Sidewall image transfer nanosheet
A method for forming active regions of a semiconductor device comprising forming a nanosheet stack on a substrate, forming the nanosheet stack comprising forming a sacrificial nanosheet layer on the substrate, and forming a nanosheet layer on the sacrificial nanosheet layer, forming an etch stop layer on the nanosheet stack, forming a mandrel layer on the etch stop layer, removing portions of the mandrel layer to form a mandrel on the etch stop layer, forming sidewalls adjacent to sidewalls of the mandrel, depositing a fill layer on exposed portions of the etch stop layer, removing the sidewalls and removing exposed portions of the etch stop layer and the nanosheet stack to expose portions of the substrate.
1. A semiconductor device comprising:
a nanosheet stack on a substrate, the nanosheet stack comprising:
a sacrificial nanosheet layer on the substrate; and
a nanosheet layer on the sacrificial nanosheet layer;
an etch stop layer on the nanosheet stack;
a mandrel on the etch stop layer;
sidewalls adjacent to sidewalls of the mandrel; and
a fill layer on exposed portions of the etch stop layer.
2. The device of claim 1 , wherein the nanosheet stack further comprises:
a second sacrificial nanosheet layer on the nanosheet layer; and
a second nanosheet layer on the second sacrificial nanosheet layer.
3. The device of claim 1 , wherein the nanosheet layer includes a first epitaxially grown semiconductor material and the sacrificial nanosheet layer includes a second epitaxially grown semiconductor material.
4. The device of claim 1 , wherein the nanosheet layer includes a first semiconductor material and the sacrificial nanosheet layer includes a second semiconductor material and the first semiconductor material is dissimilar from the second semiconductor material.
5. The device of claim 4 , wherein the first semiconductor material includes silicon and the second semiconductor material includes silicon germanium.
6. The device of claim 1 , wherein the etch stop layer includes an oxide material.
7. The device of claim 1 , wherein the etch stop layer includes a nitride material.
8. The device of claim 1 , wherein each of the sidewalls adjacent to sidewalls of the mandrel has a thickness of approximately 2-10 nm.
9. The device of claim 8 , wherein the mandrel has a width of approximately 10-50 nm.
10. The device of claim 9 further comprising multiple mandrels.
11. The device of claim 10 , wherein each of the mandrels has a width of approximately 10-50 nm.
12. The device of claim 11 further comprising sidewalls adjacent to sidewalls of each of the mandrels.
13. The device of claim 12 , wherein each of the sidewalls adjacent to sidewalls of each of the mandrels has a thickness of approximately 2-10 nm.