Model based optical proximity correction (OPC) to enhance image fidelity and process robustness has become one of the most critical components that enable optical lithography tackling 45nm node and beyond. To meet the challenges imposed by the previously unthinkable low k₁ for manufacturing with most stringent dimension control requirements, a capable model OPC to meet such an aggressive lithography challenges has been urgently called upon. In addition to providing better accuracy for the currently implemented process technologies, the new model OPC must work well with Chromeless Phase Lithography (CPL) in which the topography on the mask is rather significant, and Double Dipole Lithography (DDL) in which two masks and two exposures are needed. It must also be able to intelligently take into account the effect from the more aggressive illuminations, such as customer designed illuminator and experimental measured illuminator profile from the scanners. This capability is very important since the real illuminator pupil can impact OPC accuracy. The physical and mathematical foundation of the model must be well thought of to meet the requirement for the above-mentioned applications. We have developed a novel Eigen Decomposition Model (EDM) for model OPC treatment applicable for all types of advanced binary and phase-shifting masks. Together with a full 2D model calibration and verification methodology, the results from this new model OPC have proven to achieve a superb CD accuracy with versatile capabilities for extreme low k₁ imaging application. This report will explain how the model works with example applications and actual wafer results.

Date Published: 20 August 2004
PDF: 9 pages
Proc. SPIE 5446, Photomask and Next-Generation Lithography Mask Technology XI, (20 August 2004); doi: 10.1117/12.557794

Published in SPIE Proceedings Vol. 5446:
Photomask and Next-Generation Lithography Mask Technology XI
Hiroyoshi Tanabe, Editor(s)