Advanced microelectronics manufacturing processes require low single digit to 10ppb dissolved oxygen (DO) concentrations in the ultrapure rinse water to prevent oxidation of wafer films and layers. DO in power plant water and steam must be controlled to ppb levels to minimise corrosion.

Impurities in the rinse water such as high dissolved oxygen content, organic contaminants and gas bubbles can cause defects. Controlling oxide formation on the wafer surface is one of the reasons for reducing residual dissolved oxygen levels. As chip line widths continue to decrease, the quality of the water and the dissolved oxygen content becomes more critical.