JP2005228816A - Method for forming magnetic film, method for forming magnetic pattern, and method for manufacturing magnetic recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a formation method, or the like in a magnetic film for forming a magnetic film having a part in which coercive force is different. <P>SOLUTION: A film 5 having one kind selected from B, Ag, and Cu is formed in a thin film 4 using at least one of Fe and Co and at least one of Pd and Pt as a main constituent. An inert gas ion 6 is locally implanted into the thin film 4 in which the film 5 is formed from a part on the film 5 having one kind selected from B, Ag, and Cu for mixing one kind selected from B, Ag, and Cu into the thin film 4 before the thin film is heat-treated for forming the magnetic film 11 having a portion of which coercive force is different. A part 7, where one kind selected from B, Ag, and Cu is mixed, becomes a part 9 having high coercive force. A part 8, where one kind selected from B, Ag, and Cu is not mixed, becomes a part 10 having low coercive force. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for forming a magnetic film, a method for forming a magnetic pattern, and a method for manufacturing a magnetic recording medium. More specifically, the present invention relates to a magnetic film capable of processing a magnetic film composed of a recording portion and a non-recording portion according to a recording pattern. It is related with the formation method of this.

  A hard disk drive (HDD) is a large-capacity storage device capable of high-speed data access and high-speed transfer. In particular, in the last 10 years, the surface recording density has been improved at an annual rate of 60% to 100%, and further improvement of the recording density is required.

  In order to improve the recording density of a hard disk drive (HDD), it is necessary to reduce the track width or the recording bit length. However, when the track width is reduced, there is a problem that adjacent tracks are likely to interfere with each other. That is, the reduction of the track width has a problem that magnetic recording information is easily overwritten on an adjacent track at the time of recording, and a problem that crosstalk due to a leakage magnetic field from the adjacent track is likely to occur at the time of reproduction. Cause it to occur. These problems all cause a decrease in the S / N ratio of the reproduction signal, and cause a problem that the error rate is deteriorated.

  As a method for reducing the influence between adjacent tracks and realizing a high track density with respect to such a problem, a discrete track type magnetic recording medium (hereinafter also referred to as a discrete track medium) has been proposed. The discrete track medium currently proposed is one in which each track is magnetically separated from adjacent tracks by providing a groove between the tracks of the magnetic film as a recording portion (guard band). However, in this method, since a physical groove exists between the tracks, it is difficult to realize stable flying of the magnetic head on the magnetic recording medium.

  On the other hand, it is possible to stabilize the flying characteristics of the magnetic head on the magnetic recording medium by flattening after filling the grooves between the tracks with a nonmagnetic material, but the manufacturing process becomes complicated, There arises a problem that the manufacturing cost increases.

As a method for avoiding these problems, a processing method for locally irradiating a magnetic film with ions to modify magnetic characteristics has been studied (see, for example, Patent Documents 1 and 2). The method described in Patent Document 1 is a method of modifying the magnetic properties of the irradiated portion by irradiating a laminated film with light ions and mixing the atoms at the laminated film interface by the impact. Further, the method described in Patent Document 2 is a method for modifying the magnetic characteristics of the irradiation unit by utilizing local heat generation by irradiation with an ion beam.
Special table 2002-501300 gazette Japanese Patent Laid-Open No. 2003-22525

  The present invention provides a new means for avoiding the above-described conventional problems, and a first object of the present invention is to form a magnetic film having portions having different coercive forces. It is in providing the formation method. The second object of the present invention is to provide a method for forming a magnetic pattern using such a method, and the third object of the present invention is to provide a method for producing a magnetic recording medium using such a method. There is to do.

  The method for forming a magnetic film of the present invention that achieves the first object is a thin film mainly composed of at least one of Fe and Co and at least one of Pd and Pt, and one type selected from B, Ag, and Cu. And an inert gas ion is locally implanted into the thin film on which the film is formed from the film having one selected from B, Ag, and Cu, and selected from B, Ag, and Cu. The thin film is mixed in the thin film, and then the thin film is heat-treated.

  According to the present invention, a film having one type selected from B, Ag and Cu is formed on a thin film mainly composed of at least one of Fe and Co and at least one of Pd and Pt, and the B, Ag and Cu are formed. B is obtained by locally injecting an inert gas ion into a thin film on which the film is formed from a film having one selected from B, Ag, and Cu, and mixing in the thin film. A portion in which one kind selected from Ag and Cu is mixed becomes a magnetic film having a CuAuI type ordered structure by heat treatment, and has extremely high magnetic anisotropy. That is, at the time of heat treatment, one kind selected from B, Ag and Cu acts to promote the change to the CuAuI type ordered structure, so that one kind selected from B, Ag and Cu is mixed by the subsequent heat treatment. The part is sufficiently changed to a CuAuI type ordered structure. In a portion where one kind selected from B, Ag, and Cu is not mixed, even if heat treatment is performed, the CuAuI type ordered structure is not sufficiently changed and a low coercive force is exhibited.

  As a result, the part in which one type selected from B, Ag and Cu is locally mixed sufficiently changes to the CuAuI type ordered structure and exhibits high coercive force, and one type selected from B, Ag and Cu is present. In the unmixed portion, a magnetic film having a low coercive force is formed without sufficiently changing to the CuAuI type ordered structure.

  Therefore, according to the method for forming a magnetic film of the present invention, between a portion where one type selected from B, Ag and Cu is mixed and a portion where one type selected from B, Ag and Cu is not mixed. Magnetic films having different coercive forces can be formed. For this reason, since a discrete track medium or the like can be formed without forming a conventional groove or the like, a magnetic pattern substantially free from surface irregularities can be formed.

  In the method for forming a magnetic film of the present invention, it is preferable that a diffusion preventing film is formed between the thin film and the film having one selected from B, Ag, and Cu. According to this invention, when a film having one selected from B, Ag and Cu is formed on the thin film, the diffusion preventing film prevents one selected from B, Ag and Cu from diffusing into the thin film. Therefore, a portion where one kind selected from B, Ag and Cu is mixed shows a high coercive force, and a part where one kind selected from B, Ag and Cu is not mixed shows a magnetic film showing a low coercive force. It can be formed stably.

  In the method for forming a magnetic film according to the present invention, a portion where one kind selected from B, Ag and Cu after the heat treatment is mixed has a CuAuI type regular structure. According to the present invention, the portion where one kind selected from B, Ag, and Cu is mixed after the heat treatment has a CuAuI type regular structure, and thus exhibits extremely high magnetic anisotropy. As a result, such a magnetic film having high magnetic anisotropy has the effect of improving the thermal stability of recording magnetization.

  In the method for forming a magnetic film of the present invention, the thin film is a thin film in which a film containing at least one of Fe and Co as a main component and a film containing at least one of Pd and Pt as a main component are stacked. Is preferred.

  In the method for forming a magnetic film of the present invention, it is preferable that the thin film is a composition modulation film in which a composition of at least one of the Fe and Co and at least one of the Pd and Pt is modulated in a film thickness direction. According to the present invention, if the thin film is a composition-modulated film, it is considered that the activation energy of diffusion decreases due to the occurrence of interfacial diffusion during heat treatment, so the thin film is changed to a CuAuI type ordered structure even at a low heat treatment temperature Can be made.

  The method for forming a magnetic pattern of the present invention that achieves the second object is a thin film mainly composed of at least one of Fe and Co and at least one of Pd and Pt, and one type selected from B, Ag, and Cu. A film having an A, and an inert gas ion is implanted into a predetermined portion of the thin film on which the film is formed from a film having one selected from B, Ag, and Cu by using a mask. One kind selected from Ag and Cu is mixed in the thin film, and then the thin film is heat-treated.

  According to the present invention, as in the case of the magnetic film forming method described above, the portion where one kind selected from B, Ag and Cu is locally mixed is sufficiently changed to a CuAuI type ordered structure and is high. In the portion where the coercive force is shown and one kind selected from B, Ag and Cu is not mixed, a magnetic pattern showing a low coercive force is formed without sufficiently changing to the CuAuI type regular structure. Therefore, according to the method for forming a magnetic pattern of the present invention, a discrete track medium or the like having a magnetic pattern can be formed without forming a groove or the like as in the prior art, so that there is substantially no surface unevenness. A magnetic pattern can be formed.

  A method of manufacturing a magnetic recording medium of the present invention that achieves the third object is a method of manufacturing a magnetic recording medium having at least a nonmagnetic substrate and a magnetic film provided on the nonmagnetic substrate, The film forms a film having one kind selected from B, Ag, and Cu on a thin film mainly composed of at least one of Fe and Co and at least one of Pd and Pt, and selected from the B, Ag, and Cu. An inert gas ion is locally injected into the thin film on which the film is formed from the film having one kind, and one kind selected from B, Ag, and Cu is mixed in the thin film, and then the thin film is heat-treated. It is characterized by becoming.

  According to the present invention, a magnetic recording medium such as a discrete track medium having a predetermined magnetic pattern can be manufactured without forming a conventional groove or the like. A medium can be manufactured.

  In the method for producing a magnetic recording medium of the present invention, it is preferable that a diffusion preventing film is formed between the thin film and the film having one selected from B, Ag, and Cu.

  In the method for manufacturing a magnetic recording medium according to the present invention, the local implantation of the inert gas ions is performed using a mask.

  As described above, according to the method for forming a magnetic film, the method for forming a magnetic pattern, and the method for manufacturing a magnetic recording medium of the present invention, the coercive force of the portion where one selected from B, Ag, and Cu is mixed is increased. Can be made. As a result, a magnetic film having a different coercive force may be formed between a portion where one type selected from B, Ag and Cu is mixed and a portion where one type selected from B, Ag and Cu is not mixed. Therefore, for example, a desired magnetic pattern substantially free from surface irregularities can be formed by injecting inert gas ions into a predetermined location using a mask and mixing one selected from B, Ag, and Cu. be able to.

  In particular, by forming a portion where one kind selected from B, Ag and Cu is mixed on a disk-shaped nonmagnetic substrate as a concentric track pattern, one kind selected from B, Ag and Cu is mixed. A magnetic recording medium such as a discrete track medium provided with a predetermined magnetic pattern as a part can be manufactured without forming a conventional groove or the like. The magnetic recording medium manufactured in this way is substantially free of surface irregularities, and the manufacturing cost can be reduced.

  Hereinafter, a method for forming a magnetic film, a method for forming a magnetic pattern, and a method for manufacturing a magnetic recording medium according to the present invention will be sequentially described with reference to the drawings. Note that the scope of the present invention is not limited by the embodiments described below.

(Method of forming magnetic film)
FIG. 1 is a process diagram showing an example of a method for forming a magnetic film of the present invention. FIG. 1A shows a cross-sectional form of a laminated thin film, and FIG. 1B shows a cross-sectional form of a step of forming a film having one kind selected from B, Ag, and Cu on the thin film. FIG. 1C shows a cross-sectional form of the process of implanting inert gas ions into the thin film on which the film is formed, and FIG. 1D shows the magnetic field of the present invention formed as a result of the heat treatment. The cross-sectional form of the film is shown. FIG. 2 is a cross-sectional view in the stacking direction showing an example of a mode in which a base film and an intermediate film are provided between the substrate and the magnetic film in the magnetic film shown in FIG. FIG. 3 is a process diagram showing an example of a film forming method of the composition modulation film of the present invention.

  As shown in FIG. 1, the method for forming a magnetic film of the present invention is applied to a thin film 4 mainly composed of at least one of Fe and Co and at least one of Pd and Pt formed on a substrate 1 with B, Ag. And a film 5 having one type selected from Cu, Cu, and inert gas ions 6 are locally applied to the thin film 4 on which the film 5 is formed from the film 5 having one type selected from B, Ag, and Cu. It is characterized in that the thin film 4 is mixed with one type selected from B, Ag, and Cu and then heat-treated.

  As the substrate 1, a nonmagnetic substrate is used, and examples thereof include an aluminum alloy substrate, a glass substrate, and a silicon substrate that are generally used as substrates for magnetic films.

  The thin film 4 formed on the substrate 1 is a laminate in which first films 2 mainly containing at least one of Pd and Pt and second films 3 mainly containing at least one of Fe and Co are alternately laminated. It may be a thin film, or a composition modulation film formed by alternately depositing at least one of Pd and Pt (Pt atoms 41 in FIG. 3) and at least one of Fe and Co (Fe atoms 42 in FIG. 3).

  When the thin film 4 is a laminated thin film, the first film 2 is not particularly limited as long as it is a film containing at least one of Pd and Pt as a main component. As at least one of Pd and Pt, for example, Pd, Pt, Pd—Pt and the like are preferably exemplified, and Pt is particularly preferable. Moreover, the 2nd film | membrane 3 will not be specifically limited if it is a film | membrane which has at least one of Fe and Co as a main component. As at least one of Fe and Co, for example, Fe, Co, Fe—Co and the like are preferably exemplified, and Fe is particularly preferable.

  The laminated thin film is an element that can be formed on the substrate 1 and then heat-treated to be a magnetic film such as Pt—Fe, Pt—Co, Pt—Co—Fe having high magnetic anisotropy, and the like. It is desirable that the second film 3 is formed, and in particular, a laminated thin film in which a Pt film as the first film 2 and an Fe film as the second film 3 are laminated is desirable.

  The laminated thin film can be formed by various film forming means such as sputtering. For the lamination of the first film 2 and the second film 3, each target having each film forming element is used, and each target is sputtered at a predetermined power for a predetermined time and the first film 2 having a desired composition and the second film 3 are formed. Two films 3 can be formed.

  When the thin film 4 is a composition modulation film, it is not particularly limited as long as it is a composition modulation film in which the composition of at least one of Fe and Co and at least one of Pd and Pt is modulated. For example, as shown in FIG. Thus, a composition modulation film in which the composition of at least one of Fe and Co and at least one of Pd and Pt is modulated in the film thickness direction is desirable. For example, the composition modulation film is deposited by adjusting the film formation rate so that the thickness of at least one of Fe and Co and at least one of Pd and Pt is less than the thickness of the monoatomic layer. As a result, a film was formed. The term “modulation” as used herein does not mean that the composition of each layer in the film thickness direction is composed of only a single atom, as in a conventional laminated film in which monoatomic layers are alternately laminated, but at least Fe and Co. One and Pd and at least one of Pt represent the state which is changing continuously with a different composition in the film thickness direction.

  Examples of the composition modulation film include a composition modulation film in which Pt and Fe are alternately deposited and a portion having a high Pt ratio and a portion having a high Fe ratio are periodically arranged.

  In the exemplified composition-modulated film, in the portion where the ratio of Pt is large, the ratio of Pt with respect to the total of Pt and Fe is preferably more than 50 atomic% and not more than 90 atomic%, preferably 60 atomic% or more, 90 More preferably, it is at most atomic%. By depositing a portion having a high Pt ratio within such a range, a magnetic film having a CuAuI type regular structure with high magnetic anisotropy can be formed by subsequent heat treatment. When the ratio of Pt exceeds 90 atomic%, a magnetic film having a CuAuI type regular structure with high magnetic anisotropy may not be formed even if heat treatment is performed. In addition, the ratio of Fe in the case where the ratio of Pt exceeds 50 atomic% and is 90 atomic% or less is less than 50 atomic% and 10 atomic% or more with respect to the total of Pt and Fe.

  Specific examples of such a composition modulation film include a composition modulation film in which the ratio of Pt atoms to Fe atoms is 3: 1, 1: 1, and 1: 3, respectively. .

  The method of forming the composition modulation film is not particularly limited, and examples thereof include the following method using Pt atoms and Fe atoms as shown in FIG.

  (1) Pt atoms 41 corresponding to 75% of the amount necessary for forming a Pt monoatomic layer on the nonmagnetic substrate 1 are deposited by sputtering or the like. Since Pt atoms 41 are in an amount of 75% that cannot form a complete monoatomic layer, the formed first portion has 25% defects as shown in FIG. Become.

  (2) Next, Fe atoms 42 corresponding to 75% of the amount necessary for forming the Fe monoatomic layer are deposited on the first portion by sputtering or the like. Due to the effect of surface diffusion, the Fe atoms 42 fill the defects in the first portion with 25% of the Fe atoms 42, while the remaining 50% of the Fe atoms 42 form the second portion. As a result, as shown in FIG. 3B, the first portion has a ratio of Pt to Fe of 3: 1 and the second portion has 50% defects.

  (3) Next, Pt atoms 41 corresponding to 75% of the amount necessary for forming the Pt monoatomic layer on the second portion are deposited by sputtering or the like. Due to the effect of surface diffusion, the remaining 25% of the Pt atoms 41 form the third portion while 50% of the Pt atoms 41 fill the defects of the second portion. As a result, as shown in FIG. 3C, the second portion has a ratio of Pt to Fe of 1: 1, and the third portion has 75% defects.

  (4) Next, Fe atoms 42 corresponding to 75% of the amount necessary for forming the Fe monoatomic layer on the third portion are deposited by sputtering or the like. Fe atoms 42 are deposited so as to fill all defects in the third portion due to the effect of surface diffusion, and the third portion has a ratio of Pt to Fe of 1: 3 as shown in FIG. .

  The film formed by such steps (1) to (4) has three parts (first part, second part, third part) as one cycle, and the ratio of Pt atoms to Fe atoms is respectively The film has a compositional modulation structure which is different in each part as 3: 1, 1: 1, and 1: 3. Such a composition modulation film has a distortion due to a periodic shift of the composition ratio as compared with a laminated film in which monoatomic layers are alternately laminated, so that mutual diffusion of Pt atoms 41 and Fe atoms 42 occurs. It is easy to obtain a CuAuI type ordered structure with lower energy.

  The thin film 4 is formed until, for example, the thickness (referring to the total thickness) is 3 nm to 30 nm. If the thickness of the thin film 4 is less than 3 nm, a magnetic film having a CuAuI type regular structure with high magnetic anisotropy may not be formed by subsequent heat treatment. If the thickness of the thin film 4 exceeds 30 nm, Grain growth becomes remarkable during the heat treatment, and as a result, for example, when the obtained magnetic film is applied to a magnetic recording medium, there is a possibility that a medium noise increases. When the thin film 4 is a laminated thin film, the thickness of the first film 2 and the thickness of the second film 3 may be the same or different, and the thickness of each first film 2 and each thickness of the first film 2 may be different. The thicknesses of the two films 3 may be the same or different. Further, the number of stacked layers is not particularly limited as long as the thickness of the thin film 4 is 3 nm to 30 nm.

  The thin film 4 is a face-centered cubic (fcc) disordered phase film with a low magnetic anisotropy and coercive force before heat treatment, and a CuAuI type ordered structure magnetism that exhibits a high magnetic anisotropy after heat treatment. The film composition and the like are adjusted so as to form a film. The disordered phase having a face-centered cubic structure (fcc) is, for example, an irregular phase in which Fe atoms and Pt atoms are randomly arranged, and exhibits low magnetic anisotropy and coercivity. The CuAuI type ordered structure is a face-centered tetragonal structure (fct), and has an atomic arrangement in which, for example, Fe atoms and Pt atoms are alternately stacked in the c-axis direction.

The composition of the thin film as a magnetic film of CuAuI type ordered structure having a high magnetic anisotropy after the heat _{treatment, F 1-x M x (} F is at least one of the of Fe and Co, M is at least one of Pd and Pt X is preferably not less than 0.3 and not more than 0.65 in terms of atomic ratio.) The composition of the thin film 4 is adjusted so as to obtain such a composition. In the present invention, the heat-treated magnetic film is F _1-x M _x (F is at least one of Fe and Co, M is at least one of Pd and Pt, x is an atomic ratio of 0.3 or more, The magnetic film after heat treatment has a very high magnetic anisotropy because it has a CuAuI type ordered structure having a composition of 0.65 or less. When the crystal structure of the thin film is changed from the disordered phase of the face-centered cubic structure (fcc) to the ordered phase of the face-centered tetragonal structure (fct) contracted in the a-axis direction and contracted in the c-axis direction by the heat treatment, In the reduced c-axis direction, for example, a so-called atomic level superlattice in which Fe atoms and Pt atoms are alternately stacked is formed for each atomic layer. Produces extremely high uniaxial magnetic anisotropy in the axial direction. As a result, such a magnetic film having high magnetic anisotropy has the effect of improving the thermal stability of the recording magnetization. The change from the irregular phase to the regular phase as described above is generally referred to as an order-disorder transformation.

  The thin film 4 is composed mainly of at least one of Fe and Co and at least one of Pd and Pt, and usually contains other components for making an isolated particle magnetic recording medium. Examples of other components include oxides and fluorocarbons.

  The film 5 having one type selected from B, Ag and Cu is not particularly limited as long as it is a film having one type selected from B, Ag and Cu, but is preferably a B (boron) monoatomic film. . One kind selected from B, Ag and Cu constituting the film 5 is mixed with the thin film 4 before being heat-treated by implantation of an inert gas ion 6 which will be described later. One type selected from B, Ag, and Cu has an effect of promoting the change to the CuAuI type ordered structure (hereinafter also referred to as ordering promoting effect). In the following, one type selected from B, Ag, and Cu may be referred to as “B etc.”.

  In the region 7 where B or the like is mixed, the change to the CuAuI type ordered structure is promoted in the subsequent heat treatment. That is, there is an effect that the CuAuI-type ordered structure is easily changed. In the present invention, B or the like is locally mixed in a predetermined portion of the thin film 4 and then subjected to a heat treatment, so that only the portion 7 in which B or the like is mixed is easily changed to a CuAuI type ordered structure. The magnetic film 11 can exhibit a coercive force. As a result, the part 7 mixed with B or the like becomes a part 9 showing a high coercive force, and the part 8 not mixed with B or the like becomes a part 10 showing a low coercive force.

  The thickness of the film 5 containing B or the like cannot be determined unconditionally depending on the implantation amount of the inert gas ions 6, but is almost uniformly mixed in the film thickness direction of the thin film 4 by the implantation of the inert gas ions 6. It is preferable that it is formed with a thickness that can be used, for example, 1 nm to 3 nm. If the thickness of the film 5 having B or the like is less than 1 nm, the ordering promoting effect may not be sufficiently exhibited because B or the like is not sufficiently mixed with the thin film 4. If the thickness of the film 5 containing B or the like exceeds 3 nm, even if an inert gas ion 6 described later is implanted, B or the like is not sufficiently mixed in the thin film 4 and the ordering promoting effect is not sufficiently exhibited. is there. Formation of the film 5 having B or the like can be performed by various film forming means such as a sputtering method.

A diffusion preventing film 20 is preferably formed between the thin film 4 and the film 5 having B or the like. The diffusion preventing film 20 is a film for preventing B or the like from diffusing into the thin film 4. Examples of the elements constituting the diffusion prevention film 20 include Ti, SiO ₂ , MgO, Al ₂ O ₃ , TaN, and Cr. The thickness of the diffusion preventing film 20 is not particularly limited, but prevents diffusion of B or the like into the thin film 4 when the film 5 having B or the like is formed, and also introduces inert gas ions 6 to be described later. B etc. which comprise the film | membrane 5 which has B etc. are arbitrarily selected from the range which can fully mix in the thin film 4. FIG.

  The inert gas ions 6 are locally implanted into the thin film 4 on which the film 5 is formed from above the film 5 having B or the like before being heat-treated by the ion implantation method, and mix B or the like into the thin film 4. It works like this. As the ion species of the inert gas, any substance can be used as long as B or the like can be mixed substantially uniformly in the film thickness direction of the thin film 4, for example, in N, He, Ne, Ar, Kr, Xe, and Rn. Selected from. Further, the ion species that does not suppress the ordering promotion effect is selected.

The amount of the inert gas ions 6 implanted is not particularly limited as long as B or the like can be sufficiently mixed in the thin film 4, but is in the range of, for example, 10 ¹³ ions / cm ² to 10 ¹⁵ ions / cm ² . It is preferable to be within.

  The inert gas ions 6 are implanted by an ion implantation method. The ion implantation method uses an ion implantation apparatus. When the inert gas ions 6 are implanted, when the thickness of the thin film 4 is 3 nm to 30 nm, the implantation voltage is desirably in the range of 5 keV to 50 keV. . By injecting the inert gas ions 6 at an injection voltage within this range, for example, B or the like can be mixed in each part in the thickness direction of the thin film 4. The injection voltage is preferably set to a small value within the above range when the thin film 4 is thin, and is set to a large value within the above range when the thin film 4 is thick. Is desirable. When the injection voltage is less than 5 keV, when the thickness of the thin film 4 is 3 nm to 30 nm, B or the like cannot be sufficiently mixed in the deep part of the thin film 4, and the change to the CuAuI type ordered structure can be sufficiently promoted. There are things that cannot be done. On the other hand, when the injection voltage exceeds 50 keV, when the thickness of the thin film 4 is 3 nm to 30 nm, for example, when a base film is provided under the thin film 4 for the purpose of a soft magnetic backing layer, B or the like is included in the base film. When mixed, soft magnetic characteristics may be deteriorated.

  The heat treatment in the present invention is performed in order to obtain the magnetic film 11 having the portion 9 exhibiting a high coercive force by sufficiently changing only the portion 7 mixed with B or the like into a CuAuI type ordered structure. That is, the mixing of B or the like by local implantation of the inert gas ions 6 can promote the change to the CuAuI type ordered structure only at the portion 7 where B or the like is mixed by the subsequent heat treatment. The part 7 mixed with B or the like can be changed to a CuAuI type regular structure exhibiting a high coercive force, and the part 8 not mixed with B or the like can be brought into a state of a part 10 exhibiting a low coercive force.

  For example, in a patterned magnetic recording medium such as a discrete track type magnetic recording medium or a discrete bit type magnetic recording medium, the coercive force of the part 9 having a high coercive force and the coercive force of the part 10 having a low coercive force are used. It is desirable that the magnetic force has a difference of, for example, 2000 Oe or more. A patterned magnetic recording medium having such a coercive force difference can reduce the track width or the recording bit length without causing a decrease in S / N ratio or a deterioration in error rate.

The conditions of the heat treatment are set so that only the portion 7 mixed with B or the like can promote the change to the CuAuI type ordered structure. Such heat treatment conditions are not generally determined according to the mixing of B or the like by injecting inert gas ions 6, but the pressure of the heat treatment atmosphere is preferably 5 × 10 ⁻⁶ Torr or less, for example. When the pressure of the heat treatment atmosphere exceeds 5 × 10 ⁻⁶ Torr, the magnetic film 11 may be deteriorated due to oxidation. The heat treatment temperature is preferably in the range of 300 ° C to 750 ° C. If the heat treatment temperature is less than 300 ° C., the change to the CuAuI type ordered structure may not be sufficiently performed in the portion 7 where B or the like is mixed. If the heat treatment temperature exceeds 750 ° C., the magnetic film 11 Surface shape changes may occur. The heat treatment time is preferably 5 seconds to 10000 seconds. If the heat treatment time is less than 5 seconds, the change to the CuAuI type ordered structure may not be sufficiently performed at the site 7 where B or the like is mixed. If the heat treatment time exceeds 10,000 seconds, the substrate 1 used Depending on the material, the substrate 1 may be deformed.

  In the method for forming a magnetic film according to the present invention, since the boron monoatomic film is formed as the film 5 having B or the like on the thin film 4, the surface roughness of the magnetic film 11 obtained after the heat treatment is reduced. can do. Such a reduction in the surface roughness of the magnetic film 11 can stabilize the flying characteristics of the magnetic head that floats on the magnetic recording medium having the magnetic film 11 by an air flow, and can reduce the magnetic recording as in the prior art. Since it can manufacture without forming a groove | channel etc. in the guard band of a medium, there exists an effect that the increase in manufacturing cost can be suppressed.

  In the method for forming a magnetic film of the present invention described above, a base film 31 and an intermediate film 32 can be provided as a base between the substrate 1 and the magnetic film 11 as shown in FIG. The magnetic film 11 including the base film 31 and the intermediate film 32 has an effect of being superior in crystal orientation and recording characteristics of the magnetic film as compared with a magnetic film in which they are not provided.

  The base film 31 is provided on the substrate 1 made of a nonmagnetic material for the purpose of a soft magnetic backing layer, and is formed of a material such as NiFe, NiFeNb, FeCo or the like in a thickness range of 5 nm to 200 nm. The base film 31 can be formed by sputtering, for example.

  The intermediate film 32 is provided on the base film 31 for the purpose of controlling the crystal orientation of the magnetic film, and is formed of a material such as MgO in a thickness range of 0.5 nm to 5 nm. The intermediate film 32 can also be formed by sputtering, for example.

(Method of forming magnetic pattern)
Next, a method for forming a magnetic pattern according to the present invention will be described.

  The magnetic pattern forming method of the present invention is characterized in that in the above-described magnetic film forming method, local implantation of inert gas ions is performed using a mask. That is, a film having B or the like is formed on a thin film mainly composed of at least one of Fe and Co and at least one of Pd and Pt, and a predetermined thin film having the film formed on the film having B or the like is formed. It is characterized in that after the inert gas ions are implanted using a mask at a location and B or the like is mixed in the thin film, the thin film is heat-treated. The thin film in this case includes, for example, as shown in FIG. 1, a first film 2 mainly containing at least one of Pd and Pt and a second film 3 mainly containing at least one of Fe and Co. Any of the laminated thin films 4 and a composition modulation film in which at least one of Pd and Pt and at least one of Fe and Co are alternately deposited as shown in FIG. 3 may be used.

  The material of the mask 21 is not particularly limited, and various materials typified by a resist formed by photolithography, a silicon stencil, and the like can be arbitrarily used. In particular, in the present invention, the opening of the mask 21 is formed into a concentric track pattern for forming a discrete track medium, for example. Can be mixed. Further, by forming the opening of the mask 21 into a dot-like pattern for forming a discrete bit medium, for example, B having an effect of promoting regularization can be mixed in the thin film in the same pattern as the dot pattern. it can.

  By injecting inert gas ions into the film before the heat treatment by this method and mixing B or the like, the portion where B or the like is mixed can be formed into a concentric track pattern exhibiting a high coercive force. The portion where no is mixed can be a pattern showing a low coercive force.

  Therefore, according to the method for forming a magnetic pattern of the present invention, a magnetic pattern having substantially no surface irregularities can be formed by a very simple process by forming a portion having a high coercive force in a pattern.

  As a mask for forming a concentric track pattern provided on the discrete track medium, for example, a mask having a mask pattern with an opening width of the mask of about 30 nm to 250 nm and a mask track pitch of about 50 nm to 300 nm is used. it can. Further, as a mask for forming a dot-like bit pattern provided on a discrete bit medium, for example, a mask having a mask pattern having an opening diameter of the mask of about 10 nm to 100 nm and a mask dot pitch of about 20 nm to 200 nm is used. it can.

(Method of manufacturing magnetic recording medium)
Next, a method for manufacturing the magnetic recording medium of the present invention will be described.

  The method for producing a magnetic recording medium of the present invention utilizes the above-described method for forming a magnetic pattern, and a method for producing a magnetic recording medium having at least a nonmagnetic substrate and a magnetic film provided on the nonmagnetic substrate. The magnetic film forms a film having B or the like on a thin film mainly composed of at least one of Fe and Co and at least one of Pd and Pt, and the film is formed on the film having B or the like. An inert gas ion is locally injected into the thin film and B or the like is mixed in the thin film, and then the thin film is heat-treated. Since the manufactured magnetic recording medium is formed in the same form as shown in FIG. 2, each film will be described below using the reference numerals used in FIG. 1 or FIG.

  The magnetic recording medium to be manufactured is provided with a base film 31 and an intermediate film 32 as shown in FIG. 2 between a nonmagnetic substrate 30 (corresponding to reference numeral 1 in FIG. 1) and the magnetic film 11. . The magnetic recording medium having such a configuration has an effect that the recording magnetic field in the perpendicular recording method can be concentrated well on the recording portion of the magnetic film (excellent recording efficiency).

  According to the method for manufacturing a magnetic recording medium of the present invention, a magnetic recording medium such as a discrete track medium or a discrete bit medium, which is a patterned medium having a predetermined magnetic pattern, is formed without forming a conventional groove or the like. Since it can be manufactured, a magnetic recording medium substantially free from surface irregularities can be manufactured.

FIG. 1A is a process diagram showing an example of a method for forming a magnetic film of the present invention, FIG. 1A is a cross-sectional view of a laminated thin film, and FIG. 1B is selected from B, Ag, and Cu on the thin film. FIG. 1C is a cross-sectional view of a process of forming a film having one kind, FIG. 1C is a cross-sectional form of a process of injecting inert gas ions into the thin film on which the film is formed, and FIG. 3 is a cross-sectional view of the magnetic film of the present invention formed as a result of the above. 2D is a cross-sectional view in the stacking direction showing an example of a mode in which a base film and an intermediate film are provided between a substrate and a magnetic film in the magnetic film shown in FIG. It is process drawing which shows an example of the film-forming method of the composition modulation | alteration film | membrane of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 1st film | membrane 3 2nd film | membrane 4 Thin film 5 Film | membrane which has 1 type (B etc.) chosen from B, Ag, and Cu 6 Inert gas ion 7 1 type (B etc.) chosen from B, Ag, and Cu 8 A part where one kind selected from B, Ag and Cu (B or the like) is not mixed 9 A part showing a high coercive force 10 A part showing a low coercive force 11 A magnetic film 11
20 Diffusion prevention film 21 Mask 30 Non-magnetic substrate 31 Underlayer 32 Intermediate film 41 Pt atom 42 Fe atom

Claims (9)

  A film having one type selected from B, Ag and Cu is formed on a thin film containing at least one of Fe and Co and at least one of Pd and Pt as main components, and one type selected from B, Ag and Cu An inert gas ion is locally implanted into the thin film on which the film is formed and mixed with one selected from B, Ag, and Cu in the thin film, and then the thin film is heat treated. A method for forming a magnetic film.   2. The method of forming a magnetic film according to claim 1, wherein a diffusion preventing film is formed between the thin film and the film having one selected from B, Ag, and Cu.   3. The method of forming a magnetic film according to claim 1, wherein the portion mixed with one selected from B, Ag, and Cu after the heat treatment has a CuAuI type regular structure.   The thin film is a thin film in which a film containing at least one of Fe and Co as a main component and a film containing at least one of Pd and Pt as a main component are stacked. The method for forming a magnetic film according to any one of the above.   The thin film is a composition modulation film in which at least one of the Fe and Co and at least one of the Pd and Pt are modulated in composition in a film thickness direction. A method for forming a magnetic film as described.   A film having one type selected from B, Ag and Cu is formed on a thin film containing at least one of Fe and Co and at least one of Pd and Pt as main components, and one type selected from B, Ag and Cu An inert gas ion is implanted into a predetermined portion of the thin film from above the film having a mixture, and one type selected from B, Ag and Cu is mixed in the thin film, and then the thin film after the ion implantation is heat-treated And forming a magnetic pattern. A method of manufacturing a magnetic recording medium having at least a nonmagnetic substrate and a magnetic film provided on the nonmagnetic substrate,
The magnetic film forms a film having one type selected from B, Ag, and Cu on a thin film mainly composed of at least one of Fe and Co and at least one of Pd and Pt, and the B, Ag, and Cu An inert gas ion is locally injected into the thin film on which the film is formed from a film having one kind selected from the group consisting of B, Ag and Cu, and then mixed into the thin film. A method for producing a magnetic recording medium comprising heat treating   8. The method of manufacturing a magnetic recording medium according to claim 7, wherein a diffusion preventing film is formed between the thin film and the film having one selected from B, Ag, and Cu. 9. The method of manufacturing a magnetic recording medium according to claim 7, wherein the local implantation of the inert gas ions is performed using a mask.

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