CHEMICAL CONCENTRATION CONTROL DEVICE

摘要

A system (500) and method for ensuring constant concentration ratios in multi-fluid mixtures used in wafer processing steps. In one aspect the invention is a method for supplying a multi-fluid mixture to a process tank (330) comprising: transporting a first fluid through a first supply line (110) having means to control mass flow rate of the first fluid; transporting a second fluid through a second supply line (210) having means to control mass flow rate of the second fluid; converging the first and second fluids to form a multi-fluid mixture; repetitively measuring the concentration levels of the first and second fluids in the multi-fluid mixture with a sensor (310); and upon the sensor (310) detecting undesirable concentration levels of either the first or second fluid in the multi-fluid mixture, automatically adjusting the mass flow rate of at least one of the first and second fluids to achieve desired concentration levels.