Magnetic memory device and method of making the same

Abstract

This application provides a magnetic storage device and a method for fabricating the same. The method includes: forming a sacrificial layer on a substrate, the sacrificial layer having a first groove penetrating the sacrificial layer; forming a magnetic tunneling junction stack, a first electrode layer, and a first dielectric layer within the first groove, the magnetic tunneling junction stack located on the sides and bottom of the first groove, the first electrode layer covering the magnetic tunneling junction stack, and the first dielectric layer covering the first electrode layer and filling the remaining portion of the first groove; removing the sacrificial layer to expose both ends of the magnetic tunneling junction stack; and at least removing both ends of the magnetic tunneling junction stack, with the remaining magnetic tunneling junction stack forming a magnetic tunneling junction, and the first electrode layer forming a first electrode. This method aims to reduce sidewall metal redeposition and improve sidewall morphology.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to a magnetic storage device and a method for its fabrication. Background Technology

[0002] With the widespread use of portable computing devices and wireless communication devices, the demand for high-density, low-power non-volatile memory is increasing. Magnetic random access memory (MRAM) has become one of the important technological directions for realizing non-volatile random access memory (NV-RAM) due to its advantages such as non-volatility, high read / write speed, and low power consumption.

[0003] The magnetic tunneling junction (MTJ) is the core memory cell of MRAM devices, and its fabrication process has a significant impact on device performance, reliability, and yield. A typical structure of a device with a MTJ includes a bottom electrode, a reference layer, a barrier layer, a free layer, and a top electrode. The magnetization direction of the reference layer is fixed, while the magnetization direction of the free layer can switch between two states: when parallel, the device exhibits a low-resistance state and can store data "1"; when antiparallel, it exhibits a high-resistance state and can store data "0".

[0004] However, the sidewalls of magnetic storage devices are prone to redeposition, resulting in poor sidewall morphology. Summary of the Invention

[0005] This application provides magnetic storage devices and their fabrication methods to reduce sidewall metal redeposition and improve sidewall morphology.

[0006] In a first aspect, embodiments of this application provide a method for fabricating a magnetic storage device, comprising:

[0007] A sacrificial layer is formed on a substrate, the sacrificial layer having a first groove that penetrates the sacrificial layer;

[0008] A magnetic tunneling stack, a first electrode layer, and a first dielectric layer are formed in the first groove. The magnetic tunneling stack is located on the side and bottom of the first groove. The first electrode layer covers the magnetic tunneling stack, and the first dielectric layer covers the first electrode layer and fills the remaining first groove.

[0009] Remove the sacrificial layer to expose both ends of the magnetic tunneling stack;

[0010] At least both ends of the magnetic tunnel junction stack are removed, and the remaining magnetic tunnel junction stack forms a magnetic tunnel junction, and the first electrode layer forms a first electrode.

[0011] In some possible implementations, the ends of the magnetic tunneling stack are removed by tilting or lateral etching.

[0012] In some possible implementations, the magnetic tunneling stack includes a side portion and a middle portion, the side portion being opposite to the side surface of the first groove, and the middle portion being opposite to the bottom surface of the first groove and connected to the side portion;

[0013] Removing both ends of the magnetic tunneling stack includes: removing all the sides of the magnetic tunneling stack while retaining the middle portion of the magnetic tunneling stack.

[0014] In some possible implementations, the sides of the first groove are inclined, and the width of the opening of the first groove is smaller than the width of the bottom of the first groove.

[0015] The magnetic tunnel stack includes a side portion and a middle portion. The side portion is opposite to the side surface of the first groove, and the middle portion is opposite to the bottom surface of the first groove and is spaced apart from the side portion.

[0016] Removing both ends of the magnetic tunneling stack includes: removing the ends of the middle portion of the magnetic tunneling stack while retaining the middle portion of the middle portion of the magnetic tunneling stack.

[0017] In some possible implementations, a magnetic tunneling stack, a first electrode layer, and a first dielectric layer are formed within the first groove, including:

[0018] A magnetic tunneling stack is deposited, the magnetic tunneling stack covering the sides and bottom of the first groove, and the sacrificial layer;

[0019] A first electrode layer is deposited, which covers the magnetic tunneling stack;

[0020] A first dielectric layer is deposited, which covers the first electrode layer. The sum of the thicknesses of the first dielectric layer and the first electrode layer is greater than or equal to the depth of the first groove.

[0021] The magnetic tunneling stack, the first electrode layer, and the first dielectric layer are ground until the sacrificial layer is exposed.

[0022] In some possible implementations, before forming the magnetic tunnel junction stack, the first electrode layer, and the first dielectric layer within the first groove, the method further includes:

[0023] A spin orbital matrix layer is formed in the first groove, the spin orbital matrix layer covers the sidewalls and bottom wall of the first groove, and the magnetic tunneling stack is covered on the spin orbital matrix layer;

[0024] Removing both ends of the magnetic tunneling stack also includes:

[0025] Remove both ends of the spin orbital matrix, and stack the remaining spin orbital matrix and the magnetic tunnel junction in a direction away from the substrate.

[0026] In some possible implementations, after removing both ends of the magnetic tunneling stack, the method further includes:

[0027] A second dielectric layer is formed, which covers the magnetic tunnel junction, the first electrode, and the first dielectric layer;

[0028] A third dielectric layer is formed, which covers the second dielectric layer;

[0029] Remove part of the third dielectric layer to expose the second dielectric layer above the first dielectric layer;

[0030] Part of the second medium layer is removed, while the first medium layer is retained, wherein the removal rate of the second medium layer is greater than the removal rate of the third medium layer;

[0031] Remove at least a portion of the first dielectric layer to expose the first electrode.

[0032] In some possible implementations, a sacrificial layer is formed on the substrate, including:

[0033] Provide substrate;

[0034] A fourth dielectric layer is formed, which covers the top surface of the substrate. The fourth dielectric layer also has a plug that contacts the substrate and is exposed on the top surface of the fourth dielectric layer.

[0035] A sacrificial layer is deposited, which covers the top surface of the fourth dielectric layer and the plug;

[0036] A portion of the sacrificial layer is removed to form the first groove, in which at least a portion of the plug is exposed.

[0037] Secondly, embodiments of this application provide a magnetic storage device, including:

[0038] Substrate;

[0039] A magnetic tunnel junction is disposed on the substrate;

[0040] The first electrode is disposed on the side of the magnetic tunnel junction away from the substrate;

[0041] The magnetic tunnel junction is formed by forming a magnetic tunnel junction stack in the first groove of the sacrificial layer, and then removing the two ends of the magnetic tunnel junction stack after removing the sacrificial layer.

[0042] In some possible implementations, the sidewalls of at least one of the magnetic tunnel junction and the first electrode are inclined or convex relative to the top surface of the substrate.

[0043] The magnetic storage device and its fabrication method provided in this application involve forming a sacrificial layer with a penetrating first groove on a substrate, and sequentially forming a magnetic tunnel junction stack, a first electrode layer, and a first dielectric layer within the first groove, with the magnetic tunnel junction stack facing the sides and bottom of the first groove. After removing the sacrificial layer, the two ends of the magnetic tunnel junction stack are exposed. At least the two ends of the magnetic tunnel junction stack are removed by local etching or end trimming, leaving only the middle magnetic tunnel junction stack as the final magnetic tunnel junction. The fabrication process requires no additional processing equipment and is simple. The sacrificial layer provides the basic structure for the formation of the magnetic tunnel junction stack, and the subsequent removal of the sacrificial layer exposes the magnetic tunnel junction stack, facilitating the modification of the two ends of the subsequent magnetic tunnel junction stack to form a magnetic tunnel junction. This reduces sidewall metal re-deposition, improves sidewall morphology, achieves size miniaturization, simplifies the fabrication process, and improves device performance. Attached Figure Description

[0044] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0045] Figure 1 A flowchart illustrating the fabrication method of the magnetic storage device provided in this application;

[0046] Figure 2 This is a schematic diagram showing the formation of the fourth dielectric layer provided in this application;

[0047] Figure 3 This is a schematic diagram showing the formation of the filled hole as provided in this application;

[0048] Figure 4 This application provides a schematic diagram showing the plug after it has been formed.

[0049] Figure 5 A schematic diagram of the sacrificial layer after its formation, provided in this application;

[0050] Figure 6 This application provides a schematic diagram of the first groove after it has been formed;

[0051] Figure 7 This application provides a schematic diagram of the first groove after filling.

[0052] Figure 8 A schematic diagram of the ground material provided in this application;

[0053] Figure 9 This application provides a schematic diagram of the process after removing the sacrificial layer.

[0054] Figure 10 This is a schematic diagram of a magnetic tunnel junction formed according to this application;

[0055] Figure 11 Another schematic diagram provided in this application after the first groove has been formed;

[0056] Figure 12 Another schematic diagram provided in this application after filling the first groove;

[0057] Figure 13 Another schematic diagram of the ground material provided in this application;

[0058] Figure 14 Another schematic diagram provided in this application after removing the sacrificial layer;

[0059] Figure 15 This is another schematic diagram of a magnetic tunnel junction formed according to this application;

[0060] Figure 16 This is a schematic diagram showing the formation of the third dielectric layer provided in this application;

[0061] Figure 17 A schematic diagram showing the removal of part of the third dielectric layer provided in this application;

[0062] Figure 18 A schematic diagram showing the removal of part of the second dielectric layer provided in this application;

[0063] Figure 19 This is a schematic diagram of the first dielectric layer after removal, as provided in this application.

[0064] Explanation of reference numerals in the attached figures:

[0065] 10-Substrate;

[0066] 20 - Fourth dielectric layer; 21 - Filling hole; 22 - Plug;

[0067] 30 - Sacrificial layer; 31 - First groove;

[0068] 40-Spin-orbit moment layer;

[0069] 50-Magnetic tunnel junction stack; 50a-Side section; 50b-Middle section; 51-Magnetic tunnel junction;

[0070] 60 - First electrode layer; 61 - First electrode;

[0071] 70 - First dielectric layer;

[0072] 80 - Second dielectric layer;

[0073] 90 - Third dielectric layer.

[0074] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0075] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0076] Magnetic storage and magnetic field sensing technologies are widely used in industrial automation, automotive electronics, consumer electronics, and IoT terminals, and are particularly suitable for devices requiring high sensitivity, low power consumption, and high integration in detecting changes in magnetic fields. In such systems, magnetoresistive structures such as magnetic tunnel junctions are typically combined with electrodes and substrates to form a device unit for signal readout, in order to meet the application requirements of miniaturization, mass production, and stable readout.

[0077] There are generally two methods for fabricating magnetic tunnel junctions. The first is direct etching of the magnetic tunnel junction film stack, which involves depositing the magnetic tunnel junction film stack on a substrate and then directly photolithographically etching to form the magnetic tunnel junction. The second method is to form it using the damascus process, which involves etching through-holes in the dielectric layer, depositing the magnetic tunnel junction film stack within the through-holes, and finally performing planarization to form the magnetic tunnel junction.

[0078] As the fabrication process continues to shrink, the problems caused by the first method become increasingly unavoidable, resulting in lower device performance. On the one hand, sidewall metal redeposition becomes more severe, leading to a surge in short-circuit rates. As the linewidth decreases, the aspect ratio increases, making sidewall metal redeposition even more difficult to avoid and impossible to completely remove through cleaning processes. On the other hand, etching becomes more challenging. Due to etching selectivity issues, etching cannot perfectly stop at the barrier layer, easily leading to over-etching and damage to the bottom electrode, or under-etching causing short circuits.

[0079] The second preparation method reduces the difficulty of the main etching process; however, the uneven deposition of the magnetic tunneling film on the sidewalls of the via leads to uneven tunneling current distribution and increased leakage current. Furthermore, the deposition process window is narrow, making it difficult to improve mass production yield; planarization treatment can easily damage the top of the magnetic tunneling film.

[0080] The inventors discovered through research that related methods, such as optimizing the morphology of magnetic tunneling junctions (L-shaped, U-shaped, etc.), are insufficient to effectively treat the magnetic tunneling junction film stacks on the sidewalls; depositing the magnetic tunneling junction film stacks only at the bottom of the vias results in high process complexity and makes mass production difficult; introducing sputtering / injection processes to passivate the top of the magnetic tunneling junction film stacks exposed after planarization introduces thermal stress problems, has a small process window, and is relatively complex.

[0081] To address the aforementioned issues, this application provides a method for fabricating magnetic storage devices. This method utilizes a sacrificial layer to assist in the formation of an embedded magnetic tunnel junction (MTJ), and combines this with sidewall modification techniques to solve problems such as sidewall metal redeposition and uneven sidewall film deposition during traditional MTJ fabrication. The core of this concept lies in the fact that the formation of the MTJ follows a process route of trenching, deposition, and sidewall modification. By selectively removing the sacrificial layer and optimizing the etching process, precise control over the sidewall morphology is achieved. This not only reduces the difficulty of the main etching process but also eliminates sidewall defects through sidewall modification, thereby improving the electrical performance consistency and fabrication yield of the MTJ device.

[0082] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0083] In a first aspect, embodiments of this application provide a method for fabricating a storage device, see below. Figure 1 The preparation method specifically includes the following steps:

[0084] Step S100: A sacrificial layer is formed on the substrate, the sacrificial layer having a first groove that penetrates the sacrificial layer.

[0085] See Figures 2 to 7The substrate 10 is used to support the subsequently formed functional films and electrical connection structures, and can typically be a silicon substrate, germanium substrate, silicon-on-insulator (SOI) substrate, or germanium-on-insulator (GOI) substrate. The sacrificial layer 30 refers to a selectively removable temporary support material used to assist in the filling of the magnetic tunnel junction stack 50, the first electrode layer 60, and the first dielectric layer 70 during subsequent operations. The material of the sacrificial layer 30 includes, but is not limited to, silicon dioxide (SiO2) and spin-coated carbon (SOC), and the thickness of the sacrificial layer 30 matches the total thickness of the subsequently deposited magnetic tunnel junction stack 50, first electrode layer 60, and first dielectric layer 70.

[0086] like Figure 6 As shown, the sacrificial layer 30 has a first groove 31, which exposes the film layers beneath the sacrificial layer 30, such as the fourth dielectric layer 20 and the plug 22. The first groove 31 can define the formation region of the magnetic tunneling stack 50, the first electrode layer 60, and the first dielectric layer 70, providing a constrained deposition space to prevent lateral diffusion or pattern runaway during formation, and providing a basis for subsequent modification of both ends of the magnetic tunneling stack 50. The first groove 31 can be a rectangular groove (see...). Figure 6 Trapezoidal groove (see) Figure 11 (or a groove with rounded corners, etc.) The depth of the first groove 31 is adapted to the thickness of the sacrificial layer 30 itself.

[0087] In some possible implementations, the sacrificial layer 30 is formed by deposition, such as by chemical vapor deposition (CVD) or atomic layer deposition (ALD); the sacrificial layer 30 can also be formed by spin coating. The first groove 31 in the sacrificial layer 30 is formed by photolithography etching, that is, a photoresist layer is formed on the sacrificial layer 30, the photoresist layer is exposed and developed, and then the sacrificial layer 30 is etched using the photoresist layer as a mask to form the first groove 31.

[0088] Step S200: A magnetic tunneling stack, a first electrode layer, and a first dielectric layer are formed in the first groove. The magnetic tunneling stack is located on the side and bottom of the first groove. The first electrode layer covers the magnetic tunneling stack, and the first dielectric layer covers the first electrode layer and fills the remaining first groove.

[0089] See Figures 6 to 8The magnetic tunneling stack 50 is a multilayer magnetic tunneling functional film stack formed within the first groove 31 along its side and bottom, used to form the magnetic tunneling junction 51. The magnetic tunneling stack 50 is located on the side and bottom of the first groove 31, opposite to the sidewall and bottom wall of the first groove 31, for example, directly contacting the sidewall and bottom wall of the first groove 31, or filled with other film layers, such as a spin orbital layer 40, between it and the sidewall and bottom wall of the first groove 31.

[0090] In some possible examples, the magnetic tunnel junction stack 50 includes a free layer, a barrier layer, and a reference layer stacked together. For example, the free layer, barrier layer, and reference layer are stacked sequentially along a direction away from the substrate 10. Figure 7 Taking the illustrated orientation as an example, the free layer, barrier layer, and reference layer are arranged from bottom to top. The magnetization direction of the free layer can be altered by external factors, thus forming a parallel or antiparallel state with the reference layer, corresponding to the low-resistivity or high-resistivity state of the device. The reference layer provides a fixed magnetization direction as a comparison benchmark. The materials of the free layer and reference layer include magnetic materials, including at least one of cobalt-iron-boron, cobalt-iron, iron-boron, cobalt-boron, and nickel-iron. The reference layer and free layer can be single-layered or multi-layered; for example, the free layer can be a composite film of cobalt-iron-boron / tantalum / nickel-iron. The barrier layer is in contact with both the reference layer and the free layer, serving to separate the reference layer and the free layer while allowing quantum tunneling current to pass through, generating a tunneling magnetoresistance effect. The barrier layer can be made of an insulating material, such as an oxide, including at least one of aluminum oxide and magnesium oxide.

[0091] The magnetic tunnel junction stack 50 may further include other layers, such as pinning layers, fixing layers, and coupling layers, to improve device performance. The pinning layer is located on the side of the reference layer away from the free layer and is used to pin the magnetization direction of the reference layer, fixing its magnetization direction and making it less susceptible to change by external factors. The pinning layer is made of antiferromagnetic materials, such as manganese alloys, and may include at least one of platinum manganese, iridium manganese, nickel manganese, and iron manganese. The fixing layer and coupling layer are disposed between the pinning layer and the reference layer, with the fixing layer adjacent to the reference layer. The pinning layer, fixing layer, coupling layer, and reference layer are stacked sequentially. The magnetization direction of the fixing layer is firmly fixed by the pinning layer through an exchange bias effect. The fixing layer is made of ferromagnetic materials, including at least one of cobalt iron boron, cobalt iron, iron boron, cobalt boron, and nickel iron. The coupling layer provides strong interlayer exchange coupling, ensuring that the magnetization directions of the fixing layer and the reference layer are strictly parallel or antiparallel. The coupling layer is made of metals, such as at least one of ruthenium, tantalum, iridium, molybdenum, and tungsten. The magnetization directions of the reference layer and the fixed layer are antiparallel, and the magnetic fields generated by them cancel each other out, thus avoiding interference with the free layer.

[0092] Continue reading Figure 7 The first electrode layer 60 covers the top surface of the magnetic tunneling stack 50 and is used to form the first electrode 61 (see [reference]). Figure 10This allows for the reading and storage of data. The first electrode layer 60 is in contact with the magnetic tunnel junction stack 50. The first electrode layer 60 is made of a metal, preferably a metal with low resistivity and good process stability, to reduce the series resistance of the device and improve the reliability of the electrical connection. For example, the first electrode layer 60 is made of at least one of copper, tantalum, tungsten, aluminum, ruthenium, and their alloys.

[0093] like Figures 6 to 8 As shown, the first dielectric layer 70 covers the first electrode layer 60 and fills the remaining first groove 31, providing electrical insulation, mechanical support, and surface planarization for the first electrode layer 60 and its surrounding structure. Exemplarily, the first dielectric layer 70, the first electrode layer 60, and the magnetic tunneling layer 50 fill the first groove 31, as... Figure 8 As shown, the top surfaces of the first dielectric layer 70, the first electrode layer 60, the magnetic tunneling stack 50, and the sacrificial layer 30 can be flush. Alternatively, the first dielectric layer 70, the first electrode layer 60, and the magnetic tunneling stack 50 may not completely fill the first groove 31, such as... Figure 13 As shown, the top surface of the first dielectric layer 70 can be flush with the top surface of the sacrificial layer 30. The material of the first dielectric layer 70 includes insulating materials, such as at least one of silicon oxide, silicon nitride, and low dielectric constant materials.

[0094] Step S300: Remove the sacrificial layer to expose both ends of the magnetic tunneling stack.

[0095] See Figure 8 and Figure 9 The sacrificial layer 30 can be removed by physical etching or chemical etching, such as wet etching, dry etching, ashing, or solvent stripping, thereby exposing both ends of the magnetic tunneling stack 50. This allows for precise exposure of the magnetic tunneling stack 50, facilitating subsequent selective removal and patterning. Compared to directly etching the magnetic tunneling stack 50, the main etching target changes from the magnetic tunneling stack 50 to the sacrificial layer 30, reducing the etching difficulty at small nodes, providing good process scalability, and benefiting device miniaturization.

[0096] The sacrificial layer 30 enables selective etching, and the etchant is compatible with the material of the sacrificial layer 30. For example, if the sacrificial layer 30 is made of silicon oxide, the etchant can be a fluorocarbon (CF) gas, including at least one of carbon tetrafluoride, trifluoromethane, and octafluorocyclobutane; the etchant can also be gaseous hydrogen fluoride (HF). As another example, if the sacrificial layer 30 is made of spin-coated carbon, the etchant can be oxygen.

[0097] Step S400: At least both ends of the magnetic tunnel junction stack are removed, and the remaining magnetic tunnel junction stack forms a magnetic tunnel junction, and the first electrode layer forms a first electrode.

[0098] See Figure 9 and Figure 10 At least both ends of the exposed magnetic tunnel junction stack 50 are removed, while the magnetic tunnel junction stack 50 opposite to the bottom of the first groove 31 is retained to form a magnetic tunnel junction 51. Controlled removal of the ends of the magnetic tunnel junction stack 50 defines the effective working area, reducing edge damage, sidewall deposition, parasitic current paths, and device size variations. Thus, by removing the sacrificial layer 30 and modifying the ends of the magnetic tunnel junction stack 50, a higher-performance magnetic tunnel junction 51 can be obtained, reducing leakage current and power consumption.

[0099] During the removal of both ends of the magnetic tunnel junction stack 50, both ends of the first electrode layer 60 can also be removed simultaneously, leaving the first electrode layer 60 as the first electrode 61. Alternatively, during the removal of both ends of the magnetic tunnel junction stack 50, both ends of the first electrode layer 60 can remain intact, leaving the first electrode layer 60 as the first electrode 61. The first electrode 61 serves as an electrical connection member adjacent to and cooperating with the magnetic tunnel junction 51, enabling external connection of the magnetic tunnel junction 51.

[0100] In some possible examples, the ends of the magnetic tunnel junction stack 50 are removed by tilting or lateral etching. The exposed ends of the magnetic tunnel junction stack 50 are directionally removed using a direction-selective etching process, thereby retaining only the desired portion to form the magnetic tunnel junction 51, thus completing the fabrication of the morphology of the magnetic tunnel junction 51.

[0101] Tilt etching refers to the etching agent acting at the two ends of the magnetic tunneling layer 50 at a predetermined incident angle, where the incident angle is the angle between the ion beam and the surface of the substrate 10. For example, ion beam etching (IBE) with tilted incident angle is used, with an incident angle greater than or equal to 60 degrees and less than or equal to 75 degrees. The angle can be any one of 60 degrees, 65 degrees, 70 degrees, or 75 degrees, or any value between two of these, to ensure that the removal primarily targets the two ends of the magnetic tunneling layer 50. Lateral etching refers to material removal occurring in the horizontal direction, thereby gradually eroding the two ends of the magnetic tunneling layer 50. For example, anisotropic etching is used to continuously reduce the length of the two ends of the magnetic tunneling layer 50.

[0102] By employing tilted or lateral etching to remove the ends of the magnetic tunnel junction stack 50, a portion of the bottom area of ​​the first groove 31 can be retained in the magnetic tunnel junction stack 50. This allows for precise patterning of the magnetic tunnel junction 51. Using lateral removal of the magnetic tunnel junction stack 50 as the primary etching method eliminates sidewall metal redeposition, reduces short circuits, and avoids the impact of end-end residues, edge burrs, or localized damage on the device's electrical characteristics. This improves the fabrication controllability, process compatibility, and structural reliability of the magnetic memory device. The specific equipment type, process parameters, etchant ratio, incident angle, and applicable materials for the tilted and lateral etching methods described above can be equivalently adjusted according to actual process conditions; this embodiment is not limited in this regard.

[0103] The method for fabricating a magnetic storage device provided in this application involves forming a sacrificial layer 30 with a penetrating first groove 31 on a substrate 10, and sequentially forming a magnetic tunnel junction stack 50, a first electrode layer 60, and a first dielectric layer 70 within the first groove 31. The magnetic tunnel junction stack 50 is opposite to the side and bottom of the first groove 31. After removing the sacrificial layer 30, the two ends of the magnetic tunnel junction stack 50 are exposed. At least the two ends of the magnetic tunnel junction stack 50 are removed by local etching or end trimming, leaving only the middle magnetic tunnel junction stack 50 as the final magnetic tunnel junction 51. The fabrication process requires no additional processing equipment and is simple. The sacrificial layer 30 provides the basic structure for the formation of the magnetic tunnel junction stack 50, and the subsequent removal of the sacrificial layer 30 exposes the magnetic tunnel junction stack 50, facilitating the modification of the two ends of the subsequent magnetic tunnel junction stack 50 to form the magnetic tunnel junction 51. This reduces sidewall metal redeposition, improves sidewall morphology, achieves size miniaturization, simplifies the fabrication process, and improves device performance.

[0104] In some possible embodiments, see Figure 6 , Figure 9 and Figure 10 The magnetic tunneling stack 50 includes a side portion 50a and a middle portion 50b. The side portion 50a is opposite to the side surface of the first groove 31, and the middle portion 50b is opposite to the bottom surface of the first groove 31 and connected to the side portion 50a. Removing both ends of the magnetic tunneling stack 50 includes: removing all the side portions 50a of the magnetic tunneling stack 50, and retaining the middle portion 50b of the magnetic tunneling stack 50.

[0105] Side portion 50a and middle portion 50b are formed by dividing the magnetic tunneling stack 50 according to its spatial distribution. Side portion 50a is opposite to the side surface (i.e., sidewall) of the first groove 31, and middle portion 50b is opposite to the bottom wall of the first groove 31 and located at the bottom of the first groove 31. Middle portion 50b is connected to side portion 50a. Side portion 50a is also a removable area of ​​the magnetic tunneling stack 50, and middle portion 50b is also an effective working area of ​​the magnetic tunneling stack 50, used to form magnetic tunneling junction 51.

[0106] In some possible examples, the sides of the first groove 31 extend vertically, i.e., perpendicular to the surface of the substrate 10, and the magnetic tunnel junction stack 50 formed in the first groove 31 is a continuous film layer, i.e., the side portion 50a and the middle portion 50b are connected. The side portion 50a and the middle portion 50b are formed by continuous deposition of the same stacked thin film, which extends continuously to the sides and bottom of the first groove 31 to form the side portion 50a and the middle portion 50b.

[0107] By removing all sides 50a of the magnetic tunnel junction 51 stack and retaining the middle portion 50b of the magnetic tunnel junction stack 50, the ineffective or poor-performing areas opposite the sides of the first groove 31 can be completely peeled off, thereby avoiding edge leakage, local short circuits, or magnetic anisotropy shifts caused by sidewall residue. The retained middle portion 50b has a clear geometric profile and stable end face, which can make the effective working area of ​​the magnetic tunnel junction 51 more concentrated, reduce parameter fluctuations caused by sidewall deposition differences, and improve the consistency of device miniaturization and mass production.

[0108] In some other possible embodiments, see Figures 11 to 15 The side of the first groove 31 is inclined, and the width of the opening of the first groove 31 is smaller than the width of the bottom of the first groove 31. The magnetic tunnel stack 50 includes a side portion 50a and a middle portion 50b. The side portion 50a is opposite to the side of the first groove 31, and the middle portion 50b is opposite to the bottom surface of the first groove 31 and is spaced apart from the side portion 50a. Removing both ends of the magnetic tunnel stack 50 includes: removing the end of the middle portion 50b of the magnetic tunnel stack 50, and retaining the middle portion 50b of the magnetic tunnel stack 50.

[0109] like Figures 11 to 13 As shown, the side of the first groove 31 is inclined, that is, it intersects with the normal line perpendicular to the surface of the substrate 10. The width of the opening of the first groove 31 is smaller than the width of the bottom of the first groove 31, forming a shape that is narrow at the top and wide at the bottom, so that the magnetic tunnel stack 50 formed in the first groove 31 is segmented. Due to the shape characteristics of the first groove 31, the side of the first groove 31 is not easily exposed, so that the magnetic tunnel stack 50 is located at the bottom of the first groove 31 and a portion of the side of the first groove 31 away from the bottom of the first groove 31.

[0110] The magnetic tunneling stack 50 located at the bottom of the first groove 31 is slightly thinner at both ends and slightly thicker in the middle with a relatively uniform thickness. That is, the middle part 50b of the magnetic tunneling stack 50 maintains a relatively uniform thickness, resulting in better performance. The adhesion area on the side of the first groove 31 is relatively limited, reducing the size of the magnetic tunneling stack 50 located on the side of the first groove 31 (i.e., the side part 50a of the magnetic tunneling stack 50), thereby reducing the amount of subsequent etching of the magnetic tunneling stack 50 and reducing the etching difficulty of the magnetic tunneling stack 50.

[0111] like Figure 13 As shown, the magnetic tunnel junction stack 50 at the bottom of the first groove 31 is discontinuous with the magnetic tunnel junction stack 50 on the side of the first groove 31. The magnetic tunnel junction stack 50 at the bottom of the first groove 31 is mainly located in the area directly opposite the opening of the first groove 31 at the bottom of the first groove 31, while the magnetic tunnel junction stack 50 on the side of the first groove 31 is mainly located at the corners near the openings on the side of the first groove 31. There are fewer or no magnetic tunnel junction stacks 50 at the corners on the side and bottom of the first groove 31. Based on this segmented coverage method, the device can obtain a magnetic tunnel junction 51 with controllable morphology within a smaller layout area, reducing end residue, short circuits, and loss of control of the effective working area, and improving the film uniformity of the magnetic tunnel junction stack 50, the subsequent patterning accuracy, and the overall fabrication consistency.

[0112] Because the side portion 50a and the middle portion 50b are spaced apart, the side portion 50a can be removed simultaneously during the removal of the sacrificial layer 30. When removing the two ends of the magnetic tunnel junction stack 50, the ends of the middle portion 50b of the magnetic tunnel junction stack 50 are removed, while the middle portion 50b of the magnetic tunnel junction stack 50 is retained. This preserves the middle portion 50b of the magnetic tunnel junction stack 50, which has better performance, removes uneven ends, reduces performance fluctuations caused by end damage and edge roughness, thereby improving the read / write stability, consistency, and fabrication yield of the device.

[0113] In some possible embodiments, see Figure 6 and Figure 7 ,as well as Figure 11 and Figure 12 The process of forming a magnetic tunneling stack 50, a first electrode layer 60, and a first dielectric layer 70 within a first groove 31 includes: depositing the magnetic tunneling stack 50, which covers the sides and bottom of the first groove 31, and a sacrificial layer 30; depositing the first electrode layer 60, which covers the magnetic tunneling stack 50; depositing the first dielectric layer 70, which covers the first electrode layer 60, wherein the sum of the thickness of the first dielectric layer 70 and the thickness of the first electrode layer 60 is greater than or equal to the depth of the first groove 31; and grinding the magnetic tunneling stack 50, the first electrode layer 60, and the first dielectric layer 70 until the sacrificial layer 30 is exposed.

[0114] The magnetic tunnel junction stack 50, the first electrode layer 60, and the first dielectric layer 70 are sequentially deposited to form a film stack stacked along a direction away from the substrate 10. The magnetic tunnel junction stack 50 covers the sides, bottom, and top surface of the sacrificial layer 30 within the first groove 31, providing an initial film formation basis for subsequent end removal and device patterning, and providing a supporting interface for the deposition of the first electrode layer 60. The structure of the magnetic tunnel junction stack 50 is consistent with that of the magnetic tunnel junction 51, but the thickness of the magnetic tunnel junction stack 50 is less than the depth of the first groove 31, so that sufficient planarization margin is retained after the first electrode layer 60 and the first dielectric layer 70 are filled. The magnetic tunnel junction stack 50 can be deposited using any one or a combination of magnetron sputtering, evaporation deposition, or atomic layer deposition to adapt to different material systems and thickness control requirements. For example, the magnetic tunnel junction stack 50 can use a deposition method and material with good conformal properties, enabling uniform thickness and indiscriminate coverage of all areas, thereby improving device performance.

[0115] The first electrode layer 60 is in direct contact with the magnetic tunneling stack 50, forming a conductive lead-out path for the device. The first electrode layer 60 is tightly attached to and covers the top surface of the magnetic tunneling stack 50, forming a corresponding interlayer contact relationship between the upper and lower interfaces. The first electrode layer 60 can be formed by processes such as magnetron sputtering, electron beam evaporation, electroplating, or chemical vapor deposition. The thickness of the first electrode layer 60 can be from several nanometers to hundreds of nanometers, and the coverage continuity and electrical uniformity should be ensured. The sum of the thickness of the first electrode layer 60 and the thickness of the magnetic tunneling stack 50 is less than the depth of the first groove 31 to ensure the filling of the first dielectric layer 70.

[0116] Among them, such as Figure 7 As shown, the magnetic tunneling stack 50 within the first groove 31 is a continuous film, and the first electrode layer 60 is also a continuous film, covering only the magnetic tunneling stack 50. Figure 12 As shown, the magnetic tunnel stack 50 in the first groove 31 is a discontinuous film layer, the first electrode layer 60 is a discontinuous film layer, and the first electrode layer 60 only covers the magnetic tunnel stack 50; or, the first electrode layer 60 is a continuous film layer, the first electrode layer 60 covers the magnetic tunnel stack 50, and covers other structures exposed to the magnetic tunnel stack 50.

[0117] The first dielectric layer 70 is in direct contact with the first electrode layer 60 to isolate the first electrode layer 60. The first dielectric layer 70 can be formed by chemical vapor deposition, atomic layer deposition, spin coating and curing, sputtering deposition followed by annealing, etc. For example, the first dielectric layer 70 uses deposition processes and materials with good filling performance to be uniformly distributed in the remaining space of the first groove 31. The sum of the thickness of the first dielectric layer 70 and the thickness of the first electrode layer 60 is greater than or equal to the depth of the first groove 31, so that the first groove 31 can be filled. The first dielectric layer 70 and the sacrificial layer 30 are made of different materials to avoid damage to the first dielectric layer 70 when the sacrificial layer 30 is removed subsequently, so as to achieve selective removal of the sacrificial layer 30.

[0118] The multilayer structure formed by the magnetic tunneling stack 50, the first electrode layer 60, and the first dielectric layer 70 is polished to quantitatively remove excess film on the sacrificial layer 30 and expose its top surface. Polishing begins at the exposed top surface of the first dielectric layer 70 and proceeds gradually along a direction perpendicular to the substrate 10 until the top of the sacrificial layer 30 is exposed for subsequent removal. At this point, only the portions of the magnetic tunneling stack 50, the first electrode layer 60, and the first dielectric layer 70 located within the first groove 31 remain. Polishing can be performed using chemical mechanical planarization (CMP), which improves the smoothness of the final surface by controlling the abrasive particle size, polishing pressure, and slurry selectivity.

[0119] It is understandable that when there are multiple first grooves 31, after the polished magnetic tunnel junction stack 50, the first electrode layer 60 and the first dielectric layer 70 to the sacrificial layer 30 are exposed, the magnetic tunnel junction stack 50, the first electrode layer 60 and the first dielectric layer 70 are separated into multiple independent units, that is, the structure in each first groove 31 is independent of each other, so as to form multiple magnetic tunnel junctions 51 and improve the device storage density.

[0120] In some possible embodiments, see Figures 7 to 10 Before forming the magnetic tunnel junction stack 50, the first electrode layer 60, and the first dielectric layer 70 in the first groove 31, the method further includes: forming a spin orbital matrix layer 40 in the first groove 31, the spin orbital matrix layer 40 covering the sidewalls and bottom wall of the first groove 31, and the magnetic tunnel junction stack 50 covering the spin orbital matrix layer 40; removing both ends of the magnetic tunnel junction stack 50, and further includes: removing both ends of the spin orbital matrix layer 40, and stacking the remaining spin orbital matrix layer 40 and magnetic tunnel junction 51 in a direction away from the substrate 10.

[0121] The spin-orbit moment layer 40 utilizes the spin-orbit moment effect to drive and control the magnetization state of the magnetic tunnel junction 51 using current. The spin-orbit moment layer 40 directly contacts the sidewalls and bottom wall of the first groove 31, and a magnetic tunnel junction stack 50 is formed on the spin-orbit moment layer 40, located on the side of the spin-orbit moment layer 40 away from the substrate 10. The spin-orbit moment layer 40 can be formed by sputtering deposition, atomic layer deposition, or chemical vapor deposition. The material of the spin-orbit moment layer 40 includes heavy metals, topological insulators, high-spin Hall materials, etc. For example, the material of the spin-orbit moment layer 40 includes at least one of tantalum, tungsten, platinum, bismuth, nickel-iron, and bismuth telluride materials.

[0122] When removing the two ends of the magnetic tunnel junction stack 50, the two ends of the spin-orbit junction 40 are also removed simultaneously. This ensures that the remaining spin-orbit junction 40 and the magnetic tunnel junction 51 are precisely aligned and have a defined length, preventing parasitic conduction, edge scattering, or loss of control of the effective working area caused by end residues. The remaining spin-orbit junction 40 and the magnetic tunnel junction 51 are stacked along the direction away from the substrate 10, forming a bottom-up composite structure.

[0123] In some possible embodiments, see Figures 2 to 5 The method of forming a sacrificial layer 30 on a substrate 10 includes: providing a substrate 10; forming a fourth dielectric layer 20, the fourth dielectric layer 20 covering the top surface of the substrate 10, the fourth dielectric layer 20 also having a plug 22 therein, the plug 22 contacting the substrate 10 and exposed on the top surface of the fourth dielectric layer 20; depositing the sacrificial layer 30, the sacrificial layer 30 covering the top surface of the fourth dielectric layer 20 and the plug 22; removing a portion of the sacrificial layer 30 to form a first groove 31, the first groove 31 exposing at least a portion of the plug 22.

[0124] like Figure 2 As shown, a fourth dielectric layer 20 is deposited on the substrate 10, covering the top surface of the substrate 10. The fourth dielectric layer 20 is made of an insulating material, including but not limited to silicon dioxide, silicon nitride, and silicon oxynitride. Figure 8 As shown, the fourth dielectric layer 20 and the sacrificial layer 30 are made of different materials. The sacrificial layer 30 is formed on the fourth dielectric layer 20. During the selective removal of the sacrificial layer 30, the fourth dielectric layer 20 suffers less loss. Figure 9 As shown, during the process of etching away at least both ends of the magnetic tunnel junction stack 50, such as etching the spin orbital layer 40, the magnetic tunnel junction stack 50, and the first electrode layer 60, the fourth dielectric layer 20 will be etched, and the etching byproducts are mainly insulating materials, which can reduce the risk of short circuit in the formed magnetic tunnel junction 51 and improve device performance.

[0125] like Figure 3 and Figure 4As shown, a filling hole 21 is formed in the fourth dielectric layer 20 using a photolithography etching process, exposing the substrate 10. A conductive material is filled into the filling hole 21, covering the top surface of the fourth dielectric layer 20 and filling the hole, with the conductive material in contact with the substrate 10. The conductive material on the top surface of the fourth dielectric layer 20 is removed, leaving the conductive material within the filling hole 21. The retained conductive material forms a plug 22, which can be flush with the top surface of the fourth dielectric layer 20. Excess conductive material can be removed by grinding until the surface is flat, exposing the fourth dielectric layer 20. The conductive material can be tungsten, tantalum, molybdenum, titanium, titanium nitride, tantalum nitride, or other conductive materials.

[0126] like Figure 5 As shown, a sacrificial layer 30 is deposited on the plug 22 and the fourth dielectric layer 20, covering the top surfaces of the fourth dielectric layer 20 and the plug 22. The sacrificial layer 30 is then patterned to form a first groove 31, exposing at least a portion of the plug 22 within the first groove 31. For example, the first groove 31 exposes part or all of the two plugs 22, allowing the spin-orbit layer 40 to at least partially contact the two plugs 22, thereby enabling bidirectional flow of internal current.

[0127] It is worth noting that this embodiment describes a method for fabricating MRAM devices based on spin-orbital torque (SOT). This method is also applicable to MRAM devices based on spin-transfer torque (STT). The key difference is that for SOT MRAM devices, the number of plugs 22 is at least two, such as... Figure 14 As shown, the spin-orbit junction 40 is formed on both sides to provide current to the spin-orbit junction 40. For STT-based MRAM devices, the number of plugs 22 is at least one, and there is no need to deposit spin-orbit junctions. The plugs 22 are formed below the magnetic tunnel junction and electrically connected to it to provide vertical current to the magnetic tunnel junction and realize data writing. The subsequent fabrication methods and related figures will be described in detail using SOT-based MRAM devices as an example. The fabrication methods of STT-based MRAM devices will not be described in detail.

[0128] In some possible embodiments, see Figure 10 , Figures 16 to 19After removing both ends of the magnetic tunnel junction stack 50, the process further includes: forming a second dielectric layer 80, which covers the magnetic tunnel junction 51, the first electrode 61, and the first dielectric layer 70; forming a third dielectric layer 90, which covers the second dielectric layer 80; removing a portion of the third dielectric layer 90 to expose the second dielectric layer 80 above the first dielectric layer 70; removing a portion of the second dielectric layer 80 while retaining the first dielectric layer 70, wherein the removal rate of the second dielectric layer 80 is greater than the removal rate of the third dielectric layer 90; and removing at least a portion of the first dielectric layer 70 to expose the first electrode 61. The alternating deposition and selective etching of the high-selectivity second dielectric layer 80 and the third dielectric layer 90 eliminates the need for a mask, reducing etching difficulty and alignment issues, and improving the consistency and yield of device electrical performance.

[0129] like Figure 15 and Figure 16 As shown, the second dielectric layer 80 completely covers the formed magnetic tunnel junction 51, the first electrode 61, and the first dielectric layer 70, serving as an intermediate buffer dielectric on the outside. This provides isolation and protection for the underlying device structure during subsequent windowing and etching processes, and forms the basis for layered processing. The second dielectric layer 80 directly contacts the top surface of the magnetic tunnel junction 51, the first electrode 61, and the first dielectric layer 70.

[0130] The third dielectric layer 90 covers the top surface of the second dielectric layer 80, further enhancing surface flatness, process allowance, and the selectivity window for subsequent patterning. Thus, during subsequent removal, the etching process first acts on the third dielectric layer 90, then gradually transitions to the second dielectric layer 80 and the first dielectric layer 70. The second dielectric layer 80 and the third dielectric layer 90 can be single or multiple layers, with the third dielectric layer 90 exhibiting higher etching resistance.

[0131] like Figure 16 and Figure 17 As shown, the third dielectric layer 90 is ground, and the second dielectric layer 80 on top of the first dielectric layer 70 is exposed first. Figure 17 and Figure 18 As shown, the second dielectric layer 80 continues to be removed until the first dielectric layer 70 is exposed. The removal rate of the second dielectric layer 80 is greater than that of the third dielectric layer 90. Therefore, under the same process conditions, the third dielectric layer 90 can provide an etching buffer and boundary definition first, while the second dielectric layer 80 can more easily form a stable opening above the first dielectric layer 70. The areas not exposed can still maintain coverage and protection for the underlying magnetic tunnel junction 51 and the first electrode 61.

[0132] like Figure 18 and Figure 19As shown, at least partially exposed first dielectric layer 70 is removed, precisely exposing first electrode 61 at a predetermined location, thereby forming a window for subsequent interconnection, wire bonding, or contact conduction. Specifically, the entire wafer can be physically etched, i.e., the third dielectric layer 90, second dielectric layer 80, and first dielectric layer 70 are simultaneously etched until the first electrode 61 is exposed, to complete device fabrication. Employing layered encapsulation and step-by-step opening improves the precision of the first electrode 61 exposure position, reduces process complexity, decreases the number of masks, and lowers mask costs.

[0133] Secondly, embodiments of this application also provide a magnetic storage device, the preparation method of which is described in [reference needed]. Figures 2 to 19 The magnetic storage device includes: a substrate 10, a magnetic tunnel junction 51 disposed on the substrate 10, and a first electrode 61 disposed on the side of the magnetic tunnel junction 51 facing away from the substrate 10. The magnetic tunnel junction 51 is formed by forming a magnetic tunnel junction stack 50 in a first groove 31 of a sacrificial layer 30, and removing both ends of the magnetic tunnel junction stack 50 after removing the sacrificial layer 30.

[0134] Substrate 10 serves as the basic support platform for the device and provides mechanical support and a process substrate for subsequent magnetic stacking. The material of substrate 10 includes silicon, germanium, silicon-germanium, silicon-on-insulator (SOI), and germanium-on-insulator (GOI). The magnetic tunnel junction 51 utilizes the tunneling magnetoresistance effect to store and retrieve data. The first electrode 61 forms an electrical contact with the magnetic tunnel junction 51 and serves as a conductive path for current injection and signal readout. The first electrode 61 and the magnetic tunnel junction 51 can adopt the structures and materials described in the first aspect above, which will not be elaborated further here.

[0135] The magnetic tunnel junction 51 is not formed by direct overall etching, but rather by forming a magnetic tunnel junction stack 50 within the first groove 31 of the sacrificial layer 30, and then etching away both ends of the magnetic tunnel junction stack 50 after removing the sacrificial layer 30. The first groove 31 penetrates the sacrificial layer 30 to define the initial forming space of the magnetic tunnel junction stack 50. The first groove 31 can be a rectangular groove, a trapezoidal groove, or a groove with rounded corners. The sacrificial layer 30 can be made of selectively etchable dielectric materials such as silicon oxide or spin-coated carbon, so that it can be selectively removed in subsequent processes.

[0136] The magnetic tunnel junction stack 50 is formed conformally within the first groove 31. After removing the sacrificial layer 30, both ends of the magnetic tunnel junction stack 50 are exposed. The exposed ends of the magnetic tunnel junction stack 50 are then etched away, leaving the middle portion 50b of the magnetic tunnel junction stack 50 to form the magnetic tunnel junction 51. For example, the middle portion of the magnetic tunnel junction stack 50 opposite the bottom of the first groove 31 is retained, resulting in a magnetic tunnel junction 51 with uniform film thickness and good device performance.

[0137] In some possible examples, the sidewalls of at least one of the magnetic tunnel junction 51 and the first electrode 61 are inclined or convex relative to the top surface of the substrate 10. For example, the sidewalls of the magnetic tunnel junction 51 and / or the first electrode 61 extend outward at a predetermined angle, or form an arc-shaped, drum-shaped, trumpet-shaped, or other convex profile. The shape of the sidewalls of the magnetic tunnel junction 51 and / or the first electrode 61 is related to the ion incident angle during etching at both ends of the magnetic tunnel junction stack 50 to ensure effective removal at both ends of the magnetic tunnel junction stack 50.

[0138] The magnetic storage device provided in this application embodiment forms the final magnetic tunnel junction 51 by removing the sacrificial layer 30 and modifying both ends of the magnetic tunnel junction stack 50. This effectively avoids the influence of the two ends of the magnetic tunnel junction stack 50 on the effective working area, and reduces disturbances to the characteristics of the magnetic tunnel junction 51 caused by parasitic leakage and edge scattering. Furthermore, it can reduce sidewall metal redeposition, improve sidewall morphology, achieve size miniaturization, simplify the fabrication process, and improve device performance.

[0139] The embodiments or implementation methods described in this specification are presented in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Those skilled in the art should understand that in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are merely for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the system or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on the invention.

[0140] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0141] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for fabricating a magnetic storage device, characterized in that, include: A sacrificial layer is formed on a substrate, the sacrificial layer having a first groove that penetrates the sacrificial layer; A magnetic tunneling stack, a first electrode layer, and a first dielectric layer are formed in the first groove. The magnetic tunneling stack is located on the side and bottom of the first groove. The first electrode layer covers the magnetic tunneling stack, and the first dielectric layer covers the first electrode layer and fills the remaining first groove. Remove the sacrificial layer to expose both ends of the magnetic tunneling stack; At least both ends of the magnetic tunnel junction stack are removed, and the remaining magnetic tunnel junction stack forms a magnetic tunnel junction, and the first electrode layer forms a first electrode.

2. The preparation method according to claim 1, characterized in that, The ends of the magnetic tunneling stack are removed by tilting or lateral etching.

3. The preparation method according to claim 1, characterized in that, The magnetic tunnel stack includes a side portion and a middle portion. The side portion is opposite to the side surface of the first groove, and the middle portion is opposite to the bottom surface of the first groove and connected to the side portion. Removing both ends of the magnetic tunneling stack includes: removing all the sides of the magnetic tunneling stack while retaining the middle portion of the magnetic tunneling stack.

4. The method of claim 1, wherein, The side of the first groove is inclined, and the width of the opening of the first groove is smaller than the width of the bottom of the first groove; The magnetic tunnel stack includes a side portion and a middle portion. The side portion is opposite to the side surface of the first groove, and the middle portion is opposite to the bottom surface of the first groove and is spaced apart from the side portion. Removing both ends of the magnetic tunneling stack includes: removing the ends of the middle portion of the magnetic tunneling stack while retaining the middle portion of the middle portion of the magnetic tunneling stack.

5. The method of any one of claims 1-4, wherein, A magnetic tunneling stack, a first electrode layer, and a first dielectric layer are formed within the first groove, including: A magnetic tunneling stack is deposited, the magnetic tunneling stack covering the sides and bottom of the first groove, and the sacrificial layer; A first electrode layer is deposited, which covers the magnetic tunneling stack; A first dielectric layer is deposited, which covers the first electrode layer. The sum of the thickness of the first dielectric layer and the thickness of the first electrode layer is greater than or equal to the depth of the first groove. The magnetic tunneling stack, the first electrode layer, and the first dielectric layer are ground until the sacrificial layer is exposed.

6. The method of any one of claims 1-4, wherein, Before forming the magnetic tunnel junction stack, the first electrode layer, and the first dielectric layer within the first groove, the method further includes: A spin orbital matrix layer is formed in the first groove, the spin orbital matrix layer covers the sidewalls and bottom wall of the first groove, and the magnetic tunneling stack is covered on the spin orbital matrix layer; Removing both ends of the magnetic tunneling stack also includes: Remove both ends of the spin orbital matrix, and stack the remaining spin orbital matrix and the magnetic tunnel junction in a direction away from the substrate.

7. The method of any one of claims 1-4, wherein, After removing both ends of the magnetic tunneling stack, the process further includes: A second dielectric layer is formed, which covers the magnetic tunnel junction, the first electrode, and the first dielectric layer; A third dielectric layer is formed, which covers the second dielectric layer; Remove part of the third dielectric layer to expose the second dielectric layer above the first dielectric layer; Part of the second medium layer is removed, while the first medium layer is retained, wherein the removal rate of the second medium layer is greater than the removal rate of the third medium layer; Remove at least a portion of the first dielectric layer to expose the first electrode.

8. The method of any one of claims 1-4, wherein, Forming a sacrificial layer on the substrate includes: Provide substrate; A fourth dielectric layer is formed, which covers the top surface of the substrate. The fourth dielectric layer also has a plug that contacts the substrate and is exposed on the top surface of the fourth dielectric layer. A sacrificial layer is deposited, which covers the top surface of the fourth dielectric layer and the plug; A portion of the sacrificial layer is removed to form the first groove, in which at least a portion of the plug is exposed.

9. A magnetic memory device, comprising: include: Substrate; A magnetic tunnel junction is disposed on the substrate; The first electrode is disposed on the side of the magnetic tunnel junction away from the substrate; The magnetic tunnel junction is formed by forming a magnetic tunnel junction stack in the first groove of the sacrificial layer, and then removing the two ends of the magnetic tunnel junction stack after removing the sacrificial layer.

10. The magnetic memory device of claim 9, wherein, The sidewalls of at least one of the magnetic tunnel junction and the first electrode are inclined or convex relative to the top surface of the substrate.

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