman光谱法对金刚石薄膜表面及金刚石薄膜剥落后的硬质合金刀片表面的微观结构进行了表征．结果表明：经适当的化学侵蚀脱钻和等离子体刻蚀脱碳预处理后,金刚石薄膜涂层硬质合金刀具的界面通常存在薄的（数十nm）石墨碳层;局部区域见到金刚石粒子直接生长在WC颗粒上,金刚石膜／基横截面的典型组织层次为：金刚石薄膜／薄的石墨碳层／细小的WC层／残留的脱碳层（η相＋W相）／原始的硬质合金基体．     

CVD金刚石薄膜的介电性能研究

对直流电弧等离子体ＣＶＤ制备的金刚石薄膜的介电性能进行了研究，结果表明，金刚石薄膜的介电性能主要取决于样品的多昌性质以及表面和晶界处的非金刚石相和杂质成分。     

CVD金刚石膜高效超精密抛光技术

CVD金刚石膜作为光学透射窗口和新一代计算机芯片的材料,其表面必须得到高质量抛光,但是现存方法难以满足既高效又超精密的加工要求.本文提出机械抛光与化学机械抛光相结合的方法.首先,采用固结金刚石磨料抛光盘和游离金刚石磨料两种机械抛光方法对CVD金刚石膜进行粗加工,然后采用化学机械抛光的方法对CVD金刚石膜进行精加工.结果表明,采用游离磨料抛光时材料去除率远比固结磨料高,表面粗糙度最低达到42.2 nm.化学机械抛光方法在CVD金刚石膜的超精密抛光中表现出较大的优势,CVD金刚石膜的表面粗糙度为4.551 nm.     

Polishing of polycrystalline diamond by hot nickel surface

A microwave plasma technique has been employed to deposit polycrystalline diamond film over a molybdenum substrate button using a gas mixture of hydrogen and methane at a substrate temperature of 851°C. A CVD diamond coated molybdenum substrate button was mounted with a load against hot nickel plate and rotated for 3.45 h in a hydrogen ambient. Hot tungsten filament was used as a heat source to maintain the temperature of the nickel block and CVD diamond coated molybdenum button at 848°C. This experiment has reproducibly shown the successful polishing of polycrystalline CVD diamond by hot nickel. A Tencor profilometer and scanning electron microscope have been used to evaluate the surface smoothness and morphology before and after polishing the polycrystalline diamond thin films.     

Effects of Ti- and Zr-based interlayer coatings on the hot filament chemical vapour deposition of diamond on high speed steel

The prospect of obtaining good adhesion of diamond films onto steel substrates is highly exciting because the achievement of this objective will open up applications in the cutting and drilling industry. However, a major problem with depositing diamond onto steel is high diffusion of carbon into steel at chemical vapour deposition (CVD) temperatures leading to very low nucleation density and cementite (Fe₃C) formation. Therefore, the study of the nucleation and growth processes is timely and will yield data that can be utilised to get a better understanding of how adhesion can be improved. This work focuses on investigating the adhesion of thin diamond films on high speed steel previously coated with various interlayers such as ZrN, ZrC, TiC and TiC/Ti(C,N)/TiN. The role of seeding on nucleation density and the effect of diamond film thickness on stress development and adhesion has been investigated using SEM, XRD and Raman spectroscopy.The main emphasis in this study is the TiC interlayer which for the first time proved to be a suitable layer for diamond CVD on high speed steel (HSS). In contrast from other interlayer materials investigated here, no delamination was observed even after 3 h of CVD at 650 °C only when TiC was employed. Nevertheless, the increase of diamond film thickness on TiC coated HSS substrates led to the delamination of small areas in various regions of the substrate. This occurrence suggests that there was a distribution of adhesive toughness values at the diamond/TiC interface with stress development being dependent on film thickness.     

工艺条件对金刚石膜红外透射率影响的研究

为了优化金刚石沉积工艺,制备高透射率的CVD金刚石薄膜,采用傅里叶红外光谱仪对不同工艺条件下制备的CVD金刚石膜的红外透射率进行了测量,分析了不同工艺条件对金刚石膜红外透射率的影响,获得了最佳沉积参数.结果表明,金刚石膜的红外透射率与工艺条件密切相关,当衬底温度为750℃,碳源体积分数为2%,压强为2.5kPa时沉积的金刚石膜红外透射率最佳.     

等离子体刻蚀处理对金刚石膜粘附性能的影响

采用直流等离子体射流ＣＶＤ法在ＹＧ８质合金基体上成功地合成了多晶金刚薄膜。通常基体表面经金刚石磨盘研磨、稀硝酸化学侵蚀脱钴预处理后，沉积的金刚石薄膜的的粘附性能仍不理想。本文首次采用原位的Ａｒ－Ｈ２等离子体射流对基体表面进行适当的轰击、刻蚀处理，显著粗化了基体表面，并使基体表面显微组织和化学成分发生重大变化，并且在合适的沉积工艺条件下，沉积的金刚石膜的粘附性能显著提高。借助ＸＲＤ、ＳＥＥＭ、ＴＥＭ