Back to results
US 6,295,122 B1Granted
Illumination system and REMA objective with lens displacement and operating process therefor
AssigneeCarl Zeiss
InventorsJörg Schultz, Johannes Wangler
Life of this patent
Estimating the term…
Abstract
An illumination system for a microlithography projection illumination equipment, in which a secondary light source is imaged on a reticle . The distortion of the image can be set by at least one variable optical path between optical elements, and the uniformity of the illumination is changed because of the changed distortion, in particular, in that the uniformity is increased toward the edge.
Claims24
An illumination system for microlithographic projection equipment comprising in the listed sequence
- a light source,
- a first plurality of optical elements,
- a reticle masking system,
- a second plurality of optical elements defining a first lens group,
- a pupil plane,
- a third plurality of optical element defining a second lens group,
- a fourth plurality of optical elements defining a third lens group,
- a reticle plane,
- wherein said first plurality of optical elements collects light of said light source and illuminates said reticle masking system,
- wherein said first second and third lens group and said pupil plane define a REMA objective,
- wherein said REMA objective forms an image of said reticle masking system on said reticle plane,
- wherein said image has a distortion, and
- wherein a first optical path between two of said optical elements of said third lens group is adjustable to adjust said distortion.
10 more elements
An illumination system for microlithographic projection equipment comprising in the listed sequence
- a light source,
- a first plurality of optical elements,
- a reticle masking system,
- a second plurality of optical elements
- a reticle plane,
- wherein said first plurality of optical elements collects light of said light source and illuminates said reticle masking system,
- wherein said second plurality of optical elements define a REMA objective,
- wherein said REMA objective forms an image of said reticle masking system on said reticle plane,
- wherein said image has an aperture and wherein said aperture is changed in kind or in magnitude, by adjusting, changing or exchanging one or more optical elements of said first plurality of optical elements, and
- wherein said image has a distortion and wherein said distortion is adjusted by adjusting a first variable optical path between two of said optical elements of said second plurality of optical elements,
- and wherein said distortion is adjusted in dependence on said aperture.
8 more elements
A microlithographic projection equipment comprising in the listed sequence
- a light source,
- a first plurality of optical elements comprising a zoom axicon objective with an
- adjustable zoom and an adjustable axicon,
- a homogenizing rod,
- a reticle masking system directly adjoining said homogenizing rod,
- a second plurality of optical elements defining a first lens group,
- a pupil plane,
- a third plurality of optical elements defining a second lens group,
- a fourth plurality of optical elements defining a third lens group
- a reticle,
- a projection objective, and
- a wafer,
- wherein said first plurality of optical elements collects light of said light source and illuminates said homogenizing rod,
- wherein said first, second and third lens group and said pupil plane define a REMA objective,
- wherein said REMA objective forms a first image of said reticle masking system on said reticle plane,
- wherein said projection objective forms a second image of said reticle on said wafer, wherein said first image has a distortion and
- wherein a first optical path between two of said optical elements of said third lens group is continuously adjustable to adjust said distortion and wherein said first image has an aperture of illumination and wherein said aperture is changed in kind or in magnitude by adjusting said axicon or said zoom, and wherein said distortion is adjusted in dependence on said aperture.
14 more elements
A process for operation of a microlithographic projection equipment with
- a light source,
- a first plurality of optical elements,
- a reticle masking system,
- a second plurality of optical elements,
- a reticle plane,
- wherein said first plurality of optical elements collects light of said light source and illuminates said reticle masking system,
- wherein said second plurality of optical elements define a REMA objective,
- wherein said REMA objective forms an image of said reticle masking system on said reticle plane
- wherein said image has a distortion, an aperture of illumination, a light intensity distribution and an edge steepness,
- wherein the process comprises
- adjusting said aperture in kind or in magnitude by adjusting, changing or exchanging one or more of said optical elements of said first plurality of optical elements, and
- adjusting said distortion by varying a first variable optical path between two of said optical elements of said REMA objective in dependence on said aperture.
9 more elements
Dependencies are inferred from the claim text.