Systems and methods for selective tungsten deposition in vias

1. A method for processing a substrate, comprising:

providing a substrate including a metal layer, a dielectric layer arranged on the metal layer, and at least one of a via and a trench formed in the dielectric layer;

depositing metal using chemical vapor deposition (CVD) during a first deposition period, wherein the first deposition period is longer than a first nucleation delay period that is required to deposit the metal on the metal layer;

stopping the first deposition period prior to a second nucleation delay period, wherein the second nucleation delay period is required to deposit the metal on the dielectric layer;

performing a growth interruption treatment to interrupt growth of the metal on the dielectric layer, wherein the growth interruption treatment comprises one of:

an ammonia soak during a soak period; or

a fluorine soak during a soak period;

performing the depositing and the stopping N times, where N is an integer greater than or equal to one; and

after the performing, depositing the metal using CVD during a second deposition period that is longer than the second nucleation delay period.

2. The method of claim 1 , wherein the metal comprises tungsten.

3. The method of claim 1 , wherein the metal layer comprises tungsten.

4. The method of claim 1 , further comprising depositing a nucleation layer prior to the first deposition period.

5. The method of claim 4 , wherein the nucleation layer comprises one of fluorine-free tungsten layer and a tungsten/tungsten-nitride layer.

6. The method of claim 4 , wherein the nucleation layer has a thickness between 2 Angstroms and 30 Angstroms.

7. The method of claim 1 , wherein the growth interruption treatment comprises performing the ammonia soak during the soak period.

8. The method of claim 1 , wherein the growth interruption treatment comprises performing the fluorine soak during the soak period.

9. The method of claim 4 , further comprising performing a sputter etch process prior to the first deposition period to remove the nucleation layer in the via at a contact bottom to expose the metal layer.

10. A method for processing a substrate, comprising:

providing a substrate including a metal layer, a dielectric layer arranged on the metal layer, and at least one of a via and a trench formed in the dielectric layer;

during a first deposition period, depositing metal using physical vapor deposition (PVD);

depositing the metal using chemical vapor deposition (CVD) during a second deposition period, wherein the second deposition period is longer than a first nucleation delay period required to deposit the metal on the metal layer;

stopping the second deposition period prior to a second nucleation delay period, wherein the second nucleation delay period is required to deposit the metal on the dielectric layer;

performing a growth interruption treatment to interrupt growth of the metal on the dielectric layer, wherein the growth interruption treatment comprises one of:

an ammonia soak during a soak period; or

a fluorine soak during a soak period;

performing the CVD depositing and the stopping N times, where N is an integer greater than or equal to one; and

after the performing, depositing the metal using CVD during a third deposition period that is longer than the second nucleation delay period.

11. The method of claim 10 , wherein the metal comprises tungsten.

12. The method of claim 10 , wherein the metal layer comprises tungsten.

13. The method of claim 10 , wherein the growth interruption treatment comprises performing the ammonia soak for the soak period.

14. The method of claim 10 , wherein the growth interruption treatment comprises performing the fluorine soak for the soak period.

15. The method of claim 10 , wherein the PVD comprises directional PVD.

16. The method of claim 10 , wherein the PVD comprises non-directional PVD.

17. A method for processing a substrate, comprising:

providing a substrate including a metal layer, a dielectric layer arranged on the metal layer, and at least one of a via and a trench formed in the dielectric layer;

during a first deposition period, depositing metal using physical vapor deposition (PVD);

depositing the metal using chemical vapor deposition (CVD) during a second deposition period, wherein the second deposition period is longer than a first nucleation delay period required to deposit the metal on the metal layer;

stopping the second deposition period prior to a second nucleation delay period, wherein the second nucleation delay period is required to deposit the metal on the dielectric layer;

performing the CVD depositing and the stopping N times, where N is an integer greater than or equal to one;

after the performing, depositing the metal using CVD during a third deposition period that is longer than the second nucleation delay period; and

performing a sputter etch process to etch the metal from sidewalls of the via prior to the second deposition period and third deposition period.

18. A method for processing a substrate, comprising:

providing a substrate including a metal layer, a dielectric layer arranged on the metal layer, and at least one of a via and a trench formed in the dielectric layer;

during a first deposition period, depositing metal using physical vapor deposition (PVD);

depositing the metal using chemical vapor deposition (CVD) during a second deposition period, wherein the second deposition period is longer than a first nucleation delay period required to deposit the metal on the metal layer;

stopping the second deposition period prior to a second nucleation delay period, wherein the second nucleation delay period is required to deposit the metal on the dielectric layer;

performing the CVD depositing and the stopping N times, where N is an integer greater than or equal to one;

after the performing, depositing the metal using CVD during a third deposition period that is longer than the second nucleation delay period; and

performing a sputter etch process to etch the metal from a field of the substrate, the trench and sidewalls of the via prior to the second deposition period and the third deposition period.