In this paper, a stable lithium niobate (LN) sol was prepared using niobium pentachloride, niobium ethoxide, lithium acetate, anhydrous ethanol, and benzoylacetone (BzAcH) as a chemical modifier. The effects of different starting materials and organic solvents on the obtained gel film quality of the sols were studied and the optimization mechanism of BzAcH on the film quality was analyzed in detail. The effects of heat treatment temperature on the structure and performance of the LN thin films were also studied. X-ray diffraction (XRD) spectra showed that LN was more highly crystalline in the heat treatment temperature range of 600–800 °C. The refractive index of the LN thin films first increased and then decreased with increasing heat treatment temperature, and the LN thin film prepared at 700 °C had the largest refractive index. Light transmittance tests showed that as the heat treatment temperature increased, light transmittance decreased. Finally, it was determined that LN gel films modified with BzAcH were more highly sensitive to UV light and that after UV irradiation, it was difficult to dissolve LN gel films in organic solvent. The UV-sensitive property was utilized to realize microstructure processing of the LN thin films. The results indicated that a high-quality, non-destructive, and photoresist-free micro-fabrication method was realized. This method was used to fabricate microscale LN fine patterns with smooth sidewalls while avoiding lateral corrosion. These results are of great significance for LN thin film applications and the development of LN-based optoelectronic devices prepared by chemical methods.

本文以五氯化铌、乙醇铌、醋酸锂、无水乙醇和苯甲酰丙酮（BzAcH）为化学改性剂，制备了稳定的铌酸锂（LN）溶胶。研究了不同起始原料和有机溶剂对溶胶所得凝胶膜质量的影响，详细分析了BzAcH对膜质量的优化机理。还研究了热处理温度对LN薄膜结构和性能的影响。X 射线衍射 (XRD) 光谱表明，LN 在 600-800 °C 的热处理温度范围内具有更高的结晶度。LN薄膜的折射率随着热处理温度的升高先增大后减小，其中700℃制备的LN薄膜的折射率最大。透光率测试表明，随着热处理温度的升高，透光率下降。最后，确定了用 BzAcH 改性的 LN 凝胶膜对紫外线更敏感，并且在紫外线照射后，LN 凝胶膜难以溶解在有机溶剂中。利用紫外光敏感特性实现LN薄膜的微结构加工。结果表明，实现了一种高质量、无损、无光刻胶的微细加工方法。该方法用于制造具有光滑侧壁的微型 LN 精细图案，同时避免横向腐蚀。这些结果对LN薄膜的应用和化学方法制备的LN基光电器件的开发具有重要意义。