KR101063646B1 - Light emitting element and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a light emitting device and a method of manufacturing the same, wherein the light emitting device has at least one through hole formed in the sapphire substrate; A buffer layer is formed on the sapphire substrate; An N-nitride compound semiconductor layer, an active layer, a P-nitride compound semiconductor layer and a P-electrode are sequentially stacked on the buffer layer; N-electrodes are formed in lower portions of the buffer layer exposed in the through-holes.

Accordingly, the present invention can reduce the penetration density by forming a pattern penetrating the substrate on the sapphire substrate, and by forming an N electrode inside the penetrating pattern, a thin film of the device can be formed, and the manufacturing process and the assembly process are simplified. In addition, the effect that can be applied to a large area light emitting device is produced.

Luminescence, element, penetrating, electrode

Description

Light emitting device and method of manufacturing the same {Light emitting device and method of manufacturing the same}

1A to 1D are manufacturing process diagrams of a light emitting device according to a first embodiment of the present invention.

2A and 2B are plan views showing the shape of a pattern passing through a substrate formed on a sapphire substrate according to the present invention.

3A and 3B are cross-sectional views illustrating a process of manufacturing a plurality of light emitting devices on an sapphire substrate and separating the light emitting device chips into a single light emitting device chip according to the present invention.

4 is a cross-sectional view of a light emitting device according to a second embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100,200: Sapphire substrate 110: Pattern penetrating the substrate

120,220,320: Buffer layer

130,230,330: N-nitride compound semiconductor layer

140,240,340: active layer

150,250,350: P-nitride compound semiconductor layer

160,260,371,372,373: P-electrode 170,270,380: N-electrode

210a, 210b, 210c, 210d, 310: Through hole 300: Sapphire wafer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device and a method of manufacturing the same. More particularly, by forming a pattern penetrating a substrate on a sapphire substrate, the penetration density can be reduced, and an N electrode is formed inside the penetrating pattern, thereby providing The present invention relates to a light emitting device and a method for manufacturing the same, which can be a thin film type, can simplify the manufacturing process and assembly process, and can be applied to a large area light emitting device.

In general, in the case of a light emitting device, a group III nitride compound semiconductor is a direct transition type semiconductor having a broad emission spectrum ranging from ultraviolet to red, and has been applied to light emitting devices such as light emitting diodes and laser diodes.

In addition, since the band gap is wide, stable operation can be expected at a higher temperature than devices using other semiconductors. Therefore, applications to transistors such as field effect transistors (FETs) have been continuously studied.

Typically, a light emitting device is manufactured by stacking sapphire on a substrate with a group III nitride compound semiconductor Epi layer.

However, when the group III nitride compound semiconductor is formed on the sapphire substrate, a through potential is generated due to lattice constant mismatch between the sapphire and the group III nitride compound semiconductor, which causes a problem of deterioration of device characteristics.

In addition, since the sapphire itself is an insulator, the upper electrode and the lower electrode have to be on the same plane during the manufacturing process of the light emitting diode chip, which not only makes the manufacturing process complicated but also performs the wire bonding process that is difficult in the assembly process. There is a drawback that can only be done.

In order to solve the above problems, the present invention can reduce the penetration density by forming a pattern through the substrate in the sapphire substrate, and can form a thin film of the device by forming an N electrode inside the pattern. It is an object of the present invention to provide a light emitting device and a method of manufacturing the same, which can simplify the manufacturing process and the assembly process and can be applied to a large area light emitting device.

A preferred aspect for achieving the above objects of the present invention is that at least one through hole is formed in the sapphire substrate;

A buffer layer is formed on the sapphire substrate;

An N-nitride compound semiconductor layer, an active layer, a P-nitride compound semiconductor layer and a P-electrode are sequentially stacked on the buffer layer;

A light emitting device is provided in which an N-electrode is formed under the buffer layer so that each of the at least one through hole is entirely filled.

Another preferred aspect for achieving the above objects of the present invention comprises the steps of: forming a pattern through the substrate in the sapphire substrate;

Forming a buffer layer on the sapphire substrate having a pattern penetrating through the substrate;                         

Sequentially forming an N-nitride-based compound semiconductor layer, an active layer and a P-nitride-based compound semiconductor layer on the buffer layer;

Forming a P-electrode on the P-nitride compound semiconductor layer;

A method of manufacturing a light emitting device is provided, comprising: forming an N-electrode under the buffer layer exposed inside the penetrating pattern.

Another preferred aspect for achieving the above object of the present invention is the step of forming a plurality of spaced through holes through the substrate in the sapphire substrate;

Forming a buffer layer on the sapphire substrate on which the plurality of through holes are formed;

Forming an N-nitride-based compound semiconductor layer, an active layer, a P-nitride-based compound semiconductor layer, and a P-electrode on the buffer layer;

Forming an N-electrode in each lower portion of the buffer layer exposed in the plurality of through holes;

In order to separate into a light emitting device chip containing the N-electrode, there is provided a method of manufacturing a light emitting device comprising the step of cutting from the P-electrode to the sapphire substrate.

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

1A to 1C illustrate a manufacturing process of a light emitting device according to a first embodiment of the present invention, in which a pattern 110 penetrating a substrate is formed on a sapphire substrate 100 (FIG. 1A).

Here, the pattern 110 penetrating the substrate is preferably formed as a stripe type 110a, as shown in FIG. 2A, or a lattice shape 110b, as shown in FIG. 2B, and the pattern penetrating the substrate ( The penetrated width W of 110 is preferably 10 to 30 μm.

In addition, the distance L between the patterns 110 penetrating the substrate is preferably 10 to 30 μm.

Thereafter, a buffer layer 120 is formed on the sapphire substrate 100 on which the pattern 110 penetrating the substrate is formed (FIG. 1B).

Here, the buffer layer 120 is preferably formed by longitudinally and transverse epitaxial growth of the undoped nitride compound semiconductor layer by a MOCVD process or a HVPE process having a high growth rate.

In this case, since the buffer layer 120 formed over the region of the pattern 110 penetrating the substrate is formed by lateral epitaxial growth, the buffer layer 120 may not match the lattice constant mismatch between the sapphire substrate 100 and the grown buffer layer 120. The density of penetration potential propagated in the longitudinal direction is reduced, so that the penetration density in the entire buffer layer 120 can be reduced.

Next, an N-nitride-based compound semiconductor layer 130, an active layer 140, and a P-nitride-based compound semiconductor layer 150 are sequentially formed on the buffer layer 120, and the P-nitride-based compound semiconductor layer is sequentially formed. The P-electrode 160 is formed on the upper portion of the 150, and the N-electrode 170 is formed on the lower portion of the buffer layer 120 exposed inside the penetrating pattern 110 (FIG. 1C).

Meanwhile, in order to manufacture a plurality of light emitting devices on the sapphire substrate and separate the light emitting device chips, as illustrated in FIGS. 3A and 3B, a plurality of spaced through holes penetrating the substrate to the sapphire substrate 200 are provided. (210a, 210b, 210c, 210d); Forming a buffer layer (220) on the sapphire substrate (200) on which the through holes (210a, 210b, 210c, 210d) are formed; Forming an N-nitride compound semiconductor layer 230, an active layer 240, a P-nitride compound semiconductor layer 250, and a P-electrode 260 on the buffer layer 220; Forming N-electrodes (270) in lower portions of the buffer layer (220) exposed inside the through holes (210a, 210b, 210c, 210d); In order to separate the light emitting device chip including the at least one N-electrode, a process of cutting the P-electrode 260 from the sapphire substrate 200 may be performed.

Here, the cutting process includes a conventional scribing and breaking process for separating the wafer into individual chips.

At this time, in one light emitting device chip, at least one through hole is formed in the sapphire substrate 200 as shown in FIG. 3B; A buffer layer 220 is formed on the sapphire substrate 200; An N-nitride-based compound semiconductor layer 230, an active layer 240, a P-nitride-based compound semiconductor layer 250, and a P-electrode 260 are sequentially stacked on the buffer layer 220; N-electrodes 270 are formed in lower portions of the buffer layer 220 exposed in the through-holes.

FIG. 4 is a cross-sectional view of a light emitting device according to a second embodiment of the present invention. In this second embodiment, a large area light emitting device such as a traffic light is implemented and has a structure similar to that of FIG. After the through hole 310 is formed in the sapphire wafer 300, the buffer layer 320, the N-nitride-based compound semiconductor layer 330, the active layer 340, and the P-nitride-based compound semiconductor layer 350 are formed. The transparent electrode 360 is sequentially formed, and then, at least two P-electrodes 371, 372 and 373 spaced apart from each other are formed on the transparent electrode 360, and the buffer layer exposed inside the through holes ( N-electrodes 380 are formed in each of the lower portions of 220.

Therefore, the present invention can reduce the penetration density by forming a pattern penetrating the substrate in the sapphire substrate, and by forming an N electrode inside the penetrating pattern, a thin film of the device can be formed, and the manufacturing process and the assembly process can be simplified. There is an advantage to this.

According to the present invention, by forming a pattern penetrating the substrate on the sapphire substrate, the penetration density can be reduced, and by forming the N electrode inside the penetrating pattern, a thin film of the device can be formed and the manufacturing process and the assembly process can be simplified. In addition, there is an effect that can be applied to a large area light emitting device.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (7)

At least one through hole is formed in the sapphire substrate; A buffer layer is formed on the sapphire substrate; An N-nitride compound semiconductor layer, an active layer, a P-nitride compound semiconductor layer and a P-electrode are sequentially stacked on the buffer layer; And an N-electrode formed below the buffer layer such that the at least one through hole is entirely filled. The method of claim 1, The P-electrode, Light emitting device, characterized in that formed on at least two spaced apart from each other on the P- nitride compound semiconductor layer. Forming a pattern penetrating the substrate in the sapphire substrate; Forming a buffer layer on the sapphire substrate having a pattern penetrating through the substrate; Sequentially forming an N-nitride-based compound semiconductor layer, an active layer and a P-nitride-based compound semiconductor layer on the buffer layer; Forming a P-electrode on the P-nitride compound semiconductor layer; And forming an N-electrode under the buffer layer exposed in the penetrating pattern. The method of claim 3, wherein The pattern penetrating through the substrate is a stripe (Stripe) type, characterized in that the manufacturing method of the light emitting device. The method of claim 4, wherein The interval L between the penetrating width W of the pattern penetrating the substrate and the pattern 110 penetrating the substrate is It is 10-30 micrometers, The manufacturing method of the light emitting element characterized by the above-mentioned. The method according to any one of claims 3 to 5, The buffer layer, A method of manufacturing a light emitting device, characterized in that the undoped nitride compound semiconductor layer is formed by longitudinal and lateral epitaxial growth. Forming a plurality of spaced through holes penetrating the substrate in the sapphire substrate; Forming a buffer layer on the sapphire substrate on which the plurality of through holes are formed; Forming an N-nitride-based compound semiconductor layer, an active layer, a P-nitride-based compound semiconductor layer, and a P-electrode on the buffer layer; Forming an N-electrode in each lower portion of the buffer layer exposed in the plurality of through holes; Cutting the sapphire substrate from the P-electrode to separate the light emitting device chip including the N-electrode.

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