本文对氮化硅的增强电容耦合等离子刻蚀进行研究, 为氮化硅刻蚀工艺的优化提供参考。针对SF6+O2气体体系, 通过设计实验考察了功率、压强、气体比、氦气等对刻蚀速率和均一性的影响, 并对结果进行机理分析和讨论。实验结果表明: 功率越大, 刻蚀速率越大, 与源极射频电力相比, 偏置射频电力对刻蚀速率的影响更为显著; 压强增大, 刻蚀速率增大, 但压强增大到一定程度后, 刻蚀速率基本不变, 刻蚀均匀性随着压强增大而变差; 在保证SF6/O2总流量保持不变下, O2的比例增大, 刻蚀速率先增大后减小, 刻蚀均匀性逐步变好; He的添加可以改善刻蚀均匀性, 但He的添加量过多时, 会造成刻蚀速率降低。

In order to optimize etching process of silicon nitride (SiNx), the enhanced capacitive coupled plasma etching (ECCP)of silicon nitride was researched. With SF6+O2 as etch gas, the effects of main parameters such as power, pressure, gas rate and He gas on etch rate and uniformity has been studied, and the mechanism of test result was analysed. The results show that power increases, etch rate increases, and compared with the source RF power, the effect of the bias RF power on the etch rate is more significant; pressure increases, the etch rate increases, but the pressure increases to a certain extent, the etch rate is basically the same, the etch uniformity becomes worse with the increase of pressure; under the condition that the total flow rate of SF6/O2 is kept constant, the proportion of O2 increases, the etch rate increases and then decreases, and the etch uniformity is gradually getting better; the addition of He can improve the etch uniformity, but when the amount of He is too much, it will cause the reduction of the etch rate.