KR20130046402A - Semiconductor light emitting diode and method for manufacturing the same - Google Patents

Abstract

PURPOSE: A semiconductor light emitting device and a manufacturing method thereof are provided to improve brightness by extending the area of a light emitting layer. CONSTITUTION: An active layer is formed on an n-type semiconductor layer. A p-type semiconductor layer is formed on the active layer. A transparent electrode layer(180) is formed on a p-type semiconductor layer. A first electrode(191) is formed on the transparent electrode layer. A second electrode(192) is formed in the exposure region of the n-type semiconductor layer.

Description

Semiconductor light emitting device and method for manufacturing same {SEMICONDUCTOR LIGHT EMITTING DIODE AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a semiconductor light emitting device and a method of manufacturing the same, and more particularly, in order to increase light extraction efficiency, external extraction of light by forming irregularities composed of different heterogeneous materials before or during the formation of a semiconductor material on a substrate. The present invention relates to a semiconductor light emitting device having a heterogeneous material structure having increased efficiency and a method of manufacturing the same.

Recently, luminaires composed of LEDs (Light Emitting Diodes) have exploded in demand due to advantages such as longer lifespan, relatively low power consumption, and no emission of pollutants in the manufacturing process compared to conventional incandescent or fluorescent lamps. In addition, the light emitting device has a variety of application areas such as being applied to a display device using light emission as well as a backlight device of an illumination device or an LCD display device.

A light emitting device is a type of solid state device that converts electrical energy into light, and generally includes an active layer of semiconductor material interposed between two opposing doping layers, and when a bias is applied across the two doping layers, holes and electrons Is injected into the active layer and recombined there to generate light, which is emitted in all directions and out of the semiconductor chip through all exposed surfaces.

FIG. 1 is an exemplary view illustrating a manufacturing process of a general light emitting device. As shown in FIG. 1A, after the n-type semiconductor layer 102 is grown on a sapphire substrate 101, electrons and holes are combined to emit light. An active layer having a structure of InGaN / GaN nitride diversified well 103 can be formed, and the p-type semiconductor layer 104 is grown again.

Next, as shown in FIG. 1B, mesa etching using photolithography is performed to expose a portion of the n-type semiconductor layer 102 to form an electrode.

As shown in FIG. 1C, an n-type electrode 105 is formed on the n-type semiconductor layer 102 of the mesa-etched region, and light is transmitted through the p-type semiconductor layer 104. The p-type metal film 106 is coated and a thick p-type electrode 107 is deposited on top of the p-type metal film 106 again.

In such a conventional structure, in particular, a nitride-based LED structure, approaches to maximize the internal quantum efficiency of the active layer and approaches to extract the light generated in the active layer to the outside of the LED chip as much as possible are the main means for increasing the light extraction efficiency.

Two factors can be used to determine the light extraction efficiency of the light emitting device. First, the light loss due to the degree of transmission to the current diffusion layer, and second, the light loss due to total reflection at the interface where the light is emitted.

In relation to the first factor, a Ni / Au alloy layer having a thickness of several nm and several tens of nm is mainly used as a current diffusion layer of a conventional LED device, and about 60 to 80% of the emission wavelength depending on the thickness and alloy conditions. It has a transmittance of

In order to overcome this problem, an approach using an electrode material having a high permeability such as ITO has been recently made, but there is a problem of high contact resistance with a p-type semiconductor (GaN) layer, and thus a structure such as an np tunnel junction or an InGaN / GaN superlattice The technique which employ | adopts is applied.

The light loss due to total reflection related to the second factor is the interface at which light is emitted from the top of the light emitting device to the outside, between p-type GaN and resin or between p-type GaN and other materials in contact with air or p-type GaN. It occurs due to the difference in refractive index between adjacent materials at the interface of the substrate, the interface between the buffer layer and the sapphire substrate, etc., which are present in the lower region of the LED element.

Since the semiconductor constituting the general semiconductor light emitting device has a higher refractive index than the external environment such as a substrate, an epoxy layer or an air layer, the majority of photons generated by the combination of electrons and holes stays inside the device. Branches are affected by the structural shape and the optical properties of the materials constituting the device.

In particular, the refractive index of the material constituting the nitride semiconductor light emitting device is greater than that of the material surrounding the outside of the device (for example, air, resin, or substrate), so that photons generated inside the device do not escape to the outside. There is a problem in that it is absorbed inward and has a low external quantum efficiency.

In order to change the incident angle or the emission angle at the interface in a conventional approach to reduce the light loss due to the total reflection, patterning of regular or irregular irregularities is performed in the p-type GaN layer region by using an etching process. Method and the like.

However, especially in the case of nitride semiconductor optical devices, when the surface is roughened by a dry or wet method due to a relatively thin P-type semiconductor layer, defects may occur in the active layer directly below the P-type semiconductor. This change has a problem that the contact resistance can be increased.

Therefore, in the case of nitride semiconductors, there is a limit to the method of roughening the surface after thin film growth, and thus a method of roughening the surface during the thin film deposition process may be adopted.

It grows evenly from the substrate to the last thin film, and at the last thin film growth, the growth conditions such as group III-V ratio, temperature, and deposition rate are changed to form pit on the surface with high density, resulting in high brightness. ) Is the way to increase.

However, this method has a problem that the process of forming a high-density hole is difficult.

In order to solve this problem, the present invention has a heterogeneous material structure to increase the external extraction efficiency of light by forming irregularities composed of different heterogeneous materials before or during the formation of the semiconductor material on the substrate to increase the light extraction efficiency An object of the present invention is to provide a semiconductor light emitting device and a method of manufacturing the same.

In order to achieve the above object, the present invention provides a semiconductor light emitting device comprising: a substrate; An n-type semiconductor layer formed on the substrate; An active layer formed on the n-type semiconductor layer; A p-type semiconductor layer formed on the active layer; A transparent electrode layer formed on the p-type semiconductor layer; A first electrode formed on the transparent electrode layer; And a second electrode formed by etching the transparent electrode layer, the p-type semiconductor layer, and the active layer to form an n-type semiconductor layer, and having a different refractive index on at least one of the substrate or the semiconductor layer. Characterized by forming a protrusion consisting of.

In addition, the protrusion according to the present invention, sapphire, silicon carbide, gallium nitride (GaN), aluminum gallium nitride (AlGa1-xN, 0 <= x <= 1), gallium arsenide (GaAs), chromium (Cr), Silicon oxide (SiO 2), silicon nitride (Si 3 N 4), silicon oxynitride (SiON), hafnium oxide (HfO), silver (Ag), characterized in that it comprises two or more materials selected from aluminum (Al).

In addition, the substrate according to the present invention is characterized in that it comprises at least one of sapphire, silicon carbide, gallium arsenide (GaAs), gallium nitride (GaN), silicon (Si).

In addition, the cross-sectional shape of the protrusion according to the invention is characterized in that the shape of any one of a circle, triangle, square or polygon or point shape.

In addition, the longitudinal cross-sectional shape of the protruding portion according to the present invention is characterized in that the shape of any one of semi-circular, semi-circular truncated, semi-elliptic, semi-elliptic truncated, triangular, trapezoidal.

In addition, the outer shape of the protrusion according to the invention is characterized in that the shape of any one of hemispherical, cut hemispherical, semi-elliptic, semi-elliptic, truncated cone, truncated cone.

In addition, the protrusion according to the invention is characterized in that it has at least one joining surface and the top surface and the surfaces are flat.

In addition, the present invention provides a method of manufacturing a semiconductor light emitting device comprising the steps of: patterning in a projected pattern so that the first etching mask material having an arbitrary refractive index remains on the upper surface of the substrate; Forming an n-type semiconductor layer on the substrate; Forming an active layer on the n-type semiconductor layer; Forming a p-type semiconductor layer on the active layer; Forming a transparent electrode layer on the p-type semiconductor layer; Etching predetermined regions of the transparent electrode layer, the active layer, and the p-type semiconductor layer; Forming a first electrode on the transparent electrode layer; And forming a second electrode in an area in which the n-type semiconductor layer is exposed by etching the transparent electrode layer, the active layer, and the p-type semiconductor layer.

The present invention may further include forming a buffer layer on the substrate after the patterning in a protruding pattern such that the first etching mask material having an arbitrary refractive index remains on the upper surface of the substrate.

In addition, patterning in a protruding pattern such that a first etch mask material having an arbitrary refractive index remains on the upper surface of the substrate may include depositing a first etch mask material on the substrate; Patterning on the substrate; Etching the first etch mask material partially so that a first etch mask material remains on top of the protruding pattern formed by the patterning; Etching the substrate; And cleaning the etched substrate.

In addition, etching the first etching mask according to the present invention may include depositing a second etching mask material having an arbitrary refractive index on an upper surface of the substrate on which the first etching mask material remains; Patterning on the substrate; And partially etching the second mask material such that the second etching mask material remains on top of the protruding pattern formed by the patterning.

In addition, the first and second etching mask material according to the present invention is chromium (Cr), silicon oxide (SiO 2), silicon nitride (Si 3 N 4), silicon oxynitride (SiON), hafnium oxide (HfO), silver (Ag ), At least two materials selected from aluminum (Al).

The present invention has the effect of increasing the area of the light emitting layer in addition to the reduction of defects of the semiconductor light emitting device by manufacturing a semiconductor light emitting device, there is an effect of improving the brightness (brightness) of the light emitting device.

In addition, the present invention by forming a concave-convex leaving a mask material having a refractive index different from the substrate to improve the light extraction efficiency, it is used as a growth mask during growth of the nitride film, thereby increasing the growth of semiconductor layers such as high-quality nitride film due to the horizontal growth promotion There is an advantage.

1 is an exemplary view showing a manufacturing process of a general light emitting device.
2 is a cross-sectional view showing the configuration of a first embodiment of a semiconductor light emitting device according to the present invention;
3 is a cross-sectional view illustrating a substrate configuration of the semiconductor light emitting device according to FIG. 2.
4 is an exemplary view showing a substrate SEM image of the semiconductor light emitting device according to FIG. 2.
5 is a plan view of a substrate on which protrusions of the semiconductor light emitting device of FIG. 2 are formed;
6 is a side view showing a substrate of the semiconductor light emitting device according to FIG. 2;
7 is a flowchart illustrating a manufacturing process of a semiconductor light emitting device according to FIG. 2.
FIG. 8 is a flowchart illustrating a process of patterning a protrusion pattern in the process of manufacturing the semiconductor light emitting device of FIG. 7; FIG.
9 is a cross-sectional view showing a configuration of a second embodiment of a semiconductor light emitting device according to the present invention;
Fig. 10 is a sectional view showing the structure of the third embodiment of the semiconductor light emitting element according to the present invention.
Fig. 11 is a sectional view showing the structure of the fourth embodiment of the semiconductor light emitting element according to the present invention.
12 is a cross-sectional view illustrating a substrate configuration of the semiconductor light emitting device according to FIG. 11.
FIG. 13 is a flowchart illustrating a process of patterning a protrusion pattern in the process of manufacturing the semiconductor light emitting device of FIG. 11; FIG.

Hereinafter, exemplary embodiments of a semiconductor light emitting device and a method of manufacturing the same will be described in detail with reference to the accompanying drawings.

(Embodiment 1)

2 is a cross-sectional view showing the configuration of a first embodiment of a semiconductor light emitting device according to the present invention.

After forming the protrusions 120 having a projection shape by performing a patterning process on the substrate 110, the substrate 110 and the etching mask material are formed so that an etching mask material remains on the protrusions 120 when the etching process is performed. Part 130 is etched so that the protrusion 120 is formed on the substrate.

The substrate 110 may include at least one of sapphire, silicon carbide, gallium arsenide (GaAs), gallium nitride (GaN), aluminum gallium nitride (AlGa1-xN, 0 <= x <= 1), and silicon (Si). Material, and preferably a sapphire substrate.

In addition, the protrusion 120 formed on the substrate 110 is formed through a patterning process, and the cross-sectional shape of the protrusion 120 is formed in any one of a circle, a triangle, a rectangle, or a polygon, or a point shape. Has

In addition, the longitudinal cross-sectional shape of the protrusion 120 is made of any one of the shape of a semi-circle, semi-circular, semi-elliptic, semi-elliptic, truncated, triangular, trapezoidal, the outer shape of the protrusion 120 is hemispherical, It consists of any one of the shape of hemisphere cut off, hemispherical shape cut off, semi-elliptic shape cut off, cone shape, and truncated cone shape.

The buffer layer 140, the n-type semiconductor layer 150, the active layer 160, and the p-type semiconductor layer 170 are sequentially stacked on the substrate having the shape of the protrusion 120 formed thereon. It may be formed using vapor deposition (MOCVD). Thereafter, the transparent electrode 180 is formed on the p-type semiconductor layer 170.

In order to form the second electrode 192, the n-type semiconductor layer 150, the active layer 160, the p-type semiconductor layer 170, and the transparent electrode 180 are sequentially stacked on the substrate, and then the n-type semiconductor layer ( The predetermined regions of the transparent electrode 180, the p-type semiconductor layer 170, and the active layer 160 are etched to expose 150. In this case, a wet etching method or a dry etching method may be used.

Thereafter, the first electrode 191 is formed on the transparent electrode 180, and predetermined regions of the transparent electrode 180, the p-type semiconductor layer 170, and the active layer 160 are etched and exposed. The second electrode 192 may be formed on the layer.

When the light emitting device is completed as described above, when voltage is applied through the first electrode 191 and the second electrode 192, photons are emitted by the recombination of electrons and holes in the active layer 160.

That is, as the voltage is applied to the pn junction in the forward direction, the electrons of the n-type semiconductor layer 150 and the holes of the p-type semiconductor layer 170 are injected to the p side and the n side, respectively, so that photons recombined in the active layer 160 Emitted out of the device.

At this time, the photon generated in the active layer 160 toward the substrate collides with the protrusion 120 formed on the substrate surface, and is refracted and scattered while being extracted to the outside to increase the external emission efficiency of the light incident on the substrate.

3 is a cross-sectional view illustrating a substrate configuration of the semiconductor light emitting device of FIG. 2.

In order to form the protrusion 220 having a heterogeneous material structure on the substrate 210, a patterning process and a texturing process should be performed.

First, the etching mask material 230 having a refractive index different from that of the substrate is coated on the substrate 210, and a pattern is formed. The pattern may be formed using an E-beam, a scanner, a stepper, laser holography, or the like.

Subsequently, an etching step is performed, and the etching process is performed in such a way that the etching mask material 230 of the upper part of the pattern remains, and then the etching step of the substrate 210 is performed on the protrusion 220. The etching mask material 230 remains to form the protrusion 220 in which the heterogeneous materials are stacked.

The protrusion may have one or more bonding surfaces and a top surface, and may be shaped such that the top surface of the etch mask material 230 is flat by adjusting a pattern process and an etching process condition.

The etch mask material 230 having the flat top surface may suppress dislocation formation that may occur in the center portion of the protrusion when the protrusion is covered with the semiconductor in a semiconductor deposition process proceeding to MOCVD, MBE, and the like, and the remaining etching mask By controlling the reflection of light through the flat top surface of the material 230, the amount of light extracted to the upper portion of the chip may be effectively increased.

4 is an exemplary view showing a substrate SEM image of the semiconductor light emitting device according to FIG. 2.

Referring to this image, it can be seen that the protrusion of the structure in which the heterogeneous material is laminated by the protrusion 320 and the etching mask material 330 formed on the surface of the substrate 310 is formed.

Due to the protrusion of the structure in which heterogeneous materials are stacked on the substrate, the surface area of the substrate is increased to increase the light extraction efficiency.

In addition, by forming a protrusion having a structure in which a heterogeneous material is laminated with a mask material having a difference in refractive index from a substrate on the protrusion, the refractive and scattering effects of light are further increased.

The mask material deposited on the protruding portion may be formed of a material such as sapphire, silicon carbide, gallium nitride (GaN), gallium arsenide (GaAs), and the like, and chromium (Cr) and silicon oxide having different refractive indices from the substrate. SiO 2), silicon nitride (Si 3 N 4), or at least one of silicon oxynitride (SiON), hafnium oxide (HfO), silver (Ag), and aluminum (Al) may be stacked to further improve light extraction efficiency. In addition, the light extraction efficiency may be improved by stacking a material having a refractive index different from that of the substrate or the semiconductor material.

5 is a plan view of a substrate on which a protrusion of the semiconductor light emitting device of FIG. 2 is formed, and FIG. 6 is a side view of the substrate of the semiconductor light emitting device of FIG. 2, and a lower width 410 of the protrusion of a structure in which heterogeneous materials are stacked. ) Is 0.2 μm to 3 μm, the height 420 of the protrusions is 0.1 μm to 3 μm, and the separation distance 430 between the protrusions is preferably 0.05 μm to 1 μm, but is not limited thereto.

7 is a flowchart illustrating a manufacturing process of a semiconductor light emitting device according to FIG. 2.

Prior to the manufacturing process of the present invention may be subjected to the cleaning process of the substrate.

When the substrate is washed, the substrate is subjected to the step of patterning the pattern in which the protrusion is formed (S110).

Patterns of the protrusions include photo-lithography, e-beam lithography, ion-beam lithography, extreme ultraviolet lithography, and proximity x-ray lithography. Or imprint lithography.

Further, in the mask etching process, the etching process is performed so that the etching mask material remains on the upper part of the patterned part of the protrusion, and after the etching step of the substrate, the etching mask material remains on the upper part of the substrate. A heterogeneity material having a refractive index different from that of the refractive index may form a protrusion of a stacked structure.

After the patterning step as described above, a buffer layer may be selectively formed, and the buffer layer may contribute to securing device stability by alleviating the difference in lattice constant between the substrate and the semiconductor layer.

The buffer layer may be selected from an AlInN structure, an InGaN / GaN superlattice structure, an InGaN / GaN stacked structure, and an AlInGaN / InGaN / GaN stacked structure, and the buffer layer is formed at a low temperature of about 400 ° C. to 600 ° C. In order to achieve the single crystal growth of the grown GaN layer, the surface is finished by heat-treating at a cladding layer growth temperature.

After the formation of the buffer layer, the step of forming an n-type semiconductor layer (s120).

The n-type semiconductor layer may be formed of an n-type gallium nitride layer (n-GaN) layer, and may be doped using silicon (Si) as a dopant, proceed at a high temperature, and carry ammonia (NH 3) as a carrier. Ga, N, Si can be combined with a gas.

After the n-type semiconductor layer is formed, an active layer is formed (s130), and may be a semiconductor layer to which a light emitting material made of indium gallium nitride (InGaN) is added. In addition, materials such as AlGaN and AlInGaN may also be used as the active layer.

In this case, the active layer may form an InGaN / GaN quantum well (QW) structure, and the active layer may have a plurality of quantum well structures described above to form a multi-quantum well (MQW) structure in order to improve luminance.

After the active layer is formed, a p-type semiconductor layer is formed on the active layer (s140). The p-type semiconductor layer may be formed of a gallium nitride layer (p-GaN layer), and magnesium (Mg) may be used as a dopant. have. This process is also carried out at a high temperature and can combine Ga, N, Mg as a compound with ammonia (NH3) carrier gas.

Such an active layer can supply NH 3, TMGa, and trimethylindium (TMIn) by using nitrogen as a carrier gas at a growth temperature of 780 ° C., for example, and grow an active layer made of InGaN / GaN to a thickness of 120 kV to 1200 kPa.

Thereafter, a transparent electrode layer is formed on the p-type semiconductor layer (S150), and the transparent electrode layer may be formed of at least one of ITO, ZnO, RuOx, TiOx, and IrOx as a transparent oxide film.

In order to form an electrode pad, a partial etching process is performed from the transparent electrode layer to the n-type semiconductor layer (s160). In the case of forming the nitride-based semiconductor layer, wet etching is difficult because of the chemical properties of the nitride-based compound. It is desirable to.

After the above process, a first electrode is formed on the transparent electrode layer (s170), and a second electrode is formed on the exposed n-type semiconductor layer partially etched from the transparent electrode layer to the n-type semiconductor layer (s180). The electrode may be subjected to an oxidation process for forming the electrode and protecting the device.

FIG. 8 is a flowchart illustrating a process of patterning a pattern into a protruding pattern in the process of manufacturing the semiconductor light emitting device of FIG. 7.

The present invention can form a protrusion using a lithography process, the general lithography process is as follows.

First, a mask (reticle) is manufactured. A pattern for forming a protruding protrusion is drawn on an etch mask material by using an E-beam facility to make a mask (reticle) and deposited on the substrate.

After that, if necessary, an oxidation process may be added, and a process of developing a thin and uniform silicon oxide layer (SiO 2) may be added.

Second, photoresist (PR) is applied. PR, a light-sensitive material, is evenly applied to the wafer surface.

Third, an exposure process is performed. A light is passed through a pattern drawn on a mask using a stepper to photograph a protrusion pattern on a wafer on which a PR film is formed.

Fourth, the film of the lighted part on the wafer surface is developed.

Fifth, an etching process is performed to selectively remove unnecessary portions using chemicals or reactive gases to form protrusion patterns. This pattern formation process may be repeated continuously for each pattern layer.

In addition, in the present invention, a photosensitive material such as a photo resist (PR) may be coated, and then exposed and etched to form a protruding shape. In order to form a fine pattern, DUV (Deep Ultraviolet) having a shorter wavelength may be formed. Alternatively, you can use a stepper that uses Extreme Ultraviolet (EUV) wavelengths or a shorter laser.

Referring to the drawings, the step of depositing an etching mask on the substrate (s210), the etching mask material in the present invention is chromium (Cr), silicon oxide (SiO2), silicon nitride (Si3N4) or silicon oxynitride (SiON), hafnium oxide (HfO), silver (Ag), and aluminum (Al).

The etching mask material is formed by stacking the upper part of the protrusion in the protrusion protrusion pattern, and the light extraction efficiency is improved because the light refraction and scattering effect are large when a material having a difference in the regulation rate from the substrate is used.

After the deposition of the etch mask, a patterning step is performed (s220). The protruding protrusion patterns may include photo-lithography, e-beam lithography, ion-beam lithography, and extreme ultraviolet rays. Protruding protrusions are formed using any one of lithography (Extreme Ultraviolet Lithography), Proximity X-ray Lithography, or imprint lithography.

In addition, a portion of the substrate which should not be etched through a mask process may be formed on the substrate, and a part of the surface may be partially cut off in a top down manner with respect to the substrate surface, or a protruding structure may be formed on the substrate surface through the etching process. It may be.

Thereafter, the etching mask is etched (S230). At this time, in order to form the protruding protrusion, the etching of the etching mask material should be partially etched so that the mask material remains on the upper portion of the protrusion.

Subsequently, the substrate is subjected to an etching step (S240), and when the substrate is etched to a predetermined depth and width using an etching solution, a protrusion having a more perfect shape is generated.

After the cleaning step (s250), the cleaning step may be performed using an organic solvent, such as acetone, alcohol, and DI water.

(Second Embodiment)

9 is a cross-sectional view showing the configuration of the second embodiment of the semiconductor light emitting device according to the present invention. The same reference numerals are used for the same components as those of the first embodiment, and repeated descriptions thereof will be omitted.

In the semiconductor light emitting device according to the second exemplary embodiment, the buffer layer 140, the n-type semiconductor layer 150, the active layer 160, the p-type semiconductor layer 170, and the transparent layer are not patterned on the substrate 110. The electrode 180 is sequentially stacked to form a first electrode 191 on the transparent electrode 180, and a predetermined portion of the transparent electrode 180, the p-type semiconductor layer 170, and the active layer 160 is formed. The second electrode 192 may be formed on the n-type semiconductor 150 layer where the region is etched and exposed.

The light emitting device according to the second embodiment is a structure in which a heterogeneous material is stacked on the grown semiconductor layer instead of the substrate 110. For example, the light emitting device has a protrusion shape by performing a patterning process on the grown n-type semiconductor layer 150. After forming the protrusion 120a, the etch mask material 130 is partially etched so that the etch mask material 130a remains on the protrusion-shaped protrusion 120a, and thus, is formed on the n-type semiconductor layer 150. It is possible to form a stacked structure of dissimilar materials.

Therefore, at least one of chromium (Cr), silicon oxide (SiO 2), silicon nitride (Si 3 N 4), or silicon oxynitride (SiON), hafnium oxide (HfO), silver (Ag), and aluminum (Al) having a refractive index difference from the substrate. By stacking one or more materials, the light extraction efficiency can be further improved.

(Third Embodiment)

10 is a cross-sectional view showing the configuration of the third embodiment of the semiconductor light emitting device according to the present invention with the same reference numerals for the same components as those of the first embodiment, and repetitive description thereof will be omitted.

In the semiconductor light emitting device according to the third embodiment, the buffer layer 140, the n-type semiconductor layer 150, the active layer 160, the p-type semiconductor layer 170, and the transparent layer are not patterned on the substrate 110. The electrode 180 is sequentially stacked to form a first electrode 191 on the transparent electrode 180, and a predetermined portion of the transparent electrode 180, the p-type semiconductor layer 170, and the active layer 160 is formed. The second electrode 192 may be formed on the n-type semiconductor 150 layer where the region is etched and exposed.

In the light emitting device according to the third exemplary embodiment, the groove 110 is formed in the substrate 110, such that the protrusion 120b having a relatively protruded plane of the substrate on which the groove 111 is not formed is formed. ) Can form a protruding structure.

That is, when the pattern is formed on the substrate 110 and the etching step of the substrate 110 without the pattern is formed, the groove 111 is formed on the upper surface of the substrate 110, thereby forming the substrate. The plane of the to form a protrusion 120b protruding relative to the groove 111.

After depositing an etching mask material 130 having an arbitrary refractive index on the substrate 110, the etching mask material 130 is partially etched so that the etching mask material 130 remains on the protrusion 120b. As a result, the etch mark material 130 remains on the protrusion 120b to form the protrusion 120b in which the heterogeneous materials are stacked.

The protrusion 120b may be formed of chromium (Cr), silicon oxide (SiO 2), silicon nitride (Si 3 N 4), silicon oxynitride (SiON), hafnium oxide (HfO), silver (Ag), and aluminum having a refractive index difference from that of the substrate. It is formed by laminating at least one material of (Al).

(Example 4)

11 is a cross-sectional view showing the structure of the fourth embodiment of the semiconductor light emitting device according to the present invention.

After the patterning process is performed on the substrate 510 in a protruding pattern so that a first etching mask material having an optional refractive index different from the substrate 510 remains on the substrate 510, the first etching mask material may be partially disposed. Etching is performed so that the protrusion 520 is formed on the upper portion of the substrate, and the second etching has an optional refractive index different from that of the substrate 510 and the protrusion 520 on the upper surface of the substrate 510 on which the protrusion 520 remains. After the patterning process is performed in a pattern that protrudes so that the mask material remains, the second etching mask material is partially etched so that the second etching mask material remains on the protrusion 520 so that at least two different refractive indices are provided. Mask material is configured to protrude above the substrate 510.

The first and second etching mask materials include chromium (Cr), silicon oxide (SiO 2), silicon nitride (Si 3 N 4), silicon oxynitride (SiON), hafnium oxide (HfO), silver (Ag), and aluminum (Al). It includes a material selected from among.

The substrate 510 is made of at least one of sapphire, silicon carbide, gallium arsenide (GaAs), gallium nitride (GaN), and silicon (Si), and preferably made of a sapphire substrate.

In addition, the protrusion 520 patterned on the substrate 510 is formed through a patterning process, and the planar shape of the protrusion 520 is formed in any one of a circle, a triangle, a square, or a polygon, or a point shape. Is done.

A buffer layer 540, an n-type semiconductor layer 550, an active layer 160, and a p-type semiconductor layer 570 are sequentially stacked on the substrate on which the protrusion 520 is formed. It may be formed using vapor deposition (MOCVD). Thereafter, the transparent electrode 580 is formed on the p-type semiconductor layer 570.

In order to form the second electrode 592, the n-type semiconductor layer 550, the active layer 560, the p-type semiconductor layer 570, and the transparent electrode 580 are sequentially stacked on the substrate, and then the n-type semiconductor layer ( The predetermined regions of the transparent electrode 580, the p-type semiconductor layer 570, and the active layer 560 are etched to expose the 550. In this case, a wet etching method or a dry etching method may be used.

Thereafter, the first electrode 191 is formed on the transparent electrode 580, and the n-type semiconductor 550 in which predetermined regions of the transparent electrode 580, the p-type semiconductor layer 570, and the active layer 560 are etched and exposed. The second electrode 592 may be formed on the layer.

When the light emitting device is completed and a voltage is applied through the first electrode 591 and the second electrode 592, photons are emitted by recombination of electrons and holes in the active layer 560.

That is, as the voltage is applied to the pn junction in the forward direction, the electrons of the n-type semiconductor layer 550 and the holes of the p-type semiconductor layer 570 are injected to the p side and the n side, respectively, so that photons recombined in the active layer 560 Emitted out of the device.

At this time, photons generated in the active layer 560 toward the substrate collide with the protrusion 520 formed on the surface of the substrate and are extracted to the outside while being refracted and scattered. The flat portion is reduced by the pattern of the protrusion 520 on the substrate surface. This increases the external emission efficiency of light incident on the substrate.

12 is a cross-sectional view illustrating a substrate configuration of the semiconductor light emitting device of FIG. 11.

In order to apply the first etching mask material on the substrate 510 and form a pattern, the pattern may be formed using an E-beam, a scanner, a stepper, laser holography, or the like.

Subsequently, a mask etching step may be performed. The protrusion 520 may be formed by partially etching the mask material of the portion where the pattern is not formed so that the first etching mask material on which the pattern is formed remains. After the second etching mask material is applied, a pattern is formed, and the second mask etching step is performed, the second etching mask material 530 remains on the protrusion 520 to form the protrusion 520 in which the heterogeneous materials are stacked. It becomes possible.

The first and second etching mask materials include chromium (Cr), silicon oxide (SiO 2), silicon nitride (Si 3 N 4), silicon oxynitride (SiON), hafnium oxide (HfO), silver (Ag), and aluminum (Al). Among the materials selected, the first etching mask material and the second etching mask material are heterogeneous mask materials having different refractive indices.

FIG. 13 is a flowchart illustrating a process of patterning a protrusion pattern in the process of manufacturing the semiconductor light emitting device of FIG. 11.

Referring to the drawings, the step of patterning the protrusions in the protruding pattern so that the first etching mask material having a certain refractive index on the upper surface of the substrate deposits the first etching mask material on the substrate (s310), the etching mask The material is made of any one selected from chromium (Cr), silicon oxide (SiO 2), silicon nitride (Si 3 N 4) or silicon oxynitride (SiON), hafnium oxide (HfO), silver (Ag) and aluminum (Al). .

After the deposition of the first etching mask material, the patterning step (s320) is performed, and the first etching mask material is partially etched so that the first etching mask material remains on the pattern formed by the patterning of step s320 ( s330) to form protrusions formed on the substrate.

A second etching mask material is deposited on the upper surface of the substrate on which the first etching mask material remains (s340). The second etching mask material is a mask material having a refractive index different from that of the substrate, and includes chromium (Cr) and silicon oxide ( SiO 2), silicon nitride (Si 3 N 4), silicon oxynitride (SiON), hafnium oxide (HfO), silver (Ag), and aluminum (Al), and any one selected from materials, and the first etching mask material It is desirable for other mask materials to be deposited.

After the deposition of the second etching mask material, the patterning step (s350) is performed, and the second mask material is partially etched so that the second etching mask material remains on the pattern formed by the patterning of step s350 (s360). )do.

By performing the step s360, two kinds of mask materials having different refractive indices from those of the substrate are stacked on the substrate, so that light refraction and scattering effects are large, and light extraction efficiency is improved.

In addition, an etching solution may be used to etch the substrate to a certain depth and width, thereby creating a more perfect protrusion.

Thereafter, a cleaning step is performed using an organic solvent such as acetone, alcohol, and DI water (S370).

Accordingly, by stacking a substrate and two kinds of mask materials having different refractive indices from those of the substrate, it is possible to provide a light emitting device having improved light extraction efficiency by increasing light refraction and scattering effects.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. It can be understood that

In addition, in the course of describing an embodiment of the present invention, the thickness of the lines or the size of the components shown in the drawings may be exaggerated for clarity and convenience of description, and the above terms are considered in the present invention. As the terms defined herein may vary depending on the intention or custom of the user or operator, the definition of the terms should be made based on the contents throughout the specification.

110, 210, 310, 510: substrate 111: groove portion
120, 120a, 120b, 220, 320, 520: protrusions
130, 230, 330, 530: etching mask material 140, 540: buffer layer
150, 550: n-type semiconductor layer 160, 560: active layer
170 and 570 p-type semiconductor layers 180 and 580 transparent electrodes
191 and 591: first electrode 192 and 592: second electrode
410: lower protrusion width 420: height of the protrusion
430: separation distance between protrusions

Claims (12)

Board;
An n-type semiconductor layer formed on the substrate;
An active layer formed on the n-type semiconductor layer;
A p-type semiconductor layer formed on the active layer;
A transparent electrode layer formed on the p-type semiconductor layer;
A first electrode formed on the transparent electrode layer; And
A second electrode formed on the region where the transparent electrode layer, the p-type semiconductor layer, and the active layer are etched to expose the n-type semiconductor layer,
And at least one of the substrate and the semiconductor layer to form a protrusion made of different materials having different refractive indices.
The method of claim 1,
The protrusions include sapphire, silicon carbide, gallium nitride (GaN), aluminum gallium nitride (AlGa1-xN, 0 <= x <= 1), gallium arsenide (GaAs), chromium (Cr), silicon oxide (SiO 2), A semiconductor light emitting device comprising at least two materials selected from silicon nitride (Si 3 N 4), silicon oxynitride (SiON), hafnium oxide (HfO), silver (Ag), and aluminum (Al).
The method of claim 1,
The substrate comprises at least one of sapphire, silicon carbide, gallium arsenide (GaAs), gallium nitride (GaN), silicon (Si).
The method of claim 1,
The cross-sectional shape of the protrusion is a semiconductor light emitting device, characterized in that any one of the shape of a circle, a triangle, a square or a polygon or a point.
The method of claim 1,
The longitudinal cross-sectional shape of the protruding portion is a semiconductor light emitting device, characterized in that any one of the shape of semi-circular, semi-circular, semi-elliptic, truncated semi-elliptic, triangular, trapezoidal.
The method of claim 1,
The protrusion may have a shape of any one of a hemispherical shape, a truncated hemispherical shape, a semi-elliptic shape, a truncated semi-elliptic shape, a cone shape, and a truncated cone shape.
The method of claim 1,
And the protrusion has at least one bonding surface and an upper surface, and the surfaces are flat.
Patterning in a protruding pattern such that a first etch mask material having any refractive index remains on the substrate top surface;
Forming an n-type semiconductor layer on the substrate;
Forming an active layer on the n-type semiconductor layer;
Forming a p-type semiconductor layer on the active layer;
Forming a transparent electrode layer on the p-type semiconductor layer;
Etching predetermined regions of the transparent electrode layer, the active layer, and the p-type semiconductor layer;
Forming a first electrode on the transparent electrode layer; And
And forming a second electrode in an area in which the n-type semiconductor layer is exposed by etching the transparent electrode layer, the active layer, and the p-type semiconductor layer.
The method of claim 8,
After patterning in a protruding pattern such that a first etch mask material having an arbitrary refractive index remains on the top surface of the substrate
Forming a buffer layer on the substrate further comprising the step of manufacturing a semiconductor light emitting device.
10. The method according to claim 8 or 9,
Patterning in a protruding pattern such that a first etch mask material having any refractive index remains on the top surface of the substrate comprises depositing a first etch mask material on the substrate;
Patterning on the substrate;
Etching the first etch mask material partially so that a first etch mask material remains on top of the pattern formed by the patterning;
Etching the substrate; And
And cleaning the etched substrate.
11. The method of claim 10,
Etching the first etching mask may include depositing a second etching mask material having an arbitrary refractive index on an upper surface of the substrate on which the first etching mask material remains;
Patterning on the substrate; And
And etching the second mask material partially so that a second etching mask material remains on the pattern formed by the patterning.
The method of claim 11,
The first and second etching mask materials include chromium (Cr), silicon oxide (SiO 2), silicon nitride (Si 3 N 4), silicon oxynitride (SiON), hafnium oxide (HfO), silver (Ag), and aluminum (Al). Method of manufacturing a semiconductor light emitting device comprising at least two materials selected from among.

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