Cleaning compound and method and system for using the cleaning compound

• US 7,696,141 B2
• Filed: 02/03/2006
• Issued: 04/13/2010
• Est. Priority Date: 06/27/2003
• Status: Expired due to Fees

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Korolik, Mikhail, de Larios, John M., Redeker, Fred C., Mikhaylichenko, Katrina, Freer, Erik M., Ravkin, Michael
• Primary Examiner(s): Webb; Gregory E
• Application Number:
  US11/347,154
• Publication Number:
  US 20060128600A1
• Time in Patent Office: 1,530 Days
• Field of Search: 510/175, 134/1.3
• US Class Current: 510/175
• CPC Class Codes: B08B 7/02 by distortion, beating, or vibration of the surface to be cleaned B08B7/0007 takes precedence
• CPC Class Codes: C11D 17/0013 Liquid compositions with insoluble particles in suspension C11D17/0021, C11D17/0026, C11D17/003 take precedence
• CPC Class Codes: C11D 17/0017 Multi-phase liquid compositions
• CPC Class Codes: C11D 2111/22 Electronic devices, e.g. PCBs or semiconductors
• CPC Class Codes: C11D 3/2079 Monocarboxylic acids-salts thereof
• CPC Class Codes: C11D 9/02 on alkali or ammonium soaps
• CPC Class Codes: C11D 9/26 containing oxygen C11D9/225 takes precedence
• CPC Class Codes: C11D 9/267 containing free fatty acids
• CPC Class Codes: C23G 1/18 Organic inhibitors
• CPC Class Codes: G03F 7/425 containing mineral alkaline compounds; containing organic basic compounds, e.g. quaternary ammonium compounds; containing heterocyclic basic compounds containing nitrogen
• CPC Class Codes: G03F 7/426 containing organic halogen compounds; containing organic sulfonic acids or salts thereof; containing sulfoxides
• CPC Class Codes: H01L 21/02052 Wet cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H05K 3/26 Cleaning or polishing of the conductive pattern

Abstract

A cleaning compound is provided. The cleaning compound includes about 0.1 weight percent to about 10 weight percent of a fatty acid dispersed in water. The cleaning compound includes an amount of a base sufficient to bring a pH of the fatty acid water solution to about a level where above about 50% of the dispersed fatty acid is ionized. A method for cleaning a substrate, a system for cleaning a substrate, and a cleaning solution prepared by a process are also provided.

Claims

1. A cleaning compound, comprising:

about 0.5 weight percent to about 10 weight percent of a fatty acid dispersed in water;

an amount of a base sufficient to bring a pH of the fatty acid water solution to 10.2 or greater to a level where about 50% of the dispersed fatty acid is ionized;

a first immiscible component in a liquid phase dispersed in the water; and

a second immiscible component in a gas phase dispersed in the water.

2. The cleaning compound of claim 1 wherein the fatty acid is stearic acid.

3. The cleaning compound of claim 1, wherein the fatty acid is selected from the group consisting of lauric, palmitic, stearic, oleic, linoleic, linolenic, arachidonic, gadoleic, eurcic, butyric, caproic, caprylic, myristic, margaric, behenic, lignoseric, myristoleic, palmitoleic, nervanic, parinaric, timnodonic, brassic, clupanodonic acid and mixtures thereof.

4. The cleaning compound of claim 1, wherein the fatty acid has a particle size distribution between about 50 nanometers and 5000 micrometers.

5. The cleaning compound of claim 1, wherein an acid moiety of the fatty acid is selected from a group consisting of carbonic, sulfonic, and phosphonic moieties.

6. The cleaning compound of claim 1, wherein the fatty acid is melted prior to being added to the water.

7. The cleaning compound of claim 1, further comprising:

about 0.1 weight percent to about 10 weight percent of another fatty acid dispersed in the water.

25. The cleaning compound of claim 1, wherein the second immiscible component is an inert gas.

26. The cleaning compound of claim 1, wherein the second immiscible component is a reactive gas.

27. The cleaning compound of claim 1, wherein the first immiscible component is an alkane.

28. The cleaning compound of claim 1, wherein the first immiscible component is an oil soluble surface modifier.

8. A cleaning solution for cleaning a substrate prepared by a process comprising method operations of:

adding a fatty acid to isopropanol while agitating to achieve a dissolved fatty acid concentration between about 2% and about 20% by weight;

removing any undissolved solids from the isopropanol solution;

mixing the isopropanol solution with water to precipitate the dissolved fatty acid;

ionizing the dissolved fatty acid; and

dispersing a first immiscible component in a liquid phase in the water; and

dispersing a second immiscible component in a gas phase in the water.

9. The cleaning solution of claim 8, wherein the fatty acid is a mixture of stearic acid and palmitic acid.

10. The cleaning solution of claim 8, wherein the method operation of removing any undissolved solids from the isopropanol solution includes,

filtering the isopropanol solution.

11. The cleaning solution of claim 8, wherein the method operation of ionizing the dissolved fatty acid includes,

adding a base to the isopropanol solution after mixing the isopropanol solution with water.

12. The cleaning solution of claim 8, wherein the method operation of ionizing the dissolved fatty acid includes,

adding a base to the isopropanol solution to bring a pH of the isopranol solution to 10.2 or greater after mixing the isopropanol solution with water.

13. The cleaning solution of claim 12, wherein the base is NH₄OH and a concentration of the NH₄OH is between about 0.25% and about 10% by weight.

14. A cleaning compound for cleaning a semiconductor substrate, consisting essentially of:

about 0.5 weight percent to about 10 weight percent of a fatty acid dispersed in water;

an amount of a base sufficient to bring a pH of the fatty acid water solution to above a level where about 50% of the dispersed fatty acid is ionized;

a first immiscible component in a liquid phase dispersed in the water; and

a second immiscible component in a gas phase dispersed in the water.

15. The cleaning compound of claim 14 wherein the fatty acid is stearic acid.

16. The cleaning compound of claim 14, wherein the pH is about 10.2.

17. The cleaning compound of claim 14, wherein the fatty acid is selected from the group consisting of lauric, palmitic, stearic, oleic, linoleic, linolenic, arachidonic, gadoleic, eurcic, butyric, caproic, caprylic, myristic, margaric, behenic, lignoseric, myristoleic, palmitoleic, nervanic, parinaric, timnodonic, brassic, clupanodonic acid and mixtures thereof.

18. The cleaning compound of claim 14, wherein the fatty acid has a particle size distribution between about 50 nanometers and 5000 micrometers.

19. The cleaning compound of claim 14, wherein an acid moiety of the fatty acid is selected from a group consisting of carbonic, sulfonic, and phosphonic moieties.

20. The cleaning compound of claim 14, wherein the cleaning compound further includes about 0.1 weight percent to about 10 weight percent of another fatty acid dispersed in the water.

21. The cleaning compound of claim 14, wherein the fatty acid is melted prior to being added to the water.

23. The cleaning compound of claim 14 wherein the fatty acid is stearic acid.

24. The cleaning compound of claim 14, wherein the pH is about 10.2.

22. A cleaning compound for cleaning a semiconductor substrate, consisting of:

about 0.5 weight percent to about 10 weight percent of a fatty acid dispersed in water;

an amount of a base sufficient to bring a pH of the fatty acid water solution to above a level where about 50% of the dispersed fatty acid is ionized;

a first immiscible component in a liquid phase dispersed in the water; and

a second immiscible component in a gas phase dispersed in the water.