【作者】 陈晔；

【导师】 严晓浪； 史峥；

【作者基本信息】 浙江大学 ， 电路与系统， 2008， 博士

【摘要】 过去几十年来,微电子技术的高速发展以及各类应用对电路性能需求的日益增长使得现代集成电路系统的规模和复杂程度日趋提高,这必将对集成电路制造技术提出更高的要求。就当今主流的集成电路制造技术而言,光刻分辨率增强技术(ResolutionEnhancement Techniques,RETs)使得制造比光刻所用光源波长小两到三倍的特征尺寸成为可能,现在193nm波长的光源被用来生产65nm工艺的集成电路。光刻技术的极限已经远远超出了人们的想像。在所有的光刻分辨率增强技术中,光学邻近修正(OpticalProximity Correction,OPC)是最为成熟以及应用最为广泛的一种。它通过修改掩模图形的形状来达到补偿失真的目的。快速而高精度的修正算法、良好的版图设计风格以及精确的光刻模型是成功实施光学邻近修正的关键。本文将会介绍在这三个方面所做的工作。基于模型的光学邻近修正算法(Model-based OPC,MBOPC)是一个迭代过程。迭代的收敛性同时取决于迭代的初值以及迭代方向的选择。为了提高算法的收敛速度以及收敛范围,本文提出了一种新的矩阵式光学邻近修正算法。新算法通过考虑边之间的互相影响使得所选择的迭代方向更为有效。本文也介绍了一些加快Jacobian矩阵计算以及线性方程组求解的方法,以进一步提高新算法的计算速度。本文提出了一种有较快的修正速度且有相对精确的修正精度的边偏移建模方法。使用此方法可以为传统的光学邻近修正算法提供较为精确的迭代初值。虽然新加入的初值计算步骤需要一定的运算时间,但是精确的迭代初值减少了收敛所需的迭代次数,从而可以有效地减少总的运行时间。成功的光学邻近修正也依赖于版图设计风格。一些图形组合难以通过修正而得到足够的制造裕量,这些图形通常被称为OPC不友好的(OPC Unfriendly)。为了减少设计的回转时间,设计者必须在将版图送至代工厂之前尽可能多地找到OPC不友好的区域并加以修正。这一流程通常被称之为光刻友好的版图设计(Litho-friendlyDesign,LfD)。本文介绍了两种基于边偏移建模方法构建的OPC算法。修正速度快且易于使用的特点使得这两种算法适于在光刻友好的版图设计流程中使用。基于部分相干理论的光刻成像系统建模方法早在几十年前就被提出,并且在工业界得到了广泛的使用。然而当所制造的特征尺寸越来越小,光刻系统使用了更为高级的配置。这使得我们必须考虑更多的物理效应来保持模型的精度,比如必须使用矢量成像模型来描述有高数值孔径投射透镜的系统。制造工程师必须通过修改模型的结果来建立新的模型,这通常是困难而且是耗时的。本文介绍了一种新的光刻建模环境。除了实现了传统的建模流程之外,新工具还提供一组易于定制以及扩展的模块。使用这些模块,用户可以通过编写简明的Tcl脚本来实现的新的光刻模型。这能够大幅提高建模的效率。更多还原

【Abstract】 In the last several decades, the fast developing of microelectronic technology and growing requirements from the various kind of applications make the modern integrated circuit (IC) more complicated in scale and functionality. These will inevitably lead to the higher demands for manufacturing techniques of IC systems. As far as the state of the art of IC manufacturing systems, the technique of so called Resolution Enhancement Techniques (RETs) make it possible to product features 2 or even 3 times smaller than the wavelength of illumination system. The limits of optics have been pushed well beyond what was expected just a few years ago. As for now, illumination of 193nm wavelength is used in 45nm IC production. Among all kinds of RETs, Optical Proximity Correction (OPC) is the most sophisticated and widely used technique. It achieves the aim of canceling out distortion and improving the print-ability by modifying mask patterns. Sophisticated correction algorithm, good layout design style and accurate model of lithography system are three keys of successful OPC. In this thesis we will introduce our efforts on all these three aspects.Model-based OPC (MBOPC) is an iterative process. Its convergence depends on both the initial values and the selected direction of iteration. In this thesis, a new kind of MBOPC algorithm is introduced to improve the convergent speed and convergent range, which is based on generalized intensity distribution functions and takes the interactions between edges into account. To make the new algorithm faster, a few methods to accelerate the Jacobian matrix calculation and linear system solving process is also introduced.An edge bias modeling method is developed in this thesis, which has very fast correction speed and moderate correction accuracy. Better initial values for the iterative process of conventional model-based OPC algorithm can be provided by this method, with a little run-time penalty. The number of iterations is reduced because of the better initial values. Thus the total run-time is reduced efficiently.Successful optical proximity correction also relies on layout design style. Some pattern configurations are harder to be corrected to get enough process margin, which are usually called "OPC-unfriendly" for a particular lithographic process. To save design spin time, it is necessary to find out such patterns and fix them as many as possible by the designer before layout is sent to manufacturer. This kind of OPC-aware layout design is usually called as Litho-friendly Design (LfD). In this thesis, two OPC methods based on edge bias modeling method are introduced, which are good candidates for trial-OPC in LfD.Lithography system modeling based on partial coherence imaging theory was proposed several decades ago, and widely used in the industry. However with minimum feature sizing down, more advanced configurations are used in lithography systems. When it happens, more physical phenomena in the model should be considered to keep modeling accuracy. For example vector model should be used instead of scalar model to describe systems with extremely high NA. This reality brings RET engineers a heavy task that they should build new models for new lithographic configurations, not only by changing the model parameters but also changing the model structure itself. Usually this step is not easy and time consuming. In this thesis, a new lithography modeling environment is introduced, besides implementing the conventional modeling flow, it also provides a set of handy tools to easily customize and build models for lithography system with advanced configurations. Users can build up the model by writing a concise Tcl/Tk script using tools provided by this environment, which can greatly improve the model building efficiency.更多还原