Illumination system

• Main Authors: Op 'T Root, Wilhelmus Patrick Elisabeth Maria, Godfried, Herman Philip, Van Bussel, Hubertus Petrus Leonardus Henrica
• Format: Patent
• Language: English
• Published: 04.12.2018
• Subjects: APPARATUS SPECIALLY ADAPTED THEREFOR; CINEMATOGRAPHY; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; ELECTROGRAPHY; FREQUENCY-CHANGING; HOLOGRAPHY; MATERIALS THEREFOR; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; ORIGINALS THEREFOR; PHOTOGRAPHY; PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES; PHYSICS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

An illumination system for a lithographic apparatus includes an array of lenses configured to receive a radiation beam and focus the beam into a plurality of sub-beams, an array of reflective elements configured to receive the sub-beams and reflect the sub-beams so as to form an illumination beam, a beam splitting device configured to split the illumination beam into a first portion and a second portion wherein the first portion is directed to be incident on a lithographic patterning device, a focusing unit configured to focus the second portion of the illumination beam onto a detection plane such that an image is formed at the detection plane and wherein the image is an image of the sub-beams in which the sub-beams do not overlap with each other and an array of detector elements configured to measure the intensity of radiation which is incident on the detection plane.