REACTION-MECHANISMS GOVERNING THE SELECTED-AREA GROWTH OF III-V SEMICONDUCTORS BY CHEMICAL BEAM EPITAXY

The molecular surface chemistry underlying the selected-area growth of III-V semiconductors by chemical beam epitaxy is reviewed. Homoepitaxial growth of III-V semiconductors occurs efficiently because of high reactive sticking probabilities of the group III precursor, and efficient reaction pathways resulting in the conversion of the initial chemisorbed species into elemental Ga on the semiconductor surface. In contrast it is shown that the sticking probability of triethyl gallium on the dielectric masks employed in selected-area epitaxy is vanishingly low, and any free Ga species produced become trapped in an inert oxidized form within the surface layers