Practical method for full-chip optical proximity correction

Abstract

We describe a method for optical proximity correction (OPC) based on the principle of aerial image matching. Three basic, sub-resolution elements are used: scattering bars, anti-scattering bars, and serifs. We examine the effects of adjusting the sizes and placements of all three elements, and report the improvements achieved, in CD uniformity, printing fidelity, resolution, and depth of focus. We describe the use of a vertex-based `geometry engine' to correct very large microprocessor-style random logic chips of up to 20 million transistors. Our experience producing over 200 full-chip i-line OPC reticles, and the extensibility of the method to deep ultraviolet wavelengths, are presented.