JPH02229475A

JPH02229475A - Semiconductor light-emitting element

Info

Publication number: JPH02229475A
Application number: JP1049660A
Authority: JP
Inventors: Takashi Matsuoka; 隆志松岡; Toru Sasaki; 徹佐々木; Akinori Katsui; 勝井　明憲
Original assignee: Nippon Telegraph and Telephone Corp
Current assignee: Nippon Telegraph and Telephone Corp
Priority date: 1989-03-01
Filing date: 1989-03-01
Publication date: 1990-09-12
Anticipated expiration: 2009-12-12
Also published as: JPH06101587B2

Abstract

PURPOSE:To obtain high quality crystals with minimum defects by epitaxially growing, on a substrate, crystals having lattice conformity with a substrate. CONSTITUTION:A semiconductor light-emitting element consists of a 5mum thick N-type InGaN layer 7 grown on an MgO substrate 6 and having lattice conformity with the substrate, a 0.5mum thick light-emitting layer 8 of InGaN doped with Zn to increase a resistance and having lattice conformity with the substrate, an electrode 9 on the light-emitting layer and an ohmic electrode 10 on the N-type layer 7. When a positive voltage is applied to the electrode 9 and a negative voltage is applied to the electrode 10, the light-emitting layer 8 emits light at a wavelength of 570nm. An extremely high external quantum efficiency of 0.45% can be obtained. It can be considered that this is because when crystals having a lattice constant matched with that of the substrate are grown on the substrate those crystals have higher crystallinity. Further, if the InGaN layer used in the element of the present invention is doped with aluminum under condition such that it has lattice conformity with the substrate, the element is enabled to emit light up to a ultraviolet region of about 413nm.

Description

【発明の詳細な説明】（産業上の利用分野）本発明は、化合物半導体発光素子に関するものであり、
さらに詳細に説明するならば可視光領域の赤色から紫外
で発光する半導体発光素子に関するものである．（従来の技術）従来の可視光短波長領域の半導体発光素子としては、Ｇ
ａＮを用いたものがある．第１２図にその基本構造を示
す．この構造はＭＩＳ型である．図において１は基板の
サファイアを示す．その上にエビタキシャル成長したｎ
形ＧａＮ層２と、Ｚｎドーブ高抵抗ＧａＮ層３を有し、
電極４．５からキャリアを注入して、高抵抗層内で発光
させている。[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a compound semiconductor light emitting device,
More specifically, it concerns semiconductor light-emitting devices that emit light in the visible light range from red to ultraviolet. (Prior art) As a conventional semiconductor light emitting device in the short wavelength region of visible light, G
There is one that uses aN. Figure 12 shows its basic structure. This structure is of MIS type. In the figure, 1 indicates the sapphire substrate. On top of that, n
a Zn-doped high-resistance GaN layer 3;
Carriers are injected from the electrode 4.5 to cause light to be emitted within the high resistance layer.

（発明が解決しようとする課題）この素子で発光強度を上げるためには、熱を発生させる
ことなく、注入電流を増加させる必要がある．そのため
には、電極４と５の間の素子抵抗を下げなければならな
い．そのためには、高抵抗層を薄くする必要がある．し
かしながら、高抵抗層を薄くすると、発光層の体積が減
ることになり、そのため、発光に寄与することなく電流
が流れてしまう．その結果として、無効電流が増加し、
発光効率が減少する．このため、大木らが１９８１年の
ＧａＡｓ及び関連化合物についての国際会ｔｌ（　Ｇａ
Ａｓａｎｄ　Ｒｅｌａｔｅｄ　Ｃｏｍｐｏｕｎｄｓ国際
会！ｉ）で述べているように、この構造の素子では、外
部量子効率が０．　１２％までのものしか得られておら
ず、発光強度を十分に上げることができないという欠点
を有している．今までに製作されているＧａＮを用いた発光素子の全て
が、原理的に低発光効率であるＭＩＳ型である．そして
、サファイアとＧａＮとの間の結晶の格子定数の差と、
ＧａＮの格子定数との比が約１４％と大きいにもかかわ
らず、サファイアとＧａＮは結晶構造が似ているという
理由のみで、常にサファイア上にＧａＮが成長されてい
る．その結果として、ｐ形或いはｎ形層にＺｎを添加し
た高抵抗のＧａＮ　シか得られていない．その最も大き
な理由は、前述した大きな格子不整合によると考えられ
る．すなわち、格子不整合があれば、必ず不飽和結合を
生ずる．その不飽和結合自体がドナ・レベルを形成した
り、また、ドナとなる不純物を吸引したりする．その結
果、ＧａＮはｎ形となると考えられる．またＧａＮの窒
素蒸気圧は、一般に実用に供されているＧａＡｓやＩｎ
Ｐ等のｍ−Ｖ族のＶ族蒸気圧に比べて遥かに高い。従っ
て、格子不整合状態では、窒素空孔が生じ易いことも考
えられる．この窒素空孔がドナ・レベルを形成している
ものと推定される．この辺りのことは現在、所科学的に
証明されていないが、一般に可能性は極めて高いと考え
られている．以上のことから今までに製作されているＧ
ａｐｓあるいはＧａＮとその他の元素との混晶のエビタ
キシャル成長膜からなる発光素子は、基板とエビタキシ
ャル膜との格子不整合が大きいため、伝導性を制御でき
ず、発光効率の高い発光素子を形成できないという欠点
を有していた．（１）　　Ｙ．　Ｏｈｋｉ，　Ｙ．　Ｔ
ｏｙｏｄａ，　Ｈ．　Ｋｏｂａｙａｓｈｉ　　ａｎｄ１
．　Ａｋａｓａｋｉ　：　Ｉｎｔ．Ｓｔｍｐ．　ＧａＡ
ｓ　ａｎｄ　ＲｅｌａｔｅｄＣｏｍｐｏｕｎｄｓ　Ｊａ
ｐａｎ　（１９８１）　ＰＩ１．４７９．本発明は上記
の欠点を改善するために提案されたもので、その目的は
、大電流の注入が可能であり、発光効率の高い、発光層
の材料組成を選択することにより可視域から紫外域まで
に渡る広い波長領域の光を発する半導体発光素子を提供
することにある．（Ｌｌ！題を解決するための手段）上記の目的を達成するため、本発明は単結晶基板と、前
記単結晶基板上に成長し、かつ前記単結晶基板と異なる
組成からなる薄膜とを備える半導体発光素子において、
前記単結晶基板は複数の元素の固溶体からなる結晶構造
を有し、また前記薄膜は前記単結晶基板上に格子整合し
て成長したＩｎｘＧａ，ＡＩ．Ｎ　　（　ｘ　＋　ｙ　
＋　ｚ　−　１　，かつ、０≦ｘ，　　７．２≦１）薄
膜の少なくとも一層が含まれてなることを特徴とする半
導体発光素子を発明の特徴とするものである． ■族元素（Ｇａ，　ＡＩ．　Ｉｎ）窒化物の結晶構造は
、全てウルツ鉱型である．また、そのバンド構造は直接
遷移型である．第１３図に（００１）面上の格子定数と
バンドギャフプエネルギとの関係を示す．ｒｎＮ−Ｇａ
Ｎ間及びｆｎＮ−＾ＩＮ間のボーイングパラメータは、
それぞれ文献（２）及び（３）による．この図から判る
ように、ＩｎＮ，　ＧａＮ及びＡＩＮから成る二元，三
元、或いは四元混晶等を用いることにより、基板に格子
整合してバンドギャップエネルギの異なる材料の多Ｎｔ
ｌｌ造を形成することができる．従って、本発明と従来
技術との差異は、次の二点である．第一の差異は、本発明では基板と基板上に成長した結晶
の格子定数が整合しているのに対して、従来のものは格
子不整合であったことである．この格子不整合のため、
従来の結晶では、結晶中に転位等の多くの欠陥が生じ、
伝導型制御ができなかったり、あるいは注入したキャリ
アの寿命が発光再結合にかかる時間よハ短かったりした
．そのため、従来は発光効率の極めて低いＭＩＳ型の発
光素子しか作れなかった．ところが本発明の格子整合条
件を満たす基板を選択することにより、従来の結晶にあ
った結晶欠陥を含まない結晶を成長できる．そのため、
伝導型制御ができ、注入したキャリアの寿命も長い．こ
の格子整合というのは、エビタキシャル成長をする場合
、良質の結晶を得るためには必須の条件である．第二に、本発明ではへテロ接合が形成できるのに対して
、従来は形成できなかった．一般にこのヘテロ接合を用
いることにより、電流注入で発光する素子の発光効率が
飛躍的に向上する。このヘテロ接合は発光素子の発光効
率を上げるために必須である．（２）　　　Ｋ．　　Ｏｓａ＋ｗｕｒａ　　ｅｔ　　ａ
ｌ．　　：　　Ｊ．　　Ａｐｐｌ．　　Ｐｈｙｓ．．　
　４６（１９７５）　３４３２．（３）　　’ｌ．　Ｋｏｉｄｅ　ｅｔ　ａｌ．　：　Ｊ
．　Ａｐｐｌ．　Ｐｈｙｓ．．　６１（１９８７）　４
５４０．はじめに、本発明における複数の元素の固溶体からなる
結晶構造を有する単結晶基板と、この基坂上に格子整合
して成長した薄膜との原子の対応を、夫々の場合につい
て以下に説明する．（１）の場合（ａ）　　大方最密充填構造を有する単体元素Ｌｕ．　
Ｌｌ，Ｍｇ，　Ｓｃ，　ＴＩ，　Ｔ−及びこれらの元素
の固溶体、或いはＺｒや｝Ｉｆ等の他の元素と固溶した
単結晶基板と、前記基板上に格子整合して成長したｐ形
或いはｎ形の伝導型を有し、電気的に半絶縁性であるＩ
ｎｘＧａｙＡｌｚＮ層（ｘ＋ｙ＋ｚ−１，かつ、０≦ｘ
，ｙ，ｚ≦１）（以下、ＩｎＧａＡＩＮと記す）を一層
、或は組成ｘ，ｙ，ｚが同一或は異なる層の複数層と、
パッシベーション膜或はその他の絶縁層と、電極層とを
存することを特徴とする半導体発光素子．（ｂ）　　ウルツ鉱型構造を脊し、二元混晶ＡｌｚＧＯ
．　ＡＩＮ，ＧａＮ，　ＩｎＮ及びこれらの固溶体、或
は単体元素やＺｎＯ等の他の混晶と固溶した単結晶基板
と、前記基板上に格子整合したｒｎＧａＡＩＮ層とを有
することを特徴とする半導体発光素子．（Ｃ）　　ＮｉＡｓ構造を有し、二元混晶ＣｏＳ，　Ｃ
ｒＳ，　ＰｅＳ，ＦｅＳ．，　Ｆｅｔｅ．，　ＮｂＳ，
　ＮｉＳ，　ＰＬＢ，　Ｒｈｏ，１，　ＴｉＳ”＋ｖｐ
，　ｖｓ及びこれらの固溶体、或は単体元素や他の混晶
と固溶した単結晶基板と、前記基板上に格子整合したＩ
ｎＧａＡＩＮ層とを有することを特徴とする半導体発光
素子．（ｄ）　　六方Ｃｄ　（ＯＨ）　！構造を有する二元混
晶ｐｔｓ．，　　α−ＴａＳｚ１　　ｒ　−Ｔａｎｇ，
　ＴｔＳｚ及びこれらの固溶体、或は単体元素や他の混
晶と固溶した単結晶基板と、前記基板上に格子整合した
ＩｎＧａＡＩＮ層とを有することを特徴とする半導体発
光素子．（ｅ）　　六方晶型ペロプスカイト構造を有ｔ
ルＢａＴｉＳ３，ＳｒＴｉ５３及びこれらの固溶体、或
は単体元素や他の混晶と固溶した単結晶基板と、前記基
板上に格子整合したＩｎＧａＡＩＮ層とを有することを
特徴とする半導体発光素子．上記（１）の場合における（００１）面から見た基板と
基板上に成長したｆＧａＡＩＮの原子の配置を第１図に
示す．図中●は基板の原子を示し、ＯはＩｎＧａＡＩＮ
の原子を示す．また、基板及びＩｎＧａＡＩＮのａ軸方
向の格子定数をそれぞれａ，ａ．，ｃ軸方向の格子定数
をそれぞれＣ，Ｃ＠とする．これらの原子の記号及び格
子定数の記号は以下の説明においても同様とする．図に
示すように上記（１）の（ａ）〜（ｅ）の場合の基板と
ＩｎＧａＡＩＮとの組合せの場合、それぞれの原子は一
対一に対応する．また、格子定数の関係は、ａ　冨　ａ● である．（ＩＩ）の場合（ａ）　　面心立方構造を有し、単体元素Ａｍ，　Ｌｉ
，　Ｐｂ．Ｐｕ，　Ｓｓ及びこれらの元素の固溶体、或
は他の元素と固溶した単結晶基板と、前記基板上に格子
整合したＩｎＧａＡＩＮ層とを有することを特徴とする
半導体発光素子．（ロ）キュウビック・フロライト構造を有し、二元また
は三元混晶ＢｅＪ，　ＬＩＭｇＮ，　ＬｉＺｎＮ＋　Ｌ
ｔｚＯ＋Ｎｂｌｌ．，　ＳｃＨ．及びこれらの固溶体、
或は単体元素や他の混晶と固溶した単結晶基板と、前記
基板上に格子整合したＩｎＧａＡＩＮ層とを有すること
を特徴とする半導体発光素子．（Ｃ）　　ベロブスカイト構造を有するＢａＴｈ０３．
　ＢａＵＯ＝，ＣｓＣａＦ２，　ＣｓｌＯｓ＋　ＣｓＰ
ｂＦｚ．ＲｂＣａＯｚ，　ＲｈｌＯｘ及びこれらの固溶
体、或は単体元素や他の混晶と固溶した単結晶基板と、
前記基板上に格子整合したＩｎＧａＡＩＮ層とを有する
ことを特徴とする半導体発光素子．上記［１）の場合において、（００１）面から見た、基
板と基板上に成長したＩｎＧａＡＩＮの原子の配置を第
２図に示す．格子定数の関係は、Ｂ　ｗｍ　２””６，である．（ＩＩＩ）の場合、？ａ）　　面心立方構造を有し、単体元素Ａｇ＋　ＡＩ
＋　Ａｕ＋Ｍｏ，　Ｐｄ，　Ｐｔ及びこれらの元素の合
金、或は他の元素と合金化した単結晶基板と、前記基板
上に格子整合したＩｎＧａＡＩＮ層とを脊することを特
徴とする半導体発光素子．（ｂ）　　ペロプスカイト構造を有するＡｇＺｎＦ３＋
　ＢａＦｅＯｓ＋ＢａＭｎＯｚ．　ＢａＰｂＯ！＋　Ｂ
ａＳｎ０３＋　ＢａＴｉＯｓ，ＢａＺｒＯｓ＋　ＣａＳ
ｎ０３＋ＣａＴｉＯ．，　ＣａＺｒＯｓ＋　ＣｅＣｒ０
３，　Ｃｅｄａｒｓ，　ＣｅＧａ０３，　ＣｅＶＯ１，
ＥｕＦｅＯ■　ＥｕＴｉＯ１，　　ＦａＢｉＯｓｌ　Ｇ
ｄＦｅＯｓ．　　ＧｄＭｎ０３，　　ＫＣｄＦ＊ＩＫＣ
ｏＦｓ，　ＫＦｅＦ．．　ＫＭｇＰ３，　ＫＹＩｎＦｓ
＋　ＫＮｂＯｚ＋　ＫＮＩＦｓ＋ＫＴａＯ３，　ＫＺｎ
Ｆｓ＋　ＬａＣｏＯｓ＋　ＬａＣｒＯｓ＋　ＬａＦｅ０
１，　ＬａＧａＯｉ＋ＬａＲｈＯｓ＋　ＬａＴ！０３，
　ＬａＶＯｚ＋　ＬｉＢａＦｓ＋　ＮｄＣｒＯｓ＋　Ｎ
ｄＦｅＯｓ＋ＮｄＧａＯｓ＋　ＮｄＶＯ！，　　α−Ｐ
ｂＴｉＯｓ＋　ＰｒＣｒＯｓ＋　ＰｒＦｅＯｓ＋ＰｒＧ
ａ０３，　ＰｒＭｎＯｓ＋　ＰｒＶＯ．，　ＰｕＭｎＯ
ｓ＋　ＲｂＣｏＦｉ＋　ＲｂＭｎＦｉ，Ｓ＋ｗＣｒ０３
＋　ＳｓＦｅＯｓ＋　ＳａＶＯｓ＋　ＳｒＰｅ０３＋　
ＳｒＨｆ０２．　ＳｒＭｏＯｓ＋ＳｒＳｎＯｓ．　Ｓｒ
ＴＩＯｓ＋　ＳｒＺｒＯｓ＋　ＴａＳｎＯｓ＋　ＴＩＣ
ｏＦｓ及びこれらの固溶体、或単体元素や他の混晶と固
溶した単結晶基板と、前記碁板上に格子整合したＩｎＧ
ａＡＩＮＪＩとを有することを特徴とする半導体発光素
子．上記（ＩＩＩ）の場合、（００１）面から見た、基板と
基板上に成長したＩｎＧａＡＩＮの原子の配置を第３図
に示す．格子定数の関係は、ａ−　（３／２）””ａ．である．（■）の場合、（ａ）　　体心立方構造を有し、単体元素Ｔｈ，　ＴＩ
及びこれらの元素の固溶体、或は他の元素と固溶した単
結晶基板と、前記基板上に格子整合したＩｎＧａＡＩＮ
層とを有することを特徴とする半導体発光素子．（ｂｌ　　ＮａＣＩ型構造を有し、二元混晶ＣｏＯ＋　
ＣｒＮ＋　ＦｅＯＬ１ロ＋　　ＬＩＦ＋　　Ｌｉ”Ｆ＋
　　Ｌｉ’Ｆ，　　ＬｉＨ，　　ＭｇＯ，　　ＮｂＯ＋
　　ＰｄＨ’ＴｉＣ，　ＴｉＮ，　Ｔｉｅ’，　ＶＣ，
　ＶＣ，．，，，　ＶＮ，　ＶＯｃ及びこれらの固溶体
、或は単体元素や他の混晶と固溶した単結晶基板と、前
記基板上に格子整合したＩｎＧａＡＩＮ層とを有するこ
とを特徴とする半導体発光素子．（Ｃ）　　Ｃ　ｓ　Ｃ　Ｌ型構造を有し、二元混晶Ｃｓ
Ｂｒ，　ＣｓＣＮ，ＣｓＮＨｔ＋　ＣｓＳＨ，　ＴｈＴ
ｅ，　ＴＩＢｒ，　ＴＩＣＩ，　ＴＩＣＮ，　ＴＩＮ，
ＣａＴＩ，ＣｄＣｅ＋　　ＣｄＬａ，ＣｄＰｒ，ＭｇＣ
ｅ，ＭｇＬａ，ＭｇＰｒ，ＭｇＳｒ，　ＳｒＴ１，丁１
８１．　７ＩＳｂ及びこれらの固溶体、或は単体元素や
他の混晶と固溶した単結晶基板と、前記基板上に格子整
合したＩｎＧａＡＩＮ層とを有することを特徴とする半
導体発光素子．上記（ｒＶ）の場合、（００１）面から
見た、基板と基板上に成長したＩｎＧａＡＩＮの原子の
配置を第４図に示す．格子定数の関係は、ａ　＝　（　３　／　２　）　＋／！ａ，である．（Ｖ）の場合、（ａ）　　体心立方構造を有し、単体元素Ｅｕ＋　Ｓｒ
及びこれらの元素の合金、或は他の元素と固溶した単結
晶基板と、前記基板上に格子整合したＩｎＧａＡＩＮ層
とを有することを特徴とする半導体発光素子．（ｂ）　
　ＮａＣｌ型構造を有し、二元混晶ＡｇＦ，　ＣａＮＨ
，　ＣｅＮ，ＤｙＮ，　Ｅｒａ，　ＨｏＮ＋　ＬｕＮ，
　ＮａＦ＋　ＮａＨ，　ＮｂＣ，　ＮｂＣ＊．ｙ＋Ｎｂ
Ｎ＊−＊ｓ＊　”Ｉ’Ｎ＋　ＮｐＯ，Ｐａｄ，　Ｐｕｐ
，　ＰｕＣ，　ＰｕＮ，　Ｐｕｐ，ＳｃＮ，　　ＳｍＯ
＋　　ＴａＣ．　　ＴａＯ＋　　ｔｂＮ，　　ＴｍＮ，
　　υＣ，　　ＯＮ，　　Ｄｏ，ＹＮ，　ＹｂＮ，　Ｙ
ｂＯ，　ＺｒＢ，　ＺｒＣ，　ＺｒＮ，　ＺｒＯ及びこ
れらの固溶体、或は単体元素やＣ　ａ　Ｏ　＋　Ｃ　ｄ
　０１　Ｍ　ｎ　Ｏ等の他の混晶と固熔した単結晶基板
と、前記基板上に格子整合したＩｎＧａＡＩＮ層とを有
することを特徴とする半導体発光素子．（Ｃ）　　Ｃ　ｓ　Ｃ　１型構造を有し、二元混晶Ｃｓ
ｒ，　ＣｓＳｅＨ及びこれらの固溶体、或は単体元素や
他の混晶と固溶した単結晶基板と、前記基板上に格子整
合したＩｎＧａＡＩＮ層とを有することを特徴とする半
導体発光素子．（ｄ）　　閃亜鉛鉱型構造を有し、二元混晶ＢＡｓ．　
ＨＰＢｅＳ及びこれらの固溶体、或は単体元素や他の混
晶と固溶した単結晶基板と、前記基板上に格子整合した
ＩｎＧａＡＩＮ層とを有することを特徴とする半導体発
光素子．上記（Ｖ）の場合、（００１）面から見た、基板と基板
上に成長したＩｎＧａＡＩＮの原子の配置を第５図に示
す．格子定数の関係は、ａ−２””Ｂｏである．（ＶＩ）の場合、キエウビック・スピネル構造を有するＡ１＊ＣｄＯ４，
ＡＩｔＣｏＯ４＋　ＡＩｍＣｕ０４＋　ＡＩＦｅＮＩＯ
，＋＾ＩｘＦｅＯｉ＋　Ａ１ｔＦＩｇＯａ＋ＡＩＪｎＯ
４＋　ＡＩＩＮｌ０４１　ＡＩｔＳｎＯａ＋　Ａ１ｔＺ
ｎＯａ＋　ＣｏｚＣｕＯａ＋ＣｏｔＧｅＯ４＋　ＧｏＩ
ＭｇＯｎ＋　ＣｏｔＳｂｘＯ＋ｇ＋　ＣｏｇＳｎＯｎ．
　ＣｏｉＴｉＯｎ＋ＣＯｔＺｎＯａ，　ＣＯｉ０４＋　
（Ｃｏ，　Ｎｒ）ｓＯａ＊　ＣｒｘＣｄＯａ，　Ｃｒ＠
Ｆｅ０４，Ｃｒｘ（Ｆｅ，　Ｍｇ）Ｏｎ，　Ｃｒ！Ｍｎ
Ｏａ＋　ＣｒＪＩＯａ＋　ＣｒｔＺｎＯｓ＋ＦｅＣｒＭ
ｎＯ．，　ＦｅＭｎ（Ｚｎｏ．ｓＧｔｅ．ｓ）０４＋　
ＦｅｌＣｏ０４＋　ＦａｌＣｕＯ４＋Ｆｅ＊ＧｅＯｎ＋
　ＦｅｚＭｇ０４．　ＦｅｔＭｇＯｉ＋　Ｆｅｗ（Ｍｇ
，　Ｍｎ，　Ｆｅ）０４１ＰｅｚＭｎＯａ＋　ＦｅｚＭ
ｏＯ４＋　ＰｅＪｉ０４．　Ｆｅ茸ＴＩＯ４＋　Ｆｅ＊
Ｚｎ０４＋ＦｅｔＯａ”＋　ＧａｚＣｄＯａＩ　Ｇａｘ
ＣｏＯｎ＋　ＧａｚＣｕ０４＋　ＧａｘＭｇ０４＋Ｇａ
ＪｉＯｎ＋　ＧａｚＺｎＯ４＋　ＩｎｘＭｇＯｎ＋　Ｌ
ｉＡＩＴ｛０４，ＬＩＣｏＳｂ０４．ＬＩＣＧＶＯ４１
　ＬＩＣｒＧｅＯ＜．　ＬｉＣｒＭｎＯｎ，ＬｉＣｒＴ
ｉ０４，ＬｉＦｅＴｉ０４．ＬｉＧａＴ１０４ｌ　Ｌｉ
ＧｅＲｈ０４，　ＬｉＭｎＴｉ０４，　ＬｉＮＩＶＯａ
，　　ＬＩＪＩＦａ＋Ｌ＋ＲｈＭｎＯ４＋　ＬＩＴｉＲ
ｈ０４＋　ＬＩＶＴｉ０４＋　ＬＩＺｎＳｂＯａ＋　Ｍ
ｇｘＧｅＯｎ，ＭｇｘＳｎＯ４＋　　ＭｇｔＴＩＯａ＋
　　ＭｇｇＶＯ４，　　ＭｎｌＣｕ０４＋　　ＭｎｚＬ
ＩＯ４ｌＭｎＪｉＯｎ＋　ＭｎｇＴｉＯｎ＋　ＮｉｌＧ
ｅＯｎ＋　ＮＩｚＳＩＯｎ＋　ＲｈｇＣｏ０４＋Ｒｈｇ
ＣｕＯ４，　ＲｈｚＭｇＯｎ，　ＲｈｔＭｎＯｎ＋　Ｒ
ｈｇＺｎＯ４＋　ＴｔｓＭｇＯｎ，ＴｉｌＭｎＯａ＋　
Ｖ７ｅ０４，　ＶｔＬＩ０４＋　Ｖ！ＭｇＯ４＋　Ｖ！
ＭｎＯ４＋ＶｇＺｎＯａ，　ＺｎＭｎ（Ｍｇａ．ｓＴＩ
＊．ｓ）Ｏａ＋　ＺｎｔＳｂｔＯ＋ｔ，　ＺｌｔｔＴＬ
Ｏｉ，ＬＩＡＩｓＯ１ＣｕＦｅｓＯｓ＋　ＬＩＧａｓＯ
ｓ及びこれらの固溶体、或は単体元素や他の混晶と固溶
した単結晶基板と、前記基板上に格子整合したＩｎＧａ
ＡＩＮ層とを有することを特徴とする半導体発光素子．
上記（Ｖｌ）の場合、（００１）面から見た、基板と基
板上に成長したＩｎＧａＡＩＮの原子の配置を第６図に
示す．格子定数の関係は、ａｘｍ　５　１／ｌａ，である．このように複数の元素の固溶体からなる結晶構造を有す
る単結晶基板上に、格子整合して成長した薄膜よりなる
半導体発光素子の実施例について説明する．なお、実施
例は一つの例示であって、本発明の晴神を逸脱しない範
囲で、種々の変更あるいは改良を行いうることは言うま
でもない．（実施例１）第７図は本発明の第１の実施例を説明する図であり、発
光素子の断面を示す．本発光素子はＭｇＯ基板６の上に
成長した膜厚５ｐｍの基板に格子整合するｎＪＩＩｎＧ
ａＮ層７，膜厚０．５ｎのＺｎドープして高抵抗にした
基板に格子整合するＩｎＧａＮ発光層８，発光層の電橿
９とｎ形層７のオーミック電極１０から成る．電掻９に
正の電圧を、電極ＩＯに負の電圧を加えると発光層８は
５７０ｎ■の波長で発光した．その外部量子効率は０．
４５％と第１２図に示した素子と比較して極めて高かっ
た．発光効率がこのように高くなった原因は、基板とそ
の上に成長した結晶の格子定数の整合により成長した結
晶の結晶性が高くなったためと考えられる．また、本素
子に用いた１ｎＧａＮＮにミ基板と格子整合する条件で
アルミニュウムを添加すると約４１３ｎｍの紫外研域ま
で発光させることができる．（実施例２）第８図は本発明の第２の実施例を説明する図であり、発
光ダイオードの断面を示す．本素子の基本的構造はダブ
ルへテロ構造であり、ＡＩ．ＭｇＯ．基仮１１，　ＩＩ
Ｉ厚５ｎのＳｎドープｎ形１ｎＧａＡＩＮクラッド層１
２，　ｌ！５Ｆ厚０．５ｎのノンドーブｒｎＧａＮ活性
１１３，ａ厚２ｎのＺｎドープｐ形１ｎＧａＡＩＮクラ
ッド層１４，ｎ形クラッド層のオーミック電極１５．　
　Ｐ形クラッド層ｌ４のオーミック電橿ｌ６から成る．
ここに示した全てのＩｎＧａＮ及びＩｎＧａＡＩＮ層は
、基板に格子整合してエビタキシャル成長した半導体結
晶層である．また、クラッド層と活性層とのバンドギャ
ップエネルギ差が０．３ｅＶとなるように、ＩｎＧａＡ
ＩＮクラッド層の組成を第１３図から選んだ．そして、
電極１５．　１６にそれぞれ負と正の電圧を加えること
により、電極１５．　１６からそれぞれ電子と正孔を発
光層に注入した．その結果、波長４５０ｎｍの青色発光
を観測できた．最大光出力はｌ３１であり、外部微分量
子効率は３％であった．（実施例３）第９図は本発明の第３の実施例を説明する図であり、素
子の断面を示す．本素子はレーザである．基本的構造は
ダブルへテロ構造を有する埋め込みレーザであり、＾１
！Ｍｇ０４基板１７，膜厚５ｐ一のＳロドープｎ形１ｎ
ＧａＡＩＮクラッドＪｔ５１Ｂ，　膜１！０．ｉｎのノ
ンドーブＩｎＧａＮ活性Ｎ１９．膜厚２ｎのＺｎドーブ
Ｐ形１ｎＧａＡＩＮクラッド層２０，　ＺｎドープＰ形
１ｎＧａＡＩＮ埋め込みＷｌ２１．　Ｓｎドーブｎ形１
ｎＧａＡＩＮ埋め込み層２２，Ｐ形クラッド層のオーミ
ック電極２３，ｎ形クラッド層のオーミック電極２４か
ら成る．ここに示した全てのＩｎＧａＮ及びＩｎＧａＡ
ＩＮ層は、基板に格子整合してエビタキシャル成長した
半導体結晶層である．また、クラッド層及び埋め込み層
と活性層とのバンドギャフプエネルギ差が０．３ｅＶと
なるように、ＩｎＧａＡＩＮクラフド層の組成を第１３
図から選んだ．共振器長は３００ｎで、活性層幅は０．
８ｎである．一般に短波長発振素子で問題となるＣ　Ｏ
　Ｄ　（Ｃａｔａｓｔｏｒａｐｈｉｃ　Ｏｐｔｉｃａｌ
　Ｄａｍａｇｅ）レベルを上げるために、１！極２３は
両端面からＬｏｎ内側まで形成した．また、熱伝導を良
くするために基板の厚みを６０ｎと薄くし、ダイヤモン
ド・へ一トシンク上にマウントした．ｉｔ極２３，　２
４にそれぞれ正と負の電圧を加える．そのようにすると
一般にＩｎＰ系やＧａＡｓ系を用いた埋め込みレーザと
同様に、埋め込み層２１と２２のｐｎ接合には逆バイア
スがかかり、埋め込み層には電流は流れず、活性層にだ
け電流が流れる．また、埋め込み層やクラッド層より活
性層の屈折率の方が高いため、活性層で発生した光は活
性層に閉じ込められる．従って、電流を活性層に狭搾で
き、光を活性層に閉じ込めることができる．その結果、
低閾値電流で外部微分世子効率の高い動作が可能になる
．次に、室温でのＣＷ特性を示す．注入電流を横軸に，光
出力を縦軸にとり光出力と注入電流の関係を第１０図に
、波長を横軸にとり、任意単位の強度を縦軸にとって発
振スペクトルを第１１図に示す。(Problem to be solved by the invention) In order to increase the luminous intensity of this device, it is necessary to increase the injection current without generating heat. For this purpose, the element resistance between electrodes 4 and 5 must be lowered. To achieve this, it is necessary to make the high-resistance layer thinner. However, if the high-resistance layer is made thinner, the volume of the light-emitting layer decreases, and as a result, current flows without contributing to light emission. As a result, the reactive current increases and
Luminous efficiency decreases. For this reason, Oki et al.
Asand Related Compounds International Conference! As mentioned in i), in the device with this structure, the external quantum efficiency is 0. However, only up to 12% of the luminescence intensity can be obtained, which has the disadvantage that the luminescence intensity cannot be sufficiently increased. All of the GaN-based light-emitting devices that have been manufactured so far are of the MIS type, which has low luminous efficiency in principle. And the difference in crystal lattice constant between sapphire and GaN,
Despite the large ratio of GaN to the lattice constant of about 14%, GaN is always grown on sapphire simply because sapphire and GaN have similar crystal structures. As a result, only high-resistance GaN films with Zn added to the p-type or n-type layer have been obtained. The biggest reason for this is thought to be the large lattice mismatch mentioned above. In other words, if there is lattice mismatch, unsaturated bonds will always occur. The unsaturated bonds themselves form donor levels and also attract impurities that become donors. As a result, GaN is considered to be n-type. In addition, the nitrogen vapor pressure of GaN is
It is much higher than the V group vapor pressure of m-V group members such as P. Therefore, it is possible that nitrogen vacancies are likely to occur in the lattice mismatched state. It is assumed that these nitrogen vacancies form the donor level. Although this has not yet been scientifically proven, it is generally thought that the possibility is extremely high. Based on the above, G
Light-emitting devices made of aps or epitaxially grown films of mixed crystals of GaN and other elements have a large lattice mismatch between the substrate and the epitaxial film, so conductivity cannot be controlled, making it difficult to create light-emitting devices with high luminous efficiency. It had the disadvantage that it could not be formed. (1) Y. Ohki, Y. T
oyoda, H. Kobayashi and1
．． Akasaki: Int. Stmp. GaA
s and Related Compounds Ja
pan (1981) PI1.479. The present invention was proposed in order to improve the above-mentioned drawbacks, and its purpose is to select a material composition for the light-emitting layer that can inject a large current and has high luminous efficiency. The objective is to provide a semiconductor light emitting device that emits light in a wide wavelength range. (Means for Solving the Ll! Problem) In order to achieve the above object, the present invention includes a single crystal substrate, and a thin film grown on the single crystal substrate and having a composition different from that of the single crystal substrate. In semiconductor light emitting devices,
The single crystal substrate has a crystal structure consisting of a solid solution of a plurality of elements, and the thin film is formed of InxGa, AI. N (x + y
+ z − 1 and 0≦x, 7.2≦1) The present invention is characterized by a semiconductor light emitting device including at least one layer of a thin film. The crystal structures of group (Ga, AI, In) nitrides are all wurtzite. Moreover, its band structure is a direct transition type. Figure 13 shows the relationship between the lattice constant and band gap energy on the (001) plane. rnN-Ga
The bowing parameters between N and fnN-^IN are:
According to references (2) and (3), respectively. As can be seen from this figure, by using binary, ternary, or quaternary mixed crystals made of InN, GaN, and AIN, multi-Nt materials with different band gap energies can be lattice-matched to the substrate.
It is possible to form a structure. Therefore, the differences between the present invention and the prior art are the following two points. The first difference is that in the present invention, the lattice constants of the substrate and the crystal grown on the substrate are matched, whereas in the conventional method, the lattice constants are mismatched. Because of this lattice mismatch,
In conventional crystals, many defects such as dislocations occur in the crystal,
Either the conduction type could not be controlled, or the lifetime of the injected carriers was shorter than the time required for radiative recombination. Therefore, in the past, only MIS type light emitting devices with extremely low luminous efficiency could be made. However, by selecting a substrate that satisfies the lattice matching conditions of the present invention, it is possible to grow a crystal that does not contain the crystal defects found in conventional crystals. Therefore,
The conduction type can be controlled, and the life of the injected carriers is long. This lattice matching is an essential condition for obtaining high-quality crystals during epitaxial growth. Second, the present invention allows the formation of heterojunctions, whereas conventional methods could not. Generally, by using this heterojunction, the luminous efficiency of a device that emits light by current injection is dramatically improved. This heterojunction is essential for increasing the luminous efficiency of light-emitting devices. (2) K. Osa+wura et a
l. : J. Appl. Phys. ．．
46 (1975) 3432. (3) 'l. Koide et al. : J
．． Appl. Phys. ．． 61 (1987) 4
540. First, the atomic correspondence between a single-crystal substrate having a crystal structure consisting of a solid solution of multiple elements in the present invention and a thin film grown with lattice matching on this base slope will be explained below for each case. In the case of (1) (a) the simple element Lu has a nearly close-packed structure.
Ll, Mg, Sc, TI, T- and solid solutions of these elements, or single crystal substrates in solid solution with other elements such as Zr and }If, and p-type or n-type crystals grown in lattice matching on the substrate. It has a conductivity type of I and is electrically semi-insulating.
nxGayAlzN layer (x+y+z-1, and 0≦x
, y, z≦1) (hereinafter referred to as InGaAIN), or multiple layers with the same or different compositions x, y, z,
A semiconductor light emitting device comprising a passivation film or other insulating layer and an electrode layer. (b) Binary mixed crystal AlzGO with wurtzite structure
．． A semiconductor light emitting device characterized by having a single crystal substrate in which AIN, GaN, InN or a solid solution thereof, or a single element or other mixed crystal such as ZnO is in a solid solution, and a rnGaAIN layer lattice matched on the substrate. element. (C) Has a NiAs structure and is a binary mixed crystal CoS, C
rS, PeS, FeS. , Fete. , NbS,
NiS, PLB, Rho, 1, TiS”+vp
, vs and a solid solution thereof, or a single crystal substrate in solid solution with a single element or other mixed crystal, and a lattice-matched I on the substrate.
A semiconductor light emitting device characterized by having an nGaAIN layer. (d) Hexagonal Cd (OH)! A binary mixed crystal having the structure pts. , α-TaSz1 r -Tang,
A semiconductor light emitting device comprising: a single crystal substrate containing TtSz and a solid solution thereof, or a single element or other mixed crystal; and a lattice-matched InGaAIN layer on the substrate. (e) Has a hexagonal perovskite structure
A semiconductor light-emitting device comprising: a single-crystal substrate in which SrTiS3, SrTi53, a solid solution thereof, or a single element or other mixed crystal is formed in solid solution; and an InGaAIN layer lattice-matched on the substrate. Figure 1 shows the arrangement of the substrate and fGaAIN atoms grown on the substrate as seen from the (001) plane in case (1) above. In the figure, ● indicates atoms of the substrate, and O indicates InGaAIN.
Indicates the atom of . In addition, the lattice constants of the substrate and InGaAIN in the a-axis direction are a, a. , let the lattice constants in the c-axis direction be C and C@, respectively. The symbols for these atoms and the symbols for the lattice constants are the same in the following explanations. As shown in the figure, in the combination of the substrate and InGaAIN in cases (a) to (e) of (1) above, each atom corresponds one-to-one. Also, the relationship between the lattice constants is a, a, and a●. In the case of (II) (a) It has a face-centered cubic structure, and the simple elements Am, Li
, Pb. A semiconductor light emitting device comprising: a single crystal substrate containing Pu, Ss, a solid solution of these elements, or a solid solution of other elements; and a lattice-matched InGaAIN layer on the substrate. (b) Binary or ternary mixed crystal BeJ, LIMgN, LiZnN+ L with cubic fluorite structure
tzO+Nbll. , ScH. and solid solutions thereof,
Alternatively, a semiconductor light emitting device comprising a single crystal substrate in which a single element or other mixed crystal is dissolved in solid solution, and an InGaAIN layer lattice-matched on the substrate. (C) BaTh03. with berovskite structure.
BaUO=, CsCaF2, CslOs+ CsP
bFz. RbCaOz, RhlOx and solid solutions thereof, or single crystal substrates in solid solution with single elements or other mixed crystals,
A semiconductor light emitting device comprising: a lattice-matched InGaAIN layer on the substrate. In the case of [1] above, Figure 2 shows the arrangement of the substrate and the atoms of InGaAIN grown on the substrate, as seen from the (001) plane. The relationship between the lattice constants is B wm 2""6,. In the case of (III), ? a) It has a face-centered cubic structure, and the single element Ag+AI
+ A semiconductor light emitting device comprising: + Au+Mo, Pd, Pt, an alloy of these elements, or a single crystal substrate alloyed with other elements; and an InGaAIN layer lattice matched on the substrate. (b) AgZnF3+ with perovskite structure
BaFeOs+BaMnOz. BaPbO! ＋B
aSn03+ BaTiOs, BaZrOs+ CaS
n03+CaTiO. , CaZrOs+ CeCr0
3, Cedars, CeGa03, CeVO1,
EuFeO■ EuTiO1, FaBiOsl G
dFeOs. GdMn03, KCdF*IKC
oFs, KFeF. ．． KMgP3, KYInFs
+ KNbOz+ KNIFs+KTaO3, KZn
Fs+ LaCoOs+ LaCrOs+ LaFe0
1, LaGaOi+LaRhOs+ LaT! 03,
LaVOz+ LiBaFs+ NdCrOs+ N
dFeOs+NdGaOs+NdVO! , α-P
bTiOs+ PrCrOs+ PrFeOs+PrG
a03, PrMnOs+ PrVO. , PuMnO
s+ RbCoFi+ RbMnFi, S+wCr03
+ SsFeOs+ SaVOs+ SrPe03+
SrHf02. SrMoOs+SrSnOs. Sr.
TIOs+ SrZrOs+ TaSnOs+ TIC
oFs and a solid solution thereof, a single crystal substrate in solid solution with a single element or other mixed crystal, and InG lattice matched on the Go board.
A semiconductor light emitting device characterized by having aAINJI. In the case of (III) above, FIG. 3 shows the arrangement of the substrate and the atoms of InGaAIN grown on the substrate as seen from the (001) plane. The relationship between the lattice constants is a- (3/2)""a. It is. In the case of (■), (a) it has a body-centered cubic structure and the simple elements Th, TI
and a solid solution of these elements or a single crystal substrate in solid solution with other elements, and InGaAIN lattice matched on the substrate.
A semiconductor light emitting device characterized by having a layer. (bl Has NaCI type structure, binary mixed crystal CoO+
CrN+ FeOL1ro+ LIF+ Li”F+
Li'F, LiH, MgO, NbO+
PdH'TiC, TiN, Tie', VC,
VC,. ,,, A semiconductor light emitting device comprising a single crystal substrate in which VN, VOc and a solid solution thereof, or a single element or other mixed crystal are dissolved in solid solution, and a lattice-matched InGaAIN layer on the substrate. (C) Has a C s C L type structure and is a binary mixed crystal Cs
Br, CsCN, CsNHt+ CsSH, ThT
e, TIBr, TICI, TICN, TIN,
CaTI, CdCe+ CdLa, CdPr, MgC
e, MgLa, MgPr, MgSr, SrT1, D1
81. 1. A semiconductor light-emitting device comprising: a single-crystal substrate containing 7ISb and a solid solution thereof, or a single element or other mixed crystal; and a lattice-matched InGaAIN layer on the substrate. In the case of the above (rV), Figure 4 shows the arrangement of the substrate and the atoms of InGaAIN grown on the substrate as seen from the (001) plane. The relationship between lattice constants is a = (3/2) +/! a. In the case of (V), (a) has a body-centered cubic structure and has a simple element Eu+Sr
and a semiconductor light emitting device comprising a single crystal substrate made of an alloy of these elements or a solid solution with another element, and a lattice-matched InGaAIN layer on the substrate. (b)
Has a NaCl type structure, binary mixed crystal AgF, CaNH
, CeN, DyN, Era, HoN+ LuN,
NaF+ NaH, NbC, NbC*. y+Nb
N*-*s* ”I'N+ NpO, Pad, Pup
, PuC, PuN, Pup, ScN, SmO
+TaC. TaO+ tbN, TmN,
υC, ON, Do, YN, YbN, Y
bO, ZrB, ZrC, ZrN, ZrO and their solid solutions, or simple elements or C a O + C d
01 A semiconductor light emitting device comprising a single crystal substrate solidly fused with another mixed crystal such as M n O, and an InGaAIN layer lattice matched on the substrate. (C) Cs C 1 type structure, binary mixed crystal Cs
A semiconductor light emitting device comprising: a single crystal substrate in which CsSeH and a solid solution thereof, or a single element or other mixed crystal are dissolved therein; and an InGaAIN layer lattice-matched on the substrate. (d) Binary mixed crystal BAs. having a zincblende structure.
A semiconductor light emitting device comprising a single crystal substrate in which HPBeS and a solid solution thereof, or a single element or other mixed crystal are dissolved in solid solution, and a lattice-matched InGaAIN layer on the substrate. In the case of (V) above, FIG. 5 shows the arrangement of the substrate and the atoms of InGaAIN grown on the substrate as seen from the (001) plane. The relationship between the lattice constants is a-2""Bo. In the case of (VI), A1*CdO4 with Kiewic spinel structure,
AItCoO4+ AImCu04+ AIFeNIO
,+^IxFeOi+ A1tFIgOa+AIJnO
4+ AIINl041 AItSnOa+ A1tZ
nOa+ CozCuOa+CotGeO4+ GoI
MgOn+ CotSbxO+g+ CogSnOn.
CoiTiOn+COtZnOa, COi04+
(Co, Nr)sOa* CrxCdOa, Cr@
Fe04, Crx (Fe, Mg) On, Cr! Mn
Oa+ CrJIOa+ CrtZnOs+FeCrM
nO. , FeMn(Zno.sGte.s)04+
FelCo04+ FalCuO4+Fe*GeOn+
FezMg04. FetMgOi+ Few(Mg
, Mn, Fe)041PezMnOa+ FezM
oO4+ PeJi04. Fe mushroom TIO4+ Fe*
Zn04+FetOa”+ GazCdOaI Gax
CoOn+ GazCu04+ GaxMg04+Ga
JiOn+ GazZnO4+ InxMgOn+ L
iAIT{04, LICoSb04. LICGVO41
LICrGeO<. LiCrMnOn, LiCrT
i04, LiFeTi04. LiGaT104l Li
GeRh04, LiMnTi04, LiNIVOa
, LIJIFa+L+RhMnO4+ LITiR
h04+ LIVTi04+ LIZnSbOa+ M
gxGeOn, MgxSnO4+ MgtTIOa+
MggVO4, MnlCu04+ MnzL
IO4lMnJiOn+ MngTiOn+ NilG
eOn+ NIzSIOn+ RhgCo04+Rhg
CuO4, RhzMgOn, RhtMnOn+ R
hgZnO4+ TtsMgOn,TilMnOa+
V7e04, VtLI04+ V! MgO4+V!
MnO4+VgZnOa, ZnMn(Mga.sTI
*. s) Oa+ ZntSbtO+t, ZlttTL
Oi, LIAIsO1CuFesOs+ LIGasO
s and a solid solution thereof, or a single crystal substrate in solid solution with a single element or other mixed crystal, and InGa lattice matched on the substrate.
A semiconductor light emitting device characterized by having an AIN layer.
In the case of (Vl) above, Figure 6 shows the arrangement of the substrate and the atoms of InGaAIN grown on the substrate, as seen from the (001) plane. The relationship between the lattice constants is axm 5 1/la. An example of a semiconductor light-emitting device made of a thin film grown in a lattice-matched manner on a single-crystal substrate having a crystal structure composed of a solid solution of a plurality of elements will be described. It should be noted that the embodiments are merely illustrative, and it goes without saying that various changes and improvements can be made without departing from the scope of the present invention. (Example 1) FIG. 7 is a diagram for explaining the first example of the present invention, and shows a cross section of a light emitting element. This light emitting device is made of nJIInG that is lattice matched to a 5 pm thick substrate grown on an MgO substrate 6.
It consists of an aN layer 7, an InGaN light-emitting layer 8 which is lattice-matched to a Zn-doped substrate with a film thickness of 0.5n to give high resistance, an electric wire 9 of the light-emitting layer, and an ohmic electrode 10 of the n-type layer 7. When a positive voltage was applied to the electrode 9 and a negative voltage was applied to the electrode IO, the light emitting layer 8 emitted light at a wavelength of 570 nm. Its external quantum efficiency is 0.
45%, which is extremely high compared to the element shown in Figure 12. The reason for this increase in luminous efficiency is thought to be that the crystallinity of the grown crystal is increased due to matching of the lattice constants of the substrate and the crystal grown on it. Furthermore, if aluminum is added to the 1nGaNN used in this device under the conditions of lattice matching with the micro-substrate, it can emit light up to the ultraviolet range of approximately 413 nm. (Embodiment 2) FIG. 8 is a diagram illustrating a second embodiment of the present invention, and shows a cross section of a light emitting diode. The basic structure of this device is a double heterostructure, and AI. MgO. Mokari 11, II
Sn-doped n-type 1nGaAIN cladding layer 1 with a thickness of 5n
2, l! 5F non-doped rnGaN active layer 113 with a thickness of 0.5n, a Zn-doped p-type 1nGaAIN cladding layer 14 with a thickness of 2n, and an ohmic electrode 15 of the n-type cladding layer.
It consists of an ohmic wire l6 with a P-type cladding layer l4.
All the InGaN and InGaAIN layers shown here are semiconductor crystal layers that are lattice-matched to the substrate and grown epitaxially. In addition, InGaA
The composition of the IN cladding layer was selected from Figure 13. and,
Electrode 15. By applying negative and positive voltages to electrodes 15.16, respectively. Electrons and holes were injected into the light-emitting layer from No. 16, respectively. As a result, we were able to observe blue light emission with a wavelength of 450 nm. The maximum optical output was 131, and the external differential quantum efficiency was 3%. (Embodiment 3) FIG. 9 is a diagram illustrating a third embodiment of the present invention, and shows a cross section of the device. This device is a laser. The basic structure is a buried laser with a double heterostructure, ^1
! Mg04 substrate 17, S rhodope n-type 1n with film thickness 5p
GaAIN clad Jt51B, film 1!0. Non-doped InGaN activity N19. Zn-doped P-type 1nGaAIN cladding layer 20 with a film thickness of 2n, Zn-doped P-type 1nGaAIN embedded Wl 21. Sn dove n type 1
It consists of an nGaAIN buried layer 22, an ohmic electrode 23 of the P-type cladding layer, and an ohmic electrode 24 of the N-type cladding layer. All InGaN and InGaA shown here
The IN layer is a semiconductor crystal layer grown epitaxially with lattice matching to the substrate. In addition, the composition of the InGaAIN cladding layer was adjusted to the
Selected from the diagram. The resonator length is 300n, and the active layer width is 0.
It is 8n. Generally, CO is a problem with short wavelength oscillation devices.
D
Damage) 1 to raise the level! Pole 23 was formed from both end faces to the inside of the Lon. In addition, in order to improve heat conduction, the thickness of the substrate was reduced to 60 nm, and it was mounted on a diamond heat sink. it pole 23, 2
Apply positive and negative voltages to 4, respectively. If this is done, a reverse bias will be applied to the pn junction between the buried layers 21 and 22, and no current will flow through the buried layer, but only through the active layer, similar to buried lasers using InP or GaAs systems. ．． Furthermore, since the active layer has a higher refractive index than the buried layer or cladding layer, the light generated in the active layer is confined within the active layer. Therefore, current can be narrowed to the active layer and light can be confined to the active layer. the result,
Operation with high external differential efficiency is possible with low threshold current. Next, the CW characteristics at room temperature are shown. FIG. 10 shows the relationship between the optical output and the injected current, with the horizontal axis representing the injected current and the vertical axis representing the optical output. FIG. 11 shows the oscillation spectrum, with the horizontal axis representing the wavelength and the intensity in arbitrary units representing the vertical axis.

発振閾注入電流は４８＋ｍＡで、発振波長は４５２ｎｍ
で、端面当りの外部微分量子効率は２７％であった。ま
た、端面当りの最大光出力は１３＋ｓＷであり、横モー
ドは単一であった．ここでは、活性層としてＩｎＧａＡＩＮを選んだが、基
板に格子整合する組成のＩｎＧａＡＩＮを選べば、Ｉｎ
ＧａＮを活性層とした場合と異なった発振波長のレーザ
を同様に製作できる．また、Ｐ形電極のオーミック抵抗
を下げるために、Ｐ形クラッド層と電極との間に低抵抗
になり昌いバンドギャソプの狭いＩｎＧａＡ　ＩＮ層の
Ｐ形層をキャップ層として一層入れても良い．以上述べてきた素子構造の他に、他の素子構造であって
も基仮とその上に成長した結晶の格子定数を一敗させる
という本発明の基本原理は、極めて有効であることは言
うまでもないことである．（発明の効果）以上説明したように、本発明によれば基板と格子整合し
た結晶を基板上にエビタキシャル成長することにより、
欠陥の極めて少ない良質の結晶が得られる．その結果、
伝導型の制御も可能となり、実施例２と３に示したよう
に電流注入による発光が可能となる利点がある．電流注
入による発光はＭＩＳ型構造による発光より桁違いに強
いと一般的に言われている．本発明の実施例においても
、従来からあるＭＩＳ型素子と比べてはるかに強い発光
が得られている．青色発光などの可視の短波長頷域では
、視惑度が低い．従って、表示装置等にこの波長域の素
子を用いる場合、発光ダイオードより、より発光強度の
高いレーザが望ましい．本発明によれば、実施例にも示
したように、レーザを作ることもできるという効果があ
る。The oscillation threshold injection current is 48+mA, and the oscillation wavelength is 452nm.
The external differential quantum efficiency per end face was 27%. Furthermore, the maximum optical output per end face was 13+sW, and the transverse mode was single. Here, InGaAIN was selected as the active layer, but if InGaAIN with a composition that is lattice matched to the substrate is selected, InGaAIN can be used as the active layer.
Lasers with different oscillation wavelengths can be manufactured in the same way as when GaN is used as the active layer. Further, in order to lower the ohmic resistance of the P-type electrode, a P-type layer of InGaA IN having a low resistance and a narrow band gap may be inserted as a cap layer between the P-type cladding layer and the electrode. It goes without saying that the basic principle of the present invention, which completely eliminates the lattice constant of the substrate and the crystal grown on it, is extremely effective for other device structures as well as for the device structures described above. That's true. (Effects of the Invention) As explained above, according to the present invention, by epitaxially growing a crystal that is lattice matched to the substrate on the substrate,
Good quality crystals with extremely few defects can be obtained. the result,
The conduction type can also be controlled, and as shown in Examples 2 and 3, there is an advantage that light emission can be achieved by current injection. It is generally said that the light emitted by current injection is an order of magnitude stronger than the light emitted by the MIS type structure. In the embodiment of the present invention, much stronger light emission is obtained compared to conventional MIS type elements. Visibility is low in the visible short wavelength range such as blue light emission. Therefore, when using elements in this wavelength range in display devices, etc., it is preferable to use a laser with higher emission intensity than a light emitting diode. According to the present invention, as shown in the embodiments, a laser can also be produced.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図乃至第６図は本発明にかかる基仮とその上に成長
する■族元素（ＡＩ，　Ｇａ，　Ｉｎ）窒化物の二元．
三元及び四元混晶の（００１）面上での原子の対応を示
す。第７図及び第８図はそれぞれ本発明の実施例ｌ及び実施
例２の構造の概略を示す．第９図は本発明の実施例３におけるレーザ共振器方向に
垂直な断面構造の概略を示す。第１０図は本発明の実施例３における室温値ＩＣＷ動作
時の片端面からの光出力と注入電流との関係を示す．第１１図は本発明の実施例３における室温値・ＣＷ動作
時の発振スペクトルを示す．第１２図は従来技術の発光素子の構造の概略、第１３図
は■族元素（ＡＩ，　Ｇａ，　Ｉｎ）窒化物の（００１
１面上の格子定数とバンドギャノプエネルギとの関係を
示す．ｌ・・・・サファイア基板２・・・・ｎ形ＧａＮ層３・・・・Ｚｎドーブ高抵抗ＧａＮ層４，　５　・６　・　・　・７　・　・　・８　・　・　・９　・　・　・１０・　・　・１１　・　・　・ｌ２・　・　・ｌ３・　・　・ｌ４・　・　・１５・　・　・ｌ６・　・　・ｌ７・　・　・１８・　・　・ｌ９・　・　・２０・　・　・２ｌ・　・　・２２・　・　・２３・　・　・２４・　・　・・金電極・Ｍ．Ｏ基板・ｎＪｆＪＩｎＧａＮ層・Ｚｎドーブ高抵抗１ｎＧａＮ発光層・ｎ形オーミック電極・金電極・ＡＩＪｇ（ｌｍ基板・Ｓｎドープ［ｎＧａ八ＩＮクラッド層・ノンドーブＩ
ｎＧａＮ発光層・ＺｎドープＩｎＧａＡＩＮクラッド層・ｐ形オーミッ
ク電極・ｎ形オーミック電極・ＡＩ．？ＩｇＯ．基板・Ｓｎドーフ゜夏ｎＧａＡＩＮクラッド層・ノンドーブ
ＩｎＧａＮ発光層・Ｚｎドーフ゜ＩｎＧａＡＩＮクラ・冫ド層・Ｚｎドー
プＩｎＧａＡＩＮクラッド層・ＳｎドープｒｎＧａＡＩ
Ｎクラッド層・ｐ形オーミック電極・ｎ形オーミック電極第図弔図第６図第図第８図１６一電極第１０図第１１図＝ｉ表（ｎｍ）第９図１９−ルト゛−７゛ｔｎＧａＮｅｆＪ乙，２４−寛＊第１２図第１３図バ〉ド〜（ツア１キルヘ゜（ｅｖ）手続辛甫正魯（自発）Figures 1 to 6 show a binary structure of a base material according to the present invention and a group Ⅰ element (AI, Ga, In) nitride grown thereon.
The correspondence of atoms on the (001) plane of ternary and quaternary mixed crystals is shown. 7 and 8 schematically show the structures of Example 1 and Example 2 of the present invention, respectively. FIG. 9 schematically shows a cross-sectional structure perpendicular to the laser resonator direction in Example 3 of the present invention. FIG. 10 shows the relationship between the optical output from one end surface and the injection current during room temperature ICW operation in Example 3 of the present invention. FIG. 11 shows the oscillation spectrum at room temperature and during CW operation in Example 3 of the present invention. Fig. 12 shows an outline of the structure of a conventional light emitting device, and Fig. 13 shows a (001
The relationship between the lattice constant and band Gyanop energy on one plane is shown. l... Sapphire substrate 2... N-type GaN layer 3... Zn-doped high-resistance GaN layer 4, 5 ・ 6 ・・ 7 ・・・ 8 ・・ 9 ・・ 10 ・・１１・・・ l2・・・ l3・・・ l4・・ 15・・・ l6・・・ l7・・ 18・・・ l9・・ 20・・・ 2l・・・ 22・・・ 23・・・ 24・・・・Gold electrode・M. O substrate・nJfJInGaN layer・Zn dove high resistance 1nGaN light emitting layer・n type ohmic electrode・gold electrode・AIJg(lm substrate・Sn doped [nGa8IN cladding layer・nondoped I
nGaN light emitting layer, Zn-doped InGaAIN cladding layer, p-type ohmic electrode, n-type ohmic electrode, AI. ? IgO. Substrate, Sn-doped nGaAIN cladding layer, non-doped InGaN light-emitting layer, Zn-doped InGaAIN cladding layer, Zn-doped InGaAIN cladding layer, Sn-doped rnGaAI
N-cladding layer/p-type ohmic electrode/n-type ohmic electrode Funeral diagram Fig. 6 Fig. 8 Fig. 16 - Electrode Fig. 10 Fig. 11 = i table (nm) Fig. 9 Otsu, 24-Hiroshi * Figure 12 Figure 13 Bad ~ (Tour 1 Kilometer (ev) Procedure Xinbo Zhenglu (voluntary)

Claims

【特許請求の範囲】[Claims]

単結晶基板と、前記単結晶基板上に成長し、かつ前記単
結晶基板と異なる組成からなる薄膜とを備える半導体発
光素子において、前記単結晶基板は複数の元素の固溶体
からなる結晶構造を有し、また前記薄膜は前記単結晶基
板上に格子整合して成長したＩｎ＿ｘＧａ＿ｙＡｌ＿ｚ
Ｎ（ｘ＋ｙ＋ｚ＝１、かつ、０≦ｘ、ｙ、ｚ≦１）薄膜
の少なくとも一層が含まれてなることを特徴とする半導
体発光素子。In a semiconductor light emitting device comprising a single crystal substrate and a thin film grown on the single crystal substrate and having a composition different from that of the single crystal substrate, the single crystal substrate has a crystal structure consisting of a solid solution of a plurality of elements. , and the thin film is In_xGa_yAl_z grown on the single crystal substrate with lattice matching.
A semiconductor light emitting device comprising at least one layer of N (x+y+z=1 and 0≦x, y, z≦1) thin film.