KR101499954B1

KR101499954B1 - fabrication of vertical structured light emitting diodes using group 3 nitride-based semiconductors and its related methods

Info

Publication number: KR101499954B1
Application number: KR1020080041612A
Authority: KR
Inventors: 송준오
Original assignee: 엘지이노텍 주식회사
Priority date: 2008-05-05
Filing date: 2008-05-05
Publication date: 2015-03-06
Also published as: KR20090115902A

Abstract

The present invention relates to a group III nitride-based semiconductor light-emitting diode device having a vertical structure and a method of manufacturing the same, and includes an n-type electrode structure; A multilayer structure for a group III nitride-based semiconductor light-emitting diode device in which an n-type nitride-based clad layer, a nitride-based active layer, a p-type nitride-based clad layer, and a surface modification layer are sequentially stacked below the n-type electrode structure; A p-type electrode structure including a current blocking structure in the form of a trench formed on an upper portion of the multilayer structure for the light emitting diode device; A heat sink support formed on a bottom surface of the multi-layer structure for a light emitting diode device having the p-electrode structure, and a p-type ohmic contact electrode structure, wherein light generation efficiency and external quantum efficiency in the nitride- There is an advantage that it can be increased.

In particular, the present invention provides a method of fabricating a group III nitride-based semiconductor light-emitting diode device having a vertical structure by using sandwich-structured wafer bonding and a photon-beam, and a manufacturing method thereof.

A group III nitride-based semiconductor light emitting diode, a multilayer structure for a light emitting diode device, a surface modification layer, a sacrificial separation layer, a wafer bonding layer, a wafer bonding of a sandwich structure, a current blocking structure, a trench, Think support, substrate separation, thermo-chemical decomposition

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical structure group III nitride-based semiconductor light-emitting diode device and a fabrication method thereof,

The present invention relates to a method of manufacturing a semiconductor device having a vertical structure using a single crystal group III nitride-based semiconductor represented by the formula In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) Group III nitride-based semiconductor light-emitting diode device and a method of manufacturing the same. More specifically, a growth substrate wafer on which a light-emitting structure for a group III nitride-based semiconductor light-emitting diode device including a p-type electrode structure is grown on a growth substrate, and a wafer substrate of a sandwich structure developed by the present inventor The present invention relates to a method of fabricating a group III nitride-based semiconductor light-emitting diode device having vertical structure by combining a wafer to wafer bonding process and a lift-off process.

Recently, a light emitting diode (LED) device using a group III nitride-based semiconductor single crystal has been used as a nitride-based active layer. In x Al y Ga 1-xy N (0? X, 0? Y, x + ) The material band has a wide band gap. In particular, according to the composition of In, it is known as a material capable of emitting light in the entire region of visible light, and ultraviolet light can be generated in a microwave region depending on the composition of Al. The light emitting diode manufactured using the light emitting diode, Devices for backlighting, medical light sources including white light sources, and the like, have been widely used, and as the range of applications is gradually expanding and increasing, the development of high quality light emitting diodes is becoming very important.

FIG. 14 is a schematic structural cross-sectional view of a conventional structure-based group III nitride-based semiconductor light emitting diode device according to the related art, in which a buffer layer 20, an n-type nitride-based clad layer 30, , A nitride-based active layer 40 and a p-type nitride-based cladding layer 50 are successively grown, and the p-type nitride-based cladding layer 50 has an n-type nitride-based cladding layer Type ohmic contact electrode 60 and an electrode pad 70 are sequentially formed on the p-type nitride-based cladding layer 50. The part of the region An n-type ohmic contact electrode structure 80 is formed on the n-type nitride-based clad layer 30 which is etched and exposed to the air.

The group III nitride-based semiconductor light-emitting diode device shown in FIG. 14 is bonded to a mold cup with an adhesive on the back surface of the sapphire growth substrate, and one lead frame is connected to the n-type ohmic contact electrode structure 80 At the same time, another lead frame and the p-type electrode pad 70 are connected by wire connection. When the external voltage is applied through the n and p electrode pads, electrons and holes are injected from the n-type nitride-based clad layer 30 and the p-type nitride-based clad layer 50, respectively, A charge carrier flows into the nitride-based active layer 40, and two charge carriers are recombined to emit light. The light emitted from the nitride-based active layer 40 is emitted to the four sides of the nitride-based active layer 40. The upper light is emitted to the outside through the p-type nitride-based clad layer 50, A part of the proceeding light goes out to the outside of the light emitting diode device while advancing to the bottom part, and a part of the light goes down the sapphire growth substrate 10 and is absorbed or reflected by the solder used for assembling the light emitting diode device, Based active layer 40 including the nitride-based active layer 40, and then exits to the outside through the nitride-based active layer 40.

However, since the group III nitride-based semiconductor light-emitting diode device is fabricated in a sapphire growth substrate 10 having a low thermal conductivity and electrical insulation property as a horizontal structure, the group III nitride-based semiconductor light-emitting diode device smoothly emits a large amount of heat There is a problem that the overall characteristics of the device are deteriorated.

In addition, as shown in FIG. 14, in order to form two ohmic contact electrodes and electrode pads, it is necessary to remove a part of the nitride based active layer 40, thereby reducing the light emitting area and thus it is difficult to realize a high-quality light emitting diode device , The number of chips in a wafer of the same size is reduced, and the price competitiveness lags behind.

In addition, after the manufacturing process of the light emitting diode device is completed on the wafer, the lapping, polishing, scribing, sawing, and braking breaking of the sapphire growth substrate 10 and the cleavage plane of the Group III nitride-based semiconductor during the mechanical process such as cutting, bending, or the like.

In order to solve the problem of the group III nitride-based semiconductor light-emitting diode device having a horizontal structure as described above, the growth substrate 10 is removed so that two ohmic contact electrodes and electrode pads are opposed to the upper and lower portions of the light- A vertically structured group III nitride-based semiconductor light-emitting diode device in which an externally applied current flows in one direction to improve light-emitting efficiency is disclosed in a number of documents (US Pat. No. 6,071,795, US Pat. No. 6,335,263, US 20060189098) have.

FIG. 15 is a cross-sectional view showing a typical manufacturing process of a vertical structure group III nitride-based semiconductor light emitting diode device as an example of the prior art. As shown in FIG. 15, in a typical vertical structure light emitting diode device manufacturing method, a multi-layer structure for a light emitting diode device is formed on a sapphire growth substrate 10 using MOCVD or MBE growth equipment, a reflective p-type Ohmic contact electrode structure 90 is formed on the p-type nitride-based clad layer 50, and then a supporting substrate wafer prepared separately from the growth substrate wafer is solder bonded at a temperature of less than 300 ° C. Next, the sapphire growth substrate is removed to fabricate a vertical structure light emitting diode device.

15, an undoped GaN or InGaN buffer layer 20, an n-type nitride-based cladding layer 30, and an undoped GaN-based cladding layer 30 are grown on an upper portion of a sapphire substrate 10 using an MOCVD growth equipment. A nitride-based active layer 40 formed of InGaN and GaN, and a p-type nitride-based clad layer 50 are successively grown on the p-type nitride-based cladding layer 50 (FIG. 15A) A reflective p-type ohmic contact electrode structure 90 and a soldering reaction preventive layer 100 are sequentially formed on the substrate 100 to prepare a growth substrate wafer (FIG. 15B). Thereafter, as shown in FIG. 15C, two ohmic contact electrodes 120 and 130 are formed on the upper and lower portions of the electrically conductive supporting substrate 110, respectively, and a soldering material (not shown) for bonding the multi- 140 are deposited to prepare a supporting substrate wafer. Thereafter, the surface of the grown substrate wafer The soldering material diffusion preventing layer 100 and the soldering material 140 of the ground substrate wafer are soldered and joined as shown in FIG. 15D. Thereafter, the sapphire growth substrate 10 is irradiated with a laser having a strong energy to the rear surface of the sapphire growth substrate 10, which is the rear surface of the growth substrate wafer on which the plurality of light emitting diode devices are manufactured, from the plurality of light emitting diode devices The undoped GaN or InGaN buffer layer 20 which has been damaged by laser damage ( laser lift off ) ( LLO ) is transferred to the front side until the n-type nitride clad layer 30 is exposed using a dry etching process (FIG. 15E), and an n-type ohmic contact electrode structure 80 is formed on the n-type nitride-based clad layer 30 corresponding to the plurality of light emitting diode devices (FIG. 15F). Finally, the plurality of light emitting diode elements and the electrically conductive support substrate 110 are mechanically (e.g., mechanically, mechanically, electrically, etc.) lapping, polishing, scribing, sawing, A cutting process is performed to separate the light emitting diode into a single light emitting diode device (Fig. 15G).

However, the above-described vertical process light emitting diode device manufacturing process has various problems as described below, and it is difficult to safely secure a single vertically structured light emitting diode device in a large quantity. That is, since the soldering bonding is performed in a low temperature range, a high temperature process higher than the soldering bonding temperature can not be performed in the subsequent steps, and it is difficult to realize a thermally stable light emitting diode device. Furthermore, since the thermal expansion coefficient and the lattice constant are coupled between different dissimilar wafers, thermal stress is generated at the time of bonding, which seriously affects the reliability of the light emitting diode device.

More recently, in order to solve the problems occurring in the vertical structure group III nitride-based semiconductor light-emitting diode device manufactured by the soldering bonding, a metal thick film such as Cu, Ni or the like instead of the electrically conductive support substrate formed by soldering bonding Is formed on the reflective p-type ohmic contact electrode structure 90 by an electroplating process and is partially used for product production. However, the following processes occurring in the vertical-type light emitting diode fabrication process combined with the electroplating process, that is, mechanical cutting processes such as high temperature heat treatment, lapping, polishing, scribing, sawing, Problems such as poor performance of the device and occurrence of defects still remain as a problem to be solved.

Disclosure of the Invention The present invention has been made in recognition of the above-mentioned problems, and it is an object of the present invention to provide a growth substrate having a group represented by the formula In x Al y Ga 1-xy N (0? X, 0? Y, x + y? 1) Layer structure for a light-emitting diode device composed of a p-type electrode structure including a thin film layer for a Group III nitride-based semiconductor light-emitting diode device and an effective current blocking structure, and a wafer having a sandwich structure developed by the present inventor Nitride-based semiconductor light-emitting diode device with vertical structure by combining a wafer-to-wafer bonding process and a lift-off process.

More particularly, the present invention relates to a growth substrate wafer on which a group III nitride-based semiconductor light-emitting diode device multilayer structure is formed on the growth substrate, a dissimilar support substrate which is a heat sink support, and a temporary substrate wafer The present invention provides a group III nitride-based semiconductor light-emitting diode device having a vertical structure by performing wafer bonding with a sandwich structure and then removing the growth substrate and the temporary substrate through a lift-off process, and a manufacturing method thereof .

In order to achieve the above object,

an n-type electrode structure; A multi-layer structure for a group III nitride-based semiconductor light-emitting diode device in which an n-type nitride-based clad layer, a nitride-based active layer, a p-type nitride-based clad layer, and a surface modification layer are sequentially stacked on the bottom surface of the n-type electrode structure; A p-type electrode structure including a current blocking structure in the form of a trench and an electrode thin film layer on the top of the multilayer structure for the light emitting diode; A wafer bonding layer formed on a bottom surface of the p-type electrode structure; A heat sink support formed on a bottom surface of the wafer bonding layer; And a p-type ohmic contact electrode pad formed on a bottom surface of the heat sink support.

In the group III nitride-based semiconductor light-emitting diode device of the vertical structure of the present invention, the surface modification located on the upper surface of the multi-layer structure for the group III nitride-based semiconductor light-emitting diode device includes a superlattice structure, Type conductivity group of InGaN, GaN, AlInN, AlN, InN, AlGaN, p-type conductivity InGaN, AlInN, InN, AlGaN or a group III nitride system having a nitrogen-polar surface. In particular, the surface modification layer of the superlattice structure is composed of nitride or carbon nitride containing Group 2, Group 3, or Group 4 element components.

In the vertical group III nitride-based semiconductor light emitting diode device of the present invention, the current blocking structure, which is a part of the p-type electrode structure, is etched in the vertical direction at least deeper than the thickness of the surface modification layer, And has a trench shape in which a part of the clad layer is exposed to the air.

In the group III nitride-based semiconductor light emitting diode device of the vertical structure of the present invention, the electrode thin film layer, which is a part of the p-type electrode structure, is formed by partially depositing an electrically conductive material film on the surface modification layer and the p- ) Or through a complete deposition.

The electrically conductive electrode thin film layer in contact with the p-type nitride-based clad layer of the multilayer structure for the light-emitting diode element forms a schottky contacting interface, but contacts the surface-modified layer of the multilayered structure for the light- The electrically conductive electrode thin film layer forms an ohmic contacting interface.

The p-type electrode structure including the current blocking structure prevents horizontal current spreading in the horizontal direction while preventing vertical current injection in one direction during vertical driving of the light emitting diode device, Thereby improving the overall performance of the LED.

In the group III nitride-based semiconductor light-emitting diode device of the vertical structure of the present invention, the p-type electrode structure has a function of preventing the current concentration phenomenon in the vertical direction and improving the reflection of light, prevention of diffusion of materials, , Or a multi-layered electrode thin film layer capable of preventing oxidation of the material.

In order to achieve the above object, the present invention provides a method of fabricating a vertical structure light-emitting diode device using a multi-layer structure for a group III nitride-based semiconductor light-emitting diode device,

A growth substrate wafer in which a multi-layer structure for a group III nitride-based light-emitting diode element comprising an n-type nitride-based clad layer, a nitride-based active layer, a p-type nitride-based clad layer and a surface- ; Forming a trench-type current blocking structure on the surface modification layer using an etching process; Forming a p-type electrode structure by grafting with the current blocking structure; Forming a wafer bonding layer on the upper surface of the p-type electrode structure; Stacking a wafer bonding layer on / below a heterogeneous support substrate that is a heat sink support; Forming a sacrificial separation layer and a wafer bonding layer on the upper surface of the temporary substrate; Forming a composite by bonding a wafer with a sandwich structure in which the growth substrate and the temporary substrate are placed on the upper and lower surfaces of the heterogeneous support substrate; Removing the growth substrate and the temporary substrate from each other in a wafer-bonded composite with the sandwich structure; Forming surface irregularities and an n-type electrode structure on the lower nitride-based clad layer of the composite from which the growth substrate has been removed; And forming a p-type ohmic contact electrode pad on the rear surface of the different support substrate of the composite from which the temporary substrate has been removed.

The current blocking structure of the p-type electrode structure formed on the surface modification layer maximizes the horizontal current spreading in the horizontal direction when the device is driven. The n-type nitride- Like electrode structure, and are disposed so as to face each other at the same position in the vertical direction.

The sacrificial separation layer of the temporary substrate wafer is made of a material which is advantageous for separating the supporting substrate. In this case, when a photon-beam having a specific energy band having a strong energy is irradiated and separated, it is preferable to use ZnO, GaN, InGaN, InN, ITO, AlInN, AlGaN, ZnInN, ZnGaN, MgGaN, etching solution, Au, Ag, Pd, SiO2, SiNx, or the like.

The heterogeneous support substrate, which is a heat-sink support, is preferably electrically or thermally conductive. In this case, the heat sink support may be a plate of Si, GaAs, Ge, SiGe, AlN, GaN, AlGaN, SiC or AlSiC and a wafer of Ni, Cu, Nb, CuW, NiW, And a foil. As shown in Fig.

The wafer bonding layer on the growth substrate, the different support substrate, and the temporary substrate is formed of an electrically conductive material having a strong bonding force at a predetermined pressure and a temperature of 200 ° C or higher. At this time, it is formed of any one selected from the group consisting of Au, Ag, Al, Rh, Cu, Ni, Ti, Pd, Pt, Cr, Sn, In, Si, Ge and metallic silicide.

The process of separating the growth substrate and the support substrate uses a chemical-mechanical polishing (CMP) process, a chemical etching process using a wet etching solution, or a thermal-chemical decomposition reaction by irradiating a strong energy photon beam.

The steps of annealing and surface treatment are introduced before and after each step as well as electrical and optical characteristics of the group III nitride-based semiconductor light-emitting diode device, as means for enhancing the mechanical bonding force between the respective layers. .

As described above, since the group III nitride-based semiconductor light-emitting diode device manufactured by the present invention has the p-type electrode structure having a current blocking structure, when the vertical-type light-emitting diode device is driven, The vertical current injection of the LEDs can be prevented, and the horizontal current spreading in the horizontal direction can be promoted, thereby improving the overall performance of the LED.

In addition, according to the method of manufacturing a vertical structure group III nitride-based semiconductor light emitting diode according to the present invention, wafer bending phenomenon at the time of wafer-to-wafer bonding and fabrication without damaging a multilayered structure of a single light emitting diode device It is possible to improve the processability and yield of a fab process.

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

1 is a cross-sectional view showing a group III nitride-based semiconductor light emitting diode device of a vertical structure according to an embodiment of the present invention.

As shown in the figure, an n-type nitride-based clad layer 301, a nitride-based active layer 401, a p-type nitride-based clad layer 501, a surface modification layer 601, Including the p-type electrode structure 701 composed of the ring structure 11 and the electrode thin film layer 12, the wafer bonding layers 901 and 902, the heat sink supporter 302 and the p-type ohmic contact electrode pad 403 The light emitting diode 1 being a light emitting element having a vertical structure is formed.

In more detail, unevenness 203 is formed on the surface of the n-type nitride-based clad layer 301, which is a light-emitting surface, advantageously effectively emitting light generated in the nitride-based active layer 401 to the outside, An n-type electrode structure 303 is formed on the n-type nitride-based clad layer 301 by an ohmic contacting interface.

Although not shown, a passivation film for protecting the nitride based active layer 401 exposed through the side surface is formed on the side surface of the light emitting diode 1 having the vertical structure. At this time, the passivation film is formed of electrically insulating oxide, nitride, or fluoride, and is formed of any one selected from the group consisting of SiNx, SiO2, and Al2O3.

The surface modification layer 601 is formed on the lower surface of the p-type nitride-based cladding layer 501 of the light emitting diode 1 having the passivation film formed thereon. The current blocking structure 11 is formed on the bottom surface of the surface modification layer 601, And the electrode thin film layer 12 are formed on the p-type electrode structure 701. [

After the n-type nitride-based clad layer 301, the nitride-based active layer 401 and the p-type nitride-based clad layer 501 are grown, the surface modification layer 601 is grown continuously in the MOCVD and MBE chambers And the surface modification layer 601 may be formed of a superlattice structure, n-type conductive InGaN, GaN, AlInN, AlN, InN, AlGaN, p-type conductive InGaN, AlInN, InN, AlGaN, And a Group III nitride system having a nitrogen-polar surface.

In particular, the surface modification layer of the superlattice structure is composed of nitride or carbon nitride containing Group 2, Group 3, or Group 4 element components.

The p-type electrode structure 701 is composed of a current blocking structure 11 and an electrode thin film layer 12. The current blocking structure 11 is etched deeper than the thickness of the surface modification layer 601, Type cladding layer 501 is formed on the p-type nitride-based cladding layer 501 which is exposed to the air and has a trench shape in which a part of the p-type nitride- The electrode thin film layer 12, which is electrically conductive, is formed by vapor deposition.

1, the electrode thin film layer 12 constituting the p-type electrode structure 701 contacts the p-type nitride-based cladding layer 501 and the surface modification layer 601 at the same time. At this time, the electrode thin film layers 12a, 12b, and 12e in contact with the p-type nitride-based clad layer 501 form a schottky contacting interface, while electrons in contact with the surface modification layer 601 The conductive material films 12c and 12d are forming an ohmic contacting interface.

Meanwhile, a part of the area 11 of the current blocking structure 701 is formed of air or an electrically insulating material.

The p-type electrode structure 701 is a multi-layered structure of a metal, an alloy, or a solid solution capable of performing high reflection to light, preventing diffusion of substances, improving adhesion of materials, Respectively.

A material diffusion barrier layer (not shown) is provided between the p-type electrode structure 701 and the wafer bonding layer 901 to prevent diffusion diffusion of materials occurring during the fabrication of vertical LEDs I will.

The material constituting the material diffusion barrier layer (not shown) is determined depending on the kind of the material constituting the p-type electrode structure 701 and the wafer bonding layer 901. For example, Pt, Pd, Cu, A metal silicide is formed of a material selected from the group consisting of Rh, Re, Ti, W, Cr, Ni, Si, Ta, TiW, TiNi, NiCr, TiN, WN, CrN, TaN, TiWN and metal silicide.

The wafer bonding layers 901 and 902 are formed of an electrically conductive material film having a strong bonding force at a predetermined pressure and a temperature of 200 DEG C or more. At this time, it is formed of any one selected from the group consisting of Au, Ag, Al, Rh, Cu, Ni, Ti, Pd, Pt, Cr, Sn, In, Si, Ge and metallic silicide.

The dissimilar support substrate, which is the heat sink support 302, is preferably electrically or thermally conductive. In this case, the heat sink support may be a plate of Si, GaAs, Ge, SiGe, AlN, GaN, AlGaN, SiC or AlSiC and a wafer of Ni, Cu, Nb, CuW, NiW, And a foil. As shown in Fig.

In the group III nitride-based semiconductor light emitting diode device of the vertical structure of the present invention, the p-type electrode structure 701 serves to prevent the current blocking and the reflection of light in the vertical direction, A separate thin film layer capable of acting as a diffusion barrier, bonding between substances and improving bonding properties, or preventing oxidation of a material.

Particularly, the light emitting diode (1) device of the vertical structure according to the embodiment of the present invention uses the interface reforming layer 601 formed on the p-type nitride-based cladding layer 501 to simultaneously form a schottky contact interface and an ohmic contact interface and includes a p-type electrode structure 701, thereby improving current spreading in the horizontal direction and increasing external light emitting efficiency.

FIG. 2 is a cross-sectional view illustrating a group III nitride-based semiconductor light emitting diode device having a vertical structure according to an embodiment of the present invention.

As shown in the figure, an n-type nitride-based clad layer 301, a nitride-based active layer 401, a p-type nitride-based clad layer 501, a surface modification layer 601, A p-type electrode structure 801 composed of a p-type ohmic contact electrode pad 403 and a p-type electrode structure 801 composed of a nickel structure 11 and an electrode thin film layer 12, wafer bonding layers 901 and 902, a heat sink support 302, A light emitting diode (2) element which is a light emitting element of a vertical structure is formed.

Although not shown, a passivation film for protecting the nitride-based active layer 401 exposed through the side surface is formed on the side surface of the light emitting diode 2 having the vertical structure. At this time, the passivation film is formed of electrically insulating oxide, nitride, or fluoride, and is formed of any one selected from the group consisting of SiNx, SiO2, and Al2O3.

A surface modification layer 601 is formed on a lower surface of the p-type nitride-based cladding layer 501 of the light emitting diode 2 having the passivation film formed thereon, and a current blocking structure 11 A p-type electrode structure 801 composed of an electrode thin film layer 12 is formed.

After the n-type nitride-based clad layer 301, the nitride-based active layer 401 and the p-type nitride-based clad layer 501 are grown, the surface modification layer 601 is grown continuously in the MOCVD and MBE chambers And the surface modification layer 601 may be formed of a superlattice structure, n-type conductive InGaN, GaN, AlInN, AlN, InN, AlGaN, p-type conductive InGaN, AlInN, InN, AlGaN, And a group III nitride system having a nitrogen-polar surface formed thereon.

The p-type electrode structure 801 is composed of a current blocking structure 11 and an electrode thin film layer 12. The current blocking structure 11 is etched deeper than the thickness of the surface modification layer 601, Type cladding layer 501 is formed on the p-type nitride-based cladding layer 501 which is exposed to the air and has a trench shape in which a part of the p-type nitride- The electrode thin film layer 12, which is electrically conductive, is formed by vapor deposition.

2, the electrode thin film layer 12 constituting the p-type electrode structure 801 contacts the p-type nitride-based cladding layer 501 and the surface modification layer 601 at the same time. At this time, the electrode thin film layers 12a, 12b, and 12e in contact with the p-type nitride-based clad layer 501 form a schottky contacting interface, while electrons in contact with the surface modification layer 601 The conductive material films 12c and 12d are forming an ohmic contacting interface.

Meanwhile, a part of the region 12 of the current blocking structure 801 is formed of an electrically conductive material.

The p-type electrode structure 801 may be a multi-layered structure of a metal, an alloy, or a solid solution capable of performing high reflection to light, preventing diffusion of materials, improving adhesion of materials, Respectively.

A material diffusion barrier layer (not shown) is formed between the p-type electrode structure 801 and the wafer bonding layer 901 so as to prevent diffusion diffusion of materials occurring during the fabrication of vertical LEDs I will.

The material constituting the material diffusion barrier layer (not shown) is determined depending on the kind of the material constituting the p-type electrode structure 801 and the wafer bonding layer 901. For example, Pt, Pd, Cu, A metal silicide is formed of a material selected from the group consisting of Rh, Re, Ti, W, Cr, Ni, Si, Ta, TiW, TiNi, NiCr, TiN, WN, CrN, TaN, TiWN and metal silicide.

In the group III nitride-based semiconductor light-emitting diode device of the vertical structure of the present invention, the p-type electrode structure 801 functions as a current blocking portion for reflecting light in the vertical direction and a reflecting portion for light, A separate thin film layer capable of acting as a diffusion barrier, bonding between substances and improving bonding properties, or preventing oxidation of a material.

Particularly, the light emitting diode (2) device of the vertical structure according to the embodiment of the present invention uses the interface reforming layer 601 formed on the p-type nitride-based cladding layer 501 to simultaneously form a schottky contact interface and an ohmic contact interface and includes the p-type electrode structure 801, thereby improving the current spreading in the horizontal direction and increasing the external light emitting efficiency.

3 to 13 are cross-sectional views illustrating a method of fabricating a group III nitride-based semiconductor light emitting diode device having a vertical structure according to an embodiment of the present invention.

3 is a cross-sectional view of a growth substrate wafer on which a multi-layer structure for a group III nitride-based semiconductor light-emitting diode device is formed on a growth substrate.

3, an n-type nitride-based cladding layer 301, a nitride-based active layer 401, and a p-type conductivity-type cladding layer 301, which are basically made of an n-type conductive single crystal semiconductor material are formed on the growth substrate 101, A p-type nitride-based cladding layer 501 made of a single-crystal semiconductor material, and an interface reforming layer 601.

More specifically, the n-type nitride-based cladding layer 301 may be composed of an n-type conductive GaN layer and an AlGaN layer, and the nitride-based active layer 401 may be a multi-quantum well And an undoped InGaN layer. The upper nitride-based cladding layer 501 may be composed of a p-type conductive GaN layer and an AlGaN layer. The n-type nitride-based cladding layer 301 and the n-type nitride-based cladding layer 301 are grown before the basic multilayer structure for the light-emitting diode element composed of the Group III nitride-based semiconductor layer described above is grown by using a well-known process such as MOCVD or MBE single crystal growth Another buffer layer such as InGaN, AlN, SiC, SiCN, or GaN is formed on the uppermost growth surface of the growth substrate 101 in order to improve lattice matching with the growth surface of the growth substrate 101 201 are preferably formed.

The interface reforming layer 601 located on the p-type nitride-based cladding layer 501 is continuously formed in a growth equipment chamber using MOCVD and MBE, which are three-group group III nitride semiconductor growth equipment, A well-known superlattice structure, n-type conductive InGaN, GaN, AlInN, AlN, InN, AlGaN, p-type conductive InGaN, AlInN, InN, AlGaN, surface of a Group III nitride system having a Group III nitride system. In particular, it is preferable that the surface modification layer of the superlattice structure is composed of nitride or carbon nitride containing Group 2, Group 3, or Group 4 element components.

FIG. 4 is a cross-sectional view after etching, which is the first process for forming a current blocking structure, which is a part of a p-type electrode structure, on an upper layer of a growth substrate wafer.

Referring to FIG. 4, the p-type nitride-based cladding layer 501 is exposed to air by etching deeper than the thickness h of the interface reforming layer 601 in the vertical direction.

FIG. 5 is a cross-sectional view showing deposition of an electrically conductive material film, which is a second process for forming an electrode thin film layer which is a part of a p-type electrode structure of a growth substrate wafer.

5, the electrode thin film layer 12, which is electrically conductive, is deposited on the p-type nitride-based clad layer 501 exposed on the atmosphere and the interface reforming layer 601 to complete the p-type electrode structure 701 do. In particular, the p-type electrode structure 701 can be divided into six regions. The electrode thin film layers 12a, 12b and 12e contacting the p-type nitride-based cladding layer 501 exposed to the atmosphere are schottky contacting and the electrode thin film layers 12c and 12d contacting the upper surface of the interface reforming layer 601 form an ohmic contacting interface.

In addition, a part of the region 11 of the p-type electrode structure 701 may be composed of an oxide, an oxide, or a fluoride, which is air or electrically insulating.

6 to 7 are cross-sectional views of a wafer bonding layer formed on a p-type electrode structure.

Referring to FIG. 6, a wafer bonding layer 901, which is electrically conductive, is deposited on a portion of the upper portion of the p-type electrode structure 701. At this time, the wafer bonding layer 901 may be a multi-layer (metal, alloy, or solid solution) layer capable of performing high reflection to light, preventing diffusion of materials, ). In this case, it is formed of any one selected from the group consisting of Au, Ag, Al, Rh, Cu, Ni, Ti, Pd, Pt and Cr.

Referring to FIG. 7, a wafer bonding layer 901, which is electrically conductive, is deposited over the entire region of the p-type electrode structure 701. At this time, the wafer bonding layer 901 may be a multi-layer (metal, alloy, or solid solution) layer capable of performing high reflection to light, preventing diffusion of materials, ). In this case, it is formed of any one selected from the group consisting of Au, Ag, Al, Rh, Cu, Ni, Ti, Pd, Pt and Cr.

FIG. 8 is a cross-sectional view of a heterogeneous support substrate wafer and a temporary substrate wafer, which are heat sink supports developed by the present inventors, respectively.

8A, the heterogeneous support substrate wafer is composed of a heterogeneous support substrate 302, which is a heat sink support, and two wafer bonding layers 902 and 903 formed on the upper / lower surface of the heterogeneous support substrate 302 .

The dissimilar support substrate 302, which is a heat sink support of the heterogeneous support substrate wafer, preferably has electrical or thermal conductivity. In this case, the heat sink support may be a plate of Si, GaAs, Ge, SiGe, AlN, GaN, AlGaN, SiC or AlSiC and a wafer of Ni, Cu, Nb, CuW, NiW, The foil is preferentially selected.

The wafer bonding layers 902 and 903 formed on the upper surface and the lower surface of the different support substrate 302 as the heat sink supports of the different support substrate wafer are formed of an electrically conductive material film having a strong bonding force at a predetermined pressure and a temperature of 200 ° C or higher . At this time, it is formed of any one selected from the group consisting of Au, Ag, Al, Rh, Cu, Ni, Ti, Pd, Pt, Cr, Sn, In, Si, Ge and metallic silicide.

As shown in FIG. 8B, the temporary substrate wafer is composed of a temporary substrate 170, a sacrificial separation layer 180, and a wafer bonding layer 904.

The temporary substrate 170 of the temporary substrate wafer may have a transmittance of 70 percent or more in an optical wavelength region of 500 nanometers or less or a difference in thermal expansion coefficient between the growth substrate 101 and the growth substrate 101 is 2 pixels ppm / DEG C) or less is preferable. In this case, the temporary substrate 170 is formed of a material such as sapphire (Al ₂ O ₃ ), silicon carbide (SiC), gallium nitride (GaN), indium gallium nitride (InGaN), aluminum gallium nitride (AlGaN) and is formed of any one selected from the group consisting of spinel, lithium niobate, neodymium gallate, and gallium oxide (Ga ₂ O ₃ ).

The sacrificial separation layer 180 of the temporary substrate wafer is made of a material which is advantageous for separating the supporting substrate. In this case, when a photon-beam having a specific energy band having a strong energy is irradiated and separated, it is preferable to use ZnO, GaN, InGaN, InN, ITO, AlInN, AlGaN, ZnInN, ZnGaN, MgGaN, etching solution, Au, Ag, Pd, SiO2, SiNx, or the like.

The wafer bonding layer 904 of the temporary substrate wafer is formed of an electrically conductive material film having a strong bonding force at a predetermined pressure and a temperature of 200 ° C or higher. At this time, it is formed of any one selected from the group consisting of Au, Ag, Al, Rh, Cu, Ni, Ti, Pd, Pt, Cr, Sn, In, Si, Ge and metallic silicide.

FIG. 9 is a cross-sectional view showing a state in which a wafer bonding layer on upper and lower surfaces of a different support substrate, a wafer bonding layer of a growth substrate and a temporary substrate are aligned and then bonded to each other by a sandwich structure to form a composite body.

9, the wafer bonding layer 901 of the growth substrate wafer, the wafer bonding layer 902 on the upper surface of the heterogeneous support substrate wafer, the wafer bonding layer 903 on the lower surface of the heterogeneous support substrate wafer, The wafer bonding layer 904 of the wafer is brought into contact with each other to form the composite 3 of the sandwich structure by the wafer bonding process.

The wafer bonding may be performed by applying a predetermined hydrostatic pressure at a temperature of room temperature to 700 ° C or lower and in an atmosphere of vacuum, oxygen, argon, or nitrogen gas desirable.

Further, surface treatment and heat treatment are performed to improve the mechanical bonding force between the two materials (901/902, 903/904) and the formation of the ohmic contact interface before / after performing the wafer bonding process. Process may be introduced.

10 is a cross-sectional view showing a process of lifting off a growth substrate and a temporary substrate, respectively, in a composite of wafer bonded sandwich structures.

As shown, the process of lifting off the growth substrate 101, which is part of the growth substrate wafer, and the temporary substrate 170 of the temporary substrate wafer in the composite sandwich structure of the wafer bonded sandwich structure, A laser beam 103 which is a photon beam having a predetermined wavelength is irradiated onto the back surface of the optically transparent growth substrate 101 and the temporary substrate 170 to form an interface between the growth substrate 101 and the lower nitride- A thermal-chemical decomposition reaction is generated to separate the growth substrate 101. Further, a thermal-chemical decomposition reaction is generated at the interface between the temporary substrate 170 and the sacrificial separation layer 180 to separate and remove the temporary substrate 170.

Also, depending on the physical and chemical properties of the growth substrate 101 and the temporary substrate 170, chemical-mechanical polishing or chemical wet etching using an etching solution may be used.

11 is a cross-sectional view of a composite in which surface irregularities are introduced on the lower nitride-based clad layer after the growth substrate of the growth substrate wafer and the temporary substrate of the temporary substrate wafer are separated.

11, after the growth substrate 101 and the temporary substrate 170 are completely and completely removed, the lower nitride-based cladding layer 301 is removed from the atmosphere (see FIG. 11) by chemical wet etching or dry etching air, and recesses and protrusions 203 are formed on the surface of the lower nitride-based clad layer 301 exposed to the atmosphere by wet or dry etching.

12 is a cross-sectional view of a composite in which an n-type electrode structure is formed on a part of the upper surface of the lower nitride-based clad layer on which surface irregularities are formed.

Referring to FIG. 12, a partial n-type electrode structure 303 is formed on a part of a top surface of a lower nitride-based clad layer 301 having surface irregularities 203 formed thereon. The n-type electrode structure 303 is preferably formed of a reflective material having a reflectance of 50% or more in a wavelength band of 600 nm or less. In this case, the n-type electrode structure 303 can be made of Cr / Al / Cr / Au.

The n-type electrode structure 303 has the same shape and dimensions as those of the current blocking structure 11 of the p-type electrode structure formed on the upper surface of the upper nitride-based clad layer 501, Direction at the same position.

13 is a cross-sectional view of a light emitting diode device having a vertical structure completed after a p-type ohmic contact electrode pad is formed on the back surface of a heat sink support.

Referring to FIG. 13, a p-type ohmic contact electrode pad 403 is formed on the back surface of the heat sink support 302, on which the temporary substrate 170 is separated and removed. Finally, a vertical structure light emitting diode device is completed.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention as defined by the appended claims. something to do.

FIG. 1 is a cross-sectional view showing a group III nitride-based semiconductor light emitting diode device of a vertical structure according to a first embodiment of the present invention,

FIG. 2 is a sectional view showing a group III nitride-based semiconductor light emitting diode device of a vertical structure according to a second embodiment of the present invention,

3 to 13 are cross-sectional views illustrating a method of fabricating a group III nitride-based semiconductor light-emitting diode device having a vertical structure according to an embodiment of the present invention,

FIG. 14 is a schematic structural cross-sectional view of a group III nitride-based semiconductor light-emitting diode device of a horizontal structure according to the prior art,

15 is a cross-sectional view of a group III nitride-based semiconductor light-emitting diode device in a vertical structure according to the prior art.

Claims

an n-type electrode structure;

A n-type nitride-based clad layer, a nitride-based active layer, a p-type nitride-based clad layer, and a surface modification layer are sequentially stacked on the n-type electrode structure, a multilayer structure for the group III nitride-

A p-type electrode structure composed of a current blocking structure in the form of a trench and an electrode thin film layer on the multi-layer structure for the light emitting diode;

A wafer bonding layer formed below the p-type electrode structure;

A heat sink support formed on a bottom surface of the wafer bonding layer; And

And a p-type ohmic contact electrode pad formed on the bottom surface of the heat sink support,

Wherein the electrode thin film layer contacts the p-type nitride-based cladding layer and the surface modification layer at the same time,

Wherein a part of the p-type electrode structure is formed of air or an insulating material, and a vertical structure of the group III nitride-based semiconductor light emitting diode device.

The method according to claim 1,

The surface modification layer may be formed of a superlattice structure, n-type conductivity of InGaN, GaN, AlInN, AlN, InN, AlGaN, p-type conductivity of InGaN, AlInN, InN, AlGaN or nitrogen polarity. Group III nitride-based semiconductor light-emitting diode device having a vertical structure composed of a group III nitride-based group III nitride-based semiconductor light-emitting diode device having a surface.

3. The method of claim 2,

Wherein the surface modification layer of the superlattice structure comprises a group III nitride-based semiconductor light-emitting diode device (hereinafter, referred to as " superlattice structure ") having a vertical structure composed of nitride or carbon nitride containing Group 2, Group 3, .

The method according to claim 1,

Wherein the upper surface of the current blocking structure is disposed higher than the upper surface of the surface modification layer, and the upper surface and the lower surface of the current blocking structure have different vertical lengths.

delete

The method according to claim 1,

The refilled electroconductive electrode thin film layer in contact with the p-type nitride-based clad layer forms a schottky contacting interface, while the electrically conductive electrode thin film layer in contact with the surface modification layer has an ohmic contact interface ohmic contacting interface of a group III nitride-based semiconductor light-emitting diode device.

The method according to claim 1,

The p-type electrode structure has a function of preventing a current concentration phenomenon in the vertical direction, and a separate multi-layered structure capable of performing high reflection to light, preventing diffusion of materials, improving adhesion of materials, layer nitride semiconductor light-emitting diode device including a multi-layer electrode thin film layer.

The method according to claim 1,

The heat-sink support may include a wafer including at least one of Si, GaAs, Ge, SiGe, AlN, GaN, AlGaN, SiC, and AlSiC, and at least one of Ni, Cu, Nb, CuW, NiW, NiCu And a plate or a foil including at least one of the first group III nitride-based semiconductor light-emitting diode device and the second group III nitride-based semiconductor light-emitting diode device.

A growth substrate wafer in which a multi-layer structure for a group III nitride-based light-emitting diode device consisting of an n-type nitride-based clad layer, a nitride-based active layer, a p-type nitride-based clad layer and a surface- Preparing;

Forming a trench-type current blocking structure on the surface modification layer using an etching process;

Forming a p-type electrode structure by grafting with the current blocking structure;

Forming a wafer bonding layer on the upper surface of the p-type electrode structure;

Stacking a wafer bonding layer on / below a heterogeneous support substrate that is a heat sink support;

Forming a sacrificial separation layer and a wafer bonding layer on the upper surface of the temporary substrate;

Forming a composite by bonding wafers with a sandwich structure in which the growth substrate and the temporary substrate are placed on the upper and lower surfaces of the heterogeneous support substrate;

Removing the growth substrate and the temporary substrate from each other in a wafer-bonded composite with the sandwich structure;

Forming surface irregularities and an n-type electrode structure on the lower nitride-based clad layer of the composite from which the growth substrate has been removed;

And forming a p-type ohmic contact electrode pad on the rear surface of the hetero-substrate of the composite from which the temporary substrate has been removed.

10. The method of claim 9,

The nitride-based semiconductor light emitting device according to claim 1, wherein the step of forming the trench-type current blocking structure exposes the p-type nitride-based cladding layer to the atmosphere with the etching depth being at least deeper than the surface modification layer thickness. / RTI >

10. The method of claim 9,

A vertical structure in which an optical reflective layer, a diffusion barrier layer, a mechanical adhesive layer, or an oxidation protection layer is added in the step of forming the p-type electrode structure Group III nitride based semiconductor light emitting diode device.

10. The method of claim 9,

A group III nitride-based semiconductor light emitting element having a vertical structure in which the same dimension and shape as the current blocking structure are formed in the step of forming the n-type electrode structure, and is arranged so as to face the same position as the current blocking structure in the vertical direction / RTI >

10. The method of claim 9,

Wherein the sacrificial separation layer is an oxide, a nitride, or a metal, which is advantageous for lift-off the supporting substrate.

10. The method of claim 9,

When the sacrificial separation layer is separated and irradiated with a photon-beam having a specific energy band having a strong energy, it is preferable that the sacrificial separation layer is formed of a group consisting of ZnO, GaN, InGaN, InN, ITO, AlInN, AlGaN, ZnInN, ZnGaN, Wherein the group III nitride-based semiconductor light-emitting diode device has a vertical structure formed of any one of the selected Group III nitride-based semiconductor light-emitting diode devices.

10. The method of claim 9,

The method of manufacturing a Group III nitride-based semiconductor light-emitting diode device according to any one of claims 1 to 5, wherein the Group III nitride-based semiconductor light-emitting diode device is formed of any one selected from the group consisting of Au, Ag, Pd, SiO 2 and SiN x when etched in a wet etching solution.

10. The method of claim 9,

Wherein the temporary substrate has a difference in thermal expansion coefficient of 2 ppm (ppm) or less from the growth substrate.

10. The method of claim 9,

Wherein the heterogeneous support substrate has an excellent electrical or thermal conductivity. 2. The method of claim 1, wherein the heterogeneous support substrate has an electrical or thermal conductivity.

10. The method of claim 9,

Wherein the wafer bonding layer formed on the growth substrate and the upper portion of the support substrate is formed of an electrically conductive material having a strong bonding force at a predetermined pressure and a temperature of 200 ° C or higher.

10. The method of claim 9,

The wafer bonding layer may be formed of any one selected from the group consisting of Au, Ag, Al, Rh, Cu, Ni, Ti, Pd, Pt, Cr, Sn, In, Si, Ge and metallic silicide. Group III nitride based semiconductor light emitting diode device.

10. The method of claim 9,

The process of separating the growth substrate and the support substrate may be performed by a chemical mechanical polishing (CMP) process, a chemical etching process using a wet etching solution, or a vertical process group 3 using a thermo-chemical decomposition reaction by irradiating a strong- A method of fabricating a semiconductor light emitting diode device.

10. The method of claim 9,

The annealing process and the surface treatment process are introduced before and after each step as means for enhancing not only the electrical and optical characteristics of the group III nitride-based semiconductor light-emitting diode device but also the mechanical bonding force between the respective layers A method for manufacturing a group III nitride-based semiconductor light-emitting diode device having a vertical structure.