TWI585998B - Ultraviolet light emitting device - Google Patents

Description

Ultraviolet light emitting device

The present invention claims priority from Korean Patent No. 10-2011-0134019, filed on Dec. 13, 2011, and Korean Patent No. 10-2012-0124003, filed on Nov. 5, 2012. . This is incorporated herein by reference.

The present invention relates to a light emitting device.

A light emitting diode (LED) is a light emitting semiconductor device that converts current into light.

Since a light-emitting semiconductor device can obtain high-intensity light, a light-emitting semiconductor device has been widely used as a light source of a display, a vehicle, or a light-emitting device.

Recently, an ultraviolet light emitting device that can output ultraviolet light has been proposed.

Although the ultraviolet light is output to the outside by the ultraviolet light emitting device, most of the ultraviolet light is not output to the outside, but is absorbed or disappears in the ultraviolet light emitting device. Therefore, the extraction efficiency of light is lowered.

Embodiments provide an ultraviolet light emitting device that improves light extraction efficiency.

According to an embodiment, an ultraviolet light emitting device includes: a substrate; an light emitting structure on the substrate, comprising a plurality of composite semiconductors, each semiconductor including at least a first conductive semiconductor layer, an active layer, and a second conductive a semiconductor layer; a first electrode layer on the first conductive semiconductor layer; and a second electrode layer on the second conductive semiconductor layer, wherein the first electrode layer is separated from the side surface of the active layer, and along the active layer A peripheral portion is provided, wherein at least one of the first and second electrode layers is a reflective layer.

10‧‧‧UV light emitting device

10A‧‧‧UV light emitting device

10B‧‧‧UV light emitting device

10D‧‧‧UV light emitting device

11‧‧‧Substrate

13‧‧‧buffer layer

15‧‧‧First conductive semiconductor layer

17‧‧‧Active layer

19‧‧‧Second conductive semiconductor layer

20‧‧‧Lighting structure

21‧‧‧First electrode layer

23‧‧‧Second electrode layer

25‧‧‧Ohm layer

27‧‧‧First electrode

29‧‧‧second electrode

31‧‧‧Protective layer

41‧‧‧First District

43‧‧‧Second District

200‧‧‧Lighting device group

310‧‧‧First lead frame

320‧‧‧Second lead frame

330‧‧‧ Subject

340‧‧‧Model components

350‧‧‧ lines

1 is a bottom view of an ultraviolet light emitting device according to a first embodiment.

Figure 2 is a cross-sectional view of the ultraviolet light emitting device of Figure 1.

3 is an ultraviolet light emitting device of FIG. 1 that outputs ultraviolet light.

Fig. 4 is a bottom view of the ultraviolet light emitting device according to the second embodiment.

Figure 5 is a cross-sectional view of the ultraviolet light emitting device of Figure 4;

Figure 6 is a bottom plan view of an ultraviolet light emitting device according to a third embodiment.

Figure 7 is a cross-sectional view of the ultraviolet light emitting device of Figure 6.

Figure 8 is a bottom plan view of an ultraviolet light emitting device according to a fourth embodiment.

Figure 9 is a bottom plan view of an ultraviolet light emitting device according to a fifth embodiment.

Figure 10 is a cross-sectional view of a light-emitting device group according to the present embodiment.

In the following description of the embodiments, it will be understood that when a layer (a), a region, a pattern, or a structure is referred to as "above" another substrate, layer (or sheet), region, pad, or pattern. Or "below", he may be "directly" or "indirectly" positioned on another substrate, layer (or slice), region, mat, or pattern, or one or more intermediate layers may also be Presented. The position of this layer has been described in terms of graphics.

Hereinafter, the embodiments will be described with reference to the drawings. For convenience or clarity, the thickness and size of each layer may be enlarged, ignored, or outlined. In addition, the dimensions of the components do not fully reflect a true size.

Although the ultraviolet light emitting device described below is limited to a flip-type ultraviolet light emitting device, the device includes a substrate provided on the upper portion and a first electrode 27 and a second electrode 29 provided on the lower portion, but the embodiment It is not limited to this.

Although the ultraviolet light emitting device generates deep ultraviolet light having a wavelength of 240 to 360 nm in the following description, the embodiment is not limited thereto.

1 is a bottom view of an ultraviolet light emitting device according to a first embodiment, and FIG. 2 is a cross-sectional view of the ultraviolet light emitting device of FIG. 1.

Referring to FIGS. 1 and 2, an ultraviolet light emitting device 10 can include a substrate 11, a first conductive semiconductor layer 15, an active layer 17, a second conductive semiconductor layer 19, and a first electrode layer. 21 and a second electrode layer 23, and a first electrode 27 and a second Extremely 29.

According to the first embodiment, the ultraviolet light emitting device 10 may include a flip-chip type ultraviolet light emitting device, but the embodiment is not limited thereto.

A light emitting structure 20 can be formed by the first conductive semiconductor layer 15, the active layer 17, and the second conductive semiconductor layer 19.

The light emitting structure 20 can include a plurality of composite semiconductor layers. Between the composite semiconductor layers, one layer acts as the active layer 17 to generate light, and the other layer as the first conductive semiconductor layer 15 produces the first carrier, in other words, the electrons supplied to the active layer 17, and another layer A second carrier is produced for the second conductive semiconductor layer 19. In other words, it is a hole provided to the active layer 17, but the embodiment is not limited thereto. Light can be generated in the active layer 17 via recombination of electrons and holes. For example, the first conductive semiconductor layer 15 may be provided over the active layer 17, and the second conductive semiconductor layer 19 may be provided under the active layer 17, but the embodiment is not limited thereto.

The ultraviolet light emitting device 10 further includes a buffer layer 13 interposed between the substrate 11 and the first conductive semiconductor layer 15 to reduce lattice mismatch between the substrate 11 and the first conductive semiconductor layer 15, but is implemented The example is not limited to this.

The buffer layer 13 prevents flaws such as cracks, voids, grains, and buckling from occurring, such that the first conductive semiconductor layer 15, the active layer 17, and the second conductive semiconductor layer 19 formed on the substrate 11 do not occur. Among them.

Although not shown in the drawing, a semiconductor layer not doped with a dopant may be additionally interposed between the buffer layer 13 and the first conductive semiconductor layer 15, but the embodiment is not limited thereto.

The buffer layer 13, the first conductive semiconductor layer 15, the active layer 17, and the second conductive semiconductor layer 19 all include a II-VI composite semiconductor material, but the embodiment is not limited thereto.

The composite semiconductor material may include materials such as aluminum (Al), indium (In), gallium (Ga), and nitrogen (N), but the embodiment is not limited thereto.

The substrate 11 may comprise a material that exhibits better thermal conductivity and/or better transparency, although the embodiment is not limited thereto. For example, the substrate 11 comprises at least one selected from the group consisting of sapphire (aluminum oxide), tantalum carbide, niobium, gallium arsenide, gallium nitride, zinc oxide, antimony, gallium phosphide, indium phosphide, and antimony. However, the embodiment is not limited to this.

The first conductive semiconductor layer 15 may be formed under the substrate 11 or the buffer layer 13.

For example, the first conductive semiconductor layer 15 may include an N-type semiconductor layer containing an N-type dopant, but the embodiment is not limited thereto. The first conductive semiconductor layer 15 may include one having In _x Al _y Ga _1-xy N(0 x 1,0 y 1,0 x+y 1) a semiconductor material constituting a formula, for example, selected from the group consisting of indium aluminum gallium nitride, gallium nitride, aluminum gallium nitride, indium gallium nitride, aluminum nitride, indium nitride, and aluminum indium nitride. At least one of the groups, but the embodiment is not limited thereto. The N-type dopant may contain ruthenium, osmium, or tin, but the embodiment is not limited thereto.

The first conductive semiconductor layer 15 can serve as a conductive layer to supply electrons to the active layer 19. The first conductive semiconductor layer 15 can serve as a barrier layer to prevent the holes supplied from the second conductive semiconductor layer 19 to the active layer 17 from being transferred to the buffer layer 13.

The first conductive semiconductor layer 15 is doped with a high concentration of dopant as a conductive layer to allow electrons to move freely.

The first conductive semiconductor layer 15 includes a composite semiconductor material having an energy level equal to or greater than that of the active layer 17 as a barrier layer to prevent the holes of the active layer 17 from being transferred to the buffer layer 13.

The active layer 17 may be formed under the first conductive semiconductor layer 15.

For example, the active layer 17 recombines the electrons provided by the first conductive semiconductor layer 15 and the holes provided by the second conductive semiconductor layer 19 to emit ultraviolet light. In order to generate ultraviolet light, the active layer 17 needs to have at least one broad energy level. For example, although the active layer 17 can produce deep ultraviolet light having a wavelength of 240 to 360 nm, the embodiment is not limited thereto.

The active layer 17 may comprise one of a single quantum well (SQW) structure, a multiple quantum well (MQW) structure, a quantum dot structure, and a quantum wire structure.

The active layer 17 may have a stack structure of a well layer and a barrier layer. The barrier layer comprises a semiconductor, which is a III-VI composite, and the composite has an energy level for generating ultraviolet light, but the embodiment is not limited thereto. .

For example, the active layer 17 may be periodically formed on an indium gallium nitride well layer/gallium nitride barrier layer, or an indium gallium nitride well layer/aluminum gallium nitride barrier layer, and an indium gallium nitride well Layer/indium gallium nitride barrier layer stack structure. The energy level of the barrier layer can be higher than the energy level of the well layer. The second conductive semiconductor layer 19 may be formed under the active layer 17.

The second conductive semiconductor layer 19 may include a P-type semiconductor layer containing a P-type dopant, but the embodiment is not limited thereto. The second conductive semiconductor layer 19 may include one having InxAlyGa1-x-yN (0) x 1,0 y 1,0 x+y 1) a semiconductor material constituting a formula, for example, selected from the group consisting of indium aluminum gallium nitride, gallium nitride, aluminum gallium nitride, indium gallium nitride, aluminum nitride, indium nitride, and aluminum indium nitride. At least one of the groups, however, the embodiment is not limited thereto. The P-type dopant may include magnesium, zinc, calcium, strontium, or barium, but the examples are not limited thereto.

The second conductive semiconductor layer 19 can serve as a conductive layer to supply holes to the active layer 17.

The second conductive semiconductor layer 19 is doped with a high concentration of dopant as a conductive layer to allow the hole to move freely.

In order to prevent electrons of the active layer 17 from being transferred to the second conductive semiconductor layer 19, a third conductive semiconductor layer may be inserted into the active layer 17 and the second conductive semiconductor layer 19, but the embodiment is not limited thereto.

In more detail, in addition to the third conductive semiconductor layer, an electron blocking layer may be inserted into the active layer 17 and the second conductive semiconductor layer 19, or among the active layer 17 and the third conductive semiconductor layer, to block the active layer 17 The electrons are transferred to the second conductive semiconductor layer 19, but the embodiment is not limited thereto.

For example, the third conductive semiconductor layer and the electron blocking layer may include aluminum gallium nitride, but the embodiment is not limited thereto. For example, the electron blocking layer may have an energy level higher than that of the second conductive semiconductor layer or the third conductive semiconductor layer, but the embodiment is not limited thereto.

For example, when the third conductive semiconductor layer and the electron blocking layer comprise aluminum gallium nitride, the electron blocking layer may have a higher aluminum content than the third conductive semiconductor layer, so that the electron blocking layer may have a higher level than the third conductive semiconductor layer The energy level, but the embodiment is not limited to this.

At least one or at least two side surfaces of the active layer 17 and the second conductive semiconductor layer 19 protrude outward, but the embodiment is not limited thereto.

However, the distance between the side surface of the first conductive semiconductor layer 15 and the side surface of the active layer 17 and the second conductive semiconductor layer 19 may not coincide. In other words, the distance between the side surface of the first conductive semiconductor layer 15 and the side surface of the active layer 17 and the second conductive semiconductor layer 19 may vary depending on its position.

Preferably, in the flip-chip type ultraviolet light emitting structure, the ultraviolet light travels toward the substrate 11 in the lateral direction or forward direction.

In a flip-chip ultraviolet light emitting structure, ultraviolet light generated from the active layer 17 can travel in various directions.

Part of the ultraviolet light does not travel upward or forward toward the substrate 11, but proceeds downward toward the second conductive semiconductor layer 19. If the direction of the light traveling downward is not changed to the front, the light traveling downward may be absorbed or disappeared in the ultraviolet light-emitting device 10, so that the light extraction efficiency is significantly lowered.

In particular, as shown in FIG. 3, even if the ultraviolet light travels upward toward the substrate 11, the ultraviolet light can be output to the outside via the upper surface of the substrate 11 due to the difference in refractive index between the substrate 11, the air and the ultraviolet light wavelength. In addition to this, part of the ultraviolet light may be reflected from the upper surface of the substrate 11, and such a portion of the ultraviolet light may travel laterally or downwardly, and thus be absorbed or disappeared in the ultraviolet light emitting device 10.

According to the first embodiment, in order to solve the problem, the first and second electrode layers 21 and 23 are provided to allow the ultraviolet light emitted downward to be reflected upward, and the ultraviolet light which is emitted upward from the active layer 17 and then Reflected by the upper surface of the substrate 11, it can be reflected in the upward direction.

The first electrode layer 21 may be formed on a lower surface of the first conductive semiconductor layer 15, and the second electrode layer 23 may be formed on a lower surface of the second conductive semiconductor layer 19.

In order to form the first electrode layer 21 on the lower surface of the first conductive semiconductor layer 15, the first conductive semiconductor layer 15 covered by the active layer 17 and the second conductive semiconductor layer 19 must be exposed.

In other words, in order to expose the first conductive semiconductor layer 15, a mesa etching process may be continuously performed on the second conductive semiconductor layer 19 and the active layer 17.

The first conductive semiconductor layer 15 may be partially etched via a terrace etching method, but the embodiment is not limited thereto. The central region of the first conductive semiconductor layer 15 may protrude downward from the peripheral region of the first conductive semiconductor layer 15. The peripheral area may surround the central area, but the embodiment is not limited thereto.

The peripheral region of the first conductive semiconductor layer 15 exposed through the terrace etching method is named as the first region 41. The active layer 17 and the second conductive semiconductor layer 19 which are not left by the etching of the substrate, or the first conductive semiconductor layer 15 which is not exposed by the terrace etching, and the central region corresponding to the unexposed portion of the first conductive semiconductor layer 15 The active layer 17 and the second conductive semiconductor layer 19 are named as the second region 43. Since light is generated from the active layer 17, the second region 43 can be referred to as a light-emitting region. In addition to this, since the first region 41 does not generate light, the first region 41 may be referred to as a non-light-emitting region, but the embodiment is not limited thereto.

The first region 41 may include a second conductive semiconductor layer 19 that is removed by a portion, and the live The layer 17 is formed by the first conductive semiconductor layer 15. In other words, this groove has a depth as high as the thickness of the active layer 17 and the second conductive semiconductor layer 19. Therefore, the groove can be formed along the peripheral portion of the second region 43, that is, the light-emitting region, but the embodiment is not limited thereto. In other words, this groove can be formed along the periphery of the active layer 17 and the second conductive semiconductor layer 19. This groove may be formed on the side surfaces of the active layer 17 and the second conductive semiconductor layer 19.

The size of the first conductive semiconductor layer 15 may be larger than the size of the active layer 17 and the second conductive semiconductor layer 19, but the embodiment is not limited thereto. The first conductive semiconductor layer 15 may extend outward from the side surfaces of the active layer 17 and the second conductive semiconductor layer 19. A groove may be formed in the extended first conductive semiconductor layer 15.

At the same time, the first and second regions 41 and 43 can be clearly defined on the substrate 11. Therefore, the first region 41 may be formed in the first conductive semiconductor layer 15, and the second region 43 may be formed in the first conductive semiconductor layer 15, the active layer 17, and the second conductive semiconductor layer 19. In this case, the lower surface of the first conductive semiconductor layer 15 formed in the second region 43 may protrude downward beyond the lower surface of the first conductive semiconductor layer 15 formed in the first region 41, but this embodiment does not Limited to this.

As shown in FIG. 1, the second zone 43 may have a cross shape, but the embodiment is not limited thereto.

For example, the second zone 43 can have a round shape (see Figure 8) or a star shape (see Figure 9).

Generally, the second zone 43 has a rectangular shape. Compared with the rectangular shape, the cross type, the round shape, and the star shape make the side surface area of the active layer 17 exposed to the outside larger, and thus the light extraction efficiency can be improved.

The first electrode layer 21 may be formed on the lower surface of the first conductive semiconductor layer 15, that is, the first region 41.

For example, the first electrode layer 21 may be formed over the entire region of the first conductive semiconductor layer 15 that is exposed.

In addition, in order to prevent an electron short circuit caused by the first electrode layer 21 between the first and second conductive semiconductor layers 15 and 19, the terminal portion of the first electrode layer 21 may be spaced apart from the terminal portion of the second region 43. That is, the first conductive semiconductor layer 15 or the side surface of the etched active layer 17.

The lower surface of the first electrode layer 21 may be placed higher than the upper surface of the active layer 17. For this purpose, the central region of the first conductive semiconductor layer 15 connected to the active layer 17 may protrude downward beyond the peripheral region of the first conductive semiconductor layer 15 which is not connected to the active layer 17, but the embodiment is not limited thereto. this.

In order to completely prevent the electronic short circuit caused by the first electrode layer 21 between the first and second conductive semiconductor layers 15 and 19, a protective layer 31 may be formed on the first conductive semiconductor layer 15 provided in the second region 43. The side surfaces of the active layer 17 and the second conductive semiconductor layer 19 are as shown in FIG. 7, but the embodiment is not limited thereto.

In addition, the protective layer 31 may be formed on a lower surface of the first conductive semiconductor layer 15 and a lower surface of the first electrode layer 21 provided in a portion of the first region 41, and provided in a portion of the second region 43 The lower surface of the second electrode layer, but the embodiment is not limited thereto.

In other words, the protective layer 31 may be formed along the peripheral portion of the etched light emitting structure, that is, the peripheral regions of the side surfaces of the first conductive semiconductor layer 15, the active layer 17, and the second conductive semiconductor layer 19, but this embodiment It is not limited to this.

The first electrode layer 21 can reflect ultraviolet light emitted from the active layer 17 to the substrate 11 and reflected downward from the upper surface of the substrate 11, but the embodiment is not limited thereto.

The ultraviolet light generated from the active layer 17 can travel in all directions, and part of the ultraviolet light can travel upward or forward toward the substrate 11. Although the ultraviolet light traveling toward the substrate 11 is output to the outside via the upper surface of the substrate 11, a part of the ultraviolet light can be reflected by the upper surface of the substrate 11 to travel downward. The ultraviolet light traveling downward is reflected by the first electrode layer 21 and travels upward, so that the ultraviolet light is output to the outside via the upper surface of the substrate 11 or the side surface of the substrate 11.

Ultraviolet light having a narrow dominant wavelength is largely reflected from the upper surface of the substrate 11 toward the inside. In addition to this, the first region 41 in which the first conductive semiconductor layer 15 is exposed may occupy a larger region than the second region 43 in which the first conductive semiconductor layer 15 is not exposed. In other words, the area of the first zone 41 can be larger than the area of the second zone 43. In this case, as the ultraviolet light reflected from the upper surface of the substrate 11 disappears, the light extraction efficiency may decrease, which may cause a serious problem.

According to the first embodiment, the first electrode layer 21 is formed on the lower surface of the first conductive semiconductor layer 15 or in the first region 41, so that the ultraviolet light reflected downward from the upper surface of the substrate 11 may be upward or outward laterally. Reflection, thereby significantly improving light extraction efficiency.

Meanwhile, the second electrode layer 23 may be formed under the second conductive semiconductor layer 19 On the surface. In other words, the second electrode layer 23 may be formed on the second conductive semiconductor layer 19 and corresponding to the lower surface of the first conductive semiconductor layer 15 which is not exposed by the terrace etching method.

As shown in FIG. 3, the second electrode layer 23 reflects the ultraviolet light emitted downward from the active layer 17 to be directed upward.

The second electrode layer 23 can reflect the ultraviolet light which is reflected downward from the upper surface of the substrate 11 through the active layer 17 and the second conductive semiconductor layer 19, and is made upward.

In addition, the distance between the second electrode layer 23 and the active layer 17 may be longer than the distance between the first electrode layer 21 and the active layer 17, but the embodiment is not limited thereto.

Although not shown in the drawings, a transparent conductive layer may be interposed between the second conductive semiconductor layer 19 and the second electrode layer 23, but the embodiment is not limited thereto. The transparent electrode layer may have a current spreading function of diffusing a current from the second electrode 29 to the lateral direction, and an ohmic contact function to easily introduce a current into the second conductive semiconductor layer 19, but the embodiment is not limited thereto.

The transparent layer may comprise a layer selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), gallium zinc oxide (GZO), aluminum zinc oxide (AZO), aluminum gallium zinc oxide (AGZO), indium gallium zinc. Oxide (IGZO), cerium oxide (IrOx), cerium oxide (RuOx), cerium oxide/indium tin oxide (RuOx/ITO), nickel/cerium oxide/gold (Ni/IrOx/Au), and One of the group consisting of nickel/niobium oxide/gold/indium tin oxide (Ni/IrOx/Au/IT), but the embodiment is not limited thereto.

According to the first embodiment, the second electrode layer 23 is formed on the lower surface of the second conductive semiconductor layer 19 to reflect the ultraviolet light reflected downward from the upper surface of the substrate 11 or the ultraviolet light emitted downward from the active layer 17 Therefore, the light extraction efficiency is significantly improved.

The first and second electrode layers 21 and 23 may comprise a material having better reflectivity, but the embodiment is not limited thereto.

The first and second electrode layers 21 and 23 may comprise the same or different materials.

The first and second electrode layers 21 and 23 may form a single layer structure or a multilayer structure.

The first and second electrode layers 21 and 23 may comprise an opaque metal material having better reflectivity and conductivity. The first and second electrode layers 21 and 23 may include at least one selected from the group consisting of silver, nickel, aluminum, rhodium, palladium, iridium, ruthenium, magnesium, zinc, platinum, gold, and rhenium, or Alloy, but the embodiment is not limited thereto.

For example, the first and second electrode layers 21 and 23 may comprise a representative UV The light has a good reflective aluminum, but the embodiment is not limited thereto.

For example, the first electrode layer 21 may include aluminum, and the second electrode layer 23 may include an aluminum-nickel alloy, but the embodiment is not limited thereto.

According to the experimental results, when the first electrode layer 21 contains aluminum, the light extraction efficiency of the ultraviolet light-emitting device 10 according to the first embodiment is 16.4%. Meanwhile, when the first electrode layer 21 contains silver, the light extraction efficiency of the ultraviolet light-emitting device 10 according to the first embodiment is 13.8%. Therefore, with respect to ultraviolet light having a wavelength of 240 to 360 nm, the first electrode layer 21 containing aluminum has a reflection coefficient higher than that of the first electrode layer 21 containing silver.

Although not shown in the drawing, the lower surface of the first conductive semiconductor layer 15 exposed to the portion around the active layer 17 and the lower surface of the second conductive semiconductor layer 19 may have a rough structure. This roughness structure may have a fixed concavo-convex pattern or a random concavo-convex pattern, but the embodiment is not limited thereto.

When the first electrode layer 21 is formed over the rough structure of the first conductive semiconductor layer 15, the first electrode layer 21 represents a strong adhesive force and can be bonded to the first conductive semiconductor layer 15, thereby preventing the first electrode layer 21 from being The first conductive semiconductor layer 15 is detached. In addition, the ultraviolet light emitted downward from the active layer may be reflected or scattered due to the roughness, so that the light extraction efficiency can be further improved.

The roughness formed on the lower surface of the second conductive semiconductor layer 15 can achieve the same effects as described above.

The first electrode layer 21 and the second electrode layer 23 may be provided at different positions and spaced apart from each other by the thicknesses of the active layer 17 and the second conductive semiconductor layer 19, but the embodiment is not limited thereto.

Meanwhile, a first electrode 27 may be formed on a portion of the first electrode layer 21, and a second electrode 29 may be formed on a portion of the second electrode layer 23.

The first electrode 27 may have higher conductivity than the first electrode layer 21, and the second electrode 29 may have higher conductivity than the second electrode layer 23, but the embodiment is not limited thereto.

The first and second electrodes 27 and 29 may comprise the same material or materials different from each other.

The first and second electrodes 27 and 29 may be formed in a single layer structure or a multilayer structure.

The first and second electrodes 27 and 29 may comprise a metal material representing preferred conductivity. For example, the first and second electrodes 27 and 29 may comprise at least one selected from the group consisting of aluminum, titanium, chromium, nickel, platinum, gold, tungsten, copper, and molybdenum or alloys thereof, but implemented The example is not limited to this.

The first electrode 27 may be formed on at least one of the first electrode layers 21 in the first region 41.

Although not shown in the drawing, the first electrode 27 may be formed on the entire upper surface of the first electrode layer 21 provided in the first region 41, but the embodiment is not limited thereto.

The first electrode layer 21 not only reflects ultraviolet light as a reflective layer but also supplies power as an electrode. In this case, the first electrode 27 is not formed, but the embodiment is not limited thereto.

The second electrode layer 23 not only reflects ultraviolet light as a reflective layer, but also supplies power as an electrode. In this case, the second electrode 29 is not formed, but the embodiment is not limited thereto.

The first and second electrodes 27 and 29 may have a drum type, but the embodiment is not limited thereto.

4 is a bottom view of the ultraviolet light emitting device according to the second embodiment, and FIG. 5 is a cross-sectional view showing the ultraviolet light emitting device of FIG. 4.

The second embodiment is identical to the first embodiment except for an ohmic layer 25.

According to the second embodiment, the same reference numerals will be given to the same elements as the first embodiment, and the details thereof will be ignored.

4 and 5, the ultraviolet light emitting device 10A according to the second embodiment may include a substrate 11, a first conductive semiconductor layer 15, an active layer 17, a second conductive semiconductor layer 19, an ohmic layer 25, first and second electrodes Layers 21 and 23, and first and second electrodes 27 and 29.

The ohmic layer 25 may be interposed between the first conductive semiconductor layer 15 and the first electrode layer 21.

The first electrode layer 21 may cover the ohmic layer 25 in whole or in part, but the embodiment is not limited thereto. In other words, although the first electrode layer 21 is provided on the outer surface and the lower surface of the ohmic layer 25, the first electrode layer 21 is not provided on the inner surface of the ohmic layer 25, the embodiment is not limited to this.

The ohmic layer 25 may be provided along the periphery of the active layer 17, but the embodiment is not limited It is here. The ohmic layer 25 may have a close-loop ring type or an open-loop ring shape, but the embodiment is not limited thereto.

The ohmic layer 25 may be formed in the first region 41 defined by the exposed first conductive semiconductor layer 15 after the plate etching method.

The ohmic layer 25 can include at least one transparent conductive material. For example, the ohmic layer 25 may comprise an indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide. (IGZO), indium gallium tin oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), antimony oxide (IrOx), antimony oxide (RuOx) , niobium oxide/indium tin oxide (RuOx/ITO), nickel (Ni), silver (Ag), nickel/niobium oxide/gold (Ni/IrOx/Au), and nickel/niobium oxide/indium tin oxide At least one of the group consisting of.

The ohmic layer 25 forms a closed ring structure along the peripheral portion of the second region 43, and the second region 43 is defined by the second conductive semiconductor layer 19, which corresponds to the first conductive semiconductor layer exposed without the terrace etching method, but This embodiment is not limited to this. In other words, the ohmic layer 25 may be formed over the first conductive semiconductor layer 15 surrounding the light emitting structure 20.

For example, the ohmic layer 25 may be formed adjacent to a side surface of the active layer 17 provided to the second region 43.

The ohmic layer 25 may be spaced apart from a side surface of the active layer 17 provided in the second region 43.

The distance d between the ohmic layer 25 and the second region 43 may be in the range of 1 to 10 μm, but the embodiment is not limited thereto.

In other words, the first conductive semiconductor layer 15 of the second region 43 may protrude downward to the outside of the first conductive semiconductor layer 15 of the first region 41. The active layer 17 and the second conductive semiconductor layer 19 may be provided under the first conductive semiconductor layer 15 of the first region 41. The side surface of the first conductive semiconductor layer 15 is provided by the thickness between the lower surface of the first conductive semiconductor layer 15 of the first region 41 and the lower surface of the first conductive semiconductor layer 15 of the second region 43. In this case, the distance d between the ohmic layer 25 and the second region 43 may be in the range of 1 to about 10 μm, but the embodiment is not limited thereto.

In order to rapidly supply current to the active layer, the ohmic layer 25 is as close as possible to the active layer 17 as much as possible.

Although not shown in the figure, if an electron short circuit with the active layer 17 does not occur, ohmic The layer 25 may be connected to a side surface of the first conductive semiconductor layer 15. In this case, the first conductive semiconductor layer 15 can be etched deeper to separate the lower surface of the first conductive semiconductor layer 15 from the side surface of the active layer 17.

The ohmic layer 25 may form a rod shape along the peripheral portion of the second region 43.

The width w of the ohmic layer 25 may be in the range of about 5 to 30 μm, but the embodiment is not limited thereto.

The area of the ohmic layer 25 may be the same or narrower than the first electrode layer 21, but the embodiment is not limited thereto.

In addition to this, the ohmic layer 25 may be formed over a whole region of the first conductive semiconductor layer 15 provided in the first region 41, but the embodiment is not limited thereto.

According to the second embodiment, the ohmic layer 25 is formed over the lower surface of the first conductive semiconductor layer 15 to smoothly supply energy to the first conductive semiconductor layer 15, and performs a current spreading function, which allows current to flow in the first conductive semiconductor Extensive lateral diffusion in layer 15 improves light extraction efficiency and ensures uniform ultraviolet light.

The first electrode layer 21 may cover all of the side surfaces and the lower surface of the ohmic layer 25. In other words, the first electrode layer 21 may surround the ohmic layer 25. The ohmic layer 25 is surface-connected as much as possible to the first electrode layer 21, so that energy is supplied from the first electrode 27 to the side surface and the lower surface of the ohmic layer 25 via the first electrode layer 21. Therefore, energy can be supplied to the first conductive semiconductor layer 15 more smoothly.

Although not shown in the drawings, the first electrode layer 21 may partially overlap the lower surface and the outer surface of the ohmic layer 25, but the embodiment is not limited thereto. In other words, the first electrode layer 21 is not formed on a side surface of the first conductive semiconductor layer 15 provided in the second region 43.

Figure 6 is a bottom plan view of the ultraviolet light emitting device according to the third embodiment, and Figure 7 is a cross-sectional view showing the ultraviolet light emitting device of Figure 6.

The third embodiment is identical to the second embodiment except for the protective layer 31.

According to the third embodiment, the same reference numerals refer to the same elements of the first and second embodiments, and the details thereof will be omitted.

Referring to FIGS. 6 and 7, an ultraviolet light emitting device 10B according to a third embodiment may include a substrate 11, a first conductive semiconductor layer 15, an active layer 17, a second conductive semiconductor layer 19, an ohmic layer 25, first and second Electrode layers 21 and 23, protective layer 31, and first and second electrodes 27 And 29.

As described above, according to the first embodiment, in order to completely prevent the electronic short circuit between the first and second conductive semiconductor layers 15 and 19 caused by the first electrode layer 21, the protective layer 31 may be formed on the first conductive semiconductor layer 15. Above the side surfaces of the active layer 17 and the second conductive semiconductor layer 19, these regions are exposed as shown in FIG. 7 in the second region 43, but the embodiment is not limited thereto.

The second region 43 includes a first conductive semiconductor layer 15 that is not etched by the terrace etching, and an active layer 17 and a second conductive semiconductor layer 19 that correspond to the first conductive semiconductor layer 15.

The first region 41 may include the first conductive semiconductor layer 15 etched by the terrace etching and exposed.

The first zone 41 is a non-light emitting zone and the second zone 43 is a light emitting zone.

The protective layer 31 may be provided on the side surface of the light emitting structure 20. The protective layer 31 may be provided on the side surface of at least one of the active layers 17, but the embodiment is not limited thereto. The protective layer 31 is available for supply to the side surfaces of the first conductive semiconductor layer 15, the active layer 17, and the second conductive semiconductor layer 19 in the second region 43. In addition to this, the protective layer 31 is available for supply over the ohmic layer 25 in the second region 43 and the side surface of the first conductive semiconductor layer 17.

The protective layer 31 may be formed over the lower surface of the first conductive semiconductor layer 15 supplied to the first region 41 and interposed between the first electrode layer 21 and the first conductive semiconductor layer 15 provided in the second region 43.

The protective layer 31 may be formed on a lower surface of the first conductive semiconductor layer 15 in the first region 41, a portion of the first electrode layer 21, and a side surface of the light emitting structure 20, that is, in the second region. The first conductive semiconductor layer 15, the active layer 17, the second conductive semiconductor layer 19, and the second electrode layer 23 are disposed on the side surface of the second electrode layer 23, and may be formed on a portion of the lower surface of the second electrode layer 23.

The protective layer 31 may comprise a material or an insulating material that represents better light transmittance and low conductivity. For example, the protective layer 31 may include one selected from the group consisting of cerium oxide, cerium oxide, cerium nitride, cerium nitride, aluminum oxide, and titanium oxide, but the embodiment is not limited thereto.

According to the embodiment, the first electrode layer 21 is formed on the lower surface of the first conductive semiconductor layer 15 or formed in the first region 41, and thus is reflected upward from the upper surface of the substrate 11 toward The lower reflected ultraviolet light can significantly improve the light extraction efficiency.

According to the embodiment, the second electrode layer 23 is formed on the lower surface of the second conductive semiconductor layer 19, thereby reflecting upward ultraviolet light reflected downward from the upper surface of the substrate 11, or ultraviolet light emitted downward from the active layer 17. , the light extraction efficiency can be significantly improved.

According to an embodiment, the ohmic layer 25 is formed over the lower surface of the first conductive semiconductor layer 15 of the first region 41 to more smoothly supply energy to the first conductive semiconductor layer 15, and allows current to flow in the first conductive semiconductor layer 15 The flow to the lateral direction is wider, so that the light extraction efficiency can be improved, and uniform ultraviolet light can be ensured.

FIG. 10 is a cross-sectional view of a light emitting device group 200 in accordance with an embodiment.

Referring to FIG. 10, a light emitting device group 200 according to an embodiment includes a main body 330, first and second lead frames 310 and 320 mounted in the main body 330, and mounted in the main body 330 according to the first and third embodiments to receive from The first and second lead frames 310 and 320 are powered by the illumination device 10, and a model assembly 340 surrounding the illumination device 10.

The body 330 may include a crucible material, a synthetic resin material, or a metal material, and may have an inclined surface formed at a portion around the light emitting device 10.

The first and second lead frames 310 and 320 are electrically insulated from each other and supply energy to the light emitting device 10.

In addition to this, the first and second lead frames 310 and 320 reflect light emitted from the light-emitting device 10 to increase light efficiency, and exclude thermal energy emitted from the light-emitting device 10.

The illuminating device 10 can be fixed on one of the first lead frame 310, the second lead frame 320, and the main body 330, and can electrically connect the first and second lead frames 310 via a wire method or a wafer bonding method. And 320, but the embodiment is not limited to this.

According to the embodiment, although the light-emitting device 10 according to the first embodiment is electrically connected to the first and second lead frames 310 and 320 via the 2-line 350 for the purpose of illustration, the light-emitting device 10 according to the second embodiment may be The first and second lead frames 310 and 320 are electrically connected without the line 350, and the light emitting device 10 according to the third embodiment can be electrically connected to the first and second lead frames 310 and 320 via the 1 line 350.

Model component 340 can protect lighting device 10 around lighting device 10. In addition to this, the model component 340 can include a phosphor to change the wavelength of light emitted from the illumination device 10.

In addition, the light-emitting device group 200 includes a plate-on-chip (COB) type light-emitting device. Set the group. The body 330 can have a flat upper surface and is provided with a plurality of illumination devices 10.

Any reference to "an embodiment", "an embodiment", "an example embodiment" or the like in this specification means that at least one embodiment of the present invention includes a specific feature, structure, or characteristic of the embodiment. . Such terms appear in many places in the text, but do not necessarily refer to the same embodiment. Furthermore, when a description of a particular feature, structure, or feature is described in connection with any embodiment, it is contemplated that such features, structures, or characteristics are utilized in connection with other embodiments.

While the embodiments have been described with reference to the various embodiments of the embodiments of the present invention, it is understood that many other modifications and embodiments can be devised by those skilled in the art. In particular, various variations and modifications of the parts and/or arrangements of the combinations are possible in the scope of the invention, the invention, and the scope of the appended claims. In addition to variations and modifications in parts and/or configurations, alternative uses will also be apparent to those skilled in the art.

11‧‧‧Substrate

13‧‧‧buffer layer

15‧‧‧First conductive semiconductor layer

17‧‧‧Active layer

19‧‧‧Second conductive semiconductor layer

20‧‧‧Lighting structure

21‧‧‧First electrode layer

23‧‧‧Second electrode layer

29‧‧‧second electrode

Claims (30)

An ultraviolet light emitting device comprising: a substrate; a light emitting structure on the substrate, and comprising a plurality of composite semiconductors, the light emitting structure comprising at least a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; a first electrode layer on a first region of the first conductive semiconductor layer; a second electrode layer on the second conductive semiconductor layer; and wherein the first electrode layer is spaced apart from a side surface of the active layer And disposed along a peripheral portion of the active layer, wherein at least one of the first and second electrode layers comprises a reflective layer, and wherein one of the active layer and a side surface of the second conductive semiconductor layer or Two or more parts stand out. The ultraviolet light emitting device of claim 1, wherein the first electrode layer comprises one or two or more layers. An ultraviolet light emitting device comprising: a substrate; a light emitting structure on the substrate, and comprising a plurality of composite semiconductors, the light emitting structure comprising at least a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; a first electrode layer on a first region of the first conductive semiconductor layer; a second electrode layer on the second conductive semiconductor layer; Wherein the first electrode layer is spaced apart from a side surface of the active layer and disposed along a peripheral portion of the active layer, wherein at least one of the first and second electrode layers comprises a reflective layer, and wherein the first electrode layer The first electrode layer comprises a material to reflect ultraviolet light having a wavelength range between 240 and 360 nm. The ultraviolet light emitting device of claim 3, wherein the material is an opaque metal material. The ultraviolet light emitting device of claim 4, wherein the metal material comprises aluminum. The ultraviolet light emitting device of claim 1, wherein the first electrode layer and the second electrode layer are located at different positions corresponding to thicknesses of the active layer and the second conductive semiconductor layer. The ultraviolet light emitting device of claim 1, wherein the first conductive semiconductor layer extends to an outer side with respect to a side surface of the active layer. An ultraviolet light emitting device comprising: a substrate; a light emitting structure on the substrate, and comprising a plurality of composite semiconductors, the light emitting structure comprising at least a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; a first electrode layer on a first region of the first conductive semiconductor layer; a second electrode layer on the second conductive semiconductor layer; and wherein the first electrode layer is spaced apart from a side surface of the active layer Opened and placed along the surrounding portion of the active layer, The at least one of the first and the second electrode layers comprises a reflective layer, further comprising: a recess having a depth corresponding to at least a thickness of the active layer and the second conductive semiconductor layer. The ultraviolet light emitting device of claim 8, wherein the groove is disposed along a peripheral portion of the active layer and the second conductive semiconductor layer and is located on a lower surface of the first conductive semiconductor layer. The ultraviolet light emitting device of claim 1, wherein the first electrode layer has a lower surface disposed higher than a surface above the active layer. The ultraviolet light emitting device of claim 1, wherein the first conductive semiconductor layer comprises a central portion in contact with the active layer and a peripheral portion not in contact with the active layer. The ultraviolet light-emitting device of claim 11, wherein the central portion protrudes downward with respect to the surrounding portion. The ultraviolet light emitting device of claim 1, further comprising an ohmic layer on the first region of the first conductive semiconductor layer, wherein the ohmic layer is provided along the periphery of the active layer, and The ohmic layer has a closed loop type. The ultraviolet light-emitting device according to claim 1, wherein a distance between a side surface of the first conductive semiconductor layer and a side surface of the active layer differs depending on a position. The ultraviolet light-emitting device of claim 1, wherein a distance between a side surface of the first conductive semiconductor layer and a side surface of the second conductive semiconductor layer is different depending on a position. An ultraviolet light emitting device comprising: a substrate; a light emitting structure on the substrate, and comprising a plurality of composite semiconductors, the light emitting structure comprising at least a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; a first electrode layer on a first region of the first conductive semiconductor layer; a second electrode layer on the second conductive semiconductor layer; and wherein the first electrode layer is spaced apart from a side surface of the active layer And being disposed along a peripheral portion of the active layer, wherein at least one of the first and second electrode layers comprises a reflective layer, and further comprising a first electrode on the first electrode layer, a second The electrode is located on the second electrode layer, wherein the first electrode has a higher conductivity than the first electrode layer. An ultraviolet light emitting device comprising: a substrate; a light emitting structure on the substrate, and comprising a plurality of composite semiconductors, the light emitting structure comprising at least a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; a first electrode layer on a first region of the first conductive semiconductor layer; a second electrode layer on the second conductive semiconductor layer; An ohmic layer on the first region of the first conductive semiconductor layer, wherein the first electrode layer is spaced apart from a side surface of the active layer and disposed along a surrounding portion of the active layer, wherein the first sum At least one of the second electrode layers includes a reflective layer, and wherein the ohmic layer ohmic layer is connected to a side surface of the first conductive semiconductor layer. The ultraviolet light emitting device of claim 17, wherein the ohmic layer is disposed on a lower surface of the first conductive semiconductor layer along the periphery of the active layer. The ultraviolet light emitting device of claim 17, wherein the ohmic layer is surrounded by the first electrode layer. The ultraviolet light-emitting device of claim 17, wherein an interval between a side surface of the ohmic layer and a side surface of the first conductive semiconductor layer is in a range of 1 to 10 μm. The ultraviolet light emitting device of claim 17, wherein the ohmic layer is in contact with a side surface of the first conductive semiconductor layer. The ultraviolet light emitting device of claim 17, wherein the ohmic layer has a different width than the first electrode layer. The ultraviolet light emitting device of claim 17, wherein the first electrode layer covers all side surfaces and a lower surface of the ohmic layer. The ultraviolet light emitting device of claim 23, wherein the first electrode layer is disposed on a lower surface and an outer surface of the ohmic layer. The ultraviolet light emitting device of claim 17, wherein the ohmic layer has a width ranging from 5 to 30 micrometers. The ultraviolet light emitting device of claim 17, wherein the ohmic layer has a size smaller than or equal to the first electrode layer. The ultraviolet light emitting device of claim 17, further comprising: a protective layer on a side surface of the light emitting structure. The ultraviolet light emitting device of claim 27, wherein the protective layer is disposed on a side surface of the active layer from a side surface of the second conductive semiconductor layer to the first conductive semiconductor layer One side surface. An ultraviolet light emitting device comprising: a substrate; a light emitting structure on the substrate, and comprising a plurality of composite semiconductors, the light emitting structure comprising at least a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; a first electrode layer on a first region of the first conductive semiconductor layer; a second electrode layer on the second conductive semiconductor layer; and wherein the first electrode layer is spaced apart from a side surface of the active layer And disposed along a peripheral portion of the active layer, wherein at least one of the first and second electrode layers comprises a reflective layer, and wherein a first distance between the second electrode layer and the active layer is greater than a second distance between the first electrode layer and the active layer. The ultraviolet light emitting device of claim 1, wherein the light emitting structure is a flip type structure.