Illumination optical system, exposure apparatus, device production method, and light polarization unit
First Claim
1. An illumination optical system which illuminates an object with an illumination light, the illumination optical system comprising:
- a fly'"'"'s-eye lens having a back focal plane arranged on a pupil plane of the illumination optical system or in a vicinity of the pupil plane, the pupil plane being in a substantially optical Fourier transform relation with a predetermined plane on which the object is to be arranged;
a spatial light modulator which is arranged on an incident side of the fly'"'"'s-eye lens and which includes a plurality of mirror elements; and
a polarization unit including a plurality of optical elements each of which is capable of being arranged in an optical path of the illumination light and each of which changes a polarization state of the illumination light, whereinthe spatial light modulator is capable of changing an intensity distribution, of the illumination light, on the pupil plane, and is capable of forming the intensity distribution, on the pupil plane, in which at least a part of the illumination light is distributed to an off-axis region deviated from an optical axis of the illumination optical system,a first optical element among the plurality of optical elements of the polarization unit transforms a polarization state of the illumination light coming into the first optical element with the polarization state in which a linearly polarized light having a polarization direction in a predetermined one direction is a main component such that the at least a part of the illumination light, in the off-axis region, is linearly polarized light having a polarizing direction in a circumferential direction around the optical axis, to make the at least the part of the illumination light illuminated on the object via the off-axis region have a polarization state in which s-polarized light is a main component,an oblique light, included in the illumination light, which comes into the first optical element obliquely to the optical axis is imparted a polarization state different from a linear polarization having a polarizing direction in the circumferential direction via the first optical element and is distributed to the off-axis region, and a vertical light, included in the illumination light, which comes into the first optical element substantially vertically is imparted the linear polarization having the polarizing direction in the circumferential direction via the first optical element and is distributed to the off-axis region,the polarization unit includes a correction optical element which transforms the oblique light such that the oblique light on the pupil plane is the linearly polarized light having the polarizing direction in the circumferential direction, the correction optical element being different from the first optical element.
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Abstract
An illumination optical system which illuminates an illumination objective surface with a light from a light source. The illumination optical system includes a spatial light modulator which includes a plurality of optical elements arranged within a predetermined plane and controlled individually, and which forms a light intensity distribution in an illumination pupil of the illumination optical system; and a polarization unit which is arranged in a position optically conjugate with the predetermined plane, and which polarizes an incident light beam having a first and second partial light beams, coming into the polarization unit such that the first and second partial light beams have polarization states different from each other, and emits the polarized incident light beam as an outgoing light beam, wherein the polarization unit changes, in a cross section of the outgoing light beam, a ratio between a cross sectional areas of the first and second partial light beams.
28 Citations
24 Claims
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1. An illumination optical system which illuminates an object with an illumination light, the illumination optical system comprising:
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a fly'"'"'s-eye lens having a back focal plane arranged on a pupil plane of the illumination optical system or in a vicinity of the pupil plane, the pupil plane being in a substantially optical Fourier transform relation with a predetermined plane on which the object is to be arranged; a spatial light modulator which is arranged on an incident side of the fly'"'"'s-eye lens and which includes a plurality of mirror elements; and a polarization unit including a plurality of optical elements each of which is capable of being arranged in an optical path of the illumination light and each of which changes a polarization state of the illumination light, wherein the spatial light modulator is capable of changing an intensity distribution, of the illumination light, on the pupil plane, and is capable of forming the intensity distribution, on the pupil plane, in which at least a part of the illumination light is distributed to an off-axis region deviated from an optical axis of the illumination optical system, a first optical element among the plurality of optical elements of the polarization unit transforms a polarization state of the illumination light coming into the first optical element with the polarization state in which a linearly polarized light having a polarization direction in a predetermined one direction is a main component such that the at least a part of the illumination light, in the off-axis region, is linearly polarized light having a polarizing direction in a circumferential direction around the optical axis, to make the at least the part of the illumination light illuminated on the object via the off-axis region have a polarization state in which s-polarized light is a main component, an oblique light, included in the illumination light, which comes into the first optical element obliquely to the optical axis is imparted a polarization state different from a linear polarization having a polarizing direction in the circumferential direction via the first optical element and is distributed to the off-axis region, and a vertical light, included in the illumination light, which comes into the first optical element substantially vertically is imparted the linear polarization having the polarizing direction in the circumferential direction via the first optical element and is distributed to the off-axis region, the polarization unit includes a correction optical element which transforms the oblique light such that the oblique light on the pupil plane is the linearly polarized light having the polarizing direction in the circumferential direction, the correction optical element being different from the first optical element. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification