The Removal of Silicon and Boron in Ultra-Pure Water for Semiconductor Processes

The method of the removal of silicon and boron in ultra pure water by EDI is investigated in this paper.With the investigation of voltage,conductivity of feed water in dilute and concentrate chambers,flux of feed water in dilute,concentrate and electrodal chambers,and pH value,the optimal conditions of silicon and boron removal are obtained.When the silica in feed water is 1000μg/L,the silicon in products can be decreased to 2.66μg/L,which is the best result in our country at present.And with 50μg/L boron in feed water,less than 1μg/L boron in products can be obtained.All these results meet the requirements for ULSI (Silicon:3μg/L,Boron:1μg/L).