Building block style recipes for productivity improvement in OPC, RET and ILT flows

摘要

Traditional model-based Optical Proximity Correction (OPC) and rule-based Resolution Enhancement Technology (RET) methods have been the workhorse mask synthesis methods in volume production for logic and memory devices for more than 15 years. Rule-based OPC methods have been in standard use for over 20 years now. With continuous technical enhancements, these methods have proven themselves robust, flexible and fast enough to meet many of the technical needs of even the most advanced nodes. Inverse Lithography Technology (ILT) methods are well known to have strong benefits in finding flexible mask pattern solutions to improve process window for the most advanced design locations where traditional methods are not sufficient. However, OPC/RET requirements at each node have changed radically in the last 20 years beyond just technical requirements. The volume of engineering work to be done has also skyrocketed. The number of device layers which need OPC/RET can be 10X higher than in earlier nodes. Additionally, the number of mask layers per device layer is often 2X or more times higher with multiple patterning. Finally, the number of features to correct per mask increases ～2X with each node. These factors led to a large increase in the number of OPC engineers needed to develop the complex new OPC/RET recipes for advanced nodes. In this paper, we describe new developments which significantly improve the productivity of OPC engineers to deploy Rule Based OPC (RBOPC), Model Based OPC (MBOPC), AF, and ILT recipes in modern manufacturing flows. In addition to technical improvements such as novel multiple segment hot-spot fixing solvers and ILT hot-spot fixing necessary to support correction needs, we have re-architected the entire flow based on how OPC engineers now develop and maintain OPC/RET recipes. The re-architecture of the flow takes advantages of more recent developments in modular and structured programming methods which are known to benefit ease engineering software development applications. Therefore, this improved OPC/RET development methodology includes specifically targeted advanced new technical functions; new types of modular structures for much faster reuse of customizations; and new interfaces to flexible programming capabilities to enable easier development and integration of deep customizations for the most challenging technical needs.