STUDIES OF TMGA ADSORPTION ON THIN GAAS AND INAS (001) LAYERS

Adsorption of TMGa on thin overlayers of GaAs/AlAs and InAs/InP structures is investigated. The number of Ga monolayers is determined precisely from such structures for various TMGa exposures. Slower reaction rates for TMGa on Ga-stabilized surfaces compared to As-stabilized surfaces result in the self limiting mechanism of atomic layer epitaxy (ALE) using TMGa. On the other hand, adsorption of TMGa on InAs (001) surfaces involves more than the very top layer atoms. Exchange of In/Ga is observed with In atoms floating on top of the surface, which enhances Ga atom formation and impedes saturation as in the case of GaAs surfaces. © 1990.