Organic residues left on the device can have negative effect on the wafer quality and impact wafer yield. The organics can also be a source of food for bacteria in the ultrapure water system. Due to the quality requirements of semiconductor water, TOC must be monitored at the parts per billion level. Continuous, on-line TOC analyzers play an important role in the monitoring of water systems to help provided a reliable indication of system health. See also Dissolved organic carbon References Carbon Soil tests Water pollution Water quality indicators