Selective spacer to prevent metal oxide formation during polycide reoxidation
AssigneeMicron Technology, Inc.
InventorsKlaus Florian Schuegraf, Scott Jeffrey DeBoer, Randhir P. S. Thakur
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Abstract
A selective spacer to prevent metal oxide formation during polycide reoxidation of a feature such as an electrode and a method for forming the selective spacer are disclosed. A material such as a thin silicon nitride or an amorphous silicon film is selectively deposited on the electrode by limiting deposition time to a period less than an incubation time for the material on silicon dioxide near the electrode. The spacer is deposited only on the electrode and not on surrounding silicon dioxide. The spacer serves as a barrier for the electrode during subsequent oxidation to prevent metal oxide formation while allowing oxidation to take place over the silicon dioxide.
Claims22
An electronic device comprising:
- a first layer of oxide;
- a feature over the first layer of oxide, the feature having a surface;
- a boundary between the first layer of oxide and the feature;
- and
- a spacer comprising silicon nitride or an amorphous silicon film only on the surface of the feature.
An electronic device comprising:
- a first layer of oxide;
- an electrode on the first layer of oxide, the electrode having sidewalls;
- and
- a spacer comprising silicon nitride or an amorphous silicon film deposited only on the sidewalls of the electrode, the spacer extending to and terminating at a boundary between the first layer of oxide and the sidewalls of the electrode.
A semiconductor device, comprising:
- a first layer of oxide;
- a feature protruding from the first layer of oxide and having sidewalls, the feature including:
- a polysilicon portion;
- a portion of conductive material deposited on the polysilicon portion;
- a spacer comprising silicon nitride or an amorphous silicon film selectively deposited only on the sidewalls of the feature;
- and
- a second layer of oxide deposited on the semiconductor device, wherein the spacer is interposed between the second layer of oxide and the sidewalls of the feature.
A semiconductor device, comprising:
- a first layer of oxide;
- a feature protruding from the first layer of oxide and having sidewalls, the feature comprising:
- a layer of polysilicon;
- one or more layers of conductive materials deposited on the layer of polysilicon, wherein at least one of the layers comprises tungsten silicide;
- a silicon nitride spacer selectively deposited only on the sidewalls of the feature;
- and
- a second layer of oxide deposited on the semiconductor device, wherein the silicon nitride spacer is interposed between the second layer of oxide and the sidewalls of the feature.
A gate electrode, comprising:
- one or more layers of conductive materials etched to form a feature having sidewalls exposing the layers;
- a selectively deposited spacer comprising silicon nitride or an amorphous silicon film, wherein the spacer is deposited only on the sidewalls of the feature;
- and
- a layer of oxide disposed over the gate electrode.
An electronic device comprising:
- a first layer of oxide;
- an electrode on the first layer of oxide, the electrode having sidewalls;
- and
- spacer means for protecting the electrode from a reoxidation, the spacer means comprising silicon nitride or an amorphous silicon film and being deposited on the sidewalls of the electrode and not on the first layer of oxide.
An electronic device comprising:
- a first layer of oxide;
- an electrode including polysilicon, a refractory metal, and a dielectric over the first layer of oxide, the electrode having sidewalls;
- a boundary between the first layer of oxide and the electrode;
- and
- a spacer comprising silicon nitride or an amorphous silicon film only on the sidewalls of the electrode.
An electronic device comprising:
- a first layer of oxide;
- an electrode comprising undoped silicon over the first layer of oxide, the electrode having sidewalls;
- a boundary between the first layer of oxide and the electrode;
- and
- a spacer comprising silicon nitride or an amorphous silicon film only on the sidewalls of the electrode.
Dependencies are inferred from the claim text.