Nanosheet capacitor
A capacitive device includes a first electrode comprising a nanosheet stack, and a second electrode comprising a nanosheet stack, the second electrode arranged substantially parallel to the first electrode. A first conductive contact is arranged on a basal end of the first electrode, and a second conductive contact arranged on a basal end of the second electrode.
1. A method for forming a capacitive device, the method comprising:
forming a nanosheet stack on a substrate, the nanosheet stack including a first nanosheet layer comprising a first material and a second nanosheet layer arranged on the first nanosheet layer, the second nanosheet layer comprising a second material;
removing portions of the nanosheet stack to form a first fin and a second fin;
depositing a first insulator layer on the substrate;
implanting ions in the first fin and the second fin and annealing to form a first electrode and a second electrode;
removing the first insulator layer;
removing the first nanosheet layer from the first electrode and the second electrode to form voids between the first electrode and the substrate and the second electrode and the substrate;
depositing a second insulator layer on the substrate and in the void under the first electrode and the void under the second electrode; and
forming a first conductive contact on a basal end of the first electrode and a second metallic conductive contact on a basal end of the second electrode, wherein the first nanosheet material includes a first semiconductor material and they second nanosheet material includes a second semiconductor material.
2. The method of claim 1 , wherein the first insulator layer includes a dielectric material.
3. The method of claim 1 , wherein the second insulator layer includes a dielectric material.
4. The method of claim 1 , wherein the first conductive contact is formed by:
removing portions of the second insulator layer to form a cavity that exposes portions of the first electrode; and
depositing a conductive material in the cavity.
5. The method of claim 1 , wherein the first electrode is arranged substantially in parallel with the second electrode.
6. The method of claim 1 , wherein the first semiconductor material includes silicon germanium.
7. The method of claim 6 , wherein the second semiconductor material includes silicon.
8. A method for forming a capacitive device, the method comprising:
forming a nanosheet stack on a substrate, the nanosheet stack includes alternating layers of a first material and a second material;
removing portions of the nanosheet stack to form a first fin and a second fin;
depositing a first insulator layer on the substrate;
implanting ions in the first fin and the second fin and annealing to form a first electrode and a second electrode;
removing the first insulator layer;
removing the second material of the first fin and the second fin to form voids between the second electrode and the substrate, and the first electrode and the substrate; and
depositing a second insulator layer on the substrate and in the voids under the first electrode and the void under the second electrode, wherein first material includes a first semiconductor material and the second material includes a second semiconductor material.
9. The method of claim 8 , wherein the first insulator layer includes a dielectric material.
10. The method of claim 8 , wherein the second insulator layer includes a dielectric material.
11. The method of claim 8 , further comprising forming a conductive contact on a distal end of the first electrode.
12. The method of claim 8 , wherein the first electrode is arranged substantially in parallel with the second electrode.
13. The method of claim 8 , wherein the first semiconductor material includes silicon germanium.
14. The method of claim 13 , wherein the second semiconductor material includes silicon.