Chemical oxide removal of plasma damaged SiCOH low k dielectrics

1. A semiconductor device comprising:

a plasma etched damascene structure comprising a trench having sidewalls formed in an interlevel dielectric film;

a barrier layer comprising Si 3 N 4 formed on a silicon wafer; and

a photoresist layer formed on the interlevel dielectric film;

wherein the sidewalls are devoid of plasma-induced damage,

the interlevel dielectric film is formed on the barrier layer, and

the sidewalls are recessed from the photoresist by an amount equal to a trimming dimension associated with a removed damaged portion, whereby damage to the sidewalls of the plasma etched damascene structure is removed by:

depositing a controlled amount of gaseous hydrofluoric acid and ammonia gas onto the sidewalls of the dual damascene structure;

forming volatile reaction products from a chemical reaction between the plasma induced damages and the deposited mixture of ammonia gas and gaseous hydrofluoric acid; and

removing the volatile reaction products.

2. The semiconductor device according to claim 1 , wherein the interlevel dielectric film comprises low k material having a dielectric constant of 3.9 or less.

3. The semiconductor device according to claim 1 , wherein the damage is removed by trimming the sidewalls between 1 and 25 nm.

4. The semiconductor device of claim 1 , wherein the interlevel dielectric film comprises organic siloxanes.

5. The semiconductor device of claim 1 , wherein the volatile reaction products are removed with a vacuum.

6. The semiconductor device of claim 1 , wherein the volatile reaction products are removed with a non-reactive flushing gas.

7. The semiconductor device of claim 1 , wherein the volatile reaction products are removed with a vacuum or a non-reactive flushing gas.

8. The semiconductor device of claim 1 , wherein the trench extends through the barrier layer to the silicon wafer.

9. The semiconductor device according to claim 1 , wherein the sidewalls are recessed from the photoresist by approximately 1 to 25 nm.

10. A semiconductor device comprising:

a plasma etched dual damascene structure comprising a trench having sidewalls formed in an interlevel dielectric film; and

a photoresist layer formed on the interlevel dielectric film;

wherein the sidewalls are devoid of plasma-induced damage, and

the sidewalls are recessed from the photoresist, whereby damage to the sidewalls of the plasma etched dual damascene structure is removed by:

depositing a controlled amount of gaseous hydrofluoric acid and ammonia gas onto the sidewalls of the dual damascene structure;

forming volatile reaction products from a chemical reaction between the plasma induced damages and the deposited mixture of ammonia gas and gaseous hydrofluoric acid; and

removing the volatile reaction products,

wherein the recessed sidewalls result in a portion of the photoresist forming an overhang; and

the recessed sidewalls are recessed from the photoresist by an amount equal to a trimming dimension associated with a removed damaged portion.

11. The semiconductor device according to claim 1 , wherein sidewalls of the barrier layer are recessed from the photoresist.

12. The semiconductor device according to claim 11 , wherein both the sidewalls formed in the interlevel dielectric film and the sidewalls of the barrier layer are recessed from the photoresist by approximately 1 to 25 nm.

13. The semiconductor device according to claim 11 , wherein a portion of the photoresist overhangs both the sidewalls formed in the interlevel dielectric film and the sidewalls of the barrier layer.

14. The semiconductor device according to claim 1 , wherein:

the interlevel dielectric film is directly on the barrier layer;

the trench extends through the barrier layer to the silicon wafer;

the sidewalls of the barrier layer are recessed from the photoresist by an amount equal to the trimming dimension associated with the removed damaged portion;

the sidewalls formed in the interlevel dielectric film and the sidewalls of the barrier layer are aligned; and

the interlevel dielectric film comprises organic siloxanes.

15. A semiconductor device comprising:

a plasma etched damascene structure comprising a trench having sidewalls formed in an interlevel dielectric film;

a photoresist layer formed on the interlevel dielectric film; and

a barrier layer on a silicon wafer,

wherein the sidewalls are devoid of plasma-induced damage,

the sidewalls are recessed from the photoresist,

the interlevel dielectric film is on and contacting the barrier layer;

the trench extends through the barrier layer to the silicon wafer;

both the sidewalls formed in the interlevel dielectric film and sidewalls of the barrier layer are recessed from the photoresist by an amount equal to a trimming dimension associated with a removed damaged portion;

the sidewalls formed in the interlevel dielectric film and the sidewalls of the barrier layer are aligned;

the interlevel dielectric film comprises organic siloxanes;

the barrier layer comprises nitride; and

damage to the sidewalls of the plasma etched damascene structure is removed by:

depositing a controlled amount of gaseous hydrofluoric acid and ammonia gas onto the sidewalls of the dual damascene structure;

forming volatile reaction products from a chemical reaction between the plasma induced damages and the deposited mixture of ammonia gas and gaseous hydrofluoric acid; and

removing the volatile reaction products.

16. A semiconductor device comprising:

a damascene structure comprising a trench having sidewalls formed in an interlevel dielectric film;

a barrier layer comprising nitride on a silicon wafer; and

a photoresist layer on the interlevel dielectric film;

wherein the sidewalls are devoid of plasma-induced damage,

the interlevel dielectric film is on the barrier layer, and

the sidewalls are recessed from the photoresist by an amount equal to a trimming dimension associated with a removed damaged portion.