JP2006228315A - Method of producing thin film magnetic head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of producing a thin film magnetic head with which a main magnetic head can be formed in a desired shape. <P>SOLUTION: A method of producing a thin film magnetic recording head 100 which is equipped with a recording part 100B in which an exposed surface of the side of an air bearing surface in a main magnetic pole 10 on a gap layer 9 is formed in a tapered shape includes: a main magnetic pole layer forming process for forming a main magnetic pole layer on the gap layer; a process for forming a mask on the main magnetic pole layer; a main magnetic pole precursor forming process for forming a main magnetic pole precursor by etching the main magnetic pole layer with the mask while flowing etching gas; and a process for forming the main magnetic pole by etching the main magnetic pole precursor, wherein in the main magnetic pole layer forming process, the main magnetic pole layer is constituted of a multilayered film including Ru layers provided among a plurality of FeCo layers, and in the main magnetic pole precursor forming process, gaseous mixture gas of Cl<SB>2</SB>, BCl<SB>3</SB>and O<SB>2</SB>is used as the etching gas and the sum total flow rate of Cl<SB>2</SB>and BCl<SB>3</SB>in the gaseous mixture is 91.5 to 96 vol.%, and also the temperature of the main magnetic pole layer is 180 to 200°C. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a thin film magnetic head.

  As a magnetic recording device, an in-plane recording method for recording a signal magnetic field in the in-plane direction of a recording surface on a recording medium such as a hard disk has already been widely used, but a further increase in recording density has been realized. Therefore, a perpendicular recording type magnetic recording apparatus that records a signal magnetic field in a direction orthogonal to the recording surface has attracted attention. According to the perpendicular recording method, there is an advantage that a high linear recording density can be secured and a recorded recording medium is hardly affected by thermal fluctuation.

  When a recording operation is performed on a magnetic head for perpendicular magnetic recording, the track adjacent to the recording target track is overwritten due to the inclination (skew) of the magnetic head with respect to the extending direction of the recording target track. Therefore, it is required to suppress the occurrence of so-called side erase. As a magnetic head capable of suppressing the occurrence of side erasure, for example, an exposed surface of the main magnetic pole exposed on the air bearing surface side opposed to the recording medium is a tapered shape instead of a rectangular shape. It has been proposed (see, for example, Patent Document 1). In order to taper the exposed surface of the main pole, it is necessary to remove the side wall portion of the portion (hereinafter referred to as “main pole precursor”) which is a main pole precursor formed on the gap layer surface. However, at this time, it is desirable that the side wall surface of the main magnetic pole precursor is perpendicular to the surface of the gap layer.

  As a method for producing such a main magnetic pole precursor, a portion where a mask is formed on a main magnetic pole layer made of a single material and an etching gas is introduced and the main magnetic pole layer mask is not formed. A method of obtaining a main magnetic pole precursor by performing reactive ion etching (RIE) is known (for example, see Patent Documents 2 to 3 below).

In the manufacturing method described in Patent Document 2, permalloy (NiFe), FeN (iron nitride), FeZrN (zirconia iron nitride), FeCoZr (cobalt iron nitride), and the like are used as the material constituting the main magnetic pole layer. When etching a portion of the main magnetic pole layer where the mask is not formed, the main magnetic pole precursor is formed using BCl ₃ and a mixed gas of Cl ₂ and O ₂ as an etching gas, thereby performing side etching. A method for obtaining a suppressed main pole precursor has been proposed.

In the manufacturing method described in Patent Document 3, when etching a part of a main magnetic pole layer composed of a layer made of NiFe, FeCo or NiFeCo and a layer made of NiFe or CoNiFe, BCl ₃ and Cl _{2 are used} as etching gases. And a method using a mixed gas of O ₂ , it has been proposed to obtain a main magnetic pole precursor in which side etching is suppressed as compared with a case where a mixed gas of BCl ₃ and Cl ₂ is used as an etching gas. . Further, Patent Document 3 proposes that the main magnetic pole precursor is formed substantially perpendicular to the surface of the gap layer by further adding CO ₂ to the mixed gas.

Patent Document 4 below discloses a method in which a part of the mask is etched by RIE and a part of the main magnetic pole layer is removed by ion milling.
JP 2002-197609 A JP-A-8-269748 JP 2004-35999 A JP 11-339223 A

  By the way, it is desirable that the main magnetic pole has a multilayer structure because the recording characteristics are improved in the multilayer structure than in the single layer structure.

  However, in the method of manufacturing the main magnetic pole precursor of Patent Document 2 described above, when etching a part of the main magnetic pole layer composed of a single layer, the etching gas contains oxygen, so the main magnetic pole precursor is Oxide adheres to the side wall surface of the metal and side etching is suppressed, but the side wall surface of the main pole precursor is inclined with respect to the surface of the gap layer, making it difficult to make the main pole a desired shape. In other words, a so-called side erase occurs in which a track adjacent to a track to be recorded is overwritten during a recording operation. Such a problem may occur similarly even when the main magnetic pole has a multilayer structure.

  In the method of manufacturing the main magnetic pole precursor disclosed in Patent Document 3, the main magnetic pole precursor can be substantially perpendicular to the gap layer. However, when the main magnetic pole layer has a multilayer structure, the main magnetic pole precursor is changed to the gap layer. Instead of being formed perpendicular to the surface, side etching occurs conversely. For this reason, it becomes difficult to make the main pole have a desired shape, and so-called side erasure occurs during the recording operation.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a method of manufacturing a thin film magnetic head in which a main magnetic pole can be formed in a desired shape.

In order to solve the above problems, the present invention includes a recording head portion having a main magnetic pole for defining a track width in a recording medium on a gap layer, and an exposed surface on the air bearing surface side of the main magnetic pole having a tapered shape. In the method of manufacturing a thin film magnetic head, a main magnetic pole layer forming step for forming a main magnetic pole layer for forming the main magnetic pole on the gap layer, and a mask forming step for forming a mask on the main magnetic pole layer A main magnetic pole precursor forming step of forming a main magnetic pole precursor by etching an etching gas into a portion of the main magnetic pole layer where the mask is not formed, and sidewalls of the main magnetic pole precursor A main magnetic pole forming step of forming the main magnetic pole by removing a portion, and in the main magnetic pole layer forming step, the main magnetic pole layer is FeCo containing 40 at% or less of Co, or Fe composed of a multilayer film comprising a layer made of Ru is provided between the plurality of layers and said plurality of layers consisting of OZrO, in the main magnetic pole precursor forming step, the etching gas, Cl ₂ and BCl ₃ and O ₂ , the total flow ratio of Cl ₂ and BCl _{3 in} the etching gas is 91.5 to 96% by volume, and the temperature of the main magnetic pole layer is 180 to 200 ° C. This is a method of manufacturing a thin film magnetic head.

Also, the present invention provides a thin film magnetic head having a recording head portion having a main magnetic pole defining a track width in a recording medium on a gap layer, and an exposed surface on the air bearing surface side of the main magnetic pole having a tapered shape. In the method, a main magnetic pole layer forming step for forming a main magnetic pole layer for forming the main magnetic pole on the gap layer, a mask forming step for forming a mask on the main magnetic pole layer, and the main magnetic pole layer A main magnetic pole precursor forming step of forming a main magnetic pole precursor by etching an inflow of an etching gas into a portion where the mask is not formed, and removing a side wall portion of the main magnetic pole precursor A main magnetic pole forming step of forming a main magnetic pole, and in the main magnetic pole layer forming step, the main magnetic pole layer is formed of a composite made of FeCo containing Fe of 40 at% or less or FeCoZrO. Mixing of the layers and the provided between the plurality of layers constitute a multilayer film comprising a layer comprising the Ru, in the main magnetic pole precursor forming step, the etching gas, Cl ₂ and BCl ₃ and O ₂ A thin film magnetic head comprising: a gas, a total flow rate ratio of Cl ₂ and BCl _{3 in} the etching gas of 91.5 to 94% by volume, and a temperature of the main magnetic pole layer of 180 to 250 ° C. It is a manufacturing method.

  According to these thin film magnetic head manufacturing methods, when the etching gas is flown into the portion of the main magnetic pole layer where the mask is not formed, the main magnetic pole precursor is substantially removed from the gap layer surface. It can be formed vertically. For this reason, when the side wall portion of the main magnetic pole precursor is removed, a main magnetic pole having a desired shape can be obtained.

  In the method of manufacturing the thin film magnetic head, in the main magnetic pole precursor forming step, it is preferable that etching is performed by applying two stages of bias power so that the bias power at the previous stage is higher than the bias power at the subsequent stage. In this case, the portion of the main magnetic pole layer where the mask is not formed can be etched quickly and appropriately. Therefore, the main magnetic pole can be formed in a desired shape in a short time.

  According to the method of manufacturing a thin film magnetic head of the present invention, a main pole having a desired shape can be obtained, and occurrence of side erasure that a track adjacent to a recording target track is overwritten during a recording operation is suppressed. It is possible to obtain a thin film magnetic head that can be used.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings, the same or equivalent components are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
First, a thin film magnetic head obtained by a preferred embodiment of a method of manufacturing a thin film magnetic head according to the present invention will be described with reference to FIG. 1A is a cross-sectional view taken along a plane parallel to the air bearing surface of the thin film magnetic head, and FIG. 1B is a cross sectional view of the thin film magnetic head, which is orthogonal to the air bearing surface and crosses the main pole. A cross-sectional view along the plane is shown.

As shown in FIG. 1, a thin film magnetic head 100 includes a substrate 1 made of AlTiC (Al ₂ O ₃ .TiC) or the like, an underlayer 2, a reproducing head portion 100A, a nonmagnetic layer 3, a recording head portion 100B, an overlayer. The coat layer 4 is laminated in this order.

  The reproducing head portion 100A includes a lower shield layer 5 made of a magnetic material such as NiFe, an upper shield layer 6 made of a magnetic material such as NiFe, and a GMR element sandwiched between the lower shield layer 5 and the upper shield layer 6. 7 and an insulating layer 8 sandwiched between the lower shield layer 5 and the upper shield layer 6 and having the GMR element 7 buried therein. Therefore, the GMR element 7 is magnetically shielded by the lower shield layer 5 and the upper shield layer 6. The GMR element 7 reads magnetic information recorded on the recording medium, and is embedded in the insulating layer 8 on the air bearing surface S side. The lower shield layer 5 is formed with a thickness of about 1 μm to about 3 μm, for example, and the upper shield layer 6 is formed with a thickness of about 1.0 μm to about 4.0 μm, for example.

  The recording head portion 100B is formed on the lower gap layer 9, the main magnetic pole 10 formed on the lower gap layer 9, the embedded layer 11 in which the main magnetic pole 10 is embedded, and the embedded layer 11, and the main magnetic pole 10 is formed. An upper gap layer 12 having an opening 12a on the end side opposite to the end on the air bearing surface S side, a thin film coil 13 provided on the upper gap layer 12 and wound around the opening 12a, and an opening 12a And a light shield 14 that is connected to the main magnetic pole 10 and extends to the air bearing surface S side. Therefore, when a current is passed through the thin film coil 13, a magnetic flux is generated from the main magnetic pole 10, and this magnetic flux is released from the air bearing surface S and then returns to the main magnetic pole 10 through the write shield 14.

  A gap layer 15 is provided on the air bearing surface S side of the thin film magnetic head 100 between the write shield 14 and the upper gap layer 12. The length of the gap layer 15 along the direction away from the air bearing surface S is the same as the length of the pole portion of the main magnetic pole 10 and determines the three height of the main magnetic pole 10. On the opposite side of the gap layer 15 from the air bearing surface S, a gap layer 16 covering the thin film coil 13 and a resist 17 are sequentially laminated from the thin film coil 13 side. An opening 9a is formed in the lower gap layer 9, and an auxiliary magnetic pole 18 is embedded in the opening 9a.

  FIG. 2 is a cross-sectional view showing the main magnetic pole 10. As shown in FIG. 2, the main pole 10 has a tapered shape. That is, in the main magnetic pole 10, the width W1 on the lower gap layer 9 side is smaller than the width W2 on the upper gap layer 12 side, and the width continuously changes along the thickness direction of the main magnetic pole 10. ing. In other words, the side wall surface of the main pole 10 is inclined with respect to the surface 9 a of the lower gap layer 9.

  The main magnetic pole 10 is composed of a plurality of FeCo layers 10b made of FeCo and a Ru layer 10a provided between the FeCo10b layers and has a multilayer structure. For example, in FIG. 2, the main magnetic pole 10 has four Ru layers 10a and four FeCo layers 10b stacked alternately. Here, FeCo contains 40 at% or less of Co, and the Ru layer 10a is made of Ru.

  The thickness of the FeCo layer 10b is preferably 80 nm or less, and more preferably 40 nm. The thickness of the Ru layer 10a is preferably 0.8 nm or less, and more preferably 0.4 nm. When the thickness of the FeCo layer 10b exceeds 80 nm, the side wall surface tends to be inclined as compared with the case of 80 nm or less. When the thickness of the Ru layer 10a exceeds 0.8 nm, the thickness is 0.8 nm or less. Compared to the case, side etching tends to occur.

The underlayer 2 is made of an insulating material such as alumina (Al ₂ O ₃ ) and has a thickness of about 1 μm to about 10 μm. The nonmagnetic layer 3 is formed on the upper shield layer 6 with a thickness of 3 to 4 μm, for example. The overcoat layer 4 is made of an insulating material such as alumina (Al ₂ O ₃ ), and is formed with a thickness of about 20 μm to about 30 μm.

  According to the thin film magnetic head 100, when a recording operation is performed, occurrence of side erasure in which a track adjacent to a recording target track is overwritten is sufficiently suppressed.

  Next, a method for manufacturing the thin film magnetic head 100 will be described.

  First, as shown in FIG. 3, the base layer 2, the lower shield layer 5, the insulating layer 8, and the upper shield layer 6 are sequentially formed on the substrate 1. At this time, the insulating layer 8 is formed so that the GMR element 7 is embedded on the air bearing surface S side. Thus, the reproducing head unit 100A is obtained.

  Next, after forming the nonmagnetic layer 3 on the reproducing head portion 100A, the lower gap layer 9 is formed. Subsequently, an opening 9a is formed in the lower gap layer 9, and an auxiliary magnetic pole 18 is embedded in the opening 9a (see FIG. 1B).

  Next, the main magnetic pole layer 19 is formed on the lower gap layer 9 and the auxiliary magnetic pole 18 (main magnetic pole layer forming step). In this case, the main magnetic pole layer 19 is formed by alternately forming a plurality of FeCo layers 10b made of FeCo and a Ru layer 10a provided between the FeCo layers 10b by sputtering or plating. For example, in FIG. 4, the main magnetic pole layer 19 is formed by alternately stacking four Ru layers 10a and four FeCo layers 10b. Here, FeCo contains 40 at% or less of Co, and the Ru layer 10a is made of Ru.

  Next, a mask layer 20 is formed on the main magnetic pole layer 19 in order to form a mask when the main magnetic pole layer 19 is subjected to reactive ion etching. The mask layer 20 is made of alumina, for example.

  Subsequently, as shown in FIG. 5, an electrode film 21 made of NiFe or the like is formed on the mask layer 20, and subsequently, a plating made of NiFe, for example, is formed on the electrode film 21 in order to form a mask 20a to be described later. A film 22 is formed. At this time, the plating film 22 has the same shape as the main magnetic pole 10.

  Next, as shown in FIG. 6, the mask layer 20 is etched using the plating film 22 as a mask to obtain a mask 20a (mask formation step). As the etching, for example, reactive ion etching is used.

  Next, etching is performed on a portion of the main magnetic pole layer 19 where the mask 20a is not formed (see FIG. 7). Etching is performed by RIE, for example. Here, the RIE apparatus will be briefly described with reference to FIG.

  FIG. 8 is a schematic diagram showing a basic configuration of the RIE apparatus 30. As shown in FIG. 8, the RIE apparatus 30 is disposed in the container 23 so as to face the lower electrode 25 supporting the sample 24, the heater 26 provided in contact with the lower electrode 25, and the lower electrode 25. And an upper electrode 27. The upper electrode 27 also serves as a gas supply pipe, and an etching gas flows into the container 23 through the upper electrode 27. The upper electrode 27 is grounded. Further, a high frequency power source 28 is connected to the lower electrode 25 so that high frequency power can be applied between the lower electrode 25 and the upper electrode 27. Note that an exhaust port 23a is formed in the container 23 so that the gas in the container 23 can be discharged.

  Next, a method for etching the main magnetic pole layer 19 using the RIE apparatus 30 will be described.

In this case, the sample 24 is a stacked body in which the mask portion 20 a is formed on the main magnetic pole layer 19. In this state, the high frequency power supply 28 is turned on and high frequency power is applied between the upper electrode 27 and the lower electrode 25. On the other hand, an etching gas is caused to flow into the container 23 through the upper electrode 27. As the etching gas, a mixed gas of Cl ₂ gas, BCl ₃ gas, and O ₂ gas is used. On the other hand, the heater 26 is operated to heat the sample, that is, the laminate through the lower electrode 25. At this time, active species and ions are generated between the upper electrode 27 and the lower electrode 25, and not only physical etching is performed on the main magnetic pole layer 19 but also chemical etching is performed at the same time.

Here, the total flow rate ratio of Cl ₂ and BCl ₃ in the etching gas is 91.5 to 96% by volume, and the temperature of the heater 26 is 180 to 200 ° C. Here, the temperature of the heater 26 and the temperature of the main magnetic pole layer 19 are the same. By doing so, the main magnetic pole precursor 31 is formed (main magnetic pole precursor forming step). At this time, side etching of the main magnetic pole precursor 31 is sufficiently suppressed, and the main magnetic pole precursor 31 can be formed substantially perpendicular to the surface of the lower gap layer 9. The total flow rate ratio refers to the ratio of the total flow rate of Cl ₂ and BCl _{3 in} the total flow rate of the etching gas.

  The effect that the side etching of the main magnetic pole precursor 31 is sufficiently suppressed and the main magnetic pole precursor 31 can be formed substantially perpendicular to the surface of the lower gap layer 9 is that the main magnetic pole layer 19 is multi-layered. In the case of a film, that is, on the premise of having a plurality of FeCo layers 10b and a Ru layer 10a provided between the FeCo layers 10b. If the main magnetic pole layer 19 is a single layer film, the shape is tapered. It becomes a shape. Further, when the main magnetic pole layer 19 is a two-layer film made of different magnetic materials, an undercut occurs. More specifically, when the main magnetic pole layer 19 is a single layer film or a film having a two-layer structure made of different magnetic materials, side etching or undercut occurs. To do.

The total flow ratio of Cl ₂ and BCl _{3 in} the etching gas is preferably 94 to 96% by volume. At this time, the temperature of the main magnetic pole layer 19 is preferably 180 to 200 ° C.

When the total flow ratio of Cl ₂ and BCl _{3 in} the etching gas is 91.5 to 94% by volume, the temperature of the heater 26, that is, the temperature of the main magnetic pole layer 19 may be 180 to 250 ° C. Even in this case, side etching of the main magnetic pole precursor 31 is sufficiently suppressed, and the main magnetic pole precursor 31 can be formed substantially perpendicular to the surface of the lower gap layer 9.

If the total flow ratio of Cl ₂ and BCl _{3 in} the etching gas and the temperature of the main magnetic pole layer 19 are out of the above ranges, side etching occurs in the main magnetic pole precursor 31 or undercut, that is, on the mask 20a side. A situation may occur in which the portion is excessively etched.

  After obtaining the main magnetic pole precursor 31 in this way, the side wall portion of the main magnetic pole precursor 31 is removed by, for example, ion milling to obtain the main magnetic pole 10 (main magnetic pole forming step). At this time, the side wall portion of the main magnetic pole precursor 31 is removed so that the end surface on the air bearing surface S side of the main magnetic pole 10 has a tapered shape.

Next, as shown in FIG. 9, Al ₂ O ₃ is deposited by CVD, for example, until the main magnetic pole 10 is completely filled, and an Al ₂ O ₃ film 32 is formed.

Next, as shown in FIG. 10, the Al ₂ O ₃ film 32 is planarized by CMP (Chemical Mechanical Polishing) so that the main magnetic pole 10 is exposed, thereby forming the buried layer 11.

  Subsequently, as shown in FIG. 11, the upper gap layer 12 is stacked on the buried layer 11. Subsequently, an opening 12a is formed on the end of the main pole 10 opposite to the air bearing surface S (see FIG. 1B).

  Next, after forming the thin film coil 13 on the upper gap layer 12 by, for example, a plating method (see FIG. 1B), the gap layer 15 is formed on the air bearing surface S side by the same plating method.

  Then, an insulating layer 16 is formed so as to cover the thin film coil 13 (resist is embedded).

  Then, an electrode film (not shown) is formed on the gap layer 15 and the resist 17, and the write shield 14 is formed. In this way, the recording head unit 100B is obtained.

  Subsequently, the overcoat layer 4 is formed on the light shield 14. The thin film magnetic head 100 is completed as described above.

  According to the method of manufacturing the thin film magnetic head 100 of this embodiment, side etching of the main magnetic pole precursor 31 is sufficiently suppressed, and the main magnetic pole precursor 31 is formed substantially perpendicular to the surface of the lower gap layer 9. Therefore, the main pole 10 having a desired shape and size can be obtained. Therefore, it is possible to obtain the thin film magnetic head 100 that can sufficiently suppress the occurrence of side erasure in which the track adjacent to the recording target track is overwritten during the recording operation.

  In the present embodiment, high frequency bias power is applied when the main magnetic pole layer 19 is etched. However, during etching, the high frequency bias power is divided into two stages as shown in FIG. It is preferable that the bias power be higher than the bias power at the subsequent stage. In this case, the main magnetic pole layer 19 can be etched faster and more appropriately. In FIG. 12, the vertical axis represents RF power (W), and the horizontal axis represents time.

(Second Embodiment)
Next, a second embodiment of the method for manufacturing a thin film magnetic head of the present invention will be described.

  The manufacturing method of the thin film magnetic head of this embodiment is the same as the manufacturing method of the thin film magnetic head of the first embodiment, except that the FeCo layer 10b in the main magnetic pole layer 19 is replaced with a FeCoZrO layer made of FeCoZrO.

  Even in this case, side etching of the main magnetic pole precursor 31 is sufficiently suppressed, and the main magnetic pole precursor 31 can be formed substantially perpendicular to the surface of the lower gap layer 9, so that the desired shape and size can be obtained. The main magnetic pole 10 can be obtained. For this reason, it is possible to obtain a thin film magnetic head capable of sufficiently suppressing the occurrence of side erasure in which a track adjacent to a recording target track is overwritten during a recording operation.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, when the side wall portion of the main magnetic pole precursor 31 is removed, a part of the lower gap layer 9 is not etched. However, as shown in FIG. Thus, a so-called trim structure may be formed. In this case, it is possible to prevent an effective increase in the recording track width due to the spread of magnetic flux generated when writing a narrow track.

  Hereinafter, although the content of the present invention will be described with reference to examples and comparative examples, the present invention is not limited to the following examples.

(Examples 1-8)
First, a base layer made of alumina (Al ₂ O ₃ ) was formed with a thickness of about 1 μm on a substrate made of Altic (Al ₂ O ₃ .TiC) by sputtering.

  Next, a lower shield layer made of NiFe was formed on the base layer by plating.

Next, an insulating layer made of Al ₂ O ₃ was formed on the lower shield layer by sputtering. At this time, the insulating layer was formed so that the GMR element was buried on the air bearing surface S side.

  Subsequently, an upper shield layer made of NiFe was formed to a thickness of 3.5 μm by plating. As described above, a reproducing head portion was obtained.

  Next, after forming a nonmagnetic layer on the reproducing head, a lower gap layer made of alumina was formed. Subsequently, an opening was formed in the lower gap layer, and an auxiliary magnetic pole was embedded in this opening.

  Next, a main magnetic pole layer was formed on the lower gap layer and the auxiliary magnetic pole. In this case, a Ru layer having a thickness of about 0.2 nm is first formed by a sputtering method, and then an FeCo layer having a thickness of about 40 nm and a Ru layer having a thickness of about 0.8 nm are alternately formed by eight layers. A main magnetic pole layer was formed. The Co content in the FeCo layer was about 35 at%.

  Next, a mask layer made of alumina having a thickness of about 1300 nm was formed on the main magnetic pole layer. Subsequently, an electrode film made of NiFe was formed on the mask layer, and then a plating film made of NiFe was formed on the electrode film.

Next, using the plating film as a mask, reactive ion etching was performed on the mask layer using an RIE apparatus (E541AW, manufactured by Hitachi, Ltd.) on the alumina film to obtain an Al ₂ O ₃ mask.

Next, RIE was performed on the main magnetic pole layer using the Al ₂ O ₃ mask as a mask. RIE was performed using the RIE apparatus. The high frequency power supply was turned on and about 400 W of high frequency power was applied between the upper electrode and the lower electrode. On the other hand, an etching gas was allowed to flow into the container through the upper electrode. As an etching gas, a mixed gas of Cl ₂ gas, BCl ₃ gas and O ₂ gas was used, and the flow rate ratio thereof and the total flow rate ratio of Cl ₂ and BCl _{3 in} the etching gas were as shown in Table 1. . On the other hand, the heater was operated to heat the laminate through the lower electrode, and the heater was set to the temperature shown in Table 1. At this time, a part of the lower gap layer was removed by ion milling to obtain a trim structure.

  After obtaining the main magnetic pole precursor in this way, the side wall of the main magnetic pole precursor was removed by ion milling to obtain the main magnetic pole. At this time, the side wall portion of the main magnetic pole precursor was removed so that the end surface of the main magnetic pole on the air bearing surface side had a tapered shape.

Next, Al ₂ O ₃ was deposited by CVD until the main pole was completely filled to form an Al ₂ O ₃ film. Subsequently, the Al ₂ O ₃ film was planarized by CMP so that the main magnetic pole was exposed, and a buried layer was formed.

  Subsequently, an upper gap layer was stacked on the buried layer. Subsequently, an opening was formed on the end side opposite to the air bearing surface of the main magnetic pole. Next, after forming a thin film coil on the upper gap layer by plating, a gap layer was formed on the air bearing surface side by the same plating method.

  Then, an insulating layer was formed so as to cover the thin film coil, and then a resist was formed on the insulating layer. Then, an electrode film was formed on the gap layer and the resist, and a write shield was formed to obtain a recording head part. Finally, an overcoat layer was formed on the write shield to obtain a thin film magnetic head.

(Comparative Examples 1-7)
Except that the heater temperature, the flow rate ratio of the mixed gas of Cl ₂ gas, BCl ₃ gas and O ₂ gas, and the total flow rate ratio of Cl ₂ and BCl _{3 in} the etching gas were set to the values shown in Table 1, Examples 1 to In the same manner as in No. 8, a thin film magnetic head was obtained.

(Examples 9 to 14)
An FeCoZrO layer is used instead of the FeCo layer constituting the multilayer film, and the heater temperature, the flow rate ratio of the mixed gas of Cl ₂ gas, BCl ₃ gas and O ₂ gas, and the total flow rate of Cl ₂ and BCl _{3 in} the etching gas A thin film magnetic head was obtained in the same manner as in Examples 1 to 8, except that the ratio was set to the value shown in Table 1.

(Comparative Examples 8-12)
An FeCoZrO layer is used instead of the FeCo layer constituting the multilayer film, and the heater temperature, the flow rate ratio of the mixed gas of Cl ₂ gas, BCl ₃ gas and O ₂ gas, and the total flow rate of Cl ₂ and BCl _{3 in} the etching gas A thin film magnetic head was obtained in the same manner as in Examples 1 to 8, except that the ratio was set to the value shown in Table 1.

(Comparative Example 13)
A single layer film made of one FeCo layer is used instead of the multilayer film, and the heater temperature, the flow rate ratio of the mixed gas of Cl ₂ gas, BCl ₃ gas and O ₂ gas, and Cl ₂ and BCl ₃ in the etching gas are used. A thin film magnetic head was obtained in the same manner as in Examples 1 to 8, except that the total flow rate ratio was set to the values shown in Table 1.

(Examples 15 to 19 and Comparative Examples 14 to 15)
Example 1 except that the heater temperature, the flow rate ratio of the mixed gas of Cl ₂ gas, BCl ₃ gas and O ₂ gas, and the total flow rate ratio of Cl ₂ and BCl _{3 in} the etching gas were set to the values shown in Table 2. Similarly, a thin film magnetic head was obtained.

  During the production of the thin film magnetic head obtained as described above, the shape of the main magnetic pole precursor obtained by etching the main magnetic pole layer was observed from the air bearing surface side using a SEM (Scanning Electron Microscope). The results of Examples 1, 4, 7, 8, 9, 11, 13, and 14 are shown in FIG. 14 and Table 1, and the results of Examples 2, 3, 5, 6, 10, and 12 are shown in FIG. Show. Moreover, the result of Comparative Examples 1-12 is shown in FIG. 16 and Table 1, and the result of Comparative Example 13 is shown in FIG. 14, 15, 16, and Table 1, side etching of the main magnetic pole precursor can be sufficiently suppressed, and the main magnetic pole precursor can be formed substantially perpendicular to the surface of the lower gap layer. In this case, “◯” was displayed, and in particular, “◎” was displayed when the main magnetic pole precursor could be formed in a shape closer to the lower gap layer surface. When the side etching of the main magnetic pole precursor could not be sufficiently suppressed, “x” was displayed. From the results shown in FIGS. 14 to 17 and Table 1, according to the method for manufacturing the thin film magnetic head according to Examples 1 to 14, the main magnetic pole precursor compared to the method for manufacturing the thin film magnetic head according to Comparative Examples 1 to 13 It was found that the side etching of the main magnetic pole precursor can be sufficiently suppressed and the main magnetic pole precursor can be formed substantially perpendicular to the surface of the lower gap layer. In particular, according to the method for manufacturing a thin-film magnetic head according to Comparative Example 13, when the single-layer film is etched on the main magnetic pole layer under the same conditions as in Example 1, the end surface shape of the main magnetic pole precursor is tapered or trapezoidal. It was confirmed that

  For the thin film magnetic heads according to Examples 15 to 19 and Comparative Examples 14 to 15, the end face shape of the main magnetic pole precursor was observed in the same manner as in Examples 1 to 8, and the side wall surface and the lower gap layer of the main magnetic pole precursor were observed. The taper angle with the surface was measured. The results are shown in FIG. From the results shown in FIG. 18 and Table 2, when the multilayer film has a plurality of FeCo layers and a Ru layer provided between them, when the Co content in FeCo is 40 at% or less, the sidewalls of the multilayer film and the recording are recorded. It has been found that the taper angle between the gap layer and the gap layer is substantially vertical, but when it exceeds 40 at%, the taper angle is far from the vertical.

It is sectional drawing which shows the thin film magnetic head obtained using the manufacturing method of the thin film magnetic head of this invention. FIG. 2 is a cross-sectional view showing a main pole in the thin film magnetic head of FIG. 1. It is sectional drawing which shows 1 process of the manufacturing method of the thin film magnetic head of this invention. FIG. 4 is an enlarged cross-sectional view showing a main magnetic pole layer in FIG. 3. It is sectional drawing which shows 1 process of the manufacturing method of the thin film magnetic head of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the thin film magnetic head of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the thin film magnetic head of this invention. It is the schematic which shows the RIE apparatus used for 1 process of the manufacturing method of the thin film magnetic head of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the thin film magnetic head of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the thin film magnetic head of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the thin film magnetic head of this invention. It is a graph which shows the relationship between RF electric power and time in an RIE apparatus. It is sectional drawing which shows the modification of a main magnetic pole formation process. It is a figure which shows the SEM photograph which shows the shape of the multilayer film concerning Example 1, 4, 7, 8, 9, 11, 13, 14. It is a figure which shows the SEM photograph which shows the shape of the multilayer film which concerns on Example 2, 3, 5, 6, 10, 12. It is a figure which shows the SEM photograph which shows the shape of the multilayer film which concerns on Comparative Examples 1-12. It is a figure which shows the SEM photograph which shows the shape of the multilayer film concerning the comparative example 13. It is a graph which shows the relationship between the taper angle between the side wall of a multilayer film and a recording gap layer, and Co composition in the thin film magnetic head which concerns on Examples 15-19 and Comparative Examples 14-15.

Explanation of symbols

DESCRIPTION OF SYMBOLS 9 ... Lower gap layer (gap layer), 10 ... Main pole, 10a ... Ru layer, 10b ... FeCo layer, 19 ... Main pole layer, 31 ... Main pole precursor, 20a ... Mask, 100 ... Thin-film magnetic head, 100B ... Recording head section.

Claims (3)

In a manufacturing method of a thin film magnetic head having a main magnetic pole defining a track width in a recording medium on a gap layer, and a recording head portion in which an exposed surface on the air bearing surface side of the main magnetic pole has a tapered shape.
A main magnetic pole layer forming step for forming a main magnetic pole layer for forming the main magnetic pole on the gap layer;
Forming a mask on the main magnetic pole layer; and
A main magnetic pole precursor forming step for forming a main magnetic pole precursor by etching a portion of the main magnetic pole layer where the mask is not formed by flowing an etching gas; and
A main magnetic pole forming step of forming the main magnetic pole by removing a side wall portion of the main magnetic pole precursor,
In the main magnetic pole layer forming step, the main magnetic pole layer is a multilayer film including a plurality of layers made of FeCo containing 40 at% or less Co or FeCoZrO and a layer made of Ru provided between the plurality of layers. Configure
In the main magnetic pole precursor forming step, the etching gas is a mixed gas of Cl ₂ , BCl ₃ and O _2, and the total flow rate ratio of Cl ₂ and BCl _{3 in} the etching gas is 91.5 to 96% by volume. And a temperature of the main magnetic pole layer is set to 180 to 200 ° C. In a manufacturing method of a thin film magnetic head having a main magnetic pole defining a track width in a recording medium on a gap layer, and a recording head portion in which an exposed surface on the air bearing surface side of the main magnetic pole has a tapered shape.
A main magnetic pole layer forming step for forming a main magnetic pole layer for forming the main magnetic pole on the gap layer;
Forming a mask on the main magnetic pole layer; and
A main magnetic pole precursor forming step for forming a main magnetic pole precursor by etching a portion of the main magnetic pole layer where the mask is not formed by flowing an etching gas; and
A main magnetic pole forming step of forming the main magnetic pole by removing a side wall portion of the main magnetic pole precursor,
In the main magnetic pole layer forming step, the main magnetic pole layer is a multilayer film including a plurality of layers made of FeCo containing 40 at% or less Co or FeCoZrO and a layer made of Ru provided between the plurality of layers. Configure
In the main magnetic pole precursor forming step, the etching gas is a mixed gas of Cl ₂ , BCl ₃ and O _2, and the total flow rate ratio of Cl ₂ and BCl _{3 in} the etching gas is 91.5 to 94% by volume. And a temperature of the main magnetic pole layer is set to 180 to 250 ° C. 3. The thin film magnetic head according to claim 1, wherein in the main magnetic pole precursor forming step, the etching is performed by applying two stages of bias power so that the bias power of the previous stage is higher than the bias power of the subsequent stage. Method.

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