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US 6,746,806 B2Granted
Lithography mask blank and method of manufacturing the same
AssigneeHoya Corporation
InventorOsamu Nozawa
Life of this patent
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Abstract
In a method of annealing a workpiece which has a substrate and a light absorption film on the substrate, a laser beam is irradiated onto a workpiece to only heat the light absorption film without any temperature rise of the substrate and to anneal an internal stress of the light absorption film. A wavelength of the laser beam is selected so as to be absorbed into the light absorption film. The workpiece may be a photo mask blank (or a photo mask) or a phase shift mask blank (or a phase shift mask).
Claims11
A method of manufacturing a lithography mask blank on a glass substrate, comprising the steps of:
- depositing, on the glass substrate, at least one light absorption film which has a property of absorbing a laser beam of a predetermined wavelength which transmits the glass substrate;
- and
- irradiating the laser beam of the predetermined wavelength onto the light absorption film to selectively heat the light absorption film and to thereby alleviate its internal stress.
Dependencies are inferred from the claim text.