Optical semiconductor integrated device, method of manufacturing optical semiconductor integrated device, and optical communication system

A method of manufacturing an optical semiconductor integrated device, comprising the steps of:

• (a) successively growing a first semiconductor layer, a second semiconductor layer, and a third semiconductor layer each made of a group Ill-V compound semiconductor in an upward direction in a first opening of a first mask film in a first area of a substrate to form a first multi-layer body;
• (b) growing a fourth semiconductor layer covering an upper surface and each of side surfaces of the first multi-layer body;
• (c) removing the first mask film;
• and
• (d) successively growing a fifth semiconductor layer, a sixth semiconductor layer, and a seventh semiconductor layer each made of a group III-V compound semiconductor in the upward direction in a second opening of a second mask film in a second area of the substrate to form a second multi-layer body,
• wherein the second semiconductor layer has a refractive index larger than that of each of the first semiconductor layer and the third semiconductor layer,
• wherein at least any one of the first to third semiconductor layers includes an Al element as a constituent element, and
• wherein, in the step (d), the first multi-layer body and the second multi-layer body are formed so as to be coupled together via the fourth semiconductor layer.

A method of manufacturing an optical semiconductor integrated device, comprising the steps of:

• (a) successively growing a first semiconductor layer, a second semiconductor layer, and a third semiconductor layer each made of a group III-V compound semiconductor in an upward direction in a first opening of a first mask film in a first area of a substrate to form a first multi-layer body;
• (b) growing a fourth semiconductor layer covering an upper surface and each of side surfaces of the first multi-layer body;
• (c) removing the first mask film;
• and
• (d) successively growing a fifth semiconductor layer, a sixth semiconductor layer, and a seventh semiconductor layer each made of a group III-V compound semiconductor in the upward direction in a second opening of a second mask film in a second area of the substrate to form a second multi-layer body,
• (e) growing an eighth semiconductor layer covering an upper surface and each of side surfaces of the second multi-layer body;
• (f) removing the second mask film;
• and
• (g) successively growing a ninth semiconductor layer, a tenth semiconductor layer, and an eleventh semiconductor layer each made of a group III-V compound semiconductor in the upward direction in a third opening of a third mask film in a third area of the substrate which is located between the first and second areas thereof to form a third multi-layer body,
• wherein the second semiconductor layer has a refractive index larger than that of each of the first semiconductor layer and the third semiconductor layer,
• wherein at least any one of the first to third semiconductor layers includes an Al element as a constituent element, and
• wherein, in the step (d), the first multi-layer body and the second multi-layer body are formed so as to be coupled together via the fourth semiconductor layer.