JP2006278645A - Magnetic memory device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic memory device having a magnetoresistive effect element using a spin injection magnetization reversing mechanism, and a manufacturing method for the device which device and method prevent a malfunction due to a magnetic field leaking from wiring such as word lines or bit lines, that are formed near the magnetroresistive effect element. <P>SOLUTION: The magnetic memory device includes the magnetroresistive effect element which has a ferromagnetic layer 50, nonmagnetic layer 52 formed on the ferromagnetic layer 50, and a ferromagnetic layer 54 formed on the nonmagnetic layer 52, and which reverses the direction of magnetization of the ferromagnetic layer 54 by injection of spin; and a first wiring 78 which is formed near the magnetoresistive effect element and is made by coating a nonmagnetic conductor material 74 with a shield layer consisting of magnetic conductor materials 72, 76. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnetic memory device, and more particularly to a magnetic memory device having a magnetoresistive effect element using a spin injection magnetization reversal mechanism and a method for manufacturing the same.

  In recent years, magnetic random access memory (hereinafter referred to as MRAM: Magnetic Random Access Memory) in which magnetoresistive effect elements are arranged in a matrix has attracted attention as a rewritable nonvolatile memory. The MRAM stores information using a combination of magnetization directions in two magnetic layers, and changes in resistance (that is, changes in current or voltage) when the magnetization directions between these magnetic layers are parallel and antiparallel. The stored information is read by detecting this.

  As magnetoresistive elements that constitute the MRAM, GMR (Giant Magnetoresistive) elements and TMR (Tunneling Magnetoresistive) elements have been studied. In particular, a TMR element that can obtain a large resistance change has attracted attention as a magnetoresistive effect element used in MRAM.

  A TMR element is formed by laminating two ferromagnetic magnetic layers via a tunnel insulating film. Based on the relationship between the magnetization directions of the two ferromagnetic layers, a tunnel current flowing between the magnetic layers via the tunnel insulating film is generated. It uses a changing phenomenon. That is, the TMR element has a low element resistance when the magnetization directions of the two ferromagnetic layers are parallel, and has a high element resistance when the two ferromagnetic layers are antiparallel. By associating these two states with data “0” and data “1”, it can be used as a memory element.

  As a method of writing to the magnetoresistive effect element, current is passed through two orthogonal signal lines (for example, a bit line and a write word line), and a combined magnetic field generated from these signal lines is applied to the MTJ element. A method of changing the magnetization direction of one ferromagnetic layer (free magnetic layer) to a direction corresponding to an applied magnetic field (current magnetic field writing method) is common.

  However, in this method, the generation efficiency of the combined magnetic field generated by the bit line and the write word line and the ease of reversing the external magnetic field of the free magnetic layer influence the power consumption and reliability. In particular, when the size of the magnetoresistive effect element is reduced in order to improve the recording density, the demagnetizing field of the free magnetic layer increases, so that the magnetization switching magnetic field Hc of the free magnetic layer increases. In other words, with higher integration, the write current increases and the power consumption increases.

  In order to solve this problem, a so-called cladding structure has been proposed in which the periphery of the write word line and the bit line other than the opposing surfaces of the magnetoresistive effect element portion is shielded with a magnetic material to concentrate the magnetic flux (for example, a patent structure) Reference 1). However, since the magnetization reversal field of the free magnetic layer increases almost in inverse proportion to the reduction in element size, it is predicted that the write current will increase remarkably in the conventional current magnetic field writing method, and in fact it will be difficult to write. (For example, see Non-Patent Document 1).

  Further, when data is written, the magnetization of the free magnetic layer of a predetermined selection element is reversed by a magnetic field superimposed by applying a current to the bit line and the write word line. A current magnetic field also acts on a number of non-selected elements connected to the word line. An element in such a state is defined as a half-selected state, and magnetization reversal is likely to occur unstable, causing malfunction. In addition, an MRAM having a structure to which a select transistor is connected requires a write word line for writing in addition to a bit line and a word line, which complicates the device structure and the manufacturing process.

  From this point of view, attention has recently been focused on spin-injection magnetization reversal elements (see, for example, Non-Patent Document 1). The spin-injection magnetization reversal element is a magnetoresistive effect element configured by sandwiching an insulating layer or a nonmagnetic metal layer between two ferromagnetic layers, like the GMR element and the TMR element.

  In a spin-injection magnetization reversal element, when a current is passed from the free magnetic layer side to the fixed magnetic layer side perpendicular to the film surface, spin-polarized conduction electrons flow from the fixed magnetic layer to the free magnetic layer, Exchange interaction. As a result, torque is generated between the electrons, and when this torque is sufficiently large, the magnetic moment of the free magnetic layer is reversed from antiparallel to parallel. On the other hand, when the current application is reversed, it can be reversed from parallel to antiparallel due to the reverse effect. That is, the spin-injection magnetization reversal element is a storage element that can induce reversal of the magnetization of the free magnetic layer only by current control (application direction and applied current value) and rewrite the storage state.

In the spin-injection magnetization reversal element, the reversal current is reduced due to the volume reduction effect even if the element size is decreased and the magnetization reversal magnetic field Hc is increased. It is extremely advantageous for the conversion. Further, no write word line is required, and the device structure and manufacturing method can be simplified.
JP 2002-246666 A JP 2004-259913 A JP 2004-281599 A JP 2001-006127 A JP 2003-318460 A Kojiro Rooftop et al., “Research Trends of Spin Injection Magnetization Reversal”, Journal of Japan Society of Applied Magnetics, Vol. 28 No. 9, 2004, pp.937-948 Michael A. Seigler et al., "Use of a permanent magnet in the synthetic antiferromagnet of a spin-valve", Journal of Applied Physics, Vol. 91, p. 2176, 2002

  However, in a magnetic memory device using a spin-injection magnetization reversal element, the magnetization reversal of the free magnetic layer is induced by a leakage magnetic field from a wiring provided near the spin-injection magnetization reversal element such as a word line or a bit line. Malfunctions sometimes occurred.

  An object of the present invention is to provide a magnetic memory device having a magnetoresistive effect element using a spin-injection magnetization reversal mechanism to prevent malfunction due to a leakage magnetic field from a wiring provided near the magnetoresistive effect element such as a word line or a bit line. An object of the present invention is to provide a magnetic memory device that can be prevented and a method of manufacturing the same.

  According to one aspect of the present invention, a first ferromagnetic layer, a nonmagnetic layer formed on the first ferromagnetic layer, a second ferromagnetic layer formed on the magnetic layer, A magnetoresistive effect element that reverses the magnetization of the second ferromagnetic layer by spin injection, and is provided in the vicinity of the magnetoresistive effect element, and a nonmagnetic conductor material is covered with a magnetic conductor material. There is provided a magnetic memory device having one wiring.

  According to the present invention, in the magnetic memory device having the magnetoresistive effect element using the spin transfer magnetization reversal mechanism, the wiring provided in the vicinity of the magnetoresistive effect element has the shield wiring structure. Can prevent malfunction. In addition, the wiring electrically connected to the magnetoresistive effect element has a shield wiring structure and a connection layer made of a nonmagnetic conductor material is provided between the magnetoresistive effect element and the wiring. The magnetic coupling between the wiring and the wiring can be broken. Thereby, the influence of the leakage magnetic field from wiring can be prevented effectively.

[First Embodiment]
A magnetic memory device and a manufacturing method thereof according to a first embodiment of the present invention will be described with reference to FIGS.

  1 is a perspective view showing the structure of the magnetic memory device according to the present embodiment, FIG. 2 is a schematic cross-sectional view showing the structure of the magnetic memory device according to the present embodiment, and FIGS. 3 to 6 are diagrams for manufacturing the magnetic memory device according to the present embodiment. It is process sectional drawing which shows a method.

  First, the structure of the magnetic memory device according to the present embodiment will be explained with reference to FIGS. The magnetic memory device according to the present embodiment is a simple matrix type magnetic memory device.

  As shown in FIG. 1, an interlayer insulating film 28 is formed on the silicon substrate 10. In the interlayer insulating film 28, a word line 64 composed of a Ta film 36, a NiFe film 38, a Cu film 40, and a NiFe film 44 is embedded.

  A lower electrode layer 46 is formed on the NiFe film 44. On the lower electrode layer 46, a magnetoresistive effect element 60 in which an antiferromagnetic layer 48, a fixed magnetization layer 50, a tunnel insulating film 52, a free magnetization layer 54 and a cap layer 56 are laminated is formed.

  An interlayer insulating film 66 is formed on the interlayer insulating film 28 on which the magnetoresistive effect element 60 is formed. On the interlayer insulating film 66, a bit line 78 is formed which is made of a Ti film 70, a NiFe film 72, an Al film 74, and a NiFe film 76 and is electrically connected to the cap layer 60 of the magnetoresistive effect element 60. . An interlayer insulating film 80 is formed on the bit line 78.

  As shown in FIG. 2, a plurality of word lines 64 are formed in parallel in the Y direction, for example, and a plurality of bit lines 78 are formed in parallel in the X direction, for example. . The magnetoresistive effect element 60 is formed by being electrically connected to each intersection of the word line 64 and the bit line 78.

  Here, in the magnetic memory device according to the present embodiment, the word line 64 and the bit line 78 have a shield wiring structure in which a low-resistance nonmagnetic conductor material is surrounded by a high permeability magnetic conductor material. There are main characteristics.

  That is, the word line 64 is covered with the NiFe film 38, which is a high magnetic permeability magnetic conductor material, on the bottom and side surfaces of the Cu film 40, which is the main wiring portion made of a low-resistance nonmagnetic conductor material, and the NiFe film 44 is on the top surface. Covered by. In the bit line 78, the bottom surface of the Al film 74, which is the main wiring portion made of a low-resistance nonmagnetic conductor material, is covered with the NiFe film 72, and the side surface and top surface of the Al film 74 are covered with the NiFe film 76. .

  In this way, by providing a shield layer made of a magnetic conductor material having a high magnetic permeability so as to cover the outer periphery of the main wiring portion which is the main current path, the magnetic field generated from the main wiring portion by flowing current is It is confined by the shield layer surrounding it and the leakage magnetic field can be minimized. Thereby, the malfunction of the magnetoresistive effect element by a leakage magnetic field can be prevented.

  A magnetic material made of Co, Ni, Fe, or an alloy thereof can be used as the magnetic conductor material with high permeability applied to the shield wiring structure.

  In the magnetic memory device according to the present embodiment, the lower electrode layer 46 made of a nonmagnetic conductor material is provided between the word line 64 and the magnetoresistive effect element 60, and between the magnetoresistive effect element 60 and the bit line 78. A cap layer 56 made of a nonmagnetic conductor material is provided. The lower electrode layer 46 and the cap layer 56 have a role to electrically connect the word line 64 and bit line 78 and the magnetoresistive effect element 60 with a low resistance. It also has a role of preventing magnetic exchange coupling with the resistive element 60. That is, the lower electrode layer 46 cuts the magnetic coupling between the word line 64 and the magnetoresistive effect element 60, and the cap layer 56 provides the magnetic coupling between the magnetoresistive effect element 60 and the bit line 78. To cut.

Nonmagnetic conductor materials formed between the word line 64 and bit line 78 and the magnetoresistive element 60 include refractory metals such as Ta, Ti, and W, or nitride compounds thereof such as TaN, TiN, WN, and Ru. , Ir or other conductive oxide (RuO ₂ , IrO ₂ ) or the like can be used. Further, two or more films made of these materials may be stacked.

  Next, the method for manufacturing the magnetic memory device according to the present embodiment will be explained with reference to FIGS.

  First, a silicon oxide film is deposited on the silicon substrate 10 by, for example, a CVD method to form an interlayer insulating film 28 made of a silicon oxide film.

  Next, a wiring trench 34 having a depth of about 430 nm, for example, is formed in the interlayer insulating film 28 by photolithography and dry etching (FIG. 3A).

  Next, for example, by sputtering or CVD, for example, a Ta film having a film thickness of 10 nm is used as a base conductor material, and a NiFe film 38 having a film thickness of 30 nm, for example, is used as a low-magnetic nonmagnetic conductor material. For example, a Cu film 40 having a thickness of 600 nm is sequentially deposited (FIG. 3B). The Cu film 40 may be deposited by electrolytic plating after the seed layer is deposited by sputtering or CVD.

  Next, the Cu film 40, the NiFe film 38, and the Ta film 36 are planarized by, for example, a CMP method until the interlayer insulating film 28 is exposed (FIG. 3C).

  Next, for example, a 30 nm-thickness NiFe film 44 is deposited on the interlayer insulating film 28 in which the Ta film 36, the NiFe film 38, and the Cu film 40 are buried as a high magnetic permeability magnetic conductor material, for example, by sputtering or CVD.

  Next, a Ta film of, eg, a 50 nm-thickness is deposited on the NiFe film 44 to form a lower electrode layer 46 made of the Ta film.

  Next, an antiferromagnetic material such as PtMn, IrMn, PdPtMn or the like having a film thickness of 8 to 30 nm, for example, an IrMn film having a film thickness of 15 nm is deposited on the lower electrode layer 46 by, for example, sputtering, and the antiferromagnetic material made of the IrMn film is deposited. Layer 48 is formed.

  Next, a ferromagnetic material such as Co, CoFe, or NiFe having a film thickness of 1 to 10 nm, for example, a CoFe film having a film thickness of 4 nm, and a nonmagnetic material having a film thickness of, for example, 0. A laminated ferrimagnetic pinned magnetic layer 50 made of CoFe / Ru / CoFe is formed by laminating an 8 nm Ru film and a ferromagnetic material such as Co, CoFe, NiFe, etc., having a film thickness of 1 to 10 nm, for example, a CoFe film having a film thickness of 4 nm. Form. In the case of a structure in which the leakage magnetic field from the fixed magnetic layer 50 does not affect the free magnetic layer 54, a single CoFe film may be used.

Next, an insulating material such as 0.1 to 10 nm thick AlO, TiO, MgO, TaO, for example, an alumina (Al ₂ O ₃ ) film having a thickness of 0.6 nm is formed on the fixed magnetic layer 50 by, eg, sputtering. A tunnel insulating film 52 made of an alumina film is deposited.

  Next, a ferromagnetic material made of CoFe, CoFeB, NiFe or the like having a film thickness of 0.5 to 5 nm, for example, a CoFe film having a film thickness of 2 nm, for example, is deposited on the tunnel insulating film 52 by sputtering, for example. A magnetic layer 54 is formed.

  Next, a Ru film having a film thickness of 1 to 20 nm, for example, 10 nm, and a Ta film having a film thickness of 10 to 200 nm, for example, 40 nm are deposited on the free magnetic layer 54 by, for example, sputtering to form a nonmagnetic conductor material. A cap layer 56 made of a laminated film of a Ru film and a Ta film is formed (FIG. 4A).

  Next, a photoresist film 58 having a pattern of the magnetoresistive effect element to be formed is formed on the cap layer 56 by photolithography.

  Next, the cap layer 56, the free magnetic layer 54, the tunnel insulating film 52, the fixed magnetic layer 50, and the antiferromagnetic layer 48 are anisotropically etched by dry etching using the photoresist film 58 as a mask. Thereby, for example, the magnetoresistive effect element 60 having a size of 200 × 400 nm is formed (FIG. 4B).

  Next, the photoresist film 58 is removed by, for example, ashing.

  Next, a photoresist film 62 covering the magnetoresistive effect element 60 is formed by photolithography.

  Next, the lower electrode layer 46 and the NiFe film 44 are anisotropically etched by dry etching using the photoresist film 62 as a mask. Thereby, a word line 64 composed of the Ta film 36, the NiFe film 38, the Cu film 40, and the NiFe film 44 is formed (FIG. 4C). The word line 64 has a shield structure in which the periphery of the Cu film 40 that is a main wiring portion made of a low-resistance nonmagnetic conductor material is surrounded by NiFe films 38 and 44 that are magnetic conductor materials having high permeability.

  Next, the photoresist film 62 is removed by, for example, ashing.

  Next, a silicon oxide film is deposited by, eg, CVD, and an interlayer insulating film 66 made of the silicon oxide film is formed.

  Next, a contact hole 68 reaching the cap layer 56 of the magnetoresistive effect element 60 is formed in the interlayer insulating film 66 by photolithography and dry etching (FIG. 5A).

  Next, for example, by CVD or sputtering, a Ti film 70 having a thickness of 10 nm, for example, is used as a base conductor material, and a NiFe film 72 having a thickness of 30 nm, for example, is used as a low-magnetic nonmagnetic conductor material. For example, an Al film 74 having a thickness of 600 nm is sequentially deposited (FIG. 5B).

  Next, the Al film 74, the NiFe film 72, and the Ti film 70 are anisotropically etched by photolithography and dry etching, and patterned into the shape of the bit line to be formed.

  Next, a NiFe film 76 of, eg, a 30 nm-thickness is deposited as a high permeability magnetic conductor material by, eg, CVD or sputtering.

  Next, the NiFe film 76 is anisotropically etched by photolithography and dry etching, and patterned into the shape of the bit line to be formed. As a result, a bit line 78 composed of the Ti film 70, the NiFe film 72, the Al film 74, and the NiFe film 76 is formed (FIG. 6A). The bit line 78 has a shield structure in which the periphery of the Al film 74, which is a main wiring portion made of a low-resistance nonmagnetic conductor material, is surrounded by NiFe films 72 and 78, which are high permeability magnetic conductor materials.

  Next, a silicon oxide film, for example, is deposited on the entire surface by, eg, CVD, and an interlayer insulating film 80 made of the silicon oxide film is formed (FIG. 6B).

  Thereafter, if necessary, an insulating layer, a wiring layer, and the like are further formed on the upper layer to complete the magnetic memory device.

  As described above, according to the present embodiment, in the magnetic memory device having the magnetoresistive effect element using the spin injection magnetization reversal mechanism, the wiring provided in the vicinity of the magnetoresistive effect element has the shield wiring structure. It is possible to prevent a malfunction due to a leakage magnetic field from the wiring. In addition, the wiring electrically connected to the magnetoresistive effect element has a shield wiring structure and a connection layer made of a nonmagnetic conductor material is provided between the magnetoresistive effect element and the wiring. The magnetic coupling between the wiring and the wiring can be broken. Thereby, the influence of the leakage magnetic field from wiring can be prevented effectively.

[Second Embodiment]
A magnetic memory device and a manufacturing method thereof according to the second embodiment of the present invention will be described with reference to FIGS. The same components as those in the magnetic memory device and the manufacturing method thereof according to the first embodiment shown in FIGS. 1 to 6 are denoted by the same reference numerals, and description thereof is omitted or simplified.

  FIG. 7 is a schematic sectional view showing the structure of the magnetic memory device according to the present embodiment, and FIGS. 8 to 10 are process sectional views showing the method for manufacturing the magnetic memory device according to the present embodiment.

  First, the structure of the magnetic memory device according to the present embodiment will be explained with reference to FIG. The magnetic memory device according to the present embodiment is an active matrix magnetic memory device.

  On the surface of the silicon substrate 10, an element isolation film 12 that defines an active region is formed.

  In the active region of the silicon substrate 10 defined by the element isolation film 12, a selection transistor having a gate electrode 14 and source / drain regions 16 and 18 formed in the silicon substrate 10 on both sides thereof is formed. .

  An interlayer insulating film 20 is formed on the silicon substrate 10 on which the selection transistor is formed. Contact plugs 24 connected to the source / drain regions 16 are embedded in the interlayer insulating film 20. A ground line 26 electrically connected to the source / drain region 16 via the contact plug 24 is formed on the interlayer insulating film 20.

  An interlayer insulating film 28 is formed on the interlayer insulating film 20 on which the ground line 26 is formed. A contact plug 32 connected to the source / drain region 18 is embedded in the interlayer insulating film 28. A lower electrode layer 46 electrically connected to the source / drain region 18 through the contact plug 32 is formed on the interlayer insulating film 28.

  On the lower electrode layer 46, a magnetoresistive effect element 60 in which an antiferromagnetic layer 48, a fixed magnetization layer 50, a tunnel insulating film 52, a free magnetization layer 54 and a cap layer 56 are laminated is formed. An interlayer insulating film 66 is embedded on the interlayer insulating film 28 and the lower electrode layer 64 other than the region where the magnetoresistive element 60 is formed. On the interlayer insulating film 66 in which the magnetoresistive effect element 60 is embedded, a Ti film 70, a NiFe film 72, an Al film 74, and a NiFe film 76 are electrically connected to the cap layer 60 of the magnetoresistive effect element 60. A bit line 78 is formed. An interlayer insulating film 80 is formed on the bit line 78.

  The gate electrode 14 also functions as a word line extending in the direction perpendicular to the paper surface. A plurality of word lines and a plurality of bit lines 78 are arranged in a matrix, and an active matrix magnetic memory device is configured.

  Here, the magnetic memory device according to the present embodiment is mainly characterized in that the bit line 78 has a shield wiring structure in which a low-resistance nonmagnetic conductor material is surrounded by a high permeability magnetic conductor material. .

  That is, in the bit line 78, the bottom surface of the Al film 74, which is the main wiring portion made of a low-resistance nonmagnetic conductor material, is covered with the NiFe film 72, and the side surface and top surface of the Al film 74 are covered with the NiFe film 76. .

  In this way, by providing a shield layer made of a magnetic conductor material having a high magnetic permeability so as to cover the outer periphery of the main wiring portion which is the main current path, the magnetic field generated from the main wiring portion by flowing current is It is confined by the shield layer surrounding it and the leakage magnetic field can be minimized. Thereby, the malfunction of the magnetoresistive effect element by a leakage magnetic field can be prevented.

  In the magnetic memory device according to the present embodiment, the cap layer 56 made of a nonmagnetic conductor material is provided between the magnetoresistive effect element 60 and the bit line 78. The cap layer 56 has a role of electrically connecting the bit line 78 and the magnetoresistive effect element 60 with a low resistance, and has a magnetic exchange coupling between the bit line 78 and the magnetoresistive effect element 60. It also has a role to prevent it from occurring. That is, the cap layer 56 cuts the magnetic coupling between the magnetoresistive effect element 60 and the bit line 78.

  In the magnetic memory device according to the present embodiment, the gate electrode 14 functioning as a word line does not have a shield wiring structure. This is because, in addition to the word line being separated from the magnetoresistive effect element 60, the current flowing through the word line is not so large that the leakage magnetic field becomes a problem.

  In addition, since a current flows to the lower electrode layer 46 of the magnetoresistive effect element 60 through the contact plug 32, the current path is perpendicular to the film surface of the magnetoresistive effect element 60. Therefore, the influence of the leakage magnetic field on the magnetoresistive effect element 60 can be ignored.

  Next, the method for manufacturing the magnetic memory device according to the present embodiment will be explained with reference to FIGS.

  First, the element isolation film 12 is formed on the silicon substrate 10 by, eg, STI (Shallow Trench Isolation) method.

  Next, a selection transistor having the gate electrode 14 and the source / drain regions 16 and 18 is formed in the active region defined by the element isolation film 12 in the same manner as a normal MOS transistor forming method (FIG. 8A). ).

  Next, after a silicon oxide film is deposited on the silicon substrate 10 on which the selection transistor is formed by, for example, a CVD method, the surface is flattened by a CMP method to form an interlayer insulating film 20 made of a silicon oxide film.

  Next, contact holes 22 reaching the source / drain regions 16 are formed in the interlayer insulating film 20 by photolithography and dry etching.

  Next, after depositing a titanium nitride film and a tungsten film as a barrier metal by, for example, CVD, these conductive films are etched back or polished back, embedded in the contact holes 22 and electrically connected to the source / drain regions 16. Contact plug 24 is formed.

  Next, a conductive film is deposited and patterned on the interlayer insulating film 20 in which the contact plug 24 is embedded, and a ground line 26 electrically connected to the source / drain region 16 through the contact plug 24 is formed (FIG. 8 (b)).

  Next, a silicon oxide film is deposited on the interlayer insulating film 20 on which the ground line 26 is formed, for example, by the CVD method, and then the surface is planarized by the CMP method to form an interlayer insulating film 28 made of the silicon oxide film.

  Next, contact holes 30 reaching the source / drain regions 18 are formed in the interlayer insulating films 40 and 28 by photolithography and dry etching.

  Next, after depositing a titanium nitride film and a tungsten film as a barrier metal by, for example, a CVD method, the conductive film is etched back or polished back, embedded in the contact hole 30 and electrically connected to the source / drain region 18. A contact plug 32 is formed (FIG. 8C).

  Next, a Ta film of, eg, a 50 nm-thickness is deposited on the interlayer insulating film 28 with the contact plugs 32 buried in to form a lower electrode layer 46 made of a Ta film.

  Next, an antiferromagnetic material such as PtMn, IrMn, PdPtMn, or the like having a film thickness of 8 to 30 nm, for example, a PtMn film having a film thickness of 15 nm, is deposited on the lower electrode layer 46 by, for example, sputtering. Layer 48 is formed.

  Next, a ferromagnetic material such as Co, CoFe, or NiFe having a film thickness of 1 to 10 nm, for example, a CoFe film having a film thickness of 4 nm, and a nonmagnetic material having a film thickness of, for example, 0. A laminated ferrimagnetic pinned magnetic layer 50 made of CoFe / Ru / CoFe is formed by laminating an 8 nm Ru film and a ferromagnetic material such as Co, CoFe, NiFe, etc., having a film thickness of 1 to 10 nm, for example, a CoFe film having a film thickness of 4 nm. Form. In the case of a structure in which the leakage magnetic field from the fixed magnetic layer 50 does not affect the free magnetic layer 54, a single CoFe film may be used.

Next, an insulating material such as 0.1 to 10 nm thick AlO, TiO, MgO, TaO, for example, an alumina (Al ₂ O ₃ ) film having a thickness of 0.6 nm is formed on the fixed magnetic layer 50 by, eg, sputtering. A tunnel insulating film 52 made of an alumina film is deposited.

  Next, a ferromagnetic material made of CoFe, CoFeB, NiFe or the like having a film thickness of 0.5 to 5 nm, for example, a CoFe film having a film thickness of 2 nm, for example, is deposited on the tunnel insulating film 52 by sputtering, for example. A magnetic layer 54 is formed.

  Next, a Ru film having a film thickness of 1 to 20 nm, for example, 10 nm, and a Ta film having a film thickness of 10 to 200 nm, for example, 40 nm are deposited on the free magnetic layer 54 by, for example, sputtering to form a nonmagnetic conductor material. A cap layer 56 made of a laminated film of a Ru film and a Ta film is formed.

  Next, the cap layer 56, the free magnetic layer 54, the tunnel insulating film 52, the fixed magnetic layer 50, and the antiferromagnetic layer 48 are anisotropically etched by photolithography and dry etching, for example, a magnetoresistance having a size of 200 × 400 nm. The effect element 60 is formed (FIG. 9A).

  Next, the lower electrode layer 46 is patterned into a predetermined shape by photolithography and dry etching.

  Next, after a silicon oxide film is deposited on the interlayer insulating film 28 on which the magnetoresistive effect element 60 is formed by, for example, a CVD method, the silicon oxide film is planarized by the CMP method until the magnetoresistive effect element 60 is exposed, and the surface An interlayer insulating film 66 made of a silicon oxide film having a flattened surface is formed.

  Next, for example, by CVD or sputtering, a Ti film 70 having a thickness of 10 nm, for example, is used as a base conductor material, and a NiFe film 72 having a thickness of 30 nm, for example, is used as a low-magnetic nonmagnetic conductor material. For example, an Al film 74 having a thickness of 600 nm is sequentially deposited.

  Next, the Al film 74, the NiFe film 72, and the Ti film 70 are anisotropically etched by photolithography and dry etching, and patterned into the shape of the bit line to be formed (FIG. 10A).

  Next, a NiFe film 76 of, eg, a 30 nm-thickness is deposited as a high permeability magnetic conductor material by, eg, CVD or sputtering.

  Next, the NiFe film 76 is anisotropically etched by photolithography and dry etching, and patterned into the shape of the bit line to be formed. Thereby, a bit line 78 composed of the Ti film 70, the NiFe film 72, the Al film 74, and the NiFe film 76 is formed. The bit line 78 has a shield structure in which the periphery of the Al film 74, which is a main wiring portion made of a low-resistance nonmagnetic conductor material, is surrounded by NiFe films 72 and 78, which are high permeability magnetic conductor materials.

  Next, a silicon oxide film, for example, is deposited on the entire surface by, eg, CVD, and an interlayer insulating film 80 made of the silicon oxide film is formed (FIG. 10B).

  Thereafter, if necessary, an insulating layer, a wiring layer, and the like are further formed on the upper layer to complete the magnetic memory device.

  As described above, according to the present embodiment, in the magnetic memory device having the magnetoresistive effect element using the spin injection magnetization reversal mechanism, the wiring provided in the vicinity of the magnetoresistive effect element has the shield wiring structure. It is possible to prevent a malfunction due to a leakage magnetic field from the wiring. In addition, the wiring electrically connected to the magnetoresistive effect element has a shield wiring structure and a connection layer made of a nonmagnetic conductor material is provided between the magnetoresistive effect element and the wiring. The magnetic coupling between the wiring and the wiring can be broken. Thereby, the influence of the leakage magnetic field from wiring can be prevented effectively.

[Modified Embodiment]
The present invention is not limited to the above embodiment, and various modifications can be made.

  For example, in the above embodiment, the wiring directly connected to the magnetoresistive effect element has a shield wiring structure, but other wiring may have a shield wiring structure. In particular, it is desirable to apply a shielded wiring structure to a wiring provided in the vicinity of the magnetoresistive effect element and flowing a current that causes a leakage magnetic field. For example, in the second embodiment, the ground line 26 may have a shield wiring structure. Thereby, the influence of the leakage magnetic field from the ground line 26 can also be prevented.

  In the above-described embodiment, the case where the TMR type spin injection magnetization reversal element configured by sandwiching the tunnel insulating film between the two ferromagnetic layers is applied as the magnetoresistive effect element is described. Further, the present invention can be similarly applied to a GMR type spin injection magnetization reversal element configured by sandwiching a nonmagnetic metal intermediate layer such as Cu, Ag, Au, or Ru.

  As described above in detail, the features of the present invention are summarized as follows.

(Supplementary Note 1) A first ferromagnetic layer, a nonmagnetic layer formed on the first ferromagnetic layer, and a second ferromagnetic layer formed on the magnetic layer, and a spin layer A magnetoresistive element that reverses the magnetization of the second ferromagnetic layer by implantation of
1. A magnetic memory device comprising: a first wiring provided in the vicinity of the magnetoresistive effect element, wherein a nonmagnetic conductor material is covered with a magnetic conductor material.

(Supplementary note 2) In the magnetic memory device according to supplementary note 1,
The magnetic memory device, wherein the first wiring is electrically connected to the second ferromagnetic layer of the magnetoresistive element through a connection layer made of a nonmagnetic conductor material.

(Appendix 3) In the magnetic memory device according to Appendix 1 or 2,
The magnetic memory device, wherein the first wiring is a bit line.

(Appendix 4) In the magnetic memory device according to any one of appendices 1 to 3,
A magnetic memory device, further comprising a second wiring formed to extend in a direction crossing the first wiring and having a nonmagnetic conductive material covered with a magnetic conductive material.

(Supplementary Note 5) In the magnetic memory device according to Supplementary Note 4,
The magnetic memory device, wherein the second wiring is electrically connected to the first ferromagnetic layer of the magnetoresistive element through a connection layer made of a nonmagnetic conductor material.

(Appendix 6) In the magnetic memory device according to Appendix 4 or 5,
The magnetic memory device, wherein the second wiring is a word line.

(Appendix 7) In the magnetic memory device according to any one of appendices 1 to 4,
A magnetic memory device, further comprising: a selection transistor electrically connected to the first ferromagnetic layer of the magnetoresistive element.

(Appendix 8) In the magnetic memory device according to any one of appendices 1 to 7,
The magnetic memory device, wherein the nonmagnetic layer of the magnetoresistive effect element is a tunnel insulating film.

(Supplementary note 9) In the magnetic memory device according to supplementary note 1 or 4,
The magnetic memory material that constitutes the shield layer is made of Co, Ni, Fe, or an alloy thereof.

(Supplementary Note 10) In the magnetic memory device according to Supplementary Note 2 or 5,
The nonmagnetic conductor material constituting the connection layer is made of a material selected from the group including Ta, Ti, W, TaN, TiN, WN, Ru, and Ir, or a laminated film thereof. Magnetic memory device.

1 is a schematic cross-sectional view showing a structure of a magnetic memory device according to a first embodiment of the present invention. 1 is a perspective view illustrating a structure of a magnetic memory device according to a first embodiment of the present invention. FIG. 6 is a process cross-sectional view (part 1) illustrating the method for manufacturing the magnetic memory device according to the first embodiment of the invention; FIG. 9 is a process cross-sectional view (part 2) illustrating the method for manufacturing the magnetic memory device according to the first embodiment of the present invention; FIG. 9 is a process cross-sectional view (part 3) illustrating the method for manufacturing the magnetic memory device according to the first embodiment of the present invention; FIG. 9 is a process cross-sectional view (part 4) illustrating the method for manufacturing the magnetic memory device according to the first embodiment of the present invention; FIG. 6 is a schematic cross-sectional view showing the structure of a magnetic memory device according to a second embodiment of the present invention. It is process sectional drawing (the 1) which shows the manufacturing method of the magnetic memory device by 2nd Embodiment of this invention. It is process sectional drawing (the 2) which shows the manufacturing method of the magnetic memory device by 2nd Embodiment of this invention. It is process sectional drawing (the 3) which shows the manufacturing method of the magnetic memory device by 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Silicon substrate 12 ... Element isolation film 14 ... Gate electrode 16, 18 ... Source / drain area | region 20, 28, 66, 80 ... Interlayer insulating film 22, 30, 68 ... Contact hole 24, 32 ... Contact plug 26 ... Ground line 34 ... Wiring groove 36 ... Ta films 38, 44, 72, 76 ... NiFe film 40 ... Cu film 46 ... Lower electrode layer 48 ... Antiferromagnetic layer 50 ... Fixed magnetic layer 52 ... Tunnel insulating film 54 ... Free magnetic layer 56 ... Cap layers 58, 62 ... Photoresist film 60 ... Magnetoresistive element 64 ... Word line 70 ... Ti film 74 ... Al film 78 ... Bit line

Claims (5)

A first ferromagnetic layer; a nonmagnetic layer formed on the first ferromagnetic layer; and a second ferromagnetic layer formed on the magnetic layer. A magnetoresistive element that reverses the magnetization of the second ferromagnetic layer;
1. A magnetic memory device comprising: a first wiring provided in the vicinity of the magnetoresistive effect element and having a nonmagnetic conductor material covered with a magnetic conductor material. The magnetic memory device according to claim 1,
The magnetic memory device, wherein the first wiring is electrically connected to the second ferromagnetic layer of the magnetoresistive element through a connection layer made of a nonmagnetic conductor material. The magnetic memory device according to claim 1 or 2,
A magnetic memory device, further comprising a second wiring formed to extend in a direction crossing the first wiring and having a nonmagnetic conductive material covered with a magnetic conductive material. The magnetic memory device according to claim 3.
The magnetic memory device, wherein the second wiring is electrically connected to the first ferromagnetic layer of the magnetoresistive element through a connection layer made of a nonmagnetic conductor material. The magnetic memory device according to any one of claims 1 to 3,
A magnetic memory device, further comprising: a selection transistor electrically connected to the first ferromagnetic layer of the magnetoresistive element.

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