Fig. 1. Schematic of lithography exposure system

Fig. 2. Structure diagram of the new optical variable attenuator. (a) Two-dimensional structure; (b) three-dimensional structure

Fig. 3. Relationship between transmittance of attenuation films and incident angle

Fig. 4. Relationship between reflectance of antireflective films and incident angle

Fig. 5. Relationship between wavelength and reflectance of antireflective films

Fig. 6. Test schematic of optical variable attenuator transmittance

Fig. 7. Transmittance of attenuator at different incident angles