Manufacturing method for a thin film magnetic head

A thin film magnetic head is capable of reducing inductance by shortening a magnetic path, and also preventing a cavity from being formed in a coil insulating layer. The coil insulating layer is deposited on a lower core layer and at the rear of a recording portion, and a coil forming groove is formed in the coil insulating layer. Then, a coil layer is embedded in the coil forming groove. With this arrangement, bulges of the layers from an upper surface of the recording portion can be decreased so as to shorten a magnetic path.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a recording thin film magnetic head used with, for example, a flying magnetic head and, more particularly, to a thin film magnetic head adapted to reduce inductance and capable of handling higher recording frequencies, and a manufacturing method for the same.

2. Description of the Related Art

FIG. 27is a partial front view showing a construction of a conventional thin film magnetic head or inductive head, andFIG. 28is a partial sectional view of the thin film magnetic head cut along the line XXVIII—XXVIII shown inFIG. 27and viewed from the direction of an arrow.

Reference numeral1shown inFIGS. 27 and 28denotes a lower core layer formed of a magnetic material, such as Permalloy. An insulating layer9is deposited on the lower core layer1.

The insulating layer9includes a groove9ahaving an inner width represented by a track width Tw, the groove9aextending in a height direction or Y direction in the drawing, from a surface facing a recording medium (hereinafter referred to as “ABS” which stands for air bearing surface).

In the groove9a, a lower magnetic pole layer3magnetically connected to the lower core layer1, a gap layer46, and an upper magnetic pole layer5magnetically connected to an upper core layer48are deposited by sequentially plating in this order from bottom.

Referring toFIG. 28, a spirally formed coil layer7is provided on the insulating layer9in a portion in the height direction or the Y direction in the drawing from the groove9aformed in the insulating layer9.

The coil layer7is covered by a coil insulating layer47formed of a resist or the like, and an upper core layer48is deposited on the coil insulating layer47. The upper core layer48is magnetically connected with the upper magnetic pole layer5at a distal end portion48aand also magnetically connected to the lower core layer1at a proximal end portion48b.

In the inductive head shown inFIGS. 27 and 28, when recording current is supplied to the coil layer7, a recording field is induced in the lower core layer1and the upper core layer48. Magnetic signals are recorded in a recording medium, such as a hard disc, by a leakage field from between the lower magnetic pole layer3magnetically connected to the lower core layer1and the upper magnetic pole layer5magnetically connected to the upper core layer48.

In the inductive head shown inFIGS. 27 and 28, a lower magnetic pole layer3locally formed over the track width Tw, the gap layer46, and the upper magnetic pole layer5are provided in the vicinity of the surface facing the recording medium. This type of inductive head permits a narrower track.

The following will describe a manufacturing method for the inductive head shown inFIGS. 27 and 28. First, the insulating layer9is deposited on the lower core layer1, then the groove9ahaving the track width Tw is formed in the insulating layer9for a predetermined length in the height direction (depth direction) from the surface facing the recording medium (air bearing surface).

In the groove9a, the lower magnetic pole layer3, the gap layer46, and the upper magnetic pole layer5are continuously plated, then the coil layer7is pattern-deposited on a portion of the insulating layer9that is located behind (in the height direction) from the groove9aformed in the insulating layer9.

The coil layer7is covered by a coil insulating layer47, and the upper core layer48is formed from the top of the upper magnetic pole layer5to cover the coil insulating layer47by the flame plating process. This completes the inductive head shown inFIGS. 27 and 28.

For a trend toward higher recording densities and higher recording frequencies, it is necessary to reduce a track width and the inductance of an inductive head.

In order to reduce inductance, a magnetic path formed via the upper core layer48from the lower core layer1must be made shorter. This requires that a width T1of the coil layer7formed from the distal end portion48ato the proximal end portion48bof the upper core layer48be reduced. Reducing the width T1of the coil layer7allows the upper core layer48to be shortened so as to achieve a shorter magnetic path.

A method for forming the coil layer7by two layers could be applied to decrease the width T1of the coil layer7without changing the number of turns of the coil layer7.

In the construction of the thin film magnetic head shown inFIGS. 27 and 28, however, the magnetic path cannot be made sufficiently shorter to be able to handle higher recording frequencies in the future merely by providing the coil layer7with the double-layer construction. This makes it difficult to achieve an appropriate reduction in inductance.

A reason for the difficulty mentioned above is that the coil layer7is deposited on the insulating layer9having a thick film. Referring toFIG. 27, the insulating layer9has a film thickness H5, and the film thickness H5is larger than or substantially identical to a total film thickness H6of the lower magnetic pole layer3, the gap layer46, and the upper magnetic pole layer5. Therefore, as shown inFIG. 28, when a junction surface between the upper magnetic pole layer5and the upper core layer48is defined as a reference plane, the coil layer7deposited on the insulating layer9is positioned more closely to the upper core layer48than the reference plane.

Hence, adopting the double-layer construction directly to the coil layer7would lead to an extremely large height from the upper surface of the lower core layer1to the upper surface of the coil insulating layer47covering the coil layer7even though the width T1of the coil layer7can be reduced. As a result, the magnetic path cannot be shortened much, making it impossible to accomplish an appropriate reduction in inductance.

If the double-layer construction is simply applied to the coil layer7in the inductive head having the construction illustrated inFIG. 28, then a thickness H1of the coil insulating layer47covering the coil layer7increases, resulting in an extremely large bulge of the coil insulating layer47when the upper surface of the upper magnetic pole layer5is defined as the reference plane.

Accordingly, it becomes difficult to pattern-form the upper core layer48from above the upper magnetic pole layer5to cover the coil insulating layer47by the flame plating process, posing a problem in that a portion in the vicinity of the distal end portion48aof the upper core layer48cannot be formed into a predetermined shape.

If the width T2of each conductor of the coil layer7is decreased, and a height H2of each conductor is increased, then there should be no change in the volume of the coil layer, thus avoiding an increase in a coil resistance value. Furthermore, in this case, since the width T2of each conductor can be reduced, the width T1of the entire coil layer7can be reduced, permitting a further reduction in inductance by making a magnetic path even shorter.

On the other hand, however, another problem arises in that the increased height H2of each conductor inevitably leads to an even larger bulge of the coil insulating layer47covering the coil layer7, preventing the upper core layer48from being formed with high accuracy.

SUMMARY OF THE INVENTION

The present invention has been made with a view toward solving the problems, and it is an object of the present invention to provide a thin film magnetic head that permits a narrower track and reduced inductance by making a magnetic path shorter, and a manufacturing method for the same.

According to one aspect of the present invention, there is provided a thin film magnetic head comprising: a lower core layer; an upper core layer; and a recording portion that has magnetic pole layers and a gap layer positioned between the lower core layer and the upper core layer at a surface facing a recording medium, wherein a coil insulating layer is deposited on the lower core layer and at the rear of the recording portion in a height direction; a coil forming groove is formed in the coil insulating layer; and a coil layer for inducing a recording magnetic field to the lower core layer, the upper core layer, and the recording portion is embedded in the coil forming groove.

An object of the present invention is to realize a shorter magnetic path thereby to reduce inductance by forming a coil layer in a different position from a prior art so as to fabricate a thin film magnetic head capable of achieving a higher recording density and a higher recording frequency.

As described above, according to the present invention, the coil insulating layer is deposited on the lower core layer and at the rear in the height direction, the coil forming groove is formed in the coil insulating layer, and the coil layer is embedded in the coil forming groove.

More specifically, according to the present invention, the coil layer is formed at a position closer to the lower core layer as compared with the coil layer of the thin film magnetic head shown inFIG. 28. Hence, the present invention makes it possible to reduce the height from the top of the recording portion to the top of the insulating layer that covers the coil layer, as compared with the height in the thin film magnetic head shown inFIG. 28. Thus, the length of the upper core layer can be made smaller, allowing a more appropriate reduction in a magnetic path, with a consequent reduction in inductance.

According to the present invention, the coil forming groove is formed beforehand in the coil insulating layer deposited on the upper surface of the lower core layer, and the coil layer is embedded in the coil forming groove. This forming method is different from that for a coil insulating layer or a lower coil insulating layer disclosed in, for example, U.S. application Ser. No. 09/632,450.

To be more specific, according to the method disclosed in U.S. application Ser. No. 09/632,450, the coil layer is formed by the flame plating process, and the coil insulating layer is embedded in gaps between individual conductors of the coil layer. In this type of construction, the gaps are not completely filled with the coil insulating layer, leaving a danger of cavities being formed in the gaps.

Such cavities are apt to be produced because the coil insulating layer is isotropically formed by sputtering in extremely narrow coil gaps. If the cavities are formed, then a gas accumulating in the cavities expands due to heat generated when a magnetic head is driven, leading to a danger of causing a film in a thin film magnetic head to be deformed.

According to the present invention, the coil insulating layer is deposited on the entire surface of the lower core layer, the coil forming groove is formed in the coil insulating layer by, for example, a reactive ion etching process, and the coil layer is embedded in the coil forming groove.

Thus, in the invention, the coil insulating layer is not embedded in the extremely narrow gaps of the coil layer, eliminating the possibility of the problem in that cavities are produced in the coil insulating layer. Conversely, the coil layer is embedded in the coil forming groove according to the invention. Hence, although there is a danger of cavities being formed in the coil layer, the aforesaid problem can be solved by, for example, depositing the coil layer by electroplating or the like.

In a preferred form of the present invention, the upper surface of the coil insulating layer and the upper surface of the coil layer are flush with each other. In this case, it is preferable that the upper surface of the coil insulating layer and the upper surface of the coil layer have been etched using, for example, the CMP process.

In a preferred form of the present invention, when a junction surface between the recording portion and the upper core layer is defined as a reference plane, the upper surface of the coil insulating layer and the upper surface of the coil layer are flush with the reference plane.

Forming the coil layer such that its upper surface is flush with the reference plane makes it possible to maximize a thickness of the coil layer in a stepped portion between the lower core layer and the recording portion. Hence, decreasing the width of each conductor portion of the coil layer does not result in an increase in the coil resistance value that is inversely proportional to a sectional area. With this arrangement, the width of the entire coil layer ranging from the distal end portion to the proximal end portion of the upper core layer can be reduced, so that the magnetic path can be further shortened, permitting reduced inductance to be achieved.

In another preferred form of the invention, the coil insulating layer is an inorganic insulating layer formed of an inorganic material.

In yet another preferred form of the invention, an insulating under-layer is formed between the coil layer and the lower core layer. The insulating under-layer is deposited to provide appropriate magnetic insulation between the coil layer and the lower core layer. In the present invention, the insulating under-layer also serves as a stopper layer for preventing over-etching when the coil forming groove is formed in the coil insulating layer.

In a further preferred form of the invention, an insulating layer is deposited on the coil layer, and a second coil layer is deposited on the insulating layer. The second coil layer is electrically connected with the coil layer and induces a recording magnetic filed to the lower core layer, the upper core layer, and the recording portion. With this arrangement, the width of the coil layer can be further reduced and the magnetic path can be made even shorter with a consequent reduction in inductance.

In a further preferred form of the invention, the recording portion is constituted by a lower magnetic pole layer directly connected to the lower core layer, and a gap layer deposited on the lower magnetic pole layer, or constituted by an upper magnetic pole layer that is deposited on the lower core layer and directly connected with the upper core layer via a gap layer, or constituted by the lower magnetic pole layer directly connected with the lower core layer and an upper magnetic pole layer that is deposited on the lower magnetic pole layer via the gap layer and directly connected with the upper core layer. This arrangement makes it possible to fabricate a thin film magnetic head capable of achieving narrower gaps.

In another preferred form of the invention, the gap layer is composed of a nonmagnetic metal material that permits plating. Preferably, for the nonmagnetic metal material, one material or two or more different materials are selected from among NiP, NiPd, NiW, NiMo, Au, Pt, Rh, Pd, Ru, and Cr.

According to the invention, the recording portion may be constituted by a gap layer deposited on the lower core layer and an upper magnetic pole layer deposited on the gap layer, or the lower core layer may be provided with a protuberance jutting out toward an upper core layer integrally formed with the lower core layer, and the recording portion may be constituted by a gap layer deposited on the protuberance and the upper magnetic pole layer deposited on the gap layer.

In this case, the gap layer is preferably composed of an inorganic insulating material. As the inorganic insulating material, one material or two or more different materials are preferably selected from among Al2O3, SiO2, SiON, AlN, and AlSiN.

According to another aspect of the present invention, there is provided a manufacturing method for a thin film magnetic head, comprising:

(a) a step for depositing a recording portion composed of a magnetic pole layer and a gap layer on a lower core layer;

(b) a step for depositing a coil insulating layer on a lower core layer at the rear of the recording portion in a height direction;

(c) a step for depositing a resist layer on the coil insulating layer and forming a coil pattern on the resist layer by exposure;

(d) a step for etching the coil insulating layer exposed through the coil pattern of the resist layer to an extent, where a surface of the lower core layer is not reached, so as to form a coil forming groove in the coil insulating layer;

(e) a step for removing the resist layer;

(f) a step for embedding a conductive material in the coil forming groove formed in the coil insulating layer in step (d), thereby to deposit a coil layer in the coil forming groove;

(g) a step for etching the coil layer and the coil insulating layer such that, when an upper surface of the recording portion is defined as a reference plane, an upper surface of the coil insulating layer and an upper surface of the coil layer are flush with the reference plane; and

(h) a step for depositing an insulating layer on the coil layer and the coil insulating layer, then forming an upper core layer extending from the top of the insulating layer to the upper surface of the recording portion.

Thus, according to the present invention, after the recording portion is deposited on the lower core layer, the coil insulating layer is deposited over the entire surface of the lower core layer at the rear of the recording portion in the height direction.

Then, the resist layer having the coil pattern formed thereon is deposited on the coil insulating layer, the coil insulating layer exposed through the coil pattern formed in the resist layer is etched thereby to form a coil forming groove, which has substantially the same configuration as the coil pattern formed on the resist layer, in the coil insulating layer, then the coil layer is embedded in the coil forming groove.

According to the manufacturing method of the present invention, the coil layer can be formed in a step formed between the recording portion and the lower core layer. With this arrangement, the bulge of the insulating layer covering the coil layer that protrudes from the recording portion can be made smaller. As a result, a magnetic path can be made shorter and inductance can be reduced.

In the manufacturing method in accordance with the present invention, the coil insulating layer is first deposited on the lower core layer, then the coil forming groove is formed in the coil insulating layer. This arrangement prevents a problem in that a cavity is produced in the coil insulating layer, and also eliminates a danger in that a film in the thin film magnetic head is deformed due to heat generated when the magnetic head is driven.

Furthermore, according to the present invention, when the upper surface of the recording portion is defined as a reference plane, the coil layer and the coil insulating layer are etched in the step (g) so that the upper surface of the coil insulating layer and the upper surface of the coil layer are flush with the reference plane. Therefore, according to the present invention, the film thickness of the coil layer can be maximized in the stepped portion between the lower core layer and the recording portion. When the film thickness of the coil layer can be increased as mentioned above, reducing the width of each conductor portion of the coil layer does not cause the coil resistance value to increase. Hence, the width of the coil layer can be reduced to achieve an even shorter magnetic path.

In the present invention, the following step may be added between the step (b) and the step (c):

(i) a step for etching the coil insulating layer until its upper surface becomes flush with the upper surface of the recording portion.

In this step, the upper surface of the coil insulating layer can be formed into a flat surface since the surface of the coil insulating layer has been etched until the surface becomes flush with the upper surface of the recording portion after the coil insulating layer was deposited on the lower core layer. This provides an advantage in that the application of the resist layer and exposure of the resist layer in the subsequent step (c) can be performed with high accuracy.

In the present invention, the steps (a) and (b) may be replaced by the following steps:

(j) a step for depositing the coil insulating layer on the lower core layer;

(k) a step for forming a groove in the coil insulating layer in the height direction from a surface facing a recording medium; and

(l) a step for forming the recording portion composed of a magnetic pole layer and a gap layer in the groove.

From the step (j) to the step (l), the coil insulating layer is first deposited on the lower core layer, then the groove is formed in the coil insulating layer. In the groove, the recording portion is formed. In other words, the coil insulating layer and the recording portion are formed in a reverse order from the steps (a) and (b).

In a preferred form of the present invention, in the step (a) or (l), the recording portion is formed by the lower magnetic pole layer and the gap layer, or the gap layer and the upper magnetic pole layer, or the lower magnetic pole layer, the gap layer, and the upper magnetic pole layer.

In this case, for the gap layer, it is preferable to select a nonmagnetic metal material that permits plating together with the magnetic pole layers. Preferably, for the nonmagnetic metal material, one material or two or more different materials are selected from among NiP, NiPd, NiW, NiMo, Au, Pt, Rh, Pd, Ru, and Cr.

Alternatively, according to the present invention, in the step (a), the recording portion may be formed by the gap layer and the upper magnetic pole layer, or both side surfaces of the recording portion and the surface of the lower core layer may be etched to form a protuberance, which projects toward the recording portion from the top of the lower core layer and continues from the recording portion, so that the protuberance is made integral with the lower core layer after the recording portion is formed.

In this case, the gap layer is preferably composed of an inorganic insulating material. As the inorganic insulating material, one material or two or more different materials are preferably selected from among Al2O3, SiO2, SiON, AlN, and AlSiN.

In another preferred form of the present invention, to deposit the coil insulating layer on the lower core layer, an insulating under-layer is deposited on the lower core layer beforehand, and the coil forming groove is concavely formed in the coil insulating layer in the step (d) within a limit so that the surface of the insulating under-layer is not exposed.

The insulating under-layer serves as a “stopper layer” for preventing over-etching of the coil insulating layer in the step (d). Etching the coil insulating layer with the limit so that the surface of the insulating under-layer is not exposed ensures that at least the insulating under-layer lies between the lower core layer and the coil layer. This arrangement allows proper magnetic insulation to be provided between the lower core layer and the coil layer.

In the present invention, the coil insulating layer is preferably formed by an inorganic insulating material. This allows the surface of the coil insulating layer to be easily and properly etched in the step (g) or (i).

In a further preferred form of the present invention, in the step (h), after the insulating layer is deposited on the coil layer and the coil insulating layer, a second coil layer to be electrically connected to the coil layer is deposited on the insulating layer, then the upper core layer is formed on the second coil layer via the insulating layer. With this arrangement, the width of the coil layer can be further reduced, and inductance can be reduced by making the magnetic path shorter.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1is a partial front view showing a construction of a thin film magnetic head in accordance with an embodiment of the present invention, andFIG. 2is a partial sectional view of the thin film magnetic head cut along the line II—II shown inFIG. 1, observed from the direction of an arrow.

The thin film magnetic head shown inFIG. 1is a recording inductive head. In the present invention, a reproducing head utilizing magneto-resistance effect (MR head) may be provided under the inductive head.

Reference numeral10shown inFIGS. 1 and 2denotes a lower core layer formed by a magnetic material, such as Permalloy. When a reproducing head is provided under the lower core layer10, a shield layer for protecting a magneto-resistive element from noises may be provided separately from the lower core layer10, or the lower core layer10may serve as an upper shield layer of the reproducing head without providing the shield layer.

Referring toFIG. 1, an upper surface10aof the lower core layer10that extends from a proximal end of a lower magnetic pole layer11, which will be discussed hereinafter, may be formed such that it extends in a direction parallel to a track width or in an X direction, or may be provided with slopes10band10bthat incline in a direction away from an upper core layer16. Providing the upper surface of the lower core layer10with the slopes10band10bmakes it possible to properly prevent light fringing.

As shown inFIG. 1, a recording portion14is formed on the lower core layer10. In this embodiment, the recording portion14is a “track width restricting portion” having a track width Tw. The track width Tw is preferably 0.7 μm or less, and more preferably 0.5 μm or less. With this track width, a thin film magnetic head permitting a narrower track can be fabricated.FIG. 1does not show a plating under-layer40which is shown inFIG. 2and which will be discussed later.

In the embodiment illustrated inFIGS. 1 and 2, the recording portion14is constituted by a laminated three-layer film composed of the lower magnetic pole layer11, a gap layer12, and an upper magnetic pole layer13. The following will describe the magnetic pole layers11and13, and the gap layer12.

Referring toFIGS. 1 and 2, the lower magnetic pole layer11, which will be the bottommost layer of the recording portion14, is deposited by plating on the lower core layer10. The lower magnetic pole layer11is magnetically connected to the lower core layer10. The lower magnetic pole layer11may be formed by a material that is identical to or different from that of the lower core layer10, and may be composed of either a single-layer film or a multi-layer film.

As shown inFIGS. 1 and 2, the nonmagnetic gap layer12is deposited on the lower magnetic pole layer11.

According to the present invention, the gap layer12is preferably composed of a nonmagnetic metal material, and deposited by plating on the lower magnetic pole layer11. In the present invention, as the nonmagnetic metal material, it is preferable to select one material or two or more different materials from among NiP, NiPd, NiW, NiMo, NiRh, Au, Pt, Rh, Pd, Ru, and Cr. The gap layer12may be formed of either a single-layer film or a multi-layer film.

An upper magnetic pole layer13to be magnetically connected to the upper core layer16, which will be discussed hereinafter, is deposited by plating on the gap layer12. The upper magnetic pole layer13may be formed by a material that is identical to or different from that of the upper core layer16, and may be composed of either a single-layer film or a multi-layer film.

If the gap layer12is formed by a nonmagnetic metal material as described above, the lower magnetic pole layer11, the gap layer12, and the upper magnetic pole layer13can be sequentially deposited by plating.

In the present invention, the construction of the recording portion14is not limited to the laminated three-layer film as described above. For example, there is an embodiment according to the present invention, wherein the recording portion14is constituted by the lower magnetic pole layer11directly connected to the lower core layer10and the gap layer12deposited on the lower magnetic pole layer11, or the upper magnetic pole layer13on the lower core layer10, the upper magnetic pole layer13being directly connected to the upper core layer16via the gap layer12.

As mentioned above, the lower magnetic pole layer11and the upper magnetic pole layer13making up the recording portion14may be composed of a material identical to or different from that of the core layer to which the respective magnetic pole layers are magnetically connected. However, in order to improve a recording density, the lower magnetic pole layer11and the upper magnetic pole layer13facing the gap layer12preferably have a higher saturation magnetic flux density than the saturation magnetic flux density of the core layer to which the respective magnetic pole layers are magnetically connected. Thus, the higher saturation magnetic flux density of the lower magnetic pole layer11and the upper magnetic pole layer13makes it possible to concentrate a recording magnetic field in the vicinity of a gap with a resultant higher recording density.

As shown inFIG. 1, the recording portion14has a thickness H4. For example, the film thickness of the lower magnetic pole layer11is approximately 0.4 μm, the film thickness of the gap layer12is approximately 0.2 μm, and the film thickness of the upper magnetic pole layer13is approximately 2 μm.

Referring toFIG. 2, the recording portion14extends from the surface facing a recording medium (ABS) in the height direction or the Y direction in the drawing, and has a length L1.

The length L1is restricted as a gap depth Gd. The gap depth Gd significantly influences the electrical characteristics of the thin film magnetic head; therefore, the length L1is set to a predetermined value in advance.

In the embodiment shown inFIG. 1, the gap depth Gd is determined by the position where a Gd-defining insulating layer45is deposited over the lower core layer10. The gap depth Gd is adjusted by the length from the front end surface of the Gd-defining insulating layer45to the surface facing the recording medium (Air Bearing Surface: ABS).

In the present invention, as shown inFIG. 1, the coil insulating layer15on the lower core layer10is exposed to the surface facing the recording medium (ABS) at both sides of the recording portion14. The coil insulating layer15is located at the rear of the recording portion14in the height direction (depth direction) or the Y direction in the drawing, and deposited on the entire upper surface of the lower core layer10.

In the present invention, as shown inFIG. 2, the coil insulating layer15is provided with coil forming grooves15ain an area where a coil layer17is to be formed. The coil layer17is embedded in the coil forming grooves15a.

As shown inFIG. 2, preferably, an insulating under-layer18for securing insulation between the lower core layer and the coil layer is formed between the coil layer17and the lower core layer10. The insulating under-layer18is preferably formed by an insulating material composed of at least one of, for example, AlO, Al2O3, SiO2, Ta2O5, TiO, AlN, AlSiN, TiN, SiN, Si3N4, NiO, WO, WO3, BN, CrN, and SiON. The insulating under-layer18also functions as a “stopper layer” for preventing over-etching when forming the coil forming grooves15ain the coil insulating layer15in a manufacturing process.

The coil layer17embedded in the coil forming grooves15aprovided in the coil insulating layer15is formed according to a spiral pattern around a spiral center17a, and composed of a nonmagnetic conductive material, such as Cu, that has low electrical resistance.

In the present invention, as shown inFIG. 2, it is preferable that the upper surface of the coil insulating layer15is flush with the upper surface of the coil layer17. This makes it possible to maximize the thickness of the coil layer17within the range of the film thickness of the coil insulating layer15. Hence, decreasing the width of each conductor portion of the coil layer17does not result in an increase in the coil resistance value that is inversely proportional to a sectional area. Alternatively, the upper surface of the coil layer17may be lower than the upper surface of the coil insulating layer15.

To make the upper surface of the coil insulating layer15and the upper surface of the coil layer17flush with each other, the CMP process, for example, may be used to etch the upper surface of the coil insulating layer15and the upper surface of the coil layer17, as it will be described in conjunction with the manufacturing method, which will be discussed later. Thus, the upper surfaces of both the coil insulating layer15and the coil layer17will be etched.

Further, in the present invention, as shown inFIG. 2, when a junction surface between the recording portion14and the upper core layer16is defined as a reference plane A, it is preferable that the upper surface of the coil insulating layer15and the upper surface of the coil layer17are flush with the reference plane A. With this arrangement, the film thickness of the coil layer17can be maximized within a stepped portion formed between the recording portion14and the lower core layer10, and the width of the coil layer17can be properly reduced without causing an increase in the coil resistance value that is inversely proportional to the sectional area.

In the present invention, however, the reference plane A, the upper surface of the coil insulating layer15, and the upper surface of the coil layer17may not be formed to be flush, whereas they are flush in the example shown inFIG. 2. More specifically, the upper surface of the coil insulating layer15and the upper surface of the coil layer17may be formed to be higher or lower than the reference plane A.

It is not preferable to use an organic material for the coil insulating layer15because of the reason described below. As it will be described in detail hereinafter, when the upper surface of the coil insulating layer15and the upper surface of the coil layer17are etched using, for example, the CMP process, if the coil insulating layer15is composed of an organic material, then the stickiness peculiar to an organic material prevents proper etching of the upper surface of the coil insulating layer15, making it difficult to form the upper surface of the coil insulating layer15and the upper surface of the coil layer17to be flush.

Referring toFIG. 2, an insulating layer22composed of an organic material, such as a resist or polyimide, is deposited on the coil layer17and the coil insulating layer15. A second coil layer23is formed in a spiral pattern on the insulating layer22. A spiral center23aof the second coil layer23is electrically connected directly on the spiral center17aof the coil layer17that is flush with the junction surface between the recording portion14and the upper core layer16, namely, the reference plane A.

As shown inFIG. 2, the second coil layer23is covered by an insulating layer24composed of an organic material, such as a resist or polyimide. The upper core layer16composed of a magnetic material, such as Permalloy, is deposited on the insulating layer24by the flame plating process or the like.

As illustrated inFIG. 2, the upper core layer16has a distal end portion16athereof formed in contact with the recording portion14, while a proximal end portion16bthereof is in magnetic connection with a lifting layer or back gap layer25made of a magnetic material and formed on the lower core layer10. The lifting layer25may be omitted; if the lifting layer25is omitted, then the proximal end portion16bof the upper core layer16extends onto the lower core layer10to be in direct magnetic connection with the lower core layer10. Furthermore, as shown inFIG. 1, a width T3of the distal end portion16aof the upper core layer16is made larger than the track width Tw.

FIG. 3is a partial front view showing a construction of a thin film magnetic head in accordance with another embodiment of the present invention, andFIG. 4is a partial sectional view of the thin film magnetic head cut along the line IV—IV shown inFIG. 3, observed from the direction of the arrow.FIG. 3does not show the plating under-layer40which is shown inFIG. 4and which will be discussed later.

Reference numeral10shown inFIGS. 3 and 4denotes a lower core layer formed of a soft magnetic material with high permeability, such as a Fe—Ni type alloy or Permalloy.

In the present invention, as shown inFIG. 3, a coil insulating layer30composed of an insulating material is deposited on the lower core layer10. The insulating material is preferably an inorganic material composed of at least one of, for example, AlO, Al2O3, SiO2, Ta2O5, TiO, AlN, AlSiN, TiN, SiN, Si3N4, NiO, WO, WO3, BN, CrN, and SiON. The coil insulating layer30is formed of a single layer or a multiple layers.

Referring toFIG. 3, a thickest portion of the coil insulating layer30has a thickness H9. To be specific, the thickness H9preferably ranges from about 1.0 μm to about 4.0 μm.

According to the present invention, the coil insulating layer30has a groove30awhich extends from a surface30bof the coil insulating layer30onto the lower core layer10, and has a predetermined length L2from the surface facing a recording medium (ABS) in the height direction or the Y direction in the drawing.

Furthermore, as shown inFIG. 3, the groove30ahas a track width region H formed to have the track width Tw from the upper surface of the lower core layer10to a predetermined height H10, and a slope region B in which slope surfaces30cand30care formed such that the width of the groove30agradually increases, the slope region B extending from upper ends30dand30dof the track width region H to the surface30bof the coil insulating layer30. The groove30ais formed by, for example, anisotropic etching.

In the present invention, the width of the track width region H of the groove30a, i.e. the track width Tw, is formed to be 0.7 μm or less, and preferably 0.5 μm or less.

In the embodiment illustrated inFIG. 3, the recording portion14formed by a magnetic layer and a nonmagnetic gap layer is laminatedly formed in the track width region H.

The recording portion14is constituted by a lower magnetic pole layer11directly connected to the lower core layer10from below, a nonmagnetic gap layer12, and an upper magnetic pole layer13directly connected to an upper core layer16.

The gap layer12is preferably formed of a nonmagnetic metal material and formed by plating on the lower magnetic pole layer11. According to the present invention, as the nonmagnetic metal material, it is preferable to select one material or two or more different materials from among NiP, NiPd, NiW, NiMo, NiRh, Au, Pt, Rh, Pd, Ru, and Cr. The gap layer12may be formed of either a single-layer film or a multi-layer film.

The material and film configuration of the lower magnetic pole layer11and the upper magnetic pole layer13are the same as those of the lower magnetic pole layer11and the upper magnetic pole layer13shown inFIG. 1.

In the present invention, the construction of the recording portion14is not limited to the laminate construction of the three-layer film as described above. For example, there is an embodiment according to the present invention wherein the recording portion14is constituted by the lower magnetic pole layer11directly connected to the lower core layer10and the gap layer12deposited on the lower magnetic pole layer11, or the upper magnetic pole layer13on the lower core layer10, the upper magnetic pole layer13being directly connected to the upper core layer16via the gap layer12.

According to the present invention, as shown inFIG. 3, the upper core layer16extends from the tops of the slope surfaces30cand30cformed on the groove30ato a boundary C between the slope surfaces30cand30cand the surface30bof the coil insulating layer30, and further extends away from the lower core layer10(upward in the drawing) from the boundary C.

Referring toFIG. 3, a bottom surface of the upper core layer16is magnetically connected to the upper magnetic pole layer13. The upper core layer16is formed by a magnetic material, such as Permalloy, and may be formed of a material identical to or different from that of the upper magnetic pole layer13.

As shown inFIG. 3, a width T5of the upper core layer16in the track width direction or an X direction in the drawing is set to be larger than a width of the recording portion14formed in the track width region H, namely, the track width Tw. Setting the width T5of the upper core layer16to a larger value allows magnetic saturation to be restrained.

In the embodiment shown inFIG. 3, the film thickness of the coil insulating layer30is H9at a level in the vicinity of the boundary C between the slope30cof the groove30aand the surface30bof the coil insulating layer30. From the boundary C, the film thickness of the coil insulating layer30is gradually decreased away from the groove30a. It can be understood that the surfaces30bof the coil insulating layer30are formed to have a concave curve as shown inFIG. 1.

Thus, inFIG. 3, the surfaces30bof the coil insulating layer30are shaped to have the concave curve so that the film thickness of the coil insulating layer30gradually decreases from the groove30aaway from the groove30a. Alternatively, however, the coil insulating layer30may be formed to have virtually the same film thickness throughout, or the surfaces30bof the insulating layer30may be formed to have tapered surfaces or slope surfaces rather than the curved surfaces.

Referring toFIG. 4, the coil insulating layer30overlies the lower core layer10and extends at the rear of the recording portion14in the height direction or the X direction in the drawing. The coil insulating layer30is provided with coil forming grooves30e, and a coil layer17is embedded in the coil forming grooves30e.

In this embodiment, the insulating under-layer18shown inFIG. 2is not provided between a coil layer17and the lower core layer10. Instead, the coil insulating layer30is formed. The presence of the coil insulating layer30provides magnetic insulation between the coil layer17and the lower core layer10. The insulating under-layer18may, however, be provided between the coil layer17and the lower core layer10as shown inFIG. 2.

As shown inFIG. 4, the upper surface of the coil insulating layer30and the upper surface of the coil layer17are formed to be flush with each other so as to allow a maximum film thickness of the coil layer17within a range of the film thickness of the coil insulating layer30. It is preferable that the upper surface of the coil insulating layer30and the upper surface of the coil layer17have been etched. This may be achieved by using, for example, the CMP process, as it will be described hereinafter in conjunction with a manufacturing method.

When a junction surface between the recording portion14and the upper core layer16is defined as a reference plane A, it is preferable that the upper surface of the coil insulating layer30and the upper surface of the coil layer17are positioned to be flush with the reference plane A. This makes it possible to maximize the thickness of the coil layer17within a stepped portion between the recording portion14and the lower core layer10. Hence, decreasing the width of the coil layer17does not result in an increase in the coil resistance value that is inversely proportional to a sectional area. InFIG. 4, however, it can be seen that the upper surface of the coil insulating layer15and the upper surface of the coil layer17are positioned higher than the reference plane A.

Referring toFIG. 4, an insulating layer22is deposited on the upper surfaces of the coil insulating layer30and the coil layer17. A second coil layer23is formed in a spiral pattern on the insulating layer22. As shown inFIG. 4, a spiral center23aof the second coil layer23is directly formed on a spiral center17a of the coil layer17, which is a first layer, and the coil layer17and the second coil layer23are in electrical connection.

An insulating layer24is deposited on the second coil layer23, and the upper core layer16is deposited by, for example, the flame plating process so that it extends from the top of the recording portion14to the top of the insulating layer24. As shown inFIG. 4, a distal end portion16aof the upper core layer16is directly connected onto the recording portion14, while a proximal end portion16b is directly connected onto a lifting layer (back gap layer)25which is deposited on the lower core layer10and which is made of a magnetic material, thereby forming a magnetic path extending from the lower core layer10to the upper core layer16.

The embodiment shown inFIG. 2is different from the embodiment shown inFIG. 4in the manufacturing method, which will be described hereinafter.

In the embodiment shown inFIG. 2, the recording portion14is first deposited on the lower core layer10, then the coil insulating layer15is deposited over the lower core layer10at the rear of the recording portion14in the height direction. In the embodiment shown inFIG. 4, the coil insulating layer30is first deposited on the lower core layer10, then the groove30a(seeFIG. 3) is formed in the coil insulating layer30. Thereafter, the recording portion14is formed in the groove30a.

FIG. 5is a partial front view showing a construction of a thin film magnetic head in accordance with still another embodiment of the present invention.FIG. 6is a partial sectional view of the thin film magnetic head cut along the line VI—VI shown inFIG. 5.FIG. 5does not show a plating under-layer40which is shown inFIG. 6and which will be discussed hereinafter.

Reference numeral10shown inFIG. 5denotes a lower core layer formed of a soft magnetic material with high permeability, such as a Fe—Ni type alloy or Permalloy.

According to the present invention, a main coil insulating layer31composed of an insulating material and an auxiliary coil insulating layer32deposited on the main coil insulating layer31are deposited on the lower core layer10as shown inFIG. 5.

Preferably, both the main coil insulating layer31and the auxiliary coil insulating layer32are formed by inorganic insulating layers composed of an inorganic material. In this embodiment, however, an etching rate of the main coil insulating layer31is preferably larger than the etching rate of the auxiliary coil insulating layer32. More preferably, there is a difference of ten times or more in the etching rate.

The main coil insulating layer31is formed of at least one of, for example, AlO, SiO2, Ta2O5, TiO, AlN, AlSiN, TiN, SiN, NiO, WO, WO3, BN, CrN, and SiON. The main coil insulating layer31is composed of a single layer or multiple layers.

If, for example, the main coil insulating layer31is formed using SiO2, then the auxiliary coil insulating layer31is preferably formed using Al2O3and/or Si3N4.

If the main coil insulating layer31is formed using SiO2, the auxiliary coil insulating layer32is formed using Al2O3, and C3F8+(Ar) is employed as the gas for reactive ion etching process, then the etching rate of the main coil insulating layer31for the reactive ion etching process can be increased by approximately 15 times as compared with the etching rate of the auxiliary coil insulating layer32.

If the main coil insulating layer31is formed using SiO2, the auxiliary coil insulating layer32is formed using Si3N4, and C5F8+(Ar) is employed as the gas for the reactive ion etching process, then the etching rate of the main coil insulating layer31for the reactive ion etching process can be increased by approximately 15 times as compared with the etching rate of the auxiliary coil insulating layer32.

Referring toFIG. 5, the main coil insulating layer31is provided with a groove31ahaving a track width Tw. The groove31aextends to the rear in a predetermined length from a surface facing a recording medium in the height direction or the Y direction in the drawing. The track width Tw is preferably 0.7 μm or less, and more preferably 0.5 μm or less.

As shown inFIG. 5, the main coil insulating layer31has a thickness H6, and the thickness H6preferably ranges from about 1.0 μm to about 4.0 μm. Preferably, the auxiliary coil insulating layer32deposited on the main coil insulating layer31has a thickness H7. The thickness H7is preferably smaller than a thickness H6of the main coil insulating layer31. The auxiliary coil insulating layer32may be composed of a single-layer film or a multiple-layer film.

Referring toFIG. 5, a recording portion14composed of three layers, namely, a lower magnetic pole layer11, a nonmagnetic gap layer12, and an upper magnetic pole layer13in this order from bottom, is deposited in the groove31aprovided in the main coil insulating layer31.

The gap layer12is preferably formed of a nonmagnetic metal material and deposited by plating on the lower magnetic pole layer11. According to the present invention, as the nonmagnetic metal material, it is preferable to select one material or two or more different materials from among NiP, NiPd, NiW, NiMo, NiRh, Au, Pt, Rh, Pd, Ru, and Cr. The gap layer12may be formed of either a single-layer film or a multi-layer film.

The material and film configuration of the lower magnetic pole layer11and the upper magnetic pole layer13are the same as those of the lower magnetic pole layer11and the upper magnetic pole layer13shown inFIG. 1.

In the present invention, the construction of the recording portion14is not limited to the laminate construction of the three-layer film as described above. For example, there is an embodiment according to the present invention wherein the recording portion14is constituted by the lower magnetic pole layer11directly connected to the lower core layer10and the gap layer12deposited on the lower magnetic pole layer11, or the upper magnetic pole layer13on the lower core layer10, the upper magnetic pole layer13being directly connected to the upper core layer16via the gap layer12.

Referring toFIG. 5, the auxiliary coil insulating layer32on the main coil insulating layer31is provided with slope surfaces32aand32athat gradually spread in the direction of the track width or in an X direction in the drawing, extending from the upper end of the groove31aformed in the main coil insulating layer31to the auxiliary coil insulating layer32.

Furthermore, an upper core layer16is formed by the flame plating process or the like, extending from the surface of the upper magnetic pole layer13deposited in the groove31aover to the tops of the slope surfaces32a. Preferably, the upper core layer16is deposited so that it extends to a boundary C between the slope surfaces32aand a surface32bof the auxiliary coil insulating layer32. Forming the upper core layer16so that it extends to the boundary C allows the width of the upper core layer16to be increased, minimizing chances of occurrence of magnetic saturation at a higher recording density in the future.

Referring toFIG. 6, the main coil insulating layer31and the auxiliary coil insulating layer32overlie the lower core layer10at the rear of the recording portion14in a height direction or in a Y direction in the drawing.

Furthermore, as shown inFIG. 6, coil forming grooves31cand32care continuously formed in the auxiliary coil insulating layer32and the main coil insulating layer31. A coil layer17is embedded in the coil forming grooves31cand32c.

In this embodiment, the insulating under-layer18shown inFIG. 2is not formed between the coil layer17and the lower core layer10. Instead, the main coil insulating layer31is formed. The presence of the main coil insulating layer31provides magnetic insulation between the coil layer17and the lower core layer10. The insulating under-layer18may, however, be provided between the coil layer17and the lower core layer10as shown inFIG. 2.

As shown inFIG. 6, the upper surface of the auxiliary coil insulating layer32and the upper surface of the coil layer17are formed to be flush with each other so as to allow a maximum film thickness of the coil layer17within a range of the film thickness of the main coil insulating layer31and the auxiliary coil insulating layer32. It is preferable that the upper surface of the auxiliary coil insulating layer32and the upper surface of the coil layer17have been etched. This may be achieved by using, for example, the CMP process, as it will be described hereinafter in conjunction with a manufacturing method.

When a junction surface between the recording portion14and the upper core layer16is defined as a reference plane A, it is preferable that the upper surface of the auxiliary coil insulating layer32and the upper surface of the coil layer17are positioned to be flush with the reference plane A. This makes it possible to maximize the thickness of the coil layer17within a stepped portion between the recording portion14and the lower core layer10. Hence, decreasing the width of the coil layer17does not result in an increase in the coil resistance value that is inversely proportional to a sectional area. InFIG. 6, however, it can be seen that the upper surface of the auxiliary coil insulating layer32and the upper surface of the coil layer17are positioned higher than the reference plane A.

Referring toFIG. 6, an insulating layer22is deposited on the upper surfaces of the auxiliary coil insulating layer32and the coil layer17. A second coil layer23is deposited in a spiral pattern on the insulating layer22. As shown inFIG. 6, a spiral center23aof the second coil layer23is directly formed on a spiral center17aof the coil layer17, which is a first layer, and the coil layer17and the second coil layer23are in electrical connection.

An insulating layer24is deposited on the second coil layer23, and the upper core layer16is formed by, for example, the flame plating process so that it extends from the top of the recording portion14to the top of the insulating layer24. As shown inFIG. 6, a distal end portion16aof the upper core layer16is directly connected onto the recording portion14, while a proximal end portion16bis directly connected onto a lifting layer (back gap layer)25which is deposited on the lower core layer10and which is made of a magnetic material, thereby forming a magnetic path extending from the lower core layer10to the upper core layer16.

In this embodiment, as in the case of the embodiment shown inFIGS. 3 and 4, the main coil insulating layer31and the auxiliary coil insulating layer32are first laminatedly deposited on the lower core layer10, then the slope surfaces32aand32aare formed on the auxiliary coil insulating layer32. Thereafter, the groove31aof the main coil insulating layer31is formed, and the recording portion14is formed in the groove31a.

FIG. 7is a partial front view showing a construction of a thin film magnetic head in accordance with still another embodiment of the present invention.FIG. 8is a partial sectional view of the thin film magnetic head cut along the line VIII—VIII shown inFIG. 7.

Reference numeral10shown inFIG. 7denotes a lower core layer formed of a soft magnetic material with high permeability, such as a Fe—Ni type alloy or Permalloy.

According to the present invention, a recording portion14constituted by a nonmagnetic gap layer33and an upper magnetic pole layer36directly connected to an upper core layer16is deposited on the lower core layer10, as shown inFIG. 7. The recording portion14has a track width Tw.

The gap layer is preferably formed of an inorganic insulating material. In this case, for the inorganic insulating material, it is preferable to select one material or two or more different materials from among Al2O3, SiO2, SiON, AlN, and AlSiN.

Referring toFIG. 7, an upper surface10aof the lower core layer10that extends from a proximal end of the gap layer33may be formed such that it extends in a direction parallel to a track width or in an X direction in the drawing, or may be provided with slopes10band10bthat incline in a direction away from an upper core layer16. Providing the upper surface of the lower core layer10with the slopes10band10bmakes it possible to further properly prevent light fringing.

As shown inFIG. 7, if the lower core layer10is etched to portions denoted by10c, the lower core layer10is provided with a protuberance10djutting out toward the upper core layer16, and the recording portion14is formed on the protuberance10d, then the occurrence of light fringing can be further restrained.

The protuberance10dhas a track width Tw and a height H11. The height H11ranges, for example, from 0.2 μm to 0.5 μm.

Coil insulating layers34are deposited on both sides of the recording portion14in a track width direction or an X direction in the drawing, as shown inFIG. 7. Furthermore, the upper core layer16having a larger width than the track width Tw is formed from above the recording portion14onto the coil insulating layer34. Alternatively, the width of the upper core layer16may be the track width Tw, as indicated by dashed lines in the drawing.

Referring toFIG. 8, the coil insulating layer34is deposited on the lower core layer10at the rear of the recording portion14in a height direction or a Y direction in the drawing. Coil forming grooves34aare formed in the coil insulating layer34, and a coil layer17is embedded in the coil forming grooves34a.

The embodiment shown inFIG. 8does not have the insulating under-layer18between the lower core layer10and the coil layer17as shown inFIG. 2. Alternatively, however, the insulating under-layer18may be formed between the lower core layer10and the coil layer17, as shown inFIG. 2.

In this embodiment, a gap layer33deposited on the lower core layer10lies between the lower core layer10and the coil layer17. The gap layer33can be used as a stopper layer just like the insulating under-layer18.

Referring toFIG. 8, a Gd-defining insulating layer45is deposited on the gap layer33. The gap depth (Gd) is determined by a length L3from a front end surface of the Gd-defining insulating layer45to a surface facing a recording medium.

The coil layer17embedded in the coil forming grooves34aprovided in the coil insulating layer34is formed according to a spiral pattern around a spiral center17a, and composed of a nonmagnetic conductive material, such as Cu, that has low electrical resistance.

In the present invention, as shown inFIG. 8, it is preferable that the upper surface of the coil insulating layer34is flush with the upper surface of the coil layer17. This makes it possible to maximize the thickness of the coil layer17within the range of the film thickness of the coil insulating layer34. Hence, decreasing the width of each conductor portion of the coil layer17does not result in an increase in the coil resistance value that is inversely proportional to a sectional area.

To make the upper surface of the coil insulating layer34and the upper surface of the coil layer17flush with each other, the CMP process, for example, may be used to etch the upper surface of the coil insulating layer34and the upper surface of the coil layer17. Thus, the upper surfaces of both the coil insulating layer34and the coil layer17will be etched.

Further, in the present invention, as shown inFIG. 8, when a junction surface between the recording portion14and the upper core layer16is defined as a reference plane A, it is preferable that the upper surface of the coil insulating layer34and the upper surface of the coil layer17are flush with the reference plane A. With this arrangement, the film thickness of the coil layer17can be maximized within a stepped portion formed between the recording portion14and the lower core layer10, and the width of the coil layer17can be properly reduced without causing an increase in the coil resistance value that is inversely proportional to the sectional area.

Referring toFIG. 8, an insulating layer22composed of an organic material, such as a resist or polyimide, is deposited on the coil layer17and the coil insulating layer34. A second coil layer23is deposited in a spiral pattern on the insulating layer22. A spiral center23aof the second coil layer23is magnetically connected directly on the spiral center17aof the coil layer17that is flush with the junction surface between the recording portion14and the upper core layer16, namely, the reference plane A.

As shown inFIG. 8, the second coil layer23is covered by an insulating layer24composed of an organic material, such as a resist or polyimide. The upper core layer16composed of a magnetic material, such as Permalloy, is deposited on the insulating layer24by flame plating process or the like.

As illustrated inFIG. 8, the upper core layer16has a distal end portion16athereof formed in contact with the recording portion14, while a proximal end portion16bthereof is in magnetic connection with a lifting layer or back gap layer25made of a magnetic material and deposited on the lower core layer10. The lifting layer25may be omitted; if the lifting layer25is omitted, then the proximal end portion16bof the upper core layer16extends onto the lower core layer10to be in direct magnetic connection with the lower core layer10.

This embodiment is different from the thin film magnetic head shown inFIG. 1throughFIG. 6in that the gap layer33constituting the recording portion14is deposited on the lower core layer10such that it extends farther at the rear in the height direction than an upper magnetic pole layer36. To fabricate the recording portion14and the coil insulating layer34of a thin film magnetic head shown inFIG. 8, the gap layer33is first deposited on the lower core layer10, then the upper magnetic pole layer36is deposited on the gap layer33. Thereafter, the coil insulating layer34is deposited on the gap layer33at the rear of the upper magnetic pole layer36in the height direction.

In the inductive heads shown inFIG. 1throughFIG. 8described in detail above, when a recording current is applied to the coil layer17and the second coil layer23, a recording magnetic field is induced in the lower core layer10and the upper core layer16. A magnetic signal is recorded in a recording medium, such as a hard disk, by a leakage field from between the upper core layer16and the magnetic pole layer directly connected to the lower core layer10or between the magnetic pole layer and the other core layer if the magnetic pole layer is deposited on only one core layer.

According to the present invention, all the thin film magnetic heads shown inFIG. 1throughFIG. 8share the same construction in which the coil insulating layer is deposited on the lower core layer, the coil forming grooves are formed in the coil insulating layer, and the coil layer17is embedded in the coil forming grooves.

As shown inFIGS. 2,4,6, and8, the recording portion14is formed on the lower core layer10and in the vicinity of the surface facing a recording medium, the coil insulating layer is deposited at the rear of the recording portion14in the height direction or in the Y direction in the drawings, and the coil layer is embedded in the coil forming grooves provided in the coil insulating layer. With this arrangement, the heights of the individual layers bulging from the upper surface of the recording portion14can be reduced. Hence, even if the coil layer employs a double-layer construction, the height of the insulating layer24covering the second coil layer23that bulges from the upper surface of the recording portion14can be controlled to a minimum.

Therefore, when depositing the upper core layer16that extends from the upper surface of the recording portion14to the upper surface of the insulating layer24by the flame plating process, the possibility of occurrence of irregular reflection or the like can be minimized during exposure, permitting the upper core layer16to be formed in a predetermined shape with high accuracy.

According to the present invention, there is no need to employ the double-layer structure for the coil layers; the coil layer may be formed of a single layer, that is, only the coil layer17. In this case, the insulating layer22is deposited on the coil layer17, and the upper core layer16is formed using the flame plating process or the like such that the upper core layer16extends from the upper surface of the recording portion14to the upper surface of the insulating layer22.

When the coil layer17is deposited of a single layer, a deposited film that bulges from the upper surface of the recording portion14will have only the film thickness of the insulating layer22. Hence, the upper core layer16can be formed in a predetermined configuration with higher accuracy from the upper surface of the recording portion14to the upper surface of the insulating layer22.

According to the present invention, the coil insulating layer15is deposited on the entire surface of the lower core layer10beforehand, the coil forming grooves are formed in the coil insulating layer by using a resist, then the coil layer17is embedded in the coil forming grooves. This arrangement eliminates a danger of occurrence of defects, such as cavities, in the coil insulating layer of a fabricated thin film magnetic head.

More specifically, if, for example, the coil layer17is first deposited on the lower core layer10by the flame plating process or the like, then the gaps between the conductor portions of the coil layer17are filled with the coil insulating layer, then the coil insulating layer tends to incur cavities when the coil insulating layer is deposited by sputtering or the like. Such cavities lead to a danger in that, for example, heat generated when the magnetic head is driven causes an expansion of a gas accumulating in the cavities, resulting in deformation of the configuration of a film in the thin film magnetic head.

To avoid the above problem, in the present invention, the coil insulating layer is first deposited by the flame plating process, then the coil layer17is embedded in the coil forming grooves formed in the coil insulating layer. This arrangement eliminates the possibility of the defects, such as cavities, in the coil insulating layer. Hence, the heat generated when the magnetic head is driven should not lead to occurrence of problems, such as the deformation of the configuration of a film in the thin film magnetic head.

In the present invention, however, there is a danger of the coil layer17incurring defects, including the cavities, since the coil layer17is embedded in the coil forming grooves. This problem can be solved by depositing the coil layer17by the metal plating process or the like.

The coil layers in the thin film magnetic heads according to the embodiments shown inFIGS. 2,4,6, and8are composed of two laminated layers. The laminated double-layer coil structure is employed in order to reduce a width T4of the coil layer17thereby to reduce a length from the distal end portion16ato the proximal end portion16bof the upper core layer16. Thus, the magnetic path formed from the lower core layer10via the upper core layer16can be shortened so as to decrease the inductance. This arrangement makes it possible to manufacture a thin film magnetic head capable of handling still higher recording frequencies in the future. For example, it has been verified that, if the coil layer17, which is the first layer, is formed with five turns, and the second coil layer23is formed with four turns, then the width T4of the coil layer17can be reduced to approximately 20 μm.

As described above, the coil layer17, which is the first layer, is located at the rear of the recording portion14in the height direction, and when the junction surface between the recording portion14and the upper core layer16is defined as the reference plane A, the upper surface of the coil layer17is positioned to be flush with the reference plane A. With this arrangement, the height from the upper surface of the recording portion14to the upper surface of the bulging insulating layer24can be reduced, as compared with the case of the conventional thin film magnetic head (seeFIG. 28) having the two laminated layers constituting the coil layers.

Thus, the present invention allows the width of the coil layer to be reduced, and also allows the height in a direction Z in the drawing from the top of the lower core layer10to be reduced. As a result, the length from the distal end portion16ato the proximal end portion16bof the upper core layer16can be properly reduced, the magnetic path can be made even shorter, and the inductance can be accordingly reduced, making it possible to fabricate a thin film magnetic head capable of achieving a higher recording frequency in the future.

The thin film magnetic heads in accordance with the present invention are also capable of achieving narrower tracks. As described above, the present invention allows the track width Tw of the recording portion14to be reduced to 0.7 μm or less, preferably 0.5 μm or less, which is a value smaller than a limit value of a resolution when a resist is subjected to exposure.

According to the present invention, when the junction surface between the recording portion14and the upper core layer16is defined as the reference plane A, the upper surface of the coil layer17and the upper surface of the coil insulating layer15are positioned to be flush with the reference plane A. Hence, the flat surface extends in the height direction from the reference plane A, so that the layers can be formed without waviness.

Thus, the insulating layer22can be planarized and deposited on the coil insulating layer15and the coil layer17, and therefore, the second coil layer23can be deposited on the insulating layer22with high pattern accuracy.

FIG. 9throughFIG. 17illustrate manufacturing steps of the thin film magnetic head shown inFIG. 2.

Referring toFIG. 9, a plating under-layer40composed of a magnetic material, such as Permalloy, is first deposited on the lower core layer10, the Gd-defining insulating layer45that determines a gap depth is deposited, then a resist layer41is applied onto the plating under-layer40. A thickness H8of the resist layer41must be larger than at least the thickness H4of the recording portion14in the completed thin film magnetic head shown inFIG. 1.

Subsequently, the resist layer41is subjected to exposure to form a groove41athat has a predetermined length in the height direction (the Y direction shown in the drawing) from the surface facing a recording medium, and also has a predetermined width in the track width direction (the X direction shown in the drawing). Then, the recording portion14is formed in the groove41a.

Referring toFIG. 9, the recording portion14is constituted by the lower magnetic pole layer11, the gap layer12, and the upper magnetic pole layer13in this order from bottom, these layers being sequentially deposited by plating.

The film construction of the recording portion14formed in the groove41ais not limited to the constructions of the foregoing three layers. More specifically, the recording portion14may be constructed by the lower magnetic pole layer11and the nonmagnetic gap layer12, or by the nonmagnetic gap layer12and the upper magnetic pole layer13. Each of the magnetic pole layers11and13and the gap layer12may be composed of either a single layer or multiple layers.

Preferably, the gap layer12is formed by plating together with the magnetic pole layers11and13. For the nonmagnetic metal material that permits plating for depositing the gap layer12, one material or two or more different materials are preferably selected from among NiP, NiPd, NiW, NiMo, Au, Pt, Rh, Pd, Ru, and Cr.

In a step shown inFIG. 10, a state is illustrated wherein the resist layer41has been removed. On the lower core layer10, the recording portion14is formed in the vicinity of the ABS. In some cases, after the recording portion14is formed, the lifting layer25is formed at a position away from the recording portion14in the height direction.

It is possible to etch both side surfaces of the recording portion14shown inFIG. 10(the side surfaces in the X direction in the drawing) from the track width direction (the X direction in the drawing) by ion milling thereby to reduce the width of the recording portion14. The width of the recording portion14obtained by the ion milling is defined as the track width Tw.

The ion milling also etches the upper surface of the lower core layer10in the track width direction (the X direction in the drawing) that extends from the proximal end of the lower magnetic pole layer11, thus forming the slopes10band10bon the upper surface of the lower core layer10as shown inFIG. 1.

In a step illustrated inFIG. 11, the insulating under-layer18composed of an insulating material is deposited by sputtering such that the insulating under-layer18extends from the top of the recording portion14onto the magnetic under-layer40, and further onto the top of the lifting layer25in the height direction.

Subsequently, as shown inFIG. 11, the coil insulating layer15overlies the lower core layer10via the magnetic under-layer40and the insulating under-layer18. The coil insulating layer15may alternatively be deposited only on the lower core layer10. In this embodiment, however, the coil insulating layer15is deposited over the recording portion14and the lifting layer25.

In the next step, the coil insulating layer15is etched by employing, for example, the CMP process to the line D—D shown inFIG. 11to expose the surface of the recording portion14so as to make the upper surface of the coil insulating layer15flush with the upper surface of the recording portion14as shown inFIG. 12.

In a step illustrated inFIG. 13, a resist layer42is applied to the surface of the coil insulating layer15that has been planarized by the CMP process, then a coil pattern42ais formed in the resist layer42by exposure.

The surface of the coil insulating layer15exposed through the coil pattern42aformed in the resist layer42is etched by the reactive ion etching process or the like thereby to form coil forming grooves15ain the coil insulating layer15, the coil forming grooves15ahaving substantially the same configuration as that of the coil pattern42aformed in the resist layer42. Thereafter, the resist layer42is removed, which is illustrated inFIG. 14.

In the steps described above, it is necessary to properly adjust an etching time and so forth in order to concavely etch the coil forming grooves15ain the coil insulating layer15exposed through the coil pattern42aof the resist layer42. The etching time should be set so that the etching is stopped as soon as the surface of the insulating under-layer18is exposed.

The insulating under-layer18is provided to secure magnetic insulation between the lower core layer10and a coil layer17, which will be discussed hereinafter. In the present invention, the insulating under-layer18also functions as a stopper layer for preventing over-etching when the coil insulating layer15is etched.

If the insulating under-layer18is not provided, then it is required properly adjust the etching time, etc. to etch the coil insulating layer15with a limit so that the lower core layer10is not exposed. If the coil insulating layer15should be over-etched until the lower core layer10is exposed, then the magnetic insulation cannot be provided between the lower core layer10and the coil layer17. This would lead to a necessity of providing an additional insulating layer on the lower core layer10, complicating the manufacturing process.

In a step illustrated inFIG. 15, a conductive material, such as Cu, is embedded in the coil forming grooves15aformed in the coil insulating layer15thereby to form the coil layer17in the coil forming grooves15a. In the embodiment shown inFIG. 15, the coil layer17is deposited on the recording portion14, the coil insulating layer15, and further on the lifting layer25. In other words, the coil layer17produces a state wherein all conductor portions embedded in the coil forming grooves15aare connected on the coil insulating layer15.

To embed the coil layer17in the coil forming grooves15aprovided in the coil insulating layer15, an existing method, such as the electroplating process, the sputtering process, or the CVD process, may be used.

In the electroplating process among the available processes mentioned above, plating under-layers are first deposited on the recording portion14, the coil insulating layer15, the lifting layer25, and in the coil forming grooves15aprovided in the coil insulating layer15, then, plating layers are grown on the plating under-layer. Thus, the coil layer17as shown inFIG. 15can be formed.

As previously mentioned, the coil layer17could be formed using the sputtering process; however, using the sputtering process may cause a cavity in the coil layer17to be embedded in the coil forming grooves15a. Preferably, therefore, the electroplating process or the CVD process is used.

Next, as illustrated inFIG. 15, the coil layer17projecting from the top of the coil insulating layer15is removed. The coil layer17is etched to the line E—E by using, for example, the CMP process in order to accommodate the conductor portions of the coil layer17only within the coil forming grooves15a. Thus, the coil layer17is accommodated only in the coil forming grooves15aformed in the coil insulating layer15. In this step, when the upper surface of the recording portion14is defined as a reference plane, the upper surface of the coil insulating layer15and the upper surface of the coil layer17become flush with the reference plane. As shown inFIG. 15, when the coil layer17is etched to the line E—E, the surface of the coil insulating layer15is also etched. This state is illustrated inFIG. 16.

As set forth above, inFIG. 16, the coil layer17is in the coil forming grooves15aprovided in the coil insulating layer15, and when the upper surface of the recording portion14is defined as the reference plane, the upper surface of the coil insulating layer15and the upper surface of the coil layer17are flush with the reference plane.

Then, as illustrated inFIG. 17, the insulating layer22is deposited on the coil insulating layer15and the coil layer17. If the second coil layer23is deposited, the second coil layer23is pattern-deposited on the insulating layer22by the flame plating process, then the second coil layer23is covered by the insulating layer24. Thereafter, the upper core layer16is deposited, beginning from the top of the recording portion14onto the insulating layer24. To deposit the upper core layer16, the distal end portion16aof the upper core layer16is directly connected to the top of the recording portion14, and the proximal end portion16bis directly connected onto the lifting layer25, as illustrated inFIG. 17.

FIG. 18throughFIG. 20show steps of another manufacturing method for the thin film magnetic head shown inFIG. 2. The steps shown inFIG. 18 through 20are the modifications of the steps shown inFIG. 9throughFIG. 17; therefore, some steps shown inFIG. 9throughFIG. 17will be referred to in the following descriptions.

First, as shown inFIGS. 9 and 10, the recording portion14is formed on the lower core layer10by making use of the resist layer41, and the lifting layer25is further deposited. Then, as shown inFIG. 11, the coil insulating layer15is deposited so that the layer15extends from the top of the recording portion14to the top of the lower core layer10, and further onto the lifting layer25by the sputtering process or the like.

Subsequently, as illustrated inFIG. 18, a resist layer43is applied onto the coil insulating layer15, and a coil pattern43ais formed in the resist layer43by exposure.

Then, the coil insulating layer15exposed through the coil pattern43aformed in the resist layer43is etched by the reactive ion etching process or the like thereby to form coil forming grooves15ain the coil insulating layer15, the coil forming grooves15ahaving the same configuration as that of the coil pattern43aformed in the resist layer43. A state wherein the resist layer43has been removed is illustrated inFIG. 19.

It is necessary to properly adjust an etching time and so forth in order to form the coil forming grooves15ain the coil insulating layer15. The etching time should be set so that etching is stopped as soon as the surface of the insulating under-layer18is exposed.

The insulating under-layer18is provided to secure magnetic insulation between the lower core layer10and the coil layer17. In the present invention, the insulating under-layer18also functions as a stopper layer for preventing over-etching when the coil insulating layer15is etched.

If the insulating under-layer18is not provided, then it is required to properly adjust the etching time, etc. to etch the coil insulating layer15with a limit so that the lower core layer10is not exposed.

In a step illustrated inFIG. 20, a conductive material is embedded in the coil forming grooves15aformed in the coil insulating layer15thereby to form the coil layer17. In the embodiment shown inFIG. 20, the coil layer17is deposited on the recording portion14, the coil insulating layer15, and further on the lifting layer25.

The coil layer17is deposited by the electroplating process, the sputtering process, the CVD process, etc. If the sputtering process among the above methods is employed to deposit the coil layer17, defects, such as cavities, are apt to be produced in the coil layer17when embedding the coil layer17in the coil forming grooves15aprovided in the coil insulating layer15. Therefore, it is preferred to use the electroplating or CVD process.

Next, as illustrated inFIG. 20, the coil layer17is etched to the line F—F by using, for example, the CMP process. By etching the coil layer17to the line F—F, the conductor portions of the coil layer17are accommodated only within the coil forming grooves15a. When the upper surface of the recording portion14is defined as a reference plane, the upper surface of the coil insulating layer15and the upper surface of the coil layer17become flush with the reference plane. When the coil layer17is etched to the line F—F, the surface of the coil insulating layer15is also etched. The state wherein the coil layer17has been etched to the line F—F is the same as that illustrated inFIG. 16. Thereafter, as in the case of the step shown inFIG. 17, the insulating layer22, the second coil layer23, the insulating layer24, and the upper core layer16are formed in this order.

Implementing the steps illustrated inFIG. 18throughFIG. 20to fabricate the thin film magnetic head shown inFIG. 2will involve only one etching process for a predetermined layer by using the CMP process (FIG. 20). This permits a simplified manufacturing process to be achieved.

When the steps illustrated inFIG. 9throughFIG. 17are carried out to fabricate the thin film magnetic head shown inFIG. 2, it is necessary to implement the steps for etching predetermined layers by using the CMP process shown inFIGS. 11 and 15. On the other hand, the surface of the coil insulating layer15is planarized in the step ofFIG. 12, so that the resist layer42can be easily formed on the coil insulating layer15with high accuracy.

FIG. 21throughFIG. 27illustrate steps of the manufacturing process for the thin film magnetic head shown inFIG. 4.

First, as shown inFIG. 21, the plating under-layer40is deposited on the lower core layer10, then the coil insulating layer30is deposited on the plating under-layer40.

As illustrated inFIG. 21, a groove30athat extends in the height direction or the Y direction in the drawing for a predetermined length from the surface facing a recording medium is formed in the coil insulating layer30. The groove30ais constituted by a track width region H having an inner width defined by the track width Tw, and a slope region B wherein slope surfaces30cand30care formed such that a width of the slope region B gradually increases from both side ends30dand30dof the track width region H up to the surfaces30bof the coil insulating layer30(refer toFIG. 3).

Subsequently, as shown inFIG. 21, the recording portion14is formed in the groove30aformed in the coil insulating layer30.

Referring toFIG. 21, the recording portion14is composed of the lower magnetic pole layer11, the gap layer12, and the upper magnetic pole layer13in this order from bottom. These layers are sequentially deposited by plating.

The film construction of the recording portion14formed in the groove30ais not limited to the foregoing construction that includes the three layers. More specifically, the recording portion14may be constituted by the lower magnetic pole layer11and the nonmagnetic gap layer12, or by the nonmagnetic gap layer12and the upper magnetic pole layer13. Furthermore, each of the magnetic pole layers11and13, and the gap layer12may be composed of a single layer or multiple layers.

Preferably, the gap layer12is deposited by plating together with the magnetic pole layers11and13. For the nonmagnetic metal material that permits plating for forming the gap layer12, one material or two or more different materials are preferably selected from among NiP, NiPd, NiW, NiMo, Au, Pt, Rh, Pd, Ru, and Cr.

Subsequently, a hole is formed in the coil insulating layer30at the rear in the height direction or the Y direction in the drawing from the recording portion14, and the lifting layer25is formed in the hole by plating. Thereafter, as illustrated inFIG. 22, a resist layer44is applied onto the top of the recording portion14, the coil insulating layer30, and the lifting layer25, then a coil pattern44ais formed on the resist layer44.

Referring toFIG. 22, the surface of the coil insulating layer30is exposed through the coil pattern44aformed in the resist layer44. Then, the coil insulating layer30exposed through the coil pattern44ais etched by reactive ion etching process or the like.

Thus, coil forming grooves30eare concavely formed in the coil insulating layer30, the coil forming grooves30ehaving substantially the same configuration as that of the coil pattern44aformed in the resist layer44. Thereafter, the resist layer44is removed, which is illustrated inFIG. 23.

As shown inFIG. 23, the coil forming grooves30eare formed in the coil insulating layer30, and the coil insulating layer30is left at least on the bottom surfaces where the coil forming grooves30ehave been formed. If the coil insulating layer30is over-etched, causing the lower core layer10to be exposed at the bottom surfaces of the coil forming grooves30e, then magnetic insulation cannot be provided between the coil layer17to be embedded in the coil forming grooves30elater and the lower core layer10. For this reason, in the present invention, it is necessary to etch the coil insulating layer30with a limit so that the lower core layer10is not exposed and that the coil insulating layer30remains beneath the coil forming grooves30e.

As in the step shown inFIG. 11, the insulating under-layer18may be deposited on the plating under-layer40that has been deposited on the lower core layer10in advance, and the insulating under-layer18may be used as a stopper layer for preventing over-etching when the coil insulating layer30is etched.

In the following step, as shown inFIG. 24, a conductive material is embedded in the coil forming grooves30eformed in the coil insulating layer30thereby to form the coil layer17. In the embodiment shown inFIG. 24, the coil layer17is deposited on the recording portion14, the coil insulating layer30, and further on the lifting layer25. Hence, the coil layer17produces a state wherein all conductor portions embedded in the coil forming grooves30eare connected on the coil insulating layer15.

The coil layer17can be formed by an existing method, such as the electroplating process, the sputtering process, or the CVD process. However, employing the sputtering may cause a cavity to be formed in the coil layer17when embedding the coil layer17in the coil forming grooves30eprovided in the coil insulating layer30. Preferably, therefore, the electroplating process or the CVD process is used to deposit the coil layer17.

Next, as illustrated inFIG. 24, the coil layer17is etched to the line G—G by using, for example, the CMP process in order to accommodate the coil layer17only within the coil forming grooves30e. When the upper surface of the recording portion14is defined as a reference plane, the upper surface of the coil insulating layer30and the upper surface of the coil layer17can be made flush with the reference plane by etching the coil layer17to the line G—G.

As shown inFIG. 24, when the coil layer17is etched to the line G—G, the surface of the coil insulating layer30is also etched. This state wherein the coil layer17has been etched to the line G—G is illustrated inFIG. 25.

Referring toFIG. 25, the coil insulating layer30is deposited at the rear of the recording portion14in the height direction, and the coil forming grooves30eare provided in the coil insulating layer30. The coil layer17is embedded in the coil forming grooves30e. As shown inFIG. 25, when the upper surface of the recording portion14is defined as the reference plane, the upper surface of the coil insulating layer30and the upper surface of the coil layer17are flush with the reference plane.

Lastly, as illustrated inFIG. 26, the insulating layer22is deposited on the coil insulating layer30and the coil layer17, then the second coil layer23is deposited on the insulating layer22. Furthermore, the insulating layer24is deposited on the second coil layer23, then the upper core layer16is deposited from the top of the recording portion14onto the insulating layer24by the flame plating process or the like.

As shown inFIG. 26, the distal end portion16aof the upper core layer16is directly connected to the top of the recording portion14, and the proximal end portion16bis directly connected onto the lifting layer25.

To fabricate the thin film magnetic head shown inFIG. 6, the main coil insulating layer31and the auxiliary coil insulating layer32are deposited on the lower core layer10, then a groove is formed in the vicinity of the surfaces, which face a recording medium, of the auxiliary coil insulating layer32and the main coil insulating layer31, and the recording portion14is formed in the groove.

In the embodiment shown inFIG. 6, the etching rate of the main coil insulating layer31is larger than that of the auxiliary coil insulating layer32.

First, the groove having the slope surfaces32ashown inFIG. 5is formed in the auxiliary coil insulating layer32by ion milling or the like by making use of the aforesaid difference in etching rate, then the groove31ais formed by etching or the like in the main coil insulating layer31exposed through the groove formed in the auxiliary coil insulating layer32by using the RIE process or the like, the auxiliary coil insulating layer32functioning as a mask. This method makes it possible to form the groove31ahaving an inner width that is smaller than a resolution during exposure for a resist, thus permitting manufacture of a thin film magnetic head capable of achieving narrower tracks.

As set forth above, the groove31ais formed in the main coil insulating layer31, and the recording portion14is formed in the groove31a. Thereafter, in the same manner as the steps illustrated inFIG. 22throughFIG. 26, a resist layer having a coil pattern is formed on the auxiliary coil insulating layer32, and the auxiliary coil insulating layer32and the main coil insulating layer31exposed through the coil pattern are etched by the reactive ion etching process or the like, thereby forming the coil forming grooves31cand32cin the auxiliary coil insulating layer32and the main coil insulating layer31.

Thereafter, the coil layer17is embedded in the coil forming grooves31cand32cby electroplating or the like, and the surfaces of the coil layer17and the auxiliary coil insulating layer32are planarized by the CMP process or the like. Then, the insulating layers22and24, the second coil layer23, and the upper core layer16are deposited. Thus, the thin film magnetic head shown inFIG. 6can be fabricated.

For the thin film magnetic head shown inFIG. 8, a manufacturing method similar to that illustrated inFIG. 9throughFIG. 17, or inFIG. 18throughFIG. 20is used.

More specifically, the gap layer33is deposited on the lower core layer10first, then the upper magnetic pole layer36is deposited in the vicinity of the surface facing a recording medium by using a resist. After that, the coil insulating layer34is deposited.

In this embodiment, the gap layer33is preferably composed of an inorganic insulating material. As the inorganic insulating material, one material or two or more different materials are preferably selected from among Al2O3, SiO2, SiON, AlN, and AlSiN.

Alternatively, after the upper magnetic pole layer36is deposited, both side surfaces of the upper magnetic pole layer36and the gap layer33and the surface of the lower core layer10may be etched, and the protuberance10dwhich juts out from the top of the lower core layer10toward the recording portion14and which continues to the recording portion14may be integrally formed with the lower core layer10. With this arrangement, the occurrence of light fringing can be further controlled.

Then, a resist layer on which a coil pattern has been formed is deposited on the coil insulating layer34, and the coil forming grooves34aare formed in the coil insulating layer34by the reactive ion etching process.

Then, a conductive material is embedded by electroplating or the like in the coil forming grooves34aformed in the coil insulating layer34to form the coil layer17. The coil layer17and the coil insulating layer34are planarized by the CMP process or the like, then the insulating layers22and24, the second coil layer23, and the upper core layer16are deposited. Thus, the thin film magnetic head shown inFIG. 8can be fabricated.

In the manufacturing method for the thin film magnetic head in accordance with the present invention described in detail above, the recording portion14is formed on the lower core layer10. After the coil insulating layer is formed on the lower core layer10and at the rear of the recording portion14in the height direction, or after the coil insulating layer is deposited on the lower core layer10, the groove is formed in the coil insulating layer, and the recording portion is formed in the groove, a resist layer on which a coil pattern has been formed is deposited on the coil insulating layer.

Subsequently, the coil insulating layer exposed through the coil pattern formed on the resist layer is etched by the reactive ion etching process thereby to concavely form the coil forming grooves in the coil insulating layer. The coil forming grooves have the same configuration as that of the coil pattern formed on the resist layer.

According to the present invention, the coil insulating layer is first deposited on the entire surface of the lower core layer10, then the coil forming grooves are formed in the coil insulating layer by etching. This eliminates the danger of the coil insulating layer incurring defects, such as cavities.

A conductive material is embedded in the coil forming grooves formed in the coil insulating layer so as to form the coil layer, and the surfaces of the coil layer and the coil insulating layer are planarized by the CMP process or the like. This allows the coil layer to be properly embedded in the coil forming grooves formed in the coil insulating layer.

According to the present invention, when the upper surface of the recording portion14is defined as a reference plane, the upper surfaces of the coil insulating layer and the coil layer17can be positioned to be flush with the reference plane. Hence, even if the coil layer employs a double-layer construction, the bulge of the insulating layer that protrudes from the upper surface of the recording portion14can be controlled to a minimum. With this arrangement, a properly shortened magnetic path can be accomplished and the upper core layer can be pattern-deposited in a predetermined configuration with high accuracy.

In the present invention, the coil layer may be composed of a single layer. In this case, the width of the coil layer will be increased because of the necessity for adding to the number of turns of the coil layer formed in the first layer, leading to a disadvantage in shortening a magnetic path because the magnetic path will be longer than the coil layer composed of two layers. On the other hand, however, since the insulating layer22will be the only layer that bulges from the recording portion14, the upper core layer16can be formed in a predetermined configuration with higher accuracy.

According to the present invention, it is possible to etch by ion milling both end surfaces in the track width direction of the recording portion14formed on the lower core layer10in the step ofFIG. 10. Therefore, the present invention makes it possible to reduce the width (=track width Tw) of the recording portion14to fabricate a thin film magnetic head capable of achieving narrower tracks. According to the present invention, the track width Tw of the recording portion14is preferably set to 0.7 μm or less, and more preferably to 0.5 μm or less.

Thus, according to the present invention described in detail, the coil insulating layer is deposited on the lower core layer and at the rear of the recording portion in the height direction, and the coil layer is embedded in the coil forming grooves formed in the coil insulating layer. With this arrangement, the bulges of the layers from the top of the recording portion can be minimized, so that the magnetic path can be made shorter to reduce inductance, and the upper core layer can be formed with higher pattern accuracy.

Furthermore, according to the present invention, when the junction surface between the recording portion and the upper core layer is defined as a reference plane, the upper surface of the coil insulating layer and the upper surface of the coil layer are made flush with the reference plane. With this arrangement, the film thickness of the coil layer in a stepped portion between the lower core layer and the recording portion can be maximized. Hence, decreasing the width of the coil layer does not result in an increase in the coil resistance value, permitting a shorter magnetic path to be achieved.

According to the present invention, the coil layer preferably has a laminated double-layer construction. The use of the laminated double-layer construction allows the width of the coil layer to be decreased, so that the magnetic path can be made still shorter with a resultant lower inductance.

Even if the laminated double-layer construction is used, when the surface of the track width restriction portion is defined as a reference plane as set forth above, the upper surface of the first coil layer is made flush with the reference plane. Hence, the height from the top of the lower core layer to the top of the second coil insulating layer that covers the second coil layer can be reduced, so that the magnetic path can be shortened. At the same time, the bulge of the insulating layer covering the coil layer from the reference plane will be controlled, allowing the upper core layer to be deposited with higher pattern accuracy.

In the manufacturing method according to the present invention, after the coil insulating layer is deposited on the lower core layer and at the rear of the recording portion in the height direction, the coil forming grooves are formed in the coil insulating layer, and the coil layer is embedded in the coil forming grooves. This arrangement prevents the coil insulating layer from incurring defects, such as cavities.