JPS63141379A - Semiconductor light emitting device - Google Patents

Abstract

PURPOSE:To obtain an end luminescence-type semiconductor light emitting device generating a large output power of lights by making up an active layer and lower-upper clad layers in which the active layer is sandwiched with a multi quantum well MQW and by causing the MQW to be disordered after diffusing impurities with the exception of the active region that is composed of a plurality of stripes as well as a part of an optical waveguide. CONSTITUTION:A non-disordered region 9 and a light irradiation region 10 where n<->MQW clad layer 2P-MQW active layer 3P-MQW clad layer 4Cd/ diffused region 8Cd are not diffused are provided. Active layer 3 in the non- disordered region 9 has a higher refraction factor than that of the other parts and makes up an optical waveguide. Accordingly, lights generated at a plurality or stripes pass through the optical waveguide which is formed at the non- disordered region 9 and are condensed into one stripe in the vicinity of an end face and then, it is radiated outside out of a light radiation region 10. Since such a structure allows a plurality of stripes to generate lights, an output power of the lights is larger than that which is generated by one stripe as has been most commonly used in the conventional end luminescence-type LEDs.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor light emitting device, and particularly to an edge emitting type light emitting diode device (hereinafter abbreviated as LED).

[Conventional technology]

FIG. 4 is a perspective view showing a conventional edge-emitting IJD device. In the figure, 1 is an n-type (hereinafter abbreviated as n-) type. P
The substrate, 12 is an n-I nP cladding layer, 13 is a P-type (
(hereinafter abbreviated as P-)IttGaAsP active layer, 14 is P-
InP 2 Rad layer, 5 is P-I nG, A, P contact layer, 16 is 5IO2 insulating film, 6 is P side electrode, 7 is n
This is the side electrode.

In such a configuration, if a bias is applied between the P-side electrode 6 and nIII and the pole 7 so that PIIIlt&6 becomes positive, the pH will change to 11 without the Siα insulating film 16 between the pole 6 and the contact layer 5. Holes are injected from the rectangular portion and electrons are injected from the n9111% pole 7 into the device. The injected electrons and holes are recombined within the active layer 13 and converted into light, and the light is radiated to the outside from the end face of the LED. Most of the light generated far from the end face is reabsorbed by the crystal while propagating within the LED. Therefore, in order to efficiently convert the current back to the source and take it out of the device, a structure is generally adopted in which ohmic contacts are provided only in the vicinity of the end faces, as shown in FIG.

[Problem that the invention seeks to solve]

Conventional edge-emitting LED! ! Since the device is configured as described above, there is a problem that the light output cannot be sufficiently large compared to the surface emitting ff1 LED.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an edge-emitting type semiconductor light-emitting device that can provide a large light output.

[Means for solving problems]

In the semiconductor light emitting device according to the present invention, the active layer and the upper and lower cladding layers sandwiching the active layer are composed of multiple quantum wells (hereinafter abbreviated as MQW), and the active region composed of a plurality of stripes and the optical waveguide portion are free of impurities. It is MQWt-disordered by spreading it.

[Effect]

The active region and optical waveguide composed of a plurality of stripes in the present invention generate light in the plurality of stripe-shaped active regions near the end face, collect this light into a single waveguide, and transmit the light from the end face to the outside. radiate.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a perspective view of a semiconductor light emitting device showing an embodiment of the invention, and the same parts as in the previous figures are given the same reference numerals. . In the figure, 2 is an n-MQW cladding layer, 3 is a P-MQW active layer, 4 is a P-MQW cladding layer, and 8 is a C
d diffusion region, 9 a non-disordered region in which Cd is not diffused, and 10 a light emission region. Moreover, FIG. 2 is a diagram showing a cross section taken along the line AA' in FIG. 1, and in the diagram,
11 indicates the position of the Pn junction. Also, Figure 3 (,
) and Figure 3(b) are lines BB' and C-C' in Figure 2.
FIG. 2 is a diagram showing a refractive index distribution along a line.

Here, the n-MQW cladding layer 2. P-MQW active layer 3
．． Let Ef(n-
d), Ey(A-IJ, ), Et<p-ct), then Et(A, L, K Er(n-Ct)=Er(P-Ct)
) The prohibited band width for each layer is set so that the following relationship holds true.

In such a configuration, if a bias is applied between the P-side electrode 6 and the n-side electrode 7 so that the P-side electrode 6 becomes positive,
Current flows within the device. In this example, the Pn junction is formed over the entire surface of the device, but the diffusion potential of the Pn junction is that of the Pn junction in the non-disordered region 9 where CD is not diffused, and that of the Pn junction of the Cd diffusion region 8. smaller than Therefore, current is selectively injected only into the non-disordered region 9. The injected current is converted into light within the active layer 3. By the way, MQWis
The structure is disordered by the diffusion of impurities, and in the disordered region, the forbidden band is larger than that in the non-disordered region, and the refractive index becomes smaller. Therefore, in the lateral direction of the active layer 3 in the non-disordered region 9 (BB'l in FIG.
The refractive index distribution of J) is as shown in Figure 3 (,).

Further, the refractive index distribution in the vertical direction (line cc' in FIG. 2) is in the form shown in FIG. 3(b), like a normal double heterostructure. The active layer 3 within the non-disordered region 9 has a higher refractive index than other portions, and forms an optical waveguide. Therefore, the light generated in a plurality of stripes propagates through the waveguide formed in the non-disordered region 9, is collected into one stripe near the end face, and is radiated outside the light emitting region 10 on the end face.

According to such a configuration, since light is generated with a plurality of stripes, the light output can be increased compared to a conventional edge-emitting ID that generates light with a single stripe.

In the above embodiment, the number of stripes is three, but it goes without saying that the number of stripes may be any number.

Further, in the above embodiment, the impurity diffusion front is located in the cladding layer on the side closer to the substrate, but the diffusion may also be carried out to the substrate, and the same effect as in the above embodiment can be obtained. .

〔Effect of the invention〕

As explained above, according to the present invention, the active layer and the upper and lower cladding layers sandwiching it are composed of MQW, and the stripe portion is one stripe near the light emitting end face and branches into multiple stripes in a region away from the active layer. Since the MQW is disordered by diffusing impurities to other locations, an edge-emitting type semiconductor light-emitting device with a large optical output can be obtained, which is an extremely excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a semiconductor light emitting device according to an embodiment of the present invention, FIG. 2 is a sectional view of a stripe portion of the semiconductor light emitting device according to an embodiment of the present invention, FIG. 3(a), FIG. (b) is a diagram showing a refractive index distribution, and FIG. 4 is a perspective view showing a conventional semiconductor light emitting device il:. 1...n-InP based substrate...Fist/n-Ni MQW cladding layer, 3...-MQW active layer, 4...
・P-MQW cladding layer, 5...P-I, llG
, A, P contact layer, 8---Cd diffusion region, 9.
...Non-disordered region, 10...Light emission region, 11
...Pn junction position. Agent Masuo Oiwa Figure 3 Figure 4 procedural amendment (voluntary)

Claims (2)

[Claims] (1) A cladding layer having a multi-quantum well structure of a first conductivity type, an active layer having a multi-quantum well structure of a first, second or intrinsic conductivity type, and a second conductivity on a semiconductor substrate of a first conductivity type. A cladding layer with a type multi-quantum well structure and a contact layer of a second conductivity type are sequentially laminated, and one stripe is formed near the light emitting end face and branches into multiple stripes at a location away from the light emitting end face. A semiconductor light emitting device characterized in that a multi-quantum well structure is disordered by diffusing an impurity that causes a second conductivity type to a portion other than the separated stripes to a cladding layer or a semiconductor substrate of a first conductivity type. (2) The second conductivity type contact layer is made of InGaAs.
The optical semiconductor light emitting device according to claim 1, characterized in that it is made of a P-based material.