Methods for fabricating MOS devices having epitaxially grown stress-inducing source and drain regions
View Patent ↗Methods of fabricating a semiconductor device on and in a semiconductor substrate having a first region and a second region are provided. In accordance with an exemplary embodiment of the invention, a method comprises forming a first gate stack overlying the first region and a second gate stack overlying the second region, etching into the substrate first recesses and second recesses, the first recesses aligned at least to the first gate stack in the first region, and the second recesses aligned at least to the second gate stack in the second region, epitaxially growing a first stress-inducing monocrystalline material in the first and second recesses, removing the first stress-inducing monocrystalline material from the first recesses, and epitaxially growing a second stress-inducing monocrystalline material in the first recesses, wherein the second stress-inducing monocrystalline material has a composition different from the first stress-inducing monocrystalline material.
1. A method of fabricating a semiconductor device on and in a semiconductor substrate having a first region and a second region, the method comprising the steps of:
forming a first gate stack overlying the first region and a second gate stack overlying the second region;
etching into the substrate first recesses and second recesses, the first recesses aligned at least to the first gate stack in the first region, and the second recesses aligned at least to the second gate stack in the second region;
epitaxially growing a first stress-inducing monocrystalline material in the first and second recesses;
removing the first stress-inducing monocrystalline material from the first recesses; and
epitaxially growing a second stress-inducing monocrystalline material in the first recesses, wherein the second stress-inducing monocrystalline material has a composition different from the first stress-inducing monocrystalline material.
2. The method of claim 1 , wherein the step of epitaxially growing a first stress-inducing monocrystalline material comprises epitaxially growing a compressive stress-inducing monocrystalline material.
3. The method of claim 2 , wherein the step of epitaxially growing a compressive stress-inducing monocrystalline material comprises epitaxially growing a compressive stress-inducing monocrystalline material selected from a group consisting of SiGe and SiSn.
4. The method of claim 3 , wherein the step of epitaxially growing a compressive stress-inducing monocrystalline material comprising SiGe comprises epitaxially growing a compressive stress-inducing monocrystalline material comprising a Ge concentration of from about 20 atomic % to about 50 atomic %.
5. The method of claim 1 , wherein the step of epitaxially growing a second stress-inducing monocrystalline material comprises epitaxially growing a tensile stress-inducing monocrystalline material.
6. The method of claim 5 , wherein the step of epitaxially growing a tensile stress-inducing monocrystalline material comprises epitaxially growing a tensile stress-inducing monocrystalline material comprising SiC.
7. The method of claim 6 , wherein the step of epitaxially growing a tensile stress-inducing monocrystalline material comprising SiC comprises epitaxially growing a tensile stress-inducing monocrystalline material comprising a C concentration of from about 1 atomic % to about 2 atomic %.
8. The method of claim 1 , wherein the step of epitaxially growing a first stress-inducing monocrystalline material comprises epitaxially growing a first in situ-doped stress-inducing monocrystalline material.
9. The method of claim 8 , wherein the step of growing a first in situ-doped stress-inducing monocrystalline material comprises growing a first in situ-doped stress-inducing monocrystalline material comprising a P-type dopant.
10. The method of claim 8 , wherein the step of growing a first in situ-doped stress-inducing monocrystalline material comprises growing a first in situ-doped stress-inducing monocrystalline material comprising an N-type dopant.
11. The method of claim 1 , wherein the step of epitaxially growing a second stress-inducing monocrystalline material comprises epitaxially growing a second in situ doped stress-inducing monocrystalline material.
12. The method of claim 11 , wherein the step of growing a second in situ-doped stress-inducing monocrystalline material comprises growing a second in situ-doped stress-inducing monocrystalline material comprising an N-type dopant.
13. The method of claim 1 , wherein the step of etching into the substrate first recesses and second recesses comprises etching into the substrate first recesses and second recesses having a depth in a range of from about 50 nm to about 65 nm.
14. The method of claim 1 , further comprising the step of depositing a dielectric layer overlying the first and second regions following the step of epitaxially growing a first stress-inducing monocrystalline material.
15. The method of claim 14 , wherein the step of depositing a dielectric layer comprises depositing a compressively-stressed dielectric layer.
16. A method of fabricating a semiconductor device on and in a semiconductor substrate having a first region and a second region, the method comprising the steps of:
forming a first gate stack having first sidewalls overlying the first region;
forming a second gate stack having second sidewalls overlying the second region;
forming first sidewall spacers adjacent the first sidewalls of the first gate stack;
forming second sidewall spacers adjacent the second sidewalls of the second gate stack;
etching into the substrate first recesses and second recesses, the first recesses disposed in the first region and aligned to the first gate stack and the first sidewall spacers, and the second recesses disposed in the second region and aligned to the second gate stack and the second sidewall spacers;
epitaxially growing an in situ-doped compressive stress-inducing monocrystalline material in the first and second recesses;
removing the in situ-doped compressive stress-inducing monocrystalline material from the first recesses; and
epitaxially growing an in situ-doped tensile stress-inducing monocrystalline material in the first recesses.
17. The method of claim 16 , wherein the step of epitaxially growing an in situ-doped compressive stress-inducing monocrystalline material comprises epitaxially growing an in situ-doped compressive stress-inducing monocrystalline material selected from a group consisting of SiGe and SiSn.
18. The method of claim 16 , wherein the step of epitaxially growing an in situ-doped compressive stress-inducing monocrystalline material comprises epitaxially growing an in situ boron-doped compressive stress-inducing monocrystalline material.
19. The method of claim 16 , wherein the step of epitaxially growing an in situ-doped tensile stress-inducing monocrystalline material comprises epitaxially growing an in situ-doped tensile stress-inducing monocrystalline material comprising SiC.
20. The method of claim 16 , wherein the step of epitaxially growing an in situ-doped tensile stress-inducing monocrystalline material comprises epitaxially growing an in situ-doped tensile stress-inducing monocrystalline material that is in situ-doped with a dopant selected from a group consisting of phosphorous and arsenic.
21. The method of claim 14 , further comprising the step of:
forming first sidewall spacers on the first gate stack and on the second gate stack; and
anisotropically etching the dielectric layer to form second sidewall spacers on the first sidewall spacers that are formed on the first gate stack.