JP2005268252A - Method of manufacturing magnetic memory device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily remove a reactive product by forming an electrochemically less noble metal film 81 after etching a magnetic layer. <P>SOLUTION: A magnetic memory device 1 comprises a magneto-resistance effect element 13 which is such that a magnetic layer (first thin film) 232, a tunnel insulation layer 233, and another magnetic layer (second thin film) 234 are laminated in order. A method of the magnetic memory device 1 comprises a process wherein, after a process of forming a top pattern 130 of the magneto-resistance effect element 1 by etching or ion-milling a top electrode layer 235 and the second thin film 234 from such a state that the top electrode layer 235 formed on the second thin film 234, the second thin film 234, and the tunnel insulation layer 233 are laminated, and the electrochemically less noble metal film 81 is so formed that it may enter between the side wall of the top pattern 130 and the reactive product 71 generated by the etching or ion-milling; and a process of removing the metal film 81 as well as the reactive product 71. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a magnetic memory device that facilitates removal of reaction products generated during processing for forming a magnetoresistive element.

In a magnetic material such as a ferromagnetic material, a magnetoresistive effect is known in which the electrical resistance changes depending on the direction of magnetization, the presence or absence of magnetization, and the like. The rate of change of the electric resistance value is called a magnetoresistance ratio (MR ratio). Materials having a large magnetoresistance ratio include Giant Magneto-Resistance (GMR) materials and Colossal Magneto-Resistance (CMR) materials, which are generally metals, alloys, composite oxides, etc. It is. For example, iron (Fe), nickel (Ni), cobalt (Co), gadolinium (Gd), terbium (Tb) and alloys thereof, La _x Sr _1-x MnO ₉ (0 ≦ x ≦ 1), La _x There are materials such as complex oxides such as Ca _1-X MnO ₉ (0 ≦ x ≦ 1). In general, a ferromagnetic material has a characteristic that magnetization generated in the ferromagnetic material by a magnetic field applied from the outside remains even after the external magnetic field is removed (this is called residual magnetization).

  Therefore, if a ferromagnetic material is used as a magnetoresistive material and the residual magnetization of the ferromagnetic material is used, a nonvolatile memory that stores information by selecting an electrical resistance value depending on the magnetization direction and the presence or absence of magnetization can be configured. it can. Such a non-volatile memory is called a magnetic memory (MRAM (Magnetic Random Access Memory)).

  In recent years, many MRAMs that are being developed store information by the remanent magnetization of a ferromagnetic material of a giant magnetoresistive material, and convert the change in electrical resistance value caused by the difference in magnetization direction into a voltage. The method of reading the stored information is adopted. Further, by changing the magnetization direction of the ferromagnetic memory cell by a magnetic field induced by passing a current through the write wiring, information can be written into the memory cell or the information can be rewritten.

  As an MRAM cell, a tunnel magnetoresistive element (TMR: Tunnel Magneto-Resistance, or MTJ) having a structure in which a tunnel insulating layer (an electrical insulating film having a thickness sufficient for a tunnel current to flow) is sandwiched between two ferromagnetic layers. Magnetic Tunnel Junction) has a high magnetoresistance change rate (MR ratio) and is expected to be the device most practically used.

  Such a tunnel magnetoresistive element is processed into a desired shape by depositing a magnetic material or a tunnel insulating layer material using a sputtering method and then patterning it using a dry process such as ion milling or plasma etching. Is done. Specifically, after a magnetic material or a tunnel insulating layer material is formed on a substrate, a photosensitive resist (photoresist) is applied to the surface of the laminated film to be processed, and the resist is exposed and developed. Fine processing is performed by an ion milling device or an etching device using plasma. The dry etching (reactive ion etching) using plasma is easier to incorporate into the semiconductor wafer process, and the sheet resistance may be reduced.

  However, when dry etching or ion milling is used, residue is deposited on the sidewall of the multilayer film due to the reaction between the gas used for dry etching or ion milling and the photoresist or multilayer film material to be processed, and the resistance of the tunnel magnetoresistive element increases. Cause. The reaction product can be dissolved and removed with an aqueous solution of an acid having a low pH. At this time, however, corrosion of the laminated film material itself, corrosion of the tunnel insulating layer, and excessive oxidation occur, resulting in the tunnel magnetoresistive element. There was a problem of losing the function as (MTJ).

  For example, as shown in FIG. 7A, in the tunnel magnetoresistive element manufacturing process, a thin film mainly including a lower electrode layer 431, an antiferromagnetic material layer (not shown), and a ferromagnetic film serving as a magnetization fixed layer. 432, a tunnel insulating layer 433, a thin film 434 mainly including a ferromagnetic film serving as a memory layer, and an upper electrode layer 435 are sequentially stacked, and then a hard mask 436 made of silicon nitride is formed. Then, using the hard mask 436 as an etching mask, the thin film 434 mainly composed of the upper electrode layer 435 and the ferromagnetic film serving as the memory layer is dry-etched in the stacked film. As a result, as shown in FIG. 7B, the upper electrode 335 and the memory layer 334 are formed on the sidewalls of the upper electrode 335 and the memory layer 334 formed by etching the upper electrode layer 435 and the thin film 434 mainly composed of the ferromagnetic film serving as the memory layer. The reaction product 371 remains. This reaction product 371 can be removed by acid washing as shown in FIG. However, the acid cleaning corrodes the upper electrode 335 and the memory layer 334 made of a ferromagnetic film. Further, the tunnel insulating layer 333 is corroded or excessively oxidized.

  In order to solve the above problems, a recess is formed in the interlayer insulating film, and a ferromagnetic tunnel junction element is formed in the recess, an antiferromagnetic layer, a first ferromagnetic layer, a tunnel insulating layer, and a second ferromagnetic layer. A method of forming a ferromagnetic tunnel junction element by stacking body layers to form a multilayer film and then removing the multilayer film on the interlayer insulating film other than the recess by chemical mechanical polishing (see, for example, Patent Document 1) .) Is disclosed. However, since this manufacturing method uses chemical mechanical polishing, over polishing is required to completely polish and remove the multilayer film on the interlayer insulating film. In this case, the interlayer insulating film is also excessively polished, so-called dishing occurs, the interlayer insulating film becomes too thin locally, and high-precision processing is difficult.

JP 2001-168418 A

  The problem to be solved is that when the magnetoresistive effect element is processed with high precision by dry etching or ion milling, it does not cause corrosion of the upper electrode or ferromagnetic film, or corrosion or excessive oxidation of the tunnel insulating layer. The etching reaction product (so-called residue) is difficult to remove.

  The method for manufacturing a magnetic memory device according to the present invention comprises a first thin film mainly composed of a magnetic material, a tunnel insulating layer mainly composed of a non-magnetic material, and a second thin film mainly composed of a magnetic material. A method of manufacturing a magnetic memory device including a magnetoresistive effect element, comprising: an upper electrode layer formed on the second thin film; the second thin film; and the tunnel insulating layer, and the upper electrode layer and After the step of etching or ion milling the second thin film to form the upper pattern of the magnetoresistive effect element, the second thin film may enter between the sidewall of the upper pattern and a reaction product generated by the etching or ion milling. The main feature is that it includes a step of forming an electrochemically base metal film, and a step of removing the metal film and removing the reaction product.

  According to the method of manufacturing a magnetic memory device of the present invention, the upper electrode layer and the second thin film are etched or ion milled from the state in which the upper electrode layer, the second thin film, and the tunnel insulating layer formed on the second thin film are stacked. After the step of forming the upper pattern of the resistance effect element, a step of forming an electrochemically base metal film so as to enter between the side wall of the upper pattern and a reaction product generated by etching or ion milling. Since it is provided, the metal film grows so as to enter a slight gap between the side wall of the upper pattern and the reaction product, and stresses the reaction product. Eventually, the reaction product generated on the side wall of the upper pattern is peeled off from the side wall of the upper pattern as the metal film grows. Since the metal film is removed and the reaction product is removed, when the metal film is removed, the stress on the side wall is alleviated and the reaction product is easily peeled off from the side wall of the upper pattern. To be removed. Thus, there is an advantage that the etching reaction product can be removed without causing corrosion of the upper electrode or the thin film of the magnetic material, or corrosion or excessive oxidation of the tunnel insulating layer.

  When a magnetoresistive element is processed with high precision by dry etching or ion milling, etching reaction products (so-called residues) are produced without causing corrosion of the upper electrode or ferromagnetic film or corrosion or excessive oxidation of the tunnel insulating layer. The upper electrode formed on the magnetoresistive effect element and the thin film constituting the magnetoresistive effect element are laminated or the thin film constituting the magnetoresistive effect element is etched or ion milled. After the step of forming the upper pattern of the magnetoresistive effect element, an electrochemically base metal film is formed so as to enter between the upper pattern side wall and the reaction product generated by etching or ion milling. Realized.

  The method for manufacturing a magnetic memory device of the present invention is effective when applied to the manufacture of a magnetoresistive effect element of a magnetic memory device (for example, MRAM). First, an example of the magnetic storage device will be described with reference to the schematic configuration perspective view of FIG. 4, the circuit diagram of FIG. 5, and the schematic configuration cross-sectional view of FIG.

  As shown in FIG. 4, a plurality of (three are shown as an example in the drawing) write word lines 11 (111, 112) including a plurality of (6 shown as an example in the drawing) and intersecting each other. 113) and a plurality of bit lines 12 (121, 122) (two are shown as an example in the drawing). In each intersection region of the write word line 11 and the bit line 12, each write word line 11 is electrically connected to each bit line 12 through an insulating film (not shown), for example, an upper electrode 135 is connected. A magnetoresistive effect element (for example, TMR (Tunnel Magneto Resistance)) 13 connected via the wiring is disposed. Each magnetoresistive element 13 basically includes a fixed magnetization layer 132 made of a layer containing a ferromagnetic material from the lower layer, a tunnel insulating layer 133 made of an insulator, and a storage layer 134 made of a layer containing a ferromagnetic material that reverses magnetization. It has a laminated structure. An antiferromagnetic layer (not shown) is connected to the lower layer of the magnetization fixed layer 132 of each magnetoresistive effect element 13, and a lower electrode 131 is further formed. The lower electrode 131 is connected to the selection element 20. For example, the selection element 20 is an insulated gate field effect transistor formed on a semiconductor substrate (not shown). The lower electrode 131 is connected to one diffusion layer of the field effect transistor, the word line 25 is connected to the gate electrode 22, and the sense line 15 is connected to the other diffusion layer.

  That is, one memory cell of the magnetic memory device has a so-called one magnetoresistive effect element 13 and one selection element (for example, MOS transistor) 20 as shown in FIG.

  An example of a cross-sectional configuration of the magnetic storage device 1 will be described with reference to FIG.

  As shown in FIG. 6, the selection element 20 is formed on the semiconductor substrate 10. Here, as an example, the selection element 20 is composed of, for example, an insulated gate MOS transistor. That is, the gate electrode 22 is formed on the semiconductor substrate 10 via the gate insulating film 21, and the diffusion layers 23 and 24 are formed on the semiconductor substrate 10 on both sides of the gate electrode 22. The selection element 20 is covered with an insulating film 41. On the insulating film 41, an electrode 32 is formed on one diffusion layer 23 of the selection element 20 via a contact portion 31, and a sense line 15 is formed on the diffusion layer 24 via a contact portion 33. . On the insulating film 41, an insulating film 42 covering the electrode 32 and the sense line 15 is formed. A plug 34 connected to the electrode 32 is formed in the insulating film 42. An insulating film 43 is formed on the insulating film 42, and an electrode 35 connected to the write word line 11 and the plug 34 is formed on the insulating film 43 in parallel, for example. On the insulating film 43, an insulating film 44 that covers the write word line 11 and the electrode 36 is formed, and a plug 36 that is connected to the electrode 35 is formed.

  On the insulating film 44, a lower electrode 131 is formed on the write word line 11, passing through the intersection region with the bit line 12 and connected to the plug 36. An antiferromagnetic layer (not shown), a magnetization fixed layer 132, a tunnel insulating layer 133, a storage layer 134, and an upper portion are formed on the lower electrode 131 and in the intersection region between the write word line 11 and the bit line 12. The electrode 135 is formed by laminating in order from the lower layer. Thus, the magnetoresistive effect element 13 is basically formed of a laminated structure of the magnetization fixed layer 132, the tunnel insulating layer 133, and the storage layer 134.

  An insulating film 45 is formed on the insulating film 44 so as to cover the magnetoresistive effect element 13, and an upper electrode 135 is exposed on the surface thereof. An insulating film 46 is formed on the insulating film 45. The insulating film 46 three-dimensionally intersects (orthogonally) with the write word line and the magnetoresistive element 13 in between. A connected bit line 12 is formed.

  The configuration of the magnetic memory device described above is an example, and can be changed as appropriate except for the write word line 11, the bit line 12, the magnetoresistive effect element 13, the sense line 15, the selection element 20, and their connection relationship. it can.

  In the magnetic memory device 1 having the above configuration, the direction of the magnetic moment of the magnetization fixed layer 132 is held by an antiferromagnetic material layer (not shown). On the other hand, the direction of the magnetic moment of the storage layer 134 can be reversed by a magnetic field generated according to Ampere's law by applying a current of an appropriate direction and magnitude to the bit line 12 and the write word line 11. That is, by changing the direction of the magnetic moment of the storage layer 134, the magnetic moment of the magnetization fixed layer 132 and the storage layer 134 can be in a parallel or antiparallel state. Therefore, when a read voltage is applied to the word line 25 to make the selection element (MOS transistor) 20 conductive and an appropriate voltage is applied to the bit line 12, the magnetic moments of the magnetization fixed layer 132 and the storage layer 134 are parallel or opposite. A tunnel current of a magnitude corresponding to the parallel flows. Information can be read by detecting the magnitude of this current.

  Next, an embodiment of the method for manufacturing a magnetic memory device according to the present invention will be described with reference to the schematic sectional views of FIGS. Although one memory cell is described in the drawings, the magnetic memory device has a plurality of memory cells arranged vertically and horizontally at equal intervals in the semiconductor substrate surface.

  First, as shown in FIG. 2, the selection element 20 is formed on the semiconductor substrate 10. Here, as an example, the selection element 20 is a MOS transistor formed by a normal MOS transistor formation technique. That is, the gate electrode (word line) 22 is formed on the semiconductor substrate 10 via the gate insulating film 21, and the diffusion layers 23 and 24 are formed on the semiconductor substrate 10 on both sides of the gate electrode 22. Thereafter, after forming the insulating film 41 covering the selection element, the electrode 32 and the other diffusion layer 24 of the selection element 20 are formed on the insulation film 41 via the contact portion 31 on one diffusion layer 23 of the selection element 20. The sense line 15 is formed through the contact portion 33. Next, an insulating film 42 covering the electrode 32 and the sense line 15 is formed, and a plug 34 connected to the electrode 32 is formed. Further, after forming the insulating film 43 on the insulating film 42, the electrode 35 connected to the write word line 11 and the plug 34 is formed on the insulating film 43. Next, after forming the insulating film 44 covering the write word line 11 and the electrode 35, an opening that exposes the upper surface of the electrode 35 is formed in the insulating film 44 by a normal lithography technique and etching technique. A plug 36 is formed in the opening. Next, after cleaning the upper surface of the plug 36, a lower electrode layer 231 connected to the plug 36 is formed on the insulating film 44.

  Next, as shown in FIG. 1A, on the insulating film 44, a lower electrode layer 231, an antiferromagnetic material layer (not shown), and a magnetic material layer (first thin film) 232 that becomes a magnetization fixed layer. Then, a laminated film 230 in which a tunnel insulating layer 233, a magnetic layer (second thin film) 234 to be a storage layer, and an upper electrode layer 235 are sequentially laminated is formed. Hereinafter, FIG. 1 mainly illustrates the laminated film. In order to form the laminated film, a sputtering apparatus (for example, an ultra vacuum sputtering apparatus) can be used.

  For the lower electrode layer 231, a conductive material can be used, for example, a metal material. Here, a platinum-manganese (Pt.Mn) alloy is formed to a thickness of, for example, 30 nm.

  For the antiferromagnetic material layer, for example, one of iron / manganese alloy, nickel / manganese alloy, platinum manganese alloy, iridium / manganese alloy, rhodium / manganese alloy, cobalt oxide and nickel oxide is used. This antiferromagnetic material layer can also serve as a lower electrode used for connection to a magnetoresistive effect element and a selection element connected in series.

  The magnetic layer 232 serving as the magnetization fixed layer includes a thin film made of an element selected from the group consisting of iron, nickel, cobalt, manganese, gadolinium, and terbium, or a thin film made of an alloy containing an element selected from the above group. Alternatively, a laminated film made of an element selected from the above group can be used. For example, a ferromagnetic material such as nickel, iron or cobalt, or an alloy made of at least two of nickel, iron and cobalt is used. Here, as an example, a cobalt / iron / boron (CoFeB) compound is used and formed to a thickness of, for example, 2.5 nm. The magnetization pinned layer is formed in contact with the antiferromagnetic layer, and the magnetization pinned layer has a strong unidirectional magnetic difference due to the exchange interaction between the magnetization pinned layer and the antiferromagnetic layer. It has directionality. That is, the magnetization direction of the magnetization fixed layer is pinned by exchange coupling with the antiferromagnetic material layer.

  Note that the magnetization fixed layer may have a configuration in which a magnetic layer is stacked with a conductive layer interposed therebetween. For example, a configuration in which a conductor layer and a second magnetization fixed layer in which the first magnetization fixed layer and the magnetic layer are antiferromagnetically coupled to each other from the antiferromagnetic material layer side may be sequentially laminated. The magnetization fixed layer may have a structure in which three or more ferromagnetic layers are stacked with a conductor layer interposed therebetween. For example, ruthenium, copper, chromium, gold, silver, or the like can be used for the conductor layer.

  The tunnel insulating layer 233 has a function of cutting a magnetic coupling between the storage layer and the magnetization fixed layer and flowing a tunnel current. Therefore, aluminum oxide having a thickness of 0.5 nm to 5 nm is usually used, but other oxide films or nitride films can be used. For example, a material mainly composed of one or more selected from the group consisting of aluminum oxide, zirconium oxide, cerium oxide, yttrium oxide, aluminum nitride, and boron nitride can be used. Alternatively, magnesium oxide, silicon oxide, magnesium nitride, silicon nitride, aluminum oxynitride, magnesium oxynitride, or silicon oxynitride may be used. As described above, since the film thickness of the tunnel insulating layer 233 is as very thin as 0.5 nm to 5 nm, it can also be formed by an atomic layer deposition (ALD) method. Alternatively, it can be formed by depositing a metal film such as aluminum by sputtering and then performing plasma oxidation or nitridation. Here, as an example, the tunnel insulating layer 233 is formed of aluminum oxide, and the thickness thereof is 1 nm. The formation method was obtained by forming an aluminum film and treating it in oxygen plasma for about 30 seconds.

  The magnetic layer 234 serving as the storage layer includes a thin film made of an element selected from the group consisting of iron, nickel, cobalt, manganese, gadolinium, and terbium, or a thin film made of an alloy containing an element selected from the group, Alternatively, a laminated film made of an element selected from the above group can be used. For example, a ferromagnetic material such as nickel, iron or cobalt, or an alloy made of at least two of nickel, iron and cobalt is used. This storage layer can change the magnetization direction parallel or antiparallel to the lower magnetization fixed layer by an externally applied magnetic field. Here, as an example, cobalt is used, for example, with a thickness of 2.5 nm.

  Note that a cap layer (not shown) can be formed between the magnetic layer 234 forming the memory layer and the upper electrode layer 235 as necessary. This cap layer has functions of preventing mutual diffusion with a wiring connecting a magnetoresistive effect element and another magnetoresistive effect element (not shown), reducing contact resistance, and preventing oxidation of the memory layer. Usually, it is made of a material such as copper, tantalum nitride, tantalum, or titanium nitride.

  The upper electrode layer 235 includes titanium nitride (TiN), tantalum nitride (TaN), tantalum (Ta), titanium (Ti), tungsten (W), aluminum (Al), copper (Cu), and aluminum copper alloy (AlCu). , Ruthenium (Ru) or other metal material, polysilicon or the like.

  Next, as shown in FIG. 1B, a hard mask 61 is formed on the upper electrode layer 235. The hard mask 61 is formed of an inorganic film, for example, a silicon nitride film. Alternatively, a stacked film of a silicon nitride film and a silicon oxide film may be used. In the formation method, after forming an inorganic film for forming a hard mask on the upper electrode layer 235, the hard film 61 is formed by processing the inorganic film by a normal lithography technique and an etching technique.

  Next, as shown in FIG. 1C, using the hard mask 61 as an etching mask, the upper electrode layer 235 and the magnetic layer 234 serving as the memory layer are processed by dry etching or ion milling. As a result, the upper electrode 135 made of the upper electrode layer 235 and the memory layer 134 made of the magnetic layer 234 are formed. Hereinafter, the upper electrode 135 and the memory layer 134 formed by the etching process are referred to as an upper pattern 130.

  At this time, a reaction product (residue) 71 generated by dry etching is deposited on the sidewall of the upper pattern 130. This reaction product 71 is generated by a reaction between a gas used for dry etching and a photoresist or a laminated film material to be processed.

  Next, as shown in the enlarged view of part A in FIGS. 1 (4) and (5), an electrochemically base metal film (so as to enter between the side wall of the upper pattern 130 and the reaction product 71). (Hereinafter referred to as a metal film) 81 is formed. An example of the metal film 81 is an aluminum film, which can be formed, for example, in a gas phase or in a supercritical phase. This metal film 81 is also formed on the surfaces of the hard mask 61 and the tunnel insulating layer 233. By forming the metal film 81, the metal film 81 grows so as to enter a slight gap between the side wall of the upper pattern 130 and the reaction product 71, so that the reaction product 71 is stressed. Eventually, the reaction product 71 generated on the sidewall of the upper pattern 130 is peeled off from the sidewall of the upper pattern 130 as the metal film 81 grows.

  For the metal film 81, for example, a metal having a standard electrode potential of −1.0 V or less can be used. For example, the above-described aluminum film can be used. This aluminum film can be formed by chemical vapor deposition. In this chemical vapor deposition film formation, methylpyrrolidine alane can be used as a source gas. Alternatively, the aluminum can be formed by supercritical film formation. In this supercritical film formation, hexafluoroacetylaluminum acetonate can be used as the supercritical gas. Since the supercritical gas has an effect of dissolving a substance having chemical affinity, the aluminum film grows so as to enter between the side wall and the reaction product. In addition, the metal film 81 needs to be formed at a temperature of 300 ° C. or less, more preferably 200 ° C. or less in order to prevent deterioration of the magnetic layer.

  Next, as shown in FIG. 1 (6), one of a weakly alkaline (pH = 9.5 to 10.5) organic amine aqueous solution, an ammonium carbonate aqueous solution, and aqueous ammonia is used as an etching solution. The film 81 is removed by etching and the reaction product 71 is removed. For example, hydroxylamine, alkanolamine, aminoalcohol, dimethylimidazolidinone and the like can be used as the organic amine. The processing temperature was set to, for example, 50 ° C to 70 ° C. Within this temperature range, the metal film 81 can be selectively removed. In the etching, the metal film 81 (aluminum film) [see FIG. 1 (5)] grown between the sidewall of the upper pattern 130 and the reaction product 71 (see FIG. 1 (5)) is selectively used. When dissolved and removed, the stress on the sidewall of the upper pattern 130 is relieved, and at the same time, the reaction product 71 is peeled off. In the above etching, the standard electrode potential of aluminum is −0.5 V or less, whereas the standard electrode potential of Fe, Co, B, Ti, etc. constituting the magnetic film is larger than −0.5 V, so that the upper electrode 135, the memory layer 134 is not etched. Further, the tunnel insulating layer 233 may be dissolved in strong alkalinity (pH> 10.5), but is not etched in weak alkalinity (pH = 9.5 to 10.5). In this way, the reaction product 71 can be removed without causing corrosion of the upper electrode 135 or the memory layer 134 made of a magnetic layer, or corrosion or excessive oxidation of the tunnel insulating layer 233. The hard mask 61 is removed when the insulating film is planarized, for example.

  Alternatively, in the same chamber in which aluminum is formed, if a chelate compound and carbon dioxide are supplied as they are instead of the precursor of the film forming material (aluminum) and the reaction product is removed in the supercritical phase, the cost can be reduced. It is possible to carry out the process.

  Next, as shown in FIG. 3A, a new hard mask (not shown) is formed, and the tunnel insulating layer 233, the magnetic layer 232, the anti-reflection layer are formed by dry etching or ion milling using the hard mask. A ferromagnetic layer (not shown) and the lower electrode layer 231 are patterned to form a tunnel insulating layer 133 (233), a magnetization fixed layer 132 formed of a magnetic layer 232, an antiferromagnetic layer, and a lower electrode layer 231. A lower electrode 131 is formed. At that time, the lower electrode 131 is formed so as to be connected to a plug 36 connected to a diffusion layer of a selection transistor (not shown). Thereby, the nonvolatile memory element is completed.

  Next, as shown in FIG. 3B, after the insulating film 45 is formed on the insulating film 44 so as to cover the upper electrode 135 to the lower electrode 131, the surface is planarized and the upper electrode is formed. 135 is exposed.

  Next, as shown in FIG. 3 (3), the bit line 12 that sterically intersects (for example, orthogonally) with the write word line 11 and is connected to the upper electrode 135 is formed on the insulating film 45. Thereby, the MRAM is completed. The bit line 12 can also be formed by forming a trench wiring on the insulating film after forming an insulating film on the insulating film 45. Therefore, the magnetic storage device 1 including the magnetoresistive effect element 13 including the magnetization fixed layer 132, the tunnel insulating layer 133, and the storage layer 134 is formed in the intersection (orthogonal) region between the write word line 11 and the bit line 12.

  In the above embodiment, a cobalt (Co) film is used as the memory layer 134, an aluminum oxide film is used as the tunnel insulating layer 133, and cobalt / iron / boron (CoFeB) is used as the magnetization fixed layer 132. / Al / Ta laminated film, aluminum oxide film as tunnel insulating layer 133, Ta / Al / NiFe // MnFe / Co / Ru / Co laminated film combination as magnetization fixed layer 132, and memory layer A combination of a laminated film of NiFe / Al / Ta as 134, an aluminum oxide film as the tunnel insulating layer 133, and a laminated film of Ta / Al / CoFe / MnFe / Co / Ru / Co as the magnetization fixed layer 132 can be used. Layer 134: CoFe / Pd / Ti laminated film, tunnel insulation An aluminum oxide film 133 can be used, and a combination of Ta / Al / CoFe / MnFe / Co / Ru / Co laminated film can be used as the magnetization fixed layer 132, a Cu / Ta / NiFe laminated film can be used as the storage layer 134, and tunnel insulation. An aluminum oxide film may be used as the layer 133, and a combination of stacked films of CoFe / MnIr / Cu / NiFe / Ta / Cu / Ta may be used as the magnetization fixed layer 132. These films can employ the process described above.

  The method for manufacturing a magnetic memory device according to the present invention includes a method for manufacturing a magnetic memory device including an annular magnetoresistive effect element in addition to a method for manufacturing a magnetic memory device including a magnetoresistive effect element having a laminated structure. The present invention can also be applied to post-treatment for removing reaction products after etching of the magnetic film.

It is schematic structure sectional drawing which showed one Example which concerns on the manufacturing method of the magnetic memory device of this invention. It is schematic structure sectional drawing which showed one Example which concerns on the manufacturing method of the magnetic memory device of this invention. It is schematic structure sectional drawing which showed one Example which concerns on the manufacturing method of the magnetic memory device of this invention. It is a schematic structure perspective view explaining the principal part of MRAM. It is a circuit diagram explaining the memory cell of MRAM. It is a schematic structure sectional view explaining the principal part of MRAM. It is a schematic structure sectional view showing the manufacturing method of the conventional magnetic memory device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Magnetic memory device, 13 ... Magnetoresistive element, 71 ... Reaction product, 81 ... Metal film, 232 ... Magnetic body layer (1st thin film), 233 ... Tunnel insulating layer, 234 ... Magnetic body layer (2nd thin film) ) 235... Upper electrode layer

Claims (8)

A magnetic memory device having a magnetoresistive effect element in which a first thin film mainly composed of a magnetic material, a tunnel insulating layer mainly composed of a non-magnetic material, and a second thin film mainly composed of a magnetic material are sequentially laminated. A manufacturing method,
The upper electrode layer formed on the second thin film, the second thin film, and the tunnel insulating layer are stacked, and the upper electrode layer and the second thin film are etched or ion milled to form an upper portion of the magnetoresistive effect element. After the process of forming the pattern of
Forming an electrochemically base metal film so as to penetrate between a sidewall of the upper pattern and a reaction product generated by the etching or ion milling;
Removing the metal film and removing the reaction product. A method of manufacturing a magnetic memory device, comprising: The method of manufacturing a magnetic memory device according to claim 1, wherein the standard electrode potential of the metal film is −1.0 V or less. The method of manufacturing a magnetic memory device according to claim 1, wherein the metal film is made of aluminum. The method of manufacturing a magnetic memory device according to claim 3, wherein the metal film made of aluminum is formed by chemical vapor deposition of aluminum and supercritical film formation of aluminum. The method of manufacturing a magnetic memory device according to claim 4, wherein the metal film is formed at a temperature of 300 ° C. or lower. The method for manufacturing a magnetic memory device according to claim 4, wherein the chemical vapor deposition film formation of aluminum uses methylpyrrolidine alane as a source gas. The method of manufacturing a magnetic memory device according to claim 4, wherein the supercritical film formation of aluminum uses hexafluoroacetyl aluminum acetonate as a supercritical gas. The method of manufacturing a magnetic memory device according to claim 3, wherein the etching is wet etching using any one of an organic amine aqueous solution, an ammonium carbonate aqueous solution, and ammonia water.

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