이승형 (한국표준과학연구원)

허건 (한국표준과학연구원)

이승형 (한국표준과학연구원)

허건 (한국표준과학연구원)

김형진 (연세대학교)

김선우 (한국표준과학연구원)

김병문 (한국표준과학연구원)

오상협 (한국표준과학연구원)

As the quality control of gaseous precursors increasingly dictates device yields in advanced semiconductor manufacturing, the accurate quantification of trace metallic impurities in ammonia gas has become indispensable. Although these impurities induce critical wafer surface defects, conventional wet impinger sampling suffers from ammonia's high alkalinity, which triggers neutralization reactions to generate solid ammonium nitrate (NH₄NO₃) by-products, causing instrument clogging and metal precipitation. To overcome these limitations, we developed a robust sample pretreatment strategy that couples an 11.4% nitric acid (HNO₃) absorbing solution with a subsequent 1:10 dilution to suppress neutralization-induced matrix variations. This approach successfully eliminated salt deposition inside the system. Furthermore, we demonstrated that the matrix-induced ionization suppression of ammonium nitrate strongly correlates with the first ionization potentials of the target metallic elements, enabling systematic signal compensation. Ultimately, by resolving analytical interferences and clarifying the correlation between elemental ionization energy and the matrix effect, this optimized methodology is expected to serve as a highly reliable platform for the quality assurance of high-purity semiconductor gases.