Pyrolysis and Photolysis of Trimethylaluminum

Abstract

A vapor-phase decomposition mechanism for the trimethylaluminum(TMA) used in an Al CVD was investigated by infrared spectroscopy. In pyrolysis, the annihilation of TMA was a first-order reaction and a CH 3 radical was generated. The activation energy of the annihilation was about 0.4 eV. The generation mechanism of CH 4 from the intermediates was investigated quantitatively. It is suggested that carbon contamination can be reduced by using an H 2 carrier gas since the CH 3 radical which causes such contamination is changed into CH 4 by hydrogenation. In photolysis, the annihilation of TMA is a first-order reaction and C 2 H 6 is generated by the coupling of two CH 3 groups. The reduction of carbon contamination is also suggested because the generation of a CH 3 radical is suppressed by the generation of C 2 H 6 .