WO2014007419A1 - Nitride group semiconductor light-emitting element and method for manufacturing same - Google Patents

Abstract

The present invention relates to a nitride group semiconductor light-emitting element and a method for manufacturing the same. The purpose of the present invention is to improve optical power through high-density doping in an electrode. A nitride group semiconductor light-emitting element according to the present invention comprises a base substrate, a buffer layer, a doping reinforcing layer, a p-type semiconductor layer, an active layer, an n-type semiconductor layer, a p-type electrode, and an n-type electrode. The buffer layer of a nitride group is formed on the base substrate. The doping reinforcing layer is formed on the buffer layer, comprises a plurality of nitride layers including aluminum, a refractive index of which periodically varies, and has an electrode forming portion through which at least two continuous nitride layers among the plurality of nitride layers are exposed. The p-type semiconductor layer of a nitride group includes aluminum formed on the doping reinforcing layer to expose at least the electrode forming portion of the doping reinforcing layer. The active layer of a nitride group includes aluminum formed on the p-type semiconductor layer. The n-type semiconductor layer of a nitride group includes aluminum formed on the active layer. The p-type electrode is formed on the electrode forming portion. The n-type electrode is formed on the n-type semiconductor layer.

Description

Nitride-based semiconductor light emitting device and method of manufacturing the same

The present invention relates to a nitride semiconductor light emitting device and a method of manufacturing the same, and more particularly to a nitride based semiconductor light emitting device and a method of manufacturing the same that can improve the light output by improving the resistance characteristics.

In general, nitride semiconductor materials such as GaN, AlN, AlGaN, and AlGaInN, which include group V sources such as nitrogen (N) and group III sources such as gallium (Ga), aluminum (Al), and indium (In), are thermally stable. It has an excellent and direct transition type energy band structure, and has recently been widely used as a material for nitride-based semiconductor light emitting devices in the blue and ultraviolet regions.

Such nitride-based semiconductor light emitting devices generally have a structure of a buffer layer, an n-type semiconductor layer, an active layer, a p-type semiconductor layer, and an electrode on a substrate. In this case, the active layer is a region where electrons and holes are recombined, and has a structure in which a quantum well layer is disposed between the quantum barrier layers. The emission wavelength emitted from the nitride semiconductor light emitting device is determined by the kind of the material forming the active layer.

The active layer has a single quantum well (SQW) structure having one quantum well layer and a multi quantum well (MQW) structure having a plurality of quantum well layers. Among them, the active layer of the multi-quantum well structure is actively used because of its superior luminous efficiency and high luminous output compared to the single quantum well structure. The luminous efficiency of the nitride-based semiconductor light emitting device is basically determined by the probability of recombination of electrons and holes participating in the emission in the active layer, that is, the internal quantum efficiency.

In order to prevent absorption of light generated in the active layer, for example, the active layer aluminum composition ratio of the AlGaN-based semiconductor light emitting device should be smaller than the aluminum (Al) composition ratio of the n-type semiconductor layer or the p-type semiconductor layer.

In general, the higher the Al composition ratio, the more difficult doping is, resulting in higher resistance. Therefore, in the conventional nitride semiconductor light emitting device, since the aluminum composition ratio of the n-type semiconductor layer or the p-type semiconductor layer is higher than the aluminum composition ratio of the active layer, it is difficult to fabricate a high output nitride semiconductor light emitting device due to high doping difficulty and high resistance. I have a problem.

Accordingly, an object of the present invention is to provide a nitride-based semiconductor light emitting device and a method of manufacturing the same that can improve the light output through improved resistance characteristics.

In order to achieve the above object, the present invention provides a nitride-based semiconductor light emitting device comprising a base substrate, a buffer layer, a doping reinforcement layer, a p-type semiconductor layer, an active layer, an n-type semiconductor layer, a p-type electrode and an n-type electrode. The nitride buffer layer is formed on the base substrate. The doping reinforcement layer is formed on the buffer layer, and includes a plurality of nitride layers containing aluminum, the refractive index of which is periodically changed, and has an electrode forming portion to expose at least two consecutive nitride layers of the plurality of nitride layers. The nitride-based p-type semiconductor layer contains at least aluminum formed on the doped reinforcement layer to expose the electrode forming portion of the doped reinforcement layer. The nitride-based active layer is formed on the p-type semiconductor layer. The n-type semiconductor layer of nitride is formed on the active layer. The p-type electrode is formed on the electrode forming portion. The n-type electrode is formed on the n-type semiconductor layer.

In the nitride-based semiconductor light emitting device according to the present invention, the doping reinforcement layer includes a nitride layer having a lower aluminum composition ratio than the aluminum composition ratio of the p-type semiconductor layer, the nitride layer may be exposed to the electrode forming portion.

In the nitride semiconductor light emitting device according to the present invention, the doping reinforcement layer includes a first nitride layer doped with a p-type, and a p-type doped second nitride layer formed on the p-type nitride layer. In this case, the doping reinforcing layer may be formed by alternating the first and second nitride layer.

In the nitride-based semiconductor light emitting device according to the present invention, the first nitride layer is a material of p-type Al _x Ga _y In _1-xy N (0 <x, 0 <y, x + y ≤ 1) Can be formed. The second nitride layer may be formed of a material of p-type Al _m Ga _n In _1-mn N (0 <m, 0 <n, m + n ≦ 1).

In the nitride-based semiconductor light emitting device according to the present invention, the electrode forming portion of the doping reinforcement layer may be formed as an inclined surface, grooves or stepped surface.

In the nitride-based semiconductor light emitting device according to the present invention, the electrode forming portion of the doping reinforcement layer protrudes to one side with respect to the n-type semiconductor layer, the active layer and the p-type semiconductor layer is formed on the doping reinforcement layer, the exposed of the doping reinforcement layer It may be formed as an inclined surface inclined left and right on the upper surface portion.

In the nitride-based semiconductor light emitting device according to the present invention, the electrode forming portion of the doping reinforcement layer protrudes to one side with respect to the n-type semiconductor layer, the active layer and the p-type semiconductor layer is formed on the doping reinforcement layer, the exposed of the doping reinforcement layer It may be formed as an inclined surface inclined up and down on the upper surface portion.

In the nitride-based semiconductor light emitting device according to the present invention, the doping reinforcement layer may include a Distributed Bragg Reflector (DBR) layer formed on the buffer layer.

In the nitride based semiconductor light emitting device according to the present invention, the doping reinforcement layer may further include a superlattice layer formed between the buffer layer and the DBR layer.

In the nitride-based semiconductor light emitting device according to the present invention, the superlattice layer is a first Al _x Ga _y In _1-xy N (0 <x, 0 <y, x + y ≤ 1) layer and the first Al _x Ga _y In is formed on the _1-xy N layer, wherein the 1 Al _x Ga _y In _1-xy N layer and the 2 Al _x Ga _y In _1-xy N layer (0 <x having a different composition ratio, 0 < y, x + y ≦ 1). In this case, the superlattice layer is formed of at least one unit superlattice layer using the first and second Al _x Ga _y In _1-xy N layers as a unit superlattice layer. In addition, when the superlattice layer is formed, it may be formed by doping.

The present invention also provides a nitride-based semiconductor light emitting device comprising a base substrate, a buffer layer, a doping reinforcement layer, a p-type semiconductor layer, an active layer, an n-type semiconductor layer, a p-type electrode and an n-type electrode. The nitride buffer layer is formed on the base substrate. The doping reinforcement layer includes a plurality of nitride layers having different refractive indices stacked on the buffer layer, and has an electrode forming part exposing at least two nitride layers having different refractive indices among the plurality of nitride layers on one side thereof. The p-type semiconductor layer of nitride is formed on the doping reinforcement layer to expose the electrode forming portion. The nitride based active layer is formed on the p-type semiconductor layer. The nitride n-type semiconductor layer is formed on the active layer. The p-type electrode is formed on the electrode forming portion. The n-type electrode is formed on the n-type semiconductor layer.

The present invention also provides a method of forming a nitride-based buffer layer on a base substrate, forming a doping reinforcement layer including a plurality of nitride layers whose refractive index is periodically changed on the buffer layer, and a nitride-based nitride-containing nitride layer on the doping reinforcement layer. forming a p-type semiconductor layer, forming a nitride-based active layer containing aluminum on the p-type semiconductor layer, forming a nitride-based n-type semiconductor layer containing aluminum on the active layer, and the doping reinforcement layer Forming an electrode forming portion by exposing at least two consecutive nitride layers of the plurality of nitride layers forming the doping reinforcing layer and removing a portion of the n-type semiconductor layer, the active layer and the p-type semiconductor layer so that a portion of the semiconductor layer is exposed; And forming a p-type electrode on the electrode forming portion and on the n-type semiconductor layer. It provides a method of manufacturing a nitride-based semiconductor light emitting device comprising the step of forming an n-type electrode.

In the method of manufacturing a nitride-based semiconductor light emitting device according to the present invention, the forming of the electrode forming portion, the doping by removing a portion of the n-type semiconductor layer, the active layer and the p-type semiconductor layer using a shadow mask. Exposing a portion of the reinforcement layer, the electrode forming portion may be formed such that at least two consecutive nitride layers of the plurality of nitride layers forming the doped reinforcement layer are exposed through the inclined surface.

In the method of manufacturing a nitride-based semiconductor light emitting device according to the invention, the step of forming the electrode forming portion is to remove a portion of the n-type semiconductor layer, the active layer and the p-type semiconductor layer to expose a portion of the doping reinforcement layer. And forming at least two consecutive nitride layers of the plurality of nitride layers forming the doped reinforcement layer by irradiating a laser beam to form an electrode forming portion.

In the method of manufacturing the nitride-based semiconductor light emitting device according to the present invention, in the forming of the electrode forming portion, the electrode forming portion may be formed to include an inclined surface or at least one groove.

In the nitride-based semiconductor light emitting device according to the present invention, by forming an electrode in the doping reinforcement layer whose refractive index is periodically changed, it is possible to improve the light output by improving the reduction phenomenon of the doping concentration. For example, by forming a DBR (Distributed Bragg Reflector) layer having a periodically varying refractive index as a doping reinforcement layer, exposing at least two layers of the DBR layer to the outside, and then forming an electrode therein, the electrode has a relative refractive index among the periodically changing layers. In addition, since it is connected to the layer with a low refractive index, ie, a layer with a low aluminum composition ratio, doping of high density is possible. That is, since DBR is applied as the doping reinforcement layer, a material of Al _m Ga _n In _1-mn N (0 <m, 0 <n, m + n ≦ 1) lower than the aluminum composition ratio of the p-type semiconductor layer may be used. to be.

In addition, since the nitride semiconductor light emitting device according to the present invention has a high doping concentration, an ohmic electrode can be easily formed.

1 is a perspective view illustrating a nitride based semiconductor light emitting device according to a first exemplary embodiment of the present invention.

2 is a cross-sectional view of FIG. 1.

3 is a flowchart illustrating a method of manufacturing a nitride-based semiconductor light emitting device according to a first embodiment of the present invention.

4 to 11 illustrate each step according to the manufacturing method of FIG. 3.

12 is a cross-sectional view illustrating a nitride based semiconductor light emitting device according to a second exemplary embodiment of the present invention.

13 is a perspective view illustrating a nitride based semiconductor light emitting device according to a third exemplary embodiment of the present invention.

14 is a cross-sectional view illustrating a nitride based semiconductor light emitting device according to a fourth embodiment of the present invention.

15 is a cross-sectional view illustrating a nitride based semiconductor light emitting device according to a fifth embodiment of the present invention.

16 is a perspective view illustrating a nitride based semiconductor light emitting device according to a sixth embodiment of the present invention.

17 is a cross-sectional view of FIG. 16.

In the following description, only parts necessary for understanding the embodiments of the present invention will be described, it should be noted that the description of other parts will be omitted so as not to distract from the gist of the present invention.

The terms or words used in the specification and claims described below should not be construed as being limited to the ordinary or dictionary meanings, and the inventors are appropriate to the concept of terms in order to explain their invention in the best way. It should be interpreted as meanings and concepts in accordance with the technical spirit of the present invention based on the principle that it can be defined. Therefore, the embodiments described in the present specification and the configuration shown in the drawings are only preferred embodiments of the present invention, and do not represent all of the technical idea of the present invention, and various equivalents may be substituted for them at the time of the present application. It should be understood that there may be variations and variations.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention.

First embodiment

1 is a perspective view illustrating a nitride based semiconductor light emitting device according to a first exemplary embodiment of the present invention. 2 is a cross-sectional view of FIG. 1.

1 and 2, in the nitride-based semiconductor light emitting device 100 according to the first embodiment, a buffer layer 20, a doping reinforcement layer 30, and a p-type semiconductor layer 40 are sequentially formed on a base substrate 10. ), The active layer 50 and the n-type semiconductor layer 60 is formed. The nitride semiconductor light emitting device 100 has a structure in which a p-type electrode 70 is formed on a portion of the doping reinforcement layer 30 that is exposed to the outside, and an n-type electrode 80 is formed on the n-type semiconductor layer 60. Here, the buffer layer 20 is formed on the base substrate 10 and formed by growing a nitride material. The doping reinforcement layer 30 is formed on the buffer layer 20 and includes a plurality of nitride layers 35 and 37 whose refractive indices are periodically changed, and at least two consecutive nitride layers of the plurality of nitride layers 35 and 37 ( 35 and 37 have electrode forming portions 39 exposed. The p-type semiconductor layer 40 is formed on at least the doping reinforcement layer 30 and is formed of a nitride-based material containing aluminum. The active layer 50 is formed on the p-type semiconductor layer 40, and is formed of a nitride-based material containing aluminum. The n-type semiconductor layer 60 is formed on the active layer 50 and formed of a nitride-based material containing aluminum. The p-type electrode 70 is formed on the electrode forming portion 39 of the doping reinforcement layer 30. The n-type electrode 80 is formed on the n-type semiconductor layer 60.

The nitride based semiconductor light emitting device 100 according to the first embodiment will be described in detail as follows.

The base substrate 10 may be made of a material suitable for growing a nitride-based semiconductor single crystal. In this case, the base substrate 10 may include sapphire, silicon (Si), zinc oxide (ZnO), gallium nitride (GaN), gallium arsenide (GaAs), silicon carbide (SiC), and aluminum knight. It may be made of an element or a compound such as lide (AlN), magnesium oxide (MgO). For example, the base substrate 10 is a sapphire substrate having a C plane ({0001} plane), an R plane ({1-102}), an M plane ({1-100}), and an A plane ({11-20}). And the like can be used. The buffer layer 20, the doping reinforcement layer 30, the p-type semiconductor layer 40, the active layer 50, and the n-type semiconductor layer 60 are sequentially formed on the base substrate 10.

The buffer layer 20 may be formed of a nitride layer that is not doped with the nucleation layer. The nucleation layer is formed on the base substrate 10 to reduce the difference in lattice constant between the base substrate 10 and the p-type semiconductor layer 40. A nitride growth material such as GaN, AlN, AlGaN, InGaN, AlInN, AlGaInN, AlGaInBN may be used as the nuclear growth layer. The undoped nitride layer is used to improve crystallinity and to obtain a flat surface. A nitride-based material such as GaN, AlN, AlGaN, InGaN, AlInN, AlGaInN, AlGaInBN may be used. In this case, the buffer layer 20 is formed using metal organic chemical vapor deposition (MOCVD), hydride vapor phase epitaxy (HVPE) or molecular beam epitaxy (MBE). can do.

The doping reinforcement layer 30 is formed on the buffer layer 20 to include a plurality of nitride layers 35 and 37 whose refractive index is periodically changed. The doping reinforcement layer 30 includes an electrode forming portion 39 through which at least two consecutive nitride layers 35 and 37 of the plurality of nitride layers 35 and 37 are exposed. In this case, the electrode forming part 39 is exposed to the p-type semiconductor layer 40, the active layer 50, and the n-type semiconductor layer 60 to the outside.

The p-type semiconductor layer 40 is formed on the doping reinforcement layer 30, and is formed on the doping reinforcement layer 30 so that at least the electrode forming portion 39 of the doping reinforcement layer 30 is exposed. The p-type semiconductor layer 40 is a nitride-based semiconductor layer doped with p-type conductive impurities such as Mg, Zn and Be. The p-type semiconductor layer 40 may be formed of a p-type AlGaN-based.

The active layer 50 is formed on the p-type semiconductor layer 40. The active layer 50 may be formed in a quantum well structure using a method such as MOCVD, HVPE, MBE. In the active layer 50, light is generated by combining holes flowing through the p-type semiconductor layer 40 and electrons flowing through the n-type semiconductor layer 60, where the excitation level or energy band gap difference of the quantum well is Light of energy is emitted.

The n-type semiconductor layer 60 is formed on the active layer 50. The n-type semiconductor layer 60 is formed of AlGaN, and silicon is generally doped to do the n-type doping.

The p-type electrode 70 is formed in the electrode forming portion 39 of the doping reinforcement layer 30. The n-type electrode 80 is formed on the n-type semiconductor layer 60. In this case, the p-type electrode 70 is bonded to the plurality of nitride layers 35 and 37 exposed to the electrode forming part 39.

In this case, the doping reinforcement layer 30 includes a nitride layer having an aluminum composition ratio lower than that of the p-type semiconductor layer 40, and the nitride layer is exposed to the electrode forming part 39. The nitride layer having a low aluminum composition ratio is one of the first and second nitride layers 35 and 37. The doping reinforcement layer 30 may be formed as a distributed bragg reflector (DBR) layer. That is, the doping reinforcement layer 30 has a structure in which a p-type doped first nitride layer 35 and a p-type doped second nitride layer 37 formed on the p-type nitride layer 35 are alternately stacked. Can have The first nitride layer 35 may be formed of a material of p-type doped Al _x Ga _y In _1-xy N (0 <x, 0 <y, x + y ≦ 1). The second nitride layer 37 may be formed of a material of p-type Al _m Ga _n In _1-mn N (0 <m, 0 <n, m + n ≦ 1). For example, the doping reinforcement layer 30 may be formed to a thickness of 50nm ~ 2㎛. The thicknesses of the first and second nitride layers 35 and 37 may be formed to have a thickness of 10 nm to 200 nm, respectively.

The electrode forming part 39 of the doping reinforcement layer 30 may be formed as an inclined surface, and the first nitride layer 35 and the second nitride layer 37 are exposed to the inclined surface. In this case, the inclined surface may be formed by a shadow mask, photo-resist reflow, or laser processing. The inclined surface of the electrode forming part 39 may be formed as an inclined surface having a predetermined angle from the YZ plane with respect to the X axis.

Here, the Z axis is an axis indicating a direction in which the buffer layer 20, the doping reinforcement layer 30, the p-type semiconductor layer 40, the active layer 50, and the n-type semiconductor layer 60 are stacked on the base substrate 10. The X axis is an axis corresponding to the boundary between the p-type semiconductor layer and the exposed doping reinforcement layer 30. The Y axis is an axis indicating a direction in which the doping reinforcement layer 30 is exposed to the p-type semiconductor layer 40, the active layer 50, and the n-type semiconductor layer 60, and is an axis perpendicular to the XZ plane.

In addition, the p-type electrode 70 is formed in the electrode forming part 39 where the first and second nitride layers 35 and 37 are exposed and the first and second nitride layers 35 exposed to the electrode forming part 39. And 37).

As described above, in the nitride-based semiconductor light emitting device 100 according to the first embodiment, the p-type electrode 70 is formed in the electrode forming portion 39 of the doping reinforcement layer 30 whose refractive index is periodically changed, thereby improving the doping concentration. Through this, the light output can be improved. For example, by forming a DBR layer whose refractive index changes periodically with the doping reinforcement layer 30, exposing at least two nitride layers 35, 37 of the DBR layer to the outside and then forming a p-type electrode 70 therein, The type electrode 70 is also connected to a nitride layer having a relatively low refractive index, that is, a nitride layer having a low aluminum composition ratio, among the nitride layers 35 and 37 whose refractive index changes periodically, so that a relatively high concentration of doping is possible. That is, since the DBR is applied to the doping reinforcement layer 30, the Al _m Ga _n In _1-mn N (0 <m, 0 <n, m + n ≦ 1) lower than the aluminum composition ratio of the p-type semiconductor layer 40 is applied. Material can be used. In addition, the DBR layer may improve light output of the nitride-based semiconductor light emitting device 100 by basically reflecting light generated from the active layer 50.

For example, the doping reinforcement layer 30 may form a p-type Al _0.7 Ga _0.3 N layer as the first nitride layer 35 and a p-type Al _0.1 Ga _0.9 N layer as the second nitride layer 37. The first and second nitride layers 35 and 37 may be formed in three layers using the unit doping reinforcement layer 30a. The one or more second nitride layers 37 having a low Al composition ratio are exposed through the electrode forming part 39, and the p-type electrode 70 is formed to be connected to the exposed second nitride layers 37 so as to have a relatively high concentration. To get the doping.

In the first embodiment, the doping reinforcement layer 30 has been described as an example in which the unit doping reinforcement layer 30a is formed of three layers, but is not limited thereto. The doping reinforcement layer 30 may include one or more unit doping reinforcement layers 30a.

In addition, since the nitride-based semiconductor light emitting device 100 according to the first embodiment has a high doping concentration, an ohmic electrode can be easily formed.

A method of manufacturing the nitride semiconductor light emitting device 100 according to the first embodiment will be described with reference to FIGS. 1 to 11 as follows. 3 is a flowchart illustrating a method of manufacturing the nitride semiconductor light emitting device 100 according to the first embodiment of the present invention. 4 to 11 illustrate each step according to the manufacturing method of FIG. 3.

First, as shown in FIG. 4, the base substrate 10 is prepared in step S11. In this case, the base substrate 10 may include sapphire, silicon (Si), zinc oxide (ZnO), gallium nitride (GaN), gallium arsenide (GaAs), silicon carbide (SiC), aluminum nitride (AlN), and magnesium oxide ( Substrates made of an element or compound material such as MgO) may be used. In the first embodiment, a sapphire substrate was used as the base substrate 11.

Next, as shown in FIG. 5, the buffer layer 20 is formed on the base substrate 10 in step S13. That is, a nitride nucleus growth layer to be formed as a buffer layer 20 is formed on the base substrate 10. In this case, the nitride nucleus growth layer may be formed using MOCVD, HVPE, MBE, or MOCVPE. For example, the nitride nucleus growth layer formed using a group V source and a plurality of group III sources may be made of a material such as GaN, AlN, AlGaN, InGaN, AlInN, AlInGaN, AlInGaBN, or the like. Next, an undoped nitride layer is grown based on the nitride nucleus growth layer to form the buffer layer 20.

Next, as shown in FIG. 6, in step S15, a doping reinforcement layer 30 is formed on the buffer layer 20. That is, the doping reinforcement layer 30 is formed by alternately stacking a plurality of nitride layers 35 and 37 on which the refractive index is periodically changed on the buffer layer 20. The doping reinforcement layer 30 may be formed as a distributed bragg reflector (DBR) layer. The doping reinforcement layer 30 is formed to have a structure in which the p-type doped first nitride layer 35 and the p-type second nitride layer 37 formed on the first nitride layer 35 are alternately stacked. That is, the doping reinforcement layer 30 may be formed in a form in which the unit doping reinforcement layer 30a is laminated in multiple layers using the first and second nitride layers 35 and 37 as the unit doping reinforcement layer 30a. For example, the first nitride layer 35 may be formed of a material of Al _x Ga _y In _1-xy N (0 <x, 0 <y, x + y ≦ 1) doped with p-type. The second nitride layer 37 may be formed of a material of p-type Al _m Ga _n In _1-mn N (0 <m, 0 <n, m + n ≦ 1).

Next, as shown in FIG. 7, the p-type semiconductor layer 40 is formed on the doping reinforcement layer 30 in step S17. At this time, the p-type semiconductor layer 40 is a semiconductor layer of a nitride material doped with p-type conductive impurities such as Mg, Zn, Be and the like.

Next, as shown in FIG. 8, the active layer 50 is formed on the p-type semiconductor layer 40 in step S19. The active layer 50 may be formed in a quantum well structure using a method such as MOCVD, HVPE, MBE, MOCVPE.

Next, as shown in FIG. 9, the n-type semiconductor layer 60 is formed on the active layer 50 in step S21. The n-type semiconductor layer 60 is formed of AlGaN, and silicon may be doped to lower the driving voltage.

Next, as shown in FIGS. 10 and 11, the electrode forming part 39 is formed in the doping reinforcement layer 30 in step S23. In other words, a portion of the doped reinforcement layer 30 is exposed from the n-type semiconductor layer 60, the active layer 50, and the p-type semiconductor layer 40, and at least two consecutive nitride layers of the plurality of nitride layers 35 and 37. The electrode forming portion 39 is formed by exposing the 35 and 37. In this case, the electrode forming part 39 may be formed as an inclined surface, and the first nitride layer 35 and the second nitride layer 37 are exposed to the inclined surface. The inclined surface can be formed by a method such as a shadow mask, photoresist reflow or laser processing. 10 illustrates an example of forming an inclined surface using a shadow mask.

The shadow mask may be used to form an inclined tip of the photoresist mask, and the electrode forming part 39 may be formed as follows.

First, metal is deposited on the n-type semiconductor layer 60 to form a metal mask 91 pattern. The metal mask 91 is formed in the portion of the n-type semiconductor layer 60 left when forming the electrode forming portion 39. A photoresist mask 93 having an inclined end portion is formed on the n-type semiconductor layer 60 by using the shadow mask. The photoresist mask 93 is formed to have a predetermined thickness to cover the metal mask 91, and the portion where the electrode forming part 39 is to be formed is formed as an inclined surface that becomes thinner toward the end.

Next, a dry etching process is performed. At this time, the photoresist mask 93 is removed by a dry etching process, and the photoresist mask 93 starts to be removed from the end of the photoresist mask 93 whose thickness is gradually processed. As a result, etching is performed while the portion of the n-type semiconductor layer 60 positioned at the end of the photoresist mask 93 is exposed. As shown in FIG. 10, etching is performed in the form of an inclined surface.

In this case, the metal mask 91 is not removed during the dry etching process, and acts as an etch mask, so that the n-type semiconductor layer 60, the active layer 50, the p-type semiconductor layer 40, and the outer side of the metal mask 91 are formed. A portion of the doping reinforcement layer 30 is continuously etched.

As shown in FIG. 11, the metal mask layer is removed after the electrode forming portion 39 is formed in the doping reinforcement layer 30.

Alternatively, the electrode forming unit 39 may be formed as follows. First, a portion of the n-type semiconductor layer 60, the active layer 50, and the p-type semiconductor layer 40 is removed by a general mesa etching method to expose the doping reinforcement layer 30 to the outside. The electrode forming part 39 may be formed by irradiating a portion of the exposed doping reinforcement layer 30 with a laser. At this time, the laser generating device for irradiating the laser irradiates the laser while moving in the Y-axis direction, and increases the intensity of the laser beam in proportion to the movement distance in the Y-axis direction to irradiate the doping reinforcement layer 30 to form an electrode forming part having an inclined surface ( 39).

As shown in FIG. 1, in operation S25, the p-type electrode 70 is formed on the electrode forming unit 39, and the n-type electrode 80 is formed on the n-type semiconductor layer 60. The nitride semiconductor light emitting device 100 according to the example can be obtained. In this case, since the p-type electrode 70 is bonded to the first and second nitride layers 35 and 37 exposed to the electrode forming part 39, the doping concentration through the p-type electrode 70 may be improved. For example, the doping reinforcement layer 30 may form a p-type Al _0.7 Ga _0.3 N layer as the first nitride layer 35 and a p-type Al _0.1 Ga _0.9 N layer as the second nitride layer 37. The first and second nitride layers 35 and 37 may be formed in three layers using the unit doping reinforcement layer 30a. High concentration doping is performed by exposing at least one second nitride layer 37 having a low Al composition ratio through the electrode forming portion 39 and forming a p-type electrode 70 to be connected to the exposed second nitride layer 37. You can get it.

Second embodiment

Meanwhile, in the first embodiment, an example in which the electrode forming portion 39 of the doping reinforcement layer 30 is formed as an inclined surface is disclosed, but is not limited thereto. For example, as shown in FIG. 12, the electrode forming unit 139 may be formed as a recess.

12 is a cross-sectional view illustrating a nitride based semiconductor light emitting device 200 according to a second embodiment of the present invention.

Referring to FIG. 12, in the nitride based semiconductor light emitting device 200 according to the second exemplary embodiment, a buffer layer 120, a doping reinforcement layer 130, a p-type semiconductor layer 140, and an active layer are sequentially formed on a base substrate 110. 150 and the n-type semiconductor layer 160 are formed.

A plurality of nitride layers 135 and 137 may be formed to remove portions of the n-type semiconductor layer 160, the active layer 150, and the p-type semiconductor layer 140 so that a portion of the doping reinforcement layer 130 is exposed, and form the doping reinforcement layer 130. At least two consecutive nitride layers 135 and 137 are formed to form the groove forming electrode 139. A plurality of nitride layers 135 and 137 forming the doping reinforcement layer 130 are exposed through the inner surface of the recess forming the electrode forming unit 139.

The electrode forming unit 139 may be formed as follows. First, a portion of the n-type semiconductor layer 160, the active layer 150, and the p-type semiconductor layer 140 is removed by a general mesa etching method to expose the doping reinforcement layer 130 to the outside. In addition, an exposed portion of the doped reinforcement layer 130 may be irradiated with a laser to form an electrode forming part 139 having a hemispherical groove shape.

The p-type electrode 170 is formed to be filled in the groove of the electrode forming unit 139, and is bonded to the plurality of nitride layers 135 and 137 exposed to the groove.

As such, the nitride-based semiconductor light emitting device 200 according to the second embodiment is also bonded to a plurality of nitride layers 135 and 137 having different refractive indices forming the electrode forming unit 139 as in the first embodiment, thereby providing high concentration. The doping of the light output characteristics can be improved.

Third embodiment

Meanwhile, an example in which the electrode forming portion 139 of the doping reinforcement layer 130 according to the second embodiment is formed as a hemispherical groove is disclosed, but is not limited thereto. For example, as illustrated in FIG. 13, the electrode forming unit 239 may be formed with a plurality of recesses.

13 is a perspective view illustrating a nitride based semiconductor light emitting device 300 according to a third exemplary embodiment of the present invention.

Referring to FIG. 13, in the nitride-based semiconductor light emitting device 300 according to the third embodiment, the buffer layer 220, the doping reinforcement layer 230, the p-type semiconductor layer 240, and the active layer are sequentially formed on the base substrate 210. The structure 250 and the n-type semiconductor layer 260 are formed.

A plurality of nitride layers 235 and 237 which remove a portion of the n-type semiconductor layer 260, the active layer 250, and the p-type semiconductor layer 240 so that a portion of the doping reinforcement layer 230 is exposed, and form the doping reinforcement layer 230. At least two consecutive nitride layers 235 and 237 are formed to form a plurality of groove-shaped electrode forming portions 239. A plurality of nitride layers 235 and 237 forming the doping reinforcement layer 230 are exposed along inner surfaces of the plurality of recesses forming the electrode forming unit 239.

The electrode forming unit 239 may be formed as follows. First, a portion of the n-type semiconductor layer 260, the active layer 250, and the p-type semiconductor layer 240 is removed by a general mesa etching method to expose the doping reinforcement layer 230 to the outside. In addition, an exposed portion of the doped reinforcement layer 230 may be irradiated with a laser discontinuously to form an electrode forming part 239 having a plurality of recesses. In this case, the depths of the grooves are formed deeper than the thicknesses of two consecutive nitride layers 235 and 237 of the doping reinforcement layer 230. The grooves are preferably formed in the doping reinforcement layer 230.

The p-type electrode 270 is formed to be filled in the grooves of the electrode forming unit 239, and is bonded to the plurality of nitride layers 235 and 237 exposed to the grooves.

As described above, the nitride-based semiconductor light emitting device 300 according to the third embodiment is also bonded to a plurality of nitride layers 235 and 237 having different refractive indices forming the electrode forming unit 239 as in the first embodiment, thereby providing high concentration. The doping of the light output characteristics can be improved.

Fourth embodiment

Meanwhile, in the first embodiment, an example in which the electrode forming portion 39 of the doping reinforcement layer 30 is formed as an inclined surface is disclosed, but is not limited thereto. For example, as shown in FIG. 14, the electrode forming unit 339 may be formed in a stepped surface.

14 is a perspective view illustrating a nitride based semiconductor light emitting device 400 according to a fourth exemplary embodiment of the present invention.

Referring to FIG. 14, in the nitride based semiconductor light emitting device 400 according to the fourth exemplary embodiment, a buffer layer 320, a doping reinforcement layer 330, a p-type semiconductor layer 340, and an active layer are sequentially formed on a base substrate 310. 350 and the n-type semiconductor layer 360 is formed.

A plurality of nitride layers 335 and 337 which remove a portion of the n-type semiconductor layer 360, the active layer 350, and the p-type semiconductor layer 340 to expose a portion of the doping reinforcement layer 330, and form the doping reinforcement layer 330. At least two consecutive nitride layers 335 and 337 are formed to form a stepped electrode forming part 339.

The electrode forming unit 339 may be formed as follows. First, a portion of the n-type semiconductor layer 360, the active layer 350, and the p-type semiconductor layer 340 is removed by a general mesa etching method to expose the doping reinforcement layer 330 to the outside. An exposed portion of the doped reinforcement layer 330 may be etched to form an electrode forming portion 339 having a step shape. Alternatively, while continuously irradiating a laser to the exposed doped reinforcement layer 230, the electrode forming portion 339 having a step shape may be formed by irradiating while increasing or decreasing the intensity of the laser beam sequentially. In this case, the plurality of nitride layers 335 and 337 forming the doping reinforcement layer 330 may be exposed to the step surface and the side surface adjacent to the step surface, respectively. At least one nitride layer 335 and 337 may be exposed on the step surface and the adjacent side surface.

The p-type electrode 370 is bonded to the stepped surface of the electrode forming portion 339. As a result, the p-type electrode 370 may be bonded to the plurality of nitride layers 335 and 337 forming the plurality of stepped surfaces.

As such, the nitride-based semiconductor light emitting device 400 according to the fourth embodiment is also bonded to a plurality of nitride layers 335 and 337 having different refractive indices forming the electrode forming unit 339 as in the first embodiment, thereby providing high concentration. The doping of the light output characteristics can be improved.

Fifth Embodiment

15 is a cross-sectional view illustrating a nitride based semiconductor light emitting device 500 according to a fifth embodiment of the present invention.

Referring to FIG. 15, in the nitride based semiconductor light emitting device 500 according to the fifth embodiment, a buffer layer 420, a doping reinforcement layer 430, a p-type semiconductor layer 440, and an active layer are sequentially formed on a base substrate 410. 450 and the n-type semiconductor layer 460 are formed. The doping reinforcement layer 430 forms a superlattice layer 432 formed on the buffer layer 420, and a DBR layer 434 formed on the superlattice layer 432.

Of the DBR layers 434 which remove a portion of the n-type semiconductor layer 460, the active layer 450, and the p-type semiconductor layer 440 so that a portion of the doping reinforcement layer 430 is exposed, and forms the doping reinforcement layer 430. An inclined surface electrode forming portion 439 is formed to expose at least two consecutive nitride layers 435 and 437.

In this case, the superlattice layer 432 reduces the strain generated during the operation of the nitride-based semiconductor light emitting device 500. The superlattice layer 432 is formed on the first Al _x Ga _y In _1-xy N (0 <x, 0 <y, x + y ≦ 1) layer and the first Al _x Ga _y In _1-xy N layer. And a second Al _x Ga _y In _1-xy N layer having a composition ratio different from that of the first Al _x Ga _y In _1-xy N layer (0 <x, 0 <y, x + y ≦ 1). In this case, the superlattice layer 432 is formed of at least one unit superlattice layer using the first and second Al _x Ga _y In _1-xy N layers as the unit superlattice layer. In addition, when the superlattice layer 432 is formed, the first and second Al _x Ga _y In _1-xy N layers may be formed without doping or doping.

For example, the superlattice layer 432 is formed on the undoped first Al _x Ga _1-x N layer 431 (0 <x≤1) and the first Al _x Ga _1-x N layer 431. No. ₁ Al _x Ga _1-x N layer and the un-doped claim 2 Al _x Ga _1-x N layer (433) (0 <x≤1) with a different compositional ratio may have a structure of alternately laminated. For example, the superlattice layer 432 may be formed by stacking one or more unit superlattice layers using the first and second Al _x Ga _1-x N layers 431 and 433 as the unit superlattice layers.

The first and second Al _x Ga _1-x N layers 431 and 433 may have different aluminum composition ratios. Superlattice layer 432 may be formed to a thickness of 100nm to 1㎛. The unit layer forming the superlattice layer 432 may be formed to a thickness of 1 ~ 20nm.

In addition, the superlattice layer 432 may be formed by repeatedly forming nitride layers having different refractive indices, thereby reducing strain and improving crystallinity. (The function as the DBR can be performed together. This allows the superlattice layer 432 to reinforce the function of the DBR along with the DBR layer 434 to the light emitted from the active layer 450.)

Of course, the nitride-based semiconductor light emitting device 500 according to the fifth embodiment is also bonded to a plurality of nitride layers 435 and 437 having different refractive indices forming the electrode forming portion 439 as in the first embodiment, thereby providing a high concentration. Doping can improve the light output characteristics.

Sixth embodiment

Meanwhile, in the first embodiment, the electrode forming portion 39 of the doping reinforcement layer 30 is formed as an inclined surface, but as shown in FIG. For example, as shown in FIGS. 16 and 17, the electrode forming unit 539 may be formed as an inclined surface inclined back and forth.

16 is a perspective view illustrating a nitride based semiconductor light emitting device 600 according to a sixth embodiment of the present invention. 17 is a cross-sectional view of FIG. 16.

16 and 17, in the nitride-based semiconductor light emitting device 600 according to the sixth embodiment, the buffer layer 520, the doping reinforcement layer 530, and the p-type semiconductor layer 540 are sequentially formed on the base substrate 510. ), The active layer 550 and the n-type semiconductor layer 560 are formed.

A plurality of nitride layers 535 and 537 are formed to remove portions of the n-type semiconductor layer 560, the active layer 550, and the p-type semiconductor layer 540 so that a portion of the doping reinforcement layer 530 is exposed. The electrode forming portion 539 is formed on the inclined surface so that at least two consecutive nitride layers 535 and 537 are exposed. In this case, the inclined surface may be formed as an inclined surface having a predetermined angle in the XZ plane with respect to the Y axis. At this time, portions of the doping reinforcement layer 530 are exposed together through the inclined surface and the neighboring surface.

As such, the nitride-based semiconductor light emitting device 600 according to the sixth embodiment is also bonded to a plurality of nitride layers 535 and 537 having different refractive indices forming the electrode forming portion 539 as in the first embodiment, thereby providing high concentration. The doping of the light output characteristics can be improved.

On the other hand, the embodiments disclosed in the specification and drawings are merely presented specific examples to aid understanding, and are not intended to limit the scope of the present invention. It is apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

Claims (15)

1. A base substrate;

   A nitride buffer layer formed on the base substrate;

   A doping reinforcement layer formed on the buffer layer, the doping reinforcement layer including a plurality of nitride layers containing aluminum, the refractive index of which is periodically changed, and having an electrode forming portion to expose at least two consecutive nitride layers of the plurality of nitride layers;

   A nitride-based p-type semiconductor layer containing aluminum formed on the doped reinforcement layer to expose at least the electrode forming portion of the doped reinforcement layer;

   A nitride-based active layer containing aluminum formed on the p-type semiconductor layer;

   A nitride based n-type semiconductor layer containing aluminum formed on the active layer;

   A p-type electrode formed on the electrode forming portion;

   An n-type electrode formed on the n-type semiconductor layer;

   Nitride-based semiconductor light emitting device comprising a.
2. The method of claim 1, wherein the doping reinforcement layer,

   And a nitride layer having an aluminum composition ratio lower than that of the p-type semiconductor layer, wherein the nitride layer is exposed to the electrode forming portion.
3. The method of claim 1, wherein the doping reinforcement layer,

   a first nitride layer doped with p-type;

   And a second nitride layer doped with p-type formed on the p-type nitride layer.

   And the first and second nitride layers are alternately formed.
4. The method of claim 3,

   The first nitride layer is formed of a p-type doped Al _x Ga _y In _1-xy N (0 <x, 0 <y, x + y ≤ 1), the second nitride layer is p-type A nitride-based semiconductor light emitting device, characterized in that formed of a doped Al _m Ga _n In _1-mn N (0 <m, 0 <n, m + n ≤ 1).
5. The electrode forming portion of the doping reinforcement layer,

   A nitride-based semiconductor light emitting device, characterized in that formed in the inclined surface, groove or step surface.
6. The electrode forming portion of the doping reinforcement layer,

   Nitride-based semiconductor light emitting, characterized in that protruding to one side with respect to the n-type semiconductor layer, the active layer and the p-type semiconductor layer formed on the doping reinforcement layer, the inclined surface inclined left and right on the exposed upper surface portion of the doping reinforcement layer device.
7. The electrode forming portion of the doping reinforcement layer,

   Nitride-based semiconductor light emitting, characterized in that protruding toward one side with respect to the n-type semiconductor layer, the active layer and the p-type semiconductor layer is formed in the doping reinforcement layer, the inclined surface inclined up and down on the exposed upper surface portion of the doping reinforcement layer device.
8. The method of claim 1, wherein the doping reinforcement layer,

   A distributed bragg reflector (DBR) layer formed on the buffer layer;

   Nitride-based semiconductor light emitting device comprising a.
9. The method of claim 8, wherein the doping reinforcement layer,

   A superlattice layer formed between the buffer layer and the DBR layer;

   A nitride-based semiconductor light emitting device further comprising.
10. The method of claim 9, wherein the superlattice layer,

    A first Al _x Ga _y In _1-xy N layer (0 <x, 0 <y, x + y ≦ 1);

    A second Al _x Ga _y In _1-xy N layer formed on the first Al _x Ga _y In _1-xy N layer and having a composition ratio different from that of the first Al _x Ga _y In _1-xy N layer (0 < x, 0 <y, x + y ≦ 1);

    The superlattice layer is a nitride-based semiconductor light emitting device, characterized in that the unit superlattice layer is formed of at least one layer using the first and second Al _x Ga _y In _1-xy N layer as a unit superlattice layer. .
11. A base substrate;

    A nitride buffer layer formed on the base substrate;

    A doping reinforcing layer including a plurality of nitride layers having different refractive indices stacked on the buffer layer and having at least two nitride layers having different refractive indices among the plurality of nitride layers exposed on one side thereof;

    A nitride-based p-type semiconductor layer formed on the doping reinforcement layer to expose the electrode forming portion;

    A nitride based active layer formed on the p-type semiconductor layer;

    A nitride n-type semiconductor layer formed on the active layer;

    A p-type electrode formed on the electrode forming portion;

    An n-type electrode formed on the n-type semiconductor layer;

    Nitride-based semiconductor light emitting device comprising a.
12. Forming a nitride buffer layer on the base substrate;

    Forming a doping reinforcement layer on the buffer layer, the doping reinforcement layer including a plurality of nitride layers whose refractive index is changed periodically;

    Forming a nitride-based p-type semiconductor layer containing aluminum on the doping reinforcing layer;

    Forming a nitride-based active layer containing aluminum on the p-type semiconductor layer;

    Forming a nitride based n-type semiconductor layer containing aluminum on the active layer;

    A portion of the n-type semiconductor layer, the active layer and the p-type semiconductor layer is removed to expose a portion of the doping reinforcement layer, and at least two consecutive nitride layers of the plurality of nitride layers forming the doping reinforcement layer are exposed. Forming an electrode forming portion;

    Forming a p-type electrode on the electrode forming part and forming an n-type electrode on the n-type semiconductor layer;

    Method of manufacturing a nitride-based semiconductor light emitting device comprising a.
13. The method of claim 12, wherein forming the electrode forming part comprises:

    A portion of the doped reinforcement layer is exposed by removing a portion of the n-type semiconductor layer, the active layer and the p-type semiconductor layer by using a shadow mask, and at least two consecutive nitride layers forming the doped reinforcement layer. A method of manufacturing a nitride-based semiconductor light emitting device, characterized in that the electrode forming portion is formed so that a nitride layer is exposed through the inclined surface.
14. The method of claim 12, wherein forming the electrode forming part comprises:

    Removing a portion of the n-type semiconductor layer, the active layer and the p-type semiconductor layer to expose a portion of the doping enhancement layer;

     Irradiating at least two consecutive nitride layers of the plurality of nitride layers forming the doped reinforcement layer by irradiating a laser to form an electrode forming portion;

    Method of manufacturing a nitride-based semiconductor light emitting device comprising a.
15. The method of claim 14, wherein in the forming of the electrode forming unit,

    And the electrode forming part is formed to include an inclined surface or at least one recess.

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