KR102477250B1 - Light emitting device - Google Patents

Abstract

An embodiment is a light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, the first conductivity type semiconductor A passivation layer disposed on the layer, disposed on the passivation layer, one end penetrating the passivation layer and contacting the first conductivity-type semiconductor layer, and the other end extending in a lateral direction of the light emitting structure to the light emitting structure A first electrode extending below the lower end of the second electrode, a second electrode disposed under the second conductive semiconductor layer, an electrode pad disposed under the second electrode, and an insulating layer disposed on a side surface of the light emitting structure, , The other end of the first electrode is spaced apart from the insulating layer disposed on the side surface of the light emitting structure.

Description

Light emitting device {LIGHT EMITTING DEVICE}

The embodiment relates to a light emitting device.

Light Emitting Diode (LED) is a type of semiconductor device used as a light source or to transmit and receive signals by converting electricity into infrared rays or light using the characteristics of compound semiconductors.

Group III-V nitride semiconductors are in the limelight as a key material for light emitting devices such as light emitting diodes (LEDs) or laser diodes (LDs) due to their physical and chemical properties.

Since these light emitting diodes do not contain environmentally harmful substances such as mercury (Hg) used in existing lighting fixtures such as incandescent and fluorescent lamps, they have excellent eco-friendliness, and have advantages such as long lifespan and low power consumption, so they are superior to existing light sources. are replacing them

The embodiment provides a light emitting device capable of reducing chip thickness and easily implementing electrode pads in a light emitting structure having a small size.

A light emitting device according to an embodiment includes a light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; a passivation layer disposed on the first conductivity type semiconductor layer; A first disposed on the passivation layer, one end penetrating the passivation layer and contacting the first conductivity type semiconductor layer, and the other end extending toward the side of the light emitting structure and extending down to the lower end of the light emitting structure. electrode; a second electrode disposed below the second conductivity type semiconductor layer; an electrode pad disposed below the second electrode; and an insulating layer disposed on a side surface of the light emitting structure, and the other end of the first electrode is spaced apart from the insulating layer disposed on a side surface of the light emitting structure.

The first electrode may include an upper electrode disposed on the first conductivity type semiconductor layer; at least one contact electrode connected to the upper electrode and passing through the passivation layer to contact the first conductivity type semiconductor layer; And it is connected to one end of the upper electrode, it extends in the lateral direction of the light emitting structure includes an extension electrode that extends down to the lower end of the light emitting structure.

The expansion electrode may include a first expansion portion disposed on the passivation layer and extending from the upper electrode in a horizontal direction; and a second extension portion connected to the first extension portion and extending from the first conductivity type semiconductor layer to a lower surface of the second conductivity type semiconductor layer in a direction toward the second conductivity type semiconductor layer. .

The second expansion part does not overlap with the light emitting structure in a vertical direction, and the vertical direction may be a direction perpendicular to the top surface of the first conductivity type semiconductor layer.

A lower surface of the lower end of the second expansion part may be positioned on the same plane as a lower surface of the second electrode pad.

The second expansion part extends to be inclined with respect to a vertical line, and the vertical line may be an imaginary straight line perpendicular to the top surface of the first conductivity type semiconductor layer.

An interior angle between the vertical line and the second extension may be 0° to 15°.

A separation distance between the second expansion part and the insulating layer may increase in a direction from the first conductivity type semiconductor layer to the second conductivity type semiconductor layer.

The second expansion part may be spaced apart from a portion of an insulating layer positioned on side surfaces of the active layer and the second conductivity type semiconductor layer.

The first electrode may be positioned adjacent to one of the side sides of the upper surface of the light emitting structure.

The first electrode may include a 1-1 electrode positioned adjacent to a first side of the side of the upper surface of the light emitting structure; And it may include a first-second electrode positioned adjacent to the second side facing the first side side among the side sides of the upper surface of the light emitting structure.

The second expansion part may not overlap the contact electrode in a vertical direction, and the vertical direction may be perpendicular to a top surface of the first conductivity type semiconductor layer.

The insulating layer may include a first insulating layer disposed on a lower surface of the second conductivity-type semiconductor layer and exposing the second electrode; And a second insulating layer disposed on a side surface of the light emitting structure, and a lower end of the second expansion part may be spaced apart from the first insulating layer and the second insulating layer.

According to the embodiment, the chip thickness may be reduced, and electrode pads may be easily implemented in a light emitting structure having a small size.

1 shows an upper plan view of a light emitting device according to an embodiment.
FIG. 2 shows a bottom plan view of the light emitting device shown in FIG. 1 .
FIG. 3 shows a cross-sectional view of the light emitting device shown in FIGS. 1 and 2 in an AB direction.
4 is a cross-sectional view of the light emitting device shown in FIGS. 1 and 2 in the CD direction.
5A shows an embodiment of the first electrode shown in FIG. 3 .
FIG. 5B shows another embodiment of the first electrode shown in FIG. 3 .
6 shows a cross-sectional view of a light emitting device according to another embodiment.
7A is an upper plan view of a light emitting device according to another embodiment.
FIG. 7B is a bottom plan view of the light emitting device shown in FIG. 7A.
8A is an upper plan view of a light emitting device according to another embodiment.
FIG. 8B is a bottom plan view of the light emitting device shown in FIG. 8A.
9 is a cross-sectional view taken along line I-II of the light emitting device shown in FIGS. 8A and 8B.
10A shows an upper plan view of a light emitting device according to another embodiment, and FIG. 10B shows a lower plan view of the light emitting device shown in FIG. 10A.
11A to 11I are process charts illustrating a method of manufacturing the light emitting device shown in FIG. 6 .
12 is a cross-sectional view of a lighting device according to an embodiment.
13 is a plan view of a display device according to an embodiment.
FIG. 14 is a cross-sectional view of the display device shown in FIG. 13 in an AA′ direction according to an exemplary embodiment.

Hereinafter, embodiments will be clearly revealed through the accompanying drawings and description of the embodiments. In the description of the embodiment, each layer (film), region, pattern or structure is “on” or “under” the substrate, each layer (film), region, pad or pattern. In the case where it is described as being formed in, "up / on" and "under / under" include both "directly" or "indirectly" formed through another layer. do. In addition, the criterion for the upper/upper or lower/lower of each layer will be described based on the drawings. Also, like reference numerals denote like elements throughout the description of the drawings.

1 shows an upper plan view of a light emitting device 1000 according to an embodiment, FIG. 2 shows a lower plan view of the light emitting device 1000 shown in FIG. 1, and FIG. 3 shows a light emitting device shown in FIGS. 1 and 2 1000 shows a cross-sectional view in the AB direction, and FIG. 4 shows a cross-sectional view in the CD direction of the light emitting device 1000 shown in FIGS. 1 and 2 .

1 to 4, the light emitting device 1000 includes a light emitting structure 1110, a passivation layer 1120, a first electrode 1130, a second electrode 1140, and a second electrode pad 1145. ), and an insulation layer 1150.

The light emitting structure 1110 is disposed between the first conductivity type semiconductor layer 1112, the second conductivity type semiconductor layer 1116, and the first conductivity type semiconductor layer 1112 and the second conductivity type semiconductor layer 1116. An active layer 1114 is included. For example, the light emitting structure 1110 may have a structure in which a first conductivity type semiconductor layer 1112, an active layer 1114, and a second conductivity type semiconductor layer 1116 are sequentially disposed from top to bottom.

For example, the diameter of the light emitting structure 1110 may decrease from the first conductivity type semiconductor layer 1112 toward the second conductivity type semiconductor layer 1116, and the side of the light emitting structure 1110 may have a reverse inclined surface. there is.

Unlike general light-emitting devices having a light-transmitting substrate or supporting substrate, the light-emitting device 1000 according to the embodiment does not include a light-transmitting substrate or supporting substrate. As a result, since the chip size (eg, diameter) or volume of the light emitting element is reduced, the thickness or size of an application in which the light emitting element according to the embodiment is used, for example, a display device, can be reduced.

The first conductivity type semiconductor layer 1112 may be a semiconductor compound of group 3-5 or group 2-6, and may be doped with a first conductivity type dopant.

For example, the first conductivity-type semiconductor layer 1112 is a semiconductor having a composition formula of In _x Al _y Ga _{1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x+y≤1) and may be doped with an n-type dopant (eg, Si, Ge, Se, Te, etc.).

In order to increase light extraction, a light extraction structure, for example, a concavo-convex 1112a may be formed on the upper surface of the first conductivity type semiconductor layer 1112 .

The active layer 1114 emits light by energy generated during recombination of electrons and holes provided from the first conductivity type semiconductor layer 1112 and the second conductivity type semiconductor layer 1116. can create

The active layer 1114 may be a compound semiconductor of group 3-5 or group 2-6, and may have a single well structure, a multi-well structure, a quantum-wire structure, a quantum dot, or a quantum disk. (Quantum Disk) structure.

The active layer 1114 may have a composition formula of In _x Al _y Ga _{1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). When the active layer 1114 has a quantum well structure, the active layer 1114 has a compositional formula of In _x Al _y Ga _{1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x+y≤1) A well layer (not shown) and a barrier layer (not shown) having a composition formula of In _a Al _b Ga ₁ -a- _b N ( _0≤a≤1 , 0≤b≤1, 0≤a+b≤1) ) may be included.

An energy band gap of the well layer of the active layer 1114 may be lower than that of the barrier layer. The well layer and the barrier layer may be alternately stacked at least once.

The second conductivity type semiconductor layer 1116 may be a semiconductor compound of group 3-5 or group 2-6, and may be doped with a second conductivity type dopant.

For example, the second conductivity type semiconductor layer 1116 is a semiconductor having a composition formula of In _x Al _y Ga _{1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x+y≤1) and a p-type dopant (eg Mg, Zn, Ca, Sr, Ba) may be doped.

The light emitting structure 1110 may generate any one of red light, green light, or blue light, but is not limited thereto, and may generate visible light or ultraviolet light of various wavelengths.

For example, the first conductivity type semiconductor layer of the light emitting structure 1110 generating red light is In _x Al _y Ga _1-xy P (0≤x≤1, 0≤y≤1, 0≤x+y≤1) or A semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x+y≤1), such as AlGaP, InGaP, AlInGaP, InP, GaN , InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, and GaP may be formed of any one or more, and may include an n-type dopant.

Also, for example, the active layer of the light emitting structure 1110 generating red light is GaInP/AlGaInP, GaP/AlGaP, InGaP/AlGaP, InGaN/GaN, InGaN/InGaN, GaN/AlGaN, InAlGaN/GaN, GaAs/AlGaAs, InGaAs/AlGaAs It may be formed in any one or more pair structures, but is not limited thereto.

Also, for example, the composition of the quantum well layer of the active layer of the light emitting structure for generating red light may be (Al _p Ga _{1 -p} ) _q In _{1 - q} P layer (however, 0≤p≤1, 0≤q≤1) And, the composition of the quantum barrier layer may be (Al _p1 Ga _{1 - p1} ) _q1 In _{1 - q1} P layer (where 0≤p1≤1, 0≤q1≤1), but is not limited thereto.

Also, for example, the second conductivity-type semiconductor layer of the light emitting structure generating red light is In _x Al _y Ga _1-xy P (0≤x≤1, 0≤y≤1, 0≤x+y≤1) or In _x It may be formed of a semiconductor material having a composition formula of Al _y Ga _{1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x+y≤1), and may include a p-type dopant. .

Although not shown in FIGS. 3 and 4 , in order to prevent electrons injected into the active layer 1114 from the first conductivity type semiconductor layer 1112 from passing over to the second conductivity type semiconductor layer 1116 to increase luminous efficiency, The light emitting structure 1110 may further include an electron blocking layer disposed between the active layer 1114 and the second conductive semiconductor layer 1116 . In this case, the energy band gap of the electron blocking layer is greater than that of the barrier layer of the active layer 1114 .

The first electrode 1130 is disposed on the light emitting structure 1110, one end contacts the first conductive semiconductor layer 1112, and the other end extends toward the side of the light emitting structure 1110 to form a light emitting structure 1110 extends below the bottom of the

The passivation layer 1120 is disposed on the first conductivity type semiconductor layer 1112 . The passivation layer 1120 may be disposed between the top surface of the first conductivity type semiconductor layer 1112 and the bottom surface of the first electrode 1130 . Also, for example, the passivation layer 1120 may be disposed on the second insulating layer 1154 as well.

For example, the first electrode 1130 includes an upper electrode 1134 , a contact electrode 1136 , and an extension electrode 1132 .

The upper electrode 1134 is disposed on the passivation layer 1120 disposed on the first conductive semiconductor layer 1112 and the second insulating layer 1154 .

In FIG. 1 , the upper electrode 1134 may be disposed adjacent to an edge of the first conductivity type semiconductor layer 1121, for example, a corner of the upper surface of the first conductivity type semiconductor layer 1112, but is not limited thereto. , may be disposed at the center of the side of the upper surface of the first conductivity type semiconductor layer 1112 .

The planar shape of the upper electrode 1134 shown in FIG. 1 is a rectangle, but is not limited thereto, and in other embodiments, the planar shape of the upper electrode 1134 may be circular, elliptical, or polygonal.

The contact electrode 1136 extends from the lower surface of the upper electrode 1134 and penetrates the passivation layer 1120 to contact the upper surface of the first conductivity type semiconductor layer 1112 .

For example, the contact electrode 1136 may extend from the bottom surface of the upper electrode 1134 toward the top surface of the first conductivity type semiconductor layer 1112 and may make ohmic contact with the top surface of the first conductivity type semiconductor layer 1112. have.

The contact electrode 1136 may be spaced apart from a portion where the upper electrode 1134 and the extension electrode 1132 meet. Accordingly, the light efficiency of the light emitting device 1000 may be improved by distributing and providing current flowing through the expansion electrode 1132 to the light emitting structure 1110 .

One end of the expansion electrode 1132 is connected to one end of the upper electrode 1134, and the other end extends from the upper electrode 1134 to the lower surface of the second conductive semiconductor layer 1116 of the light emitting structure 1110.

The extension electrode 1132 may include a first extension 1132a and a second extension 1132b connected to the first extension 1132a.

The first extension 1132a may be connected to the upper electrode 1134 and may contact an edge of the passivation layer 1120 .

The second expansion unit 1132b has one end connected to the first expansion unit 1132a, extends in a direction from the first conductivity type semiconductor layer 1112 to the second conductivity type semiconductor layer 1116, and has a light emitting structure ( 1110) does not overlap in the vertical direction.

Also, the second expansion part 1132b does not overlap the contact electrode 1136 in the vertical direction. Here, the vertical direction may be a direction perpendicular to the top surface of the first conductivity type semiconductor layer 1112 .

A lower end of the second expansion part 1132b may extend to a lower end of the light emitting structure 1110 , eg, a lower surface of the second conductive semiconductor layer 1116 . For example, the lower surface of the second expansion part 1132b may extend to the lower surface of the light emitting structure to be positioned on the same plane as the lower surface of the second electrode pad 1145 . This is for die bonding or flip chip bonding to a package body, a submount, or a substrate.

In FIG. 3 , the passivation layer 1120 may expose a portion of the upper surface of the first conductivity type semiconductor layer 1112 .

The passivation layer 1120 may be formed of a light-transmitting insulating material such as SiO ₂ , SiOx, Si ₃ N ₄ , TiO ₂ , SiNx, SiO _x N _y , or Al ₂ O ₃ .

FIG. 5A shows an example of the first electrode 1130 shown in FIG. 3 .

Referring to FIG. 5A , the first electrode 1130 may include an upper electrode 1134 , a contact electrode 1136 , and an extension electrode 1132 .

For example, the contact electrode 136 may have a single straight line shape, but is not limited thereto, and may also have a circular shape, an elliptical shape, or a polygonal shape depending on the planar shape of the upper electrode 1134 .

FIG. 5B shows another embodiment 1130a of the first electrode 1130 shown in FIG. 3 .

Referring to FIG. 5B , the first electrode 1130a may include an upper electrode 1134, a plurality of contact electrodes 1136-1 to 1136-4 disposed apart from each other, and an extension electrode 1132. .

Each of the plurality of contact electrodes 1136-1 to 1136-4 contacts or is connected to the lower surface of the upper electrode 1134 and penetrates the passivation layer 1120 to contact the upper surface of the first conductivity type semiconductor layer 1112. It can be.

The plurality of contact electrodes 1136-1 to 1136-4 may have a quadrangular shape, but are not limited thereto, and may also have a circular or polygonal shape.

The second electrode 1140 is disposed under the light emitting structure 1110 and contacts the second conductivity type semiconductor layer 1116 . For example, the second electrode 1140 may be disposed on the lower surface of the light emitting structure 1110 , for example, on the lower surface of the second conductive semiconductor layer 1116 .

The second electrode 1140 is disposed between the second conductivity type semiconductor layer 1116 and the second electrode pad 1145, and the second electrode 1140 and the second conductivity type semiconductor layer 1116 may be in ohmic contact. have.

The first electrode 1130 may include an ohmic contact layer for ohmic contact with the first conductivity-type semiconductor layer 1112 and a reflective layer. For example, the first electrode 1130 may be formed of Pb, Sn, Au, Ge, Cu, Bi, Cd, Zn, Ag, Ni, Ti, or an alloy including at least one of these, and may include a single layer or a plurality of layers. can be made with

The second electrode 1140 may include an ohmic contact layer for ohmic contact with the second conductivity type semiconductor layer 1116 and a reflective layer.

For example, the ohmic contact layer of the second electrode 1140 may be a transparent conductive oxide such as ITO, or Ni or Cr. For example, the reflective layer of the second electrode 1140 includes Ag, Al, or Rh, or an alloy containing Ag, Al, or Rh, or Cu, Re, Bi, Al, Zn, W, Sn, In, Alternatively, it may be an alloy of at least one selected from Ni and silver (Ag).

In addition, the second electrode 1140 may further include at least one of a diffusion barrier layer and a bonding layer. For example, the second electrode 1140 may further include a diffusion barrier layer including at least one of Ni, Cr, Ti, Pd, Pt, W, Co, or Cu. Also, for example, the second electrode 1140 may further include a bonding layer made of gold (Au), silver (Ag), or an Au alloy.

Each of the first electrode pad 1135 and the second electrode pad 1145 is a portion bonded to a package body, a submount, or a substrate, and may be a conductive metal capable of maintaining electrical conduction. For example, each of the first electrode pad 1135 and the second electrode pad 1145 may include at least one of Au, Ni, Cu, and Al, or may be made of an alloy including at least one of these.

In addition, for example, for self-assembly of a light emitting device having a small size (eg, a diameter of less than 100 microns) when bonding with a package body, a submount, or a substrate, a second second The electrode pad 1145 may include at least one of Co, Ni, and Fe, or may be made of an alloy including at least one of these.

The insulating layer 1150 is disposed on at least one of a side surface or a bottom surface of the light emitting structure 1110 .

The insulating layer 1150 may be disposed under the second conductivity type semiconductor layer 1116 .

For example, the insulating layer 1150 may include a first insulating layer 1152 disposed on the lower surface of the second conductive semiconductor layer 1116 .

For example, the first insulating layer 1152 may be disposed on the remaining area of the lower surface of the second conductive semiconductor layer 1116 excluding the area where the second electrode 1140 is disposed. Also, for example, the first insulating layer 1152 may be disposed on an edge region of the lower surface of the second electrode 1140 disposed on the lower surface of the second conductive semiconductor layer 1116, and may be disposed on the lower surface of the second electrode 1140. A part of the lower surface may be exposed.

The second electrode pad 1145 may be disposed under the first insulating layer 1152 and the second electrode 1145 .

In order to perform die bonding with a package body, a submount, or a substrate, the lower surface of the second electrode pad 1145 and the lower surface of the second expansion part 1132b are on the same plane ( 305) may be located on.

The second electrode pad 1145 may be disposed under a portion of the lower surface of the second electrode 1140 exposed by the first insulating layer 1152, and is connected to or connected to the exposed portion of the second electrode 1140. can be contacted.

For example, the first insulating layer 1152 may cover only an upper part of the side surface of the second electrode pad 1145 . Also, the second electrode pad 1145 may be disposed under the lower surface of the second electrode 1140 exposed by the first insulating layer 1152 . The edge of the second electrode pad 1145 may have a structure extending horizontally to the lower surface of the first insulating layer 1152 to contact the lower surface of the first insulating layer 1152, but is not limited thereto. .

For example, the second electrode pad 1145 may have a structure that is convexly bent in a direction from the second conductivity type semiconductor layer 1116 toward the first conductivity type semiconductor layer 1112, but is not limited thereto.

In another embodiment, the first insulating layer completely covers the side surface of the second electrode pad 1145, and the lower surface of the first insulating layer, the lower surface of the second electrode pad 1145, and the lower surface of the second expansion part 1132b are They may be located on the same plane.

The insulating layer 1150 may further include a second insulating layer 1154 disposed on a side surface of the light emitting structure 1110 . For example, the second insulating layer 1154 may be disposed on a side surface of the first conductivity type semiconductor layer 1112 , a side surface of the active layer 1114 , and a side surface of the second conductivity type semiconductor layer 1116 .

For example, one end of the second insulating layer 1154 may extend to the edge of the upper surface of the first conductive semiconductor layer 1112 to be connected to or contact the passivation layer 1120, and the The other end may be connected to or in contact with the first insulating layer 1152 .

The insulating layer 1150 is an insulating material such as SiO ₂ , SiOx, Si ₃ N ₄ , TiO ₂ , SiNx, SiO _x N _y , or Al ₂ O ₃ may include at least one of them.

The insulating layer 1150 may be a distributed Bragg reflective layer having a multilayer structure in which at least two layers having different refractive indices are alternately stacked at least once.

The insulating layer 1150 may have a structure in which a first layer having a first refractive index and a second layer having a second refractive index smaller than the first refractive index are alternately stacked one or more times.

For example, the insulating layer 1150 may have a structure in which a TiO ₂ layer/SiO ₂ layer is stacked one or more times, and each of the first layer and the second layer may have a thickness of λ/4, and λ is the light emitting structure 1110 ) may mean the wavelength of light generated from

As shown in FIG. 3 , the second expansion portion 1132b of the first electrode 1130 includes a second insulating layer 1154 positioned on side surfaces of the active layer 1114 and the second conductive semiconductor layer 1116. It may be located apart from a part of

Also, the lowermost end of the second expansion part 1132b may be spaced apart from the first and second insulating layers 1152 and 1154 . This is to prevent an electrical short between the second expansion part 1132b and the second electrode pad 1145 during bonding with a package body, a submount, or a substrate.

For example, the second extension 1132b may be extended to be inclined with respect to the vertical line 1301, the vertical line 1301 is perpendicular to the top surface of the first conductivity type semiconductor layer, and the first extension 1132a and the second extension 1132a. It may be an imaginary straight line passing through the part where the two extension parts 1132b meet.

For example, an interior angle θ between the vertical line 1301 and the inner surface of the second extension 1132b may be greater than or equal to 0° and less than 30°. When θ is smaller than 0°, the separation distance between the lower end of the second extension part 1132b and the second electrode pad 1145 is short, and an electrical short may occur between them. Also, when θ is 30° or more, it is not easy to form the second expansion part 1132b and it may be disconnected.

When θ is 0°, the inner surface of the second extension 1132b is parallel to the vertical line 301, and when θ is a positive number, the inner surface of the second extension 1132b is on the right side of the vertical line 301. , and when θ is a negative number, it may be the case that the inner surface of the second expansion part 1132b is located on the left side 301 of the vertical line 301 .

Alternatively, for example, in order to stably secure prevention of short circuit between the lower end of the second extension 1132b and the second electrode pad 1145 and prevention of disconnection of the second extension 1132b, the vertical line 1301 and the second extension The interior angle θ between 1132b may be 0° to 15°. Or, for example, θ may be greater than 5° and less than or equal to 15°.

For example, the separation distance D1 between the second expansion part 1132b and the second insulating layer 1154 may increase from the first conductivity type semiconductor layer 1112 toward the second conductivity type semiconductor layer 1116. .

A separation distance D2 between the lowermost end of the second expansion part 1132b and the second electrode pad 1145 may be 2 nm to 5 nm.

If D2 is less than 2 nm, there may be a risk of electrical short circuit between the second expansion part 1132b and the second electrode pad 1145 during bonding with a package body, submount, or substrate. .

When D2 exceeds 5 nm, the connection between the upper electrode 1134 of the first electrode 1130 and the extension electrode 1132 may be disconnected or the extension electrode 1132 may be disconnected.

6 is a cross-sectional view of a light emitting device 1000-1 according to another embodiment. The same reference numerals as those in FIG. 3 denote the same configurations, and descriptions of the same configurations are simplified or omitted.

The passivation layer 1120a of FIG. 3 exposes a portion of the top surface of the first conductivity type semiconductor layer 1112 . On the other hand, the passivation layer 1120a of the light emitting device 1000-1 of FIG. 6 except for a portion of the upper surface of the first conductivity type semiconductor layer 1112 exposed for contact with the contact electrode 1136, The upper surface of the 1 conductivity type semiconductor layer 1112 may not be exposed.

For example, the passivation layer 1120a may cover the entire top surface of the first conductivity type semiconductor layer 1112 except for a portion of the top surface of the first conductivity type semiconductor layer 1112 that contacts the contact electrode 1136. , may be connected to or in contact with the second insulating layer 1154.

FIG. 7A shows a top plan view of a light emitting device 1000-2 according to another embodiment, and FIG. 7B shows a bottom plan view of the light emitting device 1000-2 shown in FIG. 7A. 7A and 7B may be examples including the passivation layer 1120a of FIG. 6 , but are not limited thereto, and may be equally applied to the light emitting device 1000 shown in FIG. 3 .

Referring to FIGS. 7A and 7B , the first electrode 1130a is positioned adjacent to one side (eg, 1110-3) of the side sides 1110-1 to 1110-4 of the upper surface of the light emitting structure 1110. can do.

Figure 8a shows a top plan view of a light emitting device 1000-3 according to another embodiment, Figure 8b shows a bottom plan view of the light emitting device 1000-3 shown in Figure 8a, Figure 9 is shown in Figures 8a and 8a 8B shows a cross-sectional view of the light emitting device 1000-3 in the I-II direction.

8a, 8b, and 9 may be examples including the passivation layer 1120a of FIG. 6 , but are not limited thereto, and may be equally applied to the light emitting device 100 shown in FIG. 3 .

Referring to FIGS. 8A, 8B, and 9 , the light emitting device 1000-3 may have two first electrodes 1130b1 and 1130b2.

For example, the 1-1 electrode 1130b1 may be positioned adjacent to a first side (eg, 1110-1) among the side sides 1110-1 to 1110-4 of the upper surface of the light emitting structure 1110, and The 1-2 electrode (1130b2) is a second side (eg, 1110-2) facing the first side (eg, 1110-1) of the side sides (eg, 1110-1 to 1110-4) of the upper surface of the light emitting structure 1110. ) may be located adjacent to.

The structure of each of the 1-1st and 1-2nd electrodes 1130b1 and 1130b2 may be identically applied to the description of the first electrode 1130 of FIG. 3 or FIG. 9 .

Compared to the embodiments of FIGS. 7A and 7B , the light emitting device 1000 - 3 includes two first electrodes, thereby improving current dissipation efficiency.

8A, 8B, and 9 illustrate two first electrodes, but are not limited thereto, and in another embodiment, the number of first electrodes may be three or more. Also, in another embodiment, the first electrodes may be disposed on side surfaces that do not face each other among the side sides 1110-1 to 1110-4 of the upper surface of the light emitting structure 1110.

10A is a top plan view of a light emitting device 1000-4 according to another embodiment, and FIG. 10B is a bottom plan view of the light emitting device 1000-4 shown in FIG. 10A. 10A and 10B may be examples including the passivation layer 1120a of FIG. 6 , but are not limited thereto, and may be equally applied to the light emitting device 1000 shown in FIG. 3 .

Referring to FIGS. 10A and 10B , the light emitting device 1000 - 4 may have a first electrode 1130c positioned on an edge region of an upper surface of the light emitting structure 1110 .

For example, the first electrode 1130c may be positioned at an edge adjacent to the side surfaces 1110 - 1 to 1110 - 4 of the upper surface of the light emitting structure 1110 . Compared to the light emitting devices 1000-1 to 1000-3, in the embodiment shown in FIGS. 10A and 10B, the first electrode 1130c is located at the edge adjacent to the side surfaces of the upper surface of the light emitting structure. , the light efficiency according to the current distribution can be further improved.

In another embodiment, the first electrode may be disposed in various positions according to the arrangement and structure of a conductive layer of a package body, a submount, or a substrate bonded to the first electrode.

The light emitting devices 1000, 1000-1 to 1000-4 shown in FIGS. 3, 6, 9, 7a and 7b, and 10a and 10b have a chip size (eg, maximum diameter of the chip) of 100 microns. may be less than a meter. As such, it is not easy to form bonding pads for wire bonding of light emitting devices having a diameter of less than 100 microns.

By positioning one end of the second expansion part 1132b of the first electrode 1130 that is die-bonded or flip-chip-bonded with the package body, submount, or conductive layer of the substrate to be spaced apart from the light emitting structure. , The embodiment can easily implement an electrode pad for flip chip bonding or die bonding on the same side of the light emitting structure 1110 having a small area.

11A to 11I are process charts illustrating a method of manufacturing the light emitting device 1000-1 shown in FIG. 6 .

Referring to FIG. 11A , a light emitting structure 1110 is formed on a growth substrate 1410 .

For example, a first conductivity type semiconductor layer 1112 , an active layer 1114 , and a second conductivity type semiconductor layer 1116 may be sequentially formed on the growth substrate 1410 . The side of the light emitting structure 1110 may be an inclined surface inclined with respect to the growth substrate 1410 by an isolation etching process for the light emitting structure to distinguish individual chips.

Although not shown in FIG. 11A , a buffer layer or a buffer layer is formed between the growth substrate 1410 and the light emitting structure 1110 in order to relieve stress due to a difference in lattice constant between the light emitting structure 1110 and the growth substrate 1410 . An undoped-semiconductor layer, for example, an undoped GaN layer may be further formed.

Herein, the undoped GaN may be grown into Unintentionally doped GaN (hereinafter referred to as "UID GaN"), particularly n-type UID GaN. For example, in a GaN growth process, N-vacancy in which N (sodium) is deficient may occur even in a region where n-type dopant is not supplied, and when N-vacancy increases, the concentration of surplus electrons increases, and the UID GaN manufacturing process Although not intended in, UID GaN may exhibit electrical properties similar to those doped with an n-type dopant.

The growth substrate 1410 is a substrate suitable for growing a nitride semiconductor single crystal, for example, any one of a sapphire substrate, a silicon (Si) substrate, a zinc oxide (ZnO) substrate, and a nitride semiconductor substrate, or GaN, InGaN, AlGaN, and AlInGaN. At least one of them may be a laminated template substrate.

Next, referring to FIG. 11B , a second electrode 1140 is formed on the second conductive semiconductor layer 1116 of the light emitting structure 1110 . For example, by forming a conductive material for forming the second electrode 1140 on the second conductive semiconductor layer 1116 and then patterning the conductive material through a photolithography process and an etching process, the second electrode 1140 can form

Next, referring to FIG. 11C , an insulating material is deposited on the side surface of the light emitting structure 1110 and the second conductive semiconductor layer 1116 to form an insulating layer 1150 . For example, the first insulating layer 1152 may be formed on the second conductive semiconductor layer 1116 and the second insulating layer 1154 may be formed on the side surface of the light emitting structure 1110 at the same time. An area 1152 of the upper surface of the second electrode 1140 may be exposed.

Next, referring to FIG. 11D , a second electrode pad 1145 is formed on a region of the upper surface of the first insulating layer 1152 and the exposed second electrode 1140 .

For example, by depositing a conductive material on the second conductive semiconductor layer 1116 on which the first insulating layer 1152 and the second electrode 1140 are formed, and then patterning the deposited conductive material, on the insulating layer 1152 A second electrode pad 1145 contacting the second electrode 1140 may be formed.

Next, referring to FIG. 11E , a support substrate 1401 including a temporary substrate 1420 and a sacrificial layer 1430 formed on the temporary substrate 1420 is prepared.

The second electrode pad 1145 is bonded to the sacrificial layer 1430 by an adhesive member (not shown) such as silicon. In a state where the second electrode pad 1145 is bonded to the sacrificial layer 1430 , the growth substrate 1410 is removed by a laser lift off (LLO) process. After FIG. 11e, the light emitting structure 1110 shown in FIG. 11d is rotated by 180°.

Next, referring to FIG. 11F , the buffer layer or the undoped semiconductor layer formed between the light emitting structure 1110 and the growth substrate 1410 is removed through etching or the like. Then, the light extraction structure 1112a is formed on the surface of the first conductivity-type semiconductor layer 1112 exposed by the removal of the growth substrate 1410 through etching or the like.

Next, referring to FIG. 11G , a passivation layer 1120a is formed by depositing a light-transmitting insulating material on the surface of the first conductivity-type semiconductor layer 1112 exposed by the removal of the growth substrate 1410 .

A portion of the passivation layer 1120a is etched to form a through hole 1302 exposing a portion of the surface of the first conductivity type semiconductor layer 1112 .

The embodiment shown in FIG. 3 may be implemented by patterning the passivation layer 1120a to expose the surface of the first conductivity-type semiconductor layer 1112 in the process of FIG. 11G.

Next, referring to FIG. 11H , a conductive material is deposited on the passivation layer 1120a to fill the through hole 1301 . At this time, the conductive material formed on the passivation layer 1120a is deposited to extend to the upper surface of the sacrificial layer 1430 on one side of the light emitting structure 1110 .

Then, the first electrode 1130 is formed by patterning the conductive material formed on the passivation layer 1120a. At this time, the conductive material filling the through hole 1301 may contact the surface of the first conductivity type semiconductor layer 1112 .

Next, referring to FIG. 11I , the temporary substrate 1420 may be removed by removing the sacrificial layer 1430 using chemical etching, thereby obtaining the light emitting device 1000-1 according to the embodiment.

12 is a cross-sectional view of a lighting device 1200 according to an embodiment.

Referring to FIG. 12 , the lighting device 1200 includes a substrate 1510, a body 1520, at least one light emitting element (eg, 1530-1 to 1530-5), and a light transmitting member 1540.

The substrate 1510 may be a printed circuit board including first and second wiring layers 1512 and 1514 and an insulating layer 1515 . For example, the substrate 1510 may be a flexible circuit board.

The first and second wiring layers 1512 and 1514 may be disposed spaced apart from each other on the substrate 1510, and the insulating layer 1515 may be disposed on the substrate 1510 between the first and second wiring layers 1512 and 1514. ) to electrically insulate between the first and second wiring layers 1512 and 1514. Alternatively, in another embodiment, the insulating layer 1515 may be omitted.

At least one light emitting device (eg, 1530-1 to 1530-5) is disposed on the substrate 1510 and electrically connected to the first and second wiring layers 1512 and 1514. At least one light emitting device (eg, 1530-1 to 1530-5) may be any one of the light emitting devices 1000 and 1000-1 to 1000-4 according to the above-described embodiment.

The body 1520 is disposed on the substrate 1510 and reflects light emitted from at least one light emitting device (eg, 1530-1 to 1530-5).

For example, the body 1520 may have a cavity, and at least one light emitting device (eg, 1530-1 to 1530-5) may be disposed in the cavity.

For example, the body 1520 may include the number of cavities corresponding to the number of light emitting elements, and a corresponding one of the light emitting elements may be disposed in each of the cavities.

Also, the body 1520 may have a barrier rib 1520a surrounding at least one light emitting element (eg, 1530-1 to 1530-5). A side surface of the barrier rib 1520a may be an inclined surface inclined with respect to the upper surface of the substrate 1510 and may reflect light emitted from at least one light emitting device (eg, 1530-1 to 1530-5).

In FIG. 12, the number of light emitting elements is 5, but is not limited thereto. When the lighting device 1200 includes a plurality of light emitting elements, the lighting device may be implemented as a light emitting module.

Also, for example, in another embodiment, the number of light emitting devices may be one, the body 1520 may have one cavity in which the light emitting device is disposed, and the lighting device 1200 according to the embodiment may be in the form of a light emitting device package. can be implemented

Also, for example, when the lighting device 1200 includes a plurality of light emitting elements and the plurality of light emitting elements generate blue light, red light, or green light, it may be implemented as a light emitting module or a light source of a display device expressing an image. .

Since the thickness of the light emitting elements according to the embodiment can be reduced, the size of the light emitting module or display device including the light emitting devices can be reduced, for example, in thickness.

A general horizontal type light emitting device includes a growth substrate (eg, a sapphire substrate), but the light emitting devices (eg, 1530-1 to 1530-5) of the embodiment do not include a growth substrate, so the thickness can be reduced.

While a typical vertical light emitting device has a first electrode pad and a second electrode pad disposed on opposite sides of the light emitting structure, the light emitting devices of the embodiment (eg, 1530-1 to 1530-5) have a second electrode pad ( 1145) and the second expansion part 1132b of the first electrode 1130 are located on the same side of the light emitting structure 1110, so the thickness can be reduced.

The light transmitting member 1540 is disposed in the cavity of the body 1520 to surround the light emitting devices 1530-2 to 1530-5. The light-transmitting member 1540 can prevent damage to the light emitting device due to external impact and can prevent discoloration of the light emitting devices 1530-2 to 1530-5 due to moisture. In other embodiments, the light transmitting member 1540 may be omitted.

FIG. 13 is a plan view of a display device 3000 according to an exemplary embodiment, and FIG. 14 is a cross-sectional view of the display device shown in FIG. 13 in an AA′ direction according to an exemplary embodiment.

The display device 3000 of FIG. 13 includes a mobile phone, a smart phone, a notebook computer, a digital broadcast terminal, a PDA (Personal Digital Assistants), a PMP (Portable Miltimedia Player), a navigation device, a slate PC, and a tablet. (Tablet) PCs, digital TVs, and desktop computers may be included, and may be implemented as a flat panel display or a flexible display. Also, the display device 3000 may be implemented as a display panel.

Visual information expressed by the display device 3000 may be implemented by controlling light emission of sub-pixels arranged in a matrix form. In this case, the unit pixel may be a minimum unit for realizing one color formed by a combination of R (Red), G (Green), and B (Blue). The light emitting device according to the above-described embodiment may serve as a unit pixel of the display device 3000 .

13 and 14, a display device 3000 includes a substrate 3100, a first wire electrode 3112, a second wire electrode 3114, a body 3520 including a barrier rib 3520a, and a plurality of It may include a matrix-type unit pixel array (P11 to Pnm, where n,m is a natural number >1) including light emitting elements (eg, 3530-1 to 3530-5), and a light transmitting member 3540.

The substrate 3100 may be a flexible substrate. For example, the substrate 3100 may include glass or polyimide, and may include an insulating material such as polyethylene naphthalate (PEN) or polyethylene terephthalate (PET) for insulation. The substrate 3100 may be transmissive, but is not limited thereto, and may be opaque in other embodiments.

A plurality of light emitting devices (eg, 3530-1 to 3530-5) may be disposed on the substrate 3100 in an m×n matrix form. Although FIG. 14 shows only five light emitting elements, the number of light emitting elements of the display device 3000 may be the number included in the m×n matrix.

The barrier rib 3520a is disposed between the plurality of light emitting elements (eg, 3530-1 to 3530-5), and includes a black insulator to increase contrast according to the purpose of the display device 3000 or Alternatively, a white insulator may be included to increase reflectivity.

Description of the barrier rib 1520a, the body 1520, and the light-transmitting member 1540 of FIG. 12 may be applied to the barrier rib 3520a, the body 3520, and the light-transmitting member 3540.

Each of the light emitting elements (eg, 3530-1 to 3530-5) may be one of the embodiments shown in FIGS. 3, 6, 7a, 8a, and 10a.

The first wiring electrode 3112 is disposed on the lower surface of the substrate 3100, penetrates the substrate 3100, and one end of the first electrode 1130 of each of the light emitting elements (eg, 3530-1 to 3530-5), For example, it is connected or bonded to one end of the expansion electrode 1132 .

The second wire electrode 3114 is disposed on the lower surface of the substrate 3100 to be spaced apart from the first wire electrode 3114, and passes through the substrate 3100 to each of the light emitting devices (eg, 3530-1 to 3530-5). is connected or bonded to the second electrode pad 1145 of

Each of the first and second wire electrodes 3112 and 3114 may be exposed from the lower surface of the substrate 3100, but is not limited thereto. 14, the first and second wire electrodes 3112 and 3114 pass through the substrate 3100, but is not limited thereto, and in another embodiment, the first and second wire electrodes 3112 and 3114 It may be positioned on the substrate 3100 without penetrating the substrate 3100 .

Although not shown in FIGS. 13 and 14, in order to prevent an electrical short between the first and second wire electrodes 3112 and 3114, the embodiment is a substrate between the first and second wire electrodes 3112 and 3114 ( 3100) an insulating layer may be further provided on the lower surface.

Each of the light emitting elements (eg, 3530-1 to 3530-5) includes a light emitting element emitting blue light, a light emitting element emitting red light, and a light emitting element emitting green light, and emits red light in a row direction and a column direction, respectively. A light emitting element generating light, a light emitting element generating green light, and a light emitting element generating blue light may be sequentially and repeatedly disposed. In this case, light emitting devices that emit red light, green light, and blue light, for example, unit pixels may form one image pixel.

In the unit pixel array, the area of the light emitting region of the light emitting element emitting red light (hereinafter referred to as “red light emitting region”), the area of the light emitting region of the light emitting element emitting green light (hereinafter referred to as “green light emitting region”), and blue light Areas of light emitting regions (hereinafter, referred to as “blue light emitting regions”) of light emitting elements generating light may be different from each other. For example, the areas of the green light emitting region and the red light emitting region having relatively low luminous efficiency may be larger than those of the blue light emitting region.

For example, the area of the green light emitting region may be 1 to 4 times the area of the blue light emitting region, and the area of the red light emitting region may be 1 to 3 times the area of the blue light emitting region.

Also, for example, in another embodiment, the areas of the red light emitting region and the green light emitting region may be equal to each other.

For example, the ratio of the area of the blue light emitting region, the area of the red light emitting region, and the area of the green light emitting region may be 1:2:3 or 1:3:3, but is not limited thereto.

Features, structures, effects, etc. described in the embodiments above are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified with respect to other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to these combinations and variations should be construed as being included in the scope of the present invention.

1110: light emitting structure 1120: passivation layer
1130: first electrode 1135: first electrode pad
1140: second electrode 1145: second electrode pad
1150: insulating layer.

Claims (14)

A light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer;
a passivation layer disposed on the first conductivity type semiconductor layer;
A first disposed on the passivation layer, one end penetrating the passivation layer and contacting the first conductivity-type semiconductor layer, and the other end extending toward the side of the light emitting structure and extending down to the lower end of the light emitting structure. electrode;
a second electrode disposed below the second conductivity type semiconductor layer;
an electrode pad disposed below the second electrode; and
Including an insulating layer disposed on the side of the light emitting structure,
The other end of the first electrode is spaced apart from the insulating layer disposed on the side of the light emitting structure. The method of claim 1, wherein the first electrode,
an upper electrode disposed on the first conductivity type semiconductor layer;
at least one contact electrode connected to the upper electrode and passing through the passivation layer to contact the first conductivity type semiconductor layer; and
A light emitting device including an extension electrode connected to one end of the upper electrode and extending in a lateral direction of the light emitting structure to extend below the lower end of the light emitting structure. The method of claim 2, wherein the expansion electrode,
a first expansion portion disposed on the passivation layer and extending from the upper electrode in a horizontal direction; and
A light emitting device comprising a second expansion portion connected to the first extension portion and extending from the first conductivity type semiconductor layer to the second conductivity type semiconductor layer to a lower surface of the second conductivity type semiconductor layer. According to claim 3,
The second extension portion does not overlap with the light emitting structure in a vertical direction, and the vertical direction is a light emitting device perpendicular to the top surface of the first conductivity type semiconductor layer. According to claim 4,
The lower surface of the lower end of the second expansion part is positioned on the same plane as the lower surface of the second electrode pad. According to claim 4,
The second expansion part extends to be inclined with respect to a vertical line, and the vertical line is an imaginary straight line perpendicular to the top surface of the first conductivity type semiconductor layer. According to claim 6,
An interior angle between the vertical line and the second extension is 0 ° to 15 ° light emitting element. According to claim 4,
The light emitting element of claim 1 , wherein the separation distance between the second expansion part and the insulating layer increases in a direction from the first conductivity type semiconductor layer to the second conductivity type semiconductor layer. According to claim 3,
The second expansion part spaced apart from a part of the insulating layer positioned on the active layer and the side surface of the second conductivity type semiconductor layer. According to claim 1,
The first electrode is a light emitting element positioned adjacent to any one side of the side of the upper surface of the light emitting structure. The method of claim 1, wherein the first electrode,
A 1-1 electrode positioned adjacent to a first side of the side of the upper surface of the light emitting structure; and
A light emitting device comprising a first-second electrode positioned adjacent to a second side facing the first side among side sides of the upper surface of the light emitting structure. According to claim 3,
The second expansion part does not overlap with the contact electrode in a vertical direction, and the vertical direction is a direction perpendicular to the upper surface of the first conductivity type semiconductor layer. The method of claim 3, wherein the insulating layer,
a first insulating layer disposed on a lower surface of the second conductivity-type semiconductor layer and exposing the second electrode; and
And a second insulating layer disposed on the side of the light emitting structure,
The lower end of the second expansion part is spaced apart from the first insulating layer and the second insulating layer. a substrate including a first wiring electrode and a second wiring electrode; and
It includes a plurality of light emitting elements arranged in a matrix form on the substrate,
The plurality of light emitting elements include a first light emitting element generating red light, a second light emitting element generating green light, and a second light emitting element generating blue light,
Each of the plurality of light emitting elements is a light emitting element according to any one of claims 1 to 13,
A first electrode of each of the plurality of light emitting elements is bonded to the first wire electrode, and a second electrode pad of each of the plurality of light emitting elements is bonded to the second wire electrode.

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