KR101428068B1

KR101428068B1 - group 3 nitride-based semiconductor light emitting diodes and methods to fabricate them

Info

Publication number: KR101428068B1
Application number: KR1020080033966A
Authority: KR
Inventors: 송준오
Original assignee: 엘지이노텍 주식회사
Priority date: 2008-04-12
Filing date: 2008-04-12
Publication date: 2014-08-07
Also published as: KR20090108505A

Abstract

The present invention relates to a method for manufacturing a Group III nitride-based semiconductor light-emitting diode device, which comprises forming a Group III nitride-based conductive thin film structure having a sheet resistance of 50 Ω / □ or less on the top surface of a top nitride- A group III nitride-based semiconductor light-emitting diode device having a current spreading layer and a method of manufacturing the same.

More specifically, the present invention relates to a method for manufacturing a semiconductor light emitting device, which comprises forming a p-type In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) Type In cladding layer, the p-type In x Al y Ga 1-xy N (0? X, 0? Y , x + y < / = 1) semiconductor, and ohmic contact current spreading layer through a superlattice structure to facilitate current injection in the vertical direction to improve the overall efficiency of the light emitting diode device The performance can be effectively improved.

A group III nitride-based conductive thin film structure, an ohmic contact current spreading layer, a light extracting structure, a surface irregularity

Description

Group III nitride-based semiconductor light-emitting diode device and a method of manufacturing the same,

The present invention relates to a p-type In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) semiconductor upper surface of a nitride based cladding layer of a light emitting diode for a light emitting diode, Type In.sub.xGa.sub.1-xyN (.lambda.), Which is the upper nitride-based cladding layer, is grown before forming the ohmic contact current spreading layer composed of the group III nitride-based conductive thin film structure having the sheet resistance A superlattice structure is inserted between the semiconductor and the ohmic contact current spreading layer composed of the group III nitride-based conductive thin film structure to form a current injection in the vertical direction the current injection can be facilitated and the surface irregularity process can be introduced to the upper surface of the ohmic contact current spreading layer to effectively improve the overall performance of the light emitting diode device including the driving voltage and the external light emitting efficiency.

When a forward current of a certain size is applied to a light emitting diode (LED) device, the current in the active layer in the solid-state light-emitting structure is converted into light to generate light. The earliest LED element research and development forms a compound semiconductor such as indium phosphide (InP), gallium arsenide (GaAs), and gallium phosphorus (GaP) in a p-i-n junction structure. The LED emits light of a visible light range of a wavelength band longer than the wavelength of green light, but recently, a device emitting blue and ultraviolet light is also commercialized due to research and development of the group III nitride-based semiconductor material system. Device, a light source device, and an environmental application device. Further, it is possible to combine three LED device chips of red, green, and blue, or to add a phosphor to a short wavelength pumping LED device LEDs for white light source that emits white light by grafting have been developed and the application range thereof has been extended to illumination devices. In particular, LED devices using solid single crystal semiconductors have a high efficiency of converting electrical energy into light energy, have a long life span of 5 years or more on average, and are capable of significantly reducing energy consumption and maintenance costs. It is attracting attention.

Since a light-emitting diode (hereinafter referred to as a group III nitride-based semiconductor light-emitting diode) device manufactured from the group III nitride-based semiconductor material is generally grown on an insulating growth substrate (typically, sapphire) -5 group compound semiconductor light emitting diode device, two electrodes of the LED device facing each other on the opposite sides of the growth substrate can not be provided, so that the two electrodes of the LED device must be formed on the upper part of the crystal growth material. A conventional structure of such a group III nitride-based semiconductor light-emitting diode device is schematically illustrated in FIGS. 5 and 7. FIG.

5, the group III nitride-based semiconductor light-emitting diode device includes a sapphire growth substrate 10 and a lower nitride-based clad made of an n-type conductive semiconductor material sequentially grown on the growth substrate 10 Layer 20, a nitride-based active layer 30, and a top nitride-based clad layer 40 made of a p-type conductive semiconductor material. The lower nitride-based cladding layer 20 may be composed of n-type In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) semiconductor multilayers, Is a group III nitride-based In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) semiconductor multilayer composed of different compositions of a multi-quantum well structure . The upper nitride-based cladding layer 40 may be composed of a semiconductor multilayer of p-type In x Al y Ga 1-x-y N (0? X, 0? Y, x + y? 1) In general, the lower nitride-based cladding layer / nitride-based active layer / upper nitride-based cladding layers 20, 30, and 40 formed of the Group III nitride-based semiconductor single crystal are formed by a device such as MOCVD, MBE, HVPE, sputter, . &Lt; / RTI > In order to improve the lattice matching with the sapphire growth substrate 10 prior to the growth of the n-type In x Al y Ga 1-xy N semiconductor as the lower nitride-based cladding layer 20, The buffer layer 201 may be formed therebetween.

As described above, since the sapphire growth substrate 10 is an electrically insulating material, both electrodes of the LED device must be formed on the same top surface in the direction of growth of the monocrystal semiconductor. For this purpose, the upper nitride-based clad layer 40 and the nitride- A part of the upper surface region of the lower nitride-based clad layer 20 is exposed to the atmosphere by etching (i.e., etching) a part of the active layer 30 to form the n-type In an n-type ohmic contact interface electrode and an electrode pad 80 are formed on the upper surface of the x Al y Ga 1-xy N semiconductor.

In particular, since the upper nitride-based clad layer 40 has a relatively high sheet resistance due to a low carrier concentration and a small mobility, Lt; RTI ID = 0.0 > 50 < / RTI > On the other hand, U.S. Patent No. 5,563,422 discloses that a p-type In x Al y Ga 1-xy N (40) semiconductor (n-type) semiconductor layer 40, which is a top nitride-based cladding layer 40 located in an upper layer portion of a light emitting structure for a group III nitride- Nickel-gold (NiO), which is oxidized to form an ohmic contact current spreading layer 50 which forms an ohmic contact interface with low contact resistance in the vertical direction before forming the p-type electrode 80 on the upper surface, (Ni-O-Au).

The ohmic contact current spreading layer 50 is formed on the upper surface of the p-type In x Al y Ga 1-xy N semiconductor which is the upper nitride-based cladding layer 40 while improving the current spreading in the horizontal direction , An ohmic contact interface having a low noncontact resistance in the vertical direction can be formed and current injection can be performed effectively, thereby improving the electrical characteristics of the light emitting diode device. However, the ohmic contact current spreading layer 50 made of oxidized nickel-gold shows an average transmittance as low as 70% even after heat treatment, and this low light transmittance is lower when the light generated from the light emitting diode device is emitted to the outside , And absorbs a large amount of light, thereby reducing the overall external luminous efficiency.

As described above, in order to obtain a high-luminance light-emitting diode device through a high light transmittance of the ohmic contact current spreading layer 50, a variety of semiconductors including the oxidized nickel-gold (Ni-O- A transparent conductive material such as indium tin oxide (ITO) or zinc oxide (ZnO), which is known to have an average transmittance of 90% or more, has been proposed instead of the Ohmic contact current spreading layer 50 formed of a transparent metal or an alloy. The above-mentioned transparent electroconductive material is a p-type In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) semiconductor (~ 7.5 eV or more (4.7 to 6.1 eV) and p-type In x Al y Ga 1-x y N semiconductor layer directly on the upper surface of the semiconductor, and after the subsequent process including the heat treatment, the ohmic contact interface, There is a need for a new transparent conductive material or a manufacturing process which can solve the above-mentioned problems, because it forms a schottky contact interface.

A transparent conductive material such as ITO or ZnO is formed on the upper surface of the p-type In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) semiconductor which is the upper nitride- In recent years, YK Su et al. Have reported that the above-mentioned transparent electroconductive material can be used as a good ohmic contact current spreading layer 50 of p-type In x Al y A current spreading layer having an ohmic contact interface via a superlattice structure is formed prior to the direct deposition of Ga 1-xy N (0? X, 0? Y, x + y? 1) 50) formation technology.

6, the superlattice structure has two layers a1 and b1 of a well (b1) and a barrier (a1) in a multi-quantum well structure The thickness of the barrier (a1) of the multiple quantum well structure is relatively thick compared to the thickness of the well (b1), while the thickness of the barrier (a1) of the multiple quantum well structure is thicker than that of the well (a2, b2) all have a thin thickness of 5 nm or less. Due to the above-described characteristic, the multiple quantum well structure plays a role of confinement of electrons or holes as carriers into a well b1 located between the thick barrier a1, And facilitates the transport of the liquid.

Referring to FIG. 7, a light emitting diode device having an ohmic contact current spreading layer 60 using a superlattice structure proposed by YK Su et al. Will be described. The group III nitride semiconductor light emitting diode device includes a sapphire growth substrate 10 and a lower nitride-based clad layer 20 made of an n-type conductive semiconductor material formed on the upper surface of the growth substrate 10, a nitride-based active layer 30, and a upper nitride-based clad layer 40, and a superlattice structure 90. In particular, the superlattice structure 90 is grown in situ with the same growth equipment as the lower nitride-based cladding layer 20, the nitride-based active layer 30, and the upper nitride-based cladding layer 40 Growth. The lower nitride-based cladding layer 20 may be composed of n-type In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) semiconductor multilayers, (0? X, 0? Y, x + y? 1) semiconductor multilayers composed of Group III nitride-based In x Al y Ga 1-xy N (different compositions of a multi-quantum well structure) have. The upper nitride-based cladding layer 40 may be composed of a semiconductor multilayer of p-type In x Al y Ga 1-x-y N (0? X, 0? Y, x + y? Further, the superlattice structure 90 may be formed of Group III nitride-based In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) semiconductors or other boards (0? X, 0? Y, x + y? 1) semiconductor multilayers of Group III nitride type In x Al y Ga 1-xy N having a dopant.

Depending on the composition and the type of dopant constituting the superlattice structure 90, the p-type In x Al y Ga 1-xy N (0? X, 0 Y, x + y < / = 1) to increase the net effective hole concentration by lowering the dopant activation energy of the semiconductor, or by quantum tunneling conduction through band- It is known to form an ohmic contact interface through the phenomenon of mechanical tunneling transport.

In general, the lower nitride-based cladding layer / the nitride-based active layer / the upper nitride-based cladding layer / superlattice structure 20, 30, 40 and 90 formed of the Group III nitride-based semiconductor single crystal may be formed by MOCVD, MBE, HVPE, , Or a device such as a PLD. In order to improve the lattice matching with the sapphire growth substrate 10 prior to the growth of the n-type In x Al y Ga 1-xy N semiconductor of the lower nitride-based cladding layer 20, The buffer layer 201 may be formed therebetween.

In addition, the energy conversion efficiency (lm / W) of the packaged light emitting diode device can be increased by extracting as much light as possible from the active layer in the light emitting structure for the group III nitride-based semiconductor light emitting diode device. Generally, the external luminous efficiency of the group III nitride-based semiconductor light-emitting diode is surprisingly low. This is because a large difference in refractive index between the group III nitride-based semiconductor such as GaN or the ohmic contact current spreading layer such as ITO or ZnO and the molding material causes a substantial part of the light generated in the LED structure to be emitted to the outside The light is totally reflected and then proceeds to the inner side of the LED again to be destroyed. For example, assuming that gallium nitride (GaN) has a refractive index of about 2.3 and a refractive index of a molding material of about 1.5, the amount of light totally reflected on the junction surface of the two materials is about 90% In order to solve this problem, a p-type In x Al y Ga 1-xy N (0? X, 0? Y, x + y The surface of the semiconductor or ohmic contact current spreading layer 60 is subjected to an etching process to introduce a surface texture having a predetermined shape and dimension to the surface. In this case, it was confirmed that the light extraction efficiency was significantly improved.

However, the p-type In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) semiconductor or the ohmic contact current spreading layer 60 which is the upper nitride- The step of introducing the irregularities may be performed by forming the upper nitride-based cladding layer 40 of p-type In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) semiconductors or ohmic contact current spreading layers There is a possibility of causing electrical damage to the surface of the LED 60, thereby raising the driving voltage and the leakage current of the LED device, thereby deteriorating the energy conversion efficiency.

The present invention relates to a p-type In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) upper cladding layer of a light emitting structure for a group III nitride- In order to solve the problems caused by the formation of the ohmic contact current spreading layer and the introduction of the surface irregularities, there has been proposed a method for forming a p-type In x Al y Ga 4 -type cladding layer of the Group III nitride- 1-xy N (0? X, 0? Y, x + y? 1) group III nitride-based conductive thin film structure having a superlattice structure and a sheet resistance of 50? /? To provide a light emitting diode device having a low driving voltage, a low leakage current, and a high external light emitting efficiency characteristic, and a method of manufacturing the same.

The present invention relates to a semiconductor device comprising: a growth substrate; A lower nitride-based clad layer made of an n-type conductive group III nitride-based semiconductor, a nitride-based active layer made of another group III nitride-based semiconductor material, and a p-type conductive group III nitride-based semiconductor on the upper surface of the growth substrate A light-emitting structure for a light-emitting diode element comprising a top nitride-based clad layer; A superlattice structure formed on the upper surface of the light emitting structure for the light emitting diode device; And a ohmic contact current spreading layer formed on the upper surface of the superlattice structure, wherein the group III nitride-

The superlattice structure is a multi-layer structure composed of Group 2, Group 3, or Group 4 nitride having different dopants and compositional elements,

Wherein the ohmic contact current spreading layer is composed of a group III nitride-based conductive thin film structure having a sheet resistance of 50? /? Or less.

The superlattice structure is a multi-layer composed of Group 2, Group 3 or Group 4 nitrides having different dopants and compositional elements,

The ohmic contact current spreading layer is composed of a group III nitride-based conductive thin film structure having a sheet resistance of 50? /? Or less,

And a light extracting structure in which a surface irregularity process is introduced on the top surface of the ohmic contact current spreading layer in order to improve the light extraction efficiency by changing the incident angle of light generated in the light emitting diode device. Nitride semiconductor light-emitting diode device.

The present invention provides, as a constituent means for achieving the above-mentioned object, a light emitting device using group III nitride-based semiconductor represented by the formula In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) A method of manufacturing a diode (hereinafter, referred to as a group III nitride-based semiconductor light-emitting diode)

Preparing a growth substrate for growing a light-emitting structure for a group III nitride-based semiconductor light-emitting diode device;

A nitride-based active layer made of a group III nitride-based semiconductor material having a different composition, and a nitride-based active layer made of a p-type conductive group III nitride semiconductor material Forming a light emitting structure for a group III nitride-based semiconductor light-emitting diode device in which a top nitride-based clad layer made of a nitride-based semiconductor material is successively stacked and grown;

Forming a superlattice structure on a semiconductor upper surface of a p-type In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) semiconductor which is the upper nitride-based cladding layer of the light- ;

Forming an ohmic contact current spreading layer on the superlattice structure;

Removing a part of the ohmic contact current spreading layer, the superlattice structure, the upper nitride-based clad layer, and the lower nitride-based clad layer, exposing the lower nitride-based clad layer to the atmosphere, Forming an n-type ohmic contact electrode and an electrode pad on the upper surface of the region; And

And forming a p-type schottky contact electrode and an electrode pad on a top surface of a part of the ohmic contact current spreading layer region.

The present invention provides, as still another constituent means for achieving the above-mentioned object, a group III nitride-based semiconductor represented by the formula In x Al y Ga 1-xy N (0? X, 0? Y, x + (Hereinafter referred to as a group III nitride-based semiconductor light-emitting diode) element,

Forming an ohmic contact current spreading layer on the superlattice structure;

Forming a light extracting structure in which a surface irregularity process is introduced on an upper surface of the ohmic contact current spreading layer;

Removing a portion of the light extracting structure, the ohmic contact current spreading layer, the superlattice structure, the upper nitride-based clad layer, and the lower nitride-based clad layer, exposing the lower nitride-based clad layer to the atmosphere, Forming an n-type ohmic contact electrode and an electrode pad on a top surface of a part of the clad layer; And

And forming a p-type schottky contact electrode and an electrode pad on a surface of the light extraction structure or a part of the ohmic contact current spreading layer.

A superlattice structure of an n-type conductive InGaN single layer or a p-type conductive InGaN single layer having a thickness of 5 nm or less may be formed instead of the multi-layered superlattice structure.

The ohmic contact current spreading layer is composed of a group III nitride-based conductive thin film structure having a sheet resistance of 50? /? Or less.

The lower nitride-based clad layer, the nitride-based active layer, the upper nitride-based clad layer, the superlattice structure, and the ohmic contact current spreading layer are successively grown in-situ using MOCVD, MBE, or HVPE equipment Growth.

In addition, the lower nitride-based clad layer, the nitride-based active layer, the upper nitride-based clad layer, and the superlattice structure are successively grown in an in-situ state using MOCVD, MBE, or HVPE equipment, The ohmic contact current spreading layer may be formed in an ex situ state using MOCVD, MBE, HVPE, sputter, or PLD equipment.

As described above, the present invention relates to a group III nitride-based semiconductor light-emitting device (light-emitting diode) element, wherein the upper nitride-based clad layer of the light- The ohmic contact current spreading layer composed of a group III nitride-based conductive thin film structure having superlattice structure and excellent electric conductivity is bonded to the upper surface of the semiconductor, thereby obtaining a good electrical There is also an effect of improving the luminance of the light emitting device in which the light transmittance characteristics are improved.

In addition, in a group III nitride-based semiconductor light-emitting diode device having a light extraction structure, a surface irregularity is formed on the top surface of an ohmic contact current spreading layer composed of a group III nitride-based conductive thin film structure having excellent electric conductivity by wet or dry etching It is possible to minimize the total reflection of light into the structure of the light emitting structure for an LED device, thereby further improving the overall luminance characteristic of the LED device.

Hereinafter, the group III nitride-based semiconductor light-emitting diode device manufactured according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view illustrating a first embodiment of a light emitting structure for a group III nitride-based semiconductor light emitting diode device developed by the present invention.

Referring to FIG. 1, a light emitting structure A for a light emitting diode device according to a first embodiment of the present invention, which is grown on a growth substrate 10, includes a buffer layer (not shown) The nitride-based active layer 30, the upper nitride-based clad layer 40 made of a p-type conductive semiconductor material, and the superlattice structure ( 90), and an ohmic contact current spreading layer (100).

The growth substrate 10 may be made of a material such as sapphire or silicon carbide (SiC).

The lower nitride-based clad layer 20 made of the n-type conductive semiconductor material may be formed of In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) semiconductor multi- And a buffer layer (not shown) formed on the upper surface of the growth substrate 10. The lower nitride-based clad layer 20 may be formed by doping silicon (Si).

The nitride-based active layer 30 is a region where carriers such as electrons and holes are recombined, and includes InGaN, AlGaN, GaN, AlInGaN, and the like.

The nitride-based active layer 30 may be a multilayer film in which a quantum well layer and a barrier layer are repeatedly formed. The energy band gap of the material constituting the barrier layer of the nitride based active layer 30 is larger than the energy band gap of the material constituting the well layer and the thickness of the barrier layer is larger than the thickness of the well layer Thick is common. The barrier layer and the well layer may be binary, ternary or quaternary compound nitride semiconductors represented by the formula In x Al y Ga 1-xy N (0? X, 0? Y, x + have. Furthermore, the barrier layer and the well layer may be formed by doping silicon (Si), magnesium (Mg), or the like. The emission wavelength of light emitted from the light emitting diode device is determined according to the kind of the material constituting the quantum well layer of the nitride-based active layer 30. [

The upper nitride-based clad layer 40 made of the p-type conductive semiconductor material may be formed of a p-type In x Al y Ga 1-xy N (0? X, 0? Y, x + have. The upper nitride-based clad layer 40 may be formed by doping zinc (Zn) or magnesium (Mg).

The superlattice structure 90 is formed on the upper surface of the upper nitride-based clad layer 40 made of the p-type conductive semiconductor material, and includes p-type p-type In x Al y Ga 1-xy N (0? y, x + y < / = 1) to increase the effective hole concentration by lowering the activation energy of the semiconductor dopant, or by quantum-mechanical tunneling transport phenomenon through energy band gap control Can cause.

The superlattice structure 90 is generally formed in a multi-layer structure, and the thickness of each layer constituting the superlattice structure 90 is 5 nm or less. Each layer is made of InN, InGaN, InAlN, AlGaN, GaN, AlInGaN, AlN, SiC, SiCN , MgN, ZnN, or SiN. For example, the superlattice structure 90 includes InGaN / GaN, AlGaN / GaN, InGaN / GaN / AlGaN, and AlGaN / GaN / InGaN.

Further, each layer of the superlattice structure 90 may be formed by doping silicon (Si), magnesium (Mg), zinc (Zn), or the like.

A superlattice structure 90 composed of an n-type conductive InGaN single layer or a p-type conductive InGaN single layer having a thickness of 5 nm or less may be used instead of the multi-layered superlattice structure 90 have.

The ohmic contact current spreading layer 100 is formed of a Group III nitride-based conductive thin film structure having a sheet resistance of 50? /? Or less. The group III nitride-based conductive thin film structure of the ohmic contact current spreading layer 100 has a thickness of 6 nm or more, expressed by the formula In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) And may be a single layer or a multi-layer. Further, the ohmic contact current spreading layer 100 may be formed by doping silicon (Si), magnesium (Mg), zinc (Zn), or the like.

The light-emitting structure A for the light-emitting diode element is continuously grown in an in-situ state using a device such as MOCVD, MBE, HVPE, sputter, or PLD. Further, the lower nitride-based clad layer 20, the nitride-based active layer 30, the upper nitride-based clad layer 40, and the superlattice structure 90 of the light-emitting diode for a light- The ohmic contact current spreading layer 100 may be grown on the upper surface of the superlattice structure 90 in an ex situ state after the first growth in the sheath state.

FIG. 2 is a cross-sectional view showing a second embodiment of a light emitting structure for a group III nitride-based semiconductor light emitting diode element, which is invented by the present invention.

Referring to FIG. 2, a light emitting structure B for a light emitting diode device according to a first embodiment of the present invention, which is grown on a growth substrate 10, includes a buffer layer (not shown) A nitride-based active layer 30, a top nitride-based clad layer 40 made of a p-type conductive semiconductor material, and a lower nitride-based clad layer 20 made of an n- A superlattice structure 90 and an ohmic contact current spreading layer 100.

The nitride-based active layer 30 may be a multilayer film in which a quantum well layer and a barrier layer are repeatedly formed. The energy band gap of the material constituting the barrier layer of the nitride based active layer 30 is larger than the energy band gap of the material constituting the well layer and the thickness of the barrier layer is greater than the thickness of the well layer Thick is common. The barrier layer and the well layer may be binary, ternary or quaternary compound nitride semiconductors represented by the formula In x Al y Ga 1-xy N (0? X, 0? Y, x + have. Furthermore, the barrier layer and the well layer may be formed by doping silicon (Si), magnesium (Mg), or the like. The emission wavelength of light emitted from the light emitting diode device is determined according to the kind of the material constituting the quantum well layer of the nitride-based active layer 30. [

The superlattice structure 90 repeatedly stacked on the upper nitride-based cladding layer 40 is located on the upper surface of the upper nitride-based cladding layer 40 made of the p-type conductive semiconductor material, and the p-type p-type In x Al y Ga 1-xy N (0? x, 0? y, x + y? 1) to increase the effective hole concentration by lowering the dopant activation energy of the semiconductor, or to control the energy band gap Can lead to quantum-mechanical tunneling transport phenomena.

The ohmic contact current spreading layer 100 repeatedly stacked on the superlattice structure 90 is composed of a group III nitride-based conductive thin film structure having a sheet resistance of 50? /? Or less. The group III nitride-based conductive thin film structure of the ohmic contact current spreading layer 100 may have a thickness of 6 nm or more represented by the formula In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) And may be configured as a single layer or a multi-layer having a thickness. Further, the ohmic contact current spreading layer 100 may be formed by doping silicon (Si), magnesium (Mg), zinc (Zn), or the like.

The light-emitting structure A for the light-emitting diode element is continuously grown in an in-situ state using a device such as MOCVD, MBE, HVPE, sputter, or PLD. Further, the lower nitride-based clad layer 20, the nitride-based active layer 30, the upper nitride-based clad layer 40, and the superlattice structure 90 of the light-emitting diode for a light- The ohmic contact current spreading layer 100 may be grown on the top surface of the superlattice structure 90 in an ex situ state after first growing in an in-situ state.

3 is a cross-sectional view of a group III nitride-based semiconductor light-emitting diode device as a first embodiment manufactured by the present invention.

Referring to FIG. 3, a light emitting structure A for a light emitting diode element according to the first embodiment of the present invention is grown on the upper surface of the growth substrate 10. In other words, on the upper surface of the growth substrate 10, a lower nitride-based clad layer 20 made of an n-type conductive semiconductor material including a buffer layer (not shown), a nitride-based active layer 30, Type cladding layer 40, the superlattice structure 90, the ohmic contact current spreading layer 100, the p-type short-circuit contact electrode and the electrode pad 70, and the n-type ohmic contact electrode and the electrode pad 80 .

The light emitting diode device has a structure in which the lower nitride-based clad layer 20, the nitride-based active layer 30, and the upper nitride-based clad layer 40 are continuously laminated. The nitride-based active layer 30 is formed on a part of the lower nitride-based clad layer 20 made of the n-type conductive semiconductor material, and the nitride-based active layer 30 is formed of a p- The upper nitride-based cladding layer 40 is formed. Accordingly, a part of the upper surface of the lower nitride-based cladding layer 20 is bonded to the nitride-based active layer 30, and the remaining part of the upper surface is exposed to the outside.

The superlattice structure 90 is located in a part or the whole area of the upper surface of the upper nitride-based clad layer 40 and is generally formed in a multi-layered structure. The thickness of each layer constituting the superlattice structure 90 is 5 nm or less, May be composed of InN, InGaN, InAlN, AlGaN, GaN, AlInGaN, AlN, SiC, SiCN, MgN, ZnN, or SiN. For example, the superlattice structure 90 may include silicon (Si) -doped InGaN / GaN, AlGaN / GaN, and the like.

An n-type conductive InGaN single layer or a p-type conductive InGaN single layer having a thickness of 5 nm or less may be used instead of the superlattice structure 90 at the superlattice structure 90. [

Wherein the ohmic contact current spreading layer (100) is formed of a group III nitride-based conductive thin-film structure having a sheet resistance of 50? /? Or less in a part or the entire region of the superlattice structure (90) And transmits the light emitted from the active layer 30 to the outside. For example, a group III nitride-based conductive material such as silicon (Si) -doped GaN having a sheet resistance of 50? /? Or less, silicon-doped aluminum gallium nitride (AlGaN) , MBE, HVPE, sputter, PLD, or the like, and has a thickness of 6 nm or more. The current is uniformly distributed through the p-type Schottky contact electrode and the electrode pad 70, And to increase the efficiency.

The p-type Schottky contact electrode and the electrode pad 70 are formed on a part of the upper surface of the ohmic contact current spreading layer 100 and include a material for forming a schottky contact interface with the ohmic contact current spreading layer 100, For example, a metal such as Pd / Au and may be formed by a lift off method. Pd / Au can be used to improve adhesion to the ohmic contact current spreading layer 100, and also to obtain a desired contact interface of the ohmic contact current spreading layer 100.

The n-type ohmic contact electrode and the electrode pad 80 are formed on the exposed surface of the lower nitride-based clad layer 20 made of an n-type conductive semiconductor material and can be formed using a lift-off method. The n-type ohmic contact electrode and the electrode pad 80 are made of a metal such as Cr / Al to form an ohmic contact interface with the lower nitride-based clad layer 20, The adhesion can be improved and an ohmic contact interface with the lower nitride-based clad layer 20 can be obtained.

4 is a cross-sectional view of a group III nitride-based semiconductor light-emitting diode device as a second embodiment manufactured by the present invention.

Referring to FIG. 4, a light emitting structure A for a light emitting diode element according to the first embodiment of the present invention is grown on the growth substrate 10. In other words, on the upper surface of the growth substrate 10, a lower nitride-based clad layer 20 made of an n-type conductive semiconductor material including a buffer layer (not shown), a nitride-based active layer 30, The nitride-based clad layer 40, the superlattice structure 90, the ohmic contact current spreading layer 100, the light extracting structure 110, the p-type schottky contact electrode and the electrode pad 70, and the n- And an electrode pad (80).

The ohmic contact current spreading layer 100 is formed of a group III nitride-based conductive thin-film structure having a sheet resistance of 50? /? Or less in a part or the entire region of the superlattice structure 90, And transmits the light emitted from the light source 30 to the outside. For example, a group III nitride-based conductive material such as silicon (Si) -doped GaN having a sheet resistance of 50? /? Or less, silicon-doped aluminum gallium nitride (AlGaN) , MBE, HVPE, sputter, PLD, or the like, and has a thickness of 6 nm or more. The current is uniformly distributed through the p-type Schottky contact electrode and the electrode pad 70, And to increase the efficiency.

The light extracting structure 110 is a surface texture introduced into the upper surface of the ohmic contact current spreading layer 100 to emit light generated in the nitride based active layer 30 as much as possible into the atmosphere. The light extracting structure 110 may be formed on the surface of the ohmic contact current spreading layer 100 in contact with the atmosphere by using wet or dry etching to form irregularities having a predetermined shape and dimensions, The total luminance characteristic of the LED element can be further improved.

The p-type schottky contact electrode and the electrode pad 70 are located in a part of the top surface of the light extracting structure 110 or the ohmic contact current spreading layer 100 and are in contact with the ohmic contact current spreading layer 100, A material for forming an interface, for example, a metal such as Pd / Au, and may be formed by a lift off method. Pd / Au can be used to improve adhesion to the ohmic contact current spreading layer 100, and also to obtain a desired contact interface of the ohmic contact current spreading layer 100.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Accordingly, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also within the scope of the present invention.

1 is a cross-sectional view showing a first embodiment of a light-emitting structure for a group III nitride-based semiconductor light-emitting diode element developed by the present invention,

FIG. 2 is a cross-sectional view illustrating a second embodiment of a light-emitting structure for a group III nitride-based semiconductor light-emitting diode element,

FIG. 3 is a cross-sectional view showing a first embodiment of a group III nitride-based semiconductor light-emitting diode device manufactured according to the present invention,

FIG. 4 is a cross-sectional view of a group III nitride-based semiconductor light-emitting diode device according to a second embodiment of the present invention,

5 is a cross-sectional view showing a typical example of a conventional Group III nitride-based semiconductor light-emitting diode device,

6 is a cross-sectional view for explaining a comparison between a multi-quantum well structure and a superlattice structure,

7 is a cross-sectional view showing a representative example of a conventional Group III nitride-based semiconductor light-emitting diode device.

Claims

A growth substrate;

A nitride-based active layer made of an n-type conductive semiconductor material including a buffer layer formed on the upper surface of the growth substrate, a nitride-based active layer, and a nitride-based clad layer made of a p-type conductive semiconductor material; ;

A superlattice structure formed on a part or the whole area of the upper nitride-based clad layer of the light-emitting structure for the light-emitting diode device;

An ohmic contact current spreading layer formed on a part or the whole area of the superlattice structure upper surface; / RTI >

And a multilayer film formed by alternately alternating the superlattice structure and the ohmic contact current spreading layer

Group III nitride-based semiconductor light-emitting diode device.

The method according to claim 1,

A p-type schottky contact electrode and an electrode pad formed on a part of the ohmic contact current spreading layer disposed on the upper surface of the multilayer film; And

An n-type ohmic contact electrode and an electrode pad formed on a part of the upper surface of the lower nitride-based clad layer of the light emitting structure for the light emitting diode,

Wherein the superlattice structure is a superlattice multilayer film in which two layers or three layers are one pair and are periodically repeated.

3. The method of claim 2,

Wherein each layer constituting the superlattice structure is an InN, InGaN, InAlN, AlGaN, GaN, AlInGaN, AlN, SiC, SiCN, MgN, ZnN or SiN material having a thickness of 5 nm or less. Light emitting diode device.

The method of claim 3,

Wherein each layer of the superlattice structure is a material doped with silicon (Si), magnesium (Mg), or zinc (Zn).

The method according to claim 1,

Wherein the superlattice structure can be replaced with an n-type conductive InGaN single layer or a p-type conductive InGaN single layer having a thickness of 5 nm or less.

The method according to claim 1,

Wherein the ohmic contact current spreading layer is formed of a group III nitride-based conductive thin film structure having a sheet resistance of 50? /? Or less.

The method according to claim 6,

The group III nitride-based conductive thin film structure constituting the ohmic contact current spreading layer has a thickness of 6 nm or more expressed by the formula In x Al y Ga 1-xy N (0? X, 0? Y, x + Layer nitride semiconductor light-emitting diode device.

A growth substrate;

A superlattice structure formed on a part or the whole area of the upper nitride-based clad layer of the light-emitting structure for the light-emitting diode device; And

An ohmic contact current spreading layer formed on part or all of the upper surface of the superlattice structure; And

The superlattice structure and the ohmic contact current spreading layer are alternately formed into a multilayer film alternately,

A light extracting structure having surface irregularities introduced into the upper surface of the multilayer film;

A p-type schottky contact electrode and an electrode pad formed on a part of the upper surface of the ohmic contact current spreading layer disposed on the light extracting structure or the multilayer film; And

And an n-type Ohmic contact electrode and an electrode pad formed on a part of the upper surface of the lower nitride-based clad layer of the light-emitting structure for the light-emitting diode device.

9. The method of claim 8,

10. The method of claim 9,

11. The method of claim 10,

9. The method of claim 8,

Wherein the superlattice structure can be replaced with an n-type conductive InGaN single layer or a p-type conductive InGaN single layer having a thickness of 5 nm or less. .

9. The method of claim 8,

14. The method of claim 13,

9. The method of claim 8,

Wherein the light extracting structure has a texture having a predetermined shape and dimensions formed on the surface of the ohmic contact current spreading layer.

A nitride-based active layer made of a Group III nitride-based semiconductor material; and a p-type conductive Group III nitride-based semiconductor material, which is made of an n-type conductive Group III nitride-based semiconductor material, Forming a light-emitting structure for a group III nitride-based semiconductor light-emitting diode device in which a super-nitride-based clad layer is successively stacked and grown;

Forming an ohmic contact current spreading layer on the superlattice structure;

Forming a superlattice structure and an ohmic contact current spreading layer alternately in a multilayered structure, the ohmic contact current spreading layer, the superlattice structure, the upper nitride-based clad layer, and the lower nitride- Forming an n-type ohmic contact electrode and an electrode pad on a part of the upper surface of the lower nitride-based cladding layer after exposing the lower nitride-based cladding layer to the atmosphere; And

And forming a p-type Schottky contact electrode and an electrode pad on a part of the upper surface of the ohmic contact current spreading layer disposed on the upper surface of the multi-layered film.

Removing the superlattice structure, the upper nitride-based clad layer, and a portion of the lower nitride-based clad layer and exposing the lower nitride-based clad layer to the atmosphere;

Forming an ohmic contact current spreading layer on the superlattice structure;

Forming the superlattice structure and the ohmic contact current spreading layer alternately into a multi-layered film;

Forming an n-type ohmic contact electrode and an electrode pad on a part of the upper surface of the lower nitride-based clad layer; And

17. The method of claim 16,

And forming a light extracting structure by introducing surface irregularities on the upper surface of the multilayer film to form a group III nitride-based semiconductor light-emitting diode device.

18. The method of claim 17,

And forming a light extracting structure by introducing surface irregularities on an upper surface of the multilayer film to form a group III nitride-based semiconductor light-emitting diode device.

17. The method of claim 16,

The lower nitride-based clad layer, the nitride-based active layer, the upper nitride-based clad layer, the superlattice structure, and the ohmic contact current spreading layer are formed in-situ using MOCVD, MBE, or HVPE equipment Wherein the group III nitride-based semiconductor light-emitting diode device is manufactured by a method comprising the steps of:

18. The method of claim 17,

The formation of the lower nitride-based clad layer, the nitride-based active layer, the upper nitride-based clad layer, and the superlattice structure is performed in-situ using MOCVD, MBE, or HVPE equipment, Wherein the reading layer is formed in an ex-situ state using MOCVD, MBE, sputter, PLD, or HVPE equipment. 2. The group III nitride semiconductor light-emitting diode device of claim 1,

A growth substrate;

A lower nitride-based clad layer made of an n-type conductive group III nitride-based semiconductor, a nitride-based active layer made of a group III nitride-based semiconductor material, and an upper nitride made of a p-type conductive group III nitride- A light emitting diode structure comprising a light emitting diode element made of a cladding layer;

A superlattice structure formed on the upper surface of the light emitting structure for the light emitting diode device;

And an ohmic contact current spreading layer formed on an upper surface of the superlattice structure,

A thin film structure for a group III nitride-based semiconductor light-emitting diode device having a multilayer film formed by alternately alternating a superlattice structure and an ohmic contact current spreading layer on an upper surface of the light emitting structure for the light emitting diode device.

delete

23. The method of claim 22,

Wherein the superlattice structure is a multi-layered film in which two layers or three layers are periodically repeated with one pair formed therebetween.

25. The method of claim 24,

Wherein each layer constituting the superlattice structure is an InN, InGaN, InAlN, AlGaN, GaN, AlInGaN, AlN, SiC, SiCN, MgN, ZnN or SiN material having a thickness of 5 nm or less. Thin film structure for a light emitting diode device.

26. The method of claim 25,

23. The method of claim 22,

Wherein the superlattice structure can be replaced with an n-type conductive InGaN single layer or a p-type conductive InGaN single layer having a thickness of 5 nm or less. The group III nitride based semiconductor light emitting diode device Thin film structure.

23. The method of claim 22,

29. The method of claim 28,

The group III nitride-based conductive thin film structure constituting the ohmic contact current spreading layer has a thickness of 6 nm or more expressed by the formula In x Al y Ga 1-xy N (0? X, 0? Y, x + Layer structure or a multi-layer film of a nitride having a group III nitride-based semiconductor light-emitting diode element.

23. The method of claim 22,

The light emitting structure for a light-emitting diode device, the superlattice structure, and the ohmic contact current spreading layer may be formed of a group III nitride-based semiconductor formed continuously in an in-situ state using MOCVD, MBE, or HVPE growth equipment. Thin film structure for a light emitting diode device.

23. The method of claim 22,

The light emitting diode structure and the superlattice structure for the light emitting diode device are continuously formed in an in-situ state using MOCVD, MBE, or HVPE growth equipment, and the ohmic contact current spreading layer is formed in the superlattice structure A thin film structure for a group III nitride-based semiconductor light-emitting diode device formed on an upper surface in an ex situ state by MOCVD, MBE, HVPE, sputter, or PLD growth equipment.