JPH02266575A - Semiconductor photodiode - Google Patents

Abstract

PURPOSE:To allow an incoherent light to achieve the degree of incoherence at a relatively high value by enabling first, second,..., and nth mixed crystal regions to own small first, second,..., and nth mixed crystal degree in this order. CONSTITUTION:In a region 3a where first and second electrode layers 15 and 16 of a second, semiconductor crystal layer 3 oppose each other, an ultra-grid layer having a small first, second,..., and nth mixed crystal degree in sequence is subjected to mixed crystallization. Thus, first, second,..., and nth regions M1-Mn own small first, second,..., and nth energy band gaps in this order. Therefore, in the first, second,..., and nth regions M1-Mn, light with a bandwidth having the wavelength corresponding to their first, second,..., and nth energy band gaps as the center is generated and the light is irradiated from a light- radiation edge surface 11 toward the outside as an incoherent light. Thus, an incoherent light can be obtained at a high incoherent degree value.

Description

[Detailed description of the invention]

[Industrial Field of Application 1] The present invention relates to a semiconductor light emitting diode that emits incoherent light to the outside. 2. Description of the Related Art Conventionally, semiconductor light emitting diodes as described below with reference to FIGS. 8 to 10 have 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 113 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, and a semiconductor crystal 113 is formed on the semiconductor crystal layer 3 in contact with it and has a wider energy band than the semiconductor crystal layer 2. A semiconductor crystal layer 4 having a gap and a low refractive index and having a p-type opposite to that of the semiconductor crystal layer 7
and a semiconductor crystal layer 5 formed on and in contact with the semiconductor crystal 1!4 and having the same p-type as the semiconductor crystal layer 4. 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 semiconductor crystal JI2), and semiconductor crystal layer 2 is formed on both left and right sides of the mesa.
Or, in the semiconductor crystal substrate 1 (l!1), the semiconductor crystals 1, 1, 1, 3 and 3 are formed in contact with the lower half of the semiconductor crystal layer 4, and have p-type, and are made of, for example, InP.
The semiconductor crystal layers 6L and 6R are formed on the semiconductor crystal layers 6L and 6R, respectively, in contact with the upper half of the semiconductor crystal WJ4 and the semiconductor crystal layer 5, and have n-type and are made of, for example, InP.
It has semiconductor crystal layers 7L and 7R, respectively. 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. Furthermore, on the other end side of the semiconductor stack 10 opposite to the light emitting end face 1111 in the longitudinal direction, the end faces of the semiconductor crystal layers 5.4 and 3 are aligned with the vertical plane in the thickness direction of the semiconductor stack 10. It is placed on an inclined surface 14 extending obliquely to the other hand. Further, in the semiconductor 8ili1 body 10 described above, the semiconductor crystal substrate 1 has a main surface formed of a (100) plane,
And, for example, it is made of 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 H2 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 system. Furthermore, the semiconductor crystal layer 4 is made of, for example, InP. Further, the semiconductor layer 5 is made of, for example, a 1nGaAsP 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 light emitting end surface 11 side in the longitudinal direction of 0, an electrode layer 15 extending also onto the semiconductor crystal layers 7L and 7R is arranged in an ohmic manner. Moreover, the above-mentioned main surface 10a of the above-mentioned semiconductor & f body 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 N-pole 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 (not shown) with the positive side facing the electrode layer 15 is connected between the electrode layers 15 and 16, the current from the power source is transferred to the semiconductor light emitting diode. It flows into the semiconductor crystal substrate 1 and the semiconductor crystal layers 2, 3, 4 and 5 of the stack 10 in the opposite order through the electrode layers 15 and 16. However, even if the electrode layer 15 extends over the semiconductor crystal layers 7L and 7R of the semiconductor stack 10, the current from the power source is
Since it has a polarity that gives a reverse bias to the pn junction between L and between 7R and 6R, the flow bypasses the semiconductor crystal layer 3 and flows into the semiconductor crystal layers 7L and 6L, and 7R and 6R. do not have. 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 through the electrode layers 15 and 1.
6 flows into the region 3a 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
Wavelength λ8 according to energy bandgap Eg8 of P system
Light La having a wavelength band of, for example, 1.5 μm centered on is generated. A part of the light La is confined in the region 3a by the semiconductor crystal layers 2 and 4 and propagates toward the light emitting end face 11 side, and the other part is transmitted to the electrode layer 15 of the semiconductor crystal layer 3 and Area 3 where 16 is not facing each other
b is similarly 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 λ corresponding to the energy bandgap Eaa of P system
Light having a band centered at a is emitted from the light emitting end surface 11 as incoherent light to the antireflection coating 12.
It is obtained by radiating to the outside through. Furthermore, 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 layer 3.
Incoherent light emitted from the light emitting end face 11 to the outside can be obtained with relatively high brightness depending on the value of the current flowing through the region 3a of the semiconductor crystal layer 3 of the semiconductor stack 10. Furthermore, since the incoherent light obtained by being radiated to the outside from the light emitting end face 11 is light radiated to the outside from a local region of the end face of the semiconductor crystal layer 3 on the light emitting end face 11, the light emitted Incoherent light emitted from the end surface 11 to the outside is transmitted to the semiconductor crystal layer 3.
emitted at a relatively narrow radiation angle depending on the thickness of the Therefore, according to the semiconductor device diode shown in FIGS. 8 to 10, incoherent light is emitted to the outside at a relatively high brightness and a relatively narrow radiation angle. (Problem to be Solved by the Invention 1) However, in the case of the conventional semiconductor light emitting diode shown in FIGS. In the entire region including the region 3a 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 E.8 of the InGaASP system having a composition similar to that of each part. As described above, the incoherent light obtained by being radiated to the outside from the charging/discharging tPJ02 surface 11 constitutes the semiconductor crystal layer 3 in this case over its entire region. The energy bandgap E of the InGaAsP system is
It has a band centered on the wavelength λ corresponding to g8,
Its bandwidth Wλ8 is relatively narrow. For example, a region 3a in which the electrode layers 15 and 16 of the semiconductor crystal layer 3 are facing each other has an energy band gap such that the center wavelength λ8 of the light L generated in the region 3a is at a wavelength of 1°50 μm (q). InG with Eg8
In the case of an aAsP composition, the bandwidth "Fa" is only about 500 in terms of the half-width of the luminance characteristic for the wavelength of incoherent light emitted to the outside. In the case of the conventional semiconductor light emitting diode shown in Figs. 8 to 10, the incoherent light obtained by emitting it to the outside has a degree of incoherence that is proportional to its bandwidth Wλ8, and is relatively low. However, it is an object of the present invention to propose a novel semiconductor light-emitting diode that does not have the above-mentioned drawbacks.

[Means for Solving the Problems J] The semiconductor light emitting diode according to the present invention is shown in FIGS. 8 to 10.
As in the case of the conventional semiconductor light emitting diode described above in the figure, (a) a semiconductor crystal substrate having a first conductivity type; and ■ a first semiconductor crystal substrate formed on the semiconductor crystal substrate and having a first conductivity type. (2) a second semiconductor crystal layer formed on and in contact with the first semiconductor crystal layer and having a narrower energy bandgap and a higher refractive index than the first semiconductor crystal layer; , (2) is formed on and in contact with the second semiconductor crystal layer, has a wider energy band gap and lower refractive index than the second semiconductor crystal layer, and has a conductivity type opposite to that of the first semiconductor crystal layer. and a third semiconductor crystal layer having two conductivity types,
(b) first and second electrode layers are disposed on opposing first and second main surfaces of the semiconductor stack, respectively, and (c) the semiconductor 8I It has a configuration in which one end surface in the longitudinal direction of the layered body is used as a light emitting end surface. However, the semiconductor light emitting diode according to the present invention
In a semiconductor light emitting diode having such a configuration, (d) the second semiconductor crystal layer is arranged on the light emitting end surface of the semiconductor stack in a region where the first and second electrode layers face each other; A plurality of n first, second...
. . . has an n-th region portion, and (e) the first and second regions of the second semiconductor crystal layer.
. . . The n-th region portion is the first, second, . . . n-th mixed crystal region in which the superlattice layer is mixed, and (f) The first, second, etc. n-th mixed crystal regions are sequentially smaller in the order of the first, second, and so on.
. . . has an n-th mixed crystallinity (including cases where the n-th mixed crystallization degree is substantially zero). Note that in this case, the above-mentioned first electrode layer is the first, second, . . . nth electrode layer of the above-mentioned second semiconductor crystal layer.
The first regions are opposite to each other and are separated from each other.
, second . . . nth electrode layer portion. [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. In the region where the first and second electrode layers of the second semiconductor crystal layer of the body face each other,
......The n-th region has bands each having a wavelength corresponding to the energy band gap of the first, second, etc. n-th region. Light is generated respectively. In this case, the first, second, etc. nth area portions are sequentially smaller in that order.
・The superlattice layer having the nth mixed crystallization degree is the first and second mixed crystallized regions, respectively, so the first , 2nd......nth
The first area, the second area, etc. are sequentially smaller in that order.
...has an n-th energy band gap. For this reason, the light generated in the first, second, etc. nth regions is transmitted to the first and second electrode layers of the second semiconductor crystal layer, which are opposed to each other. The light is confined by the first and second semiconductor crystal layers and propagates toward the light emitting end face with almost no absorption in that region. Therefore, in the case of the semiconductor light emitting diode according to the present invention, the light generated in the first, second, ... nth regions described above is As in the case of the conventional semiconductor light emitting diode described above, incoherent light is obtained by being radiated to the outside from the light emitting end face. In addition, in this case, the current from the power source continues to flow through the semiconductor stack as in the case of the conventional semiconductor light emitting diode described above in FIGS. 8 to 10, and therefore, the current from the power source Since the first and second electrode layers of the second semiconductor crystal layer of the semiconductor stack are continuously injected into the region facing each other, incoherent light emitted to the outside from the light emitting end face is , as in the case of the conventional semiconductor light emitting diode described above in FIGS. 8 to 10, depending on the current flowing in the region where the first and second electrode layers of the second semiconductor crystal layer face each other , relatively high brightness is obtained. 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. 8 to 10. 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 the same as the conventional semiconductor light emitting device described above in FIGS. 8 to 10. As in the case of diodes, 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. 8-10, 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, the regions in which the first and second electrode layers of the second semiconductor crystal layer are facing each other are arranged so that the first and second electrode layers are successively smaller in size as described above. . . . First and second superlattice layers each having an nth mixed crystallization degree are U-crystalized. nth mixed crystallization. Therefore, the first, second, etc. n-th #4 areas become smaller first, second, and so on in that order.
- Has an n-th energy band gap. For this reason, in the first, second...... nth region portions, the Light having a band centered on the wavelength is generated, and these lights are emitted from the charging/discharging OA'M surface to the outside as incoherent light. For this reason, the mixed crystal of the first, second,..., n-th mixed crystal region formed in the first, second,..., n-th fR region portion, respectively. The first and second degree...
. . . each of the first and second regions of the n-th mixed crystal region.
・・・・・・・・・With the nth energy band gap,
Bands of light generated in the first and second regions, bands of light generated in the second and third regions, etc.
Between the first and second energy band gaps, within the range where the bands of light generated in the (n-1) and n-th regions partially overlap with each other, ,
Between the second and third energy band gaps...
...If the values are selected in advance so as to obtain a large difference between the (n-1)th and nth energy band gaps, the light can be obtained by radiating outward from the light emitting end face. Incoherent light is obtained with one band having a much wider bandwidth than in the case of the conventional semiconductor light emitting diodes described above in FIGS. 8-10. Therefore, according to the semiconductor light emitting diode according to the present invention,
The incoherent light obtained by radiating outward from the light emitting end face has a degree of incoherence, which is shown in Figs.
A much higher value can be obtained than in the case of the conventional semiconductor light emitting diode described above with reference to FIG. Further, according to the semiconductor light emitting diode according to the present invention, the first, second, . . . , nth
The first and second areas constituting the area section...
Since the n-th mixed crystal region can be easily formed from the superlattice layer by a mixed crystal treatment thereon, a semiconductor light emitting diode can be easily provided.

Embodiment 1 Next, a first 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. 8 to 10 are denoted by the same reference numerals, and detailed description thereof will be omitted. 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. 8 to 10, except for the following points. That is, the semiconductor crystal layer I layer 3 of the semiconductor stacked body 10 is
Region 3a where electrode layers 15 and 16 are facing each other and electrode layers 15 and 16 are not facing each other! 1[InGaAs having a composition similar to that of each part in the entire region including 3b
Figures 8 to 10 have a configuration of having only one region having a P-based energy bandgap Eg8.
Instead of the case shown in the figure, in f14jiA3a where the electrodes B15 and 16 face each other, a plurality of n first , second . . . nth area portions M1, M2 . . . Mo. Then, these first, M2......n-th area portions M, M2......M are, for example, 10
A superlattice layer in which a semiconductor crystal layer made of, for example, InP and a semiconductor crystal layer made of, for example, InGaAs having a thickness of <10 OA are sequentially and alternately stacked five times is mixed crystallized. First and second...
. . . respectively in the n-th mixed crystal region, and the mixed crystallinity degrees of the first and second mixed crystal regions are the first and second mixed crystal regions, respectively. 2......nth
Degree of mixed crystallinity D 1D2...D. When, the first, second, etc., n-th mixed crystallinity degrees 7, D2, D2, D, have successively smaller values in that order. Therefore, D>D2>...
...>Dn. However, in this case, the n-th mixed crystallinity degree of the n-th mixed crystal region formed by the n-th region portion may have a value of zero, but the first, second... ... nth area M %M2・
・・・・・・・・・The first and second, respectively, are Mn.
...First and second of the n-th mixed crystal region...
...Nth degree of mixed crystallinity D1, D2...
Dn is the first, second, . . . nth area portion M
, M2......Mn, as described later, the first, second......n-th energy band gaps Eg1, E, 2...・・・Egn
(In this case, the first, second...... nth mixed crystallinity degrees DI, D2......[)n are []
Since the relationship is 1>[)2>......>Do, Egl>Eg2>...>E. have the following relationship. ), the wavelengths λ and λ2・
・・・・・・・・・λ. (In this case, λ1〈λ2〈...
. . . From the point where the light L1, L2 . . . Lo having a band centered at Bands of light L1 and L2 generated in M2, respectively, and light L2 and L3 generated in the second and third regions M2 and M3, respectively.
Band......The light L(.-1) and the light L(.-
1) and Lo. The values are selected such that the bands of 2 and 3 are effectively partially overlapped. Further, the region 3b of the semiconductor crystal layer 3 where the electrode layers 15 and 16 are not facing each other is the nth gA which is farthest from the light emitting end surface 11 in the region 3a where the electrode layers 15 and 16 are facing each other. The nth energy bandgap Eg is equal to or equal to the nth energy bandgap E9° of the region M. It has an energy band gap E (Ib) smaller than
. The nth degree of mixed crystallization of the nth mixed crystallized region is . Assuming that Bandgap Eg. A case is shown in which the value is smaller than . The above is the configuration of the first embodiment of the semiconductor light emitting diode according to the present invention. According to the semiconductor light emitting diode according to the present invention having such a configuration, except for the above-mentioned matters, FIGS.
Since it has the same structure as the conventional semiconductor light emitting diode described above in the figure, detailed explanation will be omitted, but FIGS.
As in the case of one conventional semiconductor light emitting diode described above in the figure, the required power supply (not shown) is provided between the electrode layers 15 and 16.
If a current from the power source is connected to the semiconductor stack 10 and a current is passed through the semiconductor stack 10, the semiconductor crystal layer 3 of the semiconductor stack 10 will be Region 3 where electrode layers 15 and 16 face each other
The first, second......nth area portions M, , M2......Mo in a, the first, second......・Nth area M1, M2・
...Mo energy band gap EE
・・・・・・・・・Eo. Depending on gl・g and wavelength λ, λ2......λ. Lights L and L2 each have a band centered on .
Lo is generated respectively. In this case, the first, second,..., n-th area portions M1, M2,..., Mo are sequentially smaller in that order. . . . having n-th mixed crystallinity D , D . . . D , respectively,
First, second, etc. in which the superlattice layer is mixed crystal
...in the n-th mixed crystal region, so the first and second
......n-th area M 1M2...
...Mo's first, second...n-th energy band gaps Eg1, Eg2...
...Eg. have the smallest values in that order. For this reason, the lights L1, L2, etc. generated in the first, second,..., n-th area portions M1, M2,..., Mn, respectively. ...Lo defines the region 3a of the semiconductor crystal layer 3 where the electrode layers 15 and 16 are facing each other,
Almost no light is absorbed in the region 3a, and the light is confined by the semiconductor crystal layers 2 and 4 and propagates toward the light emitting end face 11 side. Therefore, in the case of the semiconductor light emitting diode according to the present invention shown in FIGS. 1 to 3, the above-mentioned light L1, L2...
...L, but as in the case of the conventional semiconductor light emitting diode described above in FIGS. 8 to 10, incoherent light is obtained by radiating outward from the light emitting end surface 11. . In addition, in this case, the semiconductor stack 10 includes FIGS. 8 to 1.
As in the case of the conventional semiconductor light emitting diode described above in FIG. Since the electrode layers 15 and 16 of J3 are continuously injected into the region 3a facing each other, the incoherent light emitted to the outside from the light emitting end face 11 is as described above in FIGS. 8 to 10. As in the case of conventional semiconductor light emitting diodes,
A relatively high brightness can be obtained depending on the current flowing in the region M3a where the electrode layers 15 and 16 of the semiconductor crystal layer 3 are facing each other. Furthermore, the incoherent light emitted from the light emitting end face 11 to the outside (q) causes a charging OA as in the case of the conventional semiconductor light emitting diode described above in FIGS. 8 to 10.
Since the light is emitted to the outside from a local area called the end face of the semiconductor crystal layer 3 on the end face 11, the incoherent light obtained by being emitted to the outside from the light emitting end face 11 is as shown in FIGS. As in the case of the conventional semiconductor light-emitting diode described above in the figures, depending on the thickness of the semiconductor crystal layer, radiation is emitted at a relatively narrow emission angle. Therefore, in the case of the semiconductor light emitting diode according to the present invention shown in FIGS. 1 to 3, as well as in the case of the conventional semiconductor light emitting diode described above in FIGS. 8 to 10, relatively incoherent light is generated. High brightness and relatively narrow radiation angles are obtained. However, in the case of the semiconductor light emitting diode according to the present invention shown in FIGS. 1 to 3, the electrode layer 15 of the semiconductor crystal layer 3
and 16 are facing each other, as described above, the first, second, and so on are sequentially smaller in that order.
・The first and second layers in which the superlattice layer is mixed, each having the n-th mixed crystal layer D1D2...Do
. . . are respectively formed in the n-th mixed crystal region, so the first, second, . . . n-th region portions M1,
2nd...Mo's 1st, 2nd...
...nth energy band gap Eg1, Eg2・
・・・・・・・・・Eg. have the smallest values in that order. For this reason, in the first, second...... nth area portion M1, second......M, the first, second...・・・・・・Nth energy band gap E, 1, E ・・・・・・・・・Wavelength λ1, g2ゝgn λ2・・・・・・・・・λ, corresponding to the nth energy band gap E, 1, E ・・・・・・・・・E Lights L1 '2...Lo having bands are generated respectively, and these lights L1, L2......
ln is emitted from the light emitting end face 11 to the outside as incoherent light. For this reason, the first region portion M1, the second region portion M1, the second region portion M1, the second region portion M1, the second region portion M1, the second region portion M1, the second region portion Mo,
, second . 2......The n-th energy band gap Eg1, Eg2,......E is generated in the first and second region n M and the second, respectively. The bands of the lights L1 and L2 generated in the second and third region M2 and the third area, respectively, the (n-th)
The first and second between the energy band gaps E and E, between the second and third energy bands 1g2 and 1g2, between the (n-1)th and nth energy band gaps Eo(n
If the values are selected in advance such that there is a large difference between -1) and E, the incoherent light emitted from the light emitting end surface 11 to the outside can be reduced as shown in Fig. 8. - A single band having a much wider bandwidth WH than that of the conventional semiconductor light emitting diode described above in FIG. 10 can be obtained. For example, the regions 11!3a where the electrode layers 15 and 16 of the semiconductor crystal layer 3 are opposed to each other are the first to nth region portions M1 to M
Let n of o be 2, the first and second (=n> area M
1 and 2 (=n), and the first area M1 in this case is the light generated in the first area M1. is the center wavelength λ1, and the energy bandgap Eg1 is obtained at a wavelength of 1°50 μm, which is the same as the center wavelength λ8 mentioned above for the region 3a of the conventional semiconductor light emitting diode shown in FIGS. 8 to 10. The above-mentioned laminate is mixed crystal at the first mixed crystallinity degree, and the second (=n) region M in this case is
(=n) Light 2 (=n
) The above-mentioned laminate has a second (=n) mixed crystallinity degree such that L2 (=n) is the center wavelength and has an energy band gap Eg2 (Yo,.) obtained at a wavelength of 1.55 μm. In the case of a mixed crystal, the bandwidth W8 is about 1,000 melons in terms of half-width, as shown in the brightness (arbitrary scale) characteristics with respect to the wavelength (μm) of incoherent light in Figure 4. The value obtained was approximately twice that of the case of the conventional semiconductor light emitting diode (500 people) described above in FIGS. 8 to 10. Therefore, according to the semiconductor light-emitting diode according to the present invention shown in FIGS. Figures 8 to 1
A much higher value can be obtained than in the case of the conventional semiconductor light emitting diode described above with reference to FIG. Further, 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 16 of the semiconductor crystal layer 3
The i-th area portion Mi in the area 3a facing each other
(where i-1, 2......n), the light generated has a band centered on the wavelength λi according to the energy band gap E of the i-th region M1. As described above, a part of the area is in the (++1)th to first area M(
i-1) to M1 to propagate toward the light emitting end face 11 side, but in this case, the (i-1)th to first region portion M(i-1)
~Energy bandgap of M1 Ea (i-1) ~Eg
1 is the energy breadth gap Eg of the i-th region M.
Since it is wider than 1, a part of the light is the (i-1)th
The light efficiently propagates toward the light emitting end surface 11 side through the first region M(i-1) to M1. Further, the other portions of the light are formed in the (++1)th to nth region portions M as described above in the case of the semiconductor light emitting diode shown in FIGS. 8 to 10.
1, and then propagates to the region 3b where the electrode layers 15 and 16 of the semiconductor crystal layer 3 are not facing each other. In this case, the energy band gap of the (++1)th to nth region M. Eg(+1)~Eg. and the energy bandgap Egb of the region 3a is narrower than the energy bandgap E,1 of the first region Mi (however, in the case of i-n, the energy bandgap Egb of the region 3b is narrower than the energy bandgap E,1 of the first region Mi). The energy bandgap E9° of the region M. may be equal to the energy bandgap E9°), so the other part of the light L is
+1) is effectively absorbed in the region M(i+1) to Mo and the region 3b. Therefore, incoherent light emitted from the light emitting end face 11 to the outside can be obtained efficiently without the influence of reflection. Note that in the case of the semiconductor light emitting diode according to the present invention shown in FIGS. 3, between the area M2 and M3......the (nth
-1) and the nth region M(.-1) and M. It is possible that it is reflected at the boundary between the first, second...
......n-th area M1, M2...M
o's first, second......n-th energy band gap EE......E11g2 If gn has the above-mentioned value, the first and second... between the second area M1 and M2, and between the second and third area M2 and M
Between 3......(n-1)th and nth area portions M(.-1) and M. Since there is only a small difference in refractive index between them, the first and second regions M and M2
between the second and third area portions M2 and M3...
...(n-1)th and nth area portions M(.-1) and M. Reflections at the boundaries between the two do not pose a practical problem.

Embodiment 2 Next, a second embodiment of the semiconductor light emitting diode according to the present invention will be described with reference to FIGS. 5 to 7. In FIGS. 5 to 7, parts corresponding to those in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof will be omitted. The semiconductor light emitting diode according to the invention shown in FIGS. 5 to 7 has the same structure as the semiconductor light emitting diode according to the invention described above in FIGS. 1 to 3, except for the following points. That is, the electrode layer 15 has the first, second, etc. regions 3a of the semiconductor crystal layer 3 of the semiconductor stacked body 10.
. . . n-th area portions M1, M2 . . . M. Instead of the case of FIGS. 1 to 3, which have a common electrode layer for the first, second, . . .
......n-th area M1, M2...
・First and second electrode layer portions E, E2, which face Mo and are separated from each other.
...has Eo. The above is the 91Si semiconductor light emitting diode according to the present invention.
This is the configuration of the embodiment. The semiconductor light emitting diode according to the present invention having such a configuration has the same configuration as the semiconductor light emitting diode according to the present invention described above in FIGS. 1 to 3, except for the above-mentioned matters, and the electrode Electrode layer portion E included in layer 15
1E2...E each and the electrode layer 12
According to the case of the semiconductor light emitting diode according to the present invention described above in FIGS.
When the power supplies of the semiconductor crystal layer 3 and the electrode layers 15 and 16 of the semiconductor crystal layer 3 are connected to each other, the first, second, nth region portions of the region tJ3a facing each other are connected. M1, M2
.........Mn, the wavelengths λ, λ.........λ The light beams each have a band centered on L1, L2, etc.
・Since Lo occurs, detailed explanation will be omitted, but the first
As in the case of the semiconductor light emitting diode according to the present invention described above in FIGS. It is radiated and tqed at a radiation angle and with a high degree of incoherence. Further, according to the semiconductor light emitting diode according to the present invention shown in FIGS. 5 to 7, the electrode layer 15 is arranged in the first, second, . area M
7, M2......Nth electrode layer portions E, E, 2, respectively facing M3 and separated from each other. ...... Eo, so as mentioned above, the first, second...
・Nth electrode layer portion E1, E2...En
between each of the first, second, etc. and the electrode layer 16.
...By connecting each n-th power supply,
First, second...... nth area portion M, M2.
・・・・・・・・・M. In the case of odor, light having bands centered on wavelengths λ, λ2, etc., respectively, and shi,...
...When generating Lo, the first, second...
...by adjusting the n-th power source, the light L1. L
2......L luminous efficiency is in the range VXM, M2
...... Energy band gap EE of M
・Pa°゛n g1ゝ
By relying on g2...Ego, even if there is a difference in brightness between lights 4, 2, 11, such a difference in brightness cannot be compensated for. ,
Therefore, the light q emitted from the J end face 11 to the outside has good wavelength brightness characteristics, such as a halo-like brightness for wavelengths within its bandwidth WH. It will be done. Although the above description describes an embodiment in which the present invention is applied to a so-called embedded type semiconductor light emitting diode, in short, the present invention corresponds to the semiconductor crystal substrate 1 described above in FIGS. M1 to FIG. (a) ■ A semiconductor crystal substrate having a first S conductivity type, and ■ A semiconductor crystal layer described above in FIGS. 1 to 3 formed on the semiconductor crystal substrate and having a first conductivity type. (2) a first semiconductor crystal layer corresponding to the above first semiconductor crystal layer; a second semiconductor crystal layer corresponding to the semiconductor crystal layer 3 described above in FIGS. 1 to 3;
A second semiconductor crystal layer is formed on and in contact with the second semiconductor crystal layer, has a wider energy band gap and a lower refractive index than the second semiconductor crystal layer, and has a conductivity type opposite to that of the first semiconductor crystal layer. It has a semiconductor stacked body having a third semiconductor crystal layer corresponding to the semiconductor crystal layer 4 described above in FIGS. 1 to 3 having a conductivity type, and (b) the relative of the semiconductor & First and second electrode layers corresponding to the electrode layers 15 and 16 described above in FIGS. 1 to 3 are arranged facing each other on the first and second main surfaces facing each other, Furthermore, it is obvious that the present invention can also be applied to (c) a semiconductor light emitting diode in which one end face in the longitudinal direction of the semiconductor laminate is a light emitting end face. In addition, in the above description, in the case of a semiconductor light emitting diode applied to the present invention described above, the first and second semiconductor crystal layers of the second semiconductor crystal layer extending linearly in a stripe shape of the semiconductor stacked body are A portion of the light generated in the region where the electrode layers face each other is reflected at the region of the second semiconductor crystal layer where the first and second electrode layers do not face each other, resulting in a linear shape of the semiconductor stack. In order to prevent the first and second electrode layers of the second semiconductor crystal layer extending in a stripe shape from re-injecting into the region facing each other, the semiconductor stack is
The second semiconductor crystal layer has a relatively long length such that the regions where the first and second electrode layers do not face each other have a relatively good length to sufficiently absorb light therein. The present invention is applied to a semiconductor light-emitting diode in which the semiconductor stack is formed with an inclined surface on the end face side opposite to the light emitting end face side so that light is not reflected there. Although the embodiment has been described, in order to achieve the above-mentioned purpose, the semiconductor v4 layer body is
A region of the semiconductor crystal layer in which the first and second electrode layers are not facing each other is curved and extended from a region of the second semiconductor crystal layer where the first and second electrode layers are facing each other. A semiconductor light-emitting diode is configured such that the semiconductor stack has an inner surface extending diagonally across a region where the first and second electrode layers of the second semiconductor crystal layer do not face each other. It is also clear that the present invention can be applied to various semiconductor light emitting diodes in which the semiconductor laminate is configured so as to achieve the above-mentioned purpose, such as a semiconductor light emitting diode in which a groove such as the one shown in FIG. Probably. Furthermore, in the semiconductor light emitting diode according to the present invention described above, "n type" may be replaced with "p type", "p type" may be read as [n type J, or other configurations may be used that depart from the spirit of the present invention. Various modifications and changes may be made without further modification.

[Brief explanation of drawings]

FIG. 1, FIG. 2, and FIG. 3 are line plan views showing a first embodiment of a semiconductor light emitting diode according to the present invention;
They are a sectional view taken along the line -■ and a sectional view taken along the line m-■. FIG. 4 is a diagram illustrating the luminance characteristics of the light emitted from the light emitting end surface to the outside with respect to the wavelength, for explaining the semiconductor light emitting diode according to the present invention shown in FIGS. 1 to 3. FIG. 5, 6 and 7 are line plan views showing a second embodiment of the semiconductor light emitting diode according to the present invention, and its V
They are a cross-sectional view taken along the l-Vl line and a cross-sectional view taken along the ■-Vl line. FIG. 8, FIG. 9, and FIG. 10 are a linear plan view showing a conventional semiconductor light emitting diode, a cross-sectional view along the line ■-■, and a cross-sectional view along the line X-X. 1・・・・・・・・・・・・・・・・・・ Semiconductor crystal substrate 2.3.4.5 ・・・・・・・・・・・・・・・・・・... Semiconductor crystal layers 3a, 3b... Regions 6L, 6R, 7L, 7R of semiconductor crystal layer 3 ...... ...Semiconductor crystal layer 10...Semiconductor laminate 11...Light emitting end surface 12・・・・・・・・・・・・・・・・・・ Anti-reflection film 14 ・・・・・・・・・・・・・・・ Slanted surface 15.16... . . . Electrode layer M1 to Mo . . . Region 3 of semiconductor crystal layer 3
area of a

Claims (1)

[Claims] 1. A semiconductor crystal substrate having a first conductivity type, and a first semiconductor crystal substrate formed on the semiconductor crystal substrate and having the first conductivity type.
a second semiconductor crystal layer formed on and in contact with the first semiconductor crystal layer and having a narrower energy bandgap and a higher refractive index than the first semiconductor crystal layer; A second semiconductor crystal layer is formed on and in contact with the second semiconductor crystal layer, has a wider energy band gap and a lower refractive index than the second semiconductor crystal layer, and has a conductivity type opposite to that of the first semiconductor crystal layer. a third semiconductor crystal layer having a conductivity type; first and second electrode layers are provided on first and second main surfaces of the semiconductor stack that are opposite to each other; In the semiconductor light emitting diode, in which one end face in the longitudinal direction of the semiconductor laminate is arranged as a light emitting end face, the second semiconductor crystal layer is arranged such that the first and second electrode layers face each other. A plurality of n first, second...
- having an n-th region portion, the first and second regions of the second semiconductor crystal layer.
. . . The n-th region portions are the first and second mixed crystal regions in which the superlattice layer is mixed, respectively, and the first and second 2...The n-th mixed crystal region is sequentially smaller in the order of the first, second, etc.
- A semiconductor light-emitting diode characterized by having an nth mixed crystallinity (including cases where the nth mixed crystallization degree is substantially zero). 2. The semiconductor light emitting diode according to claim 1, wherein the first electrode layer is the first electrode layer of the second semiconductor crystal layer.
It has first and second...n-th electrode layer parts that respectively face the second...n-th region part and are separated from each other. A semiconductor light emitting diode characterized by: