KR20180029750A - Semiconductor device and semiconductor device package including the same - Google Patents

Abstract

An embodiment of the present invention discloses a semiconductor device including a light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer, an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer and a blocking layer disposed between the active layer and the second conductive semiconductor layer, and a semiconductor device package including the same. Wherein, the active layer includes a first well layer disposed to be closet to the blocking layer. A first intermediate layer is disposed between the first well layer of the active layer and the blocking layer. The first intermediate layer includes a (1-1)^th section with a lower aluminum composition than the blocking layer and a (1-2)^th section with a higher aluminum composition than the blocking layer. The aluminum composition of the (1-1)^th section is 50% to 70%. Accordingly, the present invention can improve a light output.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a semiconductor device and a semiconductor device package including the semiconductor device.

Embodiments relate to a semiconductor device and a semiconductor device package including the same.

Semiconductor devices including compounds such as GaN and AlGaN have many merits such as wide and easy bandgap energy, and can be used variously as light emitting devices, light receiving devices, and various diodes.

Particularly, a light emitting device such as a light emitting diode or a laser diode using a semiconductor material of Group 3-5 or 2-6 group semiconductors can be applied to various devices such as a red, Blue, and ultraviolet rays. By using fluorescent materials or combining colors, it is possible to realize a white light beam with high efficiency. Also, compared to conventional light sources such as fluorescent lamps and incandescent lamps, low power consumption, , Safety, and environmental friendliness.

In addition, when a light-receiving element such as a photodetector or a solar cell is manufactured using a semiconductor material of Group 3-5 or Group 2-6 compound semiconductor, development of a device material absorbs light of various wavelength regions to generate a photocurrent , It is possible to use light in various wavelength ranges from the gamma ray to the radio wave region. It also has advantages of fast response speed, safety, environmental friendliness and easy control of device materials, so it can be easily used for power control or microwave circuit or communication module.

Accordingly, the semiconductor device can be replaced with a transmission module of an optical communication means, a light emitting diode backlight replacing a cold cathode fluorescent lamp (CCFL) constituting a backlight of an LCD (Liquid Crystal Display) display device, White light emitting diodes (LEDs), automotive headlights, traffic lights, and gas and fire sensors. In addition, semiconductor devices can be applied to high frequency application circuits, other power control devices, and communication modules.

Particularly, a light emitting element that emits light in the ultraviolet wavelength range can be used for curing, medical use, and sterilization by curing or sterilizing action

However, since the ultraviolet semiconductor device has a relatively high aluminum composition, doping of the P-type dopant is difficult, and the activation efficiency of the P-type dopant is low, resulting in poor hole injection efficiency.

Further, if the P-type dopant is excessively injected, there is a problem that the dopant diffuses into the active layer and the light output decreases.

The embodiment provides a semiconductor device with improved light output.

The embodiment provides a semiconductor device having excellent crystallinity.

The problems to be solved in the embodiments are not limited to these, and the objects and effects that can be grasped from the solution means and the embodiments of the problems described below are also included.

A semiconductor device according to an embodiment of the present invention includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, And a blocking layer disposed between the second conductivity type semiconductor layers, wherein the active layer includes a first well layer disposed closest to the blocking layer, and the first well layer of the active layer and the blocking Wherein the first intermediate layer includes a 1-1 section having a lower aluminum composition than the blocking layer and a 1-2 section having a higher aluminum composition than the blocking layer, The aluminum composition in the 1-1 section is 50% to 70%.

The aluminum composition may be increased in the 1-2 zone as it approaches the barrier layer.

The 1-2 zone may include an undoped section.

The aluminum composition in the 1-2 zone may be 80% to 100%.

The thickness ratio between the 1-1 section and the 1-2 section may be 10: 1 to 1: 1.

The thickness of the first intermediate layer may be 2 nm to 10 nm.

The blocking layer may comprise a P-type dopant.

And a second intermediate layer disposed between the first intermediate layer and the blocking layer, and the aluminum composition of the second intermediate layer may be lower than that of the blocking layer.

The aluminum composition of the second intermediate layer may be higher than the aluminum composition of the first section.

The second intermediate layer may include a 2-1 section including no P-type dopant, and a 2-2 section including a P-type dopant.

The ratio of the thickness of the 2-1 section to the thickness of the 2-2 section may be 9: 1 to 1: 1.

The second intermediate layer may be alternately arranged between the second-first section and the second-second section.

The barrier layer may include a plurality of first barrier layers and a plurality of second barrier layers having a lower aluminum composition than the first barrier layers.

The aluminum composition of the first barrier layer may be 70% to 80%, and the aluminum composition of the second barrier layer may be 50% to 70%.

According to the embodiment, a vertical type ultraviolet light emitting device can be manufactured.

Further, the light output can be improved.

The various and advantageous advantages and effects of the present invention are not limited to the above description, and can be more easily understood in the course of describing a specific embodiment of the present invention.

1 is a conceptual diagram of a light emitting structure according to an embodiment of the present invention,
FIG. 2 is a graph showing an aluminum composition of a light emitting structure according to an embodiment of the present invention,
FIG. 3 is a graph showing an aluminum composition of a light emitting structure according to another embodiment of the present invention,
FIG. 4 is a graph illustrating the light efficiency of a semiconductor device including a conventional light emitting structure,
FIG. 5 is a graph illustrating light efficiency of a light emitting structure according to another embodiment of the present invention, and FIG.
FIG. 6 is a graph showing an aluminum composition of a light emitting structure according to another embodiment of the present invention,
7 is a conceptual diagram of a semiconductor device according to an embodiment of the present invention,
8 is a conceptual view of a semiconductor device according to another embodiment of the present invention,
FIGS. 9A and 9B are views for explaining a structure in which light output is improved according to the number of recesses,
10 is a conceptual diagram of a light emitting structure grown on a substrate,
11 is a view for explaining a process of separating a substrate,
12 is a view for explaining a process of etching a light emitting structure,
13 is a view showing a semiconductor device manufactured,
14 is a conceptual view of a semiconductor device package according to an embodiment of the present invention.

The embodiments may be modified in other forms or various embodiments may be combined with each other, and the scope of the present invention is not limited to each embodiment described below.

Although not described in the context of another embodiment, unless otherwise described or contradicted by the description in another embodiment, the description in relation to another embodiment may be understood.

For example, if the features of configuration A are described in a particular embodiment, and the features of configuration B are described in another embodiment, even if the embodiment in which configuration A and configuration B are combined is not explicitly described, It is to be understood that they fall within the scope of the present invention.

In the description of the embodiments, in the case where one element is described as being formed "on or under" another element, the upper (upper) or lower (lower) or under are all such that two elements are in direct contact with each other or one or more other elements are indirectly formed between the two elements. Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

The light emitting structure according to an embodiment of the present invention can output light in an ultraviolet wavelength band. For example, the light emitting structure may output light (UV-A) at near-ultraviolet wavelength band, output light (UV-B) at deep ultraviolet wavelength band, Can be output. The wavelength range can be determined by the composition ratio of Al of the light emitting structure 120.

Illustratively, the near ultraviolet light (UV-A) may have a wavelength in the range of 320 to 420 nm, the far ultraviolet light (UV-B) may have a wavelength in the range of 280 nm to 320 nm, The light of the wavelength band (UV-C) may have a wavelength in the range of 100 nm to 280 nm.

FIG. 1 is a conceptual diagram of a light emitting structure according to an embodiment of the present invention, and FIG. 2 is a graph showing an aluminum composition of a light emitting structure according to an embodiment of the present invention.

Referring to FIG. 1, a semiconductor device according to an embodiment includes a light emitting structure 120A including a first conductive semiconductor layer 124, a second conductive semiconductor layer 127, and an active layer 126.

The first conductive semiconductor layer 124 may be formed of a compound semiconductor such as Group III-V or Group II-VI, and the first dopant may be doped. The first conductive semiconductor layer 124 may be a semiconductor material having a composition formula of Inx1Aly1Ga1-x1-y1N (0? X1? 1, 0? Y1? 1, 0? X1 + y1? 1), for example, GaN, AlGaN, InGaN, InAlGaN, and the like. The first dopant may be an n-type dopant such as Si, Ge, Sn, Se, or Te. When the first dopant is an n-type dopant, the first conductivity type semiconductor layer 124 doped with the first dopant may be an n-type semiconductor layer.

The active layer 126 is disposed between the first conductive semiconductor layer 124 and the second conductive semiconductor layer 127. The active layer 126 is a layer where electrons (or holes) injected through the first conductive type semiconductor layer 124 and holes (or electrons) injected through the second conductive type semiconductor layer 127 meet. The active layer 126 transitions to a low energy level as electrons and holes recombine, and can generate light having ultraviolet wavelengths.

The active layer 126 may have any one of a single well structure, a multiple well structure, a single quantum well structure, a multi quantum well (MQW) structure, a quantum dot structure, Is not limited thereto.

The second conductive semiconductor layer 127 may be formed on the active layer 126 and may be formed of a compound semiconductor such as a group III-V or a II-VI group. In the second conductive semiconductor layer 127, The dopant can be doped. The second conductive semiconductor layer 127 may be a semiconductor material having a composition formula of Inx5Aly2Ga1-x5-y2N (0? X5? 1, 0? Y2? 1, 0? X5 + y2? 1) or a semiconductor material having a composition formula of AlInN, AlGaAs, GaP, GaAs , GaAsP, and AlGaInP. When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, or Ba, the second conductivity type semiconductor layer 127 doped with the second dopant may be a p-type semiconductor layer.

A blocking layer 129 may be disposed between the active layer 126 and the second conductive semiconductor layer 127. The blocking layer 129 prevents the flow of electrons supplied from the first conductivity type semiconductor layer 124 to the second conductivity type semiconductor layer 127 and prevents the probability that electrons and holes recombine in the active layer 126 . The energy band gap of the blocking layer 129 may be greater than the energy band gap of the active layer 126 and / or the second conductivity type semiconductor layer 127.

The barrier layer 129 may be formed of a semiconductor material having a composition formula of In _{x 1} Al _{y 1} Ga _{1 -x 1 -y 1} N (0 _{≦ x 1 ≦ 1} , 0 _{≦ y 1 ≦ 1} , 0 _{≦ x 1 + y 1 ≦ 1} ) InGaN, InAlGaN, and the like, but is not limited thereto.

Referring to FIG. 2, the first conductive semiconductor layer, the active layer 126, the blocking layer 129, and the second conductive semiconductor layer 127 may all include aluminum.

Therefore, the first conductive semiconductor layer 124, the active layer 126, the blocking layer 129, and the second conductive semiconductor layer 127 may be AlGaN. However, the present invention is not limited thereto. Some layers may be GaN or AlN.

The active layer 126 may have a plurality of well layers 126a and barrier layers 126b alternately arranged. The well layer 126a may have an aluminum composition of about 30% to 50% to emit ultraviolet light. The barrier layer 126b may have an aluminum composition of 50% to 70% to confine the carrier.

Illustratively, a well layer closest to the barrier layer 129 in the well layer 126a is defined as a first well layer 126a and a final barrier (not shown) disposed between the first well layer 126a and the barrier layer 129 Layer is defined as a first barrier layer 126b.

The barrier layer 129 may have an aluminum composition of 50% to 90%. The barrier layer 129 may have a plurality of first barrier layers 129a having a relatively high aluminum composition and a plurality of second barrier layers 129b having a low aluminum composition alternately. When the aluminum composition of the barrier layer 129 is less than 50%, the height of the energy barrier for blocking electrons may be insufficient, light emitted from the active layer 126 may be absorbed by the barrier layer 129, %, The electrical characteristics of the semiconductor device may deteriorate.

The aluminum composition of the first barrier layer 129a may be 70% to 90%, and the aluminum composition of the second barrier layer 129b may be 50% to 70%. However, the present invention is not limited thereto, and the aluminum composition of the first barrier layer 129a and the second barrier layer 129b may be adjusted to suit the purpose.

The first intermediate layer S10 may be disposed between the first well layer 126a of the active layer 126 and the blocking layer 129. [ The first intermediate layer S10 may include a first section S11 having a lower aluminum composition than the barrier layer 129 and a second section S12 having a higher aluminum composition than the barrier layer 129 .

The first intermediate layer S10 may be the first barrier layer 126b. Therefore, the thickness of the first intermediate layer S10 may be equal to the thickness of the adjacent barrier layer 126b. Illustratively, the thickness of the first intermediate layer S10 may be 2 nm to 10 nm. However, the present invention is not limited thereto, and the first intermediate layer S10 may be a separate semiconductor layer disposed between the first barrier layer 126b and the barrier layer 129. [

The aluminum composition of the first section S11 may be 50% to 70%. That is, the 1-1 section S11 may be substantially the same as the aluminum composition of the adjacent barrier layer 126b. The thickness of the first section S11 may be about 1 nm to 8 nm. If the thickness of the first section S11 is 1 nm or less, the Al content in the well layer 126a may increase sharply and it may be difficult to prevent crystallinity degradation. If the thickness of the first section S11 is larger than 8 nm, the efficiency of injecting holes into the active layer 126 may be lowered and the optical characteristics may be lowered.

The first-second section S12 may have a higher aluminum composition than the barrier layer 129. The aluminum composition may be increased in the first-second section S12 as the barrier layer 129 is closer to the barrier layer 129. [ The aluminum composition in the first-second section S12 may be 80% to 100%. That is, the first-second section S12 may be AlGaN or AlN. Or the first-second section S12 may be a superlattice layer in which AlGaN and AlN are alternately arranged.

The first-second section S12 may be formed to be thinner than the first-section section S11. The thickness of the first-second section S12 may be about 0.1 nm to 4 nm. If the thickness of the first-second section S12 is thinner than 0.1 nm, there may be a problem that electron movement can not be efficiently blocked. If the thickness of the first section S12 is larger than 4 nm, the efficiency of injecting holes into the active layer may be lowered.

The thickness ratio of the 1-1 section (S11) and the 1-2 section (S12) may be 10: 1 to 1: 1. When the above condition is satisfied, the electron injection can be prevented while the hole injection efficiency is not lowered.

The first-second section S12 may include an undoped section. The Mg of the barrier layer 129 may be diffused in a part of the first section although the first-second section S12 grows without supplying the dopant. However, in order to prevent the dopant from diffusing into the active layer 126, at least some regions of the first-second section S12 may include an undoped section.

FIG. 3 is a graph showing the aluminum composition of the light emitting structure 120 according to another embodiment of the present invention, FIG. 4 is a graph showing the light output of the semiconductor device including the conventional light emitting structure 120, FIG. 3 is a graph illustrating the light output of the light emitting structure 120 according to another embodiment of the present invention. FIG.

Referring to FIG. 3, all of the structures described in FIG. 2 can be applied except for the structure of the second intermediate layer S20. The second intermediate layer S20 may be disposed between the first intermediate layer S10 and the barrier layer 129. [ At this time, the aluminum composition of the second intermediate layer S20 is lower than that of the barrier layer 129 and may be higher than the aluminum composition of the first section S11. Illustratively, the aluminum composition of the second intermediate layer S20 may be from 50% to 80%.

The second intermediate layer S20 may include a second-1 section S21 not including a P-type dopant, and a second 2-section S22 including a P-type dopant.

The (2-1) -th section S21 may be an unsent section. Therefore, diffusion of the dopant into the active layer 126 during growth of the blocking layer 129 can be suppressed. The thickness of the (2-1) section S21 may be 4 nm to 19 nm. When the thickness of the second section S21 is smaller than 4 nm, diffusion of the dopant is difficult to suppress, and when the thickness is larger than 19 nm, the hole injection efficiency may be lowered.

The second-second section S22 may include a P-type dopant. The second-2 section S22 may include a dopant to improve the efficiency of injecting holes into the second-1 section S21. That is, the second-second section S22 can serve as a low-resistance layer for lowering the resistance level.

The thickness of the second-second section S22 may be 1 nm to 6 nm. If the thickness is smaller than 1 nm, it is difficult to effectively lower the resistance, and if the thickness is larger than 6 nm, the thickness of the second-1 section S21 may be reduced and diffusion of the dopant may be difficult to suppress. The ratio of the thickness of the 2-1 section S21 to the thickness of the 2-2 section S22 may be 19: 1 to 1: 1.5.

However, the second intermediate layer S20 is not necessarily limited to this, and the second intermediate layer S20 may have a super lattice structure in which the 2-1 section S21 and the 2-2 section S22 are alternately arranged.

Referring to FIG. 4, in the case of a conventional semiconductor device having a light emitting structure, the light output decreases by about 20% when the time increases by about 100 hours. Further, when about 500 hours have elapsed, it is understood that the light output is reduced by about 25%.

On the other hand, referring to FIG. 5, in the case of the semiconductor device having the light emitting structure according to the embodiment, the luminous intensity of about 3.5% was lowered even after 100 hours passed, and almost the same light output . That is, it can be seen that the embodiment has improved light output by about 20% compared to the conventional structure without the intermediate layer.

6 is a graph showing an aluminum composition of a light emitting structure according to another embodiment of the present invention.

Referring to FIG. 6, the second conductivity type semiconductor layer 129 may include a second-conductivity-type semiconductor layer 129a and a second-conductivity-type semiconductor layer 129b.

The thickness of the second-first conductivity type semiconductor layer 127a may be larger than 10 nm and smaller than 200 nm. When the thickness of the second-first conductivity type semiconductor layer 127a is smaller than 10 nm, the resistance increases in the horizontal direction, and the current injection efficiency may be lowered. In addition, when the thickness of the second-first conductivity type semiconductor layer 127a is larger than 200 nm, resistance increases in the vertical direction and the current injection efficiency may be lowered.

The aluminum composition of the second-first conductivity type semiconductor layer 127a may be higher than that of the well layer 126a. The aluminum composition of the well layer 126a to produce ultraviolet light may be about 30% to 50%. If the aluminum composition of the second-first conductivity type semiconductor layer 127a is lower than the aluminum composition of the well layer 126a, the second-first conductivity type semiconductor layer 127a absorbs light, .

The aluminum composition of the second-first conductivity type semiconductor layer 127a may be greater than 40% and less than 80%. When the aluminum composition of the second-first conductivity type semiconductor layer 127a is less than 40%, there is a problem of absorbing light. When the aluminum composition is more than 80%, the current injection efficiency is deteriorated. Illustratively, when the aluminum composition of the well layer 126a is 30%, the aluminum composition of the second-first conductivity type semiconductor layer 127a may be 40%.

The aluminum composition of the second-second conductivity type semiconductor layer 127b may be lower than the aluminum composition of the well layer 126a. When the aluminum composition of the second-conductivity-type semiconductor layer 127b is higher than the aluminum composition of the well layer 126a, the resistance between the p-ohmic electrodes becomes high, so that sufficient ohmic can not be obtained, .

The aluminum composition of the second-conductivity-type semiconductor layer 127b may be greater than 1% and less than 50%. If it is larger than 50%, the ohmic contact with the p-ohmic electrode may not be sufficiently performed. If the composition is less than 1%, the GaN composition is close to the GaN composition and the light is absorbed.

The thickness of the second-conductivity-type semiconductor layer 127b may be greater than 1 nm and less than 30 nm. As described above, since the composition of aluminum is low for the ohmic operation, the second-conductivity-type semiconductor layer 127b can absorb ultraviolet light. Therefore, it is advantageous from the viewpoint of light output to control the thickness of the second-second conductivity type semiconductor layer 127b as thin as possible.

However, if the thickness of the second-second conductivity-type semiconductor layer 127b is controlled to be 1 nm or less, the second-second conductivity-type semiconductor layer 127a May be exposed to the outside of the light emitting structure 120 may occur. In addition, when the thickness is larger than 30 nm, the amount of light absorbed becomes too large, and the light output efficiency may decrease.

The second-conductivity-type semiconductor layer 127b may include the second and third conductivity-type semiconductor layers 127c and 127d. The second to third conductivity type semiconductor layer 127c may be a surface layer in contact with the second electrode and the second to fourth conductivity type semiconductor layer 127d may be a layer that controls the composition of aluminum.

The second to third conductivity type semiconductor layer 127c may have an aluminum composition of greater than 1% and less than 20%. Or the aluminum composition may be greater than 1% and less than 10%.

If the aluminum composition is lower than 1%, there may be a problem that the light absorption rate becomes too high in the second and third conductive type semiconductor layers 127c and 127b. If the aluminum composition is higher than 20% There may be a problem that the contact resistance increases and the current injection efficiency decreases.

However, the present invention is not limited thereto, and the aluminum composition of the second and third conductivity type semiconductor layers 127c may be adjusted in consideration of current injection characteristics and light absorption rate. Alternatively, it may be adjusted according to the light output required by the product.

For example, when the current injection efficiency characteristic is more important than the light absorption rate, the composition ratio of aluminum can be adjusted to 1% to 10%. In the case of a product in which the optical output characteristics are more important than the electrical characteristics, the aluminum composition ratio of the second and third conductivity type semiconductor layers 127c may be adjusted to 1% to 20%.

When the aluminum composition ratio of the second to third conductivity type semiconductor layers 127c is larger than 1% and smaller than 20%, the resistance between the second and third conductivity type semiconductor layers 127c and the second electrode decreases, Can be lowered. Thus, the electrical characteristics can be improved. The thickness of the second and third conductivity type semiconductor layers 127c may be greater than 1 nm and less than 10 nm. Therefore, the light absorption problem can be improved.

The thickness of the second-second conductivity type semiconductor layer 127b may be smaller than the thickness of the second-type conductivity type semiconductor layer 127a. The thickness ratio of the second-first conductivity type semiconductor layer 127a and the second-type conductivity type semiconductor layer 127b may be from 1.5: 1 to 20: 1. If the thickness ratio is smaller than 1.5: 1, the thickness of the second-first conductivity type semiconductor layer 127a becomes too thin, and the current injection efficiency can be reduced. In addition, when the thickness ratio is larger than 20: 1, the thickness of the second-second conductivity-type semiconductor layer 127b becomes too thin, and the ohmic reliability may deteriorate.

The aluminum composition of the second-first conductivity type semiconductor layer 127a may be smaller as the distance from the active layer 126 increases. Further, the aluminum composition of the second-conductivity-type semiconductor layer 127b may become smaller as the distance from the active layer 126 increases. Therefore, the aluminum composition of the 2-3 conductive semiconductor layer 127c can satisfy 1% to 10%.

However, the present invention is not limited to this, and the aluminum composition of the second-first conductivity-type semiconductor layer 127a and the second-conductivity-type semiconductor layer 127b is not continuously decreased but includes a period in which there is no decrease in a certain section You may.

At this time, the aluminum reduction width of the second-second conductivity-type semiconductor layer 127b may be larger than the aluminum reduction width of the second-first conductivity type semiconductor layer 127a. That is, the rate of change of the Al composition ratio of the second-second conductivity type semiconductor layer 127b with respect to the thickness direction may be larger than the rate of change of the Al composition ratio of the second-first conductivity type semiconductor layer 127a with respect to the thickness direction. The thickness direction is a direction from the first conductivity type semiconductor layer 124 to the second conductivity type semiconductor layer 127 or a direction from the second conductivity type semiconductor layer 127 to the first conductivity type semiconductor layer 124 .

The second-first conductivity type semiconductor layer 127a is thicker than the second-type conductivity-type semiconductor layer 127b, while the aluminum composition must be higher than the well layer 126a, so that the reduction width may be relatively slow.

However, since the thickness of the second-conductivity-type semiconductor layer 127b is thin and the variation range of the aluminum composition is large, the decrease in the aluminum composition can be relatively large.

7 is a conceptual diagram of a semiconductor device according to an embodiment of the present invention.

Referring to FIG. 7, the structure of the light emitting structure 120 can be directly applied to the structure illustrated in FIGS. 1 to 6. The recess 128 may extend from the bottom of the second conductivity type semiconductor layer 127 to a portion of the first conductivity type semiconductor layer 124 through the active layer 126.

The first conductive layer 165 includes a connection electrode 167 disposed in the recess 128 and electrically connected to the first conductive semiconductor layer 124. The first electrode 142 may be disposed between the connection electrode 167 and the first conductivity type semiconductor layer 124. The first electrode 142 may be an ohmic electrode.

The distance from the upper surface of the first recess 128 to the upper surface of the light emitting structure may be 1 μm to 4 μm. If the top surface of the light emitting structure and the top surface of the first recess 128 are less than 1 μm, the reliability of the light emitting device may be degraded. If the top surface of the light emitting structure is more than 4 μm, the light extraction efficiency may be reduced due to crystal defects, .

The second conductive layer 150 may be disposed on the lower surface of the second-conductivity-type semiconductor layer and electrically connected thereto. The second conductive layer 150 may be disposed between the plurality of connection electrodes 167. The second conductive layer 150 may be electrically connected to the second electrode pad 166 by exposing a region thereof.

The second electrode 246 may be disposed between the second conductive layer 150 and the second conductive semiconductor layer 127b to be electrically connected to the second conductive semiconductor layer 127b. Since the composition of aluminum is relatively low in the surface layer of the second-conductivity-type semiconductor layer 127b, ohmic connection can be facilitated. Further, since the thickness of the second-second conductivity type semiconductor layer 127b is larger than 1 nm and smaller than 30 nm, the light absorption amount may be small.

The first conductive layer 165 and the second conductive layer 150 may be formed of a transparent conductive oxide (TCO). The transparent conductive oxide film may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), aluminum gallium zinc oxide (IZTO), indium aluminum zinc oxide (IZO) (Indium Gallium Zinc Oxide), IGTO (Indium Gallium Tin Oxide), ATO (Antimony Tin Oxide), GZO (Gallium Zinc Oxide), IZON (IZO Nitride), ZnO, IrOx, RuOx and NiO.

The first conductive layer 165 and the second conductive layer 150 may contain an opaque metal such as Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au or Hf. In addition, the first conductive layer 165 may be formed of one or a plurality of layers mixed with a transparent conductive oxide film and an opaque metal, but is not limited thereto.

The insulating layer 130 may be formed of at least one selected from the group consisting of SiO2, SixOy, Si3N4, SixNy, SiOxNy, Al2O3, TiO2, AlN, and the like. The insulating layer 130 may electrically isolate the connection electrode 167 from the active layer 126 and the second conductivity type semiconductor layer 127.

8 is a conceptual view of a semiconductor device according to another embodiment of the present invention.

The light emitting structure 120 of FIG. 8 can be applied to the structure of the light emitting structure 120 described in FIG. 1 or FIG. 6 as it is.

The first electrode 142 may be disposed on the upper surface of the recess 128 and may be electrically connected to the first conductive semiconductor layer 124. The second electrode 246 may be formed under the second conductive semiconductor layer 127.

The second electrode 246 may be in contact with and electrically connected to the second-conductivity-type semiconductor layer.

The surface layer of the second-conductivity-type semiconductor layer 127b which is in contact with the second electrode 246 has an aluminum composition of 1% to 10%, so ohmic connection can be easily performed. Further, since the thickness of the second-second conductivity type semiconductor layer 127b is larger than 1 nm and smaller than 30 nm, the light absorption amount may be small.

The first electrode 142 and the second electrode 246 may be ohmic electrodes. The first electrode 142 and the second electrode 246 may be formed of one selected from the group consisting of ITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide), IAZO (indium aluminum zinc oxide), IGZO ), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IZON (IZO Nitride), AGZO ZnO, ZnO, IrOx, RuOx, NiO, RuOx / ITO, Ni / IrOx / Au or Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ru, Mg, Zn, Pt, Au, and Hf. However, the present invention is not limited to these materials.

A second electrode pad 166 may be disposed at one corner of the semiconductor device. The central portion of the second electrode pad 166 is recessed so that the upper surface of the second electrode pad 166 may have a concave portion and a convex portion. A wire (not shown) may be bonded to the concave portion of the upper surface. Accordingly, the bonding area can be widened and the second electrode pad 166 and the wire can be bonded more firmly.

Since the second electrode pad 166 may reflect light, the light extraction efficiency may be improved as the second electrode pad 166 is closer to the light emitting structure 120.

The height of the convex portion of the second electrode pad 166 may be higher than that of the active layer 126. Therefore, the second electrode pad 166 can reflect the light emitted in the horizontal direction of the device from the active layer 126 to improve the light extraction efficiency and control the directivity angle.

The first insulating layer 131 may be partially opened from the bottom of the second electrode pad 166 so that the second conductive layer 150 and the second electrode 246 may be electrically connected. The passivation layer 180 may be formed on the top surface and side surfaces of the light emitting structure 120. The passivation layer 180 may be in contact with the first insulation layer 131 at a region adjacent to the second electrode 246 or at a lower portion of the second electrode 246.

The width d22 of the portion where the first insulating layer 131 is opened and the second electrode 246 contacts the second conductive layer 150 may be, for example, 40 to 90 占 퐉. If the thickness is larger than 90 탆, it may be difficult to secure a process margin for not exposing the second conductive layer 150 to the outside. If the second conductive layer 150 is exposed to the outside of the second electrode 246, the reliability of the device may be degraded. Thus, preferably the width d22 may be between 60% and 95% of the overall width of the second electrode pad 166. [

The first insulating layer 131 may electrically isolate the first electrode 142 from the active layer 126 and the second conductive type semiconductor layer 127. The first insulating layer 131 may electrically isolate the second electrode 246 and the second conductive layer 150 from the first conductive layer 165.

The first insulating layer 131 may be formed of at least one selected from the group consisting of SiO ₂ , SixOy, Si ₃ N ₄ , Si _x N _y , SiO _x N _y , Al ₂ O ₃ , TiO ₂ , However, the present invention is not limited thereto. The first insulating layer 131 may be formed as a single layer or a multilayer. Illustratively, the first insulating layer 131 may be a DBR (distributed Bragg reflector) having a multi-layer structure including silver oxide or Ti compound. However, the first insulating layer 131 may include various reflective structures without being limited thereto.

When the first insulating layer 131 performs the insulating function, light emitted toward the side surface of the active layer 126 may be reflected upward to improve light extraction efficiency. As described later, in the ultraviolet semiconductor device, the larger the number of the recesses 128, the more effective the light extraction efficiency.

The second conductive layer 150 may cover the second electrode 246. Accordingly, the second electrode pad 166, the second conductive layer 150, and the second electrode 246 can form one electrical channel.

The second conductive layer 150 completely surrounds the second electrode 246 and may contact the side surface and the upper surface of the first insulating layer 131. The second conductive layer 150 is made of a material having good adhesion to the first insulating layer 131 and includes at least one material selected from the group consisting of Cr, Al, Ti, Ni, Au, And may be a single layer or a plurality of layers.

The thermal and electrical reliability of the second electrode 246 can be improved when the second conductive layer 150 is in contact with the side surface and the upper surface of the first insulating layer 131. [ In addition, the first insulating layer 131 and the second electrode 246 may have a function of reflecting light emitted to the upper side.

The second conductive layer 150 may be disposed between the first insulating layer 131 and the second electrode 246 at a second distance that is a region in which the second conductive type semiconductor layer is exposed. The second conductive layer 150 may be in contact with a side surface and an upper surface of the second electrode 246 and a side surface and an upper surface of the first insulating layer 131 at a second spacing distance.

The second conductive layer 150 and the second conductive type semiconductor layer 127 may be in contact with each other to form a Schottky junction within the second spacing distance. By forming the Schottky junction, .

The second insulating layer 132 electrically insulates the second electrode 246 and the second conductive layer 150 from the first conductive layer 165. The first conductive layer 165 may be electrically connected to the first electrode 142 through the second insulating layer 132.

The first conductive layer 165 and the bonding layer 160 may be disposed along the bottom surface of the light emitting structure 120 and the shape of the recess 128. The first conductive layer 165 may be made of a material having a high reflectivity. Illustratively, the first conductive layer 165 may comprise aluminum. When the first conductive layer 165 includes aluminum, it functions to reflect the light emitted from the active layer 126 to the upper portion, thereby improving the light extraction efficiency.

The bonding layer 160 may include a conductive material. Illustratively, the bonding layer 160 may comprise a material selected from the group consisting of gold, tin, indium, aluminum, silicon, silver, nickel, and copper, or alloys thereof.

The substrate 170 may be made of a conductive material. Illustratively, substrate 170 may comprise a metal or semiconductor material. The substrate 170 may be a metal having excellent electrical conductivity and / or thermal conductivity. In this case, the heat generated during semiconductor device operation can be quickly dissipated to the outside.

The substrate 170 may comprise a material selected from the group consisting of silicon, molybdenum, silicon, tungsten, copper, and aluminum, or alloys thereof.

Irregularities may be formed on the upper surface of the light emitting structure 120. This unevenness can improve the extraction efficiency of light emitted from the light emitting structure 120. The average height may vary depending on the wavelength of ultraviolet light. In the case of UV-C, the height of the unevenness is about 300 nm to 800 nm, and the light extraction efficiency can be improved when the average height is 500 nm to 600 nm.

9A and 9B are plan views of a semiconductor device according to an embodiment of the present invention.

If the Al composition of the light emitting structure 120 is increased, the current diffusion characteristics in the light emitting structure 120 may be degraded. In addition, the amount of light emitted to the side of the active layer 126 is increased (TM mode) as compared with the GaN-based blue light emitting device. This TM mode can occur in an ultraviolet semiconductor device.

According to the embodiment, the GaN semiconductor that emits light in the ultraviolet region can form a relatively larger number of recesses 128 than the GaN semiconductor that emits blue light for current diffusion, thereby disposing the first electrode 142 .

Referring to FIG. 9A, when the composition of Al is high, the current dispersion characteristics may deteriorate. Therefore, the current is dispersed only at the neighboring point to each first electrode 142, and the current density can be drastically lowered at the far point. Therefore, the effective light-emitting region P2 can be narrowed. The effective light emitting region P2 can be defined as a region up to the boundary point where the current density is 40% or less based on the current density at the vicinity of the first electrode 142 having the highest current density. For example, the effective light-emitting region P2 can be adjusted according to the level of the injection current and the composition of Al within the range of 5 to 40 mu m from the center of the recess 128. [

In particular, the low current density region P3 between the neighboring first electrodes 142 has a low current density and hardly contributes to light emission. Therefore, the embodiment can further improve the light output by disposing the first electrode 142 in the low current density region P3 having a low current density.

In general, it is preferable to minimize the area of the recesses 128 and the first electrode 142 because the GaN semiconductor layer has a relatively good current dispersion characteristic. The larger the area of the recess 128 and the first electrode 142 is, the smaller the area of the active layer 126 is. However, in the embodiment, it is preferable to increase the number of the first electrodes 142 and reduce the low current density region P3 even if the area of the active layer 126 is sacrificed because the composition of Al is high and the current diffusion property is relatively low. .

Referring to FIG. 9B, when the number of recesses 128 is 48, the recesses 128 may not be arranged in a straight line in the transverse direction, but may be disposed in a zigzag manner. In this case, the area of the low current density region (P3) becomes narrower, and most of the active layer can participate in the light emission. When the number of the recesses 128 is 70 to 110, the current may be more efficiently dispersed, the operating voltage may be lowered, and the light output may be improved. If the number of the recesses 128 is less than 70, the electrical and optical properties may be deteriorated. If the number of the recesses 128 is more than 110, the electrical characteristics may be improved, but the volume of the light- Can be lowered.

The first area where the plurality of first electrodes 142 are in contact with the first conductivity type semiconductor layer 122 is 7.4% to 20% of the maximum cross-sectional area in the horizontal direction of the light emitting structure 120, or 10% . The first area may be the sum of the areas where the first electrodes 142 are in contact with the first conductivity type semiconductor layer 122.

If the first area of the plurality of first electrodes 142 is less than 7.4%, the sufficient current diffusion property can not be obtained and the light output decreases. If the first area is more than 20%, the area of the active layer and the second electrode is excessively reduced There is a problem that the operating voltage rises and the optical output decreases.

In addition, the total area of the plurality of recesses 128 may be 13% or more and 30% or less of the maximum cross-sectional area in the horizontal direction of the light emitting structure 120. If the total area of the recess 128 does not satisfy the above condition, it is difficult to control the total area of the first electrode 142 to 7.4% or more and 20% or less. Further, there is a problem that the operating voltage rises and the light output decreases.

The second area where the second electrode 246 contacts the second conductivity type semiconductor layer 126 may be 35% or more and 70% or less of the maximum cross-sectional area in the horizontal direction of the light emitting structure 120. The second area may be the total area at which the second electrode 246 contacts the second conductive semiconductor layer 126.

If the second area is less than 35%, the area of the second electrode becomes excessively small, which increases the operating voltage and lowers the hole injection efficiency. When the second area exceeds 70%, the first area can not be widened effectively, and there is a problem that the injection efficiency of electrons is lowered.

The first area and the second area have an inverse relationship. That is, when the number of recesses is increased in order to increase the number of first electrodes, the area of the second electrode decreases. In order to increase the light output, the dispersion characteristics of electrons and holes must be balanced. Therefore, it is important to determine a proper ratio of the first area and the second area.

The ratio of the first area where the plurality of first electrodes are in contact with the first conductivity type semiconductor layer and the second area where the second electrode is in contact with the second conductivity type semiconductor layer (first area: second area) is 1: 3 To 1:10.

If the area ratio is larger than 1:10, the first area is relatively small and the current dispersion characteristics may be deteriorated. Further, when the area ratio is smaller than 1: 3, there is a problem that the second area becomes relatively small.

11 is a view for explaining a process of separating a substrate, FIG. 12 is a view for explaining a process of etching a light emitting structure, and FIG. 13 is a view for explaining a process of etching a semiconductor Fig.

10, a buffer layer 122, a light absorption layer 123, a first conductivity type semiconductor layer 124, an active layer 126, a second conductivity type semiconductor layer 127, The second electrode 246, and the second conductive layer 150 may be sequentially formed.

At this time, the first intermediate layer and the second intermediate layer may be grown between the active layer 126 and the blocking layer 129. The first barrier layer may be grown to have a 1-1 section in which the composition of aluminum is 50% to 70% and a 1-2 section in which the aluminum composition is 80% to 100%. Also, the second intermediate layer may be grown to have the second-1 section where the P-type dopant is not doped and the second-2 section doped with the dopant.

The light absorption layer 123 includes a first light absorption layer 123a having a low aluminum composition and a second light absorption layer 123b having a high aluminum composition. A plurality of the first light absorbing layer 123a and the second light absorbing layer 123b may be alternately arranged.

The aluminum composition of the first light absorption layer 123a may be lower than the aluminum composition of the first conductivity type semiconductor layer 124. The first light absorbing layer 123a can perform a role of absorbing and separating the laser light during the LLO process. Thus, the growth substrate can be removed.

The thickness of the first light absorbing layer 123a and the aluminum composition can be appropriately adjusted to absorb a laser having a predetermined wavelength (e.g., 246 nm). The aluminum composition of the first light absorbing layer 123a may be 20% to 50%, and the thickness may be 1 nm to 10 nm. Illustratively, the first light absorbing layer 123a may be AlGaN, but is not limited thereto.

The aluminum composition of the second light absorption layer 123b may be higher than the aluminum composition of the first conductivity type semiconductor layer 124. The second light absorbing layer 123b can improve the crystallinity of the first conductivity type semiconductor layer 124 grown on the light absorbing layer 123 by increasing the aluminum composition lowered by the first light absorbing layer 123a.

Illustratively, the aluminum composition of the second light absorbing layer 123b may be from 60% to 100%, and the thickness may be from 0.1 nm to 2.0 nm. The second light absorbing layer 123b may be AlGaN or AlN.

The thickness of the first light absorbing layer 123a may be thicker than the thickness of the second light absorbing layer 123b in order to absorb the laser of the wavelength of 246 nm. The thickness of the first light absorbing layer 123a may be 1 nm to 10 nm, and the thickness of the second light absorbing layer 123b may be 0.5 nm to 2.0 nm.

The thickness ratio of the first light absorbing layer 123a and the second light absorbing layer 123b may be 2: 1 to 6: 1. When the thickness ratio is less than 2: 1, the first light absorbing layer 123a becomes thin and the laser is not sufficiently absorbed. When the thickness ratio is more than 6: 1, the second light absorbing layer 123b becomes too thin, There is a problem to lose.

The total thickness of the light absorbing layer 123 may be greater than 100 nm and less than 400 nm. If the thickness is less than 100 nm, the thickness of the first light absorbing layer 123a becomes thin and it is difficult to sufficiently absorb the 246 nm laser. If the thickness is larger than 400 nm, the aluminum composition is lowered overall and crystallinity deteriorates.

According to the embodiment, the light absorption layer 123 having a superlattice structure can be formed to improve crystallinity. With this structure, the light absorption layer 123 can function as a buffer layer for relieving lattice mismatch between the growth substrate 121 and the light emitting structure 120.

Referring to FIG. 11, in the step of removing the growth substrate 121, the growth substrate 121 can be separated by irradiating the laser L1 on the growth substrate 121 side. The laser L1 may have a wavelength band that can be absorbed by the first light absorbing layer 123a. As an example, the laser may be a KrF laser with a 248 nm wavelength band.

The growth substrate 121 and the second light absorbing layer 123b do not absorb the laser L1 because the energy band gap is large. However, the first light absorbing layer 123a having a low aluminum composition can be decomposed by absorbing the laser L1. Therefore, it can be separated together with the growth substrate 121.

Thereafter, the light absorbing layer 123-2 remaining in the first conductivity type semiconductor layer 124 can be removed by leveling.

12, after a second conductive layer 150 is formed on the second conductive semiconductor layer 127, a recess (not shown) penetrating to a part of the first conductive semiconductor layer 124 of the light emitting structure 120 128 can be formed. An insulating layer 130 may then be formed on the side surfaces of the recess 128 and on the second conductivity type semiconductor layer 127. Thereafter, the first electrode 142 may be formed on the first conductive semiconductor layer 124b exposed by the recess 128. [

Referring to FIG. 13, the first conductive layer 165 may be formed under the insulating layer 130. The first conductive layer 165 may be electrically insulated from the second conductive layer 150 by an insulating layer 130.

Thereafter, the conductive substrate 170 may be formed under the first conductive layer 165, and the second electrode pad 166 may be formed on the second conductive layer 150 exposed by the mesa etching.

14 is a conceptual view of a semiconductor device package according to an embodiment of the present invention.

The semiconductor device is composed of a package and can be used for curing a resin, a resist, SOD or SOG. Alternatively, the semiconductor device may be used for therapeutic medical use or for sterilizing air purifiers, water purifiers, and the like.

14, the semiconductor device package comprises a body 2 formed with a groove 3, a semiconductor element 1 disposed on the body 2, and a semiconductor element 1 disposed on the body 2 and electrically connected to the semiconductor element 1 And may include a pair of lead frames 5a and 5b connected thereto. The semiconductor element 1 may include all of the structures described above.

The body 2 may include a material or a coating layer that reflects ultraviolet light. The body 2 can be formed by laminating a plurality of layers 2a, 2b, 2c, and 2d. The plurality of layers 2a, 2b, 2c, 2d may be the same material or may comprise different materials.

The groove 3 may be formed so as to be wider as it is away from the semiconductor element, and a step 3a may be formed on the inclined surface.

The light-transmitting layer 4 may cover the groove 3. [ The light-transmitting layer 4 may be made of a glass material, but is not limited thereto. The light-transmitting layer 4 is not particularly limited as long as it is a material capable of effectively transmitting ultraviolet light. The inside of the groove 3 may be an empty space.

The semiconductor device may be used as a light source of an illumination system, or as a light source of an image display device or a lighting device. That is, semiconductor devices can be applied to various electronic devices arranged in a case to provide light. Illustratively, when a semiconductor device and an RGB phosphor are mixed and used, white light with excellent color rendering (CRI) can be realized.

The above-described semiconductor device is composed of a light emitting device package and can be used as a light source of an illumination system, for example, as a light source of a video display device or a lighting device.

When used as a backlight unit of a video display device, it can be used as an edge type backlight unit or as a direct-type backlight unit. When used as a light source of a lighting device, it can be used as a regulator or a bulb type. It is possible.

The light emitting element includes a laser diode in addition to the light emitting diode described above.

The laser diode may include the first conductivity type semiconductor layer, the active layer and the second conductivity type semiconductor layer having the above-described structure, like the light emitting element. Then, an electro-luminescence (electroluminescence) phenomenon in which light is emitted when an electric current is applied after bonding the p-type first conductivity type semiconductor and the n-type second conductivity type semiconductor is used, There are differences in the directionality and phase of light. That is, the laser diode can emit light having one specific wavelength (monochromatic beam) with the same phase and in the same direction by using a phenomenon called stimulated emission and a constructive interference phenomenon. It can be used for optical communication, medical equipment and semiconductor processing equipment.

As the light receiving element, a photodetector, which is a kind of transducer that detects light and converts the intensity of the light into an electric signal, is exemplified. As photodetectors, photodetectors (silicon, selenium), photodetectors (cadmium sulfide, cadmium selenide), photodiodes (for example, visible blind spectral regions or PDs with peak wavelengths in the true blind spectral region) A transistor, a photomultiplier tube, a phototube (vacuum, gas-filled), and an IR (Infra-Red) detector, but the embodiment is not limited thereto.

In addition, a semiconductor device such as a photodetector may be fabricated using a direct bandgap semiconductor, which is generally excellent in photo-conversion efficiency. Alternatively, the photodetector has a variety of structures, and the most general structure includes a pinned photodetector using a pn junction, a Schottky photodetector using a Schottky junction, and a metal-semiconductor metal (MSM) photodetector have.

The photodiode, like the light emitting device, may include the first conductivity type semiconductor layer having the structure described above, the active layer, and the second conductivity type semiconductor layer, and may have a pn junction or a pin structure. The photodiode operates by applying reverse bias or zero bias. When light is incident on the photodiode, electrons and holes are generated and a current flows. At this time, the magnitude of the current may be approximately proportional to the intensity of the light incident on the photodiode.

A photovoltaic cell or a solar cell is a type of photodiode that can convert light into current. The solar cell, like the light emitting device, may include the first conductivity type semiconductor layer, the active layer and the second conductivity type semiconductor layer having the above-described structure.

In addition, it can be used as a rectifier of an electronic circuit through a rectifying characteristic of a general diode using a p-n junction, and can be applied to an oscillation circuit or the like by being applied to a microwave circuit.

In addition, the above-described semiconductor element is not necessarily implemented as a semiconductor, and may further include a metal material as the case may be. For example, a semiconductor device such as a light receiving element may be implemented using at least one of Ag, Al, Au, In, Ga, N, Zn, Se, P, or As, Or may be implemented using a doped semiconductor material or an intrinsic semiconductor material.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

120: light emitting structure
124: First conductive type semiconductor layer
126:
127: second conductive type semiconductor layer
129: blocking layer
142: first electrode
150: second conductive layer
246: second electrode

Claims (15)

The first conductivity type semiconductor layer,
The second conductivity type semiconductor layer,
An active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer,
And a barrier layer disposed between the active layer and the second conductivity type semiconductor layer,
Wherein the active layer comprises a first well layer disposed closest to the blocking layer,
And a first intermediate layer disposed between the first well layer and the blocking layer of the active layer,
Wherein the first intermediate layer comprises
A 1-1 section where the aluminum composition is lower than that of the barrier layer, and
And the second barrier layer has a higher aluminum composition than the barrier layer,
And the aluminum composition in the 1-1 section is 50% to 70%.
The method according to claim 1,
And the aluminum composition is increased as the first and second sections become closer to the blocking layer.
The method according to claim 1,
And the first-second section includes an undoped section.
The method according to claim 1,
And the aluminum composition in the first-second section is 80% to 100%.
The method according to claim 1,
And the thickness ratio between the 1-1 section and the 1-2 section is 10: 1 to 1: 1.
The method according to claim 1,
And the thickness of the first intermediate layer is 2 nm to 10 nm.
The method according to claim 1,
Wherein the blocking layer comprises a P-type dopant.
The method according to claim 1,
And a second intermediate layer disposed between the first intermediate layer and the blocking layer,
Wherein an aluminum composition of the second intermediate layer is lower than the barrier layer.
9. The method of claim 8,
And the aluminum composition of the second intermediate layer is higher than the aluminum composition of the first section.
9. The method of claim 8,
Wherein the second intermediate layer comprises
A 2-1 section including no P-type dopant, and
And a second-2 section including a P-type dopant.
11. The method of claim 10,
And the ratio of the thickness of the second section to the thickness of the second section is from 9: 1 to 1: 1.
11. The method of claim 10,
Wherein the second intermediate layer comprises
And the second-1 section and the second-2 section are alternately arranged.
The method according to claim 1,
Wherein the barrier layer comprises:
A plurality of first barrier layers, and
And a plurality of second barrier layers having a lower aluminum composition than the first barrier layer.
14. The method of claim 13,
The aluminum composition of the first barrier layer is 70% to 80%
And the aluminum composition of the second barrier layer is 50% to 70%.
Body;
And a semiconductor device disposed on the body,
The semiconductor device may further include:
The first conductivity type semiconductor layer,
The second conductivity type semiconductor layer,
An active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer,
And a barrier layer disposed between the active layer and the second conductivity type semiconductor layer,
Wherein the active layer comprises a first well layer disposed closest to the blocking layer,
And a first intermediate layer disposed between the first well layer and the blocking layer of the active layer,
Wherein the first intermediate layer comprises
A 1-1 section where the aluminum composition is lower than that of the barrier layer, and
And a first-second section having a higher aluminum composition than the barrier layer.

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