Fourier transform infrared spectroscopy studies on thermal decomposition of tetrakis-dimethyl-amido zirconium for chemical vapor deposition of ZrN

Abstract

The decomposition behavior of tetrakis (dimethylamido) zirconium (TDMAZ) under various ambient gases was studied by using in-situ Fourier transform infrared spectroscopy (FTIR) aimed at understanding the gas. phase reactions and also at selecting the appropriate process conditions for ZrN chemical vapor deposition (CVD). The infrared absorbance of the stretching vibration at 933.37 cm(-1) was employed to monitor the degree of dissociation of the gaseous TDMAZ. In the case of argon and nitrogen atmospheres, TDMAZ starts to decompose at above 300degreesC, while in a hydrogen atmosphere it starts to decompose at above 350degreesC. To evaluate the effect of the decomposition behavior of the precursor on CVD ZrN, the ZrN films were grown at 150-375 degreesC under Ar, N-2, and H-2. A clear difference in transition temperature of controlling from surface reaction to gas phase mass transfer was observed: The ZrN growth rate decreased rapidly at above 300degreesC under Ar or N-2 atmospheres, and increased continuously with increase of the deposition temperature under an H-2 atmosphere.