Nitric acid (HNO3) is widely utilized in the semiconductor industry during the cleaning process of silicon wafers to reduce contamination by trace metals, particulates, and organic contaminants which would otherwise alter the functionality of the semiconductors. As such, the use of a high-quality acid and the control of contaminants in the acid itself are important. Since the control of environmental contaminants at the part per trillion (ppt) level is challenging, special sample handling is often required, and the acid needs to be regularly analyzed for trace elements as part of quality control.
This work presents the fully automated analysis of undiluted semiconductor-grade HNO3 using PerkinElmer’s NexION® 5000 Multi-Quadrupole ICP-MS working seamlessly with the ESI prepFAST S ultraclean sample introduction system. The automated MSA calibration capabilities of the prepFAST S delivered outstanding linearity of the calibration curves for all 40 elements. And the NexION 5000 ICP-MS effectively eliminated the spectral interferences in the samples, thanks to its multi-quadrupole technology and a true-quadrupole Universal Cell pressurized with pure reaction gases, resulting in superb background equivalent concentrations (BECs) and limits of detection (LODs) while demonstrating excellent tolerance to harsh chemicals.