JPH10183347A - Film forming apparatus for magneto-resistive head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus which forms flat and extremely thin films of several tens nm or below to multilayered films and efficiently forms multilayered films for magneto-resistive heads having the clean boundaries of the films by using an induction coupled RF plasma enhanced magnetron sputtering apparatus. SOLUTION: This apparatus has a load locking chamber 1 into and from which substrates for the magneto-resistive heads are put and which is freely changeable to the atm. pressure and high vacuum of order of <=10<-6> Pa, a pretreatment chamber 3 which has an etching device 4 to clean the substrates 1 vacuum transported into the load locking chamber and in which the high vacuum of the order of <=10<-6> Pa is provided and a vacuum film forming chamber 5 which has plural units of sputtering devices 6 for forming films of multiple layers on the substrates vacuum transported into these chambers and in which the high vacuum of the order of <=10<-7> Pa is maintained. The respective sputtering devices are constituted as the induction coupled RF plasma enhanced magnetron sputtering apparatus. The respective sputtering devices are provided with shutters in front thereof and the vacuum film forming chamber is internally provided with a permanent magnet to apply magnetic fields of a uniform and specified direction on the substrate and a turn table for moving the substrates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetoresistive effect (Ma
The present invention relates to a film forming apparatus suitable for manufacturing a magnetoresistive head for reproducing magnetic recording using gneto-resistance effect.

[0002]

2. Description of the Related Art Recently, this type of magnetoresistive head (Magnet
o-Resistance Head) is to obtain a magnetoresistive effect by layering a ferromagnetic film and a non-magnetic film. The reproduction output does not depend on the peripheral speed of the recording disk, there is no restriction on the resonance frequency by the coil, and the impedance Research and development have been conducted as being advantageous as a means for reproducing magnetic recording on which high-density recording has been performed, for example, because noise can be reduced. There are various types and structures of the magnetoresistive head. For example, a shield type magnetoresistive head having a film configuration shown in FIG. 1 is known. In the figure, a is a wear-resistant and low-thermal-expansion substrate such as AlTiC, b is a lower shield layer such as FeSiAl, c is a lower gap layer such as Al ₂ O ₃ , d is a Co-based alloy or Fe ₃ O _4. E is a SAL (Soft Adjacent Layer) layer of a ferromagnetic material such as NiFe alloy or Co amorphous, and f is T
a, a magnetic separation layer of Cu or the like, g is an MR stripe (ferromagnetic thin film) of NiFe or the like, h is an electrode of Cu, Au, W or the like, i is an upper gap layer of Al ₂ O ₃ or the like, and j is NiFe
And the upper shield layer. The MR stripe layer g converts a signal magnetic field from a recording medium into a voltage by a magnetoresistive effect, the magnetic separation layer f magnetically separates the MR stripe layer g from the SAL layer e, and the SAL layer e becomes the MR stripe layer g. A lateral bias is applied, and the hard bias layer d becomes the SAL layer e
Is used to magnetize.

[0003] It is preferable that the recording medium is magnetically recorded at an ultra-high density.
In order to favorably reproduce an ultra-high-density magnetic recording of bit / in ² or more, the ferromagnetic thin film constituting the MR stripe layer g has a single magnetic domain structure with one magnetic domain, and a nonmagnetic material such as Cu. A magnetic separation layer, a magnetic layer of Co, an antiferromagnetic layer of FeMn or the like, two or three layers are laminated to form a spin-valve magnetoresistive film, or a single domain MR stripe layer g
It has been proposed to alternately laminate, for example, eight times a layer comprising a set of a magnetic separation layer and a magnetic layer of Fe and an antiferromagnetic layer of Ni to form a magnetic multilayer film such as a giant magnetoresistive film.

Although an ion beam sputtering apparatus is used for forming such a multilayer film, productivity is poor. on the other hand,
The applicant has proposed an inductively coupled RF plasma assisted magnetron sputtering apparatus (helicon sputtering apparatus) capable of performing sputtering in an ultra-high vacuum having a configuration in which an RF induction discharge coil 1 is provided above a planar magnetron cathode k as shown in FIG. Experiments have shown that a multilayer film of a magnetoresistive head can be formed using this device.

[0005]

In order to manufacture the above-described magnetic multi-layered magnetoresistive head, an extremely thin flat magnetic film or magnetic separation layer having a clean film interface of about 0.4 to 11 nm is used. Need to be formed. For example, an Fe film having a thickness of 5.0 nm is formed on a silicon substrate, and a magnetic separation layer of Cu having a certain thickness and a NiFe layer having a thickness of 1 nm are alternately laminated thereon 20 times to form a magnetic multilayer film. (Giant magnetoresistive film), the magnetoresistance value (MR
As shown in FIG. 3, the ratio (Magnetoresistance Retio) greatly changes due to a change in the thickness of the Cu magnetic separation layer of about 10 °. It is not easy to form the magnetic separation layer with a uniform thickness of 1 nm. Although the MR value of the secondary peak near 2.1 nm in FIG. 3 is low, it is suitable for practical use because of its good sensitivity to changes in the magnetic field. In order to efficiently form a multilayered 2.1 nm Cu film or a magnetic film of about 10 nm with a flat interface and a clean interface, precise film thickness control and an extremely clean atmosphere are required. The productivity is poor, and a specific mass production apparatus for such a multilayer film using an inductively coupled RF plasma assisted magnetron sputtering apparatus (helicon sputtering apparatus) has not yet been developed.

A large number of magnetoresistive heads are manufactured by forming a necessary magnetic layer on a substrate having a diameter of about 5 inches and then cutting the substrate to a predetermined size. However, if the directions are not substantially constant in each substrate, the electric resistance value of the MR stripe layer is not constant, and a uniform magnetoresistive head cannot be obtained.

According to the present invention, an inductively coupled RF plasma-assisted magnetron sputtering apparatus is used to form a multilayer film for a magnetoresistive head in which a flat, extremely thin film having a thickness of not more than ten nm or less is formed and a film interface is clean. It is an object of the present invention to provide a well-formed device.

[0008]

According to the present invention, the atmospheric pressure at which the substrate for the magnetoresistive head is taken in and out of the atmosphere is set to 10 atmospheres.
A load lock chamber that can be changed to a high vacuum of ^-6 Pa or less,
A pretreatment chamber connected to the load lock chamber through an airtight substrate transfer path and provided with an etching device for cleaning the loaded substrate and evacuated to a high vacuum of the order of 10 ⁻⁶ Pa or less; 10 ^-7 provided with a plurality of sputtering apparatuses connected to the processing chamber and the load lock chamber via an airtight substrate transfer path and performing multilayer film formation on the substrate carried therein.
It has a vacuum film forming chamber evacuated to an ultra-high vacuum of Pa or less, and each sputtering device is provided with an inductively coupled RF plasma assisted with a magnet provided on the back of the target and an RF induction discharge coil on the target. Magnetron sputtering equipment,
A shutter is provided in front of each sputtering apparatus, a permanent magnet that applies a uniform magnetic field on the surface of the substrate to the surface of the substrate in the vacuum film forming chamber, and a turn that sequentially moves the substrate to a position facing each target. By providing a table, the above object is achieved.

An object of the present invention is to provide an ion beam etching apparatus provided with an electron cyclotron resonance type ion source, wherein the inductively coupled RF plasma-assisted magnetron sputtering apparatus has a through hole at a position facing the sputtering surface of the target. A side of the target and the RF
Provide a metal cover that covers the outer surface of the induction discharge coil,
An inductively coupled RF plasma-assisted magnetron sputtering device is arranged below the vacuum film forming chamber at intervals, the turntable is provided above the vacuum film forming chamber, a partition wall is provided at the space, and This can be achieved more appropriately by providing a turbo molecular pump in a vacuum evacuation system of a vacuum film forming chamber via a cryogenic trap.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. In FIGS. 4 and 5, reference numeral 1 denotes a large number of substrates 2 made of a thermally oxidized silicon wafer or AlTiC. An airtight load lock chamber for taking in and out of the atmosphere, a pretreatment chamber 3 having an etching device 4 for cleaning the substrate 2, and a multi-layer sputtering device 6 having a plurality of sputtering devices 6 A vacuum film forming chamber evacuated to an ultra-high vacuum of the order of 10 ⁻⁷ Pa or less for forming a film is shown, and four vacuum film forming chambers 5 are provided in the example of FIG. These rooms are
It is arranged around the transfer chamber 7 that is evacuated to a high vacuum, and communicates with each other to transfer the substrate via the transfer path provided with the gate valve 20 and the transfer chamber 7.

The load lock chamber 1 is controlled to 10 ^-6 Pa by an exhaust system 9 provided with a cryopump or a turbo molecular pump 8.
The transfer chamber 7 is evacuated to a high vacuum equal to or lower than the table, and the transfer chamber 7 is evacuated by an exhaust system comprising a combination of a titanium getter and an ion pump or an exhaust system 11 having a turbo molecular pump 10.
It is evacuated to ultra-high vacuum below ^-7 Pa. The pretreatment chamber 3 is evacuated to a high vacuum of the order of 10 ⁻⁶ Pa or less by an exhaust system 14 equipped with a turbo molecular pump 12 and a cryopump 13, and each vacuum deposition chamber 5 is cooled to a very low temperature with liquid helium. The gas was quickly evacuated to an ultra-high vacuum of the order of 10 ⁻⁷ Pa or less by an exhaust system 17 evacuated by a turbo molecular pump 16 through a trap 15.

In the load lock chamber 1, a cassette case 18 having a multi-stage tray on which the substrate 2 is placed is provided so as to be able to move up and down by an elevating table 22, and the substrate 2 is placed between the trays of the cassette case 18. The transfer arm 19 is mounted on a transfer arm 19 that can be extended, lowered, and swung freely and extends from the transfer chamber 7 and is transferred to the pretreatment chamber 3 or the vacuum film formation chamber 5. The substrate 2 on which film formation has been completed in the vacuum film formation chamber 5 is returned to the cassette case 18 in the load lock chamber 1 by the transfer arm 19. Although a frog-leg type is used as the illustrated transfer arm 19, a robot transfer device such as a magnetic levitation type can also be used.

The pretreatment chamber 3 has a relatively good ion beam straightness such as an electron cyclotron resonance type ion source 21 or a Kauffman type ion source having a relatively large diameter of about 8 inches as shown in FIG. An ion beam etching apparatus 4 equipped with an ion source is provided. The ion beam is loaded onto the substrate 2 carried from the transfer chamber 7 and held at a position facing the etching apparatus 4 by a suitable holding device (not shown). To clean the film-forming surface. The electron cyclotron resonance type ion source 21 has a known structure as shown in FIG. 6, and introduces a microwave through a microwave introduction tube 25 into a discharge chamber 24 in which an electron cyclotron resonance magnetic field is formed by a surrounding electromagnet 23. Then, a mixed gas of, for example, Ar and O ₂ introduced from the gas introduction tube 26 into the discharge chamber 24 is discharged, ions generated by the discharge are extracted by the extraction electrode 27, and the substrate 2 at the opposing position is cleaned by ion etching. Perform fine processing.

The details of the structure of each vacuum film forming chamber 5 are as shown in FIGS. 7 to 10. The lower side of the substantially circular vacuum film forming chamber 5 divided into four by a partition wall 62 is formed of Ar. A gas introduction port 60 for introducing a sputtering gas and an exhaust port 61 are provided, and an exhaust system 17 equipped with a cryogenic trap 15 of about 15 K is connected to the exhaust port 61 to form a partition wall 62 of the chamber 5. Four inductively-coupled RF plasma-assisted magnetron sputtering devices 28 with the sputter surface facing upward at equal intervals on the lower surface
Are vertically movable by a vertical moving device 29 provided with a bellows 35, and four substrates 2 are placed above a sputter surface of each sputtering device 28 via a shutter 31 which is opened and closed by being rotated by a rotating shaft 30 to vertically move. And a turntable 32 in the form of a disk that is pivotable. In addition, permanent magnets 45 and 46 for applying a magnetic field in a certain direction to the substrate 2 located thereon during film formation are provided above and below some of the sputtering devices 28 so as to be vertically movable by a lifting and lowering device 47. The shutter 31 is also moved up and down by the rotating shaft 30 which is moved up and down by the vertical movement device 29.

As shown in FIGS. 11 and 12, the inductively coupled RF plasma-assisted magnetron sputtering apparatus 28 includes a magnetic material attached to the front of a backing plate 33 in the upper end of a cylindrical case 41 extending from a flange 40. Alternatively, a nonmagnetic target 34, a magnet 36 provided on the back of the backing plate 33,
An RF induction coil 39 is provided above a cathode electrode 38 provided with an earth shield 37 surrounding the periphery of No. 4. From the periphery of the cathode electrode 38 to the front surface, a cylindrical metal cover 4 having an inner surface treatment and having a circular opening 43.
4 was attached to prevent diffusion of sputter particles, and the cathode electrode 38 was cooled by cooling water circulated through a cooling water pipe 63. When a DC or high-frequency current is applied to the cathode electrode 38 via the electrode rod 42 and an RF current is applied to the RF induction coil 39, the target 34
A plasma confined by the magnetic field of the magnet 36 is generated on the front of the target, ions in the plasma sputter the target 34, and the sputtered particles are ionized by the electric field of the RF induction coil 39, so that the turntable 3 at the opposing position is turned on.
2 to form a thin film on the surface of the substrate 2. By making the types of the targets 34 of the adjacent cathode electrodes 38 different, when one substrate 2 circulates over each cathode electrode 38, four layers of different materials can be formed on the substrates 2. The diameter of the target 34 is
A smaller substrate 2 is used.

The turntable 32 is, as shown in FIGS. 9 and 13, a table having four substantially circular through holes 48 cut from the periphery for mounting four substrates 2, for example. A step 49 for stably mounting the substrate 2 is formed around the through-hole 48, and a vertically rotating shaft 50 of the table 32 led out to the outside through the vacuum film forming chamber 5 is provided. An external elevating device 51 and a rotating device 52 are used to vertically move and turn. This vertical movement is performed to transfer the substrate 2 to and from the transfer arm 19 of the transfer chamber 7. When receiving the substrate 2 from the transfer arm 19, the table 32 waits in advance at the lowered position, and then moves up. Receiving the substrate 2, the transfer arm 19 retreats. The substrate 2 on the table 32 is transferred to the transfer arm 19 by this reverse operation.

When a magnetic film is formed on the substrate 2 on the turntable 32 by using the magnetic target 34, a pair of long permanent magnets 45 are provided on the opposite side of the film formation surface of the substrate 2 during the film formation. , 46 are applied, and a uniform magnetic field having a uniform strength of, for example, 100 Oe is applied to the film forming surface, and a constant magnetization for obtaining a magnetoresistive effect as a magnetoresistive head on the formed magnetic film. To give the direction. The permanent magnets 45 and 46 were attached to a plate-shaped holder 53, and were moved up and down by an elevating shaft 55 which is moved up and down by an external elevating device 47 so as not to hinder the elevating of the turntable 32. When a plurality of magnetic layers are formed on the substrate 2 of the magnetoresistive head, a holder 53 provided with the permanent magnets 45 and 46 is provided so as to face each of the cathode electrodes 38 on which the magnetic layers are formed. The permanent magnets 45 and 46 are arranged in a fixed positional relationship with respect to the substrate 2 in order to make the orientation constant. It should be noted that an orientation flat 5 cut linearly as shown in FIG.
14, the substrate 2 is placed in a fixed direction with respect to the through hole 48 of the turntable 32. Therefore, as shown in FIG. A locking edge 19a, a spatula-shaped flat surface 19b having a length corresponding to the shortest diameter of the substrate 2, and an arc-shaped locking edge 19c along the arc of the substrate on the root side of the transfer arm 19. The flat surface 1 is formed from the top of the locking edge 19a.
A downward slope 19d following 9b was formed. Accordingly, when the substrate 2 is placed on the transfer arm 19, as shown in FIGS. 15 and 16, the edge of the substrate 2 slides on the slope 19d, and the orientation flat 56 is along the locking edge 19a. 2 are set in a fixed direction on the transfer arm 19. Therefore, the substrate 2 can be set on the turntable 32 in a fixed direction and placed on the transfer arm 19, and if the positions of the permanent magnets 45 and 46 when forming the magnetic layer are kept constant, Since a magnetic layer with a uniform magnetization direction can be formed on a large number of substrates 2, a large number of uniform magnetoresistive heads with a uniform magnetization direction can be manufactured by uniformly cutting the substrate 2 after film formation. .

The operation in the case of forming a film having the film configuration shown in FIG. 17 for a magnetoresistive head on the substrate 2 of a silicon wafer with a thermal oxide film having a diameter of, for example, 6 inches by the apparatus having the above-described configuration will be described below. . The top configuration of this film has a thickness of 20.9
A set of ÅCu and 18ÅNiFe (permalloy) is laminated eight times.

A cassette case accommodating 16 substrates 2 is housed in a load lock chamber 1, and the inside of the chamber 1 is evacuated to a high vacuum of 10 ⁻⁶ Pa or less by an exhaust system 9, and the transfer chamber 7 is simultaneously exhausted. The system 11 is evacuated to an ultra-high vacuum of the order of 10 ^-7 Pa, and the pretreatment chamber 3 is evacuated to a high vacuum of the order of 10 ^-6 Pa or less by the exhaust system 14. Thereby, moisture and gas components adhering to the substrate 2 are eliminated. Subsequently, the partition valve of the load lock chamber 1 is opened, and the transfer arm 19 of the transfer device in the transfer chamber 7 is caused to enter the load lock chamber 1, whereby one substrate 2 is taken out from the cassette case, and the pretreatment chamber 3 is removed. Open and place it on a holding device (not shown) inside it. Then, the pretreatment chamber 3 is sealed, an Ar gas mixed with 3% oxygen gas is introduced to adjust the pressure to, for example, about 10 ⁻² Pa, and then an acceleration voltage of 300 V is applied to the ion beam etching apparatus 22. Is operated to etch and clean the film-forming surface on the lower surface of the substrate 2, and, if necessary, to etch the conductive parts and the like with a width of about 0.3 μm. The etching time in this example is 30 minutes and the etching rate is 100
Å / min, uniformity is ± 5%. By this pretreatment, the film formation surface of the substrate 2 is completely cleaned. The introduced gas may be only Ar gas or another rare gas.

When the pretreatment is completed, the air is re-evacuated to the order of 10 ⁻⁷ Pa, the partition valve is opened, the transfer arm 19 takes out the substrate 2, and the exhaust system 17 preliminarily evacuates to an ultra-high vacuum of the order of 10 ⁻⁷ Pa or less. The gate valve is opened in one of the evacuated vacuum film forming chambers 5a, and the substrate 2 is carried in through the high vacuum transfer chamber 7 without contamination. The preprocessed substrate 2 is carried in above the turntable 32 at the lowered position, and receives the substrate 2 from the transfer arm 19 when the turntable 32 is raised.

The above operation is repeated twice in total, and when the two pre-processed substrates 2 are placed on the turntable 32 at a position rotated by 180 °, the partition valve of the vacuum film forming chamber 5a is closed, and the induction coupling RF is performed. The turntable 32 is moved up and down to adjust the distance between the target 34 and the substrate 2 of the plasma assisted magnetron sputtering apparatus 28. In the vacuum film forming chamber 5a, for example, the five Nine F
e target 34 and Ni ₈₁ Fe ₁₉ (wt%) target 34 are prepared alternately, and Ar gas is introduced to adjust the pressure to the order of 10 ⁻² Pa, and each sputtering apparatus is operated. , Each substrate 2 is a sputtering device 28 of an Fe target
When the permanent magnets 45 and 46 are located at a predetermined position, for example, 150 mm above the target and behind each substrate 2, an Fe film is formed while opening each shutter 31 and monitoring with a film thickness monitor. Sputter rate is 0.2
When the film thickness reaches a predetermined value of 100 °, the shutters are closed, the turntable 32 is turned by 90 °, and each substrate is positioned above the next NiFe target sputtering apparatus. Behind them, another permanent magnets 45 and 46 are arranged and Ni is formed to a predetermined thickness of 100 mm.
An Fe film is formed. In this case, magnetron discharge can be performed on the front surface of each target 34 even in the order of 10 ⁻² Pa by applying, for example, DC 60 W to the cathode electrode 38 of the sputtering device 28 and applying 70 W of RF power to the RF induction coil 39. A high-density plasma is formed, and many of the sputtered particles sputtered at an extremely low sputter rate are ionized by the RF induction coil 39 and enter the substrate 2 to form a thin and flat film or layer.

When the lower two films having the same magnetization directions are formed in this manner, these substrates 2 are transferred to the next vacuum film forming chamber 5b which has been evacuated to an ultra-high vacuum of the order of 10 ⁻⁷ Pa or less. The substrate 2 is carried in by the transfer arm 19, and the same transfer as in the case of the vacuum film forming chamber 5a is performed, and the substrate 2 is placed at a position 180 ° away from the turntable 32. Cu and Fe targets are alternately prepared in the four sputtering apparatuses in the vacuum film forming chamber 5b.
Are positioned on each of the substrates 2 at the above-mentioned sputtering rate.
A Cu film is formed to a thickness of 0.9 mm by controlling the opening and closing of the shutter 31. Four sputtering devices 28 in one film forming chamber
The time difference in forming a film can be reduced as much as possible. In order to perform sputtering while the surface state of the film is active, it is effective to arrange four or more cathodes in the same film forming chamber. Subsequently, each substrate 2 is positioned on a NiFe target sputtering apparatus by turning the turntable 32 at 90 °, and a permanent magnet 45 is provided behind each substrate 2 so as to give the same magnetization direction as the two lower films. , 46 are positioned and the shutter is controlled while monitoring the film thickness to form an 18 ° NiFe film on the Cu film at the sputtering rate. By turning the turntable and repeating the film formation of Cu and NiFe eight times, a substrate having a magnetic multilayer film with a uniform magnetization direction for a magnetoresistive head is obtained. Then, if necessary, the substrate 2 can be transferred to another vacuum film forming chamber 5d by the transfer arm 19 to form a protective film, and then returned to the load lock chamber 1. The exhaust system 17 of each high-vacuum film forming chamber 5 is provided with a trap 15 at an extremely low temperature of about 15 K, and even a small amount of water molecules is reliably eliminated from the film forming chamber 5 to obtain a clean ultra-high vacuum. As a result, a film or layer with a clean interface can be formed. Further, in manufacturing a giant magnetoresistive (GMR) element, it is important to supply a clean gas to each of the ultra-high vacuum chambers. In this device, gas purification and internal processing such as Ni plating treatment are applied to parts such as gas pipes and valves as well as filters, and pipes are rounded as much as possible to avoid corners. So that
The flow of the sputter gas is continuously performed in the bent and run except at the time of sputtering.

The operation for forming a film on the substrate in units of two has been described above for the sake of simplicity. However, during the film formation in the vacuum film forming chamber 5b, the pre-processing chamber 3 transfers the load from the load lock chamber 1 to the substrate. The next substrate taken out is subjected to a pretreatment, carried into the vacuum film forming chamber 5a, and after film formation there, Cu and Ni are deposited in another vacuum film forming chamber 5c.
If the set of Fe is formed eight times, the substrate 2 carried into the load lock chamber 1 can be quickly formed into a film for the magnetoresistive head of the spin valve MR having the magnetic multilayer film, and the set is formed 30 times. Film formation for a giant MR magnetoresistive head is also possible.

The position of the substrate on the turntable 32 is determined by the engagement edge 19 a provided on the transfer arm 19 and the downward slope 19.
Since the direction of the substrate is accurately determined when it is placed on the transfer arm 19 by c, the direction of the substrate on the turntable 32 is also fixed, and a magnetic layer having a fixed magnetization direction can be formed on each substrate.
The substrate on which the magnetic multilayer film and the protective film have been formed is cut into a dice-like MR element with the magnetization directions aligned, and assembled into a shield type or yoke type magnetoresistive head.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetoresistive head substrate 2 of 16 silicon oxide-coated silicon wafers having a diameter of 6 inches is placed in a cassette case and housed in a load lock chamber 1, the load lock chamber 1, a transfer chamber 7, and a pretreatment chamber 3. And the vacuum film forming chamber 5 is set to 10 ⁻⁶ Pa, respectively.
The air was evacuated to the order of 10 ^-7 Pa, the order of 10 ^-6 Pa and the order of 10 ^-7 Pa, and one substrate was first loaded into the pretreatment chamber 3 by the transfer arm 19 via the vacuum transfer chamber. Ar gas mixed with 3% oxygen gas was introduced into the pretreatment chamber 3 so that 1.3 × 10 ^-2.
The pressure was adjusted to Pa, and 30
An accelerating voltage of 0 V was applied to perform etching of uniformity of ± 5% at an etching rate of 50 ° / min. Subsequently, the substrate 2 was carried into the vacuum film forming chamber 5a evacuated to the order of 10 ⁻⁷ Pa. By repeating this, when two substrates were placed on the turntable of the vacuum film forming chamber 5a, Ar gas was introduced into the chamber 5a to adjust the pressure to 7 × 10 ⁻² Pa. Then, high-frequency power of DC 60 W is applied to the two cathode electrodes 38 provided with the Fe target and the NiFe target, and 70 W is applied to the RF induction coil 39, and a permanent magnet 45, 46 applies a magnetic field of 100 Oe to the film formation surface of the substrate 2. 0.1-0.8 while giving
A 100 ° Fe film and a NiFe film were sequentially formed at a sputter rate of Å / sec. This is because the shutter opening / closing speed is mechanically several hundred milliseconds to one second, so that when the sputtering rate is 0.1 ° / sec, the film thickness of 0.1 ° can be controlled in one second. For example, since the thickness of one Si atom layer is 3 mm, this example enables control of 0.1 monolayer (0.1 layer) or less. These two substrates are further carried into the above-described vacuum film forming chamber 5b provided with two Cu and NiFe targets, and mounted on a turntable on the Cu target, and under the same conditions as the vacuum film forming chamber 5a under the same pressure and the like. Then, the turntable was intermittently rotated to form 8 layers of a 20.9 ° Cu film and an 18 ° set layer, and two magnetoresistive head substrates having the film configuration of FIG. 17 were produced. The substrate 2 was cut into a width of 3 mm to form an MR element. The MR characteristics of each element were evaluated by a DC terminal method using a four-terminal probe having a terminal distance of 5 mm. The MR ratio expressed by the amount of change / the resistivity of the MR stripe is 5.83.
%, Which was uniform and sufficiently usable for a magnetoresistive head.

[0026]

As described above, according to the present invention, a load lock chamber capable of changing the substrate for the magnetoresistive head to the atmospheric pressure and a high vacuum of the order of 10 ⁻⁶ Pa or less, and an airtight substrate transfer path in the load lock chamber. ^-6 P with an etching device connected via
a high-vacuum pre-processing chamber of a number or less, and a plurality of sputtering apparatuses connected to the pre-processing chamber and the load lock chamber via an air-tight substrate transfer path and performing multi-layer film formation on the substrate.
A vacuum deposition chamber that is evacuated to an ultra-high vacuum of ^-7 Pa or less is provided, and each sputtering device is an inductively-coupled RF plasma-assisted magnetron sputtering device. Since it is performed while applying a magnetic field in a fixed direction, an extremely thin and flat multilayer film with a clean interface can be formed, and a fixed magnetization direction is given to the magnetic film in the multilayer film, so that an MR suitable for a magnetoresistive head can be formed.
There is an effect that a substrate having a ratio can be efficiently manufactured.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a film configuration of a conventional magnetoresistive head.

FIG. 2 is a sectional view of a main part of an inductively coupled RF plasma assisted magnetron sputtering apparatus.

FIG. 3 is a diagram of a magnetoresistance value of a magnetic multilayer film.

FIG. 4 is a schematic perspective view showing an embodiment of the present invention.

FIG. 5 is a plan view of FIG. 4;

FIG. 6 is an enlarged sectional view of a main part of the electron cyclotron resonance type ion source used in the present invention.

FIG. 7 is a cut side view of the vacuum film forming chamber of FIG. 4;

8 is a sectional view taken along line 8-8 in FIG. 7;

9 is a sectional view taken along line 9-9 in FIG. 7;

FIG. 10 is a sectional view taken along lines 10-10 in FIG. 7;

FIG. 11 is an enlarged sectional view of the inductively coupled RF plasma assisted magnetron sputtering apparatus of FIG. 7;

FIG. 12 is a plan view taken along line 12-12 of FIG. 11;

FIG. 13 is an enlarged view of a portion taken along line 13-13 of FIG. 7;

FIG. 14 is an enlarged perspective view of a main part of a transfer arm.

FIG. 15 is an explanatory diagram of a state where a substrate is placed on a transfer arm with a positional shift;

FIG. 16 is an explanatory diagram of a state in which a displacement of a substrate on a transfer arm has been corrected;

FIG. 17 is a structural diagram of a multilayer film of a magnetoresistive head manufactured by the apparatus of the present invention.

[Explanation of symbols]

1 load lock chamber, 2 substrates, 3 pretreatment chamber, 4 etching equipment, 5.5a / 5b / 5c / 5d vacuum film formation chamber, 6 sputtering equipment, 7 transfer chamber, 15 trap,
16 turbo molecular pump, 17 exhaust system, 19 transfer arm, 21 electron cyclotron resonance type ion source, 28
Inductively coupled RF plasma assisted magnetron sputtering apparatus,
31 shutter, 32 turntable, 38 cathode electrode, 39 RF induction coil, 44 metal cover, 45/46 permanent magnet, 62 partition wall,

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[Procedure amendment]

[Submission date] April 24, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0022

[Correction method] Change

[Correction contents]

When the lower two films having the same magnetization directions are formed in this manner, these substrates 2 are transferred to the next vacuum film forming chamber 5b which has been evacuated to an ultra-high vacuum of the order of 10 ⁻⁷ Pa or less. The substrate 2 is carried in by the transfer arm 19, and the same transfer as in the case of the vacuum film forming chamber 5a is performed, and the substrate 2 is placed at a position 180 ° away from the turntable 32. Cu and Fe targets are alternately prepared in the four sputtering apparatuses in the vacuum film forming chamber 5b.
Are positioned on each of the substrates 2 at the above-mentioned sputtering rate.
A Cu film is formed to a thickness of 0.9 by controlling the opening and closing of the shutter 31. Four sputtering devices 28 in one film forming chamber
The time difference in forming a film can be reduced as much as possible. In order to perform sputtering while the surface state of the film is active, it is effective to arrange four or more cathodes in the same film forming chamber. Subsequently, each substrate 2 is positioned on a NiFe target sputtering apparatus by turning the turntable 32 at 90 °, and a permanent magnet 45 is provided behind each substrate 2 so as to give the same magnetization direction as the two lower films. , 46 are positioned, and the shutter is controlled while monitoring the film thickness to form 18 NiFe films on the Cu film at the sputtering rate. By turning the turntable and repeating the film formation of Cu and NiFe eight times, a substrate having a magnetic multilayer film with a uniform magnetization direction for a magnetoresistive head is obtained. Then, if necessary, the substrate 2 can be transferred to another vacuum film forming chamber 5d by the transfer arm 19 to form a protective film, and then returned to the load lock chamber 1. The exhaust system 17 of each high-vacuum film forming chamber 5 is provided with a trap 15 at an extremely low temperature of about 15 K, and even a small amount of water molecules is reliably eliminated from the film forming chamber 5 to obtain a clean ultra-high vacuum. As a result, a film or layer with a clean interface can be formed. Further, in manufacturing a giant magnetoresistive (GMR) element, it is important to supply a clean gas to each of the ultra-high vacuum chambers. In this device, gas purification and internal processing such as passivation processing and Ni plating processing are applied to parts such as gas pipes and valves as well as filters, and pipes are rounded as much as possible to avoid corners. So that
The sputter gas is kept flowing through the discard line by vent-and-run except at the time of sputtering.

Claims (6)

[Claims] 1. A load lock chamber capable of changing a substrate into and out of the atmosphere with atmospheric pressure and a high vacuum of 10 ^-6 Pa or less, and connected to the load lock chamber via an airtight substrate transfer path. A preprocessing chamber evacuated to a high vacuum of the order of 10 ⁻⁶ Pa or less, provided with an etching apparatus for cleaning the loaded and carried substrate, and an airtight substrate transport path to the preprocessing chamber and the load lock chamber. A vacuum film forming chamber evacuated to an ultra-high vacuum of 10 ⁻⁷ Pa or less equipped with a plurality of sputtering devices for forming a multi-layer film on the substrate loaded and connected therein, The sputtering apparatus is an inductively coupled RF plasma assisted magnetron sputtering apparatus having a magnet provided on the back of the target and a coil for RF induction discharge on the target, a shutter is provided in front of each sputtering apparatus, and the inside of the vacuum film forming chamber is provided. , Deposition apparatus characterized a permanent magnet providing a magnetic field of uniform fixed direction to the surface of the plate, that the substrate provided with a turntable to move sequentially to the position opposite to the respective targets. 2. A film forming apparatus for a magnetoresistive head according to claim 1, wherein said etching apparatus is an ion beam etching apparatus provided with an electron cyclotron resonance type ion source. 3. The inductively coupled RF plasma-assisted magnetron sputtering apparatus has a through hole at a position facing a sputtering surface of the target, and a side surface of the target and the R
2. The film forming apparatus for a magnetoresistive head according to claim 1, further comprising a metal cover that covers an outer surface of the F induction discharge coil. 4. An inductively coupled RF plasma-assisted magnetron sputtering apparatus is disposed below the vacuum film forming chamber at intervals, and the turntable is provided above the vacuum film forming chamber.
2. A film forming apparatus for a magnetoresistive head according to claim 1, wherein partition walls are provided at said intervals. 5. A film forming apparatus for a magnetoresistive head according to claim 1, wherein a turbo molecular pump is provided in a vacuum exhaust system of said vacuum film forming chamber via a cryogenic trap. 6. Before the substrate is transferred from the pre-processing chamber to the vacuum film forming chamber, the pre-processing chamber is re-evacuated to 10 ^-7 to 10 ^-8 Pa to allow gas to flow from the pre-processing chamber. A film forming apparatus, wherein the substrate is transported so as not to flow out to an empty film forming chamber.