KR20130066164A

KR20130066164A - Manufacturing method of semiconductor light emitting device and semiconductor light emitting device using the same method

Info

Publication number: KR20130066164A
Application number: KR1020110132878A
Authority: KR
Inventors: 박경선; 이완호; 허원구; 김성태
Original assignee: 삼성전자주식회사
Priority date: 2011-12-12
Filing date: 2011-12-12
Publication date: 2013-06-20

Abstract

PURPOSE: A semiconductor light emitting device manufacturing method and a semiconductor light emitting device which is manufactured by using the method are provided to minimize the plasma damage toward the semiconductor layer, thereby improving the efficiency of the light emitting device. CONSTITUTION: A light emitting structure which includes a first conductive type semiconductor layer(32), an active layer(34), and a second conductive semiconductor layer(36) are formed on a substrate. An insulating layer is formed on the light emitting structure by an atomic layer deposition method. A current blocking layer(42) is formed by etching the insulating layer, by using a mask. A current spreading layer is formed on the current blocking layer and an exposed second conductive semiconductor layer. An electrode is formed on the current spreading layer of an area which perpendicularly corresponded to the current blocking layer.

Description

Method for manufacturing a semiconductor light emitting device and a semiconductor light emitting device manufactured by using the same

The present invention relates to a semiconductor light emitting device manufacturing method and a semiconductor light emitting device manufactured using the same.

A semiconductor light emitting device is a semiconductor device capable of generating light of various colors based on recombination of electrons and holes at junctions of p and n type semiconductors when a current is applied. Such semiconductor light emitting devices have a number of advantages, such as long lifespan, low power supply, excellent initial driving characteristics, high vibration resistance, etc., compared to filament based light emitting devices. In particular, in recent years, group III nitride semiconductors capable of emitting light in a blue series short wavelength region have been in the spotlight.

In order to increase the merchandise value of the light emitting device using the group III nitride semiconductor, ohmic contact forming technology for smooth current injection has become important in the manufacturing process of the light emitting device.

However, when the current blocking layer is deposited by chemical vapor deposition (CVD) in the manufacturing of the light emitting device, plasma damage occurs in the light emitting device, and a schottky barrier exists between p-GaN / metal contacts. ) Becomes higher, which causes problems in the characteristics of the light emitting device, such as an increase in the operating voltage Vf of the light emitting device and a decrease in current efficiency.

Therefore, there is a demand for a method of forming a current blocking layer without plasma damage in manufacturing a light emitting device.

According to an aspect of the present invention,

Forming a light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer on a substrate; Forming an insulating film on the light emitting structure by atomic layer deposition; Etching the insulating layer using a mask to form a current blocking layer; Forming a current spreading layer on the current blocking layer and the exposed second conductive semiconductor layer; And forming an electrode on the current spreading layer in a region perpendicular to the current blocking layer.

In one embodiment of the present invention, the etching may be a wet etching.

In one embodiment of the present invention, the insulating film may be made of any one or more of SiO ₂ , Al ₂ O ₃ , Si ₃ N ₄ , SiON.

In an embodiment of the present invention, the atomic layer deposition method may use a silicon precursor and an oxygen precursor, and may form a silicon oxide film as the insulating layer by the atomic layer deposition method using the silicon precursor and the oxygen precursor.

In one embodiment of the present invention, the silicon precursor may be any one or more of Si (NCO) ₄ , SiCl ₄ , 3DMAS (Tris [dimethylamino] Silane, SiH [N (CH ₃ ) ₂ ] ₃ ).

In one embodiment of the present invention, the oxygen precursor may be any one or more of O ₂ , O ₃ , H ₂ O, N ₂ O.

In one embodiment of the present invention, the atomic layer deposition method may be performed at a temperature of less than 300 ° C.

Etching a predetermined region of the current diffusion layer, the second conductivity type semiconductor layer, and the active layer to expose a portion of an upper surface of the first conductivity type semiconductor layer; And forming an electrode on the exposed first conductive semiconductor layer.

In one embodiment of the present invention, the first conductivity type semiconductor layer may be made of n-GaN, the second conductivity type semiconductor may be made of p-GaN.

Another aspect of the invention,

Forming a light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer on a substrate; Forming an SOG film on the light emitting structure; Etching the SOG film using a mask to form a current blocking layer; Forming a current spreading layer on the current blocking layer and the exposed second conductive semiconductor layer; And forming an electrode on the current spreading layer in a region perpendicular to the current blocking layer.

In one embodiment of the present invention, the SOG film may be formed by applying any one of polysiloxane, polyimide.

In one embodiment of the present invention, the etching may be a wet etching.

According to another aspect of the present invention,

A light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer sequentially stacked on a substrate; A current blocking layer formed on a predetermined region of the light emitting structure; A current diffusion layer formed on the current blocking layer and the second conductive semiconductor layer exposed; And an electrode formed on the current spreading layer in a region perpendicular to the current blocking layer.

In one embodiment of the present invention, the current blocking layer may be formed by atomic layer deposition.

In one embodiment of the present invention, the current blocking layer may be made of an SOG film.

In one embodiment of the present invention, the first and second conductivity-type semiconductor layers may be made of GaN doped with first and second conductivity-type impurities, respectively.

In the process of manufacturing the current blocking layer, plasma damage to the semiconductor layer may be minimized, thereby improving efficiency of the light emitting device. In addition, it is possible to prevent an increase in the operating voltage Vf of the light emitting device.

1 to 9 are cross-sectional views of processes for describing a method of manufacturing a light emitting device according to an embodiment of the present invention.
10 is a flowchart showing a procedure of forming an insulating film according to an embodiment of the present invention with a silicon oxide film.
11 is a flowchart showing a procedure of forming an insulating film according to another embodiment of the present invention with a silicon oxide film.

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

However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Further, the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings may be exaggerated for clarity of description, and the elements denoted by the same reference numerals in the drawings are the same elements.

1 to 9 are cross-sectional views or plan views for each process for explaining a method of manufacturing a light emitting device according to an embodiment of the present invention.

First, referring to FIG. 1, a buffer layer 20 is formed on a semiconductor growth substrate 10. As the semiconductor growth substrate 10, a substrate made of a material such as sapphire, SiC, MgAl ₂ O ₄ , MgO, LiAlO ₂ , LiGaO ₂ , GaN, or the like may be used. In this case, the sapphire is a hexagonal-rhombo-symmetric crystal having lattice constants of 13.001 Å and 4.758 Å in the c-axis and the a-axis directions, respectively, and the C (0001) plane, the A (1120) R (1102) plane, and the like. In this case, the C-plane is relatively easy to grow the nitride film, and is stable at high temperature, and thus is mainly used as a substrate for nitride growth.

The buffer layer 20 formed on the semiconductor growth substrate 10 is for mitigation of lattice defects of the light emitting structure grown on the semiconductor growth substrate 10, and is an undoped semiconductor layer made of nitride or the like. Can be done. For example, the lattice constant difference between the sapphire substrate used as the semiconductor growth substrate and the semiconductor layer made of GaN stacked on the upper surface thereof can be alleviated, thereby increasing the crystallinity of the GaN layer. In this case, the buffer layer 20 may be undoped GaN, AlN, InGaN, etc., may be grown to a thickness of several tens to hundreds of kPa at a low temperature of 500 to 600 ℃. In this case, undoped means that the semiconductor layer is not subjected to an impurity doping process separately, and is used as a dopant when growing an impurity concentration of the level originally present in the semiconductor layer, for example, gallium nitride semiconductor using MOCVD. Si may be included at a level of about 10 ¹⁴ to 10 ¹⁸ / cm 3, although not intended.

Next, referring to FIG. 2, the light emitting structure 30 including the first conductive semiconductor layer 32, the active layer 34, and the second conductive semiconductor layer 36 is formed on the buffer layer 20. can do. In the present embodiment, the first and second conductivity-type semiconductor layers 32 and 36 may be n-type and p-type semiconductor layers, respectively, and may be formed of a nitride semiconductor. Therefore, the present invention is not limited thereto, but in the present embodiment, the first conductivity type may be understood to mean n type and the second conductivity type means p type. The first and second conductivity type semiconductor layers 32 and 36 have an Al x In y Ga (1-xy) N composition formula, where 0 ≦ x ≦ 1, 0 ≦ y ≦ 1, and 0 ≦ x + y ≦ 1. For example, a material such as GaN, AlGaN, InGaN, or the like may correspond thereto. The active layer 34 formed between the first and second conductivity type semiconductor layers 32 and 36 emits light having a predetermined energy by recombination of electrons and holes, and the quantum well layer and the quantum barrier layer alternate with each other. It may be made of a multi-quantum well (MQW) structure stacked. In the case of a multiple quantum well structure, for example, an InGaN / GaN structure may be used.

Next, as shown in FIG. 3, the insulating film 40 is formed on the light emitting structure 30 stacked on the semiconductor growth substrate 10 by atomic layer deposition (ALD). The insulating film 40 may be formed of any one or more of an oxide film such as SiO ₂ , Al ₂ O ₃ , or a nitride film such as Si ₃ N ₄ or SiON.

The atomic layer deposition method (ALD) is a method of forming a thin film through a self-limiting surface reaction on the surface of the substrate by supplying the respective reaction gases in a pulse form sequentially to the reaction tube. Therefore, the thickness and composition of the thin film can be precisely controlled, and the process can be lowered in temperature compared to the chemical vapor deposition (CVD) process.

The atomic layer deposition method (ALD) is a method for growing a desired material using a source gas that can react in a gaseous state, for example, Si (NCO) ₄ , SiCl ₄ , 3DMAS (Tris [dimethylamino] Silane, SiH [ Silicon (Si) precursors such as N (CH ₃ ) ₂ ] ₃ ) and oxygen precursors such as O ₂ , O ₃ , H ₂ O, and N ₂ O are injected into the reactor to grow a SiO ₂ film, or TMA (Tri -Methl Aluminum, Al (CH ₃ ) ₃ ) Al ₂ O ₃ is grown by exchanging source gas and H ₂ O source gas.

10 is a process flowchart illustrating a method of forming an insulating film according to an embodiment of the present invention into a silicon oxide film.

A method of forming an insulating film according to an embodiment of the present invention with reference to FIG. 10 as a silicon oxide film will be described.

First, the light emitting structures 30 stacked on the semiconductor growth substrate 10 are positioned in the reaction chamber. Subsequently, after adjusting the appropriate temperature and pressure, a agent containing a silicon (Si) precursor such as Si (NCO) ₄ , SiCl ₄ , 3DMAS (Tris [dimethylamino] Silane, SiH [N (CH ₃ ) ₂ ] ₃ ), etc. 1 gas is supplied into the chamber (S100). Then, the silicon precursor is adsorbed on the upper surface of the light emitting structure 30 (S110).

Subsequently, a purge gas, for example, N ₂ , He, or Ar gas is supplied into the chamber to remove the silicon precursor remaining in the chamber (or unreacted) (S120). Then, the silicon precursor adsorbed on the light emitting structure 30 is thinly formed at the atomic layer level.

Next, a second gas including an oxygen precursor is supplied into the chamber (S130). The second gas including the oxygen precursor serves to oxidize the silicon precursor adsorbed on the light emitting structure 30. For example, O ₂ , O ₃ , H ₂ O, N ₂ O, or the like may be used. . Accordingly, the silicon precursor and the oxygen precursor chemically react to form an atomic layer (S140).

Subsequently, a purge gas, for example, N ₂ , He, or Ar gas is supplied into the chamber to remove the oxygen precursor remaining in the chamber (S150). Then, the silicon oxide film forming process of one cycle is completed, and the silicon oxide film at the atomic layer level is formed on the light emitting structure 30.

Next, by repeatedly performing the introduction of the first gas, the adsorption step, the purge of the first gas, the introduction of the second gas, the adsorption step and the purge of the second gas n times to form a silicon oxide film having a desired thickness, A silicon oxide film having a desired thickness is formed (S160).

Thereafter, the process may be repeated to form a silicon oxide film having an appropriate thickness.

Subsequently, in order to improve the quality of the silicon oxide film, the silicon oxide film formed to an appropriate thickness may be heat treated (S170).

As the injected source gas moves independently, the reaction in the gaseous state is suppressed, and since it grows with a single layer, it is possible to deposit uniformly on the entire surface of the substrate and to precisely control the thickness of the film to be grown. There is this.

In addition, by using the atomic layer deposition method (ALD) it is possible to grow in a low temperature region, the process temperature can be maintained below 300 ° C, the lower the temperature, the longer the deposition time.

As such, when the insulating film 40 is formed by atomic layer deposition (ALD), the process is performed at a relatively low temperature, and since the plasma is not used during the process, the second conductive semiconductor layer 36 of the light emitting structure 30 is formed by plasma. This damage can be prevented.

11 is a process flowchart showing a method of forming an insulating film according to another embodiment of the present invention with a silicon oxide film.

A method of forming the insulating film 40 according to another embodiment of the present invention with reference to FIG. 11 as a silicon oxide film will be described.

The insulating film 40 may be formed of a silicon oxide film formed using a spin on glass (SOG) film.

An SOG film is coated on the light emitting structure 30 stacked on the semiconductor growth substrate 10 (S200). The SOG film is coated by spin coating, vapor deposition, bar coating, or the like. As the SOG solution for coating the SOG film, a high refractive material such as polysiloxane or polyimide may be used. However, the present invention is not limited thereto.

Next bake in a 300 ~ 400 ℃ temperature range and O ₂ or H ₂ O atmosphere (S210).

Subsequently, curing is performed to oxidize the applied SOG film (S220). Curing may be performed in an atmosphere supplied with an oxygen source. For example, it can be carried out by wet annealing in an atmosphere supplying H ₂ O. An oxygen source such as H ₂ O may be a source for oxidizing the SOG film. The curing may be carried out in a temperature range of 700 ~ 1000 ℃. By curing, the SOG film is formed of a silicon oxide film (S230).

As such, when the insulating film 40 is formed of an SOG film, plasma is not used in the same manner as in the atomic layer deposition method. Thus, the second conductive semiconductor layer 36 can be prevented from being damaged by the plasma.

4 illustrates a structure in which a mask M is formed on a portion of an upper surface of the insulating film 40. The mask M is formed in a region where the current blocking layer is to be located. The mask M may be formed through a photo-resist process or the like, and the photoresist does not dissolve (negative type) or dissolve (positive type) the photosensitive portion by the light irradiation. Will have the nature of. As shown in FIG. 4, the mask M formed using the photoresist process or the like is formed on a portion of the insulating film 40, and wet etching the surface of the insulating film 40 exposed to the outside. In this process, the masked insulating layer 40 may not be etched.

The etching solution used in the process of etching the insulating film 40 exposed to the outside may vary according to the type and thickness of the insulating film 40, and specifically, using an acid or base chemical It can be wet etched. In this case, the insulating layer 40 may be etched such that at least a portion of the second conductivity-type semiconductor layer 36 of the light emitting structure 30 is exposed to the outside.

FIG. 5 is a cross-sectional view illustrating a structure in which the second conductive semiconductor layer 36 is exposed by etching the insulating film 40 formed in a region excluding the mask M formation region.

The mask M may be removed by a photoresist solvent after an etching process, and a patterned insulating layer 40, that is, a current blocking layer CBL, may be formed on a surface where the mask M is removed. 42) remains. An electrode is formed on the current blocking layer 42 in a subsequent process.

FIG. 6 is a plan view schematically illustrating a view of the current blocking layer 42 formed by etching the insulating film 40 from above. In other words, when cut along the line V-V of FIG. 6, a cross-sectional view of the structure including the current blocking layer 42 of FIG. 5 is obtained.

As illustrated in FIG. 6, the current blocking layer 42 is formed along the region where the electrode is to be formed on the light emitting device.

When the current blocking layer is formed in this way, when an electrical signal is applied to the electrode formed on the upper portion of the current blocking layer 42 from the outside, no current flows to the current blocking layer 42 by the current blocking layer 42. The current is not concentrated in the lower region of the electrode and the current diffuses to other regions. Therefore, the current flows efficiently, thereby improving the reliability of the light emitting device and increasing the luminance.

Next, referring to FIG. 7, a current spreading layer 50 is formed on the upper surface of the current blocking layer 42. The current spreading layer 50 may be formed of a transparent conductive material such as ITO.

Next, as shown in FIG. 8, the current diffusion layer 50, the second conductivity-type semiconductor layer 36, the active layer 34 and the first conductivity-type so that a part of the first conductivity-type semiconductor layer 32 is exposed. A portion of the semiconductor layer 32 is dry etched to expose the first conductivity type semiconductor layer 32. Etching is dry etching using a known Reactive Ion Etching (RIE) method or an Inductive Coupled Plasma RIE (ICP-RIE).

Next, as shown in FIG. 9, the first electrode 60 is formed on the exposed upper surface of the first conductivity-type semiconductor layer 32, and the portion of the region corresponding to a portion perpendicular to the current blocking layer 42 is formed. The second electrode 70 is formed on the current spreading layer 50. The process of forming the first electrode 60 and the second electrode 70 may be performed at the same time, but is not limited thereto.

The first electrode 60 is formed on the upper surface of the first conductive semiconductor layer 32 that is etched and exposed, and the second electrode 70 is formed on the upper surface of the current blocking layer 42.

The first and second electrodes 60 and 70 are places where electrical signals are directly applied from the outside. The first and second electrodes 60 and 70 may be appropriately formed using a metal having high electrical conductivity, by a process such as plating, sputtering, and deposition.

The second electrode 70 is a place where an electric signal is directly applied from the outside, and in general, current is concentrated in the downward direction of the second electrode 70 so that the current is not evenly injected in the entire area of the semiconductor light emitting device. A problem arises in that the light emitting area is limited to a part of the semiconductor light emitting device. According to this embodiment, by interposing the current blocking layer 42 made of a material having high resistance and low electrical conductivity between the second electrode 70 and the second conductivity type semiconductor layer 36 to which current is directly applied, The current is evenly injected in the lateral direction without being concentrated in the lower region of the second electrode 70, thereby improving light uniformity of the semiconductor light emitting device.

The method of manufacturing a semiconductor light emitting device according to the present invention in which the current blocking layer is formed by atomic layer deposition (ALD) or an SOG film is not limited to a light emitting device having a horizontal structure as in the embodiment of the present invention. It can be applied to various types of light emitting devices, such as a light emitting device having a flip chip structure and a light emitting device having a vertical structure.

The present invention is not limited by the above-described embodiments and the accompanying drawings, but is defined by the appended claims. It will be apparent to 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 in the appended claims, As will be described below.

10: substrate 20: buffer layer
30: light emitting structure 32: first conductive semiconductor layer
34: active layer 36: second conductive semiconductor layer
40: insulating film 42: current blocking layer
50: current diffusion layer 60: first electrode
70: second electrode M: mask

Claims

Forming a light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer on a substrate;
Forming an insulating film on the light emitting structure by atomic layer deposition;
Etching the insulating layer using a mask to form a current blocking layer;
Forming a current spreading layer on the current blocking layer and the exposed second conductive semiconductor layer; And
Forming an electrode on the current spreading layer in a region perpendicular to the current blocking layer
Gt; a < / RTI > semiconductor light emitting device.

The method of claim 1,
The etching is a wet etching method of manufacturing a semiconductor light emitting device.

The method of claim 1,
The insulating film is a semiconductor light emitting device manufacturing method comprising a film of any one or more of SiO ₂ , Al ₂ O ₃ , Si ₃ N ₄ , SiON.

The method of claim 1,
The atomic layer deposition method uses a silicon precursor and an oxygen precursor, and forms a silicon oxide film as the insulating film by the atomic layer deposition method using the silicon precursor and the oxygen precursor.

5. The method of claim 4,
The silicon precursor is Si (NCO) ₄ , SiCl ₄ , 3DMAS (Tris [dimethylamino] Silane, SiH [N (CH ₃ ) ₂ ] ₃ ) Any one or more of the semiconductor light emitting device manufacturing method.

5. The method of claim 4,
The oxygen precursor is a semiconductor light emitting device manufacturing method of any one or more of O ₂ , O ₃ , H ₂ O, N ₂ O.

The method of claim 1,
The atomic layer deposition method is a semiconductor light emitting device manufacturing method made at a temperature of 300 ° C or less.

The method of claim 1,
Etching predetermined regions of the current diffusion layer, the second conductivity type semiconductor layer, and the active layer so that a part of the upper surface of the first conductivity type semiconductor layer is exposed; And
And forming an electrode on the exposed first conductive semiconductor layer.

The method of claim 1,
The first conductive semiconductor layer is made of n-GaN, the second conductive semiconductor is a semiconductor light emitting device manufacturing method consisting of p-GaN.

Forming a light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer on a substrate;
Forming an SOG film on the light emitting structure;
Etching the SOG film using a mask to form a current blocking layer;
Forming a current spreading layer on the current blocking layer and the exposed second conductive semiconductor layer; And
Forming an electrode on the current spreading layer in a region perpendicular to the current blocking layer
Gt; a < / RTI > semiconductor light emitting device.

The method of claim 10,
The SOG film is a semiconductor light emitting device manufacturing method is formed by applying any one of polysiloxane, polyimide (polyimide).

The method of claim 10,
The etching is a wet etching method of manufacturing a semiconductor light emitting device.

The method of claim 10,
Etching predetermined regions of the current diffusion layer, the second conductivity type semiconductor layer, and the active layer so that a part of the upper surface of the first conductivity type semiconductor layer is exposed; And
And forming an electrode on the exposed first conductive semiconductor layer.

The method of claim 10,
The first conductive semiconductor layer is made of n-GaN, the second conductive semiconductor is a semiconductor light emitting device manufacturing method consisting of p-GaN.

A light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer sequentially stacked on a substrate;
A current blocking layer formed on a predetermined region of the light emitting structure;
A current diffusion layer formed on the current blocking layer and the second conductive semiconductor layer exposed; And
An electrode formed on the current spreading layer in a region perpendicular to the current blocking layer
Semiconductor light emitting device comprising a.

16. The method of claim 15,
The current blocking layer is a semiconductor light emitting device formed by atomic layer deposition.

16. The method of claim 15,
The current blocking layer is a semiconductor light emitting device consisting of a SOG film.

16. The method of claim 15,
The semiconductor light emitting device of claim 1, wherein the first and second conductivity-type semiconductor layers each comprise GaN doped with first and second conductivity-type impurities.