Patent ID: 6309976
Filing Date: 2001-10-30
Classification: G03F

Abstract:
A method of performing a descum operation during fabrication of a metal mask from a metal layer deposited upon a quartz substrate patterned for exposure of a workpiece to radiation with said substrate being transparent to said radiation of a specific range of wavelengths, said method comprising the steps as follows:first form said metal layer composed of a masking metal upon said quartz substrate,then form a passivated metal layer on said metal layer,then form a photoresist mask superjacent to said passivated metal layer with at least one opening therethrough with sidewalls of said at least one opening having sidewall angles .theta. substantially less than an ideal vertical angle (90.degree.),then bake said photoresist mask, said metal layer and said substrate,then perform a descum operation to widen said at least one opening thereby forming more vertical sidewalls of said photoresist mask,then perform an isotropic etching of said metal layer with a wet etchant etching through said at least one opening through said photoresist mask to form said metal mask,then perform an after etching inspection measurement of said metal mask,then strip said photoresist mask, andthen perform an after stripping inspection measurement of said metal mask.