Study of the thermal decomposition of "captured" intermediates in the CVD of ZnO from DEZ and H2O by TGA-DTA and quadrupole mass spectroscopy

The reaction intermediates in the APCVD of ZnO from Diethylzinc (DEZ) and H2O vapors were obtained at temperatures ranging from 25 to 700 degrees C by using a water-cooled substrate. The thermal decomposition properties of the samples were studied using simultaneous Thermogravimetric analysis and differential thermal analysis (TGA-DTA). A quadrupole mass spectrometer (QMS) was used to identify the gases evolved during thermal decomposition. Changes in the TGA-DTA pattern were observed when the reactor temperature was increased and also during ageing at room temperature. Up to three endothermic peaks were observed with peak temperatures at 80-100 degrees C (peak 1), 115-125 degrees C (peak 2), and 145-155 degrees C (peak 3). QMS analysis detected only water as the volatile component during thermal decomposition. The results were analyzed in combination with the results of our previous studies. (C) 2009 Elsevier B.V. All rights reserved.