Patent Description:
Light emitting diodes, as inorganic light sources, are being diversely used in various fields, such as display devices, vehicle lamps, and general lighting. Light emitting diodes are rapidly replacing existing light sources due to their longer lifetime, lower power consumption, and quicker response speed than the existing light sources.

In particular, a display device generally displays various colors by utilizing mixed colors of blue, green, and red. Each pixel of a display device includes blue, green, and red sub pixels, and the color of a particular pixel is determined through the colors of these sub-pixels, and an image is implemented by a combination of pixels.

Light emitting diodes have been mainly used as backlight sources in display devices. However, recently, a micro LED display has been developed as a next generation display, which directly implements images by using light emitting diodes.

Document <CIT> discloses a stacked semiconductor light source comprising three LED stacks each having an n-type semiconductor layer, an active layer, and a p-type semiconductor layer. The n-type semiconductor layer of the center LED stack is contacted on the upper surface by a first conductive structure, and on a lower surface by a second conductive structure.

In <CIT> a semiconductor micro-emitter array for use in a full-color microdisplay. Each pixel includes three vertically-stacked red, green, and blue micro-emitters which are electrically contacted through contacts disposed thereon.

Document <CIT> discloses a semiconductor light emitting element having inter-light emitting unit dielectric layers that are provided between light emitting units.

Document <CIT> discloses a light emitting diode light source module including a light emitting stacked body, and a first through electrode structure and a second through electrode structure passing through a portion of the light emitting stacked body.

Light emitting devices constructed according to exemplary embodiments of the invention have excellent light reproducibility.

A light emitting device according to the invention is disclosed as recited in claim <NUM>.

The first contact structure may extend into the first light emitting part to electrically contact the first n-type semiconductor layer, and the second contact structure may extend into the second light emitting part to electrically contact the third n-type semiconductor layer.

The light emitting device may further include a third contact structure extending into the third light emitting part to electrically contact the third n-type semiconductor layer.

The light emitting device may further include a common pad disposed at a first corner of the light emitting device, and electrically coupled with the first, second, and third n-type semiconductor layers, a first pad disposed at a second corner of the light emitting device, and electrically coupled with the first p-type semiconductor layer, a second pad disposed at a third corner of the light emitting device, and electrically coupled with the second p-type semiconductor layer, and a third pad disposed at a fourth corner of the light emitting device, and electrically coupled with the third p-type semiconductor layer, in which the first, second, and third n-type semiconductor layers are electrically coupled with one another by the first to third contact structures.

The second light emitting part may have a mesa structure, such that a portion thereof in the second corner is removed, and the third light emitting part may have a mesa structure, such that portions thereof in the second and third corners are removed.

The light emitting device may further include a first color filter surrounding an outer sidewall of the first contact structure, and extending onto the first p-type semiconductor layer, a first adhesion layer surrounding an outer sidewall of the first color filter, and extending onto the first color filter, a second color filter surrounding an outer sidewall of the second contact structure, and extending onto the second p-type semiconductor layer, and a second adhesion layer surrounding an outer sidewall of the second color filter, and extending onto the second color filter.

One surface of the first contact structure may electrically contact the second n-type semiconductor layer, and the other surface of the first contact structure may electrically contact the first n-type semiconductor layer.

The light emitting device may further include a common pad disposed at a first corner of the light emitting device, and electrically coupled with the first, second, third n-type semiconductor layers, a first pad disposed at a second corner of the light emitting device, and electrically coupled with the first p-type semiconductor layer, a second pad disposed at a third corner of the light emitting device, and electrically coupled with the second p-type semiconductor layer, and a third pad disposed at a fourth corner of the light emitting device, and electrically coupled with the third p-type semiconductor layer, in which the first, second, third n-type semiconductor layers are electrically coupled with one another by the first and second contact structures.

The first light emitting part may have a mesa structure, such that the first n-type semiconductor layer and the second active layer are not formed in at least a portion of the second corner, the second light emitting part may have a mesa structure, such that portions thereof in the second and third corners are removed, and the third light emitting part has a mesa structure, such that a portion thereof in e fourth corner is removed.

The light emitting device may further include a first color filter surrounding an outer sidewall of the first contact structure, and extending onto the second p-type semiconductor layer, a first adhesion layer surrounding an outer sidewall of the first color filter, and extending onto the first color filter, a second color filter surrounding an outer sidewall of the second contact structure, and extending onto the third p-type semiconductor layer, and a second adhesion layer surrounding an outer sidewall of the second color filter, and extending onto the second color filter.

The light emitting device may further include a third contact structure extending into the first light emitting part and electrically contacting the first n-type semiconductor layer.

The first contact structure and the third contact structure may be in electrical contact with each other.

Each of the first, second, and third contact structures may include an ohmic layer, a first conductive layer, a barrier layer, a second conductive layer, and a bonding layer, and the bonding layer of the first contact structure and the bonding layer of the third contact structure may contact each other.

The light emitting device may further include a common pad disposed at a first corner of the light emitting device, and electrically coupled with the first, second, and third n-type semiconductor layers, a first pad disposed at a second corner of the light emitting device, and electrically coupled with the first p-type semiconductor layer, a second pad disposed at a third corner of the light emitting device, and electrically coupled with the second p-type semiconductor layer, and a third pad disposed at a fourth corner of the light emitting device, and electrically coupled with the third p-type semiconductor layer, in which the first, second, and third n-type semiconductor layers may be electrically coupled with one another by the first, second, and third contact structures.

The second light emitting part may have a mesa structure, such that portions thereof in the second and third corners are removed, and the third light emitting part may have a mesa structure, such that a portion thereof in the fourth corner is removed.

The light emitting device may further include a substrate disposed over a second surface of the first light emitting part opposing the first surface thereof.

The light emitting device may further include a common pad disposed on the third light emitting part, and electrically coupling the first, second, and third n-type semiconductor layers, a first pad disposed on the third light emitting part, and electrically coupled with the first p-type semiconductor layer, a second pad disposed on the third light emitting part, and electrically coupled with the second p-type semiconductor layer, and a third pad disposed on the third light emitting part, and electrically coupled with the third p-type semiconductor layer.

The light emitting device may further include a support substrate disposed on the third light emitting part, and including through electrodes electrically coupled with the common pad, the first pad, the second pad, and the third pad, respectively.

According to exemplary embodiments, as a first n-type semiconductor layer, a second n-type semiconductor layer ,and a third n-type semiconductor layer are electrically coupled in common to a common pad, current may be stably supplied thereto as compared to when a first p-type semiconductor layer, a second p-type semiconductor layer, and a third p-type semiconductor layer are coupled in common.

In order to understand the configuration and effect of the disclosure sufficiently, embodiments of the disclosure will be described with reference to the accompanying drawings. However, the disclosure is not limited to the embodiments set forth herein and may be implemented in various forms, and a variety of changes may be added.

Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure is a part.

Hereinafter, a light emitting device will be described below with reference to the accompanying drawings through various exemplary embodiments.

<FIG> is a top view of a light emitting device according to an exemplary embodiment according to the invention, and <FIG> and <FIG> are cross-sectional views taken along line A-A' of <FIG> according to exemplary embodiments according to the invention.

Referring to <FIG>, a light emitting device may include a first light emitting part LE1, a second light emitting part LE2, and a third light emitting part LE3, which are vertically stacked on a substrate <NUM>.

The substrate <NUM> may be capable of growing a gallium nitride-based semiconductor layer thereon, and may include a sapphire (Al<NUM>O<NUM>), a silicon carbide (SiC), a gallium nitride (GaN), an indium gallium nitride (InGaN), an aluminum gallium nitride (AlGaN), an aluminum nitride (AlN), a gallium oxide (Ga<NUM>O<NUM>), or silicon. Also, the substrate <NUM> may be a patterned sapphire substrate.

One surface of the substrate <NUM> may be brought into contact with the first light emitting part LE1, and the other, opposing surface may be the light extraction surface of the light emitting device. In some exemplary embodiments, the substrate <NUM> may be removed. In this case, one surface of the first light emitting part LE1 facing the substrate <NUM> may be the light extraction surface of the light emitting device. When the light extraction surface is the other surface of the substrate <NUM> or the one surface of the first light emitting part LE1, the wavelength of light emitted from the first light emitting part LE1 may be the shortest, the wavelength of light emitted from the second light emitting part LE2 may be longer than the wavelength of light emitted from the first light emitting part LE1 and shorter than the wavelength of light emitted from the third light emitting part LE3, and the wavelength of light emitted from the third light emitting part LE3 may be the longest. For example, the first light emitting part LE1 may emit blue light, the second light emitting part LE2 may emit green light, and the third light emitting part LE3 may emit red light.

The first light emitting part LE1 includes a first n-type semiconductor layer <NUM>, a first active layer <NUM>, a first p-type semiconductor layer <NUM>, and a first transparent electrode <NUM>. The second light emitting part LE2 includes a second n-type semiconductor layer <NUM>, a second active layer <NUM>, a second p-type semiconductor layer <NUM>, and a second transparent electrode <NUM>. The third light emitting part LE3 includes a third n-type semiconductor layer <NUM>, a third active layer <NUM>, a third p-type semiconductor layer <NUM>, and a third transparent electrode <NUM>.

Each of the first n-type semiconductor layer <NUM>, the second n-type semiconductor layer <NUM>, and the third n-type semiconductor layer <NUM> may be a Si-doped gallium nitride-based semiconductor layer. Each of the first p-type semiconductor layer <NUM>, the second p-type semiconductor layer <NUM>, and the third p-type semiconductor layer <NUM> may be a Mg-doped gallium nitride-based semiconductor layer. Each of the first active layer <NUM>, the second active layer <NUM>, and the third active layer <NUM> may include a multi-quantum well (MQW), and the composition ratio thereof may be determined to emit light of a desired peak wavelength. As each of the first transparent electrode <NUM>, the second transparent electrode <NUM> and the third transparent electrode <NUM>, a transparent conductive oxide (TCO), such as ZnO, indium tin oxide (ITO), zinc-doped indium tin oxide (ZITO), zinc indium oxide (ZIO), gallium indium oxide (GIO), zinc tin oxide (ZTO), fluorine-doped tin oxide (FTO), gallium-doped zinc oxide (GZO), aluminum-doped zinc oxide (AZO) may be used.

The light emitting device may further include a first contact structure CT1, which extends through a portion of the first light emitting part LE1, a second contact structure CT2, which extends through a portion of the second light emitting part LE2, and a third contact structure CT3, which extends through a portion of the third light emitting part LE3.

The first contact structure CT1, the second contact structure CT2, and the third contact structure CT3 may include ohmic layers <NUM>, <NUM>, and <NUM>, first conductive layers <NUM>, <NUM>, and <NUM>, barrier layers <NUM>, <NUM>, and <NUM>, second conductive layers <NUM>, <NUM>, and <NUM>, and bonding layers <NUM>, <NUM>, and <NUM>, respectively. At least one of the ohmic layer <NUM>, <NUM>, and <NUM> may include Cr, at least one of the first conductive layer <NUM>, <NUM>, and <NUM> may include Al, at least one of the barrier layer <NUM>, <NUM>, and <NUM> may include Ti and Ni, which are stacked a plurality of times, at least one of the second conductive layer <NUM>, <NUM>, and <NUM> may include Au, and at least one of the bonding layer <NUM>, <NUM>, and <NUM> may include In or Sn.

According to an exemplary embodiment, the first contact structure CT1, the second contact structure CT2, and the third contact structure CT3 may be disposed to overlap one another. When the light emitting device has a substantially quadrangular structure when viewed from the top, the first contact structure CT1, the second contact structure CT2, and the third contact structure CT3 may be sequentially disposed to overlap one another at a first corner CN1 of the light emitting device.

According to the invention, the light emitting device further includes a first color filter CF1, a first adhesion layer AD1, and a second adhesion layer AD2, which are disposed between the first light emitting part LE1 and the second light emitting part LE2, and a second color filter CF2 and a third adhesion layer AD3, which are disposed between the second light emitting part LE2 and the third light emitting part LE3.

Each of the first color filter CF1 and the second color filter CF2 may include a distributed Bragg reflector (DBR) having a structure, in which TiO<NUM> and SiO<NUM> are alternately stacked. However, the inventive concepts are not limited thereto, and in some exemplary embodiments, the color filters CF1 and CF2 may include other dielectric materials, such as SiNx, Al<NUM>O<NUM>, Ta<NUM>O<NUM> or the like. For example, the first color filter CF1 and the second color filter CF2 may be different in terms of the composition ratio and alternate stacking order and number of TiO<NUM> and SiO<NUM>. According to an exemplary embodiment, the first color filter CF1 may selectively pass light generated from the second light emitting part LE2 and light generated from the third light emitting part LE3, and may reflect light generated from the first light emitting part LE1. The second color filter CF2 may selectively pass light generated from the third light emitting part LE3, and may reflect light generated from the first light emitting part LE1 and light generated from the second light emitting part LE2. The first color filter CF1 and the second color filter CF2 may function as insulation layers.

Each of the first adhesion layer AD1, the second adhesion layer AD2, and the third adhesion layer AD3 may include a material, which has an adhesion property and high transmittance, such as silicon on glass (SOG), epoxy, polyimide, SU8, benzo cyclo butane (BCB) or others.

In the first light emitting part LE1, the first n-type semiconductor layer <NUM>, the first active layer <NUM>, the first p-type semiconductor layer <NUM>, and the first transparent electrode <NUM> may be sequentially stacked. The first light emitting part LE1 may have a first hole H1 (see <FIG>), which passes through the first transparent electrode <NUM>, the first p-type semiconductor layer <NUM>, and the first active layer <NUM>. The first hole H1 may have a constant width or a width that gradually decreases in a downward direction. As such, an area of the first transparent electrode <NUM> may be the same or less than an area of the first p-type semiconductor layer <NUM>, and an area of the first p-type semiconductor layer <NUM> may be the same or less than an area of the first active layer <NUM>.

The first hole H1 may partially expose the first n-type semiconductor layer <NUM>. The first contact structure CT1 may be disposed in the first hole H1, and may have a structure which projects out of the first transparent electrode <NUM>. More particularly, the top surface of the first contact structure CT1 may be disposed at a level higher than the top surface of the first transparent electrode <NUM>. According to an exemplary embodiment, in the first contact structure CT1, the ohmic layer <NUM>, the first conductive layer <NUM>, the barrier layer <NUM>, the second conductive layer <NUM>, and the bonding layer <NUM> may be sequentially stacked.

The first adhesion layer AD1 may surround the outer sidewall of the first contact structure CT1 in the first hole H1, and extend onto the first transparent electrode <NUM>. The first color filter CF1 may surround the outer sidewall of the first adhesion layer AD1 in the first hole H1, extend onto the first transparent electrode <NUM>, and be disposed between the first transparent electrode <NUM> and the first adhesion layer AD1.

In the second light emitting part LE2, the second transparent electrode <NUM>, the second p-type semiconductor layer <NUM>, the second active layer <NUM>, and the second n-type semiconductor layer <NUM> may be sequentially stacked. The second light emitting part LE2 may have a second hole H2 (see <FIG>), which passes through the second transparent electrode <NUM>, the second p-type semiconductor layer <NUM>, and the second active layer <NUM>. The second hole H2 may have a width that is constant or gradually increases in the downward direction. As such, the second active layer <NUM> may have a constant width or a width greater than the second p-type semiconductor layer <NUM>, and the second p-type semiconductor layer <NUM> may have a constant width or a width greater than the second transparent electrode <NUM>.

The second hole H2 may partially expose the second n-type semiconductor layer <NUM>. The second contact structure CT2 may be disposed in the second hole H2, and may have a structure which projects out of the second transparent electrode <NUM>. More particularly, the bottom surface of the second contact structure CT2 may be disposed at a level lower than the surface of the second transparent electrode <NUM>. In the second contact structure CT2, the bonding layer <NUM>, the second conductive layer <NUM>, the barrier layer <NUM>, the first conductive layer <NUM>, and the ohmic layer <NUM> may be sequentially stacked.

The second adhesion layer AD2 may surround the outer sidewall of the second contact structure CT2, and extend onto the second transparent electrode <NUM>.

While the first color filter CF1 is illustrated as being disposed between the first transparent electrode <NUM> and the first adhesion layer AD1, however, the inventive concepts are not limited thereto. For example, in some exemplary embodiments, the first color filter CF1 may be disposed between the second transparent electrode <NUM> and the second adhesion layer AD2.

According to an exemplary embodiment, as the first contact structure CT1 and the second contact structure CT2 are brought into electrical contact with each other, the first n-type semiconductor layer <NUM> and the second n-type semiconductor layer <NUM> may be electrically coupled with each other. The bonding layer <NUM> of the first contact structure CT1 and the bonding layer <NUM> of the second contact structure CT2 may be bonded with each other. With respect to the bonding surface of the first contact structure CT1 and the second contact structure CT2, the first contact structure CT1 and the second contact structure CT2 may have substantially symmetrical structure as each other. In particular, the bonding layer <NUM>, the second conductive layer <NUM>, the barrier layer <NUM>, the first conductive layer <NUM>, and the ohmic layer <NUM> may be disposed from the bonding surface in the first contact structure CT1, and the bonding layer <NUM>, the second conductive layer <NUM>, the barrier layer <NUM>, the first conductive layer <NUM>, and the ohmic layer <NUM> may be disposed from the bonding surface in the second contact structure CT2. In this manner, current applied to the second light emitting part LE2 and current applied to the first light emitting part LE1 may be uniform.

As the first adhesion layer AD1 and the second adhesion layer AD2 are bonded with each other, the first light emitting part LE1 and the second light emitting part LE2 may be physically bonded with each other.

In the third light emitting part LE3, the third transparent electrode <NUM>, the third p-type semiconductor layer <NUM>, the third active layer <NUM>, and the third n-type semiconductor layer <NUM> may be sequentially stacked. The third light emitting part LE3 may have a third hole H3 (see <FIG>), which passes through the third transparent electrode <NUM>, the third p-type semiconductor layer <NUM>, and the third active layer <NUM>. The third hole H3 may have a width that gradually increases in the downward direction. As such, the third active layer <NUM> may have a width greater than the third p-type semiconductor layer <NUM>, and the third p-type semiconductor layer <NUM> may have a width greater than the third transparent electrode <NUM>.

The third hole H3 may partially expose the third n-type semiconductor layer <NUM>. The third contact structure CT3 may be disposed in the third hole H3, and may have a structure which projects out of the third transparent electrode <NUM>. More particularly, the bottom surface of the third contact structure CT3 may be disposed at a level lower than the surface of the third transparent electrode <NUM>. In the third contact structure CT3, the bonding layer <NUM>, the second conductive layer <NUM>, the barrier layer <NUM>, the first conductive layer <NUM>, and the ohmic layer <NUM> may be sequentially stacked. According to an exemplary embodiment, since the first contact structure CT1, the second contact structure CT2, and the third contact structure CT3 have substantially the same structure, current transferred to the first n-type semiconductor layer <NUM>, the second n-type semiconductor layer <NUM>, and the third n-type semiconductor layer <NUM> may be uniform.

The third adhesion layer AD3 may surround the outer sidewall of the third contact structure CT3 in the third hole H3, and extend onto the third transparent electrode <NUM>. The second color filter CF2 may surround the outer sidewall of the third adhesion layer AD3 in the third hole H3, extend onto the third transparent electrode <NUM>, and be disposed between the third transparent electrode <NUM> and the third adhesion layer AD3.

As described above, according to an exemplary embodiment, as the first contact structure CT1 and the second contact structure CT2 are brought into electrical contact with each other, the first n-type semiconductor layer <NUM> and the second n-type semiconductor layer <NUM> may be electrically coupled with each other. The bonding layer of the first contact structure CT1 and the bonding layer of the second contact structure CT2 may be bonded to each other. Also, as the first adhesion layer AD1 and the second adhesion layer AD2 are bonded to each other, the first light emitting part LE1 and the second light emitting part LE2 may be physically bonded to each other.

According to another exemplary embodiment according to the invention, as shown in <FIG>, as the second contact structure CT2 and the third contact structure CT3 are brought into electrical contact with each other, the second n-type semiconductor layer <NUM> and the third n-type semiconductor layer <NUM> may be electrically coupled with each other. The bonding layer of the second contact structure CT2 and the bonding layer of the third contact structure CT3 may be bonded with each other. Also, as the second adhesion layer AD2 and the third adhesion layer AD3 are bonded with each other, the second light emitting part LE2 and the third light emitting part LE3 may be physically bonded with each other.

The light emitting device may further include a common pad CPD, which electrically couples the first n-type semiconductor layer <NUM>, the second n-type semiconductor layer <NUM> and the third n-type semiconductor layer <NUM>, a first pad PD1 electrically coupled with the first transparent electrode <NUM>, a second pad PD2 electrically coupled with the second transparent electrode <NUM>, and a third pad PD3 electrically coupled with the third transparent electrode <NUM>. Each of the common pad CPD, the first pad PD1, the second pad PD2, and the third pad PD3 may include at least one selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, Cr, Ti, and Cu. The light emitting device may further include an insulation layer IDL for electrically insulating the common pad CPD, the first pad PD1, the second pad PD2, and the third pad PD3 from the third n-type semiconductor layer <NUM>. The insulation layer IDL may include a silicon oxide or a silicon nitride, for example.

When the light emitting device has a substantially quadrangular structure when viewed from the top, the common pad CPD may be disposed at the first corner CN1, the first pad PD1 may be disposed at a second corner CN2, the second pad PD2 may be disposed at a third corner CN3, and the third pad PD3 may be disposed at a fourth corner CN4.

The common pad CPD may be electrically coupled in common with the first n-type semiconductor layer <NUM>, the second n-type semiconductor layer <NUM>, and the third n-type semiconductor layer <NUM> by the first contact structure CT1, the second contact structure CT2, and the third contact structure CT3. As the common pad CPD is coupled in common with the first n-type semiconductor layer <NUM>, the second n-type semiconductor layer <NUM>, and the third n-type semiconductor layer <NUM>, it is possible to stably supply current. As described above, while each of the first p-type semiconductor layer <NUM>, the second p-type semiconductor layer <NUM>, and the third p-type semiconductor layer <NUM> includes a Mg-doped gallium nitride-based semiconductor layer, since the doping concentration of Mg is low, each of the first p-type semiconductor layer <NUM>, the second p-type semiconductor layer <NUM>, and the third p-type semiconductor layer <NUM> may have large contact resistance. As such, as compared to a case where the common pad CPD electrically couples in common the first p-type semiconductor layer <NUM>, the second p-type semiconductor layer <NUM>, and the third p-type semiconductor layer <NUM>, by electrically coupling in common the first n-type semiconductor layer <NUM>, the second n-type semiconductor layer <NUM>, and the third n-type semiconductor layer <NUM>, it is possible to stably supply current.

Referring to <FIG>, the first pad PD1 disposed on the insulation layer EDL may be electrically coupled with the first transparent electrode <NUM> through a first via structure VS1, which passes through the third light emitting part LE3, the second color filter CF2, the third adhesion layer AD3, the second light emitting part LE2, the first adhesion layer AD1, and the first color filter CF1, and extends to the first transparent electrode <NUM>. The insulation layer IDL may have a structure, which extends on the third n-type semiconductor layer <NUM> and surrounds the outer sidewall of the first via structure VS1. In some exemplary embodiments, the first pad PD1 and the first via structure VS1 may be integrated with each other.

The second pad PD2 disposed on the insulation layer IDL may be electrically coupled with the second transparent electrode <NUM> through a second via structure VS2, which passes through the third light emitting part LE3, the second color filter CF2, the third adhesion layer AD3, the second n-type semiconductor layer <NUM>, the second active layer <NUM>, and the second p-type semiconductor layer <NUM> and extends to the second transparent electrode <NUM>. The insulation layer IDL may have a structure, which extends on the third n-type semiconductor layer <NUM> and surrounds the outer sidewall of the second via structure VS2. In some exemplary embodiments, the second pad PD2 and the second via structure VS2 may be integrated with each other.

The third pad PD3 disposed on the insulation layer IDL may be electrically coupled with the third transparent electrode <NUM> through a third via structure VS3, which passes through the third n-type semiconductor layer <NUM>, the third active layer <NUM>, and the third p-type semiconductor layer <NUM>, and extends to the third transparent electrode <NUM>. In some exemplary embodiments, the third pad PD3 and the third via structure VS3 may be integrated with each other.

Referring to <FIG>, the substrate <NUM> may be selectively removed. The light emitting device removed with the substrate <NUM> may be additionally provided with a support substrate SUB on the third light emitting part LE3. The support substrate SUB may suppress a phenomenon, in which the light emitting device removed with the substrate <NUM> is bended (or bows). The support substrate SUB may include Si.

In this case, the light emitting device may further include a seventh via structure VS7 electrically coupled with the first via structure VS1, a sixth via structure VS6 electrically coupled with the second via structure VS2, a fifth via structure VS5 electrically coupled with the third via structure VS3, and a fourth via structure VS4 electrically coupled with the common pad CPD.

<FIG> is a top view of a light emitting device according to another exemplary embodiment according to the invention, and <FIG> is a cross-sectional view taken along line A-A' of <FIG>.

Referring to <FIG> and <FIG>, a light emitting device may include a first light emitting part LE1, a first color filter CF1, a first adhesion layer AD1, a second adhesion layer AD2, a second light emitting part LE2, a third adhesion layer AD3, a second color filter CF2, and a third light emitting part LE3.

In the first light emitting part LE1, a first n-type semiconductor layer <NUM>, a first active layer <NUM>, a first p-type semiconductor layer <NUM>, and a first transparent electrode <NUM> may be sequentially stacked. In the second light emitting part LE2, a second transparent electrode <NUM>, a second p-type semiconductor layer <NUM>, a second active layer <NUM>, and a second n-type semiconductor layer <NUM> may be sequentially stacked. In the third light emitting part LE3, a third transparent electrode <NUM>, a third p-type semiconductor layer <NUM>, a third active layer <NUM>, and a third n-type semiconductor layer <NUM> may be sequentially stacked.

The light emitting device may include the first color filter CF1, the first adhesion layer AD1, and the second adhesion layer AD2, which are disposed between the first light emitting part LE1 and the second light emitting part LE2, and may include the second color filter CF2 and the third adhesion layer AD3, which are disposed between the second light emitting part LE2 and the third light emitting part LE3. The light emitting device may further include a common pad CPD, which is electrically coupled with the first n-type semiconductor layer <NUM>, the second n-type semiconductor layer <NUM>, and the third n-type semiconductor layer <NUM>, a first pad PD1 electrically coupled with the first p-type semiconductor layer <NUM>, a second pad PD2 electrically coupled with the second p-type semiconductor layer <NUM>, and a third pad PD3 electrically coupled with the third p-type semiconductor layer <NUM>.

According to the illustrated exemplary embodiment, each of the second light emitting part LE2 and the third light emitting part LE3 may have a mesa structure.

The light emitting device may have a substantially quadrangular structure when viewed from the top, and respective corners may be referred to as a first corner CN1, a second corner CN2, a third corner CN3, and a fourth corner CN4. The second light emitting part LE2 may have a mesa structure by removing a portion thereof disposed in the second corner CN2 and the third corner CN3, and the third light emitting part LE3 may have a mesa structure by removing a portion thereof disposed in the second corner CN2, the third corner CN3, and the fourth corner CN4.

In particular, the second light emitting part LE2 may have a structure, in which the second n-type semiconductor layer <NUM>, the second active layer <NUM>, the second n-type semiconductor layer <NUM>, and the second transparent electrode <NUM> disposed at the second corner CN2 are etched, and the second p-type semiconductor layer <NUM>, the second active layer <NUM>, and the second n-type semiconductor layer <NUM> disposed at the third corner CN3 are etched. At the second corner CN2, as the second adhesion layer AD2, the first color filter CF1, and the first adhesion layer AD1 disposed at the second corner CN2 are etched, the first transparent electrode <NUM> of the first light emitting part LE1 may be exposed. At the third corner CN3, the second transparent electrode <NUM> of the second light emitting part LE2 may be exposed.

The third light emitting part LE3 may have a structure, in which the third n-type semiconductor layer <NUM>, the third active layer <NUM>, the third p-type semiconductor layer <NUM>, and the third transparent electrode <NUM> disposed at the second corner CN2 and the third corner CN3 are etched, and the third n-type semiconductor layer <NUM>, the third active layer <NUM>, and the third p-type semiconductor layer <NUM> disposed at the fourth corner CN4 are etched. At the second corner CN2, as the third n-type semiconductor layer <NUM>, the third active layer <NUM>, the third p-type semiconductor layer <NUM>, the third transparent electrode <NUM>, the second color filter CF2, the third adhesion layer AD3, the second n-type semiconductor layer <NUM>, the second active layer <NUM>, the second p-type semiconductor layer <NUM>, the second transparent electrode <NUM>, the second adhesion layer AD2, the first adhesion layer AD1, and the first color filter CF1 disposed at the second corner CN2 are etched, the first transparent electrode <NUM> of the first light emitting part LE1 may be exposed. At the third corner CN3, as the third n-type semiconductor layer <NUM>, the third active layer <NUM>, the third p-type semiconductor layer <NUM>, the third transparent electrode <NUM>, the second color filter CF2, the third adhesion layer AD3, the second n-type semiconductor layer <NUM>, the second active layer <NUM>, and the second p-type semiconductor layer <NUM> disposed at the third corner CN3 are etched, the second transparent electrode <NUM> of the second light emitting part LE2 may be exposed. At the fourth corner CN4, as the third n-type semiconductor layer <NUM>, the third active layer <NUM>, and the third p-type semiconductor layer <NUM> are etched, the third transparent electrode <NUM> of the third light emitting part LE3 may be exposed.

The light emitting device may further include, in the second light emitting part LE2 and the third light emitting part LE3 having the mesa structures, a passivation layer PAL that fills the etched portions from forming the mesa structures. A first via structure VS1, a second via structure VS2, and a third via structure VS3 may be electrically coupled with the first transparent electrode <NUM>, the second transparent electrode <NUM> and the third transparent electrode <NUM>, respectively, through the passivation layer PAL.

In the illustrated exemplary embodiment, since the first light emitting part LE1, the second light emitting part LE2, the third light emitting part LE3, the first adhesion layer AD1, the second adhesion layer AD2, the third adhesion layer AD3, the first color filter CF1, the second color filter CF2, the common pad CPD, the first pad PD1, the second pad PD2, the third pad PD3, the first via structure VS1, the second via structure VS2, and the third via structure VS3 are substantially the same as those described above with reference to <FIG>, repeated descriptions thereof will be omitted to avoid redundancy.

<FIG> is a cross-sectional of a light emitting device according to still another exemplary embodiment according to the invention.

Referring to <FIG>, a light emitting device may include a first light emitting part LE1, a second light emitting part LE2, and a third light emitting part LE3, which are stacked on a substrate <NUM>.

The first light emitting part LE1 may include a first n-type semiconductor layer <NUM>, a first active layer <NUM>, a first p-type semiconductor layer <NUM>, and a first transparent electrode <NUM>, which are sequentially stacked, the second light emitting part LE2 may include a second n-type semiconductor layer <NUM>, a second active layer <NUM>, a second p-type semiconductor layer <NUM>, and a second transparent electrode <NUM>, which are sequentially stacked, and the third light emitting part LE3 may include a third n-type semiconductor layer <NUM>, a third active layer <NUM>, a third p-type semiconductor layer <NUM>, and a third transparent electrode <NUM>, which are sequentially stacked.

The light emitting device may further include a common pad CPD, which is electrically coupled with the first n-type semiconductor layer <NUM>, the second n-type semiconductor layer <NUM>, and the third n-type semiconductor layer <NUM>, a first pad PD1 electrically coupled with the first p-type semiconductor layer <NUM>, a second pad PD2 electrically coupled with the second p-type semiconductor layer <NUM>, and a third pad PD3 electrically coupled with the third p-type semiconductor layer <NUM>.

The light emitting device may further include a first contact structure CT1 which extends through a portion of first light emitting part LE1, a second contact structure CT2 which extends through a portion of the second light emitting part LE2, and a third contact structure CT3 which extends through a portion of the third light emitting part LE3. One surface of the first contact structure CT1 may be brought into electrical contact with the first n-type semiconductor layer <NUM>. The second n-type semiconductor layer <NUM> may be disposed between the other surface of the first contact structure CT1 facing away from the one surface and the second contact structure CT2, and be brought into electrical contact with the first contact structure CT1 and the second contact structure CT2. The third n-type semiconductor layer <NUM> may be disposed between the second contact structure CT2 and the third contact structure CT3, and be brought into electrical contact with the second contact structure CT2 and the third contact structure CT3.

In the first contact structure CT1, the second contact structure CT2, and the third contact structure CT3, ohmic layers <NUM>, <NUM> and <NUM>, first conductive layers <NUM>, <NUM> and <NUM>, barrier layers <NUM>, <NUM> and <NUM>, second conductive layers <NUM>, <NUM>, and <NUM>, and bonding layers <NUM>, <NUM>, and <NUM> may be sequentially stacked. Each of the first contact structure CT1, the second contact structure CT2, and the third contact structure CT3 may have a width that gradually decreases in a downward direction.

The light emitting device may further include a first color filter CF1, which surrounds the outer sidewall of the first contact structure CT1 and extends onto the first transparent electrode <NUM>, and a first adhesion layer AD1, which surrounds the outer sidewall of the first color filter CF1, extends onto the first transparent electrode <NUM>, and bonds the first light emitting part LE1 and the second light emitting part LE2 to each other.

The light emitting device may further include a second color filter CF2, which surrounds the outer sidewall of the second contact structure CT2 and extends onto the second transparent electrode <NUM>, and a second adhesion layer AD2, which surrounds the outer sidewall of the second color filter CF2, extends onto the second transparent electrode <NUM>, and bonds the second light emitting part LE2 and the third light emitting part LE3 to each other.

The light emitting device may further include an insulation layer IDL, which surrounds the outer sidewall of the third contact structure CT3 and extends onto the third transparent electrode <NUM>. The insulation layer IDL may include a silicon oxide or a silicon nitride, for example.

In the illustrated exemplary embodiment, since the first light emitting part LE1, the second light emitting part LE2, the third light emitting part LE3, the first adhesion layer AD1, the second adhesion layer AD2, a third adhesion layer AD3, the first color filter CF1, the second color filter CF2, the insulation layer IDL, the common pad CPD, the first pad PD1, the second pad PD2, the third pad PD3, the first via structure VS1, and the second via structure VS2 are substantially the same as those described above with reference to <FIG>, <FIG> and <FIG>, repeated descriptions thereof will be omitted herein.

<FIG> is a cross-sectional view of a light emitting device according to yet still another exemplary embodiment according to the invention.

The first light emitting part LE1 may include a first transparent electrode <NUM>, a first p-type semiconductor layer <NUM>, a first active layer <NUM>, and a first n-type semiconductor layer <NUM>, which are sequentially stacked, the second light emitting part LE2 may include a second transparent electrode <NUM>, a second p-type semiconductor layer <NUM>, a second active layer <NUM>, and a second n-type semiconductor layer <NUM>, which are sequentially stacked, and the third light emitting part LE3 may include a third transparent electrode <NUM>, a third p-type semiconductor layer <NUM>, a third active layer <NUM>, and a third n-type semiconductor layer <NUM>, which are sequentially stacked.

The light emitting device may further include a common pad CPD, which is electrically coupled with the first n-type semiconductor layer <NUM>, the second n-type semiconductor layer <NUM>, and the third n-type semiconductor layer <NUM>, a first pad PD1 electrically coupled with the first p-type semiconductor layer <NUM>, a second pad PD2 electrically coupled with the second p-type semiconductor layer <NUM>, and a third pad PD3 w electrically coupled with the third p-type semiconductor layer <NUM>.

The light emitting device may further include a second contact structure CT2, which extends through a portion of the second light emitting part LE2, and a third contact structure CT3, which extends through a portion of the third light emitting part LE3. One surface of the second contact structure CT2 may be brought into electrical contact with the first n-type semiconductor layer <NUM>, and the other surface of the second contact structure CT2 facing away from the one surface may be brought into electrical contact with the second n-type semiconductor layer <NUM>. One surface of the third contact structure CT3 may be brought into electrical contact with the second n-type semiconductor layer <NUM>, and the other surface of the third contact structure CT3 facing away from the one surface may be brought into electrical contact with the third n-type semiconductor layer <NUM>. The second n-type semiconductor layer <NUM> may be disposed between the second contact structure CT2 and the third contact structure CT3.

In a first contact structure CT1, the second contact structure CT2, and the third contact structure CT3, bonding layers, second conductive layers, barrier layers, first conductive layers, and ohmic layers may be sequentially stacked. Each of the first contact structure CT1, the second contact structure CT2, and the third contact structure CT3 may have a width that gradually increases in a downward direction.

The light emitting device may further include a first color filter CF1, which surrounds the outer sidewall of the second contact structure CT2 and extends onto the second transparent electrode <NUM>, and a first adhesion layer AD <NUM>, which surrounds the outer sidewall of the first color filter CF1, extends onto the first color filter CF1, and bonds the first light emitting part LE1 and the second light emitting part LE2 to each other.

The light emitting device may further include a second color filter CF2, which surrounds the outer sidewall of the third contact structure CT3 and extends onto the third transparent electrode <NUM>, and a second adhesion layer AD2, which surrounds the outer sidewall of the second color filter CF2, extends onto the second color filter CF2, and bonds the second light emitting part LE2 and the third light emitting part LE3 to each other.

In the illustrated exemplary embodiment, since the first light emitting part LE1, the second light emitting part LE2, the third light emitting part LE3, the first adhesion layer AD1, the second adhesion layer AD2, the third adhesion layer AD3, the first color filter CF1, the second color filter CF2, the insulation layer IDL, the common pad CPD, the first pad PD1, the second pad PD2, the third pad PD3, the first via structure VS1, the second via structure VS2, and the third via structure VS3 are substantially the same as those described above with reference to <FIG>, <FIG> and <FIG>, repeated descriptions thereof will be omitted.

Hereafter, a method for manufacturing the light emitting device described above with reference to <FIG> and <FIG> will be described in more detail.

<FIG> are cross-sectional views illustrating a method for manufacturing a light emitting device according to an exemplary embodiment.

Referring to <FIG>, a first n-type semiconductor layer <NUM>, a first active layer <NUM>, a first p-type semiconductor layer <NUM>, and a first transparent electrode <NUM> may be formed on a first substrate <NUM>, to form a first light emitting part LE1.

The first n-type semiconductor layer <NUM>, the first active layer <NUM>, and the first p-type semiconductor layer <NUM> may be sequentially grown on the substrate <NUM> through a process, such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). Then, the first transparent electrode <NUM> may be formed on the first p-type semiconductor layer <NUM> by using a chemical vapor deposition (CVD) process, or a physical vapor deposition (PVD) process.

Referring to <FIG>, by etching the first light emitting part LE1 to expose the first n-type semiconductor layer <NUM>, a first contact hole H1 passing through the first transparent electrode <NUM>, the first p-type semiconductor layer <NUM>, and the first active layer <NUM> may be formed.

For example, the first light emitting part LE1 may have a substantially quadrangular structure when viewed from the top, and the first hole H1 may be disposed at a first corner CN1. The first hole H1 may have a width that gradually decreases in a downward direction. As such, the first active layer <NUM> may have a width less than the first p-type semiconductor layer <NUM>, and the first p-type semiconductor layer <NUM> may have a width less than the first transparent electrode <NUM>.

Referring to <FIG>, a first color filter CF1 may be continuously formed along the surface of the first light emitting part LE1 so as not to fill the first hole H1. The first color filter CF1 may include a DBR having a structure, in which TiO<NUM> and SiO<NUM> are alternately stacked.

Referring to <FIG>, a first adhesion layer AD1 may be formed on the first light emitting part LE1 formed with the first color filter CF1, so as to fill (or bury) the first hole H1. The first adhesion layer AD1 may include SOG.

Referring to <FIG>, by etching the first adhesion layer AD1 and the first color filter CF1 filling the first hole H1, a first contact hole CH1 exposing the first n-type semiconductor layer <NUM> may be formed. For example, the first contact hole CH1 may have a width that gradually decreases in the downward direction.

Referring to <FIG>, a first contact structure CT1, which fills the inside of the first contact hole CH1 may be formed. As the first contact structure CT1, an ohmic layer <NUM>, a first conductive layer <NUM>, a barrier layer <NUM>, a second conductive layer <NUM>, and a bonding layer <NUM> may be sequentially stacked. The ohmic layer <NUM> may include Cr, the first conductive layer <NUM> may include Al, the barrier layer <NUM> may include Ti and Ni, which are stacked a plurality of times, the second conductive layer <NUM> may include Au, and the bonding layer <NUM> may include In or Sn.

Referring to <FIG>, a second light emitting part LE2 including a second n-type semiconductor layer <NUM>, a second active layer <NUM>, a second p-type semiconductor layer <NUM>, and a second transparent electrode <NUM> may be formed on a second substrate <NUM>. Then, a second hole H2, which exposes the second n-type semiconductor layer <NUM> may be formed, and a second adhesion layer AD2, which fills the inside of the second hole H2 may be formed.

Referring to <FIG>, after forming the second contact hole CH2 exposing the second n-type semiconductor layer <NUM>, the second adhesion layer AD2 filling the second hole H2 may be etched to form a second contact structure CT2 to fill the second contact hole CH2. As the second contact structure CT2, an ohmic layer <NUM>, a first conductive layer <NUM>, a barrier layer <NUM>, a second conductive layer <NUM>, and a bonding layer <NUM> may be sequentially stacked.

Referring to <FIG>, the second light emitting part LE2 may be turned over and be bonded to the first light emitting part LE1, such that the bonding layer <NUM> of the second contact structure CT2 is boned with the bonding layer <NUM> of the first contact structure CT1.

Then, the second substrate <NUM> may be removed by a laser lift-off process, or the like.

Referring to <FIG>, a third light emitting part LE3 including a third n-type semiconductor layer <NUM>, a third active layer <NUM>, a third p-type semiconductor layer <NUM> and a third transparent electrode <NUM> may be formed on a third substrate <NUM>. Then, a third hole H3, which exposes the third n-type semiconductor layer <NUM> may be formed, and a third adhesion layer AD3, which fills the inside of the third hole H3 may be formed.

After forming a third contact hole CH3 exposing the third n-type semiconductor layer <NUM>, the third adhesion layer AD3 filling the third hole H3 may be etched. Then, a second color filter CF2 may be continuously formed along the surface of the third light emitting part LE3 so as not to fill the third contact hole CH3, and a third contact structure CT3 filling the third contact hole CH3 may be formed on the second color filter CF2. The second color filter CF2 may include a DBR having a structure, in which TiO<NUM> and SiO<NUM> are alternately stacked. The second color filter CF2 may be different from the first color filter CF1 in terms of the composition ratio and alternate stacking order and number of TiO<NUM> and SiO<NUM>. As the third contact structure CT3, an ohmic layer <NUM>, a first conductive layer <NUM>, a barrier layer <NUM>, a second conductive layer <NUM>, and a bonding layer <NUM> may be sequentially stacked.

Referring to <FIG>, the third light emitting part LE3 may be turned over and be bonded to the second light emitting part LE2, such that the bonding layer <NUM> of the third contact structure CT3 faces the second n-type semiconductor layer <NUM>. As such, the second light emitting part LE2 bonded with the first light emitting part LE1 may be bonded with the third light emitting part LE3.

Then, the third substrate <NUM> may be removed by a laser lift-off process, or the like.

Referring to <FIG>, a first via hole VIA1 exposing the first transparent electrode <NUM>, a second via hole VIA2 exposing the second transparent electrode <NUM>, and a third via hole VIA3 exposing the third transparent electrode <NUM> may be formed.

The first via hole VIA1 may pass through the third light emitting part LE3, the second color filter CF2, the third adhesion layer AD3, the second light emitting part LE2, the second adhesion layer AD2, the first adhesion layer AD1, and the first color filter CF1, and may expose the first transparent electrode <NUM>.

The second via hole VIA2 may pass through the third light emitting part LE3, the second color filter CF2, the third adhesion layer AD3, the second n-type semiconductor layer <NUM>, the second active layer <NUM>, and the second p-type semiconductor layer <NUM>, and may expose the second transparent electrode <NUM>.

The third via hole VIA3 may pass through the third n-type semiconductor layer <NUM>, the third active layer <NUM> and the third p-type semiconductor layer <NUM>, and may expose the third transparent electrode <NUM>.

According to an exemplary embodiment, each of the first light emitting part LE1, the second light emitting part LE2, and the third light emitting part LE3 may have a substantially quadrangular structure when viewed from the top. The second light emitting part LE2 may be turned over and be disposed on the first light emitting part LE1, and the third light emitting part LE3 may be turned over and be disposed on the second light emitting part LE2.

The first via hole VIA1 may be disposed at a second corner CN2, the second via hole VIA2 may be disposed at a third corner CN3, and the third via hole VIA3 may be disposed at a fourth corner CN4.

Referring to <FIG>, an insulation layer IDL may be formed continuously along the surfaces of the third light emitting part LE3, the second color filter CF2, the third adhesion layer AD3, the second light emitting part LE2, the second adhesion layer AD2, the first color filter CF1, and the first adhesion layer AD1, so as not to fill the first via hole VIA1, the second via hole VIA2, and the third via hole VIA3. The insulation layer IDL may include a silicon oxide or a silicon nitride, for example.

Then, the insulation layer IDL may be etched, such that the first transparent electrode <NUM> may be exposed on the bottom of the first via hole VIA1, the second transparent electrode <NUM> may be exposed on the bottom of the second via hole VIA2, the third transparent electrode <NUM> may be exposed on the bottom of the third via hole VIA3, and a portion of the third n-type semiconductor layer <NUM> may be exposed.

Referring back to <FIG>, a first via structure VS1 filling the first via hole VIA1 and electrically contacting the first transparent electrode <NUM>, a second via structure VS2 filling the second via hole VIA2 and electrically contacting the second transparent electrode <NUM>, and a third via structure VS3 filling the third via hole VIA3 and electrically contacting the third transparent electrode <NUM> may be respectively formed.

The, a first pad PD1 electrically coupled to the first via structure VS1, a second pad PD2 electrically coupled to the second via structure VS2, a third pad PD3 electrically coupled to the third via structure VS3, and a common pad CPD electrically coupled with the third n-type semiconductor layer <NUM> may be additionally formed.

In some exemplary embodiments, the first pad PD1, the second pad PD2, and the third pad PD3 may be integrated with the first via structure VS1, the second via structure VS2 and the third via structure VS3, respectively.

Claim 1:
A light emitting device comprising:
a first light emitting part (LE1) including a first n-type semiconductor layer (<NUM>), a first active layer (<NUM>), and a first p-type semiconductor layer (<NUM>);
a second light emitting part (LE2) disposed on a first surface of the first light emitting part (LE1), and including a second n-type semiconductor layer (<NUM>), a second active layer (<NUM>), and a second p-type semiconductor layer (<NUM>), the second n-type semiconductor layer (<NUM>) having a first surface and a second surface opposing the first surface;
a third light emitting part (LE3) disposed on a first surface of the second light emitting part (LE2), and including a third n-type semiconductor layer (<NUM>), a third active layer (<NUM>), and a third p-type semiconductor layer (<NUM>);
a first color filter (CF1), a first adhesion layer (AD1, AD2) and a second adhesion layer (AD2) being disposed between the first light emitting part (LE1) and the second light emitting part (LE2), and a second color filter (CF1) and a third adhesion layer (AD2, AD3) being disposed between the second light emitting part (LE2) and the third light emitting part (LE3);
a first contact structure (CT1, CT2) electrically contacting the first surface of the second n-type semiconductor layer (<NUM>); and
a second contact structure (CT2, CT3) electrically contacting the second surface of the second n-type semiconductor layer (<NUM>),
wherein one of
i) the first contact structure (CT1) extends into the first light emitting part (LE1) to electrically contact the first n-type semiconductor layer (<NUM>); and
the second contact structure (CT2) extends into the second light emitting part (LE2) to electrically contact the third n-type semiconductor layer (<NUM>); or
ii) the first contact structure (CT2) extends into the second light emitting part (LE2); and
the second contact structure (CT3) extends into the third light emitting part (LE3) and is electrically coupled with the third n-type semiconductor layer (<NUM>).