Block level patterning process
The present application relates to an optical planarizing layer etch process. Embodiments include forming fins separated by a dielectric layer; forming a recess in the dielectric layer on each side of each fin, each recess being for a metal gate; forming sidewall spacers on each side of each recess; depositing a high-k dielectric liner in each recess and on a top surface of each of the fins; depositing a metal liner over the high-k dielectric layer; depositing a non-conformal organic layer (NCOL) over a top surface of the dielectric layer to pinch-off a top of each recess; depositing an OPL and ARC over the NCOL; etching the OPL, ARC and NCOL over a portion of the dielectric layer and recesses in a first region; and etching the portion of the recesses to remove residual NCOL present at a bottom of each recess of the portion of the recesses.
1. A method, comprising:
forming a plurality of fins separated by a dielectric layer;
forming a recess in the dielectric layer on each side of each fin, each recess being for a metal gate;
forming sidewall spacers on each side of each recess;
depositing a high-k dielectric liner in each recess and on a top surface of each of the fins;
depositing a metal liner over the high-k dielectric layer;
depositing a non-conformal organic layer (NCOL) over a top surface of the dielectric layer to pinch-off a top of each recess, wherein a residual amount of the NCOL covers side and bottom surfaces of each recess;
depositing an optical planarization layer (OPL) and anti-reflective coating (ARC) over the NCOL;
etching the OPL, ARC and NCOL over a portion of the dielectric layer and recesses in a first region; and
etching the portion of the recesses to remove the residual amount of the NCOL present at the side and bottom surfaces of each recess of the portion of the recesses.
2. The method of claim 1 , wherein the dielectric layer comprises a SiO 2 layer.
3. The method of claim 1 , wherein the sidewall spacers comprise SiN.
4. The method of claim 1 , wherein the metal liner comprises a work function metal.
5. The method of claim 1 , wherein the NCOL comprises a PVD carbon, CVD carbon or plasma polymer comprising CFx, HBrx or CHxFy.
6. The method of claim 1 , wherein the etching of the recesses comprises plasma etching (PE) or reactive ion etching (RIE) to remove the residual amount of NCOL present at the bottom of each recess.
7. The method of claim 1 , wherein the step of depositing the OPL comprises depositing a polymer by spin coating the OPL over the NCOL.
8. The method of claim 1 , wherein the etching of the OPL, ARC and NCOL comprises depositing a photoresist over the ARC with an opening over the portion of the dielectric layer and recesses and etching through the photoresist.
9. The method of claim 8 , further comprising wet etching to remove the metal liner from the portion of the dielectric layer and recesses.
10. The method of claim 9 , further comprising removing any remaining OPL, ARC and NCOL over a remaining portion of the dielectric layer and recesses.
11. A method, comprising:
forming a plurality of fins separated by a dielectric layer;
depositing a non-conformal organic layer (NCOL) over an upper surface of the dielectric layer to pinch-off a top of each recess on each side of each of the fins, wherein a residual amount of the NCOL covers side and bottom surfaces of each recess;
depositing an optical planarization layer (OPL) and anti-reflective coating (ARC) over the NCOL;
etching the OPL, ARC and NCOL over a portion of the dielectric layer and recesses in a first region; and
etching the portion of the recesses to remove the residual amount of the NCOL present at the side and bottom surfaces of each recess of the portion of the recesses.
12. The method of claim 11 , wherein the dielectric layer comprises a SiO 2 layer.
13. The method of claim 11 , further comprising:
prior to depositing the NCOL, depositing a high-k dielectric layer in each recess; and
depositing a metal liner over the high-k dielectric layer,
wherein each recess is for a metal gate.
14. The method of claim 13 , wherein the NCOL comprises a PVD carbon, CVD carbon or plasma polymer comprising CFx, HBrx or CHxFy.
15. The method of claim 14 , wherein the etching of the recesses comprises plasma etching (PE) or reactive ion etching (RIE) to remove the residual amount of NCOL present at the bottom of each recess.
16. The method of claim 11 , wherein the step of depositing the OPL comprises depositing a polymer by spin coating the OPL over the NCOL.
17. The method of claim 11 , wherein the etching of the OPL, ARC and NCOL comprises depositing a photoresist over the ARC with an opening over the portion of the dielectric layer and recesses and etching through the photoresist.
18. The method of claim 17 , further comprising wet etching to remove the metal liner from the portion of the dielectric layer and recesses.
19. The method of claim 18 , wherein the metal liner layer comprises a work function metal comprising TiN.
20. A method, comprising:
forming a plurality of fins in a silicon layer, each fin separated by a dielectric layer, each fin including a recess on each side of each fin;
depositing a high-k dielectric liner in each recess and on a top surface of each of the fins;
depositing a metal liner over the high-k dielectric layer;
depositing a non-conformal organic layer (NCOL) over a top surface of the dielectric layer to pinch-off a top of each recess, wherein a residual amount of the NCOL covers side and bottom surfaces of each recess;
depositing an optical planarization layer (OPL) and anti-reflective coating (ARC) over the NCOL;
plasma etching or reactive ion etching the OPL, ARC and NCOL over a portion of the dielectric layer and recesses in a first region;
etching the portion of the recesses to remove the residual amount of the NCOL present at the side and bottom surfaces of each recess of the portion of the recesses; and
wet etching the portion of the dielectric layer and recesses to remove the metal liner.