Microlithography illumination optical system and microlithography projection exposure apparatus including same
AssigneeCarl Zeiss SMT GmbH
InventorsMichael Patra, Markus Deguenther, Michael Layh
Life of this patent
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Abstract
A microlithography illumination optical system is used to guide illumination light from a primary light source to an object field. A mirror array of the illumination optical system has a plurality of individual mirrors, which can be tilted independently of one another by actuators and are connected to associated tilting actuators. A controller is used to activate the actuators. A raster module of the illumination optical system has a plurality of raster elements to produce a spatially distributed arrangement of secondary light sources.
Claims20
An optical system, comprising:
- a mirror array comprising a plurality of mirrors;
- a plurality of actuators, each mirror being independently tiltable via an associated actuator;
- a controller configured to activate the actuators;
- and
- a raster module comprising a plurality of raster elements configured to produce a spatially distributed arrangement of secondary light sources, the raster module being in a region of a plane of the optical system in which an emergent angle at which an illumination light part bundle leaves one of the raster elements is precisely allocated to a location region in an object field of the optical system on which the illumination light part bundle impinges,
- wherein the controller is configured so that specifying a tilting angle for each individual mirror allocates a predetermined field-dependent desired course of illumination angle intensity distributions by which object field points distributed over the object field are impinged upon, and
- wherein the optical system is a microlithography illumination optical system.
A method of adjusting a microlithography illumination optical system, the method comprising:
- determining a field-dependent course of illumination angle intensity distributions with which object field points distributed over an object field of the microlithography illumination optical system are to be impinged upon;
- determining a distribution of desired angles of incidence of illumination light part bundles on raster elements of a raster arrangement of the microlithography illumination optical system, allocated to the field-dependent course of the illumination angle intensity distributions;
- allocating a distribution of desired tilting angles to individual mirrors of a mirror array of the microlithography illumination optical system, according to the determined distribution of the desired angle of incidence;
- and
- adjusting tilting angles of the individual mirrors to coincide with desired tilting angles.
A method of producing a raster module a microlithography illumination optical system, the raster module comprising first and raster arrangements, the method comprising:
- specifying a dependency of a course of constant emergent angles of illumination light part bundles from raster elements of the second raster arrangement depending on an impingement location of the illumination light part bundles on the raster elements of the second raster arrangement and depending on an angle of incidence of the illumination light part bundles on the raster elements of the second raster arrangement;
- and
- structuring an entry face and/or an exit face of the raster elements of the second raster arrangement so that, at a predetermined illumination of the raster module, an actual dependency is produced which corresponds to the predetermined desired dependency.
A method of producing a raster module a microlithography illumination optical system, the raster module comprising first and raster arrangements, the method comprising:
- determining classes of desired dependencies of a course of constant emergent angles of illumination light part bundles from raster elements of the second raster arrangement depending on an impingement location of the illumination light part bundles on the raster elements of the second raster arrangement and depending on an angle of incidence of the illumination light part bundles on the raster elements of the second raster arrangement, which can be achieved with typical surface designs of the entry faces and/or the exit faces of the raster elements of the second raster arrangement;
- specifying a dependency, which is contained in one of the determined classes, of a course of resulting constant emergent angles of the illumination light part bundles from the raster elements of the second raster arrangement depending on the impingement location of the illumination light part bundles on the raster elements of the second raster arrangement and depending on an angle of incidence of the illumination light part bundles on the raster elements of the second raster arrangement;
- and
- structuring an entry face and/or an exit face of the raster elements of the second raster arrangement so that, at a predetermined illumination of the raster module, an actual dependency is produced which corresponds to the predetermined dependency.
Dependencies are inferred from the claim text.