JP2010134975A - Method of manufacturing magnetic storage medium, magnetic storage medium, and information storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method by which a magnetic storage medium can be manufactured by ion implantation with suppressed implantation amount, to provide a magnetic storage medium which can be manufactured by the manufacturing method and to provide an information storage medium. <P>SOLUTION: A magnetic disk 10 is manufactured by the manufacturing method including a film-depositing step (A) for depositing a magnetic film 62 by using a magnetic material on a substrate 61 and an ion implanting step (C) for implanting mixed ions formed by mixing ions of two or more elements selected from among B, C, N, O, F and Ne (except mixed ions of only B and C and except mixed ions of only N and O) locally to a region except a prescribed protective region of the magnetic film 62. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a manufacturing method for manufacturing a magnetic storage medium, a magnetic storage medium, and an information storage device including the magnetic storage medium.

  Hard disk drives (HDD) have become the mainstream of information storage devices as mass storage devices capable of high-speed data access and high-speed transfer. With respect to this HDD, the surface recording density has been increasing at a high annual rate so far, and further improvement in recording density is still required.

  In order to improve the recording density of the HDD, it is necessary to reduce the track width and the recording bit length. However, if the track width is reduced, so-called magnetic interference is likely to occur between adjacent tracks. This interference is a generic term for a phenomenon in which magnetic recording information is overwritten on a non-target adjacent track during recording, or a phenomenon in which crosstalk occurs due to a leakage magnetic field from a non-target adjacent track during reproduction. It is a thing. These phenomena all cause a decrease in the S / N ratio of the reproduction signal, and cause a deterioration in error rate.

  On the other hand, when the recording bit length is shortened, a thermal fluctuation phenomenon occurs in which the performance of storing the recording bit for a long period of time decreases due to the influence of magnetic interference.

  Discrete track type magnetic storage media and bit patterned magnetic storage media have been proposed as a method for realizing a short bit length and high track density by avoiding these interference and thermal fluctuation phenomena (for example, patents). Reference 1). In particular, in bit-patterned magnetic storage media, the positions of recording bits are determined in advance, magnetic material dots are formed at the determined recording bit positions, and the dots are made of a non-magnetic material. The When the dots of the magnetic material are separated from each other in this way, the magnetic interaction between the dots is small, and the above-described interference and thermal fluctuation phenomenon are avoided.

  Here, a conventional manufacturing method proposed in Patent Document 1 and the like as a manufacturing method of a bit patterned magnetic storage medium will be described.

  FIG. 1 is a diagram showing a conventional manufacturing method of a bit patterned magnetic storage medium.

  In the conventional manufacturing method, first, the magnetic film 2 is formed on the substrate 1 in the film forming step (A).

  Next, in the nanoimprint process (B), a resist 3 made of an ultraviolet curable resin is applied on the magnetic film 2, and a mold 4 with nano-sized holes 4 a is placed on the resist 3. As a result, the resist 3 enters the nano-sized hole 4a and the dots 3a of the resist 3 are formed. Then, the resist 3 is irradiated with ultraviolet rays through the mold 4, so that the resist 3 is cured and the dots 3 a are printed on the magnetic film 2. Further, after the resist 3 is cured, the mold 4 is removed.

  Thereafter, etching is performed in the etching step (C), so that the magnetic film is removed leaving the magnetic dots 2 a protected by the dots 3 a of the resist 3. After etching, the dots 3 a of the resist 3 are removed by chemical treatment, and only the magnetic dots 2 a remain on the substrate 1.

  In the filling step (D), the space between the magnetic dots 2a is filled with a nonmagnetic material. Thereafter, the surface is flattened through a flattening step (E), whereby the bit patterned magnetic storage medium 6 is completed (F).

  According to such a conventional manufacturing method, high-precision flattening is required in the flattening step (E) in order to stabilize the flying characteristics of the magnetic head on the magnetic storage medium 6. Therefore, the subject that it is necessary to perform a very complicated manufacturing process and the subject that manufacturing cost increases arise.

  Here, it is known that when ions are implanted into a magnetic film, the magnetic characteristics of the magnetic film change (see, for example, Patent Document 2). Then, a processing method (ion doping method) has been proposed in which ions are implanted into the magnetic film to locally change the magnetic characteristics to form a magnetic dot separation state (for example, Patent Document 3 and Patent Document 4). reference.).

According to this ion doping method, ions are implanted to change the magnetic characteristics, so that complicated manufacturing processes such as etching, filling, and flattening are not required, and an increase in manufacturing cost can be significantly suppressed.
Japanese Patent No. 1888363 Japanese Patent Laid-Open No. 07-141642 JP 2002-288813 A JP 2007-226862 A

Here, in order to realize a good separation state of the magnetic dots by the ion doping method, the saturation magnetization of the portion between the magnetic dots and subjected to the ion implantation is reduced to about 20% of the saturation magnetization before the ion implantation. It is desirable that At present, such a significant reduction in saturation magnetization often requires ion implantation with an implantation amount reaching approximately 1 × 10 ¹⁷ atoms / cm ² . However, ion implantation with such a large amount of implantation may damage the surface state of the magnetic film or the like subjected to ion implantation and impair flatness.

  Heretofore, the bit patterned magnetic storage medium has been described as an example, and the problem that the ion implantation amount is too large when the magnetic storage medium is manufactured by the ion doping method has been described. However, such a problem is not limited to the bit-patterned magnetic storage medium, and is also a problem that applies to, for example, a discrete track magnetic storage medium. That is, such a problem is commonly applied to a magnetic storage medium including a magnetic part in which information is magnetically recorded and a low magnetic part having a saturation magnetization smaller than the saturation magnetization of the magnetic part. .

  In view of the above circumstances, an object of the present application is to provide a manufacturing method capable of manufacturing a magnetic storage medium by ion implantation in which an implantation amount is suppressed, a magnetic storage medium and an information storage device that can be manufactured by such a manufacturing method. .

A magnetic storage medium manufacturing method of a basic form for achieving the above object is
A magnetic film forming process of forming a magnetic film with a magnetic material on a substrate;
Mixed ions in which ions of two or more elements selected from B, C, N, O, F, and Ne are mixed (excluding mixed ions of B and C only and mixed ions of N and O only) And an ion implantation process for locally implanting the magnetic film into other regions excluding a predetermined protective region.

A magnetic storage medium of a basic form that achieves the above object is
A substrate,
A magnetic part provided on the substrate, having a magnetic film formed of a magnetic material, on which information is magnetically recorded;
Mixed ions in which ions of two or more elements selected from B, C, N, O, F, and Ne are mixed (excluding mixed ions of B and C only and mixed ions of N and O only) And a low magnetic part having a film to be injected which is injected into a magnetic film continuous with the magnetic film of the magnetic part, and having a saturation magnetization smaller than the saturation magnetization of the magnetic part. .

An information storage device of a basic form that achieves the above object,
A substrate,
A magnetic part provided on the substrate, having a magnetic film formed of a magnetic material, on which information is magnetically recorded;
Mixed ions in which ions of two or more elements selected from B, C, N, O, F, and Ne are mixed (excluding mixed ions of B and C only and mixed ions of N and O only) A magnetic storage medium having an injected film that is injected into a magnetic film continuous with the magnetic film of the magnetic part, and a low magnetic part having a saturation magnetization smaller than the saturation magnetization of the magnetic part;
A magnetic head that records and / or reproduces information magnetically in a magnetic part in proximity to or in contact with the magnetic storage medium;
A head position control mechanism that moves the magnetic head relative to the surface of the magnetic storage medium and positions the magnetic head on a magnetic part that records and / or reproduces information by the magnetic head;
It is provided with.

According to the magnetic storage medium manufacturing method of the above basic form, for example, a low magnetic portion that occupies between magnetic dots of a bit patterned magnetic storage medium, or a low magnetic area that occupies both sides of a track of a discrete track magnetic storage medium. The magnetic part can be formed by ion implantation. This eliminates the need for complicated manufacturing processes such as etching, filling, and planarization, so that the magnetic storage medium manufacturing method of this basic form is a simple manufacturing method. Further, according to the magnetic storage medium and the information storage device of the above basic form, it is possible to manufacture with the simple manufacturing method. In each of these basic forms, the mixed ions are used for ion implantation. Here, as for the ions of each element described above, in many cases, a single ion requires a large amount of implantation reaching about 1 × 10 ¹⁷ atoms / cm ² as described above for sufficient saturation magnetization reduction. ing. However, the developer of this case finds that if mixed ions in which two or more of these ions are mixed are used, a saturation magnetization can be sufficiently reduced with a small implantation amount of 5 × 10 ¹⁶ atoms / cm ² or less. It was. This implantation amount is approximately half or less of the above-described implantation amount necessary for reducing the saturation magnetization with a single ion. With such a small amount of ion implantation, there is little risk of damaging the surface state of the magnetic film, and a magnetic storage medium can be manufactured without impairing flatness. As described above, according to each of the above basic embodiments, a magnetic storage medium can be obtained by ion implantation in which the implantation amount is suppressed.

  Incidentally, the mixed ions of only B and C and the mixed ions of only N and O are conventionally used conventionally, but these mixed ions have a viewpoint of enhancing the saturation magnetization reduction effect by mixing ions. Used independently.

  As described above, according to the present case, a manufacturing method capable of manufacturing a magnetic storage medium by ion implantation in which the implantation amount is suppressed, and a magnetic storage medium and an information storage device that can be manufactured by such a manufacturing method are obtained. Can do.

  Specific embodiments of the magnetic storage medium manufacturing method, the magnetic storage medium, and the information storage device described above for the basic form will be described below with reference to the drawings.

  FIG. 2 is a diagram showing an internal structure of a hard disk device (HDD) which is a specific embodiment of the information storage device.

  A hard disk device (HDD) 100 shown in this figure is incorporated in a host device such as a personal computer and is used as information storage means in the host device.

  In the hard disk device 100, a disk-shaped magnetic disk 10 is housed in a plurality of housings H so as to overlap in the depth direction of the figure. The magnetic disk 10 corresponds to a specific embodiment of the magnetic storage medium whose basic form has been described above.

Here, with respect to the basic form of the magnetic storage medium and the information storage device described above,
“The magnetic part is a plurality of magnetic dots regularly arranged on the substrate, and information is magnetically recorded on each,
An application mode in which the low magnetic part is an interdot separation band provided between the magnetic dots and hindering magnetic coupling between the magnetic dots is preferable.

  This application form corresponds to a bit-patterned magnetic storage medium in which magnetic dots on which bit information is recorded are provided in advance on each substrate. Since the bit-patterned magnetic storage medium effectively avoids interference and thermal fluctuation phenomena as described above, the above-described applied form corresponding to such a type of magnetic storage medium is preferable.

  The magnetic disk 10 in FIG. 2 is a bit patterned magnetic storage medium, and corresponds to a specific embodiment of this application. The magnetic disk 10 is also a so-called perpendicular magnetic storage medium in which information is recorded with a magnetic pattern by magnetization in a direction perpendicular to the front and back surfaces of each magnetic dot.

  The magnetic disk 10 rotates around the disk shaft 11 in the housing H.

  The housing H of the hard disk device 100 also houses a swing arm 20 that moves along the surface of the magnetic disk 10, an actuator 30 that is used to drive the swing arm 20, and a control circuit 50.

  The swing arm 20 holds a magnetic head 21 for writing and reading information with respect to the magnetic disk 10 at the tip. The swing arm 20 is rotatably supported by the housing H by a bearing 24. The swing arm 20 rotates within a range of a predetermined angle about the bearing 24 to move the magnetic head 21 along the surface of the magnetic disk 10. This magnetic head corresponds to an example of the magnetic head in the basic form of the information storage device described above.

  Reading and writing of information by the magnetic head 21 and movement of the swing arm 20 are controlled by the control circuit 50, and exchange of information with the host device is also performed through this control circuit 50.

  A combination of the swing arm 20, the bearing 24, the actuator 30, and the control circuit 50 corresponds to an example of the head position control mechanism in the basic form of the information storage device described above.

  FIG. 3 is a perspective view schematically showing the structure of the magnetic disk shown in FIG.

  FIG. 3 shows a part cut out from a disk-shaped magnetic disk.

  The magnetic disk 10 shown in FIG. 3 has a structure in which a plurality of magnetic dots Q are arranged in a regular arrangement on a substrate S. Information corresponding to 1 bit is magnetically recorded on each magnetic dot Q. The magnetic dots Q are arranged in a circle around the center of the magnetic disk 10, and the row of magnetic dots forms a track T. The board | substrate S is corresponded to an example of the board | substrate in the above-mentioned basic form. Further, the magnetic dot Q corresponds to an example of the magnetic portion in the basic form described above, and also corresponds to an example of the magnetic dot in the applied form described above corresponding to the bit patterned magnetic storage medium.

  Further, between the magnetic dots Q, the magnetic anisotropy and the saturation magnetization are lower than the magnetic anisotropy and the saturation magnetization of the magnetic dots Q, and the interdot separation band U that magnetically divides the magnetic dots Q from each other. It has become. Due to the interdot dot U, the magnetic interaction between the magnetic dots Q is reduced. The interdot dot band U corresponds to an example of the low magnetic part in the basic mode described above, and also corresponds to an example of the interdot dot band in the application mode described above corresponding to the bit patterned magnetic storage medium. .

  Thus, when the magnetic interaction between the magnetic dots Q is small, the magnetic interaction between the tracks T is small even when information is recorded on and reproduced from the magnetic dots Q, so that there is little so-called interference between the tracks. Further, in each magnetic dot Q, the boundary of recorded information bits does not fluctuate due to heat, and so-called thermal fluctuation phenomenon is avoided. Therefore, according to the bit patterned magnetic disk 10 as shown in FIG. 3, the track width can be reduced and the recording bit length can be reduced, and a magnetic recording medium having a high recording density can be realized.

  A method for manufacturing the magnetic disk 10 will be described below.

  The manufacturing method of the magnetic disk 10 corresponds to a specific embodiment of the magnetic storage medium manufacturing method described above with respect to the basic mode.

Here, for the basic form of this magnetic storage medium manufacturing method,
"The ion implantation process is a process in which ions are locally implanted between the plurality of locations using a plurality of locations regularly arranged in the direction in which the magnetic film spreads as the protective region." The application form is suitable.

  This application form corresponds to a magnetic storage medium manufacturing method for manufacturing a bit patterned magnetic storage medium. Since the bit-patterned magnetic storage medium effectively avoids interference and thermal fluctuation as described above, the above-described application form for manufacturing such a type of magnetic storage medium is preferable. The method of manufacturing the magnetic disk 10 described below corresponds to a specific embodiment of this application mode.

  FIG. 4 is a diagram showing a method of manufacturing the magnetic disk shown in FIGS.

  In the manufacturing method shown in FIG. 4, first, a magnetic film 62 is formed on a glass substrate 61 in the film forming step (A). This film forming step (A) corresponds to an example of a magnetic film forming process in the basic mode of the magnetic storage medium manufacturing method described above.

  In the present embodiment, the magnetic film 62 formed in this film forming step (A) has an artificial lattice structure in which Co atomic layers 62a and Pd atomic layers 62b are alternately stacked. In order to form the magnetic film 62, the thickness of the Co atomic layer 62a and the Pd atomic layer 62b is such that the Pd atomic layer 62b is thicker than the Co atomic layer 62a. is necessary. The Co atomic layer 62a has an upper limit of 2 nm, which corresponds to a thickness of about 7 atoms. When the Co atomic layer 62a has a film thickness exceeding this upper limit, it is considered that the physical properties that can be called an artificial lattice are also lost.

  A magnetic film having such an artificial lattice structure is suitable for reducing saturation magnetization by an ion doping method because its magnetic characteristics are easily deteriorated by ion implantation as will be described later. A magnetic film having an artificial lattice structure composed of a Co atomic layer and a Pd atomic layer is suitable for reducing saturation magnetization and is excellent in magnetic characteristics. Thus, it can be said that such a magnetic film is suitable for manufacturing a bit patterned magnetic storage medium using an ion doping method.

This is different from the basic form described above.
An application form that “the magnetic film forming process is a process of alternately stacking a plurality of types of atomic layers to form a magnetic film having an artificial lattice structure” is preferable.
For this application,
“The magnetic film formation process is a process of forming an artificial lattice structure magnetic film by alternately laminating Co atomic layers and Pd atomic layers as the artificial lattice structure magnetic film”. It also means that it is preferable.

  The film forming process (A) in FIG. 4 corresponds to an example of a magnetic film forming process in these application forms. In addition, the material for constituting the magnetic film having the artificial lattice structure in the basic form described above is not limited to the preferred materials shown here, and it is known that the magnetic film can be constituted by the artificial lattice structure. Any material can be used.

  As described above, in the present embodiment, the magnetic film 62 having the artificial lattice structure is formed in the film forming step (A). However, the magnetic film formation process in the basic form described above is not limited to this, and another form in which the magnetic film is formed of, for example, a Co—Cr—Pt alloy is also conceivable. This is because the Co—Cr—Pt alloy is known as a magnetic material having excellent magnetic properties and has an advantage of easy film formation.

This is different from the basic form described above.
The application form that “the magnetic film forming process is a process of forming a magnetic film with a Co—Cr—Pt alloy” is also suitable.

  The film forming process in another form of forming a magnetic film with the above Co—Cr—Pt alloy corresponds to an example of the magnetic film forming process in this applied form.

  However, in the manufacturing method of the present embodiment shown in FIG. 4, the magnetic film 62 having the above artificial lattice structure is formed in the film forming step (A), and the artificial lattice structure is further composed of a Co atomic layer and a Pd layer. The description will be continued assuming that it is composed of atomic layers.

  Next, in the nanoimprint process (B), a resist 63 made of an ultraviolet curable resin is applied on the magnetic film 62, and a mold 64 with nano-sized holes 64 a is placed on the resist 63. As a result, the resist 63 enters the nano-sized hole 64a, and the dots 63a of the resist 63 are formed. Then, the resist 63 is irradiated with ultraviolet rays through the mold 64, so that the resist 63 is cured and the dots 63 a are printed on the magnetic film 62. Further, the mold 64 is removed after the resist 63 is cured.

  After the nanoimprint process (B), the process proceeds to the ion implantation process (C). In this ion implantation step (C), the following mixed ions are irradiated from above the magnetic film 62 on which the dots 63a are printed. That is, it is a mixed ion in which ions of two or more elements selected from B, C, N, O, F, and Ne are mixed. This ion implantation step (C) corresponds to an example of the ion implantation step in the basic form described above. This ion implantation step (C) also corresponds to an example of an ion implantation process in the above-described applied mode corresponding to the manufacture of a bit patterned magnetic storage medium.

In contrast to the basic form described above,
“Having a mask forming process for forming a mask on the magnetic film that inhibits ion implantation into the protective region,
In the ion implantation process, ions are applied from above the magnetic film on which the mask is formed, so that the ions are locally implanted into other regions except for the protection region protected by the mask. An application form of “some” is also suitable.

  According to this application mode, a portion that does not require ion implantation is reliably protected by the mask, and the magnetic dot formation accuracy is high. The nanoimprint process (B) in FIG. 4 corresponds to an example of a mask formation process in this application form, and the ion implantation process (C) corresponds to an example of an ion implantation process in this application form.

Also, for this preferred application with mask formation process,
"The mask forming process is a process of forming the mask with a resist",
An application form that “the mask forming process is a process of forming the mask with a resist by a nanoimprint process” is more preferable.

  Mask formation with a resist is technically stable and high-precision mask formation can be expected. Mask formation by a nanoimprint process is preferable because a mask pattern at a nano level can be easily created. The nanoimprint process (B) shown in FIG. 4 also corresponds to an example of a mask formation process in these more preferable applications.

  In the nanoimprint described above, the resist is not completely removed even at the location where ions are to be implanted. However, when the resist is thin, ions pass through the resist and are injected into the magnetic film 62, and when the resist is thick (that is, where the dots 63a are formed), the ions stop at the resist and do not reach the magnetic film. Therefore, a desired track pattern can be formed.

  Further, in the ion implantation step (C) shown in FIG. 4, the ion acceleration voltage is set so that ions are implanted into the central portion of the magnetic film 62. This acceleration voltage varies depending on the ion species, and varies depending on the depth to the magnetic film center and the material.

  In the magnetic film 62 where ions are implanted by this ion implantation step (C), ions remain inside, and the crystal structure is reduced in strain coercive force and saturation magnetization. After the ion implantation, the resist dots 63a are removed by chemical treatment.

Here, in order to realize a good separation state of the magnetic dots by the ion doping method, it is desirable that the saturation magnetization between the magnetic dots is reduced to about 20% of the saturation magnetization before the ion implantation. . The ions of the above elements B, C, N, O, F, and Ne are about 1 × 10 ¹⁷ atoms / cm ² in order to sufficiently reduce the saturation magnetization in a single ion in many cases. There is a need for large injection volumes to reach. However, ion implantation with such an implantation amount may damage the surface state of a magnetic film or the like that undergoes ion implantation and impair flatness. Here, the developer in this case shows that if a mixed ion in which two or more of these ions are mixed is used, the saturation magnetization can be sufficiently reduced with a small implantation amount of 5 × 10 ¹⁶ atoms / cm ² or less. I found it. This implantation amount is approximately half or less of the above-described implantation amount necessary for reducing the saturation magnetization with a single ion. With such a small amount of ion implantation, there is little risk of damaging the surface state of the magnetic film 62, and a magnetic storage medium can be manufactured without impairing flatness. Details of the saturation magnetization reduction effect by the mixed ions will be described in conjunction with examples described later.

  In the present embodiment, the mixed ions as described above are implanted in this ion implantation step (C), so that the saturation magnetization of the magnetic film 62 can be obtained before the implantation without damaging the surface state of the magnetic film 62 with a small amount of ion implantation. Is reduced to about 20%.

  Through such an ion implantation step (C), an interdot separation band 62d that divides the magnetic interaction between the magnetic dots 62c is formed between the magnetic dots 62c, and a bit-patterned magnetic field is formed. The storage medium 10 is completed (D). In the interdot separation band 62d, the saturation magnetization is about 20% of the saturation magnetization of the magnetic dot 62c due to the ion implantation described above, and is sufficiently low. For this reason, information is recorded only on the magnetic dots 62c, and no information is recorded on the interdot separation band 62d.

  In the magnetic storage medium 10 manufactured by the manufacturing method shown in FIG. 4, the smoothness of the magnetic dots 62c and the interdot separation bands 62d constituting the surface is the magnetic film formed in the film forming step (A). The smoothness at 62 is maintained as it is. Therefore, the planarization step as in the prior art shown in FIG. 1 is not necessary, and the manufacturing method shown in FIG. 4 is a simple method.

  In the manufacturing method shown in FIG. 4, the magnetic dots 62c are protected by resist dots 63a printed on the magnetic film 62. Accordingly, the entire surface of the magnetic storage medium 10 can be irradiated with ions at the same time, and ion implantation to a required portion can be sufficiently realized by ion irradiation for several seconds, so that mass productivity is not impaired.

  Next, each of the first to sixth embodiments, in which the manufacturing method shown in FIG. 4 is applied to a specific material or the like, and the above-described another embodiment in which the magnetic film is formed of a Co—Cr—Pt alloy. The seventh to ninth embodiments in which the manufacturing method is applied to specific materials will be described. In each of these examples, the effect of reducing saturation magnetization by the above-described mixed ion implantation was confirmed. Further, in the confirmation, each example was appropriately compared with a comparative example.

  FIG. 5 is a diagram showing a structure common to the first to ninth embodiments and comparative examples.

  First, the first embodiment and a comparative example for the first embodiment will be described with reference to FIG.

A well-cleaned glass substrate 70 was set in a magnetron sputtering apparatus and evacuated to 5 × 10 ⁻⁵ Pa or less. Thereafter, fcc-Pd with (111) crystal orientation was formed with a film thickness of 3 nm as an underlayer 71 for crystal orientation of the magnetic layer at an Ar gas pressure of 0.67 Pa without heating the glass substrate 70. . The process of forming the underlayer 71 is not described in the manufacturing method shown in FIG.

  Subsequently, a magnetic film 72 made of a Co / Pd artificial lattice was continuously laminated with a thickness of 0.3 / 0.35 nm at an Ar gas pressure of 0.67 Pa without returning to atmospheric pressure. This film thickness structure means an artificial lattice in which a Co monoatomic layer and a Pd monoatomic layer are repeated.

  After the magnetic film 72 was formed, diamond-like carbon was formed as a protective layer 73 with a thickness of 4 nm. The process of forming the protective layer 73 is not described in the manufacturing method shown in FIG.

  A resist was applied on the protective layer 73, and a columnar resist pattern 74 having a diameter of 20 nm to 60 nm and a height of 50 nm was formed using a nanoimprint process.

In the first embodiment, mixed ions of C ions and N ions are irradiated from above the resist pattern 74 and implanted into the magnetic film 72. In this first embodiment, this mixed ion implantation was performed in ^two implantation doses of 1 × 10 ¹⁶ atoms / cm ² and 2 × 10 ¹⁶ atoms / cm ² .

  The acceleration voltage of the mixed ions was set so that ions were implanted into the central portion of the magnetic film 72. Note that the ion acceleration voltage is preferably 1 keV or more and 10 keV or less in consideration of the actual thickness of the magnetic film and damage to the magnetic film during ion implantation.

  After this ion implantation, the ratio (reduction rate) of the saturation magnetization after implantation to the saturation magnetization before implantation was measured.

  Further, after ion implantation, the resist pattern 74 was removed by SCl cleaning.

  As a comparative example for the first embodiment described above, two comparative examples, a comparative example in which ion implantation is performed instead of the above mixed ions and C ion alone and a comparative example in which N ion alone is performed, are performed. Obtained. Each of these comparative examples is performed under the same conditions as in the first example except for the ion species, and the saturation magnetization reduction rate by ion implantation for each of these comparative examples is also determined by the same measurement as in the first example. It was.

  Next, the second to seventh embodiments and comparative examples for the respective embodiments will be described.

  In addition, each Example and each Comparative Example described below are processed under the same formation conditions as those in the above-described first embodiment except for the ion species of the implanted ions.

  In the second embodiment, ion implantation was performed using mixed ions of O ions and F ions. As comparative examples for the second example, two comparative examples were obtained: a comparative example in which ion implantation was performed with O ions alone and a comparative example in which F ions were performed alone. And about the 2nd Example and each comparative example, the reduction rate of saturation magnetization was calculated | required by the same measurement as the above-mentioned 1st Example.

  In the third embodiment, ion implantation was performed using mixed ions of F ions and Ne ions. As comparative examples for the third example, two comparative examples were obtained: a comparative example in which ion implantation was performed with F ions alone and a comparative example in which Ne ions were performed alone. And the reduction rate of saturation magnetization was calculated | required about 3rd Example and each comparative example.

  In the fourth embodiment, ion implantation is performed using mixed ions of C ions and F ions. In addition, as comparative examples for the fourth example, two comparative examples were obtained: a comparative example in which ion implantation was performed with C ions alone and a comparative example in which F ions were performed alone. And the reduction rate of saturation magnetization was calculated | required about the 4th Example and each comparative example.

  In the fifth embodiment, ion implantation is performed using mixed ions of C ions and Ne ions. Further, as comparative examples for the fifth example, two comparative examples were obtained: a comparative example in which ion implantation was performed with C ions alone and a comparative example in which Ne ions were performed alone. And the reduction rate of saturation magnetization was calculated | required about 5th Example and each comparative example.

  In the sixth embodiment, ion implantation was performed using mixed ions of N ions and Ne ions. Further, as comparative examples for the sixth example, two comparative examples were obtained: a comparative example in which ion implantation was performed with N ions alone and a comparative example in which Ne ions were performed alone. And the reduction rate of saturation magnetization was calculated | required about the 6th Example and each comparative example.

  In the seventh embodiment, ion implantation was performed using mixed ions of B ions and N ions. As comparative examples for the seventh example, two comparative examples were obtained: a comparative example in which ion implantation was performed with B ions alone and a comparative example in which N ions were performed alone. And the reduction rate of saturation magnetization was calculated | required about the 7th Example and each comparative example.

  In each of the first to seventh embodiments, the reduction rate (%) which is the ratio of the saturation magnetization after implantation to the saturation magnetization before ion implantation, and the reduction rate (%) of the saturation magnetization in the comparative example for each of these embodiments Are shown in Tables 1 to 7 below.

  Each example whose saturation magnetization reduction rate is shown in each of these tables is saturated by a mixed ion in which ions of two or more elements selected from B, C, N, O, F, and Ne are mixed. This is an example in which the magnetization is reduced.

  From these tables, it can be seen that in each example using mixed ions, the reduction rate of the saturation magnetization is larger than in the comparative example using each ion constituting the mixed ion alone.

  Here, according to mixed ions of C ions and F ions (fourth embodiment) and mixed ions of C ions and Ne ions (fifth embodiment), when a single ion is used (comparative example) The improvement of the saturation magnetization reduction effect compared with is particularly remarkable. That is, according to these mixed ions, the saturation magnetization reduction rate is 15% or more larger than when any one of C, F, and Ne ions is used alone.

From this, for the above basic form,
It can be seen that the application form that “the ion implantation process is a process of implanting mixed ions including C ions and ions of one of F and Ne” is preferable.

Also, mixed ions of C ions and N ions (first embodiment), mixed ions of O ions and F ions (second embodiment), and mixed ions of N ions and Ne ions (fourth embodiment). ) And mixed ions of B ions and N ions (seventh embodiment), the saturation magnetization can be satisfactorily reduced with a particularly small ion implantation amount. That is, according to these mixed ions, a reduction rate of about 80% of saturation magnetization has already been obtained with a very small ion implantation amount of 1 × 10 ¹⁶ atoms / cm ² .

From this, for the above basic form,
"The above ion implantation process is a process of implanting mixed ions including N ions and ions of any element of B, C, or Ne",
It can be seen that the application form that “the ion implantation process is a process of implanting mixed ions including O ions and F ions” is suitable.

  Next, two reference examples for the first to seventh embodiments will be described.

  In these reference examples, the processing was performed under the same formation conditions as those in the first embodiment except for the ion species of the implanted ions.

  First, in the first reference example, ion implantation was performed using mixed ions of B ions and C ions. Further, as comparative examples for the first reference example, two comparative examples were obtained: a comparative example in which ion implantation was performed with B ions alone and a comparative example in which C ions were performed alone. And the reduction rate of saturation magnetization was calculated | required about the 1st reference example and each comparative example.

  In the second reference example, ion implantation is performed using mixed ions of N ions and O ions. In addition, as comparative examples for the second reference example, two comparative examples were obtained: a comparative example in which ion implantation was performed with N ions alone and a comparative example in which O ions were performed alone. And the reduction rate of saturation magnetization was calculated | required about the 2nd reference example and each comparative example.

  In each of the first and second reference examples, the reduction rate (%), which is the ratio of the saturation magnetization after implantation to the saturation magnetization before ion implantation, and the reduction rate (%) of the saturation magnetization in the comparative example for each of these reference examples Are shown in Table 8 and Table 9 below.

  The mixed ions used in the first and second reference examples are all mixed ions that are conventionally used conventionally. These mixed ions have been used without being aware of the improvement effect of saturation magnetization. From each of the above reference examples, it was confirmed that the effect of reducing saturation magnetization was improved in these conventionally used mixed ions as well as in each of the above examples.

  Next, an eighth embodiment and a comparative example for the eighth embodiment will be described.

  In the eighth embodiment and the comparative example, the processing is performed under the same formation conditions as those in the first embodiment except that the magnetic film subjected to ion implantation is formed of a Co—Cr—Pt alloy. It has been. That is, in the eighth embodiment, as in the first embodiment, mixed ions of C ions and N ions are used. And about this 8th Example and each comparative example, the reduction rate of saturation magnetization was calculated | required by the same measurement as the above-mentioned 1st Example.

  Subsequently, the ninth to eleventh embodiments and comparative examples for the respective embodiments will be described.

  In addition, each Example and each Comparative Example described below are processed under the same formation conditions as those in the above-described eighth embodiment except for the ion species of the implanted ions.

  In the ninth embodiment, ion implantation was performed using mixed ions of O ions and F ions. Further, as comparative examples for the ninth example, two comparative examples were obtained: a comparative example in which ion implantation was performed with O ions alone and a comparative example in which F ions were performed alone. And about the 9th Example and each comparative example, the reduction rate of the saturation magnetization was calculated | required by the same measurement as the above-mentioned 1st Example.

  In the tenth embodiment, ion implantation was performed using mixed ions of C ions and F ions. Further, as comparative examples for the tenth embodiment, two comparative examples were obtained: a comparative example in which ion implantation was performed with C ions alone and a comparative example in which F ions were performed alone. And the reduction rate of saturation magnetization was calculated | required about 10th Example and each comparative example.

  In the eleventh embodiment, ion implantation was performed using mixed ions of B ions and N ions. As comparative examples for the eleventh example, two comparative examples were obtained: a comparative example in which ion implantation was performed with B ions alone and a comparative example in which N ions were performed alone. And the reduction rate of saturation magnetization was calculated | required about the 11th Example and each comparative example.

  In each of the eighth to eleventh embodiments, the reduction rate (%), which is the ratio of the saturation magnetization after implantation to the saturation magnetization before ion implantation, and the reduction rate (%) of the saturation magnetization in the comparative example for each of these examples Are shown in Table 10 to Table 13 below.

  Each example in which the reduction rate of the saturation magnetization is shown in each of these tables, the mixed ions used in the first example, the second example, the fourth example and the seventh example described above, In this example, a magnetic film made of a Co—Cr—Pt alloy is used instead of the magnetic film having the artificial lattice structure.

  From the above tables, even in the ion implantation into the magnetic film of the Co—Cr—Pt alloy, the reduction rate of the saturation magnetization is greater with the mixed ions than with the individual ions constituting the mixed ions. I understand.

  Further, even in the ion implantation of the Co—Cr—Pt alloy into the magnetic film, the saturation magnetization is reduced as compared with the case of using a single ion according to the mixed ion of C ions and F ions (tenth embodiment). The improvement of the effect is particularly remarkable. That is, according to this mixed ion, the saturation magnetization reduction rate is 30% larger than when either the C or F ion is used.

Further, even in the ion implantation of the Co—Cr—Pt alloy into the magnetic film, mixed ions of C ions and N ions (eighth embodiment) or mixed ions of O ions and F ions (ninth embodiment). In addition, according to the mixed ions of B ions and N ions (the eleventh embodiment), the saturation magnetization can be satisfactorily reduced with a particularly small ion implantation amount. That is, according to these mixed ions, a reduction rate of about 80% of saturation magnetization has already been obtained with a very small ion implantation amount of 1 × 10 ¹⁶ atoms / cm ² .

  Next, one reference example (third reference example) for the eighth to eleventh embodiments will be described.

  In this reference example, the treatment was performed under the same formation conditions as those in the above-described eighth embodiment except for the ion species of the implanted ions.

  In the third reference example, ion implantation was performed using mixed ions of N ions and O ions. As comparative examples for the third reference example, two comparative examples were obtained: a comparative example in which ion implantation was performed with N ions alone and a comparative example in which O ions were performed alone. And the reduction rate of saturation magnetization was calculated | required about the 3rd reference example and each comparative example.

  The reduction rate (%), which is the ratio of the saturation magnetization after implantation to the saturation magnetization before ion implantation in the third reference example, and the reduction rate (%) of saturation magnetization in the comparative example relative to the third reference example are as follows. Table 14 shows.

  The mixed ion used in the third reference example is a mixed ion that may be conventionally used conventionally as described in the second reference example. From each of the above reference examples, it is confirmed that this mixed ion also improves the effect of reducing saturation magnetization on the magnetic film of the Co—Cr—Pt alloy, as in the above eighth to tenth embodiments. It was.

  As described above, the mixed magnetization in which ions of two or more elements selected from B, C, N, O, F, and Ne are mixed improves the saturation magnetization reduction effect. Such an improvement in the reduction effect is obtained for both the magnetic film having the artificial lattice structure described above and the magnetic film of the Co—Cr—Pt alloy. Further, such an improvement in the reduction effect is remarkable for specific mixed ions such as mixed ions of C ions and F ions, mixed ions of C ions and Ne ions, and the like.

  In addition, the improvement of such a reduction effect has been achieved by using conventional mixed ions of B ions and C ions, N ions and O ions without being aware of the improvement of the saturation magnetization reduction effect. It can also be obtained by mixed ions.

  In the above description, a bit patterned magnetic storage medium is illustrated as an example of the magnetic storage medium. However, the magnetic storage medium is not limited to the bit patterned type, and may be, for example, a discrete track type. good.

  In the above description, the Co—Cr—Pt alloy is exemplified as an example of the Co—Cr—Pt alloy that forms the magnetic film, but the Co—Cr—Pt alloy is not limited thereto. This Co—Cr—Pt alloy may be an alloy in which other elements are added to the Co—Cr—Pt alloy within a composition range that does not impair the magnetic properties of the Co—Cr—Pt alloy.

  In the above description, the use of a resist pattern as a preferred mask for forming magnetic dots is exemplified. On the other hand, in the ion implantation in the basic form described above, a process in which a stencil mask is arranged on the very surface of the medium so as not to contact the medium surface may be used. According to this process, the steps of resist coating and resist removal can be omitted.

  In the above description, it is shown that the nanoimprint process is used as the best example of resist patterning. However, electron beam exposure may be used for patterning.

  Hereinafter, the following additional remarks are disclosed regarding various forms including the basic form described above.

(Appendix 1)
A magnetic film forming process of forming a magnetic film with a magnetic material on a substrate;
Mixed ions in which ions of two or more elements selected from B, C, N, O, F, and Ne are mixed (excluding mixed ions of B and C only and mixed ions of N and O only) A method of manufacturing a magnetic storage medium, comprising: an ion implantation process for locally implanting the magnetic film into other regions excluding a predetermined protective region.

(Appendix 2)
2. The method of manufacturing a magnetic storage medium according to appendix 1, wherein the ion implantation process is a process of implanting mixed ions including C ions and ions of any one element of F and Ne.

(Appendix 3)
2. The method of manufacturing a magnetic storage medium according to claim 1, wherein the ion implantation process is a process of implanting mixed ions including N ions and ions of any element of B, C, and Ne. .

(Appendix 4)
2. The method of manufacturing a magnetic storage medium according to claim 1, wherein the ion implantation step is a step of implanting mixed ions including O ions and F ions.

(Appendix 5)
The ion implantation process is a process of locally implanting ions between the plurality of locations using the plurality of locations regularly arranged in the direction in which the magnetic film spreads as the protection region. 5. The method of manufacturing a magnetic storage medium according to any one of supplementary notes 1 to 4, which is characterized by the following.

(Appendix 6)
The magnetic storage medium according to any one of appendices 1 to 5, wherein the magnetic film forming process is a process of alternately stacking a plurality of types of atomic layers to form a magnetic film having an artificial lattice structure. Production method.

(Appendix 7)
The magnetic film forming process is a process of forming a magnetic film having an artificial lattice structure by alternately stacking Co atomic layers and Pd atomic layers as the magnetic film having the artificial lattice structure. 6. A method of manufacturing a magnetic storage medium according to 6.

(Appendix 8)
6. The method of manufacturing a magnetic storage medium according to any one of appendices 1 to 5, wherein the magnetic film forming process is a process of forming a magnetic film with a Co—Cr—Pt alloy.

(Appendix 9)
A mask forming step of forming a mask on the magnetic film that inhibits ion implantation into the protection region;
The ion implantation process is a process in which ions are locally implanted into other regions other than the protection region protected by the mask by applying ions from above the magnetic film on which the mask is formed. 9. The method of manufacturing a magnetic storage medium according to any one of appendices 1 to 8, wherein:

(Appendix 10)
The method of manufacturing a magnetic storage medium according to appendix 9, wherein the mask forming process is a process of forming the mask with a resist.

(Appendix 11)
11. The method of manufacturing a magnetic storage medium according to appendix 9 or 10, wherein the mask forming process is a process of forming the mask with a resist by a nanoimprint process.

(Appendix 12)
A substrate,
A magnetic part provided on the substrate and having a magnetic film formed of a magnetic material, on which information is magnetically recorded;
Mixed ions in which ions of two or more elements selected from B, C, N, O, F, and Ne are mixed (excluding mixed ions of B and C only and mixed ions of N and O only) And a low magnetic part having a film to be injected which is injected into a magnetic film continuous with the magnetic film of the magnetic part, and having a saturation magnetization smaller than the saturation magnetization of the magnetic part. Magnetic storage medium. (7)
(Appendix 13)
A plurality of the magnetic parts are regularly arranged on the substrate, each of which is a magnetic dot on which information is magnetically recorded,
13. The magnetic storage medium according to appendix 12, wherein the low magnetic part is an interdot separation band that is provided between the magnetic dots and inhibits magnetic coupling between the magnetic dots.

(Appendix 14)
A substrate,
A magnetic part provided on the substrate and having a magnetic film formed of a magnetic material, on which information is magnetically recorded;
Mixed ions in which ions of two or more elements selected from B, C, N, O, F, and Ne are mixed (excluding mixed ions of B and C only and mixed ions of N and O only) A magnetic storage medium having an injected film that is injected into a magnetic film that is continuous with the magnetic film of the magnetic part, and a low magnetic part having a saturation magnetization smaller than the saturation magnetization of the magnetic part;
A magnetic head that magnetically records and / or reproduces information on a magnetic part in proximity to or in contact with the magnetic storage medium;
A head position control mechanism that moves the magnetic head relative to the surface of the magnetic storage medium and positions the magnetic head on a magnetic part that records and / or reproduces information by the magnetic head;
An information storage device comprising:

(Appendix 15)
A plurality of magnetic portions of the magnetic storage medium are regularly arranged on the substrate, each of which is a magnetic dot on which information is magnetically recorded,
15. The information storage device according to supplementary note 14, wherein the low magnetic part of the magnetic storage medium is an interdot separation band that is provided between the magnetic dots and inhibits magnetic coupling between the magnetic dots. .

It is a figure which shows the conventional manufacturing method of a bit patterned type magnetic storage medium. It is a figure which shows the internal structure of the hard disk drive (HDD) which is one specific embodiment of an information storage device. FIG. 3 is a perspective view schematically showing the structure of the magnetic disk shown in FIG. 2. It is a figure which shows the manufacturing method of the magnetic disc shown in FIG. 2 and FIG. It is a figure which shows a structure common to each Example and comparative example from 1st to 9th.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Hard disk device 10 Magnetic disk 61 Substrate 62 Magnetic film 62a Co atomic layer 62b Pd atomic layer 62c Magnetic dot 62d Interdot separation band

Claims (10)

A magnetic film forming process of forming a magnetic film with a magnetic material on a substrate;
Mixed ions in which ions of two or more elements selected from B, C, N, O, F, and Ne are mixed (excluding mixed ions of B and C only and mixed ions of N and O only) A method of manufacturing a magnetic storage medium, comprising: an ion implantation process for locally implanting the magnetic film into other regions excluding a predetermined protective region.   2. The method of manufacturing a magnetic storage medium according to claim 1, wherein the ion implantation process is a process of implanting mixed ions including C ions and ions of any one of F and Ne.   2. The magnetic storage medium manufacturing method according to claim 1, wherein the ion implantation process is a process of implanting mixed ions including N ions and ions of any one element of B, C, and Ne. Method.   2. The method of manufacturing a magnetic storage medium according to claim 1, wherein the ion implantation process is a process of implanting mixed ions including O ions and F ions.   The ion implantation process is a process of locally implanting ions between the plurality of locations using the plurality of locations regularly arranged in the direction in which the magnetic film spreads as the protection region. The method of manufacturing a magnetic storage medium according to claim 1, wherein the magnetic storage medium is a magnetic storage medium.   6. The magnetic memory according to claim 1, wherein the magnetic film forming process is a process of alternately stacking a plurality of types of atomic layers to form a magnetic film having an artificial lattice structure. Medium production method. A substrate,
A magnetic part provided on the substrate and having a magnetic film formed of a magnetic material, on which information is magnetically recorded;
Mixed ions in which ions of two or more elements selected from B, C, N, O, F, and Ne are mixed (excluding mixed ions of B and C only and mixed ions of N and O only) And a low magnetic part having a film to be injected which is injected into a magnetic film continuous with the magnetic film of the magnetic part, and having a saturation magnetization smaller than the saturation magnetization of the magnetic part. Magnetic storage medium. A plurality of the magnetic parts are regularly arranged on the substrate, each of which is a magnetic dot on which information is magnetically recorded,
8. The magnetic storage medium according to claim 7, wherein the low magnetic part is an interdot separation band that is provided between the magnetic dots and inhibits magnetic coupling between the magnetic dots. A substrate,
A magnetic part provided on the substrate and having a magnetic film formed of a magnetic material, on which information is magnetically recorded;
Mixed ions in which ions of two or more elements selected from B, C, N, O, F, and Ne are mixed (excluding mixed ions of B and C only and mixed ions of N and O only) A magnetic storage medium having an injected film that is injected into a magnetic film that is continuous with the magnetic film of the magnetic part, and a low magnetic part having a saturation magnetization smaller than the saturation magnetization of the magnetic part;
A magnetic head that magnetically records and / or reproduces information on a magnetic part in proximity to or in contact with the magnetic storage medium;
A head position control mechanism that moves the magnetic head relative to the surface of the magnetic storage medium and positions the magnetic head on a magnetic part that records and / or reproduces information by the magnetic head;
An information storage device comprising: A plurality of magnetic portions of the magnetic storage medium are regularly arranged on the substrate, each of which is a magnetic dot on which information is magnetically recorded,
The information storage according to claim 9, wherein the low magnetic portion of the magnetic storage medium is an interdot separation band that is provided between the magnetic dots and inhibits magnetic coupling between the magnetic dots. apparatus.

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