Ion bombardment device and ion bombardment processing method

Abstract

An ion bombardment device (1) is provided with a vacuum chamber (2), a substrate support part (11), a wire (3), a discharge power source (22), a wire heating power source (3T), and a magnetic field generation mechanism (20). The wire (3) has one end (31) and the other end (32). The magnetic field generation mechanism (20) is provided with: a first magnetic field generation unit (201) that generates a first magnetic field in a region including one end (31) of the filament (3); and a second magnetic field generation unit (202) that generates a second magnetic field in a region including the other end (32) of the filament (3). The plasma in the vicinity of the end of the wire (3) is enhanced by the first magnetic field and the second magnetic field, thereby reducing variations in plasma density and variations in etching amount.

Description

Technical Field

[0001] The invention relates to an ion bombardment device for cleaning the surface of a substrate and an ion bombardment treatment method. Background Art

[0002] Generally, a hard coating is formed on the surface of a substrate (film-forming object) by a PVD method or a CVD method in order to improve the wear resistance of a cutting tool or the sliding characteristics of a sliding surface of a mechanical part. Devices used for forming the hard coating include physical vapor deposition devices such as an arc ion plating device and a sputtering device, and chemical vapor deposition devices such as a plasma CVD device.

[0003] In order to form a hard film with high adhesion using the physical vapor deposition device and the chemical vapor deposition device, it is known to purify (clean) the surface of the substrate before the film formation process. As the purification process, there is a method of generating heavy inert gas ions such as argon ions by plasma discharge and irradiating the ions to the substrate to heat the surface and clean it (ion bombardment method).

[0004] As a technology for performing the above-mentioned purification treatment, Patent Document 1 discloses an ion bombardment device for cleaning the surface of a substrate in a vacuum chamber. The ion bombardment device includes an electrode, a plurality of anodes, and a discharge power supply. The electrode and the plurality of anodes are respectively arranged in the vacuum chamber. The electrode is arranged near the inner wall surface of the vacuum chamber and releases electrons. The plurality of anodes are arranged on the opposite side of the electrode and near the inner wall surface across the processing space of the substrate and receive electrons. The discharge power supply applies a discharge voltage between the electrode and the plurality of anodes. The electrode is formed by a filament extending in the up-down direction, and the plurality of anodes are arranged at intervals in the up-down direction. When the discharge voltage is applied, electrons are released from the electrode, and plasma is generated between the electrode and the plurality of anodes. As a result, the argon ions generated in the plasma collide with the substrate to which a negative bias voltage is applied, and the surface of the substrate is cleaned.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Publication No. 2014-152356

[0008] When the surface of the substrate is cleaned using the device described in patent document 1, there is a problem that the deviation of the etching amount (cutting amount) on the surface of the substrate is easy to become large. Specifically, in the above-mentioned technology, the upper and lower ends of the wire are respectively connected with wire electrodes. When the heating current flows through the wire through the electrode, the wire generates heat and releases electrons. In this structure, the central part of the wire is easy to become high temperature compared with the upper and lower ends of the wire, and in the vacuum chamber, the plasma density of the central part in the up-down direction is also higher than the plasma density of the upper and lower parts. As a result, the etching amount of the surface of the substrate using ion bombardment is also easy to differ between the central part and the upper and lower parts in the up-down direction of the substrate. In this case, if etching is performed in the central part of the substrate where the surrounding plasma density is high, the surface of the substrate is sometimes etched away by more than the required amount. On the other hand, if etching is performed in the upper and lower parts where the surrounding plasma density is low, the surface of the substrate is sometimes not etched to the specified etching amount.

[0009] Furthermore, when the substrate is subjected to film formation after cleaning, if the etching amount of the substrate varies as described above, the hard film cannot be uniformly adhered to the surface of the substrate, making it difficult to improve the wear resistance of the substrate. Summary of the invention

[0010] An object of the present invention is to provide an ion bombardment device and an ion bombardment treatment method, which can reduce the variation in the amount of etching on the surface of a substrate by reducing the density variation of plasma formed in a vacuum chamber in a device using a wire as an electrode.

[0011] The present invention provides an ion bombardment device for cleaning the surface of a substrate by irradiating ions. The ion bombardment device includes a vacuum chamber, a substrate support portion, at least one wire, an anode, a discharge power supply, a wire heating power supply, and at least one magnetic field generating mechanism. An internal space is formed inside the vacuum chamber. The substrate support portion is arranged in the internal space and supports the substrate. The at least one wire is arranged in the internal space to extend along a specified extension direction and face the substrate. The at least one wire includes an end and another end located on the opposite side of the one end in the extension direction. The anode is arranged to be at least exposed in the internal space. The discharge power supply applies a discharge voltage between the at least one wire and the anode. The wire heating power supply applies a heating voltage between the one end and the other end of the at least one wire, thereby causing the wire to heat. The at least one magnetic field generating mechanism is arranged on the opposite side of the substrate relative to the wire. The at least one magnetic field generating mechanism includes a first magnetic field generating part and a second magnetic field generating part, the first magnetic field generating part generates a first magnetic field in a region including the one end of the at least one wire, and the second magnetic field generating part generates a second magnetic field in a region including the other end of the at least one wire.

[0012] The present invention provides an ion bombardment treatment method for cleaning the surface of a substrate, comprising the following steps: supporting a substrate by a substrate support portion arranged in an internal space of a vacuum chamber; arranging at least one wire in the internal space to extend along a specified extension direction and face the substrate; providing at least one magnetic field generating mechanism, which is arranged on the opposite side of the substrate relative to the wire and comprises a first magnetic field generating portion and a second magnetic field generating portion, wherein the first magnetic field generating portion generates a first magnetic field in a region including the one end portion of the at least one wire, and the second magnetic field generating portion generates a second magnetic field in a region including the other end portion of the at least one wire. A second magnetic field is generated, wherein the other end is located on the opposite side of the one end in the extending direction; a heating voltage is applied between the one end and the other end of the at least one wire, thereby generating heat of the at least one wire; a discharge voltage is applied between an anode and the at least one wire, thereby generating plasma, wherein the anode is configured to be at least exposed to the internal space; and the density of the plasma around the one end and the other end of the at least one wire is increased by at least the first magnetic field and the second magnetic field, and the ions contained in the plasma are irradiated onto the surface of the substrate, thereby cleaning the surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a side cross-sectional view of an ion bombardment device according to one embodiment of the present invention.

[0014] Figure 2 It is a top cross-sectional view of an ion bombardment device according to one embodiment of the present invention.

[0015] Figure 3 It is an enlarged side cross-sectional view of an ion bombardment device according to one embodiment of the present invention.

[0016] Figure 4 It is a graph showing the distribution of the etching amount of the substrate in Example 1 of the present invention and Comparative Example 1.

[0017] Figure 5 It is a graph showing the distribution of the etching amount of the substrate in Examples 1 and 2 of the present invention.

[0018] Figure 6 It is a graph showing the distribution of the etching amount of the substrate in Examples 2 and 3 of the present invention.

[0019] Figure 7 It is a graph showing the distribution of the etching amount of the substrate in Examples 3 and 4 of the present invention.

[0020] Figure 8 It is a graph showing the distribution of the etching amount of the substrate in Example 3 of the present invention and Comparative Example 1.

[0021] Fig. 9 It is a graph showing the distribution of the etching amount of the substrate in Comparative Examples 1 and 2 compared with the respective Examples of the present invention.

[0022] Fig.10 It is a top view showing the magnetic field distribution around the substrate in the example of the present invention.

[0023] Fig.11 It is a side cross-sectional view of an ion bombardment device according to a modified embodiment of the present invention. DETAILED DESCRIPTION

[0024] Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. Figure 1 It is a side cross-sectional view of the ion bombardment device 1 according to this embodiment. Figure 2 It is a top cross-sectional view of the ion bombardment device 1 . Figure 3 1 is an enlarged side cross-sectional view of the ion bombardment device 1. The ion bombardment device 1 cleans the surface of the workpiece W (substrate) by irradiating ions to the surface. In addition, the ion bombardment device 1 shown in each figure represents an example of the ion bombardment device involved in this embodiment, and the ion bombardment device involved in the present invention is not limited to the device shown in each figure. As an example, the ion bombardment device 1 cleans (purifies) the surface of the workpiece W formed of stainless steel.

[0025] The ion bombardment device 1 includes a vacuum chamber 2 , a rotating table 11 (substrate support portion), a bias power supply 18 , a plasma generating device 19 including a filament 3 and a discharge power supply 22 , a filament heating power supply 3T, and a magnetic field generating mechanism 20 .

[0026] The vacuum chamber 2 accommodates a rotating table 11 and a plurality of workpieces W arranged on the rotating table 11. Figure 1 Although not shown, a plurality of workpiece supports may be fixed to the rotating table 11, and the workpiece W may be supported by each of the workpiece supports. A cylindrical internal space S having a center line extending in the vertical direction is formed inside the vacuum chamber 2.

[0027] The internal space S of the vacuum chamber 2 (that is, the space containing the rotating table 11 and the plurality of workpieces W) is maintained in a vacuum or near-vacuum state by a vacuum pump (not shown) in each of the vacuum step, heating step, and etching step described later. In addition, although not shown, the vacuum chamber 2 includes: an inlet for introducing argon gas, which is an inert gas used in the etching step, into the vacuum chamber 2; and an outlet for discharging the argon gas from the vacuum chamber 2 to the outside.

[0028] The rotating table 11 is arranged in the internal space of the vacuum chamber 2 and supports a plurality of workpieces W. In the present embodiment, the rotating table 11 is in the shape of a disk ( Figure 2 ). The rotating table 11 supports the plurality of workpieces W and rotates around its central axis during the etching step. In addition, the rotating table 11 may also include a rotating table on which each of the plurality of workpieces W is individually arranged so that each of the plurality of workpieces W can rotate. In addition, the area occupied by the workpieces W supported by the rotating table 11 in the internal space S of the vacuum chamber 2 is referred to as the processing space WA ( Figure 3 ).

[0029] The bias power supply 18 applies a negative bias voltage to each of the plurality of workpieces W via the rotating table 11. The negative bias voltage is applied in the etching step.

[0030] The plasma generating device 19 includes a filament 3 and a discharge power source 22 . The plasma generating device 19 generates plasma in the inner space of the vacuum chamber 2 .

[0031] The wire 3 is arranged in the internal space S of the vacuum chamber 2 so as to extend in the vertical direction (the designated extension direction) and face the workpiece W on the rotating table 11. Figure 1 1 wire 3 is shown, but in this embodiment, Figure 2 , Figure 3As shown, a group of two wires 3 is arranged. Specifically, the wires 3 include a first wire 3A and a second wire 3B. The second wire 3B is arranged so that it is located on both sides of the first wire 3A in a direction perpendicular to the up-down direction (in the front-back direction in the present embodiment) across the workpiece W on the turntable 11. In other words, in the present embodiment, around the circular plate-shaped turntable 11, the first wire 3A and the second wire 3B are arranged on opposite sides of each other (separated by 180 degrees in the circumferential direction). In addition, as Figure 3 As shown, the first wire 3A and the second wire 3B are longer in the vertical direction than the vertical length of the processing space WA, and are arranged so that the first wire 3A and the second wire 3B include the processing space WA in the vertical direction.

[0032] like Figure 3 As shown, each wire 3 (first wire 3A, second wire 3B) includes an upper end 31 (one end), a lower end 32 (another end located on the opposite side of the one end in the extension direction of the wire 3), and an intermediate portion 33 disposed between the upper end 31 and the lower end 32. Each wire 3 functions as a cathode (negative electrode). As an example, Figure 3 As shown, the upper end portion 31 is located near the upper end of the processing space WA, and the lower end portion 32 is located near the lower end of the processing space WA.

[0033] On the other hand, in the present embodiment, the vacuum chamber 2 functions as an anode. The above function is achieved by configuring the inner wall surface of the vacuum chamber 2 to be exposed in the internal space S. In addition, other anodes may be configured in the internal space S of the vacuum chamber 2 as described later.

[0034] The discharge power source 22 applies a discharge voltage between each filament 3 and the vacuum chamber 2 as an anode, thereby generating plasma in the internal space S.

[0035] The wire heating power source 3T applies a heating voltage between the upper end 31 and the lower end 32 of each wire 3 (the first wire 3A and the second wire 3B), thereby heating the wire 3. Figure 3 As shown, a pair of wire electrodes 3S (electrodes) are connected to the upper end 31 and the lower end 32. Figure 3 In the figure, the wire heating power source 3T is schematically shown, but the wire heating power source 3T is electrically connected to a pair of wire electrodes 3S to apply a heating voltage to the wire 3. As an example, Figure 3 As shown, in the vertical direction, one of the wire electrodes 3S is arranged above the upper end position of the processing space WA, and the other of the wire electrodes 3S is arranged below the lower end position of the processing space WA.

[0036] In the plasma generator 19, a discharge voltage from a discharge power source 22 is applied to each filament 3, thereby generating a glow discharge. Through this glow discharge, plasma of argon gas introduced into the internal space S of the vacuum chamber 2 is generated around each filament 3. By applying a negative bias voltage to each of the plurality of workpieces W, argon ions (inert gas ions) in the plasma are accelerated toward the workpiece W facing the filament 3. As a result, the argon ions can collide with each of the plurality of workpieces W. In addition, each filament 3 generates heat by using a filament heating power source 3T, thereby releasing electrons (thermal electrons) from the filament 3 to maintain the discharge.

[0037] The magnetic field generating mechanism 20 generates a magnetic field around each wire 3, thereby increasing the density of the plasma generated around the wire 3 and improving its distribution uniformity. In the present embodiment, the magnetic field generating mechanism 20 includes a first magnetic field generating mechanism 20A and a second magnetic field generating mechanism 20B. The first magnetic field generating mechanism 20A generates a magnetic field around the first wire 3A. On the other hand, the second magnetic field generating mechanism 20B is configured to be located on both sides of the first magnetic field generating mechanism 20A in a direction perpendicular to the up and down direction with a plurality of workpieces W between them, and generates a magnetic field around the second wire 3B. In addition, the magnetic field generating mechanism 20 may also only have the first magnetic field generating mechanism 20A, but not the second magnetic field generating mechanism 20B. On the other hand, by having the first magnetic field generating mechanism 20A and the second magnetic field generating mechanism 20B, the processing speed of the workpiece W can be increased. In addition, since the time for the workpiece W to contact with the plasma can be increased during the rotation of the rotating table 11, it is possible to prevent the trace impurities contained in the internal space S from adhering to the workpiece W.

[0038] Each magnetic field generating mechanism 20 (the first magnetic field generating mechanism 20A, the second magnetic field generating mechanism 20B) is arranged on the opposite side of the workpiece W relative to the wire 3. In detail, the first magnetic field generating mechanism 20A is arranged on the opposite side of the workpiece W relative to the first wire 3A. In addition, the second magnetic field generating mechanism 20B is arranged on the opposite side of the workpiece W relative to the second wire 3A. In other words, when viewed from the workpiece W, each magnetic field generating mechanism 20 is arranged on the back of each wire 3.

[0039] Each magnetic field generating mechanism 20 includes a plurality of electromagnetic coils 200 and a coil power supply 20S. In detail, each magnetic field generating mechanism 20 has an upper electromagnetic coil 201 (first magnetic field generating unit), a lower electromagnetic coil 202 (second magnetic field generating unit) and an intermediate electromagnetic coil 203 (intermediate magnetic field generating unit). The coil power supply 20S generates magnetic fields around the wire 3 by passing current through each electromagnetic coil. In addition, in the present embodiment, each electromagnetic coil 200 is arranged outside the vacuum chamber 2, and forms a magnetic field in the internal space S through the vacuum chamber 2. In other embodiments, each electromagnetic coil 200 may also be arranged in the internal space S. In addition, a plurality of intermediate magnetic field generating units exemplified by the intermediate electromagnetic coil 203 may also be arranged.

[0040] The upper electromagnetic coil 201 generates a first magnetic field in a region including the upper end portion 31 of the corresponding wire 3. In addition, the lower electromagnetic coil 202 generates a second magnetic field in a region including the lower end portion 32 of the corresponding wire 3. In addition, the intermediate electromagnetic coil 203 is arranged between the upper electromagnetic coil 201 and the intermediate electromagnetic coil 203 in the vertical direction, and generates an intermediate magnetic field in a region including the middle portion 33 of the corresponding wire 3. Figure 3 In the embodiment, only the upper electromagnetic coil 201 of the first magnetic field generating mechanism 20A is connected to the coil power supply 20S, but the coil power supply 20S is also connected to each electromagnetic coil of the first magnetic field generating mechanism 20A and the second magnetic field generating mechanism 20B, and can flow current in a specified direction according to the polarity of the corresponding magnetic field. In addition, an independent coil power supply can also be provided for each electromagnetic coil.

[0041] In addition, each of the upper electromagnetic coil 201, the lower electromagnetic coil 202, and the middle electromagnetic coil 203 has a center line perpendicular to the up-down direction and extending in the direction (front-back direction) connecting each electromagnetic coil 200 and the workpiece W. A coil wire (not shown) is wound around the center line to form each electromagnetic coil. In addition, in this embodiment, as Figure 3 As shown, in each magnetic field generating mechanism 20, the upper electromagnetic coil 201 and the lower electromagnetic coil 202 are arranged so as to surround a pair of wire electrodes 3S respectively. Therefore, based on each wire electrode 3S connected to the end of the wire 3, a magnetic field can be formed around the upper end 31 and the lower end 32 with high precision.

[0042] In this embodiment, as an example, the polarities of the upper electromagnetic coil 201, the lower electromagnetic coil 202, and the middle electromagnetic coil 203 in each electromagnetic coil 200 are the same. Figure 3In the figure, the upper electromagnetic coil 201 of the first magnetic field generating mechanism 20A has magnetic lines of force extending forward from the upper end 31 of the first wire 3A. The same is true for the lower electromagnetic coil 202. In addition, although the direction of the magnetic lines of force is not shown in the figure, the same is true for the middle electromagnetic coil 203.

[0043] In addition, Figure 3 In the upper electromagnetic coil 201 of the second magnetic field generating mechanism 20B, magnetic lines of force are also formed extending forward from the upper end portion 31 of the second wire 3B. The same is true for the lower electromagnetic coil 202. In addition, although the direction of the magnetic lines of force is not shown in the figure, the same is true for the middle electromagnetic coil 203. In this case, when observing from the workpiece W arranged in the processing space WA, the direction of the magnetic lines of force formed by each electromagnetic coil 200 of the first magnetic field generating mechanism 20A is opposite to the direction of the magnetic lines of force formed by each electromagnetic coil 200 of the second magnetic field generating mechanism 20B. That is, in Figure 3 In the example shown, the polarities of the three electromagnetic coils 200 in the vertical direction of the first magnetic field generating mechanism 20A are the same as each other, and the polarities of the three electromagnetic coils 200 in the vertical direction of the second magnetic field generating mechanism 20B are also the same as each other. On the other hand, the polarities of the electromagnetic coils 200 of the first magnetic field generating mechanism 20A and the second magnetic field generating mechanism 20B are different (opposite) from each other.

[0044] The relationship between the polarities of the electromagnetic coils 200 of the magnetic field generating mechanisms 20 is not limited to the above relationship. More preferred polarities and the magnitude relationship of the magnetic force between the electromagnetic coils 200 will be described in detail in the embodiments described later.

[0045] Next, an outline of the ion bombardment processing steps in the above-mentioned ion bombardment device 1 will be described. The ion bombardment processing method according to the present invention includes a preparation step, a vacuum step, a heating step, and an etching step.

[0046] First, the preparation step is performed by placing the workpiece W on the rotating table 11 in the vacuum chamber 2. In addition, as described above, in the preparation step, the plurality of workpiece supports may be arranged on the rotating table 11 after each of the plurality of workpiece supports supports the plurality of workpieces W.

[0047] After the preparation step is completed, a vacuum step is performed. The vacuum step is a step of maintaining the vacuum chamber 2 in a vacuum or near-vacuum state using a vacuum pump (not shown). The pressure in the vacuum chamber 2 in the vacuum step is, for example, 0.0001 to 0.01 Pa.

[0048] If the vacuum step is completed, the heating step is performed. The heating step is a step of heating each of the plurality of workpieces W at a specified temperature for a specified time. The temperature of each of the plurality of workpieces W in the heating step is, for example, 50 to 300° C. The heating time of each of the plurality of workpieces W in the heating step is, for example, 0.5 to 2 hours.

[0049] When the heating step is completed, the etching step is performed. The etching step is a step of etching the surfaces of each of the plurality of workpieces W. Specifically, the etching step is performed as follows.

[0050] First, argon gas is introduced into the vacuum chamber 2. The amount of argon gas introduced into the vacuum chamber 2 is, for example, 50 to 500 ml / min. The pressure in the vacuum chamber 2 at this time is, for example, 0.5 to 2.0 Pa.

[0051] While introducing argon gas into the vacuum chamber 2, the filaments 3 are heated by the filament heating power supply 3T and a high voltage from the discharge power supply 22 is applied to each filament 3, so that glow discharge occurs between the vacuum chamber 2 and the filaments 3. The high voltage applied to the filaments 3 is, for example, 40 to 100 V. The heat generated by the filaments 3 promotes the release of hot electrons for glow discharge.

[0052] By the above-mentioned glow discharge, plasma of argon gas can be generated around the wire 3. The plasma contains argon ions. In this state, by applying a negative bias voltage by the bias power supply 18, the argon ions in the plasma are accelerated toward the workpiece W located on the front side (radially inner side) of each wire 3. Accordingly, the argon ions can collide with each of the multiple workpieces W. As a result, the surfaces of each of the multiple workpieces W can be etched.

[0053] In particular, in the present embodiment, each magnetic field generating mechanism 20 is arranged at the back of each wire 3 when viewed from the workpiece W. The electromagnetic coil 200 of the magnetic field generating mechanism 20 generates a strong magnetic field around the wire 3, especially around the upper end 31 and the lower end 32. The temperature of the wire 3 which receives the current from the wire heating power supply 3T and generates heat is likely to be higher in the middle portion 33 than in the upper end 31 and the lower end 32. As a result, the plasma density around the wire 3 is also likely to be larger in the central portion. However, due to the effect of the magnetic field as described above, the plasma density around the upper end 31 and the lower end 32 is increased, and a more uniform plasma distribution with a small deviation in the up and down direction (the extension direction of the wire 3) can be formed. As a result, the deviation of the etching amount in the up and down direction can also be reduced in the multiple workpieces W arranged in the processing space WA on the rotating table 11. Furthermore, by disposing the middle electromagnetic coil 203 between the upper electromagnetic coil 201 and the lower electromagnetic coil 202, it is possible to prevent the plasma density around the middle portion 33 from being relatively reduced due to the influence of the upper electromagnetic coil 201 and the lower electromagnetic coil 202, thereby further reducing the variation in plasma density.

[0054] Example

[0055] Next, one embodiment of the present invention described above will be further described based on examples. In addition, the present invention is not limited to the following examples. In each experiment, the workpiece W was subjected to an etching process (ion bombardment process) for a specified time under the following experimental conditions.

[0056] <Comparative Experiment>

[0057] Embodiment 1 (forming magnetic fields of the same polarity at the top and bottom): A first magnetic field generating mechanism 20A is arranged in the vacuum chamber 2. The upper electromagnetic coil 201 and the lower electromagnetic coil 202 form magnetic fields of the same polarity (S polarity) around the wire 3. A current of 8A is passed through the upper electromagnetic coil 201 and the lower electromagnetic coil 202. Since no current is passed through the middle electromagnetic coil 203, the middle electromagnetic coil 203 does not form a magnetic field.

[0058] Embodiment 2 (forming a magnetic field with the same polarity at the top, middle and bottom): A first magnetic field generating mechanism 20A is arranged in the vacuum chamber 2. The upper electromagnetic coil 201, the lower electromagnetic coil 202 and the middle electromagnetic coil 203 form a magnetic field with the same polarity (S pole) around the wire 3. A current of 8A is passed through the upper electromagnetic coil 201, the lower electromagnetic coil 202 and the middle electromagnetic coil 203. Although not particularly limited, in this case, the number of turns of the upper electromagnetic coil, the lower electromagnetic coil and the middle electromagnetic coil are all the same.

[0059] Embodiment 3 (forming magnetic fields of the same polarity at the top, middle and bottom, and a weaker magnetic field in the middle): A first magnetic field generating mechanism 20A is arranged in the vacuum chamber 2. The upper electromagnetic coil 201, the lower electromagnetic coil 202 and the middle electromagnetic coil 203 form magnetic fields of the same polarity (S pole) around the wire 3. A current of 8A flows through the upper electromagnetic coil 201 and the lower electromagnetic coil 202, and a current of 4A flows through the middle electromagnetic coil 203. Although not particularly limited, in this case, the number of coil turns of the upper electromagnetic coil, the lower electromagnetic coil and the middle electromagnetic coil are all the same.

[0060] Embodiment 4 (forming a magnetic field with the same polarity at the top and bottom and different polarity in the middle, with the magnetic field in the middle being weaker): The first magnetic field generating mechanism 20A is arranged in the vacuum chamber 2. The upper electromagnetic coil 201 and the lower electromagnetic coil 202 form a magnetic field with the same polarity (S pole) around the wire 3, and the middle electromagnetic coil 203 forms a magnetic field with a different polarity (N pole) from the upper electromagnetic coil 201 and the lower electromagnetic coil 202. A current of 8A flows through the upper electromagnetic coil 201 and the lower electromagnetic coil 202, and a current of 4A flows through the middle electromagnetic coil 203. Although not particularly limited, in this case, the number of turns of the upper electromagnetic coil, the lower electromagnetic coil, and the middle electromagnetic coil are all the same.

[0061] Comparative Example 1 (no magnetic field): The ion bombardment process was performed without arranging the first magnetic field generating mechanism 20A in the vacuum chamber 2 .

[0062] Comparative example 2 (only middle magnetic field, no upper and lower magnetic fields): The first magnetic field generating mechanism 20A is arranged in the vacuum chamber 2, but only 8A of current flows through the middle electromagnetic coil 203 to form a magnetic field of the specified polarity (S pole), and the upper electromagnetic coil 201 and the lower electromagnetic coil 202 do not form a magnetic field.

[0063] Figure 4 is a graph showing the etching amount distribution of the workpiece W in Example 1 and Comparative Example 1. Figure 4 In the figure, the horizontal axis represents the height of the measurement position of the etching amount, and the vertical axis represents the etching amount (depth) of each measurement position. The height of the measurement position on the horizontal axis represents the relative position of each measurement position in the vertical direction relative to the center of the wire, and the center of the vertical direction of the workpiece W is set to zero. In addition, regarding the etching amount on the vertical axis, in order to facilitate visual recognition of the cutting amount of the workpiece W, the etching amount (cutting amount) of the data on the lower side is relatively greater than the etching amount (cutting amount) of the data on the upper side. The same is true in each figure described later.

[0064] like Figure 4 As shown, when no magnetic field is formed around the wire 3 (Comparative Example 1), depending on the temperature distribution of the wire 3, the etching amount of the central part (middle part 33) of the wire 3, where the temperature is relatively high, is greater (deeper) than the etching amount of the upper end 31 and the lower end 32, and the deviation of the etching amount is large. On the other hand, when the magnetic field is formed at the upper and lower ends of the wire 3 by the upper electromagnetic coil 201 and the lower electromagnetic coil 202 (Example 1), the etching amount of the upper end 31 and the lower end 32 increases, and the etching amount of the middle part 33 decreases slightly. As a result, the uniformity in the vertical direction is improved compared with Comparative Example 1. In addition, the plasma density increases due to the above-mentioned magnetic field, so that the average etching amount of the workpiece W can be increased.

[0065] Figure 5 : is a coordinate diagram showing the etching amount distribution of the workpiece W in Example 1 and Example 2. Figure 5 As shown, when a current is passed through the intermediate electromagnetic coil 203 to form a magnetic field in the entire area in the vertical direction around the wire 3 (Example 2), the uniformity of the etching amount in the vertical direction can be further improved compared with Example 1. In addition, the plasma density is increased as a whole due to the magnetic field, so that the average etching amount on the workpiece W can be further increased.

[0066] Figure 6 : is a coordinate diagram showing the etching amount distribution of the workpiece W in Example 2 and Example 3. Figure 6As shown, compared with Example 2 which can form a good etching distribution as described above, if the current flowing into the middle electromagnetic coil 203 is weakened relative to the upper electromagnetic coil 201 and the lower electromagnetic coil 202 (Example 3), the etching amount of the middle portion 33 is increased instead, and as a result, the uniformity of the etching amount in the vertical direction can be further improved compared with Example 2. As described above, it is inferred that by weakening the magnetic field intensity of the middle portion 33 of the wire 3 whose temperature tends to be relatively high, the balance of the magnetic field around the upper end portion 31 and the lower end portion 32 is improved, and the uniformity of the plasma density is improved.

[0067] Figure 7 : is a coordinate diagram showing the etching amount distribution of the workpiece W in Example 3 and Example 4. Figure 7 As shown, compared with Example 3 which is capable of forming a good etching distribution as described above, if the polarity of the magnetic field formed by the intermediate electromagnetic coil 203 is reversed, the etching amount of the upper end 31 and the lower end 32 of the wire 3 is reduced, and as a result, the uniformity is slightly deteriorated. Based on this result, it can be inferred that the uniformity of the plasma density is slightly deteriorated because the magnetic fields between the upper electromagnetic coil 201 and the intermediate electromagnetic coil 203 and between the lower electromagnetic coil 202 and the intermediate electromagnetic coil 203 attract each other. However, in this Example 4, compared with the previous Comparative Example 1 ( Figure 4 ) compared to the uniformity in the vertical direction. In addition, the plasma density is also increased, thereby increasing the average etching amount of the workpiece W.

[0068] Figure 8 3 is a coordinate diagram showing the etching amount distribution of the workpiece W in Example 3 and Comparative Example 1. By comparing the above-mentioned Example 3 with Comparative Example 1 in the same coordinate diagram, it can be seen that the uniformity of the etching amount in the vertical direction is greatly improved. In addition, in Example 3, due to the influence of the magnetic field, the plasma density becomes larger, so that the average etching amount of the workpiece W can be increased.

[0069] Fig. 9 3 is a coordinate diagram showing the etching amount distribution of the workpiece W in Comparative Examples 1 and 2 compared with the embodiments. It can be seen that when forming a magnetic field around the wire 3, it is preferable to form a magnetic field around the upper end 31 and the lower end 32 whose temperature is easily lowered relative to the middle part 33. Fig. 9 When a magnetic field is formed only in the middle portion 33 as in Comparative Example 2, although an increase in the etching amount can be expected compared to Comparative Example 1, it is difficult to improve uniformity (reduce variation).

[0070] <Simulation results>

[0071] Next, embodiments included in the present invention will be described based on the magnetic field distribution in the vacuum chamber 2 . Fig.10FIG. 1 is a top view showing the magnetic field distribution around the workpiece W in each embodiment of the present invention, and shows the magnetic field distribution based on the magnetic field analysis simulation. Fig.10 In the figure, the upper side shows the magnetic field distribution A1 in Example 5, and the lower side shows the magnetic field distribution A2 in Example 6, with reference line CL extending in the front-rear direction and passing through each wire 3. The conditions in Examples 5 and 6 are as follows.

[0072] Embodiment 5: A first magnetic field generating mechanism 20A and a second magnetic field generating mechanism 20B are respectively arranged in a vacuum chamber 2. In the first magnetic field generating mechanism 20A, the upper electromagnetic coil 201, the lower electromagnetic coil 202 and the middle electromagnetic coil 203 form a magnetic field of the same polarity (S pole) around the wire 3. A current of 8A flows through the upper electromagnetic coil 201, the lower electromagnetic coil 202 and the middle electromagnetic coil 203. On the other hand, in the second magnetic field generating mechanism 20B, the upper electromagnetic coil 201, the lower electromagnetic coil 202 and the middle electromagnetic coil 203 form a magnetic field of the same polarity (N pole) around the wire 3. A current of 8A flows through the upper electromagnetic coil 201, the lower electromagnetic coil 202 and the middle electromagnetic coil 203. In addition, the polarity of the three electromagnetic coils 200 of the first magnetic field generating mechanism 20A is different from the polarity of the three electromagnetic coils 200 of the second magnetic field generating mechanism 20B.

[0073] Embodiment 6: The first magnetic field generating mechanism 20A and the second magnetic field generating mechanism 20B are respectively arranged in the vacuum chamber 2. In the first magnetic field generating mechanism 20A, the upper electromagnetic coil 201, the lower electromagnetic coil 202 and the middle electromagnetic coil 203 form a magnetic field of the same polarity (S pole) around the wire 3. A current of 8A flows through the upper electromagnetic coil 201, the lower electromagnetic coil 202 and the middle electromagnetic coil 203. On the other hand, in the second magnetic field generating mechanism 20B, the upper electromagnetic coil 201, the lower electromagnetic coil 202 and the middle electromagnetic coil 203 form a magnetic field of the same polarity (S pole) around the wire 3. A current of 8A flows through the upper electromagnetic coil 201, the lower electromagnetic coil 202 and the middle electromagnetic coil 203. In addition, the polarity of the three electromagnetic coils 200 of the first magnetic field generating mechanism 20A and the polarity of the three electromagnetic coils 200 of the second magnetic field generating mechanism 20B are the same as each other.

[0074] Reference Fig.10In the magnetic field distribution A1 of the fifth embodiment, since the magnetic field polarity of the first magnetic field generating mechanism 20A and the magnetic field polarity of the second magnetic field generating mechanism 20B are different (opposite) from each other, a magnetic field is formed between the two as if magnetic lines of force are connected. As a result, the magnetic field acts in a manner of surrounding the processing space WA containing the workpiece W from the radial outside to the inside, so that the workpiece W that revolves by the rotation of the turntable 11 can continue to be placed in the plasma. On the other hand, in the magnetic field distribution A2 of the sixth embodiment, the magnetic field polarity of the first magnetic field generating mechanism 20A and the magnetic field polarity of the second magnetic field generating mechanism 20B are the same as each other, and a repulsive magnetic field is formed between the two, so that a magnetic field that surrounds the processing space WA as described above is not formed. However, in this case, the uniformity of the plasma density in the up and down directions around the wire 3 by each magnetic field generating mechanism is also improved, and a stable etching process can be achieved for the workpiece W.

[0075] As described above, in the ion bombardment device 1 according to the present invention, at least one magnetic field generating mechanism 20 is disposed on the opposite side of the wire 3 from the workpiece W. The magnetic field generating mechanism 20 includes at least an upper electromagnetic coil 201 and a lower electromagnetic coil 202 .

[0076] According to this configuration, since the plasma density in the region facing the upper end portion 31 and the lower end portion 32 of the filament 3 can be enhanced by the first magnetic field generated by the upper electromagnetic coil 201 and the second magnetic field generated by the lower electromagnetic coil 202, it is possible to reduce the variation in the plasma density in the extending direction of the filament 3. As a result, it is possible to reduce the variation in the etching amount on the surface of the workpiece W in the extending direction.

[0077] In addition, in this embodiment, the upper electromagnetic coil 201 and the lower electromagnetic coil 202 have the same polarity as each other in such a manner that the orientation of the magnetic lines of force contained in the first magnetic field and passing through the upper end 31 in the processing direction and the orientation of the magnetic lines of force contained in the second magnetic field and passing through the lower end 32 in the processing direction are the same, and the processing direction is the direction connecting the magnetic field generating mechanism 20 and the workpiece W and is a direction perpendicular to the extension direction.

[0078] According to this structure, since the polarities of the first magnetic field and the second magnetic field formed around the upper end 31 and the lower end 32 of the filament 3 are the same, the magnetic field shapes of the regions corresponding to the two ends of the filament 3 can be made similar to each other, and the deviation of the plasma density in the extension direction of the filament 3 can be further reduced. In addition, even when the length of the filament 3 is relatively short, it is possible to suppress the formation of strong magnetic lines of force that attract each other in the vertical direction between the first magnetic field and the second magnetic field, and stabilize the distribution of plasma in the extension direction.

[0079] Furthermore, in the present embodiment, the wire 3 further includes an intermediate portion 33 disposed between the upper end portion 31 and the lower end portion 32, and the magnetic field generating mechanism 20 further includes an intermediate electromagnetic coil 203. The intermediate electromagnetic coil 203 is disposed between the upper electromagnetic coil 201 and the lower electromagnetic coil 202 in the extending direction, and generates an intermediate magnetic field in a region including the intermediate portion 33 of the wire 3.

[0080] According to this structure, the intermediate magnetic field of the intermediate electromagnetic coil 203 can be used to prevent the plasma density in the area facing the middle part 33 of the wire 3 from changing significantly due to the formation of the first magnetic field and the second magnetic field, and the magnetic field distribution in the extension direction around the wire 3 can be stabilized.

[0081] In addition, in the present embodiment, it is preferred that the upper electromagnetic coil 201, the lower electromagnetic coil 202, and the middle electromagnetic coil 203 have the same polarity as each other in such a manner that the orientation of the magnetic lines of force contained in the first magnetic field and passing through the one end in the processing direction (forward-backward direction), the orientation of the magnetic lines of force contained in the second magnetic field and passing through the other end in the processing direction (forward-backward direction), and the orientation of the magnetic lines of force contained in the middle magnetic field and passing through the middle part in the processing direction (forward-backward direction) are the same as each other.

[0082] According to this structure, by aligning the directions of the magnetic lines of force of the upper end 31, the middle portion 33, and the lower end 32 of the wire 3, the magnetic field distribution in the extension direction around the wire 3 can be stabilized. As a result, the distribution of plasma in the extension direction can be stabilized, and the variation in the etching amount on the surface of the workpiece W can be further reduced.

[0083] Furthermore, in the present embodiment, the magnetic force of the middle electromagnetic coil 203 may be set to be smaller than the magnetic forces of the upper electromagnetic coil 201 and the lower electromagnetic coil 202 .

[0084] According to this configuration, the magnetic field intensity around the middle portion 33 of the filament 3 where the temperature tends to be relatively higher than that of the upper end portion 31 and the lower end portion 32 is relatively weakened, thereby making the plasma distribution in the extending direction more stable.

[0085] Furthermore, in the present embodiment, it is preferable that the magnetic field generating mechanism 20 includes a first magnetic field generating mechanism 20A and a second magnetic field generating mechanism 20B.

[0086] According to this structure, two plasma regions are formed by using two wires 3 arranged around the workpiece W, thereby promoting the ion bombardment process (etching process) of the workpiece W. In addition, by providing each wire 3 with a unique magnetic field generating mechanism 20 (20A, 20B), the uniformity of the plasma density and the extending direction can be improved, and the deviation of the distribution of the etching amount on the workpiece W can be reduced.

[0087] In addition, in the present embodiment, the upper electromagnetic coil 201 and the lower electromagnetic coil 202 of the first magnetic field generating mechanism 20A have the same polarity as each other in such a manner that the magnetic force lines contained in the first magnetic field of the first magnetic field generating mechanism 20A and passing through the upper end 31 of the first wire 3A have the same orientation in the direction connecting the first magnetic field generating mechanism 20A and the workpiece W and being perpendicular to the extension direction of the first wire 3A, and the magnetic force lines contained in the second magnetic field of the first magnetic field generating mechanism 20A and passing through the lower end 32 of the first wire 3A have the same orientation in the direction connecting the first magnetic field generating mechanism 20A and the workpiece W and being perpendicular to the extension direction of the first wire 3A. In addition, the upper electromagnetic coil 201 and the lower electromagnetic coil 202 of the second magnetic field generating mechanism 20B have the same polarity as each other so that the magnetic force lines included in the first magnetic field of the second magnetic field generating mechanism 20B and passing through the upper end 31 of the second wire 3B are oriented in the direction connecting the second magnetic field generating mechanism 20B and the workpiece W and perpendicular to the extending direction of the second wire 3B, and the magnetic force lines included in the second magnetic field of the second magnetic field generating mechanism 20B and passing through the lower end 32 of the second wire 3B are oriented in the direction connecting the second magnetic field generating mechanism 20B and the workpiece W and perpendicular to the extending direction of the second wire 3B. In addition, the upper electromagnetic coil 201 and the lower electromagnetic coil 202 of the first magnetic field generating mechanism 20A and the upper electromagnetic coil 201 and the lower electromagnetic coil 202 of the second magnetic field generating mechanism 20B have opposite polarities.

[0088] According to this structure, by making the polarities of the magnetic fields of the two magnetic field generating mechanisms 20A and 20B opposite to each other, magnetic field lines of force that attract each other are formed between the two magnetic fields ( Fig.10 The magnetic field distribution A1) is adopted, therefore, the etching process on the workpiece W can be carried out stably.

[0089] In addition, in this embodiment, the upper electromagnetic coil 201 and the lower electromagnetic coil 202 include electromagnetic coils each having a center line, and the center line is perpendicular to the extension direction of the wire 3 and extends along the direction connecting the magnetic field generating mechanism 20 and the workpiece W. The ion bombardment device 1 also includes a coil power supply 20S that generates the first magnetic field and the second magnetic field respectively by passing current to the upper electromagnetic coil 201 and the lower electromagnetic coil 202 of the magnetic field generating mechanism 20 respectively.

[0090] According to this configuration, by causing the coil power source 20S to pass current through each electromagnetic coil, a magnetic field is easily formed around the upper end portion 31 and the lower end portion 32 of the wire 3 .

[0091] In addition, in the present embodiment, the ion bombardment device 1 includes a pair of upper and lower wire electrodes 3S, and the upper electromagnetic coil 201 and the lower electromagnetic coil 202 are arranged so as to surround the pair of wire electrodes 3S, respectively.

[0092] According to this configuration, by arranging each electromagnetic coil 200 based on a pair of wire electrodes 3S respectively connected to the upper end 31 and the lower end 32 of the wire 3 , a magnetic field can be reliably formed around the upper end 31 and the lower end 32 of the wire 3 .

[0093] In addition, the ion bombardment treatment method involved in the present embodiment is a method for cleaning the surface of the workpiece W. The treatment method includes the following steps: supporting the workpiece W by a rotating table 11 arranged in the internal space S of the vacuum chamber 2; arranging at least one wire 3 in the internal space S to extend along a specified extension direction and face the workpiece W; providing at least one magnetic field generating mechanism 20, which is arranged on the opposite side of the workpiece W relative to the wire 3 and includes: an upper electromagnetic coil 201 that generates a first magnetic field in a region including an upper end portion 31 of the at least one wire 3; and an upper electromagnetic coil 201 that generates a second magnetic field in a region including a lower end portion 32 of the at least one wire 3 located on the opposite side of the upper end portion 31 in the extension direction. Coil 201; applying a heating voltage between the upper end 31 and the lower end 32 of the at least one filament 3, thereby heating the at least one filament; applying a discharge voltage between an anode (vacuum chamber 2) configured to be exposed to the internal space S and the at least one filament 3; applying a discharge voltage between the at least one filament 3 that is heated and the anode, thereby generating plasma, and increasing the plasma density around the upper end 31 and the lower end 32 of the at least one filament 3 by at least the first magnetic field and the second magnetic field, and irradiating the surface of the workpiece W with ions contained in the plasma, thereby cleaning the surface.

[0094] According to this method, since the plasma density in the region facing the upper end 31 and the lower end 32 of the wire 3 can be enhanced by utilizing the first magnetic field generated by the upper electromagnetic coil 201 and the second magnetic field generated by the lower electromagnetic coil 202, the deviation of the plasma density in the extension direction of the wire 3 can be reduced. As a result, the deviation of the etching amount on the surface of the workpiece W in the extension direction can be reduced. In addition, the features included in the ion bombardment device 1 can also constitute a part of the above-mentioned ion bombardment treatment method.

[0095] Although the embodiments of the present invention have been described in detail above, these are merely examples, and the present invention is not limited in any way to the description of the above embodiments. The present invention can also adopt the following modified embodiments.

[0096] In the present invention, the workpiece W (substrate) is not limited to being formed of a conductive material, but may also be formed of an insulating material. In addition, the wire 3 and the magnetic field generating mechanism 20 may be arranged in the internal space S of the vacuum chamber 2 by one each, or by three or more each.

[0097] In addition, in the above-mentioned embodiment, the magnetic field generating mechanism 20 is described as having a technical solution with a plurality of electromagnetic coils 200, but the magnetic field generating mechanism 20 may also include a permanent magnet as a magnetic field generating unit instead of the electromagnetic coil. In this case, a ring-shaped permanent magnet may be arranged similarly to each electromagnetic coil 200, or a block-shaped permanent magnet may be arranged on the upper side of the upper electromagnetic coil 201, on the lower side of the lower electromagnetic coil 202, or the like.

[0098] In addition, the direction in which each wire 3 extends is not limited to the up-and-down direction, and the wire 3 may be extended in a horizontal direction or the like depending on the shape of the vacuum chamber 2 or the ion bombardment treatment of the wire 3 .

[0099] Fig.11 1 is a side view of an ion bombardment device 1 according to a modified embodiment of the present invention. Figure 1 ) Compared with the ion bombardment device 1, the ion bombardment device 1 has a vacuum film forming device 23. The vacuum film forming device 23 includes: a film forming evaporation source 24 arranged in the vacuum chamber 2; and a film forming power supply 26. The film forming evaporation source 24 can replace the vacuum chamber 2 and function as an anode for the wire 3. In addition, the film forming evaporation source 24 does not necessarily need to be arranged opposite to the workpiece W.

[0100] By applying a negative bias voltage to each of the multiple workpieces W, a portion of the argon ions in the plasma are accelerated toward the workpiece W located in front of the film-forming evaporation source 24, and the surface thereof is cut. In addition, when the film-forming evaporation source 24 is used as the anode of the ion bombardment device 1 in this way, the film-forming treatment of the workpiece W can also be performed after the ion bombardment treatment. In this case, the film-forming evaporation source 24 can be used as a cathode in the film-forming treatment. In addition, the film-forming treatment of the workpiece W after the ion bombardment treatment can also be performed by sputtering, arc ion plating or other methods.

[0101] The present invention provides an ion bombardment device for cleaning the surface of a substrate by irradiating ions. The ion bombardment device includes a vacuum chamber, a substrate support portion, at least one wire, an anode, a discharge power supply, a wire heating power supply, and at least one magnetic field generating mechanism. An internal space is formed inside the vacuum chamber. The substrate support portion is arranged in the internal space and supports the substrate. The at least one wire is arranged in the internal space to extend along a specified extension direction and face the substrate. The at least one wire includes an end and another end located on the opposite side of the one end in the extension direction. The anode is arranged to be at least exposed in the internal space. The discharge power supply applies a discharge voltage between the at least one wire and the anode. The wire heating power supply applies a heating voltage between the one end and the other end of the at least one wire, thereby causing the wire to heat. The at least one magnetic field generating mechanism is arranged on the opposite side of the substrate relative to the wire. The at least one magnetic field generating mechanism includes a first magnetic field generating part and a second magnetic field generating part, the first magnetic field generating part generates a first magnetic field in a region including the one end of the at least one wire, and the second magnetic field generating part generates a second magnetic field in a region including the other end of the at least one wire.

[0102] According to this configuration, since the plasma density around one end and the other end of the filament can be enhanced by the first magnetic field generated by the first magnetic field generating unit and the second magnetic field generated by the second magnetic field generating unit, the variation of the plasma density in the extension direction of the filament can be reduced. As a result, the variation of the etching amount on the surface of the substrate in the extension direction can be reduced.

[0103] In the above structure, it is preferred that: the first magnetic field generating unit and the second magnetic field generating unit have the same polarity as each other in such a manner that the orientation of the magnetic lines of force contained in the first magnetic field and passing through the one end in the processing direction is the same as the orientation of the magnetic lines of force contained in the second magnetic field and passing through the other end in the processing direction, and the processing direction is the direction connecting the at least one magnetic field generating mechanism and the substrate and is a direction perpendicular to the extension direction.

[0104] According to this structure, since the polarities of the first magnetic field and the second magnetic field formed around one end and the other end of the wire are the same, the magnetic field shapes of the regions corresponding to the two ends of the wire can be made similar to each other, and the deviation of the plasma density in the extension direction of the wire can be further reduced. In addition, even when the length of the wire is relatively short, it is possible to suppress the formation of strong magnetic lines of force that attract each other between the first magnetic field and the second magnetic field, and stabilize the distribution of plasma in the extension direction.

[0105] In the above structure, preferably: the at least one wire also includes a middle portion arranged between the one end portion and the other end portion, and the at least one magnetic field generating mechanism also includes: at least one intermediate magnetic field generating portion, which is arranged between the first magnetic field generating portion and the second magnetic field generating portion in the extension direction, and generates an intermediate magnetic field in the region of the middle portion including the at least one wire.

[0106] According to this structure, the intermediate magnetic field of the intermediate magnetic field generating unit can be used to prevent the plasma density in the area facing the middle part of the wire from changing significantly due to the formation of the first magnetic field and the second magnetic field, and the magnetic field distribution in the extension direction around the wire can be made more stable.

[0107] In the above structure, it is preferred that: the first magnetic field generating part, the second magnetic field generating part and the intermediate magnetic field generating part have the same polarity as each other in such a manner that the orientation of the magnetic field lines contained in the first magnetic field and passing through the one end in the processing direction, the orientation of the magnetic field lines contained in the second magnetic field and passing through the other end in the processing direction, and the orientation of the magnetic field lines contained in the intermediate magnetic field and passing through the intermediate part in the processing direction are the same as each other, and the processing direction is the direction connecting the at least one magnetic field generating mechanism and the substrate and is a direction perpendicular to the extension direction.

[0108] According to this structure, by aligning the directions of the magnetic lines of force at one end, the middle part and the other end of the wire, the magnetic field distribution in the extension direction around the wire can be stabilized. As a result, the distribution of plasma in the extension direction can be stabilized, and the deviation of the etching amount on the surface of the substrate can be further reduced.

[0109] In the above configuration, preferably, the magnetic force of the intermediate magnetic field generating unit is set to be smaller than the magnetic forces of the first magnetic field generating unit and the second magnetic field generating unit.

[0110] According to this configuration, the plasma distribution in the extension direction can be further stabilized by relatively weakening the magnetic field intensity around the middle portion of the filament where the temperature tends to be relatively higher than that of one end and the other end.

[0111] In the above structure, preferably: the at least one wire includes: a first wire; and a second wire, which is configured to be located on both sides of the first wire in a direction perpendicular to the extension direction with the substrate separated therefrom, and the at least one magnetic field generating mechanism includes: a first magnetic field generating mechanism, which generates a magnetic field around the first wire; and a second magnetic field generating mechanism, which is configured to be located on both sides of the first magnetic field generating mechanism in a direction perpendicular to the extension direction with the substrate separated therefrom, and generates a magnetic field around the second wire.

[0112] According to this structure, by using two filaments arranged around the substrate to form two plasma regions, the ion bombardment treatment (etching treatment) of the substrate can be promoted. In addition, by providing a unique magnetic field generating mechanism for each filament, the uniformity of the plasma density and the extension direction can be improved, and the deviation of the etching amount distribution of the substrate can be reduced.

[0113] In the above-mentioned structure, it is preferred that: the first magnetic field generating part and the second magnetic field generating part of the first magnetic field generating mechanism have the same polarity as each other in such a manner that the magnetic field lines contained in the first magnetic field of the first magnetic field generating mechanism and passing through the one end of the first wire have the same direction in the direction connecting the first magnetic field generating mechanism and the substrate and being perpendicular to the extension direction, and the magnetic field lines contained in the second magnetic field of the first magnetic field generating mechanism and passing through the other end of the first wire have the same direction in the direction connecting the first magnetic field generating mechanism and the substrate and being perpendicular to the extension direction. The magnetic force lines of one end of the second wire are oriented in the direction connecting the second magnetic field generating mechanism and the substrate and being perpendicular to the extending direction, and the magnetic force lines of the other end of the second wire, which are contained in the second magnetic field of the second magnetic field generating mechanism and pass through the second wire, are oriented in the same direction in the direction connecting the second magnetic field generating mechanism and the substrate and being perpendicular to the extending direction, the first magnetic field generating part and the second magnetic field generating part of the second magnetic field generating mechanism have the same polarity as each other, and the first magnetic field generating part and the second magnetic field generating part of the first magnetic field generating mechanism, and the first magnetic field generating part and the second magnetic field generating part of the second magnetic field generating mechanism have opposite polarities.

[0114] According to this configuration, by making the polarities of the magnetic fields of the two magnetic field generating mechanisms opposite to each other, magnetic lines of force that attract each other are formed between the two magnetic fields, so that etching processing on the substrate can be performed stably.

[0115] In the above structure, preferably: the first magnetic field generating part and the second magnetic field generating part of the at least one magnetic field generating mechanism each include an electromagnetic coil having a center line, and the center line is perpendicular to the extension direction and extends along the direction connecting the at least one magnetic field generating mechanism and the substrate, and the at least one magnetic field generating mechanism also includes: a coil power supply, which flows current to the electromagnetic coil of the first magnetic field generating part and to the electromagnetic coil of the second magnetic field generating part, respectively, so as to generate the first magnetic field and the second magnetic field, respectively.

[0116] According to this configuration, by causing a current to flow through each electromagnetic coil from the coil power source, a magnetic field can be easily formed around one end portion and around the other end portion of the wire.

[0117] In the above structure, it is preferred to further include: a pair of electrodes, respectively connected to the one end and the other end of the at least one wire, to apply the heating voltage, the electromagnetic coil of the first magnetic field generating unit is configured to surround one electrode of the pair of electrodes, and the electromagnetic coil of the second magnetic field generating unit is configured to surround the other electrode of the pair of electrodes.

[0118] According to this configuration, by arranging the electromagnetic coils based on a pair of electrodes respectively connected to one end and the other end of the wire, it is possible to reliably form a magnetic field around the one end and the other end of the wire.

[0119] The present invention provides an ion bombardment treatment method for cleaning the surface of a substrate, comprising the following steps: supporting a substrate by a substrate support portion arranged in an internal space of a vacuum chamber; arranging at least one wire in the internal space to extend along a specified extension direction and face the substrate; providing at least one magnetic field generating mechanism, which is arranged on the opposite side of the substrate relative to the wire and comprises a first magnetic field generating portion and a second magnetic field generating portion, wherein the first magnetic field generating portion generates a first magnetic field in a region including the one end portion of the at least one wire, and the second magnetic field generating portion generates a second magnetic field in a region including the other end portion of the at least one wire. A second magnetic field is generated, wherein the other end is located on the opposite side of the one end in the extending direction; a heating voltage is applied between the one end and the other end of the at least one wire, thereby generating heat of the at least one wire; a discharge voltage is applied between an anode and the at least one wire, thereby generating plasma, wherein the anode is configured to be at least exposed to the internal space; and the density of the plasma around the one end and the other end of the at least one wire is increased by at least the first magnetic field and the second magnetic field, and the ions contained in the plasma are irradiated onto the surface of the substrate, thereby cleaning the surface.

[0120] According to this method, since the plasma density in the region facing the one end and the other end of the filament can be enhanced by the first magnetic field generated by the first magnetic field generating unit and the second magnetic field generated by the second magnetic field generating unit, the variation of the plasma density in the extension direction of the filament can be reduced. As a result, the variation of the etching amount on the surface of the substrate in the extension direction can be reduced.

[0121] According to the present invention, an ion bombardment apparatus and an ion bombardment treatment method can be provided, which can reduce the variation in the etching amount on the surface of a substrate by reducing the variation in the density of plasma formed in a vacuum chamber in an apparatus using a wire as an electrode.

Claims

1. An ion bombardment device, characterized in that: Ions are irradiated onto the surface of the substrate to clean the surface, and the ion bombardment device comprises: a vacuum chamber having an inner space formed inside the vacuum chamber; A substrate support portion is disposed in the internal space and supports the substrate; at least one wire, arranged in the inner space to extend along a specified extension direction and face the substrate, and including one end and another end located on the opposite side of the one end in the extension direction; an anode configured to be exposed at least in the internal space; a discharge power source for applying a discharge voltage between the at least one filament and the anode; a wire heating power supply for applying a heating voltage between the one end and the other end of the at least one wire, thereby causing the wire to heat; and At least one magnetic field generating mechanism is arranged on the opposite side of the substrate relative to the wire, and includes a first magnetic field generating unit and a second magnetic field generating unit, wherein the first magnetic field generating unit generates a first magnetic field in a region including the one end of the at least one wire, and the second magnetic field generating unit generates a second magnetic field in a region including the other end of the at least one wire.

2. The ion bombardment device according to claim 1, characterized in that: The first magnetic field generating unit and the second magnetic field generating unit have the same polarity as each other in such a manner that the orientation of the magnetic lines of force contained in the first magnetic field and passing through the one end in the processing direction is the same as the orientation of the magnetic lines of force contained in the second magnetic field and passing through the other end in the processing direction, and the processing direction is a direction connecting the at least one magnetic field generating mechanism and the substrate and is a direction perpendicular to the extension direction.

3. The ion bombardment device according to claim 1 or 2, characterized in that: The at least one wire further comprises an intermediate portion disposed between the one end portion and the other end portion, The at least one magnetic field generating mechanism further comprises: At least one intermediate magnetic field generating portion is disposed between the first magnetic field generating portion and the second magnetic field generating portion in the extending direction, and generates an intermediate magnetic field in a region including the intermediate portion of the at least one filament.

4. The ion bombardment device according to claim 3, characterized in that: The first magnetic field generating unit, the second magnetic field generating unit, and the intermediate magnetic field generating unit have the same polarity as each other in such a manner that the orientation of the magnetic field lines contained in the first magnetic field and passing through the one end in the processing direction, the orientation of the magnetic field lines contained in the second magnetic field and passing through the other end in the processing direction, and the orientation of the magnetic field lines contained in the intermediate magnetic field and passing through the intermediate part in the processing direction are the same as each other, and the processing direction is the direction connecting the at least one magnetic field generating mechanism and the substrate and is a direction perpendicular to the extension direction.

5. The ion bombardment device according to claim 4, characterized in that: The magnetic force of the intermediate magnetic field generating unit is set to be smaller than the magnetic forces of the first magnetic field generating unit and the second magnetic field generating unit.

6. The ion bombardment device according to claim 1 or 2, characterized in that: The at least one filament comprises: 1st wire; and The second wire is arranged so as to be located on both sides of the first wire in a direction perpendicular to the extending direction with the substrate interposed therebetween, The at least one magnetic field generating mechanism comprises: a first magnetic field generating mechanism for generating a magnetic field around the first wire; and The second magnetic field generating mechanism is disposed on both sides of the first magnetic field generating mechanism in a direction perpendicular to the extending direction with the substrate interposed therebetween, and generates a magnetic field around the second wire.

7. The ion bombardment device according to claim 6, characterized in that: The first magnetic field generating portion and the second magnetic field generating portion of the first magnetic field generating mechanism have the same polarity as each other in such a manner that the magnetic field lines contained in the first magnetic field of the first magnetic field generating mechanism and passing through the one end of the first wire have the same orientation in the direction connecting the first magnetic field generating mechanism and the substrate and being perpendicular to the extending direction, and the magnetic field lines contained in the second magnetic field of the first magnetic field generating mechanism and passing through the other end of the first wire have the same orientation in the direction connecting the first magnetic field generating mechanism and the substrate and being perpendicular to the extending direction, The first magnetic field generating part and the second magnetic field generating part of the second magnetic field generating mechanism have the same polarity as each other in such a manner that the magnetic field lines contained in the first magnetic field of the second magnetic field generating mechanism and passing through the one end of the second wire have the same orientation in the direction connecting the second magnetic field generating mechanism and the substrate and being perpendicular to the extending direction, and the magnetic field lines contained in the second magnetic field of the second magnetic field generating mechanism and passing through the other end of the second wire have the same orientation in the direction connecting the second magnetic field generating mechanism and the substrate and being perpendicular to the extending direction, The first magnetic field generating section and the second magnetic field generating section of the first magnetic field generating mechanism and the first magnetic field generating section and the second magnetic field generating section of the second magnetic field generating mechanism have opposite polarities to each other.

8. The ion bombardment device according to claim 1 or 2, characterized in that: The first magnetic field generating part and the second magnetic field generating part of the at least one magnetic field generating mechanism each include an electromagnetic coil having a center line, the center line being perpendicular to the extension direction and extending along a direction connecting the at least one magnetic field generating mechanism and the substrate, The at least one magnetic field generating mechanism further comprises: The coil power supply supplies current to the electromagnetic coil of the first magnetic field generating unit and to the electromagnetic coil of the second magnetic field generating unit, respectively, to generate the first magnetic field and the second magnetic field, respectively.

9. The ion bombardment device according to claim 8, characterized in that Also includes: A pair of electrodes, respectively connected to the one end and the other end of the at least one wire, apply the heating voltage, The electromagnetic coil of the first magnetic field generating unit is arranged so as to surround one electrode of the pair of electrodes, and the electromagnetic coil of the second magnetic field generating unit is arranged so as to surround the other electrode of the pair of electrodes.

10. An ion bombardment treatment method, characterized in that: The surface of the substrate is cleaned, and the steps include: The substrate is supported by a substrate support portion disposed in the inner space of the vacuum chamber; Arrange at least one wire in the inner space to extend along a specified extension direction and face the substrate; At least one magnetic field generating mechanism is provided, the at least one magnetic field generating mechanism is arranged on the opposite side of the substrate relative to the at least one wire, and includes a first magnetic field generating part and a second magnetic field generating part, the first magnetic field generating part generates a first magnetic field in a region including the one end of the at least one wire, and the second magnetic field generating part generates a second magnetic field in a region including the other end of the at least one wire, the other end being located on the opposite side of the one end in the extending direction; applying a heating voltage between the one end and the other end of the at least one filament, thereby causing the at least one filament to heat; applying a discharge voltage between an anode and the at least one filament to generate plasma, the anode being configured to be exposed at least in the inner space; and The density of the plasma around the one end and the other end of the at least one filament is increased by at least the first magnetic field and the second magnetic field, and the surface of the substrate is irradiated with ions contained in the plasma, thereby cleaning the surface.

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