JP2001006963A - Device and method for forming film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method for forming film by which an element having superior characteristics and having a multilayered film structure can be formed, by preventing the contamination of substrates when the substrates pass through a transportation chamber. SOLUTION: A multilayered film is formed on a substrate 1 by using a film forming device having a plurality of treatment chambers (a cleaning chamber 20, a first film forming chamber 30, and a second film forming chamber 40). A substrate 1 passes through a transportation chamber 50 when the substrate 1 is moved among the treatment chambers. When the substrate 1 passes through the chamber 50, an inert gas, such as the argon gas, etc., is introduced to the chamber 50 so that the substrate 1 may pass through the chamber 50 in an inert gas atmosphere. Therefor, contamination problems, such as the moisture adsorption, etc., which conventionally occur when the substrate 1 passes through the chamber 50 can be reduced, and the quality grade and stability of a formed film can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for forming a film on a substrate in a reduced-pressure atmosphere.

[0002]

2. Description of the Related Art In recent years, a giant magnetoresistive (GMR) element having high reproduction sensitivity has been used as a thin-film magnetic head for reproduction in a magnetic disk drive. Among these GMR elements, in particular, they have high reproduction sensitivity and good productivity.
GMR elements using spin valve films have become mainstream. This type of GMR element is generally manufactured by a thin film process using a film forming apparatus having a vacuum chamber. In this specification, the term “vacuum” means not only a vacuum in a strict sense, but also a space or a state in which the pressure is lower than the atmospheric pressure (depressurized).

[0003] Since this spin valve film has a multilayer structure composed of a plurality of films, a plurality of targets are required when the spin valve film is manufactured by, for example, a sputtering apparatus. Specifically, at least four, and in some cases, five or more targets are required. When such a large number of targets are arranged in one film formation chamber (vacuum chamber), the size of the film formation chamber becomes large, the pumping speed becomes slow, and the productivity decreases. For this reason, a plurality of film formation chambers are provided, and a plurality of targets are allocated to the plurality of film formation chambers and arranged. Further, when an oxide film is included in the multilayer structure, the oxygen introduced in the step of forming the oxide film remains and may adversely affect the composition of another film. Must be formed using another film forming chamber.

On the other hand, for example, JP-A-2-282474 and JP-A-10-183347 disclose a sputtering film forming apparatus having a plurality of chambers. This film forming apparatus includes, as a vacuum chamber, an introduction chamber for introducing a substrate (wafer) from the air into each chamber in a reduced pressure atmosphere, a wafer cleaning chamber for cleaning the substrate before film formation, and a substrate cleaning apparatus. And a target chamber, and a sputtering chamber for forming a predetermined thin film on the substrate by sputtering the target, and a transfer chamber having a transfer mechanism for transferring the substrate between the chambers. In these examples of the film forming apparatus, one etching chamber and one film forming chamber are provided as a wafer cleaning chamber. In many cases, a plurality of layers are provided according to the number of layers.

In this type of film forming apparatus, each processing step such as cleaning, thin film formation, and etching is performed by sequentially transporting a substrate to be processed to each of the film forming chambers and the etching chamber. This substrate transfer is performed by a transfer mechanism in a transfer chamber.

[0006]

In the above film forming apparatus,
The substrate introduced from the introduction chamber is always transported to the film formation chamber or the etching chamber via the transport chamber. Here, as described above, each time a new group of substrates is introduced (replaced), the introduction chamber transitions between the atmospheric pressure state and the reduced pressure state, and thus is directly connected to the introduction chamber. The transported chamber contains a relatively large amount of residual impurities such as moisture, even though it is continuously exhausted. Therefore, the substrate passing through the transfer chamber adsorbs residual impurities and the like during the passage and contaminates the surface thereof, thereby adversely affecting the film quality or deteriorating the reproducibility (stability) of the film quality. And so on.

In particular, in the above-mentioned spin valve film, the present inventors have found that the interface state between the layers in the multilayer structure has an important effect on the device characteristics. That is, if contamination during passage through the transfer chamber intervenes between the film formation in one film formation chamber and the film formation in another film formation chamber, there arises a problem that required element characteristics cannot be obtained.

In order to solve this problem, a method of maintaining a sufficiently high degree of vacuum in the transfer chamber is conceivable. To this end, a method of exhausting the transfer chamber over a sufficiently long time or a method of exhausting the transfer chamber using a high-performance vacuum pump having a large exhaust capacity can be considered. However, the former method has a problem that the processing time is long, and the latter method has a problem that the equipment cost increases.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent a substrate from being contaminated when passing through a transfer chamber, thereby forming a film structure element having excellent characteristics. It is an object of the present invention to provide a film forming apparatus and method capable of forming the film.

[0010]

According to the present invention, there is provided a film forming apparatus comprising: a plurality of processing chambers for holding a substrate under reduced pressure and performing a predetermined film forming process on each of the accommodated substrates; And a connecting portion atmosphere holding means for holding the connecting portion in a predetermined inert gas atmosphere state when the substrate moves between the plurality of processing chambers. . Here, the film forming process includes, in addition to the thin film forming process, a cleaning process before forming the thin film, and a removing process or a processing process of the formed thin film. It has the same meaning in the following description.

In the film forming apparatus according to the present invention, a predetermined film forming process is performed on each of the substrates accommodated in the processing chamber, and at least when the substrate moves between the plurality of processing chambers. The connecting portion is maintained in a predetermined inert gas atmosphere state by the connecting portion atmosphere holding means.

In the film forming apparatus of the present invention, the connecting portion may constitute a common chamber arranged so as to be commonly adjacent to all of the plurality of processing chambers. In this case, the common chamber may constitute a substrate transfer chamber provided with a transfer mechanism capable of transferring a substrate between the processing chambers.

In the film forming apparatus according to the present invention, the plurality of processing chambers may include at least one film forming chamber for forming a predetermined film on the substrate. In this case, the plurality of processing chambers have at least one
One film formation chamber for forming one film and another film formation chamber for forming at least one other film on the substrate, so that a multilayer film can be formed on the substrate. Can be configured. Further, in this case,
The film formation chamber can be configured to be a processing chamber for performing film formation by sputtering.

In the film forming apparatus of the present invention, the plurality of processing chambers may include at least one cleaning chamber for cleaning the surface of the substrate.

[0015] The film forming apparatus of the present invention may further include at least one substrate introduction chamber for introducing a substrate from an atmospheric pressure atmosphere to a reduced pressure atmosphere.

In the film forming apparatus of the present invention, the inert gas may be an argon (Ar) gas.

Further, in the film forming apparatus of the present invention, further, in a state where at least the substrate is placed in any one of the processing chambers, a processing chamber atmosphere holding means for holding the processing chamber in an inert gas atmosphere state is provided. It may be provided.

Further, in the film forming apparatus according to the present invention, the predetermined film forming process includes a multi-layer film, and is used for forming a magnetoresistive element whose electric resistance characteristics change according to an external magnetic field. It may be a thing.

The film forming method according to the present invention is a film forming method for performing a film forming process on a predetermined substrate using a film forming apparatus having a plurality of processing chambers capable of maintaining a reduced pressure.
The method may include a step of performing a predetermined film forming process on a substrate housed in the processing chamber, and a step of moving the substrate in each processing chamber while holding the substrate in a predetermined inert gas atmosphere. It was made.

According to the film forming method of the present invention, a predetermined film forming process is performed on the substrate housed in the processing chamber,
At least when the substrates are mutually moved in each processing chamber, the substrates are held in a predetermined inert gas atmosphere.

In the film forming method according to the present invention, the step of performing the film forming processing may include at least one film forming step for forming a predetermined film on the substrate. In this case, the film forming step includes a step of forming at least one film on a substrate housed in any one of the processing chambers and a step of forming at least one other film on a substrate housed in another of the processing chambers. And a step of forming a film, so that a multilayer film can be formed on the substrate.

Further, in the film forming method of the present invention, the step of performing the predetermined film forming processing may include a film forming step by sputtering.

In the film forming method of the present invention, the step of performing the predetermined film forming processing may include a step of cleaning the surface of the substrate.

In the film forming method of the present invention, argon (Ar) gas may be used as the inert gas.

Further, in the film forming method of the present invention, even when a substrate is placed in any one of the processing chambers, the processing chamber may be kept in an inert gas atmosphere.

According to the film forming method of the present invention, the predetermined film forming process includes a multi-layer film, and is used for forming a magnetoresistive element whose electric resistance characteristics change according to an external magnetic field. It may be a thing.

[0027]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 4 show a configuration of a film forming apparatus according to an embodiment of the present invention. Here, FIG. 1 shows a plane configuration of the entire film forming apparatus, FIG. 2 shows a cross section taken along the line II-II in FIG. 1, and FIGS. 3 and 4 show the direction III-III in FIG. Shows a cross section taken along the arrow in FIG. However, FIGS. 2 to 4 each show a partially broken state. FIGS. 3 and 4 show a case where transfer arms 501 described later are in different states from each other.

The film forming method according to one embodiment of the present invention is embodied by the film forming apparatus according to the present embodiment, and will be described below.

[Configuration of Film Forming Apparatus] First, referring to FIG. 1, the overall configuration of the film forming apparatus will be described. This film-forming apparatus is a single-wafer type multi-chamber film-forming apparatus capable of continuously performing a cleaning process of a substrate to be formed and a film formation on the substrate by DC electric field application type sputtering. It is configured as However, the sputtering method is not limited to the DC electric field application method, but may be a high frequency electric field application method or another method.

As shown in FIG. 1, the film forming apparatus includes a load for introducing a substrate 1 on which a film is to be formed from an atmospheric pressure atmosphere into a vacuum atmosphere or returning the substrate 1 from the vacuum atmosphere to the atmospheric pressure atmosphere. An unloading chamber 10, a cleaning chamber 20 for cleaning the surface of the substrate 1, and a first film forming chamber 30 and a second film forming chamber 40 for stacking a plurality of films using the substrate 1 as a supporting base. And a transfer chamber 50 which is surrounded on all sides by the above-mentioned four processing chambers (hereinafter simply referred to as chambers) and arranged so as to be commonly connected to each of the chambers, and controls the operation of the entire apparatus. And a control unit (not shown). A gate valve 60 is provided between the transfer chamber 50 and another chamber.
-1 to 60-4 are provided. By opening and closing these gate valves 60-1 to 60-4, communication between the transfer chamber 50 and the other chambers can be established or interrupted, respectively. Here, the cleaning chamber 20, the first film forming chamber 30, and the second film forming chamber 40 correspond to a specific example of “a plurality of processing chambers” in the present invention, and the transfer chamber 50 corresponds to a “connecting part” in the present invention. This corresponds to one specific example. The load / unload chamber 10 corresponds to a specific example of “substrate introduction chamber” in the present invention.

As shown in FIG. 2, the load / unload chamber 10 has a substrate stocker 10 capable of storing a plurality of substrates 1.
1 and a vacuum gauge (not shown) for detecting the degree of vacuum in the load / unload chamber 10. Substrate stocker 10
Numeral 1 is connected to the tip (the upper end in FIG. 2) of the spindle 103 of the actuator 102 fixed to the outer wall of the load / unload chamber 10 (the lower outer wall in this figure).
The substrate stocker 101 is driven in a linear direction (vertical direction in FIG. 2) by driving the actuator 102. As the actuator 102, for example, a cylinder actuator that operates by air pressure or hydraulic pressure, or an actuator that operates by rotation of a motor is used.

The load / unload chamber 10 has an exhaust pipe 10
4 and a valve 105, a vacuum pump 106 having a high pumping capacity is connected. Although only one vacuum pump 106 is shown in FIG. 2, in practice, for example, a rotary pump, a cryopump, a turbo molecular pump, and the like are selectively and sequentially driven, or are driven in combination. The inside of the load / unload chamber 10 can be evacuated from an atmospheric pressure state to a high vacuum state. Here, the cryopump is
Create a cryogenic solid surface by operating the refrigerator,
This is a vacuum pump of the type in which gas is condensed on that surface to remove gas molecules from the space, and is capable of obtaining an ultra-high vacuum. Turbo molecular pumps alternately arrange fixed impellers (stator) and rotating impellers (rotor) at opposite angles, and the probability that gas molecules pass through this structure depends on the direction of the passage. Is a vacuum pump designed to obtain an exhaust action by using
An ultra-high vacuum of about 0 ^-7 Pa (Pascal) can be obtained. The rotary pump is a vacuum pump of a system in which a rotor is rotated to mechanically sweep out air, and a vacuum of about 1.33 Pa is obtained from the atmospheric pressure. It should be noted that the ultimate vacuum degree of the load / unload chamber 10 (that is, the vacuum degree that can be reached when exhaustion is performed for a sufficiently long time in a no-load state) is
For example, the pressure is preferably about 1.33 × 10 ⁻⁵ Pa.

The load / unload chamber 10 is also provided with an open / close door (not shown) which can be opened / closed only when the inside of the load / unload chamber is at atmospheric pressure, and through which the substrate 1 is connected to an external substrate container (not shown). ) And the substrate stocker 101.

As shown in FIGS. 1 to 4, the transfer chamber 50 has a transfer arm 50 capable of transferring the substrate 1 between the chambers.
1 is provided. The transfer arm 501 has a pantograph-like structure as shown in FIG.
The expansion and contraction operation is possible by driving the actuator 502 provided on the lower outer wall of the actuator 502, and the actuator 502 is capable of rotating (turning) around the shaft portion 503. A gripper 501a that can grip the substrate 1 is provided at the tip of the transfer arm 501. With the gate valve 60-1 open, the actuator 502
Is driven, the transfer arm 501 can grasp and take out one substrate 1 stored in the substrate stocker 101 of the load / unload chamber 10.
The state (position) of the transfer arm 501 shown in FIG.
Corresponds to the state shown in FIG. 3, and FIG. 2 and FIG.
It does not correspond to the state of.

As shown in FIG. 3, a vacuum pump 510 having a high exhaust capacity is connected to the transfer chamber 50 via an exhaust pipe 508 and a conductance valve 509 for adjusting the exhaust amount. 2, illustration of the exhaust pipe 508, the conductance valve 509, and the vacuum pump 510 is omitted. The ultimate degree of vacuum of the transfer chamber 50 is preferably, for example, about 1.33 × 10 ⁻⁶ Pa.

As shown in FIGS. 2 and 3, the transfer chamber 5
0 is also connected to a gas introduction pipe 505 for introducing an inert gas such as argon (Ar). A valve 506 for adjusting the flow rate of the introduced gas and a flow meter 507 for detecting the flow rate of the introduced gas are provided in the flow path of the gas introduction pipe 505. Here, the gas introduction pipe 505, the valve 506, and the flow meter 507 mainly correspond to a specific example of “the connection portion atmosphere holding means” in the present invention.

In the transfer chamber 50, a valve 5 is provided based on the flow rate of the introduced gas detected by the flow meter 507 and the degree of vacuum in the transfer chamber 50 detected by a vacuum gauge (not shown).
06 and the opening degree of the conductance valve 509 are adjusted. Thus, the inside of the transfer chamber 50 is maintained in an inert gas atmosphere having a predetermined gas pressure. Here, when the inert gas is argon, at least the argon gas pressure in the transfer chamber 50 when the substrate 1 is passing is maintained at, for example, about 1.33 × 10 ^{−2 to} 1.33 Pa. preferable.

As shown in FIG. 3, the cleaning chamber 20
A substrate mounting table 201 for mounting the substrate 1, an etching apparatus 202 for performing a cleaning process on the substrate 1 (not shown in FIG. 3) mounted on the substrate mounting table 201, A vacuum gauge (not shown) for detecting the degree of vacuum in the cleaning chamber 20 is provided. Substrate mounting table 2
Numeral 01 is movable up and down by an actuator 203 fixed to the lower outer wall of the cleaning chamber 20. As the etching device 202, for example, an etching device using sputtering, an etching device using an ion beam, or the like can be used.

A vacuum pump 206 having a high evacuation capacity is connected to the cleaning chamber 20 via an evacuation pipe 204 and a conductance valve 205. The vacuum pump 206 includes the load / unload chamber 10
Cryopump and turbo molecular pump described in
Alternatively, they are used in combination. The ultimate degree of vacuum of the cleaning chamber 20 is, for example, 1.33 × 1
Preferably between 0 ^-6 Pa about.

Further, a gas introduction pipe 207 for introducing an inert gas such as argon used for cleaning is connected to the cleaning chamber 20. A valve 208 for adjusting the flow rate of the introduced gas and a flow meter (not shown) are provided in the flow path of the gas introduction pipe 207. Then, the flow rate of the introduced gas detected by the flow meter and the cleaning chamber 2 detected by a vacuum gauge (not shown) are measured.
The degree of opening of the valve 208 and the conductance valve 205 is adjusted based on the degree of vacuum within 0, whereby the inside of the cleaning chamber 20 is maintained in an inert gas atmosphere at a predetermined gas pressure. I have. In the cleaning chamber 20, the surface of the substrate 1 is beaten by the atoms of the inert gas, and the substrate is cleaned. For example, when the inert gas is argon, the argon gas pressure in the cleaning chamber 20 is, for example, 1 × 10 ⁻³ Pa to 1 Pa at least during the cleaning process of the substrate 1.
It is preferable that the temperature be kept to the same extent.

As shown in FIGS. 1 and 2, the first film forming chamber 30 is provided with a substrate substrate mounting table 301a on which the substrate 1 is mounted.
, And cathode electrode portions 302-1 to 302-4 for detachably holding the sputtering targets 2-1 to 2-4, respectively.
The turntable 301 is connected to a rotation shaft 304 of an actuator 303 provided on a lower outer wall of the first film forming chamber 30, and the actuator 303 drives to be able to rotate and move up and down. The cathode electrode portions 302-1 to 302-4 are arranged on the upper surface side of the first film forming chamber 30 so as to face the turntable 301. The amount of rotation of the turntable 301 depends on whether the substrate mounting table 301a has the cathode electrode portions 302-1 to 302-.
4 is controlled so as to stop at a position facing one of the above. Although not shown, the substrate mounting table 301a of the turntable 301 is provided with a heater for heating the substrate and a cooling pipe for preventing the substrate from being heated.

A vacuum pump 308 having a high pumping capacity is connected to the first film forming chamber 30 via a pumping tube 306 and a conductance valve 307. As the vacuum pump 308, the same cryopump or turbo molecular pump as described above, or a combination thereof is used. Note that the ultimate degree of vacuum of the first film forming chamber 30 is preferably, for example, about 1.33 × 10 ⁻⁶ Pa.

The first film forming chamber 30 is connected to a gas introducing pipe 309 for introducing an inert gas such as argon used for sputtering a target. A valve 310 for adjusting the flow rate of the introduced gas and a flow meter (not shown) are provided in the flow path of the gas introduction pipe 309. The opening of the valve 310 and the conductance valve 307 is adjusted based on the flow rate of the introduced gas detected by the flow meter and the degree of vacuum in the first film forming chamber 30 detected by a vacuum gauge (not shown), Thus, the inside of the first film forming chamber 30 is maintained in an inert gas atmosphere having a predetermined gas pressure. For example, when the inert gas is argon, it is preferable that the argon gas pressure in the first film forming chamber 30 is maintained at, for example, about 1 × 10 ⁻³ Pa to 1 Pa at least during the film forming process on the substrate 1. .

Examples of the targets 2-1 and the like attached to the cathode electrode portions 302-1 to 302-4 include, for example,
Metal materials such as tantalum (Ta), titanium (Ti), permalloy (FeNi) which is an iron-nickel alloy, cobalt platinum alloy (CoPt), and platinum manganese alloy (PtMn) are used. Cathode electrode units 302-1 to 302
-4 is a DC power supply (not shown) via the cable 312
, So that the target is maintained at a negative potential during sputtering. The cathode electrode portions 302-1 to 302-4 are also cooled by a cooling pipe (not shown) to prevent overheating. If necessary, a samarium cobalt (SmCo) magnet may be provided inside the cathode electrode units 302-1-1 to 302-4, for example.

As shown in FIG. 3, the basic structure of the second film forming chamber 40 is the same as that of the first film forming chamber 30 shown in FIG.
Here, the description is omitted.

[Operation of Film Forming Apparatus] Next, FIGS.
The operation of the film forming apparatus having such a configuration will be described with reference to FIG. A series of operations described below are controlled by a control unit (not shown). In the following description, for simplicity, the gate valves 60-1 to 60-4 will be described.
Are simply referred to as gates A to D, respectively.

Here, the substrate 1 housed in the load / unload chamber 10 is transferred to the cleaning chamber 20 and the first film forming chamber 30.
A series of operations in the case of sequentially transporting the wafer to the second film forming chamber 40 and performing a multi-layer film forming process after the cleaning process will be described as an example. Here, the loading / unloading room 1
It is assumed that the substrate 1 has already been accommodated in the chamber 0, and the interior of each chamber has reached the vicinity of a predetermined degree of vacuum.

The degree of vacuum in the load / unload chamber 10 is within a predetermined range (for example, about 1.33 × 10 ⁻⁵ Pa or more) (Step S101 in FIG. 5; Y), and the transfer chamber 50
Is within a predetermined range (for example, 1.33 × 10 ⁻⁶ P
a) (step S102; Y), the control unit opens the gate A (step S103) and, as shown in FIG. One substrate 1 is taken out of the substrate stocker 101, and the transfer arm 501 is further contracted to move the substrate 1 into the transfer chamber 50 (step S1).
04). Thereafter, the gate A is closed (Step S10)
5).

Here, the degree of vacuum in the transfer chamber 50 and the cleaning chamber 20 is within a predetermined range (for example, 1.3).
(About 3 × 10 ⁻⁶ Pa) (Step S106)
a; Y, S106b; Y), the control unit opens the gate B (step S107), rotates and extends the transfer arm 501, and cleans the substrate 1 in the transfer chamber 50 as shown in FIG. To place on the substrate mounting table 201 (step S108). Then, the transfer arm 5
01, and gate B is closed (step S10).
9).

Next, the controller performs a cleaning process by sputtering on the substrate 1 in the cleaning chamber 20 (step S110 in FIG. 6). Specifically, the valve 208 is opened to introduce argon gas into the cleaning chamber 20 from the gas introduction pipe 207, and the etching apparatus 202 in the cleaning chamber 20 is controlled to strike the surface of the substrate 1 with argon atoms. Removes moisture and other contaminants from the surface.

When the cleaning of the substrate 1 is completed, the control unit opens the valve 506 and introduces argon gas into the transfer chamber 50 from the gas introduction pipe 505, and the degree of vacuum (that is, the total pressure in the transfer chamber 50). Argon gas partial pressure).
After setting the transfer chamber 50 and the cleaning chamber 20 to approximately the same degree of vacuum by setting the pressure to about 33 × 10 ^{−2 to} 1.33 Pa (step S111), the gate B is opened (step S11).
2) The substrate 1 in the cleaning chamber 20 is moved to the transfer chamber 50 by the transfer arm 501 (step S11).
3).

Here, when the degree of vacuum in the first film forming chamber 30 is within a predetermined range (for example, about 1.33 × 10 ⁻⁶ Pa or more) (step S114; Y), the control unit starts the gas introduction. Argon gas is introduced from the pipe 309 into the first film forming chamber 30, and the degree of vacuum is made substantially equal to that of the transfer chamber 50 (Step S115), and then the gate C is opened (Step S116).
Next, the transfer arm 501 is driven to move the substrate 1 in the transfer chamber 50 to the first film forming chamber 30 (Step S11).
7) The gate C is closed (step S118). The substrate 1 transported to the first film forming chamber 30 includes a turntable 301
It is mounted on the upper substrate mounting table 301a.

Here, the substrate 1 is always placed in an argon gas atmosphere during the process of going out of the cleaning chamber 20 and passing through the transfer chamber 50. For this reason, the surface of the substrate 1 is impacted by the argon atoms even while passing through the transfer chamber 50, and the residual gas such as moisture can be effectively prevented from being adsorbed on the substrate 1.

Next, the control unit controls the turntable 301 of the first film forming chamber 30 and the cathode electrode units 302-1 to 302-1.
By driving and controlling 2-4, a plurality of films are sequentially formed (step S119). For example, a five-layer film (Ta / N
When forming a film of (iFe / Co / Cu / Co), the target 2-1 of the cathode electrode portions 302-1 to 302-4 is used.
2 to 4, Ta, NiFe, Co (cobalt), and Cu (copper) are arranged, and the turntable 301 is rotated, so that the substrate 1 is placed on the cathode electrode portion 302.
The cathode electrodes are moved to fixed positions immediately below the target in the order of -1 to 302-4. Then, at each fixed position, a DC electric field is applied between the target and the substrate 1 to form a film by sputtering. More specifically, glow discharge occurs in an argon gas atmosphere, and positive ions (Ar ions in this case) in the plasma collide with the surface of the target and repel target atoms. The repelled target atoms are attracted to the electric field and are deposited on the surface of the substrate 1 on the anode, where a thin film is formed.

When the film forming process is completed, the control unit makes the degree of vacuum (argon gas pressure) between the first film forming chamber 30 and the transfer chamber 50 substantially equal (Step S120), and then opens the gate C (Step S121). Then, the transfer arm 501 is driven to move the substrate 1 in the first film forming chamber 30 to the transfer chamber 50 (Step S122). Thereafter, the gate C is closed (Step S123).

Here, if the degree of vacuum in the second film forming chamber 40 is within a predetermined range (for example, about 1.33 × 10 ⁻⁶ Pa or more) (step S124 in FIG. 7; Y), the second component is formed. Membrane chamber 40
After introducing argon gas into the transfer chamber 50 to make the degree of vacuum substantially equal to that of the transfer chamber 50 (step S125), the gate D is opened (step S126). Then, the transfer arm 50
1 to drive the substrate 1 in the transfer chamber 50 to the second film forming chamber 40.
(Step S127), and closes the gate D (Step S128).

Also in this case, the substrate 1 is always placed in an argon gas atmosphere while being transferred from the first film forming chamber 30 to the second film forming chamber 40 via the transfer chamber 50. The contamination of the substrate surface due to adsorption of residual components such as moisture is prevented.

Next, the control unit sets the argon gas pressure in the second film forming chamber 40 to a predetermined value (for example, 133 to 266 × 10 ^−2).
(Pa), and drive control of the turntable 401 and the cathode electrode units 402-1 to 402-4 of the second film forming chamber 40 to form a plurality of films sequentially (step S1).
29). For example, a two-layer film (PtMn / Ta) on the substrate 1
Is formed, the cathode electrode portions 402-1, 40
As targets 2-2 and 2-6 of 2-2, respectively.
While placing Ta and PtMn, the turntable 40
1 to rotate the substrate 1 to the cathode electrode portions 402-1,
In the order of 402-2, it is moved to a fixed position immediately below the target of each cathode electrode unit. Then, at each fixed position, a DC voltage is applied to the cathode electrode portion to form a film on the substrate 1 by sputtering.

When the film forming process is completed, the control unit makes the degree of vacuum between the second film forming chamber 40 and the transfer chamber 50 substantially equal (step S130), and then opens the gate D (step S1).
31), the substrate 1 in the second film forming chamber 40 is moved to the transfer chamber 50 by the transfer arm 501 (Step S132).
Thereafter, the gate D is closed (step S133).

Next, after evacuating the transfer chamber 50 (step S134), the control unit opens the gate A (step S135), moves the substrate 1 from the transfer chamber 50 to the load / unload chamber 10, and moves the substrate stocker. 101 (step S136). Finally, the gate A is closed (Step S1)
37).

After the formation of the multilayer film in this manner, a selective etching is performed as necessary to obtain a multilayer film structure having a predetermined shape pattern.

In this embodiment, the argon gas is introduced into the transfer chamber 50 only after the substrate cleaning processing in the cleaning chamber 20. However, the argon gas is introduced into the transfer chamber 50 before the cleaning processing. It may be.

[One Example of Structure of Thin-Film Magnetic Head] Here, an example of a multilayer film structure to be subjected to a film forming process by the film forming apparatus according to the present embodiment will be described with reference to FIGS. I do. Here, a case where the film formation target is a spin valve film used as a reproducing element of a thin film magnetic head will be described. This spin valve film is a kind of a magnetic film (GMR film) exhibiting a giant magnetoresistive (GMR) effect, and an element using this is a GMR film.
It is called an MR element. This spin valve film has been used frequently in recent years because it has a relatively simple structure, shows a large resistance change even in a weak magnetic field, and is considered preferable for mass production.

FIG. 8 shows a sectional structure of a composite type thin film magnetic head having a structure in which a recording head having an inductive magnetic transducer for recording and a reproducing head having a GMR element using a spin valve film are stacked. FIG. 9 shows the planar structure of the thin-film magnetic head shown in FIG. 8A shows a cross section taken along a line VIIIA-VIIIA perpendicular to an air bearing surface (not shown) in FIG. 9, and FIG. 9B shows air in a magnetic pole portion in FIG. It shows a cross section taken along line VIIIB-VIIIB parallel to the bearing surface. Here, the air bearing surface is the magnetic recording medium (disk medium) of the thin-film magnetic head.
And is also called a track surface.

This thin-film magnetic head includes a substrate 601 (FIG. 1).
4 to FIG. 4 (corresponding to the substrate 1)) (the upper side in FIG. 8).
Read head 61 for reading through insulating film 602
This is a composite type thin-film magnetic head having a structure in which a recording head 620 for writing data and a recording head 620 are stacked. The reproducing head 610 has a GMR element using a spin valve film.
The recording head 620 has an inductive magnetic transducer. The substrate 601 is made of, for example, Altic which is a composite material containing aluminum oxide and titanium carbide (TiC). The insulating film 602 is made of, for example, an insulating material such as aluminum oxide. As the substrate 601, for example, a wafer of about 3 inches is used.

The reproducing head 610 has the first shield film 6
11, a first shield gap film 612, a GMR film 613 having a spin valve film structure, a second shield gap film 6
14 and a second shield film 615 are sequentially stacked from the insulating film 602 side.

The first shield film 611 and the second shield film 615 are for magnetically shielding (shielding) the GMR film 613, and are disposed so as to face each other with the GMR film 613 interposed therebetween. I have. The first shield film 611 is made of, for example, nickel (Ni) and iron (Fe).
(NiFe alloy) and other magnetic materials. The second shield film 615 is made of, for example, NiF
It is made of a magnetic material such as an e-alloy or iron nitride (FeN). The second shield film 615 also has a function as a first magnetic pole in the recording head 620. The first shield gap film 612 and the second shield gap film 614 are insulating films for electrically insulating the first shield film 611 and the second shield film 615 from the GMR film 613.

The GMR film 613 is for reading information recorded on a magnetic recording medium (not shown).
It is arranged on the side of the air bearing surface 603. GMR
The length HMR from the end on the side of the air bearing surface 603 of the film 613 to the end on the opposite side is one factor that determines the reproduction output, and is called MR height. This GMR film 613
Are the portions to be subjected to the film forming process of the film forming apparatus according to the present embodiment. The detailed structure will be described later.

The GMR film 613 is electrically connected to a pair of first lead layers 616a and 616b disposed so as to face each other across the GMR film 613 in the track width direction. These first lead layers 616a, 616
Similarly to the GMR film 613, 16b is formed between the first shield gap film 612 and the second shield gap film 614, respectively. The first lead layer 61
Each of 6a and 616b has, for example, a structure in which a permanent magnet film and a conductive film are laminated. The permanent magnet film is made of, for example, an alloy of cobalt and platinum (CoPt alloy), and the conductive film is made of, for example, tantalum (Ta).

As shown in FIG. 9, the first lead layer 616
The second lead layer 61 made of, for example, copper (Cu) is provided on the side opposite to the air bearing surface 603 on the side a and 616b.
7a and 617b are electrically connected. These second lead layers 617a and 617b extend from the first lead layers 616a and 616b toward the side opposite to the air bearing surface 603, respectively.
Similarly to 16a and 616b, they are formed between the first shield gap film 612 and the second shield gap film 614, respectively.

The recording head 620 has the recording gap 62
1, photoresist 622, thin film coil 623, photoresist 624, thin film coil 625, photoresist 6
26 and the second magnetic pole 627 are connected to the second shield film 615.
From the side. The recording gap 621 is made of, for example, an insulating material such as aluminum oxide. The recording gap 621 has an opening 621a near the center of the thin-film coils 623 and 625, and the second shield film 615 and the second magnetic pole 62
7 are brought into contact with each other to connect them magnetically.

The length from the end of the photoresist 622 on the side of the air bearing surface 603 to the air bearing surface 603 is called a throat height HTH (Throat Height).
It affects the recording characteristics of the recording head. The photoresist 622 is disposed at a slight distance from the air bearing surface 603, and
3, the second magnetic pole 627 has a recording gap 6.
21. Further, the photoresist 622 has a similar opening 622a at a position corresponding to the opening 621a of the recording gap 621, so that the second shield film 615 and the second magnetic pole 627 are brought into contact with each other. The thin film coils 623 and 625 are arranged at positions corresponding to the photoresist 622, respectively. The photoresists 624 and 626 form the thin film coil 62
3, 625 are provided at positions corresponding to the thin-film coils 623, 625, respectively.

The second magnetic pole 627 is made of a magnetic material such as a NiFe alloy or iron nitride. The second magnetic pole 627 extends from the air bearing surface 603 to near the center of the thin film coils 623 and 625, and is in contact with the recording gap 621 near the air bearing surface 603. In addition, the thin film coil 62
In the vicinity of the central portion of the third shield film
15 and is magnetically connected to the second shield film 615.

As shown in FIG. 8B, the second magnetic pole 627 and the recording gap 6 on the air bearing surface 603
The positions of the portions of the first and second shield films 615 that are in contact with the recording gap 621 are arranged in a line, and have a so-called trim (Trim) structure. This structure is effective for preventing an increase in the effective track width due to the spread of the magnetic flux generated when writing in a narrow track.

The reproducing head 61 of the recording head 620
An overcoat 604 is formed on the side opposite to 0 (the upper side in FIG. 8) so as to cover the entire surface. The overcoat 604 is made of, for example, an insulating material such as aluminum oxide. Incidentally, in FIG. 9, the overcoat 604 is omitted.

The thin-film magnetic head having such a structure operates as follows. That is, a current is applied to the thin-film coils 623 and 625 of the recording head 620 to generate a magnetic flux for writing, thereby recording information on a magnetic recording medium (not shown). Further, by passing a sense current through the GMR film 613 of the reproducing head 610 and detecting a signal magnetic field from a magnetic recording medium (not shown), information recorded on the magnetic recording medium (not shown) is read.

FIG. 10 shows a G having a spin valve film structure.
FIG. 9 is a diagram illustrating an MR element 750 including an MR film 613, and is an enlarged view of a part of a cross section (FIG. 8B) parallel to an air bearing surface 603 of a reproducing head 610. The GMR film 613 of the MR element 750 of the present embodiment
On the shield gap film 612, an underlayer (not shown) made of, for example, Ta and a free layer 751 made of, for example, NiFe (permalloy) and Co (cobalt)
A non-magnetic metal layer 752 made of, for example, Cu (copper);
For example, a pinned (p) magnetic layer made of Co (cobalt)
inned) layer 753 and, for example, PtMn (platinum-manganese)
And an antiferromagnetic layer 754 composed of The antiferromagnetic layer 754 includes a protective layer 758 made of Ta or the like.
Covered by

When the pinned layer 753 and the antiferromagnetic layer 754 are stacked and heat-treated at, for example, 250 degrees Celsius, the exchange coupling at the interface between the pinned layer 753 and the antiferromagnetic layer 754 causes the magnetization direction of the pinned layer 753 to change. Is fixed. Note that the magnetization direction of the pinned layer 753 is fixed, for example, in the Y direction (a direction perpendicular to the paper surface) in FIG.

On both sides of the GMR film 613 in the X direction (left-right direction in FIG. 10) in FIG. 10, a longitudinal bias for suppressing the generation of noise (so-called Barkhausen noise) is generated by aligning the magnetization directions of the free layer 751. A bias application film is provided. This bias applying film is, for example,
It is composed of two layers of bias ferromagnetic layers 755a and 755b and bias antiferromagnetic layers 756a and 756b laminated on the bias ferromagnetic layers 755a and 755b, respectively. Due to exchange coupling at the interface between the ferromagnetic layer for bias 755a and the antiferromagnetic layer for bias 756a and the interface between the ferromagnetic layer for bias 755b and the antiferromagnetic layer for bias 756b, the vertical direction with respect to the free layer 751 (FIG. (In the X direction).

Anti-ferromagnetic layers for bias 756a, 756b
Above the first lead layers 616a and 616, respectively.
b (see FIGS. 8B and 9). 8 and 9, illustration of the bias ferromagnetic layers 755a and 755b and the bias antiferromagnetic layers 756a and 756b shown in FIG. 10 is omitted. FIG.
At 0, the first lead layers 616a and 616b are drawn so as not to be in contact with the GMR film 613. However, actually, the first lead layers 616a and 616b wrap around and come into contact with the GMR film 613. ing.

[Example of Characteristics of Multilayer Structure Film] FIG. 11 shows the characteristics of the multilayer structure film obtained by the film forming apparatus of the present embodiment and the characteristics of the multilayer structure film obtained by the conventional film forming apparatus. Is compared with and expressed. In this figure, the characteristic data α indicates that a spin valve film having a seven-layer structure as described below is used to deposit a spin chamber film in the film forming apparatus of this embodiment (that is, to hold the transfer chamber in an argon atmosphere during transfer of the substrate). The film characteristics when the film is formed using the above-described film forming apparatus are shown. In addition, the characteristic data β indicates that the same seven-layer spin valve film is processed by a conventional film forming apparatus (that is, a film forming apparatus in which the transfer chamber is simply maintained in a high vacuum state during the transfer of the substrate). It shows the film characteristics in the case of forming using.

First layer: Ta, thickness 5 nm Second layer: NiFe, thickness 7 nm Third layer: Co, thickness 1 nm Fourth layer: Cu, thickness 3 nm Fifth layer: Co, thickness 2 nm Sixth Layer: PtMn, thickness 25 nm Seventh layer: Ta, thickness 5 nm

The layer numbers are expressed as the first to seventh layers in order from the lower layer of the laminated structure.

Here, the first layer (Ta) is a free layer 751
, The second layer (NiFe) and the third layer (Co) correspond to the free layer 751, the fourth layer (Cu) corresponds to the nonmagnetic metal layer 752, and the fifth layer (Co). Corresponds to the pinned layer 753, and the sixth layer (PtMn) corresponds to the antiferromagnetic film 7.
The seventh layer (Ta) corresponds to the protective film 758 corresponding to 54.

The result of this experiment is that the first layer (Ta) to the fifth layer (Co) are formed in the first film forming chamber 30 and then the substrate 1 is formed.
From the first film forming chamber 30 via the transfer chamber 50 to the second film forming chamber 40
, And further obtained when the sixth layer (PtMn) and the seventh layer (Ta) are formed in the second film forming chamber 40. Here, in the present embodiment, the substrate 1
The argon gas pressure in the transfer chamber 50 during the movement of
It was about × 10 ⁻⁴ Pa. On the other hand, in the comparative example, the degree of vacuum of the transfer chamber 50 during the movement of the substrate 1 was set to 0.7 × 10 ⁻⁸ P
a. As a result, the characteristics of the spin valve film will be described later due to the difference in atmosphere in the transfer chamber 50 during the transfer between the fifth layer (Co) film formation step and the sixth layer (PtMn) film formation step. It became clear that it was greatly affected.

In the characteristic data shown in FIG.
The MR change rate represents the change rate of the magnetoresistance effect of the entire spin valve film having a multilayer structure, and indicates the magnetic detection sensitivity (readout sensitivity). More specifically, the rate of change in MR is such that the external magnetic field has a predetermined magnitude (for example, ± 100 O).
The rate of change of the resistance value of the spin valve film when it changes by about e (oersted) is measured, and the unit is%. The hysteresis Hc is obtained by measuring the hysteresis of the free layer 751 of the GMR film 613, and has a unit of O.
e. The sheet resistance is a value obtained by measuring the sheet resistance of the entire spin valve film, and the unit is Ω / □. The exchange magnetic field Hex is the same as that of the pinned layer 753 made of Co and PtMn.
It is a measurement of the exchange magnetic field between the anti-ferromagnetic layer 754 made of and the unit is Oe.

As is clear from FIG. 11, the MR change rate is improved to 7.0% in the present embodiment, compared to the value (5.2%) in the comparative example. Hysteresis Hc
Is 0.2 Oe smaller in the present embodiment than the value (2.0 Oe) in the comparative example. The sheet resistance is 11.5 Ω / □ in the present embodiment, which is smaller than the value (12.5 Ω / □) in the comparative example. The exchange magnetic field Hex is the value (500 Oe) in the comparative example.
In the present embodiment, it is increased to 800 Oe. That is, in all the measured items, the spin valve film formed by the film forming apparatus according to the present embodiment showed excellent performance.

As described above, according to the film forming apparatus of the present embodiment, when performing a multi-layer film forming process on a substrate using a film forming apparatus having a plurality of processing chambers, Argon gas was introduced into the transfer chamber 50 when moving between the processing chambers to allow the substrate to pass through an inert gas atmosphere. Pollution problems,
The quality of the film quality and its stability can be improved.

Although the present invention has been described with reference to some embodiments, the present invention is not limited to these embodiments, and various modifications are possible. For example, in the above-described embodiment, the case where the film forming apparatus includes one cleaning chamber and two film forming chambers has been described. However, a different number of cleaning chambers or film forming chambers may be provided. Is also possible.

The inert gas introduced into the transfer chamber 50 is not limited to argon gas, but may be another inert gas. For example, helium (He), neon (N
e), krypton (Kr), xenon (Xe), radon (Rn) and the like.

Further, in the above embodiment, after the substrate cleaning step, the inside of the transfer chamber 50 is always filled with the argon gas. However, the present invention is not limited to this. The transfer chamber 50 may be evacuated to a high vacuum while receiving the respective processes in the chamber 30 and the second film formation chamber 40, and the argon gas may be introduced into the transfer chamber only during transfer. In this case, the use amount of the argon gas can be reduced, and the exhaust pump 51 of the transfer chamber 50 can be used.
0 can be reduced.

In the above embodiment, the description has been made assuming that the thin film forming step is performed by sputtering.
The present invention is not limited to this, and can be applied to other film formation methods. For example, the present invention can be applied to thin film formation by vacuum evaporation.

Further, in the above-described embodiment, a single wafer type multi-chamber film forming apparatus has been described as an example.
In addition, the present invention is applicable to, for example, an in-line type multi-chamber film forming apparatus. In this case, the gate portion connecting the chambers may have a double gate structure, and an inert gas may be introduced between the two gate valves when the substrate passes through the gate.

Further, in the present embodiment, the explanation has been given by taking the multi-layer structure magnetoresistive film used in the thin film magnetic head as an example, but the present invention is not limited to this, and other devices such as a magnetic sensor can be used. The present invention can also be applied to the formation of a multi-layered magnetoresistive film used for detection devices such as acceleration sensors and acceleration sensors.

[0095]

As described above, the film-forming apparatus according to any one of claims 1 to 11, or the film-forming apparatus according to any one of claims 12 to 19. According to the method, a predetermined film forming process is performed on each of the substrates housed in the processing chamber, and at least when the substrate moves between the plurality of processing chambers, at least when the substrate moves between the plurality of processing chambers, Since the connecting portion is maintained in a predetermined inert gas atmosphere state, it is possible to reduce the problem of contamination which has conventionally occurred during the transfer of the substrate between the processing chambers, and to improve the quality of the formed film. This has the effect of making it possible to improve and improve its stability.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating an overall configuration of a film forming apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a cross section taken along line II-II of FIG.

FIG. 3 is a sectional view showing a section taken along line III-III of FIG.

FIG. 4 is another sectional view (in a state) showing a sectional view taken along line III-III of FIG.

FIG. 5 is a flowchart illustrating a part of the operation of the film forming apparatus.

FIG. 6 is a flowchart illustrating the operation following FIG. 5;

FIG. 7 is a flowchart illustrating the operation following FIG. 6;

FIG. 8 is a cross-sectional view illustrating a structural example of a thin-film magnetic head to be formed into a film.

FIG. 9 is a plan view illustrating a structural example of a thin-film magnetic head to be formed.

FIG. 10 is an enlarged cross-sectional view of a main part (giant magnetoresistive film) of a thin film magnetic head to be formed.

FIG. 11 is a comparison diagram showing the characteristics of spin valve films formed by a film forming apparatus according to the present embodiment and a film forming apparatus according to a comparative example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate, 10 ... Load / unload chamber, 20 ... Cleaning chamber, 30 ... 1st film-forming chamber, 40 ... 2nd film-forming chamber, 50 ...
Transfer chamber, 501: transfer arm, 505: gas introduction pipe, 5
06 ... Valve, 507 ... Flow meter.

Claims (19)

[Claims] 1. A plurality of processing chambers, each of which is maintained in a reduced pressure state and performs a predetermined film forming process on a contained substrate, and a connecting portion connecting the plurality of processing chambers, A film formation processing apparatus comprising: a connection part atmosphere holding means for holding the connection part in a predetermined inert gas atmosphere state when the substrate moves between the plurality of processing chambers. 2. The film forming apparatus according to claim 1, wherein the connecting portion constitutes a common chamber arranged so as to be commonly adjacent to all of the plurality of processing chambers. Processing equipment. 3. The apparatus according to claim 2, wherein said common chamber forms a substrate transfer chamber provided with a transfer mechanism capable of transferring the substrate between the respective processing chambers. Membrane processing equipment. 4. The processing chamber according to claim 1, wherein the plurality of processing chambers include at least one film forming chamber for forming a predetermined film on the substrate. 3. The film forming apparatus according to item 1. 5. The plurality of processing chambers includes at least one film forming chamber for forming at least one film on the substrate, and at least one other film on the substrate. The film formation processing apparatus according to claim 4, further comprising: another film formation chamber, wherein a multi-layer film can be formed on the substrate. 6. The film forming chamber according to claim 4, wherein the film forming chamber is a processing chamber for forming a film by sputtering.
Alternatively, the film forming apparatus according to claim 5. 7. The film forming apparatus according to claim 1, wherein the plurality of processing chambers include at least one cleaning chamber for cleaning a surface of the substrate. Processing equipment. 8. The apparatus according to claim 1, further comprising at least one substrate introduction chamber for introducing said substrate from an atmospheric pressure atmosphere to a reduced pressure atmosphere. Film forming apparatus. 9. The film forming apparatus according to claim 1, wherein the inert gas is an argon (Ar) gas. 10. A processing chamber atmosphere holding means for holding at least the processing chamber in an inert gas atmosphere state when the substrate is placed in one of the processing chambers. The film forming apparatus according to claim 1. 11. The predetermined film forming process is for forming a magnetoresistive effect element including a multilayer film and having an electric resistance characteristic changed according to an external magnetic field. Claim 1 to Claim 1
0. The film formation processing apparatus according to any one of 0. 12. A film forming method for performing a film forming process on a predetermined substrate using a film forming apparatus having a plurality of processing chambers capable of maintaining a reduced pressure, wherein the substrate housed in the processing chamber is provided. A step of performing a predetermined film forming process on the substrate, and a step of mutually moving the substrate in each processing chamber while maintaining the substrate in a predetermined inert gas atmosphere. Processing method. 13. The film forming method according to claim 12, wherein the step of performing the film forming processing includes at least one film forming step for forming a predetermined film on the substrate. . 14. The film forming step includes: forming at least one film on the substrate housed in one of the processing chambers; and forming at least one film on the substrate housed in another processing chamber. 14. The film forming method according to claim 13, further comprising the step of forming one other film, wherein a multilayer film is formed on the substrate. 15. The film forming method according to claim 12, wherein the step of performing the predetermined film forming process includes a film forming step by sputtering. 16. The film forming method according to claim 12, wherein the step of performing the predetermined film forming process includes a step of cleaning a surface of the substrate. . 17. Argon (A) as the inert gas.
17. The film forming method according to claim 12, wherein r) gas is used. 18. The apparatus according to claim 12, wherein even when the substrate is placed in any one of the processing chambers, the processing chamber is maintained in an inert gas atmosphere state. 18. The film forming method according to any one of items 17 to 17. 19. The method according to claim 19, wherein the predetermined film forming process is for forming a magnetoresistive element including a multilayer film and having an electric resistance characteristic that changes according to an external magnetic field. The film forming method according to any one of claims 12 to 18, wherein: