KR20180028338A - Semiconductor device and semiconductor device package including the same - Google Patents

Abstract

The present invention relates to a semiconductor device which has increased light extraction efficiency and excellent current distribution efficiency, and a semiconductor device package including the same. The semiconductor device comprises: a light emitting structure which includes a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between the first and second conductive semiconductor layers, and a plurality of recesses disposed to a partial area of the first conductive semiconductor layer through the second conductive semiconductor layer and the active layer; a first electrode disposed in the recesses and electrically connected with the first conductive semiconductor layer; second electrodes disposed on a first surface of the second conductive semiconductor layer; a first conductive layer electrically connected to the first electrode; and a second conductive layer electrically connected to the second electrode. The first surface of the second conductive reflective layer includes a surface 1-1 disposed between the centers of two recesses adjacent to each other. The first direction is a direction perpendicular to a thickness direction of the light emitting structure. The surface 1-1 includes a first section in which the second electrodes are separated in the first direction, and a second section disposed between the second electrodes. The second conductive layers are disposed in the section and the second section. A ratio of the width of the first direction of the second section to the entire width of the first direction of the first section is 1 : 0.7 or 1 : 5.

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.

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

Recently, research on ultraviolet light emitting devices has been actively conducted. However, there is a problem that it is difficult to realize a vertical type ultraviolet light emitting device, and the light extraction efficiency is relatively low.

The embodiment provides a semiconductor device with improved light extraction efficiency.

The embodiment provides a semiconductor device having excellent current dispersion efficiency.

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, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, A light emitting structure including a plurality of recesses penetrating the second conductivity type semiconductor layer and the active layer and disposed to a partial region of the first conductivity type semiconductor layer; A first electrode disposed inside the plurality of recesses and electrically connected to the first conductive semiconductor layer; A second electrode electrically connected to the second conductive semiconductor layer; A first conductive layer electrically connected to the first electrode; And a second conductive layer electrically connected to the second electrode, wherein the second conductive reflective layer includes a first-first surface disposed between centers of two recesses closest to each other in the first direction, Wherein the first direction is a direction perpendicular to a thickness direction of the light emitting structure, the first-first surface is a first section in which a second electrode spaced in the first direction is disposed, And the second conductive layer is disposed in the first section and the second section, and the width of the second section in the first direction is 1: 0.7 of the entire width in the first direction of the first section. To 1: 5.

According to the embodiment, the light extraction efficiency is improved.

Further, the current dispersion efficiency is excellent, and 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.

FIG. 1 is a conceptual diagram of a light emitting structure according to an embodiment of the present invention,
2 is a graph showing the aluminum composition of the light emitting structure,
3A and 3B are diagrams for explaining a configuration in which light output is improved in accordance with the number of recesses,
4 is a conceptual view of a semiconductor device according to the first embodiment of the present invention,
Fig. 5 is a plan view of Fig. 4,
Fig. 6 is a sectional view in the AA direction in Fig. 5,
7 is a view for explaining the configuration of the second conductive layer,
Fig. 8 is a first modification of Fig. 7,
Fig. 9 is a second modification of Fig. 7,
10 is a conceptual diagram of a semiconductor device according to a second embodiment of the present invention,
Fig. 11 is a plan view of Fig. 10,
Fig. 12 is an enlarged view of part B-1 in Fig. 11,
Fig. 13 is an enlarged view of part B-2 in Fig. 11,
Fig. 14 is a sectional view in the direction of the BB in Fig. 12,
Fig. 15 is a first modification of Fig. 14,
Fig. 16 is a second modification of Fig. 14,
FIG. 17 is a third modification of FIG. 13,
18 is a conceptual diagram of a semiconductor device according to the third embodiment of the present invention,
Fig. 19 is a plan view of Fig. 18,
Fig. 20 is a sectional view in the CC direction of Fig. 19,
Fig. 21 is a first modification of Fig. 20,
Fig. 22 is a second modification of Fig. 20,
23 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.

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 illustrating the aluminum composition of FIG. 1.

The light emitting structure 120 according to the embodiment of the present invention can output light in the ultraviolet wavelength range. 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.

1, a semiconductor device according to an embodiment includes a first conductive semiconductor layer 124, a second conductive semiconductor layer 127, a first conductive semiconductor layer 124, And an active layer 126 disposed between the active layer 126 and the active layer 127.

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 In _{x 1} Al _{y 1} Ga ₁ -x ₁ -y1 N (0? _{X1? 1} , 0 _{? Y1? 1} , 0? X1 + y1? 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, or a quantum well structure. ) Is not limited to this.

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. A second conductive semiconductor layer 127 is a semiconductor material having a compositional 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, or Ba, the second conductivity type semiconductor layer 127 doped with the second dopant may be a p-type semiconductor layer.

The second conductivity type semiconductor layer 127 may include a second conductivity type semiconductor layer 127a having a high aluminum composition and a second conductivity type semiconductor layer 127b having a relatively low aluminum composition.

The second electrode 246 may be in ohmic contact with the second-conductivity-type semiconductor layer 127b. The second electrode 246 may include a transparent electrode having a relatively small ultraviolet light absorption. Illustratively, the second electrode 246 may be, but is not limited to, ITO.

The second conductive layer 150 may inject current into the second conductive semiconductor layer 127. In addition, the second conductive layer 150 can reflect light emitted from the active layer 126.

According to the embodiment, the second electrode 246 can directly contact a semiconductor layer (for example, P-AlGaN) having a band gap higher than the energy of the wavelength of ultraviolet light. Conventionally, a second electrode 246 is disposed on a GaN layer having a small bandgap for ohmic, so that ultraviolet light is mostly absorbed in the GaN layer. However, since the second electrode 246 of the embodiment directly contacts the P-AlGaN, most of the light can transmit the second conductivity type semiconductor layer 127.

However, most of the second electrodes have a problem of absorbing ultraviolet light. Therefore, it is necessary to improve the light extraction efficiency while maintaining the ohmic contact by the second electrode.

Referring to FIG. 2, 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 prevents the electrons supplied from the first conductivity type semiconductor layer 124 from flowing out to the second conductivity type semiconductor layer 127 so that electrons and holes recombine in the active layer 126 The probability can be increased. The energy band gap of the electron 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 electron blocking layer 129 is 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. The electron blocking layer 129 may have a first layer 129b having a high aluminum composition and a second layer 129a having a low aluminum composition alternately.

The active layer 126 including the first conductivity type semiconductor layer 124, the barrier layer 126b and the well layer 126a, the second-first conductivity type semiconductor layer 127a, and the second- (127b) may all comprise aluminum. Therefore, the first conductivity type semiconductor layer 124, the barrier layer 126b, the well layer 126a, the second-first conductivity type semiconductor layer 127a, and the second-type conductivity type semiconductor layer 127b are formed of AlGaN Lt; / RTI > However, the present invention is not limited thereto.

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 second electrode and the second-conductivity-type semiconductor layer 127b becomes high, Can not be achieved.

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.

When 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 is not disposed in some regions, A region exposed to the outside of the light emitting structure 120 may occur. Therefore, it may be difficult to form one layer, and it may be difficult to perform the role of the second-second conductivity type semiconductor layer 127b. 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 a second conductivity type semiconductor layer 127c and a second conductivity type semiconductor layer 127d. The second to third conductivity type semiconductor layer 127c may be a surface layer in contact with the p-Ohmic electrode, and the second to fourth conductivity type semiconductor layer 127d may be a layer that controls the composition of aluminum.

The second-4 conductive type semiconductor layer 127d includes a second-first conductive type semiconductor layer 127a including a relatively high aluminum content and a second-third conductive type semiconductor layer 127c including a relatively low aluminum content As shown in FIG. Therefore, the problem that the crystallinity is deteriorated due to a sudden change in the aluminum content can be prevented.

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.

FIGS. 3A and 3B are views for explaining a configuration in which light output is improved in accordance with the number of recesses. FIG.

If the aluminum composition of the light emitting structure 120 is high, the current dispersion characteristics in the light emitting structure 120 may be degraded. Also, the amount of light emitted from the active layer to the side increases as compared with the GaN-based blue light emitting device (TM mode). This TM mode can mainly occur in an ultraviolet semiconductor device.

The ultraviolet semiconductor element has a lower current dispersion characteristic than the blue GaN semiconductor element. Therefore, the ultraviolet semiconductor device needs to dispose the first electrode 142 relatively larger than the blue GaN semiconductor device.

The higher the composition of aluminum, the worse the current dispersion characteristics may be. Referring to FIG. 3A, the current is dispersed only in the vicinity of each first electrode 142, and the current density may be drastically lowered at distant points. 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 center 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 a range of 40 占 퐉 from the center of the recess 128. [

The low current density region P3 has a low current density and may hardly contribute to light emission. Therefore, the embodiment can further arrange the first electrode 142 in the low current density region P3 having a low current density or improve the light output using the reflective structure.

Generally, in the case of a GaN-based semiconductor device emitting blue light, it is preferable to minimize the area of the recess 128 and the first electrode 142 because the current dispersion property is relatively good. 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, since the composition of aluminum is high and the current dispersion characteristics are relatively low, the number of the first electrodes 142 is increased to reduce the low current density region P3 even if the area of the active layer 126 is sacrificed, Or in the low current density region P3.

Referring to FIG. 3B, when the number of recesses 128 is 48, the recesses 128 can be arranged in a zigzag manner without being arranged straight in the transverse direction. 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. At this time, the diameter of the recess 128 may be 20 占 퐉 to 70 占 퐉.

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

The light emitting structure 120 of FIG. 4 may be applied to the structure of the light emitting structure 120 illustrated in FIG. 1 and FIG.

The plurality of recesses 128 may be disposed on a first surface 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 insulating layer 131 may be disposed in the recess 128 to electrically isolate the first conductive layer 165 from the second conductive semiconductor layer 127 and the active layer 126. [

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.

As described above, the first surface 127G of the second conductivity type semiconductor layer 127, which contacts the second electrode 246, has a composition of aluminum of 1% to 10%, so current injection can be facilitated.

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 pad 166 contacts the second conductive layer 150 may be, for example, 40 μm to 90 μm. 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 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 a reflecting function, light emitted toward the side surface of the active layer 126 may be reflected upward to improve light extraction efficiency. As the number of the recesses 128 increases, the light extraction efficiency may be more effective in the ultraviolet semiconductor device than in the semiconductor device that emits blue light.

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 may cover the second electrode 246 and be in contact with the side surfaces and the bottom 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 insulating layer 132 electrically isolates 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.

FIG. 5 is a plan view of FIG. 4, and FIG. 6 is a cross-sectional view taken along the line A-A of FIG.

5 and 6, the first surface 127G of the second conductivity type semiconductor layer 127 includes a plurality of first regions 127G-1 in which a plurality of recesses 128 are disposed on a plane, And a second region 127G-2 disposed between the plurality of first regions 127G-1.

The diameter of the recess 128 may be between 20 탆 and 70 탆. When the diameter of the recess 128 is less than 20 mu m, it is difficult to secure a process margin in forming the first electrode 142 disposed inside. When the diameter of the recess 128 is larger than 70 mu m, The luminous efficiency can be deteriorated because the area is reduced. Here, the diameter of the recess 128 may be a maximum diameter formed on the second conductive semiconductor layer 127.

The diameter of the first region 127G-1 may be 1.0 to 1.5 times the diameter of the recess 128. When the diameter of the first region 127G-1 is more than 1.5 times, the contact area of the second electrode 246 is reduced, which causes a problem of deterioration of the current dispersion efficiency. The first area 127G-1 may be the maximum outer diameter of the recess 128 and the distance S11 between the second electrode 246. [

The second area 127G-2 may be an entire area other than the plurality of first areas 127G-1. The second electrode 246 may be disposed entirely in the second region 127G-2.

The first area where the plurality of first electrodes 142 are in contact with the first conductivity type semiconductor layer 124 may be 7.4% to 20%, or 10% to 20% or less of the maximum cross-sectional area in the horizontal direction of the light- have. 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 124.

If the first area of the plurality of first electrodes 142 is less than 7.4%, the current output can not be sufficient and the current output of the active layer 126 and the second electrode 246 may be reduced, There is a problem that the operating voltage increases and the light output decreases.

In addition, the total area of the plurality of recesses 128 may be 10% to 30% or 13% to 30% 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 area of the second conductivity type semiconductor layer 127 may be an area excluding the total area of the recesses 128 in the maximum horizontal area of the light emitting structure 120. [ The area of the second conductivity type semiconductor layer 127 may be 70% to 90% of the maximum area of the light emitting structure 120 in the horizontal direction.

The second area (the second area in FIG. 5) where the second electrode 246 and the second conductivity type semiconductor layer 127 are in contact may be 50% or more and 70% or less of the maximum cross-sectional area in the horizontal direction of the light- . The second area may be the total area at which the second electrode 246 contacts the second conductive semiconductor layer 127.

When the second area is less than 50%, the area of the second electrode 246 becomes excessively small, so that the operating voltage rises and the efficiency of hole injection decreases. 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 area (the first region in FIG. 5) where the second electrode 246 and the second conductivity type semiconductor layer 127 are not in contact may be between 1% and 20%.

The first area and the second area have an inverse relationship. That is, when the number of the recesses 128 is increased in order to increase the number of the first electrodes 142, the area of the second electrodes 246 decreases. Therefore, in order to improve the electrical and optical properties, 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.

A ratio of a first area where the first electrodes 142 are in contact with the first conductivity type semiconductor layer 124 and a second area where the second electrode 246 contacts the second conductivity type semiconductor layer 127 The first area: the second area) may be 1: 3 to 1: 7.

If the area ratio is larger than 1: 7, the first area becomes relatively small and the current dispersion characteristics may be deteriorated. Also, when the area ratio is smaller than 1: 3, the second area becomes relatively small, and the current dispersion characteristic may be deteriorated

The ratio of the total area of the plurality of first areas 127G-1 to the area of the second area 127G-2 may be 1: 2.5 to 1:70, or 1:30 to 1:70. If the area ratio is smaller than 1: 2.5, the area of the first area 127G-1 becomes excessively large and a sufficient ohmic area of the second electrode 246 can not be ensured. If the area ratio is larger than 1:70 The area of the first area 127G-1 becomes small, which makes it difficult to secure a process margin.

The second electrode 246 may comprise a low resistance metal or metal oxide. However, the second electrode 246 reflects or transmits visible light, but absorbs ultraviolet light. Therefore, it is necessary to reduce the area of the second electrode 246 and reflect light emitted from the active layer 126 to the second conductivity type semiconductor layer 127. The area of the second area 127G-2 in which the second electrode 246 is disposed may be narrowed to secure a reflective area by widening the first area 127G-1 or a plurality of second areas 127G- It is possible to selectively arrange the reflection structure.

Since the second conductive layer 150 is disposed in the first area 127G-1 and the second area 127G-2, the light incident on the first area 127G-1 is emitted by the second conductive layer 150 Can be reflected. At this time, it is important to secure the maximum reflection area while securing the contact area of the second electrode 246 necessary for current dispersion.

The area of the second region 127G-2 may be 35% to 60% based on the maximum area of the light emitting structure 120. If the area of the second region 127G-2 is less than 35%, the contact area of the second electrode 246 may be small and the current dispersion efficiency may decrease. When the area of the second area 127G-2 exceeds 60%, the area of the first area 127G-1 becomes small, and the light extraction efficiency can be reduced.

The area of the first region 127G-1 excluding the recess 128 may be 10% to 55% based on the maximum area of the light emitting structure 120. [ When the area of the first area 127G-1 is smaller than 10%, it is difficult to have a sufficient reflection efficiency. When the area of the first area 127G-1 is larger than 55%, the area of the second area 127G- And the current dispersion efficiency is reduced.

Therefore, the ratio of the area of the first area 127G-1 to the area of the second area 127G-2 may be 1: 0.7 to 1: 6. If this relationship is satisfied, the light output can be improved by having sufficient current dispersion efficiency. In addition, a sufficient reflection area can be ensured and the light extraction effect may be improved.

Referring to FIG. 6, the first surface 127G of the second conductive type semiconductor layer 127 may include a first-first surface S 10 disposed between two adjacent recesses 128. The first-first surface S10 may include a first section S11 in which the second electrode 246 is not disposed, and a second section S12 in which the electrodes are disposed. The width of the first-first surface S10 may be 17 탆 to 45 탆.

If the width of the first-side surface S10 is less than 17 mu m, the spacing between the recesses 128 is too narrow to reduce the area in which the second electrode 246 is disposed, The spacing distance between the recesses 128 is too large to allow the area where the first electrode 142 can be disposed to be narrowed, and the electrical characteristics may be deteriorated.

The first section S11 may be a unit section constituting the first area 127G-1. In addition, the second section S12 may be a unit section constituting the second area 127G-2. The first directional width of the second section S12 may be greater than the first directional width of the first section S11. The width of the first section S11 in the first direction (distance from the recess to the second electrode) may be 1 탆 to 15 탆.

If the width of the first section S11 is less than 1 占 퐉, the first insulating layer 131a on the second conductive type semiconductor layer 127 for current diffusion may be difficult to be disposed due to the process margin. Therefore, the electrical characteristics may be deteriorated. The electrical characteristics may be deteriorated because the distance between the second electrode 246 and the first electrode 142 is excessively large. Therefore, considering the process margin and the electrical characteristics, the first direction width of the first section S11 may be arranged within the above range.

The first insulating layer 131 may include an extension 131a extending to the first surface 127G and the second electrode 246 may include an extension 131a of the first insulating layer 131, Mu] m to 4 [mu] m. If the spacing region S13 is larger than 4 mu m, the area where the second electrode 246 is disposed may be narrowed and the operation voltage may increase.

The second conductive layer 150 completely covers the second electrode 246 and can contact the side surfaces and the bottom surface of the first insulating layer 131. 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 of the first insulating layer 131 and the upper surface thereof. Further, it may have a function of reflecting incident ultraviolet light upward.

In the second conductive layer 150, a region where the second conductive layer 150 and the second conductive type semiconductor layer 127 are Schottky junctioned may be disposed in the spacing region S13. Therefore, current dispersion can be facilitated.

The first surface 127G can be controlled to have an average roughness of 7 nm or less. If the average roughness is larger than 7 nm, the interface between the second electrode 246 and the second conductive layer 150 becomes rough, and the reflectance is reduced. The average roughness may be a value obtained by calculating a height difference of the concavities and convexities formed on the first surface 127G. The average roughness may be a Root-Mean-Square (RMS) value measured by an atomic force microscope (AFM).

FIG. 7 is a view for explaining the configuration of the second conductive layer, FIG. 8 is a first modification of FIG. 7, and FIG. 9 is a second modification of FIG.

Referring to FIG. 7, the thickness d5 of the second electrode 246 may be 1 nm to 15 nm, or 1 nm to 5 nm. When the thickness d5 of the second electrode 246 is 15 nm or less, the amount of light absorbed can be reduced.

The second conductive layer 150 may include a reflective layer 151 including aluminum and a first intermediate layer 152 disposed between the second electrode 246 and the reflective layer 151. When the second electrode 246 is made of ITO, oxygen may penetrate the reflective layer 151 to form Al ₂ O ₃ . In this case, the reflection efficiency of the reflective layer 151 is lowered. In the embodiment, the first intermediate layer 152 is disposed between the reflective layer 151 and the second electrode 246 to improve the adhesion thereof and to prevent the penetration of oxygen.

The first intermediate layer 152 may include at least one of chromium (Cr) and titanium (Ti) nickel (Ni). The thickness d6 of the first intermediate layer 152 may be 0.7 m to 7 nm. The first intermediate layer 152 may further include aluminum. In this case, the adhesion between the first intermediate layer 152 and aluminum can be improved. Further, the current diffusion property can be improved by the Schottky junction by the first intermediate layer 152 contacting the first surface 127G in the spacing region.

The thickness ratio d5: d7 of the second electrode 246 and the reflective layer 151 may be 1: 2 to 1: 120. The thickness d7 of the reflective layer 151 may be 30 nm to 120 nm. When the thickness of the reflective layer 151 is smaller than 30 nm, there is a problem in that the reflectance is lowered at the ultraviolet wavelength band. Even if the thickness is larger than 120 nm, the reflection efficiency is not increased substantially.

Referring to FIG. 8, a second intermediate layer 153 may be disposed under the reflective layer 151. The second intermediate layer 153 can prevent aluminum from migrating into the neighboring layer. The second intermediate layer 153 may include at least one of Ni, Ti, No, Pt, and W, and may have a thickness of 50 nm to 200 nm.

Referring to FIG. 9, a third intermediate layer 154 may be disposed under the second intermediate layer 153. The third intermediate layer 154 may include Au, Ni or the like as a layer for bonding with another layer.

11 is a plan view of FIG. 10, FIG. 12 is an enlarged view of part B-1 in FIG. 11, and FIG. 13 is a cross- Fig.

Referring to FIG. 10, the semiconductor device according to the embodiment may be applied to the light emitting structure 120 described in FIGS. 1 to 3 and the structure of each layer described in FIG. 4 as it is. A plurality of the second electrodes 246 may be disposed on the first surface 127G of the second conductive semiconductor layer 127 disposed between the two recesses 128. [

11-13, the first surface 127G includes a first area 127G-1 surrounding the recess 128, a second area 127G-1 surrounding the first area 127G-1, 2), and a third region 127G-3 disposed between the second region 127G-2.

Here, the first region 127G-1 may be a region between the recess 128 and the second electrode 246. [ Illustratively, the area of the first area 127G-1 may be ring-shaped. The area of the first area 127G-1 may be 1% to 20% based on the maximum horizontal area of the light emitting structure 120.

The second region 127G-2 may have a remaining area excluding the recess 128 and the first region 127G-1. Illustratively, the second region 127G-2 may have a circular shape on the inner side and a polygonal shape on the outer side. Illustratively, the outside may be octagonal, but not necessarily limited thereto. The second area 127G-2 may be a plurality of areas partitioned by the third area 127G-3.

The third region 127G-3 may be disposed between the plurality of second regions 127G-2. The third region 127G-3 may be a region having a current density of 40% or less based on 100% of the current density of the first electrode 142. Therefore, the third region 127G-3 may have a low probability of participating in luminescence. According to the embodiment, the third region 127G-3 having a low light emission contribution can be configured as a reflection region to increase the light extraction efficiency.

The first surface 127G may further include a fourth region 127G-4 disposed between the third region 127G-3 and the edge region of the first surface 127G.

The second electrode 246 may include a second-first electrode 246a disposed in the second region 127G-2 and a second-second electrode 246b disposed in the fourth region 127G-4. have.

The second electrode 246 may comprise a low resistance metal or metal oxide. However, such a second electrode 246 has a problem that visible light is reflected or transmitted but ultraviolet light is absorbed.

Therefore, it is necessary to reduce the area of the second electrode 246 to an area where electrical characteristics are not significantly reduced, and reflect light emitted from the active layer 126 to the second conductivity type semiconductor layer 127. At this time, the area of the second area 127G-2 where the second electrode 246 is disposed can be narrowed and the third area 127G-3 can be widened to secure a reflection area. Since the second conductive layer 150 is disposed entirely on the first surface 127G, the light incident on the third region 127G-3 can be reflected by the second conductive layer 150. [

That is, in the embodiment, the reflection region can be utilized for the third region 127G-3 having a low light emission contribution.

The first contact area (the sum of the second region and the fourth region in FIG. 11) where the first surface 127G and the second electrode 246 make contact is between 35% and 60%, based on the maximum area of the light- %. ≪ / RTI > If the first contact area is smaller than 35%, the current dispersion efficiency may be lowered. In addition, when the first contact area exceeds 60%, the area of the third area 127G-3 becomes small, and the light extraction efficiency can be reduced.

The second contact area (the sum of the first area and the third area in Fig. 11) in which the first surface 127G and the second electrode 246 are not in contact is 10% to 10% based on the maximum area of the light emitting structure 120 55%. If the second contact area is smaller than 10%, it is difficult to have a sufficient reflection efficiency. If the second contact area is larger than 55%, the area of the second area 127G-2 becomes smaller and the current dispersion efficiency decreases .

The ratio of the second contact area to the first contact area may be from 1: 0.7 to 1: 6. If this relationship is satisfied, the light output can be improved by having sufficient current dispersion efficiency. In addition, a sufficient reflection area can be ensured and the light extraction effect may be improved.

Referring to FIG. 13, the distance d1 between the rim of the third area 127G-3 and the first surface 127G may be 1.0 μm to 10 μm. When the spacing distance d1 is smaller than 1.0 탆, the margin is small, so that the second conductive layer 150 is not properly formed when a tolerance is generated, and reliability may be lowered. In addition, if the separation distance d1 is larger than 10 mu m, the area where the second electrode 246 is disposed may be reduced, and the electrical characteristics of the semiconductor device may be deteriorated.

Fig. 14 is a sectional view taken along the line B-B in Fig. 12;

14, the first surface 127G of the second conductive type reflective layer 151 has a first surface 127G disposed between the centers of the two recesses 128 closest to each other in the first direction (X direction) (S10). Here, the first direction may be a direction perpendicular to the thickness direction of the light emitting structure 120.

The first surface S 10 includes a first section S 11 in which a second electrode 246 spaced in a first direction is disposed and a second section S 12 disposed between the second electrodes 246. can do. The second conductive layer 150 may be disposed in the first section S11 and the second section S12. The entire width of the first-first surface S10 may be 17 탆 to 45 탆.

The entire width of the first section S11 in the first direction may be 12 占 퐉 to 24 占 퐉. The first section S11 may include two divided sections on both sides of the second section S12. The width of each of the divided regions may be 6 탆 to 12 탆.

When the total width of the first section S11 is smaller than 12 占 퐉, the area of the second electrode 246 is reduced and the current dispersion efficiency is reduced. When the total width of the second section S12 is larger than 24 占 퐉, There is a problem that the reflection efficiency is reduced.

The first directional width of the second section S12 may be between 5 탆 and 16 탆. If the first direction width of the second section S12 is smaller than 5 占 퐉, there is a problem that it is difficult to secure a sufficient reflection area. If the width is larger than 16 占 퐉, the second electrode 246 becomes narrow.

The second section S12 may be disposed in an area of 40% or less based on 100% of the current density of the first electrode 142. [ The first distance W2 + S13 + S11 between the second section S12 and the center of the recess 128 may be at least 17 micrometers. The width W2 of the bottom surface of the recess 128 is 10 占 퐉 to 35 占 퐉 and the width of the third section S13 is 1 占 퐉 to 5 占 퐉 and the width of the first section S11 is 6 占 퐉 to 12 占 퐉 . Therefore, the maximum separation distance may be 52 탆 or more.

The second section S12 may be disposed in an area having a current density of 40% or less among the areas at least 17 mu m apart from the center of the recess 128. [ Illustratively, the second section S12 may be disposed in an area at least 40 microns apart from the center of the recess 128.

When the semiconductor device has a plurality of recesses 128, the second section S12 separated by 40 占 퐉 or more from each recess 128 may overlap each other. Thus, the area of the overlapping second section S12 can be adjusted according to the distance between the recesses 128. [

At this time, the second section S12 may include a half point of the first direction width of the first-first surface S10. The 1/2 point of the width in the first direction on the first-first surface S10 is a region between two adjacent recesses 128, and the probability that the current density is low is high. However, the present invention is not limited to this, and if the diameters of the plurality of recesses are different from each other, it may not necessarily include a half point of the first directional width.

The third section S13 may be a region between the second electrode 246 and the recess 128. [ The width of the third section S13 in the first direction may be 1 탆 to 5 탆.

The ratio of the width of the second section S12 to the total width of the first section S11 may be 1: 0.7 to 1: 5. When the width ratio is satisfied, the ratio of the second contact area to the first contact area can be maintained at 1: 0.7 to 1: 6. Therefore, the current dispersion efficiency and the light extraction effect can be improved.

Fig. 15 is a first modification of Fig.

Referring to FIG. 15, the second conductive layer 150 may include a reflection groove 150-1 in the second section S12. The light incident on the second section S12 may be reflected by the reflection groove 150-1 while changing its travel path. According to this configuration, the light can be reflected in various directions and the uniformity can be improved.

The angle [theta] 5 of the inclined surface may be greater than 90 degrees and greater than 150 degrees. If the angle of the inclined plane is smaller than 90 degrees or larger than 150 degrees, it may be difficult to vary the reflection angle of the incident light variously. The angle of the inclined plane can be defined as the angle formed by the bottom plane and the inclined plane.

The depth of the reflective groove 150-1 may be the same as the thickness of the first insulating layer 131. [ The thickness of the first insulating layer 131 may be 110% to 130% greater than the thickness of the second electrode 246.

The light-transmitting layer 133 may be disposed in the reflection groove 150-1. The shape of the light-transmitting layer 133 and the shape of the reflection groove 150-1 may correspond to each other. Therefore, the thickness of the light-transmitting layer 133 may be the same as the thickness of the reflection groove 150-1. Illustratively, the reflective grooves 150-1 may be formed by forming the second conductive layer 150 on the light-transmitting layer 133. [

The material of the light-transmitting layer 133 may include various materials that transmit light in the ultraviolet wavelength band. Illustratively, the light-transmitting layer 133 may include an insulating layer material. The light-transmitting layer 133 may include at least one of SiO ₂ , SixOy, Si ₃ N ₄ , Si _x N _y , SiO _x N _y , Al ₂ O ₃ , TiO ₂ and AlN.

FIG. 16A is a second modification of FIG. 14, and FIG. 16B is a plan view of a second modification.

16A, in the second section S12, a sub-recess 127 and a sub-reflective layer 135 disposed inside the sub-recess 127 may be disposed.

The sub reflection layer 135 may be disposed inside the sub-recess 127. Specifically, the sub reflection layer 135 may be disposed on the first insulation layer 131 in the sub-recess 127.

As the sub reflection layer 135, a material having a high reflectivity at an ultraviolet wavelength band can be selected. The sub reflection layer 135 may include a conductive material. Illustratively, the sub-reflective layer 135 may comprise aluminum. When the thickness of the sub reflection layer 135 is about 30 nm to 120 nm, the light in the ultraviolet wavelength range can be reflected by 80% or more. Therefore, the light emitted from the active layer 126 can be prevented from being absorbed in the semiconductor layer.

The light L1 that is obliquely emitted by the sub reflection layer 135 can be reflected upward. Therefore, the light absorption in the light emitting structure 120 can be reduced and the light extraction efficiency can be improved. Further, the directivity angle of the semiconductor device may be adjusted.

The sub reflection layer 135 may cover a part of the second electrode 246. With this configuration, the light that flows between the first insulating layer 131 and the second electrode 246 can be reflected upward. However, it may not be desirable to completely cover the second electrode 246 because the sub-reflective layer 135, such as aluminum, has relatively poor step coverage.

The thickness of the second electrode 246 may be 80% or less of the thickness of the first insulating layer 131. This makes it possible to solve problems such as cracking and peeling of the sub reflection layer 135 or the second conductive layer 150 due to a decrease in step coverage when the sub reflection layer 135 and the second conductive layer 150 are disposed.

The width of the sub reflection layer 135 may be the same as the width of the sub recess 127. The width of the first recess 128 and the width of the sub-recess 127 may be the maximum width formed on the first surface 127G of the light emitting structure 120. [

The sub-reflective layer 135 may include an extension 135a extending from the sub-recess 127 toward the second electrode 246. [ The extension 135a may electrically connect the second electrodes 246 separated by the sub-recess 127 to each other.

The sub reflection layer 135 may be disposed at a distance between the second electrode 246 and the first insulation layer 131. The sub reflection layer 135 may be disposed between the second conductivity type semiconductor layer 127 and the second insulation layer 131, An area where the Schottky junction is formed can be disposed, and current dispersion can be facilitated by forming the Schottky junction.

The angle? 4 formed by the inclined portion of the sub reflection layer 135 and the first surface of the second conductivity type semiconductor layer 127 may be 90 degrees to 145 degrees. 4 is less than 90 degrees, etching of the second conductivity type semiconductor layer 127 is difficult, and when the inclination angle is larger than 145 degrees, the area of the active layer 126 to be etched becomes large, and the luminous efficiency is lowered.

The second conductive layer 150 may cover the sub-reflective layer 135 and the second electrode 246. Accordingly, the second electrode pad 166, the second conductive layer 150, the sub reflection layer 135, and the second electrode 246 can form one electrical channel. The configuration of the second conductive layer 150 can be applied to all of the configurations described above.

Referring to FIG. 16B, the sub-reflecting layer 135 may be disposed between the plurality of recesses 128 to define a plurality of light emitting regions. The area of the light emitting region can be adjusted according to the level of the injection current and the composition of Al.

17 is a third modification of Fig.

The second conductive layer 150 may include a reflective layer 151 including aluminum and a first intermediate layer 152 disposed between the second electrode 246 and the reflective layer 151. When the second electrode 246 is made of ITO, oxygen may penetrate the reflective layer 151 to form Al ₂ O ₃ . In this case, the reflection efficiency of the reflective layer 151 is lowered. In the embodiment, the first intermediate layer 152 is disposed between the reflective layer 151 and the second electrode 246 to improve the adhesion thereof and to prevent the penetration of oxygen.

The first intermediate layer 152 may include at least one of chromium (Cr) and titanium (Ti) nickel (Ni). The thickness of the first intermediate layer 152 may be 0.7 m to 7 nm. The first intermediate layer 152 may further include aluminum. In this case, the adhesion between the first intermediate layer 152 and aluminum can be improved.

The first intermediate layer 152 may be in contact with the first surface 127G of the second conductivity type semiconductor layer 127 in the second section S12 and the third section S13. Therefore, the current dispersion efficiency can be improved by the Schottky junction.

The thickness ratio of the second electrode 246 and the reflective layer 151 may be 1: 2 to 1: 120 in the thickness ratio of the second conductive layer 150. The thickness of the reflective layer 151 may be 30 nm to 120 nm. When the thickness of the reflective layer 151 is less than 30 nm, there is a problem that the reflectance is lowered in the ultraviolet wavelength band. Even if the thickness is larger than 120 nm, the reflection efficiency is not increased substantially.

18 is a conceptual view of a semiconductor device according to a third embodiment of the present invention, and Fig. 19 is a plan view of Fig.

Referring to FIG. 18, the semiconductor device according to the embodiment may be applied to the light emitting structure 120 described in FIGS. 1 to 3 and the structure of each layer described in FIG. 4 as it is.

19, the first surface 127G includes a first region 127G-1 in which the recess 128 is disposed and a second region 127G-1 disposed between the first region 127G- -2).

The diameter of the first region 127G-1 may be 1.0 to 1.5 times the diameter of the recess 128. If the diameter of the first region 127G-1 is more than 1.5 times, the area of the second electrode 246 is reduced, which causes a problem of deterioration of the current dispersion efficiency. The first region 127G-1 may be a region between the recess 128 and the second electrode 246. [

The second area 127G-2 may be a remaining area other than the plurality of first areas 127G-1. The second electrode 246 may be disposed entirely in the second region 127G-2.

The second electrode 246 may comprise a low resistance metal or metal oxide. Therefore, the second electrode 246 has a problem of absorbing ultraviolet light. Therefore, it is necessary to reduce the amount of light absorbed by the second electrode 246 by narrowing the area of the second electrode 246.

Since the second conductive layer 150 is disposed in the first area 127G-1 and the second area 127G-2, the light incident on the first area 127G-1 is emitted by the second conductive layer 150 Can be reflected. Therefore, the light extraction efficiency can be enhanced by narrowing the area of the second region 127G-2 where the second electrode 246 is disposed and by widening the first region 127G-1. At this time, it may be important to secure the maximum reflection area while securing the area of the second electrode 246 necessary for current dispersion.

The area of the second region 127G-2 may be 35% to 60% based on the maximum area of the light emitting structure 120. If the area of the second region 127G-2 is less than 35%, the contact area of the second electrode 246 may be small and the current dispersion efficiency may decrease. When the area of the second area 127G-2 exceeds 60%, the area of the first area 127G-1 becomes small, and the light extraction efficiency can be reduced.

The area of the first region 127G-1 may be 10% to 55% based on the maximum area of the light emitting structure 120. When the area of the first area 127G-1 is smaller than 10%, it is difficult to have a sufficient reflection efficiency. When the area of the first area 127G-1 is larger than 55%, the area of the second area 127G- The current injection efficiency is reduced.

Therefore, the ratio of the area of the first area 127G-1 to the area of the second area 127G-2 may be 1: 0.7 to 1: 6. If this relationship is satisfied, the light output can be improved by having sufficient current dispersion efficiency. In addition, a sufficient reflection area can be ensured and the light extraction effect may be improved.

20 is a cross-sectional view along the line C-C in Fig.

The first surface 127G of the second conductive type reflective layer has a first-first surface S10 disposed between the centers of the first and second recesses 128a and 128b closest to each other in the first direction (X direction) . In this case, the first direction may be a direction perpendicular to the thickness direction of the light emitting structure 120.

The first-first surface S10 includes a first section S21 and a second section S22a and S22b disposed between the first section S21 and the first and second recesses 128a and 128b can do.

The second sections S22a and S22b include a second section S22a disposed between the first section S21 and the first recess 128a and a second section S22b disposed between the first section S21 and the second recess 128b And a second-second section S22b disposed between the first and second sections.

And the second electrode 246 may be disposed in the first section S21. When the second electrode 246 is disposed only in the second section S22a and S22b, the current density in the second section S22a and S22b can be improved, but the current density in the first section S21 can be relatively lowered . When the second electrode 246 is disposed in both the first section S21 and the second sections S22a and S22b, light absorption occurs both in the first section S21 and the second sections S22a and S22b And may not be good in view of light extraction efficiency.

The second conductive layer may be disposed in the first section S21 and the second sections S22a and S22b. Therefore, the second sections S22a and S22b in which the second electrode 246 is not disposed can perform the reflection function.

According to the embodiment, it may be important to appropriately set the distance between the first electrode 142 and the second electrode 246 so as to ensure the current extraction efficiency while securing the current density required for light emission.

For example, if the area of the first electrode 142 is large, the current spreading region is widened, so that the second sections S22a and S22b can be made wider. Therefore, the reflection area can be widened. However, if the area of the first electrode 142 is small, the current spreading region becomes narrow, and therefore the second sections S22a and S22b may be narrowed.

The ratio of the first directional width of the second section S22b to the diameter W1 of the first recess 128a may be 1: 1.25 to 1:14. The diameter of the recess 128 is reduced and the area of the first electrode 142 is reduced. Therefore, the intensity of the current injected through the first electrode 142 is weakened and the current density in the second section S22a and S22b may be weakened.

The diameter of the recess 128 becomes excessively large, so that the area of the first surface 127G of the second conductivity type semiconductor layer is relatively reduced. That is, the width of the first-first surface S10 is reduced. As a result, the area of the active layer 126 decreases and the light emitting region is reduced.

The diameter W1 of the recess 128 may be 20 占 퐉 to 70 占 퐉. When the diameter of the recess 128 is less than 20 mu m, it is difficult to secure a process margin in forming the first electrode 142 disposed inside. When the diameter of the recess 128 is larger than 70 mu m, The luminous efficiency can be deteriorated because the area is reduced. Here, the diameter of the recess 128 may be a maximum diameter formed on the first surface 127G of the second conductive type semiconductor layer.

The width of the first section S21 in the first direction may be 6 占 퐉 to 12 占 퐉. When the width is smaller than 6 mu m, the area of the second electrode 246 is reduced and the current dispersion efficiency is reduced. When the width is larger than 12 mu m, the second sections S22a and S22b are narrowed, There is a problem.

The first directional widths of the 2-1 section S22a and the 2-2nd section S22b may be 5 占 퐉 to 16 占 퐉, respectively. That is, the total width of the second sections S22a and S22b may be 10 to 32 탆. If the first directional widths of the 2-1 section S22a and the 2-2nd section S22b are smaller than 5 占 퐉, there is a problem that it is difficult to secure a sufficient reflection area. When the width is larger than 16 占 퐉, There is a problem that the electrode 246 is narrowed.

The ratio of the width of the first section S21 to the total width of the second sections S22a and S22b may be 1: 0.8 to 1: 5. When the width ratio is satisfied, the ratio of the area of the first area 127G-1 to the area of the second area 127G-2 can be adjusted from 1: 0.8 to 1: 6. Therefore, the current dispersion efficiency and the light extraction effect can be improved.

The first section S21 may include a half point of the first-first surface S10. Since the second electrode 246 is disposed at the center of the first-first surface S10, the current density in the first section S21 can be increased. In addition, since the current density of the first section S21 is increased, the currents are also dispersed in the second sections S22a and S22b between them, so that the current density required for light emission can be secured. However, if the diameter of the first recess 128a is different from the diameter of the second recess 128b, the first section S21 is not necessarily limited to 1/2 of the first-first surface S10, It may leave the point.

Fig. 21 is a first modification of Fig. 20, and Fig. 22 is a second modification of Fig.

The second conductive layer 150 may include a reflection groove 150-2 in the second sections S22a and S22b. Light incident on the second sections S22a and S22b may be reflected by the inclined surfaces of the reflection grooves 150-2 and changed in its travel path. With this configuration, the light uniformity can be improved.

The depth of the reflective groove 150-2 may be the same as the thickness of the first insulating layer 131. [ The thickness of the first insulating layer 131 may be 110% to 130% greater than the thickness of the second electrode 246. As described above, the thickness of the second electrode 246 may be 1 to 15 nm.

The light-transmitting layer 131b may be disposed in the reflective groove 150-2. The shape of the light-transmitting layer 131b and the shape of the reflection groove 150-2 may correspond to each other. Therefore, the thickness of the light-transmitting layer 131b may be the same as the thickness of the reflection groove 150-2. Illustratively, the reflective groove 150-2 may be formed by disposing the second conductive layer 150 on the light-transmitting layer 131b.

The material of the light-transmitting layer 131b may include various materials that transmit light in the ultraviolet wavelength range. Illustratively, the light-transmitting layer 131b may include an insulating layer material. The light-transmitting layer 131b may include at least one of SiO ₂ , SixOy, Si ₃ N ₄ , Si _x N _y , SiO _x N _y , Al ₂ O ₃ , TiO ₂ , and AlN.

The light-transmitting layer 131b may include a first insulating layer 131 disposed in the first recess 128a and extending to the second conductive semiconductor layer. However, the present invention is not limited to this, and a separate dielectric layer may be disposed.

Referring to FIG. 22, the second electrode 246 may be arranged to have a lower density as the distance from the central point of the first-first surface S 10 increases. That is, the divided second electrodes 246c, 246d, and 246e may be arranged to be smaller as they are farther from the center. The divided second electrodes 246c, 246d, and 246e may be selectively etched using a mask.

With this configuration, the current density in the second section S22a and S22b can be increased while maintaining the current density in the first section S21. In addition, by maintaining the area ratio of the first section S21 and the second sections S22a and S22b at 1: 0.8 to 1: 6, the current dispersion efficiency and the reflection efficiency can be simultaneously obtained.

23 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.

23, 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 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
142: first electrode
150: second conductive layer
246: second electrode

Claims (17)

A first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer,
A light emitting structure including a plurality of recesses penetrating the second conductivity type semiconductor layer and the active layer and disposed to a partial region of the first conductivity type semiconductor layer;
A first electrode disposed inside the plurality of recesses and electrically connected to the first conductive semiconductor layer;
A second electrode electrically connected to the second conductive semiconductor layer;
A first conductive layer electrically connected to the first electrode; And
And a second conductive layer electrically connected to the second electrode,
The second conductive type reflective layer includes a first-first surface disposed between centers of two recesses closest to the first direction, the first direction being a direction perpendicular to a thickness direction of the light emitting structure,
Wherein the first-first surface includes a first section in which a second electrode spaced apart in the first direction is disposed, and a second section disposed between the second electrodes,
The second conductive layer is disposed in the first section and the second section,
And the width of the second section in the first direction is 1: 0.7 to 1: 5 of the entire width of the first section in the first direction.
The method according to claim 1,
And the first direction width of the second section is 5 占 퐉 to 16 占 퐉.
3. The method of claim 2,
And the second section includes a half point of the first direction width of the first-first surface.
The method according to claim 1,
And the entire width of the first section in the first direction is 12 占 퐉 to 24 占 퐉.
The method according to claim 1,
And the second conductive layer has a reflective groove disposed in the second section.
6. The method of claim 5,
And a translucent layer disposed in the reflective groove.
The method according to claim 1,
A sub-recess disposed in the second section, and
And a sub-reflection layer disposed inside the sub-recess.
8. The method of claim 7,
Wherein the sub reflection layer comprises aluminum.
8. The method of claim 7,
And the sub reflection layer is electrically connected to the second electrode.
The method according to claim 1,
And the first surface of the second conductivity type semiconductor layer comprises AlGaN.
11. The method of claim 10,
Wherein the second conductive layer comprises:
A first intermediate layer comprising at least one of chromium (Cr), titanium (Ti), nickel (Ni), and
A semiconductor device comprising a reflective layer comprising aluminum.
A first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer,
A light emitting structure including a second conductive semiconductor layer and a recess disposed through the active layer to a partial region of the first conductive semiconductor layer;
A first electrode disposed inside the recess and electrically connected to the first conductive semiconductor layer;
A second electrode disposed on a first surface of the second conductive semiconductor layer; And
And a second conductive layer electrically connected to the second electrode,
Wherein the first surface includes a first section disposed within a first distance from a center of the recess with respect to a first direction and a second section disposed outside the first distance,
The first distance is at least 17 mu m, the first direction is a direction perpendicular to the thickness direction of the light emitting structure,
The second electrode is disposed in the first section,
And the second conductive layer is disposed in the first section and the second section.
13. The method of claim 12,
Wherein the first distance is 17 占 퐉 or more and 52 占 퐉 or less.
13. The method of claim 12,
A sub-recess disposed in the second section, and
And a sub-reflection layer disposed inside the sub-recess,
Wherein the subregions penetrate the second conductivity type semiconductor layer and the active layer and are disposed to a partial region of the first conductivity type semiconductor layer.
13. The method of claim 12,
And the second conductive layer includes a reflective groove disposed in the second section.
16. The method of claim 15,
And a translucent layer disposed in the reflective groove.
Body; And
And a semiconductor device disposed on the body,
The semiconductor device may further include:
A first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer,
A light emitting structure including a plurality of recesses penetrating the second conductivity type semiconductor layer and the active layer and disposed to a partial region of the first conductivity type semiconductor layer;
A first electrode disposed inside the plurality of recesses and electrically connected to the first conductive semiconductor layer;
A second electrode disposed on a first surface of the second conductive semiconductor layer;
A first conductive layer electrically connected to the first electrode; And
And a second conductive layer electrically connected to the second electrode,
Wherein the first surface of the second conductive type reflective layer includes a first-first surface disposed between the centers of two recesses closest to the first direction, the first direction being perpendicular to the thickness direction of the light emitting structure Direction,
Wherein the first-first surface includes a first section in which a second electrode spaced apart in the first direction is disposed, and a second section disposed between the second electrodes,
The second conductive layer is disposed in the first section and the second section,
And the width of the second section in the first direction is 1: 0.7 to 1: 5 the entire width of the first section in the first direction.

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