DOUBLE PATTERNING ETCHING PROCESS

• US 20130048605A1
• Filed: 08/23/2012
• Published: 02/28/2013
• Est. Priority Date: 08/26/2011
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Tang, Jing, Bhatnagar, Ajay, Ingle, Nitin, Venkataraman, Shankar, SAPRE, Kedar
• Granted Patent: US 8,759,223 B2
• Time in Patent Office: Days
• US Class Current: 216/51
• CPC Class Codes: H01J 2237/334 Etching
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H01L 21/0274 Photolithographic processes
• CPC Class Codes: H01L 21/0337 characterised by the process involved to create the mask, e.g. lift-off masks, sidewalls, or to modify the mask, e.g. pre-treatment, post-treatment
• CPC Class Codes: H01L 21/3086 characterised by the process involved to create the mask, e.g. lift-off masks, sidewalls, or to modify the mask, e.g. pre-treatment, post-treatment
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/31144 using masks

Abstract

A method of etching a substrate comprises forming on the substrate, a plurality of double patterning features composed of silicon oxide, silicon nitride, or silicon oxynitride. The substrate having the double patterning features is provided to a process zone. An etching gas comprising nitrogen tri-fluoride, ammonia and hydrogen is energized in a remote chamber. The energized etching gas is introduced into the process zone to etch the double patterning features to form a solid residue on the substrate. The solid residue is sublimated by heating the substrate to a temperature of at least about 100° C.

Claims

1. A method of etching a substrate, the method comprising:

(a) forming on the substrate, a plurality of double patterning features comprising silicon oxide, silicon nitride, or silicon oxynitride;

(b) providing in a process zone of a process chamber, the substrate having the double patterning feature;

(c) energizing in a remote chamber, an etching gas comprising nitrogen tri-fluoride, ammonia, and hydrogen;

(d) introducing the energized etching gas into the process zone of the process chamber to etch the double patterning features to form a solid residue on the substrate; and

(e) sublimating the solid residue by heating the substrate to a temperature of at least about 100°

C.

2. A method according to claim 1 wherein (a) comprises providing a substrate comprising double patterning features composed of silicon oxynitride.

3. A method according to claim 1 wherein (a) comprises providing a substrate comprising double patterning features comprising an etch-stop layer.

4. A method according to claim 1 wherein (a) comprises providing a substrate comprising double patterning features comprising a sidewall spacer.

5. A method according to claim 1 wherein the etching gas comprises a molar ratio of ammonia to nitrogen trifluoride of at least about 1:

1.

6. A method according to claim 1 wherein the etching gas comprises a molar ratio of ammonia to nitrogen trifluoride of from about 5:

1 to about 30;

1.

7. A method according to claim 1 wherein the etching gas comprises a molar ratio of ammonia to hydrogen of from about 1:

1 to about 1;

10.

8. A method according to claim 1 wherein the etching gas comprises hydrogen in a flow rate of from about 10 sccm to about 3,000 sccm;

nitrogen trifluoride in a flow rate of from about 10 sccm to about 1,000 sccm; and

ammonia in a flow rate of from about 10 sccm to about 1,000 sccm.

9. A method according to claim 1 wherein the etching gas includes a diluent gas comprising argon, helium, hydrogen, nitrogen, or mixtures thereof.

10. A method according to claim 9 wherein the etching gas comprises diluent gas in a volume of from about 80% to about 95%.

11. A method according to claim 1 wherein the etching gas is energized by applying RF or microwave power at a power level of from about 5 to about 60 watts.

12. A method according to claim 1 wherein (e) comprises maintaining the substrate at an elevated temperature of from about 115°

C. to about 200°

C.

13. A method according to claim 12 wherein the substrate is maintained at the elevated temperature for from about 10 seconds to about 300 seconds.

14. A method according to claim 1 wherein the process zone comprises a gas distributor, and wherein the substrate is heated by raising the substrate to a distance from the gas distributor of from about 0.25 mm to about 5 mm.

15. A method according to claim 14 wherein the gas distributor is heated to a temperature of from about 100°

C. to about 400°

C.

19. A method according to claim 1 wherein the etching gas comprises a molar ratio of ammonia to hydrogen fluoride of at least about 1:

3.

20. A method according to claim 1 wherein the etching gas comprises a molar ratio of ammonia to hydrogen fluoride of from about 5:

3 to about 10;

1.

16. A method of etching a substrate, the method comprising:

(a) providing in a process zone of a process chamber, a substrate having a plurality of double patterning features composed of silicon oxynitride;

(b) energizing in a remote chamber, an etching gas comprising nitrogen tri-fluoride, ammonia and hydrogen, the etching gas comprises a molar ratio of ammonia to nitrogen trifluoride of at least a 1;

1, and a molar ratio of ammonia to hydrogen of from about 1;

1 to about 1;

10;

(c) introducing the energized etching gas into the process zone of the process chamber to etch the double patterning features to form a solid residue on the substrate; and

(d) sublimating the solid residue by heating the substrate to a temperature of at least about 100°

C.

17. A method of etching a substrate, the method comprising:

(a) providing in a process zone of a process chamber, a substrate having a plurality of double patterning features composed of silicon oxynitride;

(b) energizing in a remote chamber, an etching gas comprising hydrogen in a flow rate of from about 10 sccm to about 3,000 sccm, nitrogen trifluoride in a flow rate of from about 10 sccm to about 1,000 sccm, and ammonia in a flow rate of from about 10 sccm to about 1,000 sccm;

(c) introducing the energized etching gas into the process zone of the process chamber to etch the double patterning features to form a solid residue on the substrate; and

(d) sublimating the solid residue by heating the substrate to a temperature of from about 115°

C. to about 200°

C.

18. A method of etching a substrate, the method comprising:

(a) forming on the substrate, a plurality of double patterning features comprising silicon oxide, silicon nitride, or silicon oxynitride;

(b) providing in a process zone of a process chamber, the substrate having the double patterning feature;

(c) introducing an etching gas into the process zone of the process chamber to etch the double patterning features to form a solid residue on the substrate, the etching gas comprising hydrogen fluoride, ammonia, and hydrogen; and

(d) sublimating the solid residue by heating the substrate to a temperature of from about 115°

C. to about 200°

C.