Semiconductor optical device

Abstract

A semiconductor optical device includes a GaAs substrate of a first conductivity type; a III-V compound semiconductor layer provided on the GaAs substrate; an active layer provided on the III-V compound semiconductor layer; and a cladding layer of a second conductivity type provided on the active layer, wherein the band gap energy of the III-V compound semiconductor layer is larger than the band gap energy of the GaAs substrate, wherein the band gap energy of the active layer is smaller than the band gap energy of the GaAs substrate, and wherein the thickness of the III-V compound semiconductor layer is not more than 0.2 μm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing schematically a semiconductor optical device according to a first embodiment;

FIG. 2 is a view showing schematically part of the semiconductor optical device shown in FIG. 1;

FIG. 3 is a cross-sectional view showing an example of the structure of a III-V compound semiconductor layer;

FIG. 4 is a cross-sectional view showing schematically a semiconductor optical device according to a second embodiment;

FIG. 5 is a perspective view showing schematically a semiconductor optical device according to a third embodiment;

FIG. 6 is a cross-sectional view along the line VI-VI shown in FIG. 5; and

FIGS. 7A to 7C are views showing schematically steps in a method of manufacturing a semiconductor optical device according to the third embodiment.

Claims

1. A semiconductor optical device comprising: a GaAs substrate of a first conductivity type;a III-V compound semiconductor layer provided on the GaAs substrate;an active layer provided on the III-V compound semiconductor layer; anda cladding layer of a second conductivity type provided on the active layer, wherein the band gap energy of the III-V compound semiconductor layer is larger than the band gap energy of the GaAs substrate,wherein the band gap energy of the active layer is smaller than the band gap energy of the GaAs substrate, andwherein the thickness of the III-V compound semiconductor layer is not more than 0.2 μm.

2. The semiconductor optical device according to claim 1, wherein the III-V compound semiconductor layer is made of undoped III-V compound semiconductor.

3. The semiconductor optical device according to claim 1, wherein the III-V compound semiconductor layer includes a first semiconductor layer and a second semiconductor layer alternately stacked, andwherein the band gap energy of the first semiconductor layer is different from the band gap energy of the second semiconductor layer.