MASS-SPECTROMETRIC STUDY AND MODELING OF DECOMPOSITION PROCESS OF TRIS-DIMETHYLAMINO-ARSENIC ON (001) GAAS SURFACE

Decomposition process of a new arsenic precursor, As[N(CH3)2]3, for metalorganic molecular beam epitaxy (MOMBE) was studied. It was found that a Ga-stabilized (4 x 2) GaAs surface turned to an As-stabilized (2 x 4) surface at a low substrate temperature of approximately 400-degrees-C and with a low As[N(CH3)2]3 pressure of approximately 10(-7) Torr when it was supplied without thermal precracking. This is a marked contrast to conventional As[C2H5]3 with which the As-stabilized GaAs surface is never formed without precracking. The decomposition process was modeled assuming an intermediate-state species adsorbed on the GaAs surface based on a quadrupole mass spectrometric study. The measured temperature dependence was very well explained with the present model.