Glow discharge mass spectrometry — The newest tool for high purity materials analysis

Abstract

Glow Discharge Mass Spectrometry (GDMS) is the latest application of mass spectrometry to the analysis of high purity materials. This technique exhibits high sensitivity (to 1 ppb) and quantitative accuracy using standards for a wide variety of materials. The utility of GDMS to both starting materials and finished crystals is demonstrated for gallium arsenide, silicon and other electronic materials. The high sensitivity of GDMS allows the determination of uranium and thorium at sub part per billion levels in microelectronic manufacturing materials. Using cell cooling it is possible to analyze carbon, nitrogen, and oxygen to 1 part per million or less in many materials. When standards are available analytical accuracy of 5% is easily atteined. Calibration curves are linear over at least six orders of magnitude.