Channel surface technique for fabrication of FinFET devices
View Patent ↗A FinFET (p-channel) device is formed having a fin structure with sloped or angled sidewalls (e.g., a pyramidal or trapezoidal shaped cross-section shape). When using conventional semiconductor substrates having a (100) surface orientation, the fin structure is formed in a way (groove etching) which results in sloped or angled sidewalls having a (111) surface orientation. This characteristic substantially increases hole mobility as compared to conventional fin structures having vertical sidewalls.
1. A Fin field-effect transistor (FinFET) device comprising:
a substrate;
first and second source/drain (S/D) regions of a first conductivity type disposed above the substrate;
a fin channel structure of semiconductor material disposed above the substrate and extending between the first and second S/D regions, the fin channel structure including a first fin portion, a second fin portion, and a channel portion, the channel portion of a second conductivity type, and the fin channel structure having a bottom surface with a width greater than a width of a top surface;
a gate structure disposed over the channel portion, the gate structure including a gate dielectric and a gate electrode; and
wherein the fin channel structure comprises first and second angled sidewalls.
2. The FinFET device in accordance with claim 1 wherein the fin channel structure has a trapezoidal cross-section shape.
3. The FinFET device in accordance with claim 1 wherein surfaces of the first and second angled sidewalls have (111) surface orientation.
4. The FinFET device in accordance with claim 3 wherein the top surface of the fin channel structure has a (100) surface orientation.
5. The FinFET device in accordance with claim 3 wherein the channel portion has a (100) channel orientation.
6. The FinFET device in accordance with claim 3 wherein the first and second angled sidewalls each have an angle between about 50 degrees and 60 degrees.
7. The FinFET device in accordance with claim 3 wherein the gate dielectric comprises high-K dielectric material.
8. The FinFET device in accordance with claim 1 wherein the first and second angled sidewalls each have an angle between about 40 degrees and 65 degrees.
9. The FinFET device in accordance with claim 1 wherein the first and second angled sidewalls each have an angle between about 50 degrees and 60 degrees.
10. A p-channel Fin field-effect transistor (FinFET) device comprising:
a substrate;
first and second source/drain (S/D) regions of p-type conductivity disposed above the substrate;
a fin channel structure of semiconductor material disposed on the substrate and extending between the first and second S/D regions, the fin channel structure including a first fin portion, a second fin portion, and a channel portion of n-type conductivity having a top surface, a bottom surface and two sidewalls each having a sidewall surface, and wherein the bottom surface has a width greater than a width of the top surface;
a gate structure disposed over the top surface of the channel portion, the gate structure including a gate dielectric and a gate electrode; and
wherein the two sidewall surfaces of the channel portion have a (111) surface orientation and the top surface of the channel portion has a different surface orientation.
11. The FinFET device in accordance with claim 10 wherein the fin channel structure has a trapezoidal cross-section shape.
12. The FinFET device in accordance with claim 10 wherein each of the two sidewall surfaces have an angle of between about 40 degrees and 65 degrees.
13. The FinFET device in accordance with claim 12 wherein each of the two sidewall surfaces have an angle between about 50 degrees and 60 degrees.
14. The FinFET device in accordance with claim 13 wherein the gate dielectric comprises hafnium oxide.
15. The FinFET device in accordance with claim 12 wherein the top surface of the channel portion has a (100) surface orientation.
16. A Fin field-effect transistor (FinFET) device comprising:
a substrate of semiconductor material having a (100) surface orientation;
first and second source/drain (S/D) regions of a first conductivity type;
a fin channel structure of semiconductor material disposed on the substrate and extending between the first and second S/D regions, the fin channel structure including a channel portion of a second conductivity-type, the channel portion having a top surface, a bottom surface and two sidewalls each having a sidewall surface, and wherein the bottom surface has a width greater than a width of the top surface;
a gate structure disposed over the top surface of the channel portion, the gate structure including a gate dielectric and a gate electrode; and
wherein the two sidewall surfaces of the channel portion have a (111) surface orientation and the top surface of the channel portion have a (100) surface orientation.
17. The FinFET device in accordance with claim 16 wherein the fin channel structure has a trapezoidal cross-section shape.
18. The FinFET device in accordance with claim 16 wherein each of the two sidewall surfaces have an angle of between about 40 degrees and 65 degrees.
19. The FinFET device in accordance with claim 18 wherein the gate dielectric comprises hafnium oxide.
20. The FinFET device in accordance with claim 16 wherein the channel portion has a (100) channel orientation.