METALORGANIC VAPOR-PHASE EPITAXIAL REGROWTH OF INP ON REACTIVE ION-ETCHED MESA STRUCTURES FOR P-SUBSTRATE BURIED HETEROSTRUCTURE LASER APPLICATION

Growth behavior of sulfur-doped n-InP around reactive ion-etched (RIE) mesas has been investigated for realization of p-substrate buried het erostructure laser utilizing metalorganic vapor phase epitaxy. It is f ound that the growth of n-InP layer on the sidewall of the mesa ((1 (1 ) over bar 0) plane) is significantly suppressed, as the flow rate of hydrogen sulfide (H2S) which is used for n-type doping, increased. Thi s phenomenon of growth suppression was also observed for growth of hig hly S-doped n-InP on narrow (001) facets. Taking account of both, thes e phenomena can be explained by migration enhancement of indium atoms on sulfur-terminated surfaces caused by excess H2S supply. Consequentl y, the shape of the regrown embedding layer was found to be exactly co ntrolled by the H2S flow rate. Using this technique, a p-substrate 1.3 mu m buried heterostructure laser with pnp current-blocking structure has been successfully fabricated around the RIE mesa and excellent la sing characteristics with high reliability has been realized for the f irst time.