Electrothermal vaporization–inductively coupled plasma mass spectrometry for the analysis of semiconductor-grade organometallic materials and process chemicals

Abstract

Electrothermal vaporization inductively coupled plasma mass spectrometry was applied to the detection and determination of volatile and non-volatile impurities in semiconductor-grade trimethylaluminium and the process chemicals phosphorus tribromide and phosphorus oxychloride. Adaptation of a graphite furnace combined with initial sub-ambient temperatures permits the direct analysis of otherwise hard-to-handle samples. Non-volatile impurities (Al, Ca, Cd, Cr, Cu, Fe, Ga, In, Mg, Mn, Ni, Pb, Si, Sn, Zn) are detected and determined readily because of complete analyte and matrix separation. Volatile impurities (Ga, Si, Sn, Zn) are also detected, but determination is limited owing to non-spectral mass spectrometric effects resulting from concurrent matrix evaporation. Semiquantitative analysis was applied successfully for rapid, multielemental impurity screening of electrothermally vaporized samples.