KR102582184B1 - Semiconductor device and semiconductor device package including the same - Google Patents

Abstract

An embodiment includes a light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer, wherein the active layer is It includes a plurality of barrier layers and a well layer, wherein the second conductive semiconductor layer includes a 2-1 conductive semiconductor layer and a 2-2 conductive semiconductor layer disposed on the 2-1 conductive semiconductor layer. wherein the barrier layer, the well layer, the 2-1 conduction type semiconductor layer, and the 2-2 conduction type semiconductor layer include AlGaN, and the aluminum composition of the 2-1 conduction type semiconductor layer is the well layer. Disclosed is a semiconductor device that is higher than the aluminum composition of the 2-2 conductivity type semiconductor layer, and the aluminum composition of the 2-2 conductive semiconductor layer is lower than the aluminum composition of the well layer, and a semiconductor device package including the same.

Description

Semiconductor device and semiconductor device package including the same {SEMICONDUCTOR DEVICE AND SEMICONDUCTOR DEVICE PACKAGE INCLUDING THE SAME}

The embodiment relates to a semiconductor device and a semiconductor device package including the same.

Semiconductor devices containing compounds such as GaN and AlGaN have many advantages, such as having a wide and easily adjustable band gap energy, and can be used in a variety of ways, such as light emitting devices, light receiving devices, and various diodes.

In particular, light-emitting devices such as light emitting diodes and laser diodes using group 3-5 or group 2-6 compound semiconductor materials have been developed into red, green, and green colors through the development of thin film growth technology and device materials. Various colors such as blue and ultraviolet rays can be realized, and efficient white light can also be realized by using fluorescent materials or combining colors. Compared to existing light sources such as fluorescent lights and incandescent lights, it has low power consumption, semi-permanent lifespan, and fast response speed. , has the advantages of safety and environmental friendliness.

In addition, when light-receiving devices such as photodetectors or solar cells are manufactured using group 3-5 or group 2-6 compound semiconductor materials, the development of device materials absorbs light in various wavelength ranges to generate photocurrent. By doing so, light of various wavelengths, from gamma rays to radio wavelengths, can be used. In addition, it has the advantages of fast response speed, safety, environmental friendliness, and easy control of device materials, so it can be easily used in power control, ultra-high frequency circuits, or communication modules.

Therefore, semiconductor devices can replace the transmission module of optical communication means, the light emitting diode backlight that replaces the cold cathode fluorescence lamp (CCFL) that constitutes the backlight of LCD (Liquid Crystal Display) display devices, and fluorescent or incandescent light bulbs. Applications are expanding to include white light-emitting diode lighting devices, automobile headlights and traffic lights, and sensors that detect gas or fire. Additionally, the applications of semiconductor devices can be expanded to high-frequency application circuits, other power control devices, and communication modules.

In particular, light-emitting devices that emit light in the ultraviolet wavelength range have a curing or sterilizing effect and can be used for curing, medical purposes, and sterilization.

Recently, research on ultraviolet light-emitting devices has been active, but there are still problems with the ultraviolet light-emitting devices being difficult to implement vertically, and there is a problem of crystallinity deteriorating during the process of separating the substrate.

The embodiment provides a vertical ultraviolet light emitting device.

Additionally, a light emitting device with improved light output is provided.

The problem to be solved in the embodiment is not limited to this, and it will also include means of solving the problem described below and purposes and effects that can be understood from the embodiment.

A semiconductor device according to an embodiment of the present invention is light emitting, including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer. a structure, wherein the active layer includes a plurality of barrier layers and a well layer, the second conductive semiconductor layer includes a 2-1 conductive semiconductor layer, and a second conductive semiconductor layer disposed on the 2-1 conductive semiconductor layer. It includes a 2-2 conduction type semiconductor layer, wherein the barrier layer, the well layer, the 2-1 conduction type semiconductor layer, and the 2-2 conduction type semiconductor layer include AlGaN, and the 2-1 conduction type semiconductor layer A semiconductor device wherein the aluminum composition of the layer is higher than the aluminum composition of the well layer, and the aluminum composition of the 2-2 conductivity type semiconductor layer is lower than the aluminum composition of the well layer.

The aluminum composition of the 2-1 conductive type semiconductor layer may decrease as the distance from the active layer increases.

The aluminum composition of the 2-1 conductive type semiconductor layer may decrease as the distance from the active layer increases.

The aluminum reduction width of the 2-2 conduction type semiconductor layer may be greater than the aluminum reduction width of the 2-1 conductivity type semiconductor layer.

The aluminum composition of the 2-1 conductive type semiconductor layer may be greater than 50% and less than 80%.

The thickness of the 2-1 conductive type semiconductor layer may be greater than 20 nm and less than 100 nm.

The aluminum composition of the 2-2 conductive type semiconductor layer may be greater than 1% and less than 50%.

The thickness of the 2-2 conductive type semiconductor layer may be greater than 1 nm and less than 30 nm.

The thickness of the 2-2 conductive type semiconductor layer may be greater than 5 nm and less than 30 nm.

The thickness of the 2-2 conductive type semiconductor layer may be smaller than the thickness of the 2-1 conductive type semiconductor layer.

The light emitting structure may include a plurality of recesses disposed through the second conductive semiconductor layer and the active layer to a partial area of the first conductive semiconductor layer.

It may include a first conductive layer disposed inside the plurality of recesses and including a connection electrode electrically connected to the first conductive semiconductor layer.

It may include a first electrode disposed between the first conductive semiconductor layer and the connection electrode, and a second electrode electrically connected to the 2-2 conductive semiconductor layer.

A semiconductor device according to another embodiment of the present invention includes 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 the first conductive semiconductor layer. A third conductive semiconductor layer disposed on a second conductive semiconductor layer, wherein the active layer includes a plurality of barrier layers and a well layer, and the barrier layer, the well layer, and the first to third conductive semiconductor layers. includes AlGaN, the aluminum composition of the second conductive semiconductor layer is higher than the aluminum composition of the well layer, the aluminum composition of the third conductive semiconductor layer is lower than the aluminum composition of the well layer, and the first, The third conductive semiconductor layer may include an n-type dopant, and the second conductive semiconductor layer may include a p-type dopant.

The aluminum composition of the third conductive semiconductor layer may be greater than 1% and less than 60%.

The thickness of the third conductive semiconductor layer may be less than 10 nm.

The second conductive semiconductor layer and the aluminum composition of the second conductive semiconductor layer may decrease as the distance from the active layer increases.

The thickness of the third conductive semiconductor layer may be smaller than the thickness of the second conductive semiconductor layer.

It includes a second electrode in contact with the third conductive semiconductor layer, and the second electrode may include ITO.

A semiconductor device package according to an embodiment of the present invention includes a body; and a semiconductor element disposed on the body, wherein the semiconductor element includes a first conductive semiconductor layer, a second conductive semiconductor layer, and a semiconductor layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer. A light emitting structure including an active layer, wherein the active layer includes a plurality of barrier layers and a well layer, wherein the second conductive semiconductor layer is a 2-1 conductive semiconductor layer, and the 2-1 conductive semiconductor layer. It includes a 2-2 conduction type semiconductor layer disposed on a layer, wherein the barrier layer, the well layer, the 2-1 conduction type semiconductor layer, and the 2-2 conduction type semiconductor layer include AlGaN, and the second conductivity type semiconductor layer includes AlGaN. The aluminum composition of the -1 conduction type semiconductor layer may be higher than that of the well layer, and the aluminum composition of the 2-2 conduction type semiconductor layer may be lower than that of the well layer.

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

Additionally, light output can be improved.

The various and beneficial advantages and effects of the present invention are not limited to the above-described content, and may be more easily understood through description of specific embodiments of the present invention.

1 is a conceptual diagram of a light-emitting structure according to an embodiment of the present invention,
Figure 2 is an energy band diagram of a light emitting structure according to an embodiment of the present invention,
3A is a conceptual diagram of a light emitting structure according to another embodiment of the present invention;
Figure 3b is an energy band diagram of a light emitting structure according to another embodiment of the present invention;
4 is a conceptual diagram of a semiconductor device according to an embodiment of the present invention,
5 is a conceptual diagram of a semiconductor device according to another embodiment of the present invention;
6A and 6B are plan views of a semiconductor device according to an embodiment of the present invention;
Figure 7 is a conceptual diagram of a light emitting structure grown on a substrate;
Figure 8 is a diagram for explaining the process of separating the substrate,
Figure 9 is a diagram for explaining the process of etching the light emitting structure,
Figure 10 is a diagram showing the manufactured semiconductor device,
11 is a conceptual diagram of a semiconductor device package according to an embodiment of the present invention.

The present 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.

Even if matters described in a specific embodiment are not explained in other embodiments, they may be understood as descriptions related to other embodiments, as long as there is no explanation contrary to or contradictory to the matter in the other embodiments.

For example, if a feature for configuration A is described in a specific embodiment and a feature for configuration B is described in another embodiment, the description is contrary or contradictory even if an embodiment in which configuration A and configuration B are combined is not explicitly described. Unless otherwise stated, it should be understood as falling within the scope of the rights of the present invention.

In the description of the embodiment, when an element is described as being formed “on or under” another element, or under) includes both elements that are in direct contact with each other or one or more other elements that are formed (indirectly) between the two elements. Additionally, when expressed as "on or under," it can include not only the upward direction but also the downward direction based on one element.

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

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

For example, light in the near-ultraviolet wavelength range (UV-A) may have a wavelength in the range of 320 nm to 420 nm, light in the far-ultraviolet wavelength range (UV-B) may have a wavelength in the range of 280 nm to 320 nm, and deep ultraviolet rays may have a wavelength in the range of 280 nm to 320 nm. Light in the wavelength range (UV-C) may have a wavelength ranging from 100 nm to 280 nm.

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

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

The first conductive semiconductor layer 124 may be implemented with a compound semiconductor such as group III-V or group II-VI, and may be doped with a first dopant. The first conductive semiconductor layer 124 is made of a semiconductor material with a composition formula of Inx1Aly1Ga1-x1-y1N (0≤x1≤1, 0≤y1≤1, 0≤x1+y1≤1), for example, GaN, AlGaN, It can be selected from InGaN, InAlGaN, etc. And, 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 conductive 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 semiconductor layer 124 and holes (or electrons) injected through the second conductive semiconductor layer 127 meet. The active layer 126 transitions to a low energy level as electrons and holes recombine, and can generate light having an ultraviolet wavelength.

The active layer 126 may have any one of a single well structure, a multi-well structure, a single quantum well structure, a multi quantum well (MQW) structure, a quantum dot structure, or a quantum wire structure, and the active layer 126 The structure is not limited to this.

The second conductive semiconductor layer 127 is formed on the active layer 126 and may be implemented with a compound semiconductor such as group III-V or group II-VI. The second conductive semiconductor layer 127 has a second conductive semiconductor layer 127 Dopants may be doped. The second conductive semiconductor layer 127 is a semiconductor material with a composition formula of In _x5 Al _y2 Ga _{1 -x5- y2} N (0≤x5≤1, 0≤y2≤1, 0≤x5+y2≤1) or AlInN. , AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, Ba, etc., the second conductive semiconductor layer 127 doped with the second dopant may be a p-type semiconductor layer.

The second conductive semiconductor layer 127 may include a 2-1 conductive semiconductor layer 127a with a high aluminum composition and a 2-2 conductive semiconductor layer 127b with a relatively low aluminum composition.

An electron blocking layer 129 may be disposed between the active layer 126 and the second conductive semiconductor layer 127. The electron blocking layer 129 blocks the flow of electrons supplied from the first conductive semiconductor layer 124 to the second conductive semiconductor layer 127, allowing electrons and holes to recombine within the active layer 126. You can increase your odds. The energy band gap of the electron blocking layer 129 may be larger than that of the active layer 126 and/or the second conductive semiconductor layer 127.

The electron blocking layer 129 is a semiconductor material having the composition formula In _x1 Al _y1 Ga _{1 -x1- y1} N (0≤x1≤1, 0≤y1≤1, 0≤x1+y1≤1), for example, AlGaN. , InGaN, InAlGaN, etc., but is not limited thereto. The electron blocking layer 129 may include a first layer 129b having a high aluminum composition and a second layer 129a having a low aluminum composition alternately disposed.

Referring to Figure 2, the first conductive semiconductor layer, the barrier layer 126b, the well layer 126a, the 2-1 conductive semiconductor layer 127a, and the 2-2 conductive semiconductor layer 127b. All may contain aluminum. Accordingly, the first conductive semiconductor layer 124, the barrier layer 126b, the well layer 126a, the 2-1 conductive semiconductor layer 127a, and the 2-2 conductive semiconductor layer 127b are AlGaN. It can be. However, it is not necessarily limited to this.

The thickness of the 2-1 conductive type semiconductor layer 127a may be greater than 10 nm and less than 200 nm. If the thickness of the 2-1 conductive type semiconductor layer 127a is less than 10 nm, resistance increases in the horizontal direction and current injection efficiency may decrease. Additionally, when the thickness of the 2-1 conductive type semiconductor layer 127a is greater than 200 nm, resistance increases in the vertical direction and current injection efficiency may decrease.

The aluminum composition of the 2-1 conductive type semiconductor layer 127a may be higher than that of the well layer 126a. To generate ultraviolet light, the aluminum composition of the well layer 126a may be about 30% to 50%. If the aluminum composition of the 2-1 conductive semiconductor layer 127a is lower than the aluminum composition of the well layer 126a, the light extraction efficiency will decrease because the 2-1 conductive semiconductor layer 127a absorbs light. You can.

The aluminum composition of the 2-1 conductive type semiconductor layer 127a may be greater than 40% and less than 80%. If the aluminum composition of the 2-1 conductive semiconductor layer 127a is less than 40%, there is a problem of absorbing light, and if it is greater than 80%, there is a problem that current injection efficiency deteriorates. For example, if the aluminum composition of the well layer 126a is 30%, the aluminum composition of the 2-1 conductive type semiconductor layer 127a may be 40%.

The aluminum composition of the 2-2 conductive type semiconductor layer 127b may be lower than that of the well layer 126a. If the aluminum composition of the 2-2 conductive semiconductor layer 127b is higher than the aluminum composition of the well layer 126a, the resistance between the p-ohmic electrodes increases, resulting in insufficient ohmic generation and low current injection efficiency. .

The aluminum composition of the 2-2 conductive type semiconductor layer 127b may be greater than 1% and less than 50%. If the composition is greater than 50%, sufficient ohmic contact with the p-ohmic electrode may not be achieved, and if the composition is less than 1%, there is a problem of light absorption as it is close to the GaN composition.

The thickness of the 2-2 conductive type semiconductor layer 127b may be greater than 1 nm and less than 30 nm. As described above, the 2-2 conductive semiconductor layer 127b can absorb ultraviolet light because it has a low aluminum composition for ohmic properties. Therefore, it may be advantageous in terms of light output to control the thickness of the 2-2 conductive type semiconductor layer 127b as thin as possible.

However, when the thickness of the 2-2 conductive type semiconductor layer 127b is controlled to 1 nm or less, the 2-2 conductive semiconductor layer 127b is not disposed in some sections, and the 2-1 conductive type semiconductor layer 127a ) may occur in an area exposed to the outside of the light emitting structure 120. Additionally, if the thickness is greater than 30 nm, the amount of light absorbed may become too large, reducing light output efficiency.

The 2-2nd conductive type semiconductor layer 127b may include a 2-3rd conductive type semiconductor layer 127c and a 2-4th conductive type semiconductor layer 127d. The 2-3rd conductive semiconductor layer 127c may be a surface layer in contact with the p-ohmic electrode, and the 2-4th conductive semiconductor layer 127d may be a layer that controls the composition of aluminum.

The second-third conductive semiconductor layer 127c may have an aluminum composition greater than 1% and less than 20%. Alternatively, 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 of the light absorption rate being too high in the 2-3 conductive semiconductor layer 127c, and if the aluminum composition is higher than 20%, the light absorption rate of the second electrode (p-ohmic electrode) may be too high. There may be a problem in that current injection efficiency decreases due to increased contact resistance.

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

For example, when current injection efficiency characteristics are more important than light absorption, the composition ratio of aluminum can be adjusted to 1% to 10%. In the case of products in which optical output characteristics are more important than electrical characteristics, the aluminum composition ratio of the second-third conductive semiconductor layer 127c may be adjusted to 1% to 20%.

When the aluminum composition ratio of the 2-3 conductive semiconductor layer 127c is greater than 1% and less than 20%, the resistance between the 2-3 conductive semiconductor layer 127c and the second electrode decreases, so that the operating voltage increases. It can be lowered. Therefore, electrical characteristics can be improved. The thickness of the second-third conductive type semiconductor layer 127c may be greater than 1 nm and less than 10 nm. Therefore, the light absorption problem can be improved.

The thickness of the 2-2 conductive type semiconductor layer 127b may be smaller than the thickness of the 2-1 conductive type semiconductor layer 127a. The thickness ratio of the 2-1 conductive semiconductor layer 127a and the 2-2 conductive semiconductor layer 127b may be 1.5:1 to 20:1. If the thickness ratio is less than 1.5:1, the thickness of the 2-1 conductive type semiconductor layer 127a may become too thin and current injection efficiency may decrease. Additionally, if the thickness ratio is greater than 20:1, the thickness of the 2-2 conductive type semiconductor layer 127b may become too thin and ohmic reliability may deteriorate.

The aluminum composition of the 2-1 conductive type semiconductor layer 127a may decrease as the distance from the active layer 126 increases. Additionally, the aluminum composition of the 2-2 conductive type semiconductor layer 127b may decrease as the distance from the active layer 126 increases. Accordingly, the aluminum composition of the 2-3 conductive type semiconductor layer 127c may satisfy 1% to 10%.

However, it is not necessarily limited to this, and the aluminum composition of the 2-1 conductive type semiconductor layer 127a and the 2-2 conductive type semiconductor layer 127b does not decrease continuously, but includes a section where there is no decrease in a certain section. You may.

At this time, the aluminum reduction extent of the 2-2 conduction type semiconductor layer 127b may be greater than the aluminum reduction extent of the 2-1 conduction type semiconductor layer 127a. That is, the rate of change of the Al composition ratio of the 2-2 conductive type semiconductor layer 127b in the thickness direction may be greater than the rate of change of the Al composition ratio of the 2-1 conductive type semiconductor layer 127a in the thickness direction. Here, the thickness direction is the direction from the first conductive semiconductor layer 124 to the second conductive semiconductor layer 127, or the direction from the second conductive semiconductor layer 127 to the first conductive semiconductor layer 124. It can be.

While the thickness of the 2-1 conductive type semiconductor layer 127a is thicker than that of the 2-2 conductive type semiconductor layer 127b, the aluminum composition must be higher than that of the well layer 126a, so the decrease may be relatively gentle.

However, since the 2-2 conductive type semiconductor layer 127b is thin and has a large change in aluminum composition, the decrease in aluminum composition may be relatively large.

FIG. 3A is a conceptual diagram of a light emitting structure according to another embodiment of the present invention, and FIG. 3B is a graph showing the energy Al composition ratio of the light emitting structure according to another embodiment of the present invention.

Referring to FIGS. 3A and 3B, the semiconductor device according to the embodiment includes a first conductive semiconductor layer 124, a second conductive semiconductor layer 127, a first conductive semiconductor layer 124, and a second conductive type semiconductor layer. It includes a light emitting structure (120B) including an active layer (126) disposed between the semiconductor layers (127) and a third conductive semiconductor layer (124-1) disposed on the second conductive semiconductor layer (127). .

The thickness of the second conductive semiconductor layer 127 may be greater than 20 nm and less than 200 nm. If the thickness of the second conductive semiconductor layer 127 is less than 20 nm, resistance may increase and current injection efficiency may decrease. Additionally, if the thickness of the second conductive semiconductor layer 127 is greater than 200 nm, the thickness of the second conductive semiconductor layer 127 may become too thick, which may worsen crystallinity, and the light emitted from the active layer 126 may be The probability of absorption increases.

The aluminum composition of the second conductive semiconductor layer 127 may be greater than 40% and less than 80%. If the aluminum composition of the second conductive semiconductor layer 127 is less than 40%, there is a problem of absorbing light, and if it is greater than 80%, there is a problem of poor crystallinity and insufficient current injection efficiency. The second conductive semiconductor layer 127 may be P-AlGaN doped with a p-type dopant.

The third conductive semiconductor layer 124-1 may have an aluminum composition greater than 1% and less than 60%. The third conductive semiconductor layer 124-1 may be doped with an n-type dopant. The third conductive semiconductor layer 124-1 may be n-AlGaN. Since the third conductive semiconductor layer 124-1 has excellent ITO and ohmic properties, the aluminum composition can be controlled to be relatively higher than that of the well layer 126a. Therefore, the absorbed light can be reduced and the light output can be improved.

The thickness of the third conductive semiconductor layer 124-1 may be less than 10 nm. If the thickness of the third conductive semiconductor layer 124-1 is greater than 10 nm, there is a problem that the tunneling effect is weakened. Therefore, hole injection efficiency decreases. Accordingly, the thickness of the third conductive semiconductor layer 124-1 may be smaller than that of the second conductive semiconductor layer 127.

The aluminum composition of the second conductive semiconductor layer 127 and the third conductive semiconductor layer 124-1 may decrease as the distance from the active layer 126 increases. The decrease in aluminum composition of the second conductive semiconductor layer 127 may be different from or the same as that of the third conductive semiconductor layer 124-1.

Figure 4 is a conceptual diagram of a semiconductor device according to an embodiment of the present invention.

Referring to FIG. 4, the structure of the light emitting structure 120 may be the same as that described in FIGS. 1 and 2. The recess 128 may be disposed from the bottom of the second conductive semiconductor layer 127 to a partial area of the first conductive 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. A first electrode 142 may be disposed between the connection electrode 167 and the first conductive semiconductor layer 124. The first electrode 142 may be an ohmic electrode.

It can be arranged so that the distance from the top surface of the first recess 128 to the top surface of the light emitting structure is 1um to 4um. If the upper surface of the light emitting structure and the upper surface of the first recess 128 are less than 1 um, the reliability of the light emitting device may be reduced, and if it is more than 4 um, light extraction efficiency may be reduced due to crystal defects placed inside the light emitting structure. .

The second conductive layer 150 may be disposed on the lower surface of the 2-2 conductive type semiconductor layer and electrically connected to it. The second conductive layer 150 may be disposed in an area between the plurality of connection electrodes 167. One area of the second conductive layer 150 is exposed and may be electrically connected to the second electrode pad 166.

The second electrode 246 may be disposed between the second conductive layer 150 and the 2-2 conductive semiconductor layer 127b and electrically connected to them. Since the surface layer of the 2-2 conductive type semiconductor layer 127b has a relatively low aluminum composition, ohmic connection can be easily made. Additionally, the 2-2 conductive type semiconductor layer 127b has a thickness greater than 1 nm and less than 30 nm, so the amount of light absorption may be small.

The first conductive layer 165 and the second conductive layer 150 may be formed of a transparent conductive oxide (TCO) film. Transparent conductive oxide films include ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), AZO (Aluminum Zinc Oxide), AGZO (Aluminum Gallium Zinc Oxide), IZTO (Indium Zinc Tin Oxide), IAZO (Indium Aluminum Zinc Oxide), and IGZO. (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 include an opaque metal such as Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, etc. Additionally, the first conductive layer 165 may be formed of one or more layers in which a transparent conductive oxide film and an opaque metal are mixed, but is not limited thereto.

The insulating layer 130 may be formed by selecting at least one from the group consisting of SiO ₂ , SixOy, Si ₃ N ₄ , SixNy, SiO _x N _y , Al ₂ O ₃ , TiO ₂ , AlN, etc., but is not limited thereto. No. The insulating layer 130 may electrically insulate the connection electrode 167 from the active layer 126 and the second conductive semiconductor layer 127.

Figure 5 is a conceptual diagram of a semiconductor device according to another embodiment of the present invention.

The light emitting structure 120 of FIG. 5 may have the same configuration as the light emitting structure 120 described in FIG. 1 or FIG. 3 . FIG. 5 exemplarily shows a light emitting structure 120A according to the structure of FIG. 1 .

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

The second electrode 246 may be electrically connected by contacting the 2-2 conductivity type semiconductor layer.

Since the surface layer of the 2-2 conductive type semiconductor layer 127b in contact with the second electrode 246 has an aluminum composition of 1% to 10%, ohmic connection can be easily made. Additionally, the 2-2 conductive type semiconductor layer 127b has a thickness greater than 1 nm and less than 30 nm, so the amount of light absorption 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 are made of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), and indium gallium zinc oxide (IGZO). ), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IZON (IZO Nitride), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), ZnO, IrOx, RuOx, NiO, RuOx/ITO, Ni/IrOx/Au, or Ni/IrOx/Au/ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Sn, In, It may be formed including at least one of Ru, Mg, Zn, Pt, Au, and Hf, but is not limited to these materials.

A second electrode pad 166 may be disposed in one corner area of the semiconductor device. The second electrode pad 166 may have a depressed central portion and have concave and convex portions on its upper surface. A wire (not shown) may be bonded to the concave portion of the upper surface. Accordingly, the adhesion area is expanded so that the second electrode pad 166 and the wire can be more firmly bonded.

Since the second electrode pad 166 can reflect light, light extraction efficiency can 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. Accordingly, the second electrode pad 166 reflects light emitted from the active layer 126 in the horizontal direction of the device upward, improving light extraction efficiency and controlling the beam angle.

The first insulating layer 131 is partially open at the bottom of the second electrode pad 166, so that the second conductive layer 150 and the second electrode 246 can be electrically connected. The passivation layer 180 may be formed on the top and side surfaces of the light emitting structure 120. The passivation layer 180 may contact the first insulating layer 131 in an area adjacent to the second electrode 246 or under the second electrode 246.

The width d22 of the portion where the first insulating layer 131 is open and the second electrode 246 is in contact with the second conductive layer 150 may be, for example, 40 μm to 90 μm. If it is smaller than 40㎛, there is a problem that the operating voltage increases, and if it is larger than 90㎛, it may be difficult to secure a process margin to avoid exposing the second conductive layer 150 to the outside. If the second conductive layer 150 is exposed to the outer area of the second electrode 246, the reliability of the device may decrease. Therefore, preferably, the width d22 may be 60% to 95% of the total width of the second electrode pad 166.

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

The first insulating layer 131 may be formed by selecting at least one 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 , AlN, etc. However, it is not limited to this. The first insulating layer 131 may be formed as a single layer or multiple layers. For example, the first insulating layer 131 may be a distributed Bragg reflector (DBR) with a multilayer structure including silver Si oxide or Ti compound. However, the first insulating layer 131 is not necessarily limited to this and may include various reflective structures.

When the first insulating layer 131 performs an insulating function, light emitted from the active layer 126 toward the side is reflected upward, thereby improving light extraction efficiency. As will be described later, in an ultraviolet semiconductor device, as the number of recesses 128 increases, light extraction efficiency may be more effective.

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 be in contact with the side and top surfaces of the first insulating layer 131. The second conductive layer 150 is made of a material with good adhesion to the first insulating layer 131, and includes at least one material selected from the group consisting of materials such as Cr, Al, Ti, Ni, and Au, and these materials. It may be made of an alloy and may be made of a single layer or multiple layers.

When the second conductive layer 150 is in contact with the side and top surfaces of the first insulating layer 131, the thermal and electrical reliability of the second electrode 246 can be improved. Additionally, it may have a reflection function that reflects light emitted between the first insulating layer 131 and the second electrode 246 upward.

The second conductive layer 150 may also be disposed at a second separation distance between the first insulating layer 131 and the second electrode 246, which is an area where the second conductive semiconductor layer is exposed. The second conductive layer 150 may contact the side and top surfaces of the second electrode 246 and the side and top surfaces of the first insulating layer 131 at a second separation distance.

In addition, an area where the second conductive layer 150 and the second conductive semiconductor layer 127 are in contact with each other within the second separation distance to form a Schottky junction may be disposed, and current dispersion is facilitated by forming the Schottky junction. It can happen.

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 penetrate the second insulating layer 132 and be electrically connected to the first electrode 142.

The first conductive layer 165 and the bonding layer 160 may be disposed along the lower 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 with excellent reflectivity. Exemplarily, the first conductive layer 165 may include aluminum. When the first conductive layer 165 includes aluminum, it serves to reflect light emitted from the active layer 126 upward, thereby improving light extraction efficiency.

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

The substrate 170 may be made of a conductive material. By way of example, the substrate 170 may include a metal or semiconductor material. The substrate 170 may be a metal with excellent electrical conductivity and/or thermal conductivity. In this case, the heat generated during the operation of the semiconductor device can be quickly released to the outside.

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

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

6A and 6B 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 increases, the current diffusion characteristics within the light emitting structure 120 may decrease. Additionally, the amount of light emitted from the active layer 126 to the side increases compared to a GaN-based blue light emitting device (TM mode). This TM mode can occur in ultraviolet semiconductor devices.

According to an embodiment, the GaN semiconductor that emits light in the ultraviolet wavelength range can form a relatively large number of recesses 128 to dispose the first electrode 142 compared to the GaN semiconductor that emits blue light for current diffusion. .

Referring to Figure 6a, as the Al composition increases, the current dispersion characteristics may deteriorate. Accordingly, the current is distributed only to points near each first electrode 142, and the current density may rapidly decrease at points that are far away. Accordingly, the effective light emission area P2 may be narrowed. The effective light emitting area (P2) can be defined as an area up to a boundary point where the current density is 40% or less based on the current density at a point near the first electrode 142 where the current density is highest. For example, the effective light emitting area P2 may be adjusted according to the level of the injection current and the composition of Al in the range of 5㎛ to 40㎛ from the center of the recess 128.

In particular, the low current density region P3 between the adjacent first electrodes 142 has a low current density and therefore hardly contributes to light emission. Accordingly, the embodiment may improve light output by further arranging the first electrode 142 in the low current density region P3 where the current density is low.

In general, since the GaN semiconductor layer has relatively excellent current dispersion characteristics, it is desirable to minimize the areas of the recess 128 and the first electrode 142. This is because as the area of the recess 128 and the first electrode 142 increases, the area of the active layer 126 decreases. However, in the case of the embodiment, the current diffusion characteristics are relatively low due to the high composition of Al, so it is desirable to reduce the low current density region P3 by increasing the number of first electrodes 142 even if the area of the active layer 126 is sacrificed. You can.

Referring to FIG. 6B, when the number of recesses 128 is 48, the recesses 128 may not be arranged in a straight line in the horizontal and vertical directions, but may be arranged in a zigzag manner. In this case, the area of the low current density region (P3) becomes narrower, allowing most of the active layer to participate in light emission. When the number of recesses 128 is 70 to 110, current can be distributed more efficiently, resulting in lower operating voltage and improved light output. In a semiconductor device that emits UV-C, if the number of recesses 128 is less than 70, the electrical and optical properties may deteriorate, and if the number of recesses 128 is more than 110, the electrical properties may be improved, but the volume of the light-emitting layer is reduced, thereby reducing the optical properties. This may deteriorate.

The first area where the plurality of first electrodes 142 are in contact with the first conductive semiconductor layer 122 is between 7.4% and 20%, or between 10% and 20% of the maximum cross-sectional area in the horizontal direction of the light emitting structure 120. You can. The first area may be the sum of the areas where each first electrode 142 is in contact with the first conductive semiconductor layer 122.

If the first area of the plurality of first electrodes 142 is less than 7.4%, sufficient current diffusion characteristics cannot be obtained and the light output is reduced, and if it exceeds 20%, the areas of the active layer and the second electrode are excessively reduced. As a result, there is a problem that the operating voltage increases and the optical output decreases.

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

The second area where the second electrode 246 is in contact with the second conductive semiconductor layer 126 may be between 35% and 70% of the maximum horizontal cross-sectional area of the light emitting structure 120. The second area may be the total area where the second electrode 246 is in contact with the second conductive semiconductor layer 126.

If the second area is less than 35%, the area of the second electrode becomes excessively small, causing the operating voltage to increase and hole injection efficiency to decrease. If the second area exceeds 70%, the first area cannot be effectively expanded, resulting in a decrease in electron injection efficiency.

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

The ratio (first area: second area) of the first area where the plurality of first electrodes are in contact with the first conductive semiconductor layer and the second area where the second electrode is in contact with the second conductive semiconductor layer is 1:3. It may be from 1:10 to 1:10.

When the area ratio is greater than 1:10, the first area is relatively small and the current dispersion characteristics may deteriorate. Additionally, when the area ratio becomes smaller than 1:3, there is a problem in that the second area becomes relatively smaller.

Figure 7 is a conceptual diagram of a light emitting structure grown on a substrate, Figure 8 is a diagram for explaining the process of separating the substrate, Figure 9 is a diagram for explaining the process of etching the light emitting structure, and Figure 10 is a diagram showing the manufactured semiconductor. This is a drawing showing the device.

Referring to FIG. 7, a buffer layer 122, a light absorption layer 123, a first conductive semiconductor layer 124, an active layer 126, a second conductive semiconductor layer 127, and a second conductive semiconductor layer 127 are formed on the growth substrate 121. The two electrodes 246 and the second conductive layer 150 can be formed sequentially.

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 first light absorption layers 123a and second light absorption layers 123b may be alternately arranged.

The aluminum composition of the first light absorption layer 123a may be lower than that of the first conductive semiconductor layer 124. The first light absorption layer 123a may absorb and separate the laser during the LLO process. Therefore, the growth substrate can be removed.

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

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

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

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

The thickness ratio of the first light absorption layer 123a and the second light absorption layer 123b may be 2:1 to 6:1. If the thickness ratio is less than 2:1, the first light absorption layer (123a) becomes thin, making it difficult to sufficiently absorb the laser, and if the thickness ratio is greater than 6:1, the second light absorption layer (123b) becomes too thin, making the overall aluminum composition of the light absorption layer low. There is a problem with losing.

The total thickness of the light absorption 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 absorption layer 123a becomes thin, making it difficult to sufficiently absorb the 246 nm laser, and if the thickness is greater than 400 nm, the overall aluminum composition decreases, causing a problem that crystallinity deteriorates.

According to an embodiment, crystallinity can be improved by forming the light absorption layer 123 with a superlattice structure. With this configuration, the light absorption layer 123 can function as a buffer layer that alleviates lattice mismatch between the growth substrate 121 and the light emitting structure 120.

Referring to FIG. 8, in the step of removing the growth substrate 121, the growth substrate 121 can be separated by irradiating a laser L1 from the side of the growth substrate 121. The laser L1 may have a wavelength range that the first light absorption layer 123a can absorb. As an example, the laser may be a KrF laser with a wavelength of 248 nm.

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

Thereafter, the light absorption layer 123-2 remaining on the first conductive semiconductor layer 124a may be removed by leveling.

Referring to FIG. 9, after forming the second conductive layer 150 on the second conductive semiconductor layer 127, a recess ( 128) can be formed in plural numbers. Thereafter, the insulating layer 130 may be formed on the side of the recess 128 and the second conductive 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. 10, the first conductive layer 165 may be formed below the insulating layer 130. The first conductive layer 165 may be electrically insulated from the second conductive layer 150 by the insulating layer 130.

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

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

Semiconductor devices are packaged and can be used for curing resin, resist, SOD, or SOG. Alternatively, semiconductor devices may be used for medical purposes or for sterilization of air purifiers or water purifiers.

Referring to FIG. 13, the semiconductor device package includes a body 2 in which a groove 2a is formed, a semiconductor device 1 disposed in the body 2, and a semiconductor device 1 disposed in the body 2 and electrically connected to the semiconductor device 1. It may include a pair of lead frames (3, 4) that are connected.

The body 2 may include a material or coating layer that reflects ultraviolet light. Additionally, the mold member 5 covering the semiconductor device 1 may include a material that transmits ultraviolet light.

Semiconductor devices can be used as a light source for a lighting system, a light source for an image display device, or a light source for a lighting device. In other words, the semiconductor device can be applied to various electronic devices that are placed in a case and provide light. For example, when using a mixture of semiconductor devices and RGB phosphors, white light with excellent color rendering (CRI) can be implemented.

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

When used as a backlight unit for a video display device, it can be used as an edge-type backlight unit or a direct-type backlight unit. When used as a light source for a lighting device, it can be used as a luminaire or bulb type. It can also be used as a light source for a mobile terminal. It may be possible.

Light-emitting devices include laser diodes in addition to the light-emitting diodes described above.

The laser diode, like the light emitting device, may include a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer of the above-described structure. In addition, the electro-luminescence phenomenon, in which light is emitted when a p-type first conductivity type semiconductor and an n-type second conductivity type semiconductor are bonded and an electric current flows, is used, but the directionality of the emitted light is different. There is a difference in phase. In other words, a laser diode can emit light with one specific wavelength (monochromatic beam) with the same phase and in the same direction by using a phenomenon called stimulated emission and constructive interference. Therefore, it can be used in optical communications, medical equipment, and semiconductor processing equipment.

An example of a light receiving element is a photodetector, which is a type of transducer that detects light and converts the intensity into an electrical signal. Such photodetectors include photocells (silicon, selenium), light output devices (cadmium sulfide, cadmium selenide), photodiodes (e.g., PDs with a peak wavelength in the visible blind spectral region or true blind spectral region), and photovoltaic devices (PDs). Examples include transistors, photomultiplier tubes, photoelectron tubes (vacuum, gas-encapsulated), and IR (Infra-Red) detectors, but embodiments are not limited thereto.

Additionally, semiconductor devices such as photodetectors can generally be manufactured using direct bandgap semiconductors, which have excellent light conversion efficiency. Alternatively, photodetectors have various structures, and the most common structures include a pin-type photodetector using a p-n junction, a Schottky-type photodetector using a Schottky junction, and a MSM (Metal Semiconductor Metal) type photodetector. there is.

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

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

In addition, it can be used as a rectifier in electronic circuits through the rectification characteristics of a general diode using a p-n junction, and can be applied to ultra-high frequency circuits and oscillator circuits.

In addition, the above-described semiconductor device is not necessarily implemented only as a semiconductor and may further include a metal material in some cases. For example, a semiconductor device such as a light receiving device may be implemented using at least one of Ag, Al, Au, In, Ga, N, Zn, Se, P, or As, and may be implemented using a p-type or n-type dopant. It may also be implemented using doped semiconductor materials or intrinsic semiconductor materials.

Although the above description focuses on the examples, this is only an example and does not limit the present invention, and those skilled in the art will be able to You will see that various variations and applications are possible. For example, each component specifically shown in the examples can be modified and implemented. And these variations and differences in application should be construed as being included in the scope of the present invention as defined in the appended claims.

120: Light-emitting structure
124: First conductive semiconductor layer
126: active layer
127: Second conductive semiconductor layer
127a: 2-1 conductive semiconductor layer
127b: 2-2 conductive semiconductor layer

Claims (20)

A first conductive semiconductor layer,
a second conductive semiconductor layer, and
A light emitting structure including an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer,
The active layer includes a plurality of barrier layers and a well layer,
The second conductive semiconductor layer includes a 2-1 conductive semiconductor layer and a 2-2 conductive semiconductor layer disposed on the 2-1 conductive semiconductor layer,
The plurality of barrier layers, the well layer, the 2-1 conduction type semiconductor layer, and the 2-2 conduction type semiconductor layer include AlGaN,
The aluminum composition of the 2-1 conductivity type semiconductor layer is higher than the aluminum composition of the well layer,
The aluminum composition of the 2-2 conductive type semiconductor layer is lower than the aluminum composition of the well layer,
The thickness of the 2-2 conductive type semiconductor layer is greater than 1 nm and less than 30 nm,
The aluminum composition of the 2-2 conductivity type semiconductor layer decreases with a first slope as the distance from the active layer increases,
The aluminum composition of the 2-1 conductivity type semiconductor layer decreases with a second slope as the distance from the active layer increases,
A semiconductor device wherein the first slope is greater than the second slope.
delete delete According to paragraph 1,
A semiconductor device wherein the aluminum reduction width of the 2-2 conduction type semiconductor layer is greater than the aluminum reduction width of the 2-1 conduction type semiconductor layer.
According to paragraph 1,
A semiconductor device wherein the aluminum composition of the 2-1 conductive type semiconductor layer is greater than 40% and less than 80%.
According to clause 5,
A semiconductor device wherein the thickness of the 2-1 conductive semiconductor layer is greater than 10 nm and less than 200 nm.
According to paragraph 1,
A semiconductor device wherein the aluminum composition of the 2-2 conductive type semiconductor layer is greater than 1% and less than 50%.
delete According to paragraph 1,
A semiconductor device wherein the thickness of the 2-2 conductive type semiconductor layer is smaller than the thickness of the 2-1 conductive type semiconductor layer.
According to paragraph 1,
The light emitting structure is a semiconductor device including a plurality of recesses disposed through the second conductive semiconductor layer and the active layer to a partial area of the first conductive semiconductor layer.
According to clause 10,
A semiconductor device comprising a first conductive layer disposed inside the plurality of recesses and including a connection electrode electrically connected to the first conductive semiconductor layer.
According to clause 11,
A first electrode disposed between the first conductive semiconductor layer and the connection electrode, and
A semiconductor device including a second electrode electrically connected to the 2-2 conductive semiconductor layer.
According to clause 12,
The 2-2 conductive semiconductor layer includes a 2-3 conductive semiconductor layer in contact with the second electrode,
A semiconductor device wherein the aluminum composition of the 2-3 conductive type semiconductor layer is 1% to 10%. delete delete delete delete delete delete delete

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