KR100794304B1 - Optical device and Method of fabricating the same - Google Patents

Abstract

   The present invention relates to an optical device of the present invention and a method for manufacturing the same, specifically, a transparent conductive nitrogen having a larger work function and excellent light transmittance than a transparent conducting oxide (TCO) and a transparent conducting nitride (TCN). The present invention relates to an optical device using a transparent conducting oxynitride (TCON) as a transparent electrode, and a method of manufacturing the same.

The present invention is applied to a nitride-based light emitting device, the nitride-based light emitting device is a substrate (substrate), N- type nitride cladding layer ( N- type nitride cladding layer), active layer (active layer), the nitride-based cladding layer ( P- type nitride cladding layer), and pihyeong multi-ohmic contact layer (P -type multi ohmic contact layer), and this is laminated in sequence, wherein one pihyeong multi-ohmic contact layer is transparent conducting oxides of nitrogen with excellent advantage as a transparent conductive electrode (TCON ) It is formed of a thin film having at least one thin film alone, or a thin film to which dopant is added to improve electrical conductivity. More preferably, the multilayered ohmic contact layer is formed of a metal, an alloy, a solid solution, a general conductive oxide, a transparent conductive oxide (TCO), or a transparent conductive nitride, in addition to the transparent conductive nitrogen oxide. It is a laminated structure in which phases advantageous for forming an ohmic contact interface are formed in the upper portion of a semiconductor clad layer such as (TCN).

According to the present invention, first of all, the contact interface with the P- type nitride cladding layer is improved, which not only shows excellent current-voltage characteristics but also has high TCON. The light transmittance can increase the external light emitting efficiency of the device.

Transparent conductive nitrogen oxide, multiple ohmic contact layer, nitride cladding layer, light emitting device

Description

 Optical device and method of manufacturing the same

 1 is a cross-sectional view illustrating a top-emitting light emitting diode (TELED) to which a multi-type ohmic contact electrode structure according to a first embodiment of the present invention is applied;

  FIG. 2 is a cross-sectional view illustrating a top-emitting light emitting diode (TELED) to which a multi-type ohmic contact electrode structure according to a second exemplary embodiment of the present invention is applied.

FIG. 3 is a cross-sectional view illustrating various stacked shapes of multi- p ohmic contact layers formed on the upper nitrided cladding layer according to the first and second embodiments of the present invention.

4 is a multi-p ohmic contact electrode structure (multi P- type ohmic contact) formed after the introduction of nanometer scale particles in the upper layer of the nitride-based cladding layer according to the first and second embodiments of the present invention. This is a cross-sectional view showing various stacked forms of layers).

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device and a method of manufacturing the same, and more particularly, to a figure of better performance as a transparent conductive thin film material (FOM) than a transparent conducting oxide or nitride (TCO or TCN). In the optical device and a method for manufacturing the same, a transparent conducting oxynitride (TCON) having low electrical resistance and high light transmittance is applied as a P- type transparent electrode. It is about.

   Currently, transparent conducting thin films are widely used in the optoelectronic field, the display field, and the energy industry using organic and inorganic materials. In the field of semiconductor light emitting devices such as light emitting diodes (LEDs) and laser diodes (LDs), in addition to smooth carrier injection and current spreading, the semiconductor light emitting device active layer The photon should be a material having both electrical and optical properties so as to emit as much light as possible to the outside.

   In particular, many research institutes at home and abroad related to the group III nitride light emitting diodes (III nitride LEDs), which are spotlighted as next generation lighting sources, are actively researching to develop high quality transparent conductive thin films for light emitting devices. As a result, transparent conductive materials such as indium tin oxide (ITO), which are widely known, and doped zinc oxide (ZnO), have been recently used as direct electrodes of nitride-based light emitting diodes (LEDs). It is used.

   Among the various transparent conductive oxides (TCO), the most actively researched materials are indium oxide (In2O3), tin oxide (SnO2), cadmium oxide (CdO), zinc oxide (ZnO), and indium tin oxide (ITO). In addition, since they have relatively small work function values and rapid light transmittance reduction characteristics in the wavelength range of visible and ultraviolet light, they have many problems when used as transparent electrodes of nitride-based light emitting diodes (LEDs). Summarizing the problems experienced by these materials which are partially used in current nitride based light emitting diodes are as follows.

First, conventional transparent conductive oxides (TCOs) or nitrides (TCNs) have a much smaller work function than the work function of the P- type nitride-based cladding layer. When used as a P- type ohmic contact layer, a high energy barrier to carrier flow is formed at the interface, which makes it difficult to inject holes smoothly. There are many difficulties to implement.

   Second, the conventional transparent conductive oxide (TCO) or nitride (TCN) has a low light transmittance below the wavelength range with blue light among the light generated and emitted from the nitride-based LED, so it is applied to the device emitting light in the short wavelength region Difficult to do

   Third, the conventional transparent conductive oxide (TCO) or nitride (TCN) has a large value close to the refractive index of the light (about 2), so even through the transparent conductive oxide electrode to emit light into the air There is difficulty.

   Currently, nitride semiconductors are used to commercialize electronic devices such as transistors and photo-detectors, as well as optical devices such as light emitting diodes (LEDs) and laser diodes (LDs). In order to implement an optoelectronic device having even better performance than the present, contact control technology, which is an interface property between a group III nitride semiconductor and an electrode, is very important.

   A light emitting diode (LED) using a nitride semiconductor composed of indium nitride (InN), gallium nitride (GaN), and aluminum nitride (AlN) is a top-emitting light emitting diode (TELED) and a flip chip. It is classified as a flip-chip light emitting diode (FCLED).

   Currently widely used TELED is formed so that the light generated through the P-type ohmic contact layer (P-type ohmic contact layer) in contact with the nitride nitride-based cladding layer. On the other hand, FCLED, which is manufactured with large area and high-capacity light emitting device by using heat dissipation which is relatively easy in driving than TELED, is transparent by using highly reflective type ohmic contact layer. It emits light through a sapphire substrate. Light emitting diodes using group III-nitride semiconductors have a low hole concentration in the nitride-based cladding layer, which makes it difficult to transport holes that are easily carriers in all directions in the nitride-based cladding layer. In order to make a high quality optoelectronic device using a nitride-based cladding layer, a good quality ohmic contact layer having excellent current spreadability is absolutely required. In other words, in order to realize a high quality next-generation light emitting diode using a group III nitride semiconductor, it has excellent current spreading in the lateral direction and hole injection in the vertical direction, and at the same time in the visible and short wavelength region An ohmic contact electrode structure having excellent optical properties (light transmittance or light reflectance) with respect to light should be developed / formed.

   The most widely used ohmic contact layer for TELED is formed of nickel-gold (Ni-Au) oxidized on the nitride-based cladding layer. A thin film layer of Ni-Au was sequentially deposited on the nitride nitride clad layer using an e-beam evaporator, and then heat-treated in an oxygen (O2) atmosphere to obtain a specific contact resistance of about 10-3 to 10-4 Ω㎠. It is known to form a semi-transparent ohmic contact layer with specific ohmic contact resistance. The oxidized Ni-Au ohmic contact layer has a low light transmittance of 75% or less at 460 nanometers (nm) or less, which is a wavelength range of blue light, and thus is not suitable for the next type ohmic contact layer for nitride-based light emitting diodes.

   The low specific contact resistance of the oxidized semi-transparent Ni-Au ohmic contact layer is characterized by gallium nitride (GaN) and ohmic forming a type nitride nitride cladding layer when subjected to heat treatment in a temperature of 500 ° C. to 600 ° C. and an oxygen (O 2) gas atmosphere. In the contact interface with the nickel (Ni) metal applied as the contact layer, the nickel oxide (NiO), a semiconductor oxide, is formed in an island shape, and at the same time, nickel oxide (NiO) in which gold (Au) metal is distributed in an island shape. It was found to have a structure covering the upper layer and between). In particular, nickel oxide (NiO) is formed when Ni-Au thinly deposited on the upper layer of the nitride-based cladding layer is heat-treated in an oxygen (O 2) atmosphere, and the height of the Schottky barrier formed between gallium nitride (GaN) and the electrode is increased. It reduces the width (Schottky barrier height & width: SBH & SBW) and through this electrode, the carrier can be easily supplied to the device when an external voltage is applied. The reason why the thin film layer made of thin Ni-Au oxidized as described above showed an excellent ohmic behavior, which is an excellent electrical property, is not only a role of nickel oxide (NiO), which leads to reduction of SBH & SBW, but also gold, which leads to the improvement of current spreading in the lateral direction. (Au) A metal component.

   In addition to the mechanism for the ohmic behavior of the Ni-Au thin film layer, a thin nickel-gold thin film layer is formed on the upper layer of the nitride-based cladding layer and then heat treated to form an effective hole concentration in the nitride-based cladding layer. This effective hole on the surface of the nitride-based cladding layer is removed through a reactivation process that removes the Mg-H intermetallic compound that limits the hole concentration, thereby increasing the magnesium dopant concentration on the surface of the nitride-based cladding layer. It is understood that a concentration of 1018 or more causes tunneling transport between the nitride-based cladding layer and the ohmic contact layer containing nickel oxide, thereby exhibiting ohmic behavior with low specific contact resistance.

   However, TELEDs using semi-transparent, ohmic contact electrode structures formed of oxidized Ni-Au contain gold (Au) metal components that inhibit light transmission, that is, absorb a large amount of light generated in the LED active layer. The low efficiency limits the application of large-area and high-capacity high-brightness LED applications in the future. Recently, in order to overcome some of the limitations of the devices of the top-emit type and flip chip light emitting diodes, transparent conductive oxides having an excellent light transmittance, for example, than the semi-transparent Ni-Au structure, which is conventionally used as an ohmic contact layer, for example, The research aimed at using ITO is described in T. Margalith et al., Appl. Phys. Lett. Vol. 74. p3930 (1999). Recently, the use of the ITO ohmic contact layer to implement TELED exhibiting improved output power compared to the conventional nickel-gold structure is described in Solid-State Electronics vol.47. p849 (2003). However, the ohmic contact layer of such a structure can increase the output of the light emitting diode, but has a problem of showing a relatively high operating voltage. The root cause is relatively small compared to the work function of the nitride-based semiconductor as described above. Because of the high value, a high Schottky barrier is formed at the interface between the nitride-based cladding layer and the ITO ohmic contact layer, which makes it difficult to inject a carrier smoothly, causing a large amount of heat generation and a short device life.

   As described above, when TCOs such as ITO and ZnO are directly deposited / contacted on the upper layer of the nitride-based cladding layer, high and thick SBH and SBW are generated, respectively, to prevent the formation of a high quality ohmic contact layer. GIST's research group inserts a thin second TCO layer between the nitride nitride cladding layer and the TCOs and heats them to produce particles of less than 100 nanometers (nm). The results of the formation of the layers have been published. The nanoparticles generated at these interfaces generate an electric field at the interface, and this induced electric field lowers the height and width of the schottky barrier and converts the TCO electrode exhibiting schottky behavior into ohmic behavior. Was analyzed.

The present invention was devised to fabricate an optical device having a high quality, high transparency, multi- p ohmic contact layer, and has been commonly known as a general transparent conductive oxide (TCO) such as ITO and ZnO, or Inherent high quality that can provide low specific contact resistance and high light transmittance by using transparent conductive nitrogen oxide (TCON) which has better advantages as transparent conductive thin film material than transparent conductive nitrides (TCN) such as TiN. The purpose of the present invention is to develop a transparent conductive multi-type ohmic contact electrode structure, and to provide an optical device and a manufacturing method using the same.

In order to achieve the above object, a nitride-based light emitting device according to an embodiment of the present invention includes a nitride-based nitride layer between an N- type nitride cladding layer and a P- type nitride cladding layer. In a nitride-based light emitting device (especially a light emitting diode) having a nitride active layer, a multiple-type ohmic including at least one or more transparent conducting oxynitride (TCON) above the nitride-based cladding layer. A contact layer (multi P- type ohmic contact layer), and the transparent conductive nitrogen oxide (TCON) is indium (In), tin (Sn), zinc (Zn), cadmium (Cd), gallium (Ga), aluminum (Al), magnesium (Mg), titanium (Ti), molybdenum (Mo), nickel (Ni), copper (Cu), silver (Ag), gold (Au), platinum (Pt), rhodium (Rh), At least one component of iridium (Ir), ruthenium (Ru), or palladium (Pd) metals Refers to a substance formed by combining oxygen (O) and nitrogen (N) at the same time. Preferably, the transparent conductive nitrogen oxide (TCON) may further include other metal components as dopants in order to control electrical properties. Herein, the metals applied as dopants are applied with elements classified as metals on the periodic table of elements. In addition to the metal material to be applied as a dopant, it is preferable to include fluorine (F) and sulfur (S). In addition, the addition ratio of the dopant to the transparent conductive nitrogen oxide (TCON) is preferably applied to 0.001 to 20 weight percent (wt.%).

   According to another aspect of the present invention, in addition to the transparent conductive nitrogen oxide (TCON), the multi-type ohmic contact layer may include metals and metals that are advantageous for forming ohmic contact electrodes on the upper part of the nitride-based cladding layer as follows. It can be formed by incorporating a parent alloy / solid solution, a common conducting oxide, a transparent conductive oxide (TCO), a transparent conductive nitride (TCN), and the like regardless of the stacking order.

   Metals and alloys / solid solutions based on these metals: platinum (Pt), palladium (Pd), nickel (Ni), gold (Au), rhodium (Rh), ruthenium (Ru) ), Iridium (Ir), silver (Ag), zinc (Zn), magnesium (Mg), beryllium (Be), copper (Cu), cobalt (Co), tin (Sn), rare earth metals Or an alloy / solid solution based on these metals.

   General conducting oxide: Nickel oxide (Ni-O), rhodium oxide (Rh-O), ruthenium oxide (Ru-O), iridium oxide (Ir-O), copper oxide (Cu-O), cobalt Oxide (Co-O), tungsten oxide (WO), or titanium oxide (Ti-O).

   Transparent conductive oxide (TCO): indium oxide (In2O3), tin oxide (SnO2), indium tin oxide (ITO), zinc oxide (ZnO), magnesium (MgO), cadmium oxide (CdO), magnesium zinc oxide (MgZnO) , Indium zinc oxide (InZnO), indium tin oxide (InSnO), copper aluminum oxide (CuAlO2), silver oxide (Ag2O), gallium oxide (Ga2O3), zinc tin oxide (ZnSnO), zinc indium tin oxide (ZITO), or Still other oxides to which these transparent conductive oxides are combined.

   Transparent conductive nitride (TCN): titanium nitride (TiN), chromium nitride (CrN), tungsten (WN), tantalum (TaN), niobium (NbN).

   More preferably, a third material, ie, a dopant, may be added to the above-described oxides and nitrides in order to improve the electrical properties of these materials.

In addition, in order to achieve the above object, a method of manufacturing a group III nitride light emitting device according to an embodiment of the present invention includes an N- type nitride cladding layer and a P- type nitride cladding layer. In the manufacturing method of the nitride-based light emitting device having a nitride active layer (nitride active layer) between the cladding layer,

   end. At least one transparent conducting oxynitride (TCON) in the upper layer of the nitride-based cladding layer of the light emitting structure in which the en-type nitride-based cladding layer, the active layer, and the nitride-based cladding layer are sequentially stacked on the substrate. Stacking the multi-type ohmic contact electrode structures;

   I. And heat treating the stacked multilayer electrodes to form a high quality ohmic contact layer. The transparent conductive nitrogen oxide (TCON) may include indium (In), tin (Sn), and the like. Zinc (Zn), Cadmium (Cd), Gallium (Ga), Aluminum (Al), Magnesium (Mg), Titanium (Ti), Molybdenum (Mo), Nickel (Ni), Copper (Cu), Silver (Ag) At least one of gold (Au), platinum (Pt), rhodium (Rh), iridium (Ir), ruthenium (Ru), or palladium (Pd) metals as a main component, and oxygen (O) and nitrogen ( N) refers to a material formed by binding at the same time.

   The heat treatment step is preferably performed for 10 seconds to 3 hours at 100 to 800 degrees. The heat treatment may include at least one of nitrogen (N 2), oxygen (O 2), hydrogen (H 2), air, argon (Ar), or helium (He) gas in the reactor in which the ohmic contact electrode structure is embedded. It is carried out in a gas atmosphere.

   Hereinafter, with reference to the accompanying drawings will be described in detail a preferred group group III nitride-based light emitting device and a method of manufacturing the same.

   In the drawings referred to in the following description, elements having the same function are denoted by the same reference numerals.

   1 is a cross-sectional view illustrating a light emitting diode to which a multiple multiple ohmic contact electrode structure according to a first embodiment of the present invention is applied.

   In detail, FIG. 1 (a) is a cross-sectional view showing a group III nitride-based top-emitting type light emitting diode (TELED) stacked / grown on an upper layer of sapphire 10, which is an insulating growth substrate, whereas FIG. Electrically conductive substrates, namely silicon carbide (SiC), zinc oxide (ZnO), silicon (Si), gallium arsenide (GaAs), or electroplating / bonding transfers known in many literatures, etc. A cross-sectional view showing a group III-nitride-based top-emitting light emitting diode (TELED) formed on an upper layer of a conductive material layer such as metal (Cu, Ni, Al, etc.) or alloy formed by the method.

   Referring to the drawings, the light emitting device includes a substrate 10, a low temperature nucleation layer 20, a nitride buffer layer 30, an N-type nitride cladding layer 40, a nitride-based active layer 50, and a nitride-based cladding layer ( 60), a multi-layered ohmic contact layer 70 is laminated in this order. Reference numeral 80 denotes a shaped electrode pad, and 90 denotes an N-type electrode pad.

   The substrate 10 to the nitride nitride cladding layer 60 correspond to the light emitting structure, and the multilayer structure stacked on the upper portion of the nitride nitride cladding layer 60 corresponds to the electrode structure.

   The substrate 10 may be formed of sapphire (Al 2 O 3), silicon carbide (SiC), zinc oxide (ZnO), silicon (Si), gallium arsenide (GaAs), or electroplating / bonding transfer (also known in many literatures). It is preferably formed of any one of materials such as metal (Cu, Ni, Al, etc.) or alloy (alloy) formed by a bonding transfer method.

   The low temperature nucleation layer 20 is preferably amorphous gallium nitride (GaN) or aluminum nitride (AlN) formed at a low temperature of 700 degrees or less, and may be omitted in some cases.

   Each layer from the nitride buffer layer 30 to the nitride nitride cladding layer 60 is formed on the basis of any compound selected from AlxInyGazN (x, y, z: integer), which is a general formula of a group III nitride compound, The dopant is added to the nitride cladding layer 40 and the nitride nitride cladding layer 60.

   In addition, the nitride-based active layer 50 may be a variety of known methods such as monolayer, multi quantum well (MQW), multi quantum dot / wire, or a layer in which quantum dots / lines and wells are mixed. It may be configured as. For example, when a gallium nitride (GaN) compound is applied, the buffer layer 30 is formed of GaN, and the N-type nitride cladding layer 40 is formed by adding Si, Ge, Se, Te, etc. to GaN as an n-type dopant. The active layer is formed of InGaN / GaN MQW or AlGaN / GaN MQW, and the nitride-based cladding layer 60 is formed by adding Mg, Zn, Ca, Sr, Ba, etc. to GaN as a dopant.

   An en-type ohmic contact layer (not shown) may be interposed between the en-type nitride cladding layer 40 and the en-type electrode pad 90, and the en-type ohmic contact layer is formed by sequentially stacking titanium (Ti) and aluminum (Al). Various known structures such as a layer structure can be applied.

   As described above, the multiple multi-ohmic contact layer 70, which is the core technology of the present invention, has a multi-layered ohmic including at least one or more transparent conducting oxynitride (TCON) on the upper layer of the nitride-based cladding layer 60. The transparent conductive nitrogen oxide (TCON) is provided with a contact layer 70, and indium (In), tin (Sn), zinc (Zn), cadmium (Cd), gallium (Ga), aluminum (Al), magnesium ( Mg), titanium (Ti), molybdenum (Mo), nickel (Ni), copper (Cu), silver (Ag), gold (Au), platinum (Pt), rhodium (Rh), iridium (Ir), rousse It refers to a material formed by combining at least one or more components of nium (Ru) or palladium (Pd) metals with oxygen (O) and nitrogen (N) necessarily bonded at the same time. Preferably, the transparent conductive nitrogen oxide (TCON) may further include other metal components as dopants in order to control electrical properties. Herein, the metals applied as dopants are applied with elements classified as metals on the periodic table of elements. In addition to the metal material to be applied as a dopant, it is preferable to include fluorine (F) and sulfur (S). In addition, the addition ratio of the dopant to the transparent conductive nitrogen oxide (TCON) is preferably applied to 0.001 to 20 weight percent (wt.%).

   According to another aspect of the present invention, in addition to the transparent conductive nitrogen oxide (TCON), the corrugated multiple ohmic contact layer 70 is advantageous in forming an ohmic contact electrode on the upper layer of the nitride-based cladding layer 60 as follows. metals and alloys / solid solutions based on these metals, common conducting oxides, transparent conducting oxides (TCOs), and transparent conducting nitrides (TCNs), etc. Can be formed.

   Metals and alloys / solid solutions based on these metals: platinum (Pt), palladium (Pd), nickel (Ni), gold (Au), rhodium (Rh), ruthenium (Ru) ), Iridium (Ir), silver (Ag), zinc (Zn), magnesium (Mg), beryllium (Be), copper (Cu), cobalt (Co), tin (Sn), rare earth metals Or an alloy / solid solution based on these metals.

   General conducting oxide: Nickel oxide (Ni-O), rhodium oxide (Rh-O), ruthenium oxide (Ru-O), iridium oxide (Ir-O), copper oxide (Cu-O), cobalt Oxide (Co-O), tungsten oxide (WO), or titanium oxide (Ti-O).

   Transparent conductive oxide (TCO): indium oxide (In2O3), tin oxide (SnO2), indium tin oxide (ITO), zinc oxide (ZnO), magnesium (MgO), cadmium oxide (CdO), magnesium zinc oxide (MgZnO) , Indium zinc oxide (InZnO), indium tin oxide (InSnO), copper aluminum oxide (CuAlO2), silver oxide (Ag2O), gallium oxide (Ga2O3), zinc tin oxide (ZnSnO), zinc indium tin oxide (ZITO), or Still other oxides to which these transparent conductive oxides are combined.

   Transparent conductive nitride (TCN): titanium nitride (TiN), chromium nitride (CrN), tungsten (WN), tantalum (TaN), or niobium (NbN).

   More preferably, a third material, ie, a dopant, may be added to the above-described oxides and nitrides in order to improve the electrical properties of these materials.

   In addition, the multilayered ohmic contact layer 70 is preferably formed to a thickness of 1 nanometer to 1000 nanometers.

   In addition, the deposition temperature applied to form the multiple-type ohmic contact layer 70 is in the range of 20 degrees to 1500 degrees, and the pressure in the evaporator is performed at atmospheric pressure to about 10-12 torr.

   In addition, after forming the multi-type ohmic contact layer 70, it is preferable to undergo an annealing process. Annealing is performed at a temperature in the reactor at 100 to 800 degrees for 10 seconds to 3 hours in a vacuum or gas atmosphere. At least one gas of nitrogen, argon, helium, oxygen, hydrogen, or air may be applied to the gas introduced into the reactor during the heat treatment.

   The electrode pad 80 is formed of nickel (Ni) / gold (Au), silver (Ag) / gold (Au), titanium (Ti) / gold (Au), nickel (Ni) / gold (Au), and palladium (Pd). A layer structure in which) / gold (Au), or chromium (Cr) / gold (Au) is sequentially stacked may be applied.

   The method of forming each layer is physical such as electron beam or thermal evaporator, pulsed laser deposition using laser energy source, dual-type thermal evaporator sputtering, etc. It is formed by chemical vapor deposition (CVD) using chemical reactions such as physical vapor deposition (PVD), electroplating, and metal-organic chemical vapor deposition.

   2 is a cross-sectional view illustrating a light emitting diode to which a multi-type ohmic contact electrode structure according to a second exemplary embodiment of the present invention is applied.

   In detail, FIG. 2 (a) is a cross-sectional view illustrating a group III-nitride-based top-emitting type light emitting diode (TELED) laminated / grown on an upper layer of sapphire 10, which is an insulating growth substrate, whereas FIG. Electrically conductive substrates, namely silicon carbide (SiC), zinc oxide (ZnO), silicon (Si), gallium arsenide (GaAs), or electroplating / bonding transfers known in many literatures, etc. A cross-sectional view showing a group III-nitride-based top-emitting light emitting diode (TELED) formed on an upper layer of a conductive material layer such as metal (Cu, Ni, Al, etc.) or alloy formed by the method.

   First of all, the laminated structure in which the tunnel junction layer 100 is inserted before the formed nitride-based cladding (multiple-type ohmic contact layer 70 is formed on the upper 60 layer) is a different stacked structure from the first embodiment. Have

The tunnel junction layer 100 thus introduced is a compound represented by Al a In b Ga c N x P y As z (a, b, c, x, y, z; integer) composed of group 3-5 elements. Based on any compound selected, a single layer, preferably a bi-layer, tri-layer, or more stacked structure formed to a thickness of 50 nanometers or less may be formed. Can be.

   Preferably, the superlattice structure already known in the literature is referred to as the tunnel junction layer 100. For example, a thin lamination structure formed of Group 3-5 elements such as InGaN / GaN, AlGaN / GaN, AlInN / GaN, AlGaN / InGaN, AlInN / InGaN, AlN / GaN, or AlGaAs / InGaAs, and the like, and have a maximum of 30 pairs repeatedly. Up to 30 pairs can be laminated.

   More preferably, it refers to a single crystal, poly-crystal, or amorphous material layer to which group group elements (Mg, Be, Zn) or group group elements (Si, Ge) are added.

   Referring to the drawings, the light emitting device includes a substrate 10, a low temperature nucleation layer 20, a nitride buffer layer 30, an N-type nitride cladding layer 40, a nitride-based active layer 50, and a nitride-based cladding layer ( 60), the multiple-type ohmic contact layer 70, and the tunnel junction layer 100 are sequentially stacked. Reference numeral 80 denotes a shaped electrode pad, and 90 denotes an N-type electrode pad.

   Here, the substrate 10 to the nitride-based cladding layer 60 corresponds to the light emitting structure, and the structure stacked on the upper portion of the nitride-based cladding layer 60 corresponds to the multi-type electrode structure.

   The substrate 10 may be formed of sapphire (Al 2 O 3), silicon carbide (SiC), zinc oxide (ZnO), silicon (Si), gallium arsenide (GaAs), or electroplating / bonding transfer (also known in many literatures). It is preferably formed of any one of materials such as metal (Cu, Ni, Al, etc.) or alloy (alloy) formed by a bonding transfer method.

   The low temperature nucleation layer 20 is preferably amorphous gallium nitride (GaN) or aluminum nitride (AlN) formed at a low temperature of 700 degrees or less, and may be omitted in some cases.

   Each layer from the nitride buffer layer 30 to the nitride nitride cladding layer 60 is formed on the basis of any compound selected from AlxInyGazN (x, y, z: integer), which is a general formula of a group III nitride compound, The dopant is added to the nitride cladding layer 40 and the nitride nitride cladding layer 60.

   In addition, the nitride-based active layer 50 may be a variety of known methods such as monolayer, multi quantum well (MQW), multi quantum dot / wire, or a layer in which quantum dots / lines and wells are mixed. It may be configured as. As an example, when a gallium nitride (GaN) compound is applied, the buffer layer 30 is formed of GaN, and the N-type nitride cladding layer 40 is formed by adding Si, Ge, Se, Te, or the like as Ga-type dopants to GaN. The active layer is formed of InGaN / GaN MQW or AlGaN / GaN MQW, and the nitride-based cladding layer 60 is formed by adding Mg, Zn, Ca, Sr, Ba, etc. to GaN as a dopant.

   An en-type ohmic contact layer (not shown) may be interposed between the en-type nitride cladding layer 40 and the en-type electrode pad 90, and the en-type ohmic contact layer is formed by sequentially stacking titanium (Ti) and aluminum (Al). Various known structures such as a layer structure can be applied.

   As described above, the multi-type ohmic contact layer 70, which is the core technology of the present invention, has a multi-type ohmic including at least one or more transparent conducting oxynitride (TCON) on the upper layer of the nitride-based cladding layer 60. The transparent conductive nitrogen oxide (TCON) is provided with a contact layer 70, and indium (In), tin (Sn), zinc (Zn), cadmium (Cd), gallium (Ga), aluminum (Al), magnesium ( Mg), titanium (Ti), molybdenum (Mo), nickel (Ni), copper (Cu), silver (Ag), gold (Au), platinum (Pt), rhodium (Rh), iridium (Ir), rousse It refers to a material formed by combining at least one component among nium (Ru) or palladium (Pd) metals with oxygen (O) and nitrogen (N) necessarily bonded at the same time.

   Preferably, the transparent conductive nitrogen oxide (TCON) may further include other metal components as dopants in order to control electrical properties. Herein, the metals applied as dopants are applied with elements classified as metals on the periodic table of elements. In addition to the metal material to be applied as a dopant, it is preferable to include fluorine (F) and sulfur (S). In addition, the addition ratio of the dopant to the transparent conductive nitrogen oxide (TCON) is preferably applied to 0.001 to 20 weight percent (wt.%).

   According to another aspect of the present invention, in addition to the transparent conductive nitrogen oxide (TCON), the multi-type ohmic contact layer 70 is advantageous in forming an ohmic contact electrode on the upper portion of the nitride-based cladding layer 60 as follows. metals and alloys / solid solutions based on these metals, common conducting oxides, transparent conducting oxides (TCOs), and transparent conducting nitrides (TCNs), etc. Can be formed.

   Metals and alloys / solid solutions based on these metals: platinum (Pt), palladium (Pd), nickel (Ni), gold (Au), rhodium (Rh), ruthenium (Ru) ), Iridium (Ir), silver (Ag), zinc (Zn), magnesium (Mg), beryllium (Be), copper (Cu), cobalt (Co), tin (Sn), rare earth metals Or an alloy / solid solution based on these metals.

   General conducting oxide: Nickel oxide (Ni-O), rhodium oxide (Rh-O), ruthenium oxide (Ru-O), iridium oxide (Ir-O), copper oxide (Cu-O), cobalt Oxide (Co-O), tungsten oxide (WO), or titanium oxide (Ti-O).

   Transparent conductive oxide (TCO): indium oxide (In2O3), tin oxide (SnO2), indium tin oxide (ITO), zinc oxide (ZnO), magnesium (MgO), cadmium oxide (CdO), magnesium zinc oxide (MgZnO) , Indium zinc oxide (InZnO), indium tin oxide (InSnO), copper aluminum oxide (CuAlO2), silver oxide (Ag2O), gallium oxide (Ga2O3), zinc tin oxide (ZnSnO), zinc indium tin oxide (ZITO), or Still other oxides to which these transparent conductive oxides are combined.

   Transparent conductive nitride (TCN): titanium nitride (TiN), chromium nitride (CrN), tungsten (WN), tantalum (TaN), or niobium (NbN).

   More preferably, a third material, ie, a dopant, may be added to the above-described oxides and nitrides in order to improve the electrical properties of these materials.

   In addition, the multilayered ohmic contact layer 70 is preferably formed to a thickness of 1 nanometer to 1000 nanometers.

   In addition, the deposition temperature applied to form the multi-type ohmic contact layer 70 is in the range of 20 degrees to 1500 degrees, and the pressure in the evaporator is performed at atmospheric pressure to about 10-12 torr.

   In addition, after forming the multi-type ohmic contact layer 70, it is preferable to undergo an annealing process. Annealing is performed at a temperature in the reactor at 100 to 800 degrees for 10 seconds to 3 hours in a vacuum or gas atmosphere. At least one gas of nitrogen, argon, helium, oxygen, hydrogen, or air may be applied to the gas introduced into the reactor during the heat treatment.

   The electrode pad 80 is formed of nickel (Ni) / gold (Au), silver (Ag) / gold (Au), titanium (Ti) / gold (Au), nickel (Ni) / gold (Au), and palladium (Pd). A layer structure in which) / gold (Au), or chromium (Cr) / gold (Au) is sequentially stacked may be applied.

   The method of forming each layer is physical such as electron beam or thermal evaporator, pulsed laser deposition using laser energy source, dual-type thermal evaporator sputtering, etc. It is formed by chemical vapor deposition (CVD) using chemical reactions such as physical vapor deposition (PVD), electroplating, and metal-organic chemical vapor deposition.

   3 is a cross-sectional view illustrating various stacked shapes of the multi-type ohmic contact electrode structure 70 formed on the upper part of the nitride-based cladding layer 60 according to the first and second embodiments of the present invention.

   The multi-type ohmic contact electrode structure 70 applied in the present invention includes at least one transparent conductive nitrogen oxide (TCON) generated by combining oxygen (O 2) and nitrogen (N 2) at the same time as described above. It is preferable to form in multiple multiples.

   More preferably, metals, alloys, solid solutions, common conductive oxides, transparent conductive oxides (TCO), or transparent conductive nitrides are formed rather than formed of transparent conductive nitrogen oxide (TCON) monolayer 70a as shown in FIG. 3 (a). As in (TCN), multiple forms such as Fig. 3 (b), 3 (c), or 3 (d) which are grafted irrespective of the stacking order are preferable.

4 is a multi-p ohmic contact electrode structure (multi P- type ohmic contact) formed after introducing nanometer scale particles into the upper layer of the nitride-based cladding layer according to the first and second embodiments of the present invention. This is a cross-sectional view showing various stacked forms of layers).

   The charge flow of carriers at the interface between the semiconductor cladding layer 60 and the electrode structure 70 prior to forming the multi-type ohmic contact electrode structure 70 applied in the present invention above the nitride-based cladding layer 60. Metals, alloys, solid solutions, common conducting oxides, and transparent conducting oxides that can control the Schottky barrier height and width to control the transport TCO), transparent conductive nitride (TCN), or transparent conductive nitrogen oxides (TCON) to form a nanometer size particle, and then, as described above, oxygen (O2) and nitrogen (N2) are combined to form It is preferable to include at least one transparent conductive nitrogen oxide (TCON) and to form a single layer or multiple layers of two or more layers.

   More preferably, metals, alloys, solid solutions, common conductive oxides, transparent conductive oxides (TCO), or transparent conductive nitrides are formed rather than the transparent conductive nitrogen oxide (TCON) monolayer 70a as shown in FIG. 4 (a). Multilayer forms such as (B), 4 (c), or 4 (d), which are grafted regardless of the stacking order, such as (TCN), are preferable.

   Examples of preferred multi-type ohmic contact layers 70 include nickel (Ni) / indium tin nitrous oxide (ITON) or zinc nitrous oxide (ZnON), ruthenium (Ru) / indium tin nitrous oxide (ITON) or zinc nitrous oxide. (ZnON), Iridium (Ir) / Indium Tin Nitrogen Oxide (ITON) or Zinc Nitrogen Oxide (ZnON), Nickel Oxide (Ni-O) / Indium Tin Nitrogen Oxide (ITON) or Zinc Nitrogen Oxide (ZnON), Ruthenium Oxide (Ru-O) / Indium Tin Nitrogen Oxide (ITON) or Zinc Nitrogen Oxide (ZnON), Iridium Oxide (Ir-O) / Indium Tin Nitrogen Oxide (ITON) or Zinc Nitrogen Oxide (ZnON), Nickel (Ni) / Silver (Ag) or Gold (Au) / Indium Tin Nitrogen Oxide (ITON) or Zinc Nitrogen Oxide (ZnON), Ruthenium (Ru) / Silver (Ag) or Gold (Au) / Indium Tin Nitrogen Oxide (ITON) or Zinc Nitrogen oxides (ZnON), iridium (Ir) / silver (Ag) or gold (Au) / indium tin nitrogen oxide (ITON) or zinc nitrous oxide (ZnON), nickel oxide (Ni-O) / silver (Ag) or gold (Au) / Indium Tin Nitrogen Oxide (ITON) or Ah Nitrogen oxides (ZnON), ruthenium oxides (Ru-O) / silver (Ag) or gold (Au) / indium tin nitrogen oxides (ITON) or zinc nitrogen oxides (ZnON), iridium oxides (Ir-O) / silver (Ag) or Gold (Au) / Indium Tin Nitrogen Oxide (ITON) or Zinc Nitrogen Oxide (ZnON), Indium Tin Oxide (ITO) or Zinc Oxide (ZnO) / Indium Tin Nitrogen Oxide (ITON) or Zinc Nitrogen Oxide (ZnON ), Indium tin oxide (ITON) or zinc nitrogen oxide (ZnON) / indium tin oxide (ITO) or zinc oxide (ZnO) and the like.

As described so far, according to the Group III nitride-based light emitting device according to an embodiment of the present invention and a method for manufacturing the same, a transparent conductive oxide (TCO) whose electrical and optical characteristics are used as a conventional transparent conductive thin film electrode And by applying transparent conductive nitrogen oxide (TCON), which is much better than transparent conductive nitride (TCN), it improves ohmic contact characteristics with the nitride-based cladding layer, thereby showing excellent current-voltage characteristics and high light transmittance of the transparent electrode. As a result, a high efficiency, high brightness light emitting diode can be manufactured.

Claims (16)

 An optical structure including an active layer, an N-type nitride cladding layer formed under the active layer, and a P-type nitride cladding layer formed on the active layer; And It is formed on top of the nitride-based cladding layer, and comprises a contact layer on which at least one transparent conducting oxynitride (TCON) is laminated, The transparent conductive nitrogen oxide (TCON) is indium (In), tin (Sn), zinc (Zn), cadmium (Cd), gallium (Ga), aluminum (Al), magnesium (Mg), titanium (Ti), molybdenum Ium (Mo), nickel (Ni), copper (Cu), silver (Ag), gold (Au), platinum (Pt), rhodium (Rh), iridium (Ir), ruthenium (Ru), and palladium (Pd ) At least one of the metals as a main component, characterized in that formed by combining oxygen (O) and nitrogen (N) to the main component at the same time. The method of claim 1, The transparent conductive nitrogen oxide (TCON) further includes a dopant (dopant) for adjusting the electrical properties, the dopant is optical, characterized in that it comprises at least one of metal, fluorine (F) and sulfur (S) device. The method of claim 2, The optical device, characterized in that the addition ratio of the dopant to the transparent conductive nitrogen oxide (TCON) is 0.001 to 20 weight percent (wt.%). The method of claim 1, The contact layer is a metal, a metal or an alloy or solid solution (alloy / solid solution), a conductive oxide, a transparent conductive oxide (TCO) grafted to the transparent conductive nitrogen oxide (TCON) ), And at least one of transparent conductive nitride (TCN). The method of claim 4, wherein The metal is platinum (Pt), palladium (Pd), nickel (Ni), gold (Au), rhodium (Rh), ruthenium (Ru), iridium (Ir), silver (Ag), zinc (Zn), magnesium (Mg), beryllium (Be), copper (Cu), cobalt (Co), tin (Sn), and rare earth metals; The conducting oxide is nickel oxide (Ni-O), rhodium oxide (Rh-O), ruthenium oxide (Ru-O), iridium oxide (Ir-O), copper oxide (Cu-O), cobalt At least one of oxide (Co-O), tungsten oxide (WO), and titanium oxide (Ti-O), The transparent conductive oxide (TCO) is indium oxide (In2O3), tin oxide (SnO2), zinc oxide (ZnO), magnesium oxide (MgO), cadmium oxide (CdO), magnesium zinc oxide (MgZnO), indium zinc oxide ( InZnO), indium tin oxide (InSnO), copper aluminum oxide (CuAlO2), silver oxide (Ag2O), gallium oxide (Ga2O3), zinc tin oxide (ZnSnO), and zinc indium tin oxide (ZITO) , The transparent conductive nitride (TCN) includes at least one of titanium nitride (TiN), chromium nitride (CrN), tungsten nitride (WN), tantalum nitride (TaN), and niobium nitride (NbN). . The method of claim 5, Is introduced onto the clad nitride-based cladding layer and grafted to the clad contact layer, wherein the metal, an alloy or solid solution based on the metal, the conducting oxide, and the transparent conductivity And an nanometer size particle formed of at least one of an oxide (TCO) and the transparent conductive nitride (TCN). The method of claim 1, A tunnel junction layer formed between the clad nitride-based cladding layer and the clad contact layer and having a compound represented by AlaInbGacNxPyAsz (a, b, c, x, y, z; integer) composed of group 3-5 elements. Optical device comprising a further. The method of claim 1, The transparent contact nitrogen layer stacked contact layer is an optical device, characterized in that used in any one of a light receiving device, a light emitting device, a light emitting diode, an organic light emitting diode (OLED), and a cell. Forming an optical structure including an active layer, an N-type nitride cladding layer formed under the active layer, and a P-type nitride cladding layer formed on the active layer ; And Depositing at least one transparent conducting oxynitride (TCON) on top of the P-type nitride cladding layer to form a contact layer thereon; The transparent conductive nitrogen oxide (TCON) is indium (In), tin (Sn), zinc (Zn), cadmium (Cd), gallium (Ga), aluminum (Al), magnesium (Mg), titanium (Ti), molybdenum Ium (Mo), nickel (Ni), copper (Cu), silver (Ag), gold (Au), platinum (Pt), rhodium (Rh), iridium (Ir), ruthenium (Ru), and palladium (Pd ) At least one of the metals as a main component and an oxygen (O) and nitrogen (N) is formed by combining at the same time the optical element manufacturing method. The method of claim 9, The transparent conductive nitrogen oxide (TCON) further includes a dopant (dopant) for adjusting the electrical properties, the dopant is optical, characterized in that it comprises at least one of metal, fluorine (F) and sulfur (S) Method of manufacturing the device. The method of claim 10, The method of manufacturing an optical device, characterized in that the addition ratio of the dopant to the transparent conductive nitrogen oxide (TCON) is 0.001 to 20 weight percent (wt.%). The method of claim 9, The contact layer is a metal, a metal or an alloy or solid solution (alloy / solid solution), a conductive oxide, a transparent conductive oxide (TCO) grafted to the transparent conductive nitrogen oxide (TCON) ), And at least one of transparent conductive nitride (TCN). The method of claim 12, The metal is platinum (Pt), palladium (Pd), nickel (Ni), gold (Au), rhodium (Rh), ruthenium (Ru), iridium (Ir), silver (Ag), zinc (Zn), magnesium (Mg), beryllium (Be), copper (Cu), cobalt (Co), tin (Sn), and rare earth metals; The conducting oxide is nickel oxide (Ni-O), rhodium oxide (Rh-O), ruthenium oxide (Ru-O), iridium oxide (Ir-O), copper oxide (Cu-O), cobalt At least one of an oxide (Co-O), a tungsten oxide (WO), and a titanium oxide (Ti-O), The transparent conductive oxide (TCO) is indium oxide (In2O3), tin oxide (SnO2), zinc oxide (ZnO), magnesium oxide (MgO), cadmium oxide (CdO), magnesium zinc oxide (MgZnO), indium zinc oxide ( InZnO), indium tin oxide (InSnO), copper aluminum oxide (CuAlO2), silver oxide (Ag2O), gallium oxide (Ga2O3), zinc tin oxide (ZnSnO), and zinc indium tin oxide (ZITO) , The transparent conductive nitride (TCN) includes at least one of titanium nitride (TiN), chromium nitride (CrN), tungsten nitride (WN), tantalum nitride (TaN), and niobium nitride (NbN). Method of preparation. The method of claim 13, Is introduced onto the clad nitride-based cladding layer and grafted to the clad contact layer, wherein the metal, an alloy or solid solution based on the metal, the conducting oxide, and the transparent conductivity And a nanometer size particle formed of at least one of an oxide (TCO) and the transparent conductive nitride (TCN). The method of claim 9, The method of manufacturing an optical device, characterized in that it further comprises the step of heat treatment after forming the contact layer. The method of claim 15, The heat treatment step is 10 seconds to 3 to 100 to 800 degrees in an atmosphere containing at least one of nitrogen (N 2), oxygen (O 2), hydrogen (H 2), air, argon (Ar), and helium (He) gas. Method for producing an optical element, characterized in that carried out for a time.

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