JP5045418B2 - GaN-based LED element, GaN-based LED element manufacturing method, and GaN-based LED element manufacturing template - Google Patents

Description

  The present invention relates to a GaN-based LED element, which is an LED element in which a main part of a light-emitting element structure is composed of a GaN-based semiconductor. In particular, the present invention relates to a GaN-based LED element with improved light extraction efficiency. The present invention also relates to a method for manufacturing a GaN-based LED element and a template for manufacturing a GaN-based LED element.

A GaN-based semiconductor is a compound semiconductor represented by the chemical formula Al _a In _b Ga _1-ab N (0 ≦ a ≦ 1, 0 ≦ b ≦ 1, 0 ≦ a + b ≦ 1), and is a group III nitride semiconductor. Also called a nitride-based semiconductor. A GaN-based LED element in which p-type and n-type GaN-based semiconductor layers are stacked to form a pn junction-type light-emitting portion can generate green to near-ultraviolet light. As a structure for increasing quantum efficiency in a pn junction type light emitting section, a double hetero structure, a quantum well structure, and the like are well known.

A GaN-based LED element is manufactured by forming a GaN-based semiconductor film including a light emitting portion on a substrate such as a sapphire substrate using a vapor phase growth method such as MOVPE. Recently, GaN-based LEDs have been developed in which an inclined end surface is formed on a GaN-based semiconductor film including a light-emitting portion by wet etching, thereby improving light extraction efficiency (Patent Documents 1 to 3).
JP 2006-287208 A JP 2007-116114 A JP 2007-294466 A

  A main object of the present invention is to provide a GaN-based LED element having a novel structure with improved light extraction efficiency.

The following invention is disclosed.
(1) A GaN-based LED element having a laminated structure including a substrate, a first layer made of a GaN-based semiconductor, and a second layer made of a GaN-based semiconductor and including a light emitting portion in this order, A GaN-based LED having a void formed in the first layer and having an end face of the first layer which is formed by wet etching and is inclined so as to face the substrate side exposed in the void element.
(2) The GaN-based LED element according to (1), wherein the substrate is exposed in the void.
(3) A third layer made of a GaN-based semiconductor is formed between the substrate and the first layer, and a mask layer formed on the surface of the third layer is exposed in the void. The GaN-based LED element according to (1).
(4) The GaN-based LED element according to (1), wherein a mask layer formed on the surface of the substrate is exposed in the void.
(5) The GaN-based LED element according to (4), wherein the substrate is a GaN-based semiconductor substrate.
(6) (a) A semiconductor structure having a substrate and a first layer made of a GaN-based semiconductor formed on the substrate, wherein a recess opening in the surface of the first layer is provided, Providing a semiconductor structure in which an end face of the first layer formed by wet etching and inclined to face the substrate side is exposed in the recess; and (b) the first layer A second layer made of a GaN-based semiconductor and including a light emitting portion is stacked so as to close the opening, and a void is formed at the position of the concave portion. Method.
(7) A template having a substrate and a first layer made of a GaN-based semiconductor formed on the substrate, wherein a recess is formed on the surface of the first layer, and the opening of the recess The portion is sized so that a true sphere having a diameter exceeding 5 μm cannot pass through, and the end surface of the first layer which is formed by wet etching and is inclined so as to face the substrate side is exposed in the recess. A template for manufacturing GaN-based LED elements.

  Since the GaN-based LED element according to the present invention has excellent light emission output by increasing the light extraction efficiency, it is used for applications that require high output such as indoor and outdoor lighting and automobile headlamps. In, it can use suitably.

(First embodiment)
FIG. 1 shows the structure of a GaN-based LED element according to the first embodiment of the present invention. FIG. 1A is a plan view of the LED element as viewed from the electrode arrangement surface side, and FIG. 1B is a cross-sectional view taken along the line XX in FIG.

  A GaN-based LED element 100 shown in FIG. 1 has a laminated structure including a substrate 10, a first layer 11 made of a GaN-based semiconductor, and a second layer 12 made of a GaN-based semiconductor and including a light emitting portion in this order. I have. The second layer 12 further has a structure in which an n-type layer 12a and a p-type layer 12b are stacked so that a pn junction type light emitting unit is formed. A negative electrode E1 is formed on the partially exposed surface of the n-type layer 12a. On the p-type layer 12b, a positive electrode E2 including an ohmic electrode E2a and a bonding pad E2b formed on a part of the ohmic electrode E2a is provided.

The GaN-based LED element 100 has a plurality of voids S formed in the first layer 11 as a characteristic structure. In the void S, the substrate 10, the end face 11a of the first layer, and the second layer 12 are exposed. The exposed surface of the substrate 10 constitutes a void bottom surface, the end surface 11a of the first layer constitutes a void side surface, and the exposed surface of the second layer 12 constitutes a void upper surface.
The end surface 11a of the first layer is formed by wet etching, and is inclined so as to face the substrate 10 side. In FIG. 1A, the upper end (which is also the outline of the void upper surface) of the end surface 11a of the first layer is indicated by a broken line.
Note that deposits generated when the second layer 12 is formed by vapor deposition may cover the end surface 11a of the first layer and the surface of the substrate 10 exposed in the void S. As long as it does not affect the operational effects, the end surface 11a and the surface of the substrate 10 are considered to be exposed.

Between the inside of the void S having a three-dimensional shape (filled with a gas substance) and the substrate 10 and the GaN-based semiconductor (the first layer 11 and the second layer 12) surrounding the void S, a large Due to the difference in refractive index, light scattering, irregular reflection, or similar phenomena due to the influence of the void S occurs inside the GaN-based LED element 100. Such a phenomenon hinders the occurrence of multiple reflections inside the LED element. As a result, light generated in the light emitting unit provided in the second layer 12 is efficiently extracted outside the LED element 100.
Further, the end surface 11a of the first layer forming the side wall surface of the void S is inclined so as to face the substrate 10 side, not perpendicular to the surface of the substrate 10, so that the inside of the LED element 100 becomes the element surface. Light traveling in a parallel direction (a direction parallel to the surface of the substrate 10) is easily bent in a direction intersecting with the element surface due to the influence of the end surface 11a. The bent light is transmitted through the substrate 10 when the substrate 10 is transparent, and is transmitted through the electrode E2a when the positive ohmic electrode E2a is transparent. It will be taken out.

  In a conventional GaN-based LED element using a transparent substrate (typically a sapphire substrate) having a refractive index lower than that of a GaN-based semiconductor, a waveguide structure having a GaN-based semiconductor layer as a core is formed. However, there is a problem that the state of propagating in the GaN-based semiconductor layer in the direction parallel to the layer becomes extremely stable, and the light extraction efficiency is remarkably lowered. On the other hand, the GaN-based LED element 100 exhibits high light extraction efficiency by the action of the void S even when the substrate 10 is a sapphire substrate.

  Next, preferred embodiments of each part constituting the GaN-based LED element 100 will be described.

  The substrate 10 is not particularly limited as long as it can be used for epitaxial growth of GaN-based semiconductors. Preferred substrates include sapphire substrates (A-plane, C-plane, M-plane, R-plane), spinel substrates, SiC A substrate is mentioned.

  Although not shown in FIG. 1, a known buffer layer such as a low-temperature buffer layer made of GaN or AlGaN can be arbitrarily provided between the substrate 10 and the first layer 11. In one embodiment, the buffer layer may be formed of InGaN so that the substrate 10 can be separated from the first layer 11 by a laser lift-off method after the GaN-based LED element 100 is flip-chip mounted. Good.

The film thickness of the first layer 11 can be, for example, 1 μm to 20 μm, and preferably 2 μm to 10 μm. If it is thinner than 1 μm, the action of the void S becomes weak. If it is thicker than 20 μm, the production efficiency deteriorates because the time required for the growth of the layer becomes long.
The composition of the GaN-based semiconductor constituting the first layer 11 is not particularly limited, but is preferably GaN from which a high-quality single crystal layer can be obtained relatively easily. However, when the emission wavelength of the LED element is set in the ultraviolet region, it is preferable to use AlGaN having a wider band gap than the energy of the light having the wavelength.
Impurities can be arbitrarily added to the first layer 11. However, in order not to deteriorate the crystallinity, at least a region having a distance of 2 μm or less from the substrate 10 should not be doped. It is desirable. In the example of FIG. 1, the two electrodes E1 and E2 are both formed on the second layer 12. However, when a conductive substrate is used as the substrate, either one of the electrodes is formed on the substrate. It is possible to adopt a configuration to In that case, since it is necessary to form an electrical connection between the substrate and the second layer, it is desirable to add conductivity to the first layer to impart conductivity.
In addition, various GaN-based semiconductor layers (including stacked bodies) are provided in the first layer 11 according to the purpose, such as relaxation of stress strain, reduction of dislocation density, improvement of electrostatic withstand voltage characteristics, etc. Can do.

In the GaN-based LED element 100, as shown by a broken line in FIG. 1A, the shape of the upper end of the end surface 11a of the first layer exposed in the void S (shape of the upper surface of the void) is a stripe shape, and the stripe The extending direction is a direction orthogonal to the XX line in FIG. In one embodiment, the stripe extending direction may be changed to be parallel to the XX line, or to intersect with the XX line at an angle smaller than 90 degrees.
The width of the upper base (the width of the upper surface of the void) in the trapezoidal cross section of the void S can be set to 0.1 μm to 5 μm, for example. Even if this width is narrower than 0.1 μm, there is no problem in characteristics of the LED element, but since a highly accurate processing technique is required for manufacturing, the manufacturing cost increases. When this width is larger than 5 μm, the GaN-based semiconductor is easily deposited on the end surface 11a of the first layer or on the exposed surface of the substrate 10 when the second layer 12 is grown. Shape control becomes difficult. In addition, the number of voids S that can be provided in one LED element is reduced. Therefore, the width of the upper surface of the void is more preferably 3 μm or less, and further preferably 1 μm or less.
It is preferable to form the voids S as densely as possible in order to increase the light extraction efficiency of the LED element 100. This is because as the voids S are formed more densely, the area of the inclined void side surface included in one LED element increases. However, if the number of voids S is increased too much, the area of the joint between the substrate 10 and the first layer 11 becomes small, which may cause a problem of peeling.

In the GaN-based LED element 100, the space in the void S is closed. However, the present invention is not limited, and the void can be formed so as to open to the side surface of the LED element. A void having two or more openings may be formed on the side surface of the LED element, but in this case, the first layer is divided by the void.
The shape of the upper surface of the void is not limited to the stripe shape like the void S, but may be a polygon such as a rectangle, a square, or a regular hexagon, or a shape surrounded by a curve such as a circle. You can also.
When the void upper surface is formed in the shape of a dot such as a polygon or a circle, the dot arrangement may be random, but is preferably arranged at a lattice position such as a square lattice, an oblique lattice, a triangular lattice, or a hexagonal lattice. To arrange.
The shape of the upper surface of the void may be a net shape. Examples of the net shape include the shapes shown in each of FIGS. 2A to 2F (the blacked area constitutes the net shape).

  The angle formed between the end surface 11a of the first layer exposed in the void S and the surface of the substrate 10 exposed in the void is preferably 20 to 70 degrees. This angle can be controlled by etching conditions when this end face is formed by wet etching.

The n-type layer 12a and the p-type layer 12b constituting the second layer 12 have a composition of the GaN-based semiconductor constituting each layer such that a pn junction capable of emitting light is formed at a portion where the two layers are joined. The type of impurities to be added, the amount added, etc. are set. Further, in each layer, it is desirable to add an impurity to a portion in contact with the electrode at a concentration at which the contact resistance is sufficiently low.
As an example, the n-type GaN contact layer (Si concentration 5 × 10 ¹⁸ cm ⁻³ , film thickness 3 μm), five n-type GaN barrier layers in order from the side in contact with the first layer 11. MQW layer formed by alternately stacking (film thickness 10 nm) and four n-type InGaN well layers (film thickness 5 nm), p-type Al _0.12 Ga _0.88 N cladding layer (Mg concentration 8 × 10 ¹⁹ cm ⁻³ , film thickness 100 nm), and a p-type Al _0.02 Ga _0.98 N contact layer (Mg concentration 8 × 10 ¹⁹ cm ⁻³ , film thickness 50 nm) may be stacked in this order. In this case, the n-type GaN contact layer and the MQW layer are included in the n-type layer 12a, and the p-type Al _0.12 Ga _0.88 N cladding layer and the p-type Al _0.02 Ga _0.98 N contact layer are p-type. Included in layer 12b.
In this example, the n-type GaN contact layer is a layer where a negative electrode is formed, but also plays a role of diffusing a current supplied from the negative electrode in a direction parallel to the element surface. The n-type GaN contact layer also serves as an n-type cladding layer that constitutes a double hetero-MQW light-emitting portion. Instead of using the n-type GaN contact layer also as the n-type cladding layer, an n-type AlGaN cladding layer may be provided between the n-type contact layer and the MQW layer.
In the case where a void is formed so as not to divide the first layer, an n-type contact layer can be provided in the first layer.

Of course, the configuration of the second layer is not limited to the configuration exemplified above. In the GaN-based LED element 100, the n-type layer and the p-type layer constituting the pn junction structure are stacked with the n-type layer on the lower side, but this stacking order may be reversed. The light emitting portion provided in the second layer is not limited to the pn junction type, and may be a MIS type or the like.
In addition, in the second layer, there are various GaN-based semiconductor layers depending on the purpose, such as relaxation of stress strain, reduction of dislocation density, improvement of electrostatic withstand voltage characteristics, improvement of light emission efficiency, reduction of contact resistance, etc. (Including a laminate) can be provided.

For the material, shape, formation method, and the like of the negative electrode E1, known techniques in this field can be referred to as appropriate. As a preferred form of the negative electrode E1, a portion (ohmic electrode) in contact with the n-type layer 12a is formed of a transparent conductive oxide (ITO, IZO, AZO, FTO, ZnO, etc.), and a metal as a bonding pad thereon. The thing which formed the layer is mentioned.
The surface layer of this metal layer is made of Ag (silver), Au (gold), Sn (tin), In (indium), Bi (bismuth), Cu (copper) depending on the wire or solder material used for bonding. , Zn (zinc), etc., and a single metal or an alloy thereof can be used.

  For the material, shape, formation method, and the like of the positive electrode E2, well-known techniques in this field can be referred to as appropriate. Preferably, the ohmic electrode E2a is formed of a transparent conductive oxide. When the GaN-based LED element 100 is used for flip chip mounting, a reflective film may be formed on the ohmic electrode E2a formed of a transparent conductive oxide in addition to the bonding pad. The reflective film can be a metal film, a dielectric (multilayer) film, or a laminated film thereof.

  The GaN-based LED element 100 can be manufactured as follows.

  First, as shown in FIG. 3, a first layer 11 made of a GaN-based semiconductor is formed on a wafer-sized substrate 10. The first layer 11 can be formed using a known vapor phase growth method that can be used for epitaxial growth of a GaN-based semiconductor, such as an MOVPE method, an HVPE method, or an MBE method.

Next, a SiO ₂ mask is formed on the upper surface of the first layer 11. The SiO ₂ mask is provided with a window portion (a portion from which the mask is removed) corresponding to the shape of the upper surface of the void to be formed in the first layer 11 by using a photolithography technique. Next, by dry etching (preferably RIE using a chlorine-based gas), the exposed portion of the window provided in the SiO ₂ mask is removed from the first layer 11, and the cross section is as shown in FIG. A recess T reaching the substrate 10 is formed in a substantially rectangular shape. In FIG. 4, the SiO ₂ mask is not shown.

Next, while leaving the SiO ₂ mask, the end face of the first layer 11 exposed in the recess T is etched by a wet etching method, thereby forming an inclined end face 11a as shown in FIG. In FIG. 5, the illustration of the SiO ₂ mask is omitted.
The wet etching can be performed, for example, by immersing the wafer in about 200 ° C. pyrophosphoric acid as an etching solution. As an etchant, orthophosphoric acid, sulfuric acid, KOH, etc. can be used in addition to pyrophosphoric acid. The temperature of the etching solution is preferably 150 ° C. to 300 ° C. A preferable temperature range is 200 ° C. to 300 ° C. when the end surface of the first layer is an inclined surface.
Note that Patent Documents 1 to 3 may be referred to for a method of forming an inclined end surface on the first layer by a wet etching method.
After the wet etching, the SiO ₂ mask is removed using hydrofluoric acid. It is preferable that the size of the opening of the recess T after the removal of the SiO ₂ mask is smaller because the opening is closed earlier in the step of forming the second layer later. Therefore, it is preferable that the opening has a size in which a true sphere having a diameter exceeding 5 μm cannot pass, more preferably a size in which a true sphere having a diameter exceeding 3 μm cannot pass, and a diameter exceeding 1 μm. More preferably, the size of the true sphere cannot pass. Needless to say, the size of the opening can be controlled by the size of the window provided in the SiO ₂ mask.

Next, as shown in FIG. 6, the second layer 12 made of a GaN-based semiconductor and including the light emitting portion is formed on the template manufactured by the above procedure so as to close the opening of the recess T. Thereby, a void S is formed at the position of the recess T.
The formation of the second layer 12 is preferably performed using the MOVPE method or the MBE method. By using conditions that promote lateral growth, the opening of the recess T can be closed before the GaN-based semiconductor is deposited in the recess T. In the case of the MOVPE method, it is known that lateral growth of a GaN-based semiconductor is promoted as the growth temperature is raised and the hydrogen partial pressure in the growth furnace is lowered. It is also preferable to use reduced pressure conditions in order to promote lateral growth. In that case, it is more preferable to increase the ammonia partial pressure in the growth furnace.
Of the layers constituting the second layer 12, only the layer formed at the initial stage (the layer formed before the opening of the recess T is closed) is grown under the conditions that promote lateral growth. May be. The layer formed after the opening of the recess T is closed may be grown using growth conditions optimal for each layer.

  After the second layer 12 is formed, the negative electrode E1 and the positive electrode E2 are formed using a normal method. Formation of isolation grooves for device isolation, formation of an insulating protective film, and the like may be performed as necessary. Finally, a chip-like LED element is cut out from the wafer using a scriber, a dicer, a laser processing machine, or the like.

(Second Embodiment)
FIG. 7 shows the structure of a GaN-based LED element according to the second embodiment of the present invention. Fig.7 (a) is the top view which looked at the LED element from the electrode arrangement | positioning surface side, FIG.7 (b) is sectional drawing in the position of the XX line of Fig.7 (a).

A GaN-based LED element 200 shown in FIG. 7 has a laminated structure including a substrate 10, a first layer 11 made of a GaN-based semiconductor, and a second layer 12 made of a GaN-based semiconductor and including a light emitting portion in this order. I have. A third layer 13 made of a GaN-based semiconductor is formed between the substrate 10 and the first layer 11. On the surface of the third layer 13 has the property of inhibiting the growth of a GaN-based semiconductor, the mask layer M made of SiO ₂ is partially formed. The first layer 11 grows so as to cover the surface of the mask layer M from a portion where the surface of the third layer 13 is exposed without being covered by the mask layer M. Such a growth mode is known as ELO (Epitaxial Lateral Overgrowth).
The second layer 12 further has a structure in which an n-type layer 12a and a p-type layer 12b are stacked so that a pn junction type light emitting unit is formed. A negative electrode E1 is formed on the partially exposed surface of the n-type layer 12a. On the p-type layer 12b, a positive electrode E2 including an ohmic electrode E2a and a bonding pad E2b formed on a part of the ohmic electrode E2a is provided.

The GaN-based LED element 200 has a plurality of voids S formed in the first layer 11. In the void S, the mask layer M, the end surface 11a of the first layer, and the second layer 12 are exposed. The exposed surface of the mask layer M constitutes a void bottom surface, the end surface 11a of the first layer constitutes a void side surface, and the exposed surface of the second layer 12 constitutes a void upper surface.
The end surface 11a of the first layer is formed by wet etching, and is inclined so as to face the substrate 10 side. In FIG. 7A, the upper end (which is also the outline of the void upper surface) of the end surface 11a of the first layer is indicated by a broken line.
Note that deposits generated when the second layer 12 is formed by vapor deposition may cover the end surface 11a of the first layer exposed in the void S or the surface of the mask layer M. As long as the effect of the invention is not affected, the end face 11a and the surface of the mask layer M are considered to be exposed.

When the GaN-based LED element 200 is manufactured, after the first layer 11 is formed, the mask layer M having a substantially rectangular cross section is formed on the mask layer M formed on the third layer 13 by dry etching. Reaching recess is formed. Then, the end surface of the first layer 11 exposed in the recess is etched by a wet etching method so as to be an inclined surface. The mask layer M functions as a protective film that prevents the third layer 13 from being etched during the wet etching process.
Formation of the second layer 12, the negative electrode E1, and the positive electrode E2 after the formation of the first layer 11 can be performed in the same manner as in the first embodiment.

(Third embodiment)
FIG. 8 shows the structure of a GaN-based LED element according to the third embodiment of the present invention. Fig.8 (a) is the top view which looked at the LED element from the electrode arrangement | positioning surface side, FIG.8 (b) is sectional drawing in the position of the XX line of Fig.8 (a).

A GaN-based LED element 300 shown in FIG. 8 has a laminated structure including a substrate 10, a first layer 11 made of a GaN-based semiconductor, and a second layer 12 made of a GaN-based semiconductor and including a light emitting portion in this order. I have. On the surface of the substrate 10, a mask layer M made of SiO ₂ having a property of inhibiting the growth of the GaN-based semiconductor is partially formed. The first layer 11 grows so as to cover the surface of the mask layer M from a portion where the surface of the substrate 10 is exposed without being covered with the mask layer M. By such an ELO effect, the first layer 11 becomes a high-quality crystal layer with a reduced density of dislocation defects.
The second layer 12 further has a structure in which an n-type layer 12a and a p-type layer 12b are stacked so that a pn junction type light emitting unit is formed. A negative electrode E1 is formed on the partially exposed surface of the n-type layer 12a. On the p-type layer 12b, a positive electrode E2 including an ohmic electrode E2a and a bonding pad E2b formed on a part of the ohmic electrode E2a is provided.

The GaN-based LED element 300 has a plurality of voids S formed in the first layer 11. In the void S, the mask layer M, the end surface 11a of the first layer, and the second layer 12 are exposed. The exposed surface of the mask layer M constitutes a void bottom surface, the end surface 11a of the first layer constitutes a void side surface, and the exposed surface of the second layer 12 constitutes a void upper surface.
The end surface 11a of the first layer is formed by wet etching, and is inclined so as to face the substrate 10 side. In FIG. 8A, the upper end (which is also the outline of the void upper surface) of the end surface 11a of the first layer is indicated by a broken line.
Note that deposits generated when the second layer 12 is formed by vapor deposition may cover the end surface 11a of the first layer exposed in the void S or the surface of the mask layer M. As long as the effect of the invention is not affected, the end face 11a and the surface of the mask layer M are considered to be exposed.

In the case of manufacturing the GaN-based LED element 300, after forming the first layer 11, a concave portion reaching the mask layer M having a substantially rectangular cross section is formed on the upper portion of the mask M formed on the substrate 10 by dry etching. To do. Then, the end surface of the first layer 11 exposed in the recess is etched by a wet etching method so as to be an inclined surface. In the third embodiment, when a GaN semiconductor substrate (GaN substrate, AlGaN substrate, AlN substrate, etc.) is used as the substrate 10, the mask layer M is etched in the wet etching process. Acts as a protective film to prevent
Formation of the second layer 12, the negative electrode E1, and the positive electrode E2 after the formation of the first layer 11 can be performed in the same manner as in the first embodiment.

It is a figure which shows the structure of the GaN-type LED element which concerns on one Embodiment of this invention, FIG. 1 (a) is the top view which looked at the LED element from the electrode arrangement | positioning surface side, FIG.1 (b) is FIG. It is sectional drawing in the position of the XX line of (a). It is a figure for illustrating a net shape. It is sectional drawing for demonstrating the manufacturing process of the GaN-type LED element shown in FIG. It is sectional drawing for demonstrating the manufacturing process of the GaN-type LED element shown in FIG. It is sectional drawing for demonstrating the manufacturing process of the GaN-type LED element shown in FIG. It is sectional drawing for demonstrating the manufacturing process of the GaN-type LED element shown in FIG. It is a figure which shows the structure of the GaN-type LED element which concerns on one Embodiment of this invention, FIG.7 (a) is the top view which looked at the LED element from the electrode arrangement | positioning surface side, FIG.7 (b) is FIG. It is sectional drawing in the position of the XX line of (a). It is a figure which shows the structure of the GaN-type LED element which concerns on one Embodiment of this invention, Fig.8 (a) is the top view which looked at the LED element from the electrode arrangement | positioning surface side, FIG.8 (b) is FIG. It is sectional drawing in the position of the XX line of (a).

Explanation of symbols

100, 200, 300 GaN-based LED element 10 Substrate 11 First layer 11a First layer end face 12 Second layer 12a n-type layer 12b p-type layer 13 Third layer E1 Negative electrode E2 Positive electrode S Void T Recess M Mask layer

Claims (8)

A GaN-based LED element having a laminated structure including a substrate, a first layer made of a GaN-based semiconductor, and a second layer made of a GaN-based semiconductor and including a light emitting portion in this order,
Having voids formed in the first layer;
The side wall of the through hole penetrating the first layer in the thickness direction forms a part of the boundary defining the inside and outside of the void;
The side walls are inclined obliquely to face the substrate side,
GaN-based LED element. The surface of the substrate is Na a part of a boundary mask the inner outside the void, GaN-based LED element according to claim 1. A third layer of formed GaN-based semiconductor between the substrate and the first layer, the surface of the mask layer formed on the surface of the third layer hide inside out of the void is Na a part of the boundary, GaN-based LED element according to claim 1. Has a mask layer formed on the surface of the substrate, the surface of the mask layer is Na a part of a boundary mask the inner outside the void, GaN-based LED element according to claim 1. The GaN-based LED element according to claim 4, wherein the substrate is a GaN-based semiconductor substrate. (A) A semiconductor structure having a substrate and a first layer made of a GaN-based semiconductor formed on the substrate, wherein the first layer has a through-hole penetrating the layer in the thickness direction And a step of preparing a semiconductor structure in which a side wall of the through hole is inclined so as to face the substrate side, and (b) a light emitting portion made of a GaN-based semiconductor on the first layer. Laminating a second layer including the opening so as to close the opening on the upper side of the through hole , and forming a void at the position of the through hole ;
A method for producing a GaN-based LED element. A template having a substrate and a first layer made of a GaN-based semiconductor formed on the substrate, wherein the first layer is provided with a through-hole penetrating the layer in the thickness direction , the opening on the side opposite to the substrate side of the through hole is sized to a sphere having a diameter greater than 5μm can not pass, the side wall of the through hole is inclined so as to face the substrate side, GaN -Based LED element manufacturing template. A substrate and a GaN-based semiconductor layer formed on the substrate, the GaN-based semiconductor layer is provided with a through-hole penetrating the layer in the thickness direction, and the side wall of the through-hole has the side wall A method of manufacturing a template for manufacturing a GaN-based LED element that is inclined so as to face the substrate side,
Preparing a laminate in which a first GaN-based semiconductor layer is laminated on a first substrate;
Providing a first through hole penetrating the first GaN-based semiconductor layer in the thickness direction;
Wet etching the sidewall of the first through hole;
The manufacturing method of the template for GaN-type LED element manufacture characterized by having.

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