Fig. 1. Exposure system diagram of step-and-scan lithographic tool

Fig. 2. Diagram of rectangle lighting field

Fig. 3. Scanning slit imaging optical path under trapezoidal illumination

Fig. 4. Light intensity distribution at edge of light field based on scanning method

Fig. 5. Measurement result of penumbra by using the conventional scanning method with different sampling steps

Fig. 6. Distribution of intensity of mask surface and sub-pupil of pupil plane

Fig. 7. Principle of blade edge's penumbra width measurement byproposed imaging method. (a) P100%; (b) P50%; (c) P0

Fig. 8. Diagram of pupil imaging measurement system

Fig. 9. Diagram of sampling points' number and coordinate

Fig. 10. Repeatability of blade edge's penumbra width measured by two methods. (a) In x- direction; (b) in x+ direction; (c) in y- direction; (d) in y+ direction

Fig. 11. Sampling paths of two methods for measuring blade edge's penumbra