Pyrolysis of dimethylhydrazine and its co-pyrolysis with triethylgallium

Dimethylhydrazine is a potential nitrogen precursor for organometallic vapor-phase epitaxy of GaN-based ternaries and quaternaries at relatively low temperatures. We have measured the vapor pressure of dimethylhydrazine and studied the pyrolysis characteristics of dimethylhydrazine in H-2 ambient. Results of co-pyrolysis with triethylgallium in H-2 ambient are also reported. The vapor pressure of dimethylhydrazine is given by Log P = 8.19-1780/T. Pyrolysis of the dimethylhydrazine is found to proceed by cleavage of the N-N bond followed by elimination of the methyl groups. Co-pyrolysis studies showed that an adduct and an intermediate dimer form at low temperatures then further decomposed at higher temperatures to the final product GaN. (C) 2000 Published by Elsevier Science B.V.