Suppressing lithography at a wafer edge
AssigneeInternational Business Machines Corporation
InventorsLinda Chen, Wai-Kin Li
Life of this patent
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Abstract
Damage to the rim of a semiconductor wafer caused by etching processes is reduced by forming a rim of carbonized photoresist around the outer edge of the wafer, using a wafer edge tool to carbonize the outer rim of a positive tone photoresist.
Claims20
A method of manufacturing a set of integrated circuits on a wafer comprising the steps of:
- preparing an integrated circuit substrate;
- depositing a layer of photosensitive material having a blocking thickness over said wafer;
- irradiating said photosensitive material in a blocking area at the outer edge of said wafer with a radiation dose such that said photosensitive material in said blocking area is desensitized;
- developing said photosensitive material to leave a layer of blocking material in said area;
- exposing a layer of patterning photoresist inside said blocking area with a set of images of a component pattern of a component of said set of integrated circuits;
- etching said wafer through said component pattern, while said blocking material blocks etching in said blocking area;
- and
- continuing with processing said set of integrated circuits.
A method of etching a set of apertures in a workpiece comprising the steps of:
- depositing a layer of photosensitive material having a blocking thickness over said workpiece;
- desensitizing said photosensitive material in a blocking area at the outer edge of said workpiece;
- exposing said layer of photosensitive material inside said blocking area with a set of images of said set of apertures;
- developing said photosensitive material to leave a layer of blocking material in said blocking area and an aperture pattern outside said blocking area;
- and
- etching said workpiece through said aperture pattern.
A semiconductor wafer comprising an inner area for the fabrication of integrated circuits and an outer rim resistant to etching and having a thickness such that an etching process does not etch in that area.
Dependencies are inferred from the claim text.