US-12620770-B2 - Semiconductor laser element and method of producing semiconductor laser element

US12620770B2US 12620770 B2US12620770 B2US 12620770B2US-12620770-B2

Abstract

Provided is a semiconductor laser element according to the present technology that includes a stacked body. The stacked body includes a substrate, an n-type semiconductor layer that is formed on the substrate, is formed of an n-type semiconductor material, and has a core that is a defect concentration region, an active layer that is formed on the n-type semiconductor layer, and a p-type semiconductor layer that is formed on the active layer and is formed of a p-type semiconductor material, and has a recessed portion formed from a surface of the p-type semiconductor layer to have a depth reaching the core and an ion implantation region that is formed by implanting ions into a region including the core.

Inventors

Yuichiro Kikuchi
Yukio Hoshina
Hideki Watanabe
YUTA ISOZAKI
Hidekazu Kawanishi
Masahiro Murayama
Takashi Sugiyama

Assignees

Sony Group Corporation

Dates

Publication Date: 20260505
Application Date: 20210513
Priority Date: 20200521

Claims (7)

1 . A semiconductor laser element, comprising: a stacked body that includes: a substrate; an n-type semiconductor layer on the substrate, wherein the n-type semiconductor layer comprises an n-type semiconductor material, the n-type semiconductor layer has a core, and the core is a defect concentration region, an active layer on the n-type semiconductor layer; a p-type semiconductor layer on the active layer, wherein the p-type semiconductor layer comprises a p-type semiconductor material, the p-type semiconductor layer has a recessed portion above the core, the recessed portion has a depth from a surface of the p-type semiconductor layer to the core of the n-type semiconductor layer, and the core excludes the recessed portion; and an ion implantation region having ions, wherein the ion implantation region has a specific depth from the recessed portion.
2 . The semiconductor laser element according to claim 1 , wherein the stacked body has a side surface including an end surface of the n-type semiconductor layer, the core is in contact with the side surface, and the recessed portion is between the surface of the p-type semiconductor layer and the side surface to separate the side surface from the surface of the p-type semiconductor layer.
3 . The semiconductor laser element according to claim 2 , wherein the p-type semiconductor layer comprises a ridge portion, the ridge portion extends in a direction parallel to the surface of the p-type semiconductor layer, and the recessed portion extends in a direction parallel to the ridge portion.
4 . The semiconductor laser element according to claim 1 , further comprising an insulation layer on the surface of the p-type semiconductor layer and an inner peripheral surface of the recessed portion, wherein the insulation layer covers the ion implantation region.
5 . The semiconductor laser element according to claim 1 , wherein the substrate is a c-plane Gallium Nitride (GaN) substrate, the c-plane GaN substrate comprises a n-type GaN, the c-plane GaN substrate has a main surface parallel to a c-plane of a GaN crystal, and the n-type semiconductor layer, the active layer, and the p-type semiconductor layer are associated with a crystal growth on the c-plane GaN substrate.
6 . The semiconductor laser element according to claim 1 , wherein the ions are one of boron ions, nitrogen ions, or protons, and a dose amount of the ions is one of equal to or greater than 2×10 13 cm −2 and one of less than or equal to 2×10 15 cm −2 .
7 . A method of producing a semiconductor laser element, the method comprising: preparing a stacked body that includes: a substrate, an n-type semiconductor layer on the substrate, wherein the n-type semiconductor layer comprises an n-type semiconductor material, the n-type semiconductor layer has a core, and the core is a defect concentration region, an active layer on the n-type semiconductor layer, and a p-type semiconductor layer on the active layer, wherein the p-type semiconductor layer comprises a p-type semiconductor material; forming, by etching, a recessed portion that has a depth from a surface of the p-type semiconductor layer to the core of the n-type semiconductor layer, wherein the core excludes the recessed portion; and implanting ions into a region of the stacked body including the core to form an ion implantation region, wherein the ion implantation region has a specific depth from the recessed portion.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a U.S. National Phase of International Patent Application No. PCT/JP2021/018162 filed on May 13, 2021, which claims priority benefit of Japanese Patent Application No. JP 2020-088808 filed in the Japan Patent Office on May 21, 2020. Each of the above-referenced applications is hereby incorporated herein by reference in its entirety. TECHNICAL FIELD The present technology relates to a semiconductor laser element having a ridge waveguide structure and a method of producing the semiconductor laser element. BACKGROUND ART A semiconductor laser element has a problem that it is difficult to obtain a high output due to heat generation. As a solution to the problem, junction-down mounting that joins a surface of the semiconductor laser element on the side closer to the light-emitting portion to a member such as a heat sink with high heat dissipation is performed. However, in the junction-down mounting, there is a possibility that solder creeps up to reach the side surface of the element during mounting, which causes current leakage. Meanwhile, for example, Patent Literature 1 discloses a nitride semiconductor laser element having a structure in which a groove is formed on the side surface of the element and part of the bottom surface of the element and the side surface of the element are covered by an insulating protective film. CITATION LIST Patent Literature Patent Literature 1: Japanese Patent Application Laid-open No. 2005-311309 DISCLOSURE OF INVENTION Technical Problem Here, a c-plane GaN substrate that is often used as a substrate of a semiconductor laser element has a region called a core. The core is a region in which crystal defects are concentrated and no continuity in crystal structure is provided with the surrounding region, and the surface shape of the core varies. For this reason, there is a possibility that the coverage is incomplete even if the surface of the element is covered by an insulating protective film as described in Patent Literature 1, and current leakage cannot be prevented. In view of the circumstances as described above, it is an object of the present technology to provide a semiconductor laser element capable of preventing current leakage in junction-down mounting and a method of producing the semiconductor laser element. Solution to Problem In order to achieve the above-mentioned object, a semiconductor laser element according to an embodiment of the present technology includes: a stacked body. The stacked body includes a substrate, an n-type semiconductor layer that is formed on the substrate, is formed of an n-type semiconductor material, and has a core that is a defect concentration region, an active layer that is formed on the n-type semiconductor layer, and a p-type semiconductor layer that is formed on the active layer and is formed of a p-type semiconductor material, and has a recessed portion formed from a surface of the p-type semiconductor layer to have a depth reaching the core and an ion implantation region that is formed by implanting ions into a region including the core. In accordance with this configuration, since the recessed portion having a depth reaching the core is formed and the ion implantation region having a high resistance is formed in a region including the core, it is possible to prevent current leakage due to contact of solder to the core. The stacked body may have a side surface including an end surface of the n-type semiconductor layer, the core may be exposed to the side surface, andthe recessed portion may be provided between the surface and the side surface to separate the side surface from the surface. A ridge portion that extends in a direction parallel to the surface may be provided in the p-type semiconductor layer, and the recessed portion may extend in a direction parallel to the ridge portion. The semiconductor laser element may further include an insulation layer formed on the surface and an inner peripheral surface of the recessed portion, in which the ion implantation region may be covered by the insulation layer. The substrate may be a c-plane GaN substrate, the c-plane GaN substrate being a substrate that is formed of n-type GaN and has a main surface parallel to a c-plane of a GaN crystal, and the n-type semiconductor layer, the active layer, and the p-type semiconductor layer may be formed by crystal growth on the c-plane GaN substrate. The ions may be boron ions, nitrogen ions, or protons, and a dose amount of the ions may be 2×1013 cm−2 or more and 2×1015 cm−2 or less. In order to achieve the above-mentioned object, a method of producing a semiconductor laser element according to an embodiment of the present technology includes: preparing a stacked body that includes a substrate, an n-type semiconductor layer that is formed on the substrate, is formed of an n-type semiconductor material, and has a core that is a defect concentration region, an active layer that is formed on