KR-102962302-B1 - SEMICONDUCTOR LIGHT-EMITTING ELEMENT, LIGHT-EMITTING DEVICE, AND RANGING DEVICE

Abstract

A semiconductor light-emitting device having a structure in which a substrate, a first reflector, a cavity resonator including an active layer, a second reflector, and a transparent conductive film are stacked in this order comprises a first current constriction portion composed of an oxide constriction layer, an insulating film formed on the upper surface of the second reflector and having an opening, and a second current constriction portion composed of a contact portion between a transparent conductive film and a semiconductor layer in contact with the transparent conductive film, wherein the width d2 of the second current constriction portion is smaller than the width d1 of the first current constriction portion.

Inventors

• 스가 타카코
• 우치다 타케시
• 우치다 타츠로

Assignees

• 캐논 가부시끼가이샤

Dates

Publication Date

20260508

Application Date

20221214

Priority Date

20220101

Claims (10)

1. A semiconductor light-emitting device having a structure in which a substrate, a first reflector, a cavity resonator including an active layer, a second reflector, and a transparent conductive film are stacked in this order, A first current constriction part composed of an oxidized constriction layer, and A second current constriction portion comprising an insulating film formed on the upper surface of the second reflector and having an opening, and a contact portion between the transparent conductive film and the semiconductor layer in contact with the transparent conductive film, The width d2 of the second current constriction portion is smaller than the width d1 of the first current constriction portion, and The semiconductor light-emitting element described above has a current path from the transparent conductive film to the active layer through the contact portion of the second current-constricting portion and the semiconductor portion inside the first current-constricting portion.
2. In Article 1, The opening of the insulating film in the second current constriction portion is a semiconductor light-emitting element included in the non-oxidized portion on the inner side of the oxidized constriction layer in the first current constriction portion in a planar view.
3. In Article 1, A semiconductor light-emitting device in which the width d1 of the first current narrowing portion satisfies 30㎛≤d1≤70㎛.
4. In Article 1, A tunnel joint layer is installed on the uppermost part of the second reflector, and A semiconductor light-emitting device in which the insulating film and the transparent conductive film are installed on the tunnel junction layer, and the transparent conductive film is in contact with the second reflector through the tunnel junction layer.
5. In Paragraph 4, The above tunnel junction layer includes, in a planar view, a non-oxidized portion on the inner side of the oxidation constriction layer in at least the first current constriction portion. A semiconductor light-emitting element installed at the uppermost part of the second reflector.
6. In Paragraph 4, A semiconductor light-emitting device in which the width d1 of the first current constriction portion satisfies 50㎛≤d1≤100㎛.
7. In Article 1, A semiconductor light-emitting device having a transparent insulating film installed on the above transparent conductive film.
8. In Article 1, A semiconductor light-emitting device having a third reflector made of a dielectric material further installed on the second reflector.
9. A light-emitting device comprising a plurality of semiconductor light-emitting elements as described in any one of claims 1 to 8, arranged side by side.
10. A light source comprising a semiconductor light-emitting element as described in any one of claims 1 to 8, and A sensor that detects reflected light generated by the above light source, and A measuring device having a processing unit that acquires distance information based on the detection timing of detecting the reflected light.

Description

Semiconductor light-emitting element, light-emitting device, and range-measuring device The present invention relates to a semiconductor light-emitting element, a light-emitting device, and a measuring device. Vertical cavity surface-emitting lasers (VCSELs) are attracting attention as light sources for Time-of-Flight (ToF) light detection and ranging (LiDAR). In order to improve measurement precision and increase the measurable distance, high output power of the light source is required. One possible method to achieve high output in VCSELs is to increase the emission diameter. However, simply increasing the emission diameter reduces the current density near the center of the diameter while increasing the current density at its periphery. In other words, simply increasing the emission diameter causes problems with beam control in the far-field and durability. WO 2019/107273 discloses a substrate back-emission type VCSEL in which a current-constricting structure different from an oxidation-constricting structure is installed on the substrate surface side. With this configuration, while increasing the emission diameter, the current density can be increased not only in the periphery but also in the region near the center of the emission diameter. However, in the case of a substrate back-emission type VCSEL, light is absorbed by the substrate, so depending on the wavelength, such implementation may not be possible or high output power may not be achieved. Japanese Patent Publication No. 2006-114915 discloses a substrate surface-emitting type VCSEL in which a current-constricting structure different from oxidation-constricting is installed on the surface of a device on the light-emitting side by diffusion or ion implantation. Even with such a configuration, by increasing the emission diameter, the current density can be increased not only in the periphery but also in the region near the center of the emission diameter. Japanese Patent Publication No. 2006-114915 discloses a method for forming a current-constricted structure in which current flows only through the central part by increasing the resistance of the peripheral part through ion implantation in the peripheral part of the surface of a substrate. The problem that arises when forming a current-constricted structure in this way is explained with reference to FIG. 13. The VCSEL shown in FIG. 13 has an electrode layer (701), an n-GaAs substrate (702), an n-DBR layer (704), an active region (706), an insulating layer (e.g., oxide) (707), a p-DBR layer (708), a p-GaAs layer (710), and an upper electrode (714). In such a VCSEL, a high-resistance region (712) is formed by ion implantation in the periphery of the p-GaAs layer (710), and furthermore, a current path from the second electrode (714) to the current injection region (720) is left on the upper part of the p-GaAs layer (710). Additionally, a current path from the current injection region (720) to the opening (716) is formed in the p-DBR (708). As a result, the thickness of the p-GaAs layer (710) must be formed in the order of μm. As the distance in the vertical direction of the substrate of the current injection area (720) increases (on the order of μm), the resistance increases, and as a result, the voltage of the entire semiconductor light-emitting device increases. FIG. 1 is a drawing illustrating an embodiment of the present invention. FIGS. 2a and 2b are graphs illustrating the distribution and change of current density according to an embodiment of the present invention. FIG. 3 is a drawing illustrating Example 1. Figure 4 is a drawing illustrating Example 2. Figure 5 is a drawing illustrating Example 3. FIGS. 6a and FIGS. 6b are graphs showing the distribution and change of current density according to Example 3. FIG. 7 is a drawing illustrating Example 4. FIG. 8 is a drawing illustrating Example 5. FIG. 9 is a drawing illustrating Example 6. FIG. 10 is a drawing illustrating Example 7. FIG. 11 is a drawing illustrating Example 8. FIG. 12 is a drawing illustrating Example 9. Figure 13 is a drawing illustrating a comparative example. Embodiments of the present invention are described. The present invention is not limited to the following embodiments, but includes modifications and improvements made to the following embodiments based on the ordinary knowledge of those skilled in the art, within the scope of not departing from the spirit of the present invention. With reference to FIG. 1, a semiconductor light-emitting element (100) according to one embodiment of the present invention will be described. The semiconductor light-emitting element (100) includes a substrate (101), a first Bragg distribution reflector (DBR) (102), a semiconductor cavity resonator (103), and a second DBR (104). The first DBR (102) and the second DBR (104) correspond to the first reflector and the second reflector of the present invention, respectively. A plurality of quantum well layers (140) are arranged inside the cavity