Tertiarybutylhydrazine: a new precursor for the MOVPE of Group III-nitrides

Tertiarybutylhydrazine (tBuHy), generated from tBuHy hydrocloride, was found to have a convenient vapor pressure (6.7 mbar at 20°C) for MOVPE applications. Thermolysis of tBuHy, studied by quadrupole mass spectroscopy (QMS), starts at about 220°C by homolytic cleavage into reactive tBuNH and NH2 radicals. Almost complete decomposition under QMS conditions is observed above 350°C. Mirror-like GaN epilayers with mixed cubic/hexagonal and hexagonal structure were grown on GaAs and Al2O3 substrates, respectively, at 670°C using tBuHy and Me3Ga or Et3Ga with a V/III ratio of 70. Low carbon incorporation was found in tBuHy-grown layers with respect to layers grown with Me2Hy under the same conditions.