Quantitative Infrared Spectroscopy of Tetrakis(dimethylamido)Titanium for Process Measurements

Abstract

Infrared spectroscopy has been widely used for in situ analysis of the gas phase during chemical vapor deposition (CVD) and atomic layer deposition (ALD). For both process monitoring and research applications, accurate determination of absorptivity is often necessary for quantitative work. In this study, we measure reference spectra for vapor-phase tetrakis(dimethylamido)titanium (TDMAT), an organometallic precursor commonly used for both CVD and ALD. The gas cell is heated over the temperature range of (352 to 476) K. We take steps to correct for sample emission, which otherwise is found to cause errors. Systematic changes are observed as the temperature is varied, but integrated absorbance is insensitive to temperature. The implications for infrared-based process measurements are discussed. In the course of this work, we do not observe rapid thermal decomposition of TDMAT at 476 K, which had been reported elsewhere in the literature. © 2014 The Electrochemical Society. All rights reserved.