| 摘要 |
PURPOSE: To wash off metal ions deposited to a Si oxide film of a semiconductor wafer to thereby prevent the metal ions from being readsorbed to the wafer after washing by using a washing liq. contg. a chelating agent and neutral ligand added to a water soln. contg. ammonium hydroxide and hydrogen peroxide. CONSTITUTION: To wash before oxidation, a semiconductor wafer to be washed is set in a washer and washing of the wafer is started. A washing liq. in a washing vessel uses a water soln. of ammonium hydroxide and hydrogen peroxide plus a chelating agent and neutral ligand added thereto. Thereby metal ions such as Mg ions can be surely removed and readsorption can be avoided to prevent the reduction of the reliability of an oxide film and the occurrence of defects such as increase of the leakage due to the degradation of the junction withstanding voltage and the metal ions deposited to the Si oxide film can be washed off. |
