JPS63107076A - Semiconductor light emitting element - Google Patents

Abstract

PURPOSE:To obtain an element wherein light emission of high luminance is available, converging property of light is excellent, and the efficiency of current injection into an active region containing a pn junction is more increased, by forming, on a part for forming an active region on a semiconductor plate material, at least one double heterojunction and a p-n junction extending in the vertical direction to the semiconduc tor plate material. CONSTITUTION:The title element comprises the following; a semiconductor plate material, a part for forming an active region containing a p-n junction PN, at least one double heterojunction and a p-n junction PN extending in the vertical direction to the semiconductor plate materiel which are formed on a part for forming an active region. An active region constituted of the double heterojunction and the p-n junction PN, a lower electrode E2 and an upper electrode E1 are formed. The polarity of the upper electrode is different from that of the lower electrode arranged in an arbi trary part of the semiconductor plate material other than the part where the lower electrode is arranged. For example, on an n-type GaAs substrate B, the following are formed; a cylindrical protrusion P constituted of an n-type AlGaAs layer, an n-type GaAs active layer and an n-type AlGaAs layer, a p-side electrode E1, an n-side electrode E2 made of high reflectivity material, an upper resistive layer 1 and a lower resistive layer 2.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a surface-emitting semiconductor light-emitting device, and in particular, a semiconductor light-emitting device that is most suitable for inspection of tapes, display of OA equipment, etc., or optical fiber communication. It is related to.

[Prior art/problems to be solved by the invention] A semiconductor light emitting device that emits light in a direction perpendicular to a semiconductor plate material (including a substrate and a crystal layer provided on the substrate) cannot be coupled to an optical fiber. It is easy to use, and by forming a one-dimensional or two-dimensional array structure as a surface light emitter, it is expected to have various uses such as inspection of tapes, display of OA information equipment, etc., and optical fiber communication. Since then, development has been progressing in the research field of semiconductor lasers and light emitting diodes.

Therefore, the present inventors have proposed a light emitting element having a structure as shown in FIGS. 13, 14, and 15 as a light emitting element that emits light in a direction perpendicular to the substrate. First, the light emitting element shown in FIG. 13 includes a substrate B, a cylindrical projection P provided on one side of the substrate B, and a p-side electrode E1 provided on the side peripheral surface of the cylindrical projection P and the upper surface of the substrate B. , and an n-side electrode E2 provided on the lower surface of the substrate.
There is a pn junction PN extending perpendicularly to the substrate B.
There is also a resistor 1i1Q made of 5tat or StN* under the electrode 1!1 on the upper surface of the substrate B. In this light emitting device, the active region is constituted by a homojunction, that is, the pn junction PN is formed by diffusing p-type impurity such as zinc (Zn). Further, the light emitting element shown in FIG. 14 is characterized by the protrusion P. That is, the protrusion P provided on one side of the substrate B has the shape of an elongated square column extending across the surface,
Moreover, the length of this protrusion P is at least 100 to 75,
000-, therefore, the active region including the pn junction PN extending within the protrusion P also exists in the direction that traverses the protrusion P along the side surface of the protrusion P. Furthermore, in the light emitting device shown in FIG. 15, a truncated cone-shaped through hole H extending from the upper surface to the lower surface of the substrate B is formed in the bases vi, B, and Zn is diffused into the inner wall surface of the through hole H to form an inner surface. pn junction PM extending along the wall surface
An electrode E1 is provided on the inner wall surface of the through hole H and the lower surface of the substrate B, and an annular electrode E2 is provided on the upper surface of the substrate B.

In each of these light-emitting elements, by passing a current between the electrodes El and E2, the light is emitted from the protrusion P in the ones shown in FIGS. 13 and 14, and from the through hole H in the one shown in FIG. 15 to the substrate B. On the other hand, point-like light can be emitted in the vertical direction in FIGS. 13 and 15, and linear light can be emitted in FIG. 14, respectively.

By the way, optical fiber communication is broadband, multiplex bidirectional,
It has characteristics such as noise resistance and non-inductive properties, and considering the transmission band of optical fiber, as a semiconductor material, the emission wavelength (approximately the bandgap energy of the semiconductor material) is in the low loss region of silica-based optical fiber. A high-quality epitaxial crystal with a 0.7
~0.9P, band GaAs/AlGaAs system, 1~L
In the 7P band, the InGaAsP/InP system is mainly applicable, and in addition to this, it is also used for low-cost plastic fibers that have recently been improved (AI).

Ga, In) (P + As) system 0.5 to 0.
For 7p-band light emitting devices and ultra-low loss halide or chalcogenide fibers, (AI, Ga, In)
to P+8, Sb) system and (Pb, 5n)-(Se+ Te
) series 2 to 10. Application of a band-shaped light emitting element is considered.

Although all of the light emitting elements having the above structure have a certain degree of emission wavelength bandwidth, they only emit light at a roughly constant wavelength. In optical fiber communication, it is preferable to use a light emitting element that emits light as high as possible in consideration of optical loss in the transmission band of the optical fiber. The need for multi-wavelength communications using optical fibers will continue to increase as optical fiber communications progress and demand increases, and a light-emitting element that emits light of different wavelengths can meet this demand.

Therefore, an object of the present invention is to use an OAi
It is ideal for display devices and optical fiber communications, emits light with high brightness, and has excellent light focusing properties.
It is an object of the present invention to provide a semiconductor light emitting device with further improved current injection efficiency into an active region including a pn junction.

Another object of the present invention is to provide a light emitting device that emits light at high brightness at various wavelengths and is suitable for inspection of tapes, display of 0A equipment, or optical fiber communication, particularly for multi-wavelength communication using optical fiber. An object of the present invention is to provide a semiconductor light emitting device that has excellent light focusing properties and further improves current injection efficiency into an active region including a pn junction.

[Means for solving problems]

The purpose is to provide a semiconductor plate (including a substrate and a crystal layer provided on the substrate, the same shall apply hereinafter), a portion of the semiconductor plate for forming an active region including a pn junction, and a portion for forming the active region. At least one double heterojunction and a pn junction extending perpendicularly to the semiconductor plate are formed, and an active region formed by the double heterojunction and the pn junction, a lower electrode provided on the lower surface of the semiconductor plate, and a semiconductor This is achieved by a semiconductor light-emitting element comprising an upper electrode having a different polarity from the lower electrode provided on any part of the plate material other than the part where the lower electrode is provided.

The semiconductor light emitting device of the present invention is basically as shown in FIGS. 13, 14, and 15 previously proposed by the present inventors, that is, it extends perpendicularly to the substrate. pn
It has an active region including an n-junction, and is an improved version of the one in which a resistive layer made of 5i (h, SiN*, etc.) is provided so that current can be efficiently injected into the active region.Therefore,
The light emitting device of the present invention has at least one double heterojunction and a pn
The double heterojunction and the pn junction constitute an active region, and carriers are efficiently confined in the active region, allowing high-brightness light emission to be obtained. In the case where a plurality of active regions are formed, a plurality of active regions exist in the active region forming portion, and light of different wavelengths can be emitted from the active region. This can be achieved by forming the active region forming portion with semiconductor materials having different forbidden band widths of compound semiconductors. For example, the active region forming portion may be made of AlGa
In the case of depositing an As epitaxial growth layer, A
AlGaAs layers with different I contents are sequentially epitaxially grown to form a double heterojunction, and then a p-type impurity (for example, Zn) is diffused into the active region forming part, or the layers constituting the double heterojunction are An example is a structure in which a layer of a conductivity type different from the conductivity type is epitaxially grown around the active region forming portion.

Specifically, the semiconductor materials include m-v group compound semiconductors such as GaAs, GaP, AlGaAs, and 1n.
P, InGaASP% InGaP, InAIP,
GaAsP, GaN, InAsP, InAsS
b etc., Zn5es Z which is a II-Vl group compound semiconductor
n5SZnOsCdSe, CdTe, etc., IV-VT
Group compound semiconductors pbTe, Pb5nTe, P
There are materials such as b5nSe, and SiC, which is an N-1)V group compound semiconductor, and by utilizing the advantages of each material, it is possible to vary the emission wavelength.

In the present invention, in the phrase "an active region including a pn junction extending perpendicularly to a semiconductor board material (including a substrate and a crystal layer provided on the substrate)", "perpendicular direction" is used. The meaning of the phrase need not be construed exclusively as perpendicular to the substrate at an angle of 90 degrees, but also includes angles of inclination slightly larger or smaller than 90 degrees with respect to the substrate.

〔Example〕

Hereinafter, the semiconductor light emitting device of the present invention will be explained based on Examples.

A first embodiment of the semiconductor light emitting device of the present invention is shown in FIG. 1 and FIG. This is an improved version of the one shown in Figure 1, which consists of a substrate B made of n-type GaAs and an n-type AlG epitaxially grown on the substrate B.
A cylindrical projection P formed from an aAs layer, an n-type GaAs active layer, and an n-type AlGaAs layer, and a p side electrode E1, an n-side electrode E2 made of a material with high reflectance provided on the lower surface of the substrate B, an upper resistance layer 1 interposed under the electrode E1 on the upper surface of the substrate B, and a It is composed of a lower resistance layer 2 interposed on an electrode E2 at a position facing the upper resistance layer 1. Further, a circular groove 5 is formed on the lower surface of the substrate B at a position facing the active region, and the lower abrasive layer 2 is not present in the groove 5. The protrusion P is made of the n-type AlGa ^5liiSn type G
A double heterojunction structure is formed by the aAs active layer and the n-type ^lGaAs layer, and p-type impurities (for example, Zn) are diffused along the side circumferential surface to form a diffusion region extending perpendicularly to the substrate B. A pn junction PN is formed at the diffusion front, and an active region is constituted by the double heterojunction and the pn junction PN.

In the light emitting device of this example, when a current is injected between the electrodes E1 and E2, carriers are efficiently confined within the active layer due to the band gap difference between each layer. The carriers are recombined at the bonding surface, and light is emitted from the tip of the protrusion P in a direction substantially perpendicular to the group ViB with high brightness. Moreover, the current flows from the electrode E1 on the side peripheral surface of the protrusion P through the active region to the electrode E2 provided in the groove 5, but from the electrode E1 on the upper surface of the substrate B to the electrode E2 on the lower surface of the substrate B. Since the upper and lower resistance layers 1.2 prevent current from flowing to the electrodes E2 other than the electrode E2 in the groove 5, the efficiency of current injection into the active region is further improved, resulting in an increase in response speed and an increase in luminance. will increase. Furthermore, since the electrode E2 in the groove 5 is made of a material with high reflectance, it presents a reflective surface, and among the light emitted in the active region, the light traveling in the direction of the lower surface of the substrate B is reflected upward, so that the light extraction efficiency is improved. improves the light output.

Such a light emitting element emits light from the tip of the protrusion P in a direction perpendicular to the substrate B, and the light from the active region has excellent convergence and emits light with high brightness, so it can be easily inspected,
It is ideal for display or communication purposes.For example, to connect an optical fiber and use it for communication purposes, the optical fiber can be easily connected to the top surface of the protrusion P, and high-intensity light can be transmitted to the optical fiber. can.

In the first embodiment, a pn junction PN and a double heterojunction are formed on a cylindrical protrusion P, which is similar to the light emitting device shown in FIG. 13 that was previously proposed by the present inventors. As an improvement, a second embodiment of the light emitting device shown in FIG. 14, also proposed by the present inventors, is shown in FIG.

The light emitting device of the second embodiment has the same cross section as that shown in FIG. A pn junction PM and a double heterojunction are formed within the single protrusion P, and both constitute an active region.

This light-emitting element emits light in a linear manner, whereas the first embodiment emits light in a dotted manner, so it is especially suitable for inspection of tapes, and a device of a size corresponding to the width of the tape is used. When used for inspection, it is possible to irradiate uniform and high-intensity light over the entire width of the tape, making it possible to improve inspection sensitivity. Furthermore, in the case of a two-dimensional array of light emitting elements having the above structure, for example, one in which three mutually parallel elongated protrusions P are provided on the base IB, when coupling with an optical fiber, it is necessary to align with the protrusions P. A light-emitting element with multiple protrusions P provided on the substrate B according to the purpose can be easily coupled with optical fibers, and can be used in a two-dimensional array using optical fibers arranged in three rows to form a two-dimensional array. Above all, it is extremely convenient.

In order to further narrow the light emission angle and increase the directivity of light in the light emitting element of the first embodiment, for example, as shown in FIG. The hole 15 may be formed in the protrusion P, and as shown in FIG. By inserting it into this cylindrical hole, the optical coupling efficiency with the optical fiber can be improved.

Next, an example of a method for manufacturing a semiconductor light emitting device having the structure shown in FIG.
Figure (al ~ (explained with reference to the eyes).

First, liquid phase epitaxial growth (LPE) and molecular beam epitaxial growth (MBE) were performed on n-type GaAs substrate B.
Alternatively, the n-type AlGaAs layer L1 and the n-type GaAs active layer 1i are formed using metal organic pyrolysis vapor deposition (MOCVD) or the like.
A double heterojunction is formed by sequentially epitaxially growing L2 and n-type ^IGa^3 layer L3 (Fig. 6 + al
Reference) In order to perform 0-order photolithography, n-type AI
5ift, SiN, film, etc. are formed on the top surface of the GaAsWiL3, and then a resist R is applied, and a desired pattern is exposed and developed on the top surface of the n-type AIGaAa layer L3 to perform etching, using an RIE or RIBE etching mask. (See FIG. 6(b)).

Thereafter, the n-type AIGaAsJiiL1, n-type GaAs active layer L2, and n-type AIGaAsJiL3 are ion-etched to a predetermined depth by, for example, reactive ion etching (RIE) or reactive ion beam etching (RrBE), and are etched onto the substrate B. In order to form a cylindrical protrusion P having a predetermined height, a masking agent (for example, 5totSSiN+, etc.) is applied to the upper surface of the substrate B by electron beam evaporation, sputtering, CVD, etc. on the upper surface of the substrate B. (see Figure 6(d)). Then, a p-type impurity (preferably Zn
) to form a diffusion region extending perpendicularly to the substrate B within the protrusion P, and change the conductivity type of this region to p.
This forms a pn junction PN at the interface between the n-type region in which impurities are not diffused and the diffusion front. At this time, it is also possible to form a diffusion region on the lower surface of the substrate B and make this region p-type GaAs to serve as the lower resistance layer 2. Alternatively, the lower resistance layer 2 can be formed by forming an insulating layer (Stew,
SiN, etc.) can also be formed by electron beam, sputtering, CVD, etc. (see FIG. 6 (el)).

After the diffusion process, a portion of the lower surface of the substrate B facing the protrusion P (active region composed of a double heterojunction and a pn junction PN) is etched by ion etching by RIE or RIBE, or by wet etching, etc., to remove the portion. Remove the unnecessary lower resistance layer to form a circular groove 5 (see FIG. 6(f)), and then remove the p-side electrode material on the side circumferential surface of the protrusion P, the upper surface of the substrate B, and the resist P. For example, the electrode E1 made of Cr-Au, and the substrate B
An electrode E2 made of, for example, Au is provided on the lower surface of the protrusion P and in the groove 5 as an electrode material with high reflectivity on the n side by means such as vacuum deposition (see FIG. 6). Remove resist R by lift-off method (
(See Fig. 6 Th)) As shown in Fig. 1, a double heterojunction and a
has a pn junction PN extending perpendicularly to the electrode E1 on the upper surface of the substrate B and the electrode E2 on the lower surface of the substrate B.
A semiconductor light emitting device is manufactured with upper and lower resistive layers 1.2 interposed thereon, respectively.

A third embodiment as a modification of the one shown in FIG. 2 is shown in FIG. 7. In this third embodiment, the basic structure is the same as that in FIG. The difference is that a heat dissipation layer 7 made of conductive paint (for example, conductive paint such as silver epoxy, silver polyimide, gold epoxy, or silver glass) is provided on the active area. Improves heat dissipation due to light emission.

The light emitting device shown in FIG. 8 is a fourth embodiment, and has five active layers within the cylindrical projection P of a double heterojunction structure.In other words, within the projection P there are five double heterojunctions and a pn junction PN. Therefore, a plurality of active regions exist. That is, the protrusion P has an n-type^lGaAs active layer and an n-type AlG
By epitaxially growing these two layers alternately with different AI contents to form an nW-n'' type-n type isohetero structure, carriers are efficiently confined within each active layer. This makes it possible to obtain light of different wavelengths simultaneously, making it ideal as a light source for multi-wavelength communications using optical fibers.

The manufacturing method of the light emitting device having the above structure is basically completely the same as the manufacturing method of the first embodiment shown in FIG.
N-type AlGaAs was epitaxially grown on As substrate B, and an n-type ^lGaAs active layer was further grown on this layer five times.
It is sufficient to provide n9-type IGaAsN epitaxially grown four times alternately.

In all of the above embodiments, the pn junction PN is formed by diffusion of p-type impurities (for example, Zn).
A fifth embodiment in which the junction PN is formed by a heterojunction is shown in FIG. 9 (al, O1+). In this light emitting device, the heat dissipation layer 7 that also serves as heat dissipation is made of p-type AlGaAs and forms a double heterojunction. n-type AlGaAs and pn junction PH
is formed. The upper electric bridge E1 has an annular shape so as to surround the pn junction PN exposed on the upper surface of the light emitting element, thereby providing excellent high-speed response.

Next, an example of the method for manufacturing the light emitting device of the fifth embodiment shown in FIG. 9 will be explained in the case where an n-type GaAs substrate is used.
This will be explained with reference to FIGS. 10(a) to 10('').

First, the entire upper surface of the n-type GaAs substrate B is coated with, for example, LPE.
, MBE or MOCVD etc.
sjiL1, n-type GaAs active layer L2 and n-type AlGa
The As layer L3 is epitaxially grown in sequence to form a double heterojunction (see Figure 10+8).Next, in order to perform photolithography, an n-type AIGaAsj! i
Form a film such as Sing, SiN, etc. on the top surface of L3, and then apply resist R to form a desired pattern with n-type AlG.
The upper surface of the aAs layer L3 is exposed and developed to form an etching mask for RIE or RIBE. As shown in FIG. 10 (see BL), the n-type AlGaAs layer L1 and the n-type GaAs active layer L are
2 and n-type AIGaAsJiL3 to a predetermined depth to form a cylindrical layer having a predetermined height on the substrate B (see Figure 10+8+), masking agent (for example, SlO□) is applied to the upper and lower surfaces of the substrate B. , StN, etc., which can be applied by electron beam evaporation, sputtering, CVD, etc.
Upper and lower resistive layers 1.2 are respectively provided (see FIG. 10 (dl)).

Next, p-type AlG was applied to the side circumferential surface of the columnar layer by LPE.
An aAs epitaxial growth layer is provided, and this layer is used as a heat dissipation layer 7.
This heat dissipation layer 7 and the columnar layer form a pn junction PN extending perpendicularly to the substrate B (see FIG. 10(e)).

After that, a portion of the lower surface of the substrate B facing the active region formed by the double heterojunction and the pn junction PN is subjected to RI.
The lower surface of the substrate B is etched by ion etching using E or RIBE, or by wet etching to remove the unnecessary lower resistance layer in the area to form a circular groove 5. and n in the groove 5
An electrode E2 made of, for example, Au is provided as a high-reflectance electrode material on the side by means such as vacuum deposition (see Fig. 10).
(see cup). Then, photolithography is performed (resist R' is applied along the edge of the upper surface of the heat dissipation layer 7 and patterned).
An electric IE1 made of, for example, Cr-Au is provided on R' and on the upper surface of the heat dissipation layer 7 (see Fig. 10).
1)), and finally, the unnecessary electrode E1 on the resists R and R' is removed together with the resists R and R' by the lift-off method (see Figure 10 ('')), as shown in Figure 9. A light emitting device with a structure is manufactured.

Further, Fig. 1) (al, mountain) shows a sixth embodiment, which is an improvement of the one in Fig. 15, and has a double heterojunction and a pn junction PN like the first to fifth embodiments. By efficiently confining carriers in the active layer, high-intensity light emission can be obtained from the through-hole H.

An example of the manufacturing method of the sixth embodiment will be described below.
The case where a substrate is used will be described with reference to FIGS. 12(a) to (Jl).

First, on an n-type GaAs substrate B, an n-type ^lGaAs1Ll
, n-type GaAs active layer L2 and n-type AIGaAs JWL
3 is sequentially epitaxially grown by LPE, MBE, MOCVD, etc. to form a double heterojunction. A mask layer M is applied using a known masking agent (for example, Sing, SiN, etc., which can be applied by electron beam evaporation, sputtering, CVD, etc.) (see FIG. 12 (bl)). In order to perform this, a resist R is applied on the mask layer M, and a ring-shaped pattern (
The mask layer M is patterned by ion etching by RIE using CF, gas, etc. Figure 12 (see dl).

After etching, a hole is made in the center of the n-type GaAs substrate B using, for example, RIB or RIBB, and ion etching is performed while creating a taper to penetrate the hole into the element, thereby forming a truncated cone-shaped through hole H in the element. (Figure 12(e)
), the mask layer M and the resist R applied during the above steps are present on the bottom surface of the substrate B. For example, Z as a p-type impurity.
Zn is diffused to form a diffusion region extending perpendicularly to the substrate B along the inner wall surface of the through hole H, and the conductivity type of this region is set to p type, thereby causing Zn to diffuse. A pn junction PN is formed at the interface between the n-type region and the diffusion front (see FIG. 12(f)), and a diffusion region is also formed on the upper surface of the layer L3 in this step (fl). is removed by polishing.

After the diffusion process, the resist ()R on the bottom surface of the substrate B is replaced with NH2F-
Lift off using IP buffer etching, etc.
The mask layer M is used as the lower resistance layer 2, and a p-side electrode material such as Cr is applied to the inner wall surface of the through hole H and the lower surface of the group viB.
- An electrode El made of Au is provided by means such as vacuum evaporation (see Figure 12 (illustration)) Next, in order to perform photolithography, an electrode El made of Au is provided to cover the exposed diffusion region on the upper surface of the element whose orientation is reversed. As shown in Fig. 12 (see HL), an electrode E2 made of, for example, Au-Ge is formed as an n-side electrode material on the upper surface of the element and on the resist R° in the same manner as the electrode E1. (See Figure 12 (1))
, Finally, remove unnecessary electrode E2 on resist R° from resist I
By removing -R' together with the lift-off method (see FIG. 12, 01), a light emitting device having the structure shown in FIG. 1) is manufactured.

In the present invention, the electric currents JiE1 and E2 are not limited to the sizes and shapes shown in the embodiments, but can be arbitrarily selected as long as current can be efficiently injected into the active region formed by the double heterojunction and the pn junction PN. It can be provided in any size and shape.

〔Effect of the invention〕

As is clear from the above, the semiconductor light emitting device of the present invention is
Semiconductor board material (including the substrate and the crystal layer provided on the substrate)
providing an active region forming portion including an n-junction, forming at least one double heterojunction and a pn junction extending perpendicularly to the semiconductor plate material in the active region forming portion;
By configuring the active region with double heterojunctions and p-n junctions, carriers are efficiently confined in the active region and high-intensity light is obtained.Furthermore, by forming multiple double heterojunctions, light of different wavelengths from the active region can be obtained. It emits high-intensity light, making it ideal for inspecting tapes, displaying OA equipment, and optical fiber communications (particularly multi-wavelength communications), as well as being easy to connect with optical fibers. The manufacturing process is simple and mass production is possible, and any light emitting pattern can be obtained during the manufacturing process, making it very useful in practice.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a first embodiment of a semiconductor light emitting device of the present invention, FIG. 2 is a perspective view of a second embodiment of a light emitting device of the present invention, and FIG. 3 is a circle of the first embodiment. A sectional view in the radial direction of the columnar projection and in the transverse direction of the projection of the second embodiment, FIG. 4 is a sectional view showing a modified example of the light emitting element shown in FIG. 1, and FIG. A cross-sectional view showing the coupling state of the light emitting element and the optical fiber, Fig. 6 (al to (hl) is a flowchart showing an example of the manufacturing process of the light emitting element shown in Fig. A perspective view of a third embodiment that is a modified example of the light emitting element,
FIG. 8 is a cross-sectional view of a fourth embodiment of the light emitting device of the present invention;
Figure 9 fat, (bl shows the fifth embodiment of the light emitting device of the present invention, ia) is a cross-sectional view thereof, (b) is a perspective view, and Figure 10 (al~0) is the same as in Figure 9. A flowchart showing an example of the manufacturing process of the light emitting device shown in FIG. ) is a cross-sectional view, Figure 12 (5) to (
Jl is a flowchart showing an example of the manufacturing process of the light-emitting device shown in Figure 1), Figures 13 and 14 are perspective views of the light-emitting element previously proposed by the present inventors, and Figure 15 is the same. 1 is a partially cutaway perspective view of a light emitting element previously proposed by the present inventors. B: Substrates L1 to L3: Epitaxial growth layer P: Protrusion El i P side electrode E2: N side electrode PN: pn junction H2 through hole 1 2 Upper resistance layer 2: Lower resistance layer 5: Groove 7: Heat dissipation layer 15: Cylindrical hole 20; Optical fiber M: Mask layer R, R'? Resist patent applicant New Technology Development Corporation (and 6 others) Figure 4 Figure 5 Figure 8

Claims (7)

[Claims] (1) A semiconductor plate, a portion provided on the semiconductor plate for forming an active region including a pn junction, at least one double heterojunction in the active region forming portion, and a portion extending perpendicularly to the semiconductor plate. an active region formed by this double heterojunction and pn junction, a lower electrode provided on the lower surface of the semiconductor board material, and a lower part provided in any part of the semiconductor board material other than the part where the lower electrode is provided. A semiconductor light emitting device comprising an upper electrode having a polarity different from that of the electrode. (2) Upper and lower resistance layers are provided between the upper electrode and the lower electrode so as not to impede the flow of current through the active region of the active region forming portion. 1) The semiconductor light emitting device described in item 1). (3) The semiconductor light emitting device according to claim (1) or (2), wherein the lower electrode has a light reflecting surface. (4) The semiconductor light emitting device according to any one of claims (1) to (3), wherein a heat dissipation layer is provided around the active region forming portion. (5) The active region forming portion is a columnar projection provided on the upper surface of the semiconductor plate material.
The semiconductor light emitting device according to any one of items 1) to (4). (6) Claims (1) to (4) characterized in that the active region forming portion is a single protrusion provided on the upper surface of the semiconductor board and extending across the upper surface. The semiconductor light emitting device according to any one of the items. (7) The semiconductor light emitting device according to claim (1) or (2), wherein the active region forming portion is a through hole formed in the semiconductor plate material extending from the upper surface to the lower surface of the semiconductor plate material. element.