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METHOD FOR MANUFACTURING LAYERED STRUCTURE OF MAGNETIC BODY AND BiSb, MAGNETORESISTIVE MEMORY, AND PURE SPIN INJECTION SOURCE

Foreign code F190009808
File No. S2017-0902-C0
Posted date May 8, 2019
Country WIPO
International application number 2018JP034191
International publication number WO 2019054484
Date of international filing Sep 14, 2018
Date of international publication Mar 21, 2019
Priority data
  • P2017-177564 (Sep 15, 2017) JP
Title METHOD FOR MANUFACTURING LAYERED STRUCTURE OF MAGNETIC BODY AND BiSb, MAGNETORESISTIVE MEMORY, AND PURE SPIN INJECTION SOURCE
Abstract A cell 2 of a magnetoresistive memory is provided with: a MTJ element 10 including a magnetization free layer 12; and a pure spin injection source 20. The pure spin injection source 20 includes a BiSb layer connected to the magnetization free layer 12. Magnetization reversal of the magnetization free layer 12 is enabled by applying an in-plane current to the BiSb layer.
Outline of related art and contending technology BACKGROUND ART
In recent years, the development of low power consumption non-volatile memory and has been actively carried out, the magnetic resistance memory (MRAM) is among the very promising. In addition to the non-volatile MRAM, 10ns-class high-speed operation, extremely high durability (number of times of writing 1016 or more times) or the like, very excellent characteristics. Therefore, the main memory as well as the MRAM, if a built-in in a nonvolatile memory integrated circuit, the power consumption of the integrated circuit 9 by the effect of power gating can be reduced and the expected interrupt.
The first generation of MRAM memory element (MTJ: magnetic tunnel junction) is, the magnetization reversal method is used by the magnetic field. However, the magnetization reversal by magnetic field energy consumption is large. 2000 Year of the second-generation base as a writing technique, the spin injection magnetization inverting method has been developed, been put into practical use from the year 2012. In the spin injection magnetization reversing technique, the pinned magnetic layer of the MTJ element free from the spin-polarized current is injected into the magnetic layer, the spin transfer torque (STT: by Spin transfer torque), to cause the magnetization reversal. STT-MRAM uses this technique is referred to as MRAM. In the spin injection magnetization reversal, the next spin of the spin-polarized current is injected by a IS. IS is the spin of the spin angular momentum per unit time of a certain flow rate. IS=PIhbar (hbar/2e): Planck's constant h/2 π e: elementary charge I: current P: spin polarization of the magnetic electrode material
P 1 and the upper limit of the, usually on the order of P-0.5. As can be seen from this equation, the spin injection magnetization reversal technique, a spin current does not exceed I (hbar/2e). This is, each of the spin angular momentum of the electrons not only carry hbar/2 is the physical limit in some cases. And the MRAM is a non-volatile, does not consume energy during the standby, when the data is written to the memory such as SRAM 1 orders of magnitude greater than the energy consumption is still a problem remains. In addition, a large write current required for the driving transistor is large, it is difficult to increase the storage capacity of the MRAM.
Fig. 1 is, the magnetization reversal method using a pure spin current with an embodiment of the present invention. The ferromagnetic layer a material having a strong spin-orbit interaction which are connected to each other. The current I is passed through this layer, a pure spin current IS flows in the vertical direction. Such a phenomenon is referred to as the spin Hall effect. Pure spin current density J between JS and the current density (hbar/2e) JS=, the following relationship that θ shJ. Here, θ sh is the intensity of the spin-orbit interaction is a parameter that reflects, referred to as the spin Hall angle. As a result, the current Is between the pure spin current I, the following relationship is established. IS=(hbar/2e), θ shI (L/tN)
That is, each electron is effectively, (L/tN) θ sh of the spin can be generated. If, (L/tN) can be achieved in the θ sh ≫ 1, the conventional spin injection magnetization reversal of the magnetization reversal by a spin current-pure than seen in the efficiency. In the normal (L/tN) for-5-10, 1 θ sh>spin Hall material can be used as long as the, the current required to invert the magnetization of the MRAM element 1 can be reduced and the power magnitude. Further, the pure spin injection magnetization reversal method, the magnetization inversion at high speed can be around 1 digits, 2 digits of the write energy can be reduced. In the spin Hall effect by the spin injection MRAM using the spin-orbit pure SOT(Spin-orbit-torque) MRAM referred to as torque.
Scope of claims (In Japanese)[請求項1]
 磁化自由層を含むMTJ(磁気トンネル接合)素子と、
 前記磁化自由層と接続されるBiSb層を含む純スピン注入源と、
 を備え、前記BiSb層に面内電流を流し、前記磁化自由層の磁化反転が可能であることを特徴とする磁気抵抗メモリ。

[請求項2]
 前記BiSb層は、結晶化していることを特徴とする請求項1に記載の磁気抵抗メモリ。

[請求項3]
 前記BiSb層は(012)配向を有することを特徴とする請求項1または2に記載の磁気抵抗メモリ。

[請求項4]
 前記BiSb層のトポロジカル表面状態を利用して、セルが2端子化されていることを特徴とする請求項1から3のいずれかに記載の磁気抵抗メモリ。

[請求項5]
 面内バイアス磁場の印加を行わないことを特徴とする請求項4に記載の磁気抵抗メモリ。

[請求項6]
 磁気抵抗メモリの製造方法であって、
 磁化自由層を形成するステップと、
 BiSb層を含む純スピン注入源を形成するステップと、
 を備え、前記BiSb層は、基板温度200~250℃の条件で製膜されることを特徴とする製造方法。

[請求項7]
 磁性体とBiSb層の積層構造の製造方法であって、前記BiSb層を、基板温度200~250℃の条件で製膜することを特徴とする製造方法。
する製造方法。

[請求項8]
 前記BiSb層は(012)配向を有することを特徴とする請求項6または7に記載の製造方法。

[請求項9]
 磁性体に純スピン流を注入する純スピン注入源であって、
 前記磁性体と接続されるBiSb層を含み、前記BiSb層に流れる面内電流に応じて、前記磁性体に面直方向に純スピン流を供給することを特徴とする純スピン注入源。

[請求項10]
 前記BiSb層は、結晶化していることを特徴とする請求項9に記載の純スピン注入源。

[請求項11]
 磁化自由層を含むMTJ(磁気トンネル接合)素子と、
 前記磁化自由層と接続されるBiSb層を含む純スピン注入源と、
 を備え、
 前記BiSb層が(012)配向を有し、四回対称の結晶構造の下地層が利用される磁気抵抗メモリ。
  • Applicant
  • ※All designated countries except for US in the data before July 2012
  • TOKYO INSTITUTE OF TECHNOLOGY
  • Inventor
  • PHAM NAM HAI
  • NGUYEN HUYNH DUY KHANG
IPC(International Patent Classification)
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