US20010035355A1

US20010035355A1 - Plating method and apparatus, and manufacturing method of thin film magnetic head using the same

Info

Publication number: US20010035355A1
Application number: US09/819,633
Authority: US
Inventors: Akifumi Kamijima
Original assignee: TDK Corp
Current assignee: TDK Corp
Priority date: 2000-04-28
Filing date: 2001-03-29
Publication date: 2001-11-01
Also published as: JP2001316864A; JP3343342B2

Abstract

The invention relates to a frame plating method for forming a plating film using a mold formed by patterning a resist, and has an object to provide the frame plating method in which tilting of a resist frame having a high aspect ratio is easily and certainly prevented and a desired plating film can be formed. The constitution includes a developing/washing portion 100 for developing an exposed resist layer formed on a substrate 138 and for washing a developing solution by a washing solution, and a plating portion 50 for immersing a surface of the substrate 138 in a state where the washing solution is not dried after washing but is held, into a plating solution 62 to carry out plating.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a plating method (hereinafter referred to as a frame plating method) for forming a plating film by using a mold formed by patterning a resist, a plating apparatus used in the frame plating method, and a manufacturing method of a thin film magnetic head provided with an induction type magnetic head as a recording head.

2. Description of the Related Art

A composite type thin film magnetic head including a magnetoresistive (MR) head used for data reproduction and an induction type magnetic head used for data recording is used as a magnetic head of a magnetic disk device.

The MR head includes any one of an AMR (Anisotropic Magnetoresistive) component using an AMR effect, a GMR (Giant Magnetoresistive) component using a GMR effect, and a TMR (Tunneling Magnetoresistive) component using a tunnel junction film indicating a magnetoresistive effect. As surface recording density of a magnetic recording medium becomes high, a component to be used is changed from the AMR component to the GMR component, and further, to the TMR component.

As one factor for determining the performance of the MR heads, there is optimization of MR height. The MR height is a height of the MR component from an end portion at a side of an air bearing surface (ABS) opposite to a magnetic recording surface of a magnetic recording medium to an end portion at the opposite side, and this height depends on an amount of polishing of the ABS surface in a head manufacturing process.

The induction type magnetic head realizes a ring structure having a narrow gap by a semiconductor process, and includes upper and lower magnetic poles which are laminated through an insulating film and has a gap (write gap) at the side of the ABS surface to form a closed magnetic path, and a thin film coil formed in the insulating film between the upper and lower magnetic poles. The head material is magnetized to high magnetic flux density by recording current flowing through the thin film coil, and predetermined leakage magnetic field is formed over the gap to record data.

As one factor for determining the performance of the induction type magnetic head, there is optimization of throat height (TH). The throat height is a height of the magnetic pole from the ABS surface to the end portion of the insulating film, and this height also depends on an amount of polishing of the ABS surface in the head manufacturing process. In order to improve the head efficiency of the recording head, it is necessary to make the throat height as small as possible.

In order to raise the recording density, it is necessary to raise the track density of the magnetic recording medium. For that purpose, it is necessary to realize a recording head in which magnetic pole width and gap width at the ABS surface are made narrow, and a semiconductor processing technique is used for realizing this.

The foregoing composite type thin film magnetic head is manufactured through a plurality of manufacturing processes, for example, a sputtering process, a photolithography process, a frame plating process, an etching process, a polishing process, and the like. Hereinafter, an example of a manufacturing method of the thin film magnetic head will be described in brief.

First, an Al ₂O₃TiC substrate having high hardness and excellent in wear resistance is used. When the magnetic head is completed, this substrate itself functions as a slider body of the magnetic head. The reason why the substrate having high hardness and excellent in wear resistance is used is to secure floating accuracy of the head and to obtain accurate MR height and throat height.

A film having high adhesiveness, for example, a chromium film is formed on the Al ₂O₃TiC substrate by sputtering or the like. Next, a lower shield layer made of, for example, permalloy is formed. Next, an MR component interposed between insulating films is formed on the lower shield layer.

Next, an upper shield layer made of, for example, permalloy is formed. By this, an MR head for reproduction is completed. The upper shield layer is also used as a lower magnetic pole of an induction type magnetic head for recording.

Next, an insulating film for formation of a gap is formed on the lower magnetic pole, and further, an insulating film is formed, and then, a film excellent in adhesiveness to an oxide, for example, a chromium film is formed thereon by sputtering or the like. Next, there is formed a thin film of, for example, copper, which becomes an electrode film when a frame plating method is used. Next, a copper coil of a first layer is formed by the frame plating method. As the need arises, coils of second to third layers are also formed in the same way.

After the formed thin film coil is embedded by an insulating film, an upper magnetic pole made of, for example, permalloy is formed thereon by using the frame plating method. A recording gap layer is formed by carrying out etching while the upper magnetic pole at the side of the ABS surface is used as a mask. The upper magnetic pole is formed so that it is connected to the lower magnetic pole through the coil at the opposite side of the recording gap layer so as to constitute a closed magnetic path. A protective film is formed on an upper layer of the upper magnetic pole, and the film forming process is completed.

Next, the Al ₂O₃TiC substrate is cut into rod-like substrates including several tens heads. The ABS formation surface of the rod-like substrate is polished to provide the throat height of a height of several pm. After the ABS surface is formed, the rod-like substrate is cut, so that a plurality of thin film magnetic heads are completed. In the manufacturing method of the thin film magnetic head as described above, the frame plating method is used for the formation of the thin film coil or the formation of the upper magnetic pole.

A conventional frame plating method will be described in brief with reference to FIGS. 8A to 8E and FIG. 9. The frame plating method is a method of patterning a plating film by using a mold formed by patterning a resist, as disclosed in, for example, Japanese Patent Publication No. S56-36706.

FIGS. 8A to 8E are sectional views showing a manufacturing process of a plating film using the conventional frame plating method. As shown in FIG. 8A, an electrode film 502 is formed on an insulating substrate 500 by using a sputtering method or an evaporation method. As a lower layer of the electrode film 502, an adhesive layer, for example, a Cr (chromium) film or a Ti (titanium) film, may be formed to raise the adhesiveness to the insulating substrate 500. Although there is no problem when the electrode film 502 is made of a material having conductivity, if possible, it is desirable to use the same material as a metal material to be plated.

Next, as shown in FIG. 8B, a resist is coated on the whole surface to form a

resist layer

504, and as the need arises, a pre-bake treatment of the resist layer 504 is performed. Next, exposure light is irradiated through a mask 506 on which a predetermined pattern is drawn, so that the resist layer 504 is exposed.

Next, after a heat treatment is performed as the need arises, development is carried out by an alkaline developing solution. As the alkaline developing solution, for example, tetramethylammonium hydroxide (TMAH) of a concentration of 2.38 wt % is used. Next, the developing process successively shifts to a washing process. The developing solution in the

resist layer

504 is washed by a washing solution 510, and a development dissolving reaction in the resist layer 504 is stopped, so that as shown in FIG. 8C, resist frames 508 patterned into a predetermined shape are formed. As the washing solution, for example, pure water is used.

When washing is ended, the

washing solution

510 is blown away and is dried. If necessary, the substrate 500 may be heated to dry the washing solution (see FIG. 8D).

Next, the

substrate

500 is immersed in a plating solution 512 in a plating bath, and a plating process is carried out using the resist frames 508 as a mold, so that plating films 514 are formed between the resist frames 508 (see FIG. 8E). Next, as the need arises, water washing and drying are carried out, and then, the resist frames 508 are peeled off from the substrate 500 by using an organic solvent. Next, the electrode film 502 is removed by dry etching (ion milling, reactive ion etching (RIE), etc.) or wet etching while the plating films 514 are used as a mask. The above is an outline of the frame plating method.

Like this, although the frame plating method is a technique for forming the plating

films

514 of a predetermined shape using the resist frames 508 obtained by patterning the resist layer 504 as the mask, there is a problem that such a phenomenon occurs that in the washing step when the resist frames 508 are formed, the resist frames 508 on the substrate 500 tilt as shown in FIG. 9.

For example, when the upper magnetic pole of the thin film magnetic head is formed by the frame plating method, since undulations having a relatively large difference in height are produced in a coating region of the resist

layer

504, a locally very thick resist layer 504 is formed. Since a pattern of a relatively very thin line width is formed in the thick resist layer 504, the resist frame 508 having a high aspect ratio is formed.

When the resist

frame

508 having such a high aspect ratio is formed, after the developing solution is washed, the substrate 500 is rotated to blow away the washing solution 510 adhered to the substrate, so that drying shown in FIG. 8D is carried out. At the time of this drying, surface tension of the washing solution 510, centrifugal force resulting from the rotation of the substrate, and pressing force from the washing solution are applied to the resist frame 508. It appears that the resist frame 508 is tilted by these forces at the time of drying. Incidentally, in addition to the tilting, there is also a case where bending, breaking or peeling of the pattern occurs.

This phenomenon becomes remarkable as the width of the resist frame becomes narrow, the interval becomes narrow, and the aspect ratio of the section of the resist pattern becomes large.

As a method of preventing such tilting of the resist frame, document 1 (Handbook of Resist Material for Semiconductor Integrated Circuit, Realize Corp. 1996, pp. 218-220) discloses a low surface tension rinse and a freeze drying method as surface tension action reducing methods, and discloses a high strength (high rigidity) resist and a resist hardening method in a rinse liquid as resist strength improving methods. The low surface tension rinse uses a tertiary butyl alcohol solution is used as a washing solution, and the surface tension of the washing solution operating on the resist pattern is lowered to prevent the tilting. In the freeze drying method, a washing solution after washing is frozen and is sublimated, so that drying is made in the state where the surface tension is hardly produced. The high intensity resist prevents the tilting by using a material which can withstand the various forces operating on the resist pattern. In the resist hardening method in the rinse liquid, a photo-crosslinking type resist or thermo-crosslinking type resist is used for the resist layer, and light irradiation or heating is performed in the washing solution to increase the strength of the resist layer, so that the tilting is prevented.

Japanese Patent Publication No. H06-105684 discloses a technique for carrying out drying in a state where a washing solution is made to have a critical state and the surface tension is made 0 (zero), similarly to the above surface tension reducing method. Japanese Patent No. 2762226 discloses a method in which a pressure in a sealed container is reduced to a pressure slightly smaller than a saturation vapor pressure, and the washing solution is gradually evaporated to be dried.

However, in the above surface tension reducing method and its similar technique, there easily occurs such a problem that the washing solution remains on the surface of the substrate after drying to produce a stain or the like, and plating abnormality occurs in a subsequent plating step. Besides, if the surface tension is low, a possibility that the washing solution intrudes into an interface between the resist layer and the substrate to cause pattern peeling, becomes high.

On the other hand, in the resist strength improving method, in view of reduction in cost and reduction in the number of steps, there is no satisfactory resist material under the preset circumstances.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a frame plating method in which tilting of a resist frame having a high aspect ratio is easily and certainly prevented, and a desired plating film can be formed.

Another object of the present invention is to provide a plating apparatus which is suitably used in a frame plating method in which tilting of a resist frame having a high aspect ratio is easily and certainly prevented, and a desired plating film can be formed.

Still another object of the present invention is to provide a manufacturing method of a thin film magnetic head using a frame plating method in which tilting of a resist frame having a high aspect ratio is easily and certainly prevented, and a desired plating film can be formed.

The above object is achieved by a plating method characterized in that an electrode film is formed on a substrate, a resist layer is formed on the electrode film, the resist layer is developed after exposure through a predetermined mask, a developing solution on a surface of a resist frame formed by development is washed by a washing solution, and after washing, a surface of the substrate in a state where the washing solution is held without being dried, is immersed into a plating solution to carry out plating.

Besides, the above object is achieved by a plating apparatus characterized by comprising a developing/washing portion for developing an exposed resist layer formed on a substrate and for washing a developing solution by a washing solution, and a plating portion for carrying out plating after washing by immersing a surface of the substrate in a state where the washing solution is held without being dried, into a plating solution.

The plating apparatus is characterized in that the plating portion includes an opening portion to be closed by the substrate. Besides, the plating apparatus is characterized in that the developing/washing portion includes a transporting mechanism for transporting the substrate to the opening portion.

Further, the plating apparatus is characterized by comprising a drainage receiving portion for receiving plating drainage between the developing/washing portion and the plating portion.

Further, the above object is achieved by a manufacturing method of a thin film magnetic head, which comprises a plating process of forming a plating film using a mold formed by patterning a resist and is characterized in that the plating process comprises the plating method of the present invention.

According to the present invention, in the development step at the time of forming the resist frame, the surface of the substrate is immersed into the plating solution to carry out plating, while the washing solution on the surface of the substrate after washing of the developing solution is not blown away and the layer of the washing solution is held. Accordingly, even if the resist pattern has a high aspect ratio, it can be easily and certainly formed without causing tilting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to [0040] 1D are process sectional views showing a frame plating method according to a first embodiment of the present invention;
FIGS. 2A to [0041] 2D are process sectional views showing the frame plating method according to the first embodiment of the present invention;
FIG. 3 is a schematic view showing an outline structure of a frame plating apparatus according to a second embodiment; [0042]
FIGS. 4A to [0043] 4H are process sectional views showing a manufacturing method of a thin film magnetic head using a frame plating method according to a third embodiment of the present invention;
FIGS. 5A to [0044] 5D are process sectional views showing the frame plating method in the manufacturing method of the thin film magnetic head according to the third embodiment of the present invention;
FIGS. 6A to [0045] 6C are process sectional views showing the frame plating method in the manufacturing method of the thin film magnetic head according to the third embodiment of the present invention;
FIGS. 7A to [0046] 7C are process sectional views showing the frame plating method in the manufacturing method of the thin film magnetic head according to the third embodiment of the present invention;
FIGS. 8A to [0047] 8E are sectional views showing a manufacturing process of a plating film using a conventional frame plating method; and
FIG. 9 is a view showing tilting of a resist frame in the conventional frame plating method.[0048]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A frame plating method according to a first embodiment of the present invention will be described with reference to FIGS. 1A to [0049] 1D and FIGS. 2A to 2D. FIGS. 1A to 2D are sectional views showing a manufacturing process of a plating film using the frame plating method. First, as shown in FIG. 1A, an electrode film 2 is formed on an insulating substrate 1 by using a sputtering method or an evaporation method. An adhesive layer for improving adhesiveness to the insulating substrate 1 may be formed under the electrode film 2 by, for example, a Cr (chromium) film or a Ti (titanium) film. Although there is no problem as long as the conductive film 2 is made of a material having conductivity, if possible, it is desirable to use the same material as a metal material to be plated.
Next, as shown in FIG. 1B, a resist is coated on the whole surface to form a resist [0050] layer 3, and a pre-bake treatment is carried out as the need arises. Next, exposure light is irradiated through a mask 4 on which a predetermined pattern is drawn, so that the resist layer 3 is exposed.
Next, after a heat treatment is carried out as the need arises, as shown in FIG. 1C, the exposed resist [0051] layer 3 is developed by an alkaline developing solution 5 to form resist frames 6. As the alkaline developing solution 5, for example, tetramethylammonium hydroxide (TMAH) of a concentration of 2.38 wt % can be used.
Next, the development process successively shifts to a washing process. The developing [0052] solution 5 on the surfaces of the resist frames 6 is washed by a washing solution 7, and a development dissolving reaction on the surface of the resist frames 6 is stopped, so that as shown in FIG. 1D, the resist frames 6 patterned into a predetermined shape are formed. As the washing solution 7, for example, pure water is used.
After washing is ended, as shown in FIG. 2A, the substrate is immersed into a [0053] plating solution 8 in a plating bath while the washing solution 7 is not blown away but a layer of the washing solution 7 is held on the surface of the substrate, and a plating treatment is carried out using the resist frames 6 as a mold, so that plating films 9 are formed between the resist frames 6. As the need arises, a plating pretreatment solution (for example, mixture solution of surface active agent and acid) may be sprayed on the surface of the substrate before it is immersed into the plating solution 8 and washing may be carried out by the washing solution 7. Also in this case, in the state where the washing solution 7 is not blown away but the washing solution is kept on the surface of the substrate, the substrate 1 is immersed into the plating solution 8 in the plating bath.
Next, in FIG. 2B, as the need arises, water washing and drying are made, and next, the resist [0054] frames 6 are peeled off from the substrate 1 by using an organic solvent (see FIG. 2C). Next, the electrode film 2 is removed by dry etching (ion milling, reactive ion etching (RIE), etc.) or wet etching using the plating films 9 as a mask (see FIG. 2D). Here, the frame plating method of this embodiment is completed.
Like this, in the frame plating method of this embodiment, in the washing process when the resist [0055] frames 6 are formed, a processing of blowing away the washing solution 7 is not carried out. Accordingly, since the surface tension of the washing solution 7 when the washing solution 7 is blown away by the rotation of the substrate 1, the centrifugal force, or the pressing force from the washing solution 7 are not applied to the resist frames 6, even if the resist frames 6 has a high aspect ratio, it does not tilt.
Thus, there does not occur such a case where the washing solution remains on the surface of the substrate to produce a stain, like the conventional surface tension reducing method or the like, and plating abnormality in the plating process can be decreased. Besides, since it is also not necessary to use a washing solution having low surface tension, pattern peeling in which the washing solution intrudes into the interface between the resist layer and the substrate does not also become problematic. [0056]
Further, in this embodiment, since a general resist material is used, there does not occur any problem in view of reduction in cost and reduction in the number of steps, unlike the conventional resist strength improvement method. [0057]
Accordingly, it becomes possible to easily and certainly prevent tilting of the resist frame having a high aspect ratio and to form a desired plating film. [0058]
Incidentally, in the frame plating method according to the first embodiment, the washing solution in the washing process carried out at the final stage of a photolithography process is not dried but is made to remain as it is. However, it is not desirable that the state where the washing solution is adhered to the substrate continues for a long time. First, there is a possibility that a foreign substance such as dust is adhered to the washing solution on the substrate, and causes a defect in a subsequent process. Second, there is a possibility that the electrode film for plating is rusted by water. Third, there is also a possibility that the resist frame absorbs moisture to swell, and adhesiveness is deteriorated to cause pattern peeling. Besides, in view of transportation of the substrate, there is a also a possibility that a transporting device is wetted during the transportation of the wet substrate. [0059]
Then, as a second embodiment of the present invention, a plating apparatus suitably used in the frame plating method according to the first embodiment will be described with reference to FIG. 3. FIG. 3 is a schematic view showing an outline structure of the plating apparatus according to this embodiment. As shown in FIG. 3, the plating apparatus is roughly divided into a [0060] plating portion 50 used in a plating process and a developing/washing portion 100 used in a developing/washing process carried out before the plating process. In FIG. 3, the up and down direction is almost coincident with the vertical direction, and the right and left direction is almost coincident with the horizontal direction. The developing/washing portion 100 is positioned vertically below the plating portion 50.
The [0061] plating portion 50 includes a plating bath 52 for containing a plating solution 62. The plating bath 52 includes an opening portion 90 at a bottom, and the opening peripheral end portion of the opening portion 90 is brought into close contact with the peripheral end portion of a substrate 138′ transported from the developing/washing portion 100 thereunder to close the opening portion 90, so that the plating solution 62 in the plating bath 52 can be brought into contact with the surface of the substrate without leaking.
A cathode [0062] 58 is provided at the opening periphery of the opening portion 90, and an anode 56 is provided in the bath above the opening portion 90. The anode 56 is connected to a positive terminal of a DC power source 54, and the cathode 58 is connected to a negative terminal. When the substrate 138′ closes the opening portion 90, an electrode film on the substrate 138′ is electrically connected to the cathode 58, and a plating treatment is carried out by a potential difference between the anode 56 and the electrode film through the plating solution 62. A paddle 60 is provided between the opening portion 90 and the anode 56. The paddle 60 is supported to be movable in the direction of arrows A and B above the substrate 138′ almost horizontally. In order to raise the uniformity of plating, the paddle 60 agitates the plating solution 62 in the vicinity of the surface of the substrate 138′ so that a liquid layer having a different ion concentration is not produced at the interface between the plating solution 62 and the surface of the substrate 138′.
The [0063] plating solution 62 contained in the plating bath 52 is supplied from a plating solution tank 64. In the plating solution tank 64, there is disposed an agitating wing 74 rotated by a motor 72 at a predetermined revolving speed to agitate the plating solution 62 in the tank. Besides, in the plating solution tank 64, a thermocouple 70 for measuring temperature of the plating solution 62 is provided. Temperature data measured by the thermocouple 70 is sent to a control portion 72, and the control portion 72 controls a heater 68 provided in the tank to keep the temperature of the plating solution 62 in the tank at a predetermined temperature.
The [0064] plating solution 62 in the plating solution tank 64 is introduced in the plating bath 52 by opening a valve 82 and closing a valve 80 while a pump 78 is operated. Besides, by opening a valve 86, the plating solution 62 in the plating bath is returned in the plating solution tank 64. The quantity of the plating solution 62 in the plating bath 52 can be adjusted by opening/closing a valve 84.
The developing/[0065] washing portion 100 includes a developing/washing bath 102. A substrate holder 136 on which a substrate 138 is mounted is contained in the developing/washing bath 102. The substrate holder 136 is connected to a coupling rod 140 extending from an air cylinder 132, and can be moved upward and downward substantially in the vertical direction through the driving of the air cylinder 132. By moving the coupling rod 140 in the direction of arrow C in the drawing through the driving of the air cylinder 132, the substrate 138 mounted on the substrate holder 136 is moved in the direction of arrow C′ and can be brought into close contact with the opening of the bottom of the plating bath 52. A transporting mechanism for transporting the substrate 138 to the opening portion 90 is constituted by at least the coupling rod 140 and the air cylinder 132.
Besides, the [0066] substrate holder 136 is designed such that the substrate 138 can be rotated in the direction of arrow E′ by rotating a motor 134 to rotate the coupling rod 140 in the direction of arrow E in the drawing.
A developing [0067] solution nozzle 104 for spraying the developing solution onto the surface of the substrate 138 on the substrate holder 136 is provided in the developing/washing bath 102. The developing solution nozzle 104 sprays the developing solution in a developing solution tank 114 onto the substrate 138 by opening a valve 111 and closing a valve 126 while a pump 120 is operated.
Besides, a [0068] washing solution nozzle 106 for spraying the washing solution onto the surface of the substrate 138 on the substrate holder 136 is provided in the developing/washing bath 102. The washing solution nozzle 106 sprays the washing solution in a washing solution tank 116 onto the substrate 138 by opening a valve 110 and closing a valve 128 while a pump 122 is operated.
Further, a plating [0069] pretreatment solution nozzle 108 for spraying the plating pretreatment solution (for example, mixture solution of surface active agent and acid) onto the surface of the substrate 138 on the substrate holder 136 is provided in the developing/washing bath 102. The plating pretreatment solution nozzle 108 sprays the plating pretreatment solution in a plating pretreatment solution tank 118 onto the substrate 138 by opening a valve 112 and closing a valve 130 while a pump 124 is operated.
A drainage receiving portion for receiving leak drainage of the plating solution is provided between the plating [0070] portion 50 and the developing/washing portion 100. The drainage receiving portion includes a drainage receiver 152 and an air cylinder 150 for moving the drainage receiver 152 in the horizontal direction (direction of arrow D in the drawing). The plating solution 62 is discharged from the plating bath 52 to the plating solution tank 64 through the valve 86, and when the substrate holder 136 goes down, the drainage receiver 152 is advanced to the position of a broken line 152′ by the driving of the air cylinder 150, and receives the residual plating solution 62 leaking out from the opening.
Next, the operation of a plating treatment in the plating apparatus of this embodiment will be described. When exposure of the resist layer by a projection exposure device or the like is ended, the exposed [0071] substrate 138 mounted on an X-Y stage of the exposure device is transported by a substrate transporting device, and after a heat treatment by a heat treatment device is performed as the need arises, it is mounted on the substrate holder 136 in the developing/washing bath 102 of the plating apparatus.
When the [0072] substrate 138 is mounted on the substrate holder 136, the motor 134 is driven to rotate the substrate holder 136 at a low revolving speed. At the same time, the valve 111 is opened and the valve 126 is closed while the pump 120 is operated, so that the developing solution in the developing solution tank 114 is sprayed onto the whole surface of the substrate 138 from the developing solution nozzle 104.
When the predetermined developing treatment is ended, the [0073] valve 126 is opened and the valve 111 is closed so that supply of the developing solution from the developing solution nozzle 104 is stopped.
Next, the [0074] valve 110 is opened and the valve 128 is closed while the pump 122 is operated, so that the washing solution of the washing solution tank 116 is sprayed onto the substrate 138 from the washing solution nozzle 106. When the predetermined washing treatment is ended, the valve 128 is opened and the valve 110 is closed, so that supply of the washing solution from the washing solution nozzle 106 is stopped. Incidentally, as the need arises, spraying of the plating pretreatment solution from the plating pretreatment solution nozzle 108 and spraying of the washing solution from the washing solution nozzle 106 onto the substrate 138 are carried out.
When the above process is ended, the rotation of the [0075] substrate holder 136 is stopped, and in the state where the washing solution is not blown away from the substrate 138 but the washing solution is held, the substrate holder 136 is lifted to the opening portion 90 of the plating bath 52.
The [0076] coupling rod 140 is moved in the direction of the arrow C in the drawing by the driving of the air cylinder 132, so that the substrate 138 mounted on the substrate holder 136 is brought into close contact with the opening of the opening portion 90 of the bottom of the plating bath 52. By this, the opening of the bottom of the plating bath 52 is closed by the substrate 138′, and the electrode film on the substrate 138′ is electrically connected to the cathode 58.
Next, the [0077] valve 82 is opened and the valve 80 is closed under the operation of the pump 78, so that the plating solution 62 in the plating solution tank 64 is introduced in the plating bath 52.
When the [0078] plating solution 62 reaches a predetermined level in the plating bath 52, a predetermined voltage is applied between the anode 56 and the cathode 58 from the DC power source 54 to start the plating treatment. The washing solution adhering to the surface of the substrate 138′ is diffused into the plating solution 62, and further, the agitating operation of the paddle 60 is made, and electrical plating is carried out between the electrode film on the substrate 138′ being in contact with the cathode 58 and the anode 56. By this, plating metal is deposited between the resist frames on the substrate 138′ and a plating film is formed.
After the predetermined plating film is formed, supply of electric power from the [0079] DC power source 54 is cut to stop the film growth of the plating film. Incidentally, in the plating treatment, while the plating solution 62 is introduced from the plating solution tank 64 through the valve 82, the plating solution 62 is discharged through the valves 84 and 86 to the plating solution tank 64, so that the plating solution 62 in the plating bath 52 is circulated.
Next, the [0080] valve 80 is opened and the valve 82 is closed, and the valve 86 is opened so that the plating solution 62 in the plating bath 52 is discharged to the plating solution tank 64. When the discharge of the plating solution 62 is completed, the air cylinder 132 is driven to make the substrate holder 136 go down. At the same time, the air cylinder 150 is driven to move the drainage receiver 152 to the position below the opening of the bottom of the plating bath 52, so that the leak drainage of the plating solution 62 is received.
The [0081] substrate 138 descending to a predetermined position, together with the substrate holder 136, is rotated by the motor 134 at a low speed, and at the same time, the valve 110 is opened and the valve 128 is closed while the pump 122 is operated, so that the washing solution in the washing solution tank 116 is sprayed onto the substrate 138 from the washing solution nozzle 106. Next, the substrate 138 is transported by a not-shown substrate transporting system and is transported to a processing device of a next process.
Like this, according to this embodiment, a state where the washing solution adheres to the substrate does not continue for a long time, and it is possible to extremely lower the possibility that a foreign substance such as dust adheres to the washing solution on the substrate. Besides, since a time when moisture is in contact with the electrode film for plating can be suppressed to a very short time, it is possible to almost completely remove the possibility that rust is generated in the electrode film. Besides, it is also possible to avoid the possibility that the resist frame absorbs moisture to swell. Further, since substrate transportation by a conventional substrate transporting system is not carried out, there does not occur such a case that an existing transporting device is wetted by a wet substrate. [0082]
Next, as a third embodiment of the present invention, a manufacturing method of a thin film magnetic head using the frame plating method according to the first embodiment will be described with reference to FIGS. 4A to [0083] 4H and FIGS. 5A to 7C. FIGS. 4A to 4H are process sectional views showing the manufacturing method of the thin film magnetic head, FIGS. 4A to 4D are sectional views taken along a plane passing through the center of a track of the magnetic head, and FIGS. 4E to 4H are sectional views seen in the direction of an air bearing surface (ABS).
This embodiment shows a case of a composite type thin film magnetic head in which an inductive recording head and a magnetoresistive effect (MR) reproduction head portion are integrally laminated. However, it is needless to say that the frame plating method of the embodiment can also be applied to a thin film magnetic head in which only an inductive recording head portion is provided. [0084]
First, an insulating [0085] layer 10 is laminated on a not-shown substrate made of a ceramic material such as Al₂O₃TiC. This insulating layer 10 is formed to a thickness of about 1 to 2 μm by a sputtering method or the like from an insulating material such as Al₂O₃or SiO₂.
Next, a layer for a [0086] lower shield 11 is laminated thereon, and further, an insulating layer 12 for a shield gap is laminated thereon. The layer for the lower shield 11 is formed preferably to a thickness of about 100 to 5000 nm by the sputtering method, plating method or the like from a material such as AlFeSi, NiFe, CoFe, CoFeNi, FeN, FeZrN, FeTaN, CoZrNb, or CoZrTa. The insulating layer 12 for the shield gap is formed preferably to a thickness of about 10 to 200 nm by the sputtering method or the like from an insulating material such as Al₂O₃or SiO₂.
Next, an [0087] MR component 13 on the insulating layer 12 is formed, and a lead conductor 14 is formed to be electrically connected to both ends of the MR element 13. Although the MR element 13 may be made to have a single layer structure of a magnetic material, it is desirable to make a multi-layer structure in which a magnetic layer and a nonmagnetic layer are alternately laminated. As the material of the magnetic layer, NiFe, NiFeRh, FeMn, NiMn, Co, Fe, NiO, NiFeCr, or the like is preferable, and as the material of the nonmagnetic layer, Ta, Cu, Ag or the like is preferable. Besides, as the multi-layer structure, for example, a three layer structure of NiFeRh/Ta/NiFe, or a plural-layer structure of NiFe/Cu/NiFe/FeMn, NiFe/Cu/Co/FeMn, Cu/Co/Cu/NiFe, Fe/Cr, Co/Cu, Co/Ag, or the like is made one unit, and a plurality of such units may be laminated. In the case of the multi-layer structure, it is preferable that the thickness of the magnetic layer is made 0.5 to 50 nm, especially 1 to 25 nm, and the thickness of the nonmagnetic layer is also made 0.5 to 50 nm, especially 1 to 25 nm. It is preferable that the number of repeated laminate layers of the units is 1 to 30, especially 1 to 20. It is preferable that the thickness of the whole of the MR component 13 is 5 to 100 nm, especially 10 to 60 nm. In order to laminate the layers for the MR component, the sputtering method, plating method or the like is used. It is preferable that the lead conductor 14 is formed to a film thickness of 10 to 500 nm, especially about 50 to 300 nm by the sputtering method, plating method or the like from a conductive material such as W, Cu, Au, Ag, Ta, Mo, Co, or Pt.
Next, an insulating [0088] layer 15 for a shield gap is laminated on the MR component 13 and the lead conductor 14. This insulating layer 15 is formed to a thickness of 5 to 500 nm, preferably 10 to 200 nm by the sputtering method or the like from an insulating material such as Al₂O₃or SiO₂.
The respective layers of the MR reproduction head portion described above are patterned by a general liftoff method using a resist pattern, a milling method, or a method using both these methods. [0089]
Next, a magnetic layer for a lower [0090] magnetic pole 16 of a recording head portion also serving as an upper shield of the MR component 13 is laminated, and an insulating layer for a recording gap 17 is laminated thereon. The layer for the lower magnetic pole 16 is formed to a thickness of about 500 to 4000 nm by the plating method, sputtering method or the like from a soft magnetic material such as NiFe, CoFe, CoFeNi, or FeN. The insulating layer for the recording gap 17 is formed to a thickness of about 10 to 500 nm by the sputtering method or the like from a material such as Al₂O₃or SiO₂.
Thereafter, a [0091] coil 18 and an insulating layer 19 surrounding this coil 18 are formed on the recording gap 17. The coil 18 is formed to a thickness of about 2 to 5 μm by the frame plating method or the like from a conductive material such as Cu. The insulating layer 19 is formed to a thickness of about 3 to 20 μm by thermally hardening a photoresist material.
The layer structure as shown in FIGS. 4A and 4E is obtained through the above steps. Incidentally, the [0092] coil 18 may have two layers as shown in the drawing, or three layers or more, or may have a single layer.
Next, as shown in FIGS. 4B and 4F, an upper [0093] magnetic pole 20 including a magnetic pole portion at an ABS side and a yoke portion at a rear side is formed on the thus formed insulating layer 19 by the frame plating method. The upper magnetic pole 20 is formed to a thickness of about 3 to 5 μm from a soft magnetic material such as NiFe, CoFe, CoFeNi, or FeN . At this time, the shape of the magnetic pole portion of the upper magnetic pole 20 seen from the ABS side is formed to be as shown in the drawing.
Hereinafter, the frame plating method for forming the upper [0094] magnetic pole 20 having the shape like this will be described. FIGS. 5A to 7C are process sectional views showing a forming process of the upper magnetic pole by the frame plating method according to the embodiment.
As shown in FIG. 5B, a metal under [0095] film 21 having preferably the same constituent as the layer to be plated, such as Cu, NiFe, or Au, is formed to a thickness of about 10 to 500 nm on the recording gap 17 shown in FIG. 5A.
Next, as shown in FIG. 5C, a resist [0096] material 22 is coated on the metal under film 21 and is patterned to form a resist pattern 23 as shown in FIG. 5D. In the formation of the resist pattern 23, a developing solution on the surface of the resist pattern 23 is washed by a washing solution 27 in a washing process subsequent to a developing process, and a development dissolving reaction of the surface of the resist pattern 23 is stopped. When the washing is ended, as described in the first embodiment, in the state where the washing solution 27 is not blown away but the layer of the washing solution 27 is held on the surface of the substrate, the substrate is immersed into a plating solution in a plating bath, and as shown in FIG. 6A, the resist pattern 23 is used as a mold, and a plating layer 24 is obtained by plating of a soft magnetic material such as NiFe, CoFe, CoFeNi, or FeN.
Next, as shown in FIG. 6B, the resist [0097] pattern 23 is peeled off by using an organic resin or the like. Next, as shown in FIG. 6C, the metal under film 21 after the removal of the resist pattern is removed by means such as ion milling by using the plating film 24 as a mask.
Next, as shown in FIG. 7A, an upper part and a periphery of a portion of the [0098] plating layer 24 to be left are covered with a resist layer 25. Next, as shown in FIG. 7B, the plating layer 24 and the metal under film 21 at an unnecessary portion are removed by wet etching or the like, and further, the resist layer 25 is peeled off by using an organic solvent or the like, so that the upper magnetic pole 20 as shown in FIG. 7C is formed.
With respect to FIGS. 4A to [0099] 4H again, as shown in FIGS. 4C and 4G, the thus formed upper magnetic pole 20 is used as a mask, and dry etching such as ion milling or RIE (reactive ion etching) is carried out, so that a portion not covered with the mask of the insulating layer for the recording gap 17 is removed, and further, a portion not covered with the mask is removed to the middle of the magnetic layer for the lower magnetic pole 16.
By this, as shown in FIGS. 4D and 4H, a protrusion [0100] 16 a opposite to the lower end of the upper magnetic pole 20 through the recording gap 17 and having the same width is formed at the lower magnetic pole 16. Next, after a pad bump or the like is formed, a protective layer 26 is laminated. This protective layer 26 is formed to a film thickness of about 5 to 50 μm by the sputtering method or the like from an insulating material such as Al₂O₃or SiO₂.
As described above, in this embodiment, since the frame plating method according to the first embodiment is used, the processing of blowing away the washing solution is not carried out in the washing process when the resist [0101] pattern 23 is formed. Accordingly, since the surface tension of the washing solution when the washing solution is blown away by rotating the substrate 10, the centrifugal force, and the pressing force from the washing solution are not applied to the resist pattern 23, even if an aspect ratio is high, the resist pattern 23 does not tilt. Accordingly, tilting of the resist pattern 23 having a high aspect ratio can be easily and certainly prevented and a desired plating film can be formed, and it becomes possible to manufacture a thin film magnetic head at low cost and with high accuracy.
The present invention is not limited to the above embodiments, but various modifications can be made. [0102]
For example, in the above embodiment, although the present invention is applied to the formation of the upper magnetic pole, it is naturally possible to apply the present invention to formation of a pattern formed by another frame plating method, for example, formation of a coil. [0103]
Besides, for example, although the description has been made on the thin film magnetic head as an example, the present invention is not limited to this, but can be widely applied to manufacture of a device (micro device) having a fine structure, including a semiconductor device. [0104]
As described above, according to the present invention, it is possible to realize a frame plating method in which tilting of a resist frame having a high aspect ratio can be easily and certainly prevented and a desired plating film can be formed, and a manufacturing method of a thin film magnetic head using the method. [0105]

Claims

What is claimed is:

1. A plating method, comprising the steps of:

forming an electrode film on a substrate;

forming a resist layer on the electrode film;

developing the resist layer after exposure through a predetermined mask;

washing a developing solution on a surface of a resist frame formed through development by a washing solution; and

after washing, immersing a surface of the substrate in a state where the washing solution is held without being dried, into a plating solution to carry out plating.

2. A plating apparatus, comprising:

a developing/washing port ion for developing an exposed resist layer formed on a substrate and for washing a developing solution by a washing solution; and

a plating portion for carrying out plating after washing by immersing a surface of the substrate in a state where the washing solution is held without being dried, into a plating solution.

3. A plating apparatus according to

claim 2

, wherein the plating portion includes an opening portion to be closed by the substrate.

4. A plating apparatus according to

claim 3

, wherein the developing/washing portion includes a transporting mechanism for transporting the substrate to the opening portion.

5. A plating apparatus according to

claim 2

, further comprising a drainage receiving portion for receiving plating drainage between the developing/washing portion and the plating portion.

6. A manufacturing method of a thin film magnetic head, comprising a plating process of forming a plating film using a mold formed by patterning a resist, wherein

the plating process comprises a plating method according to

claim 1

.