Long channels for transistors
A semiconductor device includes a first nanosheet stack, a second nanosheet stack, and a third nanosheet stack arranged on a substrate. The semiconductor device includes a gate arranged on the first nanosheet stack, the second nanosheet stack, and the third nanosheet stack. The semiconductor device includes a channel extending through the gate and from the first nanosheet stack, the second nanosheet stack, and to the third nanosheet stack in a serpentine fashion. The semiconductor device includes a first source/drain and a second source/drain arranged on opposing sides of the gate.
1. A method for fabricating a semiconductor device, the method comprising:
forming a gate on a first nanosheet stack, a second nanosheet stack, and a third nanosheet stack arranged on a substrate;
depositing a semiconductor material on the first nanosheet stack, the second nanosheet stack, and the third nanosheet stack;
depositing an interlayer dielectric (ILD) on the first nanosheet stack, the second nanosheet stack, and the third nanosheet stack;
forming a first trench and a second trench through the ILD on a first side of the gate, and a third trench and a fourth trench through the ILD on a second side of the gate, the second trench coupling the second nanosheet stack to the third nanosheet stack, and the third trench coupling the first nanosheet stack to the second nanosheet stack; and
depositing a metal in the first trench, the second trench, the third trench, and the fourth trench.
2. The method of claim 1 , wherein a pitch between the first nanosheet stack and the second nanosheet stack comprises at least 30 nanometers (nm).
3. The method of claim 1 , wherein depositing the semiconductor material comprises applying an epitaxial growth process.
4. The method of claim 1 , wherein subsequent to depositing the metal a channel is formed that crosses through the gate in three areas.
5. The method of claim 1 , wherein the first trench extends through the ILD to the semiconductor material on the first nanosheet stack.
6. The method of claim 5 , wherein the second trench extends through the ILD to the semiconductor material on the second nanosheet stack and the third nanosheet stack.
7. The method of claim 1 , wherein the third trench extends through the ILD to the semiconductor material on the first nanosheet stack and the second nanosheet stack, and the fourth trench extends through the ILD to the semiconductor material on the third nanosheet stack.
8. A method for fabricating a semiconductor device, the method comprising:
forming a gate on a first nanosheet stack, a second nanosheet stack, and a third nanosheet stack arranged on a substrate, the first nanosheet stack, the second nanosheet stack, and the third nanosheet stack comprising alternating layers of silicon and silicon germanium;
depositing a semiconductor material on the layer of silicon of the first nanosheet stack, the second nanosheet stack, and the third nanosheet stack;
depositing an interlayer dielectric (ILD) on the first nanosheet stack, the second nanosheet stack, and the third nanosheet stack;
forming a first trench and a second trench through the ILD on a first side of the gate, and a third trench and a fourth trench through the ILD on a second side of the gate, the second trench coupling the second nanosheet stack to the third nanosheet stack, and the third trench coupling the first nanosheet stack to the second nanosheet stack; and
depositing a metal in the first trench, the second trench, the third trench, and the fourth trench.
9. The method of claim 8 , wherein a pitch of the first nanosheet stack and the second nanosheet comprises at least 30 nanometers (nm).
10. The method of claim 8 , wherein depositing the semiconductor material is by an epitaxial growth process.
11. The method of claim 10 , wherein the semiconductor material deposited on the first nanosheet stack and the second nanosheet stack does not overlap each another.
12. The method of claim 8 , wherein after depositing the metal, a channel is formed that crosses through the gate in three areas.
13. The method of claim 8 , wherein the gate comprises a sacrificial gate material.
14. The method of claim 13 , wherein the gate is replaced with a metal gate stack before forming the first trench on the first side of the gate and the second trench on the second side of the gate.