KR20180051928A - Semiconductor device and semiconductor device package including the same - Google Patents

Abstract

An embodiment discloses a semiconductor device. The semiconductor device includes a light emitting structure which 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 first electrode electrically connected to the first conductivity type semiconductor layer and including a plurality of layers; and a second electrode electrically connected to the second conductivity type semiconductor layer. The first electrode comprises a first layer, a second layer and a third layer. The first layer comprises a first metal layer comprising a first metal. The diffusion coefficient of the first metal is larger than the diffusion coefficient of the third metal included in the third layer. The thickness of the second layer is 0.4 to 0.53 times the thickness of the first metal layer. Light extraction efficiency can be improved.

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 in which the characteristics of the first electrode are improved by minimizing the ball up phenomenon.

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 structure; A first electrode electrically connected to the first conductive semiconductor layer and including a plurality of layers; And a second electrode electrically connected to the second conductive type semiconductor layer, wherein the first electrode includes a first layer, a second layer and a third layer, and the first layer includes a first metal Wherein a diffusion coefficient of the first metal is greater than a diffusion coefficient of a third metal included in the third layer and a thickness of the second layer is 0.4 to 0.53 times the thickness of the first metal layer .

A semiconductor device according to another 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 structure; A first electrode electrically connected to the first conductive semiconductor layer and including a plurality of layers; And a second electrode electrically connected to the second conductive type semiconductor layer, wherein the first electrode includes a first layer, a second layer and a third layer, wherein the first layer includes a first region and a second region, Wherein a diffusion coefficient of the first metal included in the first layer is larger than a diffusion coefficient of a third metal included in the third layer, The ratio of the thickness of the first region to the thickness of the second region may be 3: 7 to 6.3: 3.5.

A semiconductor device package according to an embodiment of the present invention includes: a body; And a semiconductor element disposed in the body, wherein the semiconductor element includes a first conductive type semiconductor layer, a second conductive type semiconductor layer, and a second conductive type semiconductor layer disposed between the first conductive type semiconductor layer and the second conductive type semiconductor layer A light emitting structure including an active layer; A first electrode electrically connected to the first conductive semiconductor layer and including a plurality of layers; And a second electrode electrically connected to the second conductive type semiconductor layer, wherein the first electrode includes a first layer, a second layer and a third layer, and the first layer includes a first metal Wherein a diffusion coefficient of the first metal is greater than a diffusion coefficient of a third metal included in the third layer and a thickness of the second layer is 0.4 to 0.53 times the thickness of the first metal layer .

According to the embodiment, the light extraction efficiency of the semiconductor device can be improved.

In addition, the ball-up phenomenon of the first electrode (ohmic electrode) of the semiconductor device can be minimized to improve the characteristics of the first electrode.

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

1 is a conceptual view of a semiconductor device according to an embodiment of the present invention.
FIGS. 2A and 2B are diagrams for explaining a configuration in which a light output is improved according to the number of recesses in a semiconductor device according to an embodiment of the present invention. FIG.
3A and 3B are various modifications of the first electrode of the semiconductor device according to the embodiment of the present invention.
4 is an enlarged view of a portion A in Fig.
5 is a conceptual view of a capping layer of a semiconductor device according to an embodiment of the present invention.
FIGS. 6A to 6D are views for observing the ball-up phenomenon by differently configuring the first electrode among the semiconductor devices according to the embodiment of the present invention.
7 is a graph showing voltage and current values of the first electrode of FIGS. 6A to 6D through the TLM measurement method.
8 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.

The semiconductor device may include various electronic devices such as a light emitting device and a light receiving device. The light emitting device and the light receiving device may include a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer.

The semiconductor device according to this embodiment may be a light emitting device.

The light emitting device emits light by recombination of electrons and holes, and the wavelength of the light is determined by the energy band gap inherent to the material. Thus, the light emitted may vary depending on the composition of the material.

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

The semiconductor device according to the embodiment of the present invention can output light in the ultraviolet wavelength range. As an example, a semiconductor device can output light (UV-A) in the near ultraviolet wavelength range, output light (UV-B) in the far ultraviolet wavelength range, or output light You may. The wavelength range can be determined by the composition ratio of Al of the semiconductor element.

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

1, a semiconductor device 100 according to an exemplary embodiment of the present invention includes a light emitting structure 110, a first electrode 121, a second electrode 125, conductive layers 131 and 135, (140), insulating layers (151, 152), and a plurality of recesses (R).

Irregularities may be formed on the upper surface of the light emitting structure 110. This unevenness can improve the extraction efficiency of light emitted from the light emitting structure 110. 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.

The light emitting structure 110 is disposed between the first conductivity type semiconductor layer 111 and the second conductivity type semiconductor layer 112 and between the first conductivity type semiconductor layer 111 and the second conductivity type semiconductor layer 112 The active layer 113 may be formed of a single layer.

The first conductive semiconductor layer 111 may be formed of a compound semiconductor such as a Group III-V or a Group II-VI, and the first dopant may be doped. The first conductivity type semiconductor layer 111 is a semiconductor material having a composition formula of Inx1Aly1Ga1-x1-y1N (0? X1? 1, 0? Y1? 1, 0? X1 + y1? 1), for example, GaN, AlGaN, InGaN, InAlGaN, and the like. The first dopant may be an n-type dopant such as Si, Ge, Sn, Se, or Te. When the first dopant is an n-type dopant, the first conductivity type semiconductor layer 111 doped with the first dopant may be an n-type semiconductor layer.

The second conductive semiconductor layer 112 may be formed of a compound semiconductor such as a Group III-V or a Group II-VI, and the second dopant may be doped. The second conductive semiconductor layer 112 may be formed of a semiconductor material having a composition formula of Inx5Aly2Ga1-x5-y2N (0? X5? 1, 0? Y2? 1, 0? X5 + y2? 1) or a semiconductor material of AlInN, AlGaAs, GaP, GaAs , GaAsP, and AlGaInP. When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, or Ba, the second conductivity type semiconductor layer 112 doped with the second dopant may be a p-type semiconductor layer.

The active layer 113 may be disposed between the first conductive semiconductor layer 111 and the second conductive semiconductor layer 112. The active layer 113 may be a layer where electrons (or holes) injected through the first conductivity type semiconductor layer 111 and holes (or electrons) injected through the second conductivity type semiconductor layer 112 meet. As the electrons recombine with the holes, the active layer 113 transits to a low energy level and can generate light having ultraviolet wavelengths.

The active layer 113 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 plurality of recesses R may be disposed on a part of the first conductivity type semiconductor layer 111 through the active layer 113 on one side of the second conductivity type semiconductor layer 112. The first insulating layer 151 and the second insulating layer 152 are disposed in the recess R to electrically connect the first conductive layer 131 to the second conductive semiconductor layer 112 and the active layer 113, .

The first electrode 121 may be disposed on the upper surface of the recess R and may be electrically connected to the first conductive semiconductor layer 111. The first electrode 121 may be exposed by the first insulating layer 151 and may be electrically connected to the first conductive semiconductor layer 111. The first electrode 121 may be electrically insulated from the active layer 113 and the second conductivity type semiconductor layer 112 by a first insulating layer 151. The first electrode 121 may be an ohmic electrode.

The first electrode 121 may include a plurality of layers. For example, the first electrode 121 may include a first layer 122, a second layer 123, and a third layer 124. The structure of the first electrode 121 will be described later in more detail.

The first electrode 121 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide ZnO, ZnO, IrOx, AlGaO, AlGaO, AZO, ATO, GZO, IZO, RuOx, NiO, RuOx / ITO, Ni / IrOx / Au, or Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Sn, In, Ru, , Au, and Hf. However, the present invention is not limited to these materials.

The second electrode 125 may be disposed on the second conductive semiconductor layer 112. The second electrode 125 may be exposed by the first insulating layer 151 and electrically connected to the second conductive semiconductor layer 112. The second electrode 125 may be an ohmic electrode.

The second electrode 125 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide ZnO, ZnO, IrOx, ZnO, AlGaO, AZO, ATO, GZO, IZO, RuOx, NiO, RuOx / ITO, Ni / IrOx / Au, or Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Sn, In, Ru, , Au, and Hf. However, the present invention is not limited to these materials.

According to the embodiment, the second electrode 125 can directly contact a semiconductor layer (for example, P-AlGaN) having a band gap larger than the energy of the wavelength of ultraviolet light. Conventionally, a second electrode 125 is disposed on a semiconductor layer (for example, 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 125 of the embodiment directly contacts the semiconductor layer having a large bandgap (for example, P-AlGaN), most of the light can pass through the second conductivity type semiconductor layer 112.

Illustratively, the surface layer of the second conductive semiconductor layer 112 in contact with the second electrode 125 may have a composition of Al ranging from 1% to 10%. When the Al composition of the surface layer is less than 1%, there is a problem that light is excessively absorbed. When the Al composition is more than 10%, the ohmic characteristics may be deteriorated.

On the other hand, the second electrode is generally capable of absorbing ultraviolet light. Therefore, it is necessary to improve the light extraction efficiency while maintaining the ohmic contact by the second electrode. That is, in the present invention, a transparent conductive oxide film may be used for the second electrode 125 to improve the light extraction efficiency while maintaining the ohmic characteristics. The present invention can improve the light extraction efficiency by increasing the light transmittance with the transparent conductive oxide film and placing the conductive layer (reflection layer) having the reflection characteristic below the second electrode 125.

The first conductive layer 131 may be disposed along the bottom surface of the light emitting structure 110 and the shape of the recess R. The first conductive layer 131 may be electrically connected to the first electrode 121 through the second insulating layer 152. The first conductive layer 131 may be electrically insulated from the second conductive layer 135 by the second insulating layer 152.

The first conductive layer 131 may be made of a material having a high reflectivity. Illustratively, the first conductive layer 131 may comprise aluminum (Al), silver (Ag), gold (Au), or copper (Cu). When the first conductive layer 131 includes aluminum, it functions to reflect light emitted from the active layer 113 to the upper portion, thereby improving light extraction efficiency.

The second conductive layer 135 may be disposed on the second electrode 125. The second conductive layer 135 may be electrically connected to the second electrode 125. In addition, the second conductive layer 135 may be disposed to cover the second electrode 125. The second conductive layer 135 may be in contact with a side surface and a bottom surface of the first insulating layer 151. When the second conductive layer 135 is in contact with the side surface and the bottom surface of the first insulating layer 151, the thermal and electrical reliability of the second electrode 125 can be improved. The second conductive layer 135 may be made of a material having good adhesion to the first insulating layer 151.

Also, the second conductive layer 135 may be made of a material having a high reflectivity. Illustratively, the second conductive layer 135 may comprise aluminum (Al), silver (Ag), gold (Au), or copper (Cu). The second conductive layer 135 may reflect light emitted from the active layer 113 upward to improve light extraction efficiency. The second conductive layer 135 may inject current into the second conductive semiconductor layer 112.

The capping layer 140 may be disposed on the second conductive layer 135. The capping layer 140 may be electrically connected to the second electrode 135. The capping layer 140 may protect the second electrode 135. Also, the capping layer 140 may supply current to the second conductive type semiconductor layer 112. The capping layer 140 may function as a current diffusion layer.

The capping layer 140 may be formed as a single layer or multiple layers by a selected one of Ti, Ni, and Au, or a combination thereof. However, this does not limit the present invention. In particular, Ti may be disposed in a region of the capping layer 140 in contact with the second conductive layer 135. The structure of the capping layer 140 will be described later in more detail.

The first insulating layer 151 and the second insulating layer 152 may be formed of at least one selected from the group consisting of SiO2, SixOy, Si3N4, SixNy, SiOxNy, Al2O3, TiO2, . The first insulating layer 151 and the second insulating layer 152 may be formed as a single layer or a multilayer. Illustratively, the first and second insulating layers 151 and 152 may be a DBR (distributed Bragg reflector) having a multi-layered structure including silver oxide and a Ti compound. However, the first and second insulating layers 151 and 152 may include various reflective structures.

When the first and second insulating layers 151 and 152 perform a reflection function, light emitted toward the side surface of the active layer 113 may be reflected upward to improve light extraction efficiency. As the number of recesses (R) increases, the light extraction efficiency may be more effective than that of a semiconductor device emitting blue light.

Meanwhile, the second electrode pad 160 may be disposed at one corner of the semiconductor device 100. The second electrode pad 160 may be electrically connected to the second conductive layer 135 and the second electrode 125 by the first insulating layer 151. That is, the second electrode pad 160, the second conductive layer 135, and the second electrode 125 may form one electrical channel. The second electrode pad 160 is electrically insulated from the first conductive layer 131 by the second insulating layer 152.

The central portion of the second electrode pad 160 may be recessed, so that the upper surface of the second electrode pad 160 may have a concave portion and a convex portion. A wire (not shown) may be bonded to the concave portion of the second electrode pad 160. Accordingly, the bonding area can be widened and the second electrode pad 160 and the wire can be bonded more firmly.

The second electrode pad 160 may function to reflect light. Accordingly, as the second electrode pad 160 is closer to the light emitting structure 110, the light extraction efficiency of the semiconductor device 100 can be improved. The height of the convex portion of the second electrode pad 160 may be higher than that of the active layer 113. Accordingly, the second electrode pad 160 can reflect the light emitted in the horizontal direction of the device from the active layer 113 upward to improve the light extraction efficiency and control the directivity angle.

The bonding layer 170 may be further disposed along the bottom surface of the light emitting structure 110 and the shape of the recess R. [ The bonding layer 170 may be formed on the first conductive layer 131. The bonding layer 170 may include a conductive material. Illustratively, the bonding layer 170 may comprise a material selected from the group consisting of gold, tin, indium, aluminum, silicon, silver, nickel, and copper, or alloys thereof.

The substrate 180 may be disposed on the bonding layer 170. The substrate 180 may be made of a conductive material. Illustratively, the substrate 180 may comprise a metal or semiconductor material. Further, the substrate 180 may be a metal having excellent electrical conductivity and / or thermal conductivity. Illustratively, the substrate 180 may comprise a material selected from the group consisting of silicon, molybdenum, silicon, tungsten, copper, and aluminum, or alloys thereof. In this case, the heat generated during semiconductor device operation can be quickly dissipated to the outside.

A passivation layer 190 may be formed on the upper surface and the side surface of the light emitting structure 110. The passivation layer 190 may be in contact with the first insulating layer 151 in a region adjacent to the second electrode 125.

FIGS. 2A and 2B are diagrams for explaining a configuration in which a light output is improved according to the number of recesses in a semiconductor device according to an embodiment of the present invention. FIG.

As the Al composition of the light emitting structure 110 increases, the current diffusion characteristics in the light emitting structure 110 may be degraded. In addition, the amount of light emitted to the side of the active layer 113 is increased (TM mode) as compared with the GaN-based blue light emitting device. This TM mode can occur in an ultraviolet semiconductor device.

The ultraviolet semiconductor element has a lower current dispersion characteristic than the blue GaN semiconductor element. Therefore, it is necessary to dispose the first electrode 121 by forming a relatively large number of recesses (R) in the ultraviolet semiconductor device as compared with the blue GaN semiconductor device.

Referring to FIG. 2A, the current is dispersed only at the vicinity of each first electrode 121, and the current density at the far point is drastically lowered. Therefore, the effective light emitting area P1 can be narrowed.

The effective light emitting region P1 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 121 having the highest current density. For example, the effective light emitting region P1 can be adjusted according to the level of the injection current and the composition of Al in the range of 5 to 40 mu m from the center of the recess R.

The low current density region P2 may have a low current density and may hardly contribute to light emission. Therefore, the embodiment can further arrange the first electrode 121 in the low current density region P2 having a low current density or improve the light output using the reflective structure.

Generally, in the case of a GaN semiconductor layer, it is preferable to minimize the area of the recesses R and the first electrode 121 because the current dispersion characteristics are relatively good. The larger the area of the recess R and the first electrode 121 is, the smaller the area of the active layer 113 is. However, in the embodiment, since the composition of Al is high, the current diffusion characteristics are relatively decreased. Therefore, even if the area of the active layer 113 is sacrificed, the number of the first electrodes 121 is increased to reduce the low current density region P2, It may be desirable to arrange the reflective structure in the low current density region P3.

Referring to FIG. 2B, when the number of recesses R is 48, the recesses R can not be disposed in a straight line in the transverse direction, but can be disposed in a zigzag manner. In this case, the area of the low current density region P2 becomes narrower, and most of the active layers can participate in the light emission.

When the number of recesses (R) is 70 to 110, the current can be more efficiently dispersed, the operating voltage can be lowered, and the light output can be improved. In a semiconductor device that emits UV-C, when the number of recesses (R) is less than 70, the electrical and optical characteristics may be deteriorated. When the number of recesses (R) is more than 110, electrical characteristics may be improved. However, Can be lowered. At this time, the diameter of the recess R may be 20 탆 to 70 탆.

3A and 3B are various modifications of the first electrode of the semiconductor device according to the embodiment of the present invention.

First, referring to FIG. 3A, the first electrode according to the first embodiment will be described as follows.

The first electrode 121-1 is in ohmic contact with the first conductive semiconductor layer 111 (FIG. 1) and may include at least one conductive material. The first electrode 121-1 may include a plurality of layers. The first electrode 121-1 may include a first surface 121-1a in contact with the first conductivity type semiconductor layer 111 and a second surface 121-1b in contact with the first conductive layer 131 have.

The first electrode 121-1 may include a first layer 122-1, a second layer 123, and a third layer 124. [ Here, the first layer 122-1 may include a 1-1 layer 122a, a 1-2 layer 122b, and a 1-3 layer 122c. The first layer 122a, the first layer 122b, the first layer 123c, the second layer 123 and the third layer 124 may be sequentially arranged.

The first 1-1 layer 122a, the 1-2 layer 122b, the 1-3 layer 122c, the second layer 123 and the third layer 124 of the first electrode 121-1 After the deposition, a heat treatment can be performed. After the heat treatment, the metal materials in the first layer 122-1 may be mixed with each other. This will be described in more detail with reference to FIG. 3B.

Meanwhile, after heat treatment of the first electrode 121-1, a ball up phenomenon and a void may occur in the first electrode 121-1. Particularly, a ball up phenomenon may occur on the second surface 121-1b of the first electrode 121-1.

This is because the diffusion coefficients of the first metal (for example, Al) included in the first to third layers 122c and the third metal (for example, Au) included in the third layer 124 are different from each other to be. Here, the diffusion coefficient is a coefficient indicating the degree of diffusion per unit time, and as the diffusion coefficient is larger, the diffusion rate can be increased. That is, the first metal has a larger diffusion coefficient than the third metal and can have a faster diffusion rate. In other words, the first metal may have the property of diffusing toward the third layer 124.

Thus, in some areas of the first layer 122-1 where the percentage of the first metal is high, the first metal materials can move toward the third layer 124. [ Depending on the movement of the first metallic materials, some areas of the first to third layers 122c, 122c and 124 may experience a ball-up phenomenon in which the surface becomes convex . In addition, a Kirkendall void may be generated in the lower part of the ball-up area after the first metal materials are moved.

The ball-up phenomenon can reduce the efficiency of the semiconductor device. That is, a phenomenon in which current flows in the ball-up region may occur. In addition, corrosion of the first electrode 121 may occur along the ball-up area (or the void area). This may deteriorate the ohmic characteristics of the first electrode 121. In order to prevent this, it is desirable to maintain the ohmic characteristics and to minimize the occurrence of voids by controlling the configuration of the first electrode 121, particularly, the proper thickness of the first layer 122c and the second layer 123 Do.

The first layer 122-1 may be exposed by the first insulating layer 151 and may be electrically connected to the first conductive type semiconductor layer 111. [ The first layer 122-1 may be electrically connected to the first conductive type semiconductor layer 111 through the first surface 121-1a. The first layer 122-1 may include Cr, Ti, and Al. Here, Al can control the ohmic characteristic of the first electrode 121-1. As Al increases, the ohmic characteristics are improved, but the ball up phenomenon may increase. Therefore, if Al exceeds the appropriate level and becomes excessively large, the increase of the ball up and void may result in anomics.

The thickness of the first metal layer (first to third layers, 122c) including the first metal (for example, Al) in the first layer 122-1 may be 100 to 120 nm. When the thickness of the first to third layer 122c is smaller than 100 nm, the ohmic characteristics may be deteriorated. If the thickness of the first 1-3 layer 122c is larger than 120 nm, a ball-up phenomenon (or void) may occur.

On the other hand, the thickness of the first 1-3 layer 122c may be 1.5 to 2.5 times the sum of the thicknesses of the 1-1 layer 122a and the 1-2 layer 122b. If the thickness of the first 1-3 layer 122c is too small or too thick in the first layer 122-1 beyond this ratio, ohmic may not be achieved.

The plurality of layers included in the first layer 122-1 may each include a different metal material. For example, the first-first layer 122a may include Cr, and the first-second layer 122b may include Ti, but the present invention is not limited thereto.

The second layer 123 may be disposed on the first layer 122-1. Specifically, the second layer 123 may be disposed on the first to third layers 122c. The second layer 123 may serve as a barrier between the first layer 122-1 and the third layer 124. [ In particular, the second layer 123 can prevent diffusion due to the difference in diffusion coefficient between the first-third layer 122c and the third layer 124. The second layer 123 may comprise a second metal (e.g., Ni). As the Ni-containing layer becomes thicker, the ball-up phenomenon decreases, but the ohmic characteristic may deteriorate.

The thickness of the second layer 123 may be 45 to 65 nm. If the thickness of the second layer 123 is less than 45 nm, the first metal of the first layer 122-1 may diffuse toward the third layer 124 to cause voids and a ball up phenomenon. If the thickness of the second layer 123 is larger than 65 nm, the ohmic characteristics may be deteriorated.

The second layer 123 may have a thickness of 0.4 to 0.53 times the thickness of the first to third layer 122c. If the thickness of the second layer 123 is smaller than 0.4 times the thickness of the first to third layers 122c, ball up phenomenon and voids may occur. That is, the second layer 123, which acts as a barrier, has a relatively small thickness as compared with the first to third layers 122c, so that the diffusion prevention function may not be sufficiently achieved. If the thickness of the second layer 123 is larger than 0.53 times the thickness of the first to third layers 122c, the ohmic characteristics may be deteriorated. That is, since the thickness of the first to third layer 122c for controlling the ohmic characteristics is relatively small, the ohmic characteristics may be deteriorated.

The third layer 124 may be disposed on the second layer 123. The third layer 124 may be electrically connected to the first conductive layer 131 through the second surface 121-1b. The third layer 124 may comprise Au, but this does not limit the invention.

Referring to FIG. 3B, the first electrode according to the second embodiment will now be described.

The first electrode 121-2 is in ohmic contact with the first conductive semiconductor layer 111 (FIG. 1) and may include at least one conductive material. The first electrode 121-1 may include a plurality of layers. The first electrode 121-1 may include a first surface 121-2a in contact with the first conductivity type semiconductor layer 111 and a second surface 121-2b in contact with the first conductive layer 131 have.

The first electrode 121-2 may include a first layer 122-2, a second layer 123, and a third layer 124. [ The first layer 122-2 may include a first region 122d and a second region 122e.

The first electrode 121-2 according to FIG. 3B may be one in which the first electrode 121-1 according to FIG. 3A is heat-treated. After the heat treatment, the metals included in the first layer 122-1 of the first electrode 121-1 (FIG. 3A) are mixed to form the first layer 122-2 of the first electrode 121-2 (FIG. 3B) .

The first layer 122-2 may be exposed by the first insulating layer 151 and electrically connected to the first conductive type semiconductor layer 111. [ The first layer 122-2 may be electrically connected to the first conductive type semiconductor layer 111 through the first surface 121-2a. The first layer 122-2 may comprise Cr, Ti, and Al. Here, Al can control the ohmic characteristic of the first electrode 121-1.

The first layer 122-2 may include a first region 122d and a second region 122e. The first region 122d may be a region from the first surface 121-2a of the first layer 122-2 to the imaginary line L. [ The second region 122e may be an area from the imaginary line L to the interface between the first layer 122-2 and the second layer 123. [

The first region 122d and the second region 122e may include Cr, Ti, and Al. At this time, the proportion of Al in the second region 122e may be larger than the proportion of Al (first metal) in the first region 122d. The sum of the ratios of Cr and Ti in the first region 122d may be greater than the sum of the ratios of Cr and Ti in the second region 122e.

This is because the first region 122d is disposed in the region corresponding to the first-first layer 122a and the first-second layer 122b of the first layer 122-1 (FIG. 3A) before the heat treatment . That is, even if the metal materials in the first layer 121-1 (FIG. 3A) are diffused and mixed by the heat treatment, the Cr and Ti existing in the first-first layer 122a and the first- (First region) where the first-first layer 122a and the first-second layer 122b are disposed.

In addition, the second region 122d may be disposed in a region corresponding to the first to third layers 122c before the heat treatment. Therefore, even if the metal materials in the first layer 121-1 (Fig. 3A) are diffused and mixed with each other by the heat treatment, the Al existing in the first to third layers 122c is in a state in which the first to third layers 122c (The second region).

The imaginary line L may be located at a point in the first layer 122-2 that divides the first region 122d and the second region 122e by 3: 7 to 6.5: 3.5. That is, the thickness ratio of the first region 122d and the second region 122e in the first layer 122-2 may be 3: 7 to 6.5: 3.5. This is because, as described above, the thickness of the first to third layers 122c before heat treatment (Fig. 3A) is 1.5 to 2.5 times the sum of the thicknesses of the 1-1 layer 122a and the 1-2 layer 122b .

The ratio of the proportion of Al in the first region 122d to the proportion of Al in the second region 122e may be 1: 1.5 to 1: 2.5. This is because, as described above, the thickness of the first to third layers 122c before heat treatment (Fig. 3A) is 1.5 to 2.5 times the sum of the thicknesses of the 1-1 layer 122a and the 1-2 layer 122b . That is, the thickness of the first 1-3 layer 122c is relatively larger than the sum of the thicknesses of the 1-1th layer 122a and the 1-2th layer 122b, so that the 1-3th layer 122c And a large amount of Al contained in the second region 122e.

The second layer 123 may be disposed on the first layer 122-2. Specifically, the second layer 123 may be disposed on the second region 122e. The second layer 123 may serve as a barrier between the first layer 122-2 and the third layer 124. [ In particular, the second layer 123 may include a third metal (e.g., Au) that includes the first metal (e.g., Al) included in the first layer 122-2 and the third layer 124, It is possible to prevent the diffusion due to the difference in the diffusion coefficient. The second layer 123 may comprise a second metal (e.g., Ni).

The thickness of the second layer 123 may be 45 to 65 nm. If the thickness of the second layer 123 is less than 45 nm, the first metal of the first layer 122-2 may diffuse toward the third layer 124 to cause voids and ball up. If the thickness of the second layer 123 is larger than 65 nm, the ohmic characteristics may be deteriorated.

The third layer 124 may be disposed on the second layer 123. The third layer 124 may be electrically connected to the first conductive layer 131 through the second surface 121-2b. The third layer 124 may comprise Au, but this does not limit the invention.

As described above, the present invention can minimize the occurrence of ball up phenomenon and voids while maintaining the ohmic characteristic through controlling the thickness of the layer containing Al controlling the ohmic characteristic and the layer containing Ni serving as the barrier.

4 is a conceptual view of a capping layer of a semiconductor device according to an embodiment of the present invention.

Referring to FIG. 4, the capping layer 140 may include a first capping layer 141, a second capping layer 142, and an intermediate layer 143.

The first capping layer 141 may be disposed directly on the second conductive layer 135. The first capping layer 141 may be disposed on one side of the capping layer 140. The first capping layer 141 may comprise Ti. When Ti is included in the first capping layer 141, the metal materials in the intermediate layer 143 can be prevented from diffusing into the second conductive layer 135.

The second capping layer 142 may be disposed on the outermost side of the capping layer 140. That is, the second capping layer 142 may be disposed on the other side of the capping layer 140. Specifically, the second capping layer 142 may be disposed in the region farthest from the second conductive layer 135 in the capping layer 140. The second capping layer 142 may comprise Au. By including Au in the second capping layer 142, it is possible to prevent oxidation or deformation of the capping layer 140 internal materials during various processes after the capping layer 140 is formed. On the other hand, the second capping layer 142 may be omitted in some cases.

The intermediate layer 143 may be disposed between the first capping layer 141 and the second capping layer 142. The intermediate layer 143 may be a single layer or a multilayer. The intermediate layer 143 may be composed of one to six layers. If the number of the intermediate layers 143 is larger than six, the process time and process complexity may increase and the efficiency of the process may deteriorate. On the other hand, the intermediate layer 143 may be omitted in some cases.

The intermediate layer 143 may include at least one first intermediate layer 143a containing Ni. At this time, one of the first intermediate layers 143a may be disposed directly on the first capping layer 141. In addition, the intermediate layer 143 may further include at least one second intermediate layer 143b containing Ti. Of course, the second intermediate layer 143b may be omitted. When the intermediate layer 143 includes a plurality of the first intermediate layer 143a and the second intermediate layer 143b, the first intermediate layer 143a and the second intermediate layer 143b may be alternately arranged.

As such, the capping layer 140 may comprise one to eight layers. If the capping layer 140 contains more than eight layers, the process time and complexity may increase and the efficiency of the process may decrease.

The capping layer 140 may include only the first capping layer 141. In addition, the capping layer 140 may include only the first capping layer 141 and the second capping layer 142. In addition, the capping layer 140 may include both the first capping layer 141, the second capping layer 142, and the intermediate layer 143. Here, the intermediate layer 143 may be composed of one to six layers. At this time, the intermediate layer 143 may include one to three first intermediate layers 143a. In addition, the intermediate layer 143 may include 0 to 3 second intermediate layers 143b.

The capping layer 140 may be formed of one selected from the group consisting of Ti, Ti / Au, Ti / Ni, Ti / Ni / Au, Ti / Ni / Ti, Ti / Ni / Ti / Ti / Ni / Ti / Ni / Ti, Ti / Ni / Ti / Ni / Ti, Ti / Ni / Ti / / Ni / Au, Ti / Ni / Ti / Ni / Ti / Ni / Ti and Ti / Ni / Ti / Ni / Ti / Ni / Ti / Au.

In the capping layer 140, the current injection efficiency may increase as the number of the layers constituting the intermediate layer 143 increases. That is, since the capping layer 140 supplies current to the second conductive type semiconductor layer 112, the current injection efficiency may increase as the thickness of the capping layer 140 increases.

The Ti-containing layer (the first capping layer 141 or the second intermediate layer 143b) in the capping layer 140 may be alternately disposed with the layer containing Ni (the first intermediate layer 143a). As such, when stacking a plurality of different layers alternately, stress can be alleviated as compared with forming one layer thick. Therefore, even if the thickness of the entire capping layer 140 is increased, the stress of the thin film can be relaxed and the current injection efficiency can be improved.

The overall thickness of the capping layer 140 may be between 100 and 2000 nm. When the thickness of the capping layer 140 is less than 100 nm, the current injection efficiency and the protective effect of the second conductive layer 135 can be reduced. If the thickness of the capping layer 140 is greater than 2000 nm, the process time and process complexity may increase and the efficiency of the process may decrease. Also, when the thickness of the capping layer 140 is larger than 2000 nm, the stress of the thin film may increase.

The thickness of the first capping layer 141 in the capping layer 140 may range from 30 to 300 nm. If the thickness of the first capping layer 141 is less than 30 nm, the material (e.g., Ni) included in the intermediate layer 143 may be diffused into the second conductive layer 135. In such a case, a dark spot (for example, Ni diffused region) may be generated in the second conductive layer 135 and the reflectance may be reduced. If the thickness of the first capping layer 141 is greater than 300 nm, the stress of the first capping layer 141 may increase.

The thickness of the first intermediate layer 143a and the second intermediate layer 143b may be 10 to 300 nm. When the thickness of the first intermediate layer 143a is less than 10 nm, the stress relaxation effect may be insignificant when the different layers are alternately laminated. If the thickness of the first intermediate layer 143a is larger than 300 nm, the stress of the thin film may increase.

The thickness ratio of the first capping layer 141 to the first intermediate layer 143a may be 1: 1 to 3: 1. If the thickness ratio of the first capping layer 141 to the first intermediate layer 143a is less than 1: 1, the material of the intermediate layer 143 may be diffused into the second electrode 135. If the thickness ratio of the first capping layer 141 and the first intermediate layer 143a is greater than 3: 1, the thickness of the first capping layer 141 may become too large and the stress may increase.

The thickness ratio of the first intermediate layer 143a and the second intermediate layer 143b may be 1: 1 to 1: 3. When the thickness ratio between the first intermediate layer 143a and the second intermediate layer 143b is less than 1: 1, the material contained in the first intermediate layer 143a can be diffused. If the thickness ratio between the first intermediate layer 143a and the second intermediate layer 143b is greater than 1: 3, the thickness of the second intermediate layer 143b may become too large and the stress may increase.

The thickness of the second capping layer 142 may be between 30 and 300 nm. When the thickness of the second capping layer 142 is less than 30 nm, the deformation preventing effect of the capping layer 140-1 may be reduced. If the thickness of the second capping layer 142 is greater than 300 nm, the stress of the thin film may increase.

5 is an enlarged view of a portion A in Fig.

Referring to FIG. 5, a bonding layer 135a may be further disposed between the second electrode 125 and the second conductive layer 135. The bonding layer 135a can improve the bonding force between the second electrode 125 and the second conductive layer 135. [ The bonding layer 135a may be disposed so as to completely cover the second electrode 125. [ The bonding layer 135a may be disposed to cover not only the second electrode 122 but also a part of the second conductive type semiconductor layer 112 and the first insulating layer 151. [

The bonding layer 135a may be formed as a single layer or a multilayer by a selected one of Cr, ITO, and Ti, or a combination thereof. When the bonding layer 135a includes ITO, the ITO may further include various materials capable of increasing bonding strength. Illustratively, the ITO may further comprise at least one material selected from N, Zn, and Ga. These materials may be deposited together during the deposition of the ITO and placed in the entire area of the ITO, and may be disposed only on the surface of the ITO through surface treatment. However, this does not limit the material of the bonding layer 135a.

The second conductive layer 135 may be disposed so as to completely cover the second electrode 125 like the bonding layer 135a. The bonding layer 135a may be disposed so as to cover not only the second electrode 122 but also a part of the second conductive type semiconductor layer 112 and the first insulating layer 151. [

That is, the end of the second conductive layer 135 may be longer than the end of the second electrode 125 with respect to the center C of the second electrode 125 (FIG. 1). Since the second conductive layer 135 is disposed up to the side surface of the second electrode 125, the light emitted toward the side surface of the second electrode 125 can be reflected upward to improve the light extraction efficiency.

The capping layer 140 may be disposed to completely cover the second conductive layer 135. In addition, the capping layer 140 may be disposed to cover a part of the first insulating layer 151.

That is, the capping layer 140 may be longer than the end of the second conductive layer 135 with respect to the center C of the second electrode 125 (FIG. 1). Since the capping layer 140 is disposed up to the side surface of the second conductive layer 135, the protective effect of the second conductive layer 135 can be further increased.

<Experimental Example>

Contact resistivity, surface properties and The  Feature comparison

The first electrode was formed by the structure of the 1-1 layer / the 1-2 layer / the first metal layer (the 1-3 layer) / the 2nd layer / the 3rd layer. Here, Comparative Example 1, Example 1, Example 2, and Example 3 were constructed by changing the thicknesses of the first metal layer and the second layer. At this time, the first metal layer may include Al, and the second layer may include Ni. The first electrode may be heat-treated.

Table 1 discloses the thickness of each of Comparative Example 1, Example 1, Example 2 and Example 3, and the contact specific resistance value by the TLM measurement method.

Comparative Example 1 Example 1 Example 2 Example 3 Al (nm) 130 100 120 120 Ni (nm) 52 52 52 63 The contact resistivity (rho _c ) 1.84.E-03 1.84.E-03 9.78.E-04 5.86.E-03

FIGS. 6A to 6D are views for observing the ball-up phenomenon by differently configuring the first electrode among the semiconductor devices according to the embodiment of the present invention. FIG. 6A is a result of observing Comparative Example 1, FIG. 6B is a result of observing Example 1, FIG. 6C is a result of observing Example 2, and FIG. 6D is a result of observing Example 3. 7 is a graph showing voltage and current values of the first electrode of FIGS. 6A to 6D through the TLM measurement method. In the graph of FIG. 7, the larger the slope, the lower the resistance, which may mean that the ohmic characteristic is good. Hereinafter, Comparative Example 1, Example 1, Example 2, and Example 3 will be compared with reference to Table 1.

In the case of Comparative Example 1, it was confirmed that the first metal layer had a thickness of 130 nm, so that the ball up phenomenon was remarkably observed in comparison with Examples 1 to 3 (FIG. 6A). Referring to Table 1, it can be seen that the contact resistivity values are somewhat larger than those in Examples 2 and 3. Referring to FIG. 7, it can be seen that the ohmic characteristics are better than those of the first and second embodiments, but are much better than those of the third embodiment. However, as a result, Comparative Example 1 is not suitable as the first electrode in that the ball-up phenomenon is observed much.

In the case of Example 1, since the ball-up phenomenon is hardly observed, it can be seen that the surface characteristics are excellent (Fig. 6B). On the other hand, Example 1 has the largest contact resistivity value as in Comparative Example 1. However, referring to FIG. 7, it can be confirmed that the ohmic characteristic is good next to the third embodiment. As a result, in Example 1, the contact resistivity value is somewhat higher than that in Examples 2 and 3, but it can be used as the first electrode because of its excellent surface characteristics and ohmic characteristics.

In the case of Example 2, the thickness of the first metal layer (Al) was made thicker than that of Example 1. Since Al is a metal that controls the ohmic characteristics, it is confirmed that the contact resistivity of Example 2 is significantly lower than that of Example 1 (Table 1). Also, referring to FIG. 7, it can be seen that the ohmic characteristic of the second embodiment is the best. However, since the first metal layer is thickened, the ball-up phenomenon may occur more than in the first embodiment (Fig. 6C). As a result, Example 2 exhibits the best results in contact resistivity and ohmic characteristics. Therefore, the surface characteristics are somewhat lacking as compared with Examples 1 and 3, and thus it can be used as the first electrode in consideration of this.

In the case of Example 3, the thickness of the second layer (Ni) was made thicker than that of Example 2. Since Ni acts as a barrier to prevent the diffusion of metals, it can be seen that the ball-up phenomenon of Example 3 is hardly observed as compared with Example 2 (Fig. 6D). However, by increasing the thickness of the second layer, the contact resistivity was increased compared to Example 2 (Table 1), and it was confirmed that the ohmic characteristics were lowered (Fig. 7). As a result, in Example 3, the contact resistivity and the ohmic characteristic were somewhat less than those in Examples 1 and 2, but they are excellent in surface characteristics and can be used as the first electrode.

1st  Depending on the various deformations of the electrode TLM  Measurement result

Table 2 compares the Rc, Rs, and ρc through TLM measurement with various modifications of the first electrode. The first electrode may have a structure of a 1-1 layer / a 1-2 layer / a first metal layer (a 1-3 layer) / a 2nd layer / a 3rd layer. The first electrode may be heat-treated. The first metal layer may comprise Al, and the second layer may comprise Ni. Further, the first-1 layer may include Cr, the first-second layer may include Ti, and the third layer may include Au.

T1, T2-1, T2-2, T3-1, T3-2, and T3-3 are the first electrode according to the embodiment of the present invention. Here, the intermediate layer means that another layer is disposed between the second layer and the third layer. Rc, Rs, and ρc are contact resistance, surface resistance, and contact resistivity, respectively, measured by the TLM measurement method. The ohmic characteristics deteriorate as the resistance increases.

Al (nm) Ni (nm) Middle layer structure R _c R _s ρ _c R1 120 50 - 11.38 52.79 2.21.E-03 T1 300 100 Cu / Ni 1299.39 -187.99 -8.08.E + 00 R2 120 50 - 11.20 56.25 2.01.E-03 T2-1 120 100 Ti / Ni / Ti / Cu 12102.89 2556.98 5.16.E + 01 T2-2 120 5 Cu 23.63 57.53 8.73.E-03 R3 120 50 - 14.48 66.88 2.82.E-03 T3-1 60 50 - 269.23 227.86 2.86.E-01 T3-2 90 50 - 20.80 67.17 5.80.E-03 T3-3 150 50 - 10.23 46.46 2.03.E-03

In the case of T1, the first metal layer (Al) was formed to have a thickness of 300 nm to improve the ohmic characteristics, and the second layer (Ni) was formed to have a thickness of 100 nm to serve as a barrier. Further, an intermediate layer of Cu / Ni was further formed between the second layer and the third layer. Here, Cu can serve as a barrier. However, in this case, it is expected that the ohmic characteristics will be lowered because the contact resistance value is significantly increased compared to R1 due to excessive Al and Ni rather than the ohmic property improvement. In particular, the sheet resistance and contact resistivity values are negative, indicating that no ohmic is formed in T1. Therefore, T1 is not suitable as the first electrode.

In the case of T2-1, the thickness of the first metal layer is equal to R2. In T2-1, the thickness of the second layer was set to 100 nm, and an intermediate layer was further formed to observe whether the barrier function could be improved as compared with R2. However, due to the excessive thickness of the second layer and the intermediate layer, the ohmic may not be achieved. That is, T2-1 is not suitable as the first electrode because the contact resistance, sheet resistance, and contact resistivity are significantly larger than R2.

In case of T2-2, the thickness of the second layer was reduced and a Cu barrier layer was added to the intermediate layer instead. However, T2-2 is not suitable as the first electrode because the contact resistance is increased compared to R2 and the ohmic is lowered.

T3-1, and T3-2, the thicknesses of the first metal layer were 60 nm and 90 nm, respectively. In the case of T3-1, it can be seen that the contact resistance, the sheet resistance and the contact resistivity are considerably increased in comparison with R3. That is, the thickness of the first metal layer of T3-1 may be relatively small compared to the second layer, so that the ohmic layer may not be formed. Also, in the case of T3-2, it can be confirmed that the contact resistance is increased as compared with R3. That is, although the thickness of the first metal layer in T3-2 is relatively smaller than that in the second layer, the thickness of the first metal layer is thicker than that of T3-1, so that the ohmic characteristics may be deteriorated. As a result, T3-1 and T3-2 are not suitable as the first electrode because the thickness of the first metal layer is relatively smaller than that of the second layer.

In the case of T3-3, the first metal layer has a thickness of 150. In this case, it can be confirmed that the contact resistance and the sheet resistance are all decreased as compared with R3. However, referring to FIG. 6A, it can be expected that a considerable amount of ball up phenomenon and void will occur. That is, although T3-3 may improve the ohmic characteristics due to low contact resistance and sheet resistance, it is not suitable as the first electrode because the surface characteristics are poor.

8 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 treatment or medical use, or may be used for sterilizing air purifiers, water purifiers, and the like.

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

The body 2 may include a material or a coating layer that reflects ultraviolet light. The body 2 can be formed by laminating a plurality of layers 2a, 2b, 2c, 2d and 2e. The plurality of layers 2a, 2b, 2c, 2d and 2e 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, 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, And phase. 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.

100; A semiconductor device 110; Light emitting structure
121; First electrodes 122-1 and 122-2; The first layer
122a; The 1-1 layer 122b; Layer 1-2
122c; Layer 1-3 (first metal layer) 122d; The first region
122e; A second region 123; Second layer
123; Third layer 125; The second electrode
131, 135; Conductive layer 140; The capping layer

Claims (20)

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;
A first electrode electrically connected to the first conductive semiconductor layer and including a plurality of layers; And
And a second electrode electrically connected to the second conductive semiconductor layer,
Wherein the first electrode comprises a first layer, a second layer and a third layer,
Wherein the first layer comprises a first metal layer comprising a first metal,
The diffusion coefficient of the first metal is larger than the diffusion coefficient of the third metal included in the third layer,
And the thickness of the second layer is 0.4 to 0.53 times the thickness of the first metal layer. The method according to claim 1,
And the second layer is disposed between the first metal layer and the third layer. The method according to claim 1,
Wherein the thickness of the first metal layer is 100 to 120 nm. The method according to claim 1,
And the thickness of the second layer is 45 to 65 nm. The method according to claim 1,
Wherein the first metal is Al. The method according to claim 1,
And the second layer comprises Ni. The method according to claim 1,
And the third metal is Au. The method according to claim 1,
The first layer comprises: a 1-1 layer; And a 1-2 layer disposed between the first 1-1 layer and the first metal layer. 9. The method of claim 8,
Wherein the thickness of the first metal layer is 1.5 to 2.5 times the sum of the thicknesses of the first 1-1 layer and the first 1-2 layer. 9. The method of claim 8,
Wherein the first layer includes Cr, and the first layer comprises Ti. The method according to claim 1,
A reflective layer disposed on the second electrode; And a capping layer disposed on the reflective layer and including a plurality of layers. The method according to claim 1,
The light emitting structure further includes 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,
Wherein the first electrode is disposed inside the plurality of recesses. 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;
A first electrode electrically connected to the first conductive semiconductor layer and including a plurality of layers; And
And a second electrode electrically connected to the second conductive semiconductor layer,
Wherein the first electrode comprises a first layer, a second layer and a third layer,
Wherein the first layer comprises a first region and a second region,
Wherein the diffusion coefficient of the first metal included in the first layer is larger than the diffusion coefficient of the third metal included in the third layer,
The ratio of the first metal included in the second region is larger than the ratio of the first metal included in the first region,
And the thickness ratio of the first region and the second region is 3: 7 to 6.3: 3.5. 14. The method of claim 13,
And the second layer is disposed between the second region and the third layer. 14. The method of claim 13,
Wherein the first metal is Al. 16. The method of claim 15,
Wherein a ratio of a ratio of Al in the first region to a ratio of Al in the second region is 1: 1.5 to 1: 2.5. 14. The method of claim 13,
Wherein the first layer further comprises Cr and Ti. 14. The method of claim 13,
And the second layer comprises Ni. 14. The method of claim 13,
And the third metal is Au. Body; And
And a semiconductor device disposed on the body,
The semiconductor device may further include:
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;
A first electrode electrically connected to the first conductive semiconductor layer and including a plurality of layers; And
And a second electrode electrically connected to the second conductive semiconductor layer,
Wherein the first electrode comprises a first layer, a second layer and a third layer,
Wherein the first layer comprises a first metal layer comprising a first metal,
The diffusion coefficient of the first metal is larger than the diffusion coefficient of the third metal included in the third layer,
Wherein the thickness of the second layer is 0.4 to 0.53 times the thickness of the first metal layer.

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