JP2006295057A - Semiconductor light emitting element and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nitride semiconductor light emitting element capable of improving external quantum efficiency by effectively taking out light to prevent the light emitted by a light emitting layer from repeating total reflection in a semiconductor laminate and a substrate to attenuate, and to provide its manufacturing method. <P>SOLUTION: The semiconductor laminate 7 made of a nitride semiconductor and having an n-type layer 3 on the side of a substrate 1 and a p-type layer 5 on the side of the upper surface to form the light emitting layer is provided on the surface of the substrate 1. A p-side electrode 9 is provided in electric connection with the p-type layer 5 of the laminate 7, and an n-side electrode 10 is provided in electric connection with the n-type layer 3. The outermost p-type semiconductor layer of the semiconductor laminate 7 serves as a light take-out layer 6 formed to have a six-sided pyramid protrusion 6a or recess formed on a crystalline plane of ä1-101} side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor light-emitting element that generates blue light (ultraviolet to yellow) on which a nitride semiconductor is stacked on a substrate, and a method for manufacturing the same. More specifically, the present invention relates to a semiconductor light emitting device having a structure capable of efficiently extracting light emitted from a light emitting layer forming portion to the outside and improving external quantum efficiency, and a manufacturing method thereof.

  Conventionally, a semiconductor light emitting device that emits blue light includes, for example, a low temperature buffer layer 32 made of GaN, an n-type layer 33 made of GaN, and a band gap on a sapphire substrate 31, as shown in FIG. A material whose energy is smaller than that of the n-type layer 33 and determines the emission wavelength, for example, an active layer (light emitting layer) 34 made of an InGaN-based (meaning that the ratio of In and Ga can be changed variously, the same applies hereinafter) compound semiconductor; , A p-type layer 35 made of GaN or the like is laminated to form a semiconductor laminated portion 36, and a p-side (upper) electrode 38 is provided on the surface via a translucent conductive layer 37. The n-side electrode 39 is provided on the surface of the n-type layer 33 exposed by etching a part of the stacked portion 36. Note that the n-type layer 33 and the p-type layer 35 further improve the carrier confinement effect, so that the active layer side has a further band such as an AlGaN-based compound (meaning that the ratio of Al and Ga can be changed variously, the same applies hereinafter). A semiconductor layer having a large gap energy may be used.

On the other hand, the nitride semiconductor, like other compound semiconductors, has a refractive index of about 2.5, much higher than the refractive index 1 of air. For this reason, the light emitted from the light emitting layer of the nitride semiconductor layer is likely to cause total reflection when emitted from the semiconductor stacked portion into the air, and repeats total reflection within the semiconductor stacked portion without exiting from the semiconductor stacked portion. Therefore, the light extraction efficiency is on the order of 10%, which is extremely low. Therefore, for example, the top surface of the p-type layer is dry-etched into a cylindrical or hemispherical shape to form irregularities (for example, see Patent Document 1), or a semiconductor substrate is stacked to form a support substrate on the p-type layer on the surface side Then, the substrate when the semiconductor layer is laminated is removed, and the exposed n-type layer is coated with particles such as alumina grains, or a mask pattern is formed and heat-treated, and then the n-type layer is formed by RIE. Etching partially, polishing with diamond grains, etc., growing the n-type layer, adjusting the growth temperature etc. as appropriate, and re-growing the n-type layer, SiO ₂ etc. on the n-type layer surface There is known a method of forming an n-type mask and selectively regrowing an n-type layer (see, for example, Patent Document 2).
JP 2000-196152 A JP 2003-318443 A

  As described above, in the nitride semiconductor light emitting device, various measures have been taken to provide unevenness on the surface side in order to improve the light extraction efficiency as in the case of other compound semiconductor light emitting devices. However, the nitride semiconductor is chemically stable, and the surface of the nitride semiconductor layer cannot be made uneven by wet etching. Therefore, as described above, the surface of the semiconductor laminated portion laminated by dry etching such as RIE is etched according to the shape of the etching mask, or a nitride semiconductor layer is laminated on the silicon substrate, and the p-type on the surface is formed. An attempt has been made to form a support substrate on the layer surface, and then remove the silicon substrate by wet etching to form irregularities on the exposed n-type layer surface.

  However, the p-type layer of nitride semiconductor is particularly poor in crystallinity, and when the surface is etched by dry etching or the like, the crystallinity is further deteriorated by the impact of dry etching not only at the interface but also inside the p-type layer. There are problems that the series resistance increases, or that the interface has a defect having a level that absorbs light, thereby reducing the light emission characteristics and shortening the lifetime.

  In addition, although it is relatively easy to process the surface of the n-type layer, the method of exposing the n-type layer to process the surface of the n-type layer has poor crystallinity of the p-type layer of the nitride semiconductor. When a nitride semiconductor layer is laminated, it is usually laminated from an n-type semiconductor layer, and the n-type layer cannot be directly exposed as it is. Without using a sapphire substrate or SiC substrate to be stacked, a nitride semiconductor layer is stacked on a silicon substrate, a support substrate is formed on the surface of the p-type layer, and the silicon substrate is removed by etching to form an n-type layer. Not only is the manufacturing process very complicated, the silicon substrate and the nitride semiconductor do not lattice match, and the crystallinity of the nitride semiconductor layer itself formed on the silicon substrate is very poor. There's a problem. Furthermore, if you try to remove the sapphire substrate by stacking it on the sapphire substrate or SiC substrate that is currently put into practical use for growing the nitride semiconductor layer instead of the silicon substrate, the sapphire substrate is a very stable compound Therefore, there is a problem that wet etching cannot be performed, the removal of the substrate is difficult, and the crystallinity of the nitride semiconductor layer stacked upon the removal is deteriorated.

  The present invention solves such problems and effectively extracts the light so that the light emitted from the light emitting layer does not attenuate by repeated total reflection in the semiconductor laminate and the substrate, thereby improving the external quantum efficiency. It is an object of the present invention to provide a nitride semiconductor light emitting device having a structure that can be made and a method for manufacturing the same.

  The present inventors have made p by dry etching or the like while forming irregularities on the outermost surface of the semiconductor stacked portion so that the light emitted in the semiconductor layer portion of the nitride semiconductor light emitting element can be taken out as effectively as possible. To easily form irregularities without damaging the surface and the inside of the shape layer, or using a very complicated manufacturing process that removes the growth substrate by forming a support substrate on the surface side As a result of repeated studies, the p-type layer is more difficult to obtain the growth flatness than the n-type layer, and the growth temperature is set to, for example, a normal growth temperature of 950 to 950 when the p-type layer is grown. The temperature is lowered from 1100 ° C. to 740 to 900 ° C., and the ratio of the group V element to the group III element of the introduced gas is lowered from 6000 to 8000 to 100 to 5000 to grow. Found that it is possible to form the hexagonal pyramid shaped projections or recesses formed in the crystal plane of {1-101} plane on the surface of the p-type layer. And by forming such a hexagonal pyramid-shaped convex part or concave part having such a {1-101} facet surface, the light extraction efficiency can be greatly improved and the external quantum efficiency can be improved. I found it.

  Where {1-101} is strictly

Is abbreviated as described above for convenience. Further, the {1-101} plane is a generic name including a plane equivalent to the (1-101) plane due to the symmetry of the crystal.

  A semiconductor light emitting device according to the present invention includes a substrate, a semiconductor laminated layer made of a nitride semiconductor, having an n-type layer on the substrate side and a p-type layer on the upper surface side, and is provided on one surface of the substrate so as to form a light emitting layer. A semiconductor light emitting device comprising: a portion; a p-side electrode electrically connected to the p-type layer of the semiconductor stacked portion; and an n-side electrode electrically connected to the n-type layer The p-type semiconductor layer on the outermost surface of the semiconductor stacked portion is formed to have a hexagonal pyramid-shaped convex portion or concave portion formed by a {1-101} crystal plane.

  Here, the nitride semiconductor means a compound in which a group III element Ga and a group V element N or a part or all of a group III element Ga is substituted with another group III element such as Al and In, and / or Alternatively, it refers to a semiconductor made of a compound (nitride) in which a part of N of the group V element is substituted with another group V element such as P or As.

  Even if a translucent conductive layer is provided on the p-type semiconductor layer on which the convex portion or the concave portion is formed, if the thickness is about 1 μm or less, the convex portion formed on the surface of the p-type layer or The recess can be maintained as it is, and the light extraction efficiency can be improved while diffusing the current.

  The method of manufacturing a semiconductor light emitting device according to the present invention includes an n-type layer made of a nitride semiconductor, an active layer, and a p-type layer formed on a substrate by MOCVD so as to form a light emitting layer in this order. The outermost layer is grown by lowering the substrate temperature from 950 to 1100 ° C. to 740 to 900 ° C., and reducing the ratio of the introduced group V element to the group III element from 6000 to 8000 to 100 to 5000. Thus, a hexagonal pyramid-shaped convex part or concave part formed with a {1-101} crystal plane is formed on the surface of the p-type layer.

  According to the semiconductor light emitting device of the present invention, the hexagonal pyramid-shaped convex part or concave part formed with the {1-101} crystal plane is formed on the surface of the p-type layer. Total reflection can be suppressed, light is easily emitted to the outside, light extraction efficiency is improved, and external quantum efficiency is improved. Moreover, since it is a hexagonal pyramid-shaped convex or concave formed with a {1-101} crystal plane, the semiconductor layer is laminated and processed without damaging the semiconductor layer such as dry etching. In addition, since it is formed on the surface of the p-type layer, it is not necessary to remove the substrate on which the semiconductor layer is laminated, and a convex or concave portion is formed on the surface simply by controlling the growth conditions while growing the semiconductor layer. can do. As a result, the manufacturing process is very simple, and the light extraction efficiency can be increased without causing any harmful effects on the light emission characteristics, and a nitride semiconductor light emitting device with a greatly improved external quantum efficiency can be obtained at a low cost. be able to.

  In addition, according to the manufacturing method of the present invention, an n-type layer having good crystallinity is first grown on a substrate, and an active layer and a p-type layer are grown and stacked on the substrate while controlling the growth conditions. Since the convex portion or the concave portion is formed on the outermost surface of the p-type layer, a step of dry etching that damages the semiconductor layer or a step of removing the growth substrate to process the n-type layer is required. Without this, it is possible to form a convex portion or a concave portion on the outermost surface very easily. Moreover, since the growth conditions are controlled so as to form convex portions or concave portions in the p-type layer, the growth conditions are controlled by utilizing the growth characteristics of the p-type layer, which is originally inferior in crystallinity flatness. Only by controlling, a hexagonal pyramid-shaped convex part or concave part formed with a {1-101} crystal plane can be surely formed. Once such a convex part or concave part is formed, Since the convex portion or the concave portion grows as it is and grows large, when it is grown to a thickness of 0.5 to several μm, a convex portion or concave portion of about 0.5 to 2 μm can be formed. In addition, by setting the growth temperature to 900 to 850 ° C., convex portions are easily formed, and by making the growth temperature lower than 850 ° C., concave portions are also easily formed, but from the aspect of light extraction efficiency, The convex portion is preferable to the concave portion.

  Next, the semiconductor light emitting device of the present invention and the manufacturing method thereof will be described with reference to the drawings. FIG. 1 shows a perspective explanatory view of an embodiment of a semiconductor light emitting device according to the present invention in which a nitride semiconductor layer suitable for blue light emission is stacked on a sapphire substrate, an enlarged explanatory view of a convex portion, and a cross sectional explanatory view. As shown in the figure, the semiconductor laminate portion 7 is provided on the surface of the substrate 1 so as to form a light emitting layer having an n-type layer 3 on the substrate 1 side and a p-type layer 5 on the upper surface side. In addition, a p-side electrode 9 is provided in electrical connection with the p-type layer 5 of the semiconductor stacked portion 7, and an n-side electrode 10 is provided in electrical connection with the n-type layer 3. In the present invention, the p-type semiconductor layer on the outermost surface of the semiconductor multilayer portion 7 is formed so as to have a hexagonal pyramid-shaped convex portion 6a or a concave portion formed by a {1-101} plane crystal plane. Layer 6 is designated.

  In the example shown in FIG. 1, a sapphire substrate that is an insulating substrate is used for the substrate 1. Therefore, a part of the semiconductor laminated portion 7 is removed by etching, the n-type layer 3 which is a lower conductive type layer is exposed, and an n-side electrode 10 is formed on the surface thereof. However, as shown in FIG. 5 to be described later, a semiconductor substrate such as SiC can also be used as the substrate 1. Even in this case, by similarly forming the hexagonal pyramid-shaped convex part 6a or concave part formed of the {1-101} crystal plane on the outermost p-type layer, the light extraction efficiency is improved. The p-type layer and the nitride semiconductor layer are not damaged, and the convex portion or the concave portion can be formed with a simple man-hour.

The semiconductor laminated portion 7 is formed in the following structure, for example. For example, the low-temperature buffer layer 2 made of GaN is about 0.005 to 0.1 μm, and the n-type layer 3 made of Si-doped GaN or AlGaN-based compound is about 1 to 10 μm, for example, from In _0.13 Ga _0.87 N of 1 to 3 nm. Active layer 4 having a multiple quantum well (MQW) structure in which 3 to 8 pairs of well layers and 10 to 20 nm GaN barrier layers are stacked, is about 0.05 to 0.3 μm, p-type GaN or AlGaN The p-type layer 5 made of a compound semiconductor is formed by sequentially laminating about 0.2 to 1 μm. In the present invention, a hexagonal pyramid-shaped convex portion 6a formed of a {1-101} crystal plane is formed on the outermost surface of the p-type layer, for example, Al _x Ga _1-x N (0 ≦ x ≦ It is characterized in that a light extraction layer 6 made of 0.2 (for example, x = 0) is formed.

  In the example shown in FIG. 1, the n-type layer 3 is one layer and the p-type layer is composed of the p-type layer 5 and the light extraction layer 6. The p-type layer 5 is composed of a barrier layer (a layer having a large bandgap energy) that easily traps an AlGaN-based carrier on the active layer side, and a GaN contact layer that easily raises the carrier concentration on the side opposite to the active layer 4. Furthermore, another layer such as an undoped or n-type high-temperature buffer layer or a superlattice layer that relieves strain between layers can be interposed on the low-temperature buffer layer. They can also be formed of other nitride semiconductor layers. Further, in this example, the active layer 4 is sandwiched between the n-type layer 3 and the p-type layer 5, but a pn junction structure in which the n-type layer and the p-type layer are directly joined is also used. Good. Further, the active layer 4 is not limited to the MQW structure described above, but may be a single quantum well structure (SQW) or a bulk structure.

The light extraction layer 6 is formed of, for example, an Al _x Ga _1-x N layer, and has a hexagonal pyramid-shaped convex portion 6 a formed of a {1-101} crystal plane on the surface, and is 0.1 to 1 μm. It is formed to a thickness t. As a result, the height h (see FIG. 1C) of the convex portion 6a is formed to a height of about 0.1 to 1 μm. The height of the convex portion 6a depends on the thickness of the light extraction layer 6, and the height of the convex portion 6a increases as the thickness increases. The thickness t of the light extraction layer 6 means the thickness up to the top of the convex portion 6a. In order to form such a convex portion 6a, as described above, the inventors of the present invention have made extensive studies in order to improve the light extraction efficiency. In addition, for example, by reducing the growth temperature and further reducing the ratio of the group V element to the group III element, the flatness of the p-type layer is impaired, and the hexagonal pyramid formed by the crystal plane of the {1-101} plane A convex portion 6a or a concave portion is formed. Details of the growth conditions for forming the convex portion or the concave portion will be described later.

  In the example shown in FIG. 1, a convex portion is formed in the light extraction layer 6. However, as shown in FIG. 2, a hexagonal pyramid-shaped concave portion 6b formed by a {1-101} crystal plane is formed. However, the light extraction efficiency is similarly improved. In order to form such a recess 6b, the film formation temperature is set to 850 ° C. or less, so that the recess 6b can be easily formed.

Then, an n-side electrode 10 for ohmic contact is formed on the n-type layer 3 exposed by removing a part of the laminated semiconductor laminated portion 7 by etching, and a Ti film having a thickness of about 0.01 μm and a thickness of 0.1 μm. An Al film having a thickness of about 25 μm is laminated and then sintered at about 600 ° C. to form an alloy layer. A Ti film having a thickness of about 0.1 μm and 0.3 μm are formed on a part of the light extraction layer 7. The p-side electrode 9 is formed by a laminated structure with a moderately thick Au film. A passivation film such as SiO _{2 (} not shown) is provided on the entire surface except for the surfaces of the p-side electrode 9 and the n-side electrode 10.

Next, a method for manufacturing the semiconductor light emitting device shown in FIG. 1 will be described, including the method for forming the hexagonal pyramid-shaped convex portion 6a formed by the crystal plane of the {1-101} plane described above. For example, by a metal organic chemical vapor deposition method (MOCVD method), a reactive gas such as trimethylethylene gallium (TMG), ammonia (NH ₃ ), trimethylaluminum (TMA), trimethylindium (TMIn) and n together with H _{2 as} a carrier gas SiH ₄ as a dopant gas when forming a p-type, and a necessary gas such as cyclopentadienylmagnesium (Cp ₂ Mg) or dimethylzinc (DMZn) as a dopant gas when forming a p-type are sequentially grown. .

First, on the substrate 1 made of sapphire, for example, a low-temperature buffer layer 2 made of a GaN layer is formed at a low temperature of about 400 to 600 ° C., for example, about 0.005 to 0.1 μm, and then the temperature is about 600 to 1200 ° C. The n-type layer (barrier layer) 3 made of n-type GaN is formed to a thickness of about 1 to 10 μm. Next, the growth temperature is lowered to a low temperature of 400 to 600 ° C., and, for example, 3 to 8 pairs of well layers made of In _0.13 Ga _0.87 N of 1 to 3 nm and barrier layers made of GaN of 10 to 20 nm are stacked. An active layer 4 having a quantum well (MQW) structure is formed to a thickness of about 0.05 to 0.3 μm. Next, the temperature in the growth apparatus is raised to about 950 to 1100 ° C., and the p-type layer 5 made of GaN is laminated to about 0.2 to 1 μm. Thereafter, the growth temperature is lowered to 740 to 900 ° C., and the ratio of the group V element to the group III element of the introduced gas is lowered from 6000 to 8000 to 100 to 5000 to reduce Al _x Ga _1-x N (for example, x = 0). The light extraction layer 6 is formed with a thickness of about 0.2 to 1 μm. In this case, the film formation rate is about 1 μm / h to 3 μm / h, which is faster than the film formation rate of the p-type layer 5 of about 0.7 to 1 μm / h. The dopant gas is supplied so that the Mg / Ga is about 1 × 10 ⁻³ to 1 × 10 ⁻² more than the growth of the shape layer 5.

  That is, as described above, the present inventors have made extensive studies in order to improve the light extraction efficiency, and as a result, the crystal growth of the nitride semiconductor layer is difficult to grow a dense and flat film. Focusing on the fact that the growth temperature is lower than usual and the ratio of the group V element source gas to the group III element supply gas is reduced as described above, the crystal plane of the {1-101} plane is obtained. Then, it has been found that hexagonal pyramid-shaped convex portions as shown in FIG. Further, it has been found that by setting the growth temperature to about 850 ° C. or less, hexagonal pyramid-shaped recesses 6b having a {1-101} plane crystal plane as shown in FIG. In addition, when it grows at the temperature of 850 degrees C or less, although a convex part and a recessed part may be formed and mixed, even if both are mixed, there will be no trouble. This is because the incident angle of the light generated inside is changed to be smaller than the critical angle, so that an inclined surface may be formed. However, it is preferable that the convex portion is formed rather than the concave portion because even if a light-transmitting conductive layer or a protective film is formed on the concave portion, it is unlikely that the inside is buried like the concave portion.

  After that, a protective film such as SiN is provided on the surface, and in order to activate the p-type dopant, annealing is performed at about 400 to 800 ° C. for about 10 to 60 minutes, a photoresist is applied to the entire surface, and patterning is performed by a photolithography process. Then, the portion to be etched (the periphery of the chip and the n-side electrode forming portion) of the semiconductor laminated portion 7 is exposed, and etching is performed, for example, by introducing chlorine gas and silicon tetrachloride gas and applying RF power. As a result, the periphery of the chip that is exposed without being covered with the mask and the semiconductor laminated portion 7 at the place where the n-side electrode 10 is formed are etched, and the n-type layer 3 is exposed.

  After that, by lift-off method, a 0.01 μm thick Ti film and a 0.25 μm thick Al film are formed on the surface of the n-type layer 3 exposed by the etching described above, and sintered by heat treatment at about 600 ° C. The n-side electrode 10 is formed by alloying. Similarly, a Ti film is formed to a thickness of 0.1 μm and an Au film is formed to a thickness of 0.3 μm on a part of the light extraction layer 6 by the lift-off method to form the p-side electrode 9. Then, by making the chip, the LED chip having the structure shown in FIG. 1 is formed.

  By applying a voltage to the light emitting device manufactured in this way and changing the voltage, the change A of the luminance L (relative value) with respect to the current I is compared with the same change B of the conventional structure without the light extraction layer. This is shown in FIG. As is apparent from FIG. 3, the light-emitting element according to the present invention is an output when the current, which is a normal operating point, is 20 mA. ing.

  According to the present invention, since the convex portion or the concave portion is formed on the surface of the semiconductor laminated portion, the light that has been emitted is reflected directly or totally reflected within the semiconductor laminated portion and the substrate, and the light that has come to the surface side is exposed to the outside. As shown in FIG. 3, the external quantum efficiency is greatly improved. In addition, it is not necessary to perform any processing that damages the semiconductor layer, such as dry etching, in order to form the projections and recesses, so that the semiconductor layer is not damaged and the light emission characteristics are not deteriorated. At the same time, very stable characteristics can be maintained even after long-term use, and the reliability is greatly improved. Furthermore, in the semiconductor layer stacking process, convex portions and concave portions can be formed only by changing the growth conditions, so that it becomes a lower layer of the semiconductor stacked portion without interposing a special process such as dry etching. Since the n-type layer is exposed, it is not necessary to remove the substrate used for stacking the semiconductor layers, and it is not necessary to add any extra steps, so that it can be obtained by a very simple manufacturing process. As a result, a nitride semiconductor light emitting device with very high performance, high reliability, and high external quantum efficiency can be obtained at a very low cost.

In the example shown in FIG. 1, the p-side electrode 9 is formed directly on the light extraction layer 6 that is a p-type layer. However, as shown in FIG. 4, for example, about 0.1 to 2 μm or less. Even if the light-transmitting conductive layer 8 made of ZnO or ITO having a thickness or a thin alloy layer of about 2 to 100 nm of Ni and Au is provided, the convex portion 6a or the concave portion 6b on the surface can be maintained. This has the effect of diffusing the current throughout the chip while increasing the light extraction efficiency. That is, since the p-type layer 5 and the p-type light extraction layer 6 are difficult to increase the carrier concentration, the current from the p-side electrode 9 is difficult to spread over the entire chip, but such a translucent conductive layer 8 is provided. This is preferable because the current can be easily spread over the entire chip. Specifically, for example, a Ga-doped ZnO layer is formed on the semiconductor laminated portion 7 on which the convex portions 6a are formed by a method such as MBE, sputtering, vacuum deposition, PLD, ion plating, etc. The translucent conductive layer 8 made of ZnO having a thickness of about 10 ⁻⁴ Ω · cm can be provided on the order of 0.1 to 2 μm, for example, about 0.5 μm. Note that the effect of the recesses is somewhat reduced because the recesses tend to be buried. However, if the projections 6a are used, the translucent conductive layer 8 is formed along the projections 6a unless the projections 6a are too thick. The shape of the part can be maintained.

  Further, in each of the above-described examples, since the substrate is an example of a sapphire substrate that is an insulating substrate, in order to form the n-side electrode 10, a part of the semiconductor stacked portion 7 is etched to expose the n-type layer 3. However, even when the substrate is a semiconductor substrate such as SiC, a convex portion or a concave portion can be similarly formed on the surface of the semiconductor laminated portion 7. An example is shown in FIG. In this example, since the substrate is not an insulating substrate but a semiconductor, an electrode is not formed on the n-type layer 3 exposed by removing a part of the semiconductor stacked portion by etching, but on the back surface of the semiconductor substrate 1. Only the n-side electrode 10 is formed, and the rest is the same as the above example.

  That is, on the substrate 1 made of SiC, the semiconductor laminated portion 7 made of the low-temperature buffer layer 2, the n-type layer 3, the active layer 4, the p-type layer 5 and the p-type light extraction layer 6 is formed as described above. ing. In this case, the p-side electrode 9 is formed of the above-described material on the surface of the light extraction layer 6 in the substantially central portion of the chip, and the n-side electrode 10 is formed, for example, by depositing a Ni film on the entire back surface of the substrate 1 made of SiC. It is formed by doing.

It is explanatory drawing of the perspective view of the one Embodiment of the semiconductor light-emitting device by this invention, a part, and a cross section. It is a figure which shows the example of a recessed part. It is the figure which showed the characteristic of the electric current and brightness | luminance (relative value) in the semiconductor light-emitting device of the structure of FIG. 1 contrasted with the same characteristic of the structure without the conventional unevenness | corrugation. It is a figure which shows the example in which the translucent conductive layer was formed in the surface of the light extraction layer of FIG. It is sectional explanatory drawing which shows the example similar to FIG. 1 which used SiC for the board | substrate. It is perspective explanatory drawing of LED using the conventional nitride semiconductor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 3 N-type layer 4 Active layer 5 P-type layer 6 Light extraction layer 7 Semiconductor laminated portion 8 Translucent conductive layer 9 P-side electrode 10 N-side electrode

Claims (3)

  A semiconductor laminated portion made of a nitride semiconductor, having an n-type layer on the substrate side and a p-type layer on the upper surface side, and provided on one surface of the substrate so as to form a light emitting layer; A semiconductor light emitting device comprising a p-side electrode provided in electrical connection with the p-type layer and an n-side electrode provided in electrical connection with the n-type layer, wherein A semiconductor light emitting device in which the p-type semiconductor layer on the outermost surface has a hexagonal pyramid-shaped convex portion or concave portion formed by a {1-101} crystal plane.   The semiconductor light emitting element according to claim 1, wherein a translucent conductive layer is provided on the p-type semiconductor layer on which the convex portion or the concave portion is formed.   An n-type layer made of a nitride semiconductor, an active layer, and a p-type layer are stacked on the substrate by MOCVD so as to form a light emitting layer in this order, and the outermost layer of the p-type layer is set to a substrate temperature. The temperature is lowered from 950 to 1100 ° C. to 740 to 900 ° C., and the ratio of the introduced group V element to the group III element is lowered from 6000 to 8000 to 100 to 5000, thereby growing on the surface of the p-type layer. A method of manufacturing a semiconductor light emitting device, comprising forming a hexagonal pyramid-shaped convex portion or concave portion formed of a {1-101} crystal plane.

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