The chemical species exiting chamber after an aluminum chemical vapor deposition process using aluminum boro-hydride trimethylamine (ABHTMA) as a precursor were studied with a Fourier transform infrared spectroscope. which was installed in the exhaust line of the chamber. The variation in the absorption spectra of C-H, C-N, B-H, AI-H and Al-N stretching features and the morphology of the deposited films were investigated with varying temperatures using ABHTMA in two different states (normal and decomposed). The dissociation or recombination of ABHTMA in the gas phase and on the surface during deposition resulted in the change in B-H and Al-H peaks. With the information about the peaks, we could measure in real time the purity of ABHTMA and the degree of reaction in the gas phase as a function of deposition conditions. (C) 2009 Elsevier B.V. All rights reserved.