JPH02266576A - Semiconductor light-emitting diode - Google Patents

Abstract

PURPOSE:To obtain an incoherent light with a high degree of incoherence by allowing first, second,..., and nth mixed crystal regions to own a smaller degree of mixed crystallization as compared with a mixed crystal region in a region where first and second electrode layers oppose each other and further allowing them to own small degree of mixed crystallization in that order. CONSTITUTION:First, second,..., and nth regions M1-Mn which a region 3b where first and second electrode layers 15 and 16 of a second semiconductor crystal layer 3 do not oppose own small first, second,..., and nth degree of mixed crystallization in that order. Thus, the first, second,..., and nth regions own an energy band gap which becomes narrower in that order and hence have an absorption edge wavelength which becomes higher in that order in sequence. Therefore, it becomes possible to obtain an incoherent light achieved by radiating from the light radiation edge surface toward the outside with a high degree of incoherence without providing them by machining the slant surface and without achieving a longer length at a region where the first and second electrode layers of the second semiconductor crystal layer oppose each other.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a semiconductor light emitting diode that is obtained by emitting incoherent light to the outside.

[Conventional technology]

Conventionally, the semiconductor light emitting diode described below with reference to FIGS. 4 to 6 has been proposed. That is, for example, a semiconductor crystal substrate 1 having an n-type, a semiconductor crystal layer 2 formed on the semiconductor crystal substrate 1 in contact with it and having the same n-type as the semiconductor crystal substrate 1, and a semiconductor crystal layer 2 having the same n-type as the semiconductor crystal layer 2. A semiconductor crystal layer 3 is formed in contact with the semiconductor crystal layer 3 and has a narrower energy band gap and a higher refractive index than the semiconductor crystal layer 2; has a bandgap and a low refractive index, and
A semiconductor laminate including a semiconductor crystal layer 4 having a p-type opposite to that of the semiconductor crystal layer 1, and a semiconductor crystal layer 5 formed on and in contact with the semiconductor crystal layer 4 and having the same p-type as the semiconductor crystal layer 4. It has 10. In this case, as particularly shown in FIG. 10, the semiconductor laminate 10 is arranged in a direction perpendicular to the longitudinal direction of the semiconductor laminate 10 (in FIG. 9, a direction parallel to the paper surface, in FIG. 10, a direction perpendicular to the paper surface). When viewed in cross section on the plane, it stands up from the semiconductor crystal layer 2 or the semiconductor crystal substrate 1 (in the figure,
It has a mesa-like shape (standing up from the semiconductor crystal layer 2), and on both left and right sides of the mesa, on the semiconductor crystal layer 2 or the semiconductor crystal substrate 1 side, the semiconductor crystal layers 2 and 3 and the semiconductor Semiconductor crystals 86L and 6R are formed in contact with the lower half of the crystal layer 4 and are p-type and made of, for example, InP, and on the semiconductor crystal layers 6L and 6R, the semiconductor crystal layer 4
The semiconductor crystals 117L and 7R are formed in contact with the upper half of the semiconductor crystal layer 5 and are n-type, and are made of, for example, InP. Further, the semiconductor stack 10 has an end face extending perpendicularly to the thickness direction of the semiconductor stack 10 as a light emitting end face 11 at one end side in the longitudinal direction. An antireflection film 12 is attached to the surface. Further, the semiconductor stack 10 has a semiconductor crystal layer 5 on the other end side opposite to the light emitting end surface 11 side in the longitudinal direction.
．． The end faces of 4 and 3 are made of semiconductor! It is located on an inclined surface 14 extending obliquely to a vertical plane in the thickness direction of the aI body 10. Further, in the semiconductor stacked body 10 described above, the semiconductor crystal substrate 1 has a main surface formed of a (100) plane and is made of, for example, InP. Further, semiconductor crystal layers 2.3.4 and 5 are formed on the main surface of such semiconductor crystal substrate 1 by a liquid phase epitaxial growth method, a vapor phase epitaxial growth method, a molecular beam epitaxial growth method, etc., and The semiconductor crystal 1i2 is made of, for example, InP. Further, in the semiconductor crystal layer 3, neither the n-type impurity nor the n-type impurity is intentionally introduced, or even if it is introduced, it is only introduced at a significantly lower concentration than in the semiconductor crystal layers 2 and 4. For example, it is made of InGaASP type. Furthermore, the semiconductor crystal layer 4 is made of, for example, InP. Further, the semiconductor layer 5 is made of, for example, an InGaAsP system into which n-type impurities are introduced at a higher concentration than that of the semiconductor crystal layer 4. Further, one main surface 10a of the semiconductor stack 10 described above
The semiconductor stack 1 is placed on the upper surface of the semiconductor crystal layer 5.
On the charging/discharging tJJ end face 11 side in the longitudinal direction of 0, an electrode layer 15 extending also onto the semiconductor crystal layers 7L and 7R,
It is attached to Ohmic. Moreover, the above-mentioned main surface 10a of the above-mentioned semiconductor stack 10
Another electrode layer 16 is formed on the other main surface 10b facing the main surface 10b of the semiconductor stack 10, that is, on the surface of the semiconductor crystal substrate 1 opposite to the semiconductor crystal layer 2 side. It is arranged in ohmic contact with the layer 15. In this case, the electrode layer 16 may extend onto a region on the main surface 10a that does not face the electrode layer 15, as shown in the figure. The above is the structure of the conventionally proposed semiconductor light emitting diode. According to the semiconductor light emitting diode having such a configuration, if a required power source 8 (not shown) with the electrode layer 15 side positive is connected between the electrode layers 15 and 16, the current from the power source is Electrodes are applied to the semiconductor crystal substrate 1 and the semiconductor crystal layers 2, 3, 4, and 5 of the semiconductor stack 10 in the reverse order! 15 and 16. However, even if the electrode layer 15 extends over the semiconductor crystals Ji 17L and 7R of the semiconductor stack 10, the current from the power source is applied between the semiconductor crystal layers 7L and 6m and between 7R and 6R. The semiconductor crystal layer 3 has a polarity that gives a reverse bias to the pn junction of the semiconductor crystal layer 3.
It does not flow by bypassing the flow. Therefore, the current from the power source flows through the semiconductor crystal layer 3 of the semiconductor stack 10 in a constricted manner. Moreover, in this way, the semiconductor crystal layer 3 of the semiconductor stack 10
The current flowing in a constricted manner mainly flows in the region 3a where the electrodes W115 and 16 are facing each other. For this reason, mainly in each part of the region 3a of the semiconductor crystal layer 3, the InGaAs constituting the semiconductor crystal layer 3 is
Light having a wavelength band of, for example, a 1.5 μm centered on a wavelength λ8 corresponding to the energy bandgap E of the P system is generated. A part of the light L8 is confined in the region 3a by the semiconductor crystal layers 2 and 4 and propagates toward the light emitting end face 11, and the other part of the light L8 is transmitted to the electrode layer 15 of the semiconductor crystal layer 3.
Similarly, the region 3b where the semiconductor crystal layers 2 and 16 do not face each other is confined by the semiconductor crystal layers 2 and 4 and propagates toward the inclined surface 14 side. In this way, the - part of the light propagating through the region 3a of the semiconductor crystal layer 3 toward the light emitting end face 11 is prevented from being emitted because the antireflection film 12 is formed on the light emitting end face 11. The anti-reflection film 1 is coated without reflection on the end surface 11.
2 and radiates to the outside. Further, as described above, the region 3b of the semiconductor crystal layer 3 is
The other part of the light La propagating toward the inclined surface 14 reaches the inclined surface 14 while being absorbed in the region 3b during the propagation process, and is reflected at the inclined surface 14, and the reflected light is absorbed by the semiconductor crystal. Almost no light re-enters the region 3b of the layer 3. From the above, according to the conventional semiconductor light emitting diode shown in FIGS.
Wavelength λa corresponding to the energy bandgap Eoa of the system
Light La having a band centered on is emitted as incoherent light from the light emitting end face 11 through the antireflection film 12 to the outside. Further, in this case, the current from the power source continues to flow through the semiconductor stack 10, and therefore, the current from the power source is continuously injected into the region 3a of the semiconductor crystal Ji3, so that the light emitting end face Incoherent light emitted to the outside from the semiconductor crystal layer 3 of the semiconductor stack 10
A relatively high brightness can be obtained depending on the value of the current flowing in the region 3a. Furthermore, since the incoherent light obtained by being radiated to the outside from the light emitting end face 11 is the light radiated to the outside from a local region of the end face of the semiconductor crystal layer 3 on the charging/discharging 01 g plane 11, Incoherent light obtained by radiating outward from the light emitting end face 11 is emitted at a relatively narrow radiation angle depending on the thickness of the semiconductor crystal layer 3. Therefore, according to the semiconductor light emitting diodes shown in FIGS. 4 to 6, incoherent light is emitted to the outside with a relatively high brightness and a relatively narrow radiation angle. [N Problem 1 to be Solved by the Invention However, in the case of the conventional semiconductor light emitting diode described above in FIGS. In the entire region including the region 3a where the electrode layers 15 and 16 are not facing each other and the region 3b where the electrode layers 15 and 16 do not face each other, there is only one region having an energy band gap Eg2 of the 1nGaAsP system having a composition similar to that of each part. It has a structure. Therefore, when a part of the light propagates through the region 3b, it shines into the region 3b, and electrons are accumulated based on the part of the light.
Due to the band filing effect in which the energy bandgap of the region 3b becomes wider than the original width, the region 3b has an effectively wider energy bandgap than the region 3a. Therefore, it becomes difficult for the region 3b to absorb a portion of the light La propagating there, and most of the light L8 is absorbed by the inclined surface 1.
4 and reflect there. Therefore, in the above, the electrode layer 1 of the semiconductor crystal layer 3
Light L generated in the area vA3a where 5 and 16 face each other
When a part of the light a propagates to the inclined surface 14 side through the region 3b where the electrode layers 15 and 16 of the semiconductor crystal H3 are not facing each other, in the process of propagating a part of the light to the region 3b, The light reaches the inclined surface 14 while being absorbed in the region 3b, and is reflected at the inclined surface 14, and the reflected light is
Although it has been mentioned that almost no light re-enters the region 3b, the reflected light reflected on the inclined surface 14 is scattered and enters the region ii & 3b.
m re-injects into b, which cannot be ignored. For this reason, in the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6, incoherent light obtained by radiating outward from the light emitting end face 11 cannot be obtained with a high degree of incoherence. It had the following drawbacks. Further, in the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6, an inclined surface 14 must be formed on the semiconductor laminate 10 on the end surface side opposite to the light emitting end surface 11 side. It had the disadvantage that it did not. Therefore, the present invention seeks to propose a novel semiconductor light emitting diode that does not have the above-mentioned drawbacks.

[Means for Solving Problem 'a] The semiconductor light emitting diode according to the present invention has the following features as in the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6: (1) a first semiconductor crystal layer formed on the semiconductor crystal substrate and having a first conductivity type; (2) a first semiconductor crystal layer formed on the first semiconductor crystal layer and in contact with it; a second semiconductor crystal layer having a narrower energy bandgap and a higher refractive index than the semiconductor crystal layer; a semiconductor stack having a third semiconductor crystal layer having a relatively wide energy bandgap and a low refractive index and a second conductivity type opposite to the first conductivity type;
(b) 1. on the first main surface of the semiconductor stack; A first electrode layer is locally disposed on one end side in the length direction of the F2 semiconductor stack, and (c) a second main surface of the semiconductor stack opposite to the first main surface. A second electrode layer facing the first electrode layer is disposed on top, and (d) one end surface of the semiconductor laminate on which the first electrode layer is disposed is exposed to light. It has a configuration in which it has a radiation end face. However, the semiconductor light emitting diode according to the present invention
In the semiconductor device diode having such a configuration, (e) the second semiconductor crystal layer has a superlattice layer mixed in a region where the first and second electrode layers face each other; and (f) the second semiconductor crystal layer is formed of the semiconductor stack from the mixed crystal region side in a region where the first and second electrode layers do not face each other. It has a plurality of n first, second, etc. nth region portions successively connected in the longitudinal direction of the body, and (g) the second semiconductor crystal layer. The above first and second...
......The n-th region is the first and second ......n-th mixed crystal region in which the superlattice layer is mixed, and (d) The first and second...... n-th mixed crystal region portions are such that the first and second electrode layers of the second semiconductor crystal layer face each other. The mixed crystallization degree is smaller than that of the mixed crystallized region in the region where the mixed crystallization is, but the first, second, etc. nth mixed crystallization degree (
However, this also includes cases where the n-th mixed crystallinity is substantially zero). [Operation/Effect] According to the semiconductor light emitting diode according to the present invention, FIGS.
As in the case of the conventional semiconductor light emitting diode described above in FIG.
According to the case of the conventional semiconductor light emitting diode described above with reference to FIGS. Light having a band centered on a wavelength corresponding to the energy bandgap of is generated. Then, the light is transmitted to the first and second semiconductor crystal layers of the second semiconductor crystal layer.
The light is hardly absorbed in the region where the electrode layers face each other, and is confined by the first and second semiconductor crystal layers and propagates toward the light emitting end surface. Therefore, in the case of the semiconductor light emitting diode according to the present invention, as in the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6, incoherent light is obtained by radiating outward from the light emitting end face. . In addition, in this case, the semiconductor stack has, as in the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6,
The current from the power source continues to flow, and therefore, the current from the power source is continuously injected into the region where the first and second electrode layers of the second semiconductor crystal layer of the semiconductor stack are facing each other. Therefore, the incoherent light emitted to the outside from the light emitting end face is transmitted to the first and second semiconductor crystal layers, as in the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6. A relatively high brightness can be obtained depending on the current flowing in the regions where the second electrode layers face each other. In addition, incoherent light emitted from the light emitting end face to the outside is transmitted to the second semiconductor crystal on the light emitting end face, as in the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6. Since the light is emitted to the outside from a local area called the end face of the layer, the incoherent light obtained by being emitted to the outside from the light emitting end face is as shown in Figures 4 to 6.
As in the case of the conventional semiconductor light-emitting diode described above in the figures, depending on the thickness of the second semiconductor crystal layer, radiation is emitted with a relatively narrow emission angle. Therefore, also in the case of the semiconductor light emitting diode according to the present invention,
As with the conventional semiconductor light emitting diodes described above in FIGS. 4-6, incoherent light is obtained at relatively high iii and relatively narrow emission angles. However, in the case of the semiconductor light emitting diode according to the present invention, the first and second semiconductor crystal layers of the semiconductor stack
The regions where the electrode layers are not facing each other are the first, second, . . .
. . . has an n-th area portion, and those first
, second......The n-th region is a superlattice layer where the first and second electrode layers of the second semiconductor crystal layer face each other. The first, second, etc., n-th mixed region has a superlattice layer mixed with a smaller degree of mixing than the mixed crystal region. Since each part of the crystallized region is divided into regions where the first and second electrode layers of the second semiconductor crystal layer do not face each other,
The first and second electrode layers of the second semiconductor crystal layer have an energy band gap narrower than a region where they face each other,
Therefore, the second semiconductor crystal layer has a higher absorption edge wavelength than the region where the first and second electrode layers face each other. Moreover, in the case of the semiconductor light emitting diode according to the present invention, the regions where the first and second electrode layers of the second semiconductor crystal layer do not face each other have first, second...・・・
The n-th area is sequentially smaller in the order of the first, second, and
Since it has the n-th mixed crystallinity, the energy of the first, second, n-th regions becomes narrower in that order. They have a band gap, and therefore have absorption edge wavelengths that increase in order. Therefore, the first and second ′iM of the second semiconductor crystal layer
A part of the light generated in the region where the polar layers face each other is M2
When the first and second electrode layers of the semiconductor crystal layer propagate toward the side opposite to the light emitting end surface through the region where they do not face each other, a portion of the light propagates through the first and second electrode layers of the second semiconductor crystal layer. In regions where the second electrode layers do not face each other, light is absorbed more effectively than in the case of the conventional semiconductor light emitting diode described above with reference to FIGS. 4 to 6. Therefore, in the case of the semiconductor light emitting diode according to the present invention, as in the case of the conventional semiconductor light emitting diode described above with reference to FIGS. Also, #! without processing the surface. In the conductive laminate, a region of the second semiconductor crystal layer where the first and second electrode layers do not face each other,
In order to sufficiently absorb the light propagating there,
From the region where the first and M2 electrode layers of the second semiconductor crystal layer face each other, the second semiconductor crystal layer is 1st
The light propagating to the region where the second electrode layer does not face each other can be substantially prevented from re-entering the former region. Therefore, according to the semiconductor light emitting diode according to the present invention,
Unlike the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6, there is no need to process and provide the inclined surface 14 on the end surface side opposite to the light emitting end surface side of the semiconductor laminate. In addition, the semiconductor stack is not configured to have a long length so that the region where the first and second electrode layers of the second semiconductor crystal layer face each other has a good length. In addition, incoherent light emitted from the light emitting end face to the outside can be obtained with a higher degree of incoherence than in the case of the conventional semiconductor light emitting diode described above with reference to FIGS. 4 to 6. Embodiment 1 Next, an embodiment of a semiconductor light emitting diode according to the present invention will be described with reference to FIGS. 1 to 3. In FIGS. 1 to 3, parts corresponding to those in FIGS. 4 to 6 are designated by the same reference numerals, and details 1Bli5! Omit the description. The semiconductor light emitting diode according to the present invention shown in FIGS. 1 to 3 has the same structure as the conventional semiconductor light emitting diode described above in FIGS. 4 to 6, except for the following points. That is, in the region 3a where the semiconductor crystal layer 3 and the electrode layers 15 and 16 of the semiconductor stack 10 face each other, for example, a semiconductor crystal layer made of Ga, A, and s having a thickness of 80 mm and a thickness of 20 mm. The superlattice layer is a mixed crystal region in which a superlattice layer is formed by repeatedly stacking, for example, 20 layers of InGaAs-based semiconductor crystal layers having a high density. In addition, in the region 3b where the electrode layers 15 and 16 do not face each other, the semiconductor crystal layer 3 has a plurality of layers n sequentially connected in the longitudinal direction of the semiconductor stack 10 from the mixed crystal region side of the region bX3a described above. It has first, second, . . . n-th region portions M1, M2, . . . M. The first, second, etc. of these semiconductor crystal layers 3...
... n-th area M1, M2, ...
...Mn is the first layer in which the above-mentioned superlattice layer is mixed crystal.
, second......n-th mixed crystal region, respectively, and the first, second...n-th mixed crystal region, In both cases, the electrode layer 15 of the semiconductor crystal layer 3
and 16 have a smaller mixed crystallinity degree than the mixed crystallinity degree D8 of the above-mentioned mixed crystallized region in the fri region 3a facing each other, but the first, second, . . .・
... nth mixed crystallinity D , D ......
...D. has. However, in this case, the degree of mixed crystallization is higher than the nth mixed crystal. may be substantially zero. In addition, in the figure, the nth degree of mixed crystallization of the Mn mixed crystallized region portion of the nth region M2 is shown. is zero. The above is the configuration of the embodiment of the semiconductor light emitting diode according to the present invention. According to the semiconductor light emitting diode according to the present invention, FIGS.
As in the case of the conventional semiconductor light emitting diode described above in FIG. Similar to the conventional semiconductor light emitting diode, in the region where the first and second electrode layers of the second semiconductor crystal layer of the semiconductor stack are facing each other, a wavelength corresponding to the energy band gap of that region is set. Light having a band centered on is generated. Then, the light is transmitted to the first and second semiconductor crystal layers of the second semiconductor crystal layer.
The light is hardly absorbed in the region where the electrode layers face each other, and is confined by the first and second semiconductor crystal layers and propagates toward the light emitting end surface. Therefore, in the case of the semiconductor light emitting diode according to the present invention, as in the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6, incoherent light is obtained by radiating outward from the light emitting end face. . In addition, in this case, the semiconductor stack has, as in the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6,
The current from the power source continues to flow, and therefore, the current from the power source is continuously injected into the region where the first and second electrode layers of the second semiconductor crystal layer of the semiconductor stack are facing each other. Therefore, the incoherent light emitted to the outside from the light emitting end face is transmitted to the first and second semiconductor crystal layers, as in the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6. In response to the current flowing in the regions where the second electrode layer faces each other. Obtained with relatively high brightness. In addition, incoherent light obtained by radiating outward from the light emitting end face is placed on the light emitting end face as in the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6.
Since the light is emitted to the outside from a local region called the end face of the second semiconductor crystal layer, the incoherent light obtained by being emitted to the outside from the light emitting end face is as shown in Figures 4 to 6. As in the case of the conventional semiconductor light-emitting diode described above, depending on the thickness of the second semiconductor crystal layer, radiation is emitted with a relatively narrow emission angle. Therefore, also in the case of the semiconductor light emitting diode according to the present invention,
As with the conventional semiconductor light emitting diodes described above in FIGS. 4-6, incoherent light is obtained at a relatively high brightness and at a relatively narrow emission angle. However, in the case of the semiconductor light emitting diode according to the present invention shown in FIGS.
a is the first, second, . . . nth area portion M,
M2......M, and these first, second......nth area portions M1M2.
......M, the above-mentioned superlattice layer is mixed crystal as the region 3a where the electrode layers 15 and 16 of the semiconductor crystal layer 3 are facing each other. The second IL, which is mixed crystallized with a small a-crystallinity compared to the mixed crystalline region,
. . . Each part of the region 3b where the electrode layers 15 and 16 of the semiconductor crystal layer 3 are not facing each other is the electrode of the semiconductor crystal layer 3. layer 1
It has a narrower energy band gap than the region 3a where the electrode layers 15 and 16 of the semiconductor crystal layer 3 face each other, and therefore has a higher absorption edge wavelength than the region 3a where the electrode layers 15 and 16 of the semiconductor crystal layer 3 face each other. have. Moreover, in the case of the semiconductor light emitting diode according to the present invention shown in FIGS. 1 to 3, the electrode layers 15 and 1 of the semiconductor crystal layer 3 are
6 has the first and second regions 3b that are not facing each other.
......n-th area M1, M2...
...Mo is the first, second, smaller, etc. in that order.
......Nth mixed crystallinity D1, D2...
...D, so those first, second...
The n-th regions have energy band gaps that become narrower in that order, and therefore have absorption edge wavelengths that become higher in that order. Therefore, part of the light generated in the region where the first and second electrode layers of the second semiconductor crystal layer are opposed to each other is absorbed by the first and second electrode layers of the second semiconductor crystal layer. When the light propagates through the region where they do not face each other to the side opposite to the light emitting end surface side, a part of the light propagates in the region where the first and second electrode layers of the second semiconductor crystal layer do not face each other, It is absorbed more effectively than in the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6. Therefore, in the case of the semiconductor light emitting diode according to the present invention shown in FIGS. 1 to 3, the light emitting end surface side of the semiconductor stack is not the same as in the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6. A sloped surface may be processed and provided on the opposite end surface side, or the semiconductor stack may be formed on the first side of the second semiconductor crystal layer.
and the first and second electrodes of the second semiconductor crystal layer without configuring the second electrode layer to have a long length so that the regions where the second electrode layer does not face each other have a long length. Substantially preventing light propagating from a region where the layers face each other to a region where the first and second electrode layers of the second semiconductor crystal layer do not face each other to re-enter the former region. be able to. Therefore, according to the semiconductor light emitting diode according to the present invention shown in FIGS. 1 to 3, as in the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6, the semiconductor stack has a light emitting end surface. The sloped surface 14 is processed on the opposite end surface side, or the semiconductor stack is formed so that the region where the first and second electrode layers of the second semiconductor crystal layer face each other has a long length. In addition, the incoherent light emitted from the light emitting end surface to the outside without having a structure having a long length is compared to the case of the conventional semiconductor light emitting diode described above in FIGS. 4 to 6. and a high degree of incoherence. The above description describes an embodiment in which the present invention is applied to a so-called embedded semiconductor light emitting diode, but the point is that the present invention is applied to the semiconductor crystal substrate 1 described above in FIGS. 1 to 3. (a) A semiconductor crystal substrate having a first conductivity type and a semiconductor crystal layer 2 formed on the semiconductor crystal substrate and having the first conductivity type described above in FIGS. 1 to 3. A corresponding first semiconductor crystal layer and its first
is formed on and in contact with the semiconductor crystal layer of
a second semiconductor crystal layer corresponding to the semiconductor crystal layer 3 described above in FIGS. 1 to 3, which has a narrower energy band gap and higher refractive index than the semiconductor crystal layer of
is formed on and in contact with the semiconductor crystal layer of
The semiconductor crystal layer 4 described above in FIGS. 1 to 3 has a wider energy band gap and a lower refractive index than the semiconductor crystal layer 4 and has a second conductivity type opposite to the first conductivity type. and (b) on the opposing first and second main surfaces of the semiconductor stack, the layers shown in FIGS. The first and second electrode layers corresponding to the electrode layers 15 and 16 described above in FIG. 3 are arranged facing each other, and (c)
It will be obvious that the present invention can also be applied to a semiconductor light emitting diode in which one end face in the longitudinal direction of the semiconductor laminate is used as a light emitting end face. In addition, in the semiconductor light emitting diode according to the present invention described above, "n type" may be replaced with "p type" and "p type" may be replaced with "n type", or in other ways that depart from the spirit of the present invention. Various modifications and changes may be made without further modification.

[Brief explanation of drawings]

1, 2, and 3 are line plan views showing a first embodiment of a semiconductor light emitting diode according to the present invention, and its f
They are a sectional view on the f-II inspection line and a sectional view on the I[I-■ line. FIG. 4, FIG. 5, and FIG. 6 are a linear plan view showing a conventional semiconductor light emitting diode, a sectional view on the V-■ line, and a sectional view on the Vl-VT ridge line. 15.16...Electronic 8i layer M1~Mo...
. . . Region portion of region 3b of semiconductor crystal layer 3

Claims (1)

[Scope of Claims] A semiconductor crystal substrate having a first conductivity type, a first semiconductor crystal layer formed on the semiconductor crystal substrate and having the first conductivity type, and a first semiconductor crystal layer formed on the semiconductor crystal substrate and having the first conductivity type. a second semiconductor crystal layer formed on and in contact with the second semiconductor crystal layer and having a narrower energy bandgap and a higher refractive index than the first semiconductor crystal layer; and a third semiconductor crystal layer having a wider energy band gap and lower refractive index than the second semiconductor crystal layer, and a second conductivity type opposite to the first conductivity type. a laminate, a first electrode layer is locally disposed on a first main surface of the semiconductor laminate at one end in the length direction of the semiconductor laminate; A second electrode layer facing the first electrode layer is arranged on a second main surface opposite to the first main surface, and the first electrode layer of the semiconductor laminate is arranged. In the semiconductor light emitting diode in which one end face on the opposite side is a light emitting end face, the second semiconductor crystal layer has a superlattice layer of a mixed crystal in a region where the first and second electrode layers face each other. The second semiconductor crystal layer is a mixed crystal region having a
In a region where the first and second electrode layers do not face each other, a plurality of n first, second...・・・
. . . has an nth region portion, and the first and second . . . nth region portions of the second semiconductor crystal layer have a superlattice layer of mixed crystal The first and second...
. . . respectively in the n-th mixed crystal region portions, and the first and second mixed crystal region portions are the above-mentioned portions of the second semiconductor crystal layer. 1st and 2nd
The mixed crystallinity is smaller than that of the mixed crystallized region in the region where the electrode layers face each other, but the first, second,... nth mixed crystallization degree is smaller in that order. A semiconductor light-emitting diode characterized by having a crystallinity (including cases where the n-th mixed crystallinity is substantially zero).