Fabrication of vertical transport fin field effect transistors with a self-aligned separator and an isolation region with an air gap
A method of forming a vertical transport fin field effect transistor with self-aligned dielectric separators, including, forming a bottom source/drain region on a substrate, forming at least two vertical fins on the bottom source/drain region, forming a protective spacer on the at least two vertical fins, forming a sacrificial liner on the protective spacer, forming an isolation channel in the bottom source/drain region and substrate between two of the at least two vertical fins, forming an insulating plug in the isolation channel, wherein the insulating plug has a pinch-off void within the isolation channel, and forming the dielectric separator on the insulating plug.
1. A vertical transport fin field effect transistor with a self-aligned dielectric separator, comprising:
a bottom source/drain region on a substrate;
at least two vertical fins on the bottom source/drain region;
an isolation channel in the bottom source/drain region and substrate between two of the at least two vertical fins;
an insulating plug in the isolation channel, wherein the insulating plug has a pinch-off void within the isolation channel, and the insulating plug extends above the top surface of the bottom source/drain region to form an insulating cap; and
a gate dielectric layer on the sidewalls of two adjacent vertical fins of the at least two vertical fins and at least a portion of the sidewalls of the insulating cap.
2. The vertical transport fin field effect transistor of claim 1 , wherein the pinch-off void within the isolation channel forms an airgap.
3. The vertical transport fin field effect transistor of claim 1 , wherein the two of the at least two vertical fins are separated by a fin pitch in the range of about 15 nm to about 50 nm.
4. The vertical transport fin field effect transistor of claim 1 , further comprising a bottom spacer on the surface of the bottom source/drain region between each adjacent pair of the at least two vertical fins.
5. The vertical transport fin field effect transistor of claim 4 , further comprising a conductive gate electrode on the gate dielectric layer between the two adjacent vertical fins of the at least two vertical fins.
6. The vertical transport fin field effect transistor of claim 5 , further comprising the dielectric separator on the insulating plug, wherein the dielectric separator separates the gate dielectric layer and the conductive gate electrode into a gate structure on each of the two adjacent vertical fins.
7. The vertical transport fin field effect transistor of claim 6 , further comprising top source/drains on each of the two of the at least two vertical fins.
8. A vertical transport fin field effect transistor with a self-aligned dielectric separator, comprising:
a bottom source/drain region on a substrate;
at least two vertical fins on the bottom source/drain region;
an isolation channel in the bottom source/drain region and substrate between two of the at least two vertical fins;
an insulating plug in the isolation channel, wherein the insulating plug has a pinch-off void within the isolation channel, and the insulating plug extends above the top surface of the bottom source/drain region to form an insulating cap;
a gate dielectric layer on the sidewalls of two adjacent vertical fins of the at least two vertical fins and at least a portion of the sidewalls of the insulating cap; and
the dielectric separator on the insulating plug.
9. The vertical transport fin field effect transistor of claim 8 , wherein the dielectric separator has the same width as the insulating plug.
10. The vertical transport fin field effect transistor of claim 8 , wherein the two of the at least two vertical fins are separated by a fin pitch in the range of about 15 nm to about 50 nm.
11. The vertical transport fin field effect transistor of claim 10 , wherein an insulating cap is between the bottom surface of the dielectric separator and the top surface of the bottom source/drain region.
12. The vertical transport fin field effect transistor of claim 11 , wherein the dielectric separator has a width in the range of about 5 nm to about 40 nm.
13. The vertical transport fin field effect transistor of claim 12 , further comprising a gate dielectric layer on the two of the at least two vertical fins and the dielectric separator, and top source/drains on the two of the at least two vertical fins.
14. The vertical transport fin field effect transistor of claim 12 , wherein the dielectric separator is a low-K dielectric material.
15. A vertical transport fin field effect transistor with a self-aligned dielectric separator, comprising:
a bottom source/drain region on a substrate;
at least two vertical fins on the bottom source/drain region;
an isolation channel in the bottom source/drain region and substrate between two of the at least two vertical fins;
an insulating plug in the isolation channel, wherein the insulating plug has a pinch-off void within the isolation channel, and the insulating plug extends above the top surface of the bottom source/drain region to form an insulating cap, wherein the insulating cap does not extend laterally along the top surface of the bottom source/drain region;
the dielectric separator on the insulating plug, wherein the dielectric separator has a width in the range of about 5 nm to about 40 nm; and
a gate dielectric layer on the sidewalls of two adjacent vertical fins of the at least two vertical fins and at least a portion of the sidewalls of the insulating cap.
16. The vertical transport fin field effect transistor of claim 15 , further comprising a bottom spacer on the surface of the bottom source/drain region between each adjacent pair of the at least two vertical fins and the sidewalls of the insulating caps.
17. The vertical transport fin field effect transistor of claim 16 , wherein the dielectric separator is a low-K dielectric material, and the insulating plug is silicon oxide (SiO).
18. The vertical transport fin field effect transistor of claim 17 , further comprising a gate dielectric layer on two of the at least two vertical fins and the dielectric separator.