| 摘要 |
An apparatus and method is described for cleaning semiconductor wafers using a dilute aqueous solution including at least 80% deionized water, sulfuric acid, an oxidant such as hydrogen peroxide, and a small amount of hydrofluoric acid (HF), preferably in the range of about 5 ppm to about 12 ppm. The automated system mixes the water, sulfuric acid, hydrogen peroxide, and HF to form a cleaning solution having a target HF concentration within the preferred range, for example at 8 ppm. Subsequently, the system maintains the HF concentration at least within about 0.5 ppm to about 1 ppm of the target HF concentration. Thus the system allows effective and predictable cleaning of semiconductor wafers while minimizing damage to metal features, and minimizing cost and waste disposal impacts.
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