PURPOSE: To improve the manufacturing yield of a semiconductor laser device having a ridge waveguide.
CONSTITUTION: After a crystal layer whose thickness is to be the thickness of a ridge side layer 8 is formed on an active layer 4 by an epitaxial growth method, a mask is provided by a photolithography technology so as to cover the ridge side layer forming regions of the crystal layer and then an epitaxial growth layer having a required thickness is formed on the part of the crystal layer exposed from the mask to form a ridge 7. As the ridge width is determined by a photolithography technology whose controllability is excellent and ridge thickness is determined by an epitaxial growth method whose controllability is excellent, the dimensions of the ridge 7 are highly accurate. Further, the thicknesses of the ridgeside layers can be highly accurate owing to an epitaxial growth method whose controllability is excellent.
OKUYAMA TAKAYASU
KARITA HIDETAKA
FURUKOSHI KENJI
KASHIWADA YASUTOSHI
