Magnetic storage unit and preparation method thereof

Abstract

The invention provides a magnetic memory cell comprising a substrate layer which comprises two bottom electrodes arranged at an interval; the spin orbit moment layer is arranged on the upper surface of the substrate layer, and the spin orbit moment at least covers the two bottom electrodes; the magnetic tunnel junction is arranged on the upper surface of the spin orbit moment layer, and the magnetic tunnel junction at least covers the range where the two bottom electrodes are located. According to the magnetic storage unit and the preparation method thereof provided by the invention, a larger excessive etching window can be provided, the probability that the spin orbit moment layer is excessively etched and penetrated is reduced while short circuit caused by reverse sputtering is remarkably reduced, and the device yield is further improved.

Description

Technical Field

[0001] The present invention relates to the field of magnetic storage technology, and in particular to a magnetic storage unit and a preparation method thereof. Background Art

[0002] As the next generation of non-volatile magnetic random access memory, spin-orbit moment magnetic memory uses spin-orbit moment as a way to write information, making the spin-orbit moment device have a writing speed of ns. Its read and write separation mode makes it possible for the spin-orbit moment magnetic memory to achieve unlimited writing.

[0003] The existing STM memory cell architecture, whether two-terminal or three-terminal technology, is based on the magnetic tunnel junction etching stopping on the STM material. This architecture design has high requirements for etching, and this process directly affects the electrical performance of the device:

[0004] First, it is necessary to precisely control the film layer where etching stops to reduce the impact of etching damage on the performance of the spin-orbit moment layer. The spin-orbit moment layer is very thin, only a few nanometers, and it is easy to be etched through during excessive etching, resulting in a disconnection of the orbital layer and the device being scrapped;

[0005] Second, it is necessary to reduce the short circuit of the magnetic tunnel junction (reduce the metal back sputtering outside the barrier layer), and the defect rate of the device end must be at least 1000ppm before mass production is possible. Reducing short circuits is generally done by cutting the metal layer and then over-etching to remove the back sputtering, but the etching of the magnetic tunnel junction needs to stop on the spin-orbit moment layer. When the etching stops, the area outside the magnetic tunnel junction is all metal, which increases the difficulty of removing the metal back sputtering;

[0006] Third, since the distance between the bottom electrodes is usually larger than the diameter of the tunnel junction, most of the track layer is not effectively utilized. Instead, the memory generates higher heat and consumes more power during use due to the large resistance. Summary of the invention

[0007] The present invention provides a magnetic storage unit and a preparation method thereof, which can provide a larger over-etching window, significantly reduce the short circuit caused by back sputtering, and reduce the probability of the spin-orbit moment layer being penetrated by over-etching, thereby improving the device yield.

[0008] In a first aspect, the present invention provides a magnetic storage unit, comprising:

[0009] A substrate layer, the substrate layer comprising two bottom electrodes spaced apart;

[0010] A spin-orbit moment layer, disposed on the upper surface of the substrate layer, wherein the spin-orbit moment at least covers the two bottom electrodes;

[0011] A magnetic tunnel junction is arranged on the upper surface of the spin-orbit moment layer, and the magnetic tunnel junction at least covers the range where the two bottom electrodes are located.

[0012] Optionally, an edge of the magnetic tunnel junction is aligned with an edge of the spin-orbit moment layer.

[0013] Optionally, the magnetic tunnel junction includes a ferromagnetic layer, a barrier layer and a pinning layer, and the ferromagnetic layer is located above the track layer and in direct contact with the track layer.

[0014] Optionally, it also includes:

[0015] A hard mask layer is disposed on an upper surface of the magnetic tunnel junction, and an edge of the hard mask layer is aligned with an edge of the magnetic tunnel junction.

[0016] Optionally, it also includes:

[0017] A magnetic layer is disposed on the upper surface of the hard mask layer, and an edge of the magnetic layer is aligned with an edge of the hard mask layer.

[0018] Optionally, the magnetic moment direction of the magnetic layer is located in the plane of the magnetic layer or in the normal direction of the magnetic layer.

[0019] Optionally, the two bottom electrodes are arranged along the long axis direction of the spin-orbit moment, or the arrangement direction of the two bottom electrodes has an angle with the long axis direction.

[0020] Optionally, the magnetic moment direction of the free layer of the magnetic tunnel junction is arranged along the long axis direction of the free layer, or the magnetic moment direction of the free layer of the magnetic tunnel junction is arranged along the normal direction of the free layer.

[0021] In a second aspect, the present invention further provides a method for preparing a magnetic storage unit, the method comprising:

[0022] providing a substrate layer having two bottom electrodes;

[0023] forming a spin-orbit moment layer and a magnetic tunnel junction in sequence on the substrate layer;

[0024] The magnetic tunnel junction and the spin-orbit moment layer are etched once using the same mask, and the etching end point is controlled to be no higher than the lower surface of the spin-orbit moment.

[0025] Optionally, etching the magnetic tunnel junction and the spin-orbit moment layer once using the same mask comprises:

[0026] forming a hard mask layer on the upper surface of the magnetic tunnel junction;

[0027] The hard mask layer, the magnetic tunnel junction and the spin-orbit moment layer are etched once using the same mask, and the etching end point is controlled not to be higher than the lower surface of the spin-orbit moment.

[0028] Optionally, etching the hard mask layer, the magnetic tunnel junction and the spin-orbit moment layer once using the same mask comprises:

[0029] forming a magnetic layer on the upper surface of the hard mask layer;

[0030] The magnetization layer, the hard mask layer, the magnetic tunnel junction and the spin-orbit moment layer are etched once using the same mask, and the etching end point is controlled not to be higher than the lower surface of the spin-orbit moment.

[0031] In the technical solution provided by the present invention, the magnetic tunnel junction and the spin-orbit moment layer are covered with two bottom electrodes, which can effectively provide a larger over-etching window, significantly reduce the short circuit caused by back sputtering, and reduce the probability of the spin-orbit moment layer being penetrated due to over-etching, thereby improving the device yield; at the same time, since the magnetic tunnel junction and the spin-orbit moment layer are covered with two bottom electrodes, the distance between the two bottom electrodes can be reduced during preparation, which is conducive to shortening the length of the spin-orbit moment layer, reducing energy consumption, reducing the thermal effect of current, and thereby improving the device life. In addition, the magnetic storage unit provided by the present invention has strong compatibility and can be directly connected to the lower metal layer to reduce the series resistance in the loop. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A structural diagram of a magnetic storage unit according to an embodiment of the present invention;

[0033] Figure 2 for Figure 1 A top view of

[0034] Figure 3 A structural diagram of a magnetic storage unit according to another exemplary embodiment of the present invention;

[0035] Figure 4 A structural diagram of a magnetic storage unit according to another exemplary embodiment of the present invention;

[0036] Figure 5 A structural diagram of a magnetic storage unit according to another exemplary embodiment of the present invention;

[0037] Figure 6 for Figure 5 A top view of

[0038] Figure 7 A flow chart of a method for preparing a magnetic storage unit according to another embodiment of the present invention;

[0039] Figure 8 A substrate structure in a method for preparing a magnetic storage unit according to another exemplary embodiment of the present invention;

[0040] Fig. 9 A structure for preparing a through hole on a substrate in a method for preparing a magnetic storage unit in another exemplary embodiment of the present invention;

[0041] Fig.10 A structure after preparing a bottom electrode in a method for preparing a magnetic storage unit according to another exemplary embodiment of the present invention;

[0042] Fig.11 The structure after preparing the spin-orbit moment layer, the magnetic tunnel junction, the hard mask and the magnetization layer in the method for preparing a magnetic storage unit in another exemplary embodiment of the present invention;

[0043] Fig.12 The structure after etching the spin-orbit moment layer, the magnetic tunnel junction, the hard mask and the magnetization layer in the method for preparing a magnetic storage unit in another exemplary embodiment of the present invention;

[0044] Fig.13 A structure after depositing a medium and planarizing in a method for preparing a magnetic storage unit according to another exemplary embodiment of the present invention;

[0045] Fig.14 A structure after preparing a top electrode in a method for preparing a magnetic storage unit according to another exemplary embodiment of the present invention;

[0046] Fig.15 A substrate structure in a method for preparing a magnetic storage unit according to another exemplary embodiment of the present invention;

[0047] Fig.16 A structure for preparing a through hole on a substrate in a method for preparing a magnetic storage unit in another exemplary embodiment of the present invention;

[0048] Fig.17 A structure after preparing a bottom electrode in a method for preparing a magnetic storage unit according to another exemplary embodiment of the present invention;

[0049] Fig.18 The structure after preparing the spin-orbit moment layer, the magnetic tunnel junction, the hard mask and the magnetization layer in the method for preparing a magnetic storage unit in another exemplary embodiment of the present invention;

[0050] Fig.19 The structure after etching the spin-orbit moment layer, the magnetic tunnel junction, the hard mask and the magnetization layer in the method for preparing a magnetic storage unit in another exemplary embodiment of the present invention;

[0051] Fig. 20 A structure after depositing a medium and planarizing in a method for preparing a magnetic storage unit according to another exemplary embodiment of the present invention;

[0052] Fig.21A structure after preparing a top electrode in a method for preparing a magnetic storage unit according to another exemplary embodiment of the present invention;

[0053] Fig. 22 A substrate structure in a method for preparing a magnetic storage unit according to another exemplary embodiment of the present invention;

[0054] Fig.23 A structure for preparing a through hole on a substrate in a method for preparing a magnetic storage unit in another exemplary embodiment of the present invention;

[0055] Fig.24a A structure after preparing a bottom electrode in a method for preparing a magnetic storage unit according to another exemplary embodiment of the present invention;

[0056] Figure 24b for Fig.24a A top view of

[0057] Fig.25 The structure after preparing the spin-orbit moment layer, the magnetic tunnel junction and the hard mask in the method for preparing a magnetic storage unit in another exemplary embodiment of the present invention;

[0058] Fig.26 The structure after etching the spin-orbit moment layer, the magnetic tunnel junction and the hard mask in the method for preparing a magnetic storage unit in another exemplary embodiment of the present invention;

[0059] Fig. 27 A structure after depositing a medium and planarizing in a method for preparing a magnetic storage unit according to another exemplary embodiment of the present invention;

[0060] Fig.28 This is a structure after preparing a top electrode in a method for preparing a magnetic storage unit according to another exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] An embodiment of the present invention provides a magnetic storage unit, such as Figure 1-2 As shown, including:

[0063] A substrate layer, the substrate layer comprising two bottom electrodes 1 arranged at intervals;

[0064] In some embodiments, the substrate layer generally includes two bottom electrodes 1 and a dielectric, the top surfaces of the bottom electrode 1 and the dielectric have the same height, and the bottom electrode material is a metal material such as W, TiN, Ta, or TaN.

[0065] A spin-orbit moment layer 2, arranged on the upper surface of the substrate layer, wherein the spin-orbit moment at least covers the two bottom electrodes 1;

[0066] In some embodiments, the spin-orbit moment layer 2 is generally made of heavy metals or topological materials with large spin Hall angles, such as W, Ta, Pt or BiSe.

[0067] A magnetic tunnel junction 3 is arranged on the upper surface of the spin-orbit moment layer 2 , and the magnetic tunnel junction 3 at least covers the range where the two bottom electrodes 1 are located.

[0068] In some embodiments, the tunnel junction generally includes a stacked structure formed by a free layer, a barrier layer, and a reference layer, and the free layer is located at the bottom layer of the tunnel junction.

[0069] In the technical solution provided in this embodiment, the magnetic tunnel junction 3 and the spin-orbit moment layer 2 both cover the two bottom electrodes 1, which can effectively provide a larger over-etching window, significantly reducing the short circuit caused by back sputtering, and reducing the probability of the spin-orbit moment layer 2 being penetrated due to over-etching, thereby improving the device yield; at the same time, since the magnetic tunnel junction 3 and the spin-orbit moment layer 2 both cover the two bottom electrodes 1, during preparation, the distance between the two bottom electrodes 1 can be reduced, which is conducive to shortening the length of the spin-orbit moment layer 2, reducing energy consumption, reducing the thermal effect of current, and thereby improving the device life. In addition, the magnetic storage unit provided by the present invention has strong compatibility and can be directly connected to the lower metal layer to reduce the series resistance in the loop.

[0070] As an optional implementation, the edge of the magnetic tunnel junction 3 is aligned with the edge of the spin-orbit moment layer 2 .

[0071] In some embodiments, the edge of the magnetic tunnel junction 3 is aligned with the edge of the spin-orbit moment, so that the etching of the magnetic tunnel junction 3 and the spin-orbit moment can be completed in one etching process during the processing, which can effectively simplify the preparation process.

[0072] As an optional implementation, the magnetic tunnel junction includes a ferromagnetic layer, a barrier layer and a pinning layer, and the ferromagnetic layer is located above the track layer and in direct contact with the track layer.

[0073] As an optional implementation, it also includes:

[0074] A hard mask layer 4 is disposed on the upper surface of the magnetic tunnel junction 3 , and an edge of the hard mask layer 4 is aligned with an edge of the magnetic tunnel junction 3 .

[0075] In some embodiments, the hard mask material is Ta, TaN, TiN, etc. The edge of the hard mask layer 4 and the edge of the magnetic tunnel junction 3 are aligned with the edge of the spin-orbit moment, and the etching of the hard mask layer 4, the magnetic tunnel junction 3 and the spin-orbit moment can be completed in one etching process, which can effectively simplify the preparation process.

[0076] As an optional implementation, it also includes:

[0077] The magnetic layer 6 is disposed on the upper surface of the hard mask layer 4 , and the edge of the magnetic layer 6 is aligned with the edge of the hard mask layer 4 .

[0078] In some embodiments, the material of the magnetic layer 6 is a metal material such as Co, Fe, etc. The edges of the magnetic layer 6, the hard mask layer 4, and the magnetic tunnel junction 3 are aligned with the edge of the spin-orbit moment, and the etching of the magnetic layer 6, the hard mask layer 4, the magnetic tunnel junction 3, and the spin-orbit moment can be completed in one etching process, which can effectively simplify the preparation process.

[0079] As an optional implementation, the magnetic moment direction of the magnetic layer 6 is located in the plane of the magnetic layer 6 or in the normal direction of the magnetic layer 6 .

[0080] As an optional implementation, the two bottom electrodes 1 are arranged along the long axis direction of the spin-orbit moment, or the arrangement direction of the two bottom electrodes 1 forms an angle with the long axis direction.

[0081] As an optional implementation, the magnetic moment direction of the free layer of the magnetic tunnel junction 3 is arranged along the long axis direction of the free layer, or the magnetic moment direction of the free layer of the magnetic tunnel junction 3 is arranged along the normal direction of the free layer.

[0082] like Figure 3 As shown, an exemplary implementation is provided to exemplarily illustrate the technical solution of the present invention. Figure 3 The magnetic storage unit in the invention comprises:

[0083] It is composed of a bottom electrode 1, a spin-orbit moment layer 2, a tunnel junction 3, a metal hard mask 4, an optional horizontal magnetization layer 6 and a top electrode 5 arranged in sequence from bottom to top. Among them, the spin-orbit moment layer 2, the tunnel junction 3, the metal hard mask 4, and the optional horizontal magnetization layer 6 have the same phase shape and are formed by one etching. The shape after etching is a long strip shape, and the bottom electrode 1 is covered by the tunnel junction. Among them, the magnetization direction of the magnetic tunnel junction 3 is along the direction perpendicular to the wafer substrate (Z), and the optional horizontal magnetization layer 6 has a magnetization direction along the x direction, which provides a bias field for the magnetic tunnel junction 3, and can realize the tunnel junction flipping without an external field. In this device, the long axis of the tunnel junction is along the write current direction (x), and current is passed through the two bottom electrodes 1 to generate a spin current with a magnetic moment direction along the y direction. Combined with the horizontal magnetic field generated by the horizontal magnetization layer 600, the device write operation can be realized. Passing current through the bottom electrode 1 and the top electrode 5 at one end can realize the device read operation. As a preferred embodiment, the material of the bottom electrode 100 is W, and the characteristic size is 40nm; the spin-orbit moment layer 200 is W, and the thickness is 3-5nm; the free layer\medium\reference layer materials of the magnetic tunnel junction 300 are CoFeB, MgO, CoFeB, and the thickness of the free layer is 1-2nm; the size of the magnetic tunnel junction 300 is 300nm*60nm.

[0084] like Figure 4 As shown, an exemplary implementation is provided to exemplarily illustrate the technical solution of the present invention. Figure 4 The magnetic storage unit in the invention comprises:

[0085] It is composed of a bottom electrode 1, a spin-orbit moment layer 2, a tunnel junction 3, a metal hard mask 4, an optional vertical magnetization layer 6 and a top electrode 5 arranged in sequence from bottom to top. The spin-orbit moment layer 2, the tunnel junction 3, the metal hard mask 4 and the optional vertical magnetization layer 6 have the same phase shape and are formed by one etching. The shape after etching is a long strip shape, and the bottom electrode 1 is covered by the tunnel junction. The magnetic storage unit is a type-X type spin-orbit moment magnetic storage device. The magnetization direction of the magnetic tunnel junction 3 is along the direction of the wafer substrate surface (X). The optional horizontal magnetization layer 6 has a magnetization direction along the Z direction, which provides a bias field for the magnetic tunnel junction 3 and can achieve no external field flipping. In the device, the long axis of the tunnel junction is along the write current direction (X). When current is passed through the two bottom electrodes 1, a spin current with a magnetic moment along the y direction can be generated on the upper surface of the track layer. The write operation of the device can be realized by combining the Z-direction magnetic field generated by the vertical magnetization layer 6. When current is passed through the bottom electrode 1 and the top electrode 5 at one end, the read operation of the device can be realized. As a preferred embodiment, the material of the bottom electrode 1 is W, and the characteristic size is 50nm; the spin-orbit moment layer 200 is W, and the thickness is 3-5nm; the free layer\medium\reference layer materials of the magnetic tunnel junction 300 are CoFeB, MgO, CoFeB, and the thickness of the free layer is 2-4nm; the size of the magnetic tunnel junction 300 is 300nm*60nm.

[0086] like Figure 5-6 As shown, an exemplary implementation is provided to exemplarily illustrate the technical solution of the present invention. Figure 5-6 The magnetic storage unit in the invention comprises:

[0087] It is composed of a bottom electrode 1, a spin-orbit moment layer 2, a tunnel junction layer 3, a metal hard mask layer 4 and a top electrode 5 arranged in sequence from bottom to top. Among them, the spin-orbit moment layer 2, the tunnel junction layer 3 and the metal hard mask layer 4 have the same shape and are formed by one etching. The shape after etching is a long strip shape, and the bottom electrode 1 is covered by the tunnel junction. In this structure, there is a certain angle between the center line of the two bottom electrodes 1 and the X direction. Among them, the magnetization direction of the magnetic tunnel junction 3 is perpendicular to the surface direction of the wafer substrate (along the Z direction); the long axis of the tunnel junction is along the X direction. After the write current is passed, the generated spin current has an angle with the X direction. In this case, no external magnetic field is required to realize the write operation of the device. By passing current through the bottom electrode 1 and the top electrode 5 at one end, the read operation of the device can be realized; as a preferred embodiment, the material of the bottom electrode 1 is W, and the characteristic size is 50nm; the spin-orbit moment layer 200 is W, and the thickness is 3-5nm; the free layer\medium\reference layer materials of the magnetic tunnel junction 300 are CoFeB, MgO, CoFeB, and the thickness of the free layer is 1-2nm; the MTJ size is 300nm*100nm.

[0088] The present invention also provides a method for preparing a magnetic storage unit. Figure 7 As shown, the method includes:

[0089] Step 710, providing a substrate layer, wherein the substrate layer has two bottom electrodes;

[0090] Step 720, sequentially forming a spin-orbit moment layer and a magnetic tunnel junction on the substrate layer;

[0091] Step 730: Use the same mask to etch the magnetic tunnel junction and the spin-orbit moment layer once, and control the etching end point to be no higher than the lower surface of the spin-orbit moment.

[0092] As an optional implementation manner, the magnetic tunnel junction and the spin-orbit moment layer are etched once using the same mask, comprising:

[0093] forming a hard mask layer on the upper surface of the magnetic tunnel junction;

[0094] The hard mask layer, the magnetic tunnel junction and the spin-orbit moment layer are etched once using the same mask, and the etching end point is controlled not to be higher than the lower surface of the spin-orbit moment.

[0095] As an optional implementation manner, the hard mask layer, the magnetic tunnel junction, and the spin-orbit moment layer are etched once using the same mask, including:

[0096] forming a magnetic layer on the upper surface of the hard mask layer;

[0097] The magnetization layer, the hard mask layer, the magnetic tunnel junction and the spin-orbit moment layer are etched once using the same mask, and the etching end point is controlled not to be higher than the lower surface of the spin-orbit moment.

[0098] like Figure 8-14 As shown, an exemplary implementation is provided to exemplarily illustrate the technical solution of the present invention. Figure 8-14 The method for preparing a magnetic storage unit comprises:

[0099] like Figure 8 As shown, dielectric layers 7 and 8 are deposited on a substrate forming a bottom electrode 9; the material of the bottom electrode 9 is generally Cu, Ta, TaN, TiN, etc., the material of the dielectric layer 7 is SiN, SiNC, Al2O3, etc., and the material of the dielectric 8 is SiO2, SiCO, etc.;

[0100] like Fig. 9 As shown, the bottom electrode through hole is prepared by photolithography and etching.

[0101] like Fig.10 As shown, the bottom electrode material is deposited and planarized to prepare the bottom electrode 1. The material of the bottom electrode can be a metal material such as W, TiN, TaN, etc. The planarization process can be achieved by chemical mechanical grinding or etching.

[0102] like Fig.11 As shown, a spin-orbit moment layer 2, a tunnel junction 3, a hard mask 4 and an optional horizontal magnetization layer are deposited 6. The spin-orbit moment layer is made of materials with a self-selected Hall angle such as W, Pt, Ta, etc., and the optional horizontal magnetization layer is made of magnetic materials such as Co, Fe, CoFe, CoPt, FeNi, etc.;

[0103] like Fig.12 As shown, the tunnel junction is photolithographically and etched to obtain a tunnel junction of a desired shape, and a dielectric protection layer 10 is deposited. After etching, the tunnel junction is in the shape of a long strip. The material of the dielectric protection layer 10 can be SiN, SiNC and other materials.

[0104] like Fig.13 As shown, a dielectric layer 11 is deposited and planarized. The material of the dielectric layer 11 is SiO2, SiCO, etc.

[0105] like Fig.14 As shown, photolithography, etching, top electrode material filling and planarization are performed to prepare the top electrode 5. Usually, the material of the top electrode is a metal material such as Cu, W, TaN, etc.

[0106] like Figure 15-21 As shown, an exemplary implementation is provided to exemplarily illustrate the technical solution of the present invention. Figure 15-21 The method for preparing a magnetic storage unit comprises:

[0107] like Fig.15 As shown, dielectric layers 7 and 8 are deposited on a substrate forming a bottom electrode 9; the material of the bottom electrode 9 is generally Cu, Ta, TaN, TiN, etc., the material of the dielectric layer 7 is SiN, SiNC, Al2O3, etc., and the material of the dielectric 8 is SiO2, SiCO, etc.;

[0108] like Fig.16 As shown, photolithography and etching are performed to prepare bottom electrode through holes;

[0109] like Fig.17 As shown, the bottom electrode material is deposited and planarized to prepare the bottom electrode 1. The material of the bottom electrode can be a metal material such as W, TiN, TaN, etc. The planarization process can be achieved by chemical mechanical grinding or etching;

[0110] like Fig.18 As shown, a spin-orbit moment layer 2, a tunnel junction 3, a hard mask 4 and an optional horizontal magnetization layer are deposited 6. The spin-orbit moment layer is made of materials with a self-selected Hall angle such as W, Pt, Ta, BiSe, etc., and the optional horizontal magnetization layer is made of a magnetic material such as FePt or CoPt multilayer film or other magnetic multilayer film or alloy;

[0111] like Fig.19 As shown, the tunnel junction is photolithographically and etched to obtain a tunnel junction of a desired shape, and a dielectric protection layer is deposited. After etching, the shape of the tunnel junction is elliptical. The material of the dielectric protection layer 10 can be SiN, SiNC and other materials.

[0112] like Fig. 20 As shown, a dielectric layer 11 is deposited and planarized. The material of the dielectric layer 11 is SiO2, SiCO, etc.

[0113] like Fig.21 As shown, photolithography, etching, top electrode material filling and planarization are performed to prepare the top electrode 5. Usually, the material of the top electrode is a metal material such as Cu, W, TaN, etc.

[0114] like Figure 22-28 As shown, an exemplary implementation is provided to exemplarily illustrate the technical solution of the present invention. Figure 22-28 The method for preparing a magnetic storage unit comprises:

[0115] like Fig. 22As shown, dielectric layers 7 and 8 are deposited on the substrate forming the bottom electrode 9; the material of the bottom electrode 7 is usually Cu, Ta, TaN, TiN, etc., the material of the dielectric layer 8 is SiN, SiNC, Al2O3, etc., and the material of the dielectric 25 is SiO2, SiCO, etc.;

[0116] like Fig.23 As shown, photolithography and etching are performed to prepare bottom electrode through holes;

[0117] like Fig.24a As shown, the bottom electrode material is deposited and planarized to prepare the bottom electrode 1. The material of the bottom electrode can be a metal material such as W, TiN, TaN, etc. The planarization process can be achieved by chemical mechanical grinding or etching; Figure 24b As shown, in this structure, there is a certain angle between the center line of the two bottom electrodes and the X direction.

[0118] like Fig.25 As shown, a spin-orbit moment layer 2, a tunnel junction 3 and a hard mask 4. The spin-orbit moment layer is made of materials such as W, Pt, Ta, etc. with a self-selected Hall angle;

[0119] like Fig.26 As shown, the tunnel junction is photolithographically and etched to obtain a tunnel junction of the desired shape, and a dielectric protection layer is deposited. After etching, the tunnel junction is in the shape of a long strip. The material of the dielectric protection layer 10 can be SiN, SiNC and other materials.

[0120] like Fig. 27 As shown, a dielectric layer 11 is deposited and planarized. The material of the dielectric layer 11 is SiO2, SiCO, etc.

[0121] like Fig.28 As shown, photolithography, etching, top electrode material filling and planarization are performed to prepare the top electrode 5. Usually, the material of the top electrode is a metal material such as Cu, W, TaN, etc.

[0122] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A magnetic storage unit, characterized in that: include: A substrate layer, the substrate layer comprising two bottom electrodes spaced apart; A spin-orbit moment layer, disposed on the upper surface of the substrate layer, the spin-orbit moment layer at least covering the two bottom electrodes; A magnetic tunnel junction is arranged on the upper surface of the spin-orbit moment layer, and the magnetic tunnel junction at least covers the range where the two bottom electrodes are located.

2. The magnetic storage unit according to claim 1, characterized in that The edge of the magnetic tunnel junction is aligned with the edge of the spin-orbit moment layer.

3. The magnetic storage unit according to claim 1, characterized in that The magnetic tunnel junction includes a ferromagnetic layer, a barrier layer and a pinning layer. The ferromagnetic layer is located above the track layer and directly contacts the track layer.

4. The magnetic storage unit according to claim 1, characterized in that Also includes: A hard mask layer is disposed on an upper surface of the magnetic tunnel junction, and an edge of the hard mask layer is aligned with an edge of the magnetic tunnel junction.

5. The magnetic storage unit according to claim 4, characterized in that Also includes: A magnetic layer is disposed on the upper surface of the hard mask layer, and an edge of the magnetic layer is aligned with an edge of the hard mask layer.

6. The magnetic storage unit according to claim 5, characterized in that The magnetic moment direction of the magnetic layer is located in the plane of the magnetic layer or in the normal direction of the magnetic layer.

7. The magnetic storage unit according to claim 1, characterized in that The two bottom electrodes are arranged along the long axis direction of the spin-orbit moment, or the arrangement direction of the two bottom electrodes forms an angle with the long axis direction.

8. The magnetic storage unit according to claim 1, characterized in that The magnetic moment direction of the free layer of the magnetic tunnel junction is arranged along the long axis direction of the free layer, or the magnetic moment direction of the free layer of the magnetic tunnel junction is arranged along the normal direction of the free layer.

9. A method for preparing a magnetic storage unit, characterized in that: The method comprises: providing a substrate layer having two bottom electrodes; forming a spin-orbit moment layer and a magnetic tunnel junction in sequence on the substrate layer; The magnetic tunnel junction and the spin-orbit moment layer are etched once using the same mask, and the etching end point is controlled to be no higher than the lower surface of the spin-orbit moment.

10. The method according to claim 9, characterized in that The etching of the magnetic tunnel junction and the spin-orbit moment layer once using the same mask comprises: forming a hard mask layer on the upper surface of the magnetic tunnel junction; The hard mask layer, the magnetic tunnel junction and the spin-orbit moment layer are etched once using the same mask, and the etching end point is controlled not to be higher than the lower surface of the spin-orbit moment.

11. The method according to claim 10, characterized in that The hard mask layer, the magnetic tunnel junction and the spin-orbit moment layer are etched once using the same mask, comprising: forming a magnetic layer on the upper surface of the hard mask layer; The magnetization layer, the hard mask layer, the magnetic tunnel junction and the spin-orbit moment layer are etched once using the same mask, and the etching end point is controlled not to be higher than the lower surface of the spin-orbit moment.

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