Critical dimension variation correction in extreme ultraviolet lithography
AssigneeCarl Zeiss SMT GmbH
InventorsSergey Oshemkov, Vladimir Kruglyakov, Frederik Blumrich, Yuval Perets
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Abstract
A method of correcting a critical dimension (CD) variation in extreme ultraviolet (EUV) photolithography includes mapping the CD variation of a wafer exposure field formed by a photolithography system that includes an EUV photolithography photomask. Parameters of a treatment to produce a change in reflectance at a working wavelength of EUV radiation in a region of a reflective multilayer of the photomask are determined, the change in reflectance being calculated to correct the mapped CD variation. A treatment beam is directed to the region. The region is treated with the beam in accordance with the determined parameters.
Claims12
A method of correcting a critical dimension (CD) variation in extreme ultraviolet (EUV) photolithography, the method comprising:
- mapping the CD variation of a wafer exposure field formed by a photolithography system that includes an EUV photolithography photomask;
- determining one or a plurality of parameters of a treatment to produce a change in reflectance at a working wavelength of EUV radiation in a region of a reflective multilayer of the photomask, the change in reflectance being calculated to correct the mapped CD variation;
- directing a treatment beam to the region of the reflective multilayer;
- and
- treating the region of the reflective multilayer with the beam in accordance with the determined one or a plurality of parameters.
Dependencies are inferred from the claim text.