SEMICONDUCTOR LASER ELEMENT AND ITS MANUFACTURE

PROBLEM TO BE SOLVED: To avoid flowing a current into a buried layer to provide a low threshold set value, high efficiency of current characteristic, high power and high reliability, by electrically isolating mesa type active layer parts from the buried layer through a high-resistance low-concn. buffer layer. SOLUTION: A manufacturing method comprises steps forming a p-type low-concn. cover layer 40 extending to the upper side face of a mesa 100, growing a first p type InP buried layer, a buffer layer composed of a p type InP buried layer 41 and n type InP buried layer 42, and second n type InP buried layer 11 on the buffer layers 41, 42, removing an SiO2 film 7 used as a mask for the mesa 100, forming a p type InP clad additional layer 12 and growing a p type InGaAsP electrode-forming layer 13.