JP7492900B2 - Plasma Processing Equipment - Google Patents

Description

The present invention relates to technology suitable for use in plasma processing equipment.

Conventionally, plasma processing apparatuses have been known that use plasma to decompose a source gas and, for example, form a thin film on a film-forming surface of a substrate. In these plasma processing apparatuses, as shown in, for example, Patent Documents 1 and 2, a processing chamber is made up of a chamber, an electrode flange, and an insulating flange sandwiched between the chamber and the electrode flange. The processing chamber has a film-forming space (reaction chamber).

A shower plate and a heater on which a substrate is placed are provided within the processing chamber. The shower plate is connected to an electrode flange and has multiple nozzles. A space is formed between the shower plate and the electrode flange. This space is a gas introduction space into which raw material gas is introduced. In other words, the shower plate divides the processing chamber into a film formation space, where a film is formed on the substrate, and a gas introduction space.

The chamber is connected to a ground potential. This causes the heater to function as an anode electrode. Meanwhile, a high-frequency power supply is connected to the electrode flange. The electrode flange and the shower plate function as a cathode electrode. Around the electrode flange, for example, a shield cover is provided that is formed to cover the electrode flange and is connected to the chamber.

In Patent Documents 1 and 2, one end of an earth plate is connected to the bottom surface of the heater, and the other end of the earth plate is electrically connected to the vicinity of the inner bottom surface of the chamber.
In addition, in Patent Document 1, one end of another earth plate (high frequency device) is connected to the side of the heater, and the other end of this earth plate is electrically connected to the vicinity of the side surface of the chamber.

In this configuration, the gas introduced into the gas introduction space is uniformly ejected into the film formation space from each nozzle of the shower plate. At this time, the high-frequency power supply is started and a high-frequency voltage is applied to the electrode flange, generating plasma in the film formation space. The raw material gas is then decomposed by the plasma and reaches the film formation surface of the substrate, forming the desired film.

When a high-frequency voltage is applied to the electrode flange to generate plasma, the current that flows as the plasma is generated is transmitted in the order of the shower plate, heater, and earth plate. This current is then transmitted to the chamber and shield cover, and returned to the matching box. The current that flows as the plasma is generated flows through this current path.

As shown in FIG. 4 of Patent Document 1 and described in Patent Document 2, a loading/unloading section used to load and unload the substrate into the chamber is provided on the side wall of the chamber, and a door valve is provided to open and close the loading/unloading section.

However, as shown in FIG. 4 of Patent Document 1 and described in Patent Document 2, when a loading/unloading section is formed, the path of the high-frequency current flowing along the inner side of the chamber in which the loading/unloading section is formed is longer than the path of the high-frequency current flowing along the inner side of the chamber in which the loading/unloading section is not formed. This results in a large inductance in the path of the high-frequency current flowing along the inner side in which the loading/unloading section is formed.

As a result, the distribution of the return current becomes non-uniform in the circumferential direction of the substrate and heater, resulting in a non-uniform electric field gradient, which causes localized discharges (abnormal discharges) and plasma bias, affecting the uniformity of film formation.

In particular, when it is necessary to increase the high frequency voltage, there is a risk of abnormal discharge occurring near the loading/unloading section.
This causes an impedance mismatch due to abnormal discharge, which reduces the high-frequency voltage that can be applied to the electrode flange.

In Patent Document 1, this is prevented by providing a high-frequency device at a position closer to the shower plate than the door valve.
In addition, in Patent Document 2, the door valve is provided in duplicate to prevent this.

Patent No. 5883652 Republished WO2010/079756

However, as described in Patent Documents 1 and 2, if there are deforming, contacting or sliding parts in the film formation space, these may cause particles to be generated, which is undesirable.
In particular, as described in Patent Document 1, it is highly undesirable for these deforming, contacting or sliding parts to be located closer to the shower plate than the substrate during film formation processing or when the substrate is raised or lowered.

Furthermore, as in Patent Document 2, if there are moving or moving parts in the film formation space, this is not preferable since it may cause particle generation.

Furthermore, as described in Patent Documents 1 and 2, when the return current is transmitted to the shield cover via the underside of the heater, the earth plate, and the bottom of the chamber, the non-uniformity of the return current in the circumferential direction of the substrate is improved, but there is a demand to further shorten the return current path and reduce inductance.

The present invention has been made in consideration of the above circumstances, and aims to achieve the following objects.
1. Preventing particle generation.
2. Improving uniformity in plasma formation.
3. Shorten the path of high frequency return current.
4. To improve the uniformity of the distribution of high frequency return current in the circumferential direction of the substrate.
5. Reducing the inductance in the path of the high-frequency return current.
6. To improve the stability of the high frequency return current path.
7. Achieve these goals simultaneously.

The plasma processing apparatus of the present invention comprises:
A plasma processing apparatus comprising:
An electrode flange;
a chamber having a sidewall and a bottom;
an insulating flange disposed between the chamber and the electrode flange;
a processing chamber having a reaction chamber constituted by the chamber, the electrode flange, and the insulating flange;
a support part that is accommodated in the reaction chamber, on which a substrate having a processing surface is placed and that is capable of controlling a temperature of the substrate;
A lifting drive unit that lifts and lowers the support unit;
a high frequency power source connected to the electrode flange and configured to apply a high frequency voltage;
a capacitor forming portion provided around a side peripheral surface of the support portion;
a capacitor forming portion formed on the side wall of the chamber and provided on an inner circumferential surface of the chamber radially toward the center thereof at a position facing the capacitor forming portion of the support portion;
having
The support part is raised and lowered by the lifting drive part to form a gap between the capacitor formation part on the side peripheral surface of the support part and the capacitor formation part on the inner peripheral surface of the sidewall of the chamber,
The above problem was solved by forming a capacitor for high frequency return current during plasma generation between the opposing capacitor formation portions at a position covering the entire circumference of the support portion.
The plasma processing apparatus of the present invention comprises:
The capacitor forming portion on the side peripheral surface of the support portion may be formed so that a width dimension in a direction in which the support portion is lifted and lowered by the lift drive portion is substantially uniform around the entire circumference of the support portion.
The plasma processing apparatus of the present invention comprises:
The capacitor forming portion of the support portion and the capacitor forming portion of the sidewall of the chamber can be formed such that a separation distance (gap) in a radial direction of the substrate is approximately uniform around the entire circumference of the support portion.
The plasma processing apparatus of the present invention comprises:
The capacitor forming portion on the inner circumferential surface of the sidewall of the chamber may be formed to have a width dimension in a thickness direction of the substrate larger than that of the capacitor forming portion on the lateral surface of the support portion.
The plasma processing apparatus of the present invention comprises:
The capacitor formation portion may be formed continuously or discontinuously in the circumferential direction of the substrate.
The plasma processing apparatus of the present invention comprises:
An insulating member may be disposed on the side surface of the support portion above the capacitor formation portion.
The plasma processing apparatus of the present invention comprises:
An insulating member may be disposed on an upper surface of the support portion, the upper surface being radially inward from the capacitor formation portion.
The plasma processing apparatus of the present invention comprises:
a shower plate electrically connected to the electrode flange and located above the reaction chamber is provided in the processing chamber;
An inner peripheral contour of the insulating member on the upper surface of the support and an outer peripheral contour of the shower plate exposed to the reaction chamber can have corresponding shapes (they may be the same or nearly so in plan view).
The plasma processing apparatus of the present invention comprises:
The capacitor forming portion on the side surface of the support portion and the capacitor forming portion on the inner surface of the side wall of the chamber can both extend in a plane (vertical plane) along the direction in which the support portion is raised and lowered by the lifting drive portion.
The plasma processing apparatus of the present invention comprises:
a transfer unit used for transferring the substrate into or out of the reaction chamber is provided on the side wall of the chamber;
A lower end of the capacitor formation portion may be provided at a position closer to the electrode flange than the carry-in/out portion.
The plasma processing apparatus of the present invention comprises:
An insulating member may be provided on an inner circumferential surface of the side wall of the chamber between the insulating member on the upper surface of the support portion and the insulating flange in the ascending and descending direction of the support portion.
The plasma processing apparatus of the present invention comprises:
The capacitor-forming portion of the support and the capacitor-forming portion of the sidewall of the chamber may be electrically connected by capacitive coupling.
The plasma processing apparatus of the present invention comprises:
The elevation drive section may have a drive support column that drives the support section to elevate and lower, and a position restriction support column that maintains the elevation position of the support section.

The plasma processing apparatus of the present invention comprises:
A plasma processing apparatus comprising:
An electrode flange;
a chamber having a sidewall and a bottom;
an insulating flange disposed between the chamber and the electrode flange;
a processing chamber having a reaction chamber constituted by the chamber, the electrode flange, and the insulating flange;
a support part that is accommodated in the reaction chamber, on which a substrate having a processing surface is placed and that is capable of controlling a temperature of the substrate;
A lifting drive unit that lifts and lowers the support unit;
a high frequency power source connected to the electrode flange and configured to apply a high frequency voltage;
a capacitor forming portion provided around a side peripheral surface of the support portion;
a capacitor forming portion formed on the side wall of the chamber and provided on an inner circumferential surface of the chamber toward the center in a radial direction of the chamber at a position facing the capacitor forming portion of the support portion;
having
The support part is raised and lowered by the lifting drive part, and a gap is formed between the capacitor formation part on the side peripheral surface of the support part and the capacitor formation part on the inner peripheral surface of the chamber,
A capacitor for a high frequency return current during plasma generation is formed between the opposing capacitor formation portions at a position covering the entire circumference of the support portion.
As a result, a very small gap of about several millimeters is formed between the side surface of the support part and the inner surface of the side wall of the chamber. Furthermore, when a high frequency voltage is applied, the side surface of the support part and the inner surface of the side wall of the chamber are electrically connected to each other via capacitive coupling as a path for the high frequency return current.
According to this configuration, when high radio frequency power is supplied to the electrode flange, a radio frequency current can be caused to flow from the electrode flange through the support to the side wall of the chamber, thereby generating plasma between the electrode flange and the support.
In this case, when plasma is generated, the path of the high-frequency return current returning to the matching box can be the support portion, the capacitor forming portion on the side surface of the support portion, the capacitor forming portion on the inner surface of the chamber side wall, and the chamber side wall.
This allows the path of the high frequency return current to be shorter than the path via the bottom of the chamber, thereby reducing the inductance in the path of the high frequency return current.
At the same time, it is possible to form a gap between the side surface of the support part and the inner surface of the chamber side wall with a uniform width regardless of the height of the support part set by the lift drive part, so that the high frequency return current path is formed uniformly all around the circumference of the substrate.
This makes it possible to suppress non-uniformity in the electric field gradient over the entire circumference of the substrate in the circumferential direction, and to maintain a uniform distribution of the plasma processing characteristics, that is, the film formation characteristics.
In addition, the path of the high frequency return current does not pass through a position closer to the bottom of the chamber than the capacitor formation portion, which makes it possible to provide a load/unload portion on the side wall of the chamber at a position closer to the bottom than the capacitor formation portion, which is a position where the path of the high frequency return current does not pass.
This prevents the carry-in/out section from affecting the path of the high-frequency return current, thereby preventing an increase in inductance due to the carry-in/out section and reducing the inductance of the high-frequency return current.
Therefore, when plasma is generated, abnormal discharge within the loading/unloading section can be prevented, and the high frequency voltage that can be applied to the electrode flange can be increased.
At the same time, since the carry-in/out section does not affect the path of the high frequency return current, the path of the high frequency return current is formed uniformly in the circumferential direction of the substrate.
This makes it possible to suppress non-uniformity of the electric field gradient in the circumferential direction of the substrate, and to maintain a uniform distribution of the plasma processing characteristics, that is, the film formation characteristics.
In such a configuration, the side surface of the support part does not come into contact with the inner surface of the chamber side wall, and there are no moving parts other than the lifting and lowering drive part inside the processing chamber, so there are no parts that slide against each other, preventing the generation of particles (dust, etc.).

The plasma processing apparatus of the present invention comprises:
The capacitor forming portion on the side peripheral surface of the support portion has a width dimension in a direction in which the support portion is lifted and lowered by the lift drive portion that is substantially uniform around the entire circumference of the support portion.
As a result, a capacitor formed by the capacitor forming portion on the side peripheral surface of the support portion and the capacitor forming portion on the inner peripheral surface of the chamber sidewall is formed uniformly in the circumferential direction of the substrate.
Therefore, the high frequency return current path is formed uniformly in the circumferential direction of the substrate.
This makes it possible to suppress non-uniformity of the electric field gradient in the circumferential direction of the substrate, and to maintain a uniform distribution of the plasma processing characteristics, that is, the film formation characteristics.
Therefore, when generating plasma, it is possible to prevent abnormal discharge from occurring in a portion where the inductance has changed, and it is possible to increase the high frequency voltage that can be applied to the electrode flange.

The plasma processing apparatus of the present invention comprises:
The capacitor forming portion of the support portion and the capacitor forming portion of the sidewall of the chamber are spaced apart (gap) in the radial direction of the substrate substantially uniformly around the entire circumference of the support portion.
As a result, the gap formed by the capacitor forming portion of the support portion and the capacitor forming portion of the sidewall of the chamber is formed evenly all around the circumference of the substrate in the circumferential direction. Therefore, the capacitor that serves as the path of the high frequency return current is formed evenly all around the circumference of the substrate in the circumferential direction. As a result, the path of the high frequency return current can be formed evenly all around the circumference of the substrate in the circumferential direction.

The plasma processing apparatus of the present invention comprises:
The capacitor formation portion on the inner circumferential surface of the sidewall of the chamber is formed to have a width dimension in a thickness direction of the substrate larger than that of the capacitor formation portion on the lateral surface of the support portion.
As a result, even when plasma processing is performed with the height position of the susceptor (supporting part) changed, the capacitor forming part on the side peripheral surface of the supporting part can maintain a state in which the entire area faces the capacitor forming part on the inner peripheral surface of the side wall of the chamber. In this state, the formation of the necessary capacitor by the capacitor forming part is maintained without being affected by the height position of the susceptor (supporting part) that changes with the plasma processing conditions. This makes it possible to maintain the uniform formation of the path of the necessary high frequency return current.

The plasma processing apparatus of the present invention comprises:
The capacitor formation portion is formed continuously or intermittently in the circumferential direction of the substrate.
This makes it easy to arrange the capacitor formation portion in the circumferential direction of the substrate so as not to be affected by the contour shape of the substrate and the contour shape of the support portion.

The plasma processing apparatus of the present invention comprises:
An insulating member is disposed on the side peripheral surface of the support portion above the capacitor formation portion.
This allows the vicinity of the outer periphery of the upper surface of the susceptor (supporting part) to be covered with an insulating material, thus preventing deposition of a film on the capacitor formation part due to plasma intrusion around the vicinity of the outer periphery of the upper surface of the susceptor (supporting part), and stabilizing the high frequency return path.
In addition, a capacitor for a high frequency return current can be formed by a capacitor forming portion that faces the side peripheral surface of the support portion and the inner peripheral surface of the side wall of the chamber. At the same time, the area of a region where a conductive member is exposed in the capacitor forming portion on the side peripheral surface of the support portion can be specified, thereby enabling the formation of a capacitor with a desired value.
Furthermore, it is possible to prevent the occurrence of abnormal discharge to the electrode flange, shower plate, or the like at the upper position of the side peripheral surface of the support portion (susceptor).
Therefore, it is possible to suppress the occurrence of abnormal discharge between the side peripheral surface of the support portion and the inner peripheral surface of the side wall of the chamber, and as a result, it is possible to increase the upper limit of the high frequency power that can be supplied to the apparatus.

The plasma processing apparatus of the present invention comprises:
An insulating member is disposed on an upper surface of the support portion, the upper surface being radially inward from the capacitor formation portion.
This allows the upper edge of the susceptor (support) to be covered with an insulating material, preventing deposition of a film on the capacitor formation area due to plasma intrusion around the upper edge of the susceptor (support), and stabilizing the high frequency return path.
Furthermore, it is possible to prevent the occurrence of abnormal discharge to the electrode flange, shower plate, or the like near the upper edge of the support portion (susceptor).
Therefore, it is possible to suppress the occurrence of abnormal discharge between the side peripheral surface of the support portion and the inner peripheral surface of the side wall of the chamber, and as a result, it is possible to increase the upper limit of the high frequency power that can be supplied to the apparatus.

The plasma processing apparatus of the present invention comprises:
a shower plate electrically connected to the electrode flange and located above the reaction chamber is provided in the processing chamber;
An inner peripheral contour of the insulating member on the upper surface of the support and an outer peripheral contour of the shower plate exposed to the reaction chamber have corresponding shapes.
Here, the corresponding shapes of the inner peripheral contour of the insulating member on the upper surface of the support and the outer peripheral contour of the shower plate exposed to the reaction chamber mean a state in which these contours coincide when viewed in a plane, or are so close to coinciding that the plasma being formed does not affect areas outside the edge of the substrate.
This makes it possible to mainly limit the space in which plasma is formed above the substrate, which is an inner side of a line connecting an inner peripheral contour of the insulating member on the upper surface of the support portion and an outer peripheral contour of the shower plate exposed to the reaction chamber in the vertical direction. Therefore, during plasma processing, it is possible to prevent the generated plasma from reaching the vicinity of the capacitor formation portion for a substrate located radially inward of the capacitor formation portion in the chamber.
This makes it possible to prevent the plasma from affecting the capacitor formation portion, and to reliably form a capacitor in the path of the high frequency return current.
Therefore, the high frequency return current path is formed uniformly in the circumferential direction of the substrate.
Furthermore, it is possible to easily form a capacitor that serves as a path for a high-frequency return current without reducing the size of the substrate.
Moreover, since there is no need to provide any movable parts other than the elevation drive unit inside the processing chamber, it is possible to prevent particles (dust) and the like from being generated and to prevent deterioration of film formation characteristics.

The plasma processing apparatus of the present invention comprises:
The capacitor forming portion on the side peripheral surface of the support portion and the capacitor forming portion on the inner peripheral surface of the sidewall of the chamber both extend on a plane along a direction in which the support portion is lifted and lowered by the lift drive portion.
In other words, the side circumferential surface of the support part is a steep surface that rises vertically along the contour of the support part, and the inner circumferential surface of the chamber side wall is a steep surface that rises vertically along the contour of the chamber, so that the side circumferential surface of the support part and the inner circumferential surface of the chamber side wall are formed concentrically and are separated from each other with a gap in the radial direction of the chamber.
Therefore, the capacitor formation portion of the support portion and the capacitor formation portion of the chamber sidewall are formed into cylindrical shapes parallel to each other.
This allows the support to move up and down while maintaining the gap when it is raised and lowered. Also, the gap between the capacitor forming portion of the support and the capacitor forming portion of the chamber side wall can be kept constant over the entire length in the height direction. Also, the constant gap can be maintained when the support is raised and lowered.

The plasma processing apparatus of the present invention comprises:
a transfer unit used for transferring the substrate into or out of the reaction chamber is provided on the side wall of the chamber;
A lower end of the capacitor formation portion is provided at a position closer to the electrode flange than the carry-in/out portion.
This prevents the carry-in/out section from affecting the path of the return current, thereby preventing an increase in inductance due to the carry-in/out section and reducing the inductance of the high-frequency return current.
Therefore, when plasma is generated, abnormal discharge within the loading/unloading section can be prevented, and the high frequency voltage that can be applied to the electrode flange can be increased.
At the same time, since the carry-in/out section does not affect the path of the return current, the high-frequency return current path is formed uniformly in the circumferential direction of the substrate.
Furthermore, since the loading/unloading section is located on the side wall of the chamber, which is closer to the bottom than the capacitor formation section, particles generated in the loading/unloading section are prevented from reaching the substrate, thereby preventing a deterioration in the film formation characteristics.

The plasma processing apparatus of the present invention comprises:
An insulating member is provided on the inner circumferential surface of the side wall of the chamber between the insulating member on the upper surface of the support portion and the insulating flange in the lifting and lowering direction of the support portion.
Here, the inner peripheral surface of the chamber sidewall between the insulating member on the upper surface of the support and the insulating flange is the sidewall portion that is radially outward of the space in which plasma is generated. Therefore, the insulating member formed in this portion can prevent abnormal discharge from the electrode plate or shower plate to the inner peripheral surface of the chamber sidewall. At the same time, it can prevent abnormal discharge from the upper surface of the support or the non-processing surface of the substrate to the inner peripheral surface of the chamber sidewall.

The plasma processing apparatus of the present invention comprises:
The capacitor forming portion of the support and the capacitor forming portion of the sidewall of the chamber are electrically connected by capacitive coupling.
This allows a capacitor to be formed by the opposing capacitor forming portions, thereby reducing the inductance in the path of the high frequency return current and forming a substantially uniform inductance in the circumferential direction of the substrate.

The plasma processing apparatus of the present invention comprises:
The elevation drive unit has a drive support pillar that drives the support unit to elevate and lower, and a position restriction support pillar that maintains the elevation position of the support unit.
This allows the support (susceptor) to be raised and lowered while maintaining the gap of the capacitor formation portion formed around the entire circumference of the support (susceptor), and makes it possible to maintain the capacitor value within an appropriate range even when the height position of the support (susceptor) varies depending on the plasma generation conditions. Therefore, it becomes possible to maintain an approximately equal inductance in the circumferential direction of the substrate, regardless of the height position of the support (susceptor).

According to the present invention, the generation of particles is prevented, the number of particles reaching the substrate from the loading/unloading section is reduced, and the path of the high-frequency return current is shortened, without providing any deforming parts, movable parts, or contact parts in the film formation space other than the lifting/lowering drive section.
In addition to these, it is possible to improve the distribution uniformity of the high-frequency return current in the circumferential direction of the substrate and reduce the inductance in the path of the high-frequency return current, thereby achieving the effects of simultaneously achieving these.

1 is a schematic vertical cross-sectional view showing a first embodiment of a plasma processing apparatus according to the present invention; 2 is an enlarged cross-sectional view showing a capacitor formation section in the first embodiment of the plasma processing apparatus according to the present invention; FIG. 1 is an explanatory diagram showing a capacitor formation section in a plan view in a first embodiment of a plasma processing apparatus according to the present invention; 2 is a schematic vertical cross-sectional view showing a path of a high-frequency return current in the first embodiment of the plasma processing apparatus according to the present invention; FIG. 10 is a schematic vertical cross-sectional view showing a second embodiment of a plasma processing apparatus according to the present invention. FIG. 13 is an explanatory diagram showing a capacitor formation section in a plan view in a second embodiment of a plasma processing apparatus according to the present invention; FIG. FIG. 11 is an enlarged cross-sectional view showing a capacitor formation section in a third embodiment of a plasma processing apparatus according to the present invention. FIG. 11 is an enlarged cross-sectional view showing a capacitor formation section in a fourth embodiment of a plasma processing apparatus according to the present invention.

A first embodiment of a plasma processing apparatus according to the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing a plasma processing apparatus according to the present embodiment, in which reference numeral 1 denotes the plasma processing apparatus.

The plasma processing apparatus 1 according to this embodiment is a film forming apparatus using a plasma CVD method. As shown in FIG. 1, the plasma processing apparatus 1 includes a processing chamber 101 having a film forming space 2a which is a reaction chamber.
The processing chamber 101 is composed of a vacuum chamber (chamber) 2 , an electrode flange 4 , and an insulating flange 81 sandwiched between the vacuum chamber 2 and the electrode flange 4 .

The vacuum chamber 2 has a bottom (inner bottom surface) 11 and a side wall (wall portion) 24 standing upright from the periphery of the bottom (inner bottom surface) 11 .
The vacuum chamber 2 is made of aluminum, an aluminum alloy, or the like.

An opening is formed in the bottom (inner bottom surface) 11 of the vacuum chamber 2. A support 16 is inserted into this opening, and the support 16 is disposed at the lower part of the vacuum chamber 2.
The tip of the support pillar 16 is located inside the vacuum chamber 2. A plate-shaped susceptor (support portion) 15 is connected to the tip of the support pillar 16.
The bottom portion (inner bottom surface) 11 and the side wall (wall portion) 24 are formed from aluminum, an aluminum alloy, or the like.

The support pillar 16 is connected to a lifting drive unit (lifting mechanism) 16A provided outside the vacuum chamber 2. The support pillar 16 can be moved up and down by the lifting drive unit (lifting mechanism) 16A. In other words, the susceptor 15 connected to the tip of the support pillar 16 is configured to be able to be raised and lowered in the vertical direction. The susceptor 15 is housed inside the vacuum chamber 2.

Outside the vacuum chamber 2, a bellows (not shown) is provided to cover the outer periphery of the support 16. The bellows keeps the film formation space 2a sealed when the support 16 moves up and down.

An exhaust pipe 27 is connected to the vacuum chamber 2 at a height position closer to the bottom 11 than the range of vertical movement of the susceptor 15. A vacuum pump 28 is provided at the tip of the exhaust pipe 27. The vacuum pump 28 reduces the pressure inside the vacuum chamber 2 to create a vacuum state.

An electrode flange 4 is attached to the upper part of the vacuum chamber 2 via an insulating flange 81 .
In the vacuum chamber 2 , a high-frequency electrode support portion 23 is provided on the upper end of a side wall 24 .
The high-frequency electrode supporting parts 23 are each made of a conductive material such as aluminum or an aluminum alloy.
The lower end of the shield cover 13 is placed on the upper end of the high-frequency electrode support portion 23 .

The side wall 24 is generally cylindrical and has a generally constant inner diameter over the entire height of the vacuum chamber 2. The inner diameter of the side wall 24 is set to be slightly larger than the outer diameter of the susceptor 15.
The inner diameter of the side wall 24 is set to be approximately equal to the inner diameter of the high-frequency electrode support portion 23 .
An insulating member 25 is provided at the upper end of the side wall 24 along its inner circumferential surface 24a.

The insulating member 25 is exposed on the inner circumferential surface 24a of the side wall 24 at a position corresponding to the deposition space 2a where the plasma P is formed. Specifically, on the inner circumferential surface 24a of the side wall 24, it has a height corresponding to the distance from the lower end of the insulating flange 81 (described later) to the upper surface of the substrate insulating cover 82 during plasma processing.

The thickness dimension of the insulating member 25, that is, the dimension in the radial direction of the vacuum chamber 2, is not particularly limited as long as it is capable of insulating the side wall 24 during plasma generation.
The upper end of the insulating member 25 is located at the same height as the upper end of the side wall 24. The lower end of the insulating member 25 is not particularly limited as long as it reaches a conductive band portion 35 of the capacitor formation portion 30, which will be described later. The inner circumferential surface of the insulating member 25 is set so as to be flush with the inner circumferential surface 24a of the side wall 24 where the insulating member 25 is not present.

An insulating flange 81 contacts the upper end of the side wall 24 , the insulating member 25 , and the radially inner side of the high-frequency electrode support portion 23 .
The insulating flange 81 has a radial dimension smaller than that of the side wall 24. The radial cross section of the insulating flange 81 is formed into a substantially Z-shape. That is, the insulating flange 81 contacts the upper end of the side wall 24, the insulating member 25, and the radial inside of the high-frequency electrode support part 23, and has a frame part 81b extending parallel to the side wall 24.

An upper insulating flange portion 81c protruding radially outward is provided at an upper end of the frame portion 81b of the insulating flange 81. A lower insulating flange portion 81a protruding radially inward is provided at a lower end of the frame portion 81b of the insulating flange 81.
The upper insulating flange portion 81 c is in contact with the upper end of the high-frequency electrode support portion 23 to support the insulating flange 81 .

The lower end of the electrode flange 4 and the shower plate 5 are in contact with the radially inner sides of the lower insulating flange portion 81a and the frame portion 81b.
The radially inner contour of the lower insulating flange portion 81a limits the range of the electrode flange 4 and the shower plate 5 exposed to the film formation space 2a. The lower insulating flange portion 81a functions as an electrode insulating cover.

The electrode flange 4 has an upper plate 41 and a peripheral wall 43 .
The electrode flange 4 is disposed so that the opening of the peripheral wall 43 is positioned below the substrate 10 in the vertical direction.

The shower plate 5 is attached to the opening formed by the lower end of the peripheral wall 43. The upper plate 41 and the shower plate 5 are spaced apart in the vertical direction and arranged approximately parallel to each other. This forms a space 14 between the electrode flange 4 and the shower plate 5.

An upper plate 41 of the electrode flange 4 faces the shower plate 5. The upper plate 41 is provided with a gas inlet .
Furthermore, a gas introduction pipe 7 is provided between a process gas supply unit 21 provided outside the processing chamber 101 and the gas introduction port 42 .

One end of the gas introduction pipe 7 is connected to the gas introduction port 42. The other end of the gas introduction pipe 7 is connected to the process gas supply unit 21.
The gas introduction pipe 7 passes through a shield cover 13, which will be described later. A process gas is supplied from a process gas supply unit 21 to the space 14 through the gas introduction pipe 7.

The space 14 functions as a gas introduction space into which a process gas is introduced.
The shower plate 5 has a plurality of gas outlets 6 formed therein.
The process gas introduced into the space 14 is ejected from the gas ejection port 6 into the film formation space 2 a in the vacuum chamber 2 .

The electrode flange 4 and the shower plate 5 are each made of a conductive material.
A shield cover 13 is provided around the electrode flange 4 so as to cover the electrode flange 4 .
The shield cover 13 is not in contact with the electrode flange 4. The shield cover 13 is arranged so as to be electrically connected to the vacuum chamber 2.

A high frequency power source (RF power source) 9 provided outside the vacuum chamber 2 is connected to the electrode flange 4 via a matching box 12 .
The matching box 12 is attached to a shield cover 13 .
The electrode flange 4 and the shower plate 5 are configured as a cathode electrode. The vacuum chamber 2 is grounded via a shield cover 13.

The susceptor (support) 15 is a plate-like member having a flat surface. The substrate 10 is placed on the upper surface of the susceptor 15. The susceptor 15 is formed such that the normal direction of the substrate 10 placed thereon is parallel to the axis of the support 16.
The susceptor 15 may have a built-in heater. The susceptor 15 may be capable of controlling the heating and adjusting the temperature of the substrate 10 placed thereon by the heater.

The susceptor 15 functions as a ground electrode, i.e., an anode electrode. For this reason, the susceptor 15 is made of a metal having electrical conductivity. For example, the susceptor 15 is made of aluminum, an aluminum alloy, or the like.

The susceptor 15 is made of aluminum or an aluminum alloy whose surface is anodized.
When the substrate 10 is placed on the susceptor 15, the substrate 10 and the shower plate 5 are positioned close to each other and parallel to each other.

When a process gas is ejected from the gas ejection port 6 while the substrate 10 is placed on the susceptor 15 , the process gas is supplied to the space above the processing surface 10 a of the substrate 10 .
A heater wire (not shown) is provided inside the susceptor 15. The temperature of the susceptor 15 is adjusted to a predetermined temperature by the heater wire.

The heater wire protrudes downward from the rear surface of the susceptor 15 at approximately the center thereof when viewed vertically from the susceptor 15 .
The heater wire is inserted through through-holes formed in the approximate center of the susceptor 15 and in the support 16 , and is led to the outside of the vacuum chamber 2 .

The heater wire is connected to a power source (not shown) outside the vacuum chamber 2 .
The heater wire adjusts the temperature of the susceptor 15 and the substrate 10 according to the power supplied from the power source.

A substrate insulating cover (insulating member) 82 is provided around the upper surface of the susceptor 15 at a position adjacent to the outer side in the radial direction of the substrate 10 .
The substrate insulating cover 82 is disposed around the entire periphery of the substrate 10. The thickness dimension of the substrate insulating cover 82 is made larger than the thickness dimension of the substrate 10. In other words, the height of the substrate insulating cover 82 can protrude upward beyond the processing surface 10a of the substrate 10.

Alternatively, the height of the substrate insulating cover 82 may be the same as the processing surface 10a of the substrate 10. Alternatively, the height of the substrate insulating cover 82 may be lower than the processing surface 10a of the substrate 10.
The inner peripheral contour of the substrate insulating cover 82 and the outer peripheral contour of the shower plate 6 exposed to the reaction chamber 2a have corresponding shapes. That is, the inner peripheral contour of the substrate insulating cover 82 and the outer peripheral contour of the shower plate 6 exposed to the reaction chamber 2a coincide with each other in a plan view or are disposed in the vicinity of each other.

A transfer section 26 (transfer entrance) used for transferring the substrate 10 in and out is formed on a side wall 24 of the vacuum chamber 2 .
A door valve 26a for opening and closing the load/unload section 26 is provided on the outer surface of the side wall 24 of the vacuum chamber 2. The door valve 26a is slidable in the vertical direction.

When the door valve 26a slides downward (towards the bottom 11 of the vacuum chamber 2), the loading/unloading section 26 is opened and a substrate transport section such as a robot hand can be inserted from the loading/unloading section 26 to load or unload the substrate 10.
On the other hand, when the door valve 26a slides upward (towards the electrode flange 4), the loading/unloading section 26 is closed, and the substrate 10 can be processed (plasma processed).

Fig. 2 is an enlarged cross-sectional view for explaining a capacitor forming portion of the plasma processing apparatus in this embodiment. Fig. 3 is a plan view of a susceptor for explaining the capacitor forming portion of the plasma processing apparatus in this embodiment.
As shown in FIGS. 1 to 3, a capacitor forming portion 30 is formed on the side peripheral surface 15a of the susceptor 15.
As shown in FIGS. 1 to 3, a capacitor formation portion 30 is formed on the inner circumferential surface 24a of the side wall 24 of the vacuum chamber 2.

The capacitor forming portion 30 is formed by providing a conductive band portion 31 around the circumferential side surface 15 a of the susceptor 15 at a position close to the radially outer side of the substrate insulating cover 82 .
The conductive band portion 31 is provided continuously or discontinuously around the entire circumference of the susceptor 15 .
The conductive band portion 31 is provided with a substantially uniform width, that is, an equal width, over the entire circumference of the susceptor 15. In other words, the conductive band portion 31 has the same vertical dimension (width) over the entire circumference of the susceptor 15.
The width of the conductive band portion 31 is approximately the same as the thickness of the susceptor 15 or is smaller than the thickness of the susceptor 15 .

The conductive band portion 31 is provided continuously around the entire circumference of the susceptor 15. The conductive band portion 31 is disposed on the side peripheral surface 15a, which is a vertical surface.
The conductive band portion 31 is provided parallel to the upper and lower surfaces of the susceptor 15 on the peripheral side surface 15a of the susceptor 15, which has a circular contour in a plan view.
The conductive band portion 31 is provided at the same height over the entire circumference of the side circumferential surface 15a, which is a substantially cylindrical surface.
The conductive band portion 31 is provided around the entire periphery of the susceptor 15 in contact with the lower portion of the outer edge of the substrate insulating cover 82 .

The conductive band portion 31 is provided in parallel to the side peripheral surface 15a of the susceptor 15 over the entire circumference of the susceptor 15. The conductive band portion 31 extends in the vertical direction over the entire circumference of the susceptor 15, similar to the side peripheral surface 15a which forms the outer contour of the susceptor 15 extending in the vertical direction.
In plan view, the conductive band portion 31 and the outer contour of the susceptor 15 match over the entire periphery of the susceptor 15 .

On the side peripheral surface 15 a of the susceptor 15 , the distance between the conductive band portion 31 and the outer edge of the substrate insulating cover 82 is set equal over the entire circumference of the susceptor 15 .
On the side peripheral surface 15 a of the susceptor 15 , there is an area between the conductive band portion 31 and the substrate insulating cover 82 where the insulating member 33 is formed.

The insulating member 33 is provided continuously on the side peripheral surface 15 a of the susceptor 15 up to the area below the substrate insulating cover 82 .
The insulating member 33 is provided around the edge of the upper surface of the susceptor 15. The insulating member 33 is formed along the outer contour of the susceptor 15 over the entire circumference of the susceptor 15. The insulating member 33 is located outside the inner peripheral contour of the substrate insulating cover 82 in the radial direction of the susceptor 15.
On the side peripheral surface 15 a of the susceptor 15 , a portion where the conductive material is exposed and where the insulating member 33 is not formed is defined as a conductive band portion 31 .

An insulating film 32 may be formed on the upper surface of the susceptor 15 , which is located radially inward of the insulating member 33 .
Between the conductive band portion 31 and the substrate insulating cover 82 , there may be an area covered with the insulating film 32 .
The insulating film 32 may be provided continuously up to the area below the substrate insulating cover 82 .

The back surface of the susceptor 15 closer to the bottom portion 11 than the conductive band portion 31 may be covered with an insulating film.
The insulating member 33 may be formed continuously with the substrate insulating cover 82 as long as it covers the upper side of the side peripheral surface 15 a of the susceptor 15 .
Both the insulating film 32 and the insulating member 33 can be made of an insulator such as ceramic.

Furthermore, the lower side of the side surface 15a of the susceptor 15, which is closer to the bottom 11 than the conductive band portion 31, may be covered with an insulating film. In this case, the width dimension of the conductive band portion 31 can be reduced.

The insulating film 32 and the insulating member 33 may be made of anodized aluminum alloy or the like.
In the drawing, the thickness dimension of the insulating member 33 is illustrated as being greater than the thickness dimension of the insulating film 32, but this is not intended to be limiting.
The thickness of the insulating film 32 and the thickness of the insulating member 33 may be the same value. Here, the thickness of the insulating member 33 refers to the normal direction of the side peripheral surface 15a of the susceptor 15.
The substrate insulating cover 82, the insulating film 32 and the insulating member 33 constitute an insulating member.

The conductive band portion 31 is formed by exposing the conductive material on the side peripheral surface 15 a of the susceptor 15 without the insulating member 33 formed at an upper position thereon.
The conductive band portion 31 is formed on the side peripheral surface 15 a of the susceptor 15 so as to be flush with the side peripheral surface of the insulating member 33 .
The conductive band portion 31 is formed on the side peripheral surface 15a of the susceptor 15 so as to be flush with the side peripheral surface of the substrate insulating cover 82. Alternatively, the conductive band portion 31 may be recessed on the side peripheral surface 15a of the susceptor 15 from the side peripheral surface of the substrate insulating cover 82.

The capacitor forming portion 30 includes a conductive band portion 35 provided around the inner circumferential surface 24 a of the sidewall (wall portion) 24 of the vacuum chamber 2 at a position facing the conductive band portion 31 of the susceptor 15 .
The conductive band portion 35 corresponds to the conductive band portion 31 and is provided over the entire circumference of the inner circumferential surface 24a.
The conductive band portion 35 is provided with a uniform width around the entire circumference of the inner circumferential surface 24a.

Similar to the conductive band portion 31, the conductive band portion 35 is provided continuously around the entire circumference of the inner circumferential surface 24a.
Similar to the conductive band portion 31, the conductive band portion 35 is formed in a circular shape that coincides with or is concentric with the contour of the inner circumferential surface 24a, which is concentric with the contour of the susceptor 15, which is circular in plan view.
The conductive band portion 35 is provided on the inner peripheral surface 24a, which is a substantially cylindrical surface, having a larger diameter than the conductive band portion 31 formed on the side peripheral surface 15a, which is a substantially cylindrical surface.
The conductive band portion 35 is provided at the same height over the entire circumference of the inner circumferential surface 24a, which is a substantially cylindrical surface.
The conductive band portions 35 are disposed parallel to the upper and lower surfaces of the susceptor 15 .
The conductive band portion 35 is provided around the entire circumference of the inner circumferential surface 24 a and is spaced apart from the side circumferential surface 15 a which defines the contour of the susceptor 15 .

The conductive band portion 35 is provided with a uniform width over the entire circumference of the inner circumferential surface 24a. That is, the conductive band portion 35 has a uniform vertical dimension (width dimension) over the entire circumference of the inner circumferential surface 24a.
The width dimension of the conductive band portion 35 is set to be larger than the width dimension of the conductive band portion 31. This is to ensure a width dimension that allows the conductive band portion 35 to maintain a position facing the conductive band portion 31 even when the susceptor 15 moves up and down in a plasma generation state.
When the susceptor 15 moves up and down in a plasma formation state, the upper end of the conductive band portion 35 is located higher than the upper end position of the conductive band portion 31 at the upper limit position, and the lower end of the conductive band portion 35 is located lower than the lower end position of the conductive band portion 31 at the lower limit position.

A region 36 exists on the inner circumferential surface 24 a of the side wall 24 located above the upper end of the conductive band portion 35 .
A region 37 exists on the inner circumferential surface 24 a of the side wall 24 located below the lower end of the conductive band portion 35 .

The region 36 continues up to a position where the inner circumferential surface 24 a of the side wall (wall portion) 24 contacts the lower end of the insulating member 25 .
Region 36 is, for example, a position on inner circumferential surface 24 a that faces the side circumferential surface of insulating member 33 and a part of the side circumferential surface of board insulating cover 82 .

Region 37 continues to the back surface of susceptor 15 on inner surface 24a of side wall (wall portion) 24, or to a position below the lower end of side surface 15a at the lower limit position of susceptor 15 when susceptor 15 moves up and down during plasma generation.
The region 37 is, for example, a region on the side circumferential surface 15a below a position facing the lower end of the conductive band portion 31 in a plasma generating state.

The region 37 continues up to a position where it contacts the lower end of the inner circumferential surface 24 a of the side wall (wall portion) 24 .
The regions 36 and 37 are both flush with and continuous with the conductive band portion 35. The conductive band portion 35, the regions 36, and the regions 37 are located on the inner circumferential surface 24a below the insulating member 25.

That is, an inner peripheral surface 24a of the side wall (wall portion) 24 below the insulating member 25 has a conductor, for example, aluminum, exposed over the entire surface.
The conductive band portion 35 has a range defined as a surface of the capacitor formation portion 30 facing the conductive band portion 31 .
In other words, the conductive band portion 35 faces the conductive band portion 31 and is formed on the inner circumferential surface 24 a.

The distance (gap) G between the conductive band portion 31 and the conductive band portion 35 is set equal over the entire circumference of the side peripheral surface 15a and the inner peripheral surface 24a.
The distance (gap) G between the conductive band portions 31 and 35 is set approximately uniform over the entire circumferential length of the conductive band portions 31 and 35 around the entire side surface 15a and inner surface 24a.
The distance (gap) G between the conductive band portion 31 and the conductive band portion 35 means the distance between the conductive band portion 31 and the conductive band portion 35 in the radial direction of the vacuum chamber 2 .

Next, the operation of forming a film on the processing surface 10a of the substrate 10 using the plasma processing apparatus 1 will be described.
FIG. 4 is a cross-sectional view for explaining a high-frequency return current of the plasma processing apparatus in this embodiment.

First, the vacuum chamber 2 is depressurized using the vacuum pump 28. With the vacuum chamber 2 maintained at a vacuum, the door valve 26a is opened, and the substrate 10 is transferred from outside the vacuum chamber 2 to the film formation space 2a via the transfer section 26 of the vacuum chamber 2. The substrate 10 is placed on the susceptor 15. The substrate 10's position on the susceptor 15 is determined by the substrate insulating cover 82.

After the substrate 10 is carried in, the door valve 26a is closed (closing operation).
Before the substrate 10 is placed, the susceptor 15 is located at the lower part within the vacuum chamber 2 .
Before the substrate 10 is placed on the susceptor 15, the susceptor 15 is located below the load/unload section 26. In other words, the distance between the susceptor 15 and the shower plate 5 is wide, so that the substrate 10 can be easily placed on the susceptor 15 by using a robot arm (not shown).

After the substrate 10 is placed on the susceptor 15, the lifting drive unit 16A is driven to raise the support column 16. The susceptor 15 at the upper end of the support column 16 also moves upward. The substrate 10 placed on the susceptor 15 pushed upward also moves upward. This allows the distance between the shower plate 5 and the substrate 10 to be set to a desired value necessary for appropriate film formation, and this distance is maintained.
At this time, the insulating member 25 is located outside the insulating flange 81 and the substrate insulating cover 82 in the radial direction of the vacuum chamber 2 .

When the susceptor 15 is raised, the side peripheral surface 15a of the susceptor 15 and the inner peripheral surface 24a of the side wall (wall portion) 24 are maintained in a spaced apart state.
Furthermore, when the susceptor 15 stops rising, the conductive band portion 31 on the side peripheral surface 15 a of the susceptor 15 faces the conductive band portion 35 on the inner peripheral surface 24 a of the side wall (wall portion) 24 .

At this time, at least the upper end of the conductive band portion 31 is located lower than the upper end of the conductive band portion 35, and the lower end of the conductive band portion 31 is located higher than the lower end of the conductive band portion 35. In other words, the entire area of the conductive band portion 31 faces the conductive band portion 35.

Furthermore, the gap G between the conductive band portion 31 on the side surface 15a of the susceptor 15 and the conductive band portion 35 on the inner surface 24a of the side wall (wall portion) 24 is determined to a desired value so as to be the required spacing to form a capacitor in the path of the high-frequency return current described below, and this spacing is maintained.

Specifically, the gap G between the conductive band portion 31 of the susceptor 15 and the conductive band portion 35 of the sidewall 24 is set to a range of about 0.1 mm to 10 mm, more preferably, a range of about 1 mm to 8 mm, or a range of about 2 mm to 5 mm, i.e., a narrow gap.

On the side surface 15a of the susceptor 15 and the inner surface 24a of the side wall (wall portion) 24, the conductive band portion 31 and the conductive band portion 35 are formed in positions that are concentric with each other in a plan view. Therefore, a capacitor is formed in the path of the high-frequency return current along the outer periphery of the susceptor 15.

Here, the value of the capacitor serving as capacitor-forming portion 30 is set by the area of conductive band portion 31 and conductive band portion 35 which serve as opposing electrodes, and the value of gap G between conductive band portion 31 and conductive band portion 35 .
The area of the conductive band portion 31 and the conductive band portion 35, which are the opposing electrodes, is determined by the area of the conductive band portion 31, which is the exposed conductive material. Since the area of the conductive band portion 35 is larger than the area of the conductive band portion 31, the value of the capacitor is not set by the area of the conductive band portion 35.
In other words, the value of the capacitor is determined by the area of the conductive band portion 31 .

Here, since the conductive band portion 31 and the conductive band portion 35 are formed around the entire circumference of the susceptor 15, the area of the conductive band portion 31 as an opposing electrode is determined by the width dimension W of the conductive band portion 31 in the vertical direction (lifting direction).
Specifically, the width W in the vertical direction of the conductive band portion 31 is set in the range of about 20 mm to 120 mm, and more preferably, in the range of about 60 mm to 80 mm.
The above-mentioned ranges of gap G and width W are values when processing silicon wafers or the like, that is, when performing plasma processing of substrates 10 having a diameter of about Φ200 mm to Φ300 mm to Φ450 mm.

This allows the capacitors necessary for proper film formation to be formed all around the outer periphery of the susceptor 15.

The capacitor formed between the conductive band portion 31 and the conductive band portion 35 has a uniform value all along the outer periphery of the susceptor 15 .
Therefore, a uniform high-frequency return current can be generated all around the outer periphery of the susceptor 15 .

Moreover, the formation of the capacitor over the entire circumference of the susceptor 15 can be easily performed by simply setting the elevation position of the susceptor 15 by the elevation drive unit 16A.
Here, the portion of the side circumferential surface 15 a on the upper side of the conductive band portion 31 that faces the conductive band portion 35 is covered with an insulating member 33 .

Therefore, a capacitor can be reliably formed around the entire periphery of the susceptor 15 .
At the same time, a capacitor of uniform value can be reliably formed around the entire circumference of the susceptor 15 .

Then, the process gas is introduced from the process gas supply unit 21 into the space 14 via the gas introduction pipe 7 and the gas introduction port 42. Then, the process gas is ejected from the gas ejection port 6 of the shower plate 5 into the film formation space 2a.

Next, the high frequency power supply 9 is started to apply high frequency power to the electrode flange 4 .
Then, a high-frequency current flows from the surface of the electrode flange 4 along the surface of the shower plate 5, and a discharge occurs between the shower plate 5 and the susceptor 15. Then, a plasma P is generated between the shower plate 5 and the processing surface 10a of the substrate 10.

The process gas is decomposed in the plasma P thus generated, obtaining a process gas in a plasma state, and a vapor phase growth reaction occurs on the processing surface 10a of the substrate 10, forming a thin film on the processing surface 10a.
The high frequency current transmitted to the susceptor 15 flows through the capacitor forming portion 30 to the side wall (wall portion) 24 and the inner peripheral surface of the high frequency electrode supporting portion 23 (FIG. 4).
The high frequency current then returns through the shield cover 13 (return current).

At this time, the high frequency return current is not returned from the capacitor forming portion 30 to the side wall (wall portion) 24 of the vacuum chamber 2 below the conductive band portion 35 .
In other words, regardless of the presence or absence of the load/unload section 26 in the vacuum chamber 2 , the high frequency return current is not returned via the bottom 11 and the side wall 24 of the vacuum chamber 2 .

Therefore, the path of the high-frequency return current can be reduced, and the inductance can be reduced over the entire circumference of the susceptor 15 .
Furthermore, the length of the path of the high frequency return current can be made equal over the entire circumference of the susceptor 15. In other words, the inductance in the path of the high frequency return current can be made equal over the entire circumference of the susceptor 15.

Moreover, the capacitor-forming portion 30 does not have reactance via a conductor, as in the earth plate of Patent Documents 1 and 2, in the path of the high-frequency return current, so it is possible to reduce inductance.

In the plasma processing apparatus 1 of this embodiment, a gap G with a very small separation distance of about a few millimeters is formed between the side surface 15a of the susceptor (support portion) 15 and the inner surface 24a of the side wall (wall portion) 24, so that the opposing conductive band portions 31 and 35 can form a capacitor as a path for the high-frequency return current.

At this time, when plasma is formed, the path of the high-frequency return current returning to the matching box 12 can be the susceptor 15, the capacitor forming portion 30, the conductive band portion 31 on the side surface 15a of the susceptor 15, the conductive band portion 35 on the inner surface 24a of the side wall (wall portion) 24, the side wall (wall portion) 24, the high-frequency electrode support portion 23, and the shield cover 13.

This allows the path of the high-frequency return current to be shorter than if it were to pass through the bottom 11 of the vacuum chamber 2. Therefore, the inductance in the path of the high-frequency return current can be reduced.

At the same time, simply by setting the height of the susceptor 15 using the lifting and lowering drive unit 16A, it is possible to form the gap G and width dimension W between the conductive band portion 31 on the side surface 15a of the susceptor 15 and the conductive band portion 35 on the inner surface 24a of the side wall (wall portion) 24 as the capacitor forming unit 30 to a uniform width dimension around the entire circumference of the susceptor 15. As a result, the high-frequency return current path is formed evenly in the circumferential direction of the susceptor 15.

This makes it possible to suppress non-uniformity of the electric field gradient in the circumferential direction of the susceptor 15, and to maintain a uniform distribution of the plasma processing characteristics, that is, the film formation characteristics.
Therefore, when plasma is generated, abnormal discharge in the loading/unloading section 26 and the like can be prevented, and the high frequency voltage that can be applied to the electrode flange 4 can be increased.

At the same time, since the loading/unloading section 26 does not affect the path of the high-frequency return current, the path of the high-frequency return current is formed evenly in the circumferential direction of the susceptor 15.

The insulating member 25 at the upper end of the inner surface 24a of the side wall 24, the lower end of the insulating flange 81, the lower surface of the shower plate 5, the upper surface of the substrate insulating cover 82, and the processing surface 10a of the substrate 10 surround the film formation space 2a in which the plasma P is formed during plasma processing.

In this way, the insulating member 25 and the high-frequency electrode support part 23 are arranged around the film formation space 2a, and further, the insulating member 33 is arranged on the susceptor 15, so that the plasma P can be prevented from going around to approach the capacitor formation part 30. Therefore, the generated plasma P can be prevented from reaching the vicinity of the capacitor formation part 30 where the conductor is exposed.

This prevents the occurrence of abnormal discharge, achieves a stable high-frequency return, and ensures the stability of the generated plasma P. This improves the uniformity of the film formation characteristics.

In this configuration, the side surface 15a of the susceptor 15 does not come into contact with the inner surface 24a of the side wall (wall portion) 24, and there are no movable parts other than the support 16 driven by the lifting and lowering drive unit 16A inside the processing chamber 101, so it is possible to prevent the generation of particles (dust) and the like. This makes it possible to prevent the film formation characteristics from deteriorating.

A gap G is defined between the side surface 15a of the susceptor 15 and the inner surface 24a of the side wall (wall portion) 24, and this gap does not change with the vertical movement of the susceptor 15, making it possible to accurately control this gap G.

Furthermore, when the susceptor 15 is raised and lowered by the lifting drive unit 16A, the conductive band portion 31 and the conductive band portion 35 do not come into contact with each other, so that fluctuations in the capacitor due to changes in the surface condition of the conductive band portion 31 and the conductive band portion 35 can be prevented.

Furthermore, by forming a conductive band portion 31 as a capacitor forming portion 30 on the side peripheral surface 15a of the susceptor 15, only the substrate 10 and the substrate insulating cover 82 are present on the upper surface of the susceptor 15, so it is possible to easily form a capacitor that serves as a path for the high-frequency return current without reducing the size of the substrate 10.

A second embodiment of the plasma processing apparatus according to the present invention will now be described with reference to the drawings.
Fig. 5 is a cross-sectional view showing the plasma processing apparatus of this embodiment, and Fig. 6 is a plan view showing the plasma processing apparatus of this embodiment. This embodiment differs from the first embodiment described above in terms of the lifting and lowering drive unit, and other configurations corresponding to those of the first embodiment described above are denoted by the same reference numerals and description thereof will be omitted.

As shown in FIGS. 5 and 6, the plasma processing apparatus 1 of this embodiment has a structure for driving a susceptor 15 to move up and down, and a susceptor 16 has supports 16a, 16b, and 16c.
The pillars 16a, 16b, and 16c are arranged to stand parallel to each other. The pillars 16a, 16b, and 16c are arranged to stand apart from each other.

The susceptor (support) 15 is connected to the upper tip of each of the pillars 16a, 16b, and 16c. The pillars 16a, 16b, and 16c are all positioned equidistant from the center of the susceptor 15. Specifically, in a plan view, the centers of the pillars 16a, 16b, and 16c are located on a circle concentric with the susceptor 15. The pillars 16a, 16b, and 16c are positioned equidistant from each other.

The pillars 16a, 16b, and 16c move up and down as one unit. The pillars 16a, 16b, and 16c are driven as one unit by the lift drive unit 16A. Note that in the figure, the pillars 16a, 16b, and 16c are all shown as being driven by the lift drive unit 16A, but it is also possible to configure the structure so that only one is driven by the lift drive unit 15A and the other two function as guides to maintain the position of the susceptor 15.

The pillars 16a, 16b, and 16c are positioned as close as possible to the edge of the susceptor 15. This makes it easier to control the posture of the susceptor 15 using the pillars 16a, 16b, and 16c.

Here, controlling the posture of the susceptor 15 by the supports 16a, 16b, and 16c means that the upper surface of the susceptor 15 on which the substrate 10 is placed remains horizontal when the susceptor 15 is moved up and down by the lift drive unit 16A. At the same time, it means that the distance between the side peripheral surface 15a of the susceptor 15 and the inner peripheral surface 24a of the side wall 24 of the vacuum chamber 2 is maintained constant when the susceptor 15 is moved up and down by the lift drive unit 16A. Alternatively, it means that the center position of the susceptor 15 does not move when viewed from above when the susceptor 15 is moved up and down by the lift drive unit 16A.

The pillars 16 a , 16 b , and 16 c are all inserted into openings formed in the bottom (inner bottom surface) 11 of the vacuum chamber 2 .
Bellows (not shown) are provided to cover the outer periphery of the lower end side of the pillars 16a, 16b, and 16c outside the vacuum chamber 2. The bellows keeps the film formation space 2a sealed when the pillars 16a, 16b, and 16c move up and down.

In this embodiment, among the pillars 16a, 16b, and 16c, the pillars 16a, 16b, and 16c function as drive pillars driven by the elevation drive unit 16A and as attitude control pillars that maintain the elevation attitude of the susceptor (support unit) 15.
The lifting drive unit 16A can be said to have a drive column and a position control column. Here, it is meaningless to distinguish which of the columns 16a, 16b, and 16c is the drive column and which is the position control column.

In this embodiment, the three pillars 16a, 16b, and 16c enable the posture control of the susceptor 15 when the susceptor 15 is moved up and down by the lift drive unit 16A. Therefore, when the susceptor 15 is moved up and down, the separation distance G between the side surface 15a of the susceptor (support unit) 15 and the inner surface 24a of the side wall 24 of the vacuum chamber 2 can be maintained constant.

Therefore, the distance G between the conductive band portion 31 formed around the entire side surface 15a of the susceptor (support portion) 15 and the conductive band portion 35 formed on the inner surface 24a of the side wall 24 of the vacuum chamber 2 can be maintained constant.
This makes it possible to raise and lower the support portion (susceptor) while maintaining the gap G, which is a factor for setting the capacitor value, in the capacitor forming portion 30 where the capacitor is formed.

And even if the plasma formation conditions require the height position of the susceptor (support) 15 to be changed, it is possible to maintain the capacitor value within an appropriate range. Therefore, it is possible to maintain an approximately equal inductance in the circumferential direction of the substrate 10, regardless of the height position of the susceptor (support) 15.

This embodiment can achieve the same effects as the above-mentioned embodiment.

The third embodiment of the plasma processing apparatus according to the present invention will be described below with reference to the drawings.

FIG. 7 is an enlarged cross-sectional view showing a capacitor forming portion in the plasma processing apparatus of this embodiment.
This embodiment differs from the first and second embodiments described above in terms of the capacitor formation section 30. The other corresponding components are denoted by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 7 , in the capacitor formation portion 30 of this embodiment, an insulating film 36 a and an insulating film 37 a are formed on the inner circumferential surface 24 a of the side wall (wall portion) 24 of the vacuum chamber 2 in a position adjacent to the conductive band portion 35.
The insulating film 36 a is provided on the inner circumferential surface 24 a between the conductive band portion 35 and the lower end of the insulating member 25 .
The insulating film 36a is formed on the inner circumferential surface 24a so as to cover the region 36 in the first embodiment.
The insulating film 36 a may be formed integrally with the insulating member 25 .

The insulating film 37 a is provided on the inner circumferential surface 24 a which is closer to the bottom (inner bottom surface) 11 of the vacuum chamber 2 than the conductive band portion 35 .
The insulating film 37a is formed on the inner circumferential surface 24a so as to cover the region 37 in the first embodiment.

The upper end of the insulating film 37a extends to the boundary with the conductive band portion 35 and covers the inner circumferential surface 24a.
The lower end of the insulating film 37 a may be provided continuously up to a position where it contacts the bottom (inner bottom surface) 11 of the vacuum chamber 2 on the inner circumferential surface 24 a.

The insulating film 37a may be provided continuously above the position where it contacts the bottom (inner bottom surface) 11 of the vacuum chamber 2. In this case, the insulating film 37a only needs to be continuous below the lower end of the side peripheral surface 15a of the susceptor 15 that is located at a lower height position close to the load/unload section 26 (load/unload entrance) for transporting the substrate 10.

The insulating film 36a and the insulating film 37a are both made of an insulator.
The insulating films 36a and 37a may be made of anodized aluminum alloy or the like.
The insulating film 36a and the insulating film 37a have the same thickness.
The insulating films 36a and 37a form an insulating member.

The inner circumferential surfaces 24a adjacent to each other in the vertical direction of the conductive band portion 35 are covered with an insulating film 36a and an insulating film 37a.
The conductive band portion 35 is formed by removing the insulating films 36 a and 37 a formed on the entire area of the inner circumferential surface 24 a of the wall portion (side wall) 24 of the vacuum chamber 2 .

In addition, if plasma processing causes a film-forming material to adhere to the conductive material exposed as the conductive band portion 35, or if an insulating film, oxide film, etc. is formed, it is possible to re-form the conductive band portion 35 as the desired capacitor formation portion 30 by removing the deposits or the deposited film such as an insulating film or oxide film from a specified area on the inner surface 24a.
In particular, a maintenance process or the like may include a re-forming process in which the film on the inner circumferential surface 24a is removed and the conductive band portion 35 is re-formed.

The conductive band portion 35 is recessed more than the insulating film a36 and the insulating film 37a on the inner circumferential surface 24a of the wall portion (side wall) 24. In other words, the conductive band portion 35 is farther away from the side circumferential surface 15a of the susceptor 15 on the inner circumferential surface 24a of the wall portion (side wall) 24 than the insulating film a36a and the insulating film 37a.
The thickness of the insulating films 36a and 37a, that is, the recessed dimension of the conductive band portion 35, can be set to 0.1 mm to 1 mm.

In the present embodiment, the capacitor forming portion 30 can form a capacitor in the path of the high-frequency return current by the conductive band portion 31 and the conductive band portion 35 opposite the conductive band portion 31, similar to the first embodiment.

This embodiment can achieve the same effects as the above-mentioned embodiment.

The fourth embodiment of the plasma processing apparatus according to the present invention will be described below with reference to the drawings.

FIG. 8 is an enlarged cross-sectional view showing a capacitor forming portion in the plasma processing apparatus of this embodiment.
This embodiment differs from the first to third embodiments described above in terms of the capacitor formation section 30. The other corresponding components are given the same reference numerals and the description thereof will be omitted.

As shown in FIG. 7, the capacitor formation portion 30 in this embodiment has an insulating film 33 a and an insulating film 33 b formed on the side circumferential surface 15 a of the susceptor 15 at a position adjacent to the conductive band portion 31 .
The insulating film 33 a is provided on the side peripheral surface 15 a between the conductive band portion 31 and the lower end of the board insulating cover 82 .
The insulating film 33a may be continuous with the insulating film 32 formed on the upper surface of the susceptor 15. In this case, the insulating member 33 may not be provided. Alternatively, the insulating film 33a may be formed integrally with the insulating member 33.

The insulating film 33 b is provided on the side circumferential surface 15 a closer to the lower surface of the susceptor 15 than the conductive band portion 31 .
The upper end of the insulating film 33 b extends to the boundary with the conductive band portion 31 and covers the side circumferential surface 15 a.
The lower end of the insulating film 33 b is provided continuously on the side peripheral surface 15 a up to a position where it contacts the lower surface of the susceptor 15 .
Although not shown, an insulating film may be provided on the lower surface of the susceptor 15. In this case, the insulating film may be provided on the lower surface of the susceptor 15 only in the area adjacent to the side peripheral surface 15a.

The insulating films 33a and 33b are both made of an insulator.
The insulating films 33a and 33b may be made of anodized aluminum alloy or the like.
The insulating films 33a and 33b have the same thickness.
The insulating films 33a and 33b form an insulating member.

The vertically adjacent side circumferential surfaces 15a of the conductive band portion 31 are covered with an insulating film 33a and an insulating film 33b.
The conductive band portion 31 is formed by peeling off the insulating film 33 a and the insulating film 33 b formed on the entire region of the side peripheral surface 15 a of the susceptor 15 .

In addition, if plasma processing causes a film-forming material to adhere to the conductive material exposed as the conductive band portion 31, or if an insulating film, oxide film, etc. is formed, it is possible to re-form the conductive band portion 31 as the desired capacitor-forming portion 30 by removing the deposits or the deposited film such as an insulating film or oxide film from a specified area on the side surface 15a.
In particular, a maintenance process or the like may include a re-forming process in which the film on the side peripheral surface 15a is removed and the conductive band portion 31 is re-formed.

The conductive band portion 31 is recessed relative to the insulating films 33a and 33b on the side peripheral surface 15a of the susceptor 15. In other words, the conductive band portion 31 is farther away from the inner peripheral surface 24a of the wall portion (side wall) 24 on the side peripheral surface 15a of the susceptor 15 than the insulating films 33a and 33b.
The thickness of the insulating films 33a and 33b, that is, the recessed dimension of the conductive band portion 31, can be set to 0.1 mm to 1 mm.

In the present embodiment, the capacitor forming portion 30 can form a capacitor in the path of the high-frequency return current by the conductive band portion 31 and the conductive band portion 35 opposite the conductive band portion 31, similar to the first embodiment.

This embodiment can achieve the same effects as the above-mentioned embodiment.

In each of the above embodiments, the conductive band portion 31 is formed in the shape of a single line, but the capacitor formation portion 30 may be formed by combining a plurality of lines.
In each of the above embodiments, the conductive band portion 31 is formed in a continuous line shape around the entire circumference of the susceptor, but it may be divided in the circumferential direction of the susceptor 15. In this case, the conductive band portion 35 formed on the inner peripheral surface 24a of the side wall 24 may also be arranged to be divided in the circumferential direction or broken in the circumferential direction.

Furthermore, if the thickness dimension of the susceptor 15 is large, the width dimension W of the conductive band portion 31 can be set to be larger than the width dimension of the conductive band portion 35. In this case, the conductive band portion 35 acts to set the capacitor value in the capacitor forming portion 30.

In the above embodiments, the outline shape of the substrate 10 and the susceptor 15 in plan view has been described as being circular, but they may have a rectangular outline. In this case, it is preferable to have a lifting drive unit 16A having multiple support columns as described in the second embodiment. This is because more precise attitude control of the susceptor 15 is required when the outline shape of the susceptor 15 is rectangular.

In addition, instead of the insulating films 33a, 33b, 36a, and 37a, a configuration can be made in which an insulating member, like the insulating members 25 and 33, is disposed as a separate member so as to be embedded in the susceptor 15 or the side wall 24.

Furthermore, in the present invention, it is possible to combine the configurations described in each of the above embodiments individually, or to omit certain characteristic configurations.

Examples of applications of the present invention include plasma CVD devices, plasma etching devices, and plasma surface treatment devices.

1...plasma processing apparatus 2...vacuum chamber (chamber)
2a...film formation space (reaction chamber)
4...electrode flange 5...shower plate 6...gas nozzle 7...gas introduction tube 9...high frequency power source 10...substrate 10a...treatment surface 11...bottom (inner bottom surface)
12: Matching box 13: Shield cover 14: Space 15: Susceptor (supporting portion)
15a... Side peripheral surface 16, 16a, 16b, 16c... Support 16A... Lifting drive section (lifting mechanism)
23... High-frequency electrode support portion 24... Wall portion (side wall)
24a...inner circumferential surface 25, 33...insulating member 26...loading/unloading section 26a...door valve 27...exhaust pipe 28...vacuum pump 30...capacitor forming section 31, 35...conductive band section 32, 33a, 33b, 36a, 37a...insulating film 41...upper plate 42...gas inlet 43...peripheral wall 81...insulating flange 82...substrate insulating cover 101...processing chamber G...gap
W: width dimension P: plasma

Claims (13)

A plasma processing apparatus comprising:
An electrode flange;
a chamber having a sidewall and a bottom;
an insulating flange disposed between the chamber and the electrode flange;
a processing chamber having a reaction chamber constituted by the chamber, the electrode flange, and the insulating flange;
a support part that is accommodated in the reaction chamber, on which a substrate having a processing surface is placed and that is capable of controlling a temperature of the substrate;
A lifting drive unit that lifts and lowers the support unit;
a high frequency power source connected to the electrode flange and configured to apply a high frequency voltage;
a capacitor forming portion provided around a side peripheral surface of the support portion;
a capacitor forming portion formed on the side wall of the chamber and provided on an inner circumferential surface of the chamber toward the center in a radial direction of the chamber at a position facing the capacitor forming portion of the support portion;
having
The support part is raised and lowered by the lifting drive part, and a gap is formed between the capacitor formation part on the side peripheral surface of the support part and the capacitor formation part on the inner peripheral surface of the sidewall of the chamber,
A plasma processing apparatus comprising: a capacitor for a high frequency return current during plasma generation formed between the opposing capacitor formation portions at a position covering the entire circumference of the support portion. 2. The plasma processing apparatus according to claim 1, wherein the capacitor forming portion on the side surface of the support portion has a width dimension in a direction in which the support portion is raised and lowered by the lifting and lowering drive portion, which is formed to be approximately uniform around the entire circumference of the support portion. 2. The plasma processing apparatus according to claim 1, wherein the capacitor forming portion of the support portion and the capacitor forming portion of the side wall of the chamber are spaced apart from each other by a distance that is substantially uniform around the entire circumference of the support portion in the radial direction of the substrate. 2. The plasma processing apparatus according to claim 1, wherein the capacitor forming portion on the inner surface of the sidewall of the chamber is formed to have a width dimension in the thickness direction of the substrate larger than that of the capacitor forming portion on the side surface of the support portion. 2. The plasma processing apparatus according to claim 1, wherein the capacitor formation portion is formed continuously or intermittently in a circumferential direction of the substrate. 2. The plasma processing apparatus according to claim 1, wherein an insulating member is disposed on the side surface of the support portion above the capacitor forming portion. 2. The plasma processing apparatus according to claim 1, wherein an insulating member is disposed on an upper surface of the support portion, the upper surface being radially inward from the capacitor forming portion. a shower plate electrically connected to the electrode flange and located above the reaction chamber is provided in the processing chamber;
8. The plasma processing apparatus according to claim 7, wherein an inner peripheral contour of the insulating member on the upper surface of the support and an outer peripheral contour of the shower plate exposed to the reaction chamber have corresponding shapes. 2. The plasma processing apparatus according to claim 1, wherein the capacitor forming portion on the side peripheral surface of the support portion and the capacitor forming portion on the side wall of the chamber both extend in a plane (vertical plane) along the direction in which the support portion is raised and lowered by the lifting and lowering drive unit. a transfer unit used for transferring the substrate into or out of the reaction chamber is provided on the side wall of the chamber;
2. The plasma processing apparatus according to claim 1, wherein a lower end of the capacitor forming section is provided at a position closer to the electrode flange than the carry-in/out section is. 9. The plasma processing apparatus according to claim 8, wherein an insulating member is provided on the inner peripheral surface of the side wall of the chamber between the insulating member on the upper surface of the support part and the insulating flange in the lifting and lowering direction of the support part. 12. The plasma processing apparatus according to claim 1, wherein the capacitor forming portion of the support portion and the capacitor forming portion of the side wall of the chamber are electrically connected by capacitive coupling. 13. The plasma processing apparatus according to claim 12, wherein the elevation drive unit includes a drive column that drives the support unit to ascend and descend, and a position control column that maintains the elevation position of the support unit.

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