线形微波等离子体源及其在CVD金刚石中的应用

发布时间：2018-01-04 08:40

本文关键词：线形微波等离子体源及其在CVD金刚石中的应用　出处：《武汉工程大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文概括和比较了各类线形等离子体源的特点及应用,在此基础上设计了一种新型的线形同轴耦合微波等离子体源并用于沉积金刚石薄膜。本研究课题主要是针对长杆状基底材料的几何特征,设计与之匹配的新型线形同轴耦合微波等离子体源。以现在普遍使用的石英管式线形同轴耦合微波等离子体源为基础,通过重新设计天线与腔体的结构,去除了原装置中的石英管。并且在研究过程中对已经成型但是还不稳定的此装置进行了大量的改进,使其能在较高气压下得到长度为20cm的稳定均匀的线形微波等离子体源。利用改进后的线形微波等离子体CVD装置进行了长杆状氧化铍夹持杆表面沉积金刚石薄膜的研究,研究结果表明:对未经前期预处理的氧化铍表面进行金刚石薄膜沉积,由于氧化铍表面不同区域晶粒取向不同,缺陷密度不均匀,导致形核不均匀,进而生长后形核密度高的地方金刚石薄膜发生了脱落,而形核密度低的地方还没有形成连续薄膜;而经金刚石粉抛光后的氧化铍表面由于表面光滑平整,缺陷少,形核时所需的形核功高,故而形核密度低,生长后未能形成连续的金刚石薄膜;采用砂纸和金刚石粉研磨过后的氧化铍表面形貌一致,表面缺陷多且分布均匀,形核时所需的形核功低,形核后形核密度高且均匀,生长后能形成连续金刚石膜,其晶粒呈菜花状球形颗粒。综合运用SEM和Raman对氧化铍夹持杆表面沉积的金刚石薄膜进行了表征。根据表征结果,分析了球形金刚石颗粒的成分组成,及其生长过程,得出菜花状球形金刚石薄膜主要是由非晶碳和纳米级的小金刚石颗粒组成。其生长成膜过程主要是以原始晶核为中心,向四周以二次形核生长方式生长。分析形成菜花状球形金刚石颗粒的原因是由于甲烷浓度过高,碳氢基团在生长面上堆积形成二次形核,二次形核不断发生,抑制了原有晶核的长大,故而形成了由纳米小金刚石颗粒组成的较大球形金刚石颗粒。而降低甲烷浓度能有效抑制二次形核的发生,并且使晶型生长完整。
[Abstract]:In this paper, the characteristics and applications of various linear plasma sources are summarized and compared. A novel linear coaxial coupled microwave plasma source was designed and used to deposit diamond thin films. This research is mainly focused on the geometric characteristics of long rod substrates. A new type of linear coaxial coupled microwave plasma source is designed. Based on the quartz tube coaxial coupled microwave plasma source, the structure of antenna and cavity is redesigned. The quartz tube is removed from the original device and a large number of improvements have been made to the device which has been formed but not stable in the course of the research. A stable and uniform linear microwave plasma source of 20 cm in length was obtained at high pressure. Gold deposition on the surface of long rod type beryllium oxide gripping rod was carried out by using an improved linear microwave plasma CVD device. Study on the mandlite film. The results show that the diamond film is deposited on the surface of beryllium oxide without pre-treatment. The nucleation is not uniform due to the different orientation of grain and the uneven density of defects on the surface of beryllium oxide. After growth, the diamond films with high nucleation density have shedding, while the continuous films have not been formed where the nucleation density is low. However, the surface of beryllium oxide after diamond powder polishing is smooth and smooth, with less defects, high nucleation work and low nucleation density, so the continuous diamond film can not be formed after growth. The surface morphology of beryllium oxide after grinding with sand paper and diamond powder is the same, the surface defects are many and uniform, the nucleation work is low and the nucleation density is high and uniform. The diamond films deposited on the surface of beryllium oxide were characterized by SEM and Raman. The composition and growth process of spherical diamond particles were analyzed. It is concluded that the growth process of cauliflower spherical diamond films is mainly composed of amorphous carbon and nanocrystalline small diamond particles. The reason for the formation of cauliflower spherical diamond particles is that the hydrocarbon group accumulates on the growth surface and the secondary nucleation occurs continuously due to the high concentration of methane. By inhibiting the growth of the original crystal nucleus, a large spherical diamond particle composed of nanocrystalline diamond particles was formed, while the reduction of methane concentration could effectively inhibit the occurrence of secondary nucleation and make the crystal growth complete.
【学位授予单位】：武汉工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ163;TB383.2

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