Mass Spectrometric Study and Modeling of Decomposition Process of Tris-Dimethylamino-Arsenic on (001) GaAs Surface

Abstract

Decomposition process of a new arsenic precursor, As[N(CH 3 ) 2 ] 3 , for metalorganic molecular beam epitaxy (MOMBE) was studied. It was found that a Ga-stabilized (4×2) GaAs surface turned to an As-stabilized (2×4) surface at a low substrate temperature of ∼400°C and with a low As[N(CH 3 ) 2 ] 3 pressure of ∼10 -7 Torr when it was supplied without thermal precracking. This is a marked contrast to conventional As[C 2 H 5 ] 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.