KR100805324B1 - Light emitting diode for enhancing efficiency - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly efficient light emitting diode, comprising: a semiconductor layer comprising a N semiconductor layer, an active layer, and a P semiconductor layer on a transparent substrate to form a PN junction, wherein the semiconductor layer has an aspect ratio. Is at least two light emitting parts including the active layer having at least one, and are connected to each of the light emitting parts, characterized in that an electrode for electrically connecting the P semiconductor layer and the N semiconductor layer.

Providing the light emitting diode according to the present invention, by improving the structure and electrode structure of the semiconductor layer including the active layer that emits light, to prevent some of the light is absorbed due to a long progress through the total internal reflection to reduce the light efficiency In addition to improving the uneven distribution of current density due to the asymmetrical structure of the electrodes, high efficiency light emitting diodes can be realized and high efficiency light emitting diodes can be manufactured with a simple process and low cost without sub-mounts to increase the light efficiency. It becomes possible to manufacture.

Light Emitting Diode, Active Layer, Total Reflection, Aspect Ratio, P-N Junction, LED

Description

Light Emitting Diodes To Improve Efficiency {LIGHT EMITTING DIODE FOR ENHANCING EFFICIENCY}

1 is a cross-sectional view illustrating the light loss at the N electrode of a light emitting diode according to the prior art;

2a to 2b are views illustrating a traveling pattern inside the LED of light according to the aspect ratio;

3 is a perspective view showing the structure of a light emitting diode according to the prior art;

4A is a diagram illustrating the results of computer simulation of the current density flowing through the active layer according to the position of the structure of the light emitting diode according to the prior art by configuring a resistance-diode network;

4B is a graph illustrating the current density distribution on the X and Y axes as a graph on a two-dimensional plane.

5A illustrates a plan view of a structure of a light emitting diode according to the present invention;

5B is a light emitting diode according to the present invention, illustrating a cross-sectional view taken along line AA ′ of the plan view illustrated in FIG. 5A;

5C is a cross-sectional view taken along line BB ′ of the plan view of the light emitting diode according to the present invention of FIG. 5A;

FIG. 6 is a graph illustrating a distribution of current densities shown on the short axis X and the long axis Y of the light emitting diode according to the present invention illustrated in FIGS. 5A to 5C;

7a illustrates a plan view of a light emitting diode according to the present invention;

FIG. 7B is a diagram illustrating a plane taken along the line AA ′ in FIG. 7A;

7C is a view illustrating a cross section taken along line BB ′ in FIG. 7A;

8 is a view showing a result of simulating the distribution of current density along a short axis (X) and a long axis (Y) of the light emitting diodes shown in FIGS. 7A to 7C;

9A illustrates a plan view of a light emitting diode according to the present invention;

9B is a view illustrating a cross section taken along line AA ′ in FIG. 9A;

9C is a view illustrating a cross section taken along line BB ′ in FIG. 9A;

FIG. 10 is a diagram illustrating a result of simulation of current density distribution along short axis (X) and long axis (Y) of the light emitting diodes shown in FIGS. 9A to 9C;

11A illustrates a plan view of a light emitting diode according to the present invention;

FIG. 11B is a view illustrating a cross section taken along line AA ′ in FIG. 11A;

FIG. 11C is a view illustrating a cross section taken along line BB ′ in FIG. 11A;

12 is a view showing a result of simulating the distribution of current density along the short axis (X) and the long axis (Y) of the light emitting diodes shown in FIGS. 11A to 11C;

12 is a view illustrating a flowchart of a method of manufacturing a high efficiency light emitting diode due to the improvement of a partition and an electrode structure of the light emitting unit.

<Description of main parts of drawing>

400: substrate, 410: N semiconductor layer, 415: active layer, 420: P semiconductor layer,

430, 440: light emitting portion, 411: insulating layer, 413: N electrode, 417: N electrode pad

425: P electrode, 427: P electrode pad

The present invention relates to a light emitting diode having a high light efficiency, and more particularly, to improve the active layer region and the electrode structure of the light emitting diode device, thereby preventing a decrease in light efficiency caused by total reflection and non-uniform distribution of current density. It relates to a light emitting diode.

When the size of the light emitting device is large, more power can be output per device, but the large size of such a device is related to the problem of light extraction efficiency. When light is generated in the light emitting device, some of the light is easily escaped from the chip, and some may not. When the light emitted from the active layer of the light emitting device is greater than the critical angle according to the medium, the total incident light is trapped inside the light emitting device without being transmitted through the interface. This is because the phenomenon occurs.

That is, if the refractive index of the medium is less than the refractive index of the LED medium and the angle of incidence is greater than the critical angle, the light inside the LED is totally reflected at this interface back toward the LED. In this process, the light intensity inside the LED is partially absorbed by the bulk material and is reduced.

This problem is severe in LEDs in which AlInGaN is stacked on sapphire. Since sapphire and AlInGaN have a relatively high refractive index compared to LED materials such as GaAs and AlInGaP, a large number of light propagates in the above two regions and escapes to the side. Therefore, the side dimension of the device is an important consideration for AlInGaN LEDs.

In order to solve this problem, a method of improving the light efficiency by inverting the device and applying a mirror coating on the epitaxial side has been introduced.

Hereinafter, light absorption at the n-electrode of a conventional light emitting diode will be described with reference to FIG. 1.

As shown in FIG. 1, a flip chip type light emitting diode 100 is usually a substrate 102 made of sapphire (Al 2 O 3), and a mesa n-GaN layer 104 sequentially grown on the sapphire substrate 102. And an active layer 106 and a p-GaN layer 108. These epitaxial layers, n-GaN layer 104, active layer 106 and p-GaN layer 108, are grown on sapphire substrate 102 using Metal Organic Chemical Vapor Deposition (MOCVD). do.

In addition, the p-electrode 110 is formed on the p-GaN layer 108, and the n-electrode 112 is formed in some regions where the active layer 106 of the n-GaN layer 104 is not grown. In this case, the p-electrode 110 is formed to cover the entire p-GaN layer 108 so that the light generated from the active layer 108 can be reflected toward the sapphire substrate 102.

As the p-electrode, a high reflectivity Ag, Al, an alloy thereof, a high reflectivity multilayer alloy containing the same, or other suitable high reflectance material may be used. The n-electrodes 112 are typically formed of Cr / Au, which typically have a thickness of 300 μm and 4,000 μm, respectively.

In the light emitting diode 100 having such a structure, when light is emitted from the active layer 106, they proceed in three ways. First, some light rays L1 are emitted from the active layer 106 through the n-GaN layer 104 and the sapphire substrate 102 to the outside. The other partial light beam L2 is internally reflected toward the p-electrode 110 at the interface between the sapphire substrate 102 and the n-GaN layer 104 and then reflected by the p-electrode 110 to be p-GaN layer again. Radiated to outside through the 108 and the n-GaN layer 104 and the sapphire substrate 102.

Of course, some of the other rays will reach the p-electrode 110 through the p-GaN layer 108 directly from the active layer 106 and then be reflected by the p-electrode 110 and radiated back out.

However, this method not only requires a lot of other devices between the device and the package, but also increases the manufacturing cost of the device, which is not good in terms of productivity due to the final manufacturing cost.

In addition, in line with the recent adoption of large area LEDs to increase the light output of the LEDs, the problem is that the internally generated light does not escape the LEDs due to total internal reflection on the surface of the LEDs. To compensate for the disadvantages, LEDs with high aspect ratios are adopted.

The more light progressing inside the LED, the greater the refractive index of the LED, the more light is totally reflected, and in the process, the more light is absorbed and the number of light escaping to the outside decreases. Therefore, in order to increase the light efficiency of the light emitting device, it is desirable to reduce the reflected light, and also to minimize the total travel distance before the light escapes inside the LED.

As shown in FIG. 2A, the light increases more total reflection due to the increase in the size of the device, and travels a greater distance before the light escapes from the device, resulting in more light loss. Figure 2b shows that the total reflection occurs less light when the size of the device is small. That is, the traveling distance within the LED of the light is shortened.

However, LEDs with large aspect ratios also suffer from a disadvantage in that efficiency is inferior due to asymmetrical structure, in which currents are not evenly distributed and severe current crowding effects occur around the n-electrode. do. That is, although light is well escaped in the shorter axial direction, light is still not well escaped in the longer axial direction.

3 is a perspective view showing the structure of a light emitting diode according to the prior art.

An example of a light emitting device in which an aspect ratio (X: Y) is large is a structure in which an N semiconductor layer 310, an active layer 315, and a P semiconductor layer 320 are sequentially stacked on a transparent substrate 300. It is made of.

Here, the transparent electrode 323 is stacked on the P semiconductor layer 320, and a P electrode 325 is formed on a portion of the side surface of the transparent electrode 323 along a long axis thereon, and the P semiconductor layer 320 and the active layer 315 are formed thereon. The N electrode 317 corresponding to the P electrode 325 is formed on the N semiconductor layer 310 which is partially exposed.

4A is a diagram illustrating a result of computer simulation of the current density flowing through the active layer according to the position of the structure of the light emitting diode according to the prior art by configuring a resistance-diode network.

As shown in FIG. 4A, the current crowding effect is well seen around the N electrode, and when the size of the LED is 600 μm × 200 μm, the luminous efficiency is 13.7%. That is, it can be seen that the light efficiency is considerably lowered due to the uneven distribution of the current.

FIG. 4B is a graph illustrating the current density distribution on the X-axis and the Y-axis as a graph on a two-dimensional plane.

As shown in FIG. 4B, the current density distribution is relatively uniform in the shorter direction (x-axis), but the current density distribution is very uneven in the longer direction (y-axis).

In particular, high current density occurs only near the N electrode. This means that the intensity of light emission and the uniformity of wavelength are inferior in the surface of the device. In areas where the concentration of electron holes is relatively high, the intensity of light emission by electron hole bonding is large and the wavelength is shortened by band filling phenomenon.In the area where concentration of electron holes is relatively low, the intensity of emission by electron hole bonding is high. It is small and the wavelength is relatively long.

Light having a short wavelength generated in a portion where the concentration of electron holes is relatively high is partially absorbed into a low current density region having a relatively low emission wavelength, thereby deteriorating the luminous internal efficiency of the device. It is important to make the current density uniform, and there is a problem that light can easily escape in a short length direction, but light cannot easily escape in a long direction.

The technical problem of the present invention to solve the above problems is to improve the structure and electrode structure of the semiconductor layer including the active layer for generating light emission to prevent the light efficiency is lowered to be partially absorbed while a long progress by total internal reflection of light In addition, to improve the uniform distribution of current density due to the asymmetrical structure of the electrode to provide a high efficiency light emitting diode and a method of manufacturing the same.

A first feature according to the invention is a light emitting diode comprising a semiconductor layer comprising a N semiconductor layer, an active layer and a P semiconductor layer on a transparent substrate to form a PN junction, wherein the semiconductor layer has an aspect ratio of at least one; At least two light emitting parts including the active layer may be partitioned and connected to each of the light emitting parts, and an electrode may be provided to electrically connect the P semiconductor layer and the N semiconductor layer.

Here, a P electrode including a P electrode pad is provided in a portion of the P semiconductor layer, and the upper semiconductor layer and the active layer are preferably formed of an N electrode including an N electrode pad on a lower semiconductor layer exposed by being partially removed. It is also preferable that an insulator is formed between the P electrode pad and the lower N semiconductor layer of the bottom surface of the P electrode pad.

In addition, the aspect ratio of the substrate may be greater than or equal to 1 and less than 20, wherein the P electrode is connected to each of the light emitting portions, and is formed as a P electrode integrally provided on the side along the light-emitting diode shrinkage, and the N electrode is It may be formed integrally on the side of the N semiconductor layer opposite to the P electrode to be formed as one electrode.

On the other hand, the N electrode is preferably connected to the N electrode includes a branch-shaped auxiliary electrode protruding from the N electrode, the P electrode is connected to the P electrode and the branch-shaped auxiliary electrode protruding from the P electrode It is also desirable to include an electrode.

Further, an N electrode formed on the N semiconductor layer is disposed between the respective light emitting units and connected to the N electrode by being located on a side of the light emitting diode opposite to the first auxiliary electrode and the N electrode pad. It is also preferable to include a second auxiliary electrode to be.

In addition, the P electrode formed on the P semiconductor layer is located in the center of the LED, the N electrode formed on the N semiconductor layer is preferably formed on the side along the periphery of the light emitting diode including the respective light emitting portion, the P An electrode is positioned at the center of the light emitting diode, and the N electrode is formed on a side surface of the light emitting diode including the respective light emitting parts, and is connected to the N electrode to include an auxiliary electrode having a branch shape from the N electrode. It is also desirable to.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

5A to 5C are views illustrating a plan view and a cross-sectional view of the structure of the light emitting diode according to the present invention.

5A illustrates a plan view of a structure of a light emitting diode according to the present invention. As shown in FIG. 5A, light emitting parts 430 and 440 include an N semiconductor layer 410, an active layer 415, and a P semiconductor layer 420. ) And at least two aspect ratios, each having an aspect ratio of 1 or more, and an electrode structure 413 and 425 including an N electrode pad 417 and a P electrode pad 427 for electrically connecting each semiconductor layer.

The electrode structure is formed by the P electrode 425 on one side and the N electrode 413 on the other side of the contraction Y, and has a branch shape between the N electrode 413 and the active layer region of each light emitting part. By forming the auxiliary electrode 416, the asymmetrical structure of the electrode structure is removed to form a more symmetrical structure.

This is because it is possible to prevent the phenomenon that the current density distribution is concentrated toward the N electrode 413, thereby obtaining an effect of increasing the light efficiency. That is, by constructing the structures of the P electrode 425 and the N electrode 413 symmetrically in each light emitting part, the light density can be prevented from being driven to one side, thereby improving the light efficiency.

5B is a sectional view taken along the line AA ′ of the plan view illustrated in FIG. 5A as a light emitting diode according to the present invention. As shown in FIG. 5B, an N semiconductor layer 410, an active layer 415, and a P semiconductor layer 420 are stacked on the substrate 400, and a transparent electrode 423 is stacked on the P semiconductor layer 420 to emit light. A P electrode including a P electrode pad 427 electrically connecting the P semiconductor layer 420 to the P semiconductor layer 420 may be formed.

The light emitting units 440 including the P semiconductor layer 420, the active layer 415, and the N semiconductor layer 410 are divided into two, for example, by etching, and the P semiconductor layer ( A portion of the 420 and the active layer 415 are removed to expose the N semiconductor layer 410 to form the N electrode 413 thereon.

5C is a diagram illustrating a cross-sectional view taken along line BB ′ of the light emitting diode according to the present invention of FIG. 5A. 5C, the light emitting part including the P semiconductor layer 420, the active layer 415, and the N semiconductor layer 410 is divided and partitioned on both sides of the P electrode pad 427. An insulating layer 411 is formed between the N semiconductor layer 410 and the P electrode pad 427 to electrically insulate the N semiconductor layer 410 from the P electrode pad 427.

As described with reference to FIGS. 5A to 5C, the present invention solves the problem that a large number of light is absorbed by the N electrode 413 of the light emitting device due to prolonged progress by total reflection inside the light emitting units 430 and 440. To increase the aspect ratio, it is possible to escape easily with a short axis (X) without prolonged light, and to prevent the light efficiency decrease due to the uneven distribution of current density due to the asymmetrical structure of the electrode structure. To at least two light emitting parts including the P semiconductor layer 420, the active layer 415, the N semiconductor layer 410, and to form an electrode structure in a symmetrical chuck, a structure that can significantly increase the light efficiency and its manufacturing method Suggest.

In more detail, when the aspect ratio is increased, the light travels on the short axis X, so that a large number of light easily escapes to the outside. In addition, due to an asymmetric structure of the light emitting device, current is not evenly distributed and a phenomenon that the current crowding effect is severely generated only around the N electrode 413 may cause a problem of low efficiency.

In order to solve this problem, the light emitting parts 430 and 440 having an aspect ratio of 1 or more including the active layer 415 area are divided into two or more, and the P electrode 425 and the N electrode 413, in particular, the N electrode 413, in each light emitting part. It was observed in the present invention that by forming the symmetry more symmetrically, the light efficiency can be remarkably improved.

The aspect ratio defined here is not numerically specific, but is intended to improve light efficiency by reducing the long-term progress of light due to total internal reflection by increasing the aspect ratio than conventional inventions, and it is still possible to divide the light emitting diode elements into two or more light emitting portions. This is to compensate for the disadvantage that the light does not escape in the tightening direction.

In addition, it is also possible to improve the light efficiency by preventing an uneven distribution of current density through more symmetrical formation of the electrode structure. Therefore, the electrode structure can be variously formed to form the distribution of the current density most symmetrically, it is apparent that the structure can be easily derived by the proposal of the present invention.

Therefore, by dividing two or more light emitting portions including the active layer region of the light emitting diode and forming the N-electrode structure more symmetrically, the light can escape well on both the short axis and the long axis. It is possible to easily manufacture a light emitting diode of high light efficiency without process complexity and costly manufacturing cost, such as light efficiency improvement through sub mount or light efficiency improvement by forming a fine pattern on the surface of the light emitting layer.

FIG. 6 is a graph illustrating a distribution of current densities shown on the short axis X and the long axis Y of the light emitting diode according to the present invention illustrated in FIGS. 5A to 5C. As shown in FIG. 6, it can be seen that a large current density is distributed around the N electrode, and that the current density is zero between the light emitting portion and the electrode pad portion. As a result, it can be seen that the current density is excessively distributed around the N electrode of the conventional light emitting diode having a large aspect ratio, thereby reducing the optical efficiency considerably.

Here, the graph and the light efficiency shown in FIG. 6 are the results of simulation of the current density flowing through the active layer using the resistive-diode network structure in the light emitting diode structure. The maximum current density is normalized to 1, and the size of the light emitting diode is 600 μm × 200 μm. It was set as.

Luminous efficiency can be calculated through Equation 1.

[Equation 1]

That is, the luminous efficiency may be defined as a value obtained by dividing the sum of normalized currents (excluding the current density of the P electrode region) by the area of the light emitting diodes.

As such, the light emitting efficiency of the light emitting diode according to the present invention corresponding to FIG. 6 calculated through Equation 1 is represented by 14.6%. As shown in FIGS. 4A and 4B, in the asymmetric structure in which the N-electrode structure is oriented to one side by increasing the aspect ratio without partitioning the light emitting part, the luminous efficiency calculated through Equation 1 is 13.7%, but the calculated result is shown. It can be seen that the light efficiency of the light emitting diode proposed in the present invention is improved to 14.6%.

7A to 7C are views showing another embodiment of the light emitting diode according to the present invention, FIG. 7A is a view illustrating a top view of the light emitting diode according to the present invention, and FIG. 7B is taken along line AA ′ in FIG. 7A. FIG. 7C is a diagram illustrating a cross section, and FIG. 7C is a diagram illustrating a cross section taken along line BB ′.

As shown in FIG. 7A, two or more light emitting parts 430 and 440 including the active layer 515 are divided, and a P electrode 525 is on one side of the constriction Y of the light emitting diode, and an N electrode 513 on the other side. This structure is provided. In addition, by forming the branch-shaped first auxiliary electrode 516 and the N-electrode pad 517 opposite the light emitting parts 430 and 440 from the N electrode 513, the branch-shaped second auxiliary electrode 512. The distribution of the current density in each light emitting part can be made even.

Referring to FIG. 7B, the light emitting part 530 including the N semiconductor layer 510, the active layer 515, and the P semiconductor layer 520 is formed on the substrate 500, and the P electrode is formed on the P semiconductor layer 520. The P electrode including the pad 527 is formed on the N semiconductor layer 510 so as to form the N electrode 513.

In FIG. 7C, a cross-sectional view of the light emitting diode according to the present invention is illustrated in the cross-sectional view taken along the line BB ′, and the N semiconductor layer 510, the active layer 515, and the P semiconductor layer ( It can be seen that the light emitting parts 530 and 540 including 520 are partitioned.

FIG. 8 is a diagram illustrating a result of simulating distribution of current density along a short axis (X) and a short axis (Y) of the light emitting diodes shown in FIGS. 7A to 7C, and through this, the current density to one side due to the division of the light emitting unit. It can be seen that the concentration of is considerably reduced and the current density is more evenly distributed due to the more symmetrical structure of the electrode.

When the light efficiency is calculated by Equation 1, it can be confirmed that the efficiency is increased to about 16.6% by the improvement of the simple structure than the conventional light emitting diode.

9A to 9C are views showing another embodiment of the light emitting diode according to the present invention. FIG. 9A is a view illustrating a top view of the light emitting diode according to the present invention, and FIG. 9B is taken along line AA ′ in FIG. 9A. Fig. 9C is a view illustrating a cross section, and Fig. 9C is a view illustrating a cross section taken along line B-B '.

As shown in FIG. 9A, two light emitting parts 630 and 640 including an active layer are partitioned, and N electrodes 613 and 616 are formed to surround the light emitting diodes on both sides of the light emitting diode Y. The P electrode made of the P electrode pad 627 is provided at the center of the light emitting diode.

Thus, the N electrodes 613 and 616 are formed in a shape surrounding the side portions of the light emitting sections, respectively, which are symmetrical than the N electrodes formed on one side, so that the nonuniformity of the current density distribution caused by the intensive distribution of the current density around the N electrodes is considerable. Partially resolved.

Referring to FIG. 9B, a light emitting part 630 including an N semiconductor layer 610, an active layer 615, and a P semiconductor layer 620 is formed on a substrate, and a P electrode pad 627 is formed on the P semiconductor layer 620. The N-electrode 613,616 is formed on the N-semiconductor layer, and it can also be confirmed that the N-electrodes 613,616 surround the side portions of the constriction Y.

9C is a view illustrating a structure of a light emitting diode according to the present invention, taken along a BB 'cross-section, with the N semiconductor layer 610, the active layer 615, and the P electrode pad 627 at both sides. The light emitting part including the semiconductor layer 620 is partitioned.

FIG. 10 is a diagram illustrating a result of simulation of current density distribution along short axis (X) and long axis (Y) of the light emitting diodes shown in FIGS. 9A to 9C. Due to the structure, the concentration of current density on one side is considerably reduced, and the current density is more evenly distributed.

Here, when the light efficiency is calculated by Equation 1, it can be seen that the efficiency is considerably increased by improving the simpler structure than the conventional light emitting diode at 22.6%.

11A to 11C illustrate another embodiment of a light emitting diode according to the present invention. FIG. 11A illustrates a plan view of a light emitting diode according to the present invention, and FIG. 11B is taken along line AA ′ in FIG. 11A. FIG. 11C is a diagram illustrating a cross section taken along line BB ′.

As shown in FIG. 11A, two light emitting parts 730 and 740 including an active layer are partitioned, and N electrodes 713 and 716 are formed in the shape of being enclosed with light emitting diodes on both sides of the light emitting diode along the Y axis. Branch-shaped auxiliary electrodes 712, 718, 719 protruding from the N electrodes 713, 716 are formed at both sides of each light emitting part 730, 740. In addition, a P electrode formed of a P electrode pad 727 is provided at the center of the light emitting diode.

The N-electrodes 713 and 716 surround the side portions of the light emitting sections respectively partitioned, and further, the branch-shaped auxiliary electrodes 712, 718 and 719 protruding from the N electrodes 713 and 716 are formed symmetrically on both sides, thereby providing more symmetry. As a result, a structure can be formed to substantially eliminate the decrease in light efficiency due to the nonuniformity of the current density distribution caused by the intensive distribution of the current density around the N electrodes 713 and 716.

Referring to FIG. 11B, a light emitting part including an N semiconductor layer 710, an active layer 715, and a P semiconductor layer 720 is formed on a substrate, and a P electrode pad 727 is formed on the P semiconductor layer 720. The formation of the P electrode and the formation of the N electrodes 713 and 716 on the N semiconductor layer 710 may be confirmed, where the N electrodes 713 and 716 surround the side portions.

FIG. 11C is a view illustrating a structure of a light emitting diode according to the present invention, taken along a BB ′ cross-section. The N semiconductor layer 710, the active layer 715, and the P semiconductor layer ( It can be seen that the light emitting unit 730 including 720 is partitioned.

FIG. 12 is a diagram illustrating a simulation result of current density distribution according to a short axis (X) and a short axis (Y) of the light emitting diodes shown in FIGS. 11A to 11C. As a result, the concentration of the current density on one side is considerably reduced, and the current density is more evenly distributed. In addition, when the light efficiency is calculated by Equation 1, it can be seen that the efficiency is considerably improved by a simple structure improvement of the conventional light emitting diode at 24.9%.

In addition, when the light emitting diode device is large, it is apparent that the light emitting unit is partitioned into two or more regions and the electrode structure is formed more symmetrically to increase the light efficiency considerably.

As a second feature according to the present invention, FIG. 12 is a view illustrating a flowchart of a method of manufacturing a high efficiency light emitting diode due to the improvement of the partition and electrode structure of the light emitting unit.

Hereinafter, an example of the manufacturing method according to the flowchart of FIG. 12 of the manufacturing method according to the present invention will be described in detail.

An N semiconductor layer is formed on the substrate using a metal oxide chemical vapor deposition (MOCVD) or a molecular beam epitaxy (MBE) device (S10), and a P semiconductor layer is formed on the substrate using a MOCVD or MBE device. By forming the P semiconductor layer in this way, an active layer is formed in the bonding layer of the N semiconductor layer and the P semiconductor layer.

Through photolithography, a photoresist is formed on the P semiconductor layer, leaving only portions where the P semiconductor layer and the active layer are to be peeled off. The dry etching equipment is used to remove the P semiconductor layer and the active layer of the portion where the photoresist has not been applied, thereby partitioning the light emitting portion having the P semiconductor layer, the active layer, and the N semiconductor layer with an aspect ratio of 1 or more to 2 or more. The N semiconductor layer is exposed by removing the P semiconductor layer and the active layer.

In addition, in order to electrically insulate the P electrode pad and the N semiconductor layer, first, an insulator is formed on the front surface of the device using deposition equipment. A photoresist is formed on the insulator between the P semiconductor layer and the active layer divided into two or more through the photolithography process. The dry etching equipment is used to etch away the insulator in the areas where the photoresist is not applied. By removing the insulator of the remaining portion except between the P semiconductor layer and the active layer divided into two or more, an insulating layer is formed between the P electrode pad and the N semiconductor layer.

Then, a photoresist is formed on a portion other than a portion where the P electrode and the N electrode is to be formed through a photolithography process, and a metal thin film is deposited on the entire surface of the device using a deposition apparatus. The P electrode and the N electrode are formed by removing the metal thin film formed on the photoresist in a lift off process. The heat treatment reduces the contact resistance between the electrode and the semiconductor layer (S40).

While the invention has been shown and described in connection with specific embodiments thereof, it is well known in the art that various modifications and changes can be made without departing from the spirit and scope of the invention as indicated by the claims. Anyone who owns it can easily find out.

Providing the light emitting diode according to the present invention, by improving the structure and electrode structure of the semiconductor layer including the active layer that emits light to prevent some absorption while deteriorating the light efficiency while prolonged by total internal reflection of the light, the electrode It is possible to realize a high efficiency light emitting diode by improving the uneven distribution of current density due to the asymmetrical structure, and to manufacture a high efficiency light emitting diode with a simple process and a low cost without a sub mount to increase the light efficiency. It becomes possible.

Claims (10)

A light emitting diode comprising a semiconductor layer comprising a N semiconductor layer, an active layer, and a P semiconductor layer on a transparent substrate to form a P-N junction, The semiconductor layer includes at least two light emitting parts partitioned with the active layer having an aspect ratio of at least one. A P electrode including a P electrode pad electrically connected to a portion of the P semiconductor layer in the light emitting parts, and an N electrode including an N electrode pad formed on the N semiconductor layer, An insulator is formed between the P electrode pad and the N semiconductor layer. delete delete The method of claim 1, The aspect ratio of the said board | substrate is 1 or more and less than 20, The light emitting diode characterized by the above-mentioned. The method of claim 1, The P electrode is connected to each of the light emitting parts, and is formed as a P electrode integrally provided at a side along the light emitting diode constriction, and the N electrode is integrally provided at a side of the N semiconductor layer opposite to the P electrode. A light emitting diode, characterized in that formed by one electrode. The method of claim 1, The N electrode is connected to the N electrode and the light emitting diode, characterized in that it comprises a branch-shaped auxiliary electrode protruding from the N electrode. The method of claim 1, The P electrode is connected to the P electrode and the light emitting diode, characterized in that it comprises a branch-shaped auxiliary electrode protruding from the P electrode. The method of claim 1, The N electrode includes a first auxiliary electrode positioned between the light emitting parts and connected to the N electrode, and a second auxiliary electrode positioned on a side of the light emitting diode opposite the N electrode pad and connected to the N electrode. A light emitting diode characterized in that. The method of claim 1, The P electrode is located in the center of the light emitting diode, and the N electrode is a light emitting diode, characterized in that formed on the side along the outer edge of the light emitting diode. The method of claim 1, Wherein the P electrode is located in the center of the light emitting diode, the N electrode is formed on the side along the outside of the light emitting diode and is connected to the N electrode and comprises a branch-shaped auxiliary electrode protruding from the N electrode Light emitting diode.

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