JPS6395681A - Semiconductor light-emitting device - Google Patents

Abstract

PURPOSE:To introduce generated beams to the outside efficiently by forming the central sections of a clad layer, an active layer and a contact layer in multiple quantum well structure and shaping side sections except the central sections in a disordered region. CONSTITUTION:Currents flowing into a device flow only through a current path 7, a region not disordered (a central section 17, an n-type MQW clad layer 13 and an n-type InP substrate 1), by the difference of diffusion potential. Electrons injected from an n-side electrode 4 and holes from a region in which there is no SiO2 insulating film 2 between a p-side electrode 3 and a p-type MQW contact layer 11 are recombined in an active region 12 and converted into beams. Since the disordered MQW layer has a refractive index smaller than an original MQW layer, beams generated in the active region 12 are confined only in the region not disordered, and are not propagated in the cross direction of the device, thus efficiently introducing beams to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor light emitting device, and particularly to a light emitting diode device.

[Conventional technology]

FIG. 2 is a sectional view showing a conventional semiconductor light emitting device. In Figure 2, ■ is an n-type rnP substrate, 2 is a Sin insulating film, 3 is a p-side electrode, 4 is an n-side electrode, 5 is a ball lens, 6 is a resin for fixing the ball lens 5, and 7 is a current flowing current path,
8 is an n-type 1nP cladding layer, 9 is a p-type InCyaAs active layer, 10 is a p-type InP cladding layer, and 11 is a p-type 1nG layer.
aAs:1 contact layer; 12 is an active region;

Next, the operation will be explained. When a positive bias is applied between the p-side electrode 3 and the n-side electrode 4 so that the p-side becomes 10,
Electrons are injected into the device from the n-side electrode 4, and a sin
, holes are injected into the device from the region where the insulating film 2 is not present. In other words, current flows. This current flows along path 7. Electrons and holes injected into the active region 12 in the p-type 1nGaAs active layer 9 are recombined and converted into light. The light generated here propagates through the device and is guided to the outside through the ball lens 5.

[Problem that the invention seeks to solve]

Since the conventional semiconductor light emitting device is constructed as described above, the light emitted toward the substrate 1 out of the light generated in the active region 12 is directly transmitted to the ball lens 5.

The light emitted in the direction of the contact layer 11 is reflected by the n-side electrode 3, passes through the substrate 1, passes through the ball lens 5, and is guided to the outside, but the light is emitted in other directions. The light will disappear without being guided to the outside,
There were problems such as the inability to increase the light output.

The present invention has been made in view of these points, and its purpose is to provide a semiconductor light-emitting device that can efficiently guide light generated in an active region to the outside.

[Means for solving problems]

In order to achieve such an object, the present invention provides a cladding layer having a multi-quantum well structure of a first conductivity type on a semiconductor substrate of a first conductivity type, and a cladding layer of a 15th conductivity type, a second conductivity type, or The active layer has an active region having a multi-quantum well structure of an intrinsic conductivity type, and the side part, which is a region other than the active region, is a disordered region of a second conductivity type, and the center part has a multi-quantum well structure of a second conductivity type. A cladding layer having a structure region and a disordered region of a second conductivity type in a side part which is a part other than the central part, and a cladding layer having a multi-quantum well structure region of a 24th conductivity type in a central part and a part other than the central part. A contact layer having a disordered region of the second conductivity type is provided on the side portion.

[Effect]

The device of the present invention confines the light generated in the active region in the multiple quantum well structure region and efficiently guides the light to the outside.

〔Example〕

An embodiment of a semiconductor light emitting device according to the present invention is shown in FIG. In FIG. 1, 13 is an n-type multiple quantum well structure (
A craft layer 13a of the cladding layer 13 (hereinafter referred to as rMQWJ) is a p
The main region 14 has an n-type, p-type, or intrinsic conductivity type MQW active region 12 in the central part 17.
15 is a cladding layer in which the center portion 17 is a p-type MQW and the side portion 18 is a p-type disordered region;
6, the center part 17 is a p-type MQW, and the side parts 18 are p-type MQW.
The contact layer is a disordered region of the type, 1'H$pn junction.

The side part 18 as a disordered region has M due to Zn diffusion.
This area is a disordered QWwi area, and the side part 18 as a disordered MQW area is the original M Q W ? +Central part 17 which is JI area
The prohibited band width is larger. A large forbidden band width means a small refractive index, and the light generated in the active region 12 is confined in the undisordered region, that is, the central region 17, and the light can be efficiently guided to the outside.

In this example, the MQW is Ino, 53Ga
o, ntA S I n P system or InGaAsP
-InGaAs system, and the relationship between forbidden bands is as shown in the following equation +1).

Eg (active layer)≦Eg (contact layer) <Eg (cladding layer) (1) Next, the operation will be explained. When applying a positive bias such that the p side is 10 between the n-side electrode 3 and the n-side electrode 4,
SiO between the n-side electrode 3 and the p-type MQW contact layer 16
□Current flows into the device from the region where the insulating film 2 is not present. Due to the difference in diffusion potential, the current flowing into the device flows through the current path 7, that is, the non-disordered region (center 17.n-type MQW cladding layer 13.n-type!n
It flows only through the P substrate 1). In the active region 12, the electrons injected from the n-side electrode 4 and the n-side electrode 3 and the p-type MQW
Holes from the region between the contact layers 11 where the SiO□ insulating film 2 is not present are recombined and converted into light. By the way, since the disordered MQW layer has a smaller refractive index than the original MQW layer, the light generated in the active region 12 is confined only to the non-disordered region and cannot propagate in the lateral direction of the device. The system is efficiently guided to the outside.

In the above embodiment, the case of a light emitting diode device with a ball lens has been described, but the same effect can be obtained in other cases as well. Furthermore, although the device in which the SiO□ insulating film is present has been described, the same effect can be achieved even without the 5i02 insulating film.

〔Effect of the invention〕

As explained above, in the present invention, the central part of the cladding layer, the active layer, and the contact layer is made into a multiple quantum well structure region, and the side parts other than the central part are made into disordered regions.
Since the generated light can be confined in the multiple quantum well structure region and prevented from propagating in the lateral direction of the device, it is possible to efficiently guide the generated light to the outside.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a semiconductor light emitting device according to the present invention, and FIG. 2 is a sectional view showing a conventional semiconductor light emitting device. 1...n type! nP substrate, 2...SiO□ insulating film, 3
...p side electrode, 4...n side electrode, 5...ball lens, 6...resin, 7...current path, 12...active region, 13...n type MQW cladding layer, 13a...p
wall region, 14... active layer, 15... p-type rad layer, 16... p-type contact layer, 17... central part, 1
8...Side part, 19...pn junction.

Claims (2)

[Claims] (1) A cladding layer with a multi-quantum well structure of the first conductivity type on a semiconductor substrate of the first conductivity type, and an active multi-quantum well structure of the first conductivity type, second conductivity type, or intrinsic conductivity type in the central part. an active layer having a region other than the active region, the side portions of which are disordered regions of the second conductivity type, and a central portion having a multi-quantum well structure region of the second conductivity type, the portions other than the central portion; A cladding layer having a disordered region of the second conductivity type in the side part thereof, a multi-quantum well structure region of the second conductivity type in the central part, and a second conductivity type disordered region in the side part other than the central part.
A semiconductor light emitting device characterized in that a contact layer having a disordered region of a conductivity type is sequentially laminated. (2) The semiconductor light emitting device according to claim 1, wherein the semiconductor substrate is made of InP, and the cladding layer, active layer, and contact layer are made of InGaAs-based materials.