Buffered oxide etchants (BOEs) are blends of hydrofluoric acid, ammonium fluoride, surfactants, and ultrapure water utilized in the semiconductor industry to etch thin films of silicon wafers. The reduction of potential contamination of silicon wafers during the etching process is crucial, as trace metal, particulate, and organic contaminants can alter the functionality of semiconductors. Environmental contaminants at the sub-ppt level are difficult to control and can easily contaminate a BOE solution, if not properly handled.
This work presents the analysis of commercially available, undiluted BOE using PerkinElmer’s NexION® 5000 Multi-Quadrupole ICP-MS working seamlessly with ESI’s prepFAST S ultraclean sample introduction system. The automated MSA calibration capabilities of the prepFAST S delivered outstanding linearity of the calibration curves for all 50 elements analyzed. And thanks to its multi-quadrupole technology and quadrupole-based Universal Cell, the NexION 5000 ICP-MS effectively eliminated the spectral interferences in the samples, demonstrating superb background equivalent concentrations (BECs) and limits of detection (LODs) while demonstrating excellent tolerance to harsh chemicals.