随着对液晶显示器高分辨率的需求不断增长, 像素设计的尺寸越来越小, 分布在像素上方起支撑作用的柱状隔离子(Photo Spacer)尺寸也不断减小。柱状隔离子的顶部面积与底部面积的比值变大, 提高了耐压能力, 但对制程中柱状隔离子图案化的形状控制能力提出了更高的要求。在目前的材料和制程条件下, 精细化的形状存在一些工艺问题, 其中最典型的是顶部凹陷问题。基于以上问题, 对PS凹陷进行研究; 引进半导体行业中应用广泛的曝光显影模拟软件进行曝光光型分布模拟及理论分析, 提出降低曝光间隙进行改善, 经实验验证凹陷得到改善。实验结果表明, 减小曝光间隙, 由250 μm降低到150 μm, 可以有效改善PS顶部凹陷的问题。通过减小曝光间隙, 可以改变曝光光束, 即高斯光束的空间分布, 从而改变PS光阻受光分布, 进而改变PS最终形状, 即改善PS顶部凹陷问题; 且高斯光束的空间分布, 可通过曝光显影模拟得到, 可见曝光显影模拟可分析和预估实验结果, 且为问题改善提出可行的意见。

The LCD is mainly composed of two substrates and the liquid crystal in the middle. Among them, photo spacer is an important part which is placed on th bottom substrate and sustains the upper substrate. As the trend of higher and higher resolution of the display, there is a need for accurate controlling of morphology of the photo spacer in mass process. In this paper, we pay attention to one of the most common issue of very small size photo spacer that the top of it suffers concave surface which influences the supporting capacity of the photo spacer. In order to improve the problem of concave, this paper proposes to reduce the exposure gap through optical simulation and theoretical analysis, which has been verified by experiments. The results show that the spatial distribution of the Gauss beam can be changed by reducing the exposure gap, and the problem of PS top depression can be improved. Exposure pattern distribution simulation and theoretical analysis were carried out by using exposure development simulation software. It was proposed that the exposure gap should be reduced, and the experiment verified that the depression could be improved. The experimental results show that reducing the exposure gap from 250 μm to 150 μm can effectively improve the problem of PS top depression. By reducing the exposure gap, the spatial distribution of the exposure beam, i.e. the Gauss beam, can be changed, thus the distribution of the photoresist of PS can be changed, and the final shape of PS can be changed, i.e. the problem of depression at the top of PS can be improved; and the spatial distribution of the Gauss beam can be obtained by the simulation of exposure development. The simulation of exposure development can analyze and predict the experimental results, and provide feasible suggestions for the improvement of the problem.