Method for removing contamination from a substrate and for making a cleaning solution

• US 7,737,097 B2
• Filed: 02/03/2006
• Issued: 06/15/2010
• Est. Priority Date: 06/27/2003
• Status: Expired due to Fees

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Ravkin, Michael, Korolik, Mikhail, de Larios, John M., Redeker, Fred C., Mikhaylichenko, Katrina, Freer, Erik M.
• Primary Examiner(s): Webb; Gregory E
• Application Number:
  US11/346,894
• Publication Number:
  US 20060128590A1
• Time in Patent Office: 1,593 Days
• Field of Search: 510/175, 510/417
• 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 9/00 Compositions of detergents based essentially on soap compositions containing resin soap C11D15/04
• CPC Class Codes: C11D 9/02 on alkali or ammonium soaps
• CPC Class Codes: C11D 9/267 containing free fatty acids
• CPC Class Codes: C23G 1/18 Organic inhibitors
• CPC Class Codes: G03F 7/42 Stripping or agents therefor
• CPC Class Codes: H01L 21/02052 Wet cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/02057 Cleaning during device manufacture
• CPC Class Codes: H01L 21/02096 only mechanical cleaning

Abstract

A method is provided for removing contamination from a substrate. The method includes applying a cleaning solution having a dispersed phase, a continuous phase and particles dispersed within the continuous phase to a surface of the substrate. The method includes forcing one of the particles dispersed within the continuous phase proximate to one of the surface contaminants. The forcing is sufficient to overcome any repulsive forces between the particles and the surface contaminants so that the one of the particles and the one of the surface contaminants are engaged. The method also includes removing the engaged particle and surface contaminant from the surface of the substrate. A process to manufacture the cleaning material is also provided.

Claims

1. A cleaning solution for cleaning a semiconductor substrate, the cleaning solution 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 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;

wherein the cleaning solution is prepared by a process consisting essentially of;

adding a fatty acid to water;

heating the fatty acid/water solution to a temperature above a melting point temperature of the fatty acid;

stirring the mixture to one of disperse or emulsify the fatty acid within the solution;

ionizing the fatty acid within the solution while adjusting a pH of the solution to about 10.2; and

cooling the ionized fatty acid solution below the melting point temperature of the fatty acid.

2. The cleaning solution of claim 1, further comprising:

solidifying the ionized fatty acid.

3. The cleaning solution of claim 2, wherein the solidifying occurs over a 10 hour period.

4. The cleaning solution of claim 2, wherein the ionizing the fatty acid within the solution includes,

adding a base to the one of dispersed or emulsified solution.

5. The cleaning solution of claim 1, wherein the cleaning solution includes about 0.1% to about 10% by weight of the fatty acid.

6. The cleaning solution of claim 1, wherein the fatty acid is stearic acid and the melting point temperature is 70 degrees Celsius.

7. The cleaning solution of claim 2, wherein the solidifying the ionized fatty acid includes,

forming solid particles having a size between about 50 nanometers and about 5000 micrometers.

8. A cleaning solution for cleaning a substrate, the cleaning solution 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 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;

wherein the cleaning solution is prepared by a process consisting essentially of;

preparing a particle size distribution of a fatty acid to within a specified particle size distribution range;

adding the fatty acid to water;

agitating the fatty acid water mixture; and

ionizing the fatty acid in the dispersed solution while adjusting a pH of the solution to about 10.2.

9. The cleaning solution of claim 8, wherein the preparing a particle size distribution of a fatty acid to within a specified particle size distribution range includes,

milling the fatty acid.

10. The cleaning solution of claim 8, wherein the specified particle size distribution is between about 50 nanometers and about 5000 micrometers.

11. The cleaning solution of claim 8, wherein the adding the fatty acid to water includes,

melting the fatty acid.

12. The cleaning solution of claim 11, further comprising:

cooling the fatty acid in the dispersed solution to ambient temperature.

13. The cleaning solution of claim 8, further comprising:

solidifying the fatty acid over a 10 hour period.

14. The cleaning solution of claim 8, wherein the ionizing the dispersed fatty acid in the solution includes,

adding a base to the fatty acid/water solution.

15. The cleaning solution of claim 8, wherein the cleaning solution includes about 0.1% to about 10% by weight of the fatty acid.

16. The cleaning solution of claim 8, wherein the fatty acid is one of a saturated fatty acid or an unsaturated fatty acid.

17. The cleaning solution of claim 8, wherein the fatty acid is selected form a 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 solution of claim 13, wherein the base is selected from a group consisting of ammonium hydroxide (NH₄OH), sodium hydroxide (NaOH), potassium hydroxide (KOH), and tetramethyl ammonium hydroxide (TMAH).

19. The cleaning solution of claim 8, wherein the ionizing the fatty acid in the dispersed solution includes,

adjusting a pH of the dispersed solution to correspond to an ionization constant representative of above about 50% dissociation.

20. The cleaning solution of claim 19, wherein the fatty acid is stearic acid.

21. The cleaning solution of claim 8, further comprising:

adding dispersant molecules to the fatty-acid water mixture to suspend the fatty acid particles in the water.

22. A cleaning solution for cleaning a substrate, the cleaning solution 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 about 10.2;

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;

wherein the cleaning solution is prepared by a process consisting essentially of;

preparing a particle size distribution of a fatty acid to within a specified particle size distribution range;

adding the fatty acid to water;

agitating the fatty acid water mixture; and

ionizing the fatty acid in the dispersed solution at a pH corresponding to an ionization constant representative of above about 50% dissociation.