JP2020043165A - Electronic element, method of manufacturing the same, and magnetoresistive element - Google Patents
Electronic element, method of manufacturing the same, and magnetoresistive element Download PDFInfo
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Abstract
Description
本発明は、シリコン単結晶基板上に形成される高性能の結晶性の高い電子素子及びその製造方法に関し、例えば磁気抵抗素子等に関する。 The present invention relates to a high-performance electronic device with high crystallinity formed on a silicon single crystal substrate and a method of manufacturing the same, for example, a magnetoresistive device.
近年、磁気抵抗素子の研究開発が進み、磁気メモリ（ＭＲＡＭ）の記録素子、ハードディスクドライブ（ＨＤＤ）の再生ヘッド、ＨＤＤのアシスト記録のための高周波発振素子、磁気センサ等に利用されている。しかしながら、磁気抵抗素子が多結晶体で構成されているために、多数の結晶粒の存在に起因した、素子間の記録書込特性や読出特性のバラツキが問題である。また、素子の特性、例えば磁気抵抗比等の高性能化が望まれている。なお、磁気抵抗比とは、二つの状態の抵抗の差ΔＲを低い方の抵抗値Ｒで割った値をいう。 In recent years, research and development of magnetoresistive elements have progressed, and they have been used as recording elements for magnetic memories (MRAM), reproducing heads for hard disk drives (HDDs), high-frequency oscillation elements for HDD assist recording, and magnetic sensors. However, since the magnetoresistive element is made of a polycrystalline body, there is a problem in that the recording and writing characteristics and the read characteristics between the elements vary due to the presence of a large number of crystal grains. In addition, it is desired to improve the characteristics of the element, for example, a high performance such as a magnetoresistance ratio. The magnetoresistance ratio is a value obtained by dividing the difference ΔR between the resistances of the two states by the lower resistance value R.
磁気抵抗素子には、絶縁体層をトンネルバリア層として有するトンネル磁気抵抗効果層を備えるトンネル磁気抵抗素子、巨大磁気抵抗効果層を備える面直電流巨大磁気抵抗（ＣＰＰ−ＧＭＲ）素子等が知られている。トンネル磁気抵抗素子は、主たる層として、下部強磁性層と上部強磁性層と、上部と下部強磁性層の間に非磁性のトンネルバリア層を設けた構造を有する。 Known magneto-resistive elements include a tunnel magneto-resistive element having a tunnel magneto-resistive layer having an insulator layer as a tunnel barrier layer, and a plane current giant magneto-resistive (CPP-GMR) element having a giant magneto-resistive layer. ing. The tunnel magnetoresistive element has a structure in which a lower ferromagnetic layer, an upper ferromagnetic layer, and a nonmagnetic tunnel barrier layer are provided between the upper and lower ferromagnetic layers as main layers.
特許文献１では、大口径のシリコン単結晶基板上へ強磁性薄膜の（００１）面をエピタキシャル成長させた単結晶磁気抵抗素子が、報告されている。特許文献１には、磁気抵抗素子の１例として、シリコン基板と、該シリコン基板に積層されたＢ２構造の下地層と、該Ｂ２構造の下地層に積層された第１の非磁性層と、下部強磁性層及び上部強磁性層、並びに当該下部強磁性層と当該上部強磁性層の間に設けられた第２の非磁性層を有する積層体層を少なくとも一つ有する巨大磁気抵抗効果層と、を備える磁気抵抗素子が示されている。また、他の例として、シリコン基板と、該シリコン基板に積層されたＢ２構造の下地層と、該Ｂ２構造の下地層に積層された、下部強磁性層及び上部強磁性層、並びに当該下部強磁性層と当該上部強磁性層の間に設けられた絶縁体層を有する積層体層を少なくとも一つ有するトンネル磁気抵抗効果層と、を備える磁気抵抗素子が示されている。特許文献１では、前記シリコン基板はＳｉ（００１）単結晶基板を用いている。また、前記Ｂ２構造の下地層はＮｉＡｌ、ＣｏＡｌ、ＦｅＡｌである。また、前記第１の非磁性層はＡｇ、Ｖ、Ｃｒ、Ｗ、Ｍｏ、Ａｕ、Ｐｔ、Ｐｄ、Ｔａ、Ｒｕ、Ｒｅ、Ｒｈ、ＮｉＯ、ＣｏＯ、ＴｉＮ、ＣｕＮからなる群から選ばれた少なくとも一種である。下部強磁性層や上部強磁性層は、Ｃｏ基ホイスラー合金、Ｆｅ、ＣｏＦｅからなる群から選ばれた少なくとも一種からなる。前記第２の非磁性層はＡｇ、Ｃｒ、Ｗ、Ｍｏ、Ａｕ、Ｐｔ、Ｐｄ、ＴａおよびＲｈからなる群から選ばれた少なくとも一種からなる。前記絶縁体層はＮａＣｌ構造及びスピネル構造からなる絶縁体でありＭｇＯ系酸化物、Ａｌ３Ｏ４、Ｍｇ２Ａｌ２Ｏ４、ＺｎＡｌ２Ｏ４、ＭｇＣｒ２Ｏ４、ＭｇＭｎ２Ｏ４、ＣｕＣｒ２Ｏ４、ＮｉＣｒ２Ｏ４、ＧｅＭｇ２Ｏ４、ＳｎＭｇ２Ｏ４、ＴｉＭｇ２Ｏ４、ＳｉＭｇ２Ｏ４、ＣｕＡｌ２Ｏ４、Ｌｉ０．５Ａｌ２．５Ｏ４、γ−Ａｌ２Ｏ３から選ばれた少なくとも一種からなる。
Patent Document 1 reports a single crystal magnetoresistive element in which a (001) plane of a ferromagnetic thin film is epitaxially grown on a large-diameter silicon single crystal substrate. Patent Document 1 discloses, as an example of a magnetoresistive element, a silicon substrate, an underlayer having a B2 structure laminated on the silicon substrate, a first nonmagnetic layer laminated on the underlayer having the B2 structure, A giant magnetoresistive layer having at least one laminated layer having a lower ferromagnetic layer and an upper ferromagnetic layer, and a second nonmagnetic layer provided between the lower ferromagnetic layer and the upper ferromagnetic layer; Are shown. Further, as another example, a silicon substrate, a base layer of a B2 structure laminated on the silicon substrate, a lower ferromagnetic layer and an upper ferromagnetic layer laminated on the base layer of the B2 structure, and the lower ferromagnetic layer A magnetoresistive element including a magnetic layer and a tunnel magnetoresistive effect layer having at least one laminated layer having an insulator layer provided between the upper ferromagnetic layers is shown. In Patent Document 1, the silicon substrate uses a Si (001) single crystal substrate. The base layer of the B2 structure is made of NiAl, CoAl, or FeAl. The first nonmagnetic layer is at least one selected from the group consisting of Ag, V, Cr, W, Mo, Au, Pt, Pd, Ta, Ru, Re, Rh, NiO, CoO, TiN, and CuN. It is. The lower ferromagnetic layer and the upper ferromagnetic layer are made of at least one selected from the group consisting of a Co-based Heusler alloy, Fe, and CoFe. The second nonmagnetic layer is made of at least one selected from the group consisting of Ag, Cr, W, Mo, Au, Pt, Pd, Ta and Rh. The insulator layer is an insulator made of NaCl structure and spinel structure MgO-based oxide, Al 3 O 4, Mg 2 Al 2
近年、トンネル磁気抵抗素子として、例えば、下部強磁性層と上部強磁性層として、ｂｃｃ（００１）配向したＣｏＦｅＢをベースとする強磁性体を用い、トンネルバリア層として、ｃｕｂｉｃ（００１）配向したＭｇＯをベースとする非磁性層を用いる構造が知られている。しかし、実用化されているトンネル磁気抵抗素子は多結晶体である。例えば、ＭＲＡＭの記録素子直径サイズを１５ｎｍにまで小さくとすると、結晶粒サイズ（５ｎｍ程度）にくらべて高々３倍程度であることから、個々の結晶粒のわずかな傾きやラフネスが平均化されずに、素子特性として顕在化してしまうという問題がある。即ち、多結晶からなる素子構造では素子特性に限界がある。またＣｏＦｅＢをベースとする強磁性体では、記録素子直径サイズを２０ｎｍ未満にした場合に、垂直磁気異方性エネルギーが不足するために記録保持特性が保てないという問題がある。 In recent years, as a tunnel magnetoresistive element, for example, a ferromagnetic material based on CoFeB oriented in bcc (001) is used as a lower ferromagnetic layer and an upper ferromagnetic layer, and a Cubic (001) oriented MgO is used as a tunnel barrier layer. There is known a structure using a non-magnetic layer based on. However, a practically used tunnel magnetoresistive element is a polycrystalline body. For example, when the diameter of the recording element of the MRAM is reduced to 15 nm, since the size is at most three times as large as the crystal grain size (about 5 nm), slight inclination and roughness of individual crystal grains are not averaged. In addition, there is a problem that it becomes obvious as element characteristics. That is, there is a limit in element characteristics in the element structure made of polycrystal. Further, in the case of a ferromagnetic material based on CoFeB, when the diameter of the recording element is set to less than 20 nm, there is a problem that the perpendicular magnetic anisotropy energy is insufficient and the recording retention characteristics cannot be maintained.
そこで、素子として単結晶化が期待されている。単結晶化すれば、ウェーハ内に単一の結晶粒しか存在しないため、特性のバラツキを抑制する効果が望まれる。さらに、下部強磁性層・上部強磁性層としてＣｏＦｅＢ以外の材料を用いることによる特性向上がもたらされると推測される。 Therefore, single crystallization is expected as an element. If a single crystal is formed, only a single crystal grain is present in the wafer, and therefore, an effect of suppressing variation in characteristics is desired. Further, it is presumed that the characteristics are improved by using a material other than CoFeB for the lower ferromagnetic layer and the upper ferromagnetic layer.
単結晶の磁気抵抗素子として、例えば単結晶ＭｇＯ基板を用いる技術開発が進められてきた。一方、半導体技術で用いられるＳｉウェーハ上への単結晶磁気抵抗素子の実現が強く期待されていた。 Technology development using, for example, a single-crystal MgO substrate as a single-crystal magnetoresistance element has been advanced. On the other hand, the realization of a single-crystal magnetoresistive element on a Si wafer used in semiconductor technology has been strongly expected.
特許文献１では、面直電流巨大磁気抵抗（ＣＰＰ−ＧＭＲ）素子やトンネル磁気抵抗素子を、Ｓｉ（００１）単結晶基板を用いて製造することが提案されている。特許文献１では、面直電流巨大磁気抵抗（ＣＰＰ−ＧＭＲ）素子を作製した実施例では、磁気抵抗比２８％の特性が得られたことが報告されている。しかし、特許文献１では、それ以上の磁気抵抗比の実施結果は報告されていない。また、トンネル磁気抵抗素子の実施結果は報告されていない。 Patent Literature 1 proposes manufacturing a plane current giant magnetoresistance (CPP-GMR) element and a tunnel magnetoresistance element using a Si (001) single crystal substrate. Patent Literature 1 reports that an example in which a giant magnetoresistive element (CPP-GMR) was manufactured with a magnetoresistance ratio of 28% was obtained. However, Patent Literature 1 does not report a result of implementation of a higher magnetoresistance ratio. Further, the results of implementing the tunnel magnetoresistive element have not been reported.
特許文献１では、Ｓｉ（００１）単結晶基板上にＮｉＡｌのＢ２構造下地層を設けた例で、ＮｉＡｌ層の平坦性として、（００１）方向単結晶膜で最小の平均表面粗さ（Ｒａ）が１．１７ｎｍであるものが得られたことが報告されている。また、ＮｉＡｌ層上にさらにＡｇを（００１）配向単結晶成長させた例で、成膜したままでの平均表面ラフネスが０．９４ｎｍ、ポストアニールした場合の平均表面ラフネスが０．２９ｎｍまで改善したことが報告されている。平均表面ラフネスの数値が低いほど平坦性が良い。 Patent Literature 1 discloses an example in which a NiAl B2 structure underlayer is provided on a Si (001) single crystal substrate, and the flatness of the NiAl layer is the minimum average surface roughness (Ra) in a (001) direction single crystal film. Was reported to be 1.17 nm. In the example in which Ag was further grown on the NiAl layer in a (001) single crystal, the average surface roughness as formed was 0.94 nm, and the average surface roughness when post-annealed was improved to 0.29 nm. It has been reported. The lower the value of the average surface roughness, the better the flatness.
一般に、Ｂ２型構造とは、塩化セシウムを典型とするＸＹ型の結晶構造をいい、Ｘ：Ｙが１：１の組成比を持つ結晶である。 In general, the B2 type structure refers to an XY type crystal structure typified by cesium chloride, and is a crystal having a composition ratio of X: Y of 1: 1.
ところで、ＣＰＰ−ＧＭＲ素子では、算術平均表面粗さ（Ｒａ）が０．３ｎｍ程度と粗くても良好な磁気抵抗比を得ることが可能である。それは、下部強磁性層と上部強磁性層の間に設けられる第２の非磁性層がＡｇのような金属であるからである。一方、トンネル磁気抵抗素子のように、下部強磁性層と上部強磁性層の間に設けられた第２の非磁性層が絶縁体層である場合、即ち、ＭｇＯやスピネル系（例えばＭｇ２ＡｌＯ４）のような絶縁体や半導体を用いる場合は、算術平均表面粗さ（Ｒａ）が０．３ｎｍ程度では不十分な平坦度であり、表面起伏が粗いために磁気抵抗比は低くなる。磁気抵抗比は、磁気抵抗素子の最も重要な性能指標であり、ＭＲＡＭでは、その数値が高いほどデータ書込が省電力となり、かつデータ読出の信頼性が向上する。磁気センサやＨＤＤ再生ヘッドでは、その数値が高いほど感度が向上する。 By the way, in the CPP-GMR element, it is possible to obtain a good magnetoresistance ratio even if the arithmetic average surface roughness (Ra) is as coarse as about 0.3 nm. This is because the second nonmagnetic layer provided between the lower ferromagnetic layer and the upper ferromagnetic layer is made of a metal such as Ag. On the other hand, when the second nonmagnetic layer provided between the lower ferromagnetic layer and the upper ferromagnetic layer is an insulator layer, such as a tunnel magnetoresistance element, that is, MgO or a spinel-based (eg, Mg 2 AlO) In the case of using an insulator or a semiconductor as in 4 ), when the arithmetic average surface roughness (Ra) is about 0.3 nm, the flatness is insufficient, and the surface roughness is low, so that the magnetoresistance ratio is low. The magnetoresistance ratio is the most important performance index of a magnetoresistance element. In an MRAM, the higher the numerical value, the more power-saving data writing and the higher the reliability of data reading. In a magnetic sensor or HDD reproducing head, the sensitivity increases as the numerical value increases.
また、磁気抵抗素子の製造において、基板温度が５００℃等のように高いと、成膜時に使用する装置、例えば静電チャック等の上限温度（およそ４００℃）を上回ってしまい、実用的ではなかった。 In the manufacture of a magnetoresistive element, if the substrate temperature is as high as 500 ° C., the temperature exceeds the upper limit temperature (approximately 400 ° C.) of an apparatus used for film formation, for example, an electrostatic chuck or the like, which is not practical. Was.
本発明は、これらの問題を解決しようとするものであり、本発明は、Ｓｉ（００１）単結晶基板上に電子素子層を設ける際のＢ２構造下地層の表面が、より平坦化された電子素子を提供することを目的とする。また、これにより高性能化を実現した電子素子を提供することを目的とする。また、高性能化を実現した磁気抵抗素子を提供することを目的とする。また、Ｓｉ（００１）単結晶基板上に電子素子層を設ける際のＢ２構造下地層の表面をより平坦化できる、電子素子の製造方法を提供することを目的とする。 The present invention is intended to solve these problems, and the present invention provides an electronic device in which an electronic element layer is provided on a Si (001) single crystal substrate, and the surface of a B2 structure underlayer is more planarized. It is intended to provide an element. It is another object of the present invention to provide an electronic device that achieves higher performance. It is another object of the present invention to provide a magnetoresistive element that achieves high performance. It is another object of the present invention to provide a method of manufacturing an electronic device, which can flatten the surface of a B2 structure underlayer when an electronic device layer is provided on a Si (001) single crystal substrate.
本発明は、前記目的を達成するために、以下の特徴を有するものである。 The present invention has the following features to achieve the above object.
（１） 基板と、下地層と、電子素子層とが、順に積層された積層構造を有する電子素子であって、前記基板は、シリコン（００１）単結晶基板であり、前記下地層は、化学量論的組成よりＡｌを過剰に含むＸＡｌ（Ｘは、Ｎｉ及びＣｏから選択される１以上の金属）からなるＢ２型構造の単結晶の下地層であることを、特徴とする、電子素子。
（２） 前記下地層は、Ａｌを５３原子％以上６０原子％以下含むことを特徴とする、前記（１）記載の電子素子。
（３） 前記下地層は、表面にＡｌの偏析領域を有することを特徴とする、前記（１）又は（２）記載の電子素子。
（４） 前記電子素子層は、単結晶介在層を介して、前記下地層上に積層されることを特徴とする、前記（１）乃至（３）のいずれか１項記載の電子素子。
（５） 前記単結晶介在層は、ｂｃｃ構造であるＣｒ、Ｗ、Ｎｂ、Ｖ、Ｆｅ、Ｔａ、ＦｅＣｏ、ｆｃｃ構造であるＡｕ、Ａｇ、Ｐｔ、Ｐｄ、Ａｌ、Ｒｈ、Ｉｒ、ｃｕｂｉｃ構造であるＴｉＮ、ＮｂＮ、ＨｆＮ、ＭｏＮ、ＴａＮ、ＶＮ、ＺｒＮ、ＣｒＮ、ＡｌＮ、Ｌ１０構造あるいはＤ０２２構造あるいはＬ１２構造のＸＹ（Ｘ＝Ｆｅ、Ｃｏ、Ｍｎ、Ｎｉ、Ａｇ、Ｙ＝Ａｌ、Ｍｇ、Ｐｔ、Ｐｄ．Ｓｉ、Ｇａ、Ｇｅ）からなる群から選ばれた少なくとも一種であることを特徴とする、前記（４）記載の電子素子。
（６） 前記（１）乃至（５）のいずれか１項記載の電子素子が、前記電子素子層として、第１の強磁性層と、第２の強磁性層と、第１及び第２の強磁性層の間に設けられた非磁性層とを少なくとも備える磁気抵抗積層構造を有することを特徴とする、磁気抵抗素子。
（７） 前記磁気抵抗積層構造の前記非磁性層が絶縁体からなることを特徴とする、前記（６）記載の磁気抵抗素子。
（８） シリコン（００１）単結晶基板上に、化学量論的組成よりＡｌを過剰に含むＸＡｌ（Ｘは、Ｎｉ及びＣｏから選択される１以上の金属）からなるＢ２型構造の単結晶の下地層を成膜する下地層形成工程と、前記下地層上に、電子素子層を順に形成する電子素子層形成工程と、を含むことを特徴とする、電子素子の製造方法。
（９） 前記下地層形成工程は、３００℃以上４５０℃以下の温度で成膜することを特徴とする、前記（８）記載の電子素子の製造方法。
（１０） 前記下地層形成工程後で、前記電子素子層形成工程前に、単結晶介在層を、前記下地層上に積層形成する工程を含むことを特徴とする、前記（８）又は（９）記載の電子素子の製造方法。
（１１） 前記電子素子層形成工程が、第１の強磁性層の形成工程と、第１及び第２の強磁性層の間に設けられた非磁性層の形成工程と、第２の強磁性層の形成工程とを少なくとも備える磁気抵抗積層構造形成工程であることを特徴とする、前記（８）乃至（１０）のいずれか１項記載の電子素子の製造方法。
(1) An electronic element having a laminated structure in which a substrate, a base layer, and an electronic element layer are sequentially stacked, wherein the substrate is a silicon (001) single crystal substrate, and the base layer is a chemical An electronic element, characterized by being a B2-type single crystal underlayer made of XAl (X is one or more metals selected from Ni and Co) containing Al in excess of a stoichiometric composition.
(2) The electronic device according to (1), wherein the underlayer contains Al in a range of 53 atomic% to 60 atomic%.
(3) The electronic element according to (1) or (2), wherein the underlayer has an Al segregation region on a surface.
(4) The electronic element according to any one of (1) to (3), wherein the electronic element layer is stacked on the underlayer via a single crystal intervening layer.
(5) The single crystal intervening layer has a bcc structure of Cr, W, Nb, V, Fe, Ta, FeCo, and an fcc structure of Au, Ag, Pt, Pd, Al, Rh, Ir, and cubic structures. TiN, NbN, HfN, MoN, TaN, VN, ZrN, CrN, AlN, XY of L10 structure or D022 structure or L12 structure (X = Fe, Co, Mn, Ni, Ag, Y = Al, Mg, Pt, Pd The electronic device according to (4), wherein the electronic device is at least one selected from the group consisting of Si, Ga, and Ge).
(6) The electronic device according to any one of (1) to (5), wherein the electronic device layer includes a first ferromagnetic layer, a second ferromagnetic layer, and first and second ferromagnetic layers. A magnetoresistive element having a magnetoresistive laminated structure including at least a nonmagnetic layer provided between ferromagnetic layers.
(7) The magnetoresistive element according to (6), wherein the nonmagnetic layer of the magnetoresistive laminated structure is made of an insulator.
(8) On a silicon (001) single crystal substrate, a B2-type single crystal of XAl (X is one or more metals selected from Ni and Co) containing Al in excess of the stoichiometric composition A method for manufacturing an electronic element, comprising: a base layer forming step of forming a base layer; and an electronic element layer forming step of sequentially forming an electronic element layer on the base layer.
(9) The method of manufacturing an electronic element according to (8), wherein, in the underlayer forming step, the film is formed at a temperature of 300 ° C. or more and 450 ° C. or less.
(10) After the base layer forming step and before the electronic element layer forming step, the method according to (8) or (9), further comprising a step of laminating and forming a single crystal intervening layer on the base layer. The method for manufacturing an electronic device according to the above item.
(11) The electronic element layer forming step includes: forming a first ferromagnetic layer; forming a nonmagnetic layer provided between the first and second ferromagnetic layers; The method for manufacturing an electronic element according to any one of (8) to (10), wherein the method is a step of forming a magnetoresistive laminated structure including at least a layer forming step.
本発明によれば、Ｓｉ（００１）単結晶基板上に電子素子層を設ける際のＢ２構造下地層の表面が、従来技術に比べて著しく平坦化された。例えば、算術平均表面粗さ（Ｒａ）は、０．１４５ｎｍにも達した。本発明によれば、Ｓｉ（００１）単結晶基板上に電子素子層を設ける際のＢ２構造下地層の表面が、従来より平坦化されることにより、平坦面の上に、単結晶介在層を介して若しくは介さずに形成される、電子素子層の結晶性が高くなり、高性能化を実現できる。 According to the present invention, the surface of the B2 structure underlayer when the electronic element layer is provided on the Si (001) single crystal substrate is significantly flattened as compared with the prior art. For example, the arithmetic average surface roughness (Ra) has reached 0.145 nm. According to the present invention, the surface of the B2 structure underlayer when the electronic element layer is provided on the Si (001) single crystal substrate is made flatter than before, so that the single crystal intervening layer is formed on the flat surface. The crystallinity of the electronic element layer formed with or without the intermediary is increased, and high performance can be realized.
本発明によれば、電子素子層として磁気抵抗積層構造を形成した場合、磁気抵抗比が向上する。本発明の磁気抵抗素子は、従来技術のＸＡｌが化学量論比の組成の場合に比較して、磁気抵抗比が１桁以上、ほぼ２桁増加した。例えば、磁気抵抗比は、２１５％にまで達した。 According to the present invention, when a magnetoresistive laminated structure is formed as an electronic element layer, the magnetoresistance ratio is improved. In the magnetoresistive element of the present invention, the magnetoresistance ratio is increased by one digit or more, or almost two orders of magnitude, as compared with the case where the conventional XAl has a stoichiometric composition. For example, the magnetoresistance ratio has reached 215%.
本発明によれば、シリコン（００１）単結晶基板を用いて、単結晶の電子素子機能の主体となる電子素子層を成長させることが可能となる。本発明では、ＸＡｌ単結晶層の表面が平坦性に優れているので、ＸＡｌ単結晶層上に単結晶成長可能な層、たとえばｂｃｃ構造であるＣｒ、Ｗ、Ｎｂ、Ｖ、Ｆｅ、Ｔａ、ＦｅＣｏ、ｆｃｃ構造であるＡｕ、Ａｇ、Ｐｔ、Ｐｄ、Ａｌ、Ｒｈ、Ｉｒ、ｃｕｂｉｃ構造であるＴｉＮ、ＮｂＮ、ＨｆＮ、ＭｏＮ、ＴａＮ、ＶＮ、ＺｒＮ、ＣｒＮ、ＡｌＮ、Ｌ２１構造あるいはＢ２構造のＣｏ基フルホイスラー材料（Ｃｏ２ＹＺ： Ｙ＝Ｍｎ、Ｆｅ、Ｔｉ、Ｖ、Ｃｒ、 Ｚ＝Ａｌ、Ｓｉ、Ｇａ、Ｇｅ、Ｓｎ）、Ｌ１０構造あるいはＤ０２２構造のＭｎ基垂直磁化材料（ＭｎＧａ、ＭｎＧｅ）、Ｌ１０構造の垂直磁化材料（ＸＹ： Ｘ＝Ｆｅ、Ｃｏ、Ｎｉ、Ｃｒあるいはその合金、Ｙ＝Ｐｄ、Ｐｔ、Ｒｈあるいはその合金）を電極又は磁性層その他として備える電子素子を実現できる。よって、従来単結晶化できなかった電子素子の単結晶化も実現できる。 ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to grow the electronic element layer which becomes the main element of the electronic element function of a single crystal using a silicon (001) single crystal substrate. In the present invention, since the surface of the XAl single crystal layer is excellent in flatness, a layer capable of growing a single crystal on the XAl single crystal layer, for example, Cr, W, Nb, V, Fe, Ta, FeCo having a bcc structure. , Fcc structure of Au, Ag, Pt, Pd, Al, Rh, Ir, cubic structure of TiN, NbN, HfN, MoN, TaN, VN, ZrN, CrN, AlN, L21 structure or Co based full of B2 structure Heusler material (Co 2 YZ: Y = Mn, Fe, Ti, V, Cr, Z = Al, Si, Ga, Ge, Sn), Mn-based perpendicular magnetization material (MnGa, MnGe) with L10 structure or D022 structure, L10 A perpendicular magnetized material (XY: X = Fe, Co, Ni, Cr or an alloy thereof, Y = Pd, Pt, Rh or an alloy thereof) is provided as an electrode or a magnetic layer or the like. An electronic device can be achieved that. Therefore, single crystallization of an electronic element which could not be single crystallized can be realized.
本発明の組成のＢ２構造下地層を用いることにより、（００１）配向単結晶Ｓｉウェーハ上に（００１）配向した単結晶トンネル磁気抵抗素子等の電子素子を成長させることが可能になる。 By using the B2 structure underlayer having the composition of the present invention, it becomes possible to grow an electronic device such as a (001) -oriented single-crystal tunneling magneto-resistance device on a (001) -oriented single-crystal Si wafer.
本発明の方法によれば、基板温度を従来より低い温度で、ＮｉＡｌ層の成膜することが可能となる。例えば、４００℃未満での成膜工程を可能とすることができる。本発明によれば、Ｂ２構造の下地層を従来より低い温度で成膜できるので、製造工程として、省エネルギーな工程であり、静電チャックその他の機器が使用可能となるので、産業上の効果が大である。 According to the method of the present invention, it is possible to form a NiAl layer at a substrate temperature lower than before. For example, a film formation step at less than 400 ° C. can be performed. According to the present invention, since the underlayer having the B2 structure can be formed at a lower temperature than before, it is an energy-saving process as a manufacturing process, and an electrostatic chuck and other devices can be used. Is big.
本発明の実施形態について以下説明する。 An embodiment of the present invention will be described below.
本発明の実施形態では、磁気抵抗素子等の電子素子において、シリコン（００１）単結晶基板上に積層する磁気抵抗素子層の単結晶化を実現するために、シリコン（００１）単結晶基板と磁気抵抗素子層との間に、特定の組成比のＢ２型構造の単結晶の下地層を用いる。下地層として、ＸＡｌ（Ｘは、Ｎｉ及びＣｏから選択される１以上の金属）からなるＢ２型構造の単結晶の下地層であって、化学量論的組成よりＡｌを過剰に含む下地層を用いる。Ａｌの組成比は、Ｂ２構造の結晶構造を維持できる範囲内で過剰であれば、化学量論的組成（５０原子％）に比べて、平坦性が向上し、同時に磁気抵抗比が向上する。過剰とは例えば、Ａｌが５１原子％以上である。実施例の結果から、磁気抵抗比の増加が顕著に見られる５３原子％以上６０原子％以下がより好ましい。さらに、５４原子％以上５９原子％以下がより好ましく、磁気抵抗比がより改善し、安定する。さらに、５４原子％以上５８原子％以下がより好ましく、磁気抵抗比がさらに改善し、安定する。Ｂ２構造の下地層は、１０ｎｍ以上２００未満であることが好ましい。また、シリコンの上層への拡散抑制と良好な平坦性のためには、１０ｎｍ以上５０ｎｍ未満であることがより好ましい。 In an embodiment of the present invention, in an electronic element such as a magnetoresistive element, a silicon (001) single crystal substrate is magnetically integrated with a silicon (001) single crystal substrate in order to realize single crystallization of a magnetoresistive element layer laminated on the silicon (001) single crystal substrate. A single crystal base layer having a B2 type structure having a specific composition ratio is used between the resistive element layer. The underlayer is a single crystal underlayer of a B2-type structure made of XAl (X is one or more metals selected from Ni and Co), and the underlayer containing Al in excess of the stoichiometric composition. Used. If the Al composition ratio is excessive within a range where the crystal structure of the B2 structure can be maintained, the flatness is improved and the magnetoresistance ratio is improved at the same time as compared with the stoichiometric composition (50 atomic%). Excess is, for example, 51 atomic% or more of Al. From the results of the examples, it is more preferable that the ratio is at least 53 at% and at most 60 at% at which the increase in the magnetoresistance ratio is remarkably observed. Further, it is more preferably at least 54 at% and at most 59 at%, and the magnetoresistance ratio is further improved and stabilized. Further, the content is more preferably from 54 at% to 58 at%, and the magnetoresistance ratio is further improved and stabilized. The underlayer having the B2 structure preferably has a thickness of 10 nm or more and less than 200. Further, in order to suppress diffusion to the upper layer of silicon and obtain good flatness, the thickness is more preferably 10 nm or more and less than 50 nm.
本発明の実施形態の電子素子の第１及び第２の基本構造について、それぞれ図１Ａ及びＢを参照して以下説明する。 The first and second basic structures of the electronic device according to the embodiment of the present invention will be described below with reference to FIGS. 1A and 1B.
図１Ａは、本発明の電子素子の第１の基本構造を説明する断面図である。第１の基本構造は、シリコン（００１）単結晶基板１と、Ｂ２構造下地層２と、単結晶介在層３と、電子素子層（４、５、６）とを備える。電子素子が磁気抵抗素子の場合、単結晶介在層は非磁性層であり、電子素子層４、５、６は磁気抵抗積層構造であり、下部強磁性層４と非磁性層５と上部強磁性層６とを含む。
FIG. 1A is a cross-sectional view illustrating a first basic structure of the electronic device of the present invention. The first basic structure includes a silicon (001) single crystal substrate 1, a B2
図１Ｂは、本発明の電子素子の第２の基本構造を説明する断面図である。第２の基本構造は、シリコン（００１）単結晶基板１と、Ｂ２構造下地層２と、電子素子層（４、５、６）とを備える。電子素子が磁気抵抗素子の場合、電子素子層（４、５、６）は磁気抵抗積層構造であり、下部強磁性層４と非磁性層５と上部強磁性層６とを含む。
FIG. 1B is a cross-sectional view illustrating a second basic structure of the electronic device of the present invention. The second basic structure includes a silicon (001) single crystal substrate 1, a B2
第１及び第２の基本構造において、いずれもシリコン（００１）単結晶基板を用いて、単結晶の電子素子機能の主体となる電子素子層を成長させることが可能となる。ＸＡｌ単結晶層の表面が著しく平坦性に優れているので、ＸＡｌ単結晶層上に単結晶成長した層を備える電子素子を作製できる。 In each of the first and second basic structures, it is possible to grow an electronic element layer which is a main element of an electronic element function of a single crystal using a silicon (001) single crystal substrate. Since the surface of the XAl single crystal layer is extremely excellent in flatness, it is possible to manufacture an electronic device including a layer formed by single crystal growth on the XAl single crystal layer.
単結晶介在層３の材料は、ｂｃｃ構造であるＣｒ、Ｗ、Ｎｂ、Ｖ、Ｆｅ、Ｔａ、ＦｅＣｏ、ｆｃｃ構造であるＡｕ、Ａｇ、Ｐｔ、Ｐｄ、Ａｌ、Ｒｈ、Ｉｒ、ｃｕｂｉｃ構造であるＴｉＮ、ＮｂＮ、ＨｆＮ、ＭｏＮ、ＴａＮ、ＶＮ、ＺｒＮ、ＣｒＮ、ＡｌＮ、Ｌ１０構造あるいはＤ０２２構造あるいはＬ１２構造のＸＹ（Ｘ=Ｆｅ、Ｃｏ、Ｍｎ、Ｎｉ、Ａｇ、Ｙ=Ａｌ、Ｍｇ、Ｐｔ、Ｐｄ．Ｓｉ、Ｇａ、Ｇｅ）からなる群から選ばれた少なくとも一種である。膜厚は、０．５ｎｍ以上１００ｎｍ未満が好ましい。
The material of the single
電子素子層の例である磁気抵抗積層構造を構成する各層として、次の材料が挙げられる。単結晶の場合、下部強磁性層・上部強磁性層の材料としては、単結晶Ｆｅやｂｃｃ構造のＦｅＣｏ、Ｌ２１構造あるいはＢ２構造のＣｏ基フルホイスラー材料（Ｃｏ２ＹＺ： Ｙ＝Ｍｎ、Ｆｅ、Ｔｉ、Ｖ、Ｃｒ、 Ｚ＝Ａｌ、Ｓｉ、Ｇａ、Ｇｅ、Ｓｎ）、Ｌ１０構造あるいはＤ０２２構造のＭｎ基垂直磁化材料（ＭｎＧａ、ＭｎＧｅ）、Ｌ１０構造の垂直磁化材料（ＸＹ： Ｘ＝Ｆｅ、Ｃｏ、Ｎｉ、Ｃｒあるいはその合金、Ｙ＝Ｐｄ、Ｐｔ、Ｒｈあるいはその合金）といった材料が挙げられる。なお、本発明においては、トンネル磁気抵抗素子の場合、基板から非磁性トンネルバリア層までの積層構造が少なくとも単結晶であればよい。上部強磁性層が多結晶であってもよい。その場合、上部強磁性層として、多結晶ＣｏＦｅＢ等も挙げられる。トンネル磁気抵抗素子の場合、下部強磁性層の膜厚は、１ｎｍ以上５０ｎｍ未満が好ましく、上部強磁性層の膜厚は、１ｎｍ以上が好ましい。面直電流巨大磁気抵抗素子の場合、下部強磁性層の膜厚は、３ｎｍ以上１０ｎｍ未満が好ましく、上部強磁性層の膜厚は、３ｎｍ以上１０ｎｍ未満が好ましい。 The following materials may be used as layers constituting the magnetoresistive laminated structure which is an example of the electronic element layer. In the case of a single crystal, the material of the lower ferromagnetic layer and the upper ferromagnetic layer may be a single crystal Fe, FeCo having a bcc structure, a Co-based full Heusler material having an L21 structure or a B2 structure (Co 2 YZ: Y = Mn, Fe, Ti, V, Cr, Z = Al, Si, Ga, Ge, Sn), Mn-based perpendicular magnetization material (MnGa, MnGe) with L10 structure or D022 structure, perpendicular magnetization material with L10 structure (XY: X = Fe, Co) , Ni, Cr or alloys thereof, Y = Pd, Pt, Rh or alloys thereof. In the present invention, in the case of the tunnel magnetoresistive element, the laminated structure from the substrate to the nonmagnetic tunnel barrier layer may be at least a single crystal. The upper ferromagnetic layer may be polycrystalline. In that case, polycrystalline CoFeB or the like may be used as the upper ferromagnetic layer. In the case of a tunnel magnetoresistive element, the thickness of the lower ferromagnetic layer is preferably 1 nm or more and less than 50 nm, and the thickness of the upper ferromagnetic layer is preferably 1 nm or more. In the case of a giant magnetoresistive element with a plane-to-plane current, the thickness of the lower ferromagnetic layer is preferably 3 nm or more and less than 10 nm, and the thickness of the upper ferromagnetic layer is preferably 3 nm or more and less than 10 nm.
トンネル磁気抵抗素子の非磁性層としては、ＭｇＯ系酸化物（ＭｇＦｅＯ、ＭｇＭｎＯ、ＭｇＴｉＯ、ＭｇＶＯ、ＭｇＣｕＯ、ＭｇＺｎＯ）、スピネル系絶縁体（Ｍｇ２ＡｌＯ４、Ｍｇ２ＧａＯ４、γ−Ａｌ２Ｏ３）、カルコパライト系化合物半導体（ＣｕＩｎ１−ｘＧａｘＳｅ２、ＺｎＳｅ、ＣｕＧａＳｅ２、ＺｎＳ、ＣｕＩｎＳ２）等が挙げられる。非磁性層のトンネルバリア層の膜厚は、膜厚が０．５ｎｍ以上４ｎｍ未満が好ましい。 The nonmagnetic layer of the tunnel magnetoresistance element, MgO-based oxide (MgFeO, MgMnO, MgTiO, MgVO , MgCuO, MgZnO), spinel insulators (Mg 2 AlO 4, Mg 2 GaO 4, γ-Al 2 O 3 ), And chalcopyrite-based compound semiconductors (CuIn 1-x Ga x Se 2 , ZnSe, CuGaSe 2 , ZnS, CuInS 2 ). The thickness of the tunnel barrier layer of the non-magnetic layer is preferably 0.5 nm or more and less than 4 nm.
巨大磁気抵抗効果層の下部及び上部強磁性層の間に設けられる非磁性層は、Ａｇ、Ｃｒ、Ｗ、Ｍｏ、Ａｕ、Ｐｔ、Ｐｄ、ＴａおよびＲｈからなる群から選ばれた少なくとも一種からなる。非磁性層の膜厚は、１ｎｍ以上２０ｎｍ未満が好ましい。 The nonmagnetic layer provided between the lower and upper ferromagnetic layers of the giant magnetoresistive layer is made of at least one selected from the group consisting of Ag, Cr, W, Mo, Au, Pt, Pd, Ta and Rh. . The thickness of the nonmagnetic layer is preferably 1 nm or more and less than 20 nm.
なお、第１や第２の基本構造の説明では、上部強磁性層の上に形成する層については説明していないが、磁気抵抗素子の種類や種々の用途に応じて必要とされる積層構造が、上部強磁性層の上に付加される。これらを総称して、本発明では、キャップ層という。例えば、磁化固定層（ＩｒＭｎ膜等）、保護層等が挙げられる。ＦｅやＣｏなどの面内磁化をもつ材料では磁化方向固定層が必要であるが、ＳＴＴ−ＭＲＡＭに用いられる垂直磁化をもつ材料では、層間交換結合により強固な磁化固定がもたらされ、磁化方向固定層が不要である。磁気抵抗が発現するために重要な層は上部強磁性層までである。本発明では、上述の基本構造にさらにキャップ層を設けた構造で実用化される。 In the description of the first and second basic structures, the layers formed on the upper ferromagnetic layer are not described, but the laminated structure required according to the type of the magnetoresistive element and various applications. Is applied over the upper ferromagnetic layer. These are collectively referred to as a cap layer in the present invention. For example, a magnetization fixed layer (IrMn film or the like), a protective layer, or the like can be given. Materials having in-plane magnetization such as Fe and Co require a fixed magnetization direction layer, whereas materials having perpendicular magnetization used in STT-MRAM provide strong magnetization fixation due to interlayer exchange coupling, and the magnetization direction is fixed. No fixed layer is required. The layer that is important for exhibiting magnetoresistance is up to the upper ferromagnetic layer. In the present invention, it is put to practical use in a structure in which a cap layer is further provided on the above-described basic structure.
本実施形態における下地層等の各層の成膜は、従来の磁気抵抗素子で用いられている薄膜技術で実施できる。例えば、スパッタ法、真空蒸着法が挙げられる。また、ＸＡｌの組成比の調整は、スパッタ法の場合は、複数のターゲットを用いる放電出力値を制御することにより、行うことができる。また、所望の組成比を有するターゲットを予め準備してもよい。真空蒸着法の場合、複数のソースを用いて各成膜レートを制御することにより、行うことができる。また、所望の組成比を有するソースを予め準備してもよい。 The formation of each layer such as an underlayer in the present embodiment can be performed by a thin film technique used in a conventional magnetoresistive element. For example, a sputtering method and a vacuum evaporation method are mentioned. Further, in the case of the sputtering method, the composition ratio of XAl can be adjusted by controlling the discharge output value using a plurality of targets. Further, a target having a desired composition ratio may be prepared in advance. In the case of the vacuum evaporation method, the deposition can be performed by controlling the respective film formation rates using a plurality of sources. Further, a source having a desired composition ratio may be prepared in advance.
（第１の実施形態）
本実施形態は、電子素子におけるＢ２構造下地層としてＮｉＡｌを用いる場合に関する。本実施形態について、図を参照して、以下詳しく説明する。本実施形態では、第１の基本構造において、Ｂ２構造下地層としてＮｉＡｌを用い、その組成を変化させた場合の特性を調べた。本実施形態では、例として磁気抵抗素子を作製して、特性として磁気抵抗比を調べた。
(First embodiment)
This embodiment relates to a case where NiAl is used as a B2 structure underlayer in an electronic element. This embodiment will be described in detail below with reference to the drawings. In the present embodiment, in the first basic structure, NiAl was used as the B2 structure underlayer, and characteristics when the composition was changed were examined. In the present embodiment, a magnetoresistive element was manufactured as an example, and a magnetoresistance ratio was examined as a characteristic.
本実施形態の磁気抵抗素子は、シリコン（００１）単結晶基板１と、Ｂ２構造下地層２と、Ｃｒからなる単結晶介在層３と、Ｆｅ／Ｃｏからなる下部強磁性層４、Ｍｇ２ＡｌＯ４からなる非磁性層５、Ｃｏ／Ｆｅからなる上部強磁性層６の積層構造とを備える。さらに、キャップ層を備えるので、本実施形態の積層構造は、シリコン（００１）／ＮｉＡｌ／Ｃｒ／Ｆｅ／Ｃｏ／Ｍｇ２ＡｌＯ４／Ｃｏ／Ｆｅ／ＩｒＭｎ／Ｔａ／Ｒｕである。
The magnetoresistive element of this embodiment includes a silicon (001) single crystal substrate 1, a
［実施例１−１］
シリコン（００１）単結晶基板１を準備した。加熱した前記単結晶基板上に、ＮｉＡｌ膜（３０ｎｍ厚）を、アルゴンガス雰囲気で、ＮｉターゲットとＡｌターゲットを用いた多元同時スパッタ法により、エピタキシャル成長させた。基板温度の条件を、３００〜４５０℃に設定して複数の試料を作製した。ＮｉＡｌの組成比は、ＮｉターゲットとＡｌターゲットの放電出力値を制御することにより変化させて、複数の試料を作製した。次に、Ｃｒ膜（３０ｎｍ厚）を、室温、アルゴンガス雰囲気でスパッタ法により、エピタキシャル成長させた後に、２３０℃、２０分間のランプによる表面加熱処理をした。次に、Ｆｅ膜（３ｎｍ厚）を、室温、アルゴンガス雰囲気でスパッタ法により、エピタキシャル成長させた。次に、Ｃｏ膜（０．４ｎｍ厚）を、室温、アルゴンガス雰囲気でスパッタ法により、エピタキシャル成長させた。次に、Ｍｇ２ＡｌＯ４膜（２ｎｍ厚）を、室温、アルゴンガス雰囲気でスパッタ法により、エピタキシャル成長させた後に、４５０℃、６分間のランプによる表面加熱処理をした。次に、Ｃｏ膜（０．４ｎｍ厚）を、室温、アルゴンガス雰囲気でスパッタ法により、エピタキシャル成長させた。次に、Ｆｅ膜（２．５ｎｍ厚）を、室温、アルゴンガス雰囲気でスパッタ法により、エピタキシャル成長させた後に、１８０℃、７分間のランプによる表面加熱処理をした。次に、Ｆｅ膜の磁化方向固定のために、ＩｒＭｎ膜（１０ｎｍ厚）を、磁界中、室温、クリプトンガス雰囲気でスパッタ法により、エピタキシャル成長させた。ＩｒＭｎ膜は磁化方向固定層である。次に、Ｔａ膜を、室温、クリプトンガス雰囲気でスパッタ法により、成膜した。次に、Ｒｕ膜を、室温、アルゴンガス雰囲気でスパッタ法により、成膜した。Ｔａ膜およびＲｕ膜は、表面保護のための層である。
[Example 1-1]
A silicon (001) single crystal substrate 1 was prepared. A NiAl film (thickness: 30 nm) was epitaxially grown on the heated single crystal substrate by a multiple simultaneous sputtering method using an Ni target and an Al target in an argon gas atmosphere. A plurality of samples were prepared with the substrate temperature set at 300 to 450 ° C. A plurality of samples were produced by changing the composition ratio of NiAl by controlling the discharge output value of the Ni target and the Al target. Next, a Cr film (thickness: 30 nm) was epitaxially grown by a sputtering method at room temperature in an argon gas atmosphere, and then subjected to a surface heat treatment using a lamp at 230 ° C. for 20 minutes. Next, an Fe film (thickness: 3 nm) was epitaxially grown by a sputtering method at room temperature in an argon gas atmosphere. Next, a Co film (0.4 nm thick) was epitaxially grown by a sputtering method at room temperature in an argon gas atmosphere. Next, a Mg 2 AlO 4 film (2 nm thick) was epitaxially grown by a sputtering method at room temperature in an argon gas atmosphere, and then subjected to a surface heat treatment at 450 ° C. for 6 minutes using a lamp. Next, a Co film (0.4 nm thick) was epitaxially grown by a sputtering method at room temperature in an argon gas atmosphere. Next, after epitaxially growing the Fe film (2.5 nm thick) by sputtering at room temperature in an argon gas atmosphere, surface heating treatment was performed at 180 ° C. for 7 minutes using a lamp. Next, to fix the magnetization direction of the Fe film, an IrMn film (10 nm thick) was epitaxially grown by a sputtering method in a krypton gas atmosphere at room temperature in a magnetic field. The IrMn film is a magnetization direction fixed layer. Next, a Ta film was formed by a sputtering method in a krypton gas atmosphere at room temperature. Next, a Ru film was formed by a sputtering method at room temperature in an argon gas atmosphere. The Ta film and the Ru film are layers for protecting the surface.
［実施例１−２］
Ｍｇ２ＡｌＯ４からなる非磁性層５の成膜において、酸素欠損がないようにＭｇ２ＡｌＯ４スパッタ成膜直後に、酸素ガス雰囲気にＭｇ２ＡｌＯ４表面を曝露させ、その後に４５０℃、６分間のランプによる表面加熱処理を行った。酸素ガス雰囲気への曝露時間と磁気抵抗比の関係を予め調べ、磁気抵抗比が最高となるように曝露時間を決定した。
[Example 1-2]
In forming the
図２に、実施例１−１と１−２で製造した磁気抵抗素子の特性を示す。横軸がＡｌ組成比（原子％）で、縦軸が磁気抵抗比（％）である。実施例１−１による結果を黒四角印で示し、実施例１−２による結果を円印で示す。作製した磁気抵抗素子のＮｉＡｌ層の組成は、蛍光Ｘ線解析およびＩＣＰ発光分光分析により同定した。磁気抵抗比は、多端子プローブ面内通電トンネル磁気抵抗測定装置により、室温において計測した。 FIG. 2 shows the characteristics of the magnetoresistive elements manufactured in Examples 1-1 and 1-2. The horizontal axis is the Al composition ratio (atomic%), and the vertical axis is the magnetoresistance ratio (%). The results of Example 1-1 are indicated by black squares, and the results of Example 1-2 are indicated by circles. The composition of the NiAl layer of the manufactured magnetoresistive element was identified by X-ray fluorescence analysis and ICP emission spectroscopy. The magnetoresistance ratio was measured at room temperature by a multi-terminal probe in-plane conducting tunneling magnetoresistance measuring device.
実施例１−１によるものは、図２に示すように、Ａｌ組成比が４９．５原子％で磁気抵抗比２％（以下、「Ａｌ４９．５原子％でＭＲ比２％」のように示す。）、Ａｌ５０．１原子％でＭＲ比２％、Ａｌ５０．６原子％でＭＲ比５％、Ａｌ５１．５原子％でＭＲ比３７％、Ａｌ５２．４原子％でＭＲ比９８％、Ａｌ５３．２原子％でＭＲ比１４２％、Ａｌ５４原子％でＭＲ比１４９％、Ａｌ５５．９原子％でＭＲ比１４６％、Ａｌ５７．６原子％でＭＲ比１４３％、Ａｌ５９原子％でＭＲ比１４４％、Ａｌ５９．７原子％でＭＲ比１４６％、Ａｌ６０．４原子％でＭＲ比１４６％、Ａｌ６１．２原子％でＭＲ比１４４％、Ａｌ６３原子％でＭＲ比１３０％、Ａｌ６４原子％でＭＲ比１２０％、であった。
In the case of Example 1-1, as shown in FIG. 2, the Al composition ratio was 49.5 atom% and the magnetoresistance ratio was 2% (hereinafter, "Al is 49.5 atom% and the MR ratio is 2%". ), 50.1 at% Al, 2% MR ratio, 50.6 at% Al ratio, 5% MR ratio, 51.5 at% Al ratio, 37% MR ratio, 52.4 at% Al ratio, 98% MR ratio, Al 53.2% Atomic%: MR ratio 142%,
実施例１−２によるものは、図２に示すように、Ａｌ５４原子％でＭＲ比１５７％、Ａｌ５５原子％でＭＲ比２００％、Ａｌ５５．７原子％でＭＲ比２１５％、Ａｌ５７．６原子％でＭＲ比１９６％、Ａｌ５９．５原子％でＭＲ比１６５％であった。 As shown in FIG. 2, according to Example 1-2, the MR ratio was 157% at 54 atomic% of Al, the MR ratio was 200% at 55 atomic% of Al, the MR ratio was 215% at 55.7 atomic% of Al, and 57.6 atomic% of Al. And the MR ratio was 196%, and the Al ratio was 165% at 59.5 atomic%.
図２に示すように、Ａｌ組成比が、５０原子％よりも過剰、例えば、５１原子％以上６４原子％以下の広い範囲で５０原子％の場合より高い磁気抵抗比を示していることが分かる。Ａｌ組成比が５２原子％以上６４原子％以下の範囲で磁気抵抗比およそ７０％以上、Ａｌ組成比が５３原子％以上６０原子％以下で磁気抵抗比およそ１３１％以上が得られた。また、磁気抵抗素子の非磁性層の最適条件に基づいた作製を行った場合は、Ａｌ組成が５４原子％以上５９原子％以下で、さらに優れた磁気抵抗比１４９％以上を示していることが分かる。磁気抵抗比の最高値２１５％を得ることができた。 As shown in FIG. 2, it can be seen that the Al composition ratio is larger than 50 atomic%, for example, shows a higher magnetoresistance ratio in a wide range from 51 atomic% to 64 atomic% than 50 atomic%. . A magnetoresistance ratio of about 70% or more was obtained when the Al composition ratio was in the range of 52 to 64 atomic%, and a magnetoresistance ratio of about 131% or more was obtained when the Al composition ratio was 53 to 60 atomic%. Also, when the non-magnetic layer of the magnetoresistive element was manufactured based on the optimum conditions, the Al composition was found to be at least 54 at.% And at most 59 at. I understand. A maximum value of 215% of the magnetoresistance ratio was obtained.
実施例１−２のＡｌ組成比５５．７原子％における、ＮｉＡｌ層（３０ｎｍ厚）表面の５ｕｍ平方のエリアを、原子間力顕微鏡（ＡＦＭ）により観察した。図３に、ＡＦＭによる像を示す。縦横軸は、５ｕｍ平方のエリアを示し、図の濃淡は、表面の凹凸を示す。表面のＡＦＭ観察の結果によれば、算術平均表面粗さ（Ｒａ）は、０．１４５ｎｍであった。５０原子％の場合の従来技術に比べて、著しく良好な平坦性が得られた。 An area of 5 μm square on the surface of the NiAl layer (30 nm thick) at an Al composition ratio of 55.7 at% in Example 1-2 was observed by an atomic force microscope (AFM). FIG. 3 shows an image by AFM. The vertical and horizontal axes indicate an area of 5 μm square, and the shading in the figure indicates surface irregularities. According to the result of the AFM observation of the surface, the arithmetic average surface roughness (Ra) was 0.145 nm. Significantly better flatness was obtained compared to the prior art at 50 atomic%.
以上の結果から、磁気抵抗比の高低はＮｉＡｌ層の平坦性を反映すると考えられる。より平坦であるほど、より高い磁気抵抗比が得られる。本実施形態のように、（００１）配向絶縁体トンネルバリアと（００１）配向強磁性体によって構成される磁気抵抗素子においては、コヒーレントトンネリングを発現メカニズムとする磁気抵抗比が、（００１）結晶配向度に敏感である。つまり平坦性が磁気抵抗比の大小を左右する。ＸＹ型のＢ２型結晶構造は、化学量論組成ではＸ：Ｙ＝５０：５０原子％であるが、本実施形態の実施例の結果によれば、Ａｌが５０原子％よりも過剰となることにより、ＮｉＡｌ層の表面平坦性が向上することが分かる。 From the above results, it is considered that the magnitude of the magnetoresistance ratio reflects the flatness of the NiAl layer. The flatter, the higher the magnetoresistance ratio. As in the present embodiment, in the magnetoresistive element composed of the (001) -oriented insulator tunnel barrier and the (001) -oriented ferromagnetic material, the magnetoresistance ratio based on the coherent tunneling mechanism is (001) crystal orientation. Sensitive to degrees. That is, the flatness affects the magnitude of the magnetoresistance ratio. In the XY type B2 type crystal structure, the stoichiometric composition is X: Y = 50: 50 atomic%, but according to the result of the example of the present embodiment, Al is more than 50 atomic%. As a result, it is understood that the surface flatness of the NiAl layer is improved.
図４は、本実施形態の磁気抵抗素子の断面を透過型電子顕微鏡（ＴＥＭ）により観察した像を積層順に並べた図である。像では、Ｓｉウェーハから磁気抵抗素子のキャップ層を除く最上層まで単結晶成長していることが確認された。このとき、ＮｉＡｌ層とその上層のＣｒ層との界面は、原子レベルでの超平坦性を示しており、その上のＣｒ層、Ｆｅ／Ｃｏ層、Ｍｇ２ＡｌＯ４層、Ｃｏ／Ｆｅ層の平坦性および単結晶高配向性を与えている。またＮｉＡｌ層の格子面間隔および配向より、ＮｉＡｌはＢ２構造であることがわかった。Ｓｉウェーハ表面は平坦性が悪いものの、この条件で堆積したＮｉＡｌ層により、各層が平坦かつ単結晶である磁気抵抗素子が実現される。観察した際に、組成プロファイルを取得したところ、ＮｉＡｌ層表面にＡｌがわずかに偏析したことがわかった。このＡｌ偏析が表面平坦性をもたらしている可能性が考えられ、Ａｌ偏析を生じさせるためのＡｌ過剰組成である可能性が高い。 FIG. 4 is a diagram in which images obtained by observing the cross section of the magnetoresistive element of the present embodiment with a transmission electron microscope (TEM) are arranged in the stacking order. The image confirmed that single crystal was grown from the Si wafer to the uppermost layer excluding the cap layer of the magnetoresistive element. At this time, the interface between the NiAl layer and the upper Cr layer shows ultra-flatness at the atomic level, and the upper Cr layer, Fe / Co layer, Mg 2 AlO 4 layer, and Co / Fe layer It provides flatness and high single crystal orientation. Also, from the lattice spacing and orientation of the NiAl layer, it was found that NiAl had a B2 structure. Although the surface of the Si wafer has poor flatness, the NiAl layer deposited under these conditions realizes a magnetoresistive element in which each layer is flat and single crystal. Observation of the composition profile at the time of observation revealed that Al was slightly segregated on the surface of the NiAl layer. It is conceivable that this Al segregation has brought about surface flatness, and it is highly possible that the Al is an excess composition for causing Al segregation.
図４の断面ＴＥＭ像によれば、ＮｉＡｌ層上に（００１）配向した単結晶Ｃｒ層が得られている。従来技術として、単結晶ＭｇＯ基板上に成長したＣｒ（００１）層上にＬ２１構造あるいはＢ２構造のＣｏ基フルホイスラー材料（Ｃｏ２ＹＺ： Ｙ＝Ｍｎ、Ｆｅ、Ｔｉ、Ｖ、Ｃｒ、 Ｚ＝Ａｌ、Ｓｉ、Ｇａ、Ｇｅ、Ｓｎ）、Ｌ１０構造あるいはＤ０２２構造のＭｎ基垂直磁化材料（ＭｎＧａ、ＭｎＧｅ）、Ｌ１０構造の垂直磁化材料（ＸＹ： Ｘ＝Ｆｅ、Ｃｏ、Ｎｉ、Ｃｒあるいはその合金、Ｙ＝Ｐｄ、Ｐｔ、Ｒｈあるいはその合金）といった材料の形成が実現している。本実施形態のＡｌ過剰のＮｉＡｌ層を用いれば、大径Ｓｉ単結晶ウェーハ上においても、単結晶ＭｇＯ基板で開発されているこれらの高性能材料を下部強磁性層・上部強磁性層とする磁気抵抗素子の形成が可能である。 According to the cross-sectional TEM image of FIG. 4, a (001) -oriented single crystal Cr layer is obtained on the NiAl layer. As a conventional technique, a Co-based full Heusler material having an L21 structure or a B2 structure (Co 2 YZ: Y = Mn, Fe, Ti, V, Cr, Z = Al) is formed on a Cr (001) layer grown on a single crystal MgO substrate. , Si, Ga, Ge, Sn), a Mn-based perpendicular magnetic material having an L10 structure or a D022 structure (MnGa, MnGe), a perpendicular magnetic material having an L10 structure (XY: X = Fe, Co, Ni, Cr or an alloy thereof, Y = Pd, Pt, Rh or an alloy thereof). By using the AlAl-rich NiAl layer of this embodiment, even on a large-diameter Si single-crystal wafer, these high-performance materials developed on a single-crystal MgO substrate are used as a lower ferromagnetic layer and an upper ferromagnetic layer. A resistive element can be formed.
（第２の実施形態）
本実施形態は、電子素子におけるＢ２構造下地層としてＣｏＡｌを用いる場合に関する。その他は第１の実施形態で説明したと同様である。
(Second embodiment)
This embodiment relates to a case where CoAl is used as a B2 structure underlayer in an electronic device. Others are the same as those described in the first embodiment.
［実施例２］
Ｂ２構造下地層として用いるＣｏＡｌの組成を変化させた磁気抵抗素子を複数作製し、それぞれの場合の特性を調べた。図５に、本実施形態の磁気抵抗素子の特性を示す。横軸がＣｏＡｌにおけるＡｌ組成比（原子％）で、縦軸が磁気抵抗比（％）である。
[Example 2]
A plurality of magnetoresistive elements having different compositions of CoAl used as the B2 structure underlayer were manufactured, and the characteristics in each case were examined. FIG. 5 shows the characteristics of the magnetoresistive element of this embodiment. The horizontal axis is the Al composition ratio (atomic%) in CoAl, and the vertical axis is the magnetoresistance ratio (%).
実施例２によるものは、図５に示すように、Ａｌ５０．４原子％でＭＲ比３％、Ａｌ５１．７原子％でＭＲ比３％、Ａｌ５３．１原子％でＭＲ比１１８％、Ａｌ５４．６原子％でＭＲ比１５０％、Ａｌ５６原子％でＭＲ比１１０％、Ａｌ５７．５原子％でＭＲ比１１０％、Ａｌ６０原子％でＭＲ比２０％、であった。
As shown in FIG. 5, according to the second embodiment, the MR ratio is 3% at 50.4 atomic% of Al, the MR ratio is 3% at 51.7 atomic% of Al, the MR ratio is 118% at 53.1 atomic% of Al, and the Al 54.6. The atomic ratio was 150% for MR ratio, the MR ratio was 110% for
図５に示すように、ＸがＣｏの場合においても、磁気抵抗比の変化を調べた結果、Ａｌ組成比の最適範囲はＸがＮｉの場合と同様の傾向にあることがわかった。図５に示すように、Ａｌ組成比が、５０原子％よりも過剰、例えば、５２原子％以上６０原子％以下の広い範囲で、５０原子％の場合より高い磁気抵抗比を示していることが分かる。Ａｌ組成比が５３原子％以上６０原子％以下で磁気抵抗比２０％以上が得られた。また、Ａｌ組成が５４原子％以上５９原子％以下で、さらに優れた磁気抵抗比５６％以上を示していることが分かる。Ａｌ組成が５４原子％以上５８原子％以下で、さらに優れた磁気抵抗比およそ９０％以上を示していることが分かる。磁気抵抗比の最高値１５０％を得ることができた。 As shown in FIG. 5, even when X was Co, the change in the magnetoresistance ratio was examined. As a result, it was found that the optimum range of the Al composition ratio had the same tendency as when X was Ni. As shown in FIG. 5, when the Al composition ratio exceeds 50 atomic%, for example, in a wide range from 52 atomic% to 60 atomic%, a higher magnetoresistance ratio than 50 atomic% is exhibited. I understand. When the Al composition ratio was 53 atomic% or more and 60 atomic% or less, a magnetic resistance ratio of 20% or more was obtained. In addition, it can be seen that the Al composition is 54 atomic% or more and 59 atomic% or less, and shows an excellent magnetoresistance ratio of 56% or more. It can be seen that the Al composition is at least 54 at% and at most 58 at%, indicating a further excellent magnetoresistance ratio of about 90% or more. A maximum value of 150% of the magnetoresistance ratio was obtained.
（第３の実施形態）
本実施形態は、電子素子におけるＢ２構造下地層が、ＸＡｌ（Ｘは、Ｎｉ及びＣｏから選択される１以上の金属）からなるＢ２型構造の単結晶で、特に、ＸがＣｏとＮｉの複数元素からなる場合に関する。その他は第１の実施形態で説明したと同様である。
(Third embodiment)
In the present embodiment, the B2 structure underlayer in the electronic element is a single crystal having a B2 type structure made of XAl (X is one or more metals selected from Ni and Co). It relates to the case where it consists of elements. Others are the same as those described in the first embodiment.
［実施例３］
Ｂ２構造下地層として、（ＣｏｘＮｉ１００―ｘ）４５Ａｌ５５（但し、ｘは０以上１００以下。）で表される組成ｘを変化させた下地層を用いて、磁気抵抗素子を作製した。第１及び第２の実施形態から、最適なＡｌ組成比がおよそ５５原子％であるので、Ａｌ＝５５原子％とした場合の、ＮｉとＣｏを０：１００から１００：０まで混合させた場合の磁気抵抗比の変化を調べた。図６に、本実施形態の磁気抵抗素子の特性を示す。横軸がＣｏの混合割合原子％（ｘ）で、縦軸が磁気抵抗比（％）である。図６に示すように、全域において磁気抵抗比１００％以上が得られることがわかった。Ａｌ組成が上述の範囲にあれば、Ｘ＝Ｎｉ−Ｃｏの混合組成でも優れた磁気抵抗比が得られることが分かる。
[Example 3]
A magnetoresistive element was manufactured using an underlayer having a composition x represented by (Co x Ni 100-x ) 45 Al 55 (where x is 0 or more and 100 or less) as a B2 structure underlayer. . From the first and second embodiments, since the optimum Al composition ratio is about 55 atomic%, when Al = 55 atomic%, Ni and Co are mixed from 0: 100 to 100: 0. The change in the magnetoresistance ratio was examined. FIG. 6 shows the characteristics of the magnetoresistive element of this embodiment. The horizontal axis is the mixing ratio of Co at% (x), and the vertical axis is the magnetoresistance ratio (%). As shown in FIG. 6, it was found that a magnetoresistance ratio of 100% or more was obtained in the entire region. It can be seen that when the Al composition is in the above range, an excellent magnetoresistance ratio can be obtained even with a mixed composition of X = Ni-Co.
（第４の実施形態）
本実施形態は、電子素子におけるＢ２構造下地層を形成する工程の温度条件に関する。本実施形態で特に記載する点を除いて、第１の実施形態で説明したと同様である。
(Fourth embodiment)
The present embodiment relates to a temperature condition in a step of forming a B2 structure underlayer in an electronic device. This is the same as that described in the first embodiment, except for the points that are specifically described in this embodiment.
［実施例４］
本実施例では、Ａｌ組成比を５５原子％としたＢ２構造下地層を成膜する際の、シリコン基板温度を変えた場合の磁気抵抗比を調べた。図７は、本実施例の磁気抵抗比の計測結果である。横軸はＳｉ（００１）単結晶基板のウェーハ温度（３００℃から４５０℃まで）で、縦軸は作製した磁気抵抗素子の磁気抵抗比（％）である。図７によれば、ウェーハ温度が３００℃以上４５０℃以下で十分優れた磁気抵抗比が得られることが分かる。また、３４０℃まで下げた条件で製造した場合でも、ウェーハ温度が４５０℃の場合とほぼ同じ磁気抵抗比２１０％以上が得られた。よって、３４０℃以上４５０℃以下であることが、より好ましい。Ａｌ組成が最適範囲にある場合、静電ウェーハチャック機構を使用可能な最高温度４００℃未満の成膜プロセスを可能とする。
[Example 4]
In the present example, the magnetoresistance ratio when the silicon substrate temperature was changed when forming a B2 structure underlayer with an Al composition ratio of 55 atomic% was examined. FIG. 7 shows the measurement results of the magnetoresistance ratio of the present embodiment. The horizontal axis represents the wafer temperature (from 300 ° C. to 450 ° C.) of the Si (001) single crystal substrate, and the vertical axis represents the magnetoresistance ratio (%) of the manufactured magnetoresistance element. According to FIG. 7, it is understood that a sufficiently excellent magnetoresistance ratio can be obtained when the wafer temperature is 300 ° C. or more and 450 ° C. or less. In addition, even when the wafer was manufactured under the condition where the temperature was lowered to 340 ° C., a magnetoresistance ratio of 210% or more was obtained, which was almost the same as when the wafer temperature was 450 ° C. Therefore, the temperature is more preferably 340 ° C or higher and 450 ° C or lower. When the Al composition is in the optimum range, a film forming process at a maximum temperature of less than 400 ° C. in which the electrostatic wafer chuck mechanism can be used is enabled.
（第５の実施形態）
本実施形態では、第２の基本構造の電子素子（磁気抵抗素子）について説明する。第１乃至３の実施形態に示すように、Ｂ２構造の下地層の表面が平坦性がよいので、第１の基本構造でＢ２構造下地層の上に設けられる単結晶非磁性層を、適宜省略し、第２の基本構造で電子素子を作製することができる。
(Fifth embodiment)
In the present embodiment, an electronic element (magnetoresistive element) having the second basic structure will be described. As described in the first to third embodiments, since the surface of the B2 structure underlayer has good flatness, the single crystal nonmagnetic layer provided on the B2 structure underlayer in the first basic structure is appropriately omitted. Then, an electronic element can be manufactured with the second basic structure.
（第６の実施形態）
本実施形態では、Ｂ２構造下地層として、ＸＡｌ（Ｘは、Ｎｉ及びＣｏから選択される１以上の金属）からなるＢ２型構造の単結晶を用いた場合の、面直電流巨大磁気抵抗素子について説明する。本実施形態の面直電流巨大磁気抵抗素子は、（００１）シリコン基板と、該シリコン基板に積層されたＡｌ過剰のＸＡｌからなるＢ２構造の下地層と、該Ｂ２構造の下地層に積層された任意で設けられる単結晶介在層の非磁性層と、下部強磁性層及び上部強磁性層、並びに当該下部強磁性層と当該上部強磁性層の間に設けられた非磁性層を有する積層体層を少なくとも一つ有する巨大磁気抵抗効果層と、を備える。例えば、前記下地層の上に、Ｌ２１構造あるいはＢ２構造のＣｏ基フルホイスラー材料（Ｃｏ２ＹＺ： Ｙ＝Ｍｎ、Ｆｅ、Ｔｉ、Ｖ、Ｃｒ、 Ｚ＝Ａｌ、Ｓｉ、Ｇａ、Ｇｅ、Ｓｎ）である下部強磁性層、非磁性層（Ａｇ、Ａｌ、Ｍｇ）、上部強磁性層を積層し、面直電流巨大磁気抵抗素子を作製する。
(Sixth embodiment)
In the present embodiment, a plane-to-plane current giant magnetoresistance element in the case of using a B2 type single crystal made of XAl (X is one or more metals selected from Ni and Co) as a B2 structure underlayer. explain. The surface-perpendicular-to-plane giant magnetoresistive element of the present embodiment is laminated on a (001) silicon substrate, a base layer of a B2 structure composed of XAl in excess of Al laminated on the silicon substrate, and a base layer of the B2 structure. A laminated layer having a nonmagnetic layer of an optional single crystal interposed layer, a lower ferromagnetic layer and an upper ferromagnetic layer, and a nonmagnetic layer provided between the lower ferromagnetic layer and the upper ferromagnetic layer A giant magnetoresistive layer having at least one of For example, a Co-based full Heusler material having an L21 structure or a B2 structure (Co 2 YZ: Y = Mn, Fe, Ti, V, Cr, Z = Al, Si, Ga, Ge, Sn) is formed on the underlayer. A certain lower ferromagnetic layer, a nonmagnetic layer (Ag, Al, Mg), and an upper ferromagnetic layer are laminated to produce a giant magnetoresistive element with a surface-direct current.
（第７の実施形態）
第１乃至６の実施形態では、磁気抵抗素子の例について説明したが、電子素子は、磁気抵抗素子に限定されない。シリコン（００１）単結晶基板の上に、Ａｌ過剰なＸＡｌ単結晶層を形成し、その平坦性に優れた単結晶層表面の上に、単結晶成長可能な層、例えば、Ｌ２１構造あるいはＢ２構造のＣｏ基フルホイスラー材料（Ｃｏ２ＹＺ： Ｙ＝Ｍｎ、Ｆｅ、Ｔｉ、Ｖ、Ｃｒ、 Ｚ＝Ａｌ、Ｓｉ、Ｇａ、Ｇｅ、Ｓｎ）、Ｌ１０構造あるいはＤ０２２構造のＭｎ基垂直磁化材料（ＭｎＧａ、ＭｎＧｅ）、Ｌ１０構造の垂直磁化材料（ＸＹ： Ｘ＝Ｆｅ、Ｃｏ、Ｎｉ、Ｃｒあるいはその合金、Ｙ＝Ｐｄ、Ｐｔ、Ｒｈあるいはその合金）といった材料の層を、電極又は磁性層その他として備える電子素子を作製する。
(Seventh embodiment)
In the first to sixth embodiments, the example of the magnetoresistive element has been described, but the electronic element is not limited to the magnetoresistive element. An Al-excess XAl single crystal layer is formed on a silicon (001) single crystal substrate, and a layer capable of growing a single crystal, such as an L21 structure or a B2 structure, is formed on the surface of the single crystal layer having excellent flatness. Co-based full Heusler material (Co 2 YZ: Y = Mn, Fe, Ti, V, Cr, Z = Al, Si, Ga, Ge, Sn), an Mn-based perpendicular magnetization material (MnGa, An electron including a layer of a material such as MnGe) or a perpendicular magnetization material having an L10 structure (XY: X = Fe, Co, Ni, Cr or an alloy thereof, Y = Pd, Pt, Rh or an alloy thereof) as an electrode or a magnetic layer or the like. A device is manufactured.
なお、上記実施の形態等で示した例は、発明を理解しやすくするために記載したものであり、この形態に限定されるものではない。 Note that the examples shown in the above embodiments and the like are described for easy understanding of the present invention, and the present invention is not limited to these embodiments.
本発明の磁気抵抗素子等の電子素子は、単結晶化を実現可能とすることから、磁気抵抗比などの素子特性を格段に改善でき、また製造工程の省エネルギー化を図ることができるので、産業上有用である。 Since the electronic element such as the magnetoresistive element of the present invention can realize single crystallization, the element characteristics such as the magnetoresistance ratio can be remarkably improved, and energy saving in the manufacturing process can be achieved. Above is useful.
１ シリコン（００１）単結晶基板
２ Ｂ２構造下地層
３ 単結晶介在層
４ 下部強磁性層
５ 非磁性層
６ 上部強磁性層
DESCRIPTION OF SYMBOLS 1 Silicon (001)
Claims (11)
前記基板は、シリコン（００１）単結晶基板であり、
前記下地層は、化学量論的組成よりＡｌを過剰に含むＸＡｌ（Ｘは、Ｎｉ及びＣｏから選択される１以上の金属）からなるＢ２型構造の単結晶の下地層であることを、
特徴とする、電子素子。 A substrate, a base layer, and an electronic element layer are electronic elements having a stacked structure in which layers are sequentially stacked,
The substrate is a silicon (001) single crystal substrate,
The underlayer is a single crystal underlayer of a B2-type structure composed of XAl (X is one or more metals selected from Ni and Co) containing Al in excess of the stoichiometric composition,
An electronic element, characterized by:
前記下地層上に、電子素子層を順に形成する電子素子層形成工程と、
を含むことを特徴とする、電子素子の製造方法。 On a silicon (001) single crystal substrate, a B2-type single crystal underlayer made of XAl (X is one or more metals selected from Ni and Co) containing Al in excess of the stoichiometric composition is formed. An underlayer forming step of forming a film,
An electronic element layer forming step of sequentially forming electronic element layers on the underlayer,
A method for manufacturing an electronic device, comprising:
単結晶介在層を、前記下地層上に積層形成する工程を含むことを特徴とする、請求項８又は９記載の電子素子の製造方法。 After the underlayer forming step and before the electronic element layer forming step,
The method of manufacturing an electronic device according to claim 8, further comprising a step of forming a single crystal intervening layer on the underlayer.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111490157A (en) * | 2020-04-23 | 2020-08-04 | 中国科学院空天信息创新研究院 | Single crystal spinning electronic device, preparation method and three-dimensional integrated preparation method thereof |
| WO2022181642A1 (en) * | 2021-02-25 | 2022-09-01 | 国立大学法人東北大学 | Magnetic material, laminate, laminate manufacturing method, thermoelectric conversion element, and magnetic sensor |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003228815A (en) * | 2002-01-31 | 2003-08-15 | Toshiba Corp | Perpendicular magnetic recording medium and magnetic recording and reproducing device using the same |
| WO2016080373A1 (en) * | 2014-11-19 | 2016-05-26 | 株式会社 東芝 | Magneto-resistive device and magnetic memory |
| JP2017103419A (en) * | 2015-12-04 | 2017-06-08 | 国立研究開発法人物質・材料研究機構 | Single crystal magnetoresistive element, method for manufacturing the same, and method for using the same |
| WO2017135251A1 (en) * | 2016-02-02 | 2017-08-10 | 国立研究開発法人物質・材料研究機構 | Ferromagnetic tunnel junction, magnetoresistive effect element and spintronics device in which said ferromagnetic tunnel junction is used, and method of manufacturing ferromagnetic tunnel junction |
-
2018
- 2018-09-07 JP JP2018167801A patent/JP7150317B2/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003228815A (en) * | 2002-01-31 | 2003-08-15 | Toshiba Corp | Perpendicular magnetic recording medium and magnetic recording and reproducing device using the same |
| WO2016080373A1 (en) * | 2014-11-19 | 2016-05-26 | 株式会社 東芝 | Magneto-resistive device and magnetic memory |
| JP2016100415A (en) * | 2014-11-19 | 2016-05-30 | 株式会社東芝 | Magnetic resistance element and magnetic memory |
| US20170179374A1 (en) * | 2014-11-19 | 2017-06-22 | Kabushiki Kaisha Toshiba | Magnetoresistive element and magnetic memory |
| JP2017103419A (en) * | 2015-12-04 | 2017-06-08 | 国立研究開発法人物質・材料研究機構 | Single crystal magnetoresistive element, method for manufacturing the same, and method for using the same |
| US20170229643A1 (en) * | 2015-12-04 | 2017-08-10 | National Institute For Materials Science | Monocrystalline magneto resistance element, method for producing the same and method for using same |
| WO2017135251A1 (en) * | 2016-02-02 | 2017-08-10 | 国立研究開発法人物質・材料研究機構 | Ferromagnetic tunnel junction, magnetoresistive effect element and spintronics device in which said ferromagnetic tunnel junction is used, and method of manufacturing ferromagnetic tunnel junction |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111490157A (en) * | 2020-04-23 | 2020-08-04 | 中国科学院空天信息创新研究院 | Single crystal spinning electronic device, preparation method and three-dimensional integrated preparation method thereof |
| WO2022181642A1 (en) * | 2021-02-25 | 2022-09-01 | 国立大学法人東北大学 | Magnetic material, laminate, laminate manufacturing method, thermoelectric conversion element, and magnetic sensor |
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