Repair of masks to promote adhesion of patches
AssigneeInternational Business Machines Corporation
InventorsPhilip S. Flanigan, Dennis M. Hayden, Michael S. Hibbs, Timothy E. Neary
Life of this patent
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Abstract
The current invention performs short pulse laser ablation of clear defect regions on a mask prior to patching the clear defect regions. The short-pulse laser ablation removes any residue that absorbs light. Thus, the ablation completely cleans the surface of the clear defect regions, meaning that any patches of the surface will better adhere to the surface of the mask. This is particularly important during those situations where a later etch of a conductive surface added to the mask creates a solvent because the etchant interacts with residue on the mask, and wherein the solvent attacks the patch material at the patch material's interface.
Claims23
A method for repairing a mask comprising the steps of:
- determining at least one clear defect;
- cleaning a region of the clear defect by using a short pulse laser;
- and
- after cleaning the region of the clear defect, applying a patch to the region of the defect;
- wherein said cleaning step prevents the patch from lifting away from surrounding mask substrate.
A method for repairing a phase shift mask comprising the steps of:
- forming and patterning a layer of phase shift material on a surface of the mask;
- determining at least one clear defect, which is an area where the phase shift material should be but where there is no phase shift material;
- cleaning a region of the at least one clear defect by using a short pulse laser that can produce a plurality of pulses, each pulse having a pulse time less than or equal to 100 femtoseconds;
- forming a conductive layer over the surface of the mask;
- etching the at least one clear defect to remove the conductive layer covering the at least one clear defect;
- applying a patch to the region of the at least one clear defect;
- and
- etching the remaining conductive layer to remove the conductive layer from the surface of the mask.
Dependencies are inferred from the claim text.