Semiconductor laser device including ARROW structure formed without P-As interdiffusion and Al oxidation

A process for producing a semiconductor laser device, comprising the steps of:

• (a) forming above a GaAs substrate of a first conductive type a lower cladding layer made of In0.49Ga0.51P of the first conductive type;
• (b) forming above said lower cladding layer a lower optical waveguide layer made of Inx1Ga1-x1As1-y1Py1 which is undoped or said first conductive type, where x1=0.49y1 and 0≦y1≦0.3;
• (c) forming above said lower optical waveguide layer a compressive-strain quantum-well active layer made of Inx3Ga1-x3As1-y3Py3, where 0.49y3<x3≦0.4 and 0≦y3≦0.1;
• (d) forming above said compressive-strain quantum-well active layer an upper optical waveguide layer made of Inx1Ga1-x1As1-y1Py1 which is undoped or a second conductive type, where x1=0.49y1 and 0≦y1≦0.3;
• (e) forming above said upper optical waveguide layer a first upper cladding layer of said second conductive type which is made of one of In0.49Ga0.51P and AlxGa1-xAs having an approximately identical refractive index to a refractive index of In0.49Ga0.51P, where 0.45≦x≦0.55;
• (f) forming above said first upper cladding layer a first etching stop layer made of GaAs of said second conductive type;
• (g) forming above said first etching stop layer a second etching stop layer made of Inx8Ga1-x8P of said second conductive type, where 0≦x8≦1;
• (h) forming above said second etching stop layer a first current confinement layer made of GaAs of said first conductive type;
• (i) removing stripe regions of said first current confinement layer and said first etching stop layer so as to produce an intermediate layered structure in which stripe areas of said first etching stop layer are exposed, where said stripe areas of the first etching stop layer extend in a direction of a laser resonator, and correspond to at least one current injection region and low-refractive-index regions located on outer sides of the at least one current injection region and separated from the at least one current injection region or outermost ones of the at least one current injection region by a predetermined interval;
• (j) raising the temperature of said intermediate layered structure in an arsenic atmosphere;
• (k) forming above said first current confinement layer and said stripe areas of the first etching stop layer a third etching stop layer made of Inx9Ga1-x9P of said second conductive type, where 0≦x9≦1;
• (l) forming above said third etching stop layer a fourth etching stop layer made of GaAs of said second conductive type;
• (m) forming above said fourth etching stop layer a second current confinement layer made of In0.49Ga0.51P of said first conductive type;
• (n) removing stripe regions of said second current confinement layer and said fourth etching stop layer so that at least one stripe area of said third etching stop layer is exposed, where said at least one stripe area of the third etching stop layer corresponds to said at least one current injection region;
• (o) forming above said second current confinement layer and said at least one stripe area of said third etching stop layer a second upper cladding layer of said second conductive type which is made of one of In0.49Ga0.51P and AlxGa1-xAs having an approximately identical refractive index to the refractive index of In0.49Ga0.51P, where 0.45≦x≦0.55;
• and
• (p) forming above said second upper cladding layer a contact layer made of GaAs of said second conductive type.