Water usage reduction in a semiconductor fabricator

Semiconductor fabricators use immense amounts of water, a large portion of which is used to produce Ultra Pure Water (UPW) also referred to as DI (Deionized) water. Approximately 1500 gallons of city water are required to produce 1000 gallons of UPW. The cost for generating UPW is approximately $12 per 1000 gallons. Producing the UPW also involves UV lamps, filters, pumps, and recirculating systems that require energy to operate. Approximately 46 kWH can be saved for every 1000 gallons of UPW conserved. This paper describes the methodology and results of a cross-functional team to reduce UPW usage in the Fairchild Mountaintop six inch facility. The team comprised process technicians, process engineers, facility engineers, and equipment vendors. Reduction efforts included rinse sink, process, and supply modifications. The goal was to reduce the DI usage by 2 million gallons within one year. The annual savings as a result of this team's efforts are projected to approach 18 million gallons of DI water or about $214,000.