InGaAsP semiconductor laser device in which near-edge portions are filled with non-absorbent layer, and lower optical waveguide layer includes InGaP intermediate layer

摘要

In a process for producing a semiconductor laser device, an n-type cladding layer, an n-type or i-type Inx2Ga1-x2As1-y2Py2 first lower optical waveguide layer, an i-type Inx5Ga1-x5P intermediate layer, an i-type Inx2Ga1-x2As1-y2Py2 second lower optical waveguide layer, an Inx1Ga1-x1As1-y1Py1 compressive strain active layer, a p-type or i-type Inx2Ga1-x2As1-y2Py2 first upper optical waveguide layer, and an Inx5Ga1-x5P cap layer are formed on an n-type GaAs substrate. Then, near-edge portions of the cap layer are etched off with a hydrochloric acid etchant, and near-edge portions of the active region above the intermediate layer are etched off with a sulfuric acid etchant so as to produce spaces in vicinities of end facets. Next, the spaces are filled with a p-type Inx2Ga1-x2As1-y2Py2 second upper optical waveguide layer formed over the cap layer, and a p-type upper cladding layer is formed on the second upper optical waveguide layer.