KR102249624B1 - Light emitting structure and Light emitting device having the same - Google Patents

Abstract

The light emitting structure according to the embodiment includes a first conductive type semiconductor layer having a columnar shape; An active layer disposed to surround the first conductivity type semiconductor layer; And a second conductivity type semiconductor layer disposed to surround the active layer. It characterized in that it comprises a.
Compared to the stacked nano-rod structure, the light emitting structure of the embodiment has the advantage that the surface area of the active layer in contact with the semiconductor layer is dramatically increased, so that the luminous efficiency can be greatly improved, and the area in which light can resonate is also increased.

Description

Light emitting structure and light emitting device including the same {Light emitting structure and Light emitting device having the same}

The embodiment relates to a light emitting structure, a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system.

Light Emitting Device is a pn junction diode that converts electrical energy into light energy. It can be created as a compound semiconductor such as Group III and Group V on the periodic table. Various colors can be realized by controlling the composition ratio of the compound semiconductor. It is possible.

When the forward voltage is applied, the electrons in the n-layer and the holes in the p-layer are combined to emit energy equivalent to the band gap energy of the conduction band and the balance band. , This energy is mainly emitted in the form of heat or light, and when it is radiated in the form of light, it becomes a light-emitting device.

For example, nitride semiconductors are attracting great interest in the development of optical devices and high-power electronic devices due to their high thermal stability and wide bandgap energy. In particular, a blue light emitting device, a green light emitting device, and an ultraviolet (UV) light emitting device using a nitride semiconductor have been commercialized and widely used.

As the demand for high-efficiency LEDs has recently increased, improvement in light intensity has become an issue.

In particular, in the case of a light-emitting structure that directly emits light, measures have been proposed to improve the luminous intensity through various structural changes by breaking away from the simple stacked epitaxial structure.

At this time, in the direction of improvement of the light emitting structure, the crystal quality of the semiconductor layer must be improved, the light emitting region must be expanded, and the generated light must be effectively emitted to the outside of the light emitting structure.

The embodiment is to provide a light emitting structure, a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system capable of improving luminous intensity.

The light emitting structure according to the embodiment includes a first conductive type semiconductor layer having a columnar shape; An active layer disposed to surround the first conductivity type semiconductor layer; And a second conductivity type semiconductor layer disposed to surround the active layer. It characterized in that it comprises a.

In addition, the light emitting device according to the embodiment is a light emitting device including the light emitting structure of the above-described embodiment, comprising: a substrate; A first electrode layer disposed on the substrate; A mask layer disposed on the first electrode layer and having at least one hole in which the light emitting structure is to be disposed; A second electrode layer disposed on the mask layer; A second electrode pad disposed on the second electrode layer; And a first electrode pad disposed on the first electrode layer. It characterized in that it comprises a.

In another aspect, the light emitting device according to the embodiment is a light emitting device including the light emitting structure of the above-described embodiment, comprising: a first electrode layer; A mask layer disposed on an upper surface of the first electrode layer and having at least one hole in which the light emitting structure is to be disposed; A second electrode layer disposed on the mask layer; A second electrode pad disposed on the second electrode layer; And a first electrode pad disposed on a lower surface of the first electrode layer.

According to the embodiment, a light emitting device having an optimal structure capable of increasing luminous intensity, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system can be provided.

Compared to the stacked nano-rod structure, the light-emitting structure of the embodiment has the advantage that the surface area of the active layer in contact with the semiconductor layer is dramatically increased, so that the luminous efficiency can be greatly improved, and the area in which light can resonate is also increased.

In addition, when the light emitting structure is grown on the substrate, the area in contact with the substrate interface is small, so that the probability of occurrence of TDD is reduced, and thus the quality of the active layer is improved.

In addition, in the light emitting structure, when light is emitted from the active layer to the side of the light emitting structure, light extraction efficiency may be improved due to the angled shape on the side of the light emitting structure.

1 is a perspective view of a conventional light emitting structure.
2 is a perspective view of a light emitting structure according to the first embodiment.
3 is a perspective view showing a cross section of a light emitting structure according to the first embodiment.
4 is a perspective view of a light emitting structure according to a second embodiment.
5 is a perspective view of a light emitting device according to the first embodiment.
6 is a perspective view of a light emitting device according to a second embodiment.
7 is a plan view of a mask layer having holes on a substrate.
8 shows a state in which a semiconductor layer is grown in the form of a hexagonal column.
9 shows a state in which a semiconductor layer is grown with 12 prisms.
10 to 11 show a state in which a semiconductor layer is grown on a side surface of a 12-pillar semiconductor layer.
12(a) to (c) show the direction of side growth in the 12-pillar semiconductor layer.
13 to 21 are perspective views illustrating a method of manufacturing a light emitting device according to the first embodiment.

In the description of the embodiment, each layer (film), region, pattern, or structure is "on/over" or "under" of the substrate, each layer (film), region, pad, or patterns. In the case of being described as being formed in, "on/over" and "under" include both "directly" or "indirectly" formed. do. In addition, the criteria for the top/top or bottom of each layer will be described based on the drawings.

(Example)

1 is a perspective view of a conventional light emitting structure.

Referring to FIG. 1, the light emitting structure 10 has a nano rod shape, and a first conductivity type semiconductor layer 1, an active layer 2 on the first conductivity type semiconductor layer 1, and the A second conductivity type semiconductor layer 3 may be included on the active layer 2.

A number of light emitting structures in the form of a nado rod may be disposed on a substrate to be configured in a light emitting device, and such light emitting structures have an advantage of improving light extraction efficiency by increasing an area in which light can be emitted.

In addition, when growing the semiconductor layer in the form of nano-rods, the threading dislocation density (TDD) that occurs between the growth substrate and the semiconductor layer interface may be reduced, thereby suppressing the occurrence of TDD in the active layer (2). Thus, the quality of the light emitting structure can be improved.

However, the RAD light emitting structure of such a stacked structure has a narrow contact area between the active layer 2 and the first conductivity type semiconductor layer 1 and the second conductivity type semiconductor layer 3, and the area in which light can resonate is also narrow. , There is a problem that the luminous efficiency is poor.

Hereinafter, various structures of light emitting structures to overcome these problems will be proposed.

2 is a perspective view of a light emitting structure according to the first embodiment, and FIG. 3 is a perspective view showing a cross section of the light emitting structure according to the first embodiment.

2 and 3, the light emitting structure 100 according to the first embodiment includes a rod-shaped first conductivity type semiconductor layer 110 and a side surface of the first conductivity type semiconductor layer 110. An active layer 120 disposed thereon and a second conductivity type semiconductor layer 130 disposed on a side surface of the active layer 120 may be included.

In more detail, the first conductivity-type semiconductor layer 110 is a semiconductor layer that supplies electric charges (eg, electrons) to the active layer 120 and may have a polygonal or cylindrical pillar shape forming a central axis of the RAD light emitting structure.

For example, as shown in FIG. 2, the first conductivity type semiconductor layer 110 may be implemented in a hexagonal column shape.

In addition, the first conductivity type semiconductor layer 110 may be implemented as a compound semiconductor such as group 3-5, group 2-6, or the like, and may be doped with a first conductivity type dopant. When the first conductivity-type semiconductor layer 110 is an N-type semiconductor layer, the first conductivity-type dopant is an N-type dopant, and may include Si, Ge, Sn, Se, and Te, but is not limited thereto. Specifically, the first conductivity type semiconductor layer 110 may include a semiconductor material having a composition formula of InxAlyGa1-x-yN (0≤x≤1, 0≤y≤1, 0≤x+y≤1). have.

In addition, an active layer 120 may be disposed on the outer circumferential surface of the first conductivity type semiconductor layer 110. For example, the active layer 120 may be disposed to surround the outer circumferential surface of the first conductivity type semiconductor layer 110.

That is, the active layer 120 is disposed along the outer circumferential surface of the first conductivity type semiconductor layer 110, and when only the active layer 120 is viewed, a hexagonal column having a hole in which the first conductor semiconductor layer will be placed on a central axis. It can have a shape.

In the active layer 120, charges (eg, electrons) injected through the first conductivity type semiconductor layer 110 and charges (eg, holes) injected through the second conductivity type semiconductor layer 130 are It is a layer that emits light having energy determined by the energy band inherent to the material of the active layer 120.

In addition, a second conductivity type semiconductor layer 130 may be disposed on the outer circumferential surface of the active layer 120.

The second conductivity-type semiconductor layer 130 is disposed along the outer circumferential surface of the active layer 120, like the active layer 120, so that a first conductivity-type semiconductor on a central axis when the second conductivity-type semiconductor layer 130 is viewed. It may have a hexagonal column shape having a hole in which the layer 110 and the active layer 120 may be disposed.

In the second conductivity type semiconductor layer 130, the semiconductor layer may be formed of a semiconductor compound. It may be implemented with a compound semiconductor such as Group 3-5, Group 2-6, etc., and may be doped with a second conductivity type dopant.

For example, the second conductivity type semiconductor layer 130 may include a semiconductor material having a composition formula of InxAlyGa1-x-yN (0≤x≤1, 0≤y≤1, 0≤x+y≤1). I can. When the second conductivity-type semiconductor layer 130 is a p-type semiconductor layer, the second conductivity-type dopant is a p-type dopant and may include Mg, Zn, Ca, Sr, Ba, or the like.

In the light emitting structure 100 of the first embodiment described above, compared to the stacked nano-Rad light emitting structure 10, the surface area of the active layer 120 in contact with the semiconductor layer increases dramatically, so that the luminous efficiency can be greatly improved, and light can resonate. There is also an advantage of increasing the area that can be used.

In addition, when the light emitting structure is grown on the substrate, the area in contact with the substrate interface is small, so that the probability of occurrence of TDD is reduced, and thus there is an advantageous effect in improving the quality of the active layer 120.

In addition, when light is emitted from the active layer 120 to the side of the light-emitting structure, the light-emitting structure may improve light extraction efficiency due to an angled shape on the side of the light-emitting structure.

4 is a perspective view of a light emitting structure according to a second embodiment.

The light-emitting structure 101 according to the second embodiment has a shape different from that of the light-emitting structure 100 of the first embodiment, and hereinafter, a description overlapping with the first embodiment will be omitted.

Referring to FIG. 4, the light emitting structure 101 according to the second embodiment includes a first conductivity type semiconductor layer 111 disposed on a central axis of a dodecagonal pillar, and a side view of the first conductivity type semiconductor layer 111. It may include an active layer 121 disposed on and a second conductivity type semiconductor layer 131 disposed on a side surface of the active layer 121.

In more detail, the first conductivity-type semiconductor layer 111 is a semiconductor layer that supplies electrons (or holes) to the active layer 121 and may have a dodecagonal column shape.

Accordingly, the active layer 121 disposed on the outer circumferential surface of the first conductivity type semiconductor layer 111 may also be implemented in the form of a dodecagonal column having a hole in which the first conductivity type semiconductor layer 111 is disposed.

Similarly, the second conductivity-type semiconductor layer 131 disposed on the outer circumferential surface of the active layer 121 is also a dodecagonal column having a hump on a central axis in which the first conductivity-type semiconductor layer 111 and the active layer 121 are disposed. It can be implemented in a form.

In the light emitting structure 101 of the second embodiment, compared to the light emitting structure 100 of the first embodiment, the surface area of the active layer 121 is increased and the area in which light can be resonated is also increased, so that luminous efficiency can be improved. In addition, since the light emitting structure 101 of the second embodiment has a plurality of side angles compared to the light emitting structure 100 of the first embodiment, the light extraction efficiency can be further improved.

That is, when the light emitting structure of the embodiment is an n-shaped pillar, the luminous efficiency may be improved as the number of n increases, and the ideal shape of the light emitting structure may be a cylindrical pillar in terms of luminous efficiency.

5 is a perspective view of a light emitting device according to the first embodiment.

5, the light emitting device 200 according to the first embodiment includes a substrate 210, a first electrode layer 220 on the substrate 210, and an insulating layer 230 on the first electrode layer 220. , A second electrode layer 240 on the insulating layer 230, at least one light emitting structure 100 disposed on the first electrode layer 220, and a second electrode pad on the second electrode layer 240 ( 260), a first electrode pad 250 may be included on the first electrode layer 220.

In more detail, the substrate 210 may be, for example, a light-transmitting, conductive or insulating substrate. For example, the substrate 210 may use at least one of sapphire (Al2O3), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga203. A plurality of protrusions may be formed on the upper surface of the substrate 210, and the plurality of protrusions may be formed through etching of the substrate 210 or may be formed in a light extraction structure such as a separate roughness. The protrusion may have a stripe shape, a hemispherical shape, or a dome shape.

A buffer layer (not shown) may be disposed on the substrate 210. The buffer layer may be formed of at least one layer using a compound semiconductor of a group II to VI element. The buffer layer includes a semiconductor layer using a compound semiconductor of a group III-V element, for example, a composition formula of InxAlyGa1-x-yN (0≤x≤1, 0≤y≤1, 0≤x+y≤1) As a semiconductor having a, it includes at least one of compound semiconductors such as GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP, and GaP. The buffer layer may be formed in a super lattice structure by alternately disposing different semiconductor layers. The buffer layer may be formed to mitigate a difference in lattice constant between the substrate 210 and the nitride-based semiconductor layer, and may be defined as a defect control layer. The buffer layer may have a value between the lattice constant between the substrate 210 and the nitride-based semiconductor layer. Such a buffer layer may not be formed.

In addition, a first electrode layer 220 may be disposed on the buffer layer.

The first electrode layer 220 may serve as a growth layer so that the first conductivity type semiconductor layer 110 of the light emitting structure 100 can grow. In addition, the first electrode layer 220 may inject electric charges into the first conductivity type semiconductor layer 110 of the plurality of light emitting structures 100 disposed on the first electrode layer 220.

That is, the first electrode layer 220 may electrically connect the first electrode pad 250 and the first conductivity type semiconductor layer 110.

The first electrode layer 220 may have the same composition as the first conductivity type semiconductor layer 110. For example, the first electrode layer 220 may be implemented with a compound semiconductor such as Group 3-5 and Group 2-6, and may be doped with a first conductivity type dopant. When the first electrode layer 220 is an N-type semiconductor layer, the first conductive type dopant is an N-type dopant, and may include Si, Ge, Sn, Se, and Te, but is not limited thereto. In addition, the first electrode layer 220 may include a semiconductor material having a composition formula of InxAlyGa1-x-yN (0≦x≦1, 0≦y≦1, 0≦x+y≦1).

An insulating layer 230 may be disposed on the first electrode layer 220.

The insulating layer 230 may have at least one hole exposing the first electrode layer 220 so that the first conductivity type semiconductor layer 110 of the light emitting structure 100 can grow.

For example, in order to grow the first conductive semiconductor layer 110 into a hexagonal column, at least one hexagonal hole may be patterned in the insulating layer 230.

The insulating layer 230 may be formed of a photoresist material. For example, the insulating layer 230 may include SiO ₂ or SiN, but is not limited thereto.

The insulating layer 230 may be removed after the light emitting structure 100 is grown on the first electrode layer 220, but the first electrode layer 220 and the second conductive semiconductor layer 130 are electrically It may not be removed to serve as insulation to prevent it from being connected to.

At least one light emitting structure 100 is disposed on the hole in the insulating layer 230.

In this case, the first conductivity type semiconductor layer 110 of the light emitting structure 100 may be disposed on the first electrode layer 220 exposed through the hole, and the second conductivity type semiconductor layer 130 It may be disposed on the insulating layer 230 around the hole. Accordingly, the first electrode pad 250 disposed on the first electrode layer 220 may supply electrons only to the first conductivity type semiconductor layer 110 through the first electrode layer 220.

The light emitting structures 100 and 101 of the above-described embodiments may be applied.

The light emitting structure 100 may be arranged in various patterns according to a hole pattern in the insulating layer 230. For example, the light emitting structures 100 may be arranged at equal intervals and arranged in a plurality of rows and columns.

In addition, a second electrode layer 240 is disposed on the insulating layer 230 so that the second electrode layer 240 may contact a side surface of the second conductivity type semiconductor layer 130.

A second electrode pad 260 is disposed on the second electrode layer 240 to electrically connect the second electrode pad 260 and the second conductivity type semiconductor layer 130.

The second electrode layer 240 may be disposed to cover the upper surface of the insulating layer 230, or may be disposed in a pattern for connecting the second conductive type semiconductor layers 130 of the plurality of light emitting structures 100. .

For example, the second electrode layer 240 may be disposed in a bridge pattern connecting a plurality of second conductivity type semiconductor layers 130 arranged in a matrix on the insulating layer 230.

The second electrode layer 240 may include a light-transmitting ohmic layer, and may be formed by stacking a single metal, a metal alloy, or a metal oxide in multiple layers so that carrier injection can be efficiently performed.

The second electrode layer 240 includes indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), and indium gallium (IGTO). tin oxide), AZO(aluminum zinc oxide), ATO(antimony tin oxide), GZO(gallium zinc oxide), IZON(IZO Nitride), AGZO(Al-Ga ZnO), IGZO(In-Ga ZnO), ZnO, IrOx , RuOx, and NiO may be formed including at least one of, but is not limited to these materials.

In addition, a second electrode pad 260 may be disposed on the second electrode layer 240.

The second electrode pad 260 induces hole injection of the second conductivity type semiconductor layer 130 through the first electrode layer 220, and the first electrode pad 250 includes the first electrode layer 220. ) To induce charge injection into the first conductivity type semiconductor layer 110.

Holes injected by the first conductivity type semiconductor layer 110 and charges injected by the second conductivity type semiconductor layer 130 may be combined in the active layer 120 to emit light.

In this case, the active layer 120 according to the embodiment may have an increased surface area in contact with the semiconductor layer.

In addition, the light-emitting device 200 may increase light extraction efficiency by the light-emitting structure 100 having a plurality of rod patterns.

6 is a perspective view of a light emitting device according to a second embodiment.

The light-emitting device 201 according to the second embodiment has a structure different from that of the light-emitting device 200 of the first embodiment, and hereinafter, a description overlapping with the first embodiment will be omitted.

The light emitting device according to the second embodiment includes a first electrode pad 251, a first electrode layer 221 on the first electrode pad 251, and an insulating layer 231 on the first electrode layer 221. ), at least one light emitting structure 100 disposed on the first electrode layer 221, a second electrode layer 241 disposed on the insulating layer 231, and the second electrode layer 241 A second electrode pad 261 disposed on may be included.

A first electrode layer 221 may be disposed on the second electrode pad 261. In addition, an insulating layer 231 having a hole exposing a part of the first electrode layer 221 may be disposed on the first electrode layer 221. The light emitting structure 100 is disposed in the hole of the insulating layer 231, the second electrode layer 241 is disposed on the insulating layer 231 around the light emitting structure 100, and the second electrode layer 241 A second electrode pad 261 may be disposed on one side of the.

The second electrode pad 261 induces hole injection of the second conductivity type semiconductor layer 130 through the first electrode layer 221, and the first electrode pad 251 includes the first electrode layer 221. ) To induce charge injection into the first conductivity type semiconductor layer 110.

Holes injected by the first conductivity type semiconductor layer 110 and charges injected by the second conductivity type semiconductor layer 130 may be combined in the active layer 120 to emit light.

In this case, the active layer 120 according to the embodiment may have an increased surface area in contact with the semiconductor layer.

In addition, the light-emitting device 201 may increase light extraction efficiency by the light-emitting structure 100 having a plurality of rod patterns.

The first embodiment proposes a horizontal light-emitting device 200 using a rod-shaped light emitting structure 100, and the second embodiment proposes a vertical light-emitting device 201 using a rod-shaped light-emitting structure 100 However, it is natural that the rod-shaped light emitting structure 100 can be used for light emitting devices of various structures such as flip chips.

Meanwhile, the light emitting structure 100 of the above-described embodiment can be formed by vertically growing the first conductivity-type semiconductor layer 110 serving as a central axis and then laterally growing the active layer 120 and the second conductivity-type semiconductor layer 130. have.

Hereinafter, a method of growing the light emitting structure 100 in the form of a rod will be described with reference to FIGS. 7 to 11.

7 is a plan view of an insulating layer 230 having a hole on the substrate 210, FIG. 8 is a state in which a semiconductor layer is grown in a hexagonal column shape, and FIG. 9 is a state in which the semiconductor layer is grown in a dodecagonal column. Show.

Referring to FIG. 7, two sides of the hexagonal holes 231 and 232 of the insulating layer 230 that face each other may be longer than the other side.

When the long side of the hexagonal hole 232 is in the horizontal direction, the first conductivity type semiconductor layer 110 may vertically grow in the shape of a hexagonal column as shown in FIGS. 8A to 8B.

Conversely, when the long side of the hexagonal hole 231 is in the vertical direction, the first conductivity type semiconductor layer 110 may vertically grow in the form of a 12-corner column as shown in FIGS. 9(a) to (b).

In this way, after the first conductivity type semiconductor layer 110 is grown to the central axis of the rod, the active layer 120 may be grown on the outer circumferential surface of the first conductivity type semiconductor layer 110 through side growth.

10 to 11 show a state in which the semiconductor layer is grown on the side of the 12-pillar semiconductor layer, and FIGS. 12(a) to (c) show the direction in which the 12-pillar semiconductor layer is laterally grown.

From the side of the first conductivity type semiconductor layer 110 in the [1-100] direction, planes {1-101} and {1-102} appear (FIG. 11(a)), and the first conductivity type semiconductor layer 110 ) In the [11-20] direction, {11-22} appears. (Fig. 11(b))

In other words, the number of N on the {1-101} and {11-22} sides is different. In the case of {1-101}, the N rich side is exposed, but if the number of N is 1, the {11-22} side is also N The rich side is exposed. However, since the number of N is two, it is more stable than the {1-101} plane.

Therefore, in the case of the {1-101} plane, the {1-102} plane is formed as it grows by bonding with the gallium atom, whereas the {11-22} plane does not change the angle because the stable plane state is maintained.

Through this principle, the active layer 120 can be grown on the side of the first conductivity-type semiconductor layer 110, and in this case, by applying the horizontal growth process conditions to promote side growth, the active layer 120 can be smoothly formed. I can.

Hereinafter, a method of manufacturing the light emitting device of the first embodiment will be described in more detail with reference to FIGS. 13 to 21.

13 to 21 are perspective views illustrating a method of manufacturing a light emitting device according to the first embodiment.

A substrate 210 is prepared as shown in FIG. 13. The substrate 210 may be formed of a material having excellent thermal conductivity, and may be a conductive substrate or an insulating substrate. For example, the substrate 210 may use at least one of sapphire (Al2O3), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga203. A Patterned Sapphire Substrate (PSS) P may be formed on the substrate 210, but the embodiment is not limited thereto.

Further, the substrate 210 may be wet cleaned to remove impurities from the surface, and then, the first electrode layer 220 may be grown on the substrate 210.

Before the first electrode layer 220 is grown, a buffer layer or an undoped semiconductor layer may be grown in order to alleviate lattice mismatch between the substrate 210 and the first electrode layer 220, but this is not limited thereto.

The first electrode layer 220 may be implemented as a compound semiconductor such as group 3-5, group 2-6, or the like, and may be doped with a first conductivity type dopant. When the first electrode layer 220 is an N-type semiconductor layer, the first conductive type dopant is an N-type dopant, and may include Si, Ge, Sn, Se, and Te, but is not limited thereto. In addition, the first electrode layer 220 may include a semiconductor material having a composition formula of InxAlyGa1-x-yN (0≦x≦1, 0≦y≦1, 0≦x+y≦1).

The first electrode layer 220 may form an n-type GaN layer using a method such as chemical vapor deposition (CVD), molecular beam epitaxy (MBE), sputtering, or hydroxide vapor phase epitaxy (HVPE). In addition, the first electrode layer 220 contains a silane gas (SiH4) containing n-type impurities such as trimethyl gallium gas (TMGa), ammonia gas (NH3), nitrogen gas (N2), and silicon (Si) in the chamber. It can be formed by injection.

Next, referring to FIG. 14, an insulating layer 230 may be formed on the first electrode layer 220.

The insulating layer 230 may be formed of SiN or SiO ₂ , but is not limited thereto.

A plurality of holes 232 for growing the rod-shaped light emitting structure 100 may be patterned in the insulating layer 230 through photolithography or the like.

As described in FIGS. 7 to 9, in order for the rod-shaped light emitting structure 100 to grow into a hexagonal, 12-angled, or polygonal pillar, it may vary according to the shape of the hole 232 of the insulating layer 230. In the embodiment, in order to grow the rod light emitting structure 100 in the form of a hexagonal column, the hexagonal hole 232 was patterned in the GaN [11-20] direction.

Thereafter, as shown in FIG. 15, the first conductivity type semiconductor layer 110 may be vertically grown on the first electrode layer 220 exposed through the hole of the insulating layer 230.

In order to promote the vertical growth, 3D growth process conditions may be applied. Here, the 3D growth process conditions are for rapidly growing the semiconductor layer to promote growth in the vertical direction, and may include lowering the process temperature, lowering the pressure, and increasing the concentration of elements required for growth.

In addition, the first conductivity type semiconductor layer 110 may be formed of a semiconductor compound. It may be implemented as a compound semiconductor such as Group 3-5, Group 2-6, etc., and may be doped with a first conductivity type dopant. When the first conductivity-type semiconductor layer 110 is an n-type semiconductor layer, the first conductivity-type dopant is an n-type dopant and may include Si, Ge, Sn, Se, and Te, but is not limited thereto. The first conductivity type semiconductor layer 110 may include a semiconductor material having a composition formula of InxAlyGa1-x-yN (0≦x≦1, 0≦y≦1, 0≦x+y≦1). The first conductivity type semiconductor layer 110 may be formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, InP.

Next, when the first conductivity type semiconductor layer 110 grows into a hexagonal column by a predetermined height, a mask 290 may be formed on the upper surface of the first conductivity type semiconductor layer 110 as shown in FIG. 16. have. The reason for forming the mask 290 is to suppress vertical growth of the semiconductor layer on the upper surface of the first conductivity type semiconductor layer 110, and the active layer 120 in the lateral direction of the first conductivity type semiconductor layer 110 It is to promote the growth of ).

However, in the case of forming the mask 290, since a process may be added to have an inferior effect in terms of productivity, in another embodiment, side growth may be performed without the mask 290. In the case where the mask 290 is not formed, the top surface of the light emitting structure 100 is covered by the second conductive type semiconductor layer 130 that is grown last, so that the first conductive type semiconductor layer 110 and the active layer ( 120) is not exposed. Accordingly, after the light emitting structure 100 is grown, the top surface may be etched so that the first conductivity type semiconductor layer 110 and the active layer 120 are exposed from the top surface of the light emitting structure 100.

Thereafter, as shown in FIG. 17, the active layer 120 may be laterally grown on the outer circumferential surface of the first conductivity type semiconductor layer 110. Accordingly, the lower surface of the active layer 120 may be formed on the upper surface of the insulating layer 230 around the hole.

In addition, in order to promote the lateral growth of the active layer 120, a 2D growth growth condition may be applied. Here, the 2D growth conditions are for growing the semiconductor layer in a horizontal direction by slowly growing the semiconductor layer, and may include increasing the process temperature, lowering the pressure, and lowering the concentration of elements required for growth.

In the active layer 120, electrons injected through the first conductivity-type semiconductor layer 110 and holes injected through the second conductivity-type semiconductor layer 130 formed thereafter meet each other to form the active layer 120 (light emitting layer) material. It is a layer that emits light with energy determined by its own energy band. The active layer 120 may be formed of at least one of a single quantum well structure, a multi quantum well (MQW) structure, a quantum-wire structure, or a quantum dot structure. For example, the active layer 120 may be injected with trimethyl gallium gas (TMGa), ammonia gas (NH3), nitrogen gas (N2), trimethyl indium gas (TMIn), or a p-type dopant to form a multiple quantum well structure. However, it is not limited thereto.

In addition, the quantum well/quantum wall of the active layer 120 has a pair structure of at least one of InGaN/GaN, InGaN/InGaN, GaN/AlGaN, InAlGaN/GaN, GaAs(InGaAs)/AlGaAs, GaP(InGaP)/AlGaP. It may be formed, but is not limited thereto. The quantum well may be formed of a material having a band gap lower than that of the quantum wall.

Next, as shown in FIG. 18, a second conductivity type semiconductor layer 130 may be laterally grown on the outer circumferential surface of the active layer 120. Accordingly, the lower surface of the second conductivity type semiconductor layer 130 may be formed on the upper surface of the insulating layer 230 around the hole.

In addition, in order to promote the lateral growth of the second conductivity type semiconductor layer 130, a 2D growth growth condition may be applied. Here, the 2D growth conditions are for growing the semiconductor layer in a horizontal direction by slowly growing the semiconductor layer, and may include increasing the process temperature, lowering the pressure, and lowering the concentration of elements required for growth.

The second conductivity type semiconductor layer 130 may be formed of a semiconductor compound. It may be implemented with a compound semiconductor such as Group 3-5, Group 2-6, etc., and may be doped with a second conductivity type dopant. For example, the second conductivity type semiconductor layer 130 may include a semiconductor material having a composition formula of InxAlyGa1-x-yN (0≤x≤1, 0≤y≤1, 0≤x+y≤1). I can. When the second conductivity-type semiconductor layer 130 is a p-type semiconductor layer, the second conductivity-type dopant is a p-type dopant and may include Mg, Zn, Ca, Sr, Ba, or the like.

Next, as shown in FIG. 19, a second electrode layer 240 is formed on the insulating layer 230.

The second electrode layer 240 may be formed in various patterns capable of electrically connecting the second conductive type semiconductor layers 130 of the plurality of light emitting structures 100 formed on the insulating layer 230.

For example, it may be formed as a bridge pattern connecting the plurality of light emitting structures 100 and the second electrode pad 260 to be formed thereafter. Alternatively, as shown in FIG. 19, it may be formed on the entire surface of the insulating layer 230 except for a region in which the light emitting structure 100 is formed.

The second electrode layer 240 may include a light-transmitting ohmic layer, and may be formed by stacking a single metal, a metal alloy, or a metal oxide in multiple layers so that carrier injection can be efficiently performed.

For example, the second electrode layer 240 may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), IGTO(indium gallium tin oxide), AZO(aluminum zinc oxide), ATO(antimony tin oxide), GZO(gallium zinc oxide), IZON(IZO Nitride), AGZO(Al-Ga ZnO), IGZO(In-Ga ZnO) , ZnO, IrOx, RuOx, and may be formed by including at least one of NiO, but is not limited to these materials.

Next, as shown in FIG. 20, a part of the translucent electrode and the insulating layer 230 may be removed so that the first electrode layer 220 is exposed. Thereafter, a second electrode pad 260 may be formed on the second electrode layer 240 and a first electrode pad 250 may be formed on the exposed first electrode layer 220.

Next, as shown in FIG. 21, the light emitting device according to the first embodiment may be formed by removing the mask 290 disposed on the upper surface of the light emitting structure 100.

Features, structures, effects, and the like described in the embodiments above are included in at least one embodiment, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, and the like illustrated in each embodiment may be combined or modified for other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the embodiments.

Although the embodiments have been described above, these are only examples and are not intended to limit the embodiments, and those of ordinary skill in the field to which the embodiments belong are not departing from the essential characteristics of the present embodiment. It will be seen that branch transformation and application are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the embodiments set in the appended claims.

100, 101: light-emitting structure
110, 111: first conductivity type semiconductor layer
120, 121: active layer
130, 131: second conductivity type semiconductor layer
200, 201: light emitting device
210, 211: substrate
220, 221: charge injection layer
230, 231: mask layer
240, 241: second electrode layer
250, 251: first electrode pad
260, 261: second electrode pad

Claims (12)

delete delete delete delete delete Board;
A charge injection layer disposed on the substrate
A mask layer disposed on the charge injection layer and having at least one hole;
A light emitting structure disposed in the hole of the mask layer;
An electrode layer disposed on the mask layer;
A second electrode pad disposed on the electrode layer; And
A first electrode pad disposed on the charge injection layer; Including,
The light emitting structure,
A first conductivity type semiconductor layer having a columnar shape;
An active layer disposed to surround the first conductivity type semiconductor layer; And
Including; a second conductive type semiconductor layer disposed to surround the active layer,
The pillar shape is a polygonal pillar or cylindrical shape,
A light emitting device in which the first conductivity type semiconductor layer, the active layer, and the second conductivity type semiconductor layer are exposed on a top surface of the light emitting structure. The method of claim 6,
The charge injection layer electrically connects the first electrode pad and the first conductivity type semiconductor layer of the light emitting structure,
The electrode layer is a light emitting device that electrically connects second conductive semiconductor layers of the light emitting structure to the second electrode pad. delete The method of claim 7,
The electrode layer is a light emitting device formed on an upper surface of the mask layer excluding a region in which the light emitting structure is disposed. delete The method of claim 6,
The mask layer is a light emitting device that insulates the charge injection layer from the second conductivity type semiconductor layer of the light emitting structure. A charge injection layer;
A mask layer disposed on an upper surface of the charge injection layer and having at least one hole;
A light emitting structure disposed in the hole of the mask layer;
An electrode layer disposed on the mask layer;
A second electrode pad disposed on the electrode layer; And
Including; a first electrode pad disposed on the lower surface of the charge injection layer,
The light emitting structure,
A first conductivity type semiconductor layer having a columnar shape;
An active layer disposed to surround the first conductivity type semiconductor layer; And
Including; a second conductive type semiconductor layer disposed to surround the active layer,
The pillar shape is a polygonal pillar or cylindrical shape,
A light emitting device in which the first conductivity type semiconductor layer, the active layer, and the second conductivity type semiconductor layer are exposed on a top surface of the light emitting structure.

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