ON THE EFFECT OF ARSINE FOR THE DECOMPOSITION OF TRIETHYLGALLIUM DURING EPITAXIAL-GROWTH OF GAAS

We report on mass-spectrometric studies of the decomposition behavior of triethylgallium (TEG) with and without arsine in a vacuum chemical epitaxy chamber. The measurements were performed during TEG supply cycles between 420 and 540-degrees-C and were accompanied by reflectance difference observations. Concentrations of reaction products produced during TEG decomposition were found to depend strongly on the arsine input. Based on an analysis of the ratio of ethane to ethene desorption and considerations of reaction pathways, we conclude that in the absence of arsine the beta-hydride elimination process is dominant whereas the presence of arsine favors the formation and desorption of ethane. Moreover, the presence of arsine influences the amount of desorption of the diethylgallium as well as of the monoethylgallium compound.