JP2020136144A - Plasma state measuring device and film forming device - Google Patents

Abstract

To provide a plasma state measuring device capable of suppressing electrical connection between a measurement electrode and a metal film deposited on an insulating member by depositing a metal film on the insulating member, and a film forming device.SOLUTION: The plasma state measuring device includes: a support 11; an insulating member 12; a measuring electrode 13 that has a measurement end 13a1 exposed in a measurement space S and is fixed to the support 11 via the insulating member 12; and a protective member 14 that covers a part of the insulating member 12 in contact with the measurement electrode 13 and a part continuous from the part against the measurement space S.SELECTED DRAWING: Figure 1

Description

The present invention relates to a plasma state measuring device and a film forming apparatus including the plasma state measuring device.

In the film forming apparatus, a plasma state measuring apparatus is used for the purpose of measuring the state of plasma generated in the vacuum chamber included in the film forming apparatus. The plasma state measuring device includes a probe for measuring plasma, a first cover, and a second cover. The probe has a columnar shape and is made of a conductive material. The second cover is made of an insulating material and is fixed to the outer surface of the probe so as to cover the probe. The second cover has an opening for exposing the probe to the measurement space partitioned by the vacuum chamber. The first cover is made of an insulating material and further covers the probe covered by the second cover from the outside of the second cover. The first cover has a plurality of openings.

In the plasma state measuring device, the second cover rotates about the central axis of the probe as a rotation axis, so that the opening of the first cover and the portion other than the opening in the second cover can face each other. As a result, the portion of the probe exposed from the second cover is covered by the first cover with respect to the measurement space. Further, in the plasma state measuring device, the opening of the first cover and the opening of the second cover can be made to face each other by rotating the second cover around the central axis of the probe as a rotation axis. As a result, the portion of the probe exposed from the second cover is exposed to the measurement space (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-227595

By the way, when the film forming apparatus is used for forming a thin metal film, metal particles flying in the measurement space are formed between the first cover and the second cover which is an insulating member covering the probe. It may get in. As a result, when metal particles adhere to the vicinity of the opening in the second cover, a metal film is deposited in the vicinity of the opening in the second cover. When such a metal film reaches the opening of the second cover, the probe exposed from the second cover is electrically connected to the metal film deposited on the second cover. As a result, the measurement result by the plasma state measuring device is displaced due to the metal film deposited on the second cover. It should be noted that these matters are common not only to the sputtering apparatus but also to the case where the plasma state measuring apparatus is mounted on the film forming apparatus such as the plasma CVD apparatus and the ion plating apparatus.

The present invention provides a plasma state measuring apparatus and a film forming apparatus capable of suppressing electrical connection between a measurement electrode and a metal film deposited on an insulating member by depositing a metal film on the insulating member. The purpose is.

A plasma state measuring device for solving the above-mentioned problems includes a support, an insulating member, a measuring electrode having a measuring end exposed in a measurement space, and being fixed to the support via the insulating member, and the measuring electrode. The insulating member includes a portion that comes into contact with the measurement electrode and a protective member that covers a portion connected to the measurement electrode with respect to the measurement space.

In a plasma state measuring device for solving the above problems, an insulating member, a measuring electrode having a measuring end exposed in a measuring space, and the measuring electrode are fixed via the insulating member, and the insulating member is described as described above. It includes a portion that comes into contact with the measurement electrode and a support that covers a portion connected to the measurement electrode with respect to the measurement space.

The film forming apparatus for solving the above-mentioned problems includes the above-mentioned plasma state measuring apparatus.
According to each of the above configurations, a portion of the insulating member that comes into contact with the measurement electrode and a portion that is continuous from the portion are covered with a protective member with respect to the measurement space. Therefore, when the raw material of the metal film is included in the measurement space, it is possible to prevent the metal film from being deposited on the insulating member and to prevent the deposited metal film from being electrically connected to the measurement electrode.

In the plasma state measuring apparatus, the measuring electrode includes a measuring probe having a columnar shape extending toward the measuring space through a hole formed in the support, and the tip of the measuring probe is the measuring end. The base end of the measurement probe is the end to which the measurement voltage is applied, and is a protective tube having a tubular shape that is fixed to the support and extends from the hole toward the measurement space and through which the measurement probe passes. The protective tube whose measurement end is located inside the protective tube may be further provided.

According to the above configuration, since the measurement end is located inside the protection tube, the directivity of the particles toward the measurement end can be set to the extending direction of the protection tube, and the direction in which the particles flow by the plasma state measuring device. It is possible to obtain the measurement result with the addition of.

In the plasma state measuring apparatus, the measuring electrode includes a measuring probe having a columnar shape extending toward the measuring space through a hole formed in the support, and the tip of the measuring probe is the measuring end. The base end of the measurement probe is the end to which the measurement voltage is applied, the measurement electrode includes the plurality of the measurement probes, and the lengths of the plurality of measurement probes in the extending direction are different from each other. The measurement electrode is located on the side opposite to the measurement space with respect to the support and includes an electrode plate that supports the measurement probe, and each measurement probe can be attached to and detached from the electrode plate. One of the plurality of measuring probes may be attached to the electrode plate.

According to the above configuration, it is possible to obtain a measurement result at a position corresponding to the length of the measurement probe by changing the measurement probe attached to the electrode plate in a plurality of measurement probes.

In the plasma state measuring apparatus, the measuring electrode includes a measuring probe having a columnar shape extending toward the measuring space through a hole formed in the support, and the tip of the measuring probe is the measuring end. The base end of the measurement probe is the end to which the measurement voltage is applied, and the measurement electrode is located on the side opposite to the measurement space with respect to the support and includes an electrode plate that supports the measurement probe. The measurement probe may be supported by the electrode plate so that the measurement end can be displaced with respect to the support along the extending direction of the measurement probe. According to the above configuration, the position of the measurement end of the measurement probe is displaced in the extending direction of the measurement probe, so that the measurement result corresponding to the position of the measurement end can be obtained.

In the plasma state measuring device, the support has a plate shape that covers the electrode plate with respect to the measurement space and has the holes through which the measurement probe passes, and the electrode plate holds the insulating member. It may be fixed to the support via.

According to the above configuration, the plate-shaped electrode plate is fixed to the plate-shaped support covering the electrode plate via the insulating member, so that the measurement electrode is stably held to the support. It is easy, and it is difficult for a raw material for forming a metal film to enter between the electrode plate and the support.

The cross-sectional view which shows the structure of the plasma state measuring apparatus in 1st Embodiment. The block diagram which shows the typical structure of the sputtering apparatus which includes the plasma state measuring apparatus. FIG. 2 is a diagram schematically showing a structure in a plan view facing the surface of a support in a plasma state measuring device attached to the sputtering device shown in FIG. 2. The graph which shows the relationship between the rotation angle and an ion saturation current in Test Example 1. The cross-sectional view which shows the structure of the plasma state measuring apparatus in 2nd Embodiment. The cross-sectional view which shows the structure of the plasma state measuring apparatus in 3rd Embodiment. The graph which shows the relationship between the rotation angle and an ion saturation current in Test Example 2. The figure which shows typically the distribution of the erosion on the surface to be sputtered in Test Example 2 and the distribution of an ion saturation current when viewed from the direction facing the support.

[First Embodiment]
The plasma state measuring apparatus and the film forming apparatus of the first embodiment will be described with reference to FIGS. 1 to 4. In the following, the structure of the plasma state measuring device, the structure of the sputtering device which is an example of the film forming device, and the test example will be described in order.

[Structure of plasma state measuring device]
The structure of the plasma state measuring device will be described with reference to FIG. FIG. 1 shows a cross-sectional structure along a plane including a measurement electrode included in the plasma state measuring device.

As shown in FIG. 1, the plasma state measuring device 10 includes a support 11, an insulating member 12, a measuring electrode 13, and a protective member 14. The measurement electrode 13 has a measurement end 13a1 exposed in the measurement space S. The measurement electrode 13 is fixed to the support 11 via the insulating member 12. The protective member 14 covers a portion of the insulating member 12 that comes into contact with the measurement electrode 13 and a portion that is continuous from the portion of the insulating member 12 with respect to the measurement space S apart from the insulating member 12 and the measurement electrode 13.

The support 11 has, for example, a disk shape and is arranged on a stage provided in the sputtering apparatus. The support 11 is made of metal, for example. The support 11 is made of, for example, stainless steel. The support 11 includes a front surface 11F facing the measurement space S and a back surface 11R which is a surface opposite to the front surface 11F. The support 11 has recesses 11a on the front surface 11F and the back surface 11R, respectively. The recess 11a on the front surface 11F and the recess 11a on the back surface 11R overlap each other when viewed from the thickness direction of the support 11. The support 11 further includes a through hole 11b that penetrates between the recesses 11a. In a plan view facing the surface 11F, the outer shape of the recess 11a and the outer shape of the through hole 11b are circular, but other shapes other than the circular shape may be used.

The plasma state measuring device 10 includes two insulating members 12. The two insulating members 12 sandwich the support 11 in the thickness direction of the support 11. In a plan view facing the surface 11F of the support 11, each insulating member 12 has, for example, a cylindrical shape. The insulating member 12 may have a shape other than the cylindrical shape as long as it has a cylindrical shape.

The two insulating members 12 are a first insulating member 12a and a second insulating member 12b. When viewed from the thickness direction of the support 11, a part of the first insulating member 12a is fitted in the recess 11a of the surface 11F of the support 11. On the other hand, a part of the second insulating member 12b is fitted in the recess 11a of the back surface 11R of the support 11. The insulating member 12 is formed of, for example, ceramics or synthetic resin. The insulating member 12 is formed of, for example, alumina (Al ₂ O ₃ ) or silicon dioxide (SiO ₂ ).

The protective member 14 has, for example, a covered cylinder. The protective member 14 may have a shape other than the covered cylindrical shape as long as it has a tubular shape and has a lid portion. The protective member 14 accommodates the insulating member 12 located on the surface 11F of the support 11 in the space formed by the recess 11a of the support 11 and the protective member 14. Therefore, as compared with the case where the protective member has a plate shape, it is possible to prevent the metal film from being deposited on the insulating member 12 located on the surface 11F of the support 11. As a result, it is possible to prevent the metal film deposited on the insulating member 12 from being electrically connected to the measuring electrode 13. The lid portion of the protective member 14 has a through hole penetrating the lid portion along the thickness direction of the lid portion. The protective member 14 is made of metal, for example. The protective member 14 is made of, for example, stainless steel.

In the present embodiment, the measuring electrode 13 is formed by the measuring probe 13a, the first fixing member 13b, and the second fixing member 13c. The measuring probe 13a has a shape extending along the thickness direction of the support 11. The measuring probe 13a penetrates the protective member 14, the first insulating member 12a, the support 11, and the second insulating member 12b in the order described. In the measurement probe 13a, the end exposed to the measurement space S is the measurement end 13a1, and the end opposite to the measurement end 13a1 is the connection end 13a2 connected to the power supply. A voltage is applied to the connection end 13a2 by a power source. The measuring probe 13a is made of metal. The measuring probe 13a is made of, for example, stainless steel. The measuring probe 13a is, for example, a screw.

The first fixing member 13b is located between the protective member 14 and the first insulating member 12a when viewed from the thickness direction of the support 11. The first fixing member 13b is a member for fixing the measurement probe 13a to the first insulating member 12a. In a plan view facing the surface 11F of the support 11, the first fixing member 13b has, for example, an annular shape. The first fixing member 13b may have a shape other than the annular shape as long as it has an annular shape. The first fixing member 13b is made of metal. The first fixing member 13b is formed of, for example, stainless steel. The first fixing member 13b is, for example, a washer.

The second fixing member 13c sandwiches the second insulating member 12b together with the support 11 when viewed from the thickness direction of the support 11. The second fixing member 13c sandwiches the protective member 14, the first insulating member 12a, the support 11, and the second insulating member 12b together with the measuring end 13a1 of the measuring probe 13a in the thickness direction of the support 11. , A member for fixing the protective member 14 and the pair of insulating members 12 to the support 11. The second fixing member 13c has, for example, an annular shape in a plan view facing the surface 11F of the support 11. The second fixing member 13c may have a shape other than the annular shape as long as it has an annular shape. The second fixing member 13c is made of metal. The second fixing member 13c is formed of, for example, stainless steel. The second fixing member 13c is, for example, a nut.

As described above, in the present embodiment, the portion where the first fixing member 13b contacts the first insulating member 12a is the portion where the measuring electrode 13 contacts the insulating member 12, and the second fixing member 13c is the second. The portion that contacts the insulating member 12b is the portion where the measuring electrode 13 contacts the insulating member 12. Further, in the outer peripheral surface of the first insulating member 12a, a portion continuous from the contact portion in contact with the measurement electrode 13 is a part continuous from the contact portion. In the outer peripheral surface of the second insulating member 12b, a portion continuous from the contact portion in contact with the measurement electrode 13 is a part continuous from the contact portion. Then, in the first insulating member 12a, the contact portion and a part connected to the contact portion are covered by the protective member 14. On the other hand, in the second insulating member 12b, the contact portion and a part connected to the contact portion are covered with the support 11.

In this way, the portion of the insulating member 12 that comes into contact with the measurement electrode 13 and the portion that is continuous from the portion are covered with the protective member 14 with respect to the measurement space S. Therefore, when the raw material of the metal film is contained in the measurement space S, it is possible to prevent the metal film from being deposited on the insulating member 12 and to prevent the deposited metal film from being electrically connected to the measurement electrode 13. ..

The second fixing member 13c further connects the wiring W connected to the power supply to the connection end 13a2 of the measurement probe 13a. The second fixing member 13c fixes the wiring W between the outer peripheral surface and the inner peripheral surface by sandwiching the wiring W between the outer peripheral surface of the measurement probe 13a and the inner peripheral surface of the second fixing member 13c. ..

The metal member included in the plasma state measuring device 10 is not limited to the above-mentioned stainless steel, and may be formed of, for example, aluminum.

[Structure of sputtering equipment]
The structure of the sputtering apparatus will be described with reference to FIG.
As shown in FIG. 2, the sputtering apparatus 20 includes a plasma state measuring apparatus 10. In the example shown in FIG. 2, the plasma state measuring device 10 includes three measuring electrodes 13, but the number of measuring electrodes 13 may be two or less, or four or more, as long as it is one or more. It may be. The sputtering apparatus 20 includes a vacuum chamber 21 that partitions a space in which plasma is generated. The space partitioned by the vacuum chamber 21 is the measurement space S described above. The measurement space S is a space containing the raw material of the metal film, and in the present embodiment, is a space in which the sputter particles formed from the metal fly. A stage 22 that supports the support 11 is arranged in the vacuum chamber 21. The stage 22 supports the support 11 included in the plasma state measuring device 10 in a state where it can rotate about a rotation axis passing through the center of the stage 22. When film formation is performed on the processing target in the sputtering apparatus 20, the stage 22 supports the processing target.

In the vacuum chamber 21, the target 23 is located at a position facing the stage 22. The surface to be sputtered included in the target 23 is exposed in the measurement space S. The target 23 is made of metal. A DC power supply 24 is connected to the target 23. The magnetic circuit 25 is located on the opposite side of the target 23 from the stage 22. The magnetic circuit 25 forms a leakage magnetic field on the surface to be sputtered. The sputtering apparatus 20 has a rotation mechanism that rotates the magnetic circuit 25 around a rotation axis passing through the center of the target in a plan view facing the surface to be sputtered of the target 23.

The sputtering apparatus 20 further includes an exhaust unit 26 and a sputtering gas supply unit 27. The exhaust unit 26 depressurizes the inside of the vacuum chamber 21 to a predetermined pressure. The exhaust unit 26 includes, for example, a pump and a valve. The sputter gas supply unit 27 is connected to a gas cylinder located outside the vacuum tank 21. The sputter gas supply unit 27 is, for example, a mass flow controller, and supplies the sputter gas into the vacuum chamber 21 at a predetermined flow rate.

The sputtering apparatus 20 includes a DC power supply 28 connected to the measuring electrode 13 of the plasma state measuring apparatus 10. The DC power supply 28 is connected to each measurement electrode 13 one by one. Therefore, in the example shown in FIG. 2, the sputtering apparatus 20 includes three DC power supplies 28.

In the sputtering device 20, after the plasma state measuring device 10 is mounted on the sputtering device 20, the pressure inside the vacuum chamber 21 is reduced to a predetermined pressure by the exhaust unit 26. Next, the sputter gas supply unit 27 supplies the sputter gas into the vacuum chamber 21 at a predetermined flow rate, and then the DC power supply 24 applies a DC voltage to the target 23. As a result, plasma is generated from the sputtered gas in the vicinity of the surface to be sputtered of the target 23. Sputtered particles are emitted from the target 23 by the positive ions in the plasma colliding with the surface to be sputtered of the target 23.

FIG. 3 shows a structure in which the support 11 of the plasma state measuring device 10 mounted on the sputtering device 20 is viewed from a direction facing the surface 11F of the support 11. In FIG. 3, the measurement electrode 13 is schematically shown by a circle, and the protective member 14 included in the plasma state measuring device 10 is not shown.

In the example shown in FIG. 3, the support 11 has a disk shape. In a plan view facing the surface 11F of the support 11, the three measurement electrodes 13 are located on the same straight line passing through the center 11C of the support 11. The three measuring electrodes 13 are arranged at equal intervals, and one of the three measuring electrodes 13 is located at the center 11C of the support 11.

As described above, the stage 22 supports the support 11 in a state where the support 11 can rotate about the rotation axis passing through the center 11C of the support 11. In the example shown in FIG. 3, the support 11 rotates counterclockwise. When expressing the rotation angle θ of the support 11, all the measurement electrodes 13 extend along the left-right direction of the paper surface in a plan view facing the surface 11F of the support 11, and the center 11C of the support 11 C. Set the rotation angle θ to 0 ° when it is positioned in a straight line passing through. It is possible to indicate the rotation angle θ rotated counterclockwise with respect to 0 ° as a positive value and to indicate the rotation angle θ rotated clockwise with respect to 0 ° as a negative value.

[Test Example 1]
Test Example 1 will be described with reference to FIG. In Test Example 1 described below, the ion saturation current at the measurement electrode was measured by applying a bias voltage to each measurement electrode.
A plasma state measuring device including three measuring electrodes was mounted on the sputtering device, and the ion saturation current flowing through each measuring electrode was measured under the following conditions.

・ Target Aluminum target ・ Target diameter 300mm
・ Sputter gas Argon gas ・ Support made of stainless steel ・ Support diameter 300 mm
・ Measurement electrode made of stainless steel ・ Measurement end diameter 10 mm
・ Distance between target and measurement edge 45 mm
・ Pressure in the vacuum chamber 0.30Pa
・ Power supply to the target 6kW (3 seconds)
・ Bias voltage applied to the measurement electrode -100V

The three measurement electrodes are a center electrode located at the center of the support in a plan view facing the surface of the support, an outer electrode located on the outermost side in the radial direction of the support, and a diameter of the support. In the direction, it was an intermediate electrode located between the center electrode and the outer electrode. Then, in the radial direction of the support, the intermediate electrode was arranged at a position 70 mm from the center of the support, and the outer electrode was arranged at a position 140 mm from the center of the support. Further, when measuring the ion saturation current, when the position of the magnetic circuit is viewed from the direction in which the target and the support face each other and the rotation angle θ of the support is 0 °, the three measurement electrodes are used. It was fixed at a position where it overlaps with the magnetic circuit. On the other hand, when measuring the ion saturation current, the support was rotated and the ion saturation current at each measurement electrode at each rotation angle was measured.

As shown in FIG. 4, it was found that the ion saturation current at the center electrode was substantially constant regardless of the rotation angle θ of the support. Further, it was found that the ion saturation current in the intermediate electrode had a maximum value when the rotation angle was ± 60 ° and a minimum value when the rotation angle was 0 °. Further, it was found that the ion saturation current in the intermediate electrode gradually decreased as the rotation angle θ increased when the rotation angle θ was 60 ° or more and 180 ° or less. Furthermore, it was found that the ion saturation current in the intermediate electrode gradually decreased as the absolute value of the rotation angle θ increased when the rotation angle θ was −180 ° or more and −60 ° or less. It was found that the ion saturation current at the outer electrode had a maximum value when the rotation angle θ was in the vicinity of 0 °.

As described above, according to each measurement electrode, it was confirmed that the ion saturation current can be measured by arranging the plasma in the vacuum chamber in which the plasma is generated. Further, even when the ion saturation current is measured by the plasma state measuring device until the integrated electric energy of the target reaches 1.2 kWh, the first measurement is performed from the first measurement to the integrated electric energy of 1.2 kWh. It was confirmed that the results having the same tendency as the results measured in the above were obtained.

According to Test Example 1, according to the plasma state measuring device, it is possible to measure the ion saturation current according to the magnetic circuit mounted on the sputtering device. Therefore, it is also possible to select a desired magnetic circuit based on the measurement result of the plasma state measuring device.

As described above, according to the plasma state measuring apparatus and the film forming apparatus of the first embodiment, the effects described below can be obtained.
(1) A portion of the insulating member 12 that comes into contact with the measurement electrode 13 and a portion that is continuous from the portion are covered with the protective member 14 with respect to the measurement space S. Therefore, when the raw material of the metal film is contained in the measurement space S, it is possible to prevent the metal film from being deposited on the insulating member 12 and to prevent the deposited metal film from being electrically connected to the measurement electrode 13. ..

The above-mentioned first embodiment can be changed as follows.
[Protective member]
-In the above-described embodiment, as the protective member 14, a member having a covered tubular shape is exemplified. Not limited to this, the protective member 14 may be plate-shaped or hemispherical as long as the protective member 14 can cover the portion of the insulating member 12 that contacts the measurement electrode 13 and the portion that is continuous from the portion. It may be in the form.

[Plasma state measuring device]
The plasma state measuring device 10 is not limited to the stage 22 that supports the processing target, and may be supported, for example, by a member arranged in the vacuum chamber 21 or a wall portion of the vacuum chamber 21. The member arranged in the vacuum chamber 21 may be, for example, a protective plate for suppressing the accumulation of a metal film on the wall portion of the vacuum chamber 21 and the stage 22 or the like. In this case, the ion saturation current can be measured by the plasma state measuring device 10 even while the film is being formed on the object to be processed in the vacuum chamber 21.

When the ion saturation current is measured by the plasma state measuring device 10 while the film is being formed on the processing target, the plasma state measuring device 10 is used to form the film on the processing target, that is, the thickness of the thin film. It can be used as a device for monitoring. For example, the integrated value of the ion saturation current can be regarded as the amount of film formation on the processing target. Further, the slope in the integrated value can be regarded as the film formation rate. In addition, the consumption amount of the target can be grasped from the film formation amount for the processing target. Therefore, it is also possible to determine the timing of exchanging the target by using the measurement result of the ion saturation current.

[Film formation device]
The plasma state measuring device 10 is not limited to the sputtering device which is an example of the film forming apparatus, and may be mounted on another film forming apparatus such as a plasma CVD apparatus and an ion plating apparatus.

[Second Embodiment]
The plasma state measuring apparatus of the second embodiment will be described with reference to FIG.
In the plasma state measuring device of the second embodiment, as compared with the plasma state measuring device of the first embodiment, the support covers the portion of the insulating member in contact with the measuring electrode with respect to the measuring space. It's different. The structure of the plasma state measuring device will be described below.

[Structure of plasma state measuring device]
As shown in FIG. 5, the plasma state measuring device 30 includes an insulating member 31, a measuring electrode 32, and a support 33. The measurement electrode 32 has a measurement end 32a exposed in the measurement space S. The measurement electrode 32 is fixed to the support 33 via the insulating member 31, and the support 33 has a portion of the insulating member 31 that contacts the measurement electrode 32 and a portion that is continuous from the portion with respect to the measurement space S. Covering. In the present embodiment, the support 33 has a first hole 33a and two second holes 33b that penetrate the support 33 along the thickness direction of the support 33.

The measuring electrode 32 includes a measuring probe 41. The measurement probe 41 has a columnar shape extending toward the measurement space S through the first hole 33a formed in the support 33. The tip 41a of the measurement probe 41 is the measurement end 32a described above, and the base end 41b of the measurement probe 41 is the connection end to which the measurement voltage is applied. The measuring probe 41 is made of metal like the measuring probe 13a of the first embodiment. The measuring probe 41 is made of, for example, stainless steel. The measuring probe 41 is, for example, a screw. The measuring probe 41 includes a columnar portion 41c including a base end 41b and a head portion as a tip end 41a. The head protrudes from the columnar portion 41c when viewed from the direction in which the measuring probe 41 extends.

The measuring electrode 32 includes an electrode plate 42. The electrode plate 42 is located on the side opposite to the measurement space S with respect to the support 33, and supports the measurement probe 41. The electrode plate 42 has, for example, a disk shape when viewed from the direction facing the plane on which the support 33 spreads. The electrode plate 42 may have a shape other than the disc shape as long as it has a plate shape. The electrode plate 42 has a first hole 42a penetrating the electrode plate 42 in the thickness direction of the electrode plate 42, and two second holes 42b. The electrode plate 42 supports the measuring probe 41 passing through the first hole 42a.

The measurement electrode 32 includes a first fixing member 43. The first fixing member 43 has an annular shape in a plan view facing the plane on which the support 33 spreads. The first fixing member 43 fixes the measurement probe 41 to the electrode plate 42 by passing it through the base end 41b of the measurement probe 41. The first fixing member 43 is made of metal. The first fixing member 43 is made of, for example, stainless steel. The first fixing member 43 is, for example, a nut. The first fixing member 43 further connects the wiring W connected to the power supply to the base end 41b of the measurement probe 41. The first fixing member 43 fixes the wiring W between the outer peripheral surface and the inner peripheral surface by sandwiching the wiring W between the outer peripheral surface of the measurement probe 41 and the inner peripheral surface of the first fixing member 43.

The support 33 includes two second fixing members 33c. Each of the second fixing members 33c is passed through the second hole 42b included in the electrode plate 42 one by one. Further, each of the second fixing members 33c is passed through the second hole 33b included in the support 33 one by one. Each second fixing member 33c includes a columnar portion 33c1 extending along the direction in which the support 33 and the electrode plate 42 are aligned, and a head 33c2 located at the base end of the columnar portion 33c1. The head 33c2 protrudes from the columnar portion 33c1 when viewed from the direction in which the support 33 and the electrode plate 42 are aligned.

In the direction in which each of the second fixing members 33c extends, the insulating member 31 is located between the head 33c2 of the second fixing member 33c and the electrode plate 42, and the insulating member is located between the electrode plate 42 and the support 33. 31 is located. As a result, the electrode plate 42 is fixed to the support 33 via the insulating member 31. Therefore, the portion where each insulating member 31 and the electrode plate 42 come into contact with each other is a contact portion in the insulating member 31 that contacts the measurement electrode 32, and is continuous from the contact portion in the outer peripheral surface of the insulating member 31. The part to be formed is a part connected from the contact part.

The support 33 has a plate shape that covers the electrode plate 42 with respect to the measurement space S and has a first hole 33a through which the measurement probe 41 passes. The support 33 is made of metal like the support 11 of the first embodiment. The support 33 is made of, for example, stainless steel.

In this way, the plate-shaped electrode plate 42 is fixed to the plate-shaped support 33 that covers the electrode plate 42 via the insulating member 31, so that the measuring electrode 32 is fixed to the support 33. It is easy to be held stably, and it is difficult for a raw material for forming a metal film to enter between the electrode plate 42 and the support 33.

The plasma state measuring device 30 further includes a protective tube 34. The protective tube 34 has a tubular shape extending along the direction in which the measuring probe 41 extends. The protective tube 34 is fitted in the first hole 33a of the support 33. A part of the protection tube 34 protrudes from the support 33 toward the measurement space S in the direction in which the measurement probe 41 extends. As a result, the protective tube 34 covers the portion of the columnar portion 41c included in the measuring probe 41 that passes through the support 33 and the portion that protrudes from the support 33. The protective tube 34 is made of metal. The protective tube 34 is made of, for example, stainless steel.

In the present embodiment, the measuring electrode 32 includes a plurality of measuring probes 41. In the plurality of measurement probes 41, the lengths of the measurement probes 41 in the extending direction are different from each other. The extending direction of the measuring probe 41 is the direction in which the electrode plate 42 and the support 33 are aligned. Each measuring probe 41 can be attached to and detached from the electrode plate 42. One of the plurality of measurement probes 41 is attached to the electrode plate 42.

Therefore, in the plurality of measurement probes 41, by changing the measurement probe 41 attached to the electrode plate 42, it is possible to obtain the measurement result at a position corresponding to the length of the measurement probe 41.

At each timing, only one of the plurality of measurement probes 41 is attached to the electrode plate 42. That is, the measuring electrode 32 does not have a state in which one measuring probe 41 is attached to the electrode plate 42 and a state in which the other measuring probe 41 is attached to the electrode plate 42 at the same time.

In the present embodiment, the plasma state measuring device 30 further includes the same number of protection tubes 34 as the measuring probe 41 per measuring electrode 32. In the plurality of protective tubes 34, the lengths of the measuring probes 41 in the extending direction are different from each other. Each protection tube 34 is associated with one measurement probe 41 in the plurality of measurement probes 41. Each protective tube 34 has a length capable of covering a portion passing through the support 33 and a portion protruding from the support 33 in the columnar portion 41c of the measurement probe 41 to which the protective tube 34 is associated. Has

As a result, it is possible to prevent the metal film from being deposited on the columnar portion 41c of the measurement probe 41 and the sputter particles from entering between the support 33 and the electrode plate 42 through the first hole 33a through which the columnar portion 41c passes. ..

As described above, according to the plasma state measuring apparatus of the second embodiment, the following effects can be obtained in addition to the above-mentioned effect (1).
(2) In a plurality of measurement probes 41, by changing the measurement probe 41 attached to the electrode plate 42, it is possible to obtain a measurement result at a position corresponding to the length of the measurement probe 41.

(3) Since the plate-shaped electrode plate 42 is fixed to the plate-shaped support 33 that covers the electrode plate 42 via the insulating member 31, the measuring electrode 32 is stable to the support 33. In addition, it is difficult for a raw material for forming a metal film to enter between the electrode plate 42 and the support 33.

The above-mentioned second embodiment can be modified and implemented as follows.
[Measurement electrode]
The measurement probe 41 may be supported by the electrode plate 42 so that the measurement end 32a can be displaced with respect to the support 33 along the extending direction of the measurement probe 41. That is, the measurement probe 41 may be attached to the electrode plate 42 in a state where the distance between the support 33 and the measurement end 32a can be changed. This makes it possible to change the position of the measurement end 32a in the measurement space S.

Therefore, according to the above-described configuration, the effects described below can be obtained.
(4) By displacing the position of the measurement end 32a of the measurement probe 41 in the extending direction of the measurement probe 41, it is possible to obtain a measurement result according to the position of the measurement end 32a.

When the measurement probe 41 is supported by the electrode plate 42 so that the measurement end 32a can be displaced with respect to the support 33, the protective tube 34 can displace the tubular end with respect to the support 33. May be supported. As a result, the protective tube 34 can cover the columnar portion 41c of the measurement probe 41 regardless of the position of the measurement end 32a. Further, when the measurement probe 41 is supported by the electrode plate 42 so that the measurement end 32a can be displaced with respect to the support 33, the plasma state measuring devices 30 have different lengths of the protection tubes 34 in the extending direction. A plurality of protective tubes 34 may be provided.

-The measurement electrode 32 may include only one measurement probe 41. Even in this case, since the portion where the measurement electrode 32 contacts the insulating member 31 is covered with the support 33, the effect according to (1) described above can be obtained.

[Electrode plate]
-The measurement electrode 32 may include a columnar member for fixing the measurement probe 41 to the support 33 instead of the electrode plate 42. In this case, the columnar member has a through hole through which the measurement probe 41 passes and a through hole through which the second fixing member 33c passes, and is between the columnar member and the second fixing member 33c, and the columnar member. It is sufficient that the insulating member 31 is located between the support 33 and the support 33.

[Protective tube]
-The plasma state measuring device 30 does not have to include the protective tube 34. Even in this case, since the insulating member 31 is covered with the support 33, the effect according to (1) described above can be obtained.

[Third Embodiment]
The plasma state measuring apparatus of the third embodiment will be described with reference to FIGS. 6 to 8.
The plasma state measuring device of the third embodiment is different from the plasma state measuring device of the second embodiment in the structure of the measuring probe and the structure of the protective tube. Therefore, in the following, the differences from the second embodiment will be described in detail, while the structure common to the second embodiment in the third embodiment is given the same reference numerals as those in the second embodiment. The explanation is omitted. Further, in the following, the structure of the plasma state measuring device and test examples will be described in order.

[Structure of plasma state measuring device]
The structure of the plasma state measuring device will be described with reference to FIG.
As shown in FIG. 6, the plasma state measuring device 50 includes an insulating member 31, a measuring electrode 32, and a support 33, similarly to the plasma state measuring device 30 of the second embodiment.

The measuring electrode 32 includes a measuring probe 51. The measurement probe 51 has a columnar shape extending toward the measurement space S through the first hole 33a formed in the support 33. The tip of the measuring probe 51 is the measuring end 51a, and the base end of the measuring probe 51 is the connecting end 51b. The plasma state measuring device 50 further includes a protective tube 52. The protection tube 52 is fixed to the support 33 and extends from the first hole 33a toward the measurement space S. The protective tube 52 has a tubular shape through which the measuring probe 51 passes, and the measuring end 51a is located inside the protective tube 52.

Since the measurement end 51a is located inside the protection tube 52, the directivity of the particles toward the measurement end 51a can be set to the extending direction of the protection tube 52, and the plasma state measuring device 50 sets the direction in which the particles flow. It is possible to obtain a measurement result that takes into account.

The distance between the end face included in the measurement end 51a and the tubular end of the protective tube 52 can be set to, for example, several mm. Since the end face of the measurement end 51a does not have to protrude from the tubular end of the protective tube 52, the end face of the measurement end 51a and the tubular end of the protective tube 52 may be located on the same plane. However, from the viewpoint of suppressing the deposition of the metal film on the measurement end 51a and from the viewpoint of suppressing the interference between one measurement probe 51 and the other measurement probe 51, the end face of the measurement end 51a is larger than the tubular end of the protective tube 52. It is preferably located closer to the support 33.

Similar to the measurement electrode 32 of the second embodiment, the measurement electrode 32 of the present embodiment can include a plurality of measurement probes 51 having different lengths in the extending direction of the measurement probe 51.

The plasma state measuring device 50 further includes a third fixing member 53. The third fixing member 53 has an annular shape when viewed from the direction in which the protective tube 52 extends. The third fixing member 53 is located outside the protective tube 52 when viewed from the direction in which the protective tube 52 extends. The inner peripheral surface of the third fixing member 53 is in contact with the outer peripheral surface of the protective tube 52, and the third fixing member 53 is in contact with the support 33. As a result, the third fixing member 53 fixes the protective tube 52 to the support 33.

[Test Example 2]
Test Example 2 will be described with reference to FIGS. 7 and 8.
[Ion saturation current]
The same conditions as in Test Example 1 described above except that the plasma state measuring device is provided with eight measuring electrodes and the distance between the tube end of the protective tube surrounding each measuring electrode and the target, that is, the measuring distance is set to 15 mm. The ion saturation current at each measurement electrode was measured. The distance between the end face of the protective tube and the end face of the measurement end was set to 5 mm.

In the plane facing the surface of the support, the first measurement electrode to the eighth measurement electrode were arranged at equal intervals along the radial direction of the support and along the direction from the center of the support to the outer edge. Specifically, the first measurement electrode is placed in the center of the support, the second measurement electrode is placed 20 mm from the center of the support, and the third measurement electrode is placed 40 mm from the center of the support. , The fourth electrode was placed at a position 60 mm from the center of the support. Then, the 5th measurement electrode is arranged at a position of 80 mm from the center of the support, the 6th measurement electrode is arranged at a position of 100 mm from the center of the support, and the 7th measurement electrode is arranged at a position of 120 mm from the center of the support. The eighth measurement electrode was placed at a position 140 mm from the center of the support.

As shown in FIG. 7, it was confirmed that the ion saturation current at the first measurement electrode was substantially constant regardless of the rotation angle θ of the support. It was found that the ion saturation current at the second measurement electrode had a maximum value when the rotation angle θ was approximately ± 90 °, and had a minimum value when the rotation angle θ was 0 °. It was found that the ion saturation current at the third measurement electrode had a maximum value when the rotation angle θ was approximately ± 75 ° and a minimum value when the rotation angle θ was 0 °. It was found that the ion saturation current at the fourth measurement electrode had a maximum value when the rotation angle θ was approximately ± 60 ° and a minimum value when the rotation angle θ was 0 °.

It was found that the ion saturation current at the fifth measurement electrode had a maximum value when the rotation angle θ was approximately ± 50 °, and had a minimum value when the rotation angle θ was 0 °. It was found that the ion saturation current at the sixth measurement electrode had a maximum value when the rotation angle θ was approximately ± 40 ° and a minimum value when the rotation angle θ was 0 °. It was found that the ion saturation current at the 7th measurement electrode had a maximum value when the rotation angle θ was 0 °. It was found that the ion saturation current at the eighth measurement electrode had a maximum value when the rotation angle θ was 0 °.

As described above, as in Test Example 1, it was confirmed that the ion saturation current can be measured by arranging the measurement electrodes in the vacuum chamber in which the plasma is generated. Further, even when the ion saturation current is measured by the plasma state measuring device until the integrated electric energy of the target reaches 1.2 kWh, the first measurement is performed from the first measurement to the integrated electric energy of 1.2 kWh. It was confirmed that the results having the same tendency as the results measured in the above were obtained.

[Distribution of ion saturation current]
The measurement distance was set to 27 mm, and the ion saturation current at each measurement electrode was measured. Further, the measurement distance was set to 45 mm, and the ion saturation current at each measurement electrode was measured.

FIG. 8A shows the distribution of erosion on the sputtered surface in a plan view facing the sputtered surface of the target. The distribution of erosion shown in FIG. 8A is a distribution when the sputtering apparatus is not equipped with the plasma state measuring apparatus and is discharged for 8 hours under the same conditions as in Test Example 1 described above. The integrated electric energy with respect to the target was 50 kWh. The higher the density of plasma generated in the vicinity of the surface to be sputtered, the greater the erosion of the surface to be sputtered. Therefore, it can be said that the distribution of erosion on the surface to be sputtered reflects the distribution of the density of plasma formed in the vicinity of the surface to be sputtered, and by extension, the distribution of ion saturation current.

In FIG. 8A, the reference region R0 is a region in which erosion hardly occurs in the surface to be sputtered, and the first region R1, the second region R2, and the third region R3 are described above. The area that is eroded is larger.

8 (b) to 8 (d) show the distribution of the ion saturation current in the plan view facing the support. FIG. 8 (b) shows the distribution of the ion saturation current when the measurement distance is 15 mm, and FIG. 8 (c) shows the distribution of the ion saturation current when the measurement distance is 27 mm. FIG. 8 (d) ) Indicates the distribution of the ion saturation current when the measurement distance is 45 mm.

In FIGS. 8 (b) to 8 (d), the reference region R0 is a region in which the ion saturation current is substantially 0, and is the first region R1, the second region R2, the third region R3, and the fourth region. In R4, the ion saturation current is larger in the region described above.

As shown in FIGS. 8 (a) to 8 (d), the distribution of erosion on the surface to be sputtered is copied to the distribution of the ion saturation current measured by the plasma state measuring device regardless of the measurement distance. It was confirmed that there was. That is, according to the plasma state measuring device, even if the protective tube provided in the plasma state measuring device and the measuring electrode located in the protective tube are exposed in the measurement region, the state of the plasma generated in the vacuum chamber is determined. It was confirmed that it was not disturbed by the protective tube and the measuring electrode. As described above, according to the plasma state measuring device, it is possible to measure the ion saturation current so that the state of the plasma generated in the vacuum chamber is reflected almost as it is.

As described above, according to the plasma state measuring apparatus of the third embodiment, the following effects can be obtained in addition to the above-mentioned effects (1) to (3).
(5) Since the measurement end 51a is located inside the protection tube 52, the directivity of the particles toward the measurement end 51a can be set to the extending direction of the protection tube 52, and the plasma state measuring device 50 allows the particles to be directed. It is possible to obtain a measurement result in which the flow direction is taken into consideration.

The above-mentioned third embodiment can be modified and implemented as follows.
[Measurement electrode]
-Similar to the second embodiment, the measurement probe 51 may be supported by the electrode plate 42 so that the measurement end 51a can be displaced with respect to the protection tube 52 along the extending direction of the measurement probe 51. In this case, the effect according to (4) described above can be obtained. Further, in this case, the protective tube 52 may be supported by the support 33 so that the end of the cylinder can be displaced with respect to the support 33. Further, the plasma state measuring device 50 may include a plurality of protective tubes 52 having different lengths in the extending direction of the protective tubes 52.

-Similar to the second embodiment, the measurement electrode 32 may include only one measurement probe 51. Even in this case, since the portion where the measurement electrode 32 contacts the insulating member 31 is covered with the support 33, the effect according to (1) described above can be obtained.

[Third fixing member]
If the protective tube 52 can be fixed to the support 33, the third fixing member 53 may be omitted.

[Electrode plate]
-Similar to the second embodiment, the measuring electrode 32 may include a columnar member for fixing the measuring probe 41 to the support 33 instead of the electrode plate 42. In this case, the columnar member has a through hole through which the measurement probe 41 passes and a through hole through which the second fixing member 33c passes, and is between the columnar member and the second fixing member 33c, and the columnar member. It is sufficient that the insulating member 31 is located between the support 33 and the support 33.

10, 30, 50 ... Plasma state measuring device, 11, 33 ... Support, 11a ... Depression, 11b ... Through hole, 11C ... Center, 11F ... Front surface, 11R ... Back surface, 12, 31 ... Insulating member, 12a ... First Insulating member, 12b ... Second insulating member, 13, 32 ... Measuring electrode, 13a, 41, 51 ... Measuring probe, 13a1, 32a, 51a ... Measuring end, 13a 2, 51b ... Connecting end, 13b, 43 ... First fixing member , 13c, 33c ... Second fixing member, 14 ... Protective member, 20 ... Sputtering device, 21 ... Vacuum tank, 22 ... Stage, 23 ... Target, 24, 28 ... DC power supply, 25 ... Magnetic circuit, 26 ... Exhaust part, 27 ... Sputter gas supply unit, 33a, 42a ... 1st hole, 33b, 42b ... 2nd hole, 33c1, 41c ... Columnar part, 33c2 ... Head, 34, 52 ... Protective tube, 41a ... Tip, 41b ... Base end , 42 ... Electrode plate, 53 ... Third fixing member, S ... Measurement space, W ... Wiring.

Claims (7)

With the support
Insulation member and
A measurement electrode having a measurement end exposed in the measurement space and fixed to the support via the insulating member,
A plasma state measuring device including a portion of the insulating member that comes into contact with the measurement electrode and a protective member that covers a portion of the insulating member that is continuous from the portion of the insulating member with respect to the measurement space. Insulation member and
A measurement electrode with a measurement edge exposed in the measurement space,
A plasma state measuring apparatus including a portion of the insulating member in which the measuring electrode is fixed via the insulating member, and a support that covers a portion of the insulating member in contact with the measuring electrode and a portion connected to the measuring electrode with respect to the measuring space. .. The measurement electrode includes a measurement probe having a columnar shape extending toward the measurement space through a hole formed in the support, the tip of the measurement probe is the measurement end, and the base end of the measurement probe is the measurement. The end to which the voltage is applied
A protective tube fixed to the support, extending from the hole toward the measurement space, and having a tubular shape through which the measurement probe passes, wherein the measurement end is located inside the protective tube. The plasma state measuring apparatus according to claim 2. The measurement electrode includes a measurement probe having a columnar shape extending toward the measurement space through a hole formed in the support, the tip of the measurement probe is the measurement end, and the base end of the measurement probe is the measurement. The end to which the voltage is applied
The measuring electrode includes a plurality of the measuring probes, and the lengths of the measuring probes in the extending direction of the plurality of measuring probes are different from each other.
The measurement electrode is located on the side opposite to the measurement space with respect to the support, and includes an electrode plate that supports the measurement probe.
The plasma state measuring device according to claim 2, wherein each measuring probe can be attached to and detached from the electrode plate, and one of the plurality of measuring probes is attached to the electrode plate. The measurement electrode includes a measurement probe having a columnar shape extending toward the measurement space through a hole formed in the support, the tip of the measurement probe is the measurement end, and the base end of the measurement probe is the measurement. The end to which the voltage is applied
The measurement electrode is located on the side opposite to the measurement space with respect to the support, and includes an electrode plate that supports the measurement probe.
The plasma state measuring apparatus according to claim 2, wherein the measuring probe is supported on the electrode plate so that the measuring end can be displaced with respect to the support along the extending direction of the measuring probe. The support has a plate shape that covers the electrode plate with respect to the measurement space and has the holes through which the measurement probe passes.
The plasma state measuring apparatus according to claim 4 or 5, wherein the electrode plate is fixed to the support via the insulating member. A film forming apparatus including the plasma state measuring apparatus according to any one of claims 1 to 6.