KR20160072393A - Light emitting device - Google Patents

Abstract

The present invention relates to a light emitting device. Especially, the present invention relates to a light emitting device with an excellent heat discharging ability by applying a heat transfer material structure in an inner structure of a chip of the light emitting device.

Description

[0001] LIGHT EMITTING DEVICE <

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device, and more particularly, to a light emitting device having excellent heat emitting ability by introducing a heat transfer material structure into a chip internal structure of a light emitting device.

The light emitting device is a p-n junction optical semiconductor having a characteristic in which electrical energy is converted into light energy.

When a forward voltage is applied to the light emitting device, electrons in the n layer migrate to the p layer and combine with holes to emit energy in the form of heat or light. That is, the electrons of the n layer and the holes of the p layer are coupled to each other to emit energy according to the energy level difference between the conduction band and the valence band. The color of the light is determined according to the band gap energy which is the energy level difference. That is, when the energy difference is large, the light of the ultraviolet ray system of short wavelength is represented, and when the energy difference is small, the infrared ray system of long wavelength is represented.

The light emitting device is divided into a visible light emitting device (VLED), an infrared light emitting device (IR LED), and an ultraviolet light emitting device (UV LED) according to the type of light to be emitted. Among them, Is widely used for the purpose of.

On the other hand, the light emitting element has excellent light emitting efficiency, but also has a very high heating value. That is, the level of energy emitted in the form of heat is considerable. If the heat radiation is not effected effectively, the temperature in the light emitting device becomes too high, and the chip itself or the resin used for packaging deteriorates. As a result, the emission efficiency of the light emitting device deteriorates and the number of chips is shortened.

Particularly, in the case of an ultraviolet light emitting device, since the content of aluminum element in the active layer is high, the amount of heat generated by the chip itself is very high, so that the problem of degradation of optical characteristics is serious.

Specifically, heat is generated in the interface of GaN / InGaN or GaN / AlGaN region of the active layer depending on a defect or an interface state, thereby acting as an element for lowering optical characteristics. The c-plane of GaN, AlGaN, and AlN has a low thermal conductivity in the longitudinal direction. Particularly, as the size of the chip increases, the heat conduction characteristics become lower.

It is an object of the present invention to provide a light emitting device that solves the above problems and has excellent heat emission performance by introducing a heat transfer material structure into a chip internal structure of the light emitting device.

To this end, one embodiment of the present invention provides a method of < RTI ID =

A light emitting structure;

The light emitting structure includes a first conductive semiconductor layer;

An active layer formed on the first conductivity type semiconductor layer;

And a second conductivity type semiconductor layer formed on the active layer,

A plurality of holes formed in the second conductivity type semiconductor layer;

An insulating layer formed on an inner surface of the plurality of holes and a portion of the second conductivity type semiconductor body layer;

A heat transfer material structure formed inside the plurality of holes surrounded by the insulating layer;

And a second electrode layer formed on the second conductive semiconductor layer,

And the plurality of hole forming regions are located under the first electrode layer forming region electrically connected to the first conductivity type semiconductor layer.

In order to achieve the above object, according to another aspect of the present invention,

A first conductive semiconductor layer;

An active layer formed on the first conductivity type semiconductor layer;

A second conductivity type semiconductor layer formed on the active layer and having a patterned pattern portion on one side;

A plurality of holes penetrating the second conductivity type semiconductor layer and the active layer to expose a part of the first conductivity type semiconductor layer;

An insulating layer formed on an inner surface of the plurality of holes and a part of the second conductive type semiconductor layer;

A plurality of holes surrounded by the inner surface by the insulating layer, and a heat transfer material structure formed inside the pattern portion;

And a light emitting device.

According to the light emitting device of the present invention, by introducing a heat transfer material structure from the second conductivity type semiconductor layer into the hole formed in the direction from the second conductivity type semiconductor layer toward the active layer, the m-plane of the active layer exposed by the hole, the heat can be rapidly emitted in the longitudinal direction through the a-plane surface, thereby improving the reliability of the light emitting device.

1 is a cross-sectional view of a light emitting device according to an embodiment of the present invention.
2 is a plan view of a light emitting device according to an embodiment of the present invention shown in FIG.
3 to 6 are schematic views illustrating a manufacturing process of a light emitting device according to an embodiment of the present invention.
7 is a cross-sectional view of a light emitting device according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings. However, it should be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It is to be understood that the invention is not limited to the disclosed embodiments but is to be accorded the widest scope of the invention. Like reference numerals refer to like elements throughout the specification.

In the description of the embodiments, it is to be understood that each layer (film), area, pattern or structure may be referred to as being "on" or "under" the substrate, each layer Quot; on "and" under "are to be" directly "or" indirectly & All included. Also, the criteria for top, bottom, or bottom of each layer will be described with reference to the drawings.

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size of each component does not entirely reflect the actual size.

Hereinafter, a light emitting device according to the present invention will be described in detail with reference to the accompanying drawings.

A light emitting device according to an embodiment of the present invention includes:

A light emitting structure;

The light emitting structure includes a first conductive semiconductor layer;

An active layer formed on the first conductivity type semiconductor layer;

And a second conductivity type semiconductor layer formed on the active layer,

A plurality of holes formed in the second conductivity type semiconductor layer;

An insulating layer formed on an inner surface of the plurality of holes and a portion of the second conductivity type semiconductor body layer;

A heat transfer material structure formed inside the plurality of holes surrounded by the insulating layer;

And a second electrode layer formed on the second conductive semiconductor layer,

And the plurality of hole forming regions are located under the first electrode layer forming region electrically connected to the first conductivity type semiconductor layer.

1 is a cross-sectional view schematically showing a light emitting device according to an embodiment of the present invention.

1, a light emitting device according to an embodiment of the present invention includes a first conductive semiconductor layer 200 and a second conductive semiconductor layer 400 such that an active layer 300 is interposed between a first conductive semiconductor layer 200 and a second conductive semiconductor layer 400, ), The active layer 300, and the second conductive semiconductor layer 400 are formed.

The first conductive semiconductor layer 200 is a semiconductor layer doped with a first conductive dopant. When the first conductive semiconductor layer 200 is an n-type semiconductor layer, the first conductive dopant may include at least one of Si, Ge, Sn, Se, and Te, which are n-type dopants.

The first conductive semiconductor layer 200 may include a semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + And may include any one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP and InP.

1, a current diffusion layer including undoped gallium nitride, a superlattice layer 210 for electron injection, and a strain control layer are additionally formed on the first conductive semiconductor layer 200 As shown in FIG.

The active layer 300 formed on the first conductive semiconductor layer 200 may be formed as a single quantum well or a multi quantum well (MQW) structure. That is, it may be formed of at least one of GaN, InN, AlN, InGaN, AlGaN, and InAlGaN using a Group III-V compound semiconductor material. For example, the active layer 300 may have a structure in which InGaN well layers / GaN barrier layers are alternately formed.

The active layer 300 recombines carriers supplied from the first conductivity type semiconductor layer 200 and carriers supplied from the second conductivity type semiconductor layer 400 to generate light. When the first conductivity type semiconductor layer 200 is an n-type semiconductor layer, the carriers supplied from the first conductivity type semiconductor layer 200 may be electrons, and the second conductivity type semiconductor layer 400 may be p- In the case of a semiconductor layer, the carrier supplied from the second conductive type semiconductor layer 400 may be a hole.

In the present invention, although not shown in FIG. 1, an electron blocking layer is formed on the active layer 300 to serve as an electron blocking layer and a cladding layer of the active layer, thereby improving the luminous efficiency. For example, the electron blocking layer may be formed of a semiconductor having a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1) It can have an energy band gap higher than the energy band gap.

The second conductive semiconductor layer 400 formed on the active layer 300 includes a semiconductor layer doped with a second conductive dopant and may be formed as a single layer or a multilayer.

The second conductive semiconductor layer 400 may be formed of at least one of GaN, InN, AlN, InGaN, AlGaN, and InAlGaN. When the second conductive semiconductor layer 400 is a p-type semiconductor layer, The conductive dopant may include at least one of Mg, Zn, Ca, Sr, and Ba, which are p-type dopants.

In the exemplary embodiment of the present invention, the first conductive semiconductor layer 200 may be an n-type semiconductor layer and the second conductive semiconductor layer 400 may be a p-type semiconductor layer. However, the present invention is not limited thereto. In addition, a semiconductor, for example, an n-type semiconductor layer having a polarity opposite to that of the second conductivity type semiconductor layer 400 may be formed on the second conductivity type semiconductor layer 400. Accordingly, the light emitting structure can be implemented by any one of an np junction structure, a pn junction structure, an npn junction structure, and a pnp junction structure.

1, the light emitting device of the present invention includes a plurality of holes (not shown) exposing a part of the first conductive type semiconductor layer 200 through the second conductive type semiconductor layer 400 and the active layer 300, (H).

Here, it is preferable that the widths of the plurality of holes (H) are 100 to 10 nm and the depth is 50 to 1,000 nm. If the width of the hole H deviates from the above range, there is a problem that the light emitting area is reduced.

The shape of the hole H may be circular, square, line type, or the like as viewed from a plane. The size of the hole H may be a diameter of a circle, a length of one side of a square, But is not so limited.

In the present invention, it is preferable that the plurality of holes (H) are formed in a direction from the second conductive semiconductor layer (400) to the active layer (300). That is, the active layer 300 is preferably formed in a direction from the second conductive semiconductor layer 400 toward the active layer 300 in order to effectively dissipate heat generated in the active layer 300.

An insulating layer 500 is formed on the inner surfaces of the plurality of holes H and a part of the second conductive type semiconductor layer 400. Thereby preventing electrical shorts that may occur between the active layer 300 and the heat transfer material included in the heat transfer material structure 600 through the insulating layer 500.

As the material for forming the insulating layer 500, SiO ₂ , Al ₂ O ₃ . SiN _x , but is not limited thereto. The thickness of the insulating layer 500 is preferably 100 nm or less. When the thickness of the insulating layer 500 is more than 100 nm, the heat generated in the active layer 300 is not emitted through the first conductive semiconductor layer 200 and the first electrode layer 800.

The heat transfer material structure 600 may be formed in the plurality of holes H surrounded by the insulating layer 500 on the inner side. The heat transfer material structure 600 may be formed of a material having a high thermal conductivity so that the heat generated in the active layer 300 can be rapidly discharged through the second conductive semiconductor layer 400 and the second electrode layer 700.

Concretely, at least one selected from materials having excellent heat conduction effect such as Ag, Cu, Al, Cr, Au, Fe, diamond, carbon nanotubes and graphene can be used.

The light emitting device of the present invention may further include a second electrode layer 700 formed on the second conductive semiconductor layer 400. The second electrode layer 700 may be formed by laminating a single metal, a metal alloy, a metal oxide, or the like so as to efficiently perform carrier injection.

1, the second electrode layer 700 may include a reflective metal layer 701, a reflective cover metal layer 702, a bonding metal layer 703, and a contact substrate layer 704. Referring to FIG.

The second electrode layer 700 may be formed of a material having excellent electrical contact with a semiconductor and may be formed of ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, GZO, IZON, AGZO, IGZO, ZnO, IrOx, RuOx , NiO, RuOx / ITO, Ni / IrOx / Au and Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Sn, Al, Rh, Pd, Ir, Ru, Mg, Zn, , And the present invention is not limited thereto.

2 is a plan view of the light emitting device of FIG.

In the light emitting device of the present invention, the plurality of holes (H) forming regions may be formed in a region where the first electrode layer 800 is formed, which is electrically connected to the first conductive semiconductor layer 200, Can be small. That is, by forming the lower electrode of the first electrode layer 800, the heat generated in the active layer 300 can be maximized through the second conductive semiconductor layer 400 and the second electrode layer 700.

The light emitting device of the present invention as described above can be applied particularly to UV-light emitting devices which generate much heat in the active layer 300. At this time, It is preferable that it is 40 atomic% or more of the total elements, and it is preferable that it is mounted on a mounting substrate by flip-chip method in order to maximize heat emission.

A method of manufacturing a light emitting device according to an embodiment of the present invention is shown in FIGS. 3 to 6.

First, a first conductive semiconductor layer 200, an active layer 300, and a second conductive semiconductor layer 400 are formed on a substrate 100 by a conventional semiconductor deposition method. Then, Type semiconductor layer 400 and the active layer 300 to expose a part of the first conductivity type semiconductor layer 200 and to form a plurality of holes H on the inner surfaces of the plurality of holes H, An insulating layer 500 is formed on a part of the second conductive type semiconductor layer 400 through deposition (FIG. 3A).

The substrate 100 may be formed of a material having excellent thermal conductivity, and may be a conductive substrate or an insulating substrate. For example, the substrate 100 may be formed of a known material such as Al ₂ O ₃ , SiC, Si, GaAs, GaN, ZnO, GaP, InP, A concavo-convex pattern may be formed on and / or below the substrate 101, and the shape of the concavo-convex pattern may be freely selected such as a stripe shape, a lens shape, a columnar shape, and a horn shape.

In the present invention, although not shown in FIG. 3A, a buffer layer may be formed on the substrate 100. The buffer layer mitigates lattice mismatching between the light emitting structure including the first conductivity type semiconductor layer / the active layer / the second conductivity type semiconductor layer and the substrate. The material of the buffer layer may be formed of at least one selected from a group III-V compound semiconductor such as GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN.

Also, in the present invention, an undoped semiconductor layer may be formed on the buffer layer although not shown in FIG. 3A.

Forms in which the insulating layer 500 is formed are shown in Figs. 3B and 3C. As shown in FIG. 3B, the exposed region of the second conductive semiconductor layer 400 may be linear, or the exposed region of the second conductive semiconductor layer 400 may be in a dotted form, as shown in FIG. 3C.

Next, a heat transfer material structure 600 is formed inside the plurality of holes H surrounded by the insulating layer 500 by vapor deposition (FIG. 4 (a)). A plan view of the light emitting device having the heat transfer material structure 600 deposited thereon is shown in Fig. 4 (b).

Next, a second electrode layer 700 is formed on the second conductive semiconductor layer 400 (FIG. 5).

Although not shown in the drawings, the second electrode layer 700 may include a reflective metal layer, a reflective cover metal layer, a bonding metal layer, and a contact substrate layer sequentially from the layer closer to the second conductivity type semiconductor layer as described above. The material of the bonding metal layer is not limited as long as it is a metal such as AuSn capable of injecting current into the second electrode layer.

Next, the substrate 100 is removed, and the damaged layer of the first conductivity type semiconductor layer 200, which is generated when the substrate 100 is separated, is removed. Thereafter, a first electrode layer 800 electrically connected to the first conductive semiconductor layer 200 is formed after a normal isolation process and a side passivation process in accordance with the chip size. Then, a heat dissipation structure 900 is attached to the back surface of the second electrode layer 700 to complete chip packaging for heat dissipation (FIG. 6).

In a light emitting device according to another embodiment of the present invention,

A first conductive semiconductor layer;

An active layer formed on the first conductivity type semiconductor layer;

A second conductivity type semiconductor layer formed on the active layer and having a patterned pattern portion on one side;

A plurality of holes penetrating the second conductivity type semiconductor layer and the active layer to expose a part of the first conductivity type semiconductor layer;

An insulating layer formed on an inner surface of the plurality of holes and a part of the second conductive type semiconductor layer;

A plurality of holes surrounded by the inner surface by the insulating layer, and a heat transfer material structure formed inside the pattern portion;

And a control unit.

7 is a cross-sectional view of a light emitting device according to another embodiment of the present invention.

7, a light emitting device according to another embodiment of the present invention includes a patterned pattern portion 410 on one side of a second conductive semiconductor layer 400, and an insulating layer 500 The heat transfer material structure 600 is formed in the plurality of holes H surrounded by the inner side and the pattern unit 410 to further enhance heat radiation efficiency and light extraction efficiency.

At this time, the depth of the patterned portion 410 of the patterned second conductive type semiconductor layer 400 is preferably 2/3 or less based on the thickness of the second conductive type semiconductor layer 400. If the depth of the pattern portion 410 exceeds 2/3 based on the thickness of the second conductivity type semiconductor layer 400, the pattern portion 410 may interfere with the light extraction.

The shape of the pattern unit 410 may be freely selected from a stripe shape, a lens shape, a columnar shape, a horn shape, and a grid shape.

In another embodiment of the present invention, the configuration and manufacturing method of the second conductive semiconductor layer 400 other than the patterned second conductive semiconductor layer 400 are the same as those described in the above embodiment of the present invention. It is omitted.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. These changes and modifications may be made without departing from the scope of the present invention. Accordingly, the scope of the present invention should be determined by the following claims.

100: substrate
200: a first conductivity type semiconductor layer
300: active layer
400: second conductive type semiconductor layer
H: hole
500: insulating layer
600: Structure of heat transfer material
700: Second electrode layer
800: first electrode layer
900: Heat dissipation structure

Claims (14)

A light emitting structure;
The light emitting structure includes a first conductive semiconductor layer;
An active layer formed on the first conductivity type semiconductor layer;
And a second conductivity type semiconductor layer formed on the active layer,
A plurality of holes formed in the second conductivity type semiconductor layer;
An insulating layer formed on an inner surface of the plurality of holes and a portion of the second conductivity type semiconductor body layer;
A heat transfer material structure formed inside the plurality of holes surrounded by the insulating layer;
And a second electrode layer formed on the second conductive semiconductor layer,
Wherein the plurality of hole forming regions are located under the first electrode layer forming region electrically connected to the first conductivity type semiconductor layer.
The method according to claim 1,
Wherein a depth of one of the plurality of holes exceeds a thickness of the insulating layer.
3. The method of claim 2,
Wherein the plurality of holes have a width of 100 to 10,000 nm and a depth of 50 to 1,000 nm.
The method according to claim 1,
And the plurality of holes are formed in a direction from the second conductivity type semiconductor layer toward the active layer.
The method according to claim 1,
Wherein the insulating layer is formed to surround a side surface and a part of an upper surface of the light emitting structure.
The method according to claim 1,
Wherein the plurality of hole forming regions are smaller than the first electrode layer forming region electrically connected to the first conductivity type semiconductor layer, and the light emitting element is smaller than the first electrode forming region.
The method according to claim 1,
Wherein an aluminum content of the active layer is 40% or more of the total elements constituting the active layer.
A first conductive semiconductor layer;
An active layer formed on the first conductivity type semiconductor layer;
A second conductivity type semiconductor layer formed on the active layer and having a patterned pattern portion on one side;
A plurality of holes penetrating the second conductivity type semiconductor layer and the active layer to expose a part of the first conductivity type semiconductor layer;
An insulating layer formed on an inner surface of the plurality of holes and a part of the second conductive type semiconductor layer;
A plurality of holes surrounded by the inner surface by the insulating layer, and a heat transfer material structure formed inside the pattern portion;
Emitting element.
9. The method of claim 8,
Wherein a depth of a pattern portion of the patterned second conductivity type semiconductor layer is 2/3 or less based on a thickness of the second conductivity type semiconductor layer.
9. The method of claim 8,
Wherein the plurality of holes have a width of 100 to 10,000 nm and a depth of 50 to 1,000 nm.
9. The method of claim 8,
And the plurality of holes are formed in a direction from the second conductivity type semiconductor layer toward the active layer.
9. The method of claim 8,
And a second electrode layer formed on the second conductive type semiconductor layer.
9. The method of claim 8,
Wherein the plurality of hole forming regions are equal to or smaller than a first electrode layer forming region electrically connected to the first conductivity type semiconductor layer.
9. The method of claim 8,
Wherein an aluminum content of the active layer is 40% or more of the total elements constituting the active layer.

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