The study of OPC (Optical Proximity Correction) model that well predict the wafer result has been researched. As the pattern design shrink down, the need for the CD (Critical Dimension) controllability increased more than before. To achieve these requirements, OPC models must be accurate for full chip process and model inaccuracies are one of several factors which contribute to errors in the final wafer image. For that reason, robust OPC using real lithographic terms was proposed. Real lithographic system is quite different from ideal system that is used for OPC modeling. Until now, this difference was acceptable since pattern size used for OPC model was large, but as device size shrinks, this gap between ideal and real system causes degradation of OPC accuracy. So, various optical parameters such as apodization, laser band width, degree of polarization, illumination are used today in order to compensate for this issue. Especially, major issue in modeling error is related to how the illumination source is used.For this study we assess accuracy of optical model for robust OPC using ideal and actual illumination sources, and test conditions are below. 1) We examined the difference of pupil types to output model respectively.2) A parameterized test pattern layout was used by 1D test pattern types that have various lines and spaces. 3) All models were calculated in automation method so as to exclude the dependency of user skills. 4) OPC accuracies were examined by gate layer patterns on full chip level. The study is performed for 5X~4Xnm nodes lithographic processes. The main focus of the study was on usability of model that is made by measured source data in semiconductor manufacturing. Results clearly showed that the actual source for the optical model has merits and demerits.
As the minimum feature size shrinks down, i.e. low K1 lithography regime, the tool's lens aberration sensitivity and user defined illumination imperfection might play a major role in patterning error. Thus, the study of impact from lens aberration and illumination on patterning is required for good tool maintenance and yield improvement. For this purpose, we collected many cases of abnormal patterning result from production line and then simulated in terms of actual lens aberration and illumination source data. LITEL products of ISI(In-situ Interferometer) and SMI(Source Metrology Interferometer) were used for characterizing lens and illumination source. Moreover, the ACE(Analysis and Characteristic Engine) of LITEL development product was used as the simulator. In this work, deformation of pattern fidelity, for example, CD asymmetry in word line and metal contact layer, pattern bending in isolation layer and also decreasing process window in bit line layer will be discussed with experimental and simulation data. Finally, we are able to make a guideline for preventing abnormal phenomenon. From this study, we can understand which lens aberration terms and illumination imperfection take an effect of abnormal pattering result.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.