等离子体刻蚀增强CVD金刚石膜抛光的研究

发布时间：2018-04-28 06:25

本文选题：等离子体刻蚀 + 抛光　；参考：《武汉工程大学》2015年硕士论文

【摘要】：CVD金刚石以其卓越优异的性能成为未来引人注目的工程材料。它已在硬质刀具、光学、热学、声学、微电子等方面得到广泛应用。但这些领域的应用均要求CVD金刚石表面具有一定平整度。现今,由于CVD金刚石柱状生长特性导致金刚石片厚度不均、晶粒大小不一和取向各异,产生了一个较为粗糙的表面,限制了其应用范围。因此,根据不同工业应用要求,CVD金刚石表面抛光技术成为金刚石应用的至关重要的一个环节。本研究中为了降低CVD金刚石表面粗糙度,采用了ECR等离子体刻蚀与机械抛光相结合的抛光方式,充分利用机械抛光技术的低成本、方便以及ECR等离子体刻蚀的高效率、低损伤等两者的优点,从而提高机械抛光效率和金刚石表面质量。其具体工作如下:1.运用ECR等离子体刻蚀和机械抛光技术相结合的方法来抛光CVD金刚石,并和单一的机械抛光方法相比较,研究了等离子体刻蚀对后续机械抛光的影响,结果发现:金刚石经ECR等离子体刻蚀后非晶碳含量有一定程度降低,刻蚀过程在金刚石晶面形成的疏松表面有利于机械抛光,金刚石表面平均粗糙度更加快速降低。对比实验表明等离子体刻蚀对机械抛光前期的抛光效率的增强效果更为明显。2.采用ECR等离子体对金刚石片进行了刻蚀实验,研究了磁场位形、样品台大小和样品台偏压这三个工艺参数对CVD金刚石刻蚀效果的影响,并分别对样品进行了抛光处理。结果发现:(1)收敛场相比于发散场,由于对等离子体具有约束和聚焦作用,离子束更聚集且具有更高能量,产生了更强的刻蚀效果,金刚石表面缺陷层更厚,从而更为明显的提高了机械抛光效率。(2)样品台大小对刻蚀有影响。使用小样品台时,自偏压对离子束更强的汇聚作用和刻蚀后表面的场致发射,使得轰击金刚石片表面的离子能量和数量都得到了增强。相比于大样品台,更多高能离子轰击金刚石样品表面产生了更厚的缺陷层,刻蚀对机械抛光效率的增强效果更为显著。(3)随着样品台加载偏压的改变,在等离子体直流鞘层和CVD金刚石表面微区域电场的共同作用下,ECR等离子体刻蚀CVD金刚石的结果表明离子束产生了选择性刻蚀。其中在偏压为-30V时,由于粒子束轰击作用集中在高位区域,且区域较广,因此高位区域缺陷层更厚,机械抛光时更易被除去,从而具有更高的抛光效率。3.在原有的刻蚀后机械抛光的工艺基础上,增加铜质掩膜,探究了掩膜在刻蚀增强CVD金刚石机械抛光中的作用,并对抛光前后金刚石表面性能进行了检测,结果发现:(1)增加了铜质掩膜的抛光工艺具有更高的抛光效率,同时对抛光过程中CVD金刚石的减薄有一定的抑制作用,减少了CVD金刚石的损耗,从而降低了生产成本,是一种具有较高抛光效率、低成本、低损耗的抛光方法。(2)与未抛光金刚石相比,抛光后的金刚石表面光洁平整,质量有一定提高,润湿角增大。
[Abstract]:CVD diamond has become an attractive engineering material in the future due to its excellent performance. It has been widely used in hard cutting tools, optics, heat, acoustics, microelectronics and so on. However, the application of these fields all require a certain smoothness of CVD diamond surface. Nowadays, due to the columnar growth characteristics of CVD diamond, the thickness of diamond is uneven, the grain size and orientation are different, resulting in a rough surface, which limits its application. Therefore, CVD diamond surface polishing technology has become an important part of diamond application according to different industrial application requirements. In this study, in order to reduce the surface roughness of CVD diamond, ECR plasma etching and mechanical polishing are used to fully utilize the low cost and convenience of mechanical polishing technology and the high efficiency of ECR plasma etching. Low damage and other advantages of both, thereby improving mechanical polishing efficiency and diamond surface quality. Its specific work is as follows: 1. The effect of plasma etching on the subsequent mechanical polishing of CVD diamond was studied by using ECR plasma etching and mechanical polishing technology, and compared with the single mechanical polishing method. The results show that the amorphous carbon content of diamond etched by ECR plasma is reduced to a certain extent. The loose surface formed in the etching process is favorable to mechanical polishing, and the average roughness of diamond surface decreases more rapidly. The contrast experiment shows that plasma etching can enhance the polishing efficiency in the early stage of mechanical polishing more obviously. ECR plasma was used to etch diamond wafers. The effects of three technological parameters, magnetic field configuration, sample table size and bias voltage, on the etch effect of CVD diamond were studied, and the samples were polished. The results show that compared with the divergence field, the ion beam is more concentrated and has higher energy due to the confinement and focusing of the plasma, which results in stronger etching effect and thicker defect layer on the diamond surface. Thus, the mechanical polishing efficiency is improved more obviously.) the size of the sample table has an effect on the etching. When the small sample table is used, the self-bias voltage has a stronger convergent effect on the ion beam and the field emission of the etched surface increases the ion energy and the amount of ion bombarding the diamond chip surface. Compared with the large sample table, more high-energy ions bombarded the diamond sample surface to produce a thicker defect layer, and the enhancement effect of etching on the mechanical polishing efficiency was more remarkable. The results of CVD diamond etching by plasma DC sheath and microelectric field on CVD diamond surface show that the ion beam produces selective etching. When the bias voltage is -30V, the particle beam bombardment is concentrated in the high position area, and the area is wide, so the defect layer in the high position area is thicker and the mechanical polishing process is easier to be removed, so it has higher polishing efficiency. On the basis of the original mechanical polishing process after etching, the copper mask is added, and the role of mask film in etching and strengthening CVD diamond mechanical polishing is explored, and the surface properties of diamond before and after polishing are tested. The results show that the polishing process of copper mask has higher polishing efficiency, and it can restrain the thinning of CVD diamond, reduce the loss of CVD diamond, and thus reduce the production cost, the result shows that: 1) the polishing process of copper mask has higher polishing efficiency, and at the same time, it can inhibit the thinning of CVD diamond in the polishing process, thus reducing the cost of production. It is a polishing method with high efficiency, low cost and low loss. Compared with the unpolished diamond, the polished diamond surface is smooth and smooth, the quality is improved, and the wetting angle is increased.
【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

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