Method for processing the surface of a workpiece

• US 20030205254A1
• Filed: 04/21/2003
• Published: 11/06/2003
• Est. Priority Date: 05/09/1997
• Status: Active Grant

• Current Assignee: OEM Group, LLC
• Original Assignee: Semitool Incorporated (Applied Materials Incorporated)
• Inventors: Hess, Mignon P., Bergman, Eric J.
• Granted Patent: US 6,817,370 B2
• Time in Patent Office: Days
• US Class Current: 134/100.1
• CPC Class Codes: B08B 2203/005 the liquid being ozonated
• CPC Class Codes: B08B 2230/01 Cleaning with steam
• CPC Class Codes: B08B 3/02 Cleaning by the force of jets or sprays
• CPC Class Codes: B08B 3/08 the liquid having chemical or dissolving effect substances used, see the relevant classes
• CPC Class Codes: B08B 7/00 Cleaning by methods not provided for in a single other subclass or a single group in this subclass
• CPC Class Codes: H01L 21/02052 Wet cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/02054 combining dry and wet cleaning steps H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/6704 for wet cleaning or washing
• CPC Class Codes: Y10S 134/902 Semiconductor wafer

Abstract

An apparatus for supplying a mixture of a treatment liquid and ozone for treatment of a surface of a workpiece, and a corresponding method are set forth. The preferred embodiment of the apparatus comprises a liquid supply line that is used to provide fluid communication between a reservoir containing the treatment liquid and a treatment chamber housing the workpiece. A heater is disposed to heat the workpiece, either directly or indirectly. Preferably, the workpiece is heated by heating the treatment liquid that is supplied to the workpiece. One or more nozzles accept the treatment liquid from the liquid supply line and spray it onto the surface of the workpiece while an ozone generator provides ozone into an environment containing the workpiece.

Claims

1. A method for treating a workpiece, comprising the steps of:

loading the workpiece into a chamber;

supplying steam into the chamber;

allowing at least some of the steam to condense as a liquid on a surface of the workpiece, to form a layer of liquid on the workpiece; and

introducing ozone gas into the chamber.

2. The method of claim 1 wherein the ozone gas diffuses through the layer of liquid and reacts at the surface of the workpiece.

3. The method of claim 1 wherein the steam supplied into the chamber comprises saturated steam.

4. The method of claim 1 further comprising the step of pressurizing the chamber before the step of supplying steam into the chamber.

5. The method of claim 1 further comprising the step of rotating the workpiece to control a thickness of the layer of liquid.

6. The method of claim 1 wherein the step of supplying steam into the chamber comprises spraying the steam into the chamber.

7. The method of claim 1 wherein the steam heats the surface of the workpiece to a temperature greater than 100°

C.

8. The method of claim 1 further comprising the step of mixing the steam and the ozone before supplying them into the chamber.

9. The method of claim 1 further comprising the step of adding a surfactant to the steam before supplying the steam into the chamber.

10. The method of claim 1 further comprising the step of adding at least one of ammonium hydroxide, an acid hydroxide, sulfuric acid, hydrochloric acid, and hydroflouric acid to the steam before supplying the steam into the chamber.

11. The method of claim 1 further comprising the step of irradiating the workpiece with ultraviolet light to enhance the reaction of ozone at the surface of the workpiece.

12. The method of claim 1 further comprising the steps of rinsing and drying the workpiece.

13. A method for treating a workpiece, comprising the steps of:

placing the workpiece into a chamber;

introducing steam into the chamber;

heating the workpiece with the steam;

allowing steam to condense on a surface of the workpiece to form a heated liquid boundary layer on the surface of the workpiece;

introducing ozone gas into the chamber;

diffusing the ozone gas through the heated liquid boundary layer; and

reacting the ozone at the surface of the workpiece.

14. The method of claim 13 wherein the steam is introduced into the chamber at a temperature greater than 125°

C.

15. The method of claim 13 wherein the chamber is pressurized to at least 35 psia.

16. The method of claim 13 wherein the steam heats the surface of the workpiece to a temperature greater than 100°

C.

17. The method of claim 13 further comprising the step of mixing the steam and the ozone before introducing them into the chamber.

18. The method of claim 13 further comprising the step of rotating the workpiece to control a thickness of the heated liquid boundary layer.

19. A method for processing a workpiece to remove material from a surface of the workpiece, comprising the steps of:

condensing steam on the workpiece surface that is to be treated to form a liquid boundary layer that allows diffusion of ozone therethrough for reaction with the material at a liquid-solid interface between the liquid boundary layer and the material, with the steam assisting in maintaining the workpiece at an elevated temperature; and

introducing gaseous ozone to the environment around the workpiece under conditions in which the ozone diffuses through the boundary layer and reacts with the material.

20. The method of claim 19 further including the step of rotating the workpiece to assist in forming the liquid boundary layer.

21. The method of claim 19 further including the step spraying the steam towards the workpiece surface.

22. The method of claim 19 wherein the ozone gas reacts with the material, and causes removal of the material at a rate of at least 2500 angstroms per minute.

23. The method of claim 19 further including the step of providing H2SO4, HF, HCl, or NH4OH into the liquid boundary layer.