Semiconductor devices having Si and SiGe epitaxial layers
Semiconductor devices include a substrate having first and second active regions; a P-channel transistor associated with the first active region and including at least one of source and drain regions; an N-channel field-effect transistor associated with the second active region and including at least one of the source and drain regions; first and second contact pad layers each including silicon (Si) and SiGe epitaxial layers on the source and drain regions the SiGe epitaxial layers being sequentially stacked on the Si epitaxial layers; an interlayer insulating film; a first metal silicide film on the SiGe epitaxial layer of the P-channel transistor and a second metal silicide film on the Si epitaxial layer of the N-channel transistor; and contact plugs on the first and second metal silicide films.
1. A semiconductor device comprising:
a substrate having first and second active regions;
a P-channel field-effect transistor associated with the first active region and including at least one of the source and drain regions;
a N-channel field-effect transistor associated with the second active region and including at least one of the source and drain regions;
a first contact pad layer comprising silicon (Si) and SiGe epitaxial layers on the at least one of the source and drain regions of the P-channel field-effect transistor, the SiGe epitaxial layer being sequentially stacked on the Si epitaxial layer;
a second contact pad layer comprising silicon (Si) and SiGe epitaxial layers on the at least one of the source and drain regions of the N-channel field-effect transistor, the SiGe epitaxial layer being sequentially stacked on the Si epitaxial layer;
an interlayer insulating film formed on the P-channel and the N-channel field-effect transistors and including first and second contact holes, wherein the first contact hole includes a first lower region that exposes the SiGe epitaxial layer of the first contact pad layer and the second contact hole includes a second lower region that penetrates through the SiGe epitaxial layer of the second contact pad layer to expose the Si epitaxial layer of the second contact pad layer;
first and second metal silicide films formed respectively in the first and second lower regions of the contact holes; and
contact plugs formed on the first and second metal silicide films and filled in the first and second contact holes.
2. The semiconductor device of claim 1 , wherein the first metal silicide film includes germanium (Ge) and the second metal silicide film does not include Ge.
3. The semiconductor device of claim 1 , further comprising a diffusion barrier between sidewalls of the second contact holes and the second metal silicide film.
4. The semiconductor device of claim 1 , further comprising:
a device isolation film defining the first and second active regions,
wherein at least one of the first and second contact pad layers extends in a direction parallel to a principal plane of the substrate and extends over a region of the device isolation film.
5. The semiconductor device of claim 1 , wherein a thickness of the Si epitaxial layer is from about 10 Å to about 500 Å, and a thickness of the SiGe epitaxial layer is from about 30 Å to about 500 Å.
6. The semiconductor device of claim 1 , wherein a concentration of Ge in the SiGe epitaxial layer is from about 3 mole % to about 50 mole %.
7. A semiconductor device comprising:
a substrate having first and second active regions;
a P-channel field-effect transistor associated with the first active region and including at least one of the source and drain regions;
a N-channel field-effect transistor associated with the second active region and including at least one of the source and drain regions;
a first contact pad layer comprising silicon (Si) and SiGe epitaxial layers on the at least one of the source and drain regions of the P-channel field-effect transistor, the Si epitaxial layer being sequentially stacked on the SiGe epitaxial layer;
a second contact pad layer comprising silicon (Si) and SiGe epitaxial layers on the at least one of the source and drain regions of the N-channel field-effect transistor, the Si epitaxial layer being sequentially stacked on the SiGe epitaxial layer;
an interlayer insulating film formed on the P-channel and the N-channel field-effect transistors and including first and second contact holes, wherein the first contact hole includes a first lower region that penetrates through the Si epitaxial layer of the first contact pad layer to expose the SiGe epitaxial layer of the first contact pad layer and the second contact hole includes a second lower region that exposes the Si epitaxial layer of the second contact pad layer;
first and second metal silicide films formed respectively in the first and second lower regions of the contact holes; and
contact plugs formed on the first and second metal silicide films and filled in the first and second contact holes.
8. The semiconductor device of claim 7 , wherein the first metal silicide film includes germanium (Ge) and the second metal silicide film does not include Ge.
9. The semiconductor device of claim 7 , wherein at least a portion of the SiGe epitaxial layer of the first contact pad layer is buried in the first active region.
10. The semiconductor device of claim 7 , further comprising:
a device isolation film defining the first and second active regions,
wherein at least one of the first and second contact pad layers extends in a direction parallel to a principal plane of the substrate so as to extend over a region of the device isolation film.
11. The semiconductor device of claim 7 , wherein a thickness of the Si epitaxial layer is from about 10 Å to about 500 Å, and a thickness of the SiGe epitaxial layer is from about 30 Å to about 500 Å.
12. The semiconductor device of claim 7 , wherein a concentration of Ge in the SiGe epitaxial layer is from about 3 mole % to about 50 mole %.
13. A semiconductor device comprising:
a substrate having first and second active regions;
a P-channel field-effect transistor associated with the first active region and including at least one of the source and drain regions;
a N-channel field-effect transistor associated with the second active region and including at least one of the source and drain regions;
a first contact pad layer comprising a silicon (Si) epitaxial layer and a germanium (Ge) atomic layer on the at least one of the source and drain regions of the P-channel field-effect transistor, the Ge atomic layer being sequentially stacked on the Si epitaxial layer;
a second contact pad layer comprising a silicon (Si) epitaxial layer and a germanium (Ge) atomic layer on the at least one of the source and drain regions of the N-channel field-effect transistor, the Ge atomic layer being sequentially stacked on the Si epitaxial layer;
an interlayer insulating film formed on the P-channel and the N-channel field-effect transistors and including first and second contact holes, wherein the first contact hole includes a first lower region that exposes the Ge atomic layer of the first contact pad layer and the second contact hole includes a second lower region that penetrates through the Ge atomic layer of the second contact pad layer to expose the Si epitaxial layer of the second contact pad layer;
first and second metal silicide films formed respectively in the first and second lower regions of the contact holes; and
contact plugs formed on the first and second metal silicide films and filled in the first and second contact holes.
14. The semiconductor device of claim 13 , wherein the first metal silicide film includes germanium (Ge) and the second metal silicide film does not include Ge.
15. A semiconductor device comprising:
source regions;
drain regions;
a first contact pad layer;
a second contact pad layer, the first and second contact pad layers including a silicon (Si) epitaxial layer and a silicon germanium (SiGe) epitaxial layer, the Si and SiGe epitaxial layers on the source and drain regions.