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AssigneeApplied Materials, Inc.
InventorsMelvin Warren Montgomery, Alex Buxbaum, Scott Edward Fuller, Cecilia Annette Montgomery
Estimating the term…
We are able to significantly reduce variations in critical dimension from target for features in a patterned photoresist, where the patterned photoresist is generated during the fabrication of a reticle (photomask) to be used in semiconductor processing. The ability to maintain the targeted critical dimension of patterned photoresist features which were imaged using a direct write process depends upon the use of a photoresist binder resin system which provides a sufficiently dense structure to sterically hinder the movement of photoacid-labile groups after irradiation of such groups (writing of the pattern). As importantly, the photoacid groups which are used to generate the pattern need to be such that they are activated only at temperatures above about 70° C., and preferably at temperatures in the range of 110° C. to 150° C. Further improvement in uniformity of developed photoresist feature size across the reticle surface is achieved by controlling a combination of variables during development.
A method of reducing a change in critical dimension of features in a patterned photoresist, where the change occurs during the direct writing of a pattern into said photoresist, the method comprising selecting a photoresist composition which provides a sufficiently dense structure to sterically hinder the movement of photoacid generator groups which have been written upon, and wherein said photoresist composition includes photoacid-generator groups which activate to provide active photoacid at a temperature above the temperature experienced by the photoresist during the direct writing of the pattern features.
A method of improving the uniformity of feature size across a developed photoresist surface, where the photoresist composition provides a sufficiently dense structure to sterically hinder the movement of photoacid generator groups which have been written upon, wherein writing of a pattern upon said photoresist is carried out by a direct writing method, and wherein said photoacid generator groups activate to provide active photoacid at a temperature above the temperature experienced by the photoresist during the direct writing of the pattern, comprising employing a basic developer having a concentration of at least 0.13 normal.
Dependencies are inferred from the claim text.