FinFET device having a channel defined in a diamond-like shape semiconductor structure
The present disclosure provides a FinFET device. The FinFET device comprises a semiconductor substrate of a first semiconductor material; a fin structure of the first semiconductor material overlying the semiconductor substrate, wherein the fin structure has a top surface of a first crystal plane orientation; a diamond-like shape structure of a second semiconductor material disposed over the top surface of the fin structure, wherein the diamond-like shape structure has at least one surface of a second crystal plane orientation; a gate structure disposed over the diamond-like shape structure, wherein the gate structure separates a source region and a drain region; and a channel region defined in the diamond-like shape structure between the source and drain regions.
1. A method comprising:
removing a portion of a semiconductor substrate to form a fin structure, the fin structure being formed of a first semiconductor material and disposed between an isolation feature, the fin structure having a top surface facing away from the semiconductor substrate that is exposed;
removing a portion of the isolation feature to form a portion of the fin structure that extends above the isolation feature, wherein the portion of the fin structure has the top surface and opposing sidewall surfaces such that the top surface extends between the opposing sidewall surfaces, wherein the top surface remains exposed during the removal of the portion of the isolation feature, wherein removing the portion of the isolation feature to form the portion of the fin structure exposes the opposing sidewall surfaces; and
epitaxially growing a second semiconductor material directly on the opposing sidewall surfaces of the portion of the fin structure that extends above the isolation feature to form a semiconductor structure over the fin structure.
2. The method of claim 1 , further comprising forming the isolation feature around the fin structure.
3. The method of claim 1 , wherein epitaxially growing the second semiconductor material directly on the opposing sidewall surfaces of the portion of the fin structure includes epitaxially growing the second semiconductor material directly on the top surface of the portion of the fin structure.
4. The method of claim 1 , wherein the isolation feature is a shallow trench isolation structure.
5. The method of claim 1 , further comprising:
forming a high-k dielectric layer over the second semiconductor material; and
forming a metal gate electrode over the high-k dielectric layer.
6. The method of claim 5 , wherein forming the metal gate electrode over the high-k dielectric layer incudes forming the metal gate electrode directly on the isolation feature such that the metal gate electrode physically contacts the isolation feature.
7. The method of claim 1 , wherein the semiconductor structure includes a first surface, a second surface, a third surface, and a fourth surface, wherein each of the first, second, third, and fourth surfaces have the same crystal plane orientation.
8. A method comprising:
forming a fin structure of a first semiconductor material over a semiconductor substrate, wherein the fin structure has opposing sidewall surfaces and a topmost surface that extends between the opposing sidewall surfaces;
forming an isolation feature around the fin structure, wherein after forming the isolation feature around the fin structure the topmost surface of the fin structure is exposed;
removing a portion of the isolation feature to expose the opposing sidewall surfaces of the fin structure;
forming a feature of a second semiconductor material over the fin structure such that the feature physically contacts the opposing sidewall surfaces of the fin structure;
forming a gate dielectric layer directly on the feature; and
forming a gate electrode over the gate dielectric layer.
9. The method of claim 8 , wherein forming the feature of the second semiconductor material over the fin structure includes performing a epitaxial growth process.
10. The method of claim 8 , wherein the second semiconductor material is different than the first semiconductor material.
11. The method of claim 8 , wherein forming the gate electrode over the gate dielectric layer includes forming the gate electrode directly on the isolation feature such that the gate electrode physically contacts the isolation feature.
12. The method of claim 8 , wherein the feature has a first surface of a first crystal plane orientation and the fin structure is without any surface having the first crystal plane orientation.
13. The method of claim 12 , wherein the first crystal plane orientation is a (111) crystallographic orientation.
14. A method comprising:
forming a fin structure of a first semiconductor material over a semiconductor substrate, wherein the fin structure has a first sidewall and an opposing second sidewall and a topmost surface that extends from the first sidewall to the second sidewall;
forming a dielectric isolation feature along the first and second sidewalls of the fin structure, wherein after forming the dielectric isolation feature along the first and second sidewalls of the fin structure the topmost surface of the fin structure is exposed;
removing a portion of the dielectric isolation feature to expose the first sidewall of the fin structure; and
forming a second semiconductor material directly on the exposed first sidewall such that the second semiconductor material physically contacts the first sidewall of the fin structure.
15. The method of claim 14 , wherein removing the portion of the dielectric isolation feature to expose the first sidewall of the fin structure includes removing another portion of the dielectric isolation feature to expose the second sidewall of the fin structure.
16. The method of claim 15 , wherein forming the second semiconductor material directly on the exposed first sidewall such that the second semiconductor material physically contacts the first sidewall of the fin structure includes forming the second semiconductor material directly on the exposed second sidewall such that the second semiconductor material physically contacts the second sidewall of the fin structure.
17. The method of claim 14 , further comprising:
forming a gate dielectric layer over the second semiconductor material; and
forming a gate electrode over the gate dielectric layer.
18. The method of claim 17 , further comprising forming a source/drain feature adjacent the fin structure after forming the gate electrode over the gate dielectric layer.
19. The method of claim 17 , wherein the gate dielectric layer physically contacts the dielectric isolation feature, and
wherein the gate electrode physically contacts the dielectric isolation feature.
20. The method of claim 14 , wherein the first semiconductor material includes silicon and the second semiconductor material includes germanium.