A Mass Spectrometric Study of the Decomposition of Trimethylgallium (TMGa) with Trimethylarsine (TMAs)

Trimethylgallium (TMGa) pyrolysis with Trimethylarsine (TMAs) is studied. I measure the decomposition rate constant by the sampling gas method with a quadrupole mass spectrometer. The decomposition rate constant of TMGa depends on the TMGa initial partial pressure. However, the rate constant of TMGa with TMAs is almost independent of the TMGa initial partial pressure. I propose a model in which TMAs on the reactor surface inhibits the adsorption and decomposition of TMGa on the surface. The TMAs decomposition rate constant increases until TMGa/TMAs=1. It remains constant from 1 to 10. I hypothesize a model for the decomposition of TMGa with TMAs. TMAs molecules adsorb almost all of the adsorption sites. They inhibit the TMGa from adsorption on the sites. TMGa does not decompose on the surface. On the other hand, TMGa catalyzes TMAs to decompose in the gas phase through TMGa·TMAs adducts.