Method and apparatus for repair of reflective photomasks

• Main Authors: HAIGHT RICHARD A, LONGO PETER P, WAGNER ALFRED
• Format: Patent
• Language: English
• Published: 20.07.2010
• Subjects: APPARATUS SPECIALLY ADAPTED THEREFOR; CINEMATOGRAPHY; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; 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; MACHINE TOOLS; MATERIALS THEREFOR; METAL-WORKING NOT OTHERWISE PROVIDED FOR; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; ORIGINALS THEREFOR; PERFORMING OPERATIONS; PHOTOGRAPHY; PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES; PHYSICS; SOLDERING OR UNSOLDERING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; TRANSPORTING; WELDING; WORKING BY LASER BEAM

A method of selectively ablating an undesired material from a substrate includes providing a substrate with two regions; providing laser pulses; tuning a wavelength of the laser pulses to match a desired wavelength characteristic of a material and directing the tuned laser pulses onto the substrate; and controlling a pulse duration, wavelength, or both, of the laser pulses to ablate the undesired material without damaging the substrate or any adjacent material. In another embodiment, an apparatus for repairing a defect on a reflective photomask includes a femtosecond pulse width laser; a harmonic conversion cell; a filter for passing a selected EUV harmonic of the laser light; a lens arrangement configured to direct the selected EUV harmonic of the laser light onto the photomask; and a control unit connected to the laser to control an ablation of the defect on the reflective photomask.