External beam delivery system using catadioptric objective with aspheric surfaces
AssigneeKLA-Tencor Corporation
InventorJ. Joseph Armstrong
Life of this patent
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Abstract
An inspection system including a catadioptric objective that facilitates dark-field inspection is provided. The objective includes an outer element furthest from the specimen having an outer element partial reflective surface oriented toward the specimen, an inner element nearest the specimen having a center lens comprising an inner element partial reflective surface oriented away from the specimen, and a central element positioned between the outer lens and the inner lens. At least one of the outer element, inner element, and central element has an aspheric surface. The inner element is spatially configured to facilitate dark-field inspection of the specimen.
Claims31
An objective configured to inspect a specimen comprising:
- an outer element furthest from the specimen and comprising an outer element partial reflective surface oriented toward the specimen and configured to reflect light energy toward the specimen;
- an inner element nearest the specimen comprising an inner element partial reflective surface located proximate to and oriented away from the specimen, causing light energy to be reflected away from the specimen;
- and
- a central element positioned between the outer element and the inner element;
- wherein one of the outer element and central element comprises an aspheric surface, and further wherein the inner element is spatially configured to facilitate dark-field inspection of the specimen.
An objective configured to inspect a specimen, comprising:
- a Mangin element comprising a reflective surface positioned substantially proximate the specimen in an orientation causing light energy to reflect away from the specimen;
- a catadioptric element comprising a substantially curved reflective surface positioned to reflect light energy toward the specimen;
- and
- an intermediate lens configured to receive light energy reflected from the Mangin element and the catadioptric element;
- wherein one of the catadioptric element and intermediate lens comprises an aspheric surface, and further wherein the Mangin element is spatially configured to facilitate dark-field inspection of the specimen.
A specimen inspection apparatus configured to inspect a specimen, comprising:
- a light energy source;
- and
- an objective comprising:
- a Mangin element comprising a reflective surface positioned substantially proximate the specimen in an orientation causing light energy to reflect away from the specimen;
- a catadioptric element comprising a substantially curved reflective surface positioned to reflect light energy toward the specimen;
- and
- an intermediate lens configured to receive light energy reflected from the Mangin element and the catadioptric element;
- wherein one of the catadioptric element and intermediate lens comprises an aspheric surface.
Dependencies are inferred from the claim text.