Diffuser, wavefront source, wavefront sensor and projection exposure apparatus

• Main Authors: HAIDNER HELMUT, SCHRIEVER MARTIN
• Format: Patent
• Language: English
• Published: 17.06.2008
• Subjects: APPARATUS SPECIALLY ADAPTED THEREFOR; CINEMATOGRAPHY; COLORIMETRY; ELECTROGRAPHY; HOLOGRAPHY; MATERIALS THEREFOR; MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT,POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED,VISIBLE OR ULTRA-VIOLET LIGHT; MEASURING; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; ORIGINALS THEREFOR; PHOTOGRAPHY; PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES; PHYSICS; RADIATION PYROMETRY; TESTING

A wavefront source having a wavefront formation structure ( 4 a) and a diffuser with a scattering structure ( 2 b) in the beam path in front of or at the level of the wavefront formation structure; also a diffuser configured to be used therefor, and a wavefront sensor equipped therewith, as well as a corresponding projection exposure apparatus. The diffuser has a diffractive computer-generated hologram (CGH) scattering structure with a predetermined angular scattering profile. The wavefront source includes such a diffuser and/or a focusing element with a reflecting diffractive focusing structure ( 3 a) in the beam path at the level of the scattering structure or between the scattering structure ( 2 b) and the wavefront formation structure ( 4 a). The disclosed structures are used, e.g., in the wavefront measurement of projection objectives in microlithography projection exposure apparatuses in the EUV wavelength range.