Method for manufacturing magnetoresistance effect element

Method for manufacturing a magnetoresistance effect element

<p>[Prior Art Document 1]: "Phys. Rev. B45, 806 (1992), J. Appl. Phys. 69, 4774 (1981)"</p><p>[Prior Art Document 2]: "J. Appl. Phys. 89, 6943 (2001), IEEE Trans. Magn. 38, 2277 (2002)"</p><p>This specification relates to the subject matter contained in Japanese Patent Application No. 2006-032261 filed on February 9, 2006, the entire contents of which are incorporated herein by reference.</p><p>The present invention provides a method for manufacturing a magnetoresistive effect element having a structure for allowing a sense current to flow in a direction perpendicular to the film surface of the magnetoresistive effect film, as well as a magnetoresistive effect element, a magnetoresistive effect head, a magnetic recording/reproducing apparatus, and It is about magnetic memory.</p>

<p>With respect to CIP-GMR (Current-In-Plane-Giant-Magnetoresistance) obtained by allowing current to flow through the surface of the multilayer film of the sandwich structure of [ferromagnetic layer/nonmagnetic layer/ferromagnetic layer], when the ferromagnetic layer does not undergo antiferromagnetic coupling However, examples in which a large magnetoresistance effect appears have been reported so far. Specifically, the magnetization is fixed by applying an alternating bias magnetic field to one of the two ferromagnetic layers with the nonmagnetic layer interposed therebetween (the layer is referred to as a "magnetization fixed layer" or " referred to as the "pin layer"). The remaining ferromagnetic layer is oppositely magnetized by an external magnetic field (such as a signal magnetic field) (called a "magnetization free layer" or "free layer"). Accordingly, the relative angle between the magnetization directions of the two ferromagnetic layers disposed with the nonmagnetic layer therebetween is changed, whereby a large magnetoresistance effect is achieved. Multilayers of that type are called "spin valves". For details, refer to the prior art document 1.</p><p>Since the spin valve can saturate the magnetization at low magnetic field strength, the spin valve is suitable for use as an MR head. Although the MR head has already been put to practical use, the change rate of the magnetoresistance of the MR head remains at a maximum of about 20% in the present situation. An MR element exhibiting a higher rate of change of magnetoresistance (hereinafter referred to as "MR ratio") is desired.</p><p>As a candidate for such an MR device, TMR (Tunneling MagnetoResistance) using the tunnel effect has been discussed. However, such an effect is expressed as a result of electrons tunneling through the insulating layer. Therefore, the TMR element typically has a high resistance. If the MR head has a high resistance, there is a problem that the magnetic head included in the hard disk drive generates a large noise. In order to reduce the resistance, the thickness of the barrier layer must be reduced. However, it is known that when the barrier layer becomes thin, a uniform MR head cannot be manufactured, so that the MR ratio is lowered by pin holes. With respect to the TMR element, there is a difficulty in achieving compatibility between a low resistance and a high MR ratio. In TMR, current flows in a direction perpendicular to the film surface, so that the recording density of the hard disk is increased. When the size of the TMR head is reduced, the resistance is further increased, making it difficult to use the head.</p><p>In contrast, a Current-Perpendicular-to-Plane (CPP)-GMR device in which a sense current flows in a direction perpendicular to the film surface of the device is being discussed as a candidate. In a GMR device, electrons are expressed by conduction through the metal. Therefore, the GMR element has the advantage of low resistance. However, in the case of the spin valve film, the resistance to vertical conduction of current is small. Therefore, it is very important to increase the amount of change in resistance by increasing the resistance value of the region in the film that contributes to spin-dependent conduction.</p><p>In order to increase the amount of change in resistance, that is, to improve the magnetoresistance effect, a technique of inserting a resistance control layer including an insulator into the film of the spin valve has been devised. For details, refer to the prior art document 2.</p><p>The spin valve is formed of a region that spin-dependently scatters electrons (magnetization pinned layer/spacer layer/magnetization free layer) and a region with a low degree of spin-dependent scattering (ground layer, antiferromagnetic layer, protective layer, etc.). If the resistance of the former region is Rsd and the resistance of the latter region is Rsi, the magnetoresistance effect of the spin valve can be expressed as ?Rsd/(Rsi+Rsd). As a result of focusing on the improvement of the magnetoresistance effect in which the magnetoresistance effect becomes larger as Rsd is larger than Rsi, the resistance control layer including the insulator is inserted as described above.</p>

<solutionproblem><p>However, there is a limit to the improvement of the magnetoresistance effect achieved only by the current limiting effect. In order to further improve the magnetoresistance effect, it is necessary to increase the spin-dependent scattering factors of the magnetized pinned layer and the spin-dependent scattering factors of the magnetized free layer. To this end, research on half metal has been active. Here, the expression "half metal" refers to a magnetic material having a density of states of only either up-spin electrons or down-spin electrons when looking at the states of electrons near the Fermi level. Generally defined. In the case where an ideal half-metal can be realized, two states can be realized. That is, when the magnetization state of the magnetization pinned layer and the magnetization state of the magnetization free layer are antiparallel to each other and when they are parallel to each other, two states of a state of infinite resistance and another state of low resistance will be realized. can Thus, an infinite rate of MR change can be achieved. In reality, even if an ideal state cannot be realized so far, if the difference between the density of states of upspin electrons and that of downspin electrons is larger than that achieved in conventional materials, a significant increase in the MR ratio with different orders of magnitude is expected However, the half metal has major problems that hinder commercialization. Specific problems are as follows. (1) In the case of a perovskite-based half metal, it is essential to improve crystallinity. However, in the case of a polycrystalline film used in a magnetic head, it is essentially impossible to improve the crystallinity. (2) Generally, the temperature at which the half-metal characteristics can be maintained is low, and the half-metal is hardly expressed at room temperature. (3) There is a possibility that the half-metal properties will be lost at the interface between different materials constituting the spacer layer interposed between the magnetization pinned layer and the magnetization free layer. Among these, the problem of (3) is fatal. Even if a perfect half metal can be produced at room temperature, the properties of the half metal cannot be effectively utilized when a TMR film or a CPP-GMR film is formed by laminating the half metal during formation of the spacer layer.</p><p>Incidentally, from the viewpoint of the magnetoresistive effect element, a perfect half metal is not required. An essential requirement is an improvement in spin polarization in electrons conducting through the sense current. That is, the spin polarization of electrons at the Fermi level contributing to conduction. The proposed technique is to insert a functional layer to modulate the band structure in the magnetization pinned layer and the magnetization free layer, paying attention to the spin polarization rate.</p><p>According to this technique, the functional layer is formed of a very thin oxide layer or the like. This means is based on the suggestion that when an extremely thin oxide layer is inserted into a magnetized fixed or magnetized free layer formed of a metal, spin is polarized in the vicinity of the interface. When the oxide layer becomes thick, the resistance of the device increases, and adverse effects such as noise are exerted on the device as in the case of the conventional TMR device. Therefore, it is possible to achieve low resistance by forming the oxide layer as a very thin layer of about one atom.</p><p>However, in general, when the functional layer is formed to a thickness of about one atomic layer as shown in FIG. 11, the functional layer becomes an island shape or a plurality of pinholes are opened. Therefore, it is difficult to form a uniform functional layer. If the holes are open in the functional layer, the current caused by the electrons passing through the holes becomes a shunt current, so that large spin dependent scattering cannot be obtained. As a result, the spin filtering effect is reduced. Accordingly, the functional layer must be very thin and uniform.</p></solutionproblem><meansproblemsolution><p>According to a first aspect of the present invention, there is provided a method of manufacturing a magnetoresistance effect element in which a magnetization pinned layer, a nonmagnetic intermediate layer, and a magnetization free layer are sequentially stacked. The method includes the steps of: forming at least a portion of a magnetic layer to be one of the magnetization pinned layer and the magnetization free layer; forming a functional layer including at least one of oxide, nitride, and fluoride on a portion of the magnetic layer; and removing a portion of the functional layer by exposing the functional layer to any one of ion beam and plasma irradiation.</p><p>According to a second aspect of the present invention, there is provided a method of manufacturing a magnetoresistance effect element in which a magnetization fixing layer, a non-magnetic insulating intermediate layer, and a magnetization free layer are sequentially stacked. The method includes: forming the non-magnetic insulating interlayer by one of an oxide, a nitride, and a fluoride; and removing a portion of the non-magnetic insulating intermediate layer by exposing the non-magnetic insulating intermediate layer to any one of ion beam and plasma irradiation.</p></meansproblemsolution><effectiveness><p>According to the method of the present invention for manufacturing a magnetoresistive effect element, a magnetoresistive effect element exhibiting a large change amount of magnetoresistance, high reliability, and high magnetic stability can be provided. Therefore, highly sensitive magnetic detection is stably achieved. magnetic head with high signal-to-noise ratio even at high recording density and high output; a self-renewing device to which the head is mounted; and a highly integrated magnetic memory may be provided.</p></effectiveness>

<p>DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings. </p><p>(Example 1)</p><p>First, a magnetoresistance effect device manufactured by the manufacturing method according to the first embodiment of the present invention will be described. 1 is a cross-sectional view of a magnetoresistive effect device manufactured by the manufacturing method of the present invention.</p><p>The magnetoresistive effect element shown in FIG. 1 includes a first electrode 1; a substrate layer 2 formed of a Ta layer having a thickness of 5 nm and a Ru layer having a thickness of 2 nm, an antiferromagnetic layer 3 having a thickness of about 15 nm and formed of a PtMn material; It has a thickness of about 3 to 4 nm and Co<sb>90</sb>Fe<sb>10</sb> A first magnetization fixing layer 4-1 formed of a material, a magnetization antiparallel coupling layer 4-2 having a thickness of about 0.9 nm and formed of a Ru material, and a functional layer 10-1 are interposed therebetween. About 1.5 nm thick Co<sb>90</sb>Fe<sb>10</sb> a magnetized pinning layer 4 comprising a second magnetized pinning layer 4-3 bonded to the layer; a spacer layer 5 formed of a Cu material and having a thickness of about 3 nm; magnetization free layer (6); a first protective layer 7 ; a second protective layer (8); and a structure formed by laminating the second electrode 9 .</p><p>The magnetization of the first magnetization pinned layer 4-1 is essentially fixed in one direction by the adjacent antiferromagnetic layer 3 . The magnetization of the second magnetization pinned layer 4-3 is fixed in an antiparallel direction to the first magnetization pinned layer through the magnetization antiparallel coupling layer 4-2. The magnetization free layer 6 includes a ferromagnetic layer whose magnetization can change according to an external magnetic field. The spacer layer 5 is a layer that blocks magnetic coupling between the second magnetized pinned layer 4 - 3 and the magnetized free layer 6 . In the magnetoresistive effect element shown in Fig. 1, the spacer layer 5 is formed only of metal.</p><p>A magnetoresistive effect element having the above configuration is manufactured as described below. First, a 5 nm Ta layer and a 2 nm Ru layer are laminated by DC magnetron sputtering on a material such as Cu, NiFe, Ta, Ru, CuAg, etc., which will be the first electrode 1, to form a substrate layer 2) will form</p><p>PtMn to be the antiferromagnetic layer 3 is formed on the substrate layer 2 to a thickness of 15 nm by DC magnetron sputtering without breaking the atmosphere in which the substrate layer 2 was formed. After the formation of the antiferromagnetic layer 3, Co<sb>90</sb>Fe<sb>10</sb> It is laminated on the antiferromagnetic layer 3 to a thickness of 3 to 4 nm to form the first magnetization fixing layer 4-1. As a result of stacking Ru to a thickness of 0.9 nm, a magnetization antiparallel coupling layer 4-2 is formed. In the following order, Co, which is a stack member, that is, the second magnetized pinned layer 4-3<sb>90</sb>Fe<sb>10</sb> It is laminated to a thickness of 1.5 nm. During the formation of the second magnetized pinned layer 4-3, a functional layer 10-1 is formed in the second magnetized pinned layer 4-3 by the process shown in FIGS. 2A to 2E.</p><p>Specifically, the process is as follows. First, Fe is grown to a thickness of 1 nm as a part of the second magnetized pinned layer 4-3 to be an oxidized layer. Here, the term 'part of the second magnetization pinned layer 4 - 3' means the lower half of the second magnetization pinned layer divided into upper and lower regions with the functional layer 10 interposed therebetween.</p><p>By subjecting the surface of Fe, which is a part of the second magnetized pinned layer 4-3, to natural oxidation, Ion Assisted Oxidation (IAO), or plasma oxidation, the functional layer 10-1 is about 1.5 on the surface of Fe. It is caused to grow from a thickness of 3 nm to 3 nm. Here, IAO is a process for causing oxidation by introducing oxygen into a chamber while exposing oxygen to an Ar ion beam. For details, see Related Document 3 below.</p><p>Related Literature 3: "J. Appl. Phys. 91,6684 (2002)."</p><p>The ion beam is much weaker than that adopted according to normal milling requirements, and the beam voltage is set to 100V or less. The etching rate obtained when Fe is exposed to an ion beam without oxygen under these requirements has a value of about 0.1 to 3 angstroms/min.</p><p>The process requirements for native oxidation, IAO, and plasma oxidation are provided in Table 1 shown in FIG. 12 . </p><p>In Table 1, reference numeral REF denotes a process of a spin valve structure having no functional layer, as a sample to be referenced. Reference numerals A-1 to A-4 denote process conditions for related processes for preparing functional layers. Reference numerals B-1 to B-4 denote process conditions for the process of preparing the functional layer of the present invention.</p><p>The difference between the process conditions related to the conventional process for preparing the functional layer and the process conditions related to the process of the present invention for preparing the functional layer is that AIT (After Ion Treatment), that is, irradiation with a weak ion beam, natural oxidation of the oxide thin film, When formed by any of IAO, and plasma oxidation, it is performed. AIT is Fe by very weak milling<sb>50</sb>Co<sb>50</sb>To form a thin film from -O. As in the case of the previously described IAO, very weak ion beam conditions are required in this case. For example, when AIT is performed under the conditions of a beam voltage of 200 V or more and a beam current of 100 mA or more, which is adopted when a thick film having a thickness of several tens of nanometers is removed by milling, FIG. A uniform functional layer 10 cannot be prepared as shown in FIG. The treated film surface becomes rough, which results in a decrease in the MR ratio because the sense electron current 17 only partially flows through the functional layer 10 . The AIT of the present invention does not result in the functional layer being formed in an island shape or a large number of pinholes being formed in the functional layer. The oxide film to be the functional layer 10 may be formed to be a thin film having a uniform thickness as shown in FIG. 3 . As a result, the entirety of the current 17 can flow through the functional layer 10 so that a high MR ratio can be obtained.</p><p>After the functional layer 10 is formed by the above process, Co which forms the upper half of the second magnetized pinned layer 4-3<sb>90</sb>Fe<sb>10</sb> This is formed to complete the second magnetization fixing layer 4-3. Next, a spacer layer 5 made of Cu material is formed on the second magnetization fixing layer 4-3 to a thickness of 3 nm.</p><p>After the formation of the spacer layer 5, the magnetization free layer 6 is formed. As in the case of the second magnetization pinned layer 4-3, the magnetization free layer 6 may include a functional layer 10-2. can Since the manufacturing process adopted this time is also essentially the same as the process for manufacturing the second magnetized pinned layer 4-3, a description thereof will be omitted.</p><p>After the formation of the magnetization free layer 6, a first protective layer formed of Cu material and a second protective layer 8 formed of Ru material are formed while continuing under vacuum by magnetron sputtering using DC bias. </p><p>Finally, a material such as Cu, NiFe, Ta, Ru, CuAg or the like is caused to grow on the surface of the second protective layer 8 to form the second electrode 9 . Through the above-mentioned process, the magnetoresistive effect element is completed.</p><p>In this embodiment, the functional layer 10 is taken as an oxide of Fe. However, the functional layer 10 is not limited to this material. The essential requirements for the functional layer 10 are Fe, Co, Ni, Cu, Ti, V, Cr, Mn, Mg, Al, Si, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, It must be an oxide, nitride, or fluoride formed by oxidizing, nitriding, or fluorinate a metal or alloy containing at least one component selected from the group consisting of Ta, W, Re, Ir, Pt and Au. .</p><p>The difference between the properties of the magnetoresistive effect element manufactured by the manufacturing method according to the first embodiment of the present invention and the magnetoresistive effect element manufactured by the conventional manufacturing method will be described with reference to Table 1.</p><p>Referring to Table 1, in A-1, A-2, A-3, and A-4 in which the functional layer 10 is formed according to a prior art process, the MR ratio is increased compared to the sample REF in which the functional layer is not formed. . However, no significant increase was found. In contrast, in samples B-1, B-2, B-3 and B-4 when the functional layer is formed according to the process of the present invention, corresponding to the samples prepared according to the process of the present invention, the MR ratio is 10 factor is increased. Therefore, the advantages of the samples of the present invention are noteworthy. The reason is that the uniform functional layer as shown in Fig. 3 is different from that of the samples A-1, A-2, A-3 and A-4 in which the functional layers are formed in the island shape shown in Fig. 11. , is formed in samples B-1, B-2, B-3 and B-4.</p><p>6A is a cross-sectional transmission electron microscope (TEM) image of an area in the vicinity of the functional layers 10-1 and 10-2 prepared through the process of the present invention. In the illustrated samples, the functional layers 10-1, 10-2 are oxide layers, so that a whiter contrast is obtained than that of the surrounding areas. By the white contrast, a judgment can be made as to whether the functional layers are uniform or have a fragmented island shape. As shown in Fig. 6A, even if the sample is sliced as thinly as possible in the electron beam transmission direction, the essentially straight functional layers 10-1 and 10-2 do not have any discontinuities and are very thin. Meanwhile, FIG. 6B is a cross-sectional TEM image of an area of the functional layers 10-1 and 10-2 prepared through a process of the prior art. In contrast to FIG. 6A , it can be concluded that the functional layers 10 - 1 and 10 - 2 have discontinuity.</p><p>6A and 6B, the functional layers 10-1 and 10-2 are white in color and can be clearly distinguished from other portions. When it is difficult to distinguish the functional layers, the functional layers can be identified by EDX (Energy Dispersive X-ray Spectrosopy) employing a beam narrowed in size to about 1 nm. In this case, measurement points are provided at intervals of 0.5 nm to 1 nm along the growth direction of the film. The functional layers may be calculated from the half-value width of the concentration distribution of oxygen, nitride, phosphor, fluorine, etc., obtained when the distribution of the device is plotted for the measurement points.</p><p>7 shows the results obtained when the conditions for AIT were changed for Sample B-2, which is an exemplary process of the present invention. The processing time of the film<sb>50</sb>Co<sb>50</sb>It is adjusted and varied to be formed from a -O material to a thickness of 0.3 nm. As can be seen from the result, when the bin voltage exceeds 110V, the MR ratio decreases. It is understood that when the beam voltage is increased to 210V, the MR ratio has a value of 0.3%, which is lower than the MR ratio obtained in the case of the sample REF without any functional layer. From the results of this experiment, the beam voltage of the AIT is preferably 110V or less.</p><p>Irradiation of RF plasma requires or very weak energy conditions. A suitable range of this energy is 15W to 30W. In contrast, under strong energy conditions such as 100 W used to clean the substrate, the surface of the film deteriorates and the MR ratio decreases.</p><p>(1st modification)</p><p>FIG. 4 is a first modification of the first embodiment shown in FIG. 1 , and illustrates a magnetoresistive element having a single magnetized pinned layer rather than a three-layer structure (composite structure, synthetic structure). </p><p>The magnetoresistance effect element of the modified example shown in Fig. 4 includes a first electrode 1', a substrate layer 2' including a Ta layer having a thickness of 5 nm/2 a Ru layer having a thickness of 15 nm, and about 15 nm. An antiferromagnetic layer (3') formed of a PtMn material with a thickness of<sb>90</sb>Fe<sb>10</sb> A magnetization fixing layer 4' formed from the layer, a spacer layer 5' formed of Cu with a thickness of about 3 nm, Co<sb>90</sb>Fe<sb>10</sb> A magnetization free layer 6' formed as a layer, a first protective layer 7' formed of Cu to a thickness of about 1 nm, a second protective layer 8' formed from Ru to a thickness of about 5 nm, and a second The electrode 9' has a stacked structure. The functional layer 10' is inserted into the magnetization pinning layer 4'.</p><p>Also in the first modification, effects similar to those obtained in the first embodiment are produced. </p><p>(Second Modification)</p><p>FIG. 5 is a second modified example of the first embodiment shown in FIG. 1 , in which the positions of the magnetization pinned layer and the magnetization free layer are interposed with a spacer layer. The magnetoresistance effect element with the position of the layers reversed is shown.</p><p>As shown in Fig. 5, the magnetoresistance effect element of this modified example includes: a first electrode 1"; a substrate layer 2" formed of a 5 nm-thick Ta layer and a 2 nm-thick Ru layer; About 1.5 nm of Co to sandwich the functional layer 10-2"<sb>90</sb>Fe<sb>10</sb>a magnetization free layer 6" formed by affixing the layer to the magnetization layer; a spacer layer 5" formed of Cu and having a film thickness of about 3 nm; About 1.5 nm of Co to sandwich the functional layer 10-1"<sb>90</sb>Fe<sb>10</sb>a second magnetized fixing layer 4-3" formed by attaching the layer to the magnetization layer, a magnetized antiparallel coupling layer 4-2" formed of Ru and having a film thickness of about 0.9 nm; Co<sb>90</sb>Fe<sb>10</sb>The first magnetized pinned layer (4-1") formed of , and having a film thickness of about 3 to 4 nm; an antiferromagnetic layer 3" formed of PtMn and having a film thickness of about 15 nm, formed of Ru and having a film thickness of about 5 nm It has a structure in which a phosphorous protective layer 8" and a second electrode 9" are laminated. Also in the second modification, the same effect as in the first embodiment is obtained.</p><p>(Second embodiment)</p><p>Now, the manufacturing method of the magnetoresistive effect element of the second embodiment of the present invention will be described. The second embodiment differs from the first embodiment in that the material of the functional layer is changed. Accordingly, clear differences between the first embodiment and the second embodiment will be described, and similar parts will be omitted.</p><p>After forming from the first electrode 1 to the magnetization antiparallel coupling layer 4-2 through the processes described in the first embodiment, it is a lamination member and serves as the second magnetization fixing layer 4-3. Co<sb>90</sb>Fe<sb>10</sb>is laminated to 1.5 nm. During the formation of the second magnetized pinned layer 4 - 3 , the functional layer 10 - 1 is formed through the processes shown in FIGS. 2A to 2E .</p><p>Specifically, the processes are as follows. First, Fe as a part of the second magnetized pinned layer 4-3 serving as the oxidized layer<sb>50</sb>Co<sb>50</sb>was grown to a thickness of 1 nm. Here, "a part of the second magnetized pinned layer 4-3" refers to the lower half of the second magnetized pinned layer divided vertically by sandwiching the functional layer 10-1, as described in the first embodiment. means</p><p>Fe as part of the re-magnetization pinned layer (4-3)<sb>50</sb>Co<sb>50</sb>The surface of the Fe is treated by natural oxidation, ion assisted oxidation (IAO), or plasma oxidation.<sb>50</sb>Co<sb>50</sb>A functional layer 10-1 having a thickness of about 1.5 nm to 3 nm is grown on the surface of the . Here, the ion beam is very weak compared to normal milling conditions, and the beam voltage is set to 100 V or less. The ion beam under this condition was conducted without oxygen and<sb>90</sb>Fe<sb>10</sb>The etching rate when irradiated to is about 3 angstroms/min.</p><p>The process conditions for natural oxidation, IAO and plasma oxidation are as provided in Table 2 shown in FIG. 13 .</p><p>In Table 2, the reference symbol REF indicates the process of the spin valve structure without the functional layer as a reference sample. C-1 to C-4 show the process conditions of the conventional functional layer creation process. D-1 to D-4 show the process conditions of the functional layer creation process of the present invention.</p><p>The difference from the process conditions of the conventional functional layer creation process is that, as in the first embodiment, AIT (After Ion Treatment) is performed when thinning an oxide film formed by any one of natural oxidation, IAO, and plasma oxidation. By performing this AIT, the functional layer 10 can be formed into a thin film layer while maintaining a constant thickness without being island-shaped or having a plurality of pinholes.</p><p>After the functional layer 10 is formed by the above-described process, Co which becomes the upper half of the second magnetized pinned layer 4-3<sb>90</sb>Fe<sb>10</sb>Since the process from the process of forming to forming the second electrode 9 is the same as that of the first embodiment, the description is omitted.</p><p>Incidentally, in the present embodiment, the functional layer 10 is an oxide of FeCo, but as in the first embodiment, it is not limited to this. Fe, Co, Ni, Cu, Ti, V, Cr, Mn, Mg, Al, Si, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta, W, Re, Ir, Pt, Au The oxide, nitride, or fluoride may be obtained by oxidizing, nitriding, or fluorinating a metal or alloy containing at least one member selected from the group consisting of.</p><p>Next, the difference in characteristics between the magnetoresistive effect element manufactured by the manufacturing method of the second embodiment of the present invention and the magnetoresistive effect element manufactured by the conventional manufacturing method will be described with reference to Table 2. From Table 2, even when an FeCo alloy was used as the base material of the functional layer 10, the MR increase was not large in the sample group C created by the conventional process flow. However, the MR increase amount in the sample group D created by the process flow of the present invention is very large. This is also considered to be because the same functional layer 10 is obtained in group D.</p><p>When the magnetoresistance effect element is formed in the method of the second embodiment, the effect of the functional layer is only when the RF power is changed from 15W to 30W when the beam voltage is 100V or less and RF plasma is the same as in the first embodiment. can be fully utilized, and high MR can be obtained.</p><p>In addition, Co including the composition of the first and second examples<sb>1</sb><sb>-</sb><sb>X</sb>If a Fex alloy (50x100) is used, higher MR can be realized.</p><p>(Example 3) </p><p>Next, a method for manufacturing a magnetoresistive effect element, which is a third embodiment of the present invention, will be described. In the third embodiment, as in the second embodiment, the material of the functional layer 10 is changed from that of the first embodiment. Accordingly, parts clearly different from those of the first embodiment will be described, and descriptions of the same parts will be omitted.</p><p>After forming from the first electrode 1 to the magnetization antiparallel coupling layer 4-2 by the process described in the first embodiment, Co as the lamination member and the second magnetization fixing layer 4-3<sb>90</sb>Fe<sb>10</sb>is laminated to 1.5 nm. During the process of forming the second magnetized pinned layer 4-3, the functional layer 10-1 is formed by the process shown in FIGS. 2A to 2E.</p><p>Specifically, the process is as follows. First, Ti is grown to a thickness of 1 nm as a part of the second magnetized pinned layer 4-3 to be an oxidized layer. Here, "a part of the second magnetized pinned layer 4-3" refers to the lower half of the second magnetized pinned layer divided vertically by sandwiching the functional layer 10-1, as described in the first embodiment. do.</p><p>Next, the surface of Ti, which is a part of the second magnetization and pinned layer 4-3, is subjected to natural oxidation, lon assisted oxidation (IAO), or plasma oxidation, so that a film thickness of about 1.5 to 3 nm is applied to the surface. A functional layer 10-1 is grown. The ion beam is very weak compared to normal milling conditions, and the beam voltage is set to I0OV or less. When Ti is irradiated with an ion beam in the absence of oxygen under this condition, the etching rate is about 0.1 to 3 angstroms/min.</p><p>The process conditions for natural oxidation, IAO and plasma oxidation, respectively, are shown in Table 3.</p><p>In Table 3, reference numeral REF denotes a process of a spin valve structure without a functional layer as a reference sample. E-1 to E-4 show the process conditions of the conventional functional layer creation process. F-1 to F-4 show the process conditions of the functional layer creation process of the present invention.</p><p>The difference from the process conditions of the conventional functional layer creation process is that, as in the first embodiment, AIT (After Ion Treatment) is performed when thinning an oxide film formed by any one of natural oxidation, IAO, and plasma oxidation. By performing this AIT, it becomes possible to thin the functional layer 10, maintaining a uniform film thickness, without becoming an island shape or having a some pinhole.</p><p>After the functional layer 10 is formed by the above-described process, Co which becomes the upper half of the second magnetized pinned layer 4-3<sb>90</sb>Fe<sb>10</sb>Since the process from the process of forming to forming the second electrode 9 is the same as that of the first embodiment, the description is omitted.</p><p>In addition, in this embodiment, the functional layer 10 is said to be an oxide of Ti. However, not limited thereto, Fe, Co, Ni, Cu, Ti, V, Cr, Mn, Mg, Al, Si, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta, W, Any oxide, nitride, or fluoride obtained by oxidizing, nitriding, or fluorinating at least one metal or alloy selected from the group consisting of Re, Ir, Pt and Au may be sufficient.</p><p>The difference in characteristics between the magnetoresistive effect element manufactured by the manufacturing method of the third embodiment of the present invention and the magnetoresistive effect element manufactured by the conventional manufacturing method will be described with reference to Table 3. Even when Ti was used as the base material for the functional layer, the MR increase was not large in the sample group E created by the conventional process flow. However, the MR increase amount in the sample group F created by the process flow of the present invention is very large. This is also thought to be because the same functional layer is obtained in group F.</p><p>When the magnetoresistance effect element is formed in the method of the third embodiment, the same conditions as in the first embodiment are the beam voltage 100V or less and RF plasma, only when the RF power is changed from 15W to 30V, The effect can be fully utilized, and high MR can be obtained. </p><p>(Example 4)</p><p>Next, the manufacturing method of the magnetoresistive effect element of the fourth embodiment of the present invention will be described. The fourth embodiment differs from the functional layer 10 of the first embodiment in that the material is changed, as in the second embodiment. Accordingly, parts that are clearly different from the first embodiment will be described, and descriptions of the same parts will be omitted.</p><p>After forming from the first electrode 1 to the magnetization antiparallel coupling layer 4-2 by the process described in the first embodiment, Co as the lamination member and the second magnetization fixing layer 4-3<sb>90</sb>Fe<sb>10</sb>1.5 nm is laminated. During the process of forming the second magnetization sticking disease 4-3, the functional layer 10-1 is formed by the process shown in FIGS. 2A to 2E.</p><p>Specifically, the process is as follows. First, Ti is grown to a thickness of 1 nm as a part of the second magnetized pinned layer 4-3 to be an oxidized layer. Here, "a part of the second magnetized pinned layer 4-3" is the lower half of the second magnetized pinned layer divided vertically by sandwiching the functional layer 10-1, as described in the first embodiment. .</p><p>A functional layer 10-1 having a film thickness of about 1.5 to 3 nm on the surface of Zr by natural oxidation, ion beam oxidation (IAO), or plasma oxidation of the surface of Zr, which is a part of the second magnetized fixing layer 4-3 to film Here, the ion beam is very weak compared to normal milling conditions, and the beam voltage is set to 10 OV or less. When the ion beam is exposed to oxygen-free Ti under these conditions, the etching rate is about 0.1 to 3 Å/min (angstrom/min).</p><p>Process conditions for natural oxidation, IAO, and plasma oxidation, respectively, are as given in Table 4 shown in FIG. 15 .</p><p>In Table 4, reference numeral REF denotes a process of a spin valve structure without a functional layer as a reference sample. Reference numerals G-1 to G-4 indicate process conditions of the conventional functional layer creation process. Reference numerals H-1 to H-4 indicate process conditions of the functional layer creation process of the present invention.</p><p>The difference between the process conditions of the conventional functional layer creation process and the process conditions of the functional layer creation process of the present invention is, as in the first embodiment, when thinning an oxide film formed by any one of natural oxidation, IAO, and plasma oxidation. After ion treatment (AIT) is performed. By performing AIT, it becomes possible for the functional layer 10 to be formed in an island shape or to be formed in a thin film while maintaining a uniform thickness without having a plurality of pinholes.</p><p>After forming the functional layer 10 by the above-described process, Co which becomes the upper half of the second magnetized pinned layer 4-3<sb>90</sb>Fe<sb>10</sb>Since the processes from the process of forming to the process of forming the second electrode 9 are the same as those of the first embodiment, a description thereof is omitted here.</p><p>In this embodiment, the functional layer 10 is made of an oxide of Zr. However, the functional layer 10 is not limited to this material. The essential conditions for the functional layer 10 are Fe, Co, Ni, Cu, Ti, V, Cr, Mn, Mg, Al, Si, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta, It is an oxide, nitride, or fluoride formed by oxidizing, nitriding, or fluorination of a metal or alloy containing at least one of W, Re, Ir, Pt and Au.</p><p>Next, differences in characteristics between the magnetoresistive effect element manufactured by the manufacturing method of the fourth embodiment of the present invention and the magnetoresistive effect element manufactured by the conventional manufacturing method will be described with reference to Table 4. Even when Zr is used as the base material for the functional layer, the MR increase is not large in the sample group G prepared according to the conventional process flow. However, the MR increase amount in the sample group H created by the process flow of the present invention is very large. This is also considered to be because the same functional layer can be obtained in group H.</p><p>In the case of forming the magnetoresistive effect element in the method of the fourth embodiment, under the same conditions as in the first embodiment, that is, in the case of RF plasma having a beam voltage of 100 V or less, the functional layer only when the RF power is set to 15 W to 30 W can take full advantage of the effect of , and a high MR ratio can be obtained.</p><p>In the first to fourth embodiments, the thin film forming process shown in Figs. 2A to 2E was shown to be useful as a method for manufacturing the functional layer 10 of various materials. In addition, even when Ti, Cr, Zr, Hf, V, A1, Mg, or Cu is used as the functional layer 10, the same functional layer can be obtained by subjecting the material to a thinning process in the same manner, and high It will be appreciated that MR ratios can be obtained.</p><p>(Example 5)</p><p>Now, a method for manufacturing a magnetoresistive effect element according to a fifth embodiment of the present invention will be described. In the fifth embodiment, unlike the first to fourth embodiments, the functional layer 10 is a laminate. In other respects, since the fifth embodiment is essentially the same as the first to fourth embodiments, obviously different parts between the fifth embodiment and the first to fourth embodiments will be described, and descriptions of the same parts will be omitted. .</p><p>After forming the first electrode 1 to the magnetization antiparallel coupling layer 4-2 by the process described in the first embodiment, Co as the laminate and the second magnetization fixing layer 4-3<sb>90</sb>Fe<sb>10</sb>is laminated to 1.5 nm. During the process of forming the second magnetized pinned layer 4-3, the functional layer 10-1 is formed by a process as shown in FIGS. 2A-2E.</p><p>Specifically, the processes are as follows. First, Fe is formed to a thickness of 0.15 nm as a part of the second magnetization-fixing layer 4-3 serving as the oxidized layer, and then Zr is formed to a thickness of 0.15 nm. Here, the term "a part of the second magnetization-fixing layer 4-3" refers to the second magnetization-fixing layer divided into upper and lower portions through the functional layer 10-1, as described in the first embodiment. It is the lower half of the floor.</p><p>By natural oxidation, ion beam oxidation (IAO), or plasma oxidation of Fe and Zr, which are a part of the second magnetized pinned layer 4-3, a functional layer 10- having a thickness of about 1.5 to 3 nm on the surface of Fe and Zr. 1) is formed. Here, the ion beam is very weak compared to normal milling conditions, and the beam voltage is set to 10 OV or less. When the ion beam is irradiated to a multilayer body made of Fe and Zr without oxygen under this condition, the etching rate is about 0.1 to 3 Å/min.</p><p>Process conditions for natural oxidation, IAO, and plasma oxidation, respectively, are as provided in Table 5 shown in FIG. 16 .</p><p>In Table 5, reference numeral REF denotes a process of a spin valve structure without a functional layer as a reference sample. Reference numerals I-1 to I-4 indicate process conditions of the conventional functional layer creation process. Reference numerals J-1 to J-4 indicate process conditions of the functional layer creation process of the present invention.</p><p>The difference between the process conditions of the conventional functional layer creation process and the process conditions of the functional layer creation process of the present invention is similar to the case of the first embodiment when thinning an oxide film formed by any one of natural oxidation, IAO, and plasma oxidation. After ion treatment (AIT) is performed. By performing AIT, it is possible for the functional layer 10 to be thinned while maintaining a uniform film thickness without being formed in an island shape or having a plurality of pinholes.</p><p>After the functional layer 10 is formed by the above-described process, Co which becomes the upper half of the second magnetized pinned layer 4-3<sb>90</sb>Fe<sb>10</sb>Since the processes from the process of forming to the process of forming the second electrode 9 are the same as those of the first embodiment, their description is omitted.</p><p>In this embodiment, the functional layer 10 is made of an oxide of Fe-Zr. However, the functional layer 10 is not limited to this material. Essential conditions for the functional layer 10 are Fe, Co, Ni, Cu, Ti, V, Cr, Mn, Mg, Al, Si, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta , W, Re, Ir, Pt, and an oxide, nitride, or fluoride formed by oxidizing, nitriding, or fluorination of a metal or alloy containing at least one of Au.</p><p>Now, the difference in characteristics between the magnetoresistive effect element manufactured by the manufacturing method of the fifth embodiment of the present invention and the magnetoresistive effect element manufactured by the conventional manufacturing method will be described with reference to Table 5. Even when Zr is used as the base material for the functional layer, the MR increase is not large in the sample group I created by the conventional process flow. However, the MR increase amount in the sample group J created by the process flow of the present invention is very large. This is also considered to be because the same functional layer can be obtained in group J. Further, since the functional layer 10 is a multilayer body, it is possible to obtain a larger MR than the second embodiment and the third embodiment in which the functional layer 10 is formed as a single layer. The reason is thought to be that modulation of the electronic structure of the functional layer 10 causes a certain spin polarization effect on the conduction electrons, thereby creating a large spin filtering effect.</p><p>Also in the case of this embodiment, when AIT is used in the thin film process, under the same conditions as in the first embodiment, that is, RF plasma with a beam voltage of 100 V or less, only when the RF power is set to 15 W ~ 30 W of the functional layer The effect can be fully utilized, and a high MR ratio can be obtained.</p><p>The combination of the laminates in this embodiment is not limited to the above-described examples. As long as the laminate is a laminate formed of two or more materials selected from Ti, Cr, Zr, Hf, V, Al, Mg, and Cu, the same effects as in this embodiment can be exhibited.</p><p>(Example 6)</p><p>In the first to fifth embodiments, it is assumed that the functional layer is included in either or both of the magnetization fixing layer and the magnetization free layer. The sixth embodiment is the MR ratio achieved when the functional layer is embedded in either the magnetization pinned layer or the magnetization free layer, and the MR achieved when the functional layer is embedded in both the magnetization pinned layer and the magnetization free layer. Examine the differences between the ratios.</p><p>Characteristics required for the magnetoresistance effect element include magnetic characteristics as well as resistance change rate. In particular, when the coercive force Hc and the magnetization distortion λ of the magnetization free layer increase, the magnetic properties cause noise or the responsiveness to an external magnetic field that is a signal deteriorates. When the device is used as a magnetic head, the signal-to-noise (S/N) ratio is lost. Therefore, Hc and λ of the magnetization free layer should be minimized. In general, it is known that Hc and λ increase when oxygen is mixed into a ferromagnetic material. Since the functional layer of the present invention is mainly formed from an oxide layer, there is a possibility that Hc and λ increase when the functional layer is inserted into the magnetization free layer, thereby deteriorating the S/N ratio. However, there is no problem even if the functional layer is inserted into the magnetization free layer if the advantage of MR improvement is large due to loss due to deterioration of magnetic properties and improvement in MR. Moreover, there is an advantage that a configuration in which the functional layer is inserted only in the magnetization free layer is easy to realize as an actual device.</p><p>As an example, in the first embodiment, on the premise that there is a functional layer in the magnetization pinned layer, the respective situations of a case in which the functional layer is in the magnetization free layer and a case in which the functional layer is not in the magnetization free layer are given. Table 6 shown in FIG. 17 shows the results of measuring the MR ratio. At the same time, Table 6 shows the configuration in which the magnetic properties of the free layer are good (Co<sb>90</sb>Fe<sb>10</sb> 1nm/Ni<sb>80</sb>Fe<sb>20</sb> 3.5 nm).</p><p>According to Table 6, as the results of Examples 1 to 6, samples B-1 to B in which AIT was performed when thinning an oxide film formed by any one of natural oxidation, IAO, and plasma oxidation in the magnetized fixed layer. -4, L-1 to L-4, 0-1 to 0-4 had a higher MR ratio than samples A-1 to A-4, K-1 to K4, M-1 to M-4 without AIT It will be appreciated that large As is clear from the comparison between A-2 and K-2 and between M-2 and B-1 and L-1 and O-1, when the functional layer is inserted only in the magnetization fixing layer, the effect of improving the MR ratio is not significant. decreases considerably.</p><p>Compare the groups of samples B-1 to B-4, L-1 to L-4, and 0-1 to 0-4, and samples A-1 to A-4, K-1 to K4, and M-1 By comparing the groups of ~M-4, the samples in which the functional layer is inserted in the magnetization free layer can show a greater spin filtering effect. Accordingly, it becomes possible to obtain a larger MR ratio.</p><p>(Seventh embodiment)</p><p>In the magnetoresistive effect elements described in connection with the first to sixth embodiments, the spacer layer 5 is formed from copper. In the seventh embodiment, examination has been made as to whether the advantages of the present invention are derived by the magnetoresistive effect element having the resistance adjusting layer as the spacer layer 5 . The resistance control layer used here is a NOL (Nano Oxide Layer) formed from Al-O having a metal path made of Cu. The Cu metal path passes through Al-O, which is an insulating portion, and connects the magnetized pinned layer and the magnetized free layer in an ohmic manner.</p><p>A conceptual diagram of the magnetoresistive effect element of the seventh embodiment is shown in FIG. The structure of the seventh embodiment exhibits a so-called CCP (Current-Confined Path) effect, in which the current is confined to the vicinity of the spin-dependent magnetized pinned layer 104, spacer layer 105, and free layer 106. FIG. Accordingly, the MR ratio is increased. As an example, Table 7 shown in FIG. 18 shows a magnetoresistive effect element in which the functional layers described in relation to the first to fifth embodiments and the spacer layer of the Al-NOL structure having a Cu metal path are combined together. Shows the measurement results of the MR ratio in .</p><p>According to Table 7, MR ratios of magnetoresistance effect elements (P-1 to P-4, and Q-1 to Q-4) each having an Al-NOL structure spacer layer 105 having a Cu metal path. are about 6 to about MR ratios (achieved by elements A-1 to A-4, and B-1 to B-4) each having the structure described in connection with the first to fifth embodiments. 7 times.</p><p>As described above, the magnetoresistance effect device having the spacer layer 105 of the Al-NOL structure with the Cu metal path can also retain the advantages of the present invention (ie, the magnetization pinned layer and the magnetization free layer are oxidized and AIT treated). improvement of the MR ratio realized by the functional layer formed by</p><p>(Example 8)</p><p>In the first to sixth embodiments, the position of the functional layer is assumed to be located in the vicinity of a substantially intermediate position between the magnetization fixed layer and the magnetization free layer. However, the spin filtering effect in the magnetized pinned layer or the magnetized free layer should be uniform everywhere.</p><p>However, in the case of the magnetoresistive effect element having the resistance adjusting layer of the spacer shown in the seventh embodiment, the current confinement effect becomes larger as the distance to the spacer is shorter. Therefore, it is very important to increase the spin-dependent scattering phenomenon that occurs near the boundary between the magnetized pinned layer and the magnetized free layer. Therefore, the positional dependence of the functional layer with respect to the magnetized pinned layer and the magnetized free layer will be investigated.</p><p>As a comparative example, the MR ratio of the magnetoresistive effect element in which the functional layer is located at a position (1.5 nm from the boundary) between the magnetization fixed layer and the magnetization free layer of the seventh embodiment is such that the functional layer of this embodiment is one position (from the boundary). The MR ratio of the magnetoresistive effect element having the configuration positioned at the position of 0.7 nm) is compared. The results of the comparison are provided in Table 8 shown in FIG. 19 .</p><p>As is also apparent from Table 8, it can be confirmed that the MR ratios obtained in the sample R group and the MR ratios obtained in the S group are larger than the MR ratios obtained in the sample group P and the sample group Q. In addition, it is understood that the closer the functional layer to the spacer layer, the more pronounced the spin filtering effect. As in the case of the above-described embodiment, when the sample R group and the sample S group are compared with each other, it is understood that the MR ratio becomes larger in the functional layer formed through the thin film formation process as shown in FIGS. 2A to 2E.</p><p>(Example 9)</p><p>In all of the first to eighth embodiments, it was confirmed that a functional layer is provided in the magnetization fixing layer or the magnetization free layer, and the functional layer plays an important role in improving the MR ratio. However, spin-dependent scattering, which is the cause of MR ratio fluctuations, is not expressed alone in the magnetized pinned layer or the magnetized free layer. Conduction electrons are also spin dependent scattering at the boundary between the spacer layer and the magnetization pinned layer or between the magnetization free layer and the spacer layer.</p><p>Therefore, in the ninth embodiment, an examination of the position of the functional layer in the magnetization pinned layer or the magnetization free layer in which the functional layer increases spin-dependent scattering at the boundary between the spacer layer and the magnetization pinned layer or the magnetization free layer is is carried out</p><p>Fig. 8 shows the magnetoresistive effect element of the ninth embodiment. In Fig. 8, the magnetoresistive effect element of this embodiment includes a first electrode 201; a substrate layer 202 comprising a 5 nm Ta layer and a 2 nm Ru layer; an antiferromagnetic layer 203 formed from PtMn to a thickness of about 15 nm; Co with a thickness of about 3 to 4 nm<sb>90</sb>Fe<sb>10</sb>A first magnetized pinned layer 204-1 formed from, a magnetized antiparallel coupling layer 204-2 formed from Ru to a thickness of about 0.9 nm, and Co<sb>90</sb>Fe<sb>10</sb> a magnetization fixing layer 204 comprising a second magnetization fixing layer 204-3 formed from the layer; a spacer layer 205 formed from Cu to a thickness of about 3 nm; Co<sb>90</sb>Fe<sb>10</sb> a magnetization free layer 206 formed from the layer; a first protective layer 207 formed from Cu to a thickness of about 1 nm; a second protective layer 208 formed from Ru to a thickness of about 5 nm; and a structure in which the second electrode 209 is stacked.</p><p>The functional layer 210 - 1 exists along the boundary between the second magnetized pinned layer 204 - 3 and the spacer layer 205 , and the functional layer 210 - 2 includes the magnetization free layer 206 and the spacer layer ( 205) exist along the boundary between The total thickness of the second magnetization pinned layer 204 - 3 and the functional layer 210 - 1 is about 3 nm, and the total thickness of the magnetization free layer 206 and the functional layer 210 - 2 is about 3 nm.</p><p>As shown in FIG. 20, Table 9 shows the MR ratios obtained in the magnetoresistive effect element in which the functional layer is provided in the magnetization fixing layer, and the magnetoresistance effect element in which the functional layer is present along the boundary between the magnetization fixing layer and the spacer layer. shows a comparison between the magnitudes of the MR ratios obtained in The oxide layer of Fe used in the first embodiment is applied to the functional layer. The oxidation conditions, AIT conditions, etc. used for the sample groups A-1 to A-4 and B-1 to B-4 of the first embodiment are used as they are.</p><p>According to Table 9, the functional layer 210 - 1 is inserted along the boundary between the second magnetization pinned layer 204 - 3 and the spacer layer 205 , or between the magnetization free layer 206 and the spacer layer 205 . Even when the functional layer 210 - 2 is inserted along the boundary of , spin filtering effects similar to those derived in the first to eighth embodiments are derived. Moreover, as in the case of the first to eighth embodiments, samples U-1, U-2, U-3, and U-4 in which functional layers are formed through the thin film formation process shown in FIGS. 2A - 2E. ) of samples (T-1, T-2, T-3) of the magnetoresistive effect element having functional layers formed through a process not including a thin film formation process as shown in Figs. 2A - 2E. , and T-4) are understood to be larger than the MR ratios. The reason is that, as described in connection with the first embodiment and the like, a functional layer having a uniform thickness can be grown by the process shown in Figs. 2A - 2E.</p><p>As described above, in the ninth embodiment, the functional layer 210-1 is inserted along the boundary between the second magnetized pinned layer 204-3 and the spacer layer 205, or the magnetization free layer 206 and A functional layer 210 - 2 is inserted along the boundary between the spacer layers 205 . However, a functional layer may be interposed between the two boundaries. In that case, a synergistic effect of the spin filtering effect of the second magnetized pinned layer and the spin filtering effect of the magnetized free layer appears. Moreover, a magnetoresistive effect element having a higher MR ratio can be manufactured.</p><p>(Example 10)</p><p>Although all of the above-described embodiments relate to magnetoresistance effect elements having a GMR structure, the present invention is not limited to a GMR structure and may be applied to a TMR structure. In this embodiment, a magnetoresistive effect element in which a functional layer is formed from a TMR structure is shown. In the TMR structure, the functional layer of the GMR structure corresponds to the barrier layer. The magnetoresistance effect element of the TMR structure currently has a problem of reducing the RA of the reproduction head of the hard disk drive. In order to obtain a lower RA, the thickness of the barrier layer must be reduced. Further, when the thickness of the barrier layer is reduced, it causes problems of formation of pinholes in the barrier layer and a serious reduction in MR.</p><p>In Fig. 10, the magnetoresistive effect element of this embodiment includes a first electrode 201; a substrate layer 202 comprising a 5 nm Ta layer and a 2 nm Ru layer; an antiferromagnetic layer 203 formed from PtMn to a thickness of 15 nm; Co with a thickness of about 3 to 4 nm<sb>90</sb>Fe<sb>10</sb>A first magnetized pinned layer 204-1 formed from, a magnetized antiparallel coupling layer 204-2 formed from Ru to a thickness of about 0.9 nm, and Co to a thickness of about 2 nm<sb>90</sb>Fe<sb>10</sb><sb></sb>a magnetization fixing layer 204 comprising a second magnetization fixing layer 204-3 formed from the layer; a barrier layer 211 formed from AlO; about 2 nm of Co<sb>75</sb>Fe<sb>25</sb> layer and 3.5 nm Ni<sb>80</sb>Fe<sb>20</sb> a magnetization free layer 206 having a two-layer structure with layers; a first protective layer 207 formed from Cu to a thickness of about 1 nm; a second protective layer 8 formed from Ru to a thickness of about 5 nm; and a structure in which the second electrode 9 is stacked.</p><p>Table 10 shown in FIG. 21 shows the processes for forming the barrier layer 211 .</p><p>Table 10 shows that samples w-1, w-2, w-3, and w-4 for which barrier layers are formed through the processes shown in FIGS. 2A-2E are all formed from thick AlO from the beginning, samples V-1, It shows MR ratios greater than those shown by V-2, V-3, and V-4. The reason is that the number of pinholes is reduced and a uniform barrier layer is created.</p><p>In the tenth embodiment, the barrier layer is regarded as an oxide of Al. However, the barrier layer is not limited to this material. The essential requirements for the barrier layer are Fe, Co, Ni, Cu, Ti, V, Cr, Mn, Mg, Al, Si, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta, W, It is an oxide, nitride, or fluoride formed by oxidizing, nitriding, or fluorinating a metal or alloy containing at least one selected from the group consisting of Re, Ir, Pt, and Au. Even in this case, the barrier layer can be made uniform through the thin film formation process.</p><p>In a tenth embodiment, the barrier layer is subjected to the processes of the present invention. As in the case of the first to ninth embodiments, the present invention is also naturally applied as a process for forming a functional layer to be inserted into a magnetization fixing layer or a magnetization free layer.</p><p>The present invention is not limited to the described embodiments. In an actual stage, components may be implemented with modifications without departing from the gist of the present invention. Various inventions can be created by appropriate combination of a plurality of components described in the present embodiments. For example, some components may be removed from all of the components described in the above embodiments. Moreover, components described in different embodiments may also be suitably combined.</p>