JP2001007400A - Semiconductor light emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light emitting element improved so as to suppress spread of structural defects. SOLUTION: A substrate a light emitting semiconductor layer 3, having a light emitting area at the upper surface, is provided. Partitions 4a for partitioning the light emitting region into a plurality of sections. A thin film electrode 5 is provided for injecting a current, so as to cover the partitions 4a and contact the light emitting semiconductor layer 3 surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a semiconductor light emitting device, and more particularly to a semiconductor light emitting device improved so as to suppress the expansion of structural defects and point defects.

[0002]

2. Description of the Related Art FIG. 40 shows a structure (a) of a conventional light emitting device.
It is a figure which shows the light emission mechanism (b).

Referring to FIG. 40, a light emitting diode (Ligh
The t-Emitting Diode (LED) is an electro-optical conversion type semiconductor light emitting device utilizing minority carrier injection at a pn junction formed by adjacent p and n type semiconductor crystals and subsequent light emission recombination. It is.

[0004] The element itself is made of a semiconductor crystal material of about 0.3 mm square, and as shown in FIG.
The basic structure is the same as the Si rectifier.

When a positive forward voltage is applied to the p-type crystal and a negative forward voltage is applied to the n-type crystal, electrons are injected into the p region and holes are injected into the n region, as shown in FIG. Some of these minority carriers emit light by radiative recombination with majority carriers.

[0006]

One problem is that such a semiconductor light-emitting device is severely deteriorated. In particular, the ZnSe-based compound semiconductor light emitting device is easily deteriorated. Such degradation is caused by the fact that point current clusters called "bugs" are driven along with structural defects such as dislocations and stacking faults by the injection current, accumulate at the ends of the structural defects, and the structural defects are enlarged. Has been reported (Appl. Phys. Lett. 63 (1993) 3).
107).

Now, it is technically difficult to reduce the density of initial defects, and increasing the quality of a crystal increases the cost.

In order to improve this, referring to FIG.
Reduce the size of the element cut out from the wafer (360μ
m → 50 μm), and proposals have been made to use only devices that do not contain any initial defects. However, in such a method, when the element is cut, a defect or distortion is generated from the cleavage. In addition, since the light emitting area is small, the effective current increases, and the life is shortened. Furthermore, there is a problem in that mounting a small element or handling a large number of elements is expensive.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its main object to provide a semiconductor light emitting device improved so that structural defects do not multiply without increasing the cost. I do.

[0010]

A semiconductor light emitting device according to claim 1 includes a substrate. A light-emitting semiconductor layer whose upper surface is a light-emitting surface is provided on the substrate. On the light-emitting semiconductor layer, there is provided partition means for partitioning the light-emitting surface into a plurality of portions and for preventing a current from flowing to a portion of the light-emitting semiconductor layer immediately below the light-emitting surface. A thin film electrode for injecting a current is provided on the substrate so as to cover the partitioning means and contact the surface of the light emitting semiconductor layer.

In the invention according to claim 2, a pedestal electrode on which the thin-film electrode covers the periphery of the substrate is provided. The partitioning means is made of the same material as the pedestal electrode.

In the semiconductor light emitting device according to the third aspect, the thin film electrode is formed of a material capable of achieving ohmic contact with the light emitting semiconductor layer.

[0013] In the light emitting device according to the fourth aspect, the thin film electrode is formed of a light transmissive material.

In a semiconductor light emitting device according to a fifth aspect, the thin film electrode is made of Au, Pd, Ni and ITO.
(In ₂ O ₃ -5 wt% SnO ₂ ).

In the semiconductor light emitting device according to the present invention, the partitioning means has a layer structure such that no current flows through the semiconductor layer immediately below the partitioning means.

In the semiconductor light emitting device according to the present invention, the partition means is made of a material which cannot make ohmic contact with the semiconductor layer.

In the semiconductor light emitting device according to the present invention, the partitioning means may include Ti, Al, ZnS, Al ₂
It is formed of a material selected from the group consisting of O ₃ , Ni, SiO ₂ , and SiN.

In the semiconductor light emitting device according to the ninth aspect, the partitioning means comprises an upper layer formed of a light-transmitting conductor and a lower layer formed of an insulator.

In a tenth aspect of the present invention, the insulator is made of a material selected from the group consisting of SiO ₂ , SiN, Al ₂ O ₃ , diamond, epoxy resin and acrylic resin.

In the semiconductor light emitting device according to the eleventh aspect, the light transmissive conductor is formed of a material selected from the group consisting of ITO, an organic conductor, and BEDT-TTF.

In a twelfth aspect of the present invention, the light emitting semiconductor layer includes a superlattice contact layer as an upper layer. Immediately below the partitioning means, a part of the superlattice contact layer is removed. The partitioning means is provided so as to be embedded in the removed portion of the superlattice contact layer.

In the semiconductor light emitting device according to the thirteenth aspect, the light emitting semiconductor layer includes a p-type superlattice contact layer, a p-type semiconductor layer formed thereunder, and the p-type superlattice contact layer. A separate semiconductor layer provided between the first and second p-type semiconductor layers and below the partitioning means and not passing current under the partitioning means.

In the semiconductor light emitting device according to the present invention, the another semiconductor layer is formed of a material that cannot make ohmic contact with the thin film electrode.

In the semiconductor light emitting device according to a fifteenth aspect, the partitioning means is formed to have a planar shape and a lattice shape.

In the semiconductor light emitting device according to the sixteenth aspect, the partitioning means is formed in a planar shape and in a comb shape.

In a semiconductor light-emitting device according to a seventeenth aspect, the partitioning means is formed to have a planar shape and a diagonal lattice type.

In the semiconductor light emitting device according to the eighteenth aspect, the partitioning means is formed to have a planar shape and a honeycomb lattice type.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is an improvement of the electrode structure in order to solve the above-mentioned problems. As will be described below, an electric partition is provided so that the elements can be separated without actually separating them. The solution is characterized by achieving the same effect. FIGS. 1 and 2 are conceptual diagrams showing the principle of suppressing the expansion of defects by using an electric partition.

FIG. 1 is a sectional view of a semiconductor light emitting device without a partition. Referring to FIG. 1A, an In electrode 2 is provided on the back surface of single crystal substrate 1. Epitaxial layer 3 which is a light emitting semiconductor layer on single crystal substrate 1
Are formed. On the epitaxial layer 3,
A pedestal electrode 4 is provided on the outer periphery. A thin film electrode 5 is provided on single crystal substrate 1 so as to be in contact with epitaxial layer 3 and to cover pedestal electrode 4.
A lead wire 6 is connected to the thin film electrode 5 at a position above the pedestal electrode 4. The single crystal substrate 1 is mounted on an element mount 50 with an In electrode 2 interposed. Initial defects 8 usually exist in the epitaxial layer 3.

It has been clarified that the deterioration of the element progresses by injecting a current. That is, when a current 9 flows from the thin film electrode 5 to the In electrode 2, the defect expands from the initial defect 8, and finally the defect spreads over the entire element as shown in FIG. If the defect spreads over the entire device, the light emitting device will not glow. In this case, since no current flows directly below the pedestal electrode 4, it is recognized that the defect does not spread to the epitaxial layer 3 under the pedestal electrode 4.

FIG. 2 is a cross-sectional view of a semiconductor light-emitting device having an electric partition, which is a feature of the present invention.
2, the same or corresponding portions as those of the semiconductor light emitting device shown in FIG. 1 are denoted by the same reference numerals, and description thereof will not be repeated.

The semiconductor light emitting device shown in FIG.
The differences of the semiconductor light emitting device according to the present invention shown in FIG. That is, the light emitting semiconductor layer 3
Partitioning means 4a for partitioning the light emitting surface into a plurality of parts is provided on the light emitting device. A thin-film electrode layer 5 for injecting current is provided so as to cover the partitioning means 4a and come into contact with the surface of the light-emitting semiconductor layer. Partitioning means 4
“a” is formed of the same material as the pedestal electrode 5. No current is injected into the epitaxial layer 3 under the partitioning means 4a. The region where current is injected and the region where no current is injected
With such an effective arrangement, it becomes possible to provide an electrical partition in the element. Deterioration does not proceed in a region where no current is injected.

Therefore, by providing an electric partition in this way, the defect that expands from the initial defect 8 is:
Referring to FIG. 2B, part 3a of epitaxial layer 3
And does not spread over the entire device. It has been recognized that such a configuration significantly extends the life of the semiconductor light emitting device.

Next, the structure of the semiconductor light emitting device according to the present invention will be described in more detail. FIG. 3A is a perspective view of a light-emitting element without a partition. First, FIG. 3 which is an exploded perspective view
Referring to (b), a substrate 1 including an active layer and a pedestal electrode 4
The semiconductor light emitting device shown in FIG.

FIG. 4A is a perspective view of a semiconductor light emitting device having partitions. Referring to FIG. 4B which is an exploded perspective view, pedestal electrode 4 includes partitioning means 4a for partitioning the light emitting surface into a plurality of portions. A combination of the pedestal electrode 4, the substrate 1, and the thin film electrode 5 is a semiconductor light emitting device shown in FIG.

Since the pedestal electrode 4 is a portion for connecting an electric wire for injecting a current from the outside by wire bonding or the like, a material having high adhesion to the substrate and high mechanical strength is selected. However, the pedestal electrode 4 including the partition portion 4a is made of a material that cannot make ohmic contact with the semiconductor layer immediately below, and no current is injected directly below the pedestal electrode 4.

Next, the effects of the present invention will be described. FIG. 5A is a plan view when there is no partition, and FIG.
(B) is a plan view when there is a partition. In these figures, the “Dark Line Defe
cts (DLD) ".

Referring to FIG. 5A, if there is no partition, the DLD extends to the outer edge of the element. On the other hand, referring to FIG. 5B, if there is a partition, the enlargement of the defect stops at the partition. It is considered that the length of this DLD is, on average, represented by the reciprocal of the number of divided elements (in this case, 1/9). therefore,
Theoretically, the defect density is multiplied by the number divided, and the life is multiplied by the multiplied number.

FIGS. 5 (a) and 5 (b) show the case where the partitions are arranged in a lattice shape, but the present invention is not limited to this.

FIG. 6A shows an example in which a partition is formed in a lattice pattern, FIG. 6B shows an example in which a partition is formed in a comb form, and FIG. FIG. 6D shows an example in which partitioning is performed in a honeycomb lattice type. These can be used properly depending on the application. For example, if the defect is a crystal extending in the diagonal direction of the element, as shown in FIG.
It is also possible to change the orientation of the grid accordingly. However, it is necessary to provide a geometrically efficient arrangement as shown in FIG.

FIG. 7 is a schematic diagram of an electroluminescence image (ELI) showing that the current injection restriction region suppresses enlargement / extension of the DLD. This is an image obtained by observing the sample from the back surface before cutting out the LED.
FIG. 7A is a schematic diagram of the ELI before deterioration, and FIG. 7B is a schematic diagram of the ELI after deterioration. By comparing these figures, “A” in FIG.
In the pedestal electrode section (current injection limiting area) indicated by,
Thin-film electrode parts indicated by “B” and “C” (current injection area)
It can be seen from FIG. 7 that the elongation of the DLD that has been extended has stopped. This indicates that the partition portion formed of the same material as the pedestal electrode effectively functions as an electrical partition. In this case, the distance at which the DLD enters the current injection restriction region is about 10 μm. This value is almost constant in many samples. From this, considering the DLD extending from the opposite side (C for B and B for C), the width of the current injection limiting region for the partition is about 20
-30 μm is sufficient.

In the present invention, the shape of the LED is a normal LED.
There is no difference from the element. Since only the electrode for current injection is improved, it is possible to directly apply the already established low-cost LED element manufacturing technology. In general, in the improvement of the LED, the electrode structure has been recognized only to the extent that "the current can flow and the light can be transmitted", and attention has been paid only to the development of the material of the light emitting structure layer and the cladding layer. The present invention positively utilizes the effect of this electrode on the underlying LED.

[0043]

Next, a specific embodiment will be described with reference to the drawings.

Embodiment 1 The present embodiment relates to a semiconductor light emitting device in which a ZnCdSe blue-green light emitting device is formed on a ZnSe substrate and a lattice type electrode is formed on the ZnCdSe blue light emitting device. As a substrate, n
A stacked structure composed of a type ZnSe substrate (dopant: aluminum) and a mixed crystal having ZnSe as a base material was employed as an epitaxial light emitting structure. ZnSe substrate has a thickness of 700
μm was used.

On this substrate, the emission peak was 493.0 nm.
A blue-green light-emitting structure (room temperature) was formed by molecular beam epitaxy (MBE) using a homoepitaxial technique. The epitaxial emission structure, p-type contact layer laminated made of super lattice structure of ZnTe and ZnSe doped with p-type, Zn _{0. 85} doped with p-type
P-type cladding layer composed of Mg _0.15 S _0.10 Se _0.90 layer, Z
nSe layer and Zn _0.88 Cd _{0.1 2} Se layer multiple quantum well active layer having a laminated structure of, n-type doped the Zn _0.85 M
g _0.15 S _0.10 Se _0.90 layer and an n-type clad layer.

On the contact layer of this epitaxial wafer, a lattice-shaped pattern p-type electrode (light extraction portion, inner frame 360 μm × 360 μm square) made of Au / Ti is formed, and further a thin-film Au electrode having a thickness of 20 nm is formed. Was formed, and an n-type electrode made of In was formed on the back surface side of the substrate.

FIG. 8 shows a specific pattern of the grid electrode. Referring to FIG. 8, a region indicated by reference numeral 4 (including a partition portion) is a pedestal electrode portion (current injection restriction region) including the partition portion. The portion indicated by reference numeral 5 is a thin film electrode portion (current injection region). Light extraction part is 360μm ×
This is a 360 μm square area. The pedestal electrode portion for electric partitioning having a width of 20 μm has a lattice shape. Light emitted from the active layer is extracted from a rectangular region having a side of 100 μm to 110 μm. The value of 20 μm in width was determined based on a distance of 10 μm × 2 (considering extension from both sides of the lattice) at which the extension of the linear defect was stopped.

The portion indicated by the dotted line in FIG. 8 is a portion where cleavage is performed. Cleave at this part, 500μ
The chip is an m × 500 μm square chip. After the electrodes were formed, the epitaxial wafer was cut into a size of 500 μm × 500 μm square, and a chip was fixed to an element mount (stem) to obtain an LED.

When this LED was measured in the constant current mode, it was possible to obtain blue-green light of high luminance. Typical emission intensity was 1.5 mW at 20 mA. The device life was about 200 hours, which was nearly five times longer than that of a conventional blue-green LED device using ZnSe. In this element,
Since the current injection restriction region suppresses the expansion of defects, it is less susceptible to the uneven distribution of the initial defect distribution. Therefore, there is little variation in the characteristics between the elements, and the occurrence rate of defective products during mass production is reduced.

Embodiment 2 This embodiment relates to a semiconductor light emitting device in which a ZnCdAe-based white light emitting device is formed on a ZnSe substrate, and a diagonal lattice type electrode is formed thereon.

The substrate is an n-type ZnSe substrate (dopant: aluminum), and the epitaxial light emitting structure is Z
A laminated structure composed of a mixed crystal having nSe as a base was employed.
A ZnSe substrate having a thickness of 700 μm was used. On this substrate, a blue light-emitting structure having a light emission peak of 481.0 nm (room temperature) was formed by molecular beam epitaxy (MBE) using a homoepitaxial technique. This epitaxial light emitting structure is a p-doped ZnT
p-type contact layer having a stacked superlattice structure of e and ZnSe, p-type doped Zn _0.85 Mg _0.15 S _0.10 Se
_0.90 p-type cladding layer, ZnSe layer and Zn _0.88
Multiple quantum well active layer having a laminated structure of Cd _0.12 Se layer, Zn _0.85 Mg _0.15 S _0.10 Se doped to n-type
_And an n-type cladding layer composed of _0.90 layers.

The blue light emitted from the multiple quantum well active layer excites the emission center of the substrate and emits yellow light having an emission peak at 590 nm (room temperature). When these two lights overlap, white light is obtained.

On this epitaxial wafer, Au / Ti
Diagonal lattice pattern p-type electrode (light extraction part,
An inner frame (360 μm × 360 μm square) is formed.
An Au electrode was formed on the entire surface of the thin film having a thickness of 0 nm, and an n-type electrode made of In was formed on the back surface of the substrate.

FIG. 9 shows a specific pattern of the diagonal lattice type electrode.
Shown in In the figure, 4 is a pedestal electrode portion (current injection restriction region) including a partition portion, and 5 is a thin film electrode portion (current injection region).
It is. The light extraction part is a square area of 360 μm × 360 μm. A pedestal electrode for electric partitioning having a width of 20 μm is provided in a square area in a diagonal lattice pattern. The pedestal electrode for electrical partitioning forms an angle of 45 ° with respect to each side of a 360 μm × 360 μm square. The reason why the diagonal lattice pattern is adopted in the present epitaxial wafer is that in the active layer (Zn _0.88 Cd _0.12 Se) used in the present epitaxial wafer, the deterioration proceeds due to the DLD extending in the <100> crystal axis direction. Because we already know that. Light emitted from the active layer and the substrate is extracted from triangular, square, and pentagonal portions shown in white in FIG. The reason why the width of the pedestal electrode for electric partitioning is set to 20 μm is the same as in the first embodiment.

The portion shown by the dotted line in FIG. 9 is the portion where cleavage is performed. Cleave at this part, 500μ
The chip is an m × 500 μm square chip. After the electrodes were formed, the epitaxial wafer was cut into a size of 500 μm × 500 μm square, and a chip was fixed to an element mount (stem) to obtain an LED. When this LED was measured in the constant current mode, white light with high luminance could be obtained. Typical emission intensity was 1.1 mW at 20 mA. The device lifetime was about 280 hours, which was nearly seven times longer than that of a conventional blue-green LED device using ZnSe.

Embodiment 3 This embodiment relates to a semiconductor light emitting device in which a ZnSe-based blue light emitting device is formed on a ZnSe substrate and a honeycomb lattice type electrode is formed thereon.

The substrate is an n-type ZnSe substrate (dopant: aluminum), and the epitaxial light emitting structure is Z
A laminated structure composed of a mixed crystal having nSe as a base was employed.
A ZnSe substrate having a thickness of 700 μm was used. A blue light emission structure having a light emission peak of 462.0 nm (room temperature) was formed on the substrate by molecular beam epitaxy (MBE) using a homoepitaxial technique. This epitaxial light emitting structure is a p-doped ZnT
p-type contact layer having a stacked superlattice structure of e and ZnSe, p-type doped Zn _0.74 Mg _0.26 S _0.34 Se
_It comprises a p-type guide layer composed of a _0.66 layer, a p-type guide layer composed of a ZnSe layer, an active layer composed of a ZnSe layer, and an n-type guide layer composed of an n-type doped Zn _0.74 Mg _0.26 S _0.34 Se _0.66 layer.

On the contact layer of this epitaxial wafer, a honeycomb lattice-shaped pattern p-type electrode (light extraction portion, inner frame 360 μm × 360 μm square) made of Au / Ti is formed, and a thin film Au having a thickness of 20 nm is further formed. An electrode was formed, and an n-type electrode made of In was formed on the back surface of the substrate.

FIG. 10 shows a specific pattern of the honeycomb lattice type electrode. In the figure, reference numeral 4 denotes a pedestal electrode portion (current injection restriction region), and a white region indicated by 5 is a thin film electrode portion (current injection region).

The light extraction portion is a square area of 360 μm × 360 μm. A regular hexagonal pedestal electrode for electric partitioning having a width of 20 μm is arranged in a square area in a honeycomb lattice pattern. The regular hexagonal electrical partition electrode has an angle of 120 degrees at each apex as shown.

The reason for adopting the honeycomb lattice pattern in the present epitaxial wafer is that, in the active layer (ZnSe) used in the present epitaxial wafer, the point-like defects are parallel to the epitaxial plane (plane direction, omnidirectional). This is because the deterioration progresses by expanding or diffusing into ()). The honeycomb lattice (hexagonal lattice) can arrange the current injection region and the power injection restriction region without forming a gap, and further supplies the current supplied to the pedestal electrode of the outer frame to the LED through the pedestal electrode of the lattice. This is because it is possible to reduce the length of the lead to the central portion of the portion as compared with a circular or elliptical shape, and to suppress unnecessary power consumption at that portion.

The region from which the emitted light is extracted from the active layer and the substrate is extracted from the portion shown in white in FIG. 10, as in the first and second embodiments. The reason why the width of the pedestal electrode for electrical partitioning was set to 20 μm is also described in Example 1.
And 2.

Cleavage is performed at the portion indicated by the dotted line in FIG. 10 to obtain a chip of 500 μm × 500 μm square. 500 μm × 500 epitaxial wafer after electrode formation
It was cut into a size of μm square, chipped, and fixed to an element pedestal (stem) to obtain an LED.

When this LED was measured in a constant current mode, 0.2 mW of blue light could be obtained at a current of 20 mA. Extension of the device life was observed. A typical device life is about 2000 hours, which is nearly four times longer than a conventional blue LED device using ZnSe.

Example 4 FIG. 11 is a sectional view of a ZnSe-based compound semiconductor light emitting device according to Example 4. FIG. 11 is a cross-sectional view along a line X1-X1 in FIG. 8, for example.

On the conductive ZnSe single crystal substrate 31, 1
μm thick n-type ZnSe buffer layer 32, 1 μm thick n-type ZnMgSe cladding layer 33, ZnSe / ZnCdSe
Multiple quantum well active layer 34, 1 μm thick p-type ZnMgSS
e cladding layer 35, p-type ZnSe layer 3 having a thickness of 0.2 μm
6. A p-type contact layer 37 having a stacked superlattice structure of ZnTe and ZnSe is sequentially provided. At the top,
A 60 nm thick p-type ZnTe layer 38 is provided. p
The mold contact layer 37 and part of the p-type ZnTe layer 38 are removed by etching, thereby exposing the p-type ZnSe layer 36 that cannot make ohmic contact with the metal electrode. The exposed portion of the p-type ZnSe layer 36 is in contact with an electrical partition 41 (including a pedestal electrode) made of Au / Ti.

The translucent Au electrode 40 is provided so as to cover the electric partition 41 so as to be in contact with the surface of the light emitting semiconductor layer.

With this configuration, it is possible to completely prevent a current from flowing immediately below the electric partition 41. With this configuration, the life of the device is further extended.

Next, a method of manufacturing the ZnSe-based compound semiconductor light emitting device shown in FIG. 11 will be described.

Referring to FIG. 12, a ZnSe single crystal substrate 31 on which an n-type electrode 42 is formed is prepared.

Referring to FIG. 13, an n-type ZnSe buffer layer 32, an n-type ZnMgSe cladding layer 33, a ZnSe / ZnCdSe multiple quantum well active layer 34 and a p-type ZnMgSSe cladding layer 35 are sequentially formed on a single crystal substrate 31. Form. Referring to FIG. 14, a p-type ZnSe layer 36, a p-type contact layer 37, and a p-type ZnTe layer 38 are formed on cladding layer 35.

Referring to FIG. 15, on p-type ZnTe layer 38, a resist pattern 50 having an opening at a portion where an electric partition portion and a pedestal electrode are to be formed is formed.

Referring to FIG. 16, resist pattern 50
Is used as a mask, a part of the p-type ZnTe layer 38, the p-type contact layer 37, and a part of the p-type ZnSe layer 36 are etched by ion milling.

Referring to FIG. 17, resist pattern 50
Is used as a mask, Ti is deposited, and then Au is deposited. As a result, the pedestal electrode made of Au / Ti and the electric partition 41 are formed.

Referring to FIGS. 17 and 18, resist pattern 50 is removed. Referring to FIG. 19, pedestal electrode 41
When a thin-film Au electrode is formed on the substrate 1 so as to be in contact with the p-type ZnTe layer 38, the semiconductor light emitting device shown in FIG. 11 is completed.

Example 5 FIG. 20 is a sectional view of a ZnSe-based compound semiconductor light emitting device according to Example 5.

On the conductive ZnSe single crystal substrate 31,
1 μm thick n-type ZnSe buffer layer 32, 1 μm thick n
Type ZnMgSSe cladding layer 33, ZnSe and ZnCd
Se multiple quantum well active layer 34, 1 μm thick p-type ZnM
A gSSe cladding layer 35 and a p-type ZnSe layer 36 are provided. On the p-type ZnSe layer 36 and below the electrical partition 41 (including the pedestal electrode), another semiconductor layer 39 that does not allow a current to flow under the electrical partition is provided. P-type Z so as to cover another semiconductor layer 39
On the nSe layer, a laminated superlattice structure 37 and p-type ZnT
An e-layer 38 is formed. On the p-type ZnTe layer 38, an electric partition 41 and a pedestal electrode are formed. A translucent Au electrode 40 is provided on the substrate so as to cover the electric partition 41.

According to the sixth embodiment, below the pedestal electrode 41,
Since another semiconductor layer 39 that does not allow current to flow is provided below the pedestal electrode, no current flows immediately below the electrical partition. Consequently, the defect does not grow.

Next, a method of manufacturing the semiconductor light emitting device shown in FIG. 20 will be described. Referring to FIG. 21, an n-type ZnSe buffer layer 32, an n-type ZnMgSe cladding layer 33, a multiple quantum well active layer 34, a cladding layer 3 are formed on a conductive ZnSe single crystal substrate 31 having an n-type electrode 42 on the back surface.
5 are sequentially formed. On the cladding layer 35, p-type ZnS
An e-layer 36 is formed.

Referring to FIG. 22, a p-type ZnSe layer 36 is formed with a resist pattern 50 having an opening at a portion where an electrical partition portion and a pedestal electrode portion are to be formed.

Referring to FIG. 23, resist pattern 50
Is used as a mask to form an n-type layer or a semiconductor layer 39 without ohmic contact on the p-type ZnSe layer 36.

Referring to FIGS. 23 and 24, resist pattern 50 is removed. Referring to FIG. 25, p-type ZnSe
On the layer 36, a p-type contact layer 37 and p-type ZnT
Regrow e38.

Referring to FIG. 26, a resist pattern 51 having an opening in a region where an electric partition portion and a pedestal electrode are to be formed is formed.

Referring to FIG. 27, resist pattern 51
Is used as a mask, Ti is vapor-deposited on the p-type ZnTe layer 38, and then Au is vapor-deposited.
(Including a pedestal electrode).

Referring to FIGS. 27 and 28, resist pattern 51 is removed. Referring to FIG. 29, pedestal electrode 41
When the thin-film gold electrode 40 is formed so as to cover
0 is completed.

Embodiment 6 This embodiment relates to another manufacturing method of the semiconductor light emitting device shown in FIG.

Referring to FIG. 30, a buffer layer 32, a clad layer 33, a multiple quantum well active layer 34, a clad layer 35, and a p-type ZnSe layer 36 are formed on a ZnSe single crystal substrate 31 having an n-type electrode 42. Form.

Referring to FIG. 31, an n-type layer or a semiconductor layer 12 not in ohmic contact is formed on P-type ZnSe layer 36.

Referring to FIG. 32, a resist pattern 50 is formed so as to mask a portion where an electric partition portion and a pedestal electrode are to be formed.

Referring to FIG. 33, resist pattern 50
Is used as a mask to ion-mill the n-type layer or the semiconductor layer 12 not in ohmic contact.

Referring to FIGS. 33 and 34, resist pattern 50 is removed. Referring to FIG. 35, p-type ZnSe
On the layer 36, a p-type contact layer 37 and p-type ZnT
The e-layer 38 is regrown.

Referring to FIG. 36, a resist pattern 51 having an opening at a portion where an electric partition portion and a pedestal electrode are to be formed is formed.

Referring to FIG. 37, resist pattern 51
Is used as a mask, Ti is vapor-deposited on the p-type ZnTe layer 38, and Au is further vapor-deposited to form an electric partition 41 (including a pedestal electrode).

Referring to FIGS. 37 and 38, resist pattern 51 is removed. Referring to FIG. 39, a thin-film gold electrode 40 is formed on the substrate so as to cover the electrical partition 41.
Is formed, the semiconductor light emitting device according to FIG. 2 is completed.

As described above, by effectively arranging the electrodes for current injection and for limiting the current injection region, an electric partition is provided to suppress the expansion of element injection defects and suppress the deterioration of the element. The principle is not limited to LEDs, but can be applied to many other devices and materials. Examples of such a device include an organic EL device, a liquid crystal display device, a semiconductor operation device (such as a capacitor), and a magnetic storage device.

Further, if the above technique is used, the LED having the same structure as the conventional one can be realized without increasing the quality of the light emitting structure layer or cutting the element into small pieces in order to reduce the relative defect density. An LED having a device life and luminous efficiency that has not been obtained can be manufactured. Furthermore, the electrode fabrication technology itself is the same as before,
A high-performance LED can be manufactured at low cost.

The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0098]

As described above, according to the present invention,
With a simple and low-cost process, an unprecedented long-life LED light source can be manufactured. The present invention enables low-cost, long-life LED light sources to be mass-produced. Therefore, there is a great demand not only for display applications and decoration applications, which have been the main applications of LED light sources, but also for lighting applications. Can be expected. When an LED light source is used for lighting, its load on the global environment can be reduced due to its high mechanical strength, light weight, compactness, and high energy conversion efficiency.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a semiconductor light-emitting device for explaining an operation of a semiconductor light-emitting device according to a reference example.

FIG. 2 is a diagram for explaining an operation of the semiconductor light emitting device according to the embodiment of the present invention.

FIG. 3 is a diagram for explaining a structure of a semiconductor light emitting device according to a reference example.

FIG. 4 is a diagram illustrating a structure of a semiconductor light emitting device according to an embodiment.

FIG. 5 is a diagram for explaining an effect when an electric partition is performed.

FIG. 6 is a diagram showing a specific example of an electrode pattern.

FIG. 7 is an ELI showing that the electrical partition is working as an electrical partition.

FIG. 8 is a plan view showing a specific pattern of a grid electrode.

FIG. 9 is a plan view showing a specific pattern of a diagonal grid electrode.

FIG. 10 is a plan view showing a specific pattern of a honeycomb lattice type electrode.

FIG. 11 is a sectional view of a semiconductor light emitting device according to Example 4.

FIG. 12 is a cross-sectional view of the semiconductor light-emitting device in a first step of the sequence of the method for manufacturing the semiconductor light-emitting device according to the fourth embodiment.

FIG. 13 is a cross-sectional view of the semiconductor light emitting device in a second step in the sequence of the method for manufacturing the semiconductor light emitting device according to the fourth embodiment.

FIG. 14 is a cross-sectional view of the semiconductor light emitting device in a third step in the sequence of the method for manufacturing the semiconductor light emitting device according to the fourth embodiment.

FIG. 15 is a sectional view of the semiconductor light emitting device in a fourth step in the order of the method for manufacturing the semiconductor light emitting device according to the fourth embodiment.

FIG. 16 is a sectional view of the semiconductor light emitting device in a fifth step of the sequence of the method for manufacturing the semiconductor light emitting device according to the fourth embodiment.

FIG. 17 is a sectional view of the semiconductor light emitting device in a sixth step in the order of the method for manufacturing the semiconductor light emitting device according to the fourth embodiment.

FIG. 18 is a sectional view of the semiconductor light emitting device in a seventh step of the sequence of the method for manufacturing the semiconductor light emitting device according to the fourth embodiment.

FIG. 19 is a sectional view of the semiconductor light emitting device in an eighth step of the order of the method for manufacturing the semiconductor light emitting device according to the fourth embodiment.

FIG. 20 is a sectional view of a semiconductor light emitting device according to Example 5.

FIG. 21 is a cross-sectional view of the semiconductor light-emitting device in a first step of the sequence of the method for manufacturing the semiconductor light-emitting device according to the fifth embodiment.

FIG. 22 is a sectional view of the semiconductor light emitting device in a second step in the sequence of the method for manufacturing the semiconductor light emitting device according to the fifth embodiment.

FIG. 23 is a cross-sectional view of the semiconductor light-emitting element in a third step of the sequence of the method for manufacturing the semiconductor light-emitting element according to the fifth embodiment.

FIG. 24 is a cross-sectional view of the semiconductor light-emitting device in a fourth step in the sequence of the method for manufacturing the semiconductor light-emitting device according to the fifth embodiment.

FIG. 25 is a sectional view of the semiconductor light emitting device in a fifth step of the sequence of the method for manufacturing the semiconductor light emitting device according to the fifth embodiment.

FIG. 26 is a sectional view of the semiconductor light emitting device in a sixth step in the sequence of the method for manufacturing the semiconductor light emitting device according to the fifth embodiment.

FIG. 27 is a sectional view of the semiconductor light emitting device in a seventh step of the sequence of the method for manufacturing the semiconductor light emitting device according to the fifth embodiment.

FIG. 28 is a sectional view of the semiconductor light emitting device in an eighth step of the sequence of the method for manufacturing the semiconductor light emitting device according to the fifth embodiment.

FIG. 29 is a sectional view of the semiconductor light emitting device in a ninth step of the sequence of the method for manufacturing the semiconductor light emitting device according to the fifth embodiment.

FIG. 30 is a cross-sectional view of the semiconductor light-emitting element in a first step in the sequence of the method for manufacturing the semiconductor light-emitting element according to the sixth embodiment.

FIG. 31 is a sectional view of the semiconductor light emitting device in a second step in the order of the method for manufacturing the semiconductor light emitting device according to the sixth embodiment.

FIG. 32 is a cross-sectional view of the semiconductor light-emitting element in a third step in the sequence of the method for manufacturing the semiconductor light-emitting element according to the sixth embodiment.

FIG. 33 is a cross-sectional view of the semiconductor light-emitting device in a fourth step in the sequence of the method for manufacturing the semiconductor light-emitting device according to the sixth embodiment.

FIG. 34 is a cross-sectional view of the semiconductor light-emitting device in a fifth step of the sequence of the method for manufacturing the semiconductor light-emitting device according to the sixth embodiment.

FIG. 35 is a sectional view of the semiconductor light emitting device in a sixth step of the sequence of the method for manufacturing the semiconductor light emitting device according to the sixth embodiment.

FIG. 36 is a sectional view of the semiconductor light emitting device in a seventh step of the sequence of the method for manufacturing the semiconductor light emitting device according to the sixth embodiment.

FIG. 37 is a sectional view of the semiconductor light emitting device in an eighth step of the sequence of the method for manufacturing the semiconductor light emitting device according to the sixth embodiment.

FIG. 38 is a sectional view of the semiconductor light emitting device in a ninth step of the sequence of the method for manufacturing the semiconductor light emitting device according to the sixth embodiment.

FIG. 39 is a cross-sectional view of the semiconductor light-emitting element in a tenth step of the sequence of the method for manufacturing the semiconductor light-emitting element according to Example 6.

FIG. 40 is a diagram showing a structure and a light emitting mechanism of a conventional light emitting element.

FIG. 41 is a view illustrating a manufacturing step of a conventional semiconductor light emitting device.

[Explanation of symbols]

 Reference Signs List 3 epitaxial layer 4 pedestal electrode 4a partition part 5 thin film electrode

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Akihiko Saegusa 1-3-1 Shimaya, Konohana-ku, Osaka City F-term in Osaka Works, Sumitomo Electric Industries, Ltd. 5F041 AA41 AA44 CA05 CA41 CA43 CA49 CA57 CA66 CA77 CA82 CA83 CA92 CA93 CA98 DA12 DA19 FF01 FF11 5F103 AA04 DD23 DD30 HH03 JJ01 JJ03 LL01 LL02 LL16 LL17 PP11 RR10

Claims (18)

[Claims] A light-emitting semiconductor layer provided on the substrate and having an upper surface serving as a light-emitting surface; and a light-emitting surface provided on the light-emitting semiconductor layer and partitioning the light-emitting surface into a plurality of portions. Partitioning means for preventing a current from flowing to the light-emitting semiconductor layer portion immediately below the partitioning means, and covering the partitioning means, and provided on the substrate so as to contact the surface of the light-emitting semiconductor layer, A semiconductor light emitting device comprising: a thin film electrode for injecting a current. 2. The apparatus according to claim 1, further comprising a pedestal electrode provided on the periphery of the substrate, wherein the thin-film electrode covers the pedestal electrode, and the partitioning means is formed of the same material as the pedestal electrode. The semiconductor light-emitting device according to claim 1. 3. The semiconductor light emitting device according to claim 1, wherein said thin film electrode is formed of a material capable of achieving ohmic contact with said light emitting semiconductor layer. 4. The semiconductor light emitting device according to claim 1, wherein said thin film electrode is formed of a light transmissive material. 5. The semiconductor light emitting device according to claim 4, wherein said thin film electrode is selected from the group consisting of Au, Pd, Ni and ITO. 6. The semiconductor light emitting device according to claim 1, wherein said partitioning means has a layer structure in which current does not flow in a semiconductor layer immediately below said partitioning means. 7. The semiconductor light emitting device according to claim 1, wherein said partitioning means is made of a material that cannot make ohmic contact with a semiconductor layer immediately below said partitioning means. 8. The partitioning means includes Ti, Al, Zn.
_{S, Al 2 O 3, Ni} , and is formed of a material selected from the group consisting of SiO ₂ and SiN, a semiconductor light-emitting device according to claim 1. 9. The semiconductor light emitting device according to claim 6, wherein said partitioning means comprises an upper layer formed of a light transmitting conductor and a lower layer formed of an insulator. 10. The insulator is made of SiO ₂ , SiN, A
l ₂ O _3, diamond, and is formed of a material selected from the group consisting of epoxy resins and acrylic resins, semiconductor light-emitting device according to claim 9. 11. The semiconductor light emitting device according to claim 9, wherein said light transmitting conductor is formed of a material selected from the group consisting of ITO, an organic conductor, and BEDT-TTF. 12. The light-emitting semiconductor layer includes a superlattice contact layer as an upper layer, a part of the superlattice contact layer is removed immediately below the partitioning means, and the partitioning means includes a superlattice contact layer. The semiconductor light emitting device according to claim 1, wherein the semiconductor light emitting device is provided so as to be embedded in the removed portion of the lattice contact layer. 13. The light-emitting semiconductor layer, comprising: a p-type superlattice contact layer; a p-type semiconductor layer formed thereunder;
A further semiconductor layer provided between the p-type superlattice contact layer and the p-type semiconductor layer and below the partitioning means, wherein no current flows under the partitioning means.
The semiconductor light emitting device according to claim 1. 14. The another semiconductor layer is formed of a material that cannot make ohmic contact with the thin film electrode.
The semiconductor light emitting device according to claim 1. 15. The semiconductor light emitting device according to claim 1, wherein said partitioning means is formed in a planar shape and in a lattice shape. 16. The semiconductor light emitting device according to claim 1, wherein said partitioning means has a planar shape and is formed in a comb shape. 17. The semiconductor light emitting device according to claim 1, wherein said partitioning means is formed in a planar shape and in a diagonal lattice shape. 18. The semiconductor light emitting device according to claim 1, wherein said partitioning means is formed in a planar shape and has a honeycomb lattice shape.