光诱导约束刻蚀体系中羟基自由基生成的影响因素

采用荧光分析,暂态光电流响应分析,电化学交流阻抗谱(EIS)和Mott-Schottky响应分析考察了外加电位,光照时间,溶液pH等几个关键因素对光诱导约束刻蚀体系中TiO2纳米管阵列表面游离OH生成的影响.结果表明:当外加电位为1.0 V时,光电协同产生游离OH效率最高;OH的光催化生成与消耗能很快达到稳态,形成稳定的约束刻蚀剂层,有利于保持刻蚀过程中的精度;当pH为10时,TiO2纳米管光催化产生游离OH效率最高.研究结果对于调控和优化光诱导约束刻蚀平坦化铜的溶液体系,提高铜的刻蚀速度或平坦化精度有重要的指导意义.

Factors Influencing Hydroxyl Radical Formation in a Photo-Induced Confined Etching System

In this paper, we studied the formation of free ·OH on a TiO₂ nanotube array electrode in a photo-induced confined etching system. We used fluorescence spectroscopy, transient photocurrent response, electrochemical impedance spectroscopy (EIS), and Mott-Schottky analysis to investigate the influence of several key factors, including the applied potential, the illumination time, and the pHvalue. The highest efficiency for the photoelectrocatalytic formation of free ·OH on the TiO₂ nanotube array electrode was achieved at an applied potential of 1.0 V (vs a saturated calomel electrode (SCE)); the photoelectrocatalytic generation and consumption of free ·OH quickly approached a steady state in this system, as the confined etching layer formed by ·OH remained stable during illumination. This may allow good control of the etching precision during continuous etching processes. The highest efficiency for the photoelectrocatalytic formation of free ·OH on the TiO₂ nanotube array electrode was observed at pH10. The results have an important significance for regulating and optimizing photo-induced confined etching system, which can be used to improve the etching speed or the leveling precision during the planarization of copper.