JP2010092565A - Method of manufacturing main magnetic pole and main magnetic pole, and perpendicular magnetic head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a main magnetic pole by which write-core width can be narrowed. <P>SOLUTION: Etching durability of a Ta film is improved by heat-treating (anneal treating) a hard mask (Au)20 and a Ta film 18, and diffusing Au in the Ta. Thereby, in RIE (Reactive Ion Etching) in which a pattern is formed in an alumina layer 16, etching (side etching) of the Ta film 18 can be suppressed. By thus doing, spreading of the pattern formed in the alumina layer 16 more than an aperture pattern 20a formed in the hard mask (Au) 20 is suppressed, consequently write-core width of the main magnetic pole 414 can be narrowed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a main magnetic pole manufacturing method, a main magnetic pole, and a perpendicular magnetic head, and more particularly to a main magnetic pole included in a recording element for recording information on a magnetic storage medium by a perpendicular magnetic recording method, a manufacturing method thereof, and the main magnetic pole. The present invention relates to a perpendicular magnetic head.

  In recent years, there has been a growing demand for information storage devices (for example, HDDs (hard disk drives)) to have a large capacity and a high recording density. To increase the recording density, the bit length of the magnetic storage medium (magnetic disk) may be reduced. However, the conventional in-plane recording method has a limit due to large thermal fluctuation. Therefore, recently, research and development on a perpendicular recording method for recording information by magnetizing a magnetic recording medium in a perpendicular direction has been actively conducted.

  In order to increase the recording density in such a perpendicular recording type HDD, it is necessary to narrow the track on the magnetic disk as much as possible (narrow the track). However, when the track is narrowed, there is a possibility that overhanging recording to an adjacent track, that is, side erasure occurs. For this reason, recently, as a countermeasure against side erasure, a method has been proposed in which the shape of the main magnetic pole of the recording head is inverted trapezoidal (or substantially triangular). As one of the methods for manufacturing the main magnetic pole, a method using a damascene process is known (for example, see Patent Documents 1 and 2).

FIGS. 8A to 9D show a main magnetic pole forming method using a damascene process. According to this forming method, as shown in FIG. 8A, an alumina (Al ₂ O ₃ ) layer 112, a ruthenium (Ru) layer 114, and an alumina layer 116 are laminated in this order, and as an adhesion layer and a CMP stopper. After forming the tantalum (Ta) film 118 to be used, a hard mask (gold (Au)) 120 for alumina dry etching is formed. Further, after applying a resist 122 on the hard mask 120, the resist 122 is subjected to an exposure process to form a pattern 122a.

  Next, as shown in FIG. 8B, using the resist 122 as a mask, the hard mask (Au) 120 is physically anisotropic etched (ion milling) to form an opening pattern 120a.

  Next, as shown in FIG. 8C, the Ta film 118 is etched (RIE (Reactive Ion Etching)) to form an opening pattern 118a. Next, as shown in FIG. 8D, the resist 122 is removed.

  Next, as shown in FIG. 9A, the alumina layer 116 is dry-etched using the hard mask (Au) 120 as an etching mask. Next, as shown in FIG. 9B, film formation of alumina 124 for adjusting the light core width and film formation of a plating base (Ru) 126 for magnetic pole plating are performed, followed by plating of the magnetic pole material 128. I do.

  Then, as shown in FIG. 9C, the Ta film 118 is used as a CMP stopper and polished from the upper layer side using a CMP (Chemical Mechanical Polishing) method to flatten the whole. Further, as shown in FIG. 9D, the main magnetic pole 414 is manufactured by depositing the alumina 130 for the trailing shield gap.

Japanese Patent Laid-Open No. 2008-204 566 JP 2008-217846 A

However, tantalum (Ta) 116 used as an adhesion layer and a CMP stopper has lower etching resistance than a hard mask (Au). For this reason, as shown in a portion surrounded by a dotted line (reference numeral SE) in FIG. 9A, when dry etching of the alumina (Al ₂ O ₃ ) layer 116 is performed, an opening pattern of the tantalum (Ta) film 118 is formed. The edge portion 118a is etched (this is also referred to as “side etching”). As a result, the alumina layer 116 is etched in a wider range than specified by the hard mask (Au) 120 (opening pattern 120a), and as a result, the core width (light core width) of the main pole is specified by the hard mask. There is a possibility that it becomes larger than the width.

  In the semiconductor field, techniques disclosed in Japanese Patent Laid-Open Nos. 10-92791 and 2004-31805 have been proposed as methods for creating a pattern narrower than the opening defined by the hard mask. In these methods, a side wall is formed in the opening of the hard mask and the lower insulating layer is etched, and can be applied to the production of the main pole as shown in FIGS. However, even if this technique is applied, the influence of the etching resistance of tantalum (Ta) described above is not improved, and the etching resistance of the side wall itself cannot be guaranteed, so that the shape and size of the main pole are still maintained. There is concern about the impact.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a method of manufacturing a main pole capable of narrowing the write core width. It is another object of the present invention to provide a main magnetic pole and a perpendicular magnetic head capable of recording information at a high recording density.

  The main magnetic pole manufacturing method described in the present specification includes a first pattern forming member made of a first material and a second pattern forming member made of a second material having higher etching resistance than the first material. Using the opening pattern formed on the second pattern forming member and the step of forming the opening pattern on the substrate, the step of forming the opening pattern on the second pattern forming member, and the opening pattern formed on the second pattern forming member. Forming an opening pattern having a shape on the first pattern forming member, and heat-treating the second pattern forming member and the first pattern forming member, so that the second material is contained in the first material. A pattern is formed on the substrate by chemical anisotropic etching using the opening patterns formed on the first and second pattern forming members, and formed on the substrate. The A film of the main magnetic pole forming member to turn, includes the steps of forming the main magnetic pole.

  According to this, the 1st and 2nd pattern formation member in which the opening pattern was formed is heat-treated, and the 2nd material which constitutes the 2nd pattern formation member is the 1st which constitutes the 1st pattern formation member By diffusing into the material, the etching resistance of the first pattern forming member can be increased. Therefore, it is possible to suppress the first pattern forming member from being etched during the chemical anisotropic etching for forming a pattern on the substrate. As a result, the spread of the pattern formed on the substrate can be suppressed, and as a result, the width of the light core can be reduced.

  The main magnetic pole manufacturing method described in the present specification includes a first pattern forming member made of a first material and a second pattern forming member made of a second material having higher etching resistance than the first material. Using the opening pattern formed on the second pattern forming member and the step of forming the opening pattern on the substrate, the step of forming the opening pattern on the second pattern forming member, and the opening pattern formed on the second pattern forming member. A step of forming an opening pattern having a shape on the first pattern forming member, and a wall having a certain thickness made of the first material at an edge portion of the opening pattern formed on the second pattern forming member. A step of providing a member, a step of heat-treating the first and second pattern forming members and the wall-like member to diffuse the second material into the first material, and the first and second Pattern forming member and Forming a pattern on the substrate by chemical anisotropic etching using an opening pattern defined by the wall-shaped member, and forming a main magnetic pole forming member on the pattern formed on the substrate. Forming a main magnetic pole.

  According to this, the 1st, 2nd pattern formation member in which the opening pattern was formed, and the wall-shaped member provided in the edge part of the opening pattern were heat-processed, and the 2nd which comprises the 2nd pattern formation member By diffusing the material into the first material constituting the first pattern forming member and the wall member, the etching resistance of the first pattern forming member and the wall member can be increased. Therefore, it is possible to suppress the etching of the first pattern forming member and the wall-shaped member during the chemical anisotropic etching for forming the pattern on the base material. Can be suppressed. Further, since the wall-shaped member is provided at the edge portion of the opening pattern, the opening portion of the opening pattern can be narrowed, so that the spread of the pattern formed on the substrate can be further suppressed. As described above, according to the method of manufacturing the main magnetic pole described in the present specification, it is possible to narrow the pattern formed on the base material, and consequently, to narrow the write core width of the main magnetic pole. It becomes possible.

  The main magnetic pole described in the present specification is a main magnetic pole manufactured by the main magnetic pole manufacturing method described in the present specification.

  According to this, since the write core width is narrowed, information can be recorded at a high recording density.

  The perpendicular magnetic head described in this specification is a perpendicular magnetic head including the main magnetic pole described in this specification.

  According to this, since the main magnetic pole capable of recording information at a high recording density is provided, it is possible to record information at a high recording density and to reproduce the information.

  The main magnetic pole manufacturing method described in the present specification has an effect that the write core width can be reduced. Further, the main magnetic pole and the perpendicular magnetic head described in this specification have an effect that information can be recorded at a high recording density.

<< First Embodiment >>
The first embodiment of the perpendicular recording head, the main magnetic pole included in the perpendicular recording head, and the manufacturing method thereof will be described in detail below with reference to FIGS.

  FIG. 1A is a schematic diagram of a magnetic head 40 as a perpendicular magnetic head provided on the head slider 34. In the first embodiment, a perpendicular magnetic recording type magnetic head is used as the magnetic head 40, and the magnetic disk 220 is rotated by the rotation of the magnetic disk 220 (rotation in the direction of arrow D in FIG. 1A). The magnetic disk 220 moves relative to the magnetic disk 220 in the direction opposite to the arrow D direction (arrow E direction).

  The magnetic head 40 includes a recording head 41, an upper magnetic shield 42, a lower magnetic shield 43, and a reproducing sensor head (MR element) 44 provided between the magnetic shields 42 and 43.

  The recording head 41 includes a main magnetic pole 414, a return yoke 411, and an information recording coil 413. When a current is supplied to the coil 413, the magnetic flux emitted from the main magnetic pole 414 passes straight through the hard magnetic layer constituting the magnetic disk 220 and reaches the soft magnetic layer existing below the hard magnetic layer. Return to the main pole 414 via the layer and return yoke 411.

  FIG. 1B is a bottom view of the magnetic head 40 of FIG. As shown in FIG. 1B, the shape of the surface of the main pole 414 facing the magnetic disk 220 is a substantially isosceles triangle. However, the shape is not limited to this, and the shape of the surface of the main pole 414 facing the magnetic disk 220 may be trapezoidal.

  Next, a method for manufacturing the main magnetic pole 414 in the first embodiment will be described with reference to FIGS. In this embodiment, a damascene process is used as a method for manufacturing the main magnetic pole 414.

FIG. 2 is a flowchart showing a manufacturing procedure of the main magnetic pole 414, and FIGS. 3A to 4E schematically show each process of FIG. First, in step S10 of FIG. 2, a film forming process and a patterning process are performed. Specifically, as shown in FIG. 3A, an alumina (Al ₂ O ₃ ) layer 12, a ruthenium (Ru) layer 14, and an alumina (Al ₂ O ₃ ) layer 16 as a base material were laminated in this order. From above, after forming a tantalum (Ta) film 18 as a first pattern forming member used as an adhesion layer and a CMP stopper, a hard mask (gold (Au)) for alumina dry etching as a second pattern forming member ) 20 is deposited. In addition, after applying a resist 22 on the hard mask 20, an exposure process is performed using an exposure apparatus to form a pattern 22 a on the resist 22. It is assumed that the pattern 22a formed on the resist 22 has the same shape and the same size as the shape of the main magnetic pole 414 shown in FIG. 1A viewed from the right side of FIG. 1A.

  Next, in step S12 (see FIG. 2), as shown in FIG. 3B, the hard mask (Au) 20 is physically anisotropic etched (ion milling) using the resist 22 as a mask, and has the same shape as the pattern 22a. The opening pattern 20a is formed.

Next, in step S14 (see FIG. 2), as shown in FIG. 3C, the Ta film 18 is etched using a fluorine-based gas (CF ₄ , CHF _3, etc.) using the resist 22 as a mask (RIE ( Reactive Ion Etching)) to form an opening pattern 18a having the same shape as the pattern 22a.

  Next, in step S16 (see FIG. 2), the resist 22 is removed as shown in FIG.

  Next, in step S18 (see FIG. 2), the hard mask (Au) 20 and the Ta film 18 are heat-treated (annealed). This heat treatment (annealing) is desirably performed at a temperature range of 300 ° C. to 350 ° C. for about 1 minute to 5 minutes. By this annealing treatment, as shown by an arrow in FIG. 4A, gold (Au) that is the material of the hard mask 20 diffuses into tantalum (Ta) that is the material of the Ta film 18. Yes.

Next, in step S20 (see FIG. 2), as shown in FIG. 4B, the alumina (Al ₂ O ₃ ) layer 16 is dry-etched (chlorine-based gas (BCl) using the hard mask (Au) 20 as an etching mask. RIE (Reactive Ion Etching) using ₃ ). In this case, since the Au is diffused and mixed in the Ta film 18 located at the interface with the alumina (Al ₂ O ₃ ) layer 16 by the annealing treatment, the alumina (Al ₂ O ₃ ) layer 16 is dried. High etching resistance against etching (RIE). That is, the selectivity (= etching rate of the film to be etched (alumina layer 16) / etching rate of the Ta film 18 after the annealing process) is very high. Thereby, generation | occurrence | production of the side etching mentioned above can be suppressed.

  Next, in step S22 (see FIG. 2), as shown in FIG. 4C, film formation of the alumina 24 for adjusting the light core width and film formation of the plating base (Ru) 26 for magnetic pole plating are performed. Subsequently, the magnetic pole material 28 as the main magnetic pole forming member is plated.

  In step S24 (see FIG. 2), as shown in FIG. 4D, the Ta film 18 is used as a CMP stopper, and the whole is flattened by CMP (Chemical Mechanical Polishing) from the upper layer side.

Further, in step S26 (see FIG. 2), as shown in FIG. 4E, an alumina (Al ₂ O ₃ ) 30 for the trailing shield gap is formed from the upper layer side of the Ta film 18.

  In the first embodiment, the main magnetic pole 414 is manufactured through the manufacturing steps as described above.

  As described above in detail, according to the first embodiment, the hard mask (Au) 20 and the Ta film 18 are heat-treated (annealed), and Au is diffused into Ta. Since the etching resistance of the film 18 is increased, it is possible to suppress etching (side etching) of the Ta film 18 during RIE for forming a pattern on the alumina layer 16. As a result, as in the prior art (see FIG. 9A), the pattern formed on the alumina layer 16 can be prevented from spreading more than the opening pattern 20a formed on the hard mask (Au) 20, and as a result The write core width of the magnetic pole 414 can be reduced. Further, in the first embodiment, an Au and Ta alloy is not used from the beginning, and an Au and Ta film is formed, and then, in the middle of the manufacturing process of the main magnetic pole 414, Au is annealed into Ta. Since diffusion is performed, it is possible to suppress ion milling of the Ta film 18 and the underlying alumina layer 16 by physical anisotropic etching (ion milling) (see FIG. 3B). Thereby, the main magnetic pole 414 can be manufactured with high accuracy as designed.

  Further, according to the recording head 41 of the first embodiment, information can be recorded at a high recording density by narrowing the write core width of the main magnetic pole 414.

<< Second Embodiment >>
Next, a second embodiment of the present invention will be described with reference to FIGS. 5 and 6A to 7C.

  FIG. 5 is a flowchart showing the main magnetic pole manufacturing procedure according to the second embodiment. As can be seen from FIG. 5, steps S10 to S16 execute the same processing as in the first embodiment described above (the same structure as in FIG. 3D is manufactured by the processing up to this point). . However, the subsequent processing is different from that of the first embodiment.

  After step S16 is completed, in step S17a, as shown in FIG. 6A, a wall-shaped member forming layer 77 is sputtered on the upper surface of the structure in FIG. As the material of the wall-shaped member forming layer 77, tantalum (Ta) can be used as in the case of the Ta film 18.

Next, in step S17b, the wall-shaped member forming layer 77 is chemically anisotropically etched (RIE) using a fluorine-based gas (CF ₄ , CHF ₃ or the like), and exists at the edge portions of the opening patterns 20a and 18a. Remove the part other than the part that is in contact (contact). A part of the wall-shaped member forming layer 77 remaining after step S17b is referred to as a wall-shaped member (or side wall) 77 ′.

  Next, in the annealing process of step S18 (see FIG. 5), as in the first embodiment, a heat treatment is performed at a temperature range of 300 ° C. to 350 ° C. for about 1 minute to 5 minutes. In the second embodiment, 6C, Au, which is the material of the hard mask 20, diffuses into Ta, which is the material of the Ta film 18, and also diffuses into Ta, which is the material of the wall-shaped member 77 ′. It is supposed to be.

Next, in step S20, as in the first embodiment, as shown in FIG. 6D, the alumina (Al ₂ O ₃ ) layer 16 is etched using a chlorine-based gas (BCl ₃ or the like). In this case, the Ta film 18 and the wall-shaped member 77 ′ have high etching resistance against dry etching of the alumina (Al ₂ O ₃ ) layer 16 because Au is mixed by diffusion as described above. (That is, it has a high selection ratio). For this reason, the above-described side etching (see FIG. 9A) is suppressed.

Thereafter, in the same manner as in the first embodiment, in step S22 (see FIG. 5), as shown in FIG. 7 (a), as shown in FIG. 7 (a), film formation of alumina 24 for light core width adjustment and plating base for magnetic pole plating ( Ru) 26 is formed, and the magnetic pole material 28 is plated. In step S24, as shown in FIG. 7B, the Ta film 18 is polished from the upper layer side using the CMP method as a CMP stopper, and the whole is polished. Further, in step S26, the alumina (Al ₂ O ₃ ) 30 for the trailing shield gap is formed as shown in FIG. 7C, whereby the production of the main magnetic pole 414 is completed.

  As described above in detail, according to the second embodiment, the hard mask (Au) 20, the Ta film 18 and the wall-shaped member 77 ′ are heat-treated (annealed), and Au is contained in Ta. By diffusing, the etching resistance of the Ta film 18 and the etching resistance of the wall-shaped member 77 ′ are increased. Therefore, the Ta film 18 and the wall-shaped member 77 ′ are etched during the RIE for forming the pattern on the alumina layer 16 (see FIG. Side etching) can be suppressed. As a result, as in the prior art (see FIG. 9A), the pattern formed on the alumina layer 16 can be prevented from spreading more than the opening pattern 20a formed on the hard mask (Au) 20, and as a result The write core width of the magnetic pole 414 can be reduced. Further, in the second embodiment, an Au and Ta alloy is not used from the beginning, and after the Au and Ta film is formed, Au is annealed into the Ta by a heat treatment (annealing process) during the manufacturing process of the main magnetic pole 414. Since the diffusion is performed, ion milling of the Ta film 18 and the underlying alumina layer 16 by physical anisotropic etching (ion milling) can be suppressed. Further, the RIE process of the domain wall member forming layer 77 in step S17b (FIG. 6B) of FIG. 5 can be easily performed.

  Further, according to the second embodiment, since the wall-shaped member 77 ′ is provided at the edge portion of the opening patterns 20a and 18a, the width of the pattern 16a formed on the alumina layer 16 is narrower than that of the first embodiment. As a result, the write core width of the main magnetic pole 414 can be made narrower than that of the first embodiment.

  Further, according to the recording head 41 of the second embodiment, information can be recorded at a high recording density by narrowing the write core width of the main magnetic pole 414.

  Further, in the second embodiment, the wall-shaped member 77 ′ is formed into an opening pattern through a process of forming the wall-shaped member forming material 77 and a process of removing a part of the wall-shaped member forming material 77 while leaving a part thereof. Since it is provided only at the edge portion, it is possible to easily provide the wall-shaped member 77 ′ having a constant thickness at the edge portion of the opening pattern. However, the present invention is not limited to this, and the wall-shaped member 77 ′ may be provided using a method different from the above.

  In each of the above embodiments, Ta and Au are used and annealed to increase the etching resistance of Ta, and the selectivity (the etching rate of the alumina layer 16 / the etching rate of Ta after the annealing process) is increased. Explained when to do. However, the present invention is not limited to this, and various other materials may be adopted as long as the combination of materials can be set to the same etching resistance and selection ratio as described above by heat treatment (annealing). Is possible.

  Each embodiment mentioned above is an example of suitable implementation of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.

FIG. 1A is a schematic diagram of the magnetic head according to the first embodiment, and FIG. 1B is a bottom view of FIG. It is a flowchart which shows the manufacturing method of the main pole which concerns on 1st Embodiment. FIG. 3 is a diagram (part 1) schematically showing a method for manufacturing the main magnetic pole according to the first embodiment. FIG. 8 is a diagram (No. 2) schematically showing the method of manufacturing the main magnetic pole according to the first embodiment. It is a flowchart which shows the manufacturing method of the main pole which concerns on 2nd Embodiment. It is FIG. (1) which shows typically the manufacturing method of the main pole which concerns on 2nd Embodiment. It is FIG. (2) which shows typically the manufacturing method of the main pole which concerns on 2nd Embodiment. It is FIG. (1) which shows typically the manufacturing method of the main pole which concerns on a prior art. It is FIG. (2) which shows typically the manufacturing method of the main pole which concerns on a prior art.

Explanation of symbols

16 Base material (alumina layer)
16a pattern 18 Ta film (first pattern forming member)
18a Opening pattern 20 Hard mask (second pattern forming member)
20a Aperture pattern 28 Magnetic pole material (main magnetic pole forming member)
40 Magnetic head (perpendicular magnetic head)
77 'Wall-shaped member 414 Main magnetic pole

Claims (6)

Sequentially depositing a first pattern forming member made of a first material and a second pattern forming member made of a second material having a higher etching resistance than the first material on a substrate;
Forming an opening pattern in the second pattern forming member;
Using the opening pattern formed in the second pattern forming member to form an opening pattern having the same shape as the opening pattern on the first pattern forming member;
Heat-treating the second pattern forming member and the first pattern forming member to diffuse the second material into the first material;
Forming a pattern on the substrate by chemical anisotropic etching using the opening pattern formed in the first and second pattern forming members;
Forming a main magnetic pole on a pattern formed on the substrate to form a main magnetic pole, and a method of manufacturing the main magnetic pole. Sequentially depositing a first pattern forming member made of a first material and a second pattern forming member made of a second material having a higher etching resistance than the first material on a substrate;
Forming an opening pattern in the second pattern forming member;
Using the opening pattern formed in the second pattern forming member to form an opening pattern having the same shape as the opening pattern on the first pattern forming member;
Providing a wall-shaped member having a certain thickness made of the first material at an edge portion of the opening pattern formed in the second pattern forming member;
Heat-treating the first and second pattern forming members and the wall-shaped member to diffuse the second material into the first material;
Forming a pattern on the substrate by chemical anisotropic etching using an opening pattern defined by the first and second pattern forming members and the wall-shaped member;
Forming a main magnetic pole on a pattern formed on the substrate to form a main magnetic pole, and a method of manufacturing the main magnetic pole. The step of providing the wall-shaped member includes
Depositing the first material in a region including the opening pattern of the second pattern forming member;
The main magnetic pole according to claim 2, further comprising: removing a portion of the first material formed in the step of forming a film other than a portion existing at an edge portion of the opening pattern. Production method. 4. The method of manufacturing a main magnetic pole according to claim 1, wherein the first material is Ta and the second material is Au. 5. The main pole manufactured by the manufacturing method of the main pole as described in any one of Claims 1-4. A perpendicular magnetic head comprising the main magnetic pole according to claim 5.

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