摘要
HADS产品通常使用有机膜材料来减小寄生电容,以实现高像素密度(PPI)显示。本文对如何改善以顶层ITO为像素电极(Pixel Top)设计的有机膜产品的公共电极ITO与数据线间短路(DCS)不良进行了工艺优化研究。首先,通过显微镜、聚焦离子束对HADS有机膜产品DCS不良发生机理进行了分析,进而提出了第一钝化绝缘层刻蚀工序省略、保留第一钝化绝缘层至公共电极与像素电极间第二钝化绝缘层刻蚀时进行“一步刻蚀”的工艺流程变更改善方案。针对新工艺流程验证中TFT栅极过孔处第一钝化绝缘层出现的底切不良,通过调整等离子增强化学气相沉积成膜参数改善第一钝化绝缘层膜质,并选取最优成膜条件进一步调整干法刻蚀参数改善刻蚀形貌,获得了优良的栅极过孔刻蚀坡度角。优化后的“一步刻蚀”工艺进行的TFT基板,其栅极过孔第一钝化绝缘层坡度角小于40°,与栅极绝缘层间无明显刻蚀台阶。量产验证有机膜缺失导致的DCS发生率降为0。通过优化工艺,在降低产品不良率的同时还减少了工艺步骤,提升了产能。
HADS products typically use organic film materials to reduce parasitic capacitance for high PPI display.In this paper,the process optimization of the common electrode ITO and the data line short-circuit defect of the organic film product designed by the top ITO for the pixel electrode(Pixel Top)is improved.Firstly,the mechanism of DCS failure of HADS organic film products is analyzed by microscope and Focused Ion beam.A‘one-step etch’process variation improvement scheme which skips the PVX1 etch step and retains PVX1 until PVX2 etch is proposed.Aiming at the problem of PVX1 layer undercut of TFT gate via hole in the new process verification experiment,the PVX1 film quality is improved by adjusting the PECVD film formation parameters.The optimum film formation condition is selected to further adjust the dry etch process,and an excellent slope angle is obtained.On the TFT substrate which uses the optimized one-step etching process,the PVX1 slope angle of gate via hole is less than 40°and there is no significant step between the PVX1 and the GI layer,and there is no obvious step between the PVX1 and the GI layer.The mass production rate of the DCS caused by the absence of the organic film is reduced to zero.By optimizing the process,the product defect rate is reduced while the process steps are reduced and the production capacity is increased.
作者
吕艳明
操彬彬
栗芳芳
安晖
叶成枝
李法杰
杨增乾
彭俊林
冯耀耀
刘增利
陆相晚
李恒滨
LYU Yan-ming;CAO Bin-bin;LI Fang-fang;AN Hui;YE Cheng-zhi;LI Fa-jie;Yang Zeng-qian;PENG Jun-lin;FENG Yao-yao;Liu Zeng-li;LU Xiang-wan;LI Heng-bin(Hefei Xinsheng Optoelectronics Technology Co., Ltd., Hefei 230001, China)
出处
《液晶与显示》
CAS
CSCD
北大核心
2020年第3期219-226,共8页
Chinese Journal of Liquid Crystals and Displays
