【作者】 杜宏伟；

【导师】 魏昕；

【作者基本信息】 广东工业大学 ， 机械制造及其自动化， 2004， 硕士

【摘要】 钽酸锂是近年来随着通讯、信息产业迅速发展而开发并产业化的新型光电子材料。它具有机电耦合系数大、低损耗、高温稳定性、高频性能好等优良的压电、电光和热电性能。目前，钽酸锂晶片的超精密加工技术的研究还很欠缺，实际生产中通常采用化学机械抛光技术进行加工。本论文通过对钽酸锂晶片的化学机械抛光过程的实验研究和抛光运动轨迹的理论分析，研究钽酸锂晶片的抛光加工特性，探讨钽酸锂晶片化学机械抛光机理，系统分析主要工艺参数对化学机械抛光过程的影响规律。 1．采用化学腐蚀实验方法研究抛光液中氧化剂种类和浓度以及抛光液pH值对钽酸锂晶片化学去除的影响。寻找有效的氧化剂及其合适的浓度，确定合理的稳定剂及抛光液的适当pH值。次氯酸钠和过氧化氢是钽酸锂晶片化学机械抛光液中有效的氧化剂，无机碱氢氧化钾是有效的稳定剂，pH值为10适合于钽酸锂晶片化学机械抛光。 2．通过单颗粒金刚石压入钽酸锂晶片光滑表面的划痕实验，研究钽酸锂晶片的机械力学性能和断裂破坏情况，寻找合理的抛光压力。适合钽酸锂晶片化学机械抛光的抛光压力为7.25kPa。 3．理论分析抛光运动的规律并进行抛光轨迹计算机仿真，探求抛光表面形成机理，发现合适的抛光转速和抛光运动参数。适合钽酸锂晶片化学机械抛光的抛光盘转速为n_p=60rpm，工件盘中心到抛光盘中心的距离为e=100mm。 4．通过对钽酸锂晶片的化学机械抛光过程的实验研究，通过测量钽酸锂晶片在不同抛光条件下的表面粗糙度和材料去除率，详细分析了抛光垫材料和状态、抛光压力、抛光盘转速、磨料种类及粒度、抛光液组成等几个因素对抛光表面质量和材料去除率的影响规律。更多还原

【Abstract】 Tantalum lithium (LiTaO3), a novel single crystal material, developed and industrialized with the development of communication and information industries recently, owns the excellent performances such as high Mechanical-electrical coupling coefficient, lower wear-resistance, excellent high-temperature stability, excellent high-frequency capability, etc. However, researches on tantalum lithium single crystal wafer around world are still lacking. LiTaO3 wafers are machined ususlly by chemical mechnical polishing in industry. Based on the investigation of the mechanical property of tantalum lithium crystal wafer and theory analysis of polishing movement tracks, this thesis discusses its mechanism of CMP, presents its polishing characteristics and analyzes the effects of polishing condition parameters upon CMP.To find out the effective slurry with suitable type of oxidizer and concentration, chemical etching experiment was applied to the LiTaO3 wafer.the chemical etching effects were analysed by measuring etching rate and X-ray spectrum. The experimental results indicate that for LiTaO3 the oxidizers are NaClO and H2O2, the stabilizator is KOH and the most suitable pH value is 10.The scratching test was carried out with a single diamond tool to study the removal mechanism of LiTaO3 wafer by load. The AE signals were measured, and the scratched surfaces of LiTaO3 wafers in different conditions were observed by metallography microscope. The results show that the scratched surfaces change from elastic deformation area, plastic deformation area and fracture area with squama and crack. For removing material of LiTaO3 wafer by plastic deformation mode, the polishing pressure should be low than 7.25kPa.For selecting suitable CMP conditions, the movement of polishing was modelling and simulating. The analysed results show that the reasonable rotating speed np and distance e between workpiece plate center and polishing plate center are 60rpm and 100mm on Ultra-precision surface polishing machine with correction rings,respectively.The CMP experiment was carried out systematically on LiTaO3 wafer. The polished surface foughness and material removal rate in different polishing conditions were measured and the effects of polishing pad material and its condition, pressure, rotating speed of the polishing plate, the type and size of abrasive, and the properties of the polishing slurry on the surface routhness and material removal rate were analysed in details.更多还原