Direct gate patterning for vertical transport field effect transistor
Forming a semiconductor structure, including epitaxially growing a first source drain region between a first fin in an N-FET region and a second fin in a P-FET region, forming a shallow trench isolation region separating the N-FET region and the P-FET region, conformally forming an insulator on exposed surfaces of the semiconductor structure, conformally forming a work function metal layer on exposed surfaces, conformally forming a liner, conformally forming an organic planarization layer, forming a titanium nitride layer, patterning a photo resist mask, forming an first opening between the N-FET region and the P-FET region, wherein a top surface of a portion of the liner is exposed at a bottom of the first opening, removing the portion of the liner between the N-FET region and the P-FET region and removing a portion of the work function metal layer between the N-FET region and the P-FET region.
1. A method for forming a semiconductor structure, the method comprising:
epitaxially growing a first source drain region on the semiconductor structure between a first fin in an N-FET region of the semiconductor structure and a second fin in a P-FET region of the semiconductor structure;
forming a shallow trench isolation region separating the N-FET region and the P-FET region;
conformally forming an insulator on exposed surfaces of the semiconductor structure between the N-FET region and the P-FET region;
conformally forming a work function metal layer on exposed surfaces of the semiconductor structure;
conformally forming a liner on exposed surfaces of the semiconductor structure;
conformally forming an organic planarization layer on exposed surfaces of the semiconductor structure;
forming a titanium nitride layer on the exposed surfaces of the semiconductor structure;
patterning a photo resist mask on exposed surfaces of the semiconductor structure;
forming an first opening between the N-FET region and the P-FET region, wherein a top surface of a portion of the liner between the N-FET region and the P-FET region is exposed at a bottom of the first opening; and
removing the portion of the liner between the N-FET region and the P-FET region and removing a portion of the work function metal layer between the N-FET region and the P-FET region to expand the first opening, wherein a top surface of a portion of the insulator between the N-FET region and the P-FET region is exposed at a new bottom of the first opening.
2. The method according to claim 1 , further comprising:
forming a spacer on a horizontal top surface of the first source drain region, wherein a horizontal top surface of the first source drain region is coplanar with a horizontal bottom surface of the spacer.
3. The method according to claim 2 , wherein the spacer comprises a nitride.
4. The method according to claim 1 , wherein the insulator comprises hafnium oxide.
5. The method according to claim 1 , wherein the work function metal layer comprises titanium nitride.
6. The method according to claim 1 , further comprising:
epitaxially growing a second source drain region above a top surface of the first fin in the N-FET region and above a second fin in the P-FET region.
7. The method according to claim 1 , wherein the liner comprises silicon nitride.
8. The method according to claim 1 , wherein expanding the first opening between the N-FET region and the P-FET region, wherein a second bottom of the first opening is a top surface of a portion of the insulator further comprises simultaneously removing the titanium nitride layer.
9. A method for forming a semiconductor structure, the method comprising:
forming an organic planarization layer on exposed surfaces of the semiconductor structure, wherein the organic planarization layer covers a first work function metal layer;
conformally forming a second work function metal layer on the organic planarization layer, wherein a top surface of the organic planarization layer is coplanar with a bottom surface of the second work function metal layer;
patterning a photo resist mask on exposed surfaces of the semiconductor structure;
removing the second work function metal layer and the organic planarization layer selective to the photo resist mask, exposing a top surface of a liner between a first fin and a second fin; and
removing remaining portions of the second work function metal layer, portions of the liner between the first fin and the second fin, and portions of the first work function metal layer between the first fin and the second fin, selective to a remaining portion of the organic planarization layer, exposing an insulator between the first fin and the second fin and electrically separating the first work function metal layer between the first fin and the second fin.
10. The method according to claim 9 , further comprising:
epitaxially growing a first source drain region in a substrate of the semiconductor structure between the first fin and the second fin;
epitaxially growing a second source drain region above a top surface of each of the first fin and the second fin.
11. The method according to claim 9 , further comprising:
conformally forming an insulator on exposed surfaces of the semiconductor structure between the first fin and the second fin.
12. The method according to claim 9 , further comprising:
simultaneously removing portions of the second work function metal layer, portions of the liner between the first fin and the second fin, and portions of the first work function metal layer between the first fin and the second fin, selective to a remaining portion of the organic planarization layer.
13. The method according to claim 9 , wherein the first work function metal layer and the second work function metal layer each comprise titanium nitride.