KR20130103082A - Gallium nitride-based light emitting diode - Google Patents

Gallium nitride-based light emitting diode Download PDF

Info

Publication number
KR20130103082A
KR20130103082A KR1020120024430A KR20120024430A KR20130103082A KR 20130103082 A KR20130103082 A KR 20130103082A KR 1020120024430 A KR1020120024430 A KR 1020120024430A KR 20120024430 A KR20120024430 A KR 20120024430A KR 20130103082 A KR20130103082 A KR 20130103082A
Authority
KR
South Korea
Prior art keywords
gallium nitride
semiconductor layer
light emitting
emitting diode
layer
Prior art date
Application number
KR1020120024430A
Other languages
Korean (ko)
Inventor
김태균
윤여진
이진웅
김경완
Original Assignee
서울옵토디바이스주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 서울옵토디바이스주식회사 filed Critical 서울옵토디바이스주식회사
Priority to KR1020120024430A priority Critical patent/KR20130103082A/en
Publication of KR20130103082A publication Critical patent/KR20130103082A/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/04—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a quantum effect structure or superlattice, e.g. tunnel junction
    • H01L33/06—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a quantum effect structure or superlattice, e.g. tunnel junction within the light emitting region, e.g. quantum confinement structure or tunnel barrier
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/20—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a particular shape, e.g. curved or truncated substrate
    • H01L33/22—Roughened surfaces, e.g. at the interface between epitaxial layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/26—Materials of the light emitting region
    • H01L33/30—Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table
    • H01L33/32—Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table containing nitrogen
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2933/00—Details relating to devices covered by the group H01L33/00 but not provided for in its subgroups
    • H01L2933/0091—Scattering means in or on the semiconductor body or semiconductor body package

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Led Devices (AREA)

Abstract

A light emitting diode is disclosed. This light emitting diode includes: a gallium nitride substrate; A gallium nitride based first semiconductor layer on the gallium nitride substrate; A gallium nitride based second semiconductor layer positioned on the first semiconductor layer; And an active layer positioned between the first semiconductor layer and the second semiconductor layer. The active layer includes a bottom portion, a ceiling portion, and a connection portion connecting the bottom portion and the ceiling portion. Thus, a light emitting diode having an increased light emitting area is provided.

Description

Gallium nitride-based light emitting diodes {GALLIUM NITRIDE-BASED LIGHT EMITTING DIODE}

The present invention relates to a gallium nitride based light emitting diode, and more particularly to a gallium nitride based light emitting diode using a gallium nitride substrate as a growth substrate.

In general, nitrides of group III elements, such as gallium nitride (GaN), have excellent thermal stability and have a direct transition type energy band structure, and thus have recently received a lot of attention as materials for light emitting devices in the visible and ultraviolet regions. have. In particular, blue and green light emitting devices using indium gallium nitride (InGaN) have been used in various applications such as large-scale color flat panel display devices, traffic lights, indoor lighting, high density light sources, high resolution output systems, and optical communications.

Such a nitride semiconductor layer of Group III elements is difficult to fabricate homogeneous substrates capable of growing them, and therefore, such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE), etc., on heterogeneous substrates having a similar crystal structure. It has been grown through the process of. A sapphire substrate having a hexagonal system structure is mainly used as a heterogeneous substrate.

However, epitaxial layers grown on dissimilar substrates have a relatively high dislocation density due to lattice mismatch with the growth substrate and differences in coefficient of thermal expansion. Epilayers grown on sapphire substrates are generally known to have dislocation densities of at least 1E8 / cm 2. The epitaxial layer having such a high dislocation density has a limit in improving the luminous efficiency of the light emitting diode.

On the other hand, the light emitting diode includes an active layer between the first semiconductor layer and the second semiconductor layer, and emits light by the combination of electrons and holes in the active layer. When growing an epitaxial layer on a heterogeneous substrate, such as a sapphire substrate, the active layer is generally grown on the flat side of the first semiconductor layer to suppress the occurrence of crystal defects such as dislocations. Therefore, the area of the active layer is limited by the area of the light emitting diode substrate.

The problem to be solved by the present invention is to provide a light emitting diode having an improved luminous efficiency and a method of manufacturing the same.

Another object of the present invention is to provide a light emitting diode and a method of manufacturing the same, which can realize high brightness light by increasing the light emitting area of the active layer.

In one aspect of the present invention, a light emitting diode includes: a gallium nitride substrate; A gallium nitride based first semiconductor layer on the gallium nitride substrate; A gallium nitride based second semiconductor layer positioned on the first semiconductor layer; And an active layer positioned between the first semiconductor layer and the second semiconductor layer. In addition, the active layer includes a bottom portion, a ceiling portion, and a connection portion connecting the bottom portion and the ceiling portion. Here, the ceiling is located farther from the bottom surface of the substrate than the bottom of the entire thickness.

In addition, the gallium nitride substrate may have recesses and convex portions, and the first semiconductor layer and the active layer may be formed along the recesses and convex portions of the gallium nitride substrate.

According to another aspect of the present invention, there is provided a light emitting diode manufacturing method, wherein a gallium nitride substrate is patterned to form an uneven pattern having recesses and concave portions on an upper surface of the substrate, and the gallium nitride based first gallium nitride substrate having the recesses and convex portions. Forming a semiconductor layer, an active layer, and a gallium nitride based second semiconductor layer. The active layer may include a bottom portion, a ceiling portion, and a connection portion connecting the bottom portion and the ceiling portion, formed along the recessed portion and the convex portion of the gallium nitride substrate.

According to the present invention, by adopting a gallium nitride substrate can improve the crystallinity of the semiconductor layers grown thereon to improve the luminous efficiency of the light emitting diode. Furthermore, the light emitting area can be increased by forming the active layer in a three-dimensional structure instead of a two-dimensional planar structure, and thus a light emitting diode capable of realizing high light intensity can be provided.

1 is a cross-sectional view illustrating a light emitting diode according to an embodiment of the present invention.
2 to 4 are cross-sectional views illustrating a method of manufacturing a light emitting diode according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the same reference numerals denote the same components, and the width, length, thickness, etc. of the components may be exaggerated for convenience.

1 is a cross-sectional view illustrating a light emitting diode according to an embodiment of the present invention.

Referring to FIG. 1, the light emitting diode includes a gallium nitride substrate 21, a first semiconductor layer 27, an active layer 29, and a second semiconductor layer 31. In addition, the gallium nitride substrate 21 has recesses and convex portions 21a. Furthermore, the light emitting diode may include a low temperature buffer layer 23 and a two-dimensional growth layer 25, and further include electrodes connected to the first semiconductor layer 27 and the second semiconductor layer 31. Not).

The gallium nitride substrate 21 is the same substrate as the epi layer formed thereon. Therefore, there is no difference between the epi layer and the coefficient of thermal expansion and lattice matching. The gallium nitride substrate 21 may be manufactured using, for example, HVPE technology. On the other hand, the gallium nitride substrate 21 has a convex portion 21a and a recessed portion between the convex portions 21a. The convex portion 21a may be arranged in a stripe shape, but the present invention is not limited thereto. In particular, the convex portions 21a may be arranged in a mesh shape, and thus the plurality of concave portions may be spaced apart from each other. In this case, the recesses may be arranged in a matrix or honeycomb shape. Alternatively, the convex portions 21a may be arranged in a matrix form or in a honeycomb shape, and recesses may have a mesh shape.

The first semiconductor layer 27 may be, for example, an n-type gallium nitride based semiconductor layer, in particular GaN. The first semiconductor layer 27 covers the recess portion and the convex portion 21a. As shown, the first semiconductor layer 27 has a bottom portion in the recessed portion of the substrate 21 and has a ceiling portion on the convex portion 21a of the substrate 21. Further, the first semiconductor layer 27 is formed along the side surface of the convex portion 21a and has a connection portion connecting the bottom portion and the ceiling portion.

The two-dimensional growth layer 23 may be located between the first semiconductor layer 27 and the substrate 21. The two-dimensional growth layer 23 may be formed relatively thick on the upper surface of the convex portion 21a and the bottom surface of the concave portion of the substrate 21, and may have a relatively thin thickness on the side surface of the convex portion 21a.

Further, a low temperature buffer layer 23 may be located between the two-dimensional growth layer 25 and the substrate 21. The low temperature buffer layer 23 may be formed of GaN, or may be omitted.

The active layer 29 is positioned on the first semiconductor layer 27. Like the first semiconductor layer 27, the active layer 29 is continuously formed along the recesses and convex portions 21a of the substrate 21 to cover the recesses and the concave portions 21a. Accordingly, the active layer 29 includes a bottom portion, a ceiling portion, and a connection portion connecting them similarly to the first semiconductor layer 27. That is, the active layer 29 is different from the conventional two-dimensional planar structure, and has a three-dimensional structure. The ceiling of the active layer 29 is located higher than the bottom of the entire thickness. That is, the ceiling of the active layer 29 is located farther from the bottom surface of the substrate 21 than the bottom of the active layer 29.

The active layer 29 may have a single quantum well structure or a multiple quantum well structure. In particular, the active layer 29 may have a multi-quantum well structure having a barrier layer and a well layer, and the barrier layer may be formed of GaN, AlGaN or AlInGaN, and the well layer may be formed of InGaN, GaN, AlInGaN, or the like.

The second semiconductor layer 31 is positioned on the active layer 29. The second semiconductor layer 31 is, for example, a p-type gallium nitride based semiconductor layer. The second semiconductor layer 31 may have a relatively flat upper surface. Meanwhile, a cladding layer (not shown) may be interposed between the second semiconductor layer 31 and the active layer 29.

Meanwhile, electrodes (not shown) may be connected to the first semiconductor layer 27 and the second semiconductor layer 31, respectively. For example, the second semiconductor layer 31 and the active layer 29 may be partially removed to expose the first semiconductor layer 27, and the first electrode may be connected to the exposed first semiconductor layer 27. . In addition, a transparent electrode may be formed on the second semiconductor layer 31, and a second electrode may be positioned thereon.

According to this embodiment, the active layer 29 has a ceiling part and a bottom part, and a connection part connecting the ceiling part and the bottom part. That is, the active layer 29 is not flat unlike the conventional active layer, and thus has an increased light emitting area. Accordingly, there is provided a light emitting diode capable of realizing high light intensity without increasing the size of the light emitting diode.

2 to 4 are cross-sectional views illustrating a method of manufacturing a light emitting diode according to an embodiment of the present invention.

Referring to FIG. 2, first, the gallium nitride substrate 21 is patterned to form an uneven pattern having recesses and convex portions 21a. The gallium nitride substrate 21 may be patterned using photo and etching techniques. For example, after forming the SiO 2 mask layer, the gallium nitride substrate 21 may be dry or wet etched using the SiO 2 mask layer as an etching mask. At this time, the side of the iron portion 21a may be formed to be inclined 60 to 70 degrees with respect to the bottom surface.

The convex portion 21a may be arranged in a stripe shape, but is not limited thereto and may be arranged in a matrix shape or a honeycomb shape. Alternatively, the convex portion 21a may be formed in a mesh shape, and recesses may be arranged in a matrix shape or a honeycomb shape.

Referring to FIG. 3, a low temperature buffer layer 23 may be formed on the gallium nitride substrate 21. The low temperature buffer layer 23 may be grown to a three-dimensional growth condition using a MOCVD technique at a temperature of 500 ~ 600 ℃, such as 550 ℃. For example, the low temperature buffer layer 23 may be grown under a condition in which the V / III ratio is about 4000 at a process pressure of about 300 torr.

The low temperature buffer layer 23 may be formed on the recessed portion and the convex portion 21a of the gallium nitride substrate 21 and serves as a nuclear layer. However, since the gallium nitride substrate 21 may serve as a nuclear layer, the low temperature buffer layer 23 may be omitted.

Subsequently, the two-dimensional growth layer 25 is grown on the low temperature buffer layer 23. The two-dimensional growth layer 25 may be formed of, for example, an undoped gallium nitride layer, and may be grown under two-dimensional growth conditions using MOCVD techniques at about 1050 to 1100 ° C. For example, the two-dimensional growth layer 25 may be grown under a condition in which the V / III ratio is about 1000 at a process pressure of about 150 torr.

Referring to FIG. 4, a first semiconductor layer 27 is grown on the two-dimensional growth layer 25. The first semiconductor layer 27 is formed to cover the recessed portions and the convex portions 21a of the gallium nitride substrate 21. The first semiconductor layer 27 may be formed of an n-type gallium nitride layer by using a MOCVD technique, for example, at a temperature of 800 to 900 ° C., and is grown under the condition that the V / III ratio is about 2000 at a process pressure of about 200 torr. Can be. As the first semiconductor layer 27 is grown at a temperature of 800 to 900 ° C., the first semiconductor layer 27 is formed to have a substantially uniform thickness along the recessed portions and the convex portions 21a of the gallium nitride substrate 21.

Subsequently, an active layer 29 is grown on the first semiconductor layer 27 as shown in FIG. 1. The active layer 29 can be grown to conventional active layer growth conditions at a temperature of about 750 ° C. and a process pressure of about 200 torr using MOCVD techniques. Thereafter, the second semiconductor layer 31 is grown on the active layer 29, and the second semiconductor layer 31 may also be grown using conventional growth conditions. Accordingly, a light emitting diode as shown in FIG. 1 can be manufactured. In addition, the AlGaN cladding layer may be grown before the second semiconductor layer 31 is grown. In addition, the first semiconductor layer 27 may be exposed by partially removing the second semiconductor layer 31 and the active layer 29, and a first electrode may be formed on the exposed first semiconductor layer 27. Can be. Furthermore, a transparent electrode may be formed on the second semiconductor layer 31, and a second electrode may be formed on the transparent electrode.

In this embodiment, TMAl, TMGa, and TMIn may be used as the sources of Al, Ga, and In, and NH3 may be used as the source of N. In addition, SiH 4 may be used as a source of Si which is an n-type impurity, and Cp 2 Mg may be used as a source of Mg that is a p-type impurity.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments or constructions. Various changes and modifications may be made without departing from the spirit and scope of the invention. have.

Claims (11)

Gallium nitride substrates;
A gallium nitride based first semiconductor layer on the gallium nitride substrate;
A gallium nitride based second semiconductor layer positioned on the first semiconductor layer; And
It includes an active layer located between the first semiconductor layer and the second semiconductor layer,
The active layer includes a bottom portion, a ceiling portion, and a connection portion connecting the bottom portion and the ceiling portion,
Wherein the ceiling is located farther from the bottom surface of the substrate than the bottom of its entirety. The method according to claim 1,
The active layer is a continuous light emitting diode. The method according to claim 1,
The gallium nitride substrate has recesses and convex portions,
And the first semiconductor layer and the active layer are formed along recesses and convex portions of the gallium nitride substrate. The method according to claim 3,
The iron portion of the gallium nitride substrate includes a side,
The side surface of the light emitting diode inclined within a range of 60 to 70 degrees with respect to the bottom surface of the convex portion. The method according to claim 3,
And the convex portions are arranged in a matrix, honeycomb, or mesh shape. Patterning the gallium nitride substrate to form a concave-convex pattern having concave and convex portions on the upper surface of the substrate,
Forming a gallium nitride based first semiconductor layer, an active layer, and a gallium nitride based second semiconductor layer on the gallium nitride substrate having the recess and the convex portion;
The active layer may include a bottom portion, a ceiling portion, and a connection portion connecting the bottom portion and the ceiling portion, formed along the recessed portion and the convex portion of the gallium nitride substrate. The method of claim 6,
The first semiconductor layer is a light emitting diode manufacturing method formed along the recessed portion and the iron portion of the gallium nitride substrate. The method of claim 6,
The active layer has a multi-quantum well structure. The method of claim 6,
Side surface of the convex portion is a light emitting diode manufacturing method which is formed to be inclined within the range of 60 ~ 70 degrees with respect to the bottom surface of the convex portion. The method of claim 6,
The convex portions are arranged in a matrix, honeycomb or mesh shape. The method of claim 6,
The first semiconductor layer is a light emitting diode manufacturing method is grown at 800 ~ 900 ℃.
KR1020120024430A 2012-03-09 2012-03-09 Gallium nitride-based light emitting diode KR20130103082A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020120024430A KR20130103082A (en) 2012-03-09 2012-03-09 Gallium nitride-based light emitting diode

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020120024430A KR20130103082A (en) 2012-03-09 2012-03-09 Gallium nitride-based light emitting diode

Publications (1)

Publication Number Publication Date
KR20130103082A true KR20130103082A (en) 2013-09-23

Family

ID=49452570

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020120024430A KR20130103082A (en) 2012-03-09 2012-03-09 Gallium nitride-based light emitting diode

Country Status (1)

Country Link
KR (1) KR20130103082A (en)

Similar Documents

Publication Publication Date Title
US20090261376A1 (en) Nitride semiconductor light emitting diode and method of fabricating the same
KR101843513B1 (en) Gallium nitride-based light emitting diode
KR20120092326A (en) Non-polar light emitting diode having photonic crystal structure and method of fabricating the same
KR102284535B1 (en) Light emitting device and method of making the same
KR100809229B1 (en) Nitride semiconductor light emitting device and manufacturing method of the same
KR101322927B1 (en) Light emitting diode device and method for fabricating the same
KR20130099574A (en) Light emitting diode having gallium nitride substrate
US8247244B2 (en) Light emitting device and method of manufacturing the same
TWI437731B (en) Semiconductor optoelectronic device with enhanced light extraction efficiency and fabricating method thereof
KR101862407B1 (en) Nitride semiconductor light emitting device and Method for fabricating the same
KR20140071161A (en) Semiconductor Light Emitting Diode comprising Patterned Substrate having Conformity with Crystal Orientation and Manufacturing Method Thereof
KR101923673B1 (en) Method of fabricating gallium nitrded based semiconductor device
KR20130103082A (en) Gallium nitride-based light emitting diode
KR101321935B1 (en) A light emitting diode of a nitride compound and fabricating method therefor
US9548417B2 (en) Epitaxial structure with pattern mask layers for multi-layer epitaxial buffer layer growth
KR101239856B1 (en) Light-emitting diode and Method of manufacturing the same
KR20130108935A (en) Gallium nitride-based light emitting diode
KR101862406B1 (en) Nitride light emitting device and method for fabricating the same
KR101393354B1 (en) GaN BASED BUFFER LAYER AND METHOD OF FORMING THE SAME
KR101720621B1 (en) Light emitting device and method of manufacturing the same
KR20130104611A (en) Gallium nitride-based light emitting diode and light emitting device having the same
KR100722819B1 (en) Nitride semiconductor light-emitting diode and method of manufacturing the same
KR101316117B1 (en) A light emitting diode of a nitride compound and fabricating method therefor
KR20130037625A (en) Light emitting diode and manufacturing method
KR20130106926A (en) Gallium nitride-based semiconductor device

Legal Events

Date Code Title Description
WITN Withdrawal due to no request for examination