Surface reactions of dimethylaminoarsine during MOMBE of GaAs

As Doping in (Hg,Cd)Te: An Alternative Point of View

“…Interestingly, there is little evidence for coupling of [Me 2 N] with Me to give trimethylamine. 44 The mechanism outlined above for the decomposition of (Me 2 N) 3 As provides a route for the ready formation of elemental arsenic in the MOVPE process; there is no route for formation of RAs or AsH. Me 2 Cd is also known to decompose via the formation of methyl radicals (Me) [45][46][47] so the same mechanism for decomposition of (Me 2 N) 3 As would be expected to apply for MCT.…”

“…Indeed in MOMBE studies of the growth of GaAs using Me 3 Ga and (Me 2 N) 3 As, very little carbon was incorporated and much higher growth rates were observed than when using PhAsH 2 . 41,42 Mechanistic studies 44 suggest that methyl radicals generated from the decomposition of Me 3 Ga either react with surface As to give methyl arsenic species or abstract H from [Me 2 N] to increase the proportion of aziridine relative to dimethylamine. The observation of CD 3 H when using (CD 3 ) 3 Ga also supports this suggestion.…”

“…5. Proposed mechanism for the decomposition of (Me 2 N) 3 As in the presence or absence of Me 3 Ga. 43,44 whereas nitrogen-doped regions contained approximately equal, above background, levels of nitrogen and hydrogen. 61 Hydrogen was deliberately incorporated into ZnSe:N grown by MBE using a thermal cracker, leading to the observation of infrared absorption bands corresponding to N-H complexes.…”

“…Product analysis suggests that this precursor decomposes by a mechanism involving homolytic cleavage of the arsenic-nitrogen (As-N) bond and the free [Me 2 N] radicals formed disproportionate on the surface to Me 2 NH (dimethylamine) and MeN=CH 2 (N-methylmethyleneimine), which may isomerize to the more stable aziridine. 44 It is probable that all three As-N bonds break in this way so that elemental arsenic is formed readily. Also, H atoms released from the conversion of [Me 2 N] to aziridine may help in removing C from the surface.…”

A kinetic model for tris(dimethylamino) arsine decomposition on GaAs(100) surfaces

“…1,[11][12][13][14][15][16] This model is being used for research on laser-assisted growth of GaAs with TEGa and TDMAAs, which will be reported elsewhere. In this report, we will first review surface science studies on TDMAAs and proceed to present arguments on the reaction scheme and assumptions on Arrhenius parameters.…”