采用方形照明提高分辨率和焦深

Resolution and DOF Improvement through the Use of Square-shaped Illumination

:随着光学光刻技术向更小特征尺寸加工推进 ,必然要重视提高分辨率的方法。通过强、弱离轴方法的照明变形技术正引起极大的关注。特别是研究x、y定向的特征尺寸 ,照明分布形状可不一定是圆形的。介绍了采用直角特性的照明形状可提高成像质量。讨论了方形照明的用途 ,并确定了它与光学邻近校正 (OPC)、像差及其它成像因素的关系。

As optical lithography is pushed to smaller dimensions,methods of resolution enhancement are considered necessary.Illumination modification is getting a good deal of attention,through strong and weak off?axis methods.The shape of an illumination profile does not need to be circular,especially if X/Y feature orientation is considered.This paper describes the improvements in imaging that are possible through use of source shapes that have various degrees of square character.Applications are discussed and interaction with optical proximity correction(OPC),aberration,and other imaging factors are addressed.