PROCESS FOR CLEANING A SEMICONDUCTOR WAFER

• US 20090071507A1
• Filed: 08/27/2008
• Published: 03/19/2009
• Est. Priority Date: 09/19/2007
• Status: Abandoned Application

• Current Assignee: Siltronic AG (Dr. Alexander Wacker Familiengesellschaft Mit Beschrã¤Nkter Haftung)
• Original Assignee: Siltronic AG (Dr. Alexander Wacker Familiengesellschaft Mit Beschrã¤Nkter Haftung)
• Inventors: Buschhardt, Thomas, Feijoo, Diego, Zapilko, Clemens, Schwab, Guenter
• Application Number:
  US12/199,124
• Publication Number:
  US 20090071507A1
• Time in Patent Office: Days
• US Class Current: 134/3
• CPC Class Codes: C11D 2111/22 Electronic devices, e.g. PCBs or semiconductors
• CPC Class Codes: C11D 7/02 Inorganic compounds
• CPC Class Codes: C11D 7/08 Acids
• CPC Class Codes: H01L 21/02052 Wet cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/02057 Cleaning during device manufacture

Abstract

Semiconductor wafers are cleaned by forming a first liquid film on a surface of the semiconductor wafer to be cleaned, the first liquid film containing hydrogen fluoride and ozone; replacing the first liquid film with a second aqueous liquid film which contains hydrogen fluoride and ozone, the concentration of hydrogen fluoride in the second liquid film being lower than in the first liquid film; and removing the second liquid film.

Claims

1. A process for cleaning a semiconductor wafer surface, comprising forming a first aqueous liquid film on the surface, the first liquid film containing hydrogen fluoride and ozone;

replacing the first liquid film with a second aqueous liquid film which contains hydrogen fluoride and ozone, the concentration of hydrogen fluoride in the second liquid film being lower than in the first liquid film; and

removing the second liquid film.

2. The process of claim 1, wherein no more than 120 s elapse from formation of the first liquid film until removal of the second liquid film.

3. The process of claim 1, wherein no more than 60 s elapse from formation of the first liquid film until replacement of the first liquid film with the second liquid film.

4. The process of claim 1, wherein the concentration of hydrogen fluoride in the first liquid film is from 0.1 to 10 wt %.

5. The process of claim 2, wherein the concentration of hydrogen fluoride in the first liquid film is from 0.1 to 10 wt %.

6. The process of claim 1, wherein the concentration of hydrogen fluoride in the second liquid film is from 0.001 to 0.1 wt %.

7. The process of claim 2, wherein the concentration of hydrogen fluoride in the second liquid film is from 0.001 to 0.1 wt %.

8. The process of claim 4, wherein the concentration of hydrogen fluoride in the second liquid film is from 0.001 to 0.1 wt %.

9. The process of claim 1, wherein the first liquid film is replaced with the second liquid film through displacement of the first liquid film by the second liquid film, and the surface remains constantly wetted with liquid during the replacement.

10. The process of claim 1, wherein the semiconductor wafer is rotated with a rotational speed in the range of from 100 to 2000 rpm during cleaning.

11. The process of claim 1, wherein the first or second liquid film, or both liquid films, contain HCl in a concentration of from 0.2 to 2.0 wt %.

12. The process of claim 2, wherein the first or second liquid film, or both liquid films, contain HCl in a concentration of from 0.2 to 2.0 wt %.

13. The process of claim 4, wherein the first or second liquid film, or both liquid films, contain HCl in a concentration of from 0.2 to 2.0 wt %.

14. The process of claim 6, wherein the first or second liquid film, or both liquid films, contain HCl in a concentration of from 0.2 to 2.0 wt %.

15. The process of claim 1, wherein the second liquid film is displaced by ultrapure water, ultrapure water containing ozone, SC1 solution or dilute hydrochloric acid.