JP2001185718A - Manufacturing method of epitaxial wafer for high electron mobility transistor using gallium nitride based compound semiconductor - Google Patents
Manufacturing method of epitaxial wafer for high electron mobility transistor using gallium nitride based compound semiconductorInfo
- Publication number
- JP2001185718A JP2001185718A JP36739999A JP36739999A JP2001185718A JP 2001185718 A JP2001185718 A JP 2001185718A JP 36739999 A JP36739999 A JP 36739999A JP 36739999 A JP36739999 A JP 36739999A JP 2001185718 A JP2001185718 A JP 2001185718A
- Authority
- JP
- Japan
- Prior art keywords
- epitaxial wafer
- electron mobility
- compound semiconductor
- heat treatment
- based compound
- 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
- 229910002601 GaN Inorganic materials 0.000 title claims abstract description 62
- 239000004065 semiconductor Substances 0.000 title claims abstract description 39
- 150000001875 compounds Chemical class 0.000 title claims abstract description 37
- JMASRVWKEDWRBT-UHFFFAOYSA-N Gallium nitride Chemical compound [Ga]#N JMASRVWKEDWRBT-UHFFFAOYSA-N 0.000 title claims abstract description 21
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 20
- 238000010438 heat treatment Methods 0.000 claims abstract description 54
- 239000000758 substrate Substances 0.000 claims abstract description 25
- 239000013078 crystal Substances 0.000 claims abstract description 23
- 238000000034 method Methods 0.000 claims abstract description 19
- 238000001947 vapour-phase growth Methods 0.000 claims abstract description 6
- 125000004435 hydrogen atom Chemical group [H]* 0.000 claims description 11
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 6
- 239000012299 nitrogen atmosphere Substances 0.000 claims description 5
- 238000000927 vapour-phase epitaxy Methods 0.000 claims description 5
- -1 gallium nitride compound Chemical class 0.000 abstract 1
- 235000012431 wafers Nutrition 0.000 description 34
- 229910002704 AlGaN Inorganic materials 0.000 description 13
- 230000000694 effects Effects 0.000 description 10
- 229910052594 sapphire Inorganic materials 0.000 description 8
- 239000010980 sapphire Substances 0.000 description 8
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 229910052710 silicon Inorganic materials 0.000 description 4
- 239000010703 silicon Substances 0.000 description 4
- 238000000354 decomposition reaction Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000006356 dehydrogenation reaction Methods 0.000 description 3
- 238000000859 sublimation Methods 0.000 description 3
- 230000008022 sublimation Effects 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 238000001803 electron scattering Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000007847 structural defect Effects 0.000 description 2
- JLTRXTDYQLMHGR-UHFFFAOYSA-N trimethylaluminium Chemical compound C[Al](C)C JLTRXTDYQLMHGR-UHFFFAOYSA-N 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 102100031102 C-C motif chemokine 4 Human genes 0.000 description 1
- 101000777471 Homo sapiens C-C motif chemokine 4 Proteins 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 239000002019 doping agent Substances 0.000 description 1
- 239000002932 luster Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000001451 molecular beam epitaxy Methods 0.000 description 1
- 125000004433 nitrogen atom Chemical group N* 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- XCZXGTMEAKBVPV-UHFFFAOYSA-N trimethylgallium Chemical compound C[Ga](C)C XCZXGTMEAKBVPV-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Crystals, And After-Treatments Of Crystals (AREA)
- Junction Field-Effect Transistors (AREA)
Abstract
(57)【要約】
【課題】 電子移動度に優れた窒化ガリウム系化合物半
導体を用いた高電子移動度トランジスタ用エピタキシャ
ルウェハの製造方法を提供するものである。
【解決手段】 気相成長法により、基板２上に窒化ガリ
ウム系化合物半導体の結晶を成長させてエピタキシャル
ウェハ１を形成した後、該エピタキシャルウェハ１に熱
処理を施すものである。
An object of the present invention is to provide a method of manufacturing an epitaxial wafer for a high electron mobility transistor using a gallium nitride compound semiconductor having excellent electron mobility. SOLUTION: After growing a gallium nitride-based compound semiconductor crystal on a substrate 2 by a vapor phase growth method to form an epitaxial wafer 1, the epitaxial wafer 1 is subjected to a heat treatment.
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、窒化ガリウム系化
合物半導体を用いた高電子移動度トランジスタ用エピタ
キシャルウェハの製造方法に関するものである。The present invention relates to a method for manufacturing an epitaxial wafer for a high electron mobility transistor using a gallium nitride-based compound semiconductor.
【０００２】[0002]
【従来の技術】窒化ガリウム（以下、ＧａＮと示す）系
化合物半導体を用いた電子デバイスは、他の材料系の化
合物半導体には無い高周波・高出力特性や高温安定性と
いった観点から注目されており、広く研究が行われ始め
ている。中でも、ＧａＮ系化合物半導体を用いた高電子
移動度トランジスタ（以下、ＨＥＭＴと示す）は、最も
実現可能なデバイスの一つとして期待されている。2. Description of the Related Art Electronic devices using gallium nitride (hereinafter, referred to as GaN) -based compound semiconductors have been receiving attention from the viewpoint of high-frequency and high-output characteristics and high-temperature stability that are not found in other material-based compound semiconductors. Research has begun to be widely conducted. Among them, a high electron mobility transistor (hereinafter, referred to as HEMT) using a GaN-based compound semiconductor is expected as one of the most feasible devices.
【０００３】ＧａＮ系化合物半導体結晶は、一般に、有
機金属気相成長法（ＭＯＶＰＥ法）や分子線エピタキシ
ー法（ＭＢＥ法）等の気相成長法により、サファイア
（α−Ａｌ2 Ｏ3 ）や炭化珪素（ＳｉＣ）の基板上に形
成されている。[0003] In general, GaN-based compound semiconductor crystals are produced by vapor phase growth such as metal organic vapor phase epitaxy (MOVPE) or molecular beam epitaxy (MBE) or sapphire (α-Al 2 O 3 ). It is formed on a silicon (SiC) substrate.
【０００４】ＧａＮ系化合物半導体を用いたＨＥＭＴ用
エピタキシャルウェハの製造も、同様の方法を用いて行
われる。すなわち、図４に示すように、先ず、無処理又
は表面に何らかの溶液処理を施した基板４２を成長炉の
中に導入し、基板４２上に、膜厚数十ｎｍ程度で、Ｇａ
Ｎ又はＡｌＮ或いはAlGaN からなるthin buffer 層４３
をエピタキシャル成長させる。次に、buffer層４３上に
厚いi-ＧａＮ層４６を成長させ、その後、順に、スペー
サであるi-AlGaN 層４７、キャリア供給層であるn-AlGa
N 層４８、ゲート電極用障壁層であるi-AlGaN 層４９を
エピタキシャル成長させ、ＧａＮ系ＨＥＭＴ用エピタキ
シャルウェハ４１が得られる。[0004] The manufacture of an epitaxial wafer for HEMT using a GaN-based compound semiconductor is also performed by a similar method. That is, as shown in FIG. 4, first, a substrate 42 having no treatment or having undergone some solution treatment on its surface is introduced into a growth furnace, and a Ga film having a film thickness of about several tens nm is formed on the substrate 42.
Thin buffer layer 43 made of N or AlN or AlGaN
Is epitaxially grown. Next, a thick i-GaN layer 46 is grown on the buffer layer 43, and then an i-AlGaN layer 47 as a spacer and an n-AlGa layer as a carrier supply layer are sequentially formed.
The N layer 48 and the i-AlGaN layer 49 as a gate electrode barrier layer are epitaxially grown to obtain the GaN-based HEMT epitaxial wafer 41.
【０００５】これにより、i-ＧａＮ層４６とi-AlGaN 層
４７との界面に、２ＤＥＧと呼ばれる移動度の高い電子
が発生し、Ｓｉなどの不純物をドーピングしたＧａＮ系
エピタキシャルウェハよりも電子移動度を高くすること
が可能となる。As a result, electrons having high mobility called 2DEG are generated at the interface between the i-GaN layer 46 and the i-AlGaN layer 47, and the electron mobility is higher than that of a GaN-based epitaxial wafer doped with impurities such as Si. Can be increased.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、このＧ
ａＮ系ＨＥＭＴ用エピタキシャルウェハ４１の電子移動
度は、材料物性から予想される電子移動度よりも低くな
ってしまうのが現状である。However, this G
At present, the electron mobility of the aN-based HEMT epitaxial wafer 41 is lower than the electron mobility expected from the material properties.
【０００７】これは、エピタキシャル成長基板として、
ＧａＮではない基板、つまりサファイア基板やＳｉＣ基
板を用いているため、ＧａＮ系化合物半導体結晶中に様
々な構造的欠陥が存在していることに由来する。これら
の欠陥が電子の散乱要因となって、ＧａＮ系ＨＥＭＴ用
エピタキシャルウェハ４１の電子移動度が低下する原因
となっている。This is an epitaxial growth substrate,
Since a substrate other than GaN, that is, a sapphire substrate or a SiC substrate, is used, this is because various structural defects exist in the GaN-based compound semiconductor crystal. These defects cause the scattering of electrons, which causes the electron mobility of the GaN-based HEMT epitaxial wafer 41 to decrease.
【０００８】この電子移動度の低下は、結晶中の様々な
欠陥を低減することによって解決できると考えられる
が、現状においては、具体的な方策は実現されていな
い。また、電子移動度の低下は、電子の散乱要因以外に
も問題があると考えられるが、明らかになっていない。It is thought that this reduction in electron mobility can be solved by reducing various defects in the crystal. However, at present, no specific measure has been realized. Further, it is thought that the decrease in the electron mobility has a problem other than the electron scattering factor, but it has not been clarified.
【０００９】そこで本発明は、上記課題を解決し、電子
移動度に優れた窒化ガリウム系化合物半導体を用いた高
電子移動度トランジスタ用エピタキシャルウェハの製造
方法を提供することにある。Accordingly, an object of the present invention is to provide a method for manufacturing an epitaxial wafer for a high electron mobility transistor using a gallium nitride-based compound semiconductor having an excellent electron mobility.
【００１０】[0010]
【課題を解決するための手段】上記課題を解決するため
に請求項１の発明は、気相成長法により、基板上に窒化
ガリウム系化合物半導体の結晶を成長させてエピタキシ
ャルウェハを形成した後、該エピタキシャルウェハに熱
処理を施すものである。According to a first aspect of the present invention, a gallium nitride-based compound semiconductor crystal is grown on a substrate by a vapor phase growth method to form an epitaxial wafer. The epitaxial wafer is subjected to a heat treatment.
【００１１】請求項２の発明は、上記熱処理を、水素原
子が含まれない窒素雰囲気中で行う請求項１記載の窒化
ガリウム系化合物半導体を用いた高電子移動度トランジ
スタ用エピタキシャルウェハの製造方法である。According to a second aspect of the present invention, there is provided a method for manufacturing an epitaxial wafer for a high electron mobility transistor using a gallium nitride-based compound semiconductor according to the first aspect, wherein the heat treatment is performed in a nitrogen atmosphere containing no hydrogen atoms. is there.
【００１２】請求項３の発明は、上記熱処理を、大気圧
下で行う請求項１又は請求項２記載の窒化ガリウム系化
合物半導体を用いた高電子移動度トランジスタ用エピタ
キシャルウェハの製造方法である。According to a third aspect of the present invention, there is provided a method of manufacturing an epitaxial wafer for a high electron mobility transistor using a gallium nitride-based compound semiconductor according to the first or second aspect, wherein the heat treatment is performed under atmospheric pressure.
【００１３】請求項４の発明は、上記熱処理を、６００
〜８００℃の処理温度で行う請求項１乃至請求項３いず
れかに記載の窒化ガリウム系化合物半導体を用いた高電
子移動度トランジスタ用エピタキシャルウェハの製造方
法である。According to a fourth aspect of the present invention, the heat treatment is performed
The method for producing an epitaxial wafer for a high electron mobility transistor using a gallium nitride-based compound semiconductor according to any one of claims 1 to 3, wherein the method is performed at a processing temperature of 800C.
【００１４】請求項５の発明は、上記熱処理を、５〜３
０分間の処理時間で行う請求項１乃至請求項４いずれか
に記載の窒化ガリウム系化合物半導体を用いた高電子移
動度トランジスタ用エピタキシャルウェハの製造方法で
ある。According to a fifth aspect of the present invention, the heat treatment is performed by 5 to 3 times.
The method for producing an epitaxial wafer for a high electron mobility transistor using a gallium nitride-based compound semiconductor according to any one of claims 1 to 4, which is performed in a processing time of 0 minute.
【００１５】請求項６の発明は、気相成長法として有機
金属気相成長法を、Ｎ源としてアンモニアガスを用い
て、基板上に窒化ガリウム系化合物半導体の結晶を成長
させる請求項１乃至請求項５いずれかに記載の窒化ガリ
ウム系化合物半導体を用いた高電子移動度トランジスタ
用エピタキシャルウェハの製造方法である。According to a sixth aspect of the present invention, a gallium nitride-based compound semiconductor crystal is grown on a substrate by using a metalorganic vapor phase epitaxy as a vapor phase epitaxy method and using ammonia gas as an N source. Item 6. A method for producing an epitaxial wafer for a high electron mobility transistor using the gallium nitride-based compound semiconductor according to any one of Items 5.
【００１６】以上の方法によれば、熱処理により、窒化
ガリウム系化合物半導体の結晶中からＨ原子が追い出さ
れ、熱処理前と比較して、ＧａＮ系ＨＥＭＴ用エピタキ
シャルウェハの電子移動度を高くすることができる。According to the above method, H atoms are expelled from the crystal of the gallium nitride-based compound semiconductor by the heat treatment, and the electron mobility of the GaN-based HEMT epitaxial wafer can be increased as compared with before the heat treatment. it can.
【００１７】上記数値範囲を限定した理由を以下に説明
する。The reason for limiting the above numerical range will be described below.
【００１８】熱処理温度を６００〜８００℃の範囲に規
定しているのは、熱処理温度が６００℃よりも低いと熱
処理による脱Ｈ効果が殆ど得られず、また、熱処理温度
を８００℃より高くするとＧａＮ系化合物半導体の結晶
が昇華・分解してしまうためである。The reason why the heat treatment temperature is specified in the range of 600 to 800 ° C. is that if the heat treatment temperature is lower than 600 ° C., the dehydrogenation effect by the heat treatment is hardly obtained, and if the heat treatment temperature is higher than 800 ° C. This is because the crystal of the GaN-based compound semiconductor is sublimated and decomposed.
【００１９】熱処理時間を５〜３０分間の範囲に規定し
ているのは、熱処理時間が５分間よりも短いと熱処理に
よる脱Ｈ効果が殆ど得られず、また、熱処理時間を３０
分間より長くしても脱Ｈ効果は殆ど変わらないためであ
る。The reason why the heat treatment time is specified in the range of 5 to 30 minutes is that if the heat treatment time is shorter than 5 minutes, the H removal effect by the heat treatment is hardly obtained, and the heat treatment time is 30 minutes.
This is because the dehydrogenation effect hardly changes even if it is longer than minutes.
【００２０】[0020]
【発明の実施の形態】以下、本発明の好適一実施の形態
を添付図面に基いて説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.
【００２１】気相成長法としてＭＯＶＰＥ法を、Ｎ原料
としてアンモニアガス（ＮＨ3 ） を用い、ＧａＮ系ＨＥ
ＭＴ用エピタキシャルウェハを形成すると、多量（約１
×１０19ｃｍ-3）のＨ原子が結晶中に含まれてしまう。
そして、Ｇａ原子やＮ原子が少量のＨ原子と結合し、余
った結合手（ダングリングボンド）が空間電荷となって
しまう。この空間電荷により電子が散乱され、ＧａＮ系
ＨＥＭＴ用エピタキシャルウェハの電子移動度が低下す
ると考えられる。The MOVPE method is used as a vapor-phase growth method.
As ammonia gas (NHThree) GaN HE
When an epitaxial wafer for MT is formed, a large amount (about 1
× 1019cm-3) H atoms are included in the crystal.
Then, Ga atoms and N atoms combine with a small amount of H atoms,
Dangling bonds become space charges
I will. Electrons are scattered by this space charge, and GaN-based
Electron mobility of epitaxial wafer for HEMT decreases
It is thought that.
【００２２】本発明者らは、ＧａＮ系化合物半導体の結
晶中の構造的な欠陥を低減させるのではなく、基板上に
ＧａＮ系化合物半導体の結晶を成長させた後、熱処理を
行い、ＧａＮ系化合物半導体の結晶中からＨ原子を追い
出すことで、ＧａＮ系ＨＥＭＴ用エピタキシャルウェハ
の電子移動度が向上することを見出した。The present inventors do not reduce structural defects in the crystal of the GaN-based compound semiconductor, but grow the crystal of the GaN-based compound semiconductor on the substrate, and then heat-treat the crystal. It has been found that by removing H atoms from the semiconductor crystal, the electron mobility of the GaN-based HEMT epitaxial wafer is improved.
【００２３】ここで、ＧａＮ系化合物半導体の結晶を成
長させた後、４００℃以上の温度で熱処理を行うことに
より、ｐ型不純物をドープしたＧａＮ系化合物半導体の
結晶中からＨ原子を追い出すことができることは既に知
られている（特開平５−１８３１８９号公報参照）。し
かし、この場合における脱Ｈは、ｐ型ドーパントである
Ｍｇに結合したＨ原子を切り離してＭｇを活性化させ、
低抵抗で、かつ、膜厚によらず抵抗値が均一なｐ型Ｇａ
Ｎ系化合物半導体を得ることを目的とするものであっ
た。Here, after the crystal of the GaN-based compound semiconductor is grown, heat treatment is performed at a temperature of 400 ° C. or more, so that H atoms can be driven out of the crystal of the GaN-based compound semiconductor doped with p-type impurities. It is already known that this is possible (see Japanese Patent Application Laid-Open No. 5-183189). However, de-H in this case activates Mg by cutting off the H atom bonded to Mg which is a p-type dopant,
P-type Ga with low resistance and uniform resistance regardless of film thickness
The purpose was to obtain an N-based compound semiconductor.
【００２４】そこで、本発明の製造方法は、気相成長法
としてＭＯＶＰＥ法を、Ｎ原料としてアンモニアガスを
用い、サファイア基板上に、ＧａＮ系化合物半導体の結
晶を順次成長させてエピタキシャルウェハを形成した
後、そのエピタキシャルウェハに、大気圧下、Ｈ原子
（Ｈ化合物）が含まれない窒素雰囲気中、６００〜８０
０℃の温度で５〜３０分間の熱処理を施すものである。Therefore, in the manufacturing method of the present invention, an epitaxial wafer is formed by sequentially growing crystals of a GaN-based compound semiconductor on a sapphire substrate using MOVPE as a vapor phase growth method and ammonia gas as an N source. Thereafter, the epitaxial wafer is placed under atmospheric pressure in a nitrogen atmosphere containing no H atom (H compound) at 600-80.
The heat treatment is performed at a temperature of 0 ° C. for 5 to 30 minutes.
【００２５】熱処理を、Ｈ原子を含まない窒素ガス雰囲
気中で行っているのは、脱Ｈ効果をより効果的に行うた
めであると共に、Ｈ原子を含む窒素ガス雰囲気で行う
と、ＧａＮ系化合物半導体の結晶の昇華・分解反応が促
進され、高温熱処理が不可能となってしまうためであ
る。The reason why the heat treatment is performed in a nitrogen gas atmosphere containing no H atoms is to more effectively perform the dehydrogenation effect, and when the heat treatment is performed in a nitrogen gas atmosphere containing H atoms, the GaN compound This is because the sublimation / decomposition reaction of the semiconductor crystal is promoted, and high-temperature heat treatment becomes impossible.
【００２６】また、熱処理を、大気圧下で行っているの
は、減圧下で熱処理を行うと、大気圧下で熱処理を行う
場合と比較して、結晶の昇華・分解反応温度が低くな
り、高温熱処理による脱Ｈ効果が得られないためであ
る。The reason why the heat treatment is performed under the atmospheric pressure is that when the heat treatment is performed under the reduced pressure, the sublimation / decomposition reaction temperature of the crystal becomes lower than when the heat treatment is performed under the atmospheric pressure. This is because the H removal effect by the high-temperature heat treatment cannot be obtained.
【００２７】尚、本発明においては、基板としてサファ
イア基板を用いているが、ＳｉＣ基板を用いても良いこ
とは言うまでもない。In the present invention, a sapphire substrate is used as a substrate, but it goes without saying that a SiC substrate may be used.
【００２８】本発明の製造方法によれば、ＧａＮ系化合
物半導体の結晶を成長させた後、熱処理を行って脱Ｈす
ることにより、ＧａＮ系化合物半導体結晶中のダングリ
ングボンドを減少させることができる。これによって、
電子の散乱要因である空間電荷が低減し、熱処理前と比
較して、ＧａＮ系ＨＥＭＴ用エピタキシャルウェハ１の
電子移動度を高くすることができる。According to the manufacturing method of the present invention, dangling bonds in the GaN-based compound semiconductor crystal can be reduced by growing the crystal of the GaN-based compound semiconductor and then performing heat treatment to remove H. . by this,
Space charge, which is a factor of electron scattering, is reduced, and the electron mobility of the GaN-based HEMT epitaxial wafer 1 can be increased as compared with before the heat treatment.
【００２９】[0029]
【実施例】本発明の製造方法を用いて作製したＧａＮ系
ＨＥＭＴ用エピタキシャルウェハの断面図を図１に示
す。1 is a cross-sectional view of a GaN-based HEMT epitaxial wafer manufactured by the manufacturing method of the present invention.
【００３０】基板としてｃ面研磨のサファイア基板２
を、気相成長原料としてトリメチルガリウム（ＴＭ
Ｇ）、トリメチルアルミニウム（ＴＭＡ）、アンモニア
（ＮＨ3 ）、およびモノシラン（ＳｉＨ4 ）を用いた。A sapphire substrate 2 of c-plane polishing as a substrate
With trimethylgallium (TM
G), trimethyl aluminum (TMA), ammonia (NH 3 ), and monosilane (SiH 4 ).
【００３１】先ず、図１に示すように、サファイア基板
２の基板温度を５００℃にした後、サファイア基板２上
に、膜厚２０ｎｍのＧａＮ低温バッファ（LT−ＧａＮ）
層３を成長させる。その後、基板温度を１１００℃にし
た後、LT-GaN層３上に、膜厚５００ｎｍのアンドープＧ
ａＮ（i-ＧａＮ）層４を成長させる。その後、i-ＧａＮ
層４上に、順に、膜厚２５ｎｍのi-AlGaN 層５、膜厚１
μｍのi-ＧａＮ層６、膜厚２ｎｍのi-AlGaN 層７、Ｓｉ
をドープした膜厚２５ｎｍのn-AlGaN 層８を成長させ、
n-AlGaN ／ＧａＮ選択ドープ構造を有したＧａＮ系ＨＥ
ＭＴ用エピタキシャルウェハ１を多数枚作製した。この
時、i-AlGaN 層５、i-AlGaN 層７、n-AlGaN 層８のＡｌ
含有量は１８ｗｔ％、n-AlGaN 層８のキャリア濃度は
５．０×１０18ｃｍ-3である。また、i-ＧａＮ層６とi-
AlGaN 層７との界面には、２ＤＥＧと呼ばれる移動度の
高い電子が発生した。First, as shown in FIG. 1, after setting the substrate temperature of the sapphire substrate 2 to 500 ° C., a 20-nm-thick GaN low-temperature buffer (LT-GaN) is formed on the sapphire substrate 2.
Layer 3 is grown. Then, after setting the substrate temperature to 1100 ° C., a 500 nm-thick undoped G
An aN (i-GaN) layer 4 is grown. Then, i-GaN
On the layer 4, an i-AlGaN layer 5 having a thickness of 25 nm and a thickness 1
μm i-GaN layer 6, 2 nm thick i-AlGaN layer 7, Si
A 25 nm thick n-AlGaN layer 8 doped with
GaN HE with n-AlGaN / GaN selective doping structure
Many epitaxial wafers 1 for MT were produced. At this time, the Al of the i-AlGaN layer 5, the i-AlGaN layer 7, and the n-AlGaN layer 8
The content is 18 wt%, and the carrier concentration of the n-AlGaN layer 8 is 5.0 × 10 18 cm −3 . The i-GaN layer 6 and the i-GaN
At the interface with the AlGaN layer 7, electrons with high mobility called 2DEG were generated.
【００３２】次に、６枚のエピタキシャルウェハ１に、
大気圧下、Ｎ2 雰囲気中、異なる温度（４００℃，５０
０℃，６００℃，７００℃，７５０℃，８００℃）で、
それぞれ３０分間の熱処理を行い、各エピタキシャルウ
ェハ１の電気伝導特性を測定した。電気伝導特性の測定
は、Van der Pauw法を用いたＨａｌｌ測定により、室温
にて行った。また、測定に用いる電極としてＩｎを用
い、オーミック性電極を形成する際の熱処理として、４
００℃で３０分間の前熱処理を行った。尚、熱処理前に
おけるエピタキシャルウェハ１のシートキャリア濃度は
１．２×１０13ｃｍ-3であった。Next, six epitaxial wafers 1
At atmospheric pressure, in N 2 atmosphere, at different temperatures (400 ° C., 50
0 ° C, 600 ° C, 700 ° C, 750 ° C, 800 ° C)
Heat treatment was performed for 30 minutes each, and the electric conduction characteristics of each epitaxial wafer 1 were measured. The electric conductivity was measured at room temperature by Hall measurement using the Van der Pauw method. In addition, when In is used as an electrode used for measurement and heat treatment for forming an ohmic
A pre-heat treatment was performed at 00 ° C. for 30 minutes. The sheet carrier concentration of the epitaxial wafer 1 before the heat treatment was 1.2 × 10 13 cm −3 .
【００３３】電子移動度と熱処理温度との関係を図２に
示す。図２中において、横軸は熱処理温度（℃）を、縦
軸は電子移動度（ｃｍ2 ／Ｖｓ）を示している。FIG. 2 shows the relationship between the electron mobility and the heat treatment temperature. In FIG. 2, the horizontal axis indicates the heat treatment temperature (° C.), and the vertical axis indicates the electron mobility (cm 2 / Vs).
【００３４】図２に示すように、熱処理を行うことによ
って電子移動度が向上することがわかる。また、４００
〜８００℃の温度範囲において、熱処理温度は高い方が
より好ましく、熱処理温度を７００℃よりも高くする
と、電子移動度の向上効果が急激に高まり、８００℃の
熱処理後は、熱処理前と比較して電子移動度が２０％程
度向上している。尚、８００℃より高い温度での熱処理
では、ＧａＮ系化合物半導体の結晶表面に、Ｇａと思わ
れる金属光沢が観察された。これは、ＧａＮ系化合物半
導体の昇華・分解が起こったために生じたものと推定さ
れる。よって、８００℃以上の温度での熱処理は好まし
くないことがわかる。As shown in FIG. 2, it can be seen that the heat treatment improves the electron mobility. Also, 400
In the temperature range of ~ 800 ° C, it is more preferable that the heat treatment temperature is higher. When the heat treatment temperature is higher than 700 ° C, the effect of improving the electron mobility sharply increases. As a result, the electron mobility is improved by about 20%. In the heat treatment at a temperature higher than 800 ° C., metallic luster considered to be Ga was observed on the crystal surface of the GaN-based compound semiconductor. This is presumed to be caused by sublimation and decomposition of the GaN-based compound semiconductor. Therefore, it is understood that heat treatment at a temperature of 800 ° C. or more is not preferable.
【００３５】次に、５枚のエピタキシャルウェハ１に、
大気圧下、Ｎ2 雰囲気中、８００℃の温度で、それぞれ
異なる処理時間（２分，５分，１０分，１５分，３０
分）の熱処理を行い、各ＨＥＭＴ用エピタキシャルウェ
ハ１の電気伝導特性を測定した。Next, the five epitaxial wafers 1
Different treatment times (2 minutes, 5 minutes, 10 minutes, 15 minutes, 30 minutes) at a temperature of 800 ° C. in an N 2 atmosphere under atmospheric pressure.
), And the electrical conductivity of each HEMT epitaxial wafer 1 was measured.
【００３６】８００℃の熱処理時における電子移動度と
熱処理時間との関係を図３に示す。図３中において、横
軸は熱処理時間（ｍｉｎ）を、縦軸は縦軸は電子移動度
（ｃｍ2 ／Ｖｓ）を示している。FIG. 3 shows the relationship between the electron mobility and the heat treatment time during the heat treatment at 800 ° C. In FIG. 3, the horizontal axis represents the heat treatment time (min), and the vertical axis represents the electron mobility (cm 2 / Vs).
【００３７】図３に示すように、２分間の熱処理では電
子移動度の向上効果は殆どないが、熱処理時間を５分，
１０分，…と長くするにつれ電子移動度が向上すること
がわかる。しかし、熱処理時間を例えば１５分以上と長
くしても、電子移動度の向上効果は殆ど変わらず、熱処
理時間３０分で、電子移動度の向上効果は略飽和する。As shown in FIG. 3, the heat treatment for 2 minutes has almost no effect of improving the electron mobility, but the heat treatment time is 5 minutes,
It can be seen that the electron mobility improves as the length is increased to 10 minutes. However, even if the heat treatment time is increased to, for example, 15 minutes or more, the effect of improving the electron mobility hardly changes, and after 30 minutes of the heat treatment, the effect of improving the electron mobility is substantially saturated.
【００３８】以上、本発明の実施の形態は、上述した実
施の形態に限定されるものではなく、他にも種々のもの
が想定されることは言うまでもない。As described above, the embodiments of the present invention are not limited to the above-described embodiments, and it is needless to say that various other embodiments can be envisaged.
【００３９】[0039]
【発明の効果】以上要するに本発明によれば、ＧａＮ系
ＨＥＭＴ用エピタキシャルウェハを形成した後、熱処理
を行って脱Ｈすることにより、ＧａＮ系ＨＥＭＴ用エピ
タキシャルウェハの電子移動度を高くすることができる
という優れた効果を発揮する。As described above, according to the present invention, the electron mobility of a GaN-based HEMT epitaxial wafer can be increased by forming a GaN-based HEMT epitaxial wafer and then performing heat treatment to remove H. It has an excellent effect.
【図１】本発明の製造方法を用いて作製したＧａＮ系Ｈ
ＥＭＴ用エピタキシャルウェハの断面図である。FIG. 1 shows a GaN-based H produced by using the production method of the present invention.
It is sectional drawing of the epitaxial wafer for EMT.
【図２】電子移動度と熱処理温度との関係を示す図であ
る。FIG. 2 is a diagram showing a relationship between electron mobility and heat treatment temperature.
【図３】８００℃の熱処理時における電子移動度と熱処
理時間との関係を示す図である。FIG. 3 is a diagram showing the relationship between electron mobility and heat treatment time during heat treatment at 800 ° C.
【図４】ＧａＮ系ＨＥＭＴ用エピタキシャルウェハの構
造断面図である。FIG. 4 is a structural sectional view of an epitaxial wafer for GaN-based HEMT.
１ ＧａＮ系ＨＥＭＴ用エピタキシャルウェハ（エピタ
キシャルウェハ） ２ サファイア基板（基板）1 Epitaxial wafer for GaN HEMT (epitaxial wafer) 2 Sapphire substrate (substrate)
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｈ０１Ｌ 21/324 Ｆターム(参考） 4G077 AA03 BE15 DB08 FE03 5F045 AA04 AB14 AB17 AC01 AC08 AC12 AD09 AD15 AF02 AF09 BB12 CA07 DA53 DA62 GB12 HA16 5F102 FA00 GB01 GC01 GD01 GJ02 GJ10 GK04 GL04 GM04 GQ01 HC01 HC21 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 Identification code FI Theme coat ゛ (Reference) H01L 21/324 F term (Reference) 4G077 AA03 BE15 DB08 FE03 5F045 AA04 AB14 AB17 AC01 AC08 AC12 AD09 AD15 AF02 AF09 BB12 CA07 DA53 DA62 GB12 HA16 5F102 FA00 GB01 GC01 GD01 GJ02 GJ10 GK04 GL04 GM04 GQ01 HC01 HC21
Claims (6)
ム系化合物半導体の結晶を成長させてエピタキシャルウ
ェハを形成した後、該エピタキシャルウェハに熱処理を
施すことを特徴とする窒化ガリウム系化合物半導体を用
いた高電子移動度トランジスタ用エピタキシャルウェハ
の製造方法。An epitaxial wafer is formed by growing a crystal of a gallium nitride-based compound semiconductor on a substrate by a vapor phase growth method, and then subjecting the epitaxial wafer to a heat treatment. A method for manufacturing an epitaxial wafer for a high electron mobility transistor used.
素雰囲気中で行う請求項１記載の窒化ガリウム系化合物
半導体を用いた高電子移動度トランジスタ用エピタキシ
ャルウェハの製造方法。2. The method for producing an epitaxial wafer for a high electron mobility transistor using a gallium nitride-based compound semiconductor according to claim 1, wherein the heat treatment is performed in a nitrogen atmosphere containing no hydrogen atoms.
又は請求項２記載の窒化ガリウム系化合物半導体を用い
た高電子移動度トランジスタ用エピタキシャルウェハの
製造方法。3. The method according to claim 1, wherein the heat treatment is performed under atmospheric pressure.
A method of manufacturing an epitaxial wafer for a high electron mobility transistor using the gallium nitride-based compound semiconductor according to claim 2.
温度で行う請求項１乃至請求項３いずれかに記載の窒化
ガリウム系化合物半導体を用いた高電子移動度トランジ
スタ用エピタキシャルウェハの製造方法。4. The method for manufacturing an epitaxial wafer for a high electron mobility transistor using a gallium nitride-based compound semiconductor according to claim 1, wherein the heat treatment is performed at a processing temperature of 600 to 800 ° C.
で行う請求項１乃至請求項４いずれかに記載の窒化ガリ
ウム系化合物半導体を用いた高電子移動度トランジスタ
用エピタキシャルウェハの製造方法。5. The method for manufacturing an epitaxial wafer for a high electron mobility transistor using a gallium nitride-based compound semiconductor according to claim 1, wherein the heat treatment is performed for a processing time of 5 to 30 minutes.
を、Ｎ源としてアンモニアガスを用いて、基板上に窒化
ガリウム系化合物半導体の結晶を成長させる請求項１乃
至請求項５いずれかに記載の窒化ガリウム系化合物半導
体を用いた高電子移動度トランジスタ用エピタキシャル
ウェハの製造方法。6. A gallium nitride-based compound semiconductor crystal is grown on a substrate using a metalorganic vapor phase epitaxy as a vapor phase epitaxy method and ammonia gas as an N source. A method for producing an epitaxial wafer for a high electron mobility transistor using the gallium nitride-based compound semiconductor described in the above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP36739999A JP2001185718A (en) | 1999-12-24 | 1999-12-24 | Manufacturing method of epitaxial wafer for high electron mobility transistor using gallium nitride based compound semiconductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP36739999A JP2001185718A (en) | 1999-12-24 | 1999-12-24 | Manufacturing method of epitaxial wafer for high electron mobility transistor using gallium nitride based compound semiconductor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2001185718A true JP2001185718A (en) | 2001-07-06 |
Family
ID=18489224
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP36739999A Pending JP2001185718A (en) | 1999-12-24 | 1999-12-24 | Manufacturing method of epitaxial wafer for high electron mobility transistor using gallium nitride based compound semiconductor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2001185718A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006509710A (en) * | 2002-12-11 | 2006-03-23 | アンモノ・スプウカ・ジ・オグラニチョノン・オドポヴィエドニアウノシツィオン | Epitaxy substrate and manufacturing method thereof |
| US7871843B2 (en) | 2002-05-17 | 2011-01-18 | Ammono. Sp. z o.o. | Method of preparing light emitting device |
| WO2011007555A1 (en) * | 2009-07-17 | 2011-01-20 | Ｄｏｗａエレクトロニクス株式会社 | Epitaxial substrate for electronic device using transverse direction as direction of current conduction and manufacturing method therefor |
| US7905957B2 (en) | 2004-11-26 | 2011-03-15 | Ammono Sp. Z.O.O. | Method of obtaining bulk single crystals by seeded growth |
| US7935550B2 (en) | 2001-10-26 | 2011-05-03 | Ammono Sp. Z O.O. | Method of forming light-emitting device using nitride bulk single crystal layer |
| US8398767B2 (en) | 2004-06-11 | 2013-03-19 | Ammono S.A. | Bulk mono-crystalline gallium-containing nitride and its application |
-
1999
- 1999-12-24 JP JP36739999A patent/JP2001185718A/en active Pending
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7935550B2 (en) | 2001-10-26 | 2011-05-03 | Ammono Sp. Z O.O. | Method of forming light-emitting device using nitride bulk single crystal layer |
| US7871843B2 (en) | 2002-05-17 | 2011-01-18 | Ammono. Sp. z o.o. | Method of preparing light emitting device |
| JP2006509710A (en) * | 2002-12-11 | 2006-03-23 | アンモノ・スプウカ・ジ・オグラニチョノン・オドポヴィエドニアウノシツィオン | Epitaxy substrate and manufacturing method thereof |
| JP4860927B2 (en) * | 2002-12-11 | 2012-01-25 | アンモノ・スプウカ・ジ・オグラニチョノン・オドポヴィエドニアウノシツィオン | Epitaxy substrate and manufacturing method thereof |
| US8110848B2 (en) | 2002-12-11 | 2012-02-07 | Ammono Sp. Z O.O. | Substrate for epitaxy and method of preparing the same |
| US8398767B2 (en) | 2004-06-11 | 2013-03-19 | Ammono S.A. | Bulk mono-crystalline gallium-containing nitride and its application |
| US7905957B2 (en) | 2004-11-26 | 2011-03-15 | Ammono Sp. Z.O.O. | Method of obtaining bulk single crystals by seeded growth |
| WO2011007555A1 (en) * | 2009-07-17 | 2011-01-20 | Ｄｏｗａエレクトロニクス株式会社 | Epitaxial substrate for electronic device using transverse direction as direction of current conduction and manufacturing method therefor |
| JP2011023664A (en) * | 2009-07-17 | 2011-02-03 | Dowa Electronics Materials Co Ltd | Epitaxial substrate for electronic device using transverse direction as direction of current conduction and manufacturing method therefor |
| KR101321660B1 (en) * | 2009-07-17 | 2013-10-23 | 도와 일렉트로닉스 가부시키가이샤 | Epitaxial substrate for electronic device using transverse direction as direction of current conduction and manufacturing method therefor |
| US8710489B2 (en) | 2009-07-17 | 2014-04-29 | Dowa Electronics Materials Co., Ltd. | Epitaxial substrate for electronic device, in which current flows in lateral direction and method of producing the same |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9754783B2 (en) | Method for producing a semiconductor device, and semiconductor device | |
| JP2000068498A (en) | Insulating nitride film and semiconductor device using the same | |
| CN112701160A (en) | Gallium nitride-based high-electron-mobility transistor epitaxial wafer and preparation method thereof | |
| CN114250510B (en) | An epitaxial structure for gallium nitride-based radio frequency devices and its preparation method | |
| JP4063336B2 (en) | Recovery of surface-conditioned silicon carbide substrates | |
| CN112233972B (en) | Gallium nitride-based epitaxial structure and preparation method thereof | |
| TW200950152A (en) | Method of growing group III-V compound semiconductor, and method of manufacturing light-emitting device and electron device | |
| JP2010098141A (en) | Method of manufacturing semiconductor device | |
| US20150084163A1 (en) | Epitaxial substrate, semiconductor device, and method for manufacturing semiconductor device | |
| US20110169138A1 (en) | TECHNIQUES FOR ACHIEVING LOW RESISTANCE CONTACTS TO NONPOLAR AND SEMIPOLAR P-TYPE (Al,Ga,In)N | |
| CN106972058A (en) | A kind of semiconductor devices and preparation method thereof | |
| CN116960173B (en) | High electron mobility transistor epitaxial structure, preparation method and HEMT device | |
| JP3753068B2 (en) | Method for manufacturing epitaxial wafer for field effect transistor | |
| US20130171811A1 (en) | Method for manufacturing compound semiconductor | |
| JP2001185718A (en) | Manufacturing method of epitaxial wafer for high electron mobility transistor using gallium nitride based compound semiconductor | |
| CN108538714A (en) | The preparation method of III group nitride material of p-type | |
| KR102817269B1 (en) | Method for forming silicon carbide on a silicon substrate | |
| CN105849868B (en) | Nitride semiconductor layer stack and its manufacturing method and nitride compound semiconductor device | |
| JP2003178976A (en) | Semiconductor device and method of manufacturing the same | |
| JP2003037069A (en) | Method of manufacturing group III nitride compound semiconductor | |
| CN116646248A (en) | Epitaxial wafer preparation method, epitaxial wafer thereof and high-electron mobility transistor | |
| CN115632061A (en) | A GaN-based HEMT epitaxial structure and its preparation method | |
| JP2001035796A (en) | Method for manufacturing p-type gallium nitride-based compound semiconductor | |
| US20240371628A1 (en) | Method for manufacturing nitride semiconductor substrate | |
| JP2005191477A (en) | Epitaxial wafer for high electron mobility transistor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20050218 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20070906 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20070918 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20071004 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080311 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20080404 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20080715 |