Gate cut on a vertical field effect transistor with a defined-width inorganic mask
A method of cutting a gate on a VFET includes depositing a memorization layer around a spacer on a sidewall of the field effect transistor. A planarizing layer is patterned onto the memorization layer. An anti-reflective coating layer is patterned onto the planarizing layer. A photoresist layer is patterned onto the anti-reflective coating layer on ends of fins extending from a substrate. The planarizing layer, the anti-reflective coating layer, and the photoresist form a mask. The anti-reflective coating layer portion is etched from the VFET. The planarizing layer and the photoresist layer are arc etched from the VFET. The spacer is pulled down forming a void between gates on the VFET and exposing a hard mask on the fins. The hard mask is reactive ion etched vertically around the gates to form gates with a defined width mask. The memorization layer is removed from the VFET.
1. A vertical field effect transistor (VFET) comprising:
a first spacer disposed on a silicon substrate;
fins from the substrate through the spacer;
an oxide layer disposed on the fins;
a hard mask layer disposed on the oxide layer; and
a second spacer with a defined width disposed around the fins, oxide layer and hard mask layer, forming a gate around the fins.
2. The VFET of claim 1 , wherein the first spacer comprises an insulating material.
3. The VFET of claim 2 , wherein the insulating material comprises silicon nitride.
4. The VFET of claim 1 , wherein the second spacer comprises an insulating material.
5. The VFET of claim 4 , wherein the insulating material comprises silicon nitride.
6. The VFET of claim 1 , further comprising a tungsten gate disposed around the fin.
7. The VFET of claim 1 , wherein the hard mask on the fin comprises an inorganic hard mask.
8. The VFET of claim 1 , wherein the hard mask comprises a non-conducting material.
9. The VFET of claim 8 , wherein the non-conducting material comprises silicon nitride, SiBCN, SiOCN, or a combination comprising at least one of the foregoing.
10. The VFEF of claim 9 , wherein the non-conducting material comprises silicon nitride.
11. The VFET of claim 1 , wherein the gate around the fin has a defined thickness.
12. The VFET of claim 1 , wherein the gate has a width of 1 nanometer to 50 nanometers.
13. The VFET of claim 1 , wherein a distance between gates across the VFET is consistent.
14. The VFET of claim 1 , wherein the gate materials are selected from tungsten, tungsten titanium nitride, titanium, titanium nitride, tantalum, molybdenum, or a combination comprising at least one of the foregoing.
15. The VFET of claim 1 , wherein the fins are made from a material comprising silicon, silicon germanium, or a combination comprising at least one of the foregoing.
16. The VFET of claim 1 , wherein the fin is further surrounded by a work function metal layer.
17. The VFET of claim 16 , wherein the work function metal comprises aluminum, titanium, silver, copper, gold, or a combination comprising at least one of the foregoing.
18. The VFET of claim 1 , wherein the VFET has a gate to main current resistance of greater than or equal to 100 MegaOhms.
19. The VFET of claim 1 , wherein the fins are separated by shallow trench isolation regions.
20. The VFET of claim 1 , wherein the fins are oriented vertically.