PHOTOCATALYTIC SURFACE-REACTIONS IN METALORGANIC VAPOR-PHASE EPITAXY

In photo-assisted growth of semiconductors, photocatalytic surface reactions are now recognized as a fundamental concept and a useful technique for low temperature growth, high quality epilayers and multilayers, and conductivity control. Various experimental results utilizing this novel technique in metalorganic vapor-phase epitaxy (MOVPE) of wide-gap II-VI semiconductors are reviewed, and the mechanism for enhancement of growth reactions is attributed to alkyl group elimination probably from alkylzinc chemisorbed at the growth surface. From an applicational point of view, this growth technique is expected to be a key for fabrication of new blue/blue-green optoelectronic devices such as light emitting diodes and lasers by MOVPE. The possibility of photocatalytic surface reactions in other semiconductor growth is also discussed.