PZT铁电薄膜湿法刻蚀技术研究

Study on Wet-etching of PZT Thin Films

介绍了一种刻蚀效果良好的PZT薄膜的湿法刻蚀方法。在分析了刻蚀液成分对刻蚀效果影响的基础上,选择体积比为1∶2∶4∶4的BHF/HCl/NH4Cl/H2O溶液作为刻蚀液,刻蚀速率为0.016μm/s。实验表明,刻蚀得到的PZT薄膜图形表面无残留物,侧蚀比小(1.5∶1),侧面倾角约60°。刻蚀液对光刻胶和PZT薄膜底电极Pt的选择性好,该工艺适用于MEMS领域中PZT薄膜的微图形化。

In this paper, a novel wet-etching process of PZT thin films was re ported. The influences of the etchant compositions on etching effects were analyzed. Through experiments, the best concentration was found to be φ(BHF:HCl:NH_4Cl:H_2O) =1∶2∶4∶4.The etch rate was 0.016 μm/s. The PZT etchant didn't leave residues, which are mentioned in other literatures, and it showed good selectivity over photoresist mask and Pt bottom electrode. A limitedunderetch (1.5∶1) was obtained and the side wall angle was about 60°. Our experimental results proved that this process issuitable for patterning of PZT thin films in MEMS field.