Method for washing wafer and apparatus used therefor
AssigneeNEC Electronics Corporation
InventorTatsuya Suzuki
Life of this patent
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Abstract
A method including the consecutive steps of: dipping a wafer in a washing solution in a washing chamber; replacing the washing solution by a first chemical solution in the washing chamber receiving therein the wafer, the first chemical solution including at least one chemical; dipping the wafer in the first chemical solution after stopping the replacing; and replacing the first chemical solution by a second chemical solution including the at least one chemical and having a concentration lower than a concentration of said first chemical solution. The number of the particles remaining on the wafer is significantly reduced compared with a conventional method to improve the removing rate of the particles deposited onto the wafer.
Claims6
A method for washing a wafer comprising the sequential steps of:
- providing a washing chamber having a washing solution;
- dipping the wafer in the washing solution in the washing chamber;
- replacing the washing solution by a first chemical solution comprising ammonia (NH4OH) and hydrogen peroxide (H2O2) as chemicals and water in a volume ratio between the chemicals and the water of 2:X1, wherein 20≦X1≦70;
- treating the wafer with the first chemical solution;
- and
- treating the wafer by replacing the first chemical solution with a second chemical solution comprising the ammonia and hydrogen peroxide as chemicals and water in a volume ratio between the chemicals and the water of 2:X2, wherein 80≦X2≦150, said second chemical solution having a concentration lower than a concentration of said first chemical solution.
Dependencies are inferred from the claim text.