JP6068662B2 - Vacuum processing apparatus, vacuum processing method, magnetoresistive effect element manufacturing method, and magnetoresistive effect element manufacturing apparatus - Google Patents

Description

  The present invention relates to a vacuum processing apparatus, a vacuum processing method, a magnetoresistive effect element manufacturing method, and a magnetoresistive effect element manufacturing apparatus.

  The magnetoresistive effect type magnetic head is a read-only magnetic head using a magnetoresistive effect element as a magnetic sensitive element, and has been put into practical use as a reproducing unit such as a hard disk drive. In recent years, TMR (Tunneling Magneto Resistance) elements are being adopted as magnetoresistive elements.

  The TMR element has a multilayer structure in which a very thin insulator serving as a tunnel barrier is sandwiched between ferromagnetic metal electrodes, and the magnetization direction of the ferromagnetic metal electrode sandwiching the insulator is opposite to that when parallel. The effect of changing the electrical resistance of the TMR element when parallel (TMR effect) is used. Recently, MgO is used as an insulator of the TMR element, and the quality of MgO greatly affects the performance of the magnetic head.

  As a process for forming MgO, there are a process for forming MgO by RF sputtering and a process for oxidizing by flowing oxygen after forming Mg. In the latter case, for example, after the Mg single film is formed, the substrate is transferred to a vacuum vessel for oxidation treatment, and MgO is formed by flowing oxygen.

  In recent years, along with the increase in the density of hard disk drives, the size of the lead sensor has been reduced, and accordingly the specific resistance of the sensor itself has to be reduced. That is, it is necessary to make the film thickness of the insulator MgO very thin. Specifically, an MgO film thickness of 1 nm or less is required. There is also a need for improved film thickness uniformity.

  10A and 10B are diagrams illustrating the configuration of a conventional vacuum processing apparatus.

  As a conventional oxidation processing vacuum processing apparatus, there is an apparatus that introduces a gas from an opening 1003 provided in a ring (hereinafter referred to as a gas ring) above a substrate (FIG. 10A).

  Alternatively, a shower plate 1007 in which a plurality of openings 1009 are formed at a predetermined pitch is arranged above the substrate, and a gas obtained by dispersing the gas from the supply port 1006 through the openings 1009 is introduced toward the substrate 1008. Yes (see FIG. 10B: Patent Document 1).

JP 2000-294538 A

  In the prior art, when oxygen is flowed after the Mg film is formed to oxidize, oxygen supply control is performed using a mass flow controller (MFC) that controls gas flow rate. The film thickness of MgO is proportional to the oxygen supply amount. Therefore, in order to form an ultrathin MgO, an MFC capable of controlling the oxygen supply amount to an extremely small amount is necessary, but the current device performance is limited.

  In the case of a certain film thickness (about several nm), the effect of the reached particle distribution did not appear remarkably, but in the case of an extremely thin film of 1 nm or less, the reached particle distribution is strongly reflected in the film thickness distribution. For example, when oxygen is supplied to oxidize after Mg film formation, the distribution of oxygen reaching the substrate affects the MgO film thickness distribution.

  When introducing gas using the gas ring 1001 as shown to FIG. 10A, gas is supplied through the piping 1002 from the exterior of a vacuum processing apparatus. The supplied gas flows through the hollow gas ring 1001, and the gas is introduced into the vacuum container from the opening 1003 provided along the outer periphery of the gas ring 1001. The introduced gas reaches the substrate 1004 and is then exhausted by the pump 1005.

  Since more gas is ejected from the opening in the vicinity of the pipe 1002 than in the opening at a position away from the pipe 1002 as the gas introduction source, the gas distribution becomes uneven, and the substrate in the vacuum vessel It has been difficult to uniformly introduce gas into 1004.

  When the gas is introduced using the shower plate 1007 as shown in FIG. 10B, the distribution of the gas reaching the substrate 1008 (arrival particle distribution) tends to be biased near the supply port 1006 for supplying the gas.

  Further, as a structure inside the vacuum vessel of the vacuum processing apparatus, a substrate mounting portion exists between the supply port 1006 and the exhaust port communicating with the pump 1010. The gas introduced through the shower plate 1007 from the supply port 1006 located above the substrate platform flows toward the substrate platform. When the gas reaches the substrate platform, the gas flows from the center of the substrate platform to the side surface of the substrate platform, and is exhausted from an exhaust port communicating with a pump 1010 provided below the substrate platform. Is done.

  Due to such a structure inside the vacuum vessel, the pressure at the central portion of the substrate 1008 placed on the substrate placement portion tends to increase locally. As a result, a pressure gradient is generated on the surface of the substrate 1008, and the distribution of particles reaching the substrate 1008 becomes non-uniform.

  As described above, the position where the gas is introduced, the direction in which the gas is introduced, and the structure inside the vacuum vessel have a great influence on the gas distribution on the substrate surface (distribution of reached particles). It was difficult to introduce.

  In the conventional vacuum processing apparatus using the MFC, the gas ring 1001 and the shower plate 1007, an extremely thin insulator film thickness cannot be obtained, and a satisfactory film thickness distribution cannot be obtained.

  In order to control the formation of a very thin insulator film, it is necessary to uniformly reduce the pressure of the reactive gas with a good distribution. Specifically, a smaller amount of reactive gas particles are uniformly distributed on the substrate than before. A technique to reach this is needed.

  The present invention has been made in view of the above-mentioned problems of the prior art, and the reactive gas pressure during the formation of the insulator is reduced and the pressure distribution is made uniform, that is, the reactive gas particles reaching the substrate surface are more than conventional. Provided is a vacuum processing technique capable of forming an insulator serving as a tunnel barrier having an extremely thin and uniform film thickness by uniformly supplying a small amount.

A vacuum processing apparatus according to one aspect of the present invention that achieves the above object includes: a vacuum container capable of depressurization to which an exhaust means is connected; and a substrate mounting surface on which a substrate placed in the vacuum container is mounted. A vacuum processing apparatus comprising: a substrate holder provided; and a gas introduction means having a gas introduction port for introducing a reactive gas into the vacuum vessel,
The gas introduction port is located between an exhaust port constituting the exhaust unit and the substrate holder, and molecules of the reactive gas discharged from the gas introduction port into the vacuum container are introduced into the gas introduction port. It is disposed at a position that does not reach the substrate mounting surface linearly from the mouth, and is disposed at a position on a substantial central axis of the substrate mounting surface, and the reactive gas is diffused by molecular flow. It reaches the substrate mounting surface.

  According to the present invention, in the TMR element, it is possible to reduce the pressure of the insulating material, for example, the oxygen distribution pressure during the formation of MgO, and to make it uniform, and to improve the film thickness distribution of the insulating material. Can be formed.

  Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings. In the accompanying drawings, the same or similar components are denoted by the same reference numerals.

The accompanying drawings are included in the specification, constitute a part thereof, show an embodiment of the present invention, and are used to explain the principle of the present invention together with the description.
It is a figure which shows the cross-sectional structure of the vacuum processing apparatus which concerns on embodiment. It is a figure explaining the flow of the vacuum processing method concerning an embodiment. It is a block diagram of the manufacturing apparatus of the magnetoresistive effect element which concerns on embodiment. It is a cross-sectional schematic diagram which shows the structure of the vacuum processing apparatus which concerns on 1st Embodiment. It is a cross-sectional schematic diagram which shows the structure of the vacuum processing apparatus which concerns on 2nd Embodiment. It is a cross-sectional schematic diagram which shows the structure of the vacuum processing apparatus which concerns on 3rd Embodiment. It is a cross-sectional schematic diagram which shows the structure of the vacuum processing apparatus which concerns on 4th Embodiment. It is a cross-sectional schematic diagram which shows the structure of the vacuum processing apparatus which concerns on 5th Embodiment. It is a cross-sectional schematic diagram which shows the structure of the vacuum processing apparatus which concerns on 6th Embodiment. It is a figure which shows the simulation result of a pressure distribution. It is a figure which shows pressure distribution of the gas introduce | transduced from one gas introduction port match | combined with the central axis of the board | substrate in 1st Embodiment. It is a figure which shows the structure of the conventional vacuum processing apparatus. It is a figure which shows the structure of the conventional vacuum processing apparatus.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the components described in this embodiment are merely examples, and the technical scope of the present invention is determined by the scope of the claims, and is not limited by the following individual embodiments. Absent.

(First embodiment)
FIG. 1A is a diagram showing a schematic cross-sectional configuration of the vacuum processing apparatus of the first embodiment. The vacuum processing apparatus can be used for manufacturing a magnetoresistive effect element (magnetoresistance device), and includes a vacuum container 101 for performing an insulator formation process.

  A predetermined formation process is performed in another vacuum vessel, and the substrate 102 having a metal film (for example, Mg film) formed on the surface of the substrate is carried into the vacuum vessel 101. Inside the vacuum vessel 101, an insulator formation process (for example, an insulation process) for forming an insulator (for example, MgO) on the substrate 102 by the introduced gas (for example, a reactive gas such as oxygen gas). Is done. The substrate 102 that has been subjected to the insulator formation process is carried out of the vacuum vessel 101. The illustration of the transfer unit that carries in and out the substrate 102 is omitted.

  A substrate holder 103 (substrate stage) having a substrate placement surface on which a substrate 102 to be processed can be placed inside the vacuum vessel 101, and a gas (for example, oxygen gas or the like) inside the vacuum vessel 101 A pipe for introducing a reactive gas) is provided. This pipe functions as a gas introduction unit 104 that introduces gas from the gas introduction source 108 into the vacuum vessel 101. The gas introduction unit 104 includes a gas introduction port 150 for introducing a reactive gas into the vacuum vessel 101. The gas introduction unit 104 is provided with an MFC for controlling the gas supply amount.

  Further, the vacuum processing apparatus is provided with a pump 105 (turbo molecular pump) for bringing the inside of the vacuum vessel 101 into a predetermined vacuum state. The inside of the vacuum vessel 101 can be depressurized to a low pressure of 1 × 10 −5 Pa or less by the pump 105.

  The valve portion includes a plate-like valve body 106, and the moving portion 107 can move the valve body 106 of the valve portion in the vertical direction. In a state where the valve body 106 is moved downward by the moving unit 107 (lowered state), the valve body closes the exhaust port 160, and the inside of the vacuum vessel 101 is airtight.

  Further, the exhaust port 160 is opened in a state where the valve body 106 is moved upward by the moving unit 107 (upward state), and the pump 105 connected to the tip of the exhaust port 160 communicates with the inside of the vacuum vessel 101. . The pump 105 exhausts the gas introduced from the gas introduction unit 104 through the exhaust port 160. The exhaust flow rate of the pump 105 can be controlled, whereby the oxygen supply amount of the gas introduced into the vacuum vessel 101 can be controlled. Here, the exhaust port 160 and the pump 105 function as an exhaust unit capable of reducing the pressure inside the vacuum vessel 101.

  Drawing 1B is a figure explaining the flow of the vacuum processing method of the vacuum processing apparatus concerning an embodiment. The vacuum processing method of the vacuum processing apparatus includes the following steps.

  In step S 1, the substrate 102 is placed on the substrate holder 103.

  In step S <b> 2, a reactive gas is introduced from the gas introduction port 150 of the gas introduction unit 104. The reactive gas molecules released from the gas inlet into the vacuum chamber 101 are shielded from reaching the surface of the substrate 102 linearly from the gas inlet, and the substantial center of the surface of the substrate. A reaction gas is introduced into the vacuum chamber from a gas inlet arranged at a position on the shaft. The reactive gas to be introduced is, for example, oxygen gas. In this embodiment, the molecules of the reactive gas released from the gas inlet 150 into the vacuum vessel 101 are shielded by the valve body 106. As a configuration for shielding the reactive gas molecules from reaching the surface of the substrate 102 linearly, a shielding member different from the back surface of the substrate holder 103, the upper surface of the vacuum vessel, and the valve body 106 may be used. Is possible. A configuration example of the shielding structure will be specifically described later in the second to sixth embodiments.

  In step S3, the gas is allowed to reach the substrate placement surface of the substrate holder 103 by diffusion of the molecular flow.

  A metal film is formed on the substrate surface of the substrate 102 placed in the previous step S1, and in step S4, the metal film is insulated (for example, oxidized) with a gas.

  The method of manufacturing a magnetoresistive element includes a step of forming a tunnel barrier layer made of an insulator (for example, MgO) using the vacuum processing method of steps S1 to S3 described above.

  According to the vacuum processing method, it is possible to improve the film thickness distribution of the insulator (for example, MgO) to be formed, and to reduce and equalize the gas pressure during formation. In addition, according to the method of manufacturing a magnetoresistive effect element using a vacuum processing method, it is possible to form an insulator of an extremely thin film having a thickness of 1 nm or less, for example, and to provide a higher quality magnetoresistive effect element (TMR element). Is possible.

(Conditions for gas diffusion)
In the present embodiment, a configuration in which gas is introduced into the vacuum vessel 101 by one gas introduction unit 104 (gas single point introduction) will be described by taking oxygen as an example of the introduced gas. In the assumed use state of the vacuum vessel, the mean free path λ of oxygen molecules in which oxygen molecules diffuse can be obtained by the following relational expression.
λ = k · T / (√2 · π · σ ² · P) (1)
σ Oxygen molecule diameter: 0.306 nm (Van der Waals radius)
k Boltzmann coefficient: 1.38 E-23 J / K
P pressure: 1.0E-6 Pa /1.0E-5 Pa
T temperature (room temperature): 300K
When the pressure inside the vacuum vessel is 1.0E-6 Pa, the mean free path of gas oxygen molecules is λ = 1.0E + 4 (m). When the pressure is 1.0E-5Pa, the mean free path of oxygen molecules is λ = 1.0E. +3 (m). Since the diameter of the vacuum vessel 101 used in the vacuum processing apparatus is about 50 cm, the mean free process is sufficiently longer than the diameter of the vacuum vessel 101. That is, under the pressure inside the vacuum vessel 101, it is possible to perform an insulation (for example, oxidation) process using a diffusion phenomenon in the molecular flow region.

  In order to obtain desired characteristics with a simpler structure, gas is introduced from a single gas inlet that is aligned with the central axis of the substrate in a manner that does not directly hit the substrate, and the gas is concentrically drawn from the central axis into the vacuum vessel. It is preferable that the insulating treatment is performed with oxygen particles of the gas that has been diffused by the gas and reaches the substrate. Further, in order to suppress the generation of a pressure gradient due to the position of the exhaust port 160 and to allow oxygen particles to reach the substrate uniformly, the exhaust port 160 should be disposed directly below the substrate holder along the central axis of the substrate 102. good. In other words, it is preferable that oxygen, which is a reactive gas, be introduced from one gas inlet 150 by a method that does not directly hit the substrate 102 and the exhaust port 160 be arranged directly below the substrate holder along the central axis of the substrate. Conceivable.

  Moreover, since the mean free path in the assumed use state of the vacuum vessel 101 is sufficiently longer than the diameter of the vacuum vessel 101, it is considered that oxygen particles reach the wall surface of the vacuum vessel 101 almost without collision and are reflected (vacuum vessel Ignore wall adsorption probability). Since it is considered that the particles reflected by the wall surface also reach the substrate, it is desirable that the side surface of the vacuum vessel 101 is also circular in order to allow oxygen particles to uniformly reach the circular substrate.

  FIG. 2 is a cross-sectional view illustrating a schematic configuration of the vacuum processing apparatus according to the first embodiment. The gas introduction unit 104 introduces gas from the outside of the vacuum vessel 101 into the vacuum vessel via a pipe. A gas introduction port 150 provided at the tip of the gas introduction unit 104 is disposed between the substrate holder 103 and the valve body 106 so as to coincide with the central axis of the substrate 102. Here, the term “match” refers to a substantial match that takes into account tolerances when processing or assembling parts, and is not limited to a physical perfect match (the same applies to the embodiments described below). .

  The gas inlet 150 is provided with one opening for releasing a reactive gas in the vacuum vessel 101. In the present embodiment, as a method in which the gas is not directly applied to the substrate, the insulator forming process is performed by utilizing the diffusion phenomenon of the molecular flow caused by applying the gas to the valve body 106. The cross-sectional shape of the vacuum vessel 101 is circular, and the cross-sectional shape of the vacuum vessel 101, the substrate holder 103 arranged in the vacuum vessel 101, and the substrate 102 placed on the substrate holder 103 are concentric. By making the cross-sectional shape of the vacuum vessel and the substrate holder 103 and the substrate 102 concentric, uniform gas diffusion is possible. In addition, although the case where the cross-sectional shape of the vacuum vessel 101 is circular has been exemplarily described, the inside of the vacuum vessel 101 is spherical as a configuration in which reactive gas (for example, oxygen) particles uniformly reach the circular substrate. You may comprise.

  In the example shown in FIG. 2, the gas inlet 150 faces downward and faces the valve element 106. However, if the substrate holder 103 and other shielding members are arranged so that the gas is not directly applied to the substrate. The gas inlet 150 may be arranged upward. A configuration example in which the direction of the gas inlet 150 is changed and a configuration example using a shielding member will be described in later embodiments.

  In the configuration example shown in FIG. 2, the gas inlet 150 is arranged facing the valve body 106 side, and gas is introduced from the gas inlet 150. Arrows 201 and 202 in FIG. 2 schematically show how the introduced gas diffuses in the vacuum vessel 101. The gas introduced from the gas introduction port 150 reaches the valve body 106 and then diffuses from the center of the valve body 106 in the outer peripheral direction (left-right direction in FIG. 2). Then, after reaching the vicinity of the side surface of the vacuum vessel 101, it diffuses into a gas (arrow 201) directed upward of the vacuum vessel and a gas (arrow 202) directed downward of the vacuum vessel.

  The gas (arrow 202) heading below the vacuum container is exhausted by the pump 105 from the exhaust port 160. When a part of the introduced gas is exhausted by the pump 105, the gas that diffuses in the vacuum vessel 101 and reaches the substrate 102 decreases, and the reactive gas (for example, oxygen) pressure during the formation of the insulating film is reduced. can do.

  On the other hand, the gas (arrow 201) heading above the vacuum vessel diffuses above the substrate in the vacuum vessel and reaches the substrate. In this case, it is considered that the oxygen particles of the gas (arrow 201) reach the center of the substrate 102 in order from the end of the substrate 102 by introducing the gas from below the substrate 102. Due to such gas diffusion, the distribution of the diffused particles becomes uniform, and the film thickness distribution of the formed insulator can be improved.

  FIG. 9 is a diagram showing the pressure distribution of the gas introduced from one gas inlet 150 aligned with the central axis of the substrate. The horizontal axis indicates the length (m) of the valve body 106, and the vertical axis indicates the pressure (Pa). From this figure, it can be seen that the central portion of the valve body 106 is a position corresponding to the gas inlet 150, and the pressure peaks in the vicinity of the central portion of the valve body 106, resulting in an even pressure distribution on the left and right. It is possible to cause uniform gas diffusion (201, 202 in FIG. 2) due to the uniform pressure gradient.

  FIG. 8 is a diagram showing a simulation result of the pressure distribution performed for comparing the configuration of the conventional example and the configuration according to the embodiment. Reference numeral 801 denotes a case where a shower plate is used, reference numeral 802 denotes a case where a ring (gas ring) is used, and reference numeral 803 denotes a simulation result when the configuration of the present embodiment (single point gas introduction at the substrate stage) is used. Reference numeral 804 denotes a simulation result when the configuration of the second embodiment described later is used, which will be described in detail later.

  The conditions used for the simulation are as follows.

Initial vacuum vessel ultimate pressure: 5.0 × E-8Pa
Oxygen gas introduction amount: 0.01sccm
Substrate: 6 inch Si substrate Oxygen adsorption probability: 0%
Pump exhaust capacity: 3000L / s
Comparing the results of 3σ, in the configuration using the shower plate, 3σ = 6.06 × 10 ⁻⁷ (Pa), and in the configuration using the gas ring, 3σ = 2.40 × 10 ⁻⁷ (Pa). On the other hand, in the configuration of this embodiment (introducing one point of gas), 3σ = 6.32 × 10 ⁻⁸ (Pa), and the oxygen pressure distribution is improved as compared with the conventional example.

  Further, when the results of 3σ / average pressure are compared, in the configuration using the shower plate, 3σ / average pressure = 5.91%, and in the configuration using the gas ring, 3σ / average pressure = 4.06%. On the other hand, in the configuration of this embodiment (introduction of one point of gas), 3σ / average pressure = 0.81%, and the variation in oxygen pressure distribution is the same as the configuration using the conventional shower plate and the configuration using the gas ring. It can be seen that this is an improvement.

  According to the configuration of the present embodiment, it is possible to improve the film thickness distribution of the insulator. It is also possible to reduce the oxygen distribution pressure during formation.

(Second Embodiment)
In the present embodiment, as a method for not directly applying a gas (for example, a reactive gas such as oxygen gas) to the substrate 102, a configuration in which gas is introduced from below the valve body 106 (single point introduction of the valve lower gas) will be described. FIG. 3 is a cross-sectional view showing a schematic configuration of a vacuum processing apparatus according to the second embodiment. The gas introduction unit 104 introduces gas (for example, reactive gas such as oxygen gas) from the outside of the vacuum vessel 101 into the vacuum vessel via a pipe.

  An opening is provided in the central part of the valve body 106, and the gas introduction part 104 is inserted into this opening part, and the gas introduction port 150 protrudes below the valve body 106. By inserting the gas introduction part 104 into the opening part, the opening part of the valve body 106 is sealed. The moving unit 107 can move the valve body 106 in a state where the gas introduction unit 104 is inserted. In a state where the valve body 106 is moved downward (lowered state) by the moving unit 107, the valve body 106 closes the exhaust port 160, and the inside of the vacuum vessel 101 is airtight. Further, the exhaust port 160 is opened in a state where the valve body 106 is moved upward by the moving unit 107 (upward state), and the pump 105 connected to the tip of the exhaust port 160 communicates with the inside of the vacuum vessel 101. . The gas inlet 150 that protrudes downward from the valve body 106 is disposed so as to coincide with the central axis of the substrate holder 103 and the substrate 102.

  In the example shown in FIG. 3, gas is introduced downward from the gas inlet 150 below the valve body 106. Arrows 301 and 302 in FIG. 3 schematically show how the introduced gas diffuses in the vacuum vessel 101. The gas introduced from the gas inlet 150 is divided into a gas (arrow 301) directed upward of the vacuum vessel 101 and a gas (arrow 302) directed downward of the vacuum vessel.

  The gas (arrow 302) heading below the vacuum container is exhausted by the pump 105 from the exhaust port. When a part of the introduced gas is exhausted by the pump 105, the gas that diffuses in the vacuum vessel 101 and reaches the substrate 102 is reduced, and the oxygen distribution pressure at the time of formation can be reduced.

  On the other hand, the gas (arrow 301) heading above the vacuum container diffuses above the substrate in the vacuum container and reaches the substrate. In this case, by introducing the gas from below the substrate 102 (substrate mounting surface), the oxygen particles of the gas (arrow 301) sequentially reach the center of the substrate 102 from the end of the substrate 102. Due to such gas diffusion, the distribution of the diffusion particles becomes uniform, and the film thickness distribution of the formed insulator can be improved.

804 in FIG. 8 shows a simulation result when the configuration of the second embodiment is used, and 3σ = 5.43 × 10 ⁻⁸ (Pa), and the oxygen pressure distribution is improved as compared with the conventional example.

  Further, 3σ / average pressure = 1.34%, and it can be seen that the variation in the oxygen pressure distribution is improved as compared with the configuration using the conventional shower plate and the configuration using the gas ring. According to the configuration of the present embodiment, it is possible to improve the film thickness distribution of the insulator. It is also possible to reduce the oxygen distribution pressure during formation.

(Third embodiment)
In the present embodiment, a configuration in which gas is introduced toward the exhaust port of the pump 105 will be described as a method in which a gas (for example, a reactive gas such as oxygen gas) is not directly applied to the substrate. FIG. 4 is a cross-sectional view showing a schematic configuration of a vacuum processing apparatus according to the third embodiment. The gas introduction unit 104 introduces gas (for example, reactive gas such as oxygen gas) from the outside of the vacuum vessel 101 into the vacuum vessel via a pipe. A gas introduction port 150 provided at the tip of the gas introduction unit 104 is disposed between the substrate holder 103 and the pump 105 so as to coincide with the central axis of the substrate 102.

  In the configuration example shown in FIG. 4, the gas introduction port 150 is arranged facing the pump 105 side (the exhaust port 160 side in FIG. 1), and reactive gas is introduced from the gas introduction port 150 toward the pump 105. . Arrows 401 and 402 in FIG. 4 schematically show how the introduced gas diffuses in the vacuum vessel 101. The gas introduced from the gas inlet 150 is divided into a gas (arrow 401) directed upward of the vacuum container 101 and a gas (arrow 402) directed downward of the vacuum container.

  The gas (arrow 402) heading below the vacuum container is exhausted by the pump 105 from the exhaust port. When a part of the introduced gas is exhausted by the pump 105, the gas that diffuses in the vacuum vessel 101 and reaches the substrate 102 is reduced, and the oxygen distribution pressure at the time of formation can be reduced.

  On the other hand, the gas (arrow 401) heading above the vacuum container diffuses above the substrate in the vacuum container and reaches the substrate. In this case, by introducing a gas from below the substrate 102, oxygen particles of the gas (arrow 401) reach the center of the substrate 102 in order from the end of the substrate 102. Due to such gas diffusion, the distribution of the diffusion particles becomes uniform, and the film thickness distribution of the formed insulator can be improved.

(Fourth embodiment)
In the present embodiment, as a method of not directly applying a gas (for example, a reactive gas such as oxygen gas) to the substrate, molecules obtained by applying the gas to the shielding member 510 disposed between the valve body 106 and the substrate holder 103 are used. Insulating (for example, oxidation) treatment is performed by utilizing a flow diffusion phenomenon.

  FIG. 5 is a cross-sectional view showing a schematic configuration of a vacuum processing apparatus according to the fourth embodiment. The gas introduction unit 104 introduces gas (for example, reactive gas such as oxygen gas) from the outside of the vacuum vessel 101 into the vacuum vessel via a pipe. The gas inlet 150 provided at the tip of the gas inlet is disposed between the substrate holder 103 and the shielding member 510 so as to coincide with the central axis of the substrate 102.

  In the configuration example shown in FIG. 5, the gas inlet 150 is disposed facing the shielding member 510 side, and gas is introduced from the gas inlet 150. Arrows 501 and 502 in FIG. 5 schematically show how the introduced gas diffuses in the vacuum vessel 101. The gas introduced from the gas introduction port reaches the shielding member 510 and then diffuses from the center of the shielding member 510 in the outer peripheral direction (left-right direction in FIG. 5). Then, after reaching the vicinity of the side surface of the vacuum container 101, the gas diffuses into a gas (arrow 501) directed upward of the vacuum container and a gas (arrow 502) directed downward of the vacuum container.

  The gas (arrow 502) heading below the vacuum container is exhausted by the pump 105 from the exhaust port. When a part of the introduced gas is exhausted by the pump 105, the gas that diffuses in the vacuum vessel 101 and reaches the substrate 102 is reduced, and the oxygen distribution pressure at the time of formation can be reduced.

  On the other hand, the gas (arrow 501) heading above the vacuum container diffuses above the substrate in the vacuum container and reaches the substrate. In this case, by introducing a gas from below the substrate 102, oxygen particles of the gas (arrow 501) sequentially reach the center of the substrate 102 from the end of the substrate 102. Due to such gas diffusion, the distribution of the diffusion particles becomes uniform, and the film thickness distribution of the formed insulator can be improved.

(Fifth embodiment)
In this embodiment, as a method in which a gas (for example, a reactive gas such as oxygen gas) is not directly applied to the substrate, insulation is performed by utilizing a molecular flow diffusion phenomenon caused by applying a gas to the back side (back surface) of the substrate holder 103. A configuration for performing the oxidization (for example, oxidation) treatment will be described. Here, the back surface of the substrate holder 103 refers to a surface opposite to the substrate mounting surface on which the substrate holder 103 can mount the substrate 102. In the present embodiment, the back side (back surface) of the substrate holder 103 functions as a shielding member that shields the molecules of the reactive gas from reaching the surface of the substrate 102 linearly.

  FIG. 6 is a cross-sectional view illustrating a schematic configuration of a vacuum processing apparatus according to the fifth embodiment. The gas introduction unit 104 introduces gas (for example, reactive gas such as oxygen gas) from the outside of the vacuum vessel 101 into the vacuum vessel via a pipe. The gas introduction port 150 provided at the tip of the gas introduction part is arranged so as to coincide with the central axis of the substrate holder 103 and the central axis of the substrate 102.

  In the configuration example shown in FIG. 6, the gas inlet 150 is arranged facing the back side (back side) of the substrate holder 103, and gas is introduced from the gas inlet 150. Arrows 601 and 602 in FIG. 6 schematically show how the introduced gas diffuses in the vacuum vessel 101. The gas introduced from the gas inlet 150 reaches the back side of the substrate holder 103 and then diffuses from the center of the back side surface of the substrate holder 103 toward the outer periphery. Then, after reaching the vicinity of the side surface of the vacuum vessel 101, it diffuses into a gas (arrow 601) directed upward of the vacuum vessel and a gas (arrow 602) directed downward of the vacuum vessel.

  The gas (arrow 602) heading below the vacuum container is exhausted by the pump 105 from the exhaust port. When a part of the introduced gas is exhausted by the pump 105, the gas that diffuses in the vacuum vessel 101 and reaches the substrate 102 is reduced, and the oxygen distribution pressure at the time of formation can be reduced.

  On the other hand, the gas (arrow 601) heading above the vacuum container diffuses above the substrate in the vacuum container and reaches the substrate. In this case, by introducing a gas from below the substrate 102, oxygen particles of the gas (arrow 601) sequentially reach the center of the substrate 102 from the end of the substrate 102. Due to such gas diffusion, the distribution of the diffusion particles becomes uniform, and the film thickness distribution of the formed insulator can be improved.

(Sixth embodiment)
In this embodiment, as a method in which a gas (for example, a reactive gas such as oxygen gas) is not directly applied to the substrate, insulation (for example, by utilizing a molecular flow diffusion phenomenon caused by applying a gas to the upper surface of the vacuum vessel 101) A configuration for performing (oxidation) treatment will be described. In the present embodiment, the upper surface of the vacuum container 101 functions as a shielding member that shields molecules of a gas (for example, a reactive gas such as oxygen gas) from reaching the surface of the substrate 102 linearly.

  FIG. 7 is a cross-sectional view showing a schematic configuration of a vacuum processing apparatus according to the sixth embodiment. The gas introduction unit 104 introduces gas from the outside of the vacuum vessel 101 into the vacuum vessel via a pipe. The gas introduction port 150 provided at the tip of the gas introduction part is arranged so as to coincide with the central axis of the substrate holder 103 and the central axis of the substrate 102.

  In the configuration example shown in FIG. 7, the gas inlet 150 is arranged facing the upper surface 710 side of the vacuum vessel 101, and gas is introduced from the gas inlet 150. An arrow 701 in FIG. 7 schematically shows how the introduced gas diffuses in the vacuum vessel 101. The gas introduced from the gas introduction port 150 reaches the upper surface 710 of the vacuum vessel 101 and then diffuses from the center of the upper surface 710 of the vacuum vessel 101 in the outer peripheral direction (left-right direction in FIG. 7). After reaching the vicinity of the side surface of the vacuum vessel 101, the gas is divided into a gas diffusing toward the substrate 102 in the vacuum vessel 101 and a gas diffusing toward the exhaust port side of the pump 105.

  The gas diffusing to the exhaust port side of the pump 105 is exhausted by the pump 105 from the exhaust port. A part of the gas introduced to form the insulator is exhausted by the pump 105, so that the gas that diffuses in the vacuum vessel 101 and reaches the substrate 102 is reduced, and the oxygen distribution pressure at the time of formation is reduced. can do.

  On the other hand, the gas diffusing toward the substrate 102 reaches the center of the substrate 102 in order from the end of the substrate 102. Due to such gas diffusion, the distribution of the diffusion particles becomes uniform, and the film thickness distribution of the formed insulator can be improved.

(Seventh embodiment)
In the present embodiment, a configuration of a magnetoresistive effect element (TMR element) manufacturing apparatus including the configuration of the vacuum processing apparatus described in the first to sixth embodiments will be described.

  FIG. 1C is a diagram for explaining a configuration of a magnetoresistive element manufacturing apparatus. In order to manufacture a TMR element, the magnetoresistive element manufacturing apparatus includes at least one vacuum container for formation, 1 One insulating (for example, oxidation) vacuum vessel and one heat treatment vacuum vessel are provided. For example, the substrate transported from the load lock chamber 8 is transported to the forming vacuum vessel 9a (forming chamber), where the underlayer, the antiferromagnetic layer, the ferromagnetic layer, the nonmagnetic intermediate layer, and the second ferromagnetic layer are transported. Is formed on the substrate. Thereafter, the substrate is transferred to a forming vacuum vessel 9b (forming chamber), and a first metal layer (for example, a first Mg layer) is formed. Thereafter, the substrate on which the first metal layer is formed is transferred to the vacuum chamber 10 (insulation chamber) for insulation treatment, and the first metal layer is insulated (for example, oxidized). The thickness of the insulator (MgO) to be formed by applying the configuration of the vacuum processing apparatus described in the first to sixth embodiments to the vacuum container 10 (insulating chamber) for insulating processing. It is possible to improve the distribution and reduce the oxygen distribution pressure during formation.

  Thereafter, the substrate with the first metal layer insulated is returned to the forming vacuum vessel 9b, and a second metal layer (for example, a second Mg layer) is formed on the insulated first metal layer. It is formed. Thereafter, the substrate on which the second metal layer is formed is transferred to the vacuum vessel 11 for heat treatment, and heat treatment is performed. Thereafter, the heat-treated substrate returns to the forming vacuum vessel 9b, and a magnetization free layer and a protective layer are formed. Here, the load lock chamber 8, the forming vacuum containers 9 a and 9 b, the insulating processing vacuum container 10, and the heating processing vacuum container 11 are connected to the transfer chamber 12. Each vacuum vessel (chamber) is equipped with an evacuation device and can be independently evacuated, so that the substrate can be processed in a consistent vacuum. The metal layer can be selected from an Al film, a Ti film, a Zn film, or the like in addition to the Mg film.

  According to the magnetoresistive element manufacturing apparatus of the present embodiment, for example, it is possible to form an ultrathin film having a thickness of 1 nm or less, and it is possible to provide a higher quality magnetoresistive element (TMR element).

  The present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, in order to make the scope of the present invention public, the following claims are attached.

  This application claims priority based on Japanese Patent Application No. 2013-198827 filed on Sep. 25, 2013, the entire contents of which are incorporated herein by reference.

Claims (11)

Depressurizable vacuum vessel connected to an exhaust means, a substrate holder provided with a substrate placement surface for placing a substrate disposed in the vacuum vessel, and gas introduction for introducing a reactive gas into the vacuum vessel A vacuum processing apparatus having a gas introduction means having a mouth,
The gas introduction port is located between an exhaust port constituting the exhaust unit and the substrate holder, and molecules of the reactive gas discharged from the gas introduction port into the vacuum container are introduced into the gas introduction port. It is disposed at a position that does not reach the substrate mounting surface linearly from the mouth, and is disposed at a position on a substantial central axis of the substrate mounting surface, and the reactive gas is diffused by molecular flow. A vacuum processing apparatus that reaches the substrate mounting surface. The vacuum processing apparatus according to claim 1 , wherein the gas introduction port is located on a back side of the substrate holder. It said gas inlet, the vacuum processing apparatus according to claim 1 or 2, characterized in that it comprises one opening to release said reactive gas into the vacuum vessel. The exhaust means, the is configured to include an exhaust port provided in the vacuum vessel, the exhaust port according to any one of claims 1 to 3, characterized in that located immediately below the substrate holder Vacuum processing equipment. The exhaust means, said vacuum vessel, the vacuum processing apparatus according to any one of claims 1 to 4, characterized in that the pressure reduction to a low pressure of less than 1 × 10 -5 ^Pa. Depressurizable vacuum vessel connected to an exhaust means, a substrate holder provided with a substrate placement surface for placing a substrate disposed in the vacuum vessel, and gas introduction for introducing a reactive gas into the vacuum vessel A vacuum processing method of a vacuum processing apparatus having a gas introducing means having a mouth,
A placing step of placing a substrate on a substrate holder disposed in the vacuum vessel;
Molecules of the reactive gas discharged before Symbol vacuum chamber, wherein the arrival city like linearly to the surface of the substrate from the gas inlet on the substantially central axis of the surface of the substrate, said exhaust means an exhaust port for constituting a said substrate holder, the gas inlet port is located between the, and the introduction step of introducing the pre-Symbol reactive gas,
An arrival step of causing the reactive gas to reach the substrate mounting surface by diffusion of a molecular flow;
The vacuum processing method characterized by having. The vacuum processing method according to claim 6 , wherein the reactive gas is oxygen gas. A metal film is formed on the surface of the substrate, and the method further includes an oxidation step of oxidizing the metal film with the reactive gas that has reached the substrate mounting surface in the arrival step. The vacuum processing method according to claim 7 . The vacuum processing method according to claim 8 , wherein the metal film is selected from an Mg film, an Al film, a Ti film, and a Zn film. Using a vacuum processing method according to any one of claims 6 to 9, the method for manufacturing a magneto-resistance effect element, comprising a step of forming a tunnel barrier layer made of MgO. Apparatus for manufacturing a magnetoresistive element characterized by having a vacuum processing apparatus according to any one of claims 1 to 5.

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