Forming on-chip metal-insulator-semiconductor capacitor
A method is presented for forming a semiconductor structure. The method includes forming a plurality of fins on a first region of the semiconductor substrate, forming a bi-polymer structure, selectively removing the first polymer of the bi-polymer structure and forming deep trenches in the semiconductor substrate resulting in pillars in a second region of the semiconductor structure. The method further includes selectively removing the second polymer of the bi-polymer structure, doping the pillars, and depositing a high-k metal gate (HKMG) over the first and second regions to form the MIS capacitor in the second region of the semiconductor substrate.
1. A semiconductor structure for forming a metal-insulator-semiconductor (MIS) capacitor on a semiconductor substrate, the semiconductor structure comprising:
a plurality of fins formed over a first region of the semiconductor substrate;
a plurality of undoped pillars disposed in the first region of the semiconductor substrate extending within the semiconductor substrate, and being vertically misaligned with respect to the plurality of fins;
a plurality of doped pillars disposed in a second region of the semiconductor substrate; and
a high-k metal gate (HKMG) deposited over the first and second regions to form the MIS capacitor in the second region of the semiconductor substrate.
2. The structure of claim 1 , wherein a bottom spacer is disposed over and in direct contact with the plurality of undoped pillars.
3. The structure of claim 1 , wherein a top spacer is disposed in direct contact with an upper portion of the plurality of fins.
4. The structure of claim 1 , wherein the plurality of doped pillars are encapsulated by the HKMG.
5. The structure of claim 1 , wherein the plurality of fins are vertically misaligned with respect to the plurality of doped pillars.
6. The structure of claim 1 , wherein the HKMG is deposited between the doped pillars.
7. The structure of claim 6 , wherein the HKMG is deposited between the plurality of fins in the first region of the semiconductor substrate.
8. The structure of claim 7 , wherein a first dielectric material separates the HKMG of the first and second regions of the semiconductor substrate.
9. The structure of claim 8 , wherein a second dielectric material is deposited over the HKMG in the second region of the semiconductor substrate.
10. The structure of claim 9 , wherein epitaxial growth is performed over exposed regions of the plurality of fins on the first region of the semiconductor substrate.
11. A semiconductor structure for forming a metal-insulator-semiconductor (MIS) capacitor on a semiconductor substrate, the semiconductor structure comprising:
a plurality of fins formed over a first region of the semiconductor substrate;
a plurality of undoped pillars disposed in the first region of the semiconductor substrate extending within the semiconductor substrate, and being vertically misaligned with respect to the plurality of fins;
a plurality of doped pillars disposed in a second region of the semiconductor substrate;
a bottom spacer formed at least over the undoped pillars in the first region; and
a high-k metal gate (HKMG) deposited over the second region to form the MIS capacitor in the second region of the semiconductor substrate.
12. The structure of claim 11 , wherein the plurality of doped pillars are encapsulated by the HKMG.
13. The structure of claim 11 , wherein the plurality of fins are vertically misaligned with respect to the plurality of doped pillars.
14. The structure of claim 11 , wherein the plurality of undoped pillars have a same height as the plurality of doped pillars.
15. The structure of claim 11 , wherein the HKMG is deposited between the plurality of doped pillars in the second region of the semiconductor substrate.
16. The structure of claim 11 , wherein the HKMG is deposited between the plurality of fins in the first region of the semiconductor substrate.
17. The structure of claim 16 , wherein a number of the plurality of doped pillars is greater than a number of the plurality of undoped pillars.
18. The structure of claim 17 , wherein the HKMG is recessed to expose top portions of the plurality of fins and a top spacer is deposited.
19. The structure of claim 18 , wherein epitaxial growth is performed over the exposed top portions of the plurality of fins.
20. The structure of claim 19 , wherein an oxide is deposited over the top spacer in the second region and over the formed MIS capacitor.