金刚石刀具光催化辅助刃磨的抛光液研制

发布时间：2018-04-12 14:18

本文选题：金刚石刀具 + 化学机械抛光　；参考：《沈阳工业大学》2017年硕士论文

【摘要】：金刚石是自然界已知材料中硬度最大、摩擦系数最小的材料。其集多种优异的力学、光学、热学和电学等性能于一身,作为新一代信息技术中重点研发的第三代半导体材料,具有广泛的应用前景和巨大的市场潜力。随着我国人造金刚石产业的快速发展,人造金刚石刀具开始被广为应用,但受生长机制所限,制备后的金刚石晶体粗大,表面粗糙度较差,无法直接作为金刚石刀具,再加上金刚石的高硬度和良好的化学稳定性给超光滑、高精度和低损伤的平面加工带来了巨大的挑战。为此,本课题以化学机械抛光金刚石为基础,与光催化氧化技术相结合,提出全新的金刚石抛光方法。旨在建立高效平坦金刚石刀具的加工方法,及解决目前化学机械抛光中存在的抛光液易挥发、腐蚀设备、污染环境等问题。光催化辅助氧化刃磨金刚石刀具抛光液的主要研究工作如下:(1)通过光催化氧化机理分析提出光催化辅助刃磨金刚石方法,搭建光催化辅助抛光试验平台,试验选择Merc-1000型汞灯作为输出光源,氧化还原电位仪作为抛光液表征设备。采用金相显微镜、原子力显微镜等作为材料检测设备。(2)针对不同光催化剂、氧化剂、磨料、pH调节剂的选择,建立三种抛光液表征方法。经氧化还原电位与电导率表征试验得出:5nmTiO_2溶液氧化性最好,P25型TiO_2最为稳定,H_2O_2投加量为2~3ml、pH值为3时抛光液光催化活性最好。通过光催化降解甲基橙1h后完全脱色,验证了抛光液氧化性。为验证抛光可行性,建立硅片抛光材料表征试验,由7种抛光液对比抛光后得出,最佳抛光液为TiO_2(P25)+H_2O_2+紫外光+SiO_2+H+,材料去除率为(5.9mg/h),抛光后表面形貌最好。(3)建立多种金刚石刀具抛光液验证试验。在金刚石膜光催化抛光中,获得极为光滑金刚石台阶面,整体表面粗糙度从Rz387.6μm下降到Rz47.131μm。通过不同催化剂抛光液对CVD金刚石抛光,得出P25型抛光效果最好,最终表面粗糙度Ra0.399nm。在高温高压金刚石抛光中获得了0.012mg/h的材料去除率。通过Matlab建立抛光轨迹仿真,合理的抛光盘转速为60r/min,载样盘31r/min。结合以上优化工艺,研磨抛光出优质的金刚石刀具后刀面与刀刃。通过XPS能谱分析得出,在紫外光照射条件下TiO_2表面生成具有很强氧化性空穴,空穴在酸性环境中能够将水分解成具有强氧化性的羟基自由基,羟基自由基与金刚石反应生成氧化物。
[Abstract]:Diamond is the material with the highest hardness and the lowest friction coefficient among known materials in nature.It has many excellent mechanical, optical, thermal and electrical properties. As the third generation semiconductor material, it has a wide application prospect and great market potential.With the rapid development of synthetic diamond industry in China, synthetic diamond tools have been widely used. However, due to the growth mechanism, the prepared diamond crystals are coarse and the surface roughness is poor, so they can not be used as diamond cutting tools directly.In addition, the high hardness and good chemical stability of diamond pose a great challenge for ultra-smooth, high-precision and low-damage planar machining.Therefore, based on chemical-mechanical polishing diamond and photocatalytic oxidation technology, a new diamond polishing method is proposed.The purpose of this paper is to establish the machining method of high efficient and flat diamond tools and to solve the problems existing in chemical mechanical polishing such as easy volatilization of polishing fluid corrosion of equipment and pollution of environment.The main research work of photocatalytic assisted oxidation grinding diamond tool polishing liquid is as follows: (1) based on the analysis of photocatalytic oxidation mechanism, a method of photocatalytic assisted grinding of diamond is put forward, and a photocatalytic polishing test platform is set up.Merc-1000 mercury lamp was used as output light source and redox potentiometer was used as polisher.Metallographic microscope and atomic force microscope (AFM) were used as testing equipment. Three methods of characterization of polishing solution were established according to the selection of different photocatalysts, oxidants and abrasive pH modifiers.The results of redox potential and electrical conductivity test show that the best oxidizing property of the solution is the P25 type TiO_2. The dosage of H _ 2O _ 2 is 2 ~ 3 ml ~ (-1) and pH value is 3 ~ 3. The photocatalytic activity of the solution is the best.After photocatalytic degradation of methyl orange for 1 h, the oxidation property of polishing solution was verified.In order to verify the feasibility of polishing, a characterization test of silicon wafer polishing material was established. The results showed that the best polishing solution was TiOS2P25) H_2O_2 UV SiO_2 H, which was compared with seven polishing fluids.The material removal rate is 5.9 mg / h, and the surface morphology after polishing is the best.In photocatalytic polishing of diamond film, extremely smooth diamond step surface was obtained, and the overall surface roughness decreased from Rz387.6 渭 m to Rz47.131 渭 m.Through polishing CVD diamond with different catalyst polishing liquid, the result shows that P25 type polishing is the best, and the final surface roughness Ra0.399nm.The material removal rate of 0.012mg/h was obtained in high temperature and high pressure diamond polishing.The polishing trajectory simulation is established by Matlab. The reasonable rotation speed of the polishing disc is 60 r / min and the sample carrying disk is 31 r / min.Combined with the above optimization process, the surface and edge of the diamond cutting tool with high quality are lapped and polished.By XPS energy spectrum analysis, it was found that the surface of TiO_2 had strong oxidizing holes under UV irradiation, and the holes could decompose water into hydroxyl radicals with strong oxidation in acidic environment.Hydroxyl radical reacts with diamond to form oxide.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG580.15

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