Evaluation of OPC quality using automated edge placement error measurement with CD-SEM
Evaluation of OPC quality using automated edge placement error measurement with CD-SEM
复制标题
使用 CD-SEM 自动边缘放置误差测量评估 OPC 质量
DOI：
10.1117/12.663017
复制
发表时间：
2006
期刊：
影响因子：
--
通讯作者：
L. Page
中科院分区：
文献类型：
--
作者：
C. Tabery;H. Morokuma;A. Sugiyama;L. Page
光学邻近效应校正（OPC）在先进集成电路制造的光刻工艺中起着至关重要的作用。OPC中使用的光刻模型的质量对于OPC在生产中的最终性能至关重要。传统上，二维邻近功能，如线端，酒吧到酒吧或酒吧到线，只是部分的特点，因为在转移到OPC模型构建过程中的SEM信息的困难。提出了一种新的方法，边缘放置误差（EPE）测量使用CD-SEM的OPC模型的建设和过程/OPC资格流程的一部分。生成EPE测量值并不容易，因为为了量化EPE，固有地需要覆盖设计和SEM。EPE测量的质量既取决于SEM图像扫描旋转和放大的精度，也取决于设计布局图案和实现图案（晶片）之间的图案匹配的精度。这些问题在模拟中不存在，但模型校准需要在模拟和测量之间进行直接比较。测量EPE有效地将测量信息带入设计领域。日立高新技术公司开发了一种基于设计布局和检测SEM图像边缘的“全自动EPE测量功能”，作为该问题的解决方案。本研究显示了使用自动EPE测量功能的几个实际评估结果。将讨论的应用如下。1)基于设计的边缘分类和随后针对多种类型的边缘排列和方向的SEM EPE的量化。在这项研究中，我们将检查线端相邻，线端，角落，和其他关键的栅极边缘。2)基于SEM图像的EPE传单分类作为一个新的错误人口。3)在SEM图像内检测到的特征边缘与通过光刻模拟生成的多边形形状之间的比较，以确定模拟的质量。4)将SEM图像边缘轮廓转换为OASIS文件，并构建过程可变性带，以量化SEM图像中所有2D背景的CD可变性。
Optical proximity correction (OPC) plays a vital role in the lithography process of cutting-edge IC fabrication. The quality of lithography models used in OPC is fundamental to the final performance of the OPC in production. Traditionally, two-dimensional proximity features such as line-end, bar-to-bar or bar-to-line were only partially characterized because of the difficulty in transferring the SEM information into the OPC model building process. A new methodology of edge placement error (EPE) measurement using CD-SEM is proposed as part of an OPC model building and process/OPC qualification flow. It is not easy to generate EPE measurements because of the inherent need to overlay the design and the SEM in order to quantify EPE. The quality of the EPE measurement depends on both the accuracy of the SEM image scan rotation and magnification, but also on the accuracy of pattern matching between the design layout pattern and the realized pattern (wafer). These problems do not exist in simulation, but model calibration requires a direct comparison between simulation and measurement. Measuring EPE effectively brings the measurement information into the realm of the design. Hitachi High-Technologies has developed a "fully automated EPE measurement function" based on design layout and detected edges of SEM image as a solution to this issue. This study shows several practical evaluation results using the automated EPE measurement function. The applications that will be discussed are as follows. 1) Design based classification of edges and subsequent quantification of SEM EPE for many types of edge arrangement and orientation. In this study, we will examine line-end-adjacent, line-end, corner, and other critical gate edges. 2) SEM image based classification of EPE fliers as a new population of errors. 3) Comparison between the detected edge of the feature within the SEM image and a polygon shape generated by lithography simulation to determine the quality of the simulation. 4) Conversion of the SEM image edge contour into an OASIS file and construction of a process variability band to quantify CD variability for all 2D contexts in a SEM image.