Magnetic storage device

Abstract

Provided is a magnetic storage device capable of reliably electrically separating adjacent magnetoresistive effect elements. A magnetic memory device according to an embodiment includes: a lower structure; a first laminated structure provided on the lower structure; a second laminated structure provided on the lower structure and adjacent to the first laminated structure; a first boron-containing layer that is provided on a side surface of the first laminated structure and contains boron (B); and a second boron-containing layer provided on a side surface of the second laminated structure and containing boron (B), each of the first laminated structure and the second laminated structure including: a base portion including a first magnetic layer having a variable magnetization direction, a second magnetic layer having a fixed magnetization direction, and a non-magnetic layer provided between the first magnetic layer and the second magnetic layer; a conductive lower portion provided on the lower layer side of the base portion; and an upper portion provided on the upper layer side of the base portion and having conductivity.

Description

Technical Field

[0001] Embodiments of the present invention relate to a magnetic storage device. Background Art

[0002] A magnetic storage device has been proposed in which a plurality of magnetoresistive elements are integrated on a semiconductor substrate. Summary of the Invention

[0003] Provided is a magnetic storage device capable of reliably electrically isolating adjacent magnetoresistive effect elements.

[0004] The magnetic storage device of the embodiment comprises: a lower structure; a first stacked structure, arranged on the lower structure; a second stacked structure, arranged on the lower structure and adjacent to the first stacked structure; a first boron-containing layer, arranged on the side of the first stacked structure and containing boron (B); and a second boron-containing layer, the second boron-containing layer being arranged on the side of the second stacked structure and containing boron (B), the first stacked structure and the second stacked structure each including: a basic part, including a first magnetic layer having a variable magnetization direction, a second magnetic layer having a fixed magnetization direction, and a non-magnetic layer arranged between the first magnetic layer and the second magnetic layer; a lower part, arranged on the lower layer side of the basic part and having conductivity; and an upper part, which is arranged on the upper layer side of the basic part and has conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 It is a cross-sectional view schematically showing the structure of the magnetic storage device according to the embodiment.

[0006] Figure 2 Schematically shows a cross section perpendicular to the Z direction of a stacked structure and a boron-containing layer in a magnetic storage device according to an embodiment.

[0007] Figure 3 The figure schematically shows a cross section perpendicular to the Z direction of an electrode, an insulating portion of a lower insulating layer (an insulating portion provided in a region below a stacked structure), a metal-containing layer, and an extension portion of a boron-containing layer in a magnetic storage device according to an embodiment.

[0008] Figure 4 This is a cross-sectional view schematically showing a part of a method for manufacturing a magnetic storage device according to an embodiment.

[0009] Figure 5 This is a cross-sectional view schematically showing a part of a method for manufacturing a magnetic storage device according to an embodiment.

[0010] Figure 6 This is a cross-sectional view schematically showing a part of a method for manufacturing a magnetic storage device according to an embodiment.

[0011] Figure 7 This is a cross-sectional view schematically showing a part of a method for manufacturing a magnetic storage device according to an embodiment.

[0012] Figure 8 It is a perspective view schematically showing the configuration of an application example of the magnetic storage device according to the embodiment.

[0013] Description of Reference Numerals

[0014] 10…stacked structure; 11…basic part; 11a…storage layer (first magnetic layer); 11b…reference layer (second magnetic layer); 11c…tunnel barrier layer (non-magnetic layer); 12…lower part; 13…upper part; 13a…hard mask part; 13b…middle part; 20…boron-containing layer; 20a…extension part; 30…lower structure; 31…lower insulating layer; 31a…insulating part (first insulating part, second insulating part); 31b…insulating part (third insulating part); 32…electrode; 33…metal-containing layer; 40…upper insulating layer; 100, 200…wiring; 300…storage cell; 400…magnetoresistance effect element; 500…selector (switching element). DETAILED DESCRIPTION

[0015] Hereinafter, embodiments will be described with reference to the drawings.

[0016] Figure 1 It is a cross-sectional view schematically showing the structure of the magnetic storage device according to the embodiment.

[0017] The magnetic storage device of this embodiment is provided on a semiconductor substrate (not shown) and includes a plurality of stacked structures 10 , a plurality of boron-containing layers 20 , a lower structure 30 , and an upper insulating layer 40 .

[0018] Multiple stacked structures 10 are provided on the lower structure 30 and arranged in an array in the X and Y directions. Each stacked structure 10 has a structure in which multiple layers are stacked in the Z direction. Furthermore, the X, Y, and Z directions intersect with each other. Specifically, the X, Y, and Z directions are orthogonal to each other.

[0019] Each of the plurality of stacked structures 10 functions as a magnetoresistive element, ie, an MTJ (Magnetic Tunnel Junction) element. Each stacked structure 10 includes a base portion 11 , a lower portion 12 , and an upper portion 13 .

[0020] The basic portion 11 includes a memory layer (first magnetic layer) 11 a , a reference layer (second magnetic layer) 11 b , and a tunnel barrier layer (non-magnetic layer) 11 c , and functions as a basic portion of a magnetoresistive element.

[0021] The storage layer 11a is a ferromagnetic layer with a variable magnetization direction. Furthermore, variable magnetization means that the magnetization direction changes with respect to a predetermined write current. The storage layer 11a contains at least one element selected from iron (Fe) and cobalt (Co). Specifically, the storage layer 11a is formed of an FeCoB layer containing iron (Fe), cobalt (Co), and boron (B).

[0022] The reference layer 11 b is a ferromagnetic layer having a fixed magnetization direction, and includes a first layer portion and a second layer portion stacked in the Z direction. The fixed magnetization direction means that the magnetization direction does not change with respect to a predetermined write current.

[0023] The first layer portion is provided on the side closer to the tunnel barrier layer 11c and contains at least one element selected from iron (Fe) and cobalt (Co). Specifically, the first layer portion is formed of an FeCoB layer containing iron (Fe), cobalt (Co), and boron (B).

[0024] The second layer portion is provided on the side farther from the tunnel barrier layer 11c and contains at least platinum (Pt). Specifically, the second layer portion has a superlattice structure in which a plurality of platinum (Pt) layers and a plurality of cobalt (Co) layers are alternately stacked.

[0025] The tunnel barrier layer 11c is an insulating layer provided between the memory layer 11a and the reference layer 11b. Specifically, the tunnel barrier layer 11c is formed of an MgO layer containing magnesium (Mg) and oxygen (O).

[0026] When the magnetization direction of the storage layer 11a is parallel to that of the reference layer 11b, the magnetoresistive element assumes a low-resistance state with relatively low resistance. When the magnetization direction of the storage layer 11a is antiparallel to that of the reference layer 11b, the magnetoresistive element assumes a high-resistance state with relatively high resistance. Therefore, the magnetoresistive element can store binary data depending on its resistance state. The resistance state of the magnetoresistive element can be set by the direction of the current flowing through the magnetoresistive element.

[0027] also, Figure 1 The basic portion 11 of the magnetoresistive element shown has a top free type structure in which the storage layer 11a is located on the upper side of the reference layer 11b, but the basic portion 11 may also have a bottom free type structure in which the storage layer 11a is located on the lower side of the reference layer 11b.

[0028] The lower portion 12 of the stacked structure 10 is provided on the lower side of the base portion 11 and is electrically conductive. The lower portion 12 is formed from a conductive material containing at least one element selected from hafnium (Hf), tungsten (W), titanium (Ti), and aluminum (Al). For example, the lower portion 12 may be formed from any one of an Hf layer, a W layer, a Ti layer, and an Al layer, or may be a stack of two or more of these. Furthermore, the lower portion 12 may include a layer containing two or more of the elements Hf, W, Ti, and Al within the same layer. In this embodiment, Hf is contained in at least the lowermost portion of the lower portion 12.

[0029] Upper portion 13 of stacked structure 10 is located above base portion 11 and is electrically conductive. Upper portion 13 contains at least one element selected from hafnium (Hf), tungsten (W), titanium (Ti), aluminum (Al), and ruthenium (Ru). Upper portion 13 includes a hard mask portion 13a and an intermediate portion 13b.

[0030] The hard mask portion 13a is the topmost layer of the stacked structure 10 and functions as a hard mask when patterning the stacked structure 10. The hard mask portion 13a is formed from a conductive material containing at least one element selected from hafnium (Hf), tungsten (W), titanium (Ti), and aluminum (Al). For example, the hard mask portion 13a may be formed from any one of a Hf layer, a W layer, a Ti layer, and an Al layer, or may be a stack of two or more of these layers. Furthermore, the hard mask portion 13a may include a layer containing two or more of the elements Hf, W, Ti, and Al within the same layer.

[0031] The middle portion 13b is provided between the base portion 11 and the hard mask portion 13a and is formed of a conductive material, for example, a ruthenium (Ru) layer.

[0032] The plurality of boron-containing layers 20 are each provided on the side surfaces (sidewalls) of the plurality of stacked structures 10. Specifically, each boron-containing layer 20 is provided so as to surround the side surfaces of each stacked structure 10. The boron-containing layer 20 is formed of an insulating material containing boron (B). Specifically, the boron-containing layer 20 is formed of boron nitride (BN) containing boron (B) and nitrogen (N).

[0033] The boron-containing layer 20 may be provided on the entire side surface of the stacked structure 10 or on a portion of the side surface of the stacked structure 10. However, the boron-containing layer 20 is preferably provided so as to surround the entire side surface of at least the base portion 11 of the stacked structure 10. In this embodiment, the boron-containing layer 20 is provided continuously along the entire side surface of the stacked structure 10 including the base portion 11, the lower portion 12, and the upper portion 13. In addition, the boron-containing layer 20 may further include an extension portion 20a extending to the upper portion of the lower structure 30.

[0034] Figure 2 Schematically shows a cross section of the stacked structure 10 and the boron-containing layer 20 perpendicular to the Z direction. Figure 2 It can be seen that the pattern of the boron-containing layer 20 is provided so as to surround the circular pattern of the stacked structure 10 .

[0035] The lower structure 30 includes a lower insulating layer 31 , a plurality of electrodes 32 , and a plurality of metal-containing layers 33 .

[0036] The lower insulating layer 31 functions as an interlayer insulating layer and includes a plurality of insulating portions 31a disposed below each of the plurality of stacked structures 10, and an insulating portion 31b disposed outside the plurality of insulating portions 31a. Specifically, the pattern of the insulating portions 31b is arranged to surround the pattern of each insulating portion 31a. The insulating portion 31b has an upper surface lower than the upper surfaces of the plurality of insulating portions 31a. In other words, the insulating portion 31b is recessed relative to the plurality of insulating portions 31a. The lower insulating layer 31 is formed of an insulating material such as silicon oxide or silicon nitride.

[0037] The electrodes 32 are connected to the bottom surfaces of the stacked structures 10. That is, each electrode 32 is connected to the bottom surface of the lower portion 12 of each stacked structure 10. The side surfaces of each electrode 32 are surrounded by the insulating portions 31a of the lower insulating layer 31.

[0038] The plurality of metal-containing layers 33 are provided on the side surfaces of the plurality of insulating portions 31a. Specifically, each metal-containing layer 33 is provided so as to surround the side surfaces of the upper portion of each insulating portion 31a.

[0039] Each metal-containing layer 33 contains the metal element contained in each stacked structure 10. Specifically, the metal-containing layer 33 contains at least one element selected from hafnium (Hf), tungsten (W), titanium (Ti), aluminum (Al), iron (Fe), cobalt (Co), platinum (Pt), and ruthenium (Ru). In particular, the metal-containing layer 33 contains a relatively large proportion of Hf.

[0040] As described above, the boron-containing layer 20 may include the extension portion 20 a extending to the upper portion of the lower structure 30 . In this case, the extension portion 20 a is provided at a side of the metal-containing layer 33 .

[0041] Furthermore, no layer containing boron (B) is provided on the upper surface of the insulating portion 31b of the lower insulating layer 31, except for a portion near the outer edge of the insulating portion 31b (except for a portion near the boundary between the insulating portion 31a and the insulating portion 31b). In other words, a portion containing boron (B) exists on the upper surface of the insulating portion 31b near the outer edge of the insulating portion 31b.

[0042] Figure 3 Schematically shows a cross section perpendicular to the Z direction of the electrode 32, the insulating portion 31a of the lower insulating layer 31, the metal-containing layer 33, and the extending portion 20a of the boron-containing layer 20. Figure 3 It can be seen that the pattern of the insulating part 31a of the lower insulating layer 31 is set in a circular pattern surrounding the electrode 32, the pattern of the metal-containing layer 33 is set in a pattern surrounding the insulating part 31a, and the pattern of the extended part 20a of the boron-containing layer 20 is set in a pattern surrounding the metal-containing layer 33.

[0043] Upper insulating layer 40 surrounds the side surfaces of each of the multiple structures including stacked structure 10 and boron-containing layer 20. Furthermore, upper insulating layer 40 extends to the upper surface of insulating portion 31b of lower insulating layer 31. Upper insulating layer 40 functions as an interlayer insulating layer and is formed from a material different from that of boron-containing layer 20. For example, upper insulating layer 40 is formed from an insulating material such as silicon oxide or silicon nitride.

[0044] As described above, in this embodiment, the boron-containing layer 20 is provided on the side surface of the stacked structure 10. This ensures that adjacent stacked structures 10 are electrically isolated from each other as described below. In other words, adjacent magnetoresistive elements can be electrically isolated from each other.

[0045] Typically, when patterning the stacked structure 10, a hard mask is used as an etching mask to etch the stacked film used for the stacked structure 10 by IBE (Ion Beam Etching) or the like. In this case, a metal-containing layer (residual layer) containing the metal element contained in the stacked film is formed in the region between adjacent stacked structures 10, potentially impairing electrical isolation between adjacent stacked structures 10. Furthermore, a metal-containing layer (residual layer) may form on the side surfaces of the stacked structure 10, in which case electrical isolation between the memory layer 11a and the reference layer 11b may be impaired. In particular, if Hf is contained in the lower portion 12 of the stacked structure 10, a metal-containing layer (residual layer) containing Hf is formed, making it difficult to reliably remove the metal-containing layer (residual layer) containing Hf.

[0046] In the present embodiment, by providing the boron-containing layer 20 on the side surface of the stacked structure 10 , the above-mentioned problem can be prevented as described below.

[0047] Hafnium (Hf) generated by etching during patterning of the stacked structure 10 forms hafnium oxide when combined with oxygen in the interlayer insulating layer or in the atmosphere. It is not easy to remove the metal-containing layer (residue layer) containing hafnium oxide by etching.

[0048] In this embodiment, the boron-containing layer 20 is formed after the stacked structure 10 is formed. Boron (B) is more easily oxidized than hafnium (Hf). In other words, the bond between boron and oxygen is more stable than the bond between hafnium and oxygen. Therefore, if etching is performed after the boron-containing layer 20 is formed, the oxygen in the hafnium oxide in the metal-containing layer (residue layer) combines with the boron (B), reducing the hafnium oxide to hafnium (Hf). Since hafnium (Hf) is more easily etched than hafnium oxide, the metal-containing layer (residue layer) can be easily removed.

[0049] Therefore, in this embodiment, adjacent magnetoresistive elements (adjacent stacked structures 10 ) can be reliably electrically isolated from each other.

[0050] Next, refer to Figures 4 to 7 as well as Figure 1 A method for manufacturing the magnetic storage device of this embodiment will be described.

[0051] First, if Figure 4 As shown, a stacked film for the stacked structure 10 is formed on the structure including the lower insulating layer 31 and the electrode 32. Specifically, a lower partial layer 12s, a base partial layer 11s (memory layer 11a, reference layer 11b, and tunnel barrier layer 11c), an intermediate partial layer 13bs, and a hard mask layer are formed. Furthermore, the hard mask layer is patterned to form a hard mask pattern 13ap.

[0052] Then, if Figure 5As shown, using the hard mask pattern 13ap as a mask, the intermediate partial layer 13bs, the base partial layer 11s, and the lower partial layer 12s are etched by IBE. At this time, the hard mask pattern 13ap is also etched, and the height (thickness) of the hard mask pattern 13ap is reduced. This results in a pattern of the stacked structure 10 comprising the base portion 11 (memory layer 11a, reference layer 11b, and tunnel barrier layer 11c), the lower portion 12, and the upper portion 13 (the hard mask portion 13a and the intermediate portion 13b). During this etching process, overetching is performed to physically and reliably separate adjacent stacked structures 10. As a result, a portion of the lower insulating layer 31 is etched, forming a recess 31r. Furthermore, a metal-containing layer (residual layer) 33 containing the metal element contained in the stacked structure 10 is formed on the bottom and side surfaces of the recess 31r. The metal-containing layer (residual layer) 33 contains hafnium oxide and the like.

[0053] Then, if Figure 6 As shown, to cover the Figure 5 The boron-containing layer 20 is formed in the form of the structure obtained by the process. Specifically, a boron nitride (BN) layer is formed as the boron-containing layer 20.

[0054] Then, if Figure 7 As shown, the boron-containing layer 20 is anisotropically etched by RIE (Reactive Ion Etching). A gas containing chlorine (Cl) (e.g., Cl2 gas) is used as the etching gas. This anisotropic etching removes the boron-containing layer 20 formed on the upper surface of the stacked structure 10 and the bottom surface of the recess 31r of the lower insulating layer 31, leaving only the boron-containing layer 20 formed on the side surfaces of the stacked structure 10 and the side surfaces of the metal-containing layer 33. In addition, this anisotropic etching also removes the metal-containing layer 33 formed on the bottom surface of the recess 31r.

[0055] As described above, the metal-containing layer (residue layer) 33 contains hafnium oxide and the like. Boron (B) is more easily oxidized than hafnium (Hf), and the bond between boron and oxygen is more stable than that between hafnium and oxygen. Therefore, by forming the boron-containing layer 20 before the aforementioned anisotropic etching, the oxygen in the hafnium oxide bonds with boron to form hafnium. As a result, the metal-containing layer (residue layer) 33 containing hafnium can be easily removed.

[0056] Alternatively, the etching gas may contain chlorine (Cl) and boron (B) (e.g., a mixed gas of Cl2 gas and BCl3 gas). By adding the boron (B)-containing gas, the removal of the metal-containing layer (residue layer) 33 containing hafnium can be further accelerated.

[0057] Then, through Figure 7The upper insulating layer 40 is formed on the structure obtained by the process, and the upper insulating layer 40 is flattened, thereby obtaining Figure 1 The structure shown.

[0058] As described above, the above-described manufacturing method can easily remove the metal-containing layer (residue layer) 33 by forming the boron-containing layer 20. Therefore, the above-described manufacturing method can reliably electrically isolate adjacent magnetoresistive elements (adjacent stacked structures 10).

[0059] Next, an application example of the magnetic storage device of this embodiment will be described. Figure 8 It is a perspective view schematically showing the configuration of an application example of the magnetic storage device of this embodiment.

[0060] Figure 8 The illustrated memory device includes a plurality of wirings 100 , a plurality of wirings 200 , and a plurality of memory cells 300 provided between the plurality of wirings 100 and the plurality of wirings 200 .

[0061] Each of the plurality of wirings 100 extends in the X direction, and each of the plurality of wirings 200 extends in the Y direction. One of the wirings 100 and 200 corresponds to a word line, and the other of the wirings 100 and 200 corresponds to a bit line.

[0062] Each of the plurality of memory cells 300 includes a magnetoresistive element 400 and a selector (switch element) 500 , and has a structure in which the magnetoresistive elements 400 and the selectors 500 are stacked in the Z direction. That is, each memory cell 300 has a structure in which the magnetoresistive element 400 and the selector 500 are connected in series.

[0063] The basic structure of the magnetoresistive element 400 corresponds to the structure shown in the above-described embodiment (including the structure of the stacked structure 10 and the boron-containing layer 20). The selector 500 is a two-terminal switching element having the characteristic of switching from an off state to an on state when the voltage applied between the two terminals reaches a threshold voltage.

[0064] When a voltage is applied between wiring 100 and wiring 200 and the voltage applied to selector 500 exceeds a threshold voltage, selector 500 switches from an off state to an on state. As a result, current flows through magnetoresistive element 400 connected in series with selector 500, enabling writing to or reading from magnetoresistive element 400.

[0065] By applying the magnetic storage device of this embodiment to Figure 8 The memory device shown above can provide a memory device having excellent characteristics and reliability.

[0066] also, Figure 8The memory device shown has a structure in which the magnetoresistive effect element 400 is located above the selector 500 , but may also have a structure in which the magnetoresistive effect element 400 is located below the selector 500 .

[0067] While several embodiments of the present invention have been described, these embodiments are provided as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other forms and can be omitted, replaced, or modified without departing from the gist of the invention. These embodiments and their variations are intended to be within the scope and gist of the invention and to be included in the invention as set forth in the claims and their equivalents.

Claims

1. A magnetic storage device comprising: Substructure; a first stacked structure disposed on the lower structure; a second stacked structure disposed on the lower structure and adjacent to the first stacked structure; a first boron-containing layer provided on a side surface of the first stacked structure and containing boron; and a second boron-containing layer provided on a side surface of the second stacked structure and containing boron; The magnetic storage device is characterized in that The first stacked structure and the second stacked structure each include: A base portion including a first magnetic layer having a variable magnetization direction, a second magnetic layer having a fixed magnetization direction, and a non-magnetic layer provided between the first magnetic layer and the second magnetic layer; a lower portion, provided on the lower layer side of the base portion and having electrical conductivity; as well as The upper portion is provided on the upper layer side of the base portion and has conductivity.

2. The magnetic storage device according to claim 1, wherein The first boron-containing layer and the second boron-containing layer further contain nitrogen.

3. The magnetic storage device according to claim 1, wherein The first magnetic layer contains at least one element selected from iron and cobalt.

4. The magnetic storage device according to claim 1, wherein The second magnetic layer contains at least one element selected from iron and cobalt.

5. The magnetic storage device according to claim 4, wherein The second magnetic layer further contains platinum.

6. The magnetic storage device according to claim 1, wherein The non-magnetic layer contains magnesium and oxygen.

7. The magnetic storage device according to claim 1, wherein The lower portion contains at least one element selected from hafnium, tungsten, titanium, and aluminum.

8. The magnetic storage device according to claim 1, wherein The upper portion contains at least one element selected from the group consisting of hafnium, tungsten, titanium, aluminum, and ruthenium.

9. The magnetic storage device according to claim 1, wherein The lower structure includes a lower insulating layer, The lower insulating layer comprises: a first insulating portion provided in a region below the first stacked structure; a second insulating portion provided in a region below the second laminated structure; and The third insulating portion is provided in a region outside the first insulating portion and the second insulating portion, and has an upper surface lower than an upper surface of the first insulating portion and an upper surface of the second insulating portion.

10. The magnetic storage device according to claim 9, wherein The lower structure further comprises: a first electrode connected to the lower surface of the first stacked structure and having a side surface surrounded by the first insulating portion; and The second electrode is connected to the lower surface of the second stacked structure and has a side surface surrounded by the second insulating portion.

11. The magnetic storage device according to claim 9, wherein The lower structure further comprises: a first metal-containing layer, provided on a side surface of the first insulating portion, containing at least one metal element contained in the first stacked structure; and The second metal-containing layer is provided on a side surface of the second insulating portion and contains at least one metal element contained in the second stacked structure.

12. The magnetic storage device according to claim 11, wherein The first boron-containing layer includes a first extension portion disposed on a side surface of the first metal-containing layer. The second boron-containing layer includes a second extension portion disposed on a side surface of the second metal-containing layer.

13. The magnetic storage device according to claim 11, wherein Each of the first metal-containing layer and the second metal-containing layer contains at least one element selected from the group consisting of hafnium, tungsten, titanium, aluminum, iron, cobalt, platinum, and ruthenium.

14. The magnetic storage device according to claim 13, wherein No layer containing boron is provided on the upper surface of the third insulating portion except for a portion near an outer edge of the third insulating portion.

15. The magnetic storage device according to claim 1, wherein The magnetic storage device further includes an upper insulating layer that surrounds the side surfaces of the first stacked structure and the structure including the first boron-containing layer, and surrounds the side surfaces of the second stacked structure and the structure including the second boron-containing layer.

16. A method for manufacturing a magnetic storage device, characterized in that: include: forming a laminated film including a basic partial layer, a lower partial layer, and an upper partial layer on a structure including a lower insulating layer, the basic partial layer including a first magnetic layer having a variable magnetization direction, a second magnetic layer having a fixed magnetization direction, and a non-magnetic layer provided between the first magnetic layer and the second magnetic layer, the lower partial layer being provided on a lower layer side of the basic partial layer and having conductivity, and the upper partial layer being provided on an upper layer side of the basic partial layer and having conductivity; patterning the hard mask layer included in the upper layer to form a hard mask pattern; performing etching using the hard mask pattern as a mask to form a stacked structure including patterns of the base partial layer, the lower partial layer, and the upper partial layer, and forming a recess in the lower insulating layer; forming a boron-containing layer containing boron in such a manner as to cover a structure obtained by etching using the hard mask pattern as a mask; as well as The boron-containing layer is etched to remove the boron-containing layer formed on the upper surface of the stacked structure and the bottom surface of the recessed portion, while leaving the boron-containing layer formed on the side surfaces of the stacked structure.

17. The method for manufacturing a magnetic storage device according to claim 16, wherein: The boron-containing layer also contains nitrogen.

18. The method for manufacturing a magnetic storage device according to claim 16, wherein: When etching is performed using the hard mask pattern as a mask, a metal-containing layer containing the metal element contained in the stacked structure is formed on the bottom surface of the recessed portion. When the boron-containing layer is etched, the metal-containing layer formed on the bottom surface of the recess is removed.

19. The method for manufacturing a magnetic storage device according to claim 18, wherein: When etching is performed using the hard mask pattern as a mask, the metal-containing layer is formed on the side surfaces of the recess in addition to the bottom surface of the recess, When the boron-containing layer is etched, the metal-containing layer formed on the side surfaces of the recessed portion remains.

20. The method for manufacturing a magnetic storage device according to claim 18, wherein: The metal-containing layer contains at least one element selected from the group consisting of hafnium, tungsten, titanium, aluminum, iron, cobalt, platinum, and ruthenium.

Images