• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
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    • 专利摘要:
    PURPOSE: A method for forming a magnetic tunnel junction is provided to obtain excellent insulating layer and insulating layer/ferroelectric layer interface. CONSTITUTION: A nitride insulating layer(15) is formed on a bottom stack structure. A ferroelectric free layer and a protection film(18) are sequentially formed on the nitride insulating layer, to form a magnetic tunnel junction. The nitride insulating layer is formed through reactive deposition using a mixed gas of N2 and H2 as a reaction gas. Otherwise, the nitride insulating layer is formed in such a manner that a deposited Al metal thin film is heat-treated in the ambient of a mixed gas of N2 and H2 to be nitrided.
    公开号:KR20030071063A
    申请号:KR1020020010589
    申请日:2002-02-27
    公开日:2003-09-03
    发明作者:안준형
    申请人:주식회사 엘지이아이；
    IPC主号:
    专利说明:

    Magnetic tunnel junction manufacturing method {Method for manufacturing Magnetic tunnel junction}
    [9] The present invention relates to a magnetic tunnel junction, and more particularly, to a method for manufacturing a magnetic tunnel junction using a nitride insulating film.
    [10] In general, a magnetic tunnel junction (MTJ) device mainly consists of a pinned layer, two ferromagnetic films of a free layer, and an insulating film of a moving layer, and utilizes a spin polarized electron tunneling phenomenon.
    [11] The pinned layer is always fixed while the magnetic element is in operation, and only the free layer changes the direction of magnetization.
    [12] Since tunneling is related to electron spin, the characteristics of the magnetic tunnel junction are a function of the relative orientation and spin polarity of the two ferromagnetic layers.
    [13] The state of the magnetic tunnel junction element is determined by measuring the change in magnetic tunnel junction resistance as the sense current flows perpendicularly to the junction from one of the ferromagnetic layers to the other ferromagnetic layer.
    [14] The relative arrangement of the magnetization directions of the two ferromagnetic layers varies the probability of electron tunneling across the magnetic tunnel junction.
    [15] The tunneling probability of the electron carrier is highest when the magnetization directions of the two ferromagnetic layers are parallel, and minimum when the magnetization directions of the two ferromagnetic layers are parallel to each other.
    [16] That is, the resistance of the magnetic tunnel junction becomes highest when the mutual magnetization directions are anti-parallel and minimum when parallel.
    [17] The difference in the magnetic tunnel junction resistance values according to the relative magnetization directions of the two ferromagnetic layers may be uniquely defined as two bit states (0 or 1) of the two magnetic tunnel junction unit elements.
    [18] The device of the magnetic tunnel junction may be specifically used as a sensor of a magnetoresistive head (MR head) for reading data in a magnetic storage cell or a magnetic recording disk drive in a nonvolatile magnetic memory device. For the application, the resistance value of the MTJ device as well as the resistance change (TMR ratio) according to the arrangement of the relative magnetization directions must have an appropriate value.
    [19] In other words, if the resistance is too large, the speed is slow due to the impedance delay effect. On the contrary, if the resistance is too small, the output becomes small, which is not preferable.
    [20] This magnetic tunnel junction resistance depends on the interfacial properties of the insulating film and the insulating film / ferromagnetic layer positioned between the ferromagnetic layers.
    [21] Currently used insulating films are Al 2 O 3 thin films made by depositing and oxidizing Al metal, which is also reaching the limit.
    [22] 1 is a schematic structural diagram of a conventional magnetic tunnel junction.
    [23] Referring to FIG. 1, a simple magnetic tunnel junction element is completed when a thin insulating thin film 6 is deposited between two layers of ferromagnetic (5-7, 8) thin films.
    [24] Al 2 O 3 formed by depositing and then oxidizing Al metal with the insulating film 6 exhibits excellent insulation properties and stable thin film deposition properties.
    [25] However, the oxidation process has the disadvantage that the surface of the ferromagnetic metal thin film is also oxidized during the process, so that interfacial polarization loss occurs in the ferromagnetic layer, and in order to increase the response speed, Al 2 O 3 thin films are made. The limit is being reached.
    [26] Control of experimental conditions such as magnetic tunnel junction using the oxide insulating film manufactured by such a conventional method is difficult, poor reproducibility, long process time, expensive equipment is required.
    [27] In addition, it is difficult to secure the performance of the actual device using the magnetic tunnel junction.
    [28] Accordingly, an object of the present invention is to provide a magnetic tunnel junction manufacturing method for securing an excellent insulating film and the insulating film / ferromagnetic layer interface in view of the problems of the prior art mentioned above.
    [1] 1 is a schematic structural diagram of a conventional magnetic tunnel junction
    [2] 2a to 2c show a magnetic tunnel junction fabrication in accordance with the present invention
    [3] * Description of the symbols for the main parts of the drawings *
    [4] 10 substrate 11 buffer layer
    [5] 12: seed layer 13: lower antiferromagnetic layer
    [6] 14 lower ferromagnetic layer 15 nitride insulating layer
    [7] 16: upper ferromagnetic layer 17: upper ferromagnetic layer
    [8] 18: protective film
    [29] According to an aspect of the present invention for achieving the above object, the step of forming a nitride insulating film on the lower laminated structure, a ferromagnetic free layer and a protective film are formed sequentially on the nitride insulating film.
    [30] Preferably, the nitride insulating film is AlN, and the nitride insulating film is formed by reactive deposition using a mixed gas of N 2 , H 2 as a reaction gas, or using a mixed N 2 , H 2 mixed gas as an atmosphere gas. By heat treatment to nitriding.
    [31] Hereinafter, a configuration and an operation according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.
    [32] 2A to 2D are diagrams illustrating a magnetic tunnel junction fabrication according to the present invention.
    [33] First, the present invention intends to propose a fabrication process of a magnetic tunnel junction using a nitride insulating film such as AlN instead of the conventional oxide (Al 2 O 3 ) insulating film, the most important thing in the magnetic tunnel junction, in addition to the formation of a ferromagnetic layer of excellent characteristics It is to ensure the insulating film and the insulating film / ferromagnetic layer interface of excellent characteristics, and most of all, the ferromagnetic layer and the insulating film is not reacted with the ferromagnetic layer (reaction with the insulating film components, the atmosphere required to form the insulating film, etc.) during the formation of the insulating film It should not be possible to deteriorate each characteristic, but also be able to be laminated on the ferromagnetic layer.
    [34] Referring to FIG. 2A, a thin film having a single seed layer 12 or a composite layer of seed layers / buffer layers 11 and 12 is formed on the substrate 10.
    [35] The lower antiferromagnetic pinned layer 13 is formed on the seed layer 12 to fix the magnetic tunnel junction pinned layer magnetization.
    [36] The lower antiferromagnetic pinned layer 13 may be a single layer or a combination of layers.
    [37] In addition, a lower ferromagnetic pinned layer 14 is formed on the lower antiferromagnetic pinned layer 13.
    [38] Next, as shown in FIG. 2B, a nitride insulating layer 15 is formed on the bottom stack structure configured as shown in FIG. 2A.
    [39] In the first method of forming the nitride insulating layer 15, a nitride thin film is directly deposited by a reactive method using N 2 , H 2 mixed gas as a reaction gas, or second, an Al metal thin film is first deposited. An AlN insulating film is formed by nitriding the Al metal thin film by high-temperature heat treatment using an N 2 , H 2 mixed gas as an atmosphere gas.
    [40] The deposition method of the Al metal thin film or nitride thin film uses PLD, sputtering, CVD, coevaporation, MBE and the like.
    [41] Subsequent atmospheric heat treatment methods of the second method include a method of flowing mixed gas at a high temperature (natual nitridation) and forming a plasma such as rf, dc, and ECR.
    [42] In addition, when the insulating film is to be made Al-ON which can have both the characteristics of nitride and oxide, it is possible to obtain by controlling the H 2 content in the mixed gas.
    [43] Since the nitride insulating film 15 is formed through the heat treatment in a strong reducing atmosphere using the N 2 and H 2 mixed gases as described above, that is, an insulating film is formed by using an oxygen-free process to form an oxide such as Al 2 O 3 . Deterioration of magnetic properties due to oxidation of the ferromagnetic layer generated during the formation of the insulating film can be solved.
    [44] In addition, since the hydrogen ions contained in the mixed gas are kept stable by being bonded to the dangling bonding existing inside the magnetic tunnel junction, the dangling bonding does not act as a defect that impedes the spin polarization transfer. It is possible to improve the convenience and productivity of the fabrication of the bonded device, and to improve the characteristics of the device and to improve the reproducibility.
    [45] When the nitride insulating film 15 is completed, the upper ferromagnetic layer 16 and the upper antiferromagnetic layer 17 are formed to cause magnetization reversal thereon, and a protective layer 18 is formed to protect the ferromagnetic thin film. Finally, an electrode such as Au is formed by a lift-off method as an electrode.
    [46] As described above, the present invention is a process that can be easily applied to a plurality of devices or devices at the same time at the same time, even if the geometry of the specimen is changed, it can be easily applied to all devices using TMR by magnetic tunnel. In particular, it is effective to apply to a device such as a sensor of a magnetoresistive head for reading data in a magnetic storage cell or a magnetic recording disk drive in a nonvolatile magnetic memory device.
    [47] Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.
    [48] Therefore, the technical scope of the present invention should not be limited to the contents described in the examples, but should be defined by the claims.
    权利要求:
    Claims (3)
    [1" claim-type="Currently amended] Forming a nitride insulating film on the lower stacked structure;
    And forming a ferromagnetic free layer and a passivation layer sequentially on the nitride insulating film.
    [2" claim-type="Currently amended] The method of claim 1,
    And the nitride insulating film is AlN.
    [3" claim-type="Currently amended] The method of claim 1,
    The nitride insulating film is formed by reactive deposition using N 2 , H 2 mixed gas as a reaction gas, or by heat treatment of the deposited Al metal thin film using N 2 , H 2 mixed gas as an atmosphere gas. Tunnel junction manufacturing method.
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    同族专利:
    公开号 | 公开日
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    2002-02-27|Application filed by 주식회사 엘지이아이
    2002-02-27|Priority to KR1020020010589A
    2003-09-03|Publication of KR20030071063A
    优先权:
    申请号 | 申请日 | 专利标题
    KR1020020010589A|KR20030071063A|2002-02-27|2002-02-27|Method for manufacturing Magnetic tunnel junction|
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