Three-dimensional monolithic vertical field effect transistor logic gates
Techniques facilitating three-dimensional monolithic vertical field effect transistor logic gates are provided. A logic device can comprise a first vertical transport field effect transistor formed over and adjacent a substrate and a first bonding film deposited over the first vertical transport field effect transistor. The logic device can also comprise a second vertical transport field effect transistor comprising a second bonding film and stacked on the first vertical transport field effect transistor. The second bonding film can affix the second vertical transport field effect transistor to the first vertical transport field effect transistor. In addition, the logic device can comprise one or more monolithic inter-layer vias that extend from first respective portions of the second vertical transport field effect transistor to second respective portions of the first vertical transport field effect transistor and through the first bonding film and the second bonding film.
1. A method, comprising:
depositing a first bonding film on a first vertical transport field effect transistor;
forming a second vertical transport field effect transistor over and adjacent the first vertical transport field effect transistor, wherein the second vertical transport field effect transistor comprises a second bonding film;
using the second bonding film to adhere the second vertical transport field effect transistor to the first vertical transport field effect transistor, and wherein the second vertical transport field effect transistor is stacked on the first vertical transport field effect transistor; and
defining and etching one or more monolithic inter-layer vias from first respective portions of the second vertical transport field effect transistor to second respective portions of the first vertical transport field effect transistor.
2. The method of claim 1 , wherein the etching comprises etching the one or more monolithic inter-layer vias through the first bonding film and the second bonding film.
3. The method of claim 1 , further comprising:
forming the first vertical transport field effect transistor, wherein the forming the first vertical transport field effect transistor comprises forming an n-channel field effect transistor over and adjacent a substrate.
4. The method of claim 3 , wherein the forming the second vertical transport field effect transistor comprises forming a p-channel field effect transistor over the n-channel field effect transistor.
5. The method of claim 1 , further comprising:
forming the first vertical transport field effect transistor, wherein the forming the first vertical transport field effect transistor comprises forming a p-channel field effect transistor over and adjacent a substrate, and wherein the forming the second vertical transport field effect transistor comprises forming an n-channel field effect transistor over the p-channel field effect transistor.
6. The method of claim 1 , further comprising:
forming the first vertical transport field effect transistor, wherein the forming the first vertical transport field effect transistor comprises:
doping a first layer formed on a substrate;
forming a first semiconducting layer on the first layer;
forming a first gate layer around respective first elements of the first semiconducting layer;
forming a second doped layer over the first semiconducting layer; and
forming a first contact layer on the second doped layer.
7. The method of claim 6 , wherein the forming the second vertical transport field effect transistor comprises:
doping a third layer placed on the first bonding film and over the first contact layer;
forming a second semi-conducting layer on the third layer;
forming a second gate layer around respective second elements of the second semi-conducting layer;
forming a fourth layer on the second semi-conducting layer; and
forming a second contact layer on the fourth layer.
8. The method of claim 7 , further comprising defining and forming the one or more monolithic inter-layer vias, wherein the one or more monolithic inter-layer vias penetrate and contact the respective first portions of the second gate layer and extend to the respective second portions of the first gate layer.
9. The method of claim 1 , further comprising defining and forming the one or more monolithic inter-layer vias, wherein the one or more monolithic inter-layer vias extend from a first metallurgy on the first vertical transport field effect transistor to a second metallurgy on the second vertical transport field effect transistor.
10. The method of claim 1 , wherein the depositing the first bonding film comprises:
covering the first vertical transport field effect transistor with a bonding dielectric.
11. The method of claim 10 , wherein the depositing the first bonding film further comprises:
planarizing the bonding dielectric prior to the forming the second vertical transport field effect transistor.
12. The method of claim 1 , further comprising:
defining and etching a top contact layer for the second vertical transport field effect transistor; and
filling the top contact layer and the one or more monolithic inter-layer vias.
13. The method of claim 12 , further comprising:
polishing the top contact layer and the one or more monolithic inter-layer vias.
14. The method of claim 12 , wherein the top contact layer is etched prior to the etching of the one or more monolithic inter-layer vias.
15. The method of claim 1 , further comprising concurrently etching the one or more monolithic inter-layer vias.