Cleaning and drying method and apparatus

• US 6,837,944 B2
• Filed: 03/04/2002
• Issued: 01/04/2005
• Est. Priority Date: 07/25/2001
• Status: Expired due to Term

• Current Assignee: Akrion Technologies Incorporated (Akrion Incorporated)
• Original Assignee: Akrion Incorporated
• Inventors: Ciari, Richard, Novak, Richard E., Chen, Gim-Syang, Kashkoush, Ismail
• Primary Examiner(s): KORNAKOV, MIKHAIL
• Application Number:
  US10/091,011
• Publication Number:
  US 20030019507A1
• Time in Patent Office: 1,037 Days
• Field of Search: 134/26, 134/28, 134/2, 134/3, 134/41, 134/902, 216/96, 216/99, 216/108, 216/109, 510/175, 438/906
• US Class Current: 134/28
• CPC Class Codes: C23C 16/0227 by cleaning or etching
• CPC Class Codes: C30B 23/02 Epitaxial-layer growth
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• CPC Class Codes: H01L 21/02019 Chemical etching
• CPC Class Codes: H01L 21/02052 Wet cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/30604 Chemical etching
• CPC Class Codes: Y10S 438/906 Cleaning of wafer as interim step

Abstract

A method of cleaning semiconductor wafers before the epitaxial deposition comprising (A) etching silicon wafers with HF; (B) rinsing the etched wafers with ozonated ultrapure water; (C) treating the rinsed wafers with dilute SC1; (D) rinsing the treated wafers; (E) treating the wafers with dilute HF; (F) rinsing the wafers with DI water; (G) drying the wafers with nitrogen and a trace amount of IPA; wherein steps (E) through (G) are conducted in a single dryer chamber and wafers are not removed from the chamber between steps. A system comprising a single tank adapted for cleaning, etching, rinsing, and drying the wafers has means to inject HF into a DI water stream.

Claims

1. A method of cleaning semiconductor wafers before the epitaxial deposition step comprising:

(A) etching silicon wafers with HF solution;

(B) rinsing the etched wafers with ultrapure ozonated water;

(C) treating the rinsed wafers with dilute SC1 solution having ammonium hydroxide content at about 1.5% or less by weight;

(D) rinsing the treated wafers;

(E) treating the wafers with dilute HF solution;

(F) rinsing the wafers with DI water;

(G) drying the wafers with nitrogen and a trace amount of IPA;

wherein steps (E) through (G) are conducted in a single dryer chamber and wafers are not removed from the chamber between steps.

2. Method of claim 1 wherein the HF solution in step (A) is a solution of 0.5 to 5% by weight HF in water.

3. Method of claim 1 wherein the dilute HF solution in step (E) is a solution of 0.05 to 0.25% by weight HF in water.

4. Method of claim 1 wherein the dilute SC1 solution is a solution of 0.1 to 0.5% by weight ammonium hydroxide and about 0.1 to 1% by weight hydrogen peroxide.

5. Method of claim 1 wherein the ozonated water in the rinse of step (B) comprises less than about 10 part per million (ppm) ozone in water.

6. Method of claim 1 wherein dissolved oxygen (DO2) is controlled at less than 1 part per billion (ppb) in water.

7. Method of claim 1 wherein total organic carbon (TOC) is less than about 1 ppb in water.

8. Method of claim 1 wherein total dissolved silica is less than about 1 ppb in water.