JPH09283799A - Semiconductor light-emitting element - Google Patents
Semiconductor light-emitting elementInfo
- Publication number
- JPH09283799A JPH09283799A JP8664596A JP8664596A JPH09283799A JP H09283799 A JPH09283799 A JP H09283799A JP 8664596 A JP8664596 A JP 8664596A JP 8664596 A JP8664596 A JP 8664596A JP H09283799 A JPH09283799 A JP H09283799A
- Authority
- JP
- Japan
- Prior art keywords
- light emitting
- ingan
- layer
- buffer layer
- emitting device
- Prior art date
- Legal status (The legal status 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 status listed.)
- Pending
Links
- 239000004065 semiconductor Substances 0.000 title claims description 19
- 239000000463 material Substances 0.000 claims abstract description 68
- 239000000758 substrate Substances 0.000 claims abstract description 44
- 238000000034 method Methods 0.000 claims abstract description 16
- 239000013078 crystal Substances 0.000 claims description 47
- 238000005253 cladding Methods 0.000 claims description 10
- 229910010093 LiAlO Inorganic materials 0.000 claims description 5
- 238000000927 vapour-phase epitaxy Methods 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims description 2
- 230000003287 optical effect Effects 0.000 claims 1
- 229910052594 sapphire Inorganic materials 0.000 abstract description 11
- 239000010980 sapphire Substances 0.000 abstract description 11
- 229910002704 AlGaN Inorganic materials 0.000 abstract description 10
- 238000002488 metal-organic chemical vapour deposition Methods 0.000 abstract description 10
- 229910052596 spinel Inorganic materials 0.000 abstract description 4
- 239000011029 spinel Substances 0.000 abstract description 4
- 125000005842 heteroatom Chemical group 0.000 abstract 3
- 229910010092 LiAlO2 Inorganic materials 0.000 abstract 1
- 229910010936 LiGaO2 Inorganic materials 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 9
- 239000012298 atmosphere Substances 0.000 description 7
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 5
- 239000001257 hydrogen Substances 0.000 description 5
- 229910052739 hydrogen Inorganic materials 0.000 description 5
- 240000002329 Inga feuillei Species 0.000 description 4
- 229910020068 MgAl Inorganic materials 0.000 description 4
- XCZXGTMEAKBVPV-UHFFFAOYSA-N trimethylgallium Chemical compound C[Ga](C)C XCZXGTMEAKBVPV-UHFFFAOYSA-N 0.000 description 4
- IBEFSUTVZWZJEL-UHFFFAOYSA-N trimethylindium Chemical compound C[In](C)C IBEFSUTVZWZJEL-UHFFFAOYSA-N 0.000 description 4
- JLTRXTDYQLMHGR-UHFFFAOYSA-N trimethylaluminium Chemical compound C[Al](C)C JLTRXTDYQLMHGR-UHFFFAOYSA-N 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000012212 insulator Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- MHYQBXJRURFKIN-UHFFFAOYSA-N C1(C=CC=C1)[Mg] Chemical compound C1(C=CC=C1)[Mg] MHYQBXJRURFKIN-UHFFFAOYSA-N 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 239000012159 carrier gas Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
Landscapes
- Led Devices (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、半導体発光素子
（以下、「発光素子」という）に関し、詳しくは、発光
部がＩｎＧａＮ系半導体材料からなるものに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light emitting device (hereinafter referred to as "light emitting device"), and more particularly to a light emitting portion made of an InGaN-based semiconductor material.
【０００２】[0002]
【従来の技術】ＩｎＧａＮは、III-Ｖ族窒化物半導体混
晶であって、Ｉｎの組成比を高い値から低い値へと変化
させることによって、そのバンドギャップは１．９ｅＶ
から３．３９ｅＶまで変化し、赤色光〜紫外領域の光
（波長６５３ｎｍ〜３６６ｎｍ）を放出させることも可
能な化合物半導体である。2. Description of the Related Art InGaN is a III-V group nitride semiconductor mixed crystal, and its band gap is 1.9 eV by changing the composition ratio of In from a high value to a low value.
To 3.39 eV, it is a compound semiconductor that can emit light in the red light to ultraviolet region (wavelength 653 nm to 366 nm).
【０００３】従来の発光素子において、発光部の材料と
して、Ｉｎx Ｇａ1-x Ｎ、０≦ｘ≦１で表されるＩｎＧ
ａＮ系半導体材料（以下、単に「ＩｎＧａＮ系材料」と
いう）を用いたものとしては、図２に模式的に示すよう
な、ＩｎＧａＮ系材料を活性層３２ａの材料としてのみ
用い、ｐ型・ｎ型の両クラッド層３１ａ、３３ａにはＧ
ａＮまたはＡｌＧａＮ系材料を用いたダブルヘテロ接合
構造を発光部３ａとするものが知られている。また、同
図において、１ａは結晶基板、２ａはバッファ層であ
る。In the conventional light emitting device, the material of the light emitting portion is In x Ga 1 -x N, InG represented by 0 ≦ x ≦ 1
As a material using an aN-based semiconductor material (hereinafter, simply referred to as “InGaN-based material”), an InGaN-based material as shown in FIG. 2 is used only as a material for the active layer 32a, and a p-type / n-type material is used. G on both clad layers 31a and 33a
It is known that the light emitting portion 3a has a double heterojunction structure using aN or AlGaN material. Further, in the figure, 1a is a crystal substrate and 2a is a buffer layer.
【０００４】[0004]
【発明が解決しようとする課題】ＩｎＧａＮ系材料は、
Ｉｎの組成比を高くするに伴い、ＧａＮやＡｌＧａＮと
の格子定数の差が大きくなるため、図２に示すような、
ＧａＮやＡｌＧａＮをクラッド層に用いた従来の発光部
の構造では、活性層に用いられたＩｎＧａＮ系材料にお
けるＩｎの組成比を高くすることは、困難であった。従
って、発光部の材料にＩｎＧａＮ系材料が用いられた発
光素子では、青色から緑色の波長域（４５０ｎｍ〜５２
０ｎｍ程度）にかけては、比較的高輝度のものが得られ
ていたが、黄色の波長域付近では十分な輝度が得られ
ず、それよりも長い波長域、例えば、赤色光を発する発
光素子は得られていなかった。InGaN-based materials are
As the composition ratio of In increases, the difference in lattice constant between GaN and AlGaN increases, so that as shown in FIG.
In the conventional structure of the light emitting unit using GaN or AlGaN for the cladding layer, it was difficult to increase the In composition ratio in the InGaN-based material used for the active layer. Therefore, in the light emitting device using the InGaN-based material as the material of the light emitting portion, the wavelength range from blue to green (450 nm to 52 nm
0 nm), a relatively high brightness was obtained, but sufficient brightness was not obtained in the vicinity of the yellow wavelength range, and a light emitting element emitting a longer wavelength range, for example, red light was obtained. It wasn't done.
【０００５】本発明の課題は、発光部の材料、特に活性
層の材料としてＩｎＧａＮ系材料を用いながら、その結
晶性を良好に維持したままで、ＩｎＧａＮ系材料中のＩ
ｎの組成比を高い値に設定することができ、高輝度な赤
色の光を放出するように形成することも可能な発光素子
を提供することである。An object of the present invention is to use an InGaN-based material as a material of a light emitting portion, particularly an active layer, while maintaining good crystallinity of the InGaN-based material.
It is an object of the present invention to provide a light emitting element in which the composition ratio of n can be set to a high value and which can be formed so as to emit red light with high brightness.
【０００６】[0006]
【課題を解決するための手段】本発明の発光素子は、次
の特徴を有するものである。 （１）ダブルヘテロ接合構造を発光部として有し、前記
ダブルヘテロ接合構造を構成するｐ型クラッド層、活性
層、ｎ型クラッド層が、全てＩｎＧａＮ系材料によって
形成されたものであることを特徴とする発光素子。The light emitting device of the present invention has the following features. (1) It has a double heterojunction structure as a light emitting part, and the p-type clad layer, the active layer and the n-type clad layer constituting the double heterojunction structure are all formed of an InGaN-based material. Light emitting element.
【０００７】（２）活性層に用いられるＩｎＧａＮ系材
料が、Ｉｎx Ｇａ1-x Ｎ、０．７≦ｘ≦１によって決定
される材料である上記（１）記載の発光素子。(2) The light emitting device according to (1) above, wherein the InGaN-based material used for the active layer is a material determined by In x Ga 1-x N, 0.7 ≦ x ≦ 1.
【０００８】（３）活性層が、単一量子井戸構造または
多重量子井戸構造である上記（１）または（２）記載の
発光素子。(3) The light emitting device according to the above (1) or (2), wherein the active layer has a single quantum well structure or a multiple quantum well structure.
【０００９】（４）当該半導体発光素子の積層構造が、
結晶基板上にバッファ層を介してダブルヘテロ接合構造
を成長させてなる積層構造であって、結晶基板の材料
が、サファイア、６Ｈ−ＳｉＣ、ＭｇＡｌ2 Ｏ4 （スピ
ネル）、ＬｉＡｌＯ2 、ＬｉＧａＯ2 のいずれかであ
り、バッファ層の材料が、ＡｌＮ、ＧａＮ、ＩｎＧａ
Ｎ、ＡｌＧａＮのいずれかである上記（１）〜（３）記
載の発光素子。(4) The laminated structure of the semiconductor light emitting device is
A laminated structure obtained by growing a double heterojunction structure on a crystal substrate via a buffer layer, wherein the material of the crystal substrate is sapphire, 6H-SiC, MgAl 2 O 4 (spinel), LiAlO 2 , or LiGaO 2 . The material of the buffer layer is AlN, GaN, InGa
The light emitting device according to the above (1) to (3), which is either N or AlGaN.
【００１０】（５）バッファ層およびＩｎＧａＮ系半導
体材料からなるダブルヘテロ接合構造を結晶基板上に形
成する方法が、ともに有機金属気相エピタキシー（Meta
l Organic Vapor Phase Epitaxy ；ＭＯＶＰＥ）である
上記（４）記載のＩｎＧａＮ単結晶の製造方法。(5) A method of forming a double heterojunction structure composed of a buffer layer and an InGaN-based semiconductor material on a crystal substrate is both metal organic vapor phase epitaxy (Meta
l Organic Vapor Phase Epitaxy; MOVPE).
【００１１】[0011]
【作用】発光素子のダブルヘテロ接合構造において、活
性層の材料だけでなく、これを挟むｐ型・ｎ型の両クラ
ッド層の材料としてＩｎＧａＮ系材料を用いることによ
って、活性層に用いられるＩｎＧａＮ系材料を、高いＩ
ｎの組成比として、かつ、良好な結晶性で成長させるこ
とも可能となる。これによって、ＩｎＧａＮ系材料を活
性層の材料として用いたものでありながら、赤色（波長
約６５３ｎｍ付近）の領域の光を発する発光素子を製造
することも可能となる。In the double heterojunction structure of the light emitting device, the InGaN-based material used for the active layer is obtained by using the InGaN-based material not only as the material of the active layer but also as the material of both p-type and n-type cladding layers that sandwich the active-layer. Material high I
It is also possible to grow with an n composition ratio and good crystallinity. As a result, it becomes possible to manufacture a light emitting element that emits light in the red region (wavelength of about 653 nm) even though the InGaN-based material is used as the material of the active layer.
【００１２】[0012]
【発明の実施の形態】以下、本発明を詳細に説明する。
図１は、本発明の発光素子の構造の一例を示す模式図で
ある。同図に示すように、本発明の発光素子は、ダブル
ヘテロ接合構造３を発光部として有し、このダブルヘテ
ロ接合構造３を構成するｎ型クラッド層３１、活性層３
２、ｐ型クラッド層３３が全てＩｎＧａＮ系材料によっ
て形成されるものである。同図の例は、結晶基板に絶縁
体であるサファイア結晶を用いた場合の構造例である。
また、ダブルヘテロ接合構造３は結晶基板１上にバッフ
ァ層２を介して形成されている。ダブルヘテロ接合構造
における伝導型は、ｐ型・ｎ型のいずれを結晶基板側と
してもよい。図１の例では、結晶基板側をｎ型として示
している。このような構造の発光素子とすることによっ
て、活性層の結晶品質を良好な状態に維持しながら、Ｉ
ｎの組成比を所望の値まで高く設定できる。BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
FIG. 1 is a schematic view showing an example of the structure of the light emitting device of the present invention. As shown in the figure, the light emitting device of the present invention has the double heterojunction structure 3 as a light emitting portion, and the n-type cladding layer 31 and the active layer 3 constituting the double heterojunction structure 3 are formed.
2. The p-type clad layer 33 is entirely made of InGaN-based material. The example of the figure is a structural example when a sapphire crystal which is an insulator is used for the crystal substrate.
The double heterojunction structure 3 is formed on the crystal substrate 1 via the buffer layer 2. Regarding the conduction type in the double heterojunction structure, either p-type or n-type may be on the crystal substrate side. In the example of FIG. 1, the crystal substrate side is shown as n-type. With the light emitting device having such a structure, while maintaining the crystal quality of the active layer in a good state, I
The composition ratio of n can be set high to a desired value.
【００１３】結晶基板に用いられる材料は、上記サファ
イア結晶の他に、６Ｈ−ＳｉＣ、ＭｇＡｌ2 Ｏ4 （スピ
ネル）、ＬｉＡｌＯ2 、ＬｉＧａＯ2 などが挙げられ
る。サファイア結晶は、α−Ａｌ2 Ｏ3 を結晶構造とす
るものであればよく、従来よりＧａＮ単結晶などを成長
させるための基板として利用されているものを利用して
よい。特に（０００１）面が基板の上面となるように形
成されたサファイアＣ面基板が、成長層表面の平坦性お
よび成長層の結晶性を向上させる点で好ましく用いられ
る。Examples of materials used for the crystal substrate include 6H-SiC, MgAl 2 O 4 (spinel), LiAlO 2 and LiGaO 2 in addition to the above sapphire crystal. Any sapphire crystal may be used as long as it has a crystal structure of α-Al 2 O 3 , and those conventionally used as a substrate for growing a GaN single crystal or the like may be used. In particular, a sapphire C-plane substrate formed so that the (0001) plane is the upper surface of the substrate is preferably used in terms of improving the flatness of the growth layer surface and the crystallinity of the growth layer.
【００１４】バッファ層の材料としては、ＡｌＮ、Ｇａ
Ｎ、ＩｎＧａＮ、ＡｌＧａＮが好ましいものとして挙げ
られる。これらの材料のいずれかを結晶基板上に成膜し
バッファ層とすることによって、さらにその上には、良
好な結晶性でありながら十分に厚いＩｎＧａＮ単結晶か
らなるクラッド層を成長させることができる。The material of the buffer layer is AlN or Ga.
N, InGaN, and AlGaN are preferred. By forming one of these materials on a crystal substrate to form a buffer layer, a clad layer made of a sufficiently thick InGaN single crystal can be grown on the buffer layer. .
【００１５】バッファ層の膜厚は限定されるものではな
いが、０．００１μｍ〜５μｍ程度、好ましくは０．０
０５μｍ〜０．５μｍが適当な厚みである。結晶基板上
へのバッファ層の成膜方法は特に限定されず、従来のバ
ッファ層形成に用いられるＭＯＶＰＥ、ＭＢＥ、ＣＢ
Ｅ、ＧＳ−ＣＢＥ、スパッタリングなども利用できる
が、バッファ層上に結晶成長させるＩｎＧａＮクラッド
層の成長方法と同一であることが特に好ましい。The thickness of the buffer layer is not limited, but is about 0.001 μm to 5 μm, preferably 0.0
A suitable thickness is 05 μm to 0.5 μm. The method of forming the buffer layer on the crystal substrate is not particularly limited, and MOVPE, MBE, CB used in the conventional buffer layer formation.
E, GS-CBE, sputtering, etc. can also be used, but it is particularly preferable to use the same method as the growth method of the InGaN clad layer for crystal growth on the buffer layer.
【００１６】ダブルヘテロ接合構造に用いられるＩｎＧ
ａＮ系材料は、Ｉｎx Ｇａ1-x Ｎ、０≦ｘ≦１、で表さ
れる化合物半導体であればよい。また、本発明がＩｎＧ
ａＮ系材料を活性層に用い、さらにＩｎの組成比の高い
ものまでの利用を可能とすることを目的とする点から
は、活性層に用いられるＩｎＧａＮ系材料は、Ｉｎx Ｇ
ａ1-x Ｎにおける組成比を、０＜ｘ≦１とすることが好
ましい。また、黄色の波長域付近で十分な輝度を示す発
光素子を提供する点では０．７≦ｘ≦１とすることが好
ましい。またさらに、赤色で十分な輝度を示す発光素子
を提供する点では０．９≦ｘ≦１とすることが好まし
い。InG used for double heterojunction structure
The aN-based material may be a compound semiconductor represented by In x Ga 1-x N, 0 ≦ x ≦ 1. In addition, the present invention is InG
From the point of using an aN-based material for the active layer, and making it possible to use even a high In composition ratio, the InGaN-based material used for the active layer is In x G
The composition ratio in a 1-x N is preferably 0 <x ≦ 1. Further, it is preferable that 0.7 ≦ x ≦ 1 from the viewpoint of providing a light emitting device that exhibits sufficient brightness in the vicinity of the yellow wavelength range. Furthermore, it is preferable that 0.9 ≦ x ≦ 1 from the viewpoint of providing a light emitting device that exhibits sufficient brightness in red.
【００１７】ダブルヘテロ接合構造の各層の厚みは限定
されず、公知の発光素子における厚みのとおりであって
もよい。例えば、ｐ型・ｎ型の両クラッド層の厚みは、
０．１μｍ〜５μｍ程度、活性層の厚みは、０．０１μ
ｍ〜０．１μｍ程度が例示される。活性層は、ＩｎＧａ
Ｎ系材料からなる単純な薄層であってもよいが、単一量
子井戸構造または多重量子井戸構造としてもよい。The thickness of each layer of the double heterojunction structure is not limited and may be the same as the thickness of a known light emitting device. For example, the thickness of both p-type and n-type cladding layers is
About 0.1 μm to 5 μm, the thickness of the active layer is 0.01 μm
An example is about m to 0.1 μm. The active layer is InGa
Although it may be a simple thin layer made of an N-based material, it may have a single quantum well structure or a multiple quantum well structure.
【００１８】ダブルヘテロ接合構造の形成方法は限定さ
れないが、本例に示すように、結晶基板１の上にバッフ
ァ層２を成膜し、さらにその上にＩｎＧａＮ系材料から
なるダブルヘテロ接合構造を形成する方法が好ましい方
法として挙げられる。Although the method of forming the double heterojunction structure is not limited, as shown in this example, the buffer layer 2 is formed on the crystal substrate 1 and the double heterojunction structure made of InGaN-based material is further formed thereon. The method of forming is mentioned as a preferable method.
【００１９】バッファ層上に目的のＩｎＧａＮ系材料か
らなるダブルヘテロ接合構造をエピタキシャル成長させ
る方法としては、ＭＯＶＰＥ、ＭＢＥ、ＣＢＥ、ＧＳ−
ＣＢＥなどが有効な方法として挙げられる。これらの成
長方法の中でも、ＭＯＶＰＥは、高温下での結晶成長が
可能であり、他に比べて速い成長速度でありながら、良
質で厚い単結晶を得られる特に好ましい成長方法であ
る。MOVPE, MBE, CBE, GS- can be used as a method for epitaxially growing a target double heterojunction structure made of an InGaN material on the buffer layer.
CBE etc. are mentioned as an effective method. Among these growth methods, MOVPE is a particularly preferable growth method capable of growing a crystal at a high temperature and having a higher growth rate than other methods and capable of obtaining a high quality and thick single crystal.
【００２０】また、バッファ層の形成とダブルヘテロ接
合構造の形成とを、同じエピタキシャル成長方法を用い
て行なえば、材料の供給や条件設定などを簡単に変える
だけで、バッファ層の成膜から、ＩｎＧａＮ単結晶の成
長へと、その場での連続的な成長が可能となるので好ま
しい。従って、バッファ層とＩｎＧａＮ単結晶とを共に
ＭＯＶＰＥによって成長させることが、本発明による発
光素子の最も好ましい形成方法の１つである。If the buffer layer and the double heterojunction structure are formed using the same epitaxial growth method, the buffer layer can be formed and the InGaN can be formed by simply changing the material supply and the condition setting. It is preferable because continuous growth can be performed in situ for growing a single crystal. Therefore, growing both the buffer layer and the InGaN single crystal by MOVPE is one of the most preferable methods for forming the light emitting device according to the present invention.
【００２１】ｐ型側・ｎ型側の両電極は公知の態様を利
用してもよい。ただし、サファイア結晶などの絶縁体を
結晶基板として用いる場合は、基板裏面に電極を設ける
ことができない。従って、図１に示すように、上側のク
ラッド層の上面に電極Ｘを設け、結晶基板側のクラッド
層（図ではｎ型クラッド層）の上面を露出させこの部分
に電極Ｙを設ける態様や、該クラッド層の側面に電極を
設ける態様などが挙げられる。また、６Ｈ−ＳｉＣなど
導電性を有するものを結晶基板として用いる場合には、
一般的な発光素子に見られるように、結晶基板から発光
部に至る積層体を積層方向に挟んで電極を設ける態様で
あってもよい。Both the p-type side electrode and the n-type side electrode may use known modes. However, when an insulator such as sapphire crystal is used as the crystal substrate, the electrode cannot be provided on the back surface of the substrate. Therefore, as shown in FIG. 1, a mode in which the electrode X is provided on the upper surface of the upper clad layer and the upper surface of the clad layer (n-type clad layer in the figure) on the crystal substrate side is exposed, and the electrode Y is provided on this part, Examples include a mode in which an electrode is provided on the side surface of the clad layer. Further, when a conductive material such as 6H-SiC is used as the crystal substrate,
As seen in a general light emitting element, a mode may be provided in which electrodes are sandwiched in the stacking direction from the crystal substrate to the light emitting portion in the stacking direction.
【００２２】本発明による発光素子の構造は、ＡｌＧａ
Ｎを活性層とする発光素子にも応用することができる。
従来のＡｌＧａＮ系材料からなるダブルヘテロ接合構造
は、結晶基板上にバッファ層を介して成長させたＧａＮ
上に作成していた。しかし、このような構造では、Ｇａ
Ｎと、ＡｌＧａＮ系材料からなるクラッド層との間に格
子定数差が存在するためにクラッド層のＡｌ組成比を高
くすることができなかった。このような問題に対して、
本発明の発光素子の構造を応用し、結晶基板直上にバッ
ファ層を介してＡｌＧａＮクラッド層を成長させれば、
活性層に用いられるＡｌＧａＮを良好な結晶性で高いＡ
ｌ組成比とすることができ、紫外発光素子の形成が容易
となる。The structure of the light emitting device according to the present invention is AlGa
It can also be applied to a light emitting device having N as an active layer.
A conventional double heterojunction structure made of AlGaN-based material is a GaN grown on a crystal substrate via a buffer layer.
Had created above. However, in such a structure, Ga
Since there is a lattice constant difference between N and the cladding layer made of the AlGaN-based material, the Al composition ratio of the cladding layer cannot be increased. For such a problem,
By applying the structure of the light emitting device of the present invention and growing the AlGaN cladding layer directly above the crystal substrate via the buffer layer,
AlGaN used for the active layer has good crystallinity and high A
The composition ratio can be 1 and the ultraviolet light emitting device can be easily formed.
【００２３】[0023]
【実施例】以下、実施例を挙げて本発明をより具体的に
説明する。 実施例１ 本実施例では、結晶基板としてサファイアＣ面基板を用
い、その上にＡｌＮからなるバッファ層、さらにＩｎＧ
ａＮ系材料からなるダブルヘテロ接合構造をＭＯＶＰＥ
によって成長させ、発光素子を形成した。ただし、電極
の形成に関する説明は省略する。EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. Example 1 In this example, a sapphire C-plane substrate was used as a crystal substrate, and a buffer layer made of AlN and InG were further formed thereon.
MOVPE with double heterojunction structure made of aN-based material
And a light emitting device was formed. However, the description regarding the formation of the electrodes is omitted.
【００２４】（１）洗浄したサファイアＣ面基板をＭＯ
ＶＰＥ装置にセットし、反応管内を約５×１０-6Ｔｏｒ
ｒまで真空に引いた。 （２）成長雰囲気を大気圧に戻し、先ず、水素雰囲気中
において１２００℃で５分間、サファイアＣ面基板表面
のサーマルクリーニングを行った。(1) MO the washed sapphire C-plane substrate
Set it in the VPE device and set the inside of the reaction tube to about 5 × 10 -6 Tor
A vacuum was pulled to r. (2) The growth atmosphere was returned to atmospheric pressure, and first, the sapphire C-face substrate surface was thermally cleaned in a hydrogen atmosphere at 1200 ° C. for 5 minutes.
【００２５】（３）材料ガスの供給量を、ＮＨ3 ；１ｓ
ｌｍ、トリメチルアルミニウム（ＴＭＡ）；５．５μｍ
ｏｌ／ｍｉｎとし、温度６００℃、雰囲気全体の圧力７
６０Ｔｏｒｒとして、ＡｌＮを厚み５０ｎｍまで堆積さ
せ、バッファ層２とした。(3) The supply amount of the material gas is NH 3 ; 1 s
lm, trimethylaluminum (TMA); 5.5 μm
ol / min, temperature 600 ° C., total atmosphere pressure 7
AlN was deposited to a thickness of 50 nm at 60 Torr to form the buffer layer 2.
【００２６】（４）材料ガスの供給量を、ＮＨ3 ；４ｓ
ｌｍ、トリメチルガリウム（ＴＭＧ）；７．３μｍｏｌ
／ｍｉｎ、トリメチルインジウム（ＴＭＩ）；１４．０
μｍｏｌ／ｍｉｎ、ＳｉＨ4 を２０ｓｃｃｍとし、温度
８００℃として、ｎ型のＩｎ 0.2 Ｇａ0.8 Ｎを厚み５μ
ｍまで結晶成長させてｎ型クラッド層とした。(4) The supply amount of the material gas is set to NHThree4s
lm, trimethylgallium (TMG); 7.3 μmol
/ Min, trimethylindium (TMI); 14.0
μmol / min, SiHFourTo 20 sccm and the temperature
N-type In at 800 ° C 0.2Ga0.8N thickness 5μ
Crystals were grown to m to form an n-type clad layer.
【００２７】（５）材料ガスの供給量のうち、ＴＭＧを
３．６μｍｏｌ／ｍｉｎ、ＴＭＩを３６μｍｏｌ／ｍｉ
ｎに変えて、アンドープのＩｎ0.9 Ｇａ0.1 Ｎを厚み
０．１μｍまで結晶成長させて活性層とした。(5) Of the material gas supply rates, TMG is 3.6 μmol / min and TMI is 36 μmol / mi.
Instead of n, undoped In 0.9 Ga 0.1 N was crystal-grown to a thickness of 0.1 μm to form an active layer.
【００２８】（６）材料ガスの供給量のうち、ＴＭＧを
７．３μｍｏｌ／ｍｉｎ、ＴＭＩを１４μｍｏｌ／ｍｉ
ｎに変えて、これに加えてシクロペンタジエニルマグネ
シウム（Ｃｐ2 Ｍｇ）を１９０ｎｍｏｌ／ｍｉｎ流し、
ｐ型クラッド層となるＭｇドープＩｎ0.2 Ｇａ0.8 Ｎを
厚み０．５μｍまで結晶成長させた。 （７）上記ＭｇドープＩｎＧａＮは、そのままではｐ型
導電性を示さないので、窒素雰囲気中にて７００℃で１
０分間アニール処理を行いｐ型化させて、ｐ型クラッド
層とした。(6) Of the material gas supply amounts, TMG is 7.3 μmol / min and TMI is 14 μmol / mi.
In addition to this, cyclopentadienyl magnesium (Cp 2 Mg) was flown at 190 nmol / min,
Mg-doped In 0.2 Ga 0.8 N to be the p-type cladding layer was crystal-grown to a thickness of 0.5 μm. (7) Since the above Mg-doped InGaN does not show p-type conductivity as it is, the Mg-doped InGaN does not have p-type conductivity at 700 ° C. in a nitrogen atmosphere.
Annealing treatment was performed for 0 minutes to make it a p-type to obtain a p-type clad layer.
【００２９】上記（１）〜（７）の工程の後、さらにｐ
型側・ｎ型側の電極を形成することによって、ＩｎＧａ
Ｎを活性層の材料として用いながら、波長６５０ｎｍの
赤色光を高輝度で放出し得る赤色ＬＥＤが得られた。After the above steps (1) to (7), p
By forming the electrodes on the mold side and the n-type side, InGa
A red LED capable of emitting red light with a wavelength of 650 nm with high brightness was obtained while using N as a material for the active layer.
【００３０】以下実施例２〜５に、サファイア結晶以外
の材料を結晶基板として用いた場合の発光素子の製造工
程のうち、バッファ層の形成工程までだけを具体的に例
示する。バッファ層上にダブルヘテロ接合構造を形成す
る工程は、全て上記実施例１と同様である。また、その
結果得られた発光素子から発せられる発光波長も上記実
施例１と同様であった。Examples 2 to 5 below specifically exemplify only the steps of forming a buffer layer among the steps of manufacturing a light emitting device using a material other than sapphire crystal as a crystal substrate. The steps of forming the double heterojunction structure on the buffer layer are the same as those in the first embodiment. The emission wavelength emitted from the resulting light emitting device was also the same as in Example 1 above.
【００３１】実施例２ 本実施例では、６Ｈ−ＳｉＣを結晶基板として用いた場
合の例を示す。 （１）フッ酸により酸化膜を除去した（０００１）６Ｈ
−ＳｉＣ結晶基板をＳｉ面を上にしてＭＯＶＰＥ装置に
セットし、反応室を５×１０-6Ｔｏｒｒまで真空に引い
た。 （２）反応室を常圧に戻し水素雰囲気中において１２０
０℃で５分間基板表面のサーマルクリーニングを行っ
た。 （３）材料ガスの供給量を、ＮＨ3 ；１ｓｌｍ、ＴＭ
Ａ；５．５μｍｏｌ／ｍｉｎとし、成長温度１２００℃
にてＡｌＮ高温バッファ層を５０ｎｍ堆積させた。 （４）材料ガスの供給量はそのままに、更に成長温度６
００℃にてＡｌＮ低温バッファ層を５０ｎｍ堆積させ
た。Example 2 In this example, 6H-SiC is used as a crystal substrate. (1) The oxide film was removed with hydrofluoric acid (0001) 6H
The -SiC crystal substrate was set in the MOVPE apparatus with the Si side facing up, and the reaction chamber was evacuated to 5 x 10 -6 Torr. (2) The reaction chamber is returned to normal pressure, and the hydrogen atmosphere is maintained at 120
The substrate surface was thermally cleaned at 0 ° C. for 5 minutes. (3) Supply amount of material gas is NH 3 ; 1 slm, TM
A: 5.5 μmol / min, growth temperature 1200 ° C.
Then, an AlN high temperature buffer layer was deposited to a thickness of 50 nm. (4) The growth rate is set to 6 without changing the amount of material gas supplied.
A 50 nm AlN low temperature buffer layer was deposited at 00 ° C.
【００３２】実施例３ 本実施例では、ＭｇＡｌ2 Ｏ4 （スピネル）を結晶基板
として用いた場合の例を示す。 （１）洗浄した（１１１）ＭｇＡｌ2 Ｏ4 結晶基板をＭ
ＯＶＰＥ装置にセットし、反応室を５×１０-6Ｔｏｒｒ
まで真空に引いた。 （２）反応室を常圧に戻し、水素雰囲気中において１２
００℃で５分間基板表面のサーマルクリーニングを行っ
た。 （３）材料ガスの供給量を、ＮＨ3 ；１ｓｌｍ、ＴＭ
Ａ；５．５μｍｏｌ／ｍｉｎとし、成長温度６００℃に
てＡｌＮバッファ層を５０ｎｍ堆積させた。Example 3 In this example, an example of using MgAl 2 O 4 (spinel) as a crystal substrate will be described. (1) Clean (111) MgAl 2 O 4 crystal substrate
Set it in the OVPE device and set the reaction chamber to 5 × 10 -6 Torr.
Evacuated until. (2) Return the reaction chamber to atmospheric pressure, and put it in a hydrogen atmosphere for 12
The substrate surface was thermally cleaned at 00 ° C. for 5 minutes. (3) Supply amount of material gas is NH 3 ; 1 slm, TM
A; 5.5 μmol / min, and an AlN buffer layer having a thickness of 50 nm was deposited at a growth temperature of 600 ° C.
【００３３】実施例４ 本実施例では、ＬｉＡｌＯ2 を結晶基板として用いた場
合の例を示す。 （１）洗浄したＬｉＡｌＯ2 結晶基板をＭＯＶＰＥ装置
にセットし、反応室を５×１０-6Ｔｏｒｒまで真空に引
いた。 （２）反応室を常圧に戻し、水素雰囲気中において８５
０℃で５分間基板表面のサーマルクリーニングを行っ
た。 （３）材料ガスの供給量を、ＮＨ3 ；１ｓｌｍ、ＴＭ
Ａ；５．５μｍｏｌ／ｍｉｎとし、成長温度６００℃に
てＡｌＮバッファ層を５０ｎｍ堆積させた。Example 4 In this example, an example in which LiAlO 2 is used as a crystal substrate will be described. (1) The cleaned LiAlO 2 crystal substrate was set in the MOVPE apparatus, and the reaction chamber was evacuated to 5 × 10 −6 Torr. (2) Return the reaction chamber to normal pressure, and in a hydrogen atmosphere, 85
The substrate surface was thermally cleaned at 0 ° C. for 5 minutes. (3) Supply amount of material gas is NH 3 ; 1 slm, TM
A; 5.5 μmol / min, and an AlN buffer layer having a thickness of 50 nm was deposited at a growth temperature of 600 ° C.
【００３４】実施例５ 本実施例では、ＬｉＧａＯ2 を結晶基板として用いた場
合の例を示す。 （１）洗浄したＬｉＧａＯ2 結晶基板をＭＯＶＰＥ装置
にセットし、反応室を５×１０-6Ｔｏｒｒまで真空に引
いた。 （２）ＬｉＧａＯ2 は水素雰囲気において還元されるた
め、キャリアガスにすべて窒素を用い、材料ガスの供給
量を、ＮＨ3 ；１ｓｌｍ、ＴＭＡ；５．５μｍｏｌ／ｍ
ｉｎとし、成長温度６００℃にてＡｌＮバッファ層を５
０ｎｍ堆積させた。Example 5 In this example, an example of using LiGaO 2 as a crystal substrate will be described. (1) The washed LiGaO 2 crystal substrate was set in the MOVPE apparatus, and the reaction chamber was evacuated to 5 × 10 −6 Torr. (2) Since LiGaO 2 is reduced in a hydrogen atmosphere, nitrogen is used as the carrier gas, and the supply amount of the material gas is NH 3 ; 1 slm; TMA; 5.5 μmol / m
and the growth temperature is 600 ° C. and the AlN buffer layer is 5
0 nm was deposited.
【００３５】[0035]
【発明の効果】本発明によって、活性層の材料としてＩ
ｎＧａＮ系材料を用いた発光素子でありながら、従来の
ような青色の発光だけでなく、活性層に用いるＩｎＧａ
Ｎ系材料の組成比によっては、高輝度な赤色の光を放出
させることもできるようになった。According to the present invention, as a material for the active layer, I
Although it is a light emitting device using an nGaN-based material, it not only emits blue light as in the past, but also uses InGa for an active layer.
Depending on the composition ratio of the N-based material, it has become possible to emit highly bright red light.
【図１】本発明による発光素子の構造の一例を示す模式
図である。FIG. 1 is a schematic view showing an example of a structure of a light emitting device according to the present invention.
【図２】従来の発光素子において、発光部の材料として
ＩｎＧａＮ系材料を用いた場合の構造の一例を示す模式
図である。FIG. 2 is a schematic diagram showing an example of a structure in a case where an InGaN-based material is used as a material of a light emitting portion in a conventional light emitting element.
１ 結晶基板 ２ バッファ層 ３ ダブルヘテロ接合構造 ３１ ＩｎＧａＮクラッド層（図の例ではｎ型） ３２ ＩｎＧａＮ活性層 ３３ ＩｎＧａＮクラッド層（図の例ではｐ型） DESCRIPTION OF SYMBOLS 1 Crystal substrate 2 Buffer layer 3 Double heterojunction structure 31 InGaN clad layer (n-type in the example of the figure) 32 InGaN active layer 33 InGaN clad layer (p-type in the example of the figure)
───────────────────────────────────────────────────── フロントページの続き (72)発明者 平松 和政 三重県四日市市芝田１丁目４番22号 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazumasa Hiramatsu 1-2-4 Shibata, Yokkaichi-shi, Mie
Claims (5)
し、前記ダブルヘテロ接合構造を構成するｐ型クラッド
層、活性層、ｎ型クラッド層が、全てＩｎＧａＮ系半導
体材料によって形成されたものであることを特徴とする
半導体発光素子。1. A light emitting portion having a double heterojunction structure, and a p-type cladding layer, an active layer, and an n-type cladding layer forming the double heterojunction structure are all formed of an InGaN-based semiconductor material. A semiconductor light emitting device characterized by the above.
材料が、Ｉｎx Ｇａ 1-x Ｎ、０．７≦ｘ≦１によって決
定される材料である請求項１記載の半導体発光素子。2. An InGaN-based semiconductor used for an active layer
The material is InxGa 1-xN, determined by 0.7 ≦ x ≦ 1
The semiconductor light emitting device according to claim 1, which is a defined material.
量子井戸構造である請求項１または２記載の半導体発光
素子。3. The semiconductor light emitting device according to claim 1, wherein the active layer has a single quantum well structure or a multiple quantum well structure.
基板上にバッファ層を介してダブルヘテロ接合構造を成
長させてなる積層構造であって、結晶基板の材料が、サ
ファイア、６Ｈ−ＳｉＣ、ＭｇＡｌ2 Ｏ4 （スピネ
ル）、ＬｉＡｌＯ 2 、ＬｉＧａＯ2 のいずれかであり、
バッファ層の材料が、ＡｌＮ、ＧａＮ、ＩｎＧａＮ、Ａ
ｌＧａＮのいずれかである請求項１〜３記載の半導体発
光素子。4. The laminated structure of the semiconductor light emitting device is crystalline.
A double heterojunction structure is formed on the substrate through a buffer layer.
It is a laminated structure that is made longer and the material of the crystal substrate is
Fire, 6H-SiC, MgAlTwoOFour(Spine
Le), LiAlO Two, LiGaOTwoOne of
The material of the buffer layer is AlN, GaN, InGaN, A
4. The semiconductor semiconductor according to claim 1, which is any one of 1 GaN.
Optical element.
料からなるダブルヘテロ接合構造を結晶基板上に形成す
る方法が、ともに有機金属気相エピタキシーである請求
項４記載の半導体発光素子。5. The semiconductor light emitting device according to claim 4, wherein both of the methods of forming the double heterojunction structure composed of the buffer layer and the InGaN-based semiconductor material on the crystal substrate are metal organic vapor phase epitaxy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8664596A JPH09283799A (en) | 1996-04-09 | 1996-04-09 | Semiconductor light-emitting element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8664596A JPH09283799A (en) | 1996-04-09 | 1996-04-09 | Semiconductor light-emitting element |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09283799A true JPH09283799A (en) | 1997-10-31 |
Family
ID=13892775
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8664596A Pending JPH09283799A (en) | 1996-04-09 | 1996-04-09 | Semiconductor light-emitting element |
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| Country | Link |
|---|---|
| JP (1) | JPH09283799A (en) |
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| JP2000058920A (en) * | 1998-07-31 | 2000-02-25 | Xerox Corp | Semiconductor and manufacturing method thereof |
| JP2003037288A (en) * | 2001-07-26 | 2003-02-07 | Ishikawajima Harima Heavy Ind Co Ltd | Semiconductor crystal film growth method |
| JP2003037287A (en) * | 2001-07-26 | 2003-02-07 | Sanken Electric Co Ltd | Light-emitting element |
| KR100505358B1 (en) * | 2002-12-04 | 2005-07-29 | 정세영 | GaN single crystal and their manufacturing method and their manufacturing apparatus |
| KR100503693B1 (en) * | 1996-12-27 | 2005-11-14 | 프리스케일 세미컨덕터, 인크. | Method of growing gallium nitride on a spinel substrate |
| WO2006083065A1 (en) * | 2005-02-04 | 2006-08-10 | Seoul Opto Device Co., Ltd. | Light emitting device having a plurality of light emitting cells and method of fabricating the same |
| JP2009026956A (en) * | 2007-07-19 | 2009-02-05 | Sumitomo Electric Ind Ltd | LIGHT EMITTING ELEMENT, SUBSTRATE PRODUCT FOR LIGHT EMITTING ELEMENT, AND METHOD FOR PRODUCING LIGHT EMITTING ELEMENT |
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