针对氧化物工艺形成的钝化层通孔柱状不良进行系统研究, 发现通孔柱状不良发生的根本原因, 并找到了有效改善措施。通过对比两种不同设计的通孔出现的差异推测通孔柱状不良可能与膜层结构相关, 对相应的膜层进行去除验证, 确定了通孔柱状不良为1ITO 膜层导致。通过扫描电镜发现1ITO 刻蚀后仍然有小颗粒ITO残留, 对通孔柱状不良提出合理解释。最后在通孔柱状不良形成机理上, 提出了有效改善措施。ITO结晶物无法被刻蚀液刻蚀, 残留的ITO结晶物阻挡SiO2刻蚀, 从而形成通孔柱状不良。ITO一旦结晶, 延长1ITO 刻蚀时间也不能改善柱状不良, 通过降低ITO 厚度可有效减轻通孔柱状不良, 但仍然无法消除, 通过加大钝化层刻蚀反应气体, 可以有效将ITO结晶物反应抽出, 彻底消除通孔柱状不良。

The columnar defect of hole etching in oxide process was investigated in this study. The reason or sources which is responsible for the columnar defect was revealed and corresponding measures for avoiding columnar defect were effectively established．The primary reason for producing columnar defect might be related to film structure, which can be deduced from the differences between two kinds of hole. After uncovering each layer of the film, columnar defect was detected in ITO layer. The result of scanning electron microscopy (SEM) showed that small particles appeared on the ITO layer after hole etching. Based on the above-mentioned mechanism of columnar defect formation, three solutions were attempted to solve the issue. ITO crystal cannot be etched by etching solution and residual ITO crystals will impede SiO2 etching, which will produce columnar defect. Once ITO crystal was formed, extending the etching time will not remove the columnar defect. Decreasing the thickness of ITO can partially eliminate the columnar defect while completely erasing the columnar defect and etching the ITO crystal can be achieved by increasing the etching gases in passivation layer etching process