IMPURITY ANALYSIS METHOD OF HYDROFLUORIC ACID SOLUTION FOR SEMICONDUCTOR WAFER PROCESS, AND MANAGEMENT METHOD OF REPLACEMENT TIME OF HYDROFLUORIC ACID SOLUTION

摘要

PROBLEM TO BE SOLVED: To provide an impurity analysis method of hydrofluoric acid solution for semiconductor wafer process, which has high measurement sensitivity and measurement accuracy and excellent efficiency.;SOLUTION: The impurity analysis method comprises: a step A of collecting a dilute hydrofluoric acid solution from an immersion tank; a step B of measuring the mass spectral intensities of Si having mass number 28, P having mass number 31 and PO impurities having mass number 47 in the solution; a step C-1 of solidifying the collected dilute hydrofluoric acid solution by drying and concentrating the solution; a step C-2 of measuring the energy intensities of Si, P and PO elements in a solidified matter in a vacuum; and a step C-3 of measuring the mass spectral intensities of the solidified matter in a vacuum. True impurity amounts of Si, P and PO in the dilute hydrofluoric acid solution is obtained by correcting the mass spectral intensities obtained in the step B by an intensity ratio which is a ratio of mass spectral intensities of target impurities and a spectral intensity obtained by summing the mass spectral intensities of the target impurities obtained in the step C-3 and a spectral intensity of a matrix mass.;COPYRIGHT: (C)2013,JPO&INPIT