Device for controlling temperature of an optical element
AssigneeCarl Zeiss SMT GmbH
InventorMarkus Hauf
Life of this patent
Estimating the term…
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.
Claims21
A system having an optical path along which EUV radiation passes through the system during use of the system, the system comprising:
- an optical mirror comprising a substrate supporting a surface, the surface comprising a reflective surface and/or diffractive surface, the surface being in the optical path along which EUV radition passes through the system during use of the system;
- a heating device configured to heat the optical mirror;
- and
- a radiational cooling element configured to cool the optical mirror by radiation heat transfer,
- wherein:
- the optical mirror is configured so that, during use of the system, the optical mirror receives heat from the heating device while the surface is in the optical path along which the EUV radiation passes through the system;
- the heating device is configured to heat a mirror heat transfer area of the optical mirror;
- the radiational cooling element is configured to receive thermal radiation from the mirror heat transfer area;
- and
- the mirror heat transfer area is selected from the group consisting of an area substantially arranged at a periphery of the optical mirror and an area substantially facing a rear surface of the substrate of the optical mirror.
A system, comprising:
- an EUV light source configured to emit EUV radiation;
- an optical mirror comprising a substrate supporting a surface, the surface comprising a reflective surface and/or diffractive surface, the surface being configured to recieve EUV radiation from the EUV light source;
- a heating device configured to heat the optical mirror;
- and
- a radiational cooling element configured to cool the optical mirror by radiation heat transfer,
- wherein:
- the optical mirror is configured to receive heat from the heating device and EUV radiation from the EUV light source;
- the heating device is configured to heat a mirror heat transfer area of the optical mirror;
- the radiational cooling element is configured to receive thermal radiation from the mirror heat transfer area;
- and
- the mirror heat transfer area is selected from the group consisting of an area substantially arranged at a periphery of the optical mirror and an area substantially facing a rear surface of the substrate of the optical mirror.
Dependencies are inferred from the claim text.