Processes for removing residue from a workpiece

• US 20050233589A1
• Filed: 06/14/2005
• Published: 10/20/2005
• Est. Priority Date: 03/13/1998
• Status: Abandoned Application

• Current Assignee: Brian K. Aegerter, Curt T. Dundas, Gary L. Curtis, Michael Jolley, Tom L. Ritzdorf
• Original Assignee: Brian K. Aegerter, Curt T. Dundas, Gary L. Curtis, Michael Jolley, Tom L. Ritzdorf
• Inventors: Curtis, Gary L., Dundas, Curt T., Jolley, Michael, Ritzdorf, Tom L., Aegerter, Brian K.
• Application Number:
  US11/151,896
• Publication Number:
  US 20050233589A1
• Time in Patent Office: Days
• US Class Current: 438/704
• CPC Class Codes: H01L 21/31111 by chemical means
• CPC Class Codes: H01L 21/32134 by liquid etching only
• CPC Class Codes: H01L 21/67051 using mainly spraying means, e.g. nozzles
• CPC Class Codes: H01L 21/6708 using mainly spraying means, e.g. nozzles

Abstract

In a process for removing etch residue, liquid including an acid and an oxidizer is applied to the back side and peripheral edge of a wafer. The front or device side of the wafer is left unprocessed, or may be exposed to an inert fluid such as a purge gas (e.g., nitrogen or helium), to a rinse such as deionized water, or to another processing fluid such as a more highly diluted etchant. The front side of the wafer is either left unprocessed, or is processed to a lesser degree without damage to the underlying devices, metal interconnects or semiconductor layers.

Claims

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

dry plasma etching a front side of the semiconductor wafer, with the dry plasma etching leaving a residue on a back side of the wafer;

removing the residue from the back side of the wafer by;

spinning the wafer;

applying a liquid to the back side of the spinning wafer, with the liquid comprising de-ionized water, an acid and an oxidizer.

2. The method of claim 1 wherein the acid comprises HF and the oxidizer comprises dissolved ozone.

3. The method of claim 1 further including the step of applying the liquid to the edge of wafer, to remove residue from the edge.

4. The method of claim 1 further including the step of applying a fluid to the front side of the wafer.

5. The method of claim 4 with the fluid comprising a non-reactive liquid or gas.

6. The method of claim 1 with the liquid applied to the back side of the wafer adjacent to the edge of the wafer.

7. The method of claim 1 with the liquid applied to the back side of the wafer adjacent to a central location on the wafer.

8. The method of claim 1 wherein the liquid is sprayed onto the wafer.

9. The method of claim 1 wherein the liquid is at ambient temperature.

10. The method of claim 1 further comprising holding the wafer within a spinning processing chamber.

11. The method of claim 10 further comprising introducing the liquid into the processing chamber and draining the liquid from one or more outlets in a side wall of the processing chamber.

12. The method of claim 1 wherein the back side of the wafer is downfacing.

13. The method of claim 1 wherein the residue is removed from the back side without damaging the front side of the wafer.

14. The method of claim 5 wherein the non reactive fluid comprises a purge gas or DI.

15. The method of claim 1 with the liquid provided onto the wafer so that the liquid contacts substantially only the back surface of the wafer and the edge of the wafer.

16. The method of claim 1 further comprising applying the liquid to substantially the entire back side.

17. The method of claim 1 further comprising applying the liquid onto the workpiece via a moving nozzle.

18. A method for removing an etch residue from a back side of a workpiece, comprising:

spinning the wafer;

applying a liquid to the back side of the spinning wafer, with the liquid comprising de-ionized water, HF and dissolved ozone; and

preventing the liquid from substantially contacting the front side of the wafer.

19. A method for removing a dry plasma etch residue from a back surface and an edge of a workpiece comprising:

spinning the workpiece;

applying a liquid to the back side of the spinning workpiece, with the liquid comprising de-ionized water, hydrofluoric acid, and dissolved ozone; and

removing the liquid from the spinning workpiece via centrifugal force, without having the liquid substantially contact the front side of the workpiece.

20. The method of claim 19 with the liquid applied on to the workpiece adjacent to an edge of the workpiece.