| 摘要 |
To optionally forming a multilevel light intensity distribution on an illumination pupil plane, the illumination apparatus implements Köhler illumination on an illumination target surface, using as a light source the light intensity distribution formed on the illumination pupil plane on the basis of light from a light source. The illumination apparatus has a spatial light modulator, a condensing optical system, and a control unit. The spatial light modulator has a plurality of reflecting surfaces which are two-dimensionally arranged and postures of which can be controlled independently of each other. The condensing optical system condenses light from the reflecting surfaces to form a predetermined light intensity distribution on the illumination pupil plane. The control unit controls the number of reflecting surfaces contributing to arriving light, for each of points on the illumination pupil plane forming the light intensity distribution, according to a light intensity distribution to be formed on the illumination pupil plane. |
| 主权项 |
1. An illumination apparatus which forms a predetermined pupil intensity distribution on an illumination pupil plane by light from a light source and illuminates an illumination target surface with light from the predetermined pupil intensity distribution, the illumination apparatus comprising:
a spatial light modulator having a plurality of reflecting surfaces arranged two-dimensionally, postures of the respective reflecting surfaces being controlled independently of each other; a condensing optical system, arranged between the light source and a position where the predetermined pupil intensity distribution is formed, configured to convert light provided with a predetermined angle distribution by the plurality of reflecting surfaces of the spatial light modulator into a position distribution on a predetermined surface, to form a predetermined light intensity distribution on the predetermined surface; a fly's eye optical system having a plurality of optical surfaces arranged two-dimensionally on the predetermined surface, configured to form the predetermined pupil intensity distribution on the illumination pupil plane by light from the condensing optical system; and a controller configured to feed a control signal to the spatial light modulator according to the predetermined pupil intensity distribution formed on the illumination pupil plane; wherein the predetermined light intensity distribution includes at least a first zone with a first light intensity, a second zone with a second light intensity different from the first light intensity, and a third zone with a third light intensity different from the first and second light intensities, and the controller is configured to control the postures of the plurality of reflecting surfaces so that, among the plurality of reflecting surfaces, a number of reflecting surfaces of a first group, a number of reflecting surfaces of a second group, and a number of reflecting surfaces of a third group are different from each other, so that light from the reflecting surfaces of the first group reaches the first zone via the condensing optical system, so that light from the reflecting surfaces of the second group reaches the second zone via the condensing optical system, and so that light from the reflecting surfaces of the third group reaches the third zone via the condensing optical system. |
