Two dimension material fin sidewall
View Patent ↗A semiconductor structure, such as a microchip that includes a finFET, includes fins that have a 2D material, such as Graphene, upon at least the fin sidewalls. The thickness of the 2D material sidewall may be tuned to achieve desired finFET band gap control. Neighboring fins of the semiconductor structure form fin wells. The semiconductor structure may include a fin cap upon each fin and the 2D material is formed upon the sidewalls of the fin and the bottom surface of the fin wells. The semiconductor structure may include a well-plug at the bottom of the fin wells and the 2D material is formed upon the sidewalls and upper surface of the fins. The semiconductor structure may include both fin caps and well-plugs such that the 2D material is formed only upon the sidewalls of the fins.
1. A semiconductor structure fabrication method comprising:
forming neighboring fins within a semiconductor substrate separated by a fin well;
forming a well-plug within a bottom portion of the fin well such that sidewall portions of the fins are exposed to an upper portion of the fin well;
forming a 2D material upon the exposed sidewall portions of the fins and upon top surfaces of the fins within a source region, within a drain region, and within a channel region;
forming a channel mask upon the 2D material and upon the well-plugs within the channel region;
forming a source contact adjacent to the channel mask within the source region and forming a drain contact adjacent to the channel mask within the drain region;
exposing the 2D material and the well-plugs within the channel region by removing the channel mask;
forming a gate dielectric upon the exposed 2D material and upon the exposed well-plugs within the channel region; and
forming a gate upon the gate dielectric.
2. The method of claim 1 , wherein the 2D material is formed upon the sidewall portions and upon the top surface of each fin not formed upon the majority of an upper surface of the well-plug.
3. The method of claim 1 , wherein the semiconductor substrate and the fins are formed from Silicon Carbide.
4. The method of claim 1 , wherein the 2D material is Graphene.
5. The method of claim 1 , further comprising:
forming a source/drain contact mask upon the source contact, upon the drain contact, and upon the channel mask; and
simultaneously removing the channel mask and the source/drain contact mask thereupon.
6. The method of claim 5 , wherein simultaneously removing the channel mask and the source/drain contact mask thereupon comprises:
resultantly forming a channel well that exposes the 2D material and the well-plugs within the channel region.
7. The method of claim 1 , wherein forming the well-plug comprises:
forming a blanket dielectric layer upon the substrate and upon the fins; and
recessing the blanket dielectric layer by a chemical mechanical polish stopping at a plane coplanar with the top surfaces of the fins.
8. The method of claim 1 , wherein forming the well-plug comprises:
subsequently recessing the blanket layer by etching away the blanket layer within the upper portion of the fin well.
9. A semiconductor structure comprising:
a substrate;
neighboring fins within the substrate separated by a fin well;
a well-plug within a bottom portion of the fin well, wherein sidewall portions of the neighboring fins are exposed to an upper portion of the fin well;
a 2D material upon the exposed sidewall portions and upon top surfaces of the neighboring fins within a source region, within a drain region, and within a channel region;
a source contact within the source region and a drain contact within the drain region;
a gate dielectric upon the 2D material and upon the well-plugs within the channel region; and
a gate upon the gate dielectric.
10. The semiconductor structure of claim 9 , wherein the 2D material is upon the sidewall portions and upon the top surface of each neighboring fin and not upon a majority of an upper surface of the well-plug.
11. The semiconductor structure of claim 9 , wherein the semiconductor substrate is a Silicon Carbide semiconductor substrate and the fins are Silicon Carbide fins.
12. The semiconductor structure of claim 9 , wherein the 2D material is Graphene.
13. The semiconductor structure of claim 9 , wherein the gate dielectric is an Aluminum Oxide gate dielectric.
14. The semiconductor structure of claim 9 , wherein the well-plug is a silicon dioxide well-plug.
15. A finFET comprising:
a substrate;
neighboring fins within the substrate separated by a fin well;
a well-plug within a bottom portion of the fin well, wherein sidewall portions of the neighboring fins are exposed to an upper portion of the fin well;
a 2D material upon the exposed sidewall portions and upon top surfaces of the neighboring fins within a source region, within a drain region, and within a channel region;
a source contact within the source region and a drain contact within the drain region;
a gate dielectric upon the 2D material and upon the well-plugs within the channel region; and
a gate upon the gate dielectric.
16. The finFET of claim 15 , wherein the 2D material is upon the sidewall portions of and upon the top surface of each neighboring fin and not upon a majority of an upper surface of the well-plug.
17. The finFET of claim 15 , wherein the semiconductor substrate is a Silicon Carbide semiconductor substrate and the fins are Silicon Carbide fins.
18. The finFET of claim 15 , wherein the 2D material is Graphene.
19. The finFET of claim 15 , wherein the gate dielectric is an Aluminum Oxide gate dielectric.
20. The finFET of claim 15 , wherein the well-plug is a silicon dioxide well-plug.