Determination of ultra trace elements in high purity hydrogen peroxide with Agilent 8900 ICP-QQQ

Importance of the Topic

High-purity hydrogen peroxide plays a vital role in semiconductor manufacturing as a strong oxidizer for wafer cleaning, photoresist removal and copper etching. Even ultra-low levels of trace metal impurities can impair device performance and yield. With ongoing device miniaturization, analytical methods must reliably measure an expanding list of elements at ppt and sub-ppt levels to meet SEMI C30-1110 Grade 5 purity requirements.

Objectives and Study Overview

This study evaluates the performance of the Agilent 8900 triple-quadrupole ICP-MS (ICP-QQQ) for quantifying trace elements in 35% semiconductor-grade H2O2. All elements listed in the SEMI C30-1110 standard, including sulfur and phosphorus limits, were measured alongside additional analytes. The goal was to achieve accurate quantification and reliable detection limits down to sub-ppt concentrations.

Methodology and Instrumentation

Analysis was carried out using an Agilent 8900 #200 Semiconductor configuration ICP-QQQ in MS/MS mode. Key features and conditions include:

• PFA-100 nebulizer and Peltier-cooled quartz spray chamber
• Quartz torch with platinum-tipped cones and s-lens interface
• Reactive cell gases (He, H2, O2, NH3) and cool-plasma tuning to minimize interferences
• Standard addition calibration at 10, 20, 30, 40 and 50 ppt in 0.07% HNO3-stabilized H2O2 matrix
• Class 10 000 clean-room sample preparation
• Acquisition parameters optimized for each element using MS/MS separation through Q1 and Q2 quadrupoles

Main Results and Discussion

Calibration curves showed excellent linearity (R² near 1.00) from 0 to 50 ppt for all target analytes. Detection limits were mostly sub-ppt, with single-digit ppt limits for Si (25 ppt) and S (5.1 ppt). Quantitative results in H2O2 yielded concentrations below or near instrument detection limits for most elements, demonstrating Grade 5 compliance. A long-term stability test over 3 h 40 min produced relative standard deviations between 1.0% and 8.1%. Slight upward drift in boron and sulfur was attributed to clean-room air contamination.

Benefits and Practical Applications

The Agilent 8900 ICP-QQQ method offers:

• Single-technique determination of all SEMI-specified elements including S and P
• Sub-ppt detection limits for most trace metals
• Reduced spectral interferences via MS/MS and selective reaction chemistry
• Consistent, reproducible results over extended analysis sequences
• Suitability for routine QA/QC of semiconductor process chemicals

Future Trends and Applications

As device architectures continue to shrink, analytical demands will grow for even lower detection limits and expanded element coverage. Future developments may include inline process monitoring, automated sample introduction and adaptation of ICP-QQQ workflows to other high-purity matrices such as ultrapure water, photoresists and specialty solvents.

Conclusion

The Agilent 8900 ICP-QQQ in MS/MS mode successfully quantified an extensive range of trace elements in 35% semiconductor-grade H2O2 at ppt to sub-ppt levels. The method meets SEMI Grade 5 standards, delivers robust long-term stability and supports high-throughput QA/QC for semiconductor reagents.

Reference

• SEMI C30-1110, Specifications for Hydrogen Peroxide (2010)