Structure and method to preserve STI during etching
AssigneeInternational Business Machines Corporation
InventorsOmer H. Dokumaci, Bruce B. Doris
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Abstract
Disclosed is a method of protecting a semiconductor shallow trench isolation (STI) oxide from etching, the method comprising lowering, if necessary, the upper surface of said STI oxide to a level below that of adjacent silicon active areas, depositing a nitride liner upon said STI oxide and adjacent silicon active areas in a manner effective in defining a depression above said STI oxide, filling said depression with a protective film, and removing said nitride layer from said adjacent active areas.
Claims20
A method of protecting a semiconductor shallow trench isolation (STI) oxide from etching, the method comprising:
- lowering, if necessary, the upper surface of said STI oxide to a level below that of adjacent silicon active areas;
- depositing a nitride liner upon said STI oxide and adjacent silicon active areas in a manner effective in defining a depression above said STI oxide;
- filling said depression with a protective film;
- and
- removing said nitride layer from said adjacent active areas.
The method of clam 13 wherein said protective film is an organic polymer and said recessing is effected with a plasma etch.
A method of protecting a semiconductor shallow trench isolation (STI) oxide from etching, the method comprising:
- lowering, if necessary, the upper surface of said STI oxide to a level below that of adjacent silicon active areas;
- optionally depositing a silicon oxide layer over said STI oxide and adjacent silicon active areas effective in protecting said adjacent silicon active layers from stresses induced by a conformal nitride liner deposited thereon;
- executing a chemical vapor deposition to deposit said conformal nitride liner upon said STI oxide and adjacent silicon active areas in a manner effective in defining a depression above said STI oxide;
- covering said nitride liner with a protective film comprising an organic polymer;
- recessing said protective film with a plasma etch, such that said protective film remains only in said depression;
- removing said nitride layer from said adjacent active areas with a reactive ion etch;
- and
- removing said protective film from said depression with a plasma etch.
A semiconductor structure, comprising a plurality of active areas separated by one or more shallow trench isolations wherein only said shallow trench isolations are covered by a protective layer of silicon nitride.
A semiconductor structure comprising:
- a plurality of active areas separated by one or more shallow trench isolations;
- said active areas and shallow trench isolations covered by a layer of silicon nitride, wherein said layer of silicon nitride comprises depressions over said shallow trench isolations;
- a protective film disposed in said depressions.
A method of protecting a semiconductor shallow trench isolation (STI) oxide from etching, the method comprising:
- providing means for lowering, if necessary, the upper surface of said STI oxide to a level below that of adjacent silicon active areas;
- providing means for depositing a nitride liner upon said STI oxide and adjacent silicon active areas in a manner effective in defining a depression above said STI oxide;
- providing means for protecting said adjacent silicon active areas from stresses induced by said nitride liner;
- providing means for filling said depression with a protective film;
- providing means for removing said nitride layer from said adjacent active areas.
Dependencies are inferred from the claim text.