1. Field of the Invention
The present invention relates to an optical semiconductor device and a method for manufacturing the same.
2. Related Background Art
Japanese Patent Application Laid-Open Publication No. 2011-249767 discloses a semiconductor laser in which a mesa stripe having an active layer is buried in a high-resistance semiconductor layer composed of Fe-containing InP. This semiconductor laser can be formed, for example, by forming the mesa stripe and thereafter burying the mesa stripe in the high-resistance semiconductor layer. In the semiconductor laser of the foregoing Laid-Open Publication No. 2011-249767, a thin-film p-type semiconductor layer is interposed in an early stage of the step of burying the mesa structure (mesa stripe), thereby to suppress leak current flowing out from the active layer to the burying layer and obtain high optical output.