Device for controlling temperature of an optical element
AssigneeCarl Zeiss SMT GmbH
InventorMarkus Hauf
Life of this patent
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Abstract
A device serves for controlling temperature of an optical element provided in vacuum atmosphere. The device has a cooling apparatus having a radiational cooling part, arranged apart from the optical element, for cooling the optical element by radiation heat transfer. A controller serves for controlling temperature of the radiational cooling part. Further, the device comprises a heating part for heating the optical element. The heating part is connected to the controller for controlling the temperature of the heating part. The resulting device for controlling temperature in particular can be used with an optical element in a EUV microlithography tool leading to a stable performance of its optics.
Claims24
An optical system, comprising:
- a plurality of optical elements including a first optical element;
- a cooling element disposed away from the first optical element, the cooling element being configured to cool the first optical element by radiation heat transfer;
- a heating device configured to heat the first optical element;
- and
- a controller configured to control a) the cooling element according to a temperature of the first optical element;
- or b) the heating device according to the temperature of the first optical element,
- wherein the first optical element is in a vacuum atmosphere, and the system is a microlithography optical system.
An apparatus, comprising:
- an illumination system comprising an optical system which comprises:
- a plurality of mirrors comprising a first mirror;
- a cooling element disposed away from the first mirror, the cooling element being configured to cool the first mirror by radiation heat transfer;
- a heating device configured to heat the first mirror;
- and
- a controller configured to control a) the cooling element according to a temperature of the mirror;
- or b) the heating device according to the temperature of the mirror;
- and
- a projection objective,
- wherein:
- the first mirror is in a vacuum atmosphere;
- and
- the apparatus is a microlithography projection exposure apparatus.
Dependencies are inferred from the claim text.