铌酸锂(LiNbO3, LN)是一种广泛使用的介电材料, 由于其电光系数大, 透明范围大, 本征带宽宽, 因而在集成和非线性光学器件中极为重要。但绝缘体上铌酸锂薄膜(LNOI)的化学稳定性好, 刻蚀速率慢, 其微结构参数难以控制。针对以上问题, 该文开展了基于电感耦合等离子体刻蚀(ICP-RIE)的LNOI脊形微结构的制备工艺研究, 分析了腔室压强、气体总流量及刻蚀功率等参数对刻蚀速率、刻蚀倾角和表面粗糙度(RMS)的影响。研究表明, 在优化的工艺条件下, LNOI薄膜的刻蚀速率达到24.9 nm/min, 制备出刻蚀深度249 nm、刻蚀倾角76°、表面粗糙度(RMS)0.716 nm的LNOI脊形微结构。该文通过对刻蚀工艺与微观结构参数的研究, 建立了基于ICP的LNOI微结构刻蚀方法, 为控制LNOI脊形光波导和提升性能提供了工艺支撑。

Lithium niobate (LiNbO3, LN) is a widely used dielectric material. Because of its large electro-optical coefficient, large transparent range and wide eigenband, it is extremely important in integrated and nonlinear optical devices. However, due to the good chemical stability and slow etching rate of lithium niobate on insulator (LNOI), the microstructure parameters are difficult to control. In view of the abovementioned problems, the preparation process of LNOI ridge microstructures based on inductively coupled plasma etching (ICP-RIE) was studied in this paper. The effects of chamber pressure, total gas flow and etching power on the etching rate, etching angle and surface roughness (RMS) were analyzed. The research shows that under the optimized process conditions, the etching rate of LNOI reaches 24.9 nm/min, and the LNOI ridge microstructure with etching depth of 249 nm, etching angle of 76 ° and surface roughness (RMS) of 0.716 nm is prepared. Through the study of etching process and microstructure parameters, this paper creates a LNOI microstructure etching method based on ICP, which provides technological support for controlling the LNOI ridge optical waveguide and improving its performance.