Method of forming tungsten interconnect with tungsten oxidation to prevent tungsten loss
AssigneesProMOS Technologies Inc., Mosel Vitelic, Inc., Seimens Aktiengesellschaft
InventorsNien-Yu Tsai, Hong-Long Chang, Chun-Wei Chen, Ming-Li Kung
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Abstract
A method of forming a metal interconnect structure and via plugs over a dielectric layer having a plurality of vias formed therein is disclosed. The method comprises the steps of: forming tungsten via plugs in the plurality of vias; depositing a metal layer over the dielectric layer and the plurality of tungsten via plugs; patterning and etching the metal layer using a photoresist layer to form the metal interconnect structure; oxidizing the metal interconnect structure and the tungsten via plugs to form a metal oxide layer over the metal interconnect structure and tungsten via plugs; and performing a wet strip on the metal interconnect structure.
Claims12
A method of forming a metal interconnect structure and via plugs over a dielectric layer having a plurality of vias formed therein, the method comprising:
- forming tungsten via plugs in said plurality of vias;
- depositing a metal layer over said dielectric layer and said plurality of tungsten via plugs;
- patterning and etching said metal layer using a photoresist layer to form said metal interconnect structure;
- after patterning and etching said metal layer, removing said photoresist layer using an ashing process;
- oxidizing said metal interconnect structure and said tungsten via plugs to form a metal oxide layer over said metal interconnect structure and tungsten via plugs;
- and
- subsequent to the oxidizing of said metal interconnect, performing a wet strip on said metal interconnect structure.
A method of forming a metal interconnect structure and tungsten via plugs over a dielectric layer having a plurality of vias formed therein, said vias being filled with said tungsten via plugs, the method comprising:
- depositing a metal layer over said dielectric layer and over said tungsten via plugs;
- patterning and etching said metal layer using a photoresist layer to form said metal interconnect structure;
- after patterning and etching said metal layer, removing said photoresist layer using an ashing process;
- oxidizing said metal interconnect structure and any exposed tungsten via plugs to form a metal oxide layer over said metal interconnect structure and said exposed tungsten via plugs;
- and
- subsequent to the oxidizing of said metal interconnect, performing a wet strip on said metal interconnect structure.
Dependencies are inferred from the claim text.