台阶处光刻工艺的优化与研究

摘要

光刻胶剖面形貌和关键尺寸（CD）是光刻工艺的关键参数，而实际光刻工艺中受到前层次图形的影响，尤其是后端布线工艺受到前面工序高低台阶影响十分严重。文章基于光学干涉原理及King的胶厚理论模型和光刻胶Swing Curve曲线研究了光刻胶跨越高台阶对成像的影响，分析了造成光刻胶剖面和关键尺寸变化的主要原因。一是台阶处衬底的反射影响了光刻胶剖面形貌；二是高台阶处光刻胶厚度比正常厚度变薄导致光刻曝光条件不适用于高台阶处光刻胶。最后通过优化胶厚及增加底部抗反射层有效解决CD差异和改善光刻胶形貌。%Profile and critical dimension are key process data in lithography process which are affected by substrate morphology. The study on photo resist spans high level imaging effects resulting in low optical plastic CD morphology of the main reasons, due to the reflection and bench nearby stepped substrate photo resist thickness change. By selecting the right photo resist thickness and increasing bottom antireflective layer can effectively resolve CD difference and improve photo resist profile.