Magnetic storage device and preparation method thereof

Abstract

The invention provides a preparation method of a magnetic storage device, and the method comprises the steps: providing a substrate which comprises a metal interconnection layer and a metal through hole layer which are sequentially arranged from bottom to top; a spin orbit moment forming layer, a magnetic tunnel junction lamination layer and a hard mask layer are arranged on the substrate from bottom to top; etching the hard mask layer and the magnetic tunnel junction lamination layer to form a magnetic tunnel junction unit; forming a cap-shaped dielectric layer on the side wall of the magnetic tunnel junction unit; the cap-shaped dielectric layer is used as a mask, self-alignment etching is carried out on the spin orbit moment forming layers, so that intervals are formed between the spin orbit moment forming layers corresponding to adjacent magnetic tunnel junctions, and the spin orbit moment forming layers are in conductive connection with the corresponding bottom through holes. According to the magnetic storage device and the preparation method thereof provided by the invention, the preparation difficulty of the magnetic storage device can be reduced.

Description

Technical Field

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

[0002] In the manufacturing process of magnetic memory, for example, in the manufacturing process of spin-orbit moment magnetic memory, the etching endpoint of the magnetic tunnel junction stops at the upper surface of the spin-orbit rectangular layer. Before forming an independent device, the spin-orbit rectangular layer of a single device needs to be separated from the spin-orbit rectangular layer of an adjacent device. In the prior art, the etching of the spin-orbit rectangular layer uses a mask shared with the top electrode, but the etching process of the top electrode is relatively complicated, involving multiple metal etchings and dielectric etchings, and the etching depth is large, which makes it difficult to control the etching endpoint. Summary of the invention

[0003] The magnetic storage device and the preparation method thereof provided by the present invention can reduce the difficulty of preparing the magnetic storage device.

[0004] In a first aspect, the present invention provides a method for preparing a magnetic storage device, comprising:

[0005] Providing a substrate, the substrate comprising a metal interconnection layer and a metal through-hole layer arranged in sequence from bottom to top;

[0006] Arranging a spin-orbit rectangular layer, a magnetic tunnel junction stack and a hard mask layer from bottom to top on the substrate;

[0007] Etching the hard mask layer and the magnetic tunnel junction stack to form a magnetic tunnel junction unit;

[0008] forming a cap-shaped dielectric layer on the side wall of the magnetic tunnel junction unit;

[0009] The cap-shaped dielectric layer is used as a mask to perform self-aligned etching on the spin-orbit rectangular layers so that the spin-orbit rectangular layers corresponding to adjacent magnetic tunnel junctions are spaced apart, wherein the spin-orbit rectangular layers are conductively connected to the corresponding bottom through holes.

[0010] Optionally, forming a cap-shaped dielectric layer on the sidewall of the magnetic tunnel junction unit includes:

[0011] Forming one or more dielectric layers on the substrate on which the magnetic tunnel junction unit is prepared, wherein the dielectric layers cover the magnetic tunnel junction unit;

[0012] The dielectric layer outside the side wall of the magnetic tunnel junction unit is etched to form a cap-shaped dielectric layer on the side wall of the magnetic tunnel junction unit.

[0013] Optionally, forming a cap-shaped dielectric layer on the sidewall of the magnetic tunnel junction unit includes:

[0014] Using SiN, SiCN, SiON and Al 2 O 3 One or more materials in the etching process form one or more dielectric layers to be etched;

[0015] The one or more dielectric layers to be etched are etched to form the cap-shaped dielectric layer.

[0016] Optionally, after the spin-orbit rectangular layer is self-aligned and etched using the cap-shaped dielectric layer as a mask, the method further includes:

[0017] A dielectric layer is formed and a top electrode is formed on the dielectric layer.

[0018] Optionally, forming a cap-shaped dielectric layer on the sidewall of the magnetic tunnel junction unit includes:

[0019] A cap-shaped dielectric layer is formed on the side wall of the magnetic tunnel junction unit so that the cap-shaped dielectric layer covers at least a portion of the corresponding metal through-hole layer, so that the spin-orbit rectangular layer forms a conductive contact with the corresponding metal through-hole layer during the self-aligned etching process.

[0020] Optionally, before arranging the spin-orbit rectangular layer, the magnetic tunnel junction stack and the hard mask layer from bottom to top on the substrate, the method further includes:

[0021] A bottom electrode layer is formed on the substrate, and the bottom electrode layer is etched.

[0022] Optionally, forming a cap-shaped dielectric layer on the sidewall of the magnetic tunnel junction unit includes:

[0023] A cap-shaped dielectric layer is formed on the side wall of the magnetic tunnel junction unit so that the cap-shaped dielectric layer covers at least a portion of the corresponding bottom electrode layer, so that the spin-orbit rectangular layer forms a conductive contact with the corresponding bottom electrode layer during the self-aligned etching process.

[0024] Optionally, using the cap-shaped dielectric layer as a mask, performing self-aligned etching on the spin-orbit rectangular layer includes:

[0025] During the self-aligned etching process, the etching stop position is set at the top of the dielectric layer below the spin track rectangular layering.

[0026] In a second aspect, the present invention further provides a magnetic storage device, comprising:

[0027] A substrate, the substrate comprising a metal interconnection layer and a metal through-hole layer arranged in sequence from bottom to top;

[0028] The spin track rectangular layer is arranged on the upper surface of the substrate, and the spin track rectangular layer is conductively connected to the metal through hole layer;

[0029] A magnetic tunnel junction unit, comprising a magnetic tunnel junction stack and a hard mask layer formed sequentially from bottom to top on the upper surface of the spin-orbit rectangular layer;

[0030] A cap-shaped dielectric layer is disposed around the sidewall of the magnetic tunnel junction unit, and the bottom outer edge of the cap-shaped dielectric layer is aligned with the outer edge of the spin-orbit rectangular layer.

[0031] Optionally, the spin-track rectangular layer covers at least a portion of the metal through-hole layer, so that the spin-track rectangular layer forms a conductive contact with the metal through-hole layer; or,

[0032] A bottom electrode is also disposed on the upper surface of the metal through-hole layer, and the spin-orbit rectangular layer covers at least a portion of the bottom electrode, so that the spin-orbit rectangular layer forms a conductive contact with the bottom electrode.

[0033] In the technical solution provided by the present invention, after the etching of the magnetic tunnel junction unit is completed, a cap-shaped dielectric layer is formed on the side wall of the magnetic tunnel junction unit, and the cap-shaped dielectric layer is used as a mask to perform etching of the spin-orbit rectangular layer. During the etching process, only the etching of the cap-shaped dielectric layer and the etching of the spin-orbit rectangular layer are involved, and the etching process is simple, and the difficulty of controlling the etching depth is low. At the same time, since the self-aligned etching is performed by using the cap-shaped dielectric layer as a mask, the size of the spin-orbit rectangular layer can be accurately controlled by adjusting the thickness of the dielectric cover layer around the side wall of the magnetic tunnel junction unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1a A schematic diagram of a base structure provided for a method for preparing a magnetic storage device according to an embodiment of the present invention;

[0035] Figure 1b A schematic diagram of the structure of a method for preparing a magnetic storage device according to an embodiment of the present invention after forming a spin-orbit rectangular layer, a magnetic tunnel junction stack and a hard mask layer;

[0036] Figure 1c This is a schematic structural diagram of a method for preparing a magnetic storage device according to an embodiment of the present invention after etching a magnetic tunnel junction stack and a hard mask layer;

[0037] Figure 1d This is a structural schematic diagram of a method for preparing a magnetic storage device according to an embodiment of the present invention before etching a cap-shaped dielectric layer;

[0038] Figure 1e This is a structural schematic diagram of a method for preparing a magnetic storage device according to an embodiment of the present invention after etching a cap-shaped dielectric layer;

[0039] Figure 1fThis is a schematic diagram of the structure of a method for preparing a magnetic storage device according to an embodiment of the present invention after etching spin track rectangles into layers;

[0040] Figure 1g This is a structural schematic diagram of a method for preparing a magnetic storage device according to an embodiment of the present invention after a medium is filled;

[0041] Figure 1h A schematic diagram of the structure of a method for preparing a magnetic storage device according to an embodiment of the present invention after a groove is formed;

[0042] Figure 1i This is a schematic structural diagram of a method for preparing a magnetic storage device according to an embodiment of the present invention after a metal material is filled in a groove;

[0043] Figure 2a A schematic diagram of a base structure provided for a method for preparing a magnetic storage device according to another embodiment of the present invention;

[0044] Figure 2b A schematic diagram of the structure of a method for preparing a magnetic storage device according to another embodiment of the present invention after forming a spin-orbit rectangular layer, a magnetic tunnel junction stack and a hard mask layer;

[0045] Figure 2c A schematic diagram of the structure of a method for preparing a magnetic storage device according to another embodiment of the present invention after etching a magnetic tunnel junction stack and a hard mask layer;

[0046] Figure 2d This is a structural schematic diagram of a method for preparing a magnetic storage device according to another embodiment of the present invention before etching a cap-shaped dielectric layer;

[0047] Figure 2e This is a structural schematic diagram of a method for preparing a magnetic storage device according to another embodiment of the present invention after etching a cap-shaped dielectric layer;

[0048] Figure 2f This is a schematic diagram of the structure of a method for preparing a magnetic storage device according to another embodiment of the present invention after etching spin track rectangles into layers;

[0049] Figure 2g It is a structural schematic diagram of a method for preparing a magnetic storage device after filling a medium according to another embodiment of the present invention;

[0050] Figure 2h A schematic structural diagram of a method for preparing a magnetic storage device after forming a groove according to another embodiment of the present invention;

[0051] Figure 2i This is a schematic structural diagram of a method for preparing a magnetic storage device according to another embodiment of the present invention after a metal material is filled in a groove;

[0052] Figure 3aA schematic diagram of a base structure provided for a method for preparing a magnetic storage device according to another embodiment of the present invention;

[0053] Figure 3b A schematic diagram of the structure of a method for preparing a magnetic storage device according to another embodiment of the present invention after forming a spin-orbit rectangular layer, a magnetic tunnel junction stack and a hard mask layer;

[0054] Figure 3c A schematic diagram of the structure of a method for preparing a magnetic storage device according to another embodiment of the present invention after etching a magnetic tunnel junction stack and a hard mask layer;

[0055] Figure 3d This is a structural schematic diagram of a method for preparing a magnetic storage device according to another embodiment of the present invention before etching a cap-shaped dielectric layer;

[0056] Figure 3e This is a structural schematic diagram of a method for preparing a magnetic storage device according to another embodiment of the present invention after etching a cap-shaped dielectric layer;

[0057] Figure 3f This is a schematic diagram of the structure of a method for preparing a magnetic storage device according to another embodiment of the present invention after etching spin track rectangles into layers;

[0058] Figure 3g It is a structural schematic diagram of a method for preparing a magnetic storage device after filling a medium according to another embodiment of the present invention;

[0059] Figure 3h A schematic structural diagram of a method for preparing a magnetic storage device after forming a groove according to another embodiment of the present invention;

[0060] Figure 3i This is a structural schematic diagram of a method for preparing a magnetic storage device according to another embodiment of the present invention after a metal material is filled in a groove. 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 method for preparing a magnetic storage device, comprising:

[0063] Providing a substrate, the substrate comprising a metal interconnection layer and a metal through-hole layer arranged in sequence from bottom to top;

[0064] Arranging a spin-orbit rectangular layer, a magnetic tunnel junction stack and a hard mask layer from bottom to top on the substrate;

[0065] Etching the hard mask layer and the magnetic tunnel junction stack to form a magnetic tunnel junction unit;

[0066] forming a cap-shaped dielectric layer on the side wall of the magnetic tunnel junction unit;

[0067] The cap-shaped dielectric layer is used as a mask to perform self-aligned etching on the spin-orbit rectangular layers so that the spin-orbit rectangular layers corresponding to adjacent magnetic tunnel junctions are spaced apart, wherein the spin-orbit rectangular layers are conductively connected to the corresponding bottom through holes.

[0068] In the technical solution provided by the embodiment of the present invention, after the etching of the magnetic tunnel junction unit is completed, a cap-shaped dielectric layer is formed on the side wall of the magnetic tunnel junction unit, and the cap-shaped dielectric layer is used as a mask to perform etching of the spin-orbit rectangular layer. During the etching process, only the etching of the cap-shaped dielectric layer and the etching of the spin-orbit rectangular layer are involved, and the etching process is simple, and the difficulty of controlling the etching depth is low. At the same time, since the self-aligned etching is performed by using the cap-shaped dielectric layer as a mask, the size of the spin-orbit rectangular layer can be accurately controlled by adjusting the thickness of the dielectric cover layer around the side wall of the magnetic tunnel junction unit.

[0069] As an optional implementation manner, forming a cap-shaped dielectric layer on the sidewall of the magnetic tunnel junction unit includes:

[0070] Forming one or more dielectric layers on the substrate on which the magnetic tunnel junction unit is prepared, wherein the dielectric layers cover the magnetic tunnel junction unit;

[0071] The dielectric layer outside the side wall of the magnetic tunnel junction unit is etched to form a cap-shaped dielectric layer on the side wall of the magnetic tunnel junction unit.

[0072] As an optional implementation manner, forming a cap-shaped dielectric layer on the sidewall of the magnetic tunnel junction unit includes:

[0073] One or more materials selected from SiN, SiCN, SiON and Al2O3 are used to form one or more dielectric layers to be etched;

[0074] The one or more dielectric layers to be etched are etched to form the cap-shaped dielectric layer.

[0075] As an optional implementation, after the spin-orbit rectangular layer is self-aligned and etched using the cap-shaped dielectric layer as a mask, the method further includes:

[0076] A dielectric layer is formed and a top electrode is formed on the dielectric layer, wherein the process of forming the top electrode adopts a damascene method or a dual damascene method.

[0077] As an optional implementation manner, forming a cap-shaped dielectric layer on the sidewall of the magnetic tunnel junction unit includes:

[0078] A cap-shaped dielectric layer is formed on the side wall of the magnetic tunnel junction unit so that the cap-shaped dielectric layer covers at least a portion of the corresponding metal through-hole layer, so that the spin-orbit rectangular layer forms a conductive contact with the corresponding metal through-hole layer during the self-aligned etching process.

[0079] As an optional implementation, before the spin-orbit rectangular layer, the magnetic tunnel junction stack and the hard mask layer are arranged from bottom to top on the substrate, the method further includes:

[0080] A bottom electrode layer is formed on the substrate, and the bottom electrode layer is etched.

[0081] As an optional implementation manner, forming a cap-shaped dielectric layer on the sidewall of the magnetic tunnel junction unit includes:

[0082] A cap-shaped dielectric layer is formed on the side wall of the magnetic tunnel junction unit, so that the cap-shaped dielectric layer covers at least a portion of the corresponding bottom electrode layer, so that the spin-orbit rectangular layer forms a conductive contact with the corresponding bottom electrode layer during the self-aligned etching process. In some embodiments, during the formation of the cap-shaped dielectric layer, etching of the horizontal portion may cause a reduction in the dielectric thickness of the side tunnel junction unit side wall. In this case, the reduced thickness caused by the etching process of the horizontal portion can be known based on prior experience, thereby achieving precise adjustment of the cap-shaped dielectric thickness.

[0083] As an optional implementation, using the cap-shaped dielectric layer as a mask, performing self-aligned etching on the spin-orbit rectangular layer includes:

[0084] In the self-aligned etching process, the etching stop position is set at the top of the dielectric layer below the spin track rectangular layer. In some preferred embodiments, the etching stop position is lower than the top of the dielectric layer below the spin track rectangular layer, so that over-etching is formed in the dielectric layer below the spin track rectangular layer to ensure that the spin track rectangular layer is completely disconnected after etching is terminated.

[0085] like Figures 1a to 1i , shows an exemplary implementation, including:

[0086] A substrate 100 is provided and a bottom electrode 130 is formed on the substrate 100. The substrate 100 includes a metal interconnection layer 110 and a metal through-hole layer 120 arranged in sequence from bottom to top. After the bottom electrode 130 is formed, the substrate 100 is Figure 1a As shown;

[0087] A spin-orbit rectangular layer 140, a magnetic tunnel junction stack 150 and a hard mask layer 160 are arranged from bottom to top on the substrate 100 to form a Figure 1b The structure shown in FIG. 1 , wherein the spin-orbit rectangular layer 140 may be formed by a combination of one or more of the materials tungsten (W), tantalum (Ta) and platinum (Pt) or an alloy of the above materials; the magnetic tunnel junction stack 150 includes a free magnetic layer, a tunneling layer and a fixed magnetic layer stacked in sequence from bottom to top; the hard mask layer 160 may be tantalum (Ta), tantalum nitride (TaN), titanium (Ti) and titanium nitride (TiN), etc.

[0088] The hard mask layer 160 and the magnetic tunnel junction stack 150 are etched to form a magnetic tunnel junction unit; the structure of the magnetic tunnel junction unit is as follows: Figure 1c As shown; during the etching process, the etching stop position is at the upper surface of the spin track rectangular layer 140.

[0089] A cap-shaped dielectric layer is formed on the side wall of the magnetic tunnel junction unit; wherein the cap-shaped dielectric layer is formed on the side wall of the magnetic tunnel junction unit, comprising: forming two dielectric layers 171 and 172 on the substrate 100 on which the magnetic tunnel junction unit is prepared, wherein the dielectric layer covers the magnetic tunnel junction unit, and its structure is as follows Figure 1d As shown; the dielectric layer outside the side wall of the magnetic tunnel junction unit is etched to form a cap-shaped dielectric layer on the side wall of the magnetic tunnel junction unit, and its structure is as shown Figure 1e shown.

[0090] Using the cap-shaped dielectric layer as a mask, the spin-orbit rectangular layers are self-aligned and etched to form a gap between the spin-orbit rectangular layers 140 corresponding to the adjacent magnetic tunnel junctions, wherein the spin-orbit rectangular layers 140 are conductively connected to the corresponding bottom electrodes 130. The structure after the self-aligned etching is as follows: Figure 1f As shown;

[0091] The intervals between the spin-orbit rectangular layers 140 and the intervals between the cap-shaped dielectric layers are filled with dielectric 180, and the upper surface of the dielectric layer 180 is higher than the upper surface of the magnetic tunnel junction unit. The structure is as follows: Figure 1g shown.

[0092] The top through hole and the through hole and the groove 181 corresponding to the top electrode are formed on the dielectric layer 180 by using the dual damascene process. The structure is as follows: Figure 1h shown.

[0093] The metal material 190 is filled in the through hole and the groove to form a metal plug of the top electrode and the top through hole, and the structure thereof is as follows: Figure 1i shown.

[0094] like Figure 2a to Figure 2i, shows an exemplary implementation, including:

[0095] A substrate 100 is provided and a bottom electrode 130 is formed on the substrate 100. The substrate 100 includes a metal interconnection layer 110 and a metal through-hole layer 120 arranged in sequence from bottom to top. After the bottom electrode 130 is formed, the substrate 100 is Figure 2a As shown;

[0096] A spin-orbit rectangular layer 140, a magnetic tunnel junction stack 150 and a hard mask layer 160 are arranged from bottom to top on the substrate 100 to form a Figure 2b The structure shown in FIG. 1 , wherein the spin-orbit rectangular layer 140 may be formed by a combination of one or more of the materials tungsten (W), tantalum (Ta) and platinum (Pt) or an alloy of the above materials; the magnetic tunnel junction stack 150 includes a free magnetic layer, a tunneling layer and a fixed magnetic layer stacked in sequence from bottom to top; the hard mask layer 160 may be tantalum (Ta), tantalum nitride (TaN), titanium (Ti) and titanium nitride (TiN), etc.

[0097] The hard mask layer 160 and the magnetic tunnel junction stack 150 are etched to form a magnetic tunnel junction unit; the structure of the magnetic tunnel junction unit is as follows: Figure 2c As shown; during the etching process, the etching stop position is at the upper surface of the spin track rectangular layer 140.

[0098] A cap-shaped dielectric layer is formed on the side wall of the magnetic tunnel junction unit; wherein the cap-shaped dielectric layer is formed on the side wall of the magnetic tunnel junction unit, comprising: forming a dielectric layer 170 on the substrate 100 on which the magnetic tunnel junction unit is prepared, wherein the dielectric layer covers the magnetic tunnel junction unit, and its structure is as follows Figure 2d As shown; the dielectric layer outside the side wall of the magnetic tunnel junction unit is etched to form a cap-shaped dielectric layer on the side wall of the magnetic tunnel junction unit, and its structure is as shown Figure 2e shown.

[0099] Using the cap-shaped dielectric layer as a mask, the spin-orbit rectangular layers are self-aligned and etched to form a gap between the spin-orbit rectangular layers 140 corresponding to the adjacent magnetic tunnel junctions, wherein the spin-orbit rectangular layers 140 are conductively connected to the corresponding bottom electrodes 130. The structure after the self-aligned etching is as follows: Figure 2f As shown;

[0100] The intervals between the spin-orbit rectangular layers 140 and the intervals between the cap-shaped dielectric layers are filled with dielectric 180, and the upper surface of the dielectric layer 180 is higher than the upper surface of the magnetic tunnel junction unit. The structure is as follows: Figure 2g shown.

[0101] The top through hole and the through hole and the groove 181 corresponding to the top electrode are formed on the dielectric layer 180 by using the dual damascene process. The structure is as follows: Figure 2h shown.

[0102] The metal material 190 is filled in the through hole and the groove to form a metal plug of the top electrode and the top through hole, and the structure thereof is as follows: Figure 2i shown.

[0103] like Figures 3a to 3i , shows an exemplary implementation, including:

[0104] A substrate 100 is provided, wherein the substrate 100 includes a metal interconnection layer 110 and a metal through-hole layer 120 arranged in sequence from bottom to top; Figure 3a As shown;

[0105] A spin-orbit rectangular layer 140, a magnetic tunnel junction stack 150 and a hard mask layer 160 are arranged from bottom to top on the substrate 100 to form a Figure 3b The structure shown in FIG. 1 , wherein the spin-orbit rectangular layer 140 may be formed by a combination of one or more of the materials tungsten (W), tantalum (Ta) and platinum (Pt) or an alloy of the above materials; the magnetic tunnel junction stack 150 includes a free magnetic layer, a tunneling layer and a fixed magnetic layer stacked in sequence from bottom to top; the hard mask layer 160 may be tantalum (Ta), tantalum nitride (TaN), titanium (Ti) and titanium nitride (TiN), etc.

[0106] The hard mask layer 160 and the magnetic tunnel junction stack 150 are etched to form a magnetic tunnel junction unit; the structure of the magnetic tunnel junction unit is as follows: Figure 3c As shown; during the etching process, the etching stop position is at the upper surface of the spin track rectangular layer 140.

[0107] A cap-shaped dielectric layer is formed on the side wall of the magnetic tunnel junction unit; wherein the cap-shaped dielectric layer is formed on the side wall of the magnetic tunnel junction unit, comprising: forming a dielectric layer 170 on the substrate 100 on which the magnetic tunnel junction unit is prepared, wherein the dielectric layer covers the magnetic tunnel junction unit, and its structure is as follows Figure 3d As shown; the dielectric layer outside the side wall of the magnetic tunnel junction unit is etched to form a cap-shaped dielectric layer on the side wall of the magnetic tunnel junction unit, and its structure is as shown Figure 3e shown.

[0108] Using the cap-shaped dielectric layer as a mask, the spin-orbit rectangular layers are self-aligned and etched to form a gap between the spin-orbit rectangular layers 140 corresponding to the adjacent magnetic tunnel junctions, wherein the spin-orbit rectangular layers 140 are conductively connected to the corresponding metal through-hole layers 130. The structure after the self-aligned etching is as follows: Figure 3f As shown;

[0109] The intervals between the spin-orbit rectangular layers 140 and the intervals between the cap-shaped dielectric layers are filled with dielectric 180, and the upper surface of the dielectric layer 180 is higher than the upper surface of the magnetic tunnel junction unit. The structure is as follows: Figure 3g shown.

[0110] A groove 181 corresponding to the top electrode is formed on the dielectric layer 180 by using a Damascene process. The structure is as follows: Figure 3h shown.

[0111] The groove is filled with a metal material 190 to form a top electrode, the structure of which is as follows: Figure 3i shown.

[0112] In each of the above embodiments, as an optional method, the thickness of the cap-shaped dielectric layer can be adjusted according to demand. When forming the cap-shaped dielectric layer, the bottom of the cap-shaped dielectric layer covers at least a portion of the corresponding bottom electrode or bottom through hole, so that after the spin-orbit rectangular stratification is etched, the spin-orbit rectangular stratification forms a conductive contact with the bottom electrode or the bottom through hole.

[0113] In the above embodiments, as an optional method, the cap-shaped dielectric layer can be a single layer, a double layer or a multi-layer. The material of the cap-shaped dielectric layer can be, for example, SiN, SiCN, SiON and Al. 2 O 3 It can be a single-layer structure formed by one of the materials, or it can be a two or more stacked-layer structure formed by two or more materials.

[0114] In the above-mentioned embodiments, as an optional manner, during the etching process of the cap-shaped dielectric layer, reactive ion etching or ion beam etching may be used.

[0115] In the above embodiments, as an option, the material of the hard mask layer may be, for example, one or a combination of two or more of tantalum (Ta), tantalum nitride (TaN), titanium (Ti) and titanium nitride (TiN).

[0116] In the above embodiments, as an optional method, in order to avoid chemical corrosion caused by reactive ion etching that damages the magnetism of the tunnel junction, an ion beam etching method may be used, for example, during the etching process of the hard mask and the magnetic tunnel junction stack.

[0117] An embodiment of the present invention further provides a magnetic storage device, comprising:

[0118] A substrate, the substrate comprising a metal interconnection layer and a metal through-hole layer arranged in sequence from bottom to top;

[0119] The spin track rectangular layer is arranged on the upper surface of the substrate, and the spin track rectangular layer is conductively connected to the metal through hole layer;

[0120] A magnetic tunnel junction unit, comprising a magnetic tunnel junction stack and a hard mask layer formed sequentially from bottom to top on the upper surface of the spin-orbit rectangular layer;

[0121] A cap-shaped dielectric layer is disposed around the sidewall of the magnetic tunnel junction unit, and the outer edge of the bottom of the cap-shaped dielectric layer is aligned with the outer edge of the spin-orbit rectangular layer.

[0122] As an optional implementation, the spin-track rectangular stratification covers at least a portion of the metal via layer, so that the spin-track rectangular stratification forms a conductive contact with the metal via layer.

[0123] As an optional implementation, a bottom electrode is further provided on the upper surface of the metal via layer, and the spin-orbit rectangular layer covers at least a portion of the bottom electrode so that the spin-orbit rectangular layer forms a conductive contact with the bottom electrode.

[0124] 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 method for preparing a magnetic storage device, characterized in that: include: Providing a substrate, the substrate comprising a metal interconnection layer and a metal through-hole layer arranged in sequence from bottom to top; Arranging a spin-orbit rectangular layer, a magnetic tunnel junction stack and a hard mask layer from bottom to top on the substrate; Etching the hard mask layer and the magnetic tunnel junction stack to form a magnetic tunnel junction unit; forming a cap-shaped dielectric layer on the side wall of the magnetic tunnel junction unit; The cap-shaped dielectric layer is used as a mask to perform self-aligned etching on the spin-orbit rectangular layers so that the spin-orbit rectangular layers corresponding to adjacent magnetic tunnel junctions are spaced apart, wherein the spin-orbit rectangular layers are conductively connected to the corresponding bottom through holes.

2. The method according to claim 1, characterized in that: Forming a cap-shaped dielectric layer on the sidewall of the magnetic tunnel junction unit includes: Forming one or more dielectric layers on the substrate on which the magnetic tunnel junction unit is prepared, wherein the dielectric layers cover the magnetic tunnel junction unit; The dielectric layer outside the side wall of the magnetic tunnel junction unit is etched to form a cap-shaped dielectric layer on the side wall of the magnetic tunnel junction unit.

3. The method according to claim 1 or 2, characterized in that: Forming a cap-shaped dielectric layer on the sidewall of the magnetic tunnel junction unit includes: One or more materials selected from SiN, SiCN, SiON and Al2O3 are used to form one or more dielectric layers to be etched; The one or more dielectric layers to be etched are etched to form the cap-shaped dielectric layer.

4. The method according to claim 1, characterized in that: After the spin-orbit rectangular layer is self-aligned and etched using the cap-shaped dielectric layer as a mask, the method further includes: A dielectric layer is formed and a top electrode is formed on the dielectric layer.

5. The method according to claim 1, characterized in that Forming a cap-shaped dielectric layer on the sidewall of the magnetic tunnel junction unit includes: A cap-shaped dielectric layer is formed on the side wall of the magnetic tunnel junction unit so that the cap-shaped dielectric layer covers at least a portion of the corresponding metal through-hole layer, so that the spin-orbit rectangular layer forms a conductive contact with the corresponding metal through-hole layer during the self-aligned etching process.

6. The method according to claim 1, characterized in that Before the spin-orbit rectangular layer, the magnetic tunnel junction stack and the hard mask layer are arranged from bottom to top on the substrate, the method further includes: A bottom electrode layer is formed on the substrate, and the bottom electrode layer is etched.

7. The method according to claim 6, characterized in that Forming a cap-shaped dielectric layer on the sidewall of the magnetic tunnel junction unit includes: A cap-shaped dielectric layer is formed on the side wall of the magnetic tunnel junction unit so that the cap-shaped dielectric layer covers at least a portion of the corresponding bottom electrode layer, so that the spin-orbit rectangular layer forms a conductive contact with the corresponding bottom electrode layer during the self-aligned etching process.

8. The method according to claim 1, characterized in that Using the cap-shaped dielectric layer as a mask, self-aligned etching of the spin-orbit rectangular layer comprises: During the self-aligned etching process, the etching stop position is set at the top of the dielectric layer below the spin track rectangular layering.

9. A magnetic storage device, characterized in that: include: A substrate, the substrate comprising a metal interconnection layer and a metal through-hole layer arranged in sequence from bottom to top; The spin track rectangular layer is arranged on the upper surface of the substrate, and the spin track rectangular layer is conductively connected to the metal through hole layer; A magnetic tunnel junction unit, comprising a magnetic tunnel junction stack and a hard mask layer formed sequentially from bottom to top on the upper surface of the spin-orbit rectangular layer; A cap-shaped dielectric layer is disposed around the sidewall of the magnetic tunnel junction unit, and the bottom outer edge of the cap-shaped dielectric layer is aligned with the outer edge of the spin-orbit rectangular layer.

10. The magnetic storage device according to claim 9, characterized in that The spin track rectangular layer covers at least a portion of the metal through hole layer, so that the spin track rectangular layer forms a conductive contact with the metal through hole layer; or, A bottom electrode is also disposed on the upper surface of the metal through-hole layer, and the spin-orbit rectangular layer covers at least a portion of the bottom electrode, so that the spin-orbit rectangular layer forms a conductive contact with the bottom electrode.

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