Selective area growth of III-V semiconductors by chemical beam epitaxy: study of reaction mechanisms

The localized growth of III-V epitaxial structures on substrates patterned with dielectric masks provides a flexible technique for the monolithic integration of electronic and optoelectronic devices. Chemical beam epitaxy (CBE) is an attractive growth technique for use in this approach and interest has consequently focussed on the reaction mechanisms which give rise to selective area growth in CBE. In the present paper we therefore seek to describe the molecular surface chemistry involved. In contrast it is shown that the sticking probability of Gp III precursors on the dielectric masks employed in selected area epitaxy is vanishingly low, and any free Gp III species produced become trapped in an inert oxidized form within the surface layers. As a result the production of metallic Gp III species on the surface does not occur, hence growth of the III-V semiconductor is not observed. Adsorption of the Gp V species on the dielectric mask is shown to promote decomposition of the Gp III precursors, resulting in a loss of selective growth at high V-III incident flux ratios or low growth temperatures.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.