Claims
- 1. A cleaning solution formed by mixing an amount of citric acid and an amount of ammonia in deionized water, the amount of citric acid being in a range from about 0.18% by weight to about 0.22% by weight, the amount of ammonia being in a range from about 0.0225% by weight to about 0.0275% by weight, and the cleaning solution having a pH of about 4.
- 2. The cleaning solution of claim 1, wherein a source of ammonia is a solution formed by mixing ammonia in deionized water.
- 3. The cleaning solution of claim 2, wherein the amount of citric acid is about 0.2% by weight and the amount of ammonia is about 0.025% by weight.
- 4. A concentrated cleaning solution for cleaning semiconductor substrates, the concentrated cleaning solution being formed by mixing an amount of citric acid and an amount of ammonia in deionized water, the amount of citric acid being in a range from about 3.6% by weight to about 4.4% by weight, the amount of ammonia being in a range from about 0.45% by weight to about 0.55% by weight, and the concentrated cleaning solution having a pH of about 3.8.
- 5. The concentrated cleaning solution of claim 4, wherein a source of ammonia is a solution formed by mixing ammonia in deionized water.
- 6. The concentrated cleaning solution of claim 5, wherein the amount of citric acid is about 4% by weight and the amount of ammonia is about 0.5% by weight.
- 7. A method for cleaning a semiconductor substrate having a polished copper layer comprising:
providing a concentrated cleaning solution formed by mixing an amount of citric acid and an amount of ammonia in deionized water, the amount of citric acid being in a range from about 3.6% by weight to about 4.4% by weight, the amount of ammonia being in a range from about 0.45% by weight to about 0.55% by weight, and the concentrated cleaning solution having a pH of about 3.8; placing the semiconductor substrate having a polished copper layer in a scrubbing apparatus; mixing one unit volume of the concentrated cleaning solution with 20 unit volumes of deionized water proximate to the scrubbing apparatus to obtain a cleaning solution having a pH of about 4; and scrubbing the semiconductor substrate in the scrubbing apparatus in the presence of the cleaning solution.
Parent Case Info
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 09/227,494, entitled “Methods and Apparatus for Cleaning Semiconductor Substrates After Polishing of Copper Film,” filed Jan. 7, 1999, which is a continuation-in-part of U.S. patent application Ser. No. 08/955,393, entitled “Methods and Apparatus for Cleaning Semiconductor Substrates after Polishing of Copper Film,” filed Oct. 21, 1997. The disclosures of these priority applications are incorporated herein by reference.
Continuations (1)
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Number |
Date |
Country |
Parent |
09568793 |
May 2000 |
US |
Child |
09945110 |
Aug 2001 |
US |
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
09227494 |
Jan 1999 |
US |
Child |
09568793 |
May 2000 |
US |
Parent |
08955393 |
Oct 1997 |
US |
Child |
09227494 |
Jan 1999 |
US |