Determination of Organic Contaminants in Sulfuric Acid using Wet Oxidation Type Total Organic Carbon Analyzer

Introduction

Sulfuric acid (H₂ SO₄) is widely used in the semiconductor industry for the manufacturing of integrated circuits to resist stripping and wafer cleaning. Any organic contaminants remaining on the wafer surfaces could have a detrimental effect on the wafers as well as the process equipment. Total Organic Carbon (TOC) can be used to indicate organic contaminants in sulfuric acid. The TOC-L series catalytic combustion system with High Salt Kit has been used to measure TOC in sulfuric acid. To prevent damage by fumes from concentrated 96% sulfuric acid, the sample was diluted 10 times and SO₂ scrubbers were used to protect the instrument. Using this configuration, sulfuric acid with TOC content of less than 10 ppm can be measured. Due to the more sophisticated integrated circuits, there is an increasing demand in the semiconductor industry for ultra pure sulfuric acid with lesser organic impurities. To analyze low TOC content, a wet oxidation type TOC analyzer can be used as it has better detection limit than catalytic combustion type TOC analyzer. This application news describes the use of wet oxidation type TOC analyzer to measure TOC in sulfuric acid.

November 12, 2018 GMT