Method for making field effect devices and capacitors with thin film dielectrics and resulting devices
AssigneeAgere Systems Guardian Corp.
InventorGlenn B. Alers
Life of this patent
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Abstract
An electronic device having an improved capacitor structure is formed by depositing a metal layer defining a first electrode on a film of high dielectric constant material, and then depositing the dielectric layer of the capacitor structure on the first electrode. This resulting structure is then exposed to a nitrogen plasma and the top electrode is formed. Exposing the first electrode to a plasma of pure nitrogen prevents the partial oxidation of the first electrode and reduces the density of charge traps at the electrode/dielectric interface. The dielectric film is passivated with the nitrogen material before forming the top electrode to prevent interdiffusion between the electrode and the dielectric.
Claims12
A method of making an electronic device having a capacitor structure comprising in sequence:
- depositing a metal layer defining a first electrode of the capacitor on a film of dielectric material;
- depositing a second dielectric layer on the first electrode to form the dielectric layer of the capacitor;
- exposing the film of dielectric to a pure nitrogen plasma to reduce the density of charge traps at the dielectric/electrode interface;
- and depositing a second metal layer on the second dielectric layer to define the second electrode of the capacitor structure.
A method of making a capacitor structure of an electronic device having a thin film of dielectric material, the method comprising:
- a) providing a substrate;
- b) depositing a first film of dielectric material on said substrate to define a first dielectric layer;
- c) depositing a first layer of metallic material on said first dielectric layer;
- d) patterning the first layer of metallic material to define a first electrode of the capacitors;
- e) depositing a second layer of dielectric material on the first electrode to define the dielectric layer of the capacitor;
- f) exposing the second dielectric layer to a pure nitrogen plasma to reduce the density of charge traps at the interface between the first electrode and the second dielectric layer;
- and
- g) forming a second electrode overlying said second dielectric layer to complete said capacitor structure.
A method of making a capacitor structure incorporated in an electronic device having a thin film of dielectric material, the method comprising in sequence:
- (a) providing a substrate comprising a MOS device having at least one gate electrode;
- (b) depositing a first film of dielectric material on said MOS device overlying said gate electrode to define a first dielectric layer;
- (c) depositing a first layer of metallic material on said first dielectric layer;
- (d) patterning the first layer of metallic material to define a first electrode;
- (e) depositing a layer of tantalum oxide on the first electrode to define a second dielectric layer;
- (f) exposing the second dielectric layer to a first plasma comprising pure nitrogen and a second plasma containing oxygen, wherein the first and second plasmas are each applied at a substrate temperature in the range 100-500° C. to reduce the density of charge traps at the interface between the first electrode and the second dielectric layer;
- and
- (g) forming a second electrode overlying said second dielectric layer to complete said capacitor structure.
Dependencies are inferred from the claim text.