Patent Publication Number: US-10784441-B2

Title: Perpendicularly magnetized spin-orbit magnetic device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part application of and claims the priority benefit of U.S. application Ser. No. 16/219,980, filed on Dec. 14, 2018, now pending. The prior U.S. application Ser. No. 16/219,980 is a divisional application of and claims the priority benefit of U.S. application Ser. No. 15/358,157, filed on Nov. 22, 2016, now patented. The prior application Ser. No. 15/358,157 claims the priority benefit of Taiwan application serial no. 105124742, filed on Aug. 4, 2016. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     Field of the Disclosure 
     The disclosure relates to a perpendicularly magnetized spin-orbit magnetic device. 
     Description of Related Art 
     Magnetic random access memory (MRAM) has advantages of fast speed, low power consumption, high density, non-volatile, and has almost unlimited read and write times, and is predicted as a mainstream of memories coming in the next generation. A main structure of a memory device in the MRAM is a stacked structure formed by stacking a pinned layer of three-layer materials with ferromagnet/non-magnetic metal/ferromagnet, a tunneling barrier layer and a free layer of a magnetic material. Such stacked structure can be referred to as a magnetic tunnel junction (MTJ) device. Since a write current only flows through the selected MTJ device, and magnetic switching is determined by an intensity of the write current and an intensity of an external magnetic field, it avails decreasing the write current after the MTJ device is miniaturized, and effects of simultaneously improving write selectivity and decreasing the write current are theoretically achieved. 
     The MTJ devices using a spin-orbit-torque (SOT) mechanism to implement read and write operations can be divided into in-plan MTJ devices and perpendicular MTJ devices. Compared to the in-plan MTJ device, the perpendicular MTJ device has a lower operating current, a higher device density and better data storability. A perpendicular spin torque transfer random access memory (pSTT-RAM) is regarded as a memory of the new generation, which records digital information of 0 and 1 through spin transfer switching, and takes the perpendicular MTJ as a main magnetic memory cell structure, which has good thermal stability, and an operating current thereof is smaller compared with that of the other type of the magnetic memory. 
     If the SOT mechanism is adopted to implement the MRAM structure, an operating speed and write reliability can be further improved. A switching mechanism of the SOT in a perpendicular film plane magnetic torque is to introduce the write current to a heavy metal layer. The heavy metal layer may produce a spin transfer torque (STT) based on a spin Hall effect and the external magnetic field. Moreover, the write current may produce a Rashba torque (RT) after passing through a perpendicular electric field at a material interface and the external magnetic field. Since the STT and the RT are all perpendicular to a direction of the write current and parallel to the film plane, the two torques are added to form the SOT. Therefore, if a magnetic field is applied to the ferromagnetic material on the film plane that is perpendicular to the magnetic torque, the SOT is produced to switch the magnetic torque of the ferromagnetic layer to achieve an effect of writing the memory device. However, the above mechanism requires to additionally input the write current and apply the external magnetic field. Manufacturers hope to simplify design complexity of an operation mechanism used for controlling the magnetic memory cell structure in case that the SOT mechanism is used as a mechanism for reading and writing the magnetic memory cells. 
     SUMMARY OF THE DISCLOSURE 
     The disclosure provides a perpendicularly magnetized spin-orbit magnetic device including a heavy metal layer, a magnetic tunnel junction, a first antiferromagnetic layer, a first block layer and a first stray field applying layer. The magnetic tunnel junction is disposed on the heavy metal layer. The first block layer is disposed between the magnetic tunnel junction and the first antiferromagnetic layer. The first stray field applying layer is disposed between the first antiferromagnetic layer and the first block layer. The magnetic tunnel junction comprises a free layer, a tunneling barrier layer, and pinned layer. The tunneling barrier layer is disposed on the free layer. The pinned layer is disposed on the tunneling barrier layer. A film plane area of the free layer is greater than a film plane area of the tunneling barrier layer and a film plane area of the pinned layer. 
     In order to make the aforementioned and other features and advantages of the disclosure comprehensible, several exemplary embodiments accompanied with figures are described in detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure. 
         FIG. 1  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device. 
         FIG. 2  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device according to a first embodiment of the disclosure. 
         FIG. 3  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device according to a second embodiment of the disclosure. 
         FIG. 4A  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device according to a third embodiment of the disclosure. 
         FIG. 4B  is a simulation schematic diagram of a stray magnetic field of the perpendicularly magnetized spin-orbit magnetic device of  FIG. 4A . 
         FIG. 5  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device according to a fourth embodiment of the disclosure. 
         FIG. 6  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device according to a fifth embodiment of the disclosure. 
         FIG. 7A  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device according to a sixth embodiment of the disclosure. 
         FIG. 7B  is a simulation schematic diagram of a stray magnetic field of the perpendicularly magnetized spin-orbit magnetic device of  FIG. 7A . 
         FIG. 8  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device according to a seventh embodiment of the disclosure. 
         FIG. 9  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device according to an eighth embodiment of the disclosure. 
         FIG. 10  is a simulation schematic diagram of a free layer and a first stray field applying layer implementing a stray magnetic field according to the second embodiment of the disclosure. 
         FIG. 11  is another simulation schematic diagram of a free layer and a first stray field applying layer implementing a stray magnetic field according to the second embodiment of the disclosure. 
         FIG. 12  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device according to a third embodiment of the disclosure. 
         FIG. 13  is another structure view of a of the perpendicularly magnetized spin-orbit magnetic devices according to the third embodiment of the disclosure. 
         FIG. 14  is the other structure view of the perpendicularly magnetized spin-orbit magnetic devices according to the third embodiment of the disclosure. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
       FIG. 1  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device  100 . The perpendicularly magnetized spin-orbit magnetic device  100  mainly includes a magnetic tunnel junction  110  and a heavy metal layer  150 . In the present embodiment, the magnetic tunnel junction  110  includes a pinned layer  120 , a tunneling barrier layer  130  and a free layer  140 . The pinned layer  120  is, for example, a material stacking layer of ferromagnet/non-magnetic metal/ferromagnet consisting of a lower pinned layer  126 , a coupling layer  124  and an upper pinned layer  122 . A magnetic moment vector  123  of the upper pinned layer  122  and a magnetic moment vector  127  of the lower pinned layer  126  are opposite to each other and perpendicular to a film plane to present a vertical coupling arrangement without being changed by an operating magnetic field or other factors. 
     The pinned layer  120  is disposed on the tunneling barrier layer  130 . The tunneling barrier layer  130  can be disposed on the free layer  140 . The free layer  140  is a memory layer in the perpendicularly magnetized spin-orbit magnetic device  100 . The heavy metal layer  150  may receive an input current Ic from an electrode contact of the perpendicularly magnetized spin-orbit magnetic device  100 . Moreover, the input current Ic may flow through the heavy metal layer  150  to produce a plurality of spin currents with different directions due to a spin Hall effect (SHE), so as to produce a resultant moment together with an external magnetic field H, such that a magnetic moment of the free layer  140  is switched to achieve a data read/write effect. 
     In order to facilitate description, coordinate axes X, Y, Z are set in the figures of the embodiments of the disclosure to facilitate subsequent description. An X-axis direction is an extending direction of the film plane, a Y-axis direction is an upward direction perpendicular to a paper surface, and a Z-axis direction is a direction perpendicular to the film plane. The film plane of each layer is parallel to an XY plane, and arrows  127 ,  141  used for representing magnetic moment directions of magnetic moment vectors belong to the positive Z-axis direction, and arrows  123 ,  142  belong to the negative Z-axis direction, and the others are deduced by analogy. In the present embodiment, a provided direction of the external magnetic field H and a transfer direction of the input current Ic belong to the positive X-axis direction. 
     The perpendicularly magnetized spin-orbit magnetic device  100  in  FIG. 1  still adopts the input current Ic input from external and the external magnetic field H in order to achieve the data read/write operation. For example, when the input current Ic is a positive value and the external magnetic field H is applied, a direction of a spin transfer torque induced by the free layer  140  is upward and perpendicular to the paper surface (i.e. the positive Y-axis direction), such that the direction of the magnetic moment in the free layer  140  is changed from the arrow  141  into the arrow  142 . Comparatively, when the input current Ic is a negative value (i.e. a flow direction of the input current Ic is a reverse direction) and the external magnetic field H is applied, the direction of the spin transfer torque induced by the free layer  140  is downward and perpendicular to the paper surface (i.e. the negative Y-axis direction), such that the direction of the magnetic moment in the free layer  140  is changed from the arrow  142  into the arrow  141 . However, if the external magnetic field H is not applied, the spin transfer torque is not generated. 
     The embodiment of the disclosure provides a perpendicularly magnetized spin-orbit magnetic device, in which an antiferromagnetic layer, a block layer and a stray field applying layer are additionally added to generate a stray magnetic field, so as to produce a situation the same with that of the external magnetic field to the free layer of the magnetic tunnel junction, and provide a magnetic moment switching effect to the perpendicularly magnetized spin-orbit magnetic device when the input current is input. Embodiments are provided below to describe the spirit of the disclosure in detail, though the disclosure is not limited to the provided embodiment, and the embodiments can also be suitably combined. 
       FIG. 2  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device  200  according to a first embodiment of the disclosure. A material of the upper pinned layer  122  and the lower pinned layer  126  in  FIG. 2  can be a ferromagnetic material with perpendicular anisotropy. The upper pinned layer  122  and the lower pinned layer  126  can be a single layer structure or a multi-layer composite structure. The upper pinned layer  122  and the lower pinned layer  126  of the single layer structure are, for example, implemented by ferromagnetic materials of ferrous (Fe), cobalt (Co), nickel (Ni), gadlinium (Gd), terbium (Tb), dysprosium (Dy), boron (B) etc., or an alloy of the above elements (i.e., CoFeB, CoFe, NiFe . . . etc.). A shape of the upper pinned layer  122  or the lower pinned layer  126  may be a round or an oval. The upper pinned layer  122  and the lower pinned layer  126  of the multi-layer composite structure can be a composite layer structure of a ferromagnetic material and a metal material, for example, a composite layer structure composed of elements such as Co/platinum (Pt), Co/Ni, Co/palladium (Pd), etc. A material of the coupling layer  124  can be Ruthenium (Ru), and the thickness of the coupling layer  124  can be 5 Å to 20 Å. The tunneling barrier layer  130  is an insulating material having a magnetic tunnel condition under a specified thickness. For example, a material of the tunneling barrier layer  130  can be MgO. The insulating materials can be magnesium oxide, aluminium oxide, magnesium, or a combination thereof. 
     A material of the free layer  140  can be a ferromagnetic material with perpendicular anisotropy. The free layer  140  mainly implements the data read/write operation through switching of the magnetic moment in the magnetic film layer, so that the ferromagnetic material of the free layer  140  can be Fe, Co, Ni, Gd, Tb, Dy, B or an alloy of the above elements, for example, CoFeB, NF, FeB, etc. A thickness of the free layer  140  can be 10 Å to 100 Å. The free layer  140  can be a single layer structure or a multi-layer composite structure. If the free layer is a composite structure formed by multi-layer ferromagnetic materials, the material of the multi-layer composite structure can be a composite structure consisting of elements such as Co/Pt, Co/Ni, Co/Pd, etc. The magnetic moment vector of the free layer  140  is arranged by perpendicular to the film plane. A material of the heavy metal layer  150  can be a material generating a spin Hall effect and/or a quantum spin Hall effect such as tantalum (Ta), platinum (Pt), tungsten (W), or a combination thereof. A thickness of the heavy metal layer  150  can be 20 Å to 200 Å. 
     The perpendicularly magnetized spin-orbit magnetic device  200  of  FIG. 2  additionally has a first antiferromagnetic layer  230 , a first stray field applying layer  220  and a first block layer  210 . The first stray field applying layer  220  is disposed between the first antiferromagnetic layer  230  and the first block layer  210 . The first antiferromagnetic layer  230  contacts the first stray field applying layer  220  to define a direction of a magnetic moment in the first stray field applying layer  220  to be parallel to the film plane, as shown by arrows  231  and  232 . In detail, in order to ensure that the first antiferromagnetic layer  230  may define the direction of the magnetic moment, the first antiferromagnetic layer  230  is processed with a field annealing treatment of a predetermined temperature, so as to use the first antiferromagnetic layer  230  to fix the direction of the magnetic moment in the first stray field applying layer  220  (for example, the X-axis magnetic moment direction indicated by the arrow  221 ). The first antiferromagnetic layer  230  can be composed of an antiferromagnetic material, and the antiferromagnetic material can be platinum-manganese alloy (PtMn), magnesium oxide (MnO), iridium-manganese alloy (IrMn), chromium oxide (CrO), or a combination thereof. A thickness of the first antiferromagnetic layer  230  can be 50 Å to 200 Å. 
     In other words, the first stray field applying layer  220  is influenced by the first antiferromagnetic layer  230  (for example, the magnetic moment directions indicated by the arrows  231 ,  232 ) to produce a closed magnetic circle parallel to the film plane and strayed outside the first stray field applying layer  220 , so as to produce a stray magnetic field Hs. In the present embodiment, the direction of the magnetic moment in the first stray field applying layer  220  is shown as the arrow  221 . The first stray field applying layer  220  can be composed of a ferromagnetic material, and the ferromagnetic material can be Fe, Co, Ni, Gd, Tb, Dy, B or an alloy of the above elements. A thickness of the first stray field applying layer  220  can be 30 Å to 3 kÅ. The first block layer  210  is used for blocking the first antiferromagnetic layer  230  from transferring a magnetic moment arrangement direction, i.e. to avoid the current Ic in the heavy metal layer  150  from being influenced by the first antiferromagnetic layer  230 . On the other hand, since a spin current is produced in the heavy metal layer  150 , the first block layer  210  is required to block the spin current in the heavy metal layer  150  from influencing the first stray field applying layer  220 . The first block layer  210  may have a predetermined thickness obtained through experiments, so as to effectively block transferring of the spin current between the metals or the ferromagnetic materials of the upper and lower layers, such that operation mechanisms of each layer can be pure without influencing each other. A material of the first block layer  210  can be magnesium oxide, aluminium oxide, magnesium, or a combination thereof. 
     In this way, regarding the free layer  140 , the function of the stray magnetic field Hs is the same with that of the external magnetic field H of  FIG. 1 . In other words, to operate the perpendicularly magnetized spin-orbit magnetic device  200 , it is only required to provide the input current Ic to the heavy metal layer  150 , and the free layer  140  may implement magnetic moment switching to generate the stray magnetic field Hs, so as to implement the read/write function of the data memorized by the free layer  140  without additionally providing the external magnetic field H. In this way, complexity of the perpendicularly magnetized spin-orbit magnetic device  200  in the read/write operation is simplified. 
     In the embodiment of the disclosure, the first block layer  210 , the first stray field applying layer  220  and the first antiferromagnetic layer  230  are disposed under the heavy metal layer  150 . In the present embodiment, the heavy metal layer  150  of  FIG. 2  is disposed on the first block layer  210 , the first block layer  210  is disposed on the first stray field applying layer  220 , and the first stray field applying layer  220  is disposed on the first antiferromagnetic layer  230 . In other embodiment complied with the spirit of the disclosure, the first block layer, the first stray field applying layer and the first antiferromagnetic layer can also be disposed above the pinned layer  120  of the magnetic tunnel junction  110 . The first stray field applying layer referred in the embodiments of this specification can be called as an external filed layer. 
     It should be noted that in the embodiment of the disclosure, shapes of the magnetic tunnel junction  110  and the first stray field applying layer  220  in the perpendicularly magnetized spin-orbit magnetic device  200  and areas of film planes are compared, and data simulation is performed to the stray magnetic field to analyze a shape and an area proportion between the free layer  140  of the magnetic tunnel junction  110  and the magnetic tunnel junction  110  in order to obtain the better stray magnetic field Hs, or being influenced by magnetic fields of other directions. Shapes of the magnetic tunnel junction  110 , the heavy metal layer  150 , the first block layer  210 , the first stray field applying layer  220  or the first antiferromagnetic layer  230  can be rounds, ovals, squares or rectangles. 
     In the following description, it is assumed that the shapes of the magnetic tunnel junction  110 , the heavy metal layer  150 , the first block layer  210 , the first stray field applying layer  220  and the first antiferromagnetic layer  230  are all rounds, and the shapes of each layer (including the free layer  140 ) in the magnetic tunnel junction  110  are also rounds. The heavy metal layer  150  has a first film plane area A 1  on the XY plane, and the magnetic tunnel junction  110  has a second film plane area A 2  on the XY plane. In the present embodiment, the first film plane area A 1  is greater than the second film plane area A 2 . The first stray field applying layer  220  and the first antiferromagnetic layer  230  have a same third film plane area A 3  on the XY plane. It should be noted that regarding the free layer  140 , a “horizontal direction stray magnetic field Hs” is a magnetic field component of the stray magnetic field Hs parallel to the film plane of the free layer  140  (i.e. parallel to the XY plane), and the horizontal direction stray magnetic field Hs may effectively produce the spin transfer switching effect to the free layer  140 . A “vertical direction stray magnetic field Hs” is a magnetic field component of the stray magnetic field Hs perpendicular to the film plane of the free layer  140  (i.e. parallel to the Z-axis direction). The vertical direction stray magnetic field Hs is hard to produce the spin transfer switching effect to the free layer  140 , but may interfere the spin transfer switching effect to make the transfer switching effect much worse. When the third film plane area A 3  of the first stray field applying layer  220  is the same with the second film plane area A 2  of the free layer  140 , and the shapes thereof are consistent, through simulations of the stray magnetic field Hs in  FIG. 2  to  FIG. 5 , it is known that the horizontal direction stray magnetic field Hs at a boundary of the free layer  140  of  FIG. 2  is larger than the horizontal direction stray magnetic field Hs at the boundary of the free layer  140  in  FIG. 3 ,  FIG. 4  and  FIG. 5 . However, the vertical direction stray magnetic field Hs at the boundary of the free layer  140  of  FIG. 2  is also larger than the vertical direction stray magnetic field Hs at the boundary of the free layer  140  in  FIG. 3 ,  FIG. 4  and  FIG. 5 . 
       FIG. 3  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device  300  according to a second embodiment of the disclosure. The first antiferromagnetic layer  330  defines a direction of the magnetic moment in the first stray field applying layer  320  to be parallel to the film plane, as shown by arrows  231  and  232 . The direction of the magnetic moment in the first stray field applying layer  320  is indicated by the arrow  221 . A difference between  FIG. 2  and  FIG. 3  is that the third film plane area A 3  of the first antiferromagnetic layer  330  and the first stray field applying layer  320  is smaller than the first film plane area A 1  of the heavy metal layer  150 , and the third film plane area A 3  is greater than the second film plane area A 2  of the magnetic tunnel junction  110 . A film plane area of the first block layer  310  is A 1 . Through simulations of the stray magnetic field Hs in  FIG. 2  to  FIG. 5 , it is known that the horizontal direction stray magnetic field Hs and the vertical direction stray magnetic field Hs at the boundary of the free layer  140  of  FIG. 3  are all larger than the horizontal direction stray magnetic field Hs and the vertical direction stray magnetic field Hs at the boundary of the free layer  140  in  FIG. 4  and  FIG. 5 , and are all smaller than the horizontal direction stray magnetic field Hs and the vertical direction stray magnetic field Hs at the boundary of the free layer  140  in  FIG. 2 . 
       FIG. 4A  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device  400  according to a third embodiment of the disclosure, and  FIG. 4B  is a simulation schematic diagram of the stray magnetic field Hs of the perpendicularly magnetized spin-orbit magnetic device  400  of  FIG. 4A . The first antiferromagnetic layer  430  defines a direction of the magnetic moment in the first stray field applying layer  420  to be parallel to the film plane, as shown by arrows  231  and  232 . The direction of the magnetic moment in the first stray field applying layer  420  is indicated by the arrow  221 . A difference between  FIG. 4A  and  FIG. 2 ,  FIG. 3  is that the third film plane area A 3  of the first antiferromagnetic layer  430  and the first stray field applying layer  420  is equal to the first film plane area A 1  of the heavy metal layer  150 . A film plane area of the first block layer  410  is A 1 . Through simulation of the stray magnetic field Hs and  FIG. 4B , it is known that the horizontal direction stray magnetic field Hs (a magnetic field Hsx in  FIG. 4B ) sensed by the whole free layer  140  in  FIG. 4B  is more average, and a value of the vertical direction stray magnetic field Hs (a magnetic field Hsz in  FIG. 4B ) is smaller than the simulation of  FIG. 2  and  FIG. 3 . In detail, an average value of the magnetic field Hsx is smaller than the horizontal direction stray magnetic field Hs of the free layer  140  of  FIG. 2  and  FIG. 3 , and is greater than the horizontal direction stray magnetic field Hs of the free layer  140  of  FIG. 5 . The average value of the magnetic field Hsz is smaller than the vertical direction stray magnetic field Hs of the free layer  140  of  FIG. 2  and  FIG. 3 , and is greater than the vertical direction stray magnetic field Hs of the free layer  140  of  FIG. 5 . 
       FIG. 5  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device  500  according to a fourth embodiment of the disclosure. A difference between  FIG. 5  and  FIG. 2 ,  FIG. 3 ,  FIG. 4  is that the third film plane area A 3  of the first antiferromagnetic layer  530  and the first stray field applying layer  520  is greater than the first film plane area A 1  of the heavy metal layer  150 . The first block layer  510  has the first film plane area A 1 . In this way, through simulation of the stray magnetic field Hs, it is known that the horizontal direction stray magnetic field Hs sensed by the whole free layer  140  in  FIG. 5  is more average, and a value of the vertical direction stray magnetic field Hs is smaller than the simulation of  FIG. 2 ,  FIG. 3  and  FIG. 4 . In other words, an average value of the horizontal direction stray magnetic field Hs of the free layer  140  of  FIG. 5  is smaller than the horizontal direction stray magnetic field Hs of  FIG. 2  to  FIG. 4 , and an average value of the vertical direction stray magnetic field Hs of the free layer  140  of  FIG. 5  is also smaller than the horizontal direction stray magnetic field Hs of  FIG. 2  to  FIG. 4 . In this way, based on the simulation of  FIG. 2  to  FIG. 5 , in order to make the free layer  140  to have the even horizontal direction stray magnetic field Hs and avoid obtaining a larger vertical direction stray magnetic field Hs, the film plane area of the first antiferromagnetic layer and the first stray field applying layer is preferably to be greater than or equal to the film plane area of the heavy metal layer. 
     The first block layer, the first stray field applying layer and the first antiferromagnetic layer can also be disposed above the pinned layer  120  of the magnetic tunnel junction  110 , and structures of perpendicularly magnetized spin-orbit magnetic devices  600 ,  700 ,  800  of  FIG. 6  to  FIG. 8  are taken as examples for description.  FIG. 6  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device  600  according to a fifth embodiment of the disclosure. In the present embodiment, the first block layer  610  is disposed on the pinned layer  120  of the magnetic tunnel junction  110 . The first stray field applying layer  620  is disposed on the first block layer  610 , and the first antiferromagnetic layer  630  is disposed on the first stray field applying layer  620 . The first antiferromagnetic layer  630  defines a direction of the magnetic moment in the first stray field applying layer  620  to be parallel to the film plane (i.e. parallel to the XY plane), as shown by arrows  631  and  632 . An arrow  621  is used to indicate the direction of the magnetic moment in the first stray field applying layer  620 . Since the first stray field applying layer  620  is located away from the heavy metal layer  150 , the first block layer  610  is not required to block the spin current in the heavy metal layer  150  from influencing the first stray field applying layer  620 . However, the first block layer  610  is still required to block the first antiferromagnetic layer  630  from transferring the magnetic moment arrangement direction of the coupling layer  124  in the pinned layer  120 . Functions and materials of the first block layer  610 , the first stray field applying layer  620  and the first antiferromagnetic layer  630  are the same as that of the corresponding layers of  FIG. 2 . 
     In  FIG. 6 , the first stray field applying layer  620  and the first antiferromagnetic layer  630  have the same film plane area A 3 . It is assumed that the first block layer  610  has the second film plane area A 2 , and the third film plane area A 3  of the first stray field applying layer  620  and the first antiferromagnetic layer  630  is smaller than the second film plane area A 2  of the free layer  140 . Through the simulation of the stray magnetic field Hs, it is known that a magnetic field reception of the free layer  140  of  FIG. 6  is similar to the simulation of  FIG. 2 . In case of a more detailed comparison, the horizontal direction stray magnetic field Hs at the boundary of the free layer  140  of  FIG. 2  is slightly greater than the horizontal direction stray magnetic field Hs at the boundary of the free layer  140  of  FIG. 6 , and the vertical direction stray magnetic field Hs at the boundary of the free layer  140  of  FIG. 6  is slightly greater than the vertical direction stray magnetic field Hs at the boundary of the free layer  140  of  FIG. 2 . Namely, compared with the free layer  140  of  FIG. 6 , the free layer  140  of  FIG. 2  may effectively implement the spin transfer switching effect, and may slightly decrease the influence of the vertical direction stray magnetic field Hs. 
       FIG. 7A  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device  700  according to a sixth embodiment of the disclosure, and  FIG. 7B  is a simulation schematic diagram of the stray magnetic field Hs of the perpendicularly magnetized spin-orbit magnetic device  700  of  FIG. 7A . The first antiferromagnetic layer  730  defines a direction of the magnetic moment in the first stray field applying layer  720  to be parallel to the film plane, as shown by arrows  631  and  632 . The direction of the magnetic moment in the first stray field applying layer  720  is indicated by the arrow  621 . A difference between  FIG. 6  and  FIG. 7A  is that the third film plane area A 3  of the first antiferromagnetic layer  730  and the first stray field applying layer  720  is equal to the second film plane area A 2  of the magnetic tunnel junction  110 . The first block layer  710  has the second film plane area A 2 . The stray magnetic field Hs sensed by the free layer  140  of  FIG. 7A  may refer to the simulation waveform of  FIG. 7B . Through simulations of the stray magnetic field Hs in  FIG. 6  to  FIG. 8  and  FIG. 7B , it is known that the horizontal direction stray magnetic field Hs (a magnetic field Hsx in  FIG. 7B ) sensed by the whole free layer  140  in  FIG. 7B  is more average. In detail, the horizontal direction stray magnetic field Hs and the vertical direction stray magnetic field Hs at the boundary of the free layer  140  of  FIG. 7B  are all greater than the horizontal direction stray magnetic field Hs and the vertical direction stray magnetic field Hs at the boundary of the free layer  140  of  FIG. 6 , and are smaller than the horizontal direction stray magnetic field Hs and the vertical direction stray magnetic field Hs at the boundary of the free layer  140  of  FIG. 8 . 
       FIG. 8  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device  800  according to a seventh embodiment of the disclosure. The first antiferromagnetic layer  830  defines a direction of the magnetic moment in the first stray field applying layer  820  to be parallel to the film plane, as shown by arrows  631  and  632 . The direction of the magnetic moment in the first stray field applying layer  820  is indicated by the arrow  621 . A difference between  FIG. 6  and  FIG. 8  is that the third film plane area A 3  of the first antiferromagnetic layer  830  and the first stray field applying layer  820  is greater than the second film plane area A 2  of the magnetic tunnel junction  110 . The first block layer  810  has the second film plane area A 2 . Through simulation of the stray magnetic field Hs, it is known that the magnetic field sensed by the free layer  140  of  FIG. 8  is similar to the simulation of  FIG. 5 . Namely, the horizontal direction stray magnetic field Hs sensed by the whole free layer  140  in  FIG. 8  is more average and weaker compared to the horizontal direction stray magnetic field Hs of the free layer  140  in  FIG. 6 ,  FIG. 7 , and the vertical direction stray magnetic field Hs of the free layer  140  in  FIG. 8  is relatively less compared to the vertical direction stray magnetic field Hs of the free layer  140  in  FIG. 6 ,  FIG. 7 . In this way, based on the simulation of the stray magnetic field Hs of  FIG. 6  to  FIG. 8 , in order to make the free layer  140  to have the even horizontal direction stray magnetic field Hs and avoid obtaining a larger vertical direction stray magnetic field Hs, the film plane area of the first antiferromagnetic layer and the first stray field applying layer is preferably to be greater than or equal to the film plane area of the pinned layer  120 . 
     In the embodiment of the disclosure, the block layer, the stray field applying layer and the antiferromagnetic layer can also be disposed under the heavy metal layer  150  and above the pinned layer  120  of  FIG. 1 , so as to strengthen an intensity of the stray magnetic field in the free layer  140 . Even more, if sizes of the upper and lower stray field applying layers are properly adjusted, the vertical direction stray magnetic fields generated by the two stray field applying layers are probably counteracted, so as to decrease a chance of interfering the free layer  140 . 
       FIG. 9  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device  900  according to an eighth embodiment of the disclosure. In  FIG. 9 , the heavy metal layer  150  is disposed on the first block layer  910 , the first block layer  910  is disposed on the first stray field applying layer  920 , and the first stray field applying layer  920  is disposed on the first antiferromagnetic layer  930 . The first antiferromagnetic layer  930  defines a direction of the magnetic moment in the first stray field applying layer  920  to be parallel to the film plane, as shown by arrows  231  and  232 . The direction of the magnetic moment in the first stray field applying layer  920  is indicated by an arrow  221 . A second block layer  912  is disposed on the pinned layer  120  of the magnetic tunnel junction  110 , a second stray field applying layer  922  is disposed on the second block layer  912 , and a second antiferromagnetic layer  932  is disposed on the second stray field applying layer  922 . The second antiferromagnetic layer  932  defines a direction of the magnetic moment in the second stray field applying layer  922  to be parallel to the film plane, as shown by arrows  631  and  632 . The direction of the magnetic moment in the second stray field applying layer  922  is indicated by an arrow  621 . In this way, a magnetic intensity of a horizontal direction stray magnetic field Hs 1  generated by the first stray field applying layer  920  is added with a magnetic intensity of a horizontal direction stray magnetic field Hs 2  generated by the second stray field applying layer  922  in the horizontal direction, such that the free layer  140  may obtain the strongest intensity of the horizontal direction stray magnetic field Hs sensed by the free layer  140  in  FIG. 2  to  FIG. 9 . Comparatively, since the vertical direction stray magnetic field Hs 1  and the vertical direction stray magnetic field Hs 2  are opposite to each other, the two vertical direction stray magnetic fields Hs 1  and Hs 2  are slightly counteracted at the free layer  140  of  FIG. 9 . Namely, a value of the vertical direction stray magnetic field parallel to the Z-axis direction at the free layer  140  is decreased, so as to decrease a chance of interfering the free layer  140  when the free layer  140  implements the spin transfer switching effect. 
     In an embodiment of the disclosure, it is also deeply analysed whether the shape of the stray field applying layer and the shape of the free layer are interfered with each other to influence the stray magnetic field sensed by the free layer.  FIG. 10  is a simulation schematic diagram of the free layer  140  and the first stray field applying layer  220  implementing the stray magnetic field Hs according to the second embodiment of the disclosure. For simplicity&#39;s sake, only a left part of  FIG. 10  illustrates the free layer  140  and the first stray field applying layer  220  located below the heavy metal layer, and an upper right part of  FIG. 10  illustrates an intensity simulation diagram of the horizontal direction stray magnetic field Hsx generated by the first stray field applying layer  220 , and a lower right part of  FIG. 10  illustrates an intensity simulation diagram of the vertical direction stray magnetic field Hsz generated by the first stray field applying layer  220 . It is assumed that the shapes of the free layer  140  and the first stray field applying layer  220  are all rounds, a diameter of the free layer  140  is 300 nm, and a distance between the free layer  140  and the first stray field applying layer  220  is 5 nm. In the intensity simulation diagram of the horizontal direction stray magnetic field Hsx, a line L 1   x/a  line L 2   x/a  line L 3   x  respectively represent the horizontal direction stray magnetic fields Hsx generated when the diameter of the first stray field applying layer  220  is respectively 200 nm/300 nm/400 nm. In the intensity simulation diagram of the vertical direction stray magnetic field Hsz, a line L 1   z/a  line L 2   z/a  line L 3   z  respectively represent the vertical direction stray magnetic fields Hsz generated when the diameter of the first stray field applying layer  220  is respectively 200 nm/300 nm/400 nm. According to the simulation diagram of  FIG. 10 , it is known that the smaller the diameter of the first stray field applying layer  220  is, the larger the horizontal direction stray magnetic field Hsx at the boundary of the free layer  140  is, and the larger the interference of the vertical direction stray magnetic field Hsz is. Comparatively, the larger the diameter of the first stray field applying layer  220  is, the smaller the horizontal direction stray magnetic field Hsx at the boundary of the free layer  140  is, and the smaller the interference of the vertical direction stray magnetic field Hsz is. 
       FIG. 11  is another simulation schematic diagram of the free layer  140  and the first stray field applying layer  220  implementing the stray magnetic field Hs according to the second embodiment of the disclosure. Similar to  FIG. 10 , only a left part of  FIG. 11  illustrates the free layer  140  and the first stray field applying layer  220  located below the heavy metal layer, and an upper right part and a lower right part of  FIG. 11  respectively illustrate an intensity simulation diagram of the horizontal direction stray magnetic field Hsx and an intensity simulation diagram of the vertical direction stray magnetic field Hsz generated by the first stray field applying layer  220 . A difference between  FIG. 10  and  FIG. 11  is that the shape of the free layer  140  is a round, though the shape of the first stray field applying layer  220  is a square. In the intensity simulation diagram of the horizontal direction stray magnetic field Hsx, a line L 1   x/a  line L 2   x/a  line L 3   x  respectively represent the horizontal direction stray magnetic fields Hsx generated when a side length of the first stray field applying layer  220  is respectively 200 nm/300 nm/400 nm. In the intensity simulation diagram of the vertical direction stray magnetic field Hsz, a line L 1   z/a  line L 2   z/a  line L 3   z  respectively represent the vertical direction stray magnetic fields Hsz generated when the side length of the first stray field applying layer  220  is respectively 200 nm/300 nm/400 nm. Similar to  FIG. 10 , according to the simulation diagram of  FIG. 11 , it is known that the smaller the side length of the first stray field applying layer  220  is, the larger the horizontal direction stray magnetic field Hsx at the boundary of the free layer  140  is, and the larger the interference of the vertical direction stray magnetic field Hsz is. Comparatively, the larger the side length of the first stray field applying layer  220  is, the smaller the horizontal direction stray magnetic field Hsx at the boundary of the free layer  140  is, and the smaller the interference of the vertical direction stray magnetic field Hsz is. 
       FIG. 12  is a cross-sectional view of a structure of a perpendicularly magnetized spin-orbit magnetic device according to a ninth embodiment of the disclosure. The perpendicularly magnetized spin-orbit magnetic device  1000  in  FIG. 12  mainly includes an upper electrode  1260 , a cover layer  1270 , a magnetic tunnel junction  1210 , the heavy metal layer  150 , a first block layer  1210 , a first stray field applying layer  1220  and a first antiferromagnetic layer  1230 . The magnetic tunnel junction  1210  includes the pinned layer  120 , the tunneling barrier layer  130  and a free layer  1240 . The upper electrode  1260  can be a bit line or been connected to the bit line. The heavy metal layer  150  can be a word line or been connected to the word line. The pinned layer  120  is, for example, a material stacking layer of ferromagnet/non-magnetic metal/ferromagnet consisting of the lower pinned layer  126 , the coupling layer  124  and the upper pinned layer  122 . Functions and materials of the above layers are the same as that of the corresponding layers in the second embodiment of  FIG. 3 . A material of the upper electrode  1260  can be copper (Cu), aluminium (Ai), tantalum (Ta), . . . etc. or an alloy of the above elements. A thickness of the upper electrode  1260  can be 1 kÅ to 6 kÅ. The cover layer  1270  can be composed of an non-magnetic material such as Ta, titanium (Ti) . . . etc. or an alloy of the above elements. A thickness of the cover layer  1270  can be less than 1 kÅ. 
     A difference between  FIG. 3  and  FIG. 12  of the embodiments is that a film plane area A 1240  of the free layer  1240  is larger than the second film plane area A 2  of the lower pinned layer  126 . In detail, in order to avoid imperfections in part of the semiconductor process (e.g., a etching process), the residue remaining of the free layer  1240  in the semiconductor process may cross the heavy metal layer  150  and the lower pinned layer  126 , thereby causing the heavy metal layer  150  and the lower pinned layer  126  to be shorted to each other. Therefore, the third embodiment is designed such that the film plane area A 1240  of the free layer  1240  is larger than the second film plane area A 2  of the lower fixed layer  126 , so that the residue remaining of the free layer  1240  in the free layer  1240  does not come into contact with the heavy metal layer  150 . Thereby, the heavy metal layer  150  and the lower fixed layer  126  is prevented from being short to each other. In the ninth embodiment of  FIG. 12 , the film plane area A 1240  of the free layer  1240  is also greater than the second film plane area A 2  of the lower pinned layer  126 , the coupling layer  124 , the upper pinned layer  122  and/or a tunneling barrier layer  130 . From another point of view, a distance L between the boundary of the second film plane area A 2  of the lower pinned layer  126  and the boundary of the film plane area A 1240  of the free layer  1240  is designed to more than 0.1 μm and less than 1.0 μm. 
     If the film plane area A 1240  of the free layer  1240  is too large, the free layer  1240  will require a larger driving current to perform the spin-orbit-torque (SOT) mechanism. In order to prevent the film plane area A 1240  of the free layer  1240  from being excessively large and affecting the magnetic inversion characteristics of the perpendicularly magnetized spin-orbit magnetic device  1000 , it is designed to make the film plane area A 1240  of the free layer  1240  smaller than the third film plane area A 3  of the heavy metal layer  150  in the ninth embodiment. In other embodiments of the disclosure, it may not limited the relationship between the film plane area A 1240  of the free layer  1240  and the third film plane area A 3  of the first stray field applying layer  1220 . In other words, the film plane area A 1240  of the free layer  1240  may greater than the third film plane area A 3  of the first stray field applying layer  1220 , although it may require the larger driving current to perform the SOT mechanism. 
       FIG. 13  is another structure view of a of the perpendicularly magnetized spin-orbit magnetic devices according to the ninth embodiment of the disclosure. It includes four upper electrodes  1260  in strip shape extending in the Y-axis direction, twelve (3 times 4) perpendicularly magnetized spin-orbit magnetic devices (e.g., an element region  1001 , which is framed here by a dashed line, presents a partial structure of one of the perpendicularly magnetized spin-orbit magnetic devices), three heavy metal layers  150  in strip shape extending in the X-axis direction, and a layer  1310  carrying the above elements in the ninth embodiment of  FIG. 13 . The layer  1310  includes the first stray field applying layer  1220  and the first antiferromagnetic layer  1230 . A shape of the free layer  1240  is a round or an oval in  FIG. 13 ; a shape of each layer in the pinned layer  120  and a shape of the tunneling barrier layer  130  are also a round or an oval. The film plane area A 1240  of the free layer  1240  is larger than the second film plane area A 2  of the lower pinned layer  126 . In other words, the first stray field applying layer can cover a plurality of perpendicularly magnetized spin-orbit magnetic devices (e.g., twelve (3 times 4) perpendicularly magnetized spin-orbit magnetic devices in  FIG. 13 ). 
       FIG. 14  is the other structure view of the perpendicularly magnetized spin-orbit magnetic devices according to the ninth embodiment of the disclosure. A difference between  FIG. 2  and  FIG. 3  is that a shape of each of layers  1410  of  FIG. 14  is different from the shape of the layer  1310  of  FIG. 13 . Each of the four layers  1410  is composed of the first stray field applying layer  1220  and the first antiferromagnetic layer  1230 , and the shape of each of the four layers  1410  is a strip shape structure extending in the Y-axis direction (that is, extending along the bit line). That is, the extending direction of the first antiferromagnetic layer  1230  is perpendicular to the extending direction of the heavy metal layer  150 , and the first antiferromagnetic layer  1230  is disposed corresponding to the upper electrode  1260  (e.g., the bit line). 
     In summary, the perpendicularly magnetized spin-orbit magnetic device provided by the embodiments of the disclosure may spontaneously produce a stray closed magnetic circle to the free layer in the magnetic tunnel junction to provide the stray magnetic field through the antiferromagnetic layer, the block layer and the stray field applying layer, so as to provide a switching effect to a magnetic moment in the memory cell structure when an input current is input as that does of an external magnetic field. In this way, operation complexity of the perpendicularly magnetized spin-orbit magnetic device is simplified. Since the perpendicularly magnetized spin-orbit magnetic device itself may produce the stray magnetic field without using the external magnetic field, and magnetic moment switching of the free layer of the magnetic tunnel junction in the perpendicularly magnetized spin-orbit magnetic device can be implemented only by introducing the input current, the design complexity of the operation mechanism used for controlling the perpendicularly magnetized spin-orbit magnetic device can be greatly simplified. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosure without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.