JP7849640B2 - Plasma processing equipment - Google Patents

Description

This disclosure relates to a plasma processing apparatus.

Plasma processing devices are known that generate plasma inside a vacuum chamber using an antenna. Depending on the type of plasma processing device, a predetermined plasma treatment is applied to the object to be treated using the generated plasma. Specifically, plasma processing devices are known to perform, for example, a defilm removal treatment that removes a coating from the surface of the object to be treated.

Furthermore, for example, Patent Document 1 discloses a defilm removal device that removes a coating from a coated material by irradiating the coated material with an ion stream. This conventional defilm removal device places the coated material in an ion stream concentration section where two or more ion streams overlap, and removes the coating from the coated material by irradiating the coated material with an ion stream.

International Publication No. 2016/163278

However, the conventional techniques described above had the problem of not being able to accurately remove the film from the material being treated.

This disclosure was made in view of the above-mentioned problems, and aims to provide a plasma processing apparatus that can process materials with high precision.

To solve the above problems, a plasma processing apparatus according to one aspect of the present disclosure comprises a vacuum vessel for housing an object to be processed, a high-frequency window for introducing a high-frequency magnetic field for generating plasma into the vacuum vessel, an antenna provided on the outside of the vacuum vessel facing the high-frequency window and generating the high-frequency magnetic field, a turntable that rotates inside the vacuum vessel, and an application mechanism for applying a predetermined bias voltage to the object to be processed, wherein the application mechanism comprises a holder provided on the turntable for holding the object to be processed, and an electrode plate electrically connected to the holder inside the vacuum vessel, and applies the bias voltage from the electrode plate to the object to be processed located between the antenna and the rotation axis of the turntable.

According to one aspect of this disclosure, a plasma processing apparatus capable of processing an object with high precision can be provided.

This figure illustrates the main components of a plasma processing apparatus according to Embodiment 1 of this disclosure. This is a cross-sectional view showing the main components of the plasma processing apparatus described above. This is a plan view illustrating an example of the configuration of the high-frequency window shown in Figure 1. This figure illustrates an example of the holder configuration shown in Figure 1. This graph shows an example of the relationship between the electron density of the plasma and the sheath thickness in the plasma processing apparatus described above. This diagram illustrates an example of the relationship between the workpiece and the sheath during the film removal process. This is a cross-sectional view showing the main components of a plasma processing apparatus according to Embodiment 2 of this disclosure. This figure illustrates the main components of a plasma processing apparatus according to Embodiment 3 of the present disclosure. Figure 8 is a cross-sectional view showing the main components of the plasma processing apparatus. This figure illustrates the main components of a plasma processing apparatus according to Embodiment 4 of this disclosure. Figure 10 is a top view showing the main components of the plasma processing apparatus. This figure illustrates the main components of a plasma processing apparatus according to Embodiment 5 of the present disclosure. Figure 12 illustrates an example of the configuration of the electrode plate and holder of the plasma processing apparatus shown in Figure 12. This figure illustrates the main components of a plasma processing apparatus according to Embodiment 6 of this disclosure. Figure 14 is a cross-sectional view showing the main components of the plasma processing apparatus. This figure illustrates an example of the holder configuration shown in Figure 14.

[Embodiment 1]
Hereinafter, Embodiment 1 of the present disclosure will be described in detail with reference to Figures 1 to 4. Figure 1 is a diagram illustrating the main components of the plasma processing apparatus 1 according to Embodiment 1 of the present disclosure. Figure 2 is a top view showing the main components of the plasma processing apparatus 1. Figure 3 is a plan view illustrating an example of the configuration of the high-frequency window WR shown in Figure 1. Figure 4 is a diagram illustrating an example of the configuration of the holder H shown in Figure 1.

In the following explanation, a plasma processing apparatus 1 is described as an example, which uses inductively coupled plasma to perform a defilm removal process to regenerate the surface of a workpiece W, which is the object to be processed, by removing the coating from the surface of the workpiece W.

However, this disclosure can be applied to a plasma processing apparatus that performs metal surface treatments such as carburizing, nitriding, ashing, or etching on the surface of a workpiece W, as a predetermined plasma treatment. Furthermore, this disclosure can be applied to a plasma processing apparatus that performs a film deposition treatment to deposit a predetermined film on the surface of a workpiece W by plasma CVD (Chemical Vapor Deposition) or sputtering, as a predetermined plasma treatment.

<Configuration of Plasma Processing System 1>
As shown in Figure 1, the plasma processing apparatus 1 of this embodiment 1 comprises a vacuum vessel 2, a turntable 3, a high-frequency window WR, an antenna 7, and an application mechanism SM. In the plasma processing apparatus 1, the workpiece W is transported in and out of the vacuum vessel 2 through a door provided in the vacuum vessel 2 by a transport mechanism (not shown). In addition to this description, the vacuum vessel 2 may be opened and the workpiece W may be replaced one by one, or each time the workpiece W is changed on the turntable 3.

The workpiece W may be a metalworking drill made of a metallic material such as tungsten carbide or high-speed tool steel. Alternatively, the workpiece W may be a tool other than a drill, such as an end mill, mold, special tool, or special part for automobiles or aircraft. The plasma processing apparatus 1 removes a coating, such as a diamond-like carbon film, that has been formed on the surface of the workpiece W by the predetermined plasma treatment described above.

<Vacuum container 2>
The vacuum vessel 2 is constructed, for example, from a metal material and includes a vessel body 2a for forming a processing chamber that performs the predetermined plasma treatment on the workpiece W. The vessel body 2a is configured, for example, in a cylindrical shape, as shown in Figures 1 and 2. Furthermore, an upper lid 2c and a lower lid 2d are airtightly attached to the upper and lower openings of the vessel body 2a, and the vacuum vessel 2 is configured to be vacuumed to a predetermined degree by a vacuum pump (not shown) with the workpiece W inside. The vacuum vessel 2 is also grounded via a grounding wire (not shown), and a predetermined processing gas such as argon can be introduced into the vacuum vessel 2 as appropriate.

<Turntable 3>
The turntable 3 is constructed, for example, from a metal material, and comprises a disc-shaped table body 3a and a rotating shaft 3b located in the center of the table body 3a. In the turntable 3, the rotating shaft 3b is rotatably and airtightly attached to the lower lid 2d of the vacuum container 2, and a drive mechanism (not shown) is connected to the rotating shaft 3b. In the turntable 3, the table body 3a rotates in the R1 direction inside the vacuum container 2 as the rotating shaft 3b rotates in the R1 direction shown in Figure 1.

The table body 3a is provided with, for example, multiple holders H for holding the workpieces W, and a predetermined plasma treatment is sequentially performed on the workpieces W inside the plasma treatment area PA described later. In other words, the table body 3a rotates at a predetermined rotational speed (for example, 10 rpm), and the defilm removal treatment for each workpiece W is completed by, for example, several rotations of the table body 3a. It is preferable that the diameter of the table body 3a be as close as possible to the inner diameter of the container body 2a, that is, the inner wall surface 2b of the container body 2a, in order to effectively utilize the high-density plasma inside the plasma treatment area PA.

<High-frequency window WR>
The high-frequency window WR comprises a metal plate 5 and a dielectric plate 6, and is configured to introduce a high-frequency magnetic field that generates plasma into the interior of the container body 2a of the vacuum vessel 2. Specifically, in the vacuum vessel 2, the high-frequency window WR is attached to the container body 2a so as to close an opening 2b1 provided in the inner wall surface 2b of the container body 2a.

The metal plate 5 is made of one metal selected from the group including, for example, copper, aluminum, zinc, nickel, tin, silicon, titanium, iron, chromium, niobium, carbon, molybdenum, tungsten, or cobalt, or an alloy thereof, and is provided on the container body 2a side as shown in Figures 1 and 2. Furthermore, the metal plate 5 is provided with a plurality of slits 5S, as illustrated in Figure 3. These slits 5S are provided at predetermined intervals along the extending direction of the antenna 7.

Furthermore, each slit 5S is composed of a rectangular opening, for example, shown in Figure 3 by dimensions L1 and L2. In slit 5S, dimensions L1 and L2 are, for example, values within the range of 30 mm to 60 mm and 5 mm to 30 mm. Figure 11, shown later, shows the opening dimension L3 of the opening 2b1 to which the high-frequency window WR is installed. This opening dimension L3 is set to a value within the range of 40 mm to 80 mm, and is set larger than the dimension L1 of the slit 5S in order to efficiently introduce the high-frequency magnetic field into the vacuum vessel 2.

The dielectric plate 6 is made of, for example, a ceramic material such as alumina, silicon carbide, or silicon nitride, or an inorganic material such as quartz glass or alkali-free glass, or a synthetic resin plate such as fluororesin, and is provided on the antenna 7 side of the metal plate 5. The dielectric plate 6 is attached to the metal plate 5 so as to cover at least the slits 5S. As a result, in the high-frequency window WR, the high-frequency magnetic field generated from the antenna 7 is supplied to the inside of the vacuum container 2 by passing through the dielectric plate 6 and the multiple slits 5S in the metal plate 5. Since the multiple slits 5S are blocked by the dielectric plate 6, the vacuum state inside the vacuum container 2 is maintained.

In the plasma processing apparatus 1 of this embodiment 1, by forming the high-frequency window WR together with the metal plate 5 on which the slit 5S is formed, in addition to the dielectric plate 6, it is possible to increase the mechanical strength of the high-frequency window WR while ensuring the function of introducing a high-frequency magnetic field into the vacuum vessel 2. This reduces the risk of damage to the dielectric plate 6.

<Antenna 7>
The antenna 7 is, for example, linearly shaped and made of a metal material such as copper. The antenna 7 is positioned vertically on the outside of the container body 2a, facing the high-frequency window WR. Furthermore, the antenna 7 generates a high-frequency magnetic field using high-frequency power from the power supply 8, and introduces this magnetic field into the container body 2a through the high-frequency window WR.

Specifically, one end of the antenna 7 is electrically connected to a power supply 8 via an impedance adjustment unit (not shown) having a matching circuit. The other end of the antenna 7 is electrically grounded via a variable capacitor (not shown). The power supply 8 supplies, for example, 13.56 MHz high-frequency power to one end of the antenna 7 via the impedance adjustment unit. In the plasma processing apparatus 1, a control unit (not shown) controls the supply of high-frequency power to the antenna 7 by changing the capacitance of the variable capacitor.

As a result, in the plasma processing apparatus 1 of this embodiment 1, the high-frequency magnetic field generated from the antenna 7 is introduced into the vacuum vessel 2 through the high-frequency window WR, and plasma can be generated inside the vacuum vessel 2. This plasma has a density distribution equivalent to the magnetic field distribution inversely proportional to the distance from the antenna 7, and also has a highly directional distribution that spreads throughout the inside of the vacuum vessel 2. Thus, in the plasma processing apparatus 1 of this embodiment 1, a high-density plasma can be widely generated inside the vacuum vessel 2, forming the plasma processing region PA described later, and the workpiece W can be processed with high precision inside the plasma processing region PA.

<Applying mechanism SM>
The application mechanism SM comprises a holder H provided on the turntable 3 to hold the workpiece W, and an electrode plate SM2 electrically connected to the holder H inside the vacuum container 2. The application mechanism SM also has a power supply SM1 provided outside the container body 2a, which applies a predetermined bias voltage from the power supply SM1 to the workpiece W located between the antenna 7 and the rotation axis 3b of the turntable 3 via the electrode plate SM2 and the holder H. The plasma processing area PA is the area where a predetermined plasma processing is performed on the workpiece W. This plasma processing area PA is defined by the area to which the bias voltage from the electrode plate SM2 can be applied to the workpiece W, that is, the installation location of the electrode plate SM2 and the area where the holder H and the electrode plate SM2 are in contact with each other. In the plasma processing apparatus 1 of this embodiment 1, a predetermined plasma processing is performed on the workpiece W inside the plasma processing area PA while the bias voltage from the application mechanism SM is applied.

The power supply SM1 is configured, for example, using a DC power supply, a pulse power supply, or an AC power supply. In the application mechanism SM, the control unit is configured to change the bias voltage from the power supply SM1 according to the details of the plasma treatment on the workpiece W and the electron density of the plasma in the plasma treatment area PA, thereby ensuring that the plasma treatment is performed appropriately.

The electrode plate SM2 is formed, for example, in a semicircular shape and is installed inside the vacuum chamber 2 between the antenna 7 and the rotation axis 3b of the turntable 3. The electrode plate SM2 applies a bias voltage to the workpiece W located between the antenna 7 and the rotation axis 3b via the holder H. In other words, the application mechanism SM applies the bias voltage to the workpiece W only when the workpiece W held by the holder H is located in or near the high-frequency window WR and opposite the electrode plate SM2.

Furthermore, the dimensions of the electrode plate SM2 in the direction of rotation of the turntable 3 (i.e., along the arrow R1 in Figure 1) are set to a value within the range of 2 to 4 times the dimensions of the slit 5S in the same direction of rotation. In other words, in the plasma processing apparatus 1 of this embodiment 1, the plasma processing area PA inside the vacuum vessel 2 is set to correspond to the above dimensions of the electrode plate SM2. Also, inside the vacuum vessel 2, the area where the electrode plate SM2 is not installed functions as a cooling area CA where the workpiece W can be cooled, as the predetermined plasma processing is not performed on the workpiece W in that area.

Furthermore, as described above, since the electrode plate SM2 is defined based on the dimensions of the slit 5S in the rotational direction, in this embodiment 1, a bias voltage can be reliably and easily applied to the workpiece W, and a compact plasma processing apparatus 1 can be constructed that can perform plasma processing more appropriately.

Furthermore, if the dimension of the electrode plate SM2 in the rotational direction of the turntable 3 is set to a value less than twice the dimension of the slit 5S in the same rotational direction, it may not be possible to enlarge the plasma processing area PA, and thus it may not be possible to easily increase the number of workpieces W processed per unit time. Also, if the dimension of the electrode plate SM2 in the rotational direction of the turntable 3 is set to a value exceeding four times the dimension of the slit 5S in the same rotational direction, it may become difficult to construct a compact plasma processing apparatus 1, requiring an increase in the number of antennas 7 installed or a larger high-frequency window WR.

Furthermore, the application mechanism SM has a plurality of holders H provided at predetermined intervals along the circumference of the turntable 3a. Each of the plurality of holders H is for holding the workpiece W on the turntable 3a. In this embodiment 1, as described above, as the turntable 3a rotates, a bias voltage is applied from the electrode plate SM2 within the plasma processing area PA where the electrode plate SM2 is installed, allowing predetermined plasma processing to be performed sequentially on multiple workpieces W.

As shown in Figure 4, the holder H comprises cylindrical support members H1 and H2, and a cylindrical conductive member H3. The holder H also includes a holding member H4 for holding a spring H5 as an elastic member, and a roller H6 as a sliding member. The support members H1 and H2 are made of, for example, a dielectric material and are provided on the table body 3a of the turntable 3. Furthermore, support member H1 is rotatably supported by support member H2 while holding the workpiece W.

The spring H5 is configured to bias the roller H6 on the surface side of the electrode plate SM2. The spring H5 is held in an elastically deformable state by a holding member H4, which is made of, for example, a dielectric material. The roller H6 is rotatably held by the holding member H4 while biased by the spring H5. The conductive member H3, spring H5, and roller H6 are made of metallic material and are electrically connected sequentially to form a bias voltage application path from the electrode plate SM2 to the workpiece W. This configuration ensures that the holder H can reliably perform more uniform processing on the workpiece W.

The plasma processing apparatus 1 of this embodiment 1, configured as described above, comprises a vacuum vessel 2 for housing a workpiece W, a high-frequency window WR for introducing a high-frequency magnetic field into the vacuum vessel 2, and an antenna 7 provided opposite the high-frequency window WR for generating a high-frequency magnetic field. The plasma processing apparatus 1 also comprises a turntable 3 on which the workpiece W is placed and rotated, and an application mechanism SM for applying a predetermined bias voltage to the workpiece W. The application mechanism SM comprises a holder H provided on the turntable 3 for holding the workpiece W, and an electrode plate SM2 electrically connected to the holder H inside the vacuum vessel 2.

With the above configuration, this embodiment 1 provides a plasma processing apparatus 1 capable of processing a workpiece W with high precision. Specifically, in this embodiment 1, the inside of the vacuum vessel 2 is defined as a plasma processing region PA by the electrode plate SM2. Therefore, a high-density plasma can be utilized in this plasma processing region PA while applying a voltage to the workpiece W. This allows for a high electron density of the plasma and a large film removal rate (processing rate) for the workpiece W. As a result, this embodiment 1 enables high-precision processing of the workpiece W. Furthermore, in this embodiment 1, as shown in Figures 1 and 2, a single plasma source having one antenna 7 and one high-frequency window WR can be used to sequentially perform predetermined plasma processing on multiple workpieces W. As a result, this embodiment 1 provides a low-cost plasma processing apparatus 1 that can efficiently perform plasma processing on multiple workpieces W.

The effects of the plasma processing apparatus 1 of this embodiment 1 will be described in detail below, with reference to Figures 5 and 6. Figure 5 is a graph showing an example of the relationship between the electron density of the plasma and the sheath thickness in the plasma processing apparatus 1. Figure 6 is a diagram illustrating an example of the relationship between the workpiece W and the sheath SA in the film removal process.

As shown in Figure 5, in the plasma processing apparatus 1 of this embodiment 1, for example, when the control unit controls the power supply 8 to change the power supplied to the antenna 7 (high-frequency power), the electron density of the plasma generated in the plasma processing region PA changes as shown on the horizontal axis of Figure 5. Also, in the plasma processing apparatus 1 of this embodiment 1, for example, when the control unit controls the power supply SM1 to change the bias voltage, the sheath thickness of the sheath SA (Figure 6) generated around the workpiece W in the plasma processing region PA changes according to the electron density of the plasma for each bias voltage. Here, the sheath SA is, as is well known, a shielding layer that is generated to surround the workpiece W by the bias voltage and inhibits the approach of plasma ions to the workpiece W.

Specifically, when the bias voltage is, for example, -100V, the sheath thickness changes according to the electron density of the plasma, as shown by curve 71 in Figure 5. Furthermore, when the bias voltage is, for example, -250V, the sheath thickness changes according to the electron density of the plasma, as shown by curve 72 in Figure 5. Also, when the bias voltage is, for example, -500V, the sheath thickness changes according to the electron density of the plasma, as shown by curve 73 in Figure 5. In other words, as is clear from curves 71 to 73 in Figure 5, the higher the electron density of the plasma in the plasma processing region PA, and the smaller the absolute value of the bias voltage applied to the workpiece W, the smaller the sheath thickness can be, allowing for more precise plasma processing of the workpiece W.

Furthermore, as shown in 601 of Figure 6, when the workpiece W is the drill described above, as shown in 602 and 603 of Figure 6, the sheath thickness around the workpiece W in a cross-sectional view differs depending on the electron density of the plasma. Specifically, when the electron density of the plasma is low, the thickness of the sheath SA increases, as shown in 602 of Figure 6. As a result, the plasma ions P1 are prevented from approaching the surface of the workpiece W by the relatively thick sheath SA. Consequently, when the electron density of the plasma is low and the sheath thickness is large, it becomes difficult to perform the defilm removal process uniformly on the workpiece W.

On the other hand, when the electron density of the plasma can be increased, as in the plasma processing apparatus 1 of this embodiment 1, the thickness of the sheath SA can be reduced compared to that shown in 602 of Figure 6, as shown in 603 of Figure 6. Therefore, in the plasma processing apparatus 1 of this embodiment 1, the plasma ions P1 are prevented from approaching the surface of the workpiece W by the relatively thin sheath SA. In other words, in the plasma processing apparatus 1 of this embodiment 1, the plasma ions P1 can approach the surface of the workpiece W more easily, and a uniform film removal process can be performed.

Furthermore, in the plasma processing apparatus 1 of this embodiment 1, a cooling region CA is set inside the vacuum vessel 2 that allows the workpiece W to be cooled without the predetermined plasma processing being performed. This allows the plasma processing apparatus 1 of this embodiment 1 to suppress the temperature rise of the workpiece W due to plasma processing, and to easily lower the temperature of the workpiece W. As a result, the plasma processing apparatus 1 can significantly suppress the temperature rise of the workpiece W, and significantly reduce the occurrence of damage to the workpiece W.

Furthermore, in the plasma processing apparatus 1 of this embodiment 1, in the application mechanism SM, a plurality of holders H are provided on the turntable 3 at predetermined intervals, and the electrode plate SM2 is installed inside the vacuum container 2 between the antenna 7 and the rotation axis 3b of the turntable 3, and a bias voltage is applied to the workpiece W located between the antenna 7 and the rotation axis 3b via the holders H. In other words, the application mechanism SM applies the bias voltage to the workpiece W only when the workpiece W held by the holder H is located near the high-frequency window WR and in a position opposite the electrode plate SM2. As a result, the plasma processing apparatus 1 of this embodiment 1 can perform plasma processing more appropriately on each of the plurality of workpieces W.

[Embodiment 2]
Embodiment 2 of this disclosure will be described in detail with reference to Figure 7. Figure 7 is a cross-sectional view showing the main components of the plasma processing apparatus 1 according to Embodiment 2 of this disclosure. For the sake of convenience of explanation, components having the same function as those described in Embodiment 1 will be denoted by the same reference numerals, and their descriptions will not be repeated.

The main difference between this second embodiment and the first embodiment is the addition of a contact member 2e that rotates the support member H1 in accordance with the rotation of the turntable 3.

As shown in Figure 7, in the plasma processing apparatus 1 of this second embodiment, a contact member 2e is provided on the inner wall surface 2b of the vacuum vessel 2. This contact member 2e is constructed in a rod shape using, for example, a metal material. One end of the contact member 2e is attached to the inner wall surface 2b such that it protrudes from the inner wall surface 2b into the interior side of the vessel body 2a. The other end (protruding end) of the contact member 2e is configured to be able to contact the support member H1 of the holder H.

Furthermore, in the plasma processing apparatus 1 of this second embodiment, when the support member H1 of the holder H comes into contact with the other end of the contact member 2e in accordance with the rotation of the turntable 3, the support member H1 is pressed (kicked) against the other end of the contact member 2e in accordance with the rotation. As a result, the holder H rotates (rotates on its own axis) with the support member H1 supporting the workpiece W in accordance with the rotation of the turntable 3.

With the above configuration, the plasma processing apparatus 1 of this second embodiment achieves the same effects as that of the first embodiment. Furthermore, in the plasma processing apparatus 1 of this second embodiment, the support member H1 of the holder H is rotated by contact with the contact member 2e, so that the workpiece W can be processed more uniformly and reliably.

[Embodiment 3]
Embodiment 3 of this disclosure will be described in detail with reference to Figures 8 and 9. Figure 8 is a diagram illustrating the main components of the plasma processing apparatus 1 according to Embodiment 3 of this disclosure. Figure 9 is a cross-sectional view showing the main components of the plasma processing apparatus 1 shown in Figure 8. For the sake of convenience of explanation, components having the same function as those described in Embodiment 1 above will be denoted by the same reference numerals, and their descriptions will not be repeated.

The main difference between this third embodiment and the first embodiment is that this third embodiment includes a turntable 13 having two table bodies 13a1 and 13a2 arranged parallel to each other along the extension direction of the antenna 7, and multiple workpieces W are arranged along the extension direction.

As shown in Figures 8 and 9, the plasma processing apparatus 1 of this embodiment 3 is provided with a turntable 13 comprising, for example, two opposing table bodies 13a1 and 13a2 arranged in upper and lower stages along the extension direction of the antenna 7. This turntable 13 is constructed using, for example, a metal material, similar to the turntable 3 of embodiment 1, and is equipped with a rotating shaft 13b connected to the center of each of the table bodies 13a1 and 13a2. This rotating shaft 13b is rotatably and airtightly attached to the lower lid 2d of the vacuum vessel 2, and a drive mechanism (not shown) is connected to the rotating shaft 13b. In the turntable 13, the table bodies 13a1 and 13a2 are configured to rotate in the R1 direction inside the vacuum vessel 2 as the rotating shaft 13b rotates in the R1 direction shown in Figure 8.

Multiple holders H for holding workpieces W are provided on the table body 13a1 at predetermined intervals around the circumferential direction of the table body 13a1, so that the workpieces W face the table body 13a2. Multiple holders H for holding workpieces W are provided on the table body 13a2 at predetermined intervals around the circumferential direction of the table body 13a2, so that the workpieces W face the table body 13a1. In other words, in the plasma processing apparatus 1 of this embodiment 3, multiple workpieces W are arranged in two stages, upper and lower, facing each other inside the vacuum vessel 2.

Furthermore, in the application mechanism SM, for example, an electrode plate SM3, which is configured to have the same shape as electrode plate SM2, is installed on the upper cover 2c side of the table body 13a1. The application mechanism SM is configured to apply a bias voltage from the power supply SM1 to the workpiece W held on the table body 13a2 via electrode plate SM2 and holder H, and to apply a bias voltage from the power supply SM1 to the workpiece W held on the table body 13a1 via electrode plate SM3 and holder H.

With the above configuration, the plasma processing apparatus 1 of this third embodiment achieves the same effects as that of the first embodiment. Furthermore, in the plasma processing apparatus 1 of this third embodiment, since multiple workpieces W are arranged in two stages, upper and lower, facing each other inside the vacuum chamber 2, the number of workpieces processed per unit time can be easily increased.

In the above description, we have described a case in which multiple workpieces W are provided, for example, two table bodies 13a1 and 13a2, along the extension direction of the antenna 7. However, this disclosure is not limited to this, and for example, in a single table body provided with a holder H, a support member is provided above the holder H to support the workpieces W, and the workpieces W are held in two stages, upper and lower.

[Embodiment 4]
Embodiment 4 of this disclosure will be described in detail with reference to Figures 10 and 11. Figure 10 is a diagram illustrating the main components of the plasma processing apparatus 1 according to Embodiment 4 of this disclosure. Figure 11 is a top view showing the main components of the plasma processing apparatus 1 shown in Figure 10. For the sake of convenience of explanation, components having the same function as those described in Embodiment 1 above will be denoted by the same reference numerals, and their descriptions will not be repeated.

The main difference between this embodiment 4 and the above-described embodiment 1 is the addition of a cooling mechanism CM that cools the workpiece W using a cooling plate CM1.

As shown in Figures 10 and 11, in the plasma processing apparatus 1 of this embodiment 4, a cooling mechanism CM is provided in the cooling region CA inside the vacuum vessel 2. The cooling mechanism CM comprises, for example, a cooling plate CM1 formed in an arc shape using a metal material, and a pipe CM2 provided on the inner wall surface 2b side of the container body 2a of the cooling plate CM1 for circulating a cooling medium such as water.

Specifically, the cooling plate CM1 is positioned inside the vacuum vessel 2 in the cooling region CA opposite the antenna 7 with respect to the rotation axis 3b of the turntable 3. The cooling plate CM1 is also installed inside the container body 2a such that its surface is in contact with the holder H. The piping CM2 is kept airtight against the bottom lid 2d and is led out of the vacuum vessel 2, connected to a circulation mechanism (not shown) that circulates the cooling medium.

With the above configuration, the plasma processing apparatus 1 of this embodiment 4 achieves the same effects as that of embodiment 1. Furthermore, in the plasma processing apparatus 1 of this embodiment 4, a cooling mechanism CM having a cooling plate CM1 for cooling the workpiece W is provided, so the workpiece W can be cooled at a faster speed, and the processing rate can be faster than that of the workpiece W.

In other words, in the plasma processing apparatus 1 of this embodiment 4, the cooling performance for the workpiece W is improved, so in plasma processing (film removal processing), the ion current from the plasma to the workpiece W can be increased, and the film removal rate can be increased.

Furthermore, in the plasma processing apparatus 1 of this fourth embodiment, the workpiece W can be cooled at a higher speed, thereby suppressing the temperature rise in the workpiece W associated with plasma processing and significantly reducing damage to the workpiece W caused by thermal load due to the temperature rise. Moreover, in this fourth embodiment, the cooling plate CM1 cools the workpiece W by contacting the holder H without directly contacting the workpiece W, so the workpiece W can be cooled reliably without damaging it.

In the descriptions of Embodiments 2 and 4 above, a configuration was described in which the support member H1 of the holder H is rotated (rotated on its own axis) by contact with the contact member 2e and the cooling plate CM1, respectively. However, this disclosure is not limited thereto, and for example, a rotation mechanism such as a gear may be provided that is connected to the holder H and rotates the support member H1 of the holder H using rotational force from a drive mechanism that drives the rotation axis 3b of the turntable 3.

[Embodiment 5]
Embodiment 5 of the present disclosure will be described in detail with reference to Figures 12 and 13. Figure 12 is a diagram illustrating the main components of the plasma processing apparatus 1 according to Embodiment 5 of the present disclosure. Figure 13 is a diagram illustrating an example of the configuration of the electrode plate SM4 and holder H of the plasma processing apparatus 1 shown in Figure 12. For the sake of convenience of explanation, components having the same function as those described in Embodiment 1 above will be denoted by the same reference numerals, and their descriptions will not be repeated.

The main difference between this embodiment 5 and the above-described embodiment 1 is that the disc-shaped electrode plate SM4 is provided with a conductive portion SM4A and an insulating portion SM4B.

As shown in Figures 12 and 13, in the plasma processing apparatus 1 of this embodiment 5, the application mechanism SM includes an electrode plate SM4 fixed to the container body 2a on the lower lid 2d side of the table body 3a of the turntable 3. This electrode plate SM4 has a hole (not shown) through which a rotating shaft 3b is rotatably inserted, and includes, for example, a conductive portion SM4A made of the same electrode material as the electrode plate SM1, and an insulating portion SM4B made of an insulating material such as a fluororesin such as Teflon (registered trademark) or ceramics.

Furthermore, the insulating portion SM4B is assembled to the conductive portion SM4A so as to be on the same plane as the conductive portion SM4A. In the application mechanism SM, when the roller H6 of the holder H slides on the surface of the conductive portion SM4A, the bias voltage from the power supply SM1 is applied to the workpiece W. On the other hand, when the roller H6 of the holder H slides on the surface of the insulating portion SM4B, the bias voltage from the power supply SM1 is not applied to the workpiece W. In other words, in this embodiment 5, the plasma processing area PA can be defined by defining the size of the conductive portion SM4A in the electrode plate SM4.

With the above configuration, the plasma processing apparatus 1 of this embodiment 5 achieves the same effects as that of embodiment 1. Furthermore, in the plasma processing apparatus 1 of this embodiment 5, the roller H6 of the holder H constantly slides on the surface of the electrode plate SM4, stabilizing the operation of the roller H6 and ensuring a stable holding state of the workpiece W by the holder H.

[Embodiment 6]
Embodiment 6 of the present disclosure will be described in detail with reference to Figures 14 to 16. Figure 14 is a diagram illustrating the main components of the plasma processing apparatus 1 according to Embodiment 6 of the present disclosure. Figure 15 is a cross-sectional view showing the main components of the plasma processing apparatus 1 shown in Figure 14. Figure 16 is a diagram illustrating an example of the configuration of the holder H shown in Figure 14. For the sake of convenience of explanation, components having the same function as those described in Embodiment 1 above will be denoted by the same reference numerals, and their descriptions will not be repeated.

The main difference between this embodiment 6 and the above-described embodiment 1 is that the application mechanism SM uses an arc-shaped electrode plate SM5.

As shown in Figures 15 and 16, in the plasma processing apparatus 1 of this embodiment 6, the application mechanism SM includes an electrode plate SM5 fixed to the container body 2a on the lower lid 2d side of the table body 3a of the turntable 3. This electrode plate SM5 is configured, for example, in an arc shape along the outer circumferential surface of the table body 3a.

Furthermore, in the application mechanism SM, the roller H6 of the holder H slides along the inner circumferential surface of the electrode plate SM5, as shown in Figure 16. In the application mechanism SM, when the roller H6 of the holder H slides along the inner circumferential surface of the electrode plate SM5, a bias voltage from the power supply SM1 is applied to the workpiece W.

With the above configuration, the plasma processing apparatus 1 of this embodiment 6 achieves the same effects as that of embodiment 1.

〔summary〕
To solve the above problems, a plasma processing apparatus according to a first aspect of the present disclosure comprises a vacuum vessel for housing an object to be processed, a high-frequency window for introducing a high-frequency magnetic field for generating plasma into the vacuum vessel, an antenna provided on the outside of the vacuum vessel facing the high-frequency window and generating the high-frequency magnetic field, a turntable that rotates inside the vacuum vessel, and an application mechanism for applying a predetermined bias voltage to the object to be processed, wherein the application mechanism comprises a holder provided on the turntable for holding the object to be processed, and an electrode plate electrically connected to the holder inside the vacuum vessel, and applies the bias voltage from the electrode plate to the object to be processed located between the antenna and the rotation axis of the turntable.

According to the above configuration, a plasma processing apparatus capable of processing objects with high precision can be provided.

A second aspect of this disclosure is a plasma processing apparatus according to the first aspect, wherein in the application mechanism, a plurality of holders are provided on the turntable at predetermined intervals, and the electrode plate is installed between the antenna and the rotation axis of the turntable.

According to the above configuration, plasma treatment can be performed more appropriately on each of the multiple objects to be treated.

A third aspect of the present disclosure is a plasma processing apparatus according to the first or second aspect, wherein the application mechanism may apply the bias voltage to the workpiece held in the holder only when the workpiece is located near the high-frequency window and in a position opposite the electrode plate.

According to the above configuration, plasma treatment can be performed more appropriately on the workpiece.

A fourth aspect of the present disclosure is a plasma processing apparatus according to any of the first to third aspects, wherein the high-frequency window comprises a metal plate having a plurality of slits and a dielectric plate provided on the antenna side of the metal plate so as to cover the plurality of slits, and the dimension of the electrode plate in the rotational direction of the turntable may be within a range of 2 to 4 times the dimension of the slits in the rotational direction.

According to the above configuration, a compact plasma processing apparatus can be constructed that reliably and easily applies a bias voltage to the workpiece, and that can perform plasma processing more appropriately.

A fifth aspect of the present disclosure is a plasma processing apparatus according to any of the first to fourth aspects, wherein the holder may include a support member provided on the turntable and rotatably supporting the workpiece, a conductive member electrically connected to the workpiece supported by the support member, a sliding member sliding on the surface of the electrode plate, and an elastic member provided between the conductive member and the sliding member and biasing the sliding member toward the surface of the electrode plate.

According to the above configuration, more uniform processing of the workpiece can be reliably achieved.

A sixth aspect of this disclosure is a plasma processing apparatus according to the fifth aspect, wherein a contact member may be provided inside the vacuum vessel that contacts the support member of the holder and rotates the support member in accordance with the rotation of the turntable.

According to the above configuration, more uniform processing of the workpiece can be performed more reliably.

A seventh aspect of this disclosure is a plasma processing apparatus according to any of the first to sixth aspects, which may be provided with a cooling mechanism that includes a cooling plate located inside the vacuum vessel in a region opposite to the antenna with respect to the rotation axis of the turntable, and uses the cooling plate to cool the object to be processed.

With the above configuration, the workpiece can be cooled more quickly, thus enabling a faster processing rate.

A seventh aspect of this disclosure is a plasma processing apparatus of the eighth aspect, wherein the cooling plate may be in contact with the holder.

According to the above configuration, the object being processed can be cooled reliably without damaging it.

A ninth aspect of this disclosure is a plasma processing apparatus according to any of the first to eighth aspects, wherein a plurality of the objects to be processed may be arranged inside the vacuum vessel along the extension direction in which the antenna extends.

According to the above configuration, the number of items processed per unit time can be easily increased.

This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this disclosure.

1. Plasma processing apparatus 2. Vacuum vessel 2e. Contact member 3. Turntable 3b. Rotating shaft 5. Metal plate (high-frequency window)
5S Slit 6 Dielectric Plate (High-Frequency Window)
7 Antenna W Work (workpiece to be processed)
SM: Application mechanism; SM1: Power supply; SM2, SM3, SM4, SM5: Electrode plates; H: Holder; H1, H2: Support members; H3: Conductive members; H5: Spring (elastic member)
H6 Roller (sliding member)
CM Cooling mechanism CM1 Cooling plate WR High-frequency window

Claims (9)

A vacuum container that houses the object to be processed,
A high-frequency window is used to introduce a high-frequency magnetic field that generates plasma inside the vacuum container into the vacuum container,
An antenna is provided on the outside of the vacuum vessel so as to face the high-frequency window and generates the high-frequency magnetic field,
A turntable that rotates inside the vacuum container,
The system comprises an application mechanism for applying a predetermined bias voltage to the workpiece,
The aforementioned application mechanism is
A holder provided on the turntable for holding the object to be processed,
The vacuum container includes an electrode plate electrically connected to the holder,
A plasma processing apparatus that applies the bias voltage from the electrode plate to the object to be processed, which is located between the antenna and the rotation axis of the turntable. In the aforementioned application mechanism,
Multiple holders are provided on the turntable at predetermined intervals, and
The plasma processing apparatus according to claim 1, wherein the electrode plate is installed between the antenna and the rotation axis of the turntable. The plasma processing apparatus according to claim 1, wherein the application mechanism applies the bias voltage to the workpiece held in the holder only when the workpiece is located near the high-frequency window and in a position opposite the electrode plate. The high-frequency window comprises a metal plate having a plurality of slits, and a dielectric plate provided on the antenna side of the metal plate so as to cover the plurality of slits.
The plasma processing apparatus according to claim 1, wherein the dimension of the electrode plate in the rotational direction of the turntable is within the range of two to four times the dimension of the slit in the rotational direction. The aforementioned holder is
A support member provided on the turntable and which rotatably supports the object to be processed,
A conductive member electrically connected to the workpiece supported by the support member,
A sliding member that slides on the surface of the electrode plate,
The plasma processing apparatus according to claim 1, further comprising an elastic member provided between the conductive member and the sliding member, which biases the sliding member toward the surface side of the electrode plate. The plasma processing apparatus according to claim 5, wherein a contact member is provided inside the vacuum vessel that contacts the support member of the holder and rotates the support member in accordance with the rotation of the turntable. The plasma processing apparatus according to claim 1, further comprising a cooling plate located inside the vacuum vessel in a region opposite to the antenna with respect to the rotation axis of the turntable, and a cooling mechanism for cooling the object to be processed using the cooling plate. The plasma processing apparatus according to claim 7, wherein the cooling plate is in contact with the holder. Plasma processing apparatus according to any one of claims 1 to 8, wherein a plurality of objects to be processed are arranged inside the vacuum vessel along the extension direction in which the antenna extends.