Fig. 1. Schematic of illumination system comprising multi-degree-of-freedom integrated uniformity correction unit. (a) Schematic of illumination system in lithography machine; (b) schematic of multi-degree-of-freedom uniformity correction

Fig. 2. Relationship between light intensity at any point of reticle plane and that in pupil region at corrected plane

Fig. 3. Schematic of interaction between correction fingers with change in xy plane and pupil region. (a) Correction fingers moving along y direction; (b) adjusting correction finger width

Fig. 4. Schematic of interaction between correction fingers with different defocusing distances and pupil region. (a) Interaction of correction fingers and pupil in yz plane; (b) interaction of correction fingers and pupil in axonometric projection; (c) interaction of correction fingers and pupil in xy plane

Fig. 5. Computational model for describing influence of correction finger defocusing distance on shaded pupil region

Fig. 6. Simulation model for 65 nm node illumination system in lithography machine

Fig. 7. Layout of fingers

Fig. 8. Relationship between correction finger width and corresponding integrated illumination uniformity after correction

Fig. 9. Correction finger positions and integrated uniformity curve obtained after correction by finger movement alone y direction. (a) Correction finger positions and (b) corrected integrated uniformity curves under conventional illumination mode with σ=0.15; (c) correction finger positions and (d) corrected integrated uniformity curves under annular illumination mode with σin=0.16 and σout=0.36

Fig. 10. Correction finger positions and integrated uniformity curves when illumination parameter is most of coherence factor, and correction finger width, distance from illumination light and defocusing distance are kept constant. (a) Correction finger positions and (b) corrected integrated uniformity curves under conventional illumination mode with σ=0.93; (c) correction finger positions and (d) corrected integrated uniformity curves under annular illumination mode with σin=0.76 and σout=0.96

Fig. 11. Correction finger positions when illumination parameter is most of coherence factor and integrated uniformity curves obtained after correction by adjusting correction finger defocusing distance, and correction finger width and distance from illumination light are kept constant. (a) Correction finger positions and (b) corrected integrated uniformity curves under conventional illumination mode with σ=0.93; (c) correction finger positions and (d) corrected integrated uniformity curves under annular

Table 1. Simulation results by multi-degree-of-freedom uniformity correction method