CMOS implementation of germanium and III-V nanowires and nanoribbons in gate-all-around architecture
Architectures and techniques for co-integration of heterogeneous materials, such as group III-V semiconductor materials and group IV semiconductors (e.g., Ge) on a same substrate (e.g. silicon). In embodiments, multi-layer heterogeneous semiconductor material stacks having alternating nanowire and sacrificial layers are employed to release nanowires and permit formation of a coaxial gate structure that completely surrounds a channel region of the nanowire transistor. In embodiments, individual PMOS and NMOS channel semiconductor materials are co-integrated with a starting substrate having a blanket layers of alternating Ge/III-V layers. In embodiments, vertical integration of a plurality of stacked nanowires within an individual PMOS and individual NMOS device enable significant drive current for a given layout area.
1. A method of forming a pair of semiconductor devices on a substrate, the method comprising:
disposing on a first region of the substrate a first stack of semiconductor layers including a crystalline group IV semiconductor layer overlying a first sacrificial layer;
disposing on a second region of the substrate a second stack of semiconductor layers including a crystalline group III-V semiconductor layer overlying a second sacrificial layer;
etching the first stack to define a first nanowire comprising the group IV semiconductor layer;
etching the second stack to define a second nanowire comprising the group III-V semiconductor layer;
forming a first gate stack coaxially wrapping completely around the group IV crystalline layer along a longitudinal channel length of the first nanowire; and
forming a second gate stack coaxially wrapping completely around the group III-V crystalline layer along a longitudinal channel length of the second nanowire;
wherein the first sacrificial layer is the crystalline group III-V semiconductor layer and wherein the second sacrificial layer is the crystalline group IV semiconductor layer and wherein disposing the first and second stacks of semiconductor layers on the substrate comprises epitaxially growing the both the crystalline group III-V semiconductor layer and the crystalline group IV semiconductor layer over both the first and second regions of the substrate.
2. The method of claim 1 , further comprising:
forming a p-type source and drain region electrically coupled with a channel of the first nanowire; and
forming an n-type source and drain region electrically coupled with a channel of the second nanowire.
3. The method of claim 1 , wherein etching the first stack of semiconductor layers further comprises removing the first sacrificial layer selectively to the group IV semiconductor layer to form a gap between the group IV semiconductor layer and the substrate along the longitudinal channel length; and
wherein etching the second stack of semiconductor layers further comprises removing the second sacrificial layer selectively to the group III-V semiconductor layer to form a gap between the group III-V semiconductor layer and the substrate along the longitudinal channel length.
4. The method of claim 1 , wherein epitaxially growing the group IV semiconductor layer further comprises epitaxially growing a material consisting essentially of Ge; and
wherein epitaxially growing the group III-V semiconductor layer comprises growing a material consisting essentially of GaAs.
5. The method of claim 1 , wherein etching the first stack of semiconductor layers further comprises removing the group III-V semiconductor layer selectively to the group IV semiconductor layer to form a gap between the group IV semiconductor layer and the substrate in the first region; and wherein
etching the second stack of semiconductor layers further comprises removing the group IV semiconductor layer selectively to the group III-V semiconductor layer to form a gap between the group III-V semiconductor layer and the substrate in the second region.
6. The method of claim 1 , wherein disposing the first and second stacks of semiconductor layers on the substrate comprises epitaxially growing a third sacrificial layer over the substrate in the first and second regions; and
wherein etching the first stack of semiconductor layers further comprises removing the group III-V semiconductor layer and the third sacrificial layer selectively to the group IV semiconductor layer to form a gap between the group IV semiconductor layer and the substrate in the first region that is wider than a thickness of the group III-V semiconductor layer; and
wherein etching the second stack of semiconductor layers further comprises removing the group IV semiconductor layer and the third sacrificial layer selectively to the group III-V semiconductor layer to form a gap between the group III-V semiconductor layer and the substrate in the second region that is wider than a thickness of the group IV semiconductor layer.
7. The method of claim 1 , wherein epitaxially growing the group IV semiconductor layer further comprises epitaxially growing a material consisting essentially of Ge; and
wherein epitaxially growing the group III-V semiconductor layer comprises growing a material consisting essentially of GaAs; and
wherein epitaxially growing the third sacrificial layer comprises growing a material comprising SiGe or AlGaAs.
8. The method of claim 1 , further comprising epitaxially growing a crystalline semiconductor transition layer coaxially wrapping completely around at least one of the group IV crystalline layer or group III-V crystalline layer.
9. A method of forming a pair of semiconductor devices on a substrate, the method comprising:
disposing on a first region of the substrate a first stack of semiconductor layers including a crystalline group IV semiconductor layer overlying a first sacrificial layer;
disposing on a second region of the substrate a second stack of semiconductor layers including a crystalline group III-V semiconductor layer overlying a second sacrificial layer;
etching the first stack to define a first nanowire comprising the group IV semiconductor layer;
etching the second stack to define a second nanowire comprising the group III-V semiconductor layer;
forming a first gate stack coaxially wrapping completely around the group IV crystalline layer along a longitudinal channel length of the first nanowire; and
forming a second gate stack coaxially wrapping completely around the group III-V crystalline layer along a longitudinal channel length of the second nanowire wherein forming the first and second gate stacks further comprises depositing, by atomic layer deposition, a high-K dielectric material around a released portions of the first and second nanowire, and wherein forming the first gate stack further comprises depositing a first work function metal around the released portion of the first nanowire and wherein forming the second gate stack further comprises depositing a second work function metal around the released portion of the second nanowire.
10. The method of claim 9 , further comprising:
forming a p-type source and drain region electrically coupled with a channel of the first nanowire; and
forming an n-type source and drain region electrically coupled with a channel of the second nanowire.
11. The method of claim 9 , wherein etching the first stack of semiconductor layers further comprises removing the first sacrificial layer selectively to the group IV semiconductor layer to form a gap between the group IV semiconductor layer and the substrate along the longitudinal channel length; and
wherein etching the second stack of semiconductor layers further comprises removing the second sacrificial layer selectively to the group III-V semiconductor layer to form a gap between the group III-V semiconductor layer and the substrate along the longitudinal channel length.
12. The method of claim 9 , wherein epitaxially growing the group IV semiconductor layer further comprises epitaxially growing a material consisting essentially of Ge; and
wherein epitaxially growing the group III-V semiconductor layer comprises growing a material consisting essentially of GaAs.
13. The method of claim 9 , wherein the first sacrificial layer is the crystalline group III-V semiconductor layer and wherein the second sacrificial layer is the crystalline group IV semiconductor layer; and
wherein disposing the first and second stacks of semiconductor layers on the substrate comprises epitaxially growing the both the crystalline group III-V semiconductor layer and the crystalline group IV semiconductor layer over both the first and second regions of the substrate.
14. The method of claim 13 , wherein etching the first stack of semiconductor layers further comprises removing the group III-V semiconductor layer selectively to the group IV semiconductor layer to form a gap between the group IV semiconductor layer and the substrate in the first region; and wherein
etching the second stack of semiconductor layers further comprises removing the group IV semiconductor layer selectively to the group III-V semiconductor layer to form a gap between the group III-V semiconductor layer and the substrate in the second region.
15. The method of claim 13 , wherein disposing the first and second stacks of semiconductor layers on the substrate comprises epitaxially growing a third sacrificial layer over the substrate in the first and second regions; and
wherein etching the first stack of semiconductor layers further comprises removing the group III-V semiconductor layer and the third sacrificial layer selectively to the group IV semiconductor layer to form a gap between the group IV semiconductor layer and the substrate in the first region that is wider than a thickness of the group III-V semiconductor layer; and
wherein etching the second stack of semiconductor layers further comprises removing the group IV semiconductor layer and the third sacrificial layer selectively to the group III-V semiconductor layer to form a gap between the group III-V semiconductor layer and the substrate in the second region that is wider than a thickness of the group IV semiconductor layer.
16. The method of claim 13 , wherein epitaxially growing the group IV semiconductor layer further comprises epitaxially growing a material consisting essentially of Ge; and
wherein epitaxially growing the group III-V semiconductor layer comprises growing a material consisting essentially of GaAs; and
wherein epitaxially growing the third sacrificial layer comprises growing a material comprising SiGe or AlGaAs.
17. The method of claim 9 , further comprising epitaxially growing a crystalline semiconductor transition layer coaxially wrapping completely around at least one of the group IV crystalline layer or group III-V crystalline layer.