摘要 |
A method for cleaning a semiconductor wafer which includes the sequential steps of cleaning the wafer in a dilute hydrofluoric acid bath, cleaning the wafer in a first ozone bath, cleaning the wafer in a dilute hydrofluoric acid/hydrogen peroxide/hydrogen chloride bath, followed by cleaning the wafer in a second ozone bath. The method uses the dilute hydrofluoric acid/hydrogen peroxide/hydrochloric acid bath instead of the conventional DHF bath and RCA2 bath. Hence, the amount of chemicals consumed and the number of baths used by the cleaning station are lowered. In addition, ozone is passed into an overflow loath so that the highly reactive ozone can be utilized to clean the wafer without putting additional load on the cleaning station. Therefore, the cleaning operation can be carried out in a smaller cleaning station using somewhat lower temperature and lower concentration chemical solutions. The efficiency is as high as a multi-bath station, but chemicals are not wasted. Furthermore, the throughput is high and stable without causing too many safety and environmental problems.
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