Process and apparatus for treating a workpiece using ozone

• US 7,264,680 B2
• Filed: 06/03/2004
• Issued: 09/04/2007
• Est. Priority Date: 05/09/1997
• Status: Expired due to Fees

• Current Assignee: OEM Group, LLC
• Original Assignee: Semitool Incorporated (Applied Materials Incorporated)
• Inventors: Bergman, Eric J., Gebhart, Thomas Maximilia
• Primary Examiner(s): KORNAKOV, MIKHAIL
• Application Number:
  US10/859,668
• Publication Number:
  US 20040216763A1
• Time in Patent Office: 1,188 Days
• Field of Search: 134/2, 134/3, 134/19, 134/26, 134/28, 134/30, 134/33, 134/34, 134/36, 134/37, 134/25.4, 134/31, 134/32, 134/42, 438/906
• US Class Current: 134/31
• CPC Class Codes: B08B 2203/005 the liquid being ozonated
• CPC Class Codes: B08B 2203/007 Heating the liquid
• CPC Class Codes: B08B 2230/01 Cleaning with steam
• CPC Class Codes: B08B 3/00 Cleaning by methods involving the use or presence of liquid or steam B08B9/00 takes precedence
• CPC Class Codes: B08B 3/02 Cleaning by the force of jets or sprays
• CPC Class Codes: B08B 3/044 using agitated containers in which the liquid and articles or material are placed by means of ultrasonic vibrations B08B3/12; cleaning casks or barrels by agitating B08B9/0817; mixers with shaking, oscillating or vibrating mechanisms B01F31/00
• 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 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/6704 for wet cleaning or washing
• CPC Class Codes: H01L 21/67051 using mainly spraying means, e.g. nozzles
• CPC Class Codes: H01L 23/49582 Metallic layers on lead frames
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 3/3426 characterised by the leads
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10S 438/906 Cleaning of wafer as interim step

Abstract

A method for cleaning a semiconductor workpiece having a metal layer in a processing chamber includes the steps of introducing a liquid solution including dissolved carbon dioxide onto the workpiece, and introducing ozone into the processing chamber. The ozone oxidizes contaminants on the workpiece, while the carbon dioxide inhibits corrosion of the metal layer. The liquid solution is preferably heated to a temperature greater than 40° C., and preferably comprises deionized water injected with carbon dioxide gas. The workpiece is preferably rotated within the processing chamber during the cleaning process. The ozone may be entrained in the liquid solution before the liquid solution is introduced onto the workpiece, or the ozone may be introduced separately into the processing chamber.

Claims

1. A method for cleaning a semiconductor workpiece having one or more metal areas, comprising the steps of:

placing the semiconductor workpiece into a processing chamber;

spinning the semiconductor workpiece;

introducing an aqueous liquid solution onto the semiconductor workpiece, with the metal areas subject to corrosion by the aqueous liquid solution generating ozone in an ozone gas generator;

introducing the ozone gas into the processing chamber;

introducing carbon dioxide gas into the processing chamber by injecting it downstream the ozone gas generator;

with the ozone gas oxidizing contaminants on the semiconductor workpiece, and the carbon dioxide gas inhibiting corrosion of exposed metal areas by the aqueous liquid solution.

2. The method of claim 1 further comprising heating the aqueous liquid solution to 50-90°

C.

3. The method of claim 1 wherein the ozone is entrained in the liquid solution before the liquid solution is introduced onto the workpiece.

4. The method of claim 1 wherein the liquid solution and the ozone gas are introduced separately into the processing chamber.

5. The method of claim 1 wherein the liquid solution is sprayed onto the workpiece.

6. The method of claim 1 wherein the carbon dioxide gas is dissolved in the liquid solution.

7. A method for cleaning a semiconductor wafer having one or more metal surfaces, comprising:

placing the wafer into a chamber;

rotating the wafer in the chamber;

providing a liquid injected with carbon dioxide gas onto the wafer with the liquid forming a liquid layer on the wafer;

separately and with the metal surfaces subject to corrosion by the liquid;

providing ozone gas into the chamber with the ozone gas diffusing through the liquid layer and reacting with a contaminant on the wafer to clean the wafer; and

with the carbon dioxide gas reducing corrosion of exposed metal surfaces by the liquid.

8. The method of claim 7 further comprising entraining the ozone gas in the liquid provided sprayed onto the wafer.

9. The method of claim 7 with the ozone gas provided into the chamber as a dry gas.

10. The method of claim 7 further comprising injecting the ozone gas into the liquid.

11. A method for cleaning a semiconductor wafer having one or more metal surfaces, comprising:

placing the wafer into a chamber;

rotating the wafer in the chamber;

spraying a liquid including water injected with carbon dioxide gas onto the rotating wafer with the liquid forming a liquid layer on the rotating wafer, separately;

providing ozone gas into the chamber from an ozone generator, with the ozone gas diffusing through the liquid layer and reacting with a contaminant on the wafer to clean the wafer; and

with the carbon dioxide gas reducing corrosion of exposed metal surfaces by the liquid.

12. The method of claim 11 wherein the chamber has a carbon dioxide gas inlet and an ozone gas inlet separate from the carbon dioxide gas inlet, and wherein the carbon dioxide gas is provided into the chamber through the carbon dioxide gas inlet separately from the ozone gas.

13. The method of claim 11 wherein the ozone gas is separately provided into the chamber as a dry gas.