铌酸锂原子级抛光缺陷形貌演化机理研究

doi:10.3901/JME.2025.13.474

摘要/Abstract

摘要： 铌酸锂晶体由于具有优良的压电、声电、电光、非线性光学等特性，被誉为“光学硅”，并已成为探测、通讯等领域中关键器件的重要基体材料。但由于铌酸锂材料自身的软脆特性，在研磨及化学机械抛光过程中不可避免会产生划痕、麻点等缺陷降低器件使用性能，且当前缺陷的演化机理仍不明确。针对现有问题，研究了不同研磨液对铌酸锂表面缺陷产生的影响；探究了不同抛光时间铌酸锂表面缺陷的演化规律；仿真分析了抛光液中磨粒对缺陷的作用情况，阐明了铌酸锂原子尺度抛光的表面平坦化机理。结果表明，使用4% 1 μm粒径氧化铝、0.6% H₂O₂、pH=11的研磨液可有效减小缺陷深度；由于磨粒在抛光过程中对缺陷边缘的冲蚀作用较大，研磨阶段产生的划痕逐渐演化为单一的麻点缺陷；麻点缺陷深度随抛光时间增加而减小，宽度随抛光时间增加先增大后减小。使用新型抛光液抛光9 h后，表面缺陷被全部消除，表面粗糙度Sa由研磨后51.49 nm降至0.10 nm，实现了原子级抛光。

关键词: 铌酸锂, 化学机械抛光, 缺陷, 演化机理, 表面粗糙度

Abstract: Lithium niobate crystal is known as "silicon of photonics" due to its excellent piezoelectric, acoustic-electric, electro-optical, and nonlinear optical properties. It has become an important substrate material for key devices in the fields of detection and communication. However, due to the soft and brittle characteristics of lithium niobate, it is inevitable to produce scratches, pits and other defects in the grinding and chemical mechanical polishing process to reduce the performance of the device. And the evolution of the defect removal mechanism is still unclear. In view of the existing problems, the effect of different grinding slurries on the surface defects of lithium niobate is studied. The evolution of lithium niobate surface defects after different polishing times is investigated. The effect of abrasive particles in the polishing solution on the defects is simulated and the surface flattening mechanism of lithium niobate atomic scale polishing is elucidated. The results show that the use of 4% 1 μm Al₂O₃, 0.6% H₂O₂, and pH value 11 grinding slurry can effectively reduce the defect depth. Due to the larger erosion effect of the abrasive particles on the defect edge during the polishing process, the scratches generated during the grinding stage gradually evolved into a single pit. The depth of the pits decreases with the increase of the polishing time, and the width increases and then decreases with the increase of the polishing time. After 9 hours of polishing with new polishing slurry, the surface defects were completely eliminated, and the surface roughness Sa is reduced to 0.10 nm, realizing atomic scale polishing.

Key words: lithium niobate, chemical mechanical polishing, defects, evolution mechanism, surface roughness

中图分类号:

TG356

郭江, 杨哲, 徐海俊, 李琳光, 王东周, 张鹏飞. 铌酸锂原子级抛光缺陷形貌演化机理研究[J]. 机械工程学报, 2025, 61(13): 474-482.

GUO Jiang, YANG Zhe, XU Haijun, LI Linguang, WANG Dongzhou, ZHANG Pengfei. Study on the Evolution Mechanism of Defects Morphology in Atomic Scale Polishing of LiNbO₃[J]. Journal of Mechanical Engineering, 2025, 61(13): 474-482.

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