WO2018190618A1 - Semiconductor device - Google Patents

Abstract

An embodiment provides a semiconductor device comprising: a substrate; a semiconductor structure disposed on the substrate and including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer interposed between the first conductive semiconductor layer and the second conductive semiconductor layer; a first electrode disposed on the first conductive semiconductor layer; and a second electrode disposed on the second conductive semiconductor layer, wherein: at least one of the first electrode and the second electrode includes a junction layer disposed on the first conductive semiconductor layer or the second conductive semiconductor layer, a reflective layer disposed on the junction layer, a capping layer disposed on the reflective layer, and a bonding layer disposed on the capping layer; and the capping layer is obtained by alternately laminating a first layer and second layer at least once, the first layer contains Ti, and the ratio between the thicknesses of the first layer and the second layer ranges from 4:7 to 20:3.

Description

Semiconductor device

The embodiment relates to a semiconductor device.

A semiconductor device including a compound such as GaN, AlGaN, etc. has many advantages, such as having a wide and easy-to-adjust band gap energy, and can be used in various ways as a light emitting device, a light receiving device, and various diodes.

Particularly, light emitting devices such as light emitting diodes and laser diodes using semiconductors of Group 3-5 or Group 2-6 compound semiconductors have been developed through the development of thin film growth technology and device materials. Various colors such as blue and ultraviolet light can be realized, and efficient white light can be realized by using fluorescent materials or combining colors.Low power consumption, semi-permanent lifespan, and fast response speed compared to conventional light sources such as fluorescent and incandescent lamps can be realized. It has the advantages of safety, environmental friendliness.

In addition, when a light-receiving device such as a photodetector or a solar cell is also manufactured using a group 3-5 or 2-6 compound semiconductor material of a semiconductor, the development of device materials absorbs light in various wavelength ranges to generate a photocurrent. As a result, light in various wavelengths can be used from gamma rays to radio wavelengths. It also has the advantages of fast response speed, safety, environmental friendliness and easy control of device materials, making it easy to use in power control or microwave circuits or communication modules.

Therefore, the semiconductor device may replace a light emitting diode backlight, a fluorescent lamp, or an incandescent bulb, which replaces a cold cathode tube (CCFL) constituting a backlight module of an optical communication means, a backlight of a liquid crystal display (LCD) display device. Applications are expanding to include white LED lighting devices, automotive headlights and traffic lights, and sensors that detect gas or fire. In addition, the semiconductor device may be extended to high frequency application circuits, other power control devices, and communication modules.

The semiconductor device may increase the rate of change of the operating voltage over time under high current and high temperature conditions. Therefore, there is a discussion about the causes and ways to solve them.

In addition, there is a problem in that light generated in the semiconductor structure is not absorbed or transmitted through the pad and thus the light efficiency is lowered.

The embodiment provides a semiconductor device having improved reliability.

The embodiment provides a blue light emitting device having a horizontal structure.

In addition, it provides a semiconductor device excellent in light efficiency by preventing light loss due to absorption.

The problem to be solved in the examples is not limited thereto, and the object or effect that can be grasped from the solution means or the embodiment described below will also be included.

A semiconductor device according to an embodiment of the present invention, a substrate; A semiconductor structure disposed on the substrate, the semiconductor 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 disposed on the first conductive semiconductor layer; And a second electrode disposed on the second conductive semiconductor layer, wherein at least one of the first electrode and the second electrode is disposed on the first conductive semiconductor layer or the second conductive semiconductor layer. Bonding layer; A reflective layer disposed on the bonding layer; A capping layer disposed on the reflective layer; And a bonding layer disposed on the capping layer, wherein the capping layer includes a first layer and a second layer alternately stacked at least one or more times, and the first layer comprises Ti, and the first layer And a ratio of the thickness of the second layer is 4: 7 to 20: 3 to improve the peeling phenomenon between the semiconductor structure and the bonding layer.

Semiconductor device according to an embodiment of the present invention; A semiconductor structure disposed on the substrate, the semiconductor 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 disposed on the first conductive semiconductor layer and electrically connected to the first conductive semiconductor layer; And a second electrode disposed on the second conductive semiconductor layer and electrically connected to the second conductive semiconductor layer, wherein the first branch is disposed on the first electrode and the first conductive semiconductor layer. electrode; And a first pad electrode disposed on the first branch electrode, wherein the second electrode comprises: a second branch electrode disposed on the second conductive semiconductor layer; And a second pad disposed on the second branch electrode, wherein the first branch electrode and the second branch electrode have openings.

The first branch electrode and the second branch electrode include Ag, and the width of the opening of the first branch electrode is 30 compared to the length of the minimum width of the first branch electrode in a direction perpendicular to the thickness direction of the semiconductor structure. % To 60%, the width of the opening of the second branch electrode may be 30% to 60% of the length of the minimum width of the second branch electrode in a direction perpendicular to the thickness direction of the semiconductor structure.

The thickness of the first branch electrode and the second branch electrode may be 3nm to 300nm.

The length ratio of the length from the top surface of the second pad electrode to the top surface of the first pad electrode and the length from the bottom surface of the second pad electrode to the top surface of the first pad electrode in the thickness direction of the semiconductor structure is 1 : 2.0 to 1: 2.2.

A first ohmic layer disposed between the first conductive semiconductor layer and the first branch electrode; A second ohmic layer disposed between the second conductive semiconductor layer and the second branch electrode; And a current blocking layer disposed between the second ohmic layer and the second conductive semiconductor layer.

The current blocking layer may be disposed on an area overlapping the second branch electrode vertically.

According to the embodiment, by changing the structure of the electrode of the semiconductor device can be improved in the harsh conditions of high current, high temperature.

Moreover, the semiconductor element which is excellent in light extraction efficiency can be manufactured.

In addition, a semiconductor device having improved thermal reliability can be manufactured.

Various and advantageous advantages and effects of the present invention are not limited to the above description, and will be more readily understood in the course of describing specific embodiments of the present invention.

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

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

3 is a cross-sectional view taken along line II ′ of FIG. 1.

4 is a conceptual diagram of a first electrode of a semiconductor device according to an embodiment of the present disclosure.

FIG. 5 is a graph showing internal stresses according to thicknesses of a first layer and a second layer among capping layers of the first electrode.

6 is a graph illustrating ohmic characteristics of an electrode according to various modifications.

7 is a graph illustrating reflectances of electrodes according to various modifications.

8A to 8E are graphs illustrating the rate of change of the VF1 value of the semiconductor device according to various deformations of the electrode.

9A to 9E are graphs illustrating a change rate of VF 3 values of semiconductor devices according to various deformations of electrodes.

10A to 10E illustrate light emission distributions of semiconductor devices according to various deformations of electrodes.

11A to 11E illustrate the appearance of semiconductor devices according to various deformations of electrodes.

12A to 12E are detailed photographs of the appearance specificities of FIGS. 11A to 11E.

13A to 13E are cross-sectional views of electrodes according to various modifications.

14A to 14E illustrate the occurrence of peeling of electrodes according to various modifications.

15A to 15E illustrate the occurrence of peeling of electrodes according to various modifications.

16 is a perspective view of a semiconductor device according to another exemplary embodiment.

17 is a plan view of a semiconductor device according to another exemplary embodiment.

18 is a cross-sectional view taken along the line AA ′ of FIG. 17.

19 is a cross-sectional view of the portion BB ′ in FIG. 17.

20 is a cross-sectional view taken along line CC ′ in FIG. 17.

FIG. 21 is a cross-sectional view of a portion DD ′ in FIG. 17.

FIG. 22 is a cross-sectional view of part II ′ in FIG. 17.

23 is an enlarged view of a branch electrode of a semiconductor device according to example embodiments.

24A to 24F are flowcharts illustrating a method of manufacturing another semiconductor device, according to an embodiment.

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

Although matters described in a specific embodiment are not described in other embodiments, it may be understood as descriptions related to other embodiments unless there is a description that is contrary to or contradictory to the matters in other embodiments.

For example, if a feature is described for component A in a particular embodiment and a feature for component B in another embodiment, a description that is contrary or contradictory, even if the embodiments in which configuration A and configuration B are combined are not explicitly described. Unless otherwise, it should be understood to fall within the scope of the present invention.

In the description of the embodiment, when one element is described as being formed "on or under" of another element, it is on (up) or down (on). or under) includes both two elements being directly contacted with each other or one or more other elements are formed indirectly between the two elements. In addition, when expressed as "on" or "under", it may include the meaning of the downward direction as well as the upward direction based on one element.

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

The semiconductor device according to the 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 in the material. Thus, the light emitted may vary depending on the composition of the material.

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

1 is a perspective view of a semiconductor device according to an embodiment of the present invention. 2 is a plan view of a semiconductor device according to an embodiment of the present invention. 3 is a cross-sectional view taken along line II ′ of FIG. 1.

1 to 3, a semiconductor device 100A according to an embodiment of the present invention may include a substrate 110, a semiconductor structure 120, a current blocking layer 130, a second ohmic layer 140, and a second ohmic layer 140. It may include the first electrode 150 and the second electrode 160.

Substrate 110 may comprise a translucent, conductive or insulating substrate. The substrate 110 may be a material or a carrier wafer suitable for growing a semiconductor material. The substrate 110 may be made of a material selected from sapphire (Al 2 O 3), SiC, Si, GaAs, GaN, ZnO, Si, GaP, InP, Ge, and Ga 2 O 3, but the present invention is not limited thereto. The upper surface of the substrate 110 may include an uneven structure to improve light extraction efficiency.

Meanwhile, a buffer layer (not shown) may be further disposed between the substrate 110 and the semiconductor structure 120 to reduce the difference in lattice constant.

The semiconductor structure 120 may be disposed on the substrate 110. In the semiconductor structure 120, the first conductive semiconductor layer 121, the active layer 123, and the second conductive semiconductor layer 122 may be sequentially disposed.

The first conductive semiconductor layer 121 may be formed of a compound semiconductor such as a group III-V group or a group II-VI, and may be doped with a first dopant. The first conductive semiconductor layer 121 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 can be selected. The first dopant may be an n-type dopant such as Si, Ge, Sn, Se, or Te. When the first dopant is an n-type dopant, the first conductive semiconductor layer 121 doped with the first dopant may be a semiconductor layer including an n-type dopant.

The active layer 123 may be disposed between the first conductive semiconductor layer 121 and the second conductive semiconductor layer 122. The active layer 123 is a layer where electrons (or holes) injected through the first conductive semiconductor layer 121 and holes (or electrons) injected through the second conductive semiconductor layer 122 meet each other. The active layer 123 transitions to a low energy level as electrons and holes recombine, and may generate light having visible or ultraviolet wavelengths.

The active layer 123 includes a well layer and a barrier layer, and includes any one of a single well structure, a multi well structure, a single quantum well structure, a multi quantum well (MQW) structure, a quantum dot structure, or a quantum line structure. The structure of the active layer 123 is not limited thereto.

The second conductivity type semiconductor layer 122 may be disposed on the active layer 123. The second conductive semiconductor layer 122 may be formed of a compound semiconductor such as a group III-V group or a group II-VI, and may be doped with a second dopant. The second conductive semiconductor layer 122 is a semiconductor material having a composition formula of Inx5Aly2Ga1-x5-y2N (0≤x5≤1, 0≤y2≤1, 0≤x5 + y2≤1) or AlInN, AlGaAs, GaP, GaAs It may be made of a material selected from GaAsP, AlGaInP. The second dopant may be a p-type dopant such as Mg, Zn, Ca, Sr, Ba, or the like. When the second dopant is a p-type dopant, the second conductive semiconductor layer 122 doped with the second dopant may be a semiconductor layer including the p-type dopant.

However, the present invention is not limited thereto, and the first conductive semiconductor layer may be a semiconductor layer including an n-type dopant, and the second conductive semiconductor layer may be a semiconductor layer including a p-type dopant.

The current blocking layer (CBL) 130 may be disposed on the second conductive semiconductor layer 122. In detail, the current blocking layer 130 may be disposed in a region in which the second electrode 160, which will be described later, is disposed in the second conductive semiconductor layer 122. That is, the current blocking layer 130 may be disposed between the second electrode 160 and the second conductive semiconductor layer 122. In addition, the current blocking layer 130 may overlap the second electrode 160 in the vertical direction (Z-axis direction). The current blocking layer 130 may improve the luminous efficiency of the light emitting device by alleviating the phenomenon in which current is concentrated.

The current blocking layer 130 may be made of a material having electrical insulation or schottky contact. The current blocking layer 130 may be made of oxide, nitride, or metal. For example, the current blocking layer 130 may include at least one of SiO 2, SiO x, SiO x N y, Si 3 N 4, Al 2 O 3, TiO x, Ti, Al, and Cr. The current blocking layer 130 may be omitted in some cases.

The second ohmic layer 140 may be disposed on the second conductive semiconductor layer 122 and the current blocking layer 130. The second ohmic layer 140 may be made of a material having high light transmittance to increase light extraction efficiency. The second ohmic layer 140 may be omitted in some cases.

The second ohmic layer 140 may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IZAZO), indium gallium zinc oxide (IGZO), and indium gallium (IGTO). tin oxide), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IZO (IZO Nitride), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), ZnO, IrOx , RuOx, NiO, RuOx / ITO, Ni / IrOx / Au, or Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Sn, In, Ru, Mg, Zn, It may comprise at least one of Pt, Au, Hf, but is not limited to such materials.

Meanwhile, the semiconductor structure 120 may include a recess M formed by mesa etching. That is, a recess M may be formed in a region in which the first electrode 150 to be described later is disposed in the semiconductor structure 120. The recess M may penetrate the second conductive semiconductor layer 122 and the active layer 123 to a portion of the first conductive semiconductor layer 121. The recess M may be formed by mesa etching after the formation of the semiconductor structure 120, the current blocking layer 130, and the second ohmic layer 140.

The first electrode 150 may be disposed on the first conductivity type semiconductor layer 121. In detail, the first electrode 150 may be disposed on a portion of the first conductivity-type semiconductor layer 121 exposed by the recess M. Referring to FIG. The first electrode 150 may include a first pad electrode 150a and a plurality of first branch electrodes 150b.

The first pad electrode 150a may be a region in which wires are bonded. The first pad electrode 150a may have a larger area than the first branch electrode 150b for wire bonding. In detail, the first pad electrode 150a may have a wider width in the X-axis direction than the first branch electrode 150b. However, the shape of the first pad electrode 150a is not particularly limited.

The first branch electrode 150b may extend from the first pad electrode 150a. The first branch electrode 150b may extend from the first pad electrode 150a toward the second pad electrode 160a. In this case, the first branch electrode 150b may have a longer length in the Y-axis direction than the first pad electrode 150a. Therefore, the current injection efficiency and the current dispersion efficiency of the semiconductor device 100A may be improved by the first branch electrode 150b, thereby improving luminous efficiency.

In particular, the first branch electrodes 150b may be disposed on both sides of the first branch electrode 150b based on a center line parallel to the Y-axis direction of the semiconductor structure 120. In addition, the first branch electrodes 150b may be disposed one by one between the second branch electrodes 160b spaced apart from each other. Therefore, the current may be uniformly distributed by the first branch electrode 150b. 1 and 2, two first branch electrodes 150b are illustrated, but the present invention is not limited thereto.

The second electrode 160 may be disposed on the second conductive semiconductor layer 122. In detail, the second electrode 160 may be disposed in an area of the second ohmic layer 140 that vertically overlaps the current blocking layer 130. The second electrode 160 may include a second pad electrode 160a and a plurality of second branch electrodes 160b.

The second pad electrode 160a may be an area where the wire is bonded. The second pad electrode 160a may have a larger area than the second branch electrode 160b for wire bonding. In detail, the second pad electrode 160a may have a wider length in the X-axis direction than the second branch electrode 160b. However, the shape of the second pad electrode 160a is not particularly limited.

The second branch electrode 160b may extend from the second pad electrode 160a. The second branch electrode 160b may extend from the second pad electrode 160a toward the first pad electrode 150a. In this case, the second branch electrode 160b may have a longer length in the Y-axis direction than the second pad electrode 160a. Therefore, the current injection efficiency and the current dispersion efficiency of the semiconductor device 100A may be improved by the second branch electrode 160b, thereby improving light emission efficiency.

In particular, the second branch electrode 160b may be disposed on a centerline parallel to the Y-axis direction of the semiconductor structure 120. In addition, the second branch electrodes 160b may be disposed on both sides with respect to the center line parallel to the Y-axis direction. In detail, the second branch electrodes 160b and the first branch electrodes 150b may be alternately disposed one by one. In this case, the number of the second branch electrodes 160b may be greater than the number of the first branch electrodes 150b. By increasing the number of the second branch electrodes 160b, the injection efficiency of the holes may be further improved. In FIG. 1 and FIG. 2, three second branch electrodes 160b are illustrated, but the present invention is not limited thereto.

Meanwhile, in FIG. 3, the first electrode 150 is disposed to have a relatively short length compared to FIGS. 1 and 2. However, the first electrode 150 illustrated in FIG. 3 may be the first pad electrode 150a. That is, in the cross-sectional view, only the first pad electrode 150a of the first electrode 150 may be illustrated.

In addition, the second electrode 160 illustrated in FIG. 3 may include a second pad electrode 160a and a second branch electrode 160b. That is, since the second pad electrode 160a and the second branch electrode 160b are disposed to have a predetermined thickness, they may be seen as one configuration in cross-sectional view.

In addition, the current blocking layer 130 may be disposed in an area corresponding to the second electrode 160. Accordingly, as shown in FIG. 3, the current blocking layer 130 may overlap vertically (Z-axis direction) with both the second pad electrode 160a and the second branch electrode 160b of the second electrode 160. Can be. In addition, although not shown, the current blocking layer 130 may be disposed below the second branch electrode (see FIGS. 1 and 2) disposed above and below the second branch electrode disposed at the center of the semiconductor device 100A. have.

The first electrode 150 and the second electrode 160 may include a plurality of layers. Specifically, the first and second electrodes 150 and 160 may include a bonding layer, a reflective layer, a diffusion barrier layer, and a bonding layer. Can be. This structure may be equally applied to the pad electrodes 150a and 160a of the first and second electrodes 150 and 160 and the branch electrodes 150b and 160b. This will be described later.

4 is a conceptual diagram of a first electrode of a semiconductor device according to an embodiment of the present disclosure. FIG. 5 is a graph showing internal stresses according to thicknesses of a first layer and a second layer among capping layers of the first electrode.

Referring to FIG. 4, the first electrode 150 may include a bonding layer 151, a reflective layer 152, a capping layer 153, and a bonding layer 154. Meanwhile, although only the first electrode 150 is illustrated in the drawing, the same may be applied to the second electrode 160. In addition, this may be equally applied to the pad electrodes 150a and 160a and the branch electrodes 150b and 160b of each of the first and second electrodes 150 and 160.

The bonding layer 151 may be disposed on a portion of the first conductivity type semiconductor layer 121 exposed by the recess M. Referring to FIG. The bonding layer 151 may easily bond the first conductivity-type semiconductor layer 121 and the electrode 150. That is, the bonding layer 151 may improve the bonding force between the first conductivity type semiconductor layer 121 and the reflective layer 152. In addition, the bonding layer 151 may improve ohmic characteristics of the first conductivity-type semiconductor layer 121. The bonding layer 151 may include Cr.

The reflective layer 152 may be disposed on the bonding layer 151. The reflective layer 152 may be made of a material having excellent reflectance. For example, the reflective layer 152 may include at least one selected from Al, Ag, Rh, Cu, Re, Bi, Al, Zn, W, Sn, In, or Ni, or an alloy thereof. The reflective layer 152 may reflect light emitted from the active layer 123 to improve light output.

The capping layer 153 may be disposed on the reflective layer 152. The capping layer 153 may be a barrier layer that prevents diffusion of materials included in the reflective layer 152 and the bonding layer 154. The capping layer 153 may include a plurality of layers. That is, the capping layer 153 may have a structure in which the first layers 153a-n and n≥1 and the second layers 153b-n and n≥1 are alternately stacked at least once. Hereinafter, for convenience, the plurality of first layers and the second layers may be described as 153a and 153b, respectively. As the capping layer 153 has a structure in which a plurality of layers are stacked, an internal stress in the capping layer 153 may be relaxed.

The first layers 153a-n may be disposed on the reflective layer 152. In addition, the second layer 153b-n may be disposed on the first layer 153a-n. In this case, the first first layer on the reflective layer 152 may be defined as the first-first layer 153a-1. The closer to the bonding layer 154, the 1-2 layers (not shown), the 1-3 layers (not shown),... It may be defined as the first-n layer 153a-n and n≥1. In addition, the first second layer on the first-first layer 153a-1 may be defined as the second-first layer 153b-1. The closer to the bonding layer 154, the second to second layers (not shown), the second to third layers (not shown),. It may be defined as the second-n layer 153b-n and n≥1.

The first layer 153a may include Ti. The second layer 153b may include any one selected from Ni and Pt, and more preferably, Ni. Since a plurality of first and second layers 153a and 153b including different materials are stacked, internal stress of the capping layer 153 may be alleviated. Therefore, the phenomenon in which the electrode is peeled off by the internal stress of the capping layer can be prevented.

In exemplary embodiments, the first layer 153a and the second layer 153b may have internal stresses opposite to each other. That is, if the internal stress of the first layer 153a is a compressive stress, the internal stress of the second layer 153b may be a tensile stress. The reverse is also possible, and does not limit the form of internal stresses here. As the first and second layers 153a and 153b have opposite internal stresses, the internal stresses of the capping layer 153 may be canceled out. On the other hand, the first layer 153a and the second layer 153b having internal stresses opposite to each other are merely examples for carrying out the present invention, and the present invention is not limited thereto.

The ratio of the thicknesses of the first layer 153a and the second layer 153b may be 4: 7 to 20: 3. Preferably, the ratio of the thicknesses of the first layer 153a and the second layer 153b may be 9: 7 to 20: 3. In addition, the first layer 153a may be thicker than the second layer 153b. When the ratio of the thicknesses of the first and second layers 153a and 153b is out of the above range, the internal stress of any one layer may be relatively high. Therefore, the effect of alleviating internal stresses that are opposite to each other is insignificant and peeling of the electrode may occur.

Meanwhile, the thickness of the first layer 153a may be 20 to 100 nm. In addition, when the second layer 153b includes Ni, the thickness of the second layer 153b may be 35 nm or less. Here, the second layer 153b of the capping layer 153 may have a stronger role as a barrier layer than the first layer 153a. In this case, the minimum thickness of the second layer 153b may be 15 nm. Therefore, more preferably, the thickness of the second layer 153b may be 15 to 35 nm. However, even if the second layer 153b is smaller than 15 nm, the capping layer 153 may act as a barrier layer if the thickness of the first layer 153a is sufficiently thick.

In particular, referring to FIG. 5, in the case of Ti, an internal stress may have a value of 0 or negative in a section of 20 to 100 nm. In addition, in the case of Ni, the internal stress has a positive value, and as the thickness becomes thicker, the internal stress may increase. Therefore, as shown in FIG. 5, internal stresses between the first layer 153a and the second layer 153b may be canceled in a section in which Ti and Ni have opposite stresses. As shown in FIG. 4, the stress acting on the reflective layer 152 bonded to the capping layer 153 is directed toward the side, thereby peeling between the electrode and the semiconductor structure 120 or between the electrode and the second ohmic layer 140. The phenomenon can be prevented.

That is, when the first layer 153a and the second layer 153b have the same kind of internal stress, deformation may occur in the capping layer 153 under high current and high temperature conditions. In addition, such deformation may also occur in the reflective layer 152 bonded to the capping layer 153. That is, the deformation of the capping layer 153 may cause the reflective layer 152 to be lifted upward. As a result, a phenomenon in which the electrode 150 is lifted from the first conductivity-type semiconductor layer 121 may occur and the operating voltage may increase, thereby reducing the reliability of the semiconductor device 100A. In addition, such peeling may occur between the electrode 160 and the second conductivity-type semiconductor layer 122.

However, when the first layer 153a has an internal stress opposite to that of the second layer 153b, the internal stress in the capping layer 153 may be canceled out to minimize deformation. The force toward the side may act on the reflective layer 152 bonded to the capping layer 153. As a result, deformation of the reflective layer 152 bonded to the capping layer 153 is also minimized to prevent peeling of the electrode and to improve the reliability of the semiconductor device.

Meanwhile, 0, which is an internal stress that Ti has when 20 nm or 100 nm, may be a minimum internal stress. In addition, -1.4 x 10 < -14 > d / cm, which is an internal stress that Ti has when 45 nm, may be the maximum internal stress. Here, the maximum internal stress has a negative value because it is a stress acting in the opposite direction to Ni.

Meanwhile, in the case of Ni of FIG. 5, it may have a stress value such as Equation (1). Here, S may mean internal stress (dynes / cm), and T may mean thickness (cm).

According to an experimental result to be described later, when the first layers 153a and Ti are 100 nm and the second layers 153b and Ni are 15 nm, peeling of the electrode 150 may be prevented. At this time, the internal stress of the first layer 153a may be approximately 0 (see FIG. 5). In addition, according to Equation 1, the internal stress of the second layer 153b may be 1.6 × 10 −14 d / cm.

That is, when the internal stress of the second layer 153b is 1.6 × 10 −14 d / cm, the peeling phenomenon of the electrode may be prevented even if the first layer 153a does not have the opposite internal stress. In other words, the internal stress of the first and second layers 153a and 153b does not cancel, and even if the second layer 153b has an internal stress of 1.6 × 10 −14 d / cm, the electrode may not be peeled. have. Therefore, the sum of 0, the internal stress of the first layer 153a, and 1.6 × 10-14 d / cm, the internal stress of the second layer 153b, is acceptable for the first layer 153a and the second layer 153b. It may be the maximum possible internal stress value (A). That is, the maximum internal stress value A of the capping layer 153 may be 1.6 × 10 −14 d / cm.

Meanwhile, the maximum internal stress of the first layer 153a may be −1.4 × 10 −14 d / cm (FIG. 5). When the first layer 153a has a maximum internal stress, the second layer 153b having a stress opposite to the first layer 153a may also have a maximum internal stress. In addition, the sum of the maximum internal stress of each of the first layer 153a and the second layer 153b may be 1.6 × 10 −14 d / cm (the maximum allowable internal stress value A). Thus, when the first layer 153a has a maximum internal stress of −1.4 × 10 −14 d / cm, the maximum internal stress of the second layer 153b may be 3.0 × 10 −14 d / cm. In addition, when the second layer 153b has the maximum internal stress, the thickness of the second layer 153b may be about 3.5 × 10 −6 cm (35 nm).

As described above, the thickness of the first layer 153a may be 20 to 100 nm. When the thickness of the first layer 153a is smaller than 20 nm, the first and second layers 153a and 153b may have the same internal stress, thereby causing an electrode peeling phenomenon. In addition, when the thickness of the first layer 153a is greater than 100 nm, the first and second layers 153a and 153b may have the same internal stress, thereby causing an electrode peeling phenomenon.

The thickness of the second layer 153b may be 15 to 35 nm. When the thickness of the second layer 153b is less than 15 nm, the thickness may be too thin, thereby minimizing the role of the barrier layer between the reflective layer 152 and the bonding layer 154. When the thickness of the second layer 153b is greater than 35m, the internal stress is too large, the effect of canceling the internal layer of the first layer 153a is insignificant, and peeling of the electrode may occur.

On the other hand, the internal stress value according to Equation 1 and the thickness according to Figure 5 is only one example for the practice of the present invention, this is not limited to the invention.

The bonding layer 154 may be disposed on the capping layer 153. The bonding layer 154 may be a layer for wire bonding. For example, the bonding layer 154 may be any one selected from Au and Ag, or an alloy thereof, but the present invention is not limited thereto.

Experimental Example

Hereinafter, an experimental example of a semiconductor device to which electrodes of various structures are applied will be described with reference to FIGS. 6 to 15E. Specifically, Comparative Example 1, Comparative Example 2, Comparative Example 3, Example 1 and Example 2 were configured to compare ohmic characteristics, reflectance, operating voltage, light emission distribution, appearance characteristics and peeling phenomenon.

Table 1 shows the structure of the electrode of Comparative Example 1, Comparative Example 2, Comparative Example 3, Example 1 and Example 2. On the other hand, the structure of the electrode is the same for both the first electrode and the second electrode, it can be equally applied to both the pad electrode and the branch electrode of each electrode.

	Bonding layer	Reflective layer	Capping layer	Bonding layer	Other
Comparative Example 1	Cr	Al	Ni	Au	-
Comparative Example 2	Cr	Al	Ni	Au	SiO2 passivation
Comparative Example 3	Cr	Al	Ti / Ru / Cr / Pt	Au	Step difference between Ti / Ru and Cr / Pt
Example 1	Cr	Al	Ti / Ni / Ti / Ni / Ti	Au	-
Example 2	Cr	Al	Ti / Pt / Ti / Pt / Ti / Pt	Au	-

Referring to Table 1, the bonding layer 151, the reflective layer 152 and the bonding layer 154 may be made of the same material in both Comparative Examples 1-3 and Examples 1 and 2. That is, each layer of the electrode 150 may be similarly formed in addition to the structure of the capping layer 153.

Here, the thicknesses of the bonding layer 151 and the bonding layer 154 of Comparative Examples 1-3 and Examples 1 and 2 may be the same. In addition, the thicknesses of the reflective layers 152 of Comparative Examples 1-3 and Examples 1 and 2 may be 300 or 360 nm. In the case of the reflective layer 152 including Al, it may have a similar level of reflectivity typically at a thickness of 300 to 360 nm.

On the other hand, in Comparative Example 2, the passivation layer may be disposed of SiO 2 on the same electrode as Comparative Example 1. In addition, in Comparative Example 3, a step (see FIG. 13C) may be disposed in the middle of the capping layer 153 (between Ti / Ru and Cr / Pt). That is, the width (length in the direction perpendicular to the height direction) of Cr / Al / Ti / Ru may be larger than the width of Cr / Pt / Au.

Embodiment 1 and Embodiment 2 may be an electrode according to an embodiment of the present invention described above. Specifically, Example 1 has a structure of a first layer / second layer / first layer / second layer / first layer, wherein the first layer includes Ti and the second layer contains Ni. can do. In addition, the first layer 153a may have a thickness of 100 nm, and the second layer 153b may have a thickness of 15 nm. Example 2 has a structure of a first layer / second layer / first layer / second layer / first layer / second layer, wherein the first layer comprises Ti and the second layer is formed of Pt. It may include. In addition, the first layer may have a thickness of 100 nm, and the second layer may have a thickness of 50 nm.

Table 2 compares the sheet resistance and reflectance of Comparative Examples 1 and 3 and Examples 1 and 2.

	Cr / Al / Ni / Au (Comparative Example 1)	Cr / Al / Ti / Ru (Comparative Example 3-1)	Cr / Pt / Au (Comparative Example 3-2)	Cr / Al / Ti / Ni / Ti / Ni / Ti / Au (Example 1)	Cr / Al / (Ti / Pt) Х3 / Au (Example 2)
Sheet resistance (mΩ / sq.)	11.4	106.5	13.0	7.0-11.0	12.0
reflectivity(%)	71.7	-	39.8	-	-

Here, in Comparative Example 3, a sheet resistance was obtained by separately separating the lower layer Cr / Al / Ti / Ru (Comparative Example 3-1) and the upper layer Cr / Pt / Au (Comparative Example 3-2) each having a step difference. And reflectance was measured. In addition, in the case of reflectance, the reflectance layer 152 was made of the same material having a similar level of thickness, and the reflectance was measured only in Comparative Example 1.

It can be seen that the sheet resistance is almost the same level except for the lower layer of Comparative Example 3. In addition, the reflectance may have a nearly similar level except for the upper layer of Comparative Example 3.

6 is a graph illustrating ohmic characteristics of a semiconductor device according to various deformations of an electrode. 7 is a graph illustrating reflectances of semiconductor devices according to various deformations of electrodes. Meanwhile, Comparative Example 3-3 and Comparative Example 3-4 disclosed in FIGS. 6 and 7 may be obtained by separating the aforementioned Comparative Example 3 into another structure. That is, Comparative Example 3-3 may have a structure of Cr / Al / Ti, and Comparative Example 3-4 may be Ti / Ru / Cr / Pt / Au.

Referring to FIG. 6, it can be seen that not only Comparative Examples 1 and 3 and Examples 1 and 2 but also other structures have similar resistance values. In addition, referring to FIG. 7, when the Al reflecting layer has a thickness of 300 or 360 nm, it can be seen that the electrode has a similar level of reflectance (70 to 80%). In addition, when the Al reflection layer does not exist, it can be confirmed that the reflectance is remarkably inferior as compared with the case where the Al reflection layer is present.

That is, by combining Tables 2 and 6 and 7, it can be seen that the electrode according to an embodiment of the present invention has the same level as the conventional electrode in its characteristics.

8A to 8E are graphs illustrating the rate of change of the VF1 value of the semiconductor device according to various deformations of the electrode. 9A to 9E are graphs illustrating a change rate of VF 3 values of semiconductor devices according to various deformations of electrodes. 8A to 8E show the characteristics of Comparative Example 1, Comparative Example 2, Comparative Example 3, Example 1 and Example 2 in order, and FIGS. 9A to 9E show Comparative Example 1, Comparative Example 2 and comparison in order. The characteristics of Example 3, Example 1 and Example 2 are shown.

VF1 and VF3 may refer to a forward operating voltage when forward current is supplied. Also, ΔVF1 and ΔVF3 may refer to a rate of change of the operating voltage over time. ΔVF1 was measured under the condition of 90 A / cm 2, 1 mA and ΔVF 3 was measured under the condition of 90 A / cm 2, 95 mA. In addition, ΔVF1 and ΔVF3 were measured at 0, 24, 96 and 168 hours, respectively. In addition, in Comparative Example 1, Comparative Example 2, Comparative Example 3, Example 1 and Example 2, each of a total of 10 samples were added to measure the measurement.

The larger the rate of change of VF1 and VF3, the greater the change in operating voltage. Therefore, it may be desirable in terms of reliability that ΔVF1 and ΔVF3 remain at a constant level. In particular, in the case of ΔVF1, it is preferable in terms of reliability, and in the case of ΔVF3, it may be desirable in terms of reliability. In particular, in the case of ΔVF 3, since the semiconductor device operates at a high current, the semiconductor device may generate heat. Therefore, the reliability of the semiconductor element can be judged under the severe conditions of high temperature and high current by the measurement result of (DELTA) VF3.

In Comparative Example 1, ΔVF1 (FIG. 8A) is maintained at a constant level, but ΔVF3 (FIG. 9A) is rapidly increased (up to 0.18V). In Comparative Example 2, ΔVF1 (FIG. 8B) tends to decrease somewhat (up to −3.5%), and ΔVF3 (FIG. 9B) slightly increases (up to + 0.07V). In Comparative Example 3, ΔVF1 (FIG. 8C) tends to decrease rapidly (up to −6.5%), but it can be seen that ΔVF3 (FIG. 9C) maintains a constant level. In Example 1, it can be seen that both ΔVF1 (FIG. 8D) and ΔVF3 (FIG. 9D) maintain a constant level. In Example 2, ΔVF1 (FIG. 8E) tends to decrease somewhat (up to -2.5%), but it can be seen that ΔVF3 (FIG. 9E) maintains a constant level.

That is, in the case of Comparative Example 1 and Comparative Example 3, it can be seen that the reliability is significantly lower than the other cases. In addition, in the case of Example 1, both ΔVF1 and ΔVF3 maintain a constant level, it can be seen that the ten samples all exhibit similar characteristics, the best reliability. In addition, in the case of Example 2, ΔVF1 is somewhat reduced but within an acceptable range, it can be seen that ΔVF3 exhibits certain characteristics and is appropriate in terms of reliability.

10A to 10E illustrate light emission distributions of semiconductor devices according to various deformations of electrodes. Specifically, FIGS. 10A to 10E show light emission distributions of Comparative Example 1, Comparative Example 2, Comparative Example 3, Example 1 and Example 2 in order. Here, the red area may mean a light emitting area.

In the case of Comparative Example 1, light emission is easy, but it can be seen that the light emitting region is distributed in a region adjacent to the first electrode 150 (see FIGS. 1 to 3). In Comparative Examples 2 and 3, the light emitting regions are evenly distributed in comparison with Comparative Example 1, but the light emission is slightly inferior. In the case of Example 1, it can be seen that the light emitting regions are evenly distributed, and light emission is easily performed. In the case of Example 2, it can be seen that light emission is slightly insignificant.

As a result, in the case of Example 1, light emission is effectively performed, and in particular, it can be seen that the light emission area is evenly distributed, thereby increasing the current dispersion efficiency.

11A to 11E illustrate the appearance of semiconductor devices according to various deformations of electrodes. 12A to 12E are detailed photographs of the appearance specificities of FIGS. 11A to 11E. 13A to 13E are cross-sectional views of electrodes according to various modifications. Specifically, FIGS. 11A to 11E, FIGS. 12A to 12E, and FIGS. 13A to 13E show the appearance of Comparative Example 1, Comparative Example 2, Comparative Example 3, Example 1 and Example 2 in order. In addition, FIGS. 11A to 13E may observe changes in the electrodes after the reliability evaluation according to FIGS. 9A to 9E.

Although not shown, an electrode disposed on the left side of FIGS. 11A through 11E may be the second electrode 160, and an electrode disposed on the right side may be the first electrode 150. In addition, as described above, each of the first and second electrodes may include pad electrodes 150a and 160a and branch electrodes 150b and 160b. In addition, both the first electrode 150 and the second electrode 160 may have the same structure.

12A and 12B may observe the end of the first branch electrode 150b. 12C may observe the second pad electrode 150a. 12D and 12E may observe part of the first branch electrode 150b. 13A to 13E may observe a part of the second branch electrode.

Referring to FIGS. 11A and 11B, in Comparative Examples 1 and 2, when observed on the top surface, it was found that no outliers were found in appearance. However, referring to FIGS. 12A and 12B, it can be seen that a fine peeling phenomenon occurs in the first electrodes of Comparative Examples 1 and 2 when viewed from the side. That is, in the case of Comparative Examples 1 and 2, it can be seen that the non-contact phenomenon occurs with the semiconductor element by peeling the electrode. As a result, in Comparative Examples 1 and 2, it can be seen that the operating voltage ΔVF 3 is increased by peeling the electrode.

11C to 11E, in the case of Comparative Example 3 and Examples 1 and 2, the singularity of the appearance on the electrode can be observed. In particular, referring to FIGS. 12C to 12E, it can be seen that the material in the electrode has escaped to the outside of the electrode. However, it can be seen that the operating voltage ΔVF3 of Comparative Examples 3 and 1 and 2 is maintained at a constant level even when such a phenomenon (phenomena in which the material in the electrode escapes to the outside) occurs.

Meanwhile, referring to FIGS. 13A and 13B, in Comparative Examples 1 and 2, a phenomenon in which the material in the electrode escapes to the outside of the electrode was not observed. However, referring to FIGS. 13C to 13E, it can be seen that in Comparative Examples 3 and 1 and 2, pores are observed in the reflective layer Al. Therefore, it can be seen that the material exiting the outside of the electrode is Al in the reflective layer.

That is, in the exemplary embodiment of the present invention, the first layer 153a and the second layer 153b included in the capping layer 153 may have opposite internal stresses. Therefore, internal stresses of the first layer 153a and the second layer 153b cancel each other, thereby minimizing deformation of the capping layer 153 and the reflective layer 152 bonded thereto. That is, the peeling phenomenon of the electrode can be prevented.

Thus, in the case of Comparative Examples 1 and 2, since the capping layer contains only Ni having a positive internal stress, it can be seen that the peeling phenomenon of the electrode occurs (Figs. 12A and 12B). In addition, in Examples 1 and 2, since the internal stress of the capping layer is canceled and the reflective layer is forced toward the side, it can be seen that the material of the reflective layer has escaped to the outside of the electrode (FIGS. 12D and 12E). .

14A to 14E illustrate the occurrence of peeling of electrodes according to various modifications. 15A to 15E illustrate the occurrence of peeling of electrodes according to various modifications. Specifically, FIGS. 14A to 14E and 15A to 15E show the appearance of Comparative Example 1, Comparative Example 2, Comparative Example 3, Example 1 and Example 2 in order. In addition, FIGS. 14A to 15E may observe changes in electrodes after the reliability evaluation according to FIGS. 9A to 9E. 14A to 14E may observe the peeling phenomenon of the end of the second branch electrode, and FIGS. 15A to 15E may observe the peeling phenomenon of the end of the first branch electrode.

14A to 14E, it can be seen that the second electrode has relatively clean appearance characteristics. In addition, it turns out that peeling phenomenon of an electrode does not occur generally. In other words, even when the semiconductor device is driven under severe conditions, it can be seen that the second electrode generally has excellent reliability.

On the other hand, referring to Figure 15a to 15e, in the case of the first electrode, it can be seen that the phenomenon of peeling of the electrode and the phenomenon that the material inside the electrode is released. As a result, when the semiconductor device is driven under severe conditions, it can be seen that more reliability problems occur in the first electrode than in the second electrode.

Specifically, in the case of Comparative Example 1, the peeling phenomenon of the electrode was observed. Accordingly, it can be seen that Comparative Example 1 has a result of increasing the operating voltage as shown in FIG. 9A.

In Comparative Example 2, no peeling phenomenon was observed in the electrode observed in FIG. 15B. However, peeling phenomenon occurred in the electrode observed in FIG. 12B. Therefore, it can be seen that Comparative Example 2 has the result that the operating voltage slightly rises as shown in FIG. 9B.

In Comparative Example 3 and Examples 1 and 2, no peeling phenomenon of the electrode was observed. Accordingly, it can be seen that Comparative Example 3 and Examples 1 and 2 have a constant operating voltage as shown in FIGS. 9C to 9E.

As a result, it can be confirmed that Example 1 has the best reliability in terms of operating voltage, light emission distribution, and appearance characteristics.

As such, in the semiconductor device according to the exemplary embodiment, the capping layers of the first electrode and the second electrode may include a plurality of layers. Specifically, the capping layer may have a structure in which the first layer and the second layer are alternately arranged at least one or more times. By alternately stacking the first and second layers, the internal stress in the capping layer can be relaxed. In this case, the first layer and the second layer may have internal stresses opposite to each other. Alternatively, the internal stress of the first layer may be zero, and the second layer may have a thin thickness to have an internal stress such that deformation of the capping layer does not occur.

Therefore, the stress between the first layer and the second layer is canceled out and the peeling phenomenon of the electrode can be prevented. In particular, lifting of the electrode can be prevented even under high current and high temperature conditions, thereby improving reliability of the semiconductor device.

16 is a perspective view of a semiconductor device according to another exemplary embodiment.

Referring to FIG. 16, a semiconductor device 100B according to another embodiment may include a substrate 110, a semiconductor structure 120 disposed on the substrate 110, and a second ohmic layer disposed on the semiconductor structure 120. 140, the first electrode 150 and the second electrode 160 may be electrically connected to the semiconductor structure 120.

The semiconductor device 100B according to another embodiment may have a length P1 of 1100 μm to 1300 μm in the Y-axis direction, and a length P2 of 550 μm to 650 μm in the X-axis direction. The semiconductor device 100B may be half the length in the Y-axis direction. However, it is not limited to this length.

The substrate 110 may be an insulating substrate 110. The substrate 110 may be made of a material selected from sapphire (Al 2 O 3), SiC, GaN, ZnO, Si, GaP, InP, and Ge, but is not limited thereto.

The substrate 110 may also emit light from the side surface of the substrate 110 to improve light extraction efficiency. In addition, a plurality of uneven patterns Ps may be formed on the substrate 110. The uneven pattern Ps may improve light extraction efficiency.

The semiconductor structure 120 may be disposed on the substrate 110. The semiconductor structure 120 according to another embodiment may include a first conductive semiconductor layer 121, an active layer 122, and a second conductive semiconductor layer 123.

The first conductive semiconductor layer 121 may be formed of a compound semiconductor such as a group III-V group or a group II-VI, and may be doped with a first dopant. The first conductive semiconductor layer 121 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 can be selected. The first dopant may be an n-type dopant such as Si, Ge, Sn, Se, or Te. When the first dopant is an n-type dopant, the first conductive semiconductor layer 121 doped with the first dopant may be an n-type semiconductor layer.

The active layer 122 may be disposed between the first conductive semiconductor layer 121 and the second conductive semiconductor layer 123. The active layer 122 is a layer where electrons (or holes) injected through the first conductivity type semiconductor layer 121 and holes (or electrons) injected through the second conductivity type semiconductor layer 123 meet each other. The active layer 122 transitions to a low energy level as electrons and holes recombine, and may generate light having visible or ultraviolet wavelengths.

The active layer 122 includes a well layer and a barrier layer, and includes any one of a single well structure, a multi well structure, a single quantum well structure, a multi quantum well (MQW) structure, a quantum dot structure, or a quantum line structure. The structure of the active layer 122 is not limited thereto.

The second conductive semiconductor layer 123 is disposed on the active layer 122, and may be implemented as a compound semiconductor such as a group III-V group or a group II-VI, and a second conductive semiconductor layer 123 may be formed on the second conductive semiconductor layer 123. Dopants may be doped. The second conductive semiconductor layer 123 may be a semiconductor material having a composition formula of Inx5Aly2Ga1-x5-y2N (0≤x5≤1, 0≤y2≤1, 0≤x5 + y2≤1) or AlInN, AlGaAs, GaP, GaAs It may be made of a material selected from GaAsP, AlGaInP. When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, or Ba, the second conductive semiconductor layer 123 doped with the second dopant may be a p-type semiconductor layer.

The semiconductor structure 120 may include metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), molecular beam growth (Molecular Beam). Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), Sputtering, or the like.

The second ohmic layer 140 may be disposed on the second conductive semiconductor layer 123. The second ohmic layer 140 may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IZAZO), indium gallium zinc oxide (IGZO), and indium gallium (IGTO). tin oxide), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IZO (IZO Nitride), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), ZnO, IrOx , RuOx, NiO, RuOx / ITO, Ni / IrOx / Au, or Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Sn, In, Ru, Mg, Zn, It may include at least one of Pt, Au, Hf, but is not limited to these materials.

A portion of the second ohmic layer 140 may be exposed. However, the present invention is not limited thereto, and an insulating layer (not shown) covering the second ohmic layer 140 may be disposed. The insulating layer (not shown) may transmit light, and at least one selected from the group consisting of SiO 2, SixOy, Si 3 N 4, SixNy, SiO x Ny, Al 2 O 3, TiO 2, AlN, and the like, is not limited thereto.

The second ohmic layer 140 may improve light extraction to improve light transmission. For example, the light generated from the active layer 122 may pass through the second ohmic layer 140 and may be emitted to the upper portion of the semiconductor device 100B. In addition, the second ohmic layer 140 may improve the film non-conductivity to improve the operating voltage.

A current blocking layer 130 (CBL) may be disposed between the second ohmic layer 140 and the second conductive semiconductor layer 123. Thus, the second ohmic layer 140 may partially protrude in the first direction (Z-axis direction). This current blocking layer 130 will be described later with reference to FIG. 18.

The first electrode 150 may be disposed on the first conductivity type semiconductor layer 121. The first electrode 150 may include a first branch electrode 150b and a first pad electrode 150a.

The first branch electrode 150b may be disposed on the first conductivity type semiconductor layer 121. The first ohmic layer 141 may be disposed between the first branch electrode 150b and the first conductive semiconductor layer 121.

The second ohmic layer 140 may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IZAZO), indium gallium zinc oxide (IGZO), and indium gallium (IGTO). tin oxide), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IZO (IZO Nitride), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), ZnO, IrOx , RuOx, NiO, RuOx / ITO, Ni / IrOx / Au, or Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Sn, In, Ru, Mg, Zn, It may include at least one of Pt, Au, Hf, but is not limited to these materials.

The first branch electrode 150b may be disposed on the second ohmic layer 140. The first branch electrode 150b may include silver and may have an opening. The opening may comprise a void. The thickness of the first branch electrode 150b may be 3 nm to 300 nm, and the first branch electrode 150b may have various thicknesses.

The first pad electrode 150a may be disposed on the first branch electrode 150b. The first pad electrode 150a may be an area where the wire is bonded. The shape of the first pad electrode 150a is not particularly limited.

The second electrode 160 may be disposed on the second conductive semiconductor layer 123. The second electrode 160 may include a second branch electrode 160b and a second pad electrode 160a.

The second branch electrode 160b may be disposed on the second ohmic layer 140. The second branch electrode 160b may be disposed on the current blocking layer 130 to overlap the current blocking layer 130 in the first direction (Z-axis direction). For example, the second branch electrode 160b may be disposed on the second ohmic layer 140 partially protruding in the first direction (Z direction). The thickness of the second branch electrode 160b may be 3 nm to 300 nm, and the second branch electrode 160b may have various thicknesses.

The second branch electrode 160b may include silver and may have an opening.

The second pad electrode 160a may be disposed on a portion of the second branch electrode 160b. The second pad electrode 160a may be an area where the wire is bonded. The shape of the second pad electrode 160a is not particularly limited. The second pad electrode 160a may have a shape different from that of the first pad electrode 150a to distinguish it from the first pad electrode 150a. For example, the second pad electrode 160a may be circular, but is not particularly limited thereto.

In addition, the first branch electrode 150b and the second branch electrode 160b have reflectances of up to 95% for light of 440 mm to 460 mm. The first pad electrode 150a and the second pad electrode 160a include Cr, Al, Ni, and Au, and have a reflectance of up to 70% for light of 440 mm to 460 mm. By such a configuration, the first branch electrode 150b and the second branch electrode 160b have higher light reflectance than the first pad electrode 150a and the second pad electrode 160a to prevent loss due to light absorption. Extraction efficiency can be improved.

17 is a plan view of a semiconductor device according to another exemplary embodiment, FIG. 18 is a cross-sectional view of part AA ′ of FIG. 17, FIG. 19 is a cross-sectional view of part BB ′ of FIG. 17, and FIG. FIG. 21 is a sectional view of the DD 'portion in FIG. 17, and FIG. 22 is a sectional view of the II' portion in FIG.

Referring to FIG. 17, a semiconductor device 100B according to another exemplary embodiment may include a first side surface S1 and a third side surface S3 facing each other on a plane, and a second side surface S2 and a fourth side surface facing each other. S4) may be included. The first to fourth side surfaces may be the outermost surface of the semiconductor device 100B or the substrate 110 of the embodiment.

In addition, the semiconductor device 100B may include a first center line C1 that bisects the first side surface S1 and a third side S3, and a second portion that bisects the second side surface S2 and the fourth side surface S4. It may include a center line (C2).

The first pad electrode 150a and the second pad electrode 160a may be disposed on one side of the first center line C1, respectively. In addition, the first pad electrode 150a and the second pad electrode 160a may be electrically separated from each other, and wires having different polarities may be bonded.

The first pad electrode 150a and the second pad electrode 160a may be disposed on the second center line C2. With this configuration, the dispersion efficiency of the current injected into the first conductive semiconductor layer 121 and the second conductive semiconductor layer 123 can be improved.

The first branch electrode 150b may be disposed on the first conductive semiconductor layer 121 and the second ohmic layer 140. The first branch electrode 150b may be disposed below the second branch electrode 160b in the first direction (Z-axis direction). In addition, the first pad electrode 150a may be disposed below the second pad electrode 160a in the first direction (Z-axis direction). In addition, the second ohmic layer 140 may be disposed below the second ohmic layer 140 in the first direction (Z-axis direction).

A portion of the first branch electrode 150b may be disposed on the first center line. The first branch electrode 150b and the second branch electrode 160b may be symmetrically disposed about the first center line. By such a configuration, the current injected into the first conductivity-type semiconductor layer 121 and the second conductivity-type semiconductor layer 123 may be uniformly dispersed, thereby improving light efficiency.

The first branch electrode 150b and the second branch electrode 160b may be alternately disposed in a second direction (X-axis direction). For example, the first branch electrode 150b, the second branch electrode 160b, the first branch electrode 150b, the second branch electrode 160b, and the first branch in the second-first direction X1 from the first side surface. The electrodes 150b may be arranged in order.

The width W1 of the first branch electrode 150b may be in the range of 4 μm to 5 μm in the second-first direction X1. In addition, the width W2 of the first pad electrode 150a in the first-first direction Y1 may be about 90 μm to about 100 μm. When the first pad electrode 150a is circular, the diameter of the first pad electrode 150a may be about 90 μm to about 100 μm in the first-first direction Y1.

In addition, a surface of the first conductive semiconductor layer 121 is exposed between the first branch electrode 150b and the second ohmic layer 140 or between the first ohmic layer 141 and the second ohmic layer 140. Can have By such a configuration, electrical insulation between the first conductive semiconductor layer 121 and the second conductive semiconductor layer 123 can be provided.

The width W3 of the second branch electrode 160b may be in the range of 4 μm to 5 μm in the second-first direction X1. In addition, the width W4 may be about 90 μm to about 100 μm in the first-first direction Y1 of the second pad electrode 160a. When the second pad electrode 160a has a circular shape, the second pad electrode 160a may have a diameter of about 90 μm to about 100 μm in the first-first direction (Y1 axis direction).

Referring to FIG. 18, the current blocking layer 130 may be disposed between the semiconductor structure 120 and the second ohmic layer 140. The current blocking layer 130 may be disposed in an area that vertically overlaps the second branch electrode 160b. By such a configuration, the phenomenon in which current is concentrated can be alleviated to improve the luminous efficiency of the semiconductor device 100B.

In addition, the current blocking layer 130 may include a material having electrical insulation or a Schottky contact. The current blocking layer 130 may be made of oxide, nitride, or metal. For example, the current blocking layer 130 may include at least one of SiO 2, SiO x, SiO x N y, Si 3 N 4, Al 2 O 3, TiO x, Ti, Al, and Cr.

In addition, due to the arrangement of the current blocking layer 130, a portion of the second ohmic layer 140 overlapping the current blocking layer 130 may protrude in the first direction (Z-axis direction). The protruding thickness may be the same as the thickness (length in the Z-axis direction) of the current blocking layer 130.

The second branch electrode 160b may be disposed on the protruding second ohmic layer 140. That is, the second electrode 160 may be disposed on the second ohmic layer 140 to overlap the current blocking layer 130 in the first direction (Z-axis direction).

The second branch electrode 160b may include silver (Ag). By such a configuration, the second branch electrode 160b may improve light reflection. For example, the second branch electrode 160b has a reflectance of up to 95% for light of 440 mm to 460 mm. The second pad electrode 160a includes Cr, Al, Ni, Au, and has a reflectance of up to 70% for light of 440 mm to 460 mm. In this configuration, the second branch electrode 160b has a higher light reflectance than the second pad electrode 160a, thereby preventing loss due to light absorption to improve light extraction efficiency.

Accordingly, light loss of the light R1 of the first path may be less than that of light R2 of the second path.

In addition, the second branch electrode 160b may include an opening. The porosity of the second branch electrode 160b may be 30% to 60% of the area of the second branch electrode 160b.

The second branch electrode 160b may be formed of a plurality of second branch electrode particles 160b-1, 160b-2, and 160b-3. For example, the second branch electrode 160b includes the 2-1 branch electrode particles 160b-1, the second-2 branch electrode particles 160b-2, and the second-3 branch electrode particles 160b-3. can do. Here, the 2-1 branch electrode particles to the 2-3 branch electrode particles 160b-1, 160b-2, and 160b-3 may be connected in one form for electrical connection.

In addition, the width of the opening in the second direction (X-axis direction) of the first branch electrode 150b may be 30% to 60% of the length of the minimum width of the first branch electrode 150b.

For example, the length L1 of the minimum width in the second direction (X-axis direction) of the second branch electrode 160b may be 4.5 μm to 5.5 μm. Here, the length of the minimum width in the second direction (X-axis direction) of the second branch electrode 160b may be a length between both ends in the second direction of the second branch electrode 160b. The width L2 of the opening portion in the second direction (X-axis direction) of the second branch electrode 160b may be 1.35 μm to 3.3 μm.

And the width L2a of the opening, the second-2 branch electrode particles 160b-2, and the second gap between the 2-1 branch electrode particles 160b-1 and the second-2 branch electrode particles 160b-2. The length L2b of the sum of the widths of the openings between the -3 kinds of electrode particles 160b-3 may be 1.35 μm to 3.3 μm.

Referring to FIG. 19, the second pad electrode 160a may be disposed on the second branch electrode 160b. In addition, as described above, the second branch electrode 160b may include an opening. In addition, the light generated by the semiconductor structure 120 may move in the third path R3. In this case, the light of the third path R3 may be reflected by the second branch electrode 160b. In addition, as described above, since the second branch electrode 160b reflects light with a higher reflectance than the second pad electrode 160a, light efficiency due to absorption in the second branch electrode may be reduced, thereby improving light efficiency. .

In addition, the light generated by the semiconductor structure 120 may move in the fourth path R4. In this case, light may pass through the opening of the second branch electrode 160b and may be emitted to the upper portion of the semiconductor device 100B. By such a configuration, some of the light generated in the semiconductor structure 120 may be emitted to the upper portion of the semiconductor device 100B without being reflected by all of the second branch electrodes 160b. Thus, the light extraction efficiency of the semiconductor device 100B according to another embodiment may be improved.

Referring to FIG. 20, the semiconductor structure 120 penetrates through the second conductive semiconductor layer 123 and the active layer 122 to expose a portion of the first conductive semiconductor layer 121, and the first conductive semiconductor layer 121. The groove may be formed up to a part of the area.

The first ohmic layer 141 may be disposed on the exposed upper surface of the first conductive semiconductor layer 121. The first electrode 150 may be disposed on the first ohmic layer 141.

The first electrode 150 may include a first branch electrode 150b and a first pad electrode 150a.

The first branch electrode 150b may be disposed to overlap the first ohmic layer 141 in the first direction (Z-axis direction).

The first branch electrode 150b may include silver (Ag). Like the second branch electrode 160b, the first branch electrode 150b may improve light reflection. In addition, the first branch electrode 150b has a reflectance of up to 95% for light of 440 mm to 460 mm. The first pad electrode 150a includes Cr, Al, Ni, Au, and has a reflectance of up to 70% for light of 440 mm to 460 mm. By such a configuration, the first branch electrode 150b has a higher light reflectance than the first pad electrode 150a, thereby preventing loss due to light absorption to improve light extraction efficiency.

By such a configuration, the light R5 of the fifth path may have less light loss than the light R6 of the sixth path.

In addition, the first branch electrode 150b may include an opening. The porosity of the first branch electrode 150b may be 30% to 60% of the area of the first branch electrode 150b.

The first branch electrode 150b may be formed of a plurality of first branch electrode particles 150b-1 and 150b-2 150b-3. For example, the first branch electrode 150b includes the first-first branch electrode particles 150b-1, the first-second branch electrode particles 150b-2, and the first-three branch electrode particles 150b-3. can do. Here, the first-first branch electrode particles to the first-three branch electrode particles 150b-1 and 150b-2 150b-3 may be connected in one form for electrical connection.

For example, as in the second branch electrode 160b, the length L3 of the maximum line width in the second direction (X-axis direction) of the first branch electrode 150b may be 4.5 μm to 5.5 μm. Here, the length L3 of the maximum line width in the second direction (X-axis direction) of the first branch electrode 150b may be a length between both ends in the second direction (X-axis direction) of the first branch electrode 150b. Can be. The width L4 of the opening portion in the second direction (X-axis direction) of the first branch electrode 150b may be 1.35 μm to 3.3 μm.

And the width L4a of the opening, the first-second branch electrode particles 150b-2, and the first-first branch electrode particles 150b-1 and the first-second branch electrode particles 150b-2. The sum of the widths L4b of the openings between the 1-3 electrode particles 150b-3 may be 1.35 μm to 3.3 μm.

The first pad electrode 150a may be disposed on the first ohmic layer 141. In addition, the first pad electrode 150a may be smaller than or equal to a width that is a length of the first ohmic layer 141 in the second direction (X-axis direction). However, it is not limited to this length.

An upper surface T1 of the first pad electrode 150a may be positioned above the upper surface T2 of the second ohmic layer 140 in the first direction (Z-axis direction).

Referring to FIG. 21, light generated in the semiconductor structure 120 may move in the seventh path R7. In this case, the seventh path R7 light may be reflected by the first branch electrode 150b. In addition, as described above, since the first branch electrode 150b reflects light with a higher reflectance than the first pad electrode 150a, the light efficiency due to absorption in the first branch electrode 150b is small, thereby improving light efficiency. Can be.

In addition, the light generated by the semiconductor structure 120 may move to the eighth path R8. In this case, light may pass through the opening of the first branch electrode 150b and may be emitted to the upper portion of the semiconductor device 100B. By such a configuration, some of the light generated in the semiconductor structure 120 may be emitted to the upper portion of the semiconductor device 100B without being reflected by all of the second branch electrodes 160b. Thus, the light extraction efficiency of the semiconductor device 100B according to another embodiment may be improved.

Referring to FIG. 22, the substrate 110 disposed below may have a thickness d1 of 1000 mm to 1400 mm, but is not limited thereto. The thickness d2 of the first conductive semiconductor layer 121 may be 6 μm to 8 μm, and the thickness d3 of the active layer 122 may be 200 nm to 300 nm.

The thickness d4 of the second conductivity-type semiconductor layer 123 may be 200 nm to 300 nm, and the thickness d5 of the second ohmic layer 140 may be 1 nm to 10 nm. The first ohmic layer 141 may have a thickness of 1 nm to 10 nm, similarly to the second ohmic layer 140.

The length d6 of the first conductive semiconductor layer 121 exposed from the upper surface of the semiconductor structure 120 in the first direction (Z-axis direction) to the lowest surface may be 0.9 μm to 1.1 μm. The thickness d7 of the second pad electrode 160a, which is the length from the uppermost surface to the lowermost surface of the second pad electrode 160a, may be about 2.4 μm to about 2.6 μm.

In addition, an upper surface T2 of the second pad electrode 160a may be the uppermost portion of the semiconductor structure 120. In addition, an upper surface of the first pad electrode 150a may be positioned below in the first direction (Z-axis direction) rather than the upper surface of the second pad electrode 160a.

In the first direction (Z-axis direction) from the top surface T2 of the second pad electrode 160a to the top surface T1 of the first pad electrode 150a, the length and the bottom surface of the second pad electrode 160a are formed. The length ratio of the lengths up to the top surface T1 of the first pad electrode 150a may be 1: 2.0 to 1: 2.2.

In the first direction (Z-axis direction) from the top surface T2 of the second pad electrode 160a to the top surface T1 of the first pad electrode 150a, the length and the bottom surface of the second pad electrode 160a are formed. When the length ratio of the length to the uppermost surface T1 of the first pad electrode 150a is smaller than 1: 2.0, there may be a problem in that the sheet resistance of the first pad electrode is small and the operating voltage increases.

The bottom surface of the second pad electrode 160a and the length in the first direction (Z-axis direction) from the top surface T2 of the second pad electrode 160a to the top surface T1 of the first pad electrode 150a. When the length ratio of the lengths to the uppermost surface T1 of the first pad electrode 150a is greater than 1: 2.2, there may be a problem that the package volume increases when the package is mounted.

The second pad electrode 160a may be disposed on a portion of the second branch electrode 160b.

23 is an enlarged view of a branch electrode of a semiconductor device according to example embodiments.

Referring to FIG. 23, the first and second branch electrodes 160b may include openings. In addition, the openings of the openings may have various shapes, and the width of the openings may also vary.

The first and second branch electrodes 160b may include a plurality of branch electrode particles and may be connected to one another.

24A to 24F are flowcharts illustrating a method of manufacturing a semiconductor device, according to another exemplary embodiment. Specifically, FIGS. 24A to 24F are cross-sectional views taken along line II ′ of FIG. 17 in a manufacturing order.

Referring to FIG. 24A, a semiconductor structure 120 may be formed on the substrate 110. The semiconductor structure 120 may be formed in the order of the first conductivity type semiconductor layer 121, the active layer 122, and the second conductivity type semiconductor layer 123.

The substrate 110 may be formed of a material selected from sapphire (Al 2 O 3), SiC, GaAs, GaN, ZnO, Si, GaP, InP, and Ge, but is not limited thereto.

The substrate 110 may include an uneven pattern Ps on an upper surface thereof. The uneven pattern Ps may be a micro size, but is not limited thereto. The uneven pattern Ps improves light efficiency by reducing crystal defects and total internal reflection of the semiconductor structure 120 growing thereon.

The uneven pattern Ps may be formed by wet or dry etching, but is not limited thereto.

The semiconductor structure 120 may be formed on the substrate 110. The semiconductor structure 120 may be formed in the order of the first conductivity type semiconductor layer 121, the active layer 122, and the second conductivity type semiconductor layer 123.

The semiconductor structure 120 may emit blue light. In addition, the semiconductor structure 120 may include a metal organic chemical vapor deposition (MOCVD), a chemical vapor deposition (CVD), a plasma-enhanced chemical vapor deposition (PECVD), a molecular beam growth method (PECVD). Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), sputtering, or the like can be formed.

Referring to FIG. 24B, a current blocking layer 130 may be formed on the second conductive semiconductor layer 123. The current blocking layer 130 may be formed on a portion of the second conductive semiconductor layer 123.

The current blocking layer 130 may be formed using a crystal growth method, and the crystal growth method may include metal organic chemical vapor deposition (MOCVD), molecular beam deposition (MBE), or hydride or halide vapor phase epitaxy (HVPE). ) Or SVPE (sublimation vapor phase epitaxy), but is not limited thereto.

The current blocking layer 130 may be a semi-insulating layer or a compound semiconductor layer doped with impurities with a material layer having a high resistivity. The current blocking layer 130 may prevent the current from entering the active layer 122 so that the injected current is refracted to flow away from the second electrode 160 to improve light extraction efficiency.

Referring to FIG. 24C, a second ohmic layer 140 may be formed on the semiconductor structure 120 and the current blocking layer 130. The second ohmic layer 140 may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IZAZO), indium gallium zinc oxide (IGZO), and indium gallium (IGTO). It may include at least one of tin oxide), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IZO (IZO Nitride), AGZO (Al-Ga ZnO), and IGZO. It is not limited to such a material.

Referring to FIG. 24D, a hole penetrating through the second ohmic layer 140, the second conductive semiconductor layer 123, and the active layer 122 and exposing a portion of the first conductive semiconductor layer 121 is formed. can do. The hole h may be made by mesa etching.

The first ohmic layer 141 may be formed on the exposed upper surface of the first conductive semiconductor layer 121. The first ohmic layer 141 may be an ohmic electrode, and the first ohmic layer 141 may be indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), or indium aluminum zinc oxide (AZO). ), Indium gallium zinc oxide (IGZO), indium gallium tin oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IZON (IZO Nitride), AGZO (Al-Ga) ZnO) and IGZO, but may be formed, but is not limited thereto.

Referring to FIG. 24E, a first branch electrode 150b may be formed on the first ohmic layer 141 and the first ohmic layer 141. The second ohmic layer 140 may be formed on an area overlapping the current blocking layer 130 in the thickness direction of the semiconductor device 100B.

The second branch electrode 160b may be formed on an area overlapping the second ohmic layer 140 in the thickness direction of the semiconductor device 100B.

The first branch electrode 150b and the second branch electrode 160b may be formed by E-beam or sputtering, but are not limited thereto.

The first branch electrode 150b and the second branch electrode 160b may include silver (Ag). The first branch electrode 150b and the second branch electrode 160b may be disposed on the first ohmic layer 141 and the second ohmic layer 140, and then heat-treated at 300 ° C. to 650 ° C. FIG.

Silver may migrate during heat treatment. For example, silver can move particles during heat treatment. Thus, the first branch electrode 150b and the second branch electrode 160b may include openings. Thus, a predetermined interval may be formed between the first branch electrode particles 150b and the second branch electrode particles.

In addition, the porosity can be controlled by adjusting the temperature and the injection material. For example, the porosity of the first branch electrode 150b and the second branch electrode 160b may increase when oxygen (O 2) or air is injected in the heat treatment step. In addition, when the temperature is increased, the porosity of the first branch electrode 150b and the second branch electrode 160b may increase.

Referring to FIG. 24F, the first pad electrode 150a and the second pad electrode 160a may be formed on the first branch electrode 150b and the second branch electrode 160b, respectively. The first pad electrode 150a and the second pad electrode 160a may include at least one of Ag, Ni, Cr, and Ti, but are not limited thereto.

The first pad electrode 150a and the second pad electrode 160a may be formed by an E-beam, but are not limited thereto.

In addition, an insulating layer (not shown) may be formed on the semiconductor device 100B after the first pad electrode 150a and the second pad electrode 160a are formed. The insulating layer may be formed to cover the upper surface of the semiconductor device 100B except for a portion of the upper surface of the first pad electrode 150a and a portion of the upper surface of the second pad electrode 160a. The insulating layer (not shown) may be formed by selecting at least one selected from the group consisting of SiO 2, SixOy, Si 3 N 4, SixNy, SiO x Ny, Al 2 O 3, TiO 2, AlN, and the like, but is not limited thereto.

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

The above-described semiconductor device may be configured as a light emitting device package and used as a light source of an illumination system. For example, the semiconductor device may be used as a light source or a light source of an image display device.

When used as a backlight unit of an image display device, it can be used as an edge type backlight unit or a direct type backlight unit, when used as a light source of a lighting device can be used as a luminaire or bulb type, and also used as a light source of a mobile terminal. It may be.

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

Like the light emitting device, the laser diode may include the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer having the above-described structure. In addition, although the p-type first conductivity type semiconductor and the n-type second conductivity type semiconductor are bonded to each other, an electric-luminescence phenomenon is used in which light is emitted when an electric current flows. There is a difference in the direction and phase of the light. That is, a laser diode may emit light having a specific wavelength (monochromatic beam) in the same direction with the same phase by using a phenomenon called stimulated emission and a constructive interference phenomenon. Due to this, it can be used for optical communication, medical equipment and semiconductor processing equipment.

For example, a photodetector may be a photodetector, which is a type of transducer that detects light and converts its intensity into an electrical signal. Such photodetectors include photovoltaic cells (silicon, selenium), photoelectric devices (cadmium sulfide, cadmium selenide), photodiodes (e.g. PD having peak wavelength in visible blind or true blind spectral regions) Transistors, photomultipliers, phototubes (vacuum, gas encapsulation), infrared (Infra-Red) detectors, and the like, but embodiments are not limited thereto.

In addition, a semiconductor device such as a photodetector may generally be manufactured using a direct bandgap semiconductor having excellent light conversion efficiency. Alternatively, the photodetector has various structures, and the most common structures include a pin photodetector using a pn junction, a Schottky photodetector using a Schottky junction, a metal semiconductor metal (MSM) photodetector, and the like. have.

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

Photovoltaic cells or solar cells are a type of photodiodes that can convert light into electrical current. The solar cell may include the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer having the above-described structure similarly to the light emitting device.

In addition, through the rectification characteristics of a general diode using a p-n junction it may be used as a rectifier of an electronic circuit, it may be applied to an ultra-high frequency circuit and an oscillation circuit.

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

Although the above description has been made based on the embodiments, these are merely examples and are not intended to limit the present invention. Those skilled in the art to which the present invention pertains may not have been exemplified above without departing from the essential characteristics of the present embodiments. It will be appreciated that many variations and applications are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

Claims (10)

1. Board;

   A semiconductor structure disposed on the substrate, the semiconductor 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 disposed on the first conductive semiconductor layer; And

   A second electrode disposed on the second conductivity type semiconductor layer,

   At least one of the first electrode and the second electrode may include a bonding layer disposed on the first conductive semiconductor layer or the second conductive semiconductor layer; A reflective layer disposed on the bonding layer; A capping layer disposed on the reflective layer; And a bonding layer disposed on the capping layer,

   The capping layer, the first layer and the second layer are alternately laminated at least one or more times,

   The first layer comprises Ti,

   The ratio of the thickness of the first layer and the second layer is 4: 7 to 20: 3.
2. The method of claim 1,

   The ratio of the thickness of the first layer and the second layer is 9: 7 to 20: 3.
3. The method of claim 1,

   The thickness of the first layer is thicker than the thickness of the second layer.
4. The method of claim 1,

   When the internal stress of the first layer is a compressive stress, the internal stress of the second layer is a tensile stress,

   And when the internal stress of the first layer is a tensile stress, the internal stress of the second layer is a compressive stress.
5. The method of claim 1,

   The sum of the internal stresses of the first layer and the second layer is not more than 1.6Х10-14d / cm,

   The internal stress of the first layer is from 0 to -1.4Х10-14d / cm,

   The internal stress of the second layer is 3.0 Х 10-14 d / cm or less.
6. The method of claim 1,

   The semiconductor device has a thickness of 20 nm to 100 nm.
7. The method of claim 1,

   The second layer includes any one selected from Ni and Pt.
8. The method of claim 7, wherein

   If the second layer comprises Ni, the thickness of the second layer is 35nm or less.
9. The method of claim 1,

   The first electrode includes a first pad electrode and at least one first branch electrode extending from the first pad electrode.

   The second electrode includes a second pad electrode and at least one second branch electrode extending from the second pad electrode.
10. The method of claim 9,

    The first pad electrode and the second pad electrode are disposed on one side and the other side of the semiconductor device, respectively.

    The first branch electrode extends toward the second pad electrode, and the second branch electrode extends toward the first pad electrode.

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