Method for post-etch and strip residue removal on coral films

• US 6,949,411 B1
• Filed: 12/27/2001
• Issued: 09/27/2005
• Est. Priority Date: 12/27/2001
• Status: Expired due to Fees

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Mikhaylichenko, Katrina, deLarios, John, Ravkin, Michael
• Primary Examiner(s): Coleman, W. David
• Assistant Examiner(s): NGUYEN, KHIEM D
• Application Number:
  US10/033,644
• Time in Patent Office: 1,370 Days
• Field of Search: 438/626, 438/633, 438/638, 438/710, 438/906, 438/FOR.389, 438/115, 438/691, 438/692, 438/700, 438/782, 430/134, 430/331
• US Class Current: 438/115
• CPC Class Codes: H01L 21/02063 the processing being the formation of vias or contact holes
• CPC Class Codes: H01L 21/67046 using mainly scrubbing means, e.g. brushes
• CPC Class Codes: H01L 21/76814 post-treatment or after-treatment, e.g. cleaning or removal of oxides on underlying conductors
• CPC Class Codes: Y10S 438/906 Cleaning of wafer as interim step

Abstract

A method for cleaning a semiconductor wafer is provided which includes plasma etching a feature into a low K dielectric layer having a photoresist mask where the plasma etching generates etch residues. The method also includes ashing the semiconductor wafer to remove the photoresist mask where the ashing generating ashing residues. The method further includes removing the etching residues and the ashing residues from the low K dielectric layer where the removing is enhanced by scrubbing the low K dielectric layer of the semiconductor wafer with a wet brush that applies a fluid mixture including a cleaning chemistry and a wetting agent.

Claims

1. A method for cleaning a semiconductor wafer, comprising:

plasma etching a feature into a low K dielectric layer having a photoresist mask, the plasma etching generating etch residues;

ashing the semiconductor wafer to remove the photoresist mask, the ashing generating ashing residues; and

removing the etching residues and the ashing residues from the low K dielectric layer having the plasma etched feature, the removing being enhanced by scrubbing the low K dielectric layer of the semiconductor wafer with a wet brush that applies a fluid mixture including a cleaning chemistry and a wetting agent.

2. A method for cleaning a semiconductor wafer as recited in claim 1, wherein the wetting agent is a surfactant and the cleaning chemistry includes a combination of NH₄OH, H₂O₂, and deionized (DI) water.

3. A method for cleaning a semiconductor wafer as recited in claim 2, wherein the surfactant is selected from a group comprising fluorosurfactants and hydrocarbon surfactants.

4. A method for cleaning a semiconductor wafer as recited in claim 3, wherein the surfactant has a concentration between about 0.005 percent by weight to about 0.1 percent by weight.

5. A method for cleaning a semiconductor wafer as recited in claim 3, wherein the surfactant has a concentration of about 0.01 percent by weight.

6. A method for cleaning a semiconductor wafer as recited in claim 2, wherein the combination ratio of NH₄OH, H₂O₂, and DI water is between about 1:

4;

10 and about 1;

4;

30.

7. A method for cleaning a semiconductor wafer as recited in claim 6, wherein the combination ratio of NH₄OH, H₂O₂, and DI water is about 1:

4;

20.

8. A method for cleaning a semiconductor wafer as recited in claim 1, further comprising:

scrubbing the low K dielectric layer using the brush while applying deionized (DI) water after removing the etching residues and the ashing residues.

9. A method for cleaning a semiconductor wafer, comprising:

plasma etching a feature into a low K dielectric layer, the plasma etching generating etch residues in and around the feature;

subjecting the semiconductor wafer to an ashing operation, the ashing operation generating ashing residues; and

scrubbing the low K dielectric layer having the plasma etched feature, using a mixture fluid including a cleaning chemistry and a wetting agent, the wetting agent being configured to condition the low K dielectric layer to facilitate cleaning of the etch residues and the ashing residues with the cleaning chemistry.

10. A method for cleaning a semiconductor wafer as recited in claim 9, further comprising:

scrubbing the low K dielectric layer using the brush while applying deionized (DI) water after removing the etching residues and the ashing residues.

11. A method for cleaning a semiconductor wafer as recited in claim 9, wherein the wetting agent is a surfactant and the cleaning chemistry includes a combination of NH₄OH, H₂O₂, and deionized (DI) water.

12. A method for cleaning a semiconductor wafer as recited in claim 11, wherein the surfactant is selected from a group comprising fluorinated surfactants and hydrocarbon surfactants.

13. A method for cleaning a semiconductor wafer as recited in claim 11, wherein the surfactant has a concentration between about 0.005 percent by weight to about 0.1 percent by weight.

14. A method for cleaning a semiconductor wafer as recited in claim 11, wherein the surfactant has a concentration of about 0.01 percent by weight.

15. A method for cleaning a semiconductor wafer as recited in claim 11, wherein the combination ratio of NH₄OH, H₂O₂, and DI water is between about 1:

4;

10 and about 1;

4;

30.

16. A method for cleaning a semiconductor wafer as recited in claim 11, wherein the combination ratio of NH₄OH, H₂O₂, and DI water is about 1:

4;

20.

17. A method for cleaning a semiconductor wafer, comprising:

plasma etching a feature into a low K dielectric layer, the plasma etching generating etch residues in and around the feature;

subjecting the semiconductor wafer to an ashing operation, the ashing operation generating ashing residues;

scrubbing the low K dielectric layer having the plasma etched feature, using a mixture fluid including a cleaning chemistry and a wetting agent, the wetting agent being configured to condition the low K dielectric layer to facilitate cleaning of the etch residues and the ashing residues with the cleaning chemistry; and

scrubbing the low K dielectric layer having the plasma etched feature, using the brush while applying deionized (DI) water after removing the etching residues and the ashing residues.

18. A method for cleaning a semiconductor wafer as recited in claim 17, wherein the wetting agent is a surfactant and the cleaning chemistry includes a combination of NH₄OH, H₂O₂, and deionized (DI) water.

19. A method for cleaning a semiconductor wafer as recited in claim 17, wherein the surfactant is selected from a group comprising fluorinated surfactants and hydrocarbon surfactants.

20. A method for cleaning a semiconductor wafer as recited in claim 18, wherein the surfactant has a concentration between about 0.005 percent by weight to about 0.1 percent by weight.

21. A method for cleaning a semiconductor wafer as recited in claim 18, wherein the surfactant has a concentration of about 0.01 percent by weight.

22. A method for cleaning a semiconductor wafer as recited in claim 18, wherein the combination ratio of NH₄OH, H₂O₂, and DI water is between about 1:

4;

10 and about 1;

4;

30.

23. A method for cleaning a semiconductor wafer as recited in claim 18, wherein the combination ratio of NH₄OH, H₂O₂, and DI water is about 1:

4;

20.

24. A method for cleaning a semiconductor wafer, comprising:

plasma etching a feature into a low K dielectric layer, the plasma etching generating etch residues in and around the feature;

subjecting the semiconductor wafer to an ashing operation, the ashing operation generating ashing residues;

scrubbing the low K dielectric layer having the plasma etched feature, using a mixture fluid including a cleaning chemistry and a wetting agent, the wetting agent being configured to condition the low K dielectric layer to facilitate cleaning of the etch residues and the ashing residues with the cleaning chemistry, the wetting agent being a surfactant and the cleaning chemistry being a standard clean-1 (SC-1) solution including a combination of NH₄OH, H₂O₂, and deionized (DI) water, the surfactant having a concentration between about 0.005 percent by weight to about 0.1 percent by weight, combination ratio of NH₄OH, H₂O₂, and DI water being between about 1;

4;

10 and about 1;

4;

30; and

scrubbing the low K dielectric layer having the plasma etched feature, using the brush while applying deionized (DI) water after removing the etching residues and the ashing residues.