Microlithographic projection exposure apparatus
AssigneeCarl Zeiss SMT GmbH
InventorsAndras G. Major, Manfred Maul, Gundula Weiss, Jochen Hetzler
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Abstract
A microlithographic projection exposure apparatus includes a projection light source. The apparatus also includes a heating light source for generating heating light which is at least partly absorbed by an optical element. An illumination optical unit directs the heating light onto the optical element such that the heating light has a predefined intensity distribution on an optical surface of the optical element. The illumination optical unit includes a deflection element which is a diffractive optical element or a refractive freeform element. The deflection element simultaneously directs the heating light impinging thereon in different directions.
Claims20
An apparatus configured to image a mask onto a layer, the apparatus comprising:
- a projection light source configured to generate projection light to which the layer is light-sensitive;
- an optical element having an optical surface subjected to the projection light during use of the apparatus;
- a heating light source configured to generate heating light to which the layer is not light-sensitive, the heating light source being different from the projection light source, the heating light being at least partly absorbed by the optical element during use of the apparatus;
- an illumination optical unit configured so that, during use of the apparatus, the illumination optical unit directs the heating light onto the optical element so that the heating light has a predetermined intensity on the optical surface,
- wherein:
- the illumination optical unit comprises a deflection element;
- the deflection element comprises a diffractive optical element or a refractive freeform element;
- the deflection element is configured so that, at a given point in time during use of the apparatus, heating light impinging on the deflection element is directed by the deflection element into different directions;
- and
- the apparatus is a microlithographic projection exposure apparatus.
A method, comprising:
- using a microlithographic projection exposure apparatus to image a mask onto a layer using projection light, the layer being light-sensitive to the projection light;
- and
- simultaneously exposing an optical element of the microlithographic projection exposure apparatus to heating light to heat an optical surface of the optical element, the heating light being different from the projection light,
- wherein the microlithographic exposure apparatus comprises a deflection unit on which the heating light impinges during the method, and the deflection unit deflects the heating light simultaneously in different directions.
Dependencies are inferred from the claim text.