DE-112024002480-T5 - SURFACE EMITE ELEMENT

Abstract

A surface light-emitting element comprises a substrate, a first multilayer reflector, a semiconductor structure layer, a metal oxide film, and a second multilayer reflector. The first multilayer reflector is formed on the substrate. The semiconductor structure layer comprises a first semiconductor layer with a first conductivity type, formed on the first multilayer reflector; a light-emitting layer, formed on the first semiconductor layer; and a second semiconductor layer, formed on the light-emitting layer, with a second conductivity type opposite to the first. The metal oxide film is translucent, formed on the second semiconductor layer, covers a region at the center of the top surface of the second semiconductor layer, is electrically connected to the second semiconductor layer in a region, is partially formed at a circumferential edge region of the first region, and is insulated from the surface of the second semiconductor layer in the circumferential edge region. The second multilayer reflector is shaped in such a way that it covers one region on the semiconductor structure layer and forms a resonator between the first multilayer reflector and the second multilayer reflector.

Inventors

• Masaru Kuramoto

Assignees

• STANLEY ELECTRIC CO., LTD.

Dates

Publication Date

20260513

Application Date

20240603

Priority Date

20230609

Claims (9)

1. A surface light-emitting element comprising: a substrate; a first multilayer reflector formed on the substrate; a semiconductor structure layer comprising a first semiconductor layer with a first conductivity type formed on the first multilayer reflector, a light-emitting layer formed on the first semiconductor layer, and a second semiconductor layer formed on the light-emitting layer having a second conductivity type opposite to the first conductivity type; a metal oxide film with a translucency or transmittance formed on the second semiconductor layer, covering a region at the center of the top surface of the second semiconductor layer, electrically connected to the second semiconductor layer in that region, partially formed at a circumferential edge region of that region, and insulated from the top surface of the second semiconductor layer in that circumferential edge region; and a second multilayer reflector shaped to cover one region on the semiconductor structure layer and to form a resonator between the first multilayer reflector and the second multilayer reflector.
2. Surface light emission element according to Claim 1 , wherein in the second semiconductor layer a second part along the circumferential edge has a high hydrogen concentration compared to a first part along the one region at the top.
3. Surface light emission element according to Claim 2 , where the hydrogen concentration in the second part is twice as high or more and less than five times the hydrogen concentration in the first part.
4. Surface light emission element according to Claim 1 or 2 , wherein the metal oxide film is shaped with respect to one aspect such that it does not reach an outer edge of the circumferential edge region, in a top view from a direction perpendicular to the top of the second semiconductor layer.
5. Surface light emission element according to Claim 1 or 2 , wherein the metal oxide film has a central part covering one region and an extension part extending radially from the central part, viewed in a top view in a direction perpendicular to the top of the second semiconductor layer.
6. Surface light emission element according to Claim 1 or 2 , wherein the metal oxide film is formed from a first metal oxide film covering one region and from a second metal oxide film shaped such that it is separated from the first metal oxide film at the circumferential edge part, in a top view from a direction perpendicular to the top of the second semiconductor layer.
7. Surface light emission element according to Claim 6 , which has a connecting part that extends radially from the first metal oxide film and connects the first metal oxide film to the second metal oxide film.
8. Surface light emission element according to Claim 1 or 2 , which has an insulating layer with an electrically insulating property formed at the circumferential edge region of the second semiconductor layer.
9. Surface light emission element according to Claim 1 or 2 , where the metal oxide film has a film thickness of 10 nm to 100 nm.

Description

TECHNICAL AREA The present invention relates to a surface emitter element or surface light emission element. TECHNICAL BACKGROUND The surface emitter element, or surface light emitter element, is known as a type of semiconductor laser. For example, patent document 1 discloses a surface emitter laser (VCSEL = Vertical Cavity Surface Emitting Laser) comprising a semiconductor structure layer, which includes an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer, and has a projecting part formed on a top surface of the p-type semiconductor layer, further comprising an insulating layer formed on a top surface of the p-type semiconductor layer, and a transparent electrode layer, which includes the insulating layer and is formed on the top surface of the p-type semiconductor layer. CITATED DOCUMENTS PATENT LITERATURE Patent document 1: JP-A-2021-197437 REVELATION OF THE INVENTION PROBLEMS TO BE SOLVED BY INVENTION In the surface emitter, or VCSEL, disclosed in patent document 1, for example, a threshold current increases in conjunction with a long current application period, which can reduce the emitted light output. As a countermeasure, attempts are made, for example, to increase the threshold current using hydrogen, which is injected or introduced into the p-type semiconductor layer. However, depending on the hydrogen concentration in the p-type semiconductor layer, the current flow can be excessively suppressed, which can lead to a reduced light-emitting area of the surface emitter laser. The present invention has been carried out taking into account the point described above, and one objective of it is to provide a surface light emission element which can avoid a reduction of a light emission area or a light-emitting area, while also avoiding a reduction of an optical output. SOLUTIONS FOR THE PROBLEMS A surface light-emitting element according to the present invention comprises a substrate, a first multilayer reflector, a semiconductor structure layer, a metal oxide film, and a second multilayer reflector. The first multilayer reflector is formed on the substrate. The semiconductor structure layer comprises a first semiconductor layer with a first conductivity type, formed on the first multilayer reflector; a light-emitting layer, formed on the first semiconductor layer; and a second semiconductor layer, formed on the light-emitting layer, having a second conductivity type opposite to the first. The metal oxide film is translucent, formed on the second semiconductor layer, covers a region of a central portion of a top surface of the second semiconductor layer, is electrically connected to the second semiconductor layer in a region, is partially formed at a circumferential edge portion of a region, and is insulated from a surface of the second semiconductor layer in the circumferential edge region. The second multilayer reflector is shaped in such a way that it covers one region on the semiconductor structure layer and forms a resonator between the first multilayer reflector and the second multilayer reflector. BRIEF DESCRIPTION OF THE DRAWINGS 1 is a perspective view of a surface emitter laser or VCSEL according to Example 1.2 is a top view of the surface emitter laser according to Example 1.3 This is a cross-sectional view of the surface emitter laser according to Example 1.4 This is a cross-sectional view of a surface emitter laser according to a conventional example.5 is a top view of a surface emitter laser according to a modification of Example 1.6 is a top view of a surface emitter laser according to a modification of Example 1.7 is a top view of a surface emitter laser according to a modification of Example 1.8 is a cross-sectional view of a surface emitter laser according to Example 2. DESCRIPTION OF PREFERRED EXECUTION EXAMPLES The following describes specific examples of the present invention with reference to the drawings. It should be noted that the same components are identified by the same reference numerals in the drawings and that descriptions of overlapping or corresponding components are omitted. [Example 1] Using 1 until 3 A configuration of a Vertical Cavity Surface Emitter Laser or VCSEL 100 (hereinafter referred to as Surface Emitter Laser 100) is described according to Example 1. 1 This is a perspective view of the Surface Emitter Laser 100. 2 is a top view of the surface emitter laser 100, and 3 is a cross-sectional view taken along line 3-3 of the surface emitter laser 100, which is located in 2 This is illustrated. It should be noted that an up-down direction is shown in the drawing. 3 a height direction of the surface emitter laser 100 is. A substrate 11 is a flat, plate-shaped, transparent substrate with a rectangular top surface. The substrate 11 is a growth or cultivation substrate that allows the growth or cultivation of a semiconductor crystal on its top surface. The substrate 11 is made, for example, of a material that is translucent or transm