Patent ID: 8372651

Claim:
A method of monitoring a surfactant in a process for making a microelectronic component comprising: a. adding the surfactant to a process for making a microelectronic component, wherein an absorbance of the surfactant is capable of being measured, wherein the absorbance is ultraviolet-visible absorbance; b. sampling fluid from the process; c. measuring the absorbance of the surfactant in the sample; d. correlating the absorbance of the surfactant in the sample with the concentration of the surfactant in the process; and e. taking action to maintain the concentration of the surfactant in the process at a desired level, wherein the desired level is a dilution ratio of about 200 parts total volume to about one part surfactant volume; wherein the sampling comprises adding a chromogenic agent into the fluid, the chromogenic agent comprising 4,5,6,7-Tetrachloro-2′,4′,5′,7′-tetraiodofluorescein disodium salt.