Fig. 1. Schematic diagram of relationship among design rules, lithography model, line edge roughness, and design-process collaborative optimization

Fig. 2. Comparison between thin-mask model and thick-mask model^［15］. (a) Kirchhoff approximation of photomask; (b) diffraction near-field model of thick mask

Fig. 3. Dense pattern and isolated pattern of resist shrinkage effect of NTD^[30]. (a) Dense pattern; (b) isolated pattern

Fig. 4. Complete flow scheme of OPC

Fig. 5. Mask deviation prediction by NNC^[47]

Fig. 6. Research flow of LER

Fig. 7. CD SEM image of dense image and its average grey level curve^[64]

Fig. 8. Comparison of model results of extraction accuracy improvements of key dimensions and roughness^[64].(a) Traditional threshold algorithm; (b) improved algorithm; (c) comparison of line width roughness extracted by two algorithms and corresponding power spectral density curves

Fig. 9. DTCO process^[70]