Determination of trace impurities in organometallic semiconductor-grade reagents and process chemicals with electrothermal vaporization–inductively coupled plasma atomic emission spectrometry

Abstract

Both volatile and non-volatile impurities in semiconductor-grade organometallic reagents are determined by electrothermal vaporization–inductively coupled plasma atomic emission spectrometry (ETV–ICP-AES). Solid or liquid materials are dispensed directly onto a graphite microboat, and application of an appropriate time–temperature programme separates impurities based on their volatility. Calibration methods for volatile impurities (e.g., Si, Sn, Zn in trimethylaluminium) including external calibration, exponential dilution, and direct vapour sampling provide semi-quantitative results. Determination of non-volatile impurities by ETV-ICP-AES can be reasonably performed with aqueous external standard calibration.