Simplified gate stack process to improve dual channel CMOS performance

1. A semiconductor device comprising:

at least one of a first semiconductor region and a second semiconductor region different from the first semiconductor region, at least one of the first semiconductor region and second semiconductor region including:

a first semiconductor channel comprising a first semiconductor material;

a first set of spacers extending from the top surface of the semiconductor channel, wherein between the first set of spacers defines a first gate; and

an annealed semiconductor-rich surface on a portion of the top surface of the semiconductor channel between the first set of spacers, the annealed semiconductor-rich surface directly contacting the first gate,

wherein the first gate includes a first high-k dielectric layer in contact with the spacers, and a first metal gate material in contact with the high-k dielectric layer.

2. The semiconductor device of claim 1 , wherein the first semiconductor region is a p-field effect transistor (pFET) region including comprising:

a SiGe channel that defines the first semiconductor channel; and

a Si-rich region on a portion of the top surface of the SiGe channel that defines the annealed semiconductor-rich surface, and

wherein the second semiconductor region is an n-field effect transistor (nFET) region comprising:

a Si channel; and

a second set of spacers extending from the top surface of the Si channel, wherein between the second set of spacers defines a second gate,

wherein the second gate includes a second high-k dielectric layer in contact with the second set of spacers, and a second metal gate material in contact with the second high-k dielectric layer.

3. The semiconductor device of claim 2 further comprising a first high-k dielectric layer in contact with the first set of spacers.

4. The semiconductor device of claim 3 further comprising a second high-k dielectric layer in contact with the second set of spacers.

5. The semiconductor device of claim 4 , wherein the first high-k dielectric layer and second high-k dielectric layer are independently selected from silicon nitride, aluminum oxide, zirconium oxide, titanium oxide, tantalum pentoxide, barium-strontium-titanate, strontium-titanate-oxide, lead-zirconium-titanate, and combinations thereof.

6. The semiconductor device of claim 3 further comprising an ozone layer on the Si-rich layer.

7. The semiconductor device of claim 6 , wherein the ozone layer is between the Si-rich layer and the first high-k dielectric layer.

8. The semiconductor device of claim 7 further comprising an ozone layer on the Si channel between the second set of spacers.

9. The semiconductor device of claim 8 , wherein the ozone layer is between the Si channel and the second high-k dielectric layer.

10. The semiconductor device of claim 2 , further comprising source and drain regions within the n-field effect transistor (nFET) region and the p-field effect transistor (pFET) region.

11. The semiconductor device of claim 2 , wherein the first gate material and second gate material are independently selected from TiN, TiAl, TaN, and combinations thereof.

12. The semiconductor device of claim 2 , wherein the Si-rich layer has a concentration of Ge that is at least 10% lower than the concentration of Ge in the SiGe channel.

13. The semiconductor device of claim 2 , wherein the Si-rich layer has a concentration of Ge that is at least 5% lower than the concentration of Ge in the SiGe channel.

14. A semiconductor device comprising:

at least one of a first semiconductor region and a second semiconductor region different from the first semiconductor region, the first semiconductor region including a first semiconductor channel having an annealed semiconductor-rich upper surface, while the second semiconductor region includes a second semiconductor channel excluding the annealed semiconductor-rich upper surface,

wherein the first semiconductor region further comprises:

a first set of spacers extending from the top surface of the first semiconductor channel, wherein between the first set of spacers defines a first gate, the first gate including a first high-k dielectric layer in contact with the spacers, and a first metal gate material in contact with the high-k dielectric layer,

wherein the annealed semiconductor-rich upper surface directly contacts the first gate.

15. The semiconductor device of claim 14 , wherein the first semiconductor region is a p-field effect transistor (pFET) region including comprising:

SiGe material that defines the first semiconductor channel; and

a Si-rich region on a portion of the top surface of the SiGe material that defines the annealed semiconductor-rich surface.

16. The semiconductor device of claim 15 , wherein the second semiconductor region is an n-field effect transistor (nFET) region comprising:

Si material that defines the second semiconductor channel; and

a second set of spacers extending from the top surface of the Si material,

wherein a region between the second set of spacers defines a second gate, and

wherein the second gate includes a second high-k dielectric layer in contact with the second set of spacers, and a second metal gate material in contact with the second high-k dielectric layer.

17. The semiconductor device of claim 16 further comprising an ozone layer on the Si-rich layer.

18. The semiconductor device of claim 17 , wherein the ozone layer is between the Si-rich layer and the first high-k dielectric layer.

19. The semiconductor device of claim 18 further comprising an ozone layer on the Si channel between the second set of spacers.

20. The semiconductor device of claim 19 , wherein the ozone layer is between the Si channel and the second high-k dielectric layer.