Method to form a contact hole

1. A method of forming a contact opening; comprising the steps of:

a) providing a gate structure over a substrate; the gate structure having gate structure sidewalls;

b) forming a nitride liner over said gate structure and said substrate; the nitride liner having sidewalls;

c) providing a dielectric layer over the nitride liner;

d) forming a contact photoresist pattern over the dielectric layer;

e) performing a contact opening etch by etching the dielectric layer to form a contact opening and a residual spacer;

said contact opening exposes portions of said nitride liner over said gate structure sidewalls and over said substrate adjacent to said gate structure;

said residual spacer is over the sidewalls of said nitride liner;

f) striping said contact photoresist pattern;

g) performing a plasma treatment comprising gases containing fluorine, nitrogen and hydrogen to deposit a by-products layer over said residual spacer and said dielectric layer; and

h) removing said by-products layer and said residual spacer.

2. The method of claim 1 which further comprises:

removing said by-products layer and said residual spacer using a process of: (1) heating; (2) DI rinsing; or (3) IR or UV radiating.

3. The method of claim 1 which further comprises: said residual spacer is comprised of oxide;

step (e) further comprises forming a polymer layer over said residual spacer and said nitride liner; and

step (f) further comprises striping said contact photoresist pattern and said polymer layer.

4. The method of claim 1 which further comprises: etching said nitride liner using a nitride etch to expose the surface of said substrate in said contact opening; forming a contact to said substrate in said contact opening;

forming a first insulation layer over said contact and said substrate and said dielectric layer.

5. The method of claim 1 wherein said gate structure is comprised of a gate dielectric, a gate electrode and a nitride hard mask.

6. The method of claim 1 wherein said dielectric layer is comprised of oxide and said residual spacer is comprised of oxide.

7. The method of claim 1 wherein the contact opening etch comprises: a RF bias power between 500 and 1000 W, a process pressure between 5 and 200 mTorr, a carbon fluoride containing gas with a flow between 3 and 50 sccm, a O 2 flow between 0 and 50 sccm, a CH 2 F 2 or CH 3 F flow between 0 and 50 sccm, a inert gas flow between 0 and 1000 sccm.

8. The method of claim 1 wherein the stripping of said contact photoresist pattern comprises: a microwave bias power between 100 and 1000 W, a process pressure between 5 and 5000 mTorr, an O2/N2 ratio between 10:1 and 20:1.

9. The method of claim 1 wherein the plasma treatment in a down stream plasma tool comprises flowing N 2 and H 2 and using microwave or RF energy to create a nitrogen and hydrogen plasma upstream of a treatment chamber where the substrate is held; adding NF 3 to the nitrogen and hydrogen plasma and flowing the gases into the treatment chamber to plasma treat the substrate.

10. The method of claim 1 wherein the plasma treatment comprises:

flowing NF 3 between 5 and 1000 sccm, flowing N 2 between 5 and 5000 sccm, flowing H 2 between 5 and 2000 sccm, at a microwave power between 50 and 5000 W; the nitrogen and hydrogen feeds flow through a plasma applicator before entering a chamber.

11. The method of claim 1 wherein the plasma treatment comprises: flowing gas with a molar composition of NF 3 between 1 and 75%, N 2 between 1 and 99% and H 2 between 1 and 75%; the nitrogen and hydrogen feeds flow through a plasma applicator before entering a chamber.

12. The method of claim 1 wherein the plasma treatment comprises: flowing gas with a molar composition of NF 3 between 1 and 30%, N 2 between 70 and 95% and H 2 between 1 and 30%; the nitrogen and hydrogen feeds flow through a plasma applicator before entering a chamber.

13. The method of claim 1 wherein the removal of said by-products layer and said residual spacer comprises heating the substrate to a temperature greater than 50° C. in a N 2 gas or air ambient.

14. The method of claim 1 wherein the by-products layer is comprised of NxHyFz with x between 1 and 10; y between 1 and 7; and z between 1 and 7.

15. A method of forming a contact opening comprising the steps of:

a) providing a gate structure over a substrate;

b) providing spacers over the sidewalls of the gate structure;

c) forming a nitride liner over said spacers and said gate structure and said substrate;

d) providing a dielectric layer over the nitride liner; said dielectric layer is comprised of oxide;

e) forming a contact photoresist pattern over the dielectric layer;

f) etching the dielectric layer using fluorocarbons to form a contact opening, a residual spacer and a polymer layer;

said contact opening exposes portions of said nitride liner over the sidewalls of said gate structure and over said substrate adjacent to said gate structure;

said residual spacer is over sidewalls of said nitride liner; said polymer layer is over said residual spacer and said nitride liner;

said residual spacer is comprise of oxide;

(1) the etching to form said contact opening comprises:

carbon fluoride, O 2 , and CH 2 F 2 etchants;

g) striping said contact photoresist pattern and said polymer layer;

h) performing a NF 3 and nitrogen and hydrogen plasma treatment to deposit a by-products layer over said residual spacer and said dielectric layer; and

i) removing said by-products layer and said residual spacer using one of the following processes: (1) heat; (2) DI rinse; or (3) IR or UV radiation.

16. The method of claim 15 which further includes:

etching said nitride liner using a nitride etch to expose the surface of said substrate in said contact opening;

forming a contact to said substrate in said contact opening;

forming a first insulation layer over said contact and said substrate and dielectric layer.

17. The method of claim 15 wherein said residual spacer is comprised of over 90% oxide.

18. The method of claim 15 wherein the etching to form said contact opening comprises: a RF bias power between 500 and 1000 W, a process pressure between 5 and 200 mTorr, a carbon fluoride containing gas with a flow between 3 and 50 sccm, an O 2 flow between 0 and 50 sccm, a CH 2 F 2 or CH 3 F flow between 0 and 50 sccm and an inert gas flow between 0 and 1000 sccm.

19. The method of claim 15 wherein step h) further comprises placing said substrate in a plasma treatment tool; said plasma treatment tool selected from the group consisting of a Microwave tool, ICP tool, a MERIE tool, and a RIE tool.

20. The method of claim 15 wherein the plasma treatment comprises: flowing NF 3 between 5 and 1000 sccm, flowing N 2 between 5 and 5000 sccm, flowing H 2 between 5 and 2000 sccm, at a microwave power between 50 and 5000 W; the nitrogen and hydrogen feeds flow through a plasma applicator before entering a chamber; the NF 3 flow does not pass thru a plasma applicator.

21. The method of claim 15 wherein the NF 3 and nitrogen and hydrogen plasma treatment comprises: flowing gas with a composition of NF 3 between 1 and 75%, N 2 between 1 and 99% and H 2 between 1 and 75%; the nitrogen and hydrogen feeds flow through a plasma applicator before entering a chamber; and the NF 3 flow does not pass thru a plasma applicator.

22. The method of claim 15 wherein the plasma treatment comprises: flowing gas with a molar composition of NF 3 between 1 and 30%, nitrogen between 70 and 95% and H 2 between 1 and 30%; the nitrogen and hydrogen feeds flow through a plasma applicator before entering a chamber; and the NF 3 flow does not pass thru a plasma applicator.

23. The method of claim 15 wherein the by-products layer is comprised of NxHyFz with x between 1 and 10; y between 1 and 7; and z between 1 and 7.

24. A method of forming a contact opening; comprising the steps of:

a) providing a gate structure over a substrate; the gate structure having gate structure sidewalls;

b) forming a nitride liner over said gate structure and said substrate; the nitride liner having sidewalls;

c) providing a dielectric layer over the nitride liner;

d) forming a contact photoresist pattern over the dielectric layer;

e) performing a contact opening etch by etching the dielectric layer to form a contact opening;

said contact opening exposes portions of said nitride liner over said gate structure sidewalls and over said substrate adjacent to said gate structure;

f) striping said contact photoresist pattern;

g) performing a plasma treatment comprising gases containing fluorine, nitrogen and hydrogen to deposit a by-products layer over said dielectric layer; and

h) removing said by-products layer.

25. The method of claim 24 which further comprises:

in step e) performing the contact opening etch by etching the dielectric layer to form the contact opening and a residual spacer; said residual spacer is over the sidewalls of said nitride liner; and

in step h) removing said by-products layer and said residual spacer using a process of: (1) heating; (2) DI rinsing; or (3) IR or UV radiation.

26. The method of claim 24 which further comprises:

In step e) performing the contact opening etch by etching the dielectric layer to form the contact opening and a residual spacer; said residual spacer is over the sidewalls of said nitride liner; and

the contact opening etch comprises flowing a carbon fluoride containing gas; and

in step h) removing said by-products layer and said residual spacer using a process of: (1) heating; (2) Dl rinsing; or (3) IR or UV radiation.