JP2009224000A - Method of manufacturing magnetic head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a magnetic head which suppresses degradation of yield and is suited for reducing the size of a reading element. <P>SOLUTION: This method comprises: a step (a) for forming a laminate film 12 providing a magneto-resistance effect on a substrate; a step (b) for forming a first recess 20 by removing the laminate film from magnetic domain control areas MC defined in both sides of a reading element area RE on the surface of the substrate; a step (c) for forming a magnetic domain film 27 in the first recess and on the laminate film; a step (d) for patterning the magnetic domain film so as to leave the magnetic domain control film in the area of a part adjacent to the edge of the first recess in the first recess or on the upper surface of the laminate film; and a step (e) for polishing a part of the magnetic domain control film to remove it under conditions that the magnetic domain control film remains in the first recess. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a magnetic head, and more particularly, to a method for manufacturing a magnetic head in which a magnetoresistive film is patterned to manufacture a read element having a fine core width.

  A conventional method for manufacturing a read element of a magnetic head will be described. After the magnetoresistive film is formed on the substrate, the reading element region is covered with a resist pattern. Using this resist pattern as an etching mask, the magnetoresistive film on both sides of the reading element region is removed by ion milling to form a recess. After a magnetic domain control film for applying bias magnetization to the magnetization free layer of the reading element is deposited in the recess and on the magnetoresistive effect film, the resist pattern is removed together with the magnetic domain control film deposited thereon. .

  In order to reduce the dimension (core width) of the reading element in the track direction, the width of the resist pattern must be reduced and appropriate ion milling conditions must be applied. However, it is difficult to reduce the core width to 100 nm or less due to limitations of the resist pattern formation process and the ion milling process.

  In order to narrow the core width, a method combining ion milling and chemical mechanical polishing (CMP) is promising (see Patent Document 1). In this method, the magnetic domain control film is left in the recesses formed on both sides of the reading element region, and the magnetic domain control film in other regions is removed by CMP.

JP 2006-351668 A

  It has been found that it is difficult to maintain a high manufacturing yield when the core width is narrowed by the conventional method combining ion milling and CMP.

  An object of the present invention is to provide a method of manufacturing a magnetic head that suppresses a decrease in yield and is suitable for miniaturization of a reading element.

The manufacturing method of this magnetic head is:
(A) forming a laminated film showing a magnetoresistive effect on a substrate;
(B) removing the laminated film in the magnetic domain control region defined on both sides of the reading element region on the surface of the substrate to form a first recess;
(C) forming a magnetic domain control film in the first recess and on the laminated film;
(D) The magnetic domain control film is disposed so that the magnetic domain control film remains in a part of the first concave portion and a part of the upper surface of the laminated film adjacent to the edge of the first concave portion. Patterning, and
(E) polishing and removing a part of the magnetic domain control film under a condition that the magnetic domain control film remains in the first recess.

  Prior to polishing the magnetic domain control film, the magnetic domain control film is patterned. Therefore, the polishing time can be shortened as compared with the case where the polishing is performed with the magnetic domain control film formed on the entire surface. When the polishing time is shortened, damage to the reading element region during the polishing process can be reduced. As a result, the reading element can be miniaturized.

  A method of manufacturing a magnetic head according to the first embodiment will be described with reference to FIGS.

As shown in FIG. 1A, a base film 11, a magnetoresistive film 12, a cap film 13, and a hard mask film 14 are deposited in this order on a substrate 10 by sputtering. As will be described later, the substrate 10 is formed by forming a magnetic shield film on a substrate such as aluminum titanium carbide and forming an insulating film such as Al ₂ O ₃ thereon.

  As shown in FIG. 1B, the base film 11 is composed of, for example, two layers in which a Ta film 11a having a thickness of 3 nm and a NiFe film 11b having a thickness of 2 nm are stacked in this order. The magnetoresistive film 12 is made of, for example, a 7 nm thick pinning layer 12 a made of IrMn, a 1.8 nm thick pinned layer 12 b made of CoFe, a 0.8 nm thick nonmagnetic intermediate layer 12 c made of Ru, and CoFeB. A reference layer 12d with a thickness of 2.4 nm, a tunnel insulating layer 12e made of MgO, a free layer 12f with a thickness of 3 nm made of NiFe, and a Ta film 12g with a thickness of 5 nm are stacked in this order. The magnetoresistive film 12 functions as a tunnel magnetoresistive (TMR) element.

  The cap film 13 is made of, for example, Ru and has a thickness of 10 nm. The hard mask film 14 is made of Ta, for example, and has a thickness of 50 nm.

As shown in FIG. 1C, magnetic domain control regions MC are defined on both sides of the reading element region RE. By etching the hard mask film 14 using the resist pattern as an etching mask, openings matching the magnetic domain control region MC are formed in the hard mask film 14. For the etching of the hard mask film 14, for example, reactive ion etching (RIE) using CF ₄ and Ar can be applied.

  The cap film 13 and the magnetoresistive film 12 in the opening formed in the hard mask film 14 are removed by ion milling. Thereby, the recess 20 is formed in the magnetic domain control region MC, and the base film 11 is exposed on the bottom surface of the recess 20. In the reading element region RE, a ridge-shaped convex portion 21 in which the magnetoresistive effect film 12, the cap film 13, and the hard mask film 14 are stacked remains. By this ion milling, the hard mask film 14 becomes thin. For example, the hard mask film 14 having a thickness of 50 nm is thinned to a thickness of 20 nm. It is preferable to use a material having higher ion milling resistance than each layer of the magnetoresistive film 12 as the hard mask film 14. Examples of such a material include SiC, Ru and the like in addition to Ta.

  FIG. 1D shows a plan view of the substrate after the recess 20 is formed. A cross-sectional view taken along one-dot chain line 1C-1C in FIG. 1D corresponds to FIG. 1C. An xyz orthogonal coordinate system in which the surface of the substrate 10 is the yz plane and the normal direction is the x-axis direction is defined. The y direction corresponds to the track width direction, the x direction corresponds to the trailing direction, and the surface cut by a plane parallel to the xy plane faces the magnetic recording medium.

  Each of the magnetic domain control regions MC has a planar shape in which a substantially isosceles trapezoidal part and a substantially rectangular part are connected. The lower base of the isosceles trapezoid and one long side of the rectangle are shared. The magnetic domain control region MC is arranged so that the upper bases of the isosceles trapezoidal portions are parallel to each other. A reading element region RE is defined between the upper bases of the isosceles trapezoidal portions.

  The reading element region RE has a strip-like planar shape elongated in the z-axis direction. For example, the width W1 is 100 nm, and the length L1, that is, the length of the upper base of the isosceles trapezoidal portion is 4 μm. The dimension W2 of each magnetic domain control region MC in the y direction, that is, the sum of the height of the isosceles trapezoidal part and the length of the short side of the rectangular part is 5 μm, and the dimension in the z direction, that is, the bottom of the isosceles trapezoidal part The length and the length of the long side of the rectangular portion are 7 μm.

  In addition, you may make each planar shape of the magnetic domain control area | region MC into a rectangle.

As shown in FIG. 1E, an insulating film 25 made of Al ₂ O ₃ , a CrTi film 26, a magnetic domain control film 27 made of a hard magnetic material such as CoCrPt, and a CrTi film 28 are formed in this order on the entire surface of the substrate by sputtering. Deposit. The thicknesses of the insulating film 25, the lower CrTi film 26, the magnetic domain control film 27, and the upper CrTi film 28 are, for example, 7 nm, 5 nm, 20 nm, and 10 nm, respectively. Note that an insulating material other than Al ₂ O ₃ may be used for the insulating film 25. For the magnetic domain control film 27, a hard magnetic material other than CoCrPt, such as CoPt, may be used.

  The formation of the lower CrTi film 26 and the upper CrTi film 28 is not essential. Further, instead of the lower CrTi film 26, a laminated structure of a TiW film and a Ta film may be employed.

  The recess 20 is filled with a laminated structure of these films. On the upper surface of the upper CrTi film 28, a recess 28A reflecting the shape of the recess 20 is formed.

  As shown in FIGS. 1F and 1G, a resist pattern 30 is formed on the CrTi film 28 so as to include the two concave portions 20 and the convex portions 21 formed in the reading element region in plan view. 1F corresponds to a cross-sectional view taken along one-dot chain line 1F-1F in FIG. 1G. The resist pattern 30 extends slightly outside the edge of the recess 20. FIG. 1G shows a case where the resist pattern 30 has a substantially rectangular planar shape. For this reason, the triangular region 22 defined between the oblique sides opposite to each other of the isosceles trapezoidal portion of the recess 20 is also covered with the resist pattern 30.

  The edge of the resist pattern 30 may be substantially aligned with the edge of the recess 20 or may be disposed slightly inside the edge of the recess 20.

  As shown in FIG. 1H, the resist pattern 30 may have a planar shape whose edge is along the oblique side of the isosceles trapezoidal portion of the recess 20.

  As shown in FIG. 1I, the CrTi film 28, the magnetic domain control film 27, the CrTi film 26, and the insulating film 25 in a region not covered with the resist pattern 30 are removed by ion milling. The hard mask film 14 acts as a stopper at the time of ion milling.

  As shown in FIG. 1J, the resist pattern 30 is removed. The laminated structure composed of the insulating film 25, the CrTi film 26, the magnetic domain control film 27, and the CrTi film 28 has a partial region (protrusion) adjacent to the edge of the recess 20 in the recess 20 and the surface of the hard mask film 14. (Including the upper surface of the part 21).

  If the edge of the resist pattern 30 shown in FIG. 1F is arranged slightly inside the edge of the recess 20, a groove is generated along the edge of the recess 20 far from the ridge-shaped protrusion 21. On the ridge-shaped convex portion 21, a laminated structure including the insulating film 25, the CrTi film 26, the magnetic domain control film 27, and the CrTi film 28 remains.

  As shown in FIG. 1K, the stacked structure composed of the insulating film 25, the CrTi film 26, the magnetic domain control film 27, and the CrTi film 28 protrudes above the hard mask film 14 (above the opening surface of the recess 21). The part which has been removed is removed by CMP. At this time, CMP is performed under the condition that the polishing rate of the hard mask film 14 is slower than the polishing rate of the magnetic domain control film 27 and the like. For this reason, the hard mask film 14 acts as a polishing stopper layer. In the recess 20, a laminated structure including the insulating film 25, the CrTi film 26, the magnetic domain control film 27, and the CrTi film 28 remains.

The CMP conditions are, for example, as follows.
・ Polishing pressure 200g / cm ²
・ Head speed 31rpm
-Lower platen rotation speed 30rpm
・ Abrasives Abrasive Alumina, pH 4
The polishing time is a polishing time required when it is assumed that an Al ₂ O ₃ film, a CrTi film, and a CoCrPt film are formed on the entire surface of the substrate having a flat surface (hereinafter referred to as “standard polishing time”). Can be predicted from. In this example, the polishing time was 50% of the standard polishing time.

  After CMP, the triangular region 22 shown in FIG. 1G can be observed with an optical microscope to confirm the presence or absence of a remaining film. Further, when the resist pattern 30 has the planar shape shown in FIG. 1H, it is difficult to observe the remaining film in the triangular region 22. However, when the structure shown in FIG. 1H is adopted, the volume of the portion to be removed by CMP becomes small, so that the CMP time can be shortened.

As shown in FIG. 1L, the hard mask film 14 shown in FIG. 1K is removed by RIE using CF ₄ and Ar. The etching rate of the cap film 13 is 1/10 or less of the etching rate of the hard mask film 14 made of Ta. For example, a 20 nm thick Ta film is removed in 10 to 30 seconds.

As shown in FIG. 1M, a resist pattern 35 that covers a part of the convex portion 21 of the reading element region and the magnetic domain control film 27 on both sides thereof is formed.
As shown in FIG. 1N, the laminated film in a region not covered with the resist pattern 35 is removed to the upper surface of the base layer 11 by ion milling. If the edge of the resist pattern 30 is disposed slightly inside the edge of the recess 20 at the stage shown in FIG. 1F, the outer edge of the recess 20 is formed at the stage shown in FIG. 1J as described above. Along the groove. In the CMP process shown in FIG. 1K, slurry or the like may remain in the groove. The remaining slurry or the like is removed by the ion milling process shown in FIG. 1N.

As shown in FIG. 1O, an insulating film 38 made of Al ₂ O _{3 is} deposited on the entire surface of the substrate by sputtering.

  The steps up to the stage shown in FIG. 1P will be described. The resist pattern 35 is removed together with the insulating film 38 deposited thereon. As a result, the cap film 13 formed in the reading element region is exposed. An upper magnetic shield film 39 is formed in a partial region including the reading element region.

  Hereinafter, a method for forming the upper magnetic shield film 39 will be described. On the entire surface of the substrate, a stacked layer of a Ta film and a NiFe film to be a seed layer for plating is formed by sputtering. A resist film is formed on the seed layer. By exposing and developing the resist film, an opening is formed in a region where the upper magnetic shield film 39 is to be disposed. NiFe is plated in the region where the opening is formed. After plating, the resist pattern is removed. The seed layer in the unplated region is removed by ion milling.

  In the first embodiment, the magnetic domain control film 27 and the like are patterned before the CMP process shown in FIG. 1K. For this reason, polishing time can be shortened. As the polishing time becomes longer, damage is likely to occur due to shear stress generated in the magnetoresistive film 12 or the like in the reading element region. As a result, the MR ratio of the reading element is lowered.

  In order to reduce damage to the magnetoresistive film 12 in the reading element region, the cap film 13 and the hard mask film 14 disposed thereon may be thickened. However, when these films are thickened, microfabrication becomes difficult in the milling process shown in FIG. 1C. In the first embodiment, since the polishing time can be shortened, damage to the magnetoresistive effect film 13 in the read element region can be reduced without increasing the thickness of the cap film 13 and the hard mask film 14. Thereby, the fall of MR ratio is suppressed.

  In particular, when the core width of the reading element is 100 nm or less, the influence of damage that occurs during polishing becomes obvious. In the first embodiment, a hard mask film 14 having a thickness of about 20 nm remains on the magnetoresistive film 12 in the read element region during polishing. Even when the remaining hard mask film 14 is thinner than 20 nm, an effect of suppressing a decrease in MR ratio can be obtained. Thus, the first embodiment can be expected to have a particularly remarkable effect when the core width is 100 nm or less.

  In the state of FIG. 1E in which the magnetic domain control film 27 is formed on the entire surface of the substrate, when the magnetic domain control film 27 and the like are removed by CMP, the magnetic domain control film 27 remains on a partial region of the hard mask film 14. Is seen. This is because the polishing rate is not uniform within the substrate surface. In addition, since the CrTi film and the magnetic domain control film 27 have different in-plane distribution tendency of the polishing rate, it is not easy to prevent the film from remaining. If excessive polishing is performed, the film can be prevented from remaining, but damage to the magnetic domain resistance effect film 12 in the reading element region is increased.

  FIG. 2A is a front view of the air bearing surface (surface facing the medium) of the magnetic head manufactured by the method according to the first embodiment. An xyz orthogonal coordinate system is defined in which the air bearing surface is the xy plane, the trailing direction is the x axis, the track width direction is the y axis, and the direction perpendicular to the air bearing surface is the z axis. FIG. 2B shows a cross-sectional view parallel to the zx plane of the magnetic head.

  On the substrate 100 made of aluminum titanium carbide or the like, the reading element unit 105 and the recording element unit 115 are laminated in this order. The read element unit 105 includes a lower magnetic shield layer 101, a read element 102, and an upper magnetic shield layer 103. The recording element unit 115 includes a main magnetic pole 110, a main magnetic pole auxiliary layer 111, an auxiliary magnetic pole 112, and a connection part 114. The main magnetic pole 110, the main magnetic pole auxiliary layer 111, the auxiliary magnetic pole 112, and the connection portion 114 constitute a part of a magnetic path of a magnetic field generated during magnetic recording. A recording coil 113 is arranged so as to link with the magnetic path.

  The method according to the first embodiment is applied to the formation of the reading element unit 105. The recording element portion 115 can be formed by a known method.

  FIG. 3 shows a schematic diagram of a magnetic disk apparatus using a magnetic head manufactured by the method according to the above embodiment. A slider 122 is attached to the tip of the suspension arm 123 supported by the rotary actuator 124 with a support called a gimbal. A magnetic head 121 is attached to the end of the slider 122. As the reading element of the magnetic head 121, one manufactured by the method according to the first embodiment is used.

  The magnetic head 121 floats from the surface of the magnetic disk 120 by a minute height. A large number of concentric tracks 125 are defined on the surface of the magnetic disk 120. By rotating the suspension arm 123 by driving the rotary actuator 124, the magnetic head 121 can be moved to a different position with respect to the radial direction of the magnetic disk 120.

  Next, a method for manufacturing a magnetic head according to the second embodiment will be described with reference to FIGS. 4A to 4D.

  The cross-sectional view shown in FIG. 4A is the same as FIG. 1J, and the process up to this structure is the same as the process from FIG. 1A to FIG. 1J of the first embodiment. On the upper surface of the CrTi film 28, a recess 28A reflecting the shape of the recess 20 appears. The thickness of the film is adjusted so that the upper surface of the CrTi film 28 in the recess 28A and the lower surface of the hard mask film 14 of the protrusion 21 have substantially the same height.

  As shown in FIG. 4B, a polishing stopper film 40 made of Ta is formed on the entire surface of the substrate by sputtering. At this time, the polishing stopper film 40 formed on the CrTi film 28 in the concave portion 28A and the hard mask film 14 in the convex portion 21 are arranged at substantially the same height. Note that a material having high polishing resistance other than Ta may be used for the polishing stopper film 40. For example, SiC or Ru may be used.

  As shown in FIG. 4C, the magnetic domain control film 27 and the like deposited above the opening surface of the recess 20 are removed by CMP. This CMP is performed under conditions where the polishing rate of the hard mask film 14 and the polishing stopper film 40 is slower than the polishing rate of the CrTi film 28, the magnetic domain control film 27, the CrTi film 26, and the insulating film 25. For example, the polishing time is 50% of the standard polishing time. Convex portions including the magnetic domain control film 27 and the like are generated in the region where the ridge-shaped convex portion 21 is disposed and the region along the edge of the concave portion 20. Since the convex portion has a very small area in plan view, a high pressure is applied to the polishing stopper film 40 deposited on the convex portion in the initial stage of polishing. As a result, this portion of the polishing stopper film 40 is polished. Thereafter, the underlying magnetic domain control film 27 and the like are polished.

  Polishing is stopped in a state where the polishing stop film 40 deposited on the bottom of the recess 28A remains. The hard mask film 14 remains on the uppermost surface of the convex portion 21.

  As shown in FIG. 4D, the polishing stopper film 40 and the hard mask film 14 are removed by RIE. The subsequent processes are the same as the processes after the stage shown in FIG. 1L of the first embodiment.

  In the second embodiment, the polishing can be stopped with good reproducibility by the polishing stop film 40 formed on the hard mask film 14 in the convex portion 21 and the magnetic domain control film 27 in the concave portion 20. The polishing stopper film 40 formed on the magnetic domain control film 27 in the recess 20 is disposed in the vicinity of the hard mask film 14 of the protrusion 21. For this reason, the high effect which suppresses the excessive grinding | polishing of the convex part 21 is anticipated compared with 1st Example.

  A polishing stopper film 40 (hereinafter referred to as “a polishing stopper film 40 on both sides of the convex portion 21”) formed on the magnetic domain control film 27 in the concave portion 20 and a hard mask formed in the convex portion 21. Although it is preferable to adjust the thickness of each film so that the film 14 is at the same height, it need not be exactly the same height. When the upper surface of the polishing stopper film 40 on both sides of the convex portion 21 is lower than the lower surface of the hard mask film 14 in the convex portion 21, the polishing stopper film 40 cannot exhibit a sufficient polishing stop function. For this reason, it is preferable to make the upper surface of the polishing stopper film 40 on both sides of the convex portion 21 higher than the lower surface of the hard mask film 14 in the convex portion 21. Further, the height of the upper surface of the polishing stopper film 40 on both sides of the convex portion 21 is made equal to the upper surface of the hard mask film 14 in the convex portion 21 or slightly higher than the upper surface of the hard mask film 14. preferable. If the upper surface of the polishing stopper film 40 on both sides of the convex portion 21 is too high, the polishing stops at the polishing stopper film 40 and it becomes difficult to remove the magnetic domain control film 27 on the convex portion 21 by polishing. Therefore, the height difference between the upper surface of the polishing stopper film 40 on both sides of the convex portion 21 and the upper surface of the hard mask film 14 in the convex portion 21 is preferably 20 nm or less.

  A magnetic head manufacturing method according to the third embodiment will be described with reference to FIGS. 5A to 5E.

  The cross-sectional view shown in FIG. 5A is the same as FIG. 1E, and the process up to this structure is the same as the process from FIG. 1A to FIG. 1E of the first embodiment. On the upper surface of the CrTi film 28, a recess 28A reflecting the shape of the recess 20 appears. The film thickness is adjusted so that the upper surface of the CrTi film 28 formed on the bottom surface of the concave portion 28A and the lower surface of the hard mask film 14 of the convex portion 21 have substantially the same height.

  As shown in FIG. 5B, a polishing stop film 50 made of Ta is formed on the CrTi film 28 by sputtering. At this time, the polishing stopper film 50 formed on the CrTi film 28 in the concave portion 28A and the hard mask film 14 in the convex portion 21 are arranged at substantially the same height.

  In plan view, a resist pattern 51 is formed on the polishing stopper film 50 so as to include the two concave portions 20 and the convex portions 21 formed in the reading element region. The resist pattern 51 has the same planar shape as the resist pattern 30 shown in FIG. 1G or FIG. 1H.

  As shown in FIG. 5C, each film from the polishing stopper film 50 to the insulating film 25 in the region not covered with the resist pattern 51 is removed. For example, the polishing stopper film 50 is removed by RIE, and the film below it is removed by ion milling.

  As shown in FIG. 5D, the resist pattern 51 is removed. As shown in FIG. 5E, the magnetic domain control film 27 and the like deposited above the opening surface of the recess 20 are removed by CMP. This CMP is performed under the condition that the polishing rate of the hard mask film 14 and the polishing stopper film 50 is slower than the polishing rate of the CrTi film 28, the magnetic domain control film 27, the CrTi film 26, and the insulating film 25. For example, the polishing time is 50% of the standard polishing time. Polishing is stopped in a state where the hard mask film 14 in the convex portion 21 is exposed and the polishing stopper film 50 remains on the magnetic domain control film 27 in the concave portion 20.

  As shown in FIG. 5F, the polishing stopper film 50 and the hard mask film 14 are removed by RIE. The subsequent processes are the same as the processes after the stage shown in FIG. 1L of the first embodiment.

  Also in the third embodiment, as in the case of the second embodiment, excessive polishing of the convex portion 21 is suppressed, and an effect of reducing the shear stress applied to the convex portion 21 is expected.

  The preferred relationship between the height of the hard mask film 14 in the convex portion 21 and the polishing stopper film 50 on both sides of the convex portion 21 is that the hard mask film 14 in the convex portion 21 and the convex portion 21 in the second embodiment are used. This is the same as the preferable height relationship with the polishing stopper film 40 on both sides of the two.

  A magnetic head manufacturing method according to the fourth embodiment will be described with reference to FIGS. 6A to 6E.

  The cross-sectional view shown in FIG. 6A is the same as FIG. 1C, and the process up to this structure is the same as the process from FIG. 1A to FIG. 1C of the first embodiment.

  As shown in FIG. 6B, a resist film 60 is formed on the entire surface of the substrate. As the resist film 60, it is preferable to use a two-layer resist for lift-off. The thickness of the resist film 60 is, for example, 0.25 μm to 1.0 μm. In the resist film 60, an opening 60A that includes the two concave portions 20 and the convex portions 21 formed in the reading element region in a plan view is formed. On the substrate surface in the opening 60A and the resist film 60, the insulating film 25, the CrTi film 26, the magnetic domain control film 27, and the CrTi film 28 are deposited in this order. On the upper surface of the CrTi film 28, a recess 28A reflecting the shape of the recess 20 appears. The thickness of the film is adjusted so that the upper surface of the CrTi film 28 in the recess 28 </ b> A and the upper surface of the hard mask film 14 in the convex portion 21 have substantially the same height.

  As shown in FIG. 6C, the resist film 60 is removed together with the magnetic domain control film 27 and the like deposited thereon. When removing the resist film 60, ultrasonic waves are applied. The magnetic domain control film 27 and the like that have covered the side surface of the opening 60A remain as if they were standing vertically. Depending on the application conditions of the ultrasonic wave, a wall that is substantially vertically cut may be removed. Further, the magnetic domain control film 27 and the like remain in the recess 20.

  As shown in FIG. 6D, the magnetic domain control film 27 and the like deposited above the opening surface of the recess 20 are removed by CMP. This CMP is performed under the condition that the polishing rate of the hard mask film 14 is slower than the polishing rate of the CrTi film 28, the magnetic domain control film 27, the CrTi film 26, and the insulating film 25. For example, the polishing time is 50% of the standard polishing time. The hard mask film 14 functions as a polishing stopper layer.

  As shown in FIG. 6E, the hard mask film 14 is removed by RIE. The subsequent processes are the same as the processes after the stage shown in FIG. 1L of the first embodiment.

  In the second embodiment, the magnetic domain control film 27 and the like are patterned by ion milling, but it is also possible to pattern by the lift-off method as in the fourth embodiment.

  A magnetic head manufacturing method according to the fifth embodiment will be described with reference to FIGS. 7A to 7D.

  The sectional view shown in FIG. 7A is the same as FIG. 6C, and the process up to this structure is the same as the process up to the structure of FIG. 6C of the fourth embodiment. In the fifth embodiment, the thickness of each film is adjusted so that the upper surface of the CrTi film 28 in the concave portion 28A is substantially the same height as the lower surface of the hard mask film 14 in the convex portion 21. Yes.

  As shown in FIG. 7B, a polishing stopper film 70 made of Ta is deposited on the surface of the laminated structure including the magnetic domain control film 27 and the like and the hard mask film 14 by sputtering. The polishing stopper film 70 formed on the CrTi film 28 in the recess 28A and the hard mask film 14 in the protrusion 21 are arranged at substantially the same height.

  As shown in FIG. 7C, the magnetic domain control film 27 and the like deposited above the opening surface of the recess 20 are removed by CMP. This CMP is performed under the condition that the polishing rate of the hard mask film 14 and the polishing stopper film 70 is slower than the polishing rate of the CrTi film 28, the magnetic domain control film 27, the CrTi film 26, and the insulating film 25. For example, the polishing time is 50% of the standard polishing time. The hard mask film 14 and the polishing stop film 70 can stop the polishing with good reproducibility.

  As shown in FIG. 7D, the hard mask film 14 and the polishing stopper film 70 are removed by RIE. The subsequent processes are the same as the processes after the stage shown in FIG. 1L of the first embodiment.

  In the fifth embodiment, the polishing stopper film 70 is disposed in the vicinity of the convex portion 21 in the reading element region. For this reason, similarly to the second embodiment, excessive polishing of the convex portion 21 can be suppressed, and the shear stress applied to the convex portion 21 can be reduced.

  The preferred height relationship between the hard mask film 14 in the convex portion 21 and the polishing stopper film 70 on both sides of the convex portion 21 is the same as the hard mask film 14 in the convex portion 21 and the convex portion 21 in the second embodiment. This is the same as the preferable height relationship with the polishing stopper film 40 on both sides of the two.

  With reference to FIGS. 8A to 8D, a method of manufacturing a magnetic head according to the sixth embodiment will be described.

  The steps until the CrTi film 28 shown in FIG. 8A is formed are the same as the steps up to the structure shown in FIG. 6B of the fourth embodiment. In the sixth embodiment, as in the case of the fifth embodiment, the upper surface of the CrTi film 28 in the recess 28A is substantially the same height as the lower surface of the hard mask film 21 in the protrusion 21. A polishing stopper film 80 made of Ta is formed on the CrTi film 28 by sputtering. The polishing stopper film 80 in the recess 28A is disposed at substantially the same height as the hard mask film 14 in the protrusion 21.

  As shown in FIG. 8B, the resist film 60 shown in FIG. 8A is removed together with the magnetic domain control film 27 and the like deposited thereon. The magnetic domain control film 27 and the like that have covered the side surface of the opening 60A remain as if they were standing vertically. Depending on the application conditions of the ultrasonic wave, a wall that is substantially vertically cut may be removed. Further, the magnetic domain control film 27 and the like remain in the recess 20.

  As shown in FIG. 8C, the magnetic domain control film 27 and the like deposited above the opening surface of the recess 20 are removed by CMP. This CMP is performed under the condition that the polishing rate of the hard mask film 14 and the polishing stopper film 80 is slower than the polishing rate of the CrTi film 28, the magnetic domain control film 27, the CrTi film 26, and the insulating film 25. For example, the polishing time is 50% of the standard polishing time. Since the area in plan view of the portion protruding above the opening surface of the recess 20 is very small, a large pressure is applied to this portion in the initial stage of polishing. For this reason, the polishing stopper film 80 formed on the protruding portion is removed. The hard mask film 14 and the polishing stopper film 80 can stop the polishing with good reproducibility.

  As shown in FIG. 8D, the hard mask film 14 and the polishing stopper film 80 are removed by RIE. The subsequent processes are the same as the processes after the stage shown in FIG. 1L of the first embodiment.

  In the sixth embodiment, a polishing stopper film 80 is disposed in the vicinity of the convex portion 21 in the reading element region. For this reason, similarly to the second embodiment, excessive polishing of the convex portion 21 can be suppressed, and the shear stress applied to the convex portion 21 can be reduced.

  The preferable relationship between the height of the hard mask film 14 in the convex portion 21 and the polishing stopper film 80 on both sides of the convex portion 21 is the same as that of the hard mask film 14 in the convex portion 21 and the convex portion 21 in the second embodiment. This is the same as the preferable height relationship with the polishing stopper film 40 on both sides of the two.

  In FIG. 9, the defect rate of the TMR element manufactured by the method by the 1st-6th Example and a comparative example is shown. The horizontal axis represents the relative time when the polishing time of the CMP process for the magnetic domain control film 27 and the like is 100% as the standard polishing time. In the manufacturing method according to the comparative example, CMP is performed with the magnetic domain control film 27 and the like formed on the entire surface as shown in FIG. 1E. The vertical axis represents the defective rate of the manufactured TMR element as a relative value when the defective rate of the TMR element manufactured at a polishing time of 300% using the method according to the comparative example is 1.

  In the method according to the comparative example, when the polishing time is 30%, 50%, and 150%, the magnetic domain control film 27 that should originally be removed remains in the region where the recess 20 shown in FIG. 1E is not formed, A good TMR element could not be produced. In the first to sixth embodiments, no residual magnetic domain control film 27 was observed even when the polishing time was 30%, 50%, and 150%.

  In the comparative example, when the polishing time is set to 300%, the remaining of the magnetic domain control film 27 is not observed, but the defective product rate is increased. This is considered to be due to the occurrence of damage due to CMP on the convex portion 21 shown in FIG. 1E. In the first to sixth embodiments, since the polishing time can be shortened, the damage received by the convex portion 21 is reduced. For this reason, the defective product rate is low. In the first to sixth embodiments, the defective product rate increases as the polishing time becomes longer because the convex portion 21 is damaged according to the polishing time.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

  The following appendices are further disclosed with respect to the embodiments including the first to sixth examples.

(Appendix 1)
(A) forming a laminated film showing a magnetoresistive effect on a substrate;
(B) removing the laminated film in the magnetic domain control region defined on both sides of the reading element region on the surface of the substrate to form a first recess;
(C) forming a magnetic domain control film in the first recess and on the laminated film;
(D) By patterning the magnetic domain control film, at least a part of the first concave portion of at least one of the first concave portions passes through the upper surface of the laminated film in the reading element region from at least a part of the first concave portion. Leaving the magnetic domain control film continuously covering up to a part;
(E) A method of manufacturing a magnetic head including a step of polishing and removing a part of the magnetic domain control film under a condition that the magnetic domain control film remains in the first recess.

(Appendix 2)
The step (a) includes a step of forming a hard mask film on the laminated film and patterning the hard mask film,
In the step (b), the stacked film is etched using the patterned hard mask film as an etching mask,
In the step (c), the magnetic domain control film is formed on the patterned hard mask film,
The magnetic head manufacturing method according to appendix 1, wherein the polishing is performed under the condition that the polishing speed of the hard mask film is slower than the polishing speed of the magnetic domain control film in the step (e), and the polishing is stopped with the hard mask film. Method.

(Appendix 3)
The upper surface of the magnetic domain control film formed in the step (c) includes a second recess reflecting the shape of the inner surface of the first recess,
The step (d) further includes a step of forming a polishing stopper film on the patterned magnetic domain control film and on the laminated film,
In the step (e), the magnetic domain control film is polished under a condition that the polishing rate of the polishing stopper film is lower than the polishing rate of the magnetic domain control film, and the magnetic domain control film in the first recess is over the magnetic domain control film. 3. The method of manufacturing a magnetic head according to appendix 1 or 2, wherein the polishing is stopped in a state where the polishing stop film remains.

(Appendix 4)
The upper surface of the magnetic domain control film formed in the step (c) includes a second recess reflecting the shape of the inner surface of the first recess,
The step (c) further includes a step of forming a polishing stopper film on the magnetic domain control film,
In the step (d), the polishing stopper film is patterned into the same planar shape as the magnetic domain control film,
In the step (e), the magnetic domain control film is polished under a condition that the polishing rate of the polishing stopper film is lower than the polishing rate of the magnetic domain control film, and the magnetic domain control film in the first recess is over the magnetic domain control film. 3. The method of manufacturing a magnetic head according to appendix 1 or 2, wherein the polishing is stopped in a state where the polishing stop film remains.

(Appendix 5)
The step (b) further includes a step of forming, on a planar view, a resist pattern having an opening including the reading element region and the first recess on the stacked film,
In the step (c), the magnetic domain control film is formed on the resist pattern,
The magnetic head manufacturing method according to appendix 1 or 2, wherein in the step (d), the magnetic domain control film is patterned by removing the resist pattern together with the magnetic domain control film formed on the resist pattern. Method.

(Appendix 6)
The upper surface of the magnetic domain control film formed in the step (c) includes a second recess reflecting the shape of the inner surface of the first recess,
The step (d) includes a step of covering the patterned surface of the magnetic domain control film and a region where the magnetic domain control film is not formed with a polishing stopper film,
In the step (e), the magnetic domain control film is polished under a condition that the polishing rate of the polishing stopper film is lower than the polishing rate of the magnetic domain control film, and the magnetic domain control film in the first recess is over the magnetic domain control film. The method for manufacturing a magnetic head according to appendix 5, wherein the polishing is stopped in a state where the polishing stopper film remains.

(Appendix 7)
The upper surface of the magnetic domain control film formed in the step (c) includes a second recess reflecting the shape of the inner surface of the first recess,
The step (c) further includes a step of forming a polishing stopper film on the magnetic domain control film,
In the step (d), the polishing stopper film formed on the resist pattern is also removed together with the resist pattern,
In the step (e), the magnetic domain control film is polished under a condition that the polishing rate of the polishing stopper film is lower than the polishing rate of the magnetic domain control film, and the magnetic domain control film in the first recess is over the magnetic domain control film. The method for manufacturing a magnetic head according to appendix 5, wherein the polishing is stopped in a state where the polishing stopper film remains.

(1A) is a cross-sectional view of the apparatus in the middle of the manufacturing method of the magnetic head according to the first embodiment, (1B) is a cross-sectional view of the base film and the magnetoresistive film, (1C) and (1D) are a sectional view and a plan view of the device in the middle of the method of manufacturing the magnetic head according to the first embodiment. (1E) and (1F) are cross-sectional views of the apparatus in the middle of the manufacturing method of the magnetic head according to the first embodiment, and (1G) and (1H) are the manufacturing of the magnetic head according to the first embodiment. It is a top view of the apparatus in the middle of the method. (1I) to (1K) are cross-sectional views of the apparatus in an intermediate stage of the magnetic head manufacturing method according to the first embodiment. (1L) to (1N) are cross-sectional views of the apparatus in the middle of the method of manufacturing the magnetic head according to the first embodiment. (1O) and (1P) are sectional views of the apparatus in the middle of the method of manufacturing the magnetic head according to the first embodiment. (2A) is a front view of a magnetic head including a reading element manufactured by the method according to the first embodiment, and (2B) is a sectional view thereof. 1 is a schematic diagram of a hard disk drive. (4A) to (4D) are cross-sectional views of the apparatus in the middle of the method of manufacturing the magnetic head according to the second embodiment. (5A) to (5C) are cross-sectional views of the apparatus in the middle of the method of manufacturing the magnetic head according to the third embodiment. (5D) to (5F) are cross-sectional views of the apparatus in the middle of the method of manufacturing the magnetic head according to the third embodiment. (6A) to (6C) are cross-sectional views of the apparatus in the middle of the method of manufacturing a magnetic head according to the fourth embodiment. (6D) and (6E) are cross-sectional views of the apparatus in the middle of the method of manufacturing a magnetic head according to the fourth embodiment. 7A to 7D are cross-sectional views of the apparatus in the middle of the method of manufacturing the magnetic head according to the fifth embodiment. 8A to 8D are cross-sectional views of the apparatus in the middle of the method of manufacturing a magnetic head according to the sixth embodiment. It is a graph which shows the defect rate of the TMR element manufactured with the method by an Example and a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Substrate 11 Base film 12 Magnetoresistance effect film 13 Cap film 14 Hard mask film 20 Recess 21 Projection 22 Triangular region 25 Insulating film 26 CrTi film 27 Magnetic domain control film 28 CrTi film 28A Recess 30 Resist pattern 35 Resist pattern 38 Insulating film 39 Upper magnetic shield film 40, 50 Polishing stop film 51 Resist pattern 60 Resist film 60A Opening 70 Polishing stop film 100 Substrate 101 Lower shield film 102 Read element 103 Upper shield film 105 Read element section 110 Main magnetic pole 111 Main magnetic pole auxiliary layer 112 Auxiliary Magnetic pole 113 Recording coil 114 Connection portion 115 Recording element portion 120 Magnetic disk 121 Magnetic head 122 Slider 123 Suspension arm 124 Rotary actuator 125 Track

Claims (5)

(A) forming a laminated film showing a magnetoresistive effect on a substrate;
(B) removing the laminated film in the magnetic domain control region defined on both sides of the reading element region on the surface of the substrate to form a first recess;
(C) forming a magnetic domain control film in the first recess and on the laminated film;
(D) By patterning the magnetic domain control film, at least a part of the first concave portion of at least one of the first concave portions passes through the upper surface of the laminated film in the reading element region from at least a part of the first concave portion. Leaving the magnetic domain control film continuously covering up to a part;
(E) A method of manufacturing a magnetic head including a step of polishing and removing a part of the magnetic domain control film under a condition that the magnetic domain control film remains in the first recess. The step (a) includes a step of forming a hard mask film on the laminated film and patterning the hard mask film,
In the step (b), the stacked film is etched using the patterned hard mask film as an etching mask,
In the step (c), the magnetic domain control film is formed on the patterned hard mask film,
2. The magnetic head according to claim 1, wherein in the step (e), polishing is performed under a condition that a polishing rate of the hard mask film is slower than a polishing rate of the magnetic domain control film, and the polishing is stopped by the hard mask film. Manufacturing method. The upper surface of the magnetic domain control film formed in the step (c) includes a second recess reflecting the shape of the inner surface of the first recess,
The step (d) further includes a step of forming a polishing stopper film on the patterned magnetic domain control film and on the laminated film,
In the step (e), the magnetic domain control film is polished under a condition that the polishing rate of the polishing stopper film is lower than the polishing rate of the magnetic domain control film, and the magnetic domain control film in the first recess is over the magnetic domain control film. The method of manufacturing a magnetic head according to claim 1, wherein the polishing is stopped in a state where the polishing stop film remains. The upper surface of the magnetic domain control film formed in the step (c) includes a second recess reflecting the shape of the inner surface of the first recess,
The step (c) further includes a step of forming a polishing stopper film on the magnetic domain control film,
In the step (d), the polishing stopper film is patterned into the same planar shape as the magnetic domain control film,
In the step (e), the magnetic domain control film is polished under a condition that the polishing rate of the polishing stopper film is lower than the polishing rate of the magnetic domain control film, and the magnetic domain control film in the first recess is over the magnetic domain control film. The method of manufacturing a magnetic head according to claim 1, wherein the polishing is stopped in a state where the polishing stop film remains. The step (b) further includes a step of forming, on a planar view, a resist pattern having an opening including the reading element region and the first recess on the stacked film,
In the step (c), the magnetic domain control film is formed on the resist pattern,
3. The magnetic head according to claim 1, wherein, in the step (d), the magnetic domain control film is patterned by removing the resist pattern together with the magnetic domain control film formed on the resist pattern. Production method.

Images