Magnetic storage device

Abstract

A magnetic storage device according to one embodiment comprises a substrate, a first stack and a second stack. The second stack is located on the same side as the first stack relative to the substrate and is further away from the substrate than the first stack. The first stack and the second stack respectively include a reference layer, a tunnel barrier layer, a storage layer and a first non-magnetic layer. The tunnel barrier layer is disposed on a direction side perpendicular to the substrate relative to the reference layer. The storage layer is disposed on the direction side relative to the tunnel barrier layer. The first non-magnetic layer is disposed on the direction side relative to the storage layer. The heat absorption rate of the first non-magnetic layer of the first stack is smaller than the heat absorption rate of the first non-magnetic layer of the second stack.

Description

[0001] [Related applications]

[0002] This application claims priority based on Japanese Patent Application No. 2019-166174 (filing date: September 12, 2019). This application incorporates all the contents of the basic application by reference. Technical Field

[0003] Embodiments generally relate to a magnetic storage device. Background Art

[0004] A magnetic storage device (MRAM: Magnetoresistive Random Access Memory) using a magnetoresistive effect element as a storage element is known. Summary of the invention

[0005] The embodiment provides a magnetic storage device capable of suppressing variation in characteristics between magnetoresistive elements formed in different layers.

[0006] The magnetic storage device of the embodiment comprises a substrate, a first stacked body and a second stacked body. The second stacked body is located on the same side as the first stacked body relative to the substrate and is further away from the substrate than the first stacked body. The first stacked body and the second stacked body respectively include a reference layer, a tunnel barrier layer, a storage layer and a first non-magnetic layer. The tunnel barrier layer is arranged on the direction side perpendicular to the substrate relative to the reference layer. The storage layer is arranged on the direction side relative to the tunnel barrier layer. The first non-magnetic layer is arranged on the direction side relative to the storage layer. The heat absorption rate of the first non-magnetic layer of the first stacked body is smaller than the heat absorption rate of the first non-magnetic layer of the second stacked body. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a block diagram for explaining the structure of the magnetic storage device according to the first embodiment.

[0008] Figure 2 This is a circuit diagram for explaining the configuration of a memory cell array of the magnetic memory device according to the first embodiment.

[0009] Figure 3 It is a cross-sectional view for explaining the structure of the memory cell array of the magnetic memory device according to the first embodiment.

[0010] Figure 4 It is a cross-sectional view for explaining the structure of the memory cell array of the magnetic memory device according to the first embodiment.

[0011] Figure 5(A) and (B) are cross-sectional views for explaining the structure of the magnetoresistive element of the magnetic storage device according to the first embodiment.

[0012] Figure 6 It is a schematic diagram for explaining the method of manufacturing the memory cell array in the magnetic memory device according to the first embodiment.

[0013] Figure 7 It is a schematic diagram for explaining the method of manufacturing the memory cell array in the magnetic memory device according to the first embodiment.

[0014] Figure 8 It is a schematic diagram for explaining the method of manufacturing the memory cell array in the magnetic memory device according to the first embodiment.

[0015] Fig. 9 It is a schematic diagram for explaining the method of manufacturing the memory cell array in the magnetic memory device according to the first embodiment.

[0016] Fig.10 It is a schematic diagram for explaining the method of manufacturing the memory cell array in the magnetic memory device according to the first embodiment.

[0017] Fig.11 (A) and (B) are schematic diagrams for explaining the effects of the first embodiment.

[0018] Fig.12 (A) and (B) are schematic diagrams for explaining the structure of a magnetoresistive element in a magnetic storage device according to a first modification of the first embodiment.

[0019] Fig.13 (A) and (B) are schematic diagrams for explaining the structure of a magnetoresistive element in a magnetic storage device according to a second modification of the first embodiment.

[0020] Fig.14 (A) and (B) are schematic diagrams for explaining the structure of a magnetoresistive element in the magnetic storage device according to the second embodiment.

[0021] Fig.15 (A) and (B) are schematic diagrams for explaining the structure of a magnetoresistive element in a magnetic storage device according to a first modification of the second embodiment.

[0022] Fig.16 (A) and (B) are schematic diagrams for explaining the structure of a magnetoresistive element in a magnetic storage device according to a second modification of the second embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, the implementation mode will be described with reference to the accompanying drawings. In addition, in the following description, common reference symbols are marked for components having the same function and structure. In addition, in the case of distinguishing multiple components having a common reference symbol, the common reference symbol is marked with an additional mark to distinguish them. In addition, in the case where there is no need to distinguish multiple components, only the common reference symbol is marked for these multiple components without an additional mark. Here, the additional mark is not limited to a subscript or a superscript, for example, it includes lowercase letters added to the end of the reference symbol, and an index indicating an arrangement.

[0024] 1. First Implementation Method

[0025] The magnetic storage device of the first embodiment is described below. The magnetic storage device of the first embodiment is a perpendicular magnetization type magnetic storage device that uses an element having a magnetoresistive effect (MTJ element or also called a magnetoresistive effect element) through a magnetic tunnel junction (MTJ) as a resistive switching element.

[0026] 1.1 Composition

[0027] First, the configuration of the magnetic storage device according to the first embodiment will be described.

[0028] 1.1.1 Composition of magnetic storage devices

[0029] Figure 1 FIG. 1 is a block diagram showing the structure of a magnetic storage device according to the first embodiment. Figure 1 As shown, the magnetic memory device 1 includes a memory cell array 10 , a row selection circuit 11 , a column selection circuit 12 , a decoding circuit 13 , a writing circuit 14 , a reading circuit 15 , a voltage generating circuit 16 , an input / output circuit 17 , and a control circuit 18 .

[0030] The memory cell array 10 includes a plurality of memory cells MC corresponding to rows and columns. Specifically, memory cells MC in the same row are connected to the same word line WL, and memory cells MC in the same column are connected to the same bit line BL.

[0031] The row selection circuit 11 is connected to the memory cell array 10 via the word line WL. The row selection circuit 11 is supplied with the decoding result (row address) of the address ADD from the decoding circuit 13. The row selection circuit 11 sets the word line WL corresponding to the row based on the decoding result of the address ADD to a selected state. Hereinafter, the word line WL set to the selected state is referred to as a selected word line WL. In addition, the word lines WL other than the selected word line WL are referred to as non-selected word lines WL.

[0032] The column selection circuit 12 is connected to the memory cell array 10 via the bit line BL. The column selection circuit 12 is supplied with the decoding result (column address) of the address ADD from the decoding circuit 13. The column selection circuit 12 sets the row based on the decoding result of the address ADD to the selected state. Hereinafter, the bit line BL set to the selected state is referred to as the selected bit line BL. In addition, the bit lines BL other than the selected bit line BL are referred to as the non-selected bit lines BL.

[0033] The decoding circuit 13 decodes the address ADD from the input / output circuit 17. The decoding circuit 13 supplies the decoding result of the address ADD to the row selection circuit 11 and the column selection circuit 12. The address ADD includes the selected column address and row address.

[0034] The write circuit 14 writes data into the memory cell MC. The write circuit 14 includes, for example, a write driver (not shown).

[0035] The read circuit 15 reads data from the memory cell MC. The read circuit 15 includes, for example, a sense amplifier (not shown).

[0036] The voltage generating circuit 16 generates voltages for various operations of the memory cell array 10 using a power supply voltage supplied from outside the magnetic memory device 1 (not shown). For example, the voltage generating circuit 16 generates various voltages required for a write operation and outputs them to the write circuit 14. In addition, for example, the voltage generating circuit 16 generates various voltages required for a read operation and outputs them to the read circuit 15.

[0037] The input-output circuit 17 transmits the address ADD from the outside of the magnetic storage device 1 to the decoding circuit 13. The input-output circuit 17 transmits the command CMD from the outside of the magnetic storage device 1 to the control circuit 18. The input-output circuit 17 sends and receives various control signals CNT between the outside of the magnetic storage device 1 and the control circuit 18. The input-output circuit 17 transmits the data DAT from the outside of the magnetic storage device 1 to the write circuit 14, and outputs the data DAT transmitted from the read circuit 15 to the outside of the magnetic storage device 1.

[0038] The control circuit 18 controls the operations of the row selection circuit 11 , column selection circuit 12 , decoding circuit 13 , writing circuit 14 , reading circuit 15 , voltage generating circuit 16 , and input / output circuit 17 in the magnetic storage device 1 based on the control signal CNT and the command CMD.

[0039] 1.1.2 Composition of Memory Cell Array

[0040] Next, regarding the configuration of the memory cell array of the magnetic memory device of the first embodiment, the following is described using Figure 2 Provide explanation. Figure 2 FIG. 1 is a circuit diagram showing the configuration of a memory cell array of a magnetic memory device according to the first embodiment. Figure 2 In FIG. 1 , word lines WL are categorized and represented by an index including two lower case letters ("u" and "d") and an index ("<>").

[0041] like Figure 2 As shown, the memory cells MC (MCu and MCd) are arranged in a matrix in the memory cell array 10, and a correspondence relationship is established with one of the plurality of bit lines BL (BL<0>, BL<1>, ..., BL<N>)) and one of the plurality of word lines WLd (WLd<0>, WLd<1>, ..., WLd<M>) and WLu (WLu<0>, WLu<1>, ..., WLu<M>) (M and N are arbitrary integers). That is, the memory cell MCd<i, j> (0≦i≦M, 0≦j≦N) is connected between the word line WLd and the bit line BL<j>, and the memory cell MCu<i, j> is connected between the word line WLu and the bit line BL<j>.

[0042] In addition, the reference numerals "d" and "u" are added for convenience to identify the memory cells MC disposed below and above (for example, with respect to the bit line BL), respectively. An example of the three-dimensional structure of the memory cell array 10 is described below.

[0043] The memory cell MCd<i, j> includes a switching element SELd<i, j> and a magnetoresistive element MTJd<i, j> connected in series. The memory cell MCu<i, j> includes a switching element SELu<i, j> and a magnetoresistive element MTJu<i, j> connected in series.

[0044] The switch element SEL has a function as a switch that controls the supply of current to the magnetoresistive element MTJ when data is written to and read from the corresponding magnetoresistive element MTJ. More specifically, for example, when the voltage applied to the memory cell MC is lower than the threshold voltage Vth, the switch element SEL in a certain memory cell MC acts as an insulator with a larger resistance value to block the current (becomes an off state), and when the voltage is higher than the threshold voltage Vth, the switch element SEL acts as a conductor with a smaller resistance value to allow the current to flow (becomes an on state). That is, the switch element SEL has a function of switching to allow the current to flow or block according to the magnitude of the voltage applied to the memory cell MC, regardless of the direction of the flowing current.

[0045] The switching element SEL may also be, for example, a two-terminal switching element. When the voltage applied between the two terminals is below a threshold, the switching element is in a "high resistance" state, such as an electrically non-conductive state. When the voltage applied between the two terminals is above a threshold, the switching element becomes a "low resistance" state, such as an electrically conductive state. The switching element may have this function regardless of the polarity of the voltage. For example, the switching element may also include at least one chalcogen selected from the group consisting of Te (tellurium), Se (selenium) and S (sulfur). Alternatively, it may also contain a sulfide as a compound containing the chalcogen. In addition, the switching element may also include at least one element selected from the group consisting of B (boron), Al (aluminum), Ga (gallium), In (indium), C (carbon), Si (silicon), Ge (germanium), Sn (tin), As (arsenic), P (phosphorus), Sb (antimony), titanium (Ti), and bismuth (Bi). More specifically, the switching element may include at least two elements selected from germanium (Ge), antimony (Sb), tellurium (Te), titanium (Ti), arsenic (As), indium (In), and bismuth (Bi). Furthermore, the switching element may also include an oxide of at least one element selected from titanium (Ti), vanadium (V), chromium (Cr), niobium (Nb), molybdenum (Mo), hafnium (Hf), and tungsten (W).

[0046] The magnetoresistive element MTJ can switch its resistance value between a low resistance state and a high resistance state by controlling the current supplied by the switch element SEL. The magnetoresistive element MTJ functions as a memory element capable of writing data by changing the resistance state and storing and reading the written data in a nonvolatile manner.

[0047] Next, the cross-sectional structure of the memory cell array 10 is shown using Figure 3 and Figure 4 Provide explanation. Figure 3 and Figure 4 An example of a cross-sectional view for explaining the configuration of a memory cell array of the magnetic memory device according to the first embodiment is shown. Figure 3 and Figure 4 These are cross-sectional views of the memory cell array 10 observed from different intersecting directions.

[0048] like Figure 3 and Figure 4 As shown, the memory cell array 10 is provided on a semiconductor substrate 20. In the following description, the plane parallel to the surface of the semiconductor substrate 20 is set as an XY plane, and the axis perpendicular to the XY plane is set as a Z axis. Here, the positive direction of the Z axis, unless otherwise specified, may be a direction perpendicularly away from the surface of the semiconductor substrate 20, or may be a direction perpendicularly approaching the surface of the semiconductor substrate 20. In addition, in the XY plane, the axis along the word line WL is set as the X axis, and the axis along the bit line BL is set as the Y axis. That is, Figure 3 and Figure 4 These are cross-sectional views when the memory cell array 10 is viewed along the Y axis and the X axis.

[0049] On the upper surface of the semiconductor substrate 20, for example, a plurality of conductors 21 are provided. The plurality of conductors 21 have conductivity and function as word lines WLd. The plurality of conductors 21 are arranged, for example, along the Y axis and extend along the X axis. Figure 3 and Figure 4 In the above description, the case where the plurality of conductors 21 are provided on the semiconductor substrate 20 is described, but the present invention is not limited thereto. For example, the plurality of conductors 21 may be provided away from the semiconductor substrate 20 and upward.

[0050] On the upper surface of one conductor 21, a plurality of elements 22 are provided, each of which functions as a magnetoresistance effect element MTJd. The plurality of elements 22 provided on the upper surface of one conductor 21 are arranged, for example, along the X-axis. That is, on the upper surface of one conductor 21, a plurality of elements 22 arranged along the X-axis are connected in common. In addition, the details of the configuration of the element 22 are described below.

[0051] On the upper surface of each of the plurality of elements 22, an element 23 that functions as a switch element SELd is provided. The upper surface of each of the plurality of elements 23 is connected to any one of the plurality of conductors 24. The plurality of conductors 24 are conductive and function as bit lines BL. The plurality of conductors 24 are arranged, for example, along the X-axis and extend along the Y-axis. That is, a plurality of elements 23 arranged along the Y-axis are commonly connected to one conductor 24. Figure 3 and Figure 4In the above description, the case where the plurality of elements 23 are respectively provided on the element 22 and the conductor 24 is described, but the present invention is not limited thereto. For example, the plurality of elements 23 may be respectively connected to the element 22 and the conductor 24 via conductive contact plugs (not shown).

[0052] A plurality of elements 25 each functioning as a magnetoresistance effect element MTJu are provided on the upper surface of a conductor 24. The plurality of elements 25 provided on the upper surface of a conductor 24 are arranged, for example, along the Y axis. That is, the plurality of elements 25 arranged along the Y axis are commonly connected to the upper surface of a conductor 24. In addition, the element 25 has, for example, the same structure as the element 22.

[0053] On the upper surface of each of the plurality of elements 25, an element 26 that functions as a switch element SELu is provided. The upper surface of each of the plurality of elements 26 is connected to any one of the plurality of conductors 27. The plurality of conductors 27 are conductive and function as word lines WLu. The plurality of conductors 27 are arranged, for example, along the Y axis and extend along the X axis. That is, a plurality of elements 26 arranged along the X axis are commonly connected to one conductor 27. Figure 3 and Figure 4 In the above description, the case where the plurality of elements 26 are respectively provided on the element 25 and the conductor 27 is described, but the present invention is not limited thereto. For example, the plurality of elements 26 may be respectively connected to the element 25 and the conductor 27 via conductive contact plugs (not shown).

[0054] Due to the above configuration, the memory cell array 10 has a structure in which a group of two word lines WLd and WLu corresponds to one bit line BL. Furthermore, the memory cell array 10 has a memory cell MCd disposed between the word line WLd and the bit line BL, and a memory cell MCu disposed between the bit line BL and the word line WLu. In other words, the memory cell array 10 has a structure in which a plurality of memory cells MC are disposed at different heights along the Z axis. Figure 3 and Figure 4 In the cell structure shown in , the memory cell MCd is corresponding to the lower layer, and the memory cell MCu is corresponding to the upper layer. That is, of the two memory cells MC connected to one bit line BL, the memory cell MC arranged in the upper layer of the bit line BL corresponds to the memory cell MCu marked with the additional mark "u", and the memory cell MC arranged in the lower layer corresponds to the memory cell MCd marked with the additional mark "d".

[0055] 1.1.3 Magnetoresistance effect element

[0056] Next, regarding the configuration of the magnetoresistive element of the magnetic device of the first embodiment, Figure 5 Provide explanation. Figure 5FIG. 1 is a cross-sectional view showing the structure of a magnetoresistive element of the magnetic storage device according to the first embodiment. Figure 5 For example, Figure 3 and Figure 4 The magnetoresistance effect elements MTJu and MTJd shown in FIG. 1 are examples of cross sections obtained by cutting the magnetoresistance effect elements MTJu and MTJd along a plane perpendicular to the Z axis (for example, an XZ plane). Figure 5 (A) and Figure 5 (B) Corresponding.

[0057] like Figure 5 As shown, the magnetoresistance effect element MTJu, for example, includes a non-magnetic body 31u functioning as a capping layer CAP1 (Capping layer), a non-magnetic body 32u functioning as a heat absorption layer HAL (Heat absorption layer), a non-magnetic body 33u functioning as a magnetic anisotropy enhancement layer HkEL (Hk enhancement layer), a non-magnetic body 34u functioning as a capping layer CAP2, a ferromagnetic body 35u functioning as a storage layer SL (Storage layer), a non-magnetic body 36u functioning as a tunnel barrier layer TB (Tunnel barrier layer), a ferromagnetic body 37u functioning as a reference layer RL (Reference layer), a non-magnetic body 38u functioning as a spacer layer SP (Spacer layer), a ferromagnetic body 39u functioning as a shift cancelling layer SCL (Shift cancelling layer), and a non-magnetic body 40u functioning as a buffer layer BUF (Buffer layer). The magnetoresistance effect element MTJd, for example, includes a non-magnetic 31d functioning as a covering layer CAP1, a non-magnetic 32d functioning as a heat absorption layer HAL, a non-magnetic 33d functioning as a magnetic anisotropy strengthening layer HkEL, a non-magnetic 34d functioning as a covering layer CAP2, a ferromagnet 35d functioning as a storage layer SL, a non-magnetic 36d functioning as a tunnel barrier layer TB, a ferromagnet 37d functioning as a reference layer RL, a non-magnetic 38d functioning as a spacer layer SP, a ferromagnet 39d functioning as a shift compensation layer SCL, and a non-magnetic 40d functioning as a buffer layer BUF.

[0058] The capping layers CAP1 and CAP2, the magnetic anisotropy enhancement layer HkEL, the storage layer SL, the tunnel barrier layer TB, the reference layer RL, the spacer layer SP, the shift compensation layer SCL, and the buffer layer BUF have the same structure between the magnetoresistive effect element MTJu and the magnetoresistive effect element MTJd. On the other hand, the heat absorption layer HAL has different structures between the magnetoresistive effect element MTJu and the magnetoresistive effect element MTJd.

[0059] The magnetoresistance effect element MTJu is, for example, stacked with a plurality of films in the order of non-magnetic 40u, ferromagnetic 39u, non-magnetic 38u, ferromagnetic 37u, non-magnetic 36u, ferromagnetic 35u, non-magnetic 34u, non-magnetic 33u, non-magnetic 32u, and non-magnetic 31u from the side of the bit line BL toward the side of the word line WLu (in the Z-axis direction perpendicular to the substrate). The magnetoresistance effect element MTJd is, for example, stacked with a plurality of films in the order of non-magnetic 40d, ferromagnetic 39d, non-magnetic 38d, ferromagnetic 37d, non-magnetic 36d, ferromagnetic 35d, non-magnetic 34d, non-magnetic 33d, non-magnetic 32d, and non-magnetic 31d from the side of the word line WLd toward the side of the bit line BL (in the Z-axis direction). The magnetoresistance effect elements MTJu and MTJd function as, for example, perpendicular magnetization type MTJ elements in which the magnetization directions of the magnetic bodies constituting the magnetoresistance effect elements MTJu and MTJd are oriented perpendicularly to the film surfaces.

[0060] In addition, the magnetoresistance effect elements MTJu and MTJd have different structures (for example, materials or film thickness, etc.) in a part of the layers as described above, but include the same number of layers, for example. In addition, without being limited to the example of the structure, the magnetoresistance effect elements MTJu and MTJd may include more layers not shown between the layers 31u to 40u and between 31d to 40u, respectively, within the range of including the same number of layers.

[0061] The non-magnetic bodies 31u and 31d are non-magnetic conductive films, and each has a function as an upper electrode for improving the electrical connectivity of the word line WLu and the bit line BL. In addition, the non-magnetic bodies 31u and 31d, for example, include a high melting point metal. The so-called high melting point metal refers to a material having a melting point higher than that of iron (Fe) and cobalt (Co), and for example, includes at least one element selected from zirconium (Zr), hafnium (Hf), tungsten (W), chromium (Cr), molybdenum (Mo), niobium (Nb), titanium (Ti), tantalum (Ta), vanadium (V), ruthenium (Ru), and platinum (Pt).

[0062] The non-magnetic bodies 32u and 32d are non-magnetic bodies that adjust the heat flowing into the magnetoresistance effect elements MTJu and MTJd respectively when manufacturing the memory cell array 10, and have different heat absorption rates. More specifically, the heat absorption rate of the non-magnetic body 32u is set to be greater than the heat absorption rate of the non-magnetic body 32d. That is, when a certain amount of heat is applied to the memory cell array 10, the temperature of the magnetoresistance effect element MTJu becomes higher than the temperature of the magnetoresistance effect element MTJd because the non-magnetic body 32u absorbs more heat than the non-magnetic body 32d. The heat absorption rate is a ratio defined together with the reflectivity of light, and is "(reflectivity) + (heat absorption rate) = 1". From the viewpoint of suppressing the increase in the resistance value of the magnetoresistance effect elements MTJu and MTJd, the non-magnetic bodies 32u and 32d preferably contain a material having the same degree of resistivity as the non-magnetic bodies 31u and 31d. Therefore, the non-magnetic bodies 32u and 32d may respectively contain at least one element selected from zirconium (Zr), hafnium (Hf), tungsten (W), chromium (Cr), molybdenum (Mo), niobium (Nb), titanium (Ti), tantalum (Ta), vanadium (V), ruthenium (Ru), and platinum (Pt), for example.

[0063] In addition, when the non-magnetic body 32d is formed in n different layers from the layer forming the non-magnetic body 36d, the non-magnetic body 32u is also formed in n different layers (n is an integer greater than 2) from the layer forming the non-magnetic body 36u. Figure 5 In the example, the case where the non-magnetic bodies 32u and 32d are formed in different layers four layers above along the Z axis from the layers forming the non-magnetic bodies 36u and 36d, respectively.

[0064] The non-magnetic materials 33u and 33d are non-magnetic materials that contain at least one element selected from iridium (Ir), ruthenium (Ru), rhodium (Rh), molybdenum (Mo), iron (Fe), and cobalt (Co), and have the function of strengthening the perpendicular magnetic anisotropy of the ferromagnetic materials 35u and 35d, respectively.

[0065] As described above, non-magnetic body 32u and 32d are designed in a manner with mutually different heat absorption rates, so any one of the elements and film thicknesses selected can be designed to be different from each other, and the elements and / or film thicknesses are different from each other. For example, in the case where non-magnetic body 31d, non-magnetic body 32d, and non-magnetic body 33d mainly include ruthenium (Ru), non-magnetic body 31u, non-magnetic body 32u, and non-magnetic body 33u can respectively mainly include ruthenium (Ru), tantalum (Ta), and ruthenium (Ru). Here, tantalum (Ta) is a heat absorption rate greater than ruthenium (Ru), so the heat absorption rate of magnetoresistance effect element MTJu can be made greater than the heat absorption rate of magnetoresistance effect element MTJd.

[0066] In addition, the situation where the non-magnetic body 31d, the non-magnetic body 32d, and the non-magnetic body 33d all mainly contain ruthenium (Ru) includes the situation where the composition of the non-magnetic bodies 31d, 32d, and 33d is the same in the magnetoresistance effect element MTJd, and the heat absorption layer HAL cannot be distinguished from other layers (the example is the cover layer CAP1 and the magnetic anisotropy strengthening layer HkEL). This state includes the situation where the heat absorption layer HAL is explicitly not included in the magnetoresistance effect element MTJd. That is, the present embodiment includes the situation where the magnetoresistance effect element MTJd does not contain the heat absorption layer HAL, and the magnetoresistance effect element MTJu contains the heat absorption layer HAL. Similarly, the present embodiment includes the situation where the magnetoresistance effect element MTJu does not contain the heat absorption layer HAL, and the magnetoresistance effect element MTJd contains the heat absorption layer HAL.

[0067] The non-magnetic bodies 34u and 34d respectively include non-magnetic oxides, and have the function of strengthening the perpendicular magnetic anisotropy of the ferromagnetic bodies 35u and 35d, the function of suppressing the increase of the damping constant in the ferromagnetic bodies 35u and 35d, and the function of suppressing the diffusion of impurities into the ferromagnetic bodies 35u and 35d during the crystallization process of the ferromagnetic bodies 35u and 35d. Specifically, for example, the non-magnetic bodies 34u and 34d include magnesium oxide (MgO) or rare earth oxides. In the case of including magnesium oxide (MgO), the non-magnetic bodies 34u and 34d respectively have a body-centered cubic (bcc: Body-centered cubic) crystal structure (NaCl crystal structure with film surface orientation on the (001) plane) and can function as a seed material that becomes a core for growing a crystalline film from the interface with the ferromagnetic bodies 35u and 35d with high quality. In addition, when rare earth oxides are included, the non-magnetic bodies 34u and 34d can absorb boron (B) included in the ferromagnetic bodies 35u and 35d, respectively, thereby contributing to the high-quality crystallization of the ferromagnetic bodies 35u and 35d. In addition, generally speaking, oxides have insulating properties, so from the perspective of reducing resistance, it is more desirable that the film thickness of the non-magnetic bodies 34u and 34d is at most a few nanometers (nm).

[0068] The ferromagnets 35u and 35d are ferromagnets having an easy magnetization axis direction in a direction perpendicular to the film surface and having a magnetization direction along the Z axis toward either the bit line BL side or the word line WL side. The ferromagnets 35u and 35d include at least one of iron (Fe), cobalt (Co), and nickel (Ni), and may further include boron (B). More specifically, for example, the ferromagnets 35u and 35d include iron cobalt boron (FeCoB) or iron boride (FeB), and may have a body-centered cubic crystal structure.

[0069] The non-magnetic bodies 36u and 36d are non-magnetic insulators and, for example, contain magnesium oxide (MgO). The non-magnetic bodies 36u and 36d function as seed materials that form the cores of the crystalline film growth from the interface with the ferromagnetic body 35u and the interface with the ferromagnetic body 35d in the crystallization process of the ferromagnetic bodies 35u and 35d, respectively. The non-magnetic bodies 36u and 36d are respectively arranged between the ferromagnetic body 35u and the ferromagnetic body 37u, and between the ferromagnetic body 35d and the ferromagnetic body 37d, and form a magnetic tunneling junction together with these two ferromagnetic bodies.

[0070] The ferromagnets 37u and 37d are ferromagnets that have an easy magnetization axis direction in a direction perpendicular to the film surface, and have a magnetization direction along the Z axis toward either the bit line BL side or the word line WL side. The ferromagnets 37u and 37d, for example, contain at least one of iron (Fe), cobalt (Co), and nickel (Ni), and may further contain boron (B). More specifically, for example, the ferromagnets 37u and 37d contain iron cobalt boron (FeCoB) or iron boride (FeB), and may have a body-centered cubic crystal structure. The magnetization direction of the ferromagnets 37u and 37d is fixed. Figure 5 In the example, they are oriented toward the ferromagnets 39u and 39d, respectively. In addition, the so-called "fixed magnetization direction" means that the magnetization direction does not change due to the current (spin torque) of a magnitude that can reverse the magnetization direction of the ferromagnets 35u and 35d.

[0071] In addition, Figure 5 Although not shown in the figure, the ferromagnets 37u and 37d may also be laminated bodies including a plurality of layers. Specifically, for example, the laminated bodies constituting the ferromagnets 37u and 37d may also be structures having a layer containing the material as an interface layer with the non-magnets 36u and 36d on one side and a non-magnetic conductive volume layer as an intermediary. The non-magnetic conductive body may, for example, include at least one metal selected from tantalum (Ta), hafnium (Hf), tungsten (W), zirconium (Zr), molybdenum (Mo), niobium (Nb), and titanium (Ti), or a nitride or oxide of the metal. The more ferromagnets may, for example, include at least one multilayer film selected from a multilayer film of cobalt (Co) and platinum (Pt) (Co / Pt multilayer film), a multilayer film of cobalt (Co) and nickel (Ni) (Co / Ni multilayer film), and a multilayer film of cobalt (Co) and palladium (Pd) (Co / Pd multilayer film).

[0072] The non-magnetic materials 38u and 38d are non-magnetic conductive materials, and contain at least one element selected from the group consisting of ruthenium (Ru), osmium (Os), iridium (Ir), vanadium (V), and chromium (Cr), for example.

[0073] The ferromagnets 39u and 39d are ferromagnets that have easy magnetization axes in a direction perpendicular to the film surface and have magnetization directions along the Z axis toward either the bit line BL side or the word line WL side. The magnetization directions of the ferromagnets 39u and 39d are fixed in the same manner as the ferromagnets 37u and 37d, and are Figure 5 In the example, they are oriented toward the directions of the ferromagnets 37u and 37d, respectively. The ferromagnets 39u and 39d, for example, include at least one alloy selected from cobalt platinum (CoPt), cobalt nickel (CoNi), and cobalt palladium (CoPd). The ferromagnets 39u and 39d, like the ferromagnets 37u and 37d, may also be a laminate including a plurality of layers. In this case, the ferromagnets 39u and 39d, for example, may include at least one multilayer film selected from a multilayer film of cobalt (Co) and platinum (Pt) (Co / Pt multilayer film), a multilayer film of cobalt (Co) and nickel (Ni) (Co / Ni multilayer film), and a multilayer film of cobalt (Co) and palladium (Pd) (Co / Pd multilayer film).

[0074] The ferromagnets 37u and 39u, and the ferromagnets 37d and 39d are anti-ferromagnetically coupled via the non-magnets 38u and 38d, respectively. That is, the ferromagnets 37u and 39u, and the ferromagnets 37d and 39d are coupled in a manner having magnetization directions antiparallel to each other. Figure 5 In the example, the magnetization directions of the ferromagnets 37u and 39u, and the magnetization directions of the ferromagnets 37d and 39d are facing each other. The coupling structure of the ferromagnet 37u, the non-magnet 38u, and the ferromagnet 39u, and the coupling structure of the ferromagnet 37u, the non-magnet 38u, and the ferromagnet 39u are called SAF (Synthetic Anti-Ferromagnetic) structure. Thus, the ferromagnet 39u can offset the influence of the leakage magnetic field of the ferromagnet 37u on the magnetization direction of the ferromagnet 35u, and the ferromagnet 39d can offset the influence of the leakage magnetic field of the ferromagnet 37d on the magnetization direction of the ferromagnet 35d.

[0075] The non-magnetic bodies 40u and 40d are non-magnetic conductors and have the function of serving as electrodes for improving electrical connectivity with the bit line BL and the word line WLd, respectively. In addition, the non-magnetic body 38 may include at least one element selected from zirconium (Zr), hafnium (Hf), tungsten (W), chromium (Cr), molybdenum (Mo), niobium (Nb), titanium (Ti), tantalum (Ta), vanadium (V), iridium (Ir), ruthenium (Ru), rhodium (Rh), and platinum (Pt), and may further include boron (B).

[0076] In the first embodiment, a spin injection writing method is adopted in which a write current is directly flowed into the magnetoresistive element MTJ, and a spin torque is injected into the storage layer SL and the reference layer RL by the write current to control the magnetization direction of the storage layer SL and the magnetization direction of the reference layer RL. The magnetoresistive element MTJ can take either a low resistance state or a high resistance state by making the magnetization directions of the storage layer SL and the reference layer RL parallel or antiparallel relative to each other.

[0077] If a certain magnitude of write current Ic0 is Figure 5 If the magnetoresistive element MTJ flows in the direction of the arrow A1 in FIG. 1 , that is, from the storage layer SL toward the reference layer RL, the magnetization directions of the storage layer SL and the reference layer RL become parallel. In this parallel state, the resistance value of the magnetoresistive element MTJ becomes the lowest, and the magnetoresistive element MTJ is set to a low resistance state. This low resistance state is called a "P (Parallel) state" and is defined as a state of data "0", for example.

[0078] In addition, if a write current Ic1 greater than the write current Ic0 is Figure 5 If the magneto-resistance element MTJ flows in the direction of arrow A2, that is, from the reference layer RL toward the storage layer SL (opposite to arrow A1), the relative relationship between the magnetization directions of the storage layer SL and the reference layer RL becomes antiparallel. In this antiparallel state, the resistance value of the magneto-resistance element MTJ becomes the highest, and the magneto-resistance element MTJ is set to a high resistance state. This high resistance state is called the "AP (Anti-Parallel) state" and is defined as the state of data "1", for example.

[0079] In the following description, the data definition method is described, but the definition method of data "1" and data "0" is not limited to the example. For example, the P state may be defined as data "1" and the AP state may be defined as data "0".

[0080] 1.2 Method for manufacturing magnetoresistance effect element

[0081] Next, a method for manufacturing the memory cell array of the magnetic memory device according to the first embodiment will be described.

[0082] Figures 6 to 10 It is a schematic diagram for explaining the method of manufacturing the memory cell array of the magnetic memory device according to the first embodiment.

[0083] First, if Figure 6As shown in FIG. 1 , a plurality of conductors 21 extending along the X-axis are formed on the semiconductor substrate 20 in an array along the Y-axis. After the spaces between the plurality of conductors 21 are filled with an insulator not shown, a plurality of elements 22 are formed on the upper surfaces of the plurality of conductors 21. The plurality of elements 22 each include, for example, Figure 5 (B) The multilayer film corresponding to the magnetoresistive element MTJd described above. Figure 6 In the laminated film formed in the corresponding step, the ferromagnetic body 35d is formed in an amorphous state.

[0084] Next, if Figure 7 As shown in FIG. 1 , an element 23 is formed on the upper surface of each of the plurality of elements 22. Furthermore, a plurality of conductors 24 extending along the Y axis and arranged along the X axis are formed so as to be electrically connected on the upper surfaces of the plurality of elements 23 arranged along the Y axis. In addition, an insulator 28 functioning as an interlayer insulating film INSd is appropriately formed between the plurality of elements 22, between the plurality of elements 23, and between the plurality of conductors 24.

[0085] By following Figure 7 The steps described are from the step of forming other structures BEOLd immediately after the step of forming the magnetoresistive effect element MTJd is completed to the step of forming the magnetoresistive effect element MTJu immediately before the step of forming the magnetoresistive effect element MTJu is completed. Through this step, the thermal history T_BEOLd is input to the plurality of elements 22. In addition, the so-called "thermal history" of a certain step refers to the total amount of heat input to the object from the beginning to the end of the step, and the unit of the thermal history is joule (J).

[0086] Next, if Figure 8 As shown in FIG. 1 , a plurality of elements 25 are formed on the upper surface of each of the plurality of conductors 24. The plurality of elements 25 each include, for example, Figure 5 (A) The multilayer film corresponding to the magnetoresistive element MTJu described above. Figure 8 In the laminated film formed in the corresponding step, the ferromagnetic body 35u is formed in an amorphous state.

[0087] Next, if Fig. 9 As shown in FIG. 1 , an element 26 is formed on the upper surface of each of the plurality of elements 25. Furthermore, a plurality of conductors 27 extending along the X-axis and arranged along the Y-axis are formed so as to be electrically connected on the upper surfaces of the plurality of elements 26 arranged along the X-axis. In addition, an insulator 29 functioning as an interlayer insulating film INSu is appropriately formed between the plurality of elements 25, between the plurality of elements 26, between the plurality of conductors 27, and above the plurality of conductors 27.

[0088] By following Fig. 9The steps described above are steps of forming other structures BEOLu from immediately after the step of forming the magnetoresistive element MTJu to immediately before the annealing step. Through these steps, the heat history T_BEOLu is input to the plurality of elements 22 and the plurality of elements 25.

[0089] In addition, as described above, the plurality of elements 22 and the plurality of elements 25 are formed so that the heat absorption rates are different from each other. However, the heat history T_BEOLu (and T_BEOLd) is different from the heating method such as lamp annealing that rapidly applies a large amount of heat in a short period of time, and the laminated body on the semiconductor substrate 20 is heated over a relatively long period of time. Therefore, in the formation step of the structure BEOLu, the difference in the heat history caused by the difference in heat absorption rate between the plurality of elements 22 and the plurality of elements 25 is so small that it can be ignored. Therefore, the heat history T_BEOLu input to the plurality of elements 22 and the plurality of elements 25 can be regarded as the same regardless of the difference in heat absorption rate.

[0090] Next, if Fig.10 As shown, the structure formed by the above steps is heated by an annealing step. As a result, the ferromagnets 35d (and 37d) in the plurality of elements 22 and the ferromagnets 35u (and 37u) in the plurality of elements 25 are converted from an amorphous state to a crystalline state. As a result, the plurality of elements 22 and the plurality of elements 25 can obtain the characteristics of the magnetoresistive effect elements MTJd and MTJu, respectively.

[0091] In addition, this annealing step is lamp annealing that rapidly applies a large amount of heat in a short period of time. Therefore, thermal histories T_postd and T_postu related to the magnitude of the heat absorption rate are input to the plurality of elements 22 and the plurality of elements 25, respectively. In other words, the thermal history T_postd input to the plurality of elements 22 is smaller than the thermal history T_postu input to the plurality of elements 25.

[0092] Based on the above, the total thermal history Td (=T_BEOLd+T_BEOLu+T_postd) is input to the plurality of elements 22, and the total thermal history Tu (=T_BEOLu+T_postu) is input to the plurality of elements 25, and the manufacturing of the memory cell array 10 is completed.

[0093] In addition, in the above example, the case where the annealing step is performed after the conductor 27 is provided is described, but the present invention is not limited thereto. For example, the annealing step may be performed after the plurality of elements 26 are provided and before the conductor 27 is provided. In this case, during the annealing step, the heat history T_postu and T_postd respectively input to the plurality of elements 22 and 25 from above the semiconductor device 1 are blocked by the conductor 27, thereby preventing the heat history input to the plurality of elements 22 and 25 from being lost by a desired amount.

[0094] 1.3 Effects of this Implementation

[0095] According to the first embodiment, it is possible to suppress the variation in characteristics between magnetoresistive effect elements formed in different layers. This effect will be described below.

[0096] The magnetoresistance effect element MTJd is formed in a lower layer than the magnetoresistance effect element MTJu. Therefore, the heat history T_BEOLd input during the film forming process of other structures formed after the formation of the magnetoresistance effect element MTJd and before the formation of the magnetoresistance effect element MTJu is inputted to the magnetoresistance effect element MTJd more than the magnetoresistance effect element MTJu. Therefore, if the magnetoresistance effect elements MTJu and MTJd are designed to have the same heat absorption rate, there is a possibility that a difference in the amount of the heat history T_BEOLd will occur in the total heat history Tu and Td inputted until the annealing process, and this difference may cause a difference in the characteristics of the magnetoresistance effect elements MTJu and MTJd.

[0097] According to the first embodiment, the heat absorption rate of the non-magnetic body 32d is designed to be smaller than the heat absorption rate of the non-magnetic body 32u. Specifically, when the non-magnetic body 32d is formed in a manner mainly containing ruthenium (Ru), the non-magnetic body 32u is formed in a manner mainly containing tantalum (Ta) as a material having a heat absorption rate greater than ruthenium (Ru). Thus, when the same amount of heat is applied for a short time by annealing, the thermal history T_postd input to the magnetoresistance effect element MTJd is smaller than the thermal history T_postu input to the magnetoresistance effect element MTJu (T_postd<T_postu). Therefore, by setting the difference between the thermal history T_postd and the thermal history T_postu to an appropriate size (for example, about T_BEOLd), the total thermal history Td (=T_BEOLd+T_BEOLu+T_postd) input to the magnetoresistance effect element MTJd when manufacturing the memory cell array 10 can be made equal to the total thermal history Tu (=T_BEOLu+T_postu) input to the magnetoresistance effect element MTJu.

[0098] Below, use Fig.11 , additional explanation.

[0099] Fig.11 FIG. 1 is a diagram for explaining the effect of the first embodiment. Fig.11 In FIG. 1 , the horizontal axis represents the temperature applied to the magnetoresistive element MTJ during the annealing process, and the vertical axis represents the characteristics of two magnetoresistive elements MTJ having different heat absorption rates when the annealing temperature is changed from T1 to T3. Specifically, Fig.11 In (A), the change of the magnetic resistance ratio TMRu with a larger heat absorption rate is shown as line Lu1, and the change of the magnetic resistance ratio TMRd with a smaller heat absorption rate is shown as line Ld1. Fig.11In (B), the change of the antiferromagnetic coupling force Hexu with a larger heat absorption rate is represented by line Lu2, and the change of the antiferromagnetic coupling force Hexd with a smaller heat absorption rate is represented by line Ld2. Fig.11 , the case where the same thermal history T_BEOL is input to the magnetoresistive elements MTJu and MTJd during film formation is shown (that is, the thermal history other than the annealing treatment is not considered).

[0100] like Fig.11 As shown in (A), the line Ld1 representing the change of the magnetoresistance ratio TMRd is shifted to the right side of the paper (positive direction of the horizontal axis) with respect to the line Lu1 representing the change of the magnetoresistance ratio TMRu in a delayed response to the annealing temperature. Specifically, the magnetoresistance ratio TMRd when the annealing temperature T2 is applied is equal to the magnetoresistance ratio TMRu when the annealing temperature (T2-Δ) is applied, and the magnetoresistance ratio TMRd when the annealing temperature (T2+Δ) is applied is equal to the magnetoresistance ratio TMRu when the annealing temperature T2 is applied (Δ>0).

[0101] In addition, if Fig.11 As shown in (B), the line Ld2 representing the change of the antiferromagnetic coupling force Hexd is shifted to the right side of the paper (positive direction of the horizontal axis) with respect to the line Lu2 representing the change of the antiferromagnetic coupling force Hexu in a delayed response to the annealing temperature. Specifically, the antiferromagnetic coupling force Hexd when the annealing temperature T2 is applied is equal to the antiferromagnetic coupling force Hexu when the annealing temperature (T2-Δ) is applied, and the antiferromagnetic coupling force Hexd when the annealing temperature (T2+Δ) is applied is equal to the antiferromagnetic coupling force Hexu when the annealing temperature T2 is applied.

[0102] In this way, by making the heat absorption rates of the magnetoresistive effect elements MTJu and MTJd different from each other, the heat histories input during the annealing process can be made different from each other. As a result, the difference T_BEOLd in the heat histories generated between the magnetoresistive effect elements MTJ formed in different layers can be offset, so that the total heat histories Tu and Td can be made equal. Therefore, the uneven characteristics between the magnetoresistive effect elements MTJ can be suppressed.

[0103] 1.4 Variation 1

[0104] In the first embodiment, the storage layer SL is formed in the top free structure above the reference layer RL, and the heat absorption layer HAL is formed above the storage layer SL. However, the present invention is not limited thereto. For example, the heat absorption layer HAL may be formed below the storage layer SL in the top free structure. In the following, for the sake of convenience, the differences from the first embodiment are mainly described.

[0105] Fig.12is a cross-sectional view showing the structure of a magnetoresistive element of a magnetic storage device according to a first variation of the first embodiment, and corresponds to the first embodiment. Figure 5 .

[0106] like Fig.12 As shown, the magnetoresistance effect element MTJu, for example, is stacked with multiple films in the order of a non-magnetic 32uA functioning as a heat absorption layer HAL, a non-magnetic 41u functioning as a crystal separation layer (Crystal separationlayer) CSL, a non-magnetic 40u, a ferromagnetic 39u, a non-magnetic 38u, a ferromagnetic 37u, a non-magnetic 36u, a ferromagnetic 35u, a non-magnetic 34u, a non-magnetic 33u, and a non-magnetic 31u from the bit line BL side toward the word line WLu side (in the Z-axis direction). The magnetoresistance effect element MTJd, for example, is stacked with multiple films in the order of a non-magnetic 32dA functioning as a heat absorption layer HAL, a non-magnetic 41d functioning as a crystal separation layer CSL, a non-magnetic 40d, a ferromagnet 39d, a non-magnetic 38d, a ferromagnet 37d, a non-magnetic 36d, a ferromagnet 35d, a non-magnetic 34d, a non-magnetic 33d, and a non-magnetic 31d, from the word line WLd side toward the bit line BL side (in the Z-axis direction).

[0107] When the non-magnetic body 32dA is formed in n different layers from the layer forming the non-magnetic body 36d, the non-magnetic body 32uA is similarly formed in n different layers (n is an integer greater than 2) from the layer forming the non-magnetic body 36u. Fig.12 In the example, it is shown that non-magnetic bodies 32uA and 32dA are formed in 6 different layers below along the Z axis from the layers forming non-magnetic bodies 36u and 36d, respectively. In addition, non-magnetic bodies 32uA and 32dA are equivalent to non-magnetic bodies 32u and 32d in the first embodiment except for the different layers formed, so the description is omitted.

[0108] The non-magnetic bodies 41u and 41d are layers in an amorphous state and have the function of separating the crystalline structure between the upper layer and the lower layer. In addition, the non-magnetic bodies 41u and 41d are preferably not crystallized by annealing (e.g., at a high temperature of about 400°C) and remain in an amorphous state. Therefore, the non-magnetic bodies 41u and 41d may include, for example, hafnium boride (HfB).

[0109] By forming the heat absorption layer HAL below the storage layer SL in the above manner, the crystallinity of each layer in the magnetoresistive element MTJ can be maintained. Therefore, the heat absorption rate between the upper magnetoresistive element MTJu and the lower magnetoresistive element MTJd can be made different while maintaining the characteristics such as magnetic anisotropy or magnetoresistance ratio.

[0110] 1.5 Example 2

[0111] In the first embodiment, the cover layer CAP1 is formed on the upper layer of the heat absorbing layer HAL in the top free structure, but the present invention is not limited thereto. For example, the cover layer CAP1 may not be formed. Hereinafter, for convenience of description, the differences from the first embodiment will be mainly described.

[0112] Fig.13 is a cross-sectional view showing the structure of a magnetoresistive element of a magnetic storage device according to a second variation of the first embodiment, and corresponds to the first embodiment. Figure 5 .

[0113] like Fig.13 As shown, the magnetoresistance effect elements MTJu and MTJd in the second variation of the first embodiment are formed with non-magnetic bodies 32u and 32d at the top layer, respectively. In this case, the heat absorption rate between the magnetoresistance effect elements MTJu and MTJd can also be made different, thereby achieving the same effect as the first embodiment.

[0114] 2. Second Implementation Method

[0115] Next, the magnetic storage device of the second embodiment is described. In the first embodiment, the case where the magnetoresistance effect element MTJ is a top free structure is described, and in the second embodiment, the case where the magnetoresistance effect element MTJ of the bottom free structure is a bottom free structure is described. The magnetoresistance effect element MTJ of the bottom free structure is formed by forming the storage layer SL below the reference layer.

[0116] 2.1 Magnetoresistance effect element

[0117] The magnetoresistance effect element of the magnetic device of the second embodiment is constructed using Fig.14 Provide explanation. Fig.14 2 is a cross-sectional view showing the structure of a magnetoresistive element of a magnetic storage device according to the second embodiment, and corresponds to the structure of the first embodiment. Figure 5 .

[0118] like Fig.14As shown, the magnetoresistance effect element MTJu, for example, includes a non-magnetic body 51u functioning as a covering layer CAP1, a non-magnetic body 52u functioning as a heat absorption layer HAL, a ferromagnetic body 53u functioning as a shift compensation layer SCL, a non-magnetic body 54u functioning as a spacer layer, a ferromagnetic body 55u functioning as a reference layer RL, a non-magnetic body 56u functioning as a tunnel barrier layer TB, a ferromagnetic body 57u functioning as a storage layer SL, a non-magnetic body 58u functioning as an under layer, a non-magnetic body 59u functioning as a magnetic anisotropy strengthening layer HkEL, and a non-magnetic body 60u functioning as a buffer layer BUF. The magnetoresistance effect element MTJd, for example, includes a non-magnetic 51d functioning as a covering layer CAP1, a non-magnetic 52d functioning as a heat absorption layer HAL, a ferromagnet 53d functioning as a shift compensation layer SCL, a non-magnetic 54d functioning as a spacer layer, a ferromagnet 55d functioning as a reference layer RL, a non-magnetic 56d functioning as a tunnel barrier layer TB, a ferromagnet 57d functioning as a storage layer SL, a non-magnetic 58d functioning as a base layer, a non-magnetic 59d functioning as a magnetic anisotropy strengthening layer HkEL, and a non-magnetic 60d functioning as a buffer layer BUF.

[0119] When the non-magnetic body 52d is formed in n different layers from the layer forming the non-magnetic body 56d, the non-magnetic body 52u is similarly formed in n different layers (n is an integer greater than 2) from the layer forming the non-magnetic body 56u. Fig.14 In the example, the non-magnetic bodies 52u and 52d are respectively formed in different layers four layers above along the Z axis from the layers forming the non-magnetic bodies 56u and 56d.

[0120] The capping layer CAP1, the shift compensation layer SCL, the spacer layer SP, the reference layer RL, the tunnel barrier layer TB, the storage layer SL, the magnetic anisotropy enhancement layer HkEL, and the buffer layer BUF are the same as those in the first embodiment, and have the same structure between the magnetoresistance effect element MTJu and the magnetoresistance effect element MTJd. In addition, the base layer UL is the same as the capping layer CAP2 in the first embodiment, and has the same structure between the magnetoresistance effect element MTJu and the magnetoresistance effect element MTJd. On the other hand, the heat absorption layer HAL is such that the heat absorption rate of the magnetoresistance effect element MTJu is greater than the heat absorption rate of the magnetoresistance effect element MTJd.

[0121] By configuring in the above manner, the heat absorption layer HAL can be formed above the storage layer SL when the magnetoresistance effect element MTJ is made into a bottom free structure. Therefore, the heat absorption rate between the upper magnetoresistance effect element MTJu and the lower magnetoresistance effect element MTJd can be different, thereby suppressing the unevenness of the characteristics between the layers.

[0122] 2.2 Variation 1

[0123] In the second embodiment, the case where the heat absorption layer HAL is formed above the storage layer SL in the bottom free structure is described, but the present invention is not limited thereto. For example, the heat absorption layer HAL may also be formed below the storage layer SL in the bottom free structure. In the following, for the sake of convenience, the differences from the second embodiment are mainly described.

[0124] Fig.15 is a cross-sectional view showing the structure of a magnetoresistive element of a magnetic storage device according to a first variation of the second embodiment, and corresponds to the structure of the magnetoresistive element of the second embodiment. Fig.14 .

[0125] like Fig.15 As shown, the magnetoresistance effect element MTJu, for example, is stacked with multiple films in the order of a non-magnetic 52uA functioning as a heat absorption layer HAL, a non-magnetic 61u functioning as a crystal separation layer CSL, a non-magnetic 60u, a non-magnetic 59u, a non-magnetic 58u, a ferromagnet 57u, a non-magnetic 56u, a ferromagnet 55u, a non-magnetic 54u, a ferromagnet 53u, and a non-magnetic 51u from the bit line BL side toward the word line WLu side (in the Z-axis direction). The magnetoresistance effect element MTJd, for example, is stacked with multiple films in the order of a non-magnetic 52dA functioning as a heat absorption layer HAL, a non-magnetic 61d functioning as a crystal separation layer CSL, a non-magnetic 60d, a non-magnetic 59d, a non-magnetic 58d, a ferromagnet 57d, a non-magnetic 56d, a ferromagnet 55d, a non-magnetic 54d, a ferromagnet 53d, and a non-magnetic 51d, from the word line WLd side toward the bit line BL side (in the Z-axis direction).

[0126] When the non-magnetic body 52dA is formed in n different layers from the layer forming the non-magnetic body 56d, the non-magnetic body 52uA is similarly formed in n different layers (n is an integer greater than 2) from the layer forming the non-magnetic body 56u. Fig.15 In the example, non-magnetic bodies 52uA and 52dA are respectively formed from the layers forming non-magnetic bodies 56u and 56d in different layers 4 below along the Z axis. Non-magnetic bodies 52uA and 52dA are the same as non-magnetic bodies 52u and 52d in the second embodiment except for the different layers formed, so the description is omitted.

[0127] The non-magnetic bodies 61u and 61d are layers in an amorphous state and have the function of separating the crystalline structure between the upper layer and the lower layer. In addition, the non-magnetic bodies 61u and 61d are preferably not crystallized by annealing (e.g., at a high temperature of about 400°C) and remain in an amorphous state. Therefore, the non-magnetic bodies 61u and 61d may include, for example, hafnium boride (HfB).

[0128] Since the structure is constructed as described above, even if the heat absorption layer HAL is formed below the storage layer SL, the crystallinity of each layer in the magnetoresistive element MTJ can be maintained. Therefore, the heat absorption rate between the upper magnetoresistive element MTJu and the lower magnetoresistive element MTJd can be made different while maintaining the characteristics such as magnetic anisotropy or magnetoresistance ratio.

[0129] 2.3 Variation 2

[0130] In the second embodiment, the cover layer CAP1 is formed on the upper layer of the heat absorbing layer HAL in the bottom free structure, but the present invention is not limited thereto. For example, the cover layer CAP1 may not be formed. Hereinafter, for convenience of description, the differences from the second embodiment will be mainly described.

[0131] Fig.16 is a cross-sectional view showing the structure of a magnetoresistive element of a magnetic storage device according to a second variation of the second embodiment, and corresponds to the second embodiment. Fig.14 .

[0132] like Fig.16 As shown, the magnetoresistance effect elements MTJu and MTJd in the second variation of the second embodiment are formed with non-magnetic bodies 52u and 52d at the top layer, respectively. In this case, the heat absorption rate between the magnetoresistance effect elements MTJu and MTJd can also be made different, thereby achieving the same effect as the second embodiment.

[0133] 3. Others

[0134] In addition, the present invention is not limited to the first and second embodiments described above, and various modifications can be applied.

[0135] In the first embodiment and the second embodiment, the case where materials are included in order to make the heat absorption rate between the upper heat absorption layer HAL and the lower heat absorption layer HAL different is described, but it is not limited to this. For example, the upper heat absorption layer HAL can be formed to have a thicker film thickness than the lower heat absorption layer HAL regardless of whether it mainly contains the same elements as the lower heat absorption layer HAL. As a result, the heat absorption rate of the upper heat absorption layer HAL can be greater than the heat absorption rate of the lower heat absorption layer HAL. Therefore, during the annealing process, the input thermal history can be made different from each other, and the difference T_BEOLd in the thermal history generated between the magnetoresistance effect elements MTJu and MTJd formed in different layers can be offset by this difference. Therefore, the total thermal history Tu and Td can be made equal, so that the characteristic unevenness between the magnetoresistance effect elements MTJu and MTJd can be suppressed.

[0136] Several embodiments of the present invention have been described, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the subject matter of the invention. These embodiments or their variations are included in the scope or subject matter of the invention, and are included in the invention described in the claims and their equivalents.

Claims

1. A magnetic storage device, characterized in that have: substrate; a first laminate; and a second laminated body located on the same side of the substrate as the first laminated body, disposed above the first laminated body in a first direction perpendicular to the substrate, and further away from the substrate than the first laminated body; The first layered body and the second layered body each include: Reference layer; a tunnel barrier layer, disposed above the reference layer in the first direction; A storage layer, arranged above the tunnel barrier layer in the first direction; a first non-magnetic layer, disposed above the storage layer in the first direction, and functioning as a heat absorbing layer; and a second non-magnetic layer disposed above or below the first non-magnetic layer in the first direction, To function as a covering; and The first non-magnetic layer of the first laminate includes an element and a film thickness different from those of the first non-magnetic layer of the second laminate; The heat absorption rate of the first non-magnetic layer of the first laminate is lower than the heat absorption rate of the first non-magnetic layer of the second laminate.

2. The magnetic storage device according to claim 1, characterized in that The first non-magnetic layer of the first laminate includes ruthenium, The first nonmagnetic layer of the second layered body includes tantalum.

3. The magnetic storage device according to claim 1, characterized in that The film thickness of the first non-magnetic layer of the first laminate is thinner than the film thickness of the first non-magnetic layer of the second laminate.

4. The magnetic storage device according to claim 1, characterized in that The first layered body and the second layered body each further include: a third non-magnetic layer disposed between the first non-magnetic layer and the second non-magnetic layer and comprising at least one element selected from the group consisting of ruthenium, iridium, rhodium, molybdenum, iron, and cobalt; and The second non-magnetic layer is provided between the memory layer and the first non-magnetic layer, and includes an oxide.

5. The magnetic storage device according to claim 1, characterized in that The second non-magnetic layer comprises metal, and The second non-magnetic layer is located farther from the substrate than the reference layer, the tunnel barrier layer, the memory layer, and the first non-magnetic layer.

6. The magnetic storage device according to claim 1, characterized in that The first layered body and the second layered body each further include: shift compensation layer and spacer layer; and The reference layer is disposed above the shift compensation layer in the first direction; and The spacer layer is disposed between the shift compensation layer and the reference layer, and contains at least one element selected from ruthenium, osmium, iridium, vanadium, and chromium.

7. The magnetic storage device according to claim 1, characterized in that The memory layer and the reference layer include at least one element selected from the group consisting of iron, cobalt, and nickel.

8. The magnetic storage device according to claim 1, characterized in that The first stacked body or the second stacked body has a first resistance value according to a first current flowing from the memory layer to the reference layer, and The first stacked body or the second stacked body has a second resistance value in response to a second current flowing from the reference layer to the memory layer.

9. The magnetic storage device according to claim 8, characterized in that The first resistance value is smaller than the second resistance value.

10. The magnetic storage device according to claim 1, characterized in that The first stacked body and the second stacked body each include a switch element connected in series with the memory layer, the reference layer, and the tunnel barrier layer.

11. A magnetic storage device, characterized in that have: substrate; a first laminate; and a second laminated body located on the same side of the substrate as the first laminated body, disposed above the first laminated body in a first direction perpendicular to the substrate, and further away from the substrate than the first laminated body; The first layered body and the second layered body each include: The first non-magnetic layer functions as a heat absorbing layer; a second non-magnetic layer provided above the first non-magnetic layer in the first direction and functioning as a cover layer; a reference layer disposed below the first non-magnetic layer in the first direction; a tunnel barrier layer, disposed below the reference layer in the first direction; and a storage layer disposed below the tunnel barrier layer in the first direction; and The first non-magnetic layer of the first laminate includes an element and a film thickness different from those of the first non-magnetic layer of the second laminate; The heat absorption rate of the first non-magnetic layer of the first laminate is lower than the heat absorption rate of the first non-magnetic layer of the second laminate.

12. The magnetic storage device according to claim 11, characterized in that The first non-magnetic layer of the first laminate includes ruthenium, The first nonmagnetic layer of the second layered body includes tantalum.

13. The magnetic storage device according to claim 11, characterized in that The film thickness of the first non-magnetic layer of the first laminate is thinner than the film thickness of the first non-magnetic layer of the second laminate.

14. The magnetic storage device according to claim 11, characterized in that The first layered body and the second layered body each further include: shift compensation layer and spacer layer; and The reference layer is disposed below the shift compensation layer in the first direction; and The spacer layer is disposed between the shift compensation layer and the reference layer, and contains at least one element selected from ruthenium, osmium, iridium, vanadium, and chromium.

15. The magnetic storage device according to claim 11, characterized in that The memory layer and the reference layer include at least one element selected from the group consisting of iron, cobalt, and nickel.

16. The magnetic storage device according to claim 11, characterized in that The first stacked body or the second stacked body has a first resistance value according to a first current flowing from the memory layer to the reference layer, and The first stacked body or the second stacked body has a second resistance value in response to a second current flowing from the reference layer to the memory layer.

17. The magnetic storage device according to claim 16, characterized in that The first resistance value is smaller than the second resistance value.

18. The magnetic storage device according to claim 11, characterized in that The first stacked body and the second stacked body each include a switch element connected in series with the memory layer, the reference layer, and the tunnel barrier layer.

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