Multi-threshold voltage (Vt) workfunction metal by selective atomic layer deposition (ALD)

1. A method of forming a multi-threshold voltage device, comprising:

(a) providing a substrate having a first layer disposed thereon, wherein the substrate comprises a first feature and a second feature disposed within the first layer;

(b) depositing a blocking layer atop the substrate, the first feature, and the second feature;

(c) selectively removing a portion of the blocking layer from atop the substrate to expose the first feature;

(d) subsequently, selectively depositing a first work function layer atop the first feature but not atop a remainder of the blocking layer;

(e) removing the remainder of the blocking layer to expose the second feature; and

(f) depositing a second work function layer atop the first work function layer and the second feature.

2. The method of claim 1 , wherein the blocking layer is one of a carbon-containing layer or an oxygen-containing layer.

3. The method of claim 2 , wherein the carbon-containing layer is an amorphous carbon hard mask layer.

4. The method of claim 2 , wherein the carbon-containing layer is deposited via one of a spin-on coating process, chemical vapor deposition process, or atomic layer deposition process.

5. The method of claim 1 , wherein the blocking layer has a thickness of about 5 to about 200 nm.

6. The method of claim 1 , wherein the first work function layer has a thickness of about 0.5 nm to about 10 nm, and wherein the second work function layer has a thickness of about 0.5 nm to about 10 nm.

7. The method of claim 1 , wherein removing a portion of the blocking layer further comprises patterning the blocking layer using a plasma formed from one of an oxygen containing gas or a hydrogen containing gas.

8. The method of claim 1 , further comprising depositing the first work function layer via an atomic layer deposition process.

9. The method of claim 8 , further comprising exposing the substrate to one or more precursor gases to selectively deposit the first work function layer atop the first feature.

10. The method of claim 9 , further comprising exposing the blocking layer to a first gas that delays formation of the first work function layer atop the blocking layer.

11. The method of claim 10 , wherein the first gas is hydrogen chloride.

12. The method of claim 9 , wherein the precursor gas comprises one of tungsten, molybdenum, niobium, cobalt, nickel, vanadium, aluminum, or ruthenium.

13. The method of claim 1 , wherein depositing the second work function layer further comprises exposing the substrate to a second precursor gas.

14. The method of claim 13 , wherein the second precursor gas comprises one of tungsten, molybdenum, niobium, cobalt, nickel, vanadium, aluminum, or ruthenium.

15. The method of claim 1 , repeating (b)-(f) to obtain a first selected work function in the first feature and a second selected work function in the second feature.

16. The method of claim 1 , wherein the first feature and second feature are each formed atop a first conductivity well and a second conductivity well.

17. A method of forming a multi-threshold voltage device, comprising:

(a) providing a substrate having a first layer disposed thereon, wherein the substrate comprises a first feature and a second feature disposed within the first layer;

(b) depositing one of a carbon-containing layer or an oxygen-containing layer atop the substrate, the first feature, and the second feature, wherein the carbon-containing layer or the oxygen-containing layer has a thickness of about 1 to about 200 nm;

(c) selectively removing a portion of the carbon-containing layer or oxygen-containing layer from atop the substrate to expose the first feature;

(d) selectively depositing a first work function layer atop the first feature, but not atop a remainder of the carbon-containing layer or oxygen-containing layer, via an atomic layer deposition process, wherein the first work function layer has a thickness of about 0.5 nm to about 4 nm;

(e) removing the remainder of the carbon-containing layer or oxygen-containing layer to expose the second feature; and

(f) depositing a second work function layer atop the first work function layer and the second feature via an atomic layer deposition process, wherein the second work function layer has a thickness of about 0.5 nm to about 4 nm.

18. The method of claim 1 , wherein the second work function layer is deposited directly atop the first work function layer and the second feature.

19. The method of claim 17 , wherein the second work function layer is deposited directly atop the first work function layer and the second feature.

20. A non-transitory computer readable medium having instructions stored thereon that, when executed, cause a method for forming a multi-threshold voltage device, the method comprising:

(a) providing a substrate having a first layer disposed thereon, wherein the substrate comprises a first feature and a second feature disposed within the first layer;

(b) depositing a blocking layer atop the substrate, the first feature, and the second feature;

(c) selectively removing a portion of the blocking layer from atop the substrate to expose the first feature;

(d) subsequently, selectively depositing a first work function layer atop the first feature but not atop a remainder of the blocking layer;

(e) removing the remainder of the blocking layer to expose the second feature; and

(f) depositing a second work function layer atop the first work function layer and the second feature.