JP7264710B2 - Plasma processing equipment - Google Patents

Description

The present invention relates to a plasma processing apparatus.

2. Description of the Related Art Conventionally, a plasma processing apparatus has been known that decomposes a raw material gas using plasma to form a thin film on a film-forming surface of a substrate, for example. In this plasma processing apparatus, for example, as shown in Patent Documents 1 and 2, a processing chamber is configured by a chamber, an electrode flange, and an insulating flange sandwiched between the chamber and the electrode flange. The processing chamber has a film formation space (reaction chamber).

A shower plate and a heater on which the substrate is placed are provided in the processing chamber.
A shower plate has a plurality of jets connected to the electrode flange. A space is formed between the shower plate and the electrode flange. This space is a gas introduction space into which the raw material gas is introduced. That is, the shower plate partitions the processing chamber into a film forming space in which a film is formed on the substrate and a gas introducing space.

The chamber is connected to ground potential. The heater thereby functions as an anode electrode. On the other hand, a high frequency power supply is connected to the electrode flange. The electrode flange and shower plate act as the cathode electrode. Around the electrode flange, for example, a shield cover or the like is provided so as to cover the electrode flange and connected to the chamber.

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

In such a configuration, the gas introduced into the gas introduction space is uniformly ejected from each ejection port of the shower plate into the film formation space. At this time, a high frequency power source is activated to apply a high frequency voltage to the electrode flange, thereby generating plasma in the film forming space. A desired film is formed by the material gas decomposed by the plasma reaching the film-forming surface of the substrate.

When a high-frequency voltage is applied to the electrode flange to generate plasma, the current that flows with the generation of plasma is transmitted through the shower plate, the heater, and the ground plate in that order. This current is then transmitted to the chamber and shield cover and returned to the matching box. Current associated with plasma generation flows through such a current path.

By the way, as described in FIG. 4 of Patent Document 1 and Patent Document 2, the side wall of the chamber is provided with a loading/unloading portion used for loading or unloading the substrate into the chamber. is provided.
However, as described in FIG. 4 of Patent Document 1 and Patent Document 2, when a loading/unloading portion is formed, the path of the high-frequency current flowing through the inner surface of the chamber in which the loading/unloading portion is formed is different from that of the loading/unloading portion. is longer than the path of the high-frequency current flowing through the inner surface of the chamber where there is no . As a result, the inductance increases in the path of the high-frequency current flowing through the inner surface on which the loading/unloading portion is formed.
As a result, the distribution of the return current is not uniform in the circumferential direction of the substrate and the heater, and the electric field gradient becomes non-uniform, causing local discharge (abnormal discharge) and plasma bias, which affects the uniformity of the film formation. There was a problem.

In particular, when the size of the substrate increases, it is necessary to increase the high-frequency voltage, which may cause abnormal discharge near the loading/unloading section.
For this reason, there is a problem that an impedance mismatch occurs due to the abnormal discharge, and the high-frequency voltage that can be applied to the electrode flange is reduced.

In Patent Document 1, a high-frequency device is provided at a position closer to the shower plate than the door valve to prevent this.
Moreover, in Patent Document 2, the door valve is doubled to prevent this.

Japanese Patent No. 5883652 Republished WO2010/079756

However, as described in Patent Literatures 1 and 2, if there is a deformed portion, a contact portion, or a sliding portion in the film forming space, it may cause generation of particles, which is not preferable.
In particular, as described in Patent Document 1, during the film formation process or when the substrate is raised and lowered, these deformed portions, contact portions, or sliding portions are positioned closer to the shower plate than the substrate. If there is a part, it is highly undesirable.

Further, as in Patent Document 2, if there is a movable part in the film formation space, it may cause generation of particles, which is not preferable. In the technique described in Patent Literature 2, when the substrate is loaded and unloaded, the heater must be raised and lowered by a height corresponding to the loading/unloading portion of the ground plate. Accordingly, the ground plate is greatly deformed. For this reason, many particles may be generated.

In addition, as described in Patent Documents 1 and 2, when the return current is transmitted to the shield cover via the lower surface of the heater, the ground plate, and the bottom of the chamber, the return current is non-uniform in the circumferential direction of the substrate. Although the performance is improved, there is a demand for further shortening the path of the return current to reduce the inductance.

The present invention has been made in view of the above circumstances, and aims to achieve the following objects.
1. To prevent generation of particles.
2. To reduce deformation parts, movable parts, and contact parts in the film formation space.
3. To shorten the path of the high-frequency return current.
4. To improve the distribution uniformity of the high-frequency return current in the circumferential direction of the substrate.
5. To reduce the inductance in the path of the high frequency return current.
6. Facilitating adjustment of inductance in the path of high frequency return currents.
7. To facilitate adjustment of plasma generation conditions.
8. Realize these at the same time.

The present invention is a plasma processing apparatus,
an electrode flange;
a chamber having sidewalls and a bottom;
an insulating flange positioned between the chamber and the electrode flange;
a processing chamber comprising the chamber, the electrode flange, and the insulating flange and having a reaction chamber;
a support unit on which a substrate having a processing surface is placed in the reaction chamber and capable of controlling the temperature of the substrate;
an elevation drive unit that drives the support unit up and down;
a high-frequency power source connected to the electrode flange and applying a high-frequency voltage;
a base plate having an upper surface electrically connected to the lower surface of the support and positioned radially outward of the support;
a base elevation driving unit that vertically drives the base plate independently of the support;
a capacitor forming portion provided around the edge of the upper surface of the base plate;
a capacitor formation portion formed on the side wall of the chamber and provided around a lower surface facing the bottom portion at a position opposed to the capacitor formation portion of the base plate;
has
elevating the base plate by the base elevating drive unit to form a gap between the upper surface of the base plate and the lower surface of the chamber;
The above problem is solved by forming a capacitor for a high-frequency return current during plasma formation at a position corresponding to the entire circumference of the substrate between the capacitor forming portions facing each other.
In the present invention, the capacitor forming portion is provided around the edge of the upper surface of the base plate, and the lower surface, which is formed on the side wall of the chamber and faces the bottom, is provided at a position facing the capacitor forming portion of the base plate. A width dimension in a radial direction of the substrate may be substantially uniform in a circumferential direction of the substrate in the capacitor forming portion provided around the periphery.
In the present invention, the capacitor forming portion is provided around the edge of the upper surface of the base plate, and the lower surface, which is formed on the side wall of the chamber and faces the bottom, is provided at a position facing the capacitor forming portion of the base plate. The circumferential capacitor forming portion may be formed continuously or intermittently in the circumferential direction of the substrate.
In the present invention, an insulating member may be arranged on at least one of the upper surface of the base plate and the lower surface of the chamber, which face each other.
In the present invention, at least the capacitor forming portion provided around the edge of the upper surface of the base plate is formed to be more concave than the insulating member on the upper surface of the adjacent base plate ,
The capacitor forming portion formed on the side wall of the chamber and circumferentially arranged at a position facing the capacitor forming portion of the base plate on the lower surface toward the bottom is positioned higher than the insulating member on the lower surface of the adjacent chamber. It can be concavely formed or it can be flush and continuous with an adjacent region of the lower surface .
According to the present invention, an insulating member may be arranged on the upper surface of the support portion and radially outward of the substrate.
In the present invention, the base plate and the support can be electrically connected by an earth plate.
The processing chamber of the present invention is provided with a shower plate electrically connected to the electrode flange and positioned above the reaction chamber,
An inner peripheral contour of the capacitor forming portion of the base plate may have a larger shape than an outer peripheral contour of the shower plate exposed to the reaction chamber.
The side wall of the chamber of the present invention is formed with a stepped portion that is circumferentially provided so that the diameter of the reaction chamber is larger at a position closer to the bottom than at a position closer to the electrode flange, The capacitor forming portion may be formed on the lower surface of the stepped portion facing the bottom portion.
In the present invention, the inner peripheral contour of the stepped portion may have a shape larger than the outer peripheral contour of the support portion.
In the present invention, the side wall of the chamber is provided with a loading/unloading part used for loading/unloading the substrate into/from the reaction chamber,
The lower surface of the stepped portion may be provided at a position closer to the electrode flange than the loading/unloading portion.
In the present invention, the capacitor formation portion on the top surface of the base plate facing the bottom surface of the chamber may be electrically connected to the capacitor formation portion on the bottom surface facing the top surface of the base plate. .

The present invention is a plasma processing apparatus,
an electrode flange;
a chamber having sidewalls and a bottom;
an insulating flange positioned between the chamber and the electrode flange;
a processing chamber comprising the chamber, the electrode flange, and the insulating flange and having a reaction chamber;
a support unit on which a substrate having a processing surface is placed in the reaction chamber and capable of controlling the temperature of the substrate;
an elevation drive unit that drives the support unit up and down;
a high-frequency power source connected to the electrode flange and applying a high-frequency voltage;
a base plate electrically connected to the support and positioned radially outward of the support;
a base elevation driving unit that vertically drives the base plate independently of the support;
a capacitor forming portion provided around the edge of the upper surface of the base plate;
a capacitor formation portion formed on the side wall of the chamber and provided around a lower surface facing the bottom portion at a position opposed to the capacitor formation portion of the base plate;
has
elevating the base plate by the base elevating drive unit to form a gap between the upper surface of the base plate and the lower surface of the chamber;
A capacitor for a high-frequency return current during plasma formation is formed at a position along the entire circumference of the substrate between the capacitor forming portions facing each other.

In this configuration, for example, a very small gap of several millimeters is formed between the upper surface of the base plate and the lower surface of the chamber. Further, when a high frequency voltage is applied, the upper surface of the base plate and the lower surface of the chamber are electrically connected to each other through capacitive coupling as a path for a high frequency return current.
According to this configuration, when high-frequency power is supplied to the electrode flange, high-frequency current can flow from the electrode flange to the chamber via the support portion and the base plate. Therefore, plasma can be generated between the electrode flange and the support.

At this time, the path of the high-frequency return current returning to the matching box during plasma formation can be the support, base plate, capacitor formation, and chamber.
This allows the path of the high-frequency return current to be shorter than when passing through the bottom of the chamber. Therefore, the inductance in the path of the high frequency return current can be reduced.

At the same time, it is possible to form the gap between the support portion and the electrode flange of the shower plate or the like to a dimension corresponding to the plasma generation conditions only by setting the height of the support portion by the elevation drive portion. Therefore, an optimum gap can be formed between the substrate and the shower plate for plasma generation conditions and film forming conditions.
At the same time, it is possible to form the gap between the upper surface and the lower surface of the base plate to have a uniform width dimension simply by setting the height of the base plate by the base elevating drive section. Therefore, the high-frequency return current paths are evenly formed in the circumferential direction of the substrate.

Moreover, the gap between the upper surface and the lower surface of the base plate can be set independently of the gap between the supporting portion and the electrode flange of the shower plate or the like. Therefore, the inductance and the plasma generation conditions can be set independently without affecting each other.
As a result, non-uniformity of the electric field gradient can be suppressed in the circumferential direction of the substrate, and a uniform distribution of plasma processing characteristics, that is, film formation characteristics, can be maintained.

Also, the path of the high frequency return current does not pass through a position closer to the bottom than the capacitor forming part. As a result, it is possible to provide the loading/unloading section on the side wall of the chamber, which is located closer to the bottom than the capacitor formation section, which is a position through which the path of the high-frequency return current does not pass.
As a result, it is possible to prevent the loading/unloading section from affecting the path of the high-frequency return current. As a result, it is possible to prevent an increase in inductance due to the carry-in/out section, and to reduce the inductance of the high-frequency return current.

Therefore, when plasma is generated, abnormal discharge in the carry-in/out 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 evenly formed in the circumferential direction of the substrate.

As a result, non-uniformity of the electric field gradient can be suppressed in the circumferential direction of the substrate, and a uniform distribution of plasma processing characteristics, that is, film formation characteristics, can be maintained.
In such a configuration, the upper surface of the base plate and the lower surface of the chamber do not come into contact with each other, and there is no part in the processing chamber that moves or deforms a large lifting distance to the extent that the substrate is carried in or out. can be prevented from occurring.

According to the present invention, the width dimension in the radial direction of the substrate may be substantially uniform in the circumferential direction of the substrate.
As a result, capacitors formed by the upper surface of the base plate and the lower surface of the chamber are evenly formed in the circumferential direction of the substrate.
Therefore, the high-frequency return current paths are evenly formed in the circumferential direction of the substrate.
As a result, non-uniformity of the electric field gradient can be suppressed in the circumferential direction of the substrate, and a uniform distribution of plasma processing characteristics, that is, film formation characteristics, can be maintained.
Therefore, when generating plasma, it is possible to prevent abnormal discharge from occurring at a portion where the inductance fluctuates, and to increase the high-frequency voltage that can be applied to the electrode flange.

In the present invention, the capacitor forming portion can be formed continuously or intermittently in the circumferential direction of the substrate.
This facilitates disposing the capacitor forming portion in the circumferential direction of the substrate so as not to be affected by the contour shape of the substrate, the contour shape of the support portion, and the contour shape of the base plate.

Specifically, in a plasma processing apparatus that plasma-processes a rectangular substrate, the capacitor forming portions can be arranged as four straight lines corresponding to the four sides of the substrate.
In this case, the four straight lines corresponding to the four sides of the substrate can be further divided into shorter line segments in the capacitor forming portion.
Alternatively, a plurality of capacitor forming portions can be formed concentrically.

Alternatively, in a plasma processing apparatus that plasma-processes a substrate having a circular contour, a plurality of arc-shaped capacitor forming portions can be arranged so as to have the same central angle, corresponding to the circular edge of the substrate.
In this case, the arc-shaped capacitor forming portion can be divided into shorter arcs.
Alternatively, a plurality of capacitor forming portions can be formed concentrically.

Note that it is possible to divide the capacitor formation portion as appropriate. At this time, it is necessary that the capacitors formed by the capacitor forming portion can be regarded as substantially uniform in the circumferential direction of the substrate.

In the present invention, an insulating member may be arranged on at least one of the upper surface of the base plate and the lower surface of the chamber, which face each other.
As a result, at least one of the capacitor forming portions facing each other is covered with the insulating member, so that the conductive members are not arranged to face each other while being exposed.
Therefore, it is possible to suppress the occurrence of abnormal discharge between the upper surface of the base plate and the lower surface of the chamber. As a result, the upper limit of high frequency power that can be supplied to the device can be increased.

As a result, it is possible to prevent the plasma from affecting the capacitor formation portion and to reliably form the capacitor in the path of the high-frequency return current.
Therefore, the high-frequency return current paths are evenly formed in the circumferential direction of the substrate.
As a result, non-uniformity of the electric field gradient can be suppressed in the circumferential direction of the substrate, and a uniform distribution of plasma processing characteristics, that is, film formation characteristics, can be maintained.
Therefore, when generating plasma, it is possible to prevent abnormal discharge from occurring at a portion where the inductance fluctuates, and to increase the high-frequency voltage that can be applied to the electrode flange.

According to the present invention, the capacitor forming portion of the supporting portion may be formed in a concave shape with respect to the upper surface of the adjacent base plate.
As a result, the support section is moved up and down by the up-and-down driving section and the base plate is moved up and down by the base up-and-down driving section to form a very small gap of about several millimeters between the upper surface of the base plate and the lower surface of the chamber. , the gap between the base plate and the lower surface can be accurately controlled independently of the height position of the support portion.
Furthermore, even if the upper surface of the base plate and the lower surface of the chamber come into contact with each other while the base plate is being raised and lowered by the base raising/lowering drive unit, the capacitor forming portion does not come into contact with the lower surface of the chamber. can be prevented.

According to the present invention, an insulating member may be arranged on the upper surface of the support portion and radially outward of the substrate.
Thereby, the insulating member can maintain an electrically insulated state radially inside the capacitor forming portion. Therefore, it is possible to prevent the generated plasma from reaching the vicinity of the capacitor formation portion with respect to the substrate located radially inside the capacitor formation portion during plasma processing.

In the present invention, the base plate and the support can be electrically connected by an earth plate.
As a result, the support section is moved up and down by the elevation driving section and the base plate is raised and lowered by the base elevation driving section, and the path of the high-frequency return current returning to the matching box during plasma formation is divided into the support section, the base plate, the capacitor formation section, and the chamber. , can be

The processing chamber of the present invention is provided with a shower plate electrically connected to the electrode flange and positioned above the reaction chamber,
An inner peripheral contour of the capacitor forming portion of the base plate may have a larger shape than an outer peripheral contour of the shower plate exposed to the reaction chamber.
As a result, it is possible to easily form a capacitor that serves as a high-frequency return current path without reducing the substrate size.
Moreover, since it is not necessary to provide a movable part other than the elevation driving part in the processing chamber, it is possible to prevent the generation of particles (dust) and the like, thereby preventing deterioration of film formation characteristics.
Also, the generated plasma can be prevented from reaching the capacitor formation portion.

The side wall of the chamber of the present invention is formed with a stepped portion that is circumferentially provided so that the diameter of the reaction chamber is larger at a position closer to the bottom than at a position closer to the electrode flange,
The capacitor forming portion may be formed on the lower surface of the stepped portion facing the bottom portion.
As a result, plasma generated at a position closer to the electrode flange than the lower surface of the stepped portion in the vertical direction is prevented from approaching the capacitor forming portion, and the generated plasma does not reach the vicinity of the capacitor forming portion. can be prevented.

As a result, it is possible to prevent the plasma from affecting the capacitor formation portion and to reliably form the capacitor in the path of the high frequency device return current.
Therefore, the high-frequency return current paths are evenly formed in the circumferential direction of the substrate.
As a result, non-uniformity of the electric field gradient can be suppressed in the circumferential direction of the substrate, and a uniform distribution of plasma processing characteristics, that is, film formation characteristics, can be maintained.
Therefore, when generating plasma, it is possible to prevent abnormal discharge from occurring at a portion where the inductance fluctuates, and to increase the high-frequency voltage that can be applied to the electrode flange.

In the present invention, the inner peripheral contour of the stepped portion may have a shape larger than the outer peripheral contour of the support portion.
As a result, plasma generated at a position closer to the electrode flange than the lower surface of the stepped portion in the vertical direction is prevented from approaching the capacitor forming portion by the stepped portion, and the generated plasma reaches the vicinity of the capacitor forming portion. You can prevent it from being lost.

As a result, it is possible to prevent the plasma from affecting the capacitor formation portion and to reliably form the capacitor in the path of the high frequency device return current.
Therefore, the high-frequency return current paths are evenly formed in the circumferential direction of the substrate.
As a result, non-uniformity of the electric field gradient can be suppressed in the circumferential direction of the substrate, and a uniform distribution of plasma processing characteristics, that is, film formation characteristics, can be maintained.
Therefore, when generating plasma, it is possible to prevent abnormal discharge from occurring at a portion where the inductance fluctuates, and to increase the high-frequency voltage that can be applied to the electrode flange.

In the present invention, the side wall of the chamber is provided with a loading/unloading part used for loading/unloading the substrate into/from the reaction chamber,
The lower surface of the stepped portion may be provided at a position closer to the electrode flange than the loading/unloading portion.
As a result, it is possible to prevent the loading/unloading section from affecting the path of the return current. As a result, it is possible to prevent an increase in inductance due to the carry-in/out section, and to reduce the inductance of the high-frequency return current.

Therefore, when plasma is generated, abnormal discharge in the carry-in/out 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 evenly formed in the circumferential direction of the substrate.
Furthermore, since the loading/unloading part is positioned on the side wall of the chamber, which is closer to the bottom than the capacitor forming part, particles generated at the loading/unloading part are prevented from reaching the substrate, thereby preventing deterioration of film formation characteristics. can be prevented.

In the present invention, the capacitor formation portion on the top surface of the base plate facing the bottom surface of the chamber may be electrically connected to the capacitor formation portion on the bottom surface facing the top surface of the base plate. .
As a result, it is possible to form a capacitor by the capacitor forming portions facing each other, reduce the inductance in the path of the high-frequency return current, and form substantially equal inductance in the circumferential direction of the substrate.
At the same time, it becomes possible to independently control the elevation position of the base plate and the height position of the support portion.

According to the present invention, it is possible to prevent the generation of particles and reduce the number of particles reaching the substrate from the carry-in/out section without providing any deformation section, movable section, or contact section other than the elevation drive section in the deposition space. It becomes possible to produce an effect. According to the present invention, it is possible to shorten the path of the high-frequency return current, improve the uniformity of the distribution 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. It becomes possible to produce an effect. ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to produce the effect that an inductance can be easily adjusted in the path|route of a high frequency return current. ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to produce the effect that plasma generation conditions can be easily adjusted and these can be achieved at the same time.

1 is a schematic longitudinal sectional view showing a first embodiment of a plasma processing apparatus according to the present invention; FIG. It is an explanatory view showing a base plate in a first embodiment of a plasma processing apparatus according to the present invention. It is an explanatory view showing a capacitor formation part in a plasma processing apparatus concerning a 1st embodiment of the present invention. 2 is an enlarged cross-sectional view showing a capacitor forming portion in the plasma processing apparatus according to the first embodiment of the present invention; FIG. 1 is a schematic vertical cross-sectional view showing a path of a high-frequency return current in the plasma processing apparatus according to the first embodiment of the present invention; FIG. FIG. 7 is an enlarged cross-sectional view showing a capacitor forming portion in a plasma processing apparatus according to a second embodiment of the present invention; FIG. 5 is an explanatory diagram showing another example of a capacitor forming portion in the embodiment of the plasma processing apparatus according to the present invention; FIG. 5 is an explanatory diagram showing another example of a capacitor forming portion in the embodiment of the plasma processing apparatus according to the present invention; FIG. 5 is an explanatory diagram showing another example of a capacitor forming portion in the embodiment of the plasma processing apparatus according to the present invention; FIG. 5 is an explanatory diagram showing another example of a capacitor forming portion in the embodiment of the plasma processing apparatus according to the present invention; FIG. 5 is an explanatory diagram showing another example of a capacitor forming portion in the embodiment of the 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 this embodiment. FIG. 2 is an explanatory diagram showing the base plate of the plasma processing apparatus according to the present embodiment, and is a view taken in the direction of arrow II in FIG. In the figure, reference numeral 1 denotes a plasma processing apparatus.
In addition, in each drawing used for the following explanation, in order to make each component large enough to be recognized on the drawing, the dimensions and proportions of each component may be changed from the actual ones as appropriate. .

A plasma processing apparatus 1 according to this embodiment is a film forming apparatus using a plasma CVD method.
The plasma processing apparatus 1 includes, as shown in FIG. 1, a processing chamber 101 having a film formation space 2a, which is a reaction chamber in which a substrate 10 is accommodated.
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 side walls (walls) 24 erected 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 through this opening, and the support 16 is arranged at the bottom of the vacuum chamber 2 . The tip of the strut 16 is located inside the vacuum chamber 2 . A plate-like susceptor (supporting portion) 15 is connected to the tip of the support 16 .

Another opening is formed in the bottom (inner bottom) 11 of the vacuum chamber 2 . A support 18 is inserted through this opening, and the support 18 is arranged in parallel with the support 16 at the bottom of the vacuum chamber 2 . The tip of the strut 18 is located inside the vacuum chamber 2 below the susceptor (supporting portion) 15 . A frame-shaped base plate 17 having a through hole in the central portion is connected to the tip of the support 18 .

The contour shape of the base plate 17 is set larger than that of the susceptor (supporting portion) 15 .
The susceptor (supporting portion) 15 and the base plate 17 are vertically spaced apart from each other.
The susceptor (supporting portion) 15 and the base plate 17 are arranged parallel to each other.
A support 16 penetrates through a central through hole of the frame-shaped base plate 17 .
The base plate 17 and the struts 16 are not in contact with each other.

The column 16 is connected to an elevation driving section 16A provided outside the vacuum chamber 2 . The column 16 can be controlled to move in the vertical direction by an elevation driving section 16A. That is, the susceptor 15 connected to the tip of the support 16 is configured to be vertically controllable.

The column 18 is connected to a base elevation driving section (elevating driving section) 16A provided outside the vacuum chamber 2 . The support column 18 can be controlled to move vertically by a base elevation drive section (elevation drive section) 16A. That is, the base plate 17 connected to the tip of the column 18 is configured to be vertically controllable.

In the present embodiment, the struts 16 and 18 are both vertically movable by the same elevation drive section (base elevation drive section) 16A. It may be possible to move up and down by an up-and-down driving section.

The susceptor (supporting portion) 15 and the base plate 17 can be moved up and down in conjunction with each other by a base elevation driving portion (lifting driving portion) 16A.
Further, the susceptor (supporting portion) 15 and the base plate 17 can be separately moved up and down within the movable range of the earth plate 19, which will be described later, by a base elevation driving portion (lifting driving portion) 16A.

Bellows (not shown) are provided outside the vacuum chamber 2 so as to cover the outer peripheries of the struts 16 and 18 . The bellows keep the deposition space 2a sealed when the support 16 and the support 18 move up and down.
An exhaust pipe 27 is connected to the vacuum chamber 2 at a position closer to the bottom portion 11 than the base plate 17 is. A vacuum pump 28 is provided at the tip of the exhaust pipe 27 . The vacuum pump 28 reduces the pressure so that the inside of the vacuum chamber 2 is in a vacuum state.

An electrode flange 4 is attached to the top of the vacuum chamber 2 via an insulating flange 81 .
In the vacuum chamber 2 , a stepped portion 25 and a high-frequency electrode support portion 23 are provided at the upper end of the wall portion 24 . The stepped portion 25 and the high-frequency electrode support portion 23 are each made of a conductive material.
The stepped portion 25 and the high-frequency electrode support portion 23 are made of aluminum, an aluminum alloy, or the like.

The stepped portion 25 is placed on the upper end of the wall portion 24 . The stepped portion 25 is provided around the chamber 2 so as to protrude radially inward. That is, the inner diameter dimension of the step portion 25 is smaller than the inner diameter dimension of the wall portion 24 of the chamber 2 .
The high-frequency electrode support portion 23 has substantially the same inner diameter as the stepped portion 25 and is stacked on the stepped portion 25 .
A lower end of the shield cover 13 is placed on the upper end of the high-frequency electrode support portion 23 .

The susceptor 15 is positioned radially inside the stepped portion 25 and/or the high-frequency electrode support portion 23 .
The upper surface of the susceptor 15 is positioned closer to the shower plate 5 than the lower surface of the stepped portion 25 .
The step portion 25 and/or the high frequency electrode support portion 23 and the susceptor 15 are separated from each other.

An insulating flange 81 is in contact with the radially inner side of the stepped portion 25 and/or the high-frequency electrode support portion 23 .
The insulating flange 81 has a smaller radial dimension than the wall portion 24 . A radial cross section of the insulating flange 81 is formed in a substantially Z shape. In other words, the insulating flange 81 has a frame portion 81 b that contacts the stepped portion 25 and/or the high-frequency electrode support portion 23 radially inwardly and that extends parallel to the wall portion 24 .

An upper insulating flange portion 81c that protrudes radially outward is provided at the upper end of the frame portion 81b of the insulating flange 81 . A lower insulating flange portion 81a that protrudes radially inward is provided at the 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 so as 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 side of the lower insulating flange portion 81a and the frame portion 81b.
In addition, the radially inner contour of the lower insulating flange portion 81a limits the range in which the electrode flange 4 and the shower plate 5 are exposed to the film forming 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 arranged so that the opening of the peripheral wall 43 is located below the substrate 10 in the vertical direction. A 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 substantially parallel to each other. A space 14 is thereby formed between the electrode flange 4 and the shower plate 5 .

An upper plate 41 of the electrode flange 4 faces the shower plate 5 . A gas introduction port 42 is provided in the upper plate 41 .
A gas introduction pipe 7 is provided between the 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 section 21 .
The gas introduction pipe 7 passes through a shield cover 13, which will be described later. A process gas is supplied to the space 14 from the process gas supply section 21 through the gas introduction pipe 7 .

The space 14 functions as a gas introduction space into which process gas is introduced.
A plurality of gas ejection ports 6 are formed in the shower plate 5 .
The process gas introduced into the space 14 is jetted from the gas jet port 6 into the film forming space 2a inside the vacuum chamber 2 .

The electrode flange 4 and 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 out of contact with the electrode flange 4 . A shield cover 13 is arranged to be electrically connected to the vacuum chamber 2 .

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

The susceptor 15 is a plate-like member having a flat surface. A substrate 10 is placed on the upper surface of the susceptor 15 . The susceptor 15 is formed so that the normal direction of the mounted substrate 10 is parallel to the axis of the support 16 .
The susceptor 15 may incorporate a heater. The susceptor 15 may heat and adjust the temperature of the mounted substrate 10 with a heater.

The susceptor 15 functions as a ground electrode, ie an anode electrode. Therefore, the susceptor 15 is made of a conductive metal or the like. For example, the susceptor 15 is made of aluminum, an aluminum alloy, or the like.
The susceptor 15 may be provided with an insulating film 15a on its upper surface.

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.
When the 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 heater wire adjusts the temperature of the susceptor 15 to a predetermined temperature.

The heater wire protrudes downward from the rear surface of the susceptor 15 at the approximate center of the susceptor 15 when viewed in the vertical direction.
The heater wire is inserted through through-holes formed in the substantially central portion of the susceptor 15 and the support 16 and led to the outside of the vacuum chamber 2 . The heater wire is connected to a power supply (not shown) outside the vacuum chamber 2 .
The heater wire adjusts the temperatures of the susceptor 15 and the substrate 10 according to the power supplied from the power supply.

A substrate insulating cover 82 is provided around the upper surface of the susceptor 15 at a position adjacent to the radially outer side of the substrate 10 .
A substrate insulating cover 82 is provided around the entire circumference of the substrate 10 . The thickness dimension of the substrate insulating cover 82 is made larger than the thickness dimension of the substrate 10 . That is, the height of the substrate insulating cover 82 can protrude upward from the processing surface 10 a of the substrate 10 .
A substrate insulating cover 82 can be provided to cover the side surface of the susceptor 15 .

Alternatively, the height of the substrate insulating cover 82 can be the same as the processing surface 10 a of the substrate 10 .
Alternatively, the height of the substrate insulating cover 82 can be lower than the processing surface 10a of the substrate 10 .

The base plate 17 is a frame-shaped plate member having a flat surface.
The base plate 17 is made of a conductive metal or the like. For example, the base plate 17 is made of aluminum, an aluminum alloy, or the like.

One end of a flexible earth plate 19 is connected to the upper surface of the base plate 17 . The other end of the earth plate 19 is connected to the bottom surface of the susceptor 15 .

The earth plates 19 are arranged along the outer peripheral edge of the susceptor 15 at substantially equal intervals.
A large number of earth plates 19 are arranged along the inner peripheral edge of the base plate 17 at substantially equal intervals.
The earth plate 19 is made of, for example, a nickel-based alloy or an aluminum alloy.
The ground plate 19 is electrically connected to the top surface of the base plate 17 and the bottom surface of the susceptor 15 .
Therefore, when an insulating film is provided on the upper surface of the base plate 17 and the lower surface of the susceptor 15, the insulating film on the upper surface of the base plate 17 and the lower surface of the susceptor 15 is removed at the connection position of the ground plate 19. FIG.

A side wall 24 of the vacuum chamber 2 is formed with a loading/unloading section 26 (loading/unloading port) used for loading or unloading the substrate 10 .
A door valve 26 a for opening and closing the loading/unloading section 26 is provided on the outer surface of the side wall 24 of the vacuum chamber 2 . The door valve 26a is vertically slidable.

When the door valve 26a is slid downward (toward the bottom 11 of the vacuum chamber 2), the loading/unloading section 26 is opened and the substrate 10 can be loaded or unloaded.
On the other hand, when the door valve 26a is slid upward (in the direction toward the electrode flange 4), the carry-in/out section 26 is closed, and the substrate 10 can be processed (film formation process).

3A and 3B are arrow views in the IIIA direction and the IIIB direction in FIG. 1 for explaining the capacitor forming portion of the plasma processing apparatus according to the present embodiment. In the figure, the upper half of the page is a view of the lower surface of the step portion viewed upward, and the lower half of the page is a view of the upper surfaces of the susceptor and the base plate viewed downward.
FIG. 4 is an enlarged cross-sectional view for explaining the capacitor forming portion of the plasma processing apparatus according to this embodiment.

A capacitor forming portion 30 is formed on the outer peripheral edge of the base plate 17, as shown in FIGS.
As shown in FIGS. 1, 3 and 4, a capacitor forming portion 30 is formed on the inner peripheral edge portion of the stepped portion 25 .

As the capacitor forming portion 30 , a conductive band portion 31 is provided around the upper surface of the base plate 17 at a position close to the radially outer side of the substrate insulating cover 82 .
The conductive band portion 31 is provided over the entire circumference of the base plate 17 .
The conductive band portion 31 is provided with the same width, that is, substantially uniformly, over the entire circumference of the base plate 17 .

The conductive band portion 31 is continuously provided over the entire circumference of the base plate 17 .
The conductive band portion 31 is provided parallel to each side of the rectangular base plate 17 .
The conductive band portion 31 is provided along the entire circumference of the base plate 17 so as to be separated from the substrate insulating cover 82 which is the outer edge of the susceptor 15 in plan view.

The conductive band portion 31 is provided along the entire circumference of the base plate 17 so as to be separated from the contour of the base plate 17 .
The distance between the conductive band portion 31 and the outer contour of the base plate 17 is set equal over the entire circumference of the base plate 17 .

A region covered with the insulating film 32 exists between the conductive band portion 31 and the substrate insulating cover 82 in plan view.
The insulating film 32 may be provided continuously up to the lower side of the substrate insulating cover 82 , that is, the lower side of the susceptor 15 .

A region covered with an insulating film 33 exists on the surface of the base plate 17 closer to the side wall (wall portion) 24 than the conductive band portion 31 .
The insulating film 33 may be provided continuously up to the side end face of the base plate 17 .

Both the insulating film 32 and the insulating film 33 are made of an insulator.
The insulating film 32 and the insulating film 33 can be made of an alumite alloy or the like.
Insulating film 32 and insulating film 33 have the same thickness dimension.
The substrate insulating cover 82, the insulating film 32 and the insulating film 33 constitute an insulating member.

The conductive band portion 31 is formed on the upper surface of the base plate 17 by removing the insulating films 32 and 33 formed on the entire surface.
The conductive band portion 31 is recessed from the insulating films 32 and 33 on the upper surface of the base plate 17 .
The conductive band portion 31 is provided on the upper surface of the base plate 17 positioned below the substrate insulating cover 82 .

As the capacitor forming portion 30 , a conductive band portion 35 is provided around the lower surface of the stepped portion 25 at a position facing the conductive band portion 31 of the base plate 17 .
The conductive band portion 35 is provided along the entire circumference of the step portion 25 corresponding to the conductive band portion 31 .
The conductive band portion 35 is provided with a uniform width over the entire circumference of the stepped portion 25 .

The conductive band portion 35 is provided continuously over the entire circumference of the stepped portion 25 in the same manner as the conductive band portion 31 .
Similar to the conductive band portion 31 , the conductive band portion 35 is provided parallel to each side of the inner contour of the rectangular stepped portion 25 .
The conductive band portion 35 is provided along the entire circumference of the stepped portion 25 so as to be separated from the inner contour of the stepped portion 25 .

The distance between the conductive band portion 35 and the inner contour of the stepped portion 25 is the same over the entire circumference of the stepped portion 25 .
The conductive band portion 35 is provided along the entire circumference of the stepped portion 25 so as to be separated from the inner surface of the upper end of the wall portion (side wall) 24 .
The distance between the conductive band portion 35 and the outer contour of the base plate 17 is set to be the same over the entire circumference of the base plate 17 as in the case of the conductive band portion 31 .

In addition, in the present embodiment, a region 36 exists between the conductive band portion 35 and the inner contour of the stepped portion 25 .
Further, a region 37 exists on the surface of the step portion 25 adjacent to the side wall (wall portion) 24 rather than the conductive band portion 35 .

The region 37 is continuous up to a position where the end face of the side wall (wall portion) 24 in the stepped portion 25 is in contact.
Both the regions 36 and 37 are flush with and continuous with the conductive band portion 35 . Conductive band portion 35 , region 36 and region 37 are located on the lower surface of stepped portion 25 .
In other words, the lower surface of the stepped portion 25 exposes the entire conductor made of, for example, aluminum.

The range of the conductive band portion 35 is defined as the lower surface of the stepped portion 25 facing the conductive band portion 31 .
That is, the conductive band portion 35 is formed on the lower surface of the stepped portion 25 by facing the conductive band portion 31 .

Next, the action of forming a film on the processing surface 10a of the substrate 10 using the plasma processing apparatus 1 will be described.
FIG. 5 is a cross-sectional view for explaining the high-frequency return current of the plasma processing apparatus according to this embodiment.

First, the pressure inside the vacuum chamber 2 is reduced using the vacuum pump 28 . The door valve 26 a is opened while the inside of the vacuum chamber 2 is maintained in a vacuum state, and the substrate 10 is loaded from the outside of the vacuum chamber 2 toward the film formation space 2 a through the loading/unloading section 26 of the vacuum chamber 2 . The substrate 10 is placed on the susceptor 15 . A substrate insulating cover 82 defines the mounting position of the substrate 10 on the susceptor 15 .
At this time, the base plate 17 is located closer to the bottom portion 11 than the susceptor 15 is.

After loading the substrate 10, the door valve 26a is closed (closing operation).
The susceptor 15 and the base plate 17 are positioned below in the vacuum chamber 2 before the substrate 10 is placed.
The susceptor 15 is located below the loading/unloading section 26 before the substrate 10 is placed.
That is, since the distance between the susceptor 15 and the shower plate 5 is large, the substrate 10 can be easily placed on the susceptor 15 using a robot arm (not shown).

After the substrate 10 is placed on the susceptor 15, the base elevation drive section (up-and-down drive section) 16A is activated to raise the columns 16 and 18. As shown in FIG. The substrate 10 placed on the susceptor 15 pushed upward also moves upward. As a result, the distance between the shower plate 5 and the substrate 10 is determined to a desired value so as to be the distance necessary for proper film formation, and this distance is maintained.

At this time, the susceptor 15 and the base plate 17 are raised together.
As a result, the peripheral portion of the upper surface of the base plate 17 approaches the lower surface of the stepped portion 25 .

Next, the base elevation driving section 16A is activated to raise and lower the support column 18 to set the gap G between the upper surface of the base plate 17 and the lower surface of the step portion 25 to a desired value.
At this time, the deformation of the ground plate 19 keeps the susceptor 15 and the base plate 17 electrically connected.
Further, since the ground plate 19 has flexibility, the susceptor 15 and the base plate 17 can change their vertical positions relative to each other.

Here, the gap G between the upper surface of the base plate 17 and the lower surface of the stepped portion 25 is determined to a desired value so as to form a capacitor in the path of a high-frequency return current, which will be described later. is maintained.
Specifically, the gap G between the upper surface of the base plate 17 and the lower surface of the stepped portion 25 is set to a range of approximately 0.1 mm to 10 mm, that is, a narrow gap.

On the upper surface of the base plate 17 and the lower surface of the stepped portion 25, the conductive band portion 31 and the conductive band portion 35 are formed at positions overlapping each other in plan view. Therefore, along the outer periphery of the base plate 17, a capacitor is formed in the path of the high frequency return current.
As a result, a capacitor necessary for proper film formation is formed along the entire circumference of the base plate 17 .

A capacitor formed between the conductive band portion 31 and the conductive band portion 35 has a uniform value along the entire circumference of the susceptor 15 .
Therefore, a uniform high-frequency return current can be formed along the outer circumference of the susceptor 15 .

Moreover, the formation of the capacitors along the entire periphery of the base plate 17 can be easily and independently performed simply by setting the elevation position of the base plate 17 by the base elevation driving section 16A without affecting the position setting of the susceptor 15. can be done.

Here, the peripheral portion of the conductive band portion 31 is covered with an insulating film 32 and an insulating film 33 .
Therefore, capacitors can be reliably formed on the entire circumference of the base plate 17 .
At the same time, capacitors with uniform values can be reliably formed around the entire circumference of the base plate 17 .

After that, the process gas is introduced into the space 14 from the process gas supply unit 21 through 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 forming space 2a.

Next, the high frequency power source 9 is activated 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 discharge occurs between the shower plate 5 and the susceptor 15 . Plasma P is generated between the shower plate 5 and the processing surface 10 a of the substrate 10 .

The process gas is decomposed in the plasma P generated in this way, the process gas in a plasma state is obtained, a vapor phase growth reaction occurs on the processing surface 10a of the substrate 10, and a thin film is formed on the processing surface 10a.
The high-frequency current transmitted to the susceptor 15 flows through the ground plate 19, the base plate 17, and the capacitor-forming portion 30 to the stepped portion 25 and the inner peripheral surfaces of the high-frequency electrode support portion 23 (FIG. 5).
Then, the high-frequency current is returned through the shield cover 13 (return current).

At this time, no high-frequency return current is returned from the capacitor forming portion 30 to the side wall (wall portion) 24 of the vacuum chamber 2 below the stepped portion 25 .
That is, regardless of the presence or absence of the loading/unloading section 26 in the vacuum chamber 2 , the high-frequency return current is not returned through the bottom 11 and side walls 24 of the vacuum chamber 2 .

Therefore, it is possible to reduce the inductance over the entire circumference of the susceptor 15 and the base plate 17 by reducing the path of the high frequency return current.
Also, the distance of the path of the high-frequency return current can be made equal over the entire circumference of the susceptor 15 and the base plate 17 . That is, the inductance in the path of the high-frequency return current can be made the same over the entire circumference of the susceptor 15 and the base plate 17 .

Moreover, since the capacitor forming portion 30 acts as a capacitor instead of a reactance, it is possible to reduce the inductance.

In the plasma processing apparatus 1 according to the present embodiment, a very small gap G of about several millimeters is formed between the upper surface of the base plate 17 and the lower surface of the stepped portion 25 so that the conductive band portion 31 and the opposing conductive band portion 31 are formed. Conductive band 35 can form a capacitor as a path for high frequency return current.

At this time, the path of the high frequency return current returning to the matching box 16 during plasma formation is defined as the susceptor 15, the ground plate 19, the base plate 17, the capacitor forming portion 30, the step portion 25, the high frequency electrode support portion 23, and the shield cover 13. be able to.

As a result, the path of the high-frequency return current can be made shorter than when passing through the bottom 11 of the chamber 2 . Therefore, the inductance in the path of the high frequency return current can be reduced.

At the same time, the gap G between the base plate 17 and the stepped portion 25 is formed to have a uniform width dimension over the entire circumference of the susceptor 15 and the base plate 17 simply by setting the height of the base plate 17 by the base elevation drive section 16A. It becomes possible to

Therefore, high-frequency return current paths are evenly formed in the circumferential direction of the susceptor 15 and the base plate 17 .
As a result, non-uniformity of the electric field gradient can be suppressed in the circumferential direction of the susceptor 15 and the base plate 17, and the uniform distribution of the plasma processing characteristics, that is, the film formation characteristics can be maintained.

Moreover, the height of the base plate 17 can be set independently of the susceptor 15 .
Therefore, the height of the susceptor 15 set with respect to the shower plate 5 can be optimized independently of the gap G between the base plate 17 and the stepped portion 25 only by plasma processing conditions.

At the same time, independent of the height of the susceptor 15 set with respect to the shower plate 5, it is easy to optimize the gap G between the base plate 17 and the stepped portion 25 for the high-frequency return current path. becomes possible.

Thereby, both the height of the susceptor 15 and the height of the base plate 17 can be optimized.
Therefore, it is readily possible to simultaneously optimize plasma processing conditions and capacitors in the path of high frequency device return currents.

Therefore, when plasma is generated, abnormal discharge can be prevented in the carry-in/out section 26 and the like, 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 portion 26 does not affect the path of the high-frequency return current, the path of the high-frequency return current is evenly formed in the circumferential direction of the susceptor 15 .

In such a configuration, the upper surface of the base plate 17 and the lower surface of the stepped portion 25 are not in contact with each other, and the earth plate 19 is adapted only to the setting of the gap G between the base plate 17 and the stepped portion 25, which is a narrow gap. Since the structure allows only very small deformations, it is possible to suppress the generation of particles (dust) and the like.

Conductive band portion 31 is recessed from insulating films 32 and 33 , and conductive band portion 35 is flush with and continuous with regions 36 and 37 .
The film thickness of the insulating film 32 and the insulating film 33, that is, the recessed dimension of the conductive band portion 31 can be set to 0.1 to 1 mm.

As a result, after the susceptor 15 and the base plate 17 are raised and lowered by the base elevation drive section (elevation drive section) 16A, the base plate 17 is raised and lowered by the base elevation drive section (elevation drive section) 16A. As a result, when forming a gap G between the upper surface of the base plate 17 and the lower surface of the stepped portion 25, the gap G can be accurately controlled.

Furthermore, even if the upper surface of the base plate 17 and the lower surface of the stepped portion 25 come into contact with each other while the base plate 17 is being moved up and down by the base lifting drive portion (lifting drive portion) 16A, the conductive band portion 31 and the conductive band portion 35 do not abut. Therefore, it is possible to prevent the capacitor from fluctuating due to a change in the surface state of the conductive band portions 31 and 35 .

A step portion 25 and a high-frequency electrode support portion 23 are arranged around the film forming space 2 a , and a step portion 25 and a high-frequency electrode support portion 23 are arranged around the susceptor 15 .
At the same time, the upper surface of the base plate 17 and the lower surface of the stepped portion 25 are positioned below the lower surface of the susceptor 15 .
Therefore, it is possible to prevent the plasma P from approaching the capacitor forming portion 30 and prevent the generated plasma P from reaching the vicinity of the capacitor forming portion 30 .

A second embodiment of the plasma processing apparatus according to the present invention will be described below with reference to the drawings.
FIG. 6 is an enlarged cross-sectional view showing a capacitor forming portion in this embodiment. In this embodiment, the difference from the above-described first embodiment is the capacitor forming portion 30. Configurations corresponding to those of the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.

As shown in FIG. 6, the capacitor forming portion 30 of the present embodiment has an insulating film 36a and an insulating film 37a formed on the lower surface of the stepped portion 25 at a position close to the conductive band portion 35. As shown in FIG.
The insulating film 36 a is provided between the conductive band portion 35 and the inner contour of the stepped portion 25 .
The insulating film 36a is formed to cover the region 36 in the first embodiment.

The insulating film 37 a is provided on the surface of the step portion 25 closer to the side wall (wall portion) 24 than the conductive band portion 35 .
The insulating film 37a is formed to cover the region 37 in the first embodiment.
The insulating film 37 a may be provided continuously up to a position in contact with the upper end surface of the side wall (wall portion) 24 in the stepped portion 25 .

Both the insulating film 36a and the insulating film 37a are made of an insulator.
The insulating film 36a and the insulating film 37a can be made of an alumite alloy or the like.
Insulating film 36a and insulating film 37a have the same thickness dimension.
The insulating film 36a and the insulating film 37a form an insulating member.

A peripheral portion of the conductive band portion 35 is covered with an insulating film 36a and an insulating film 37a.
The conductive band portion 35 is formed by removing the insulating film 36 and the insulating film 37 formed on the entire surface on the lower surface of the stepped portion 25 .
The conductive band portion 35 is recessed from the insulating films 36 a and 37 a on the lower surface of the step portion 25 .
The film thickness of the insulating film 36a and the insulating film 37a, that is, the recessed dimension of the conductive band portion 35 can be set to 0.1 mm to 1 mm.

In the capacitor forming portion 30 of the present embodiment, since the conductive band portion 31 is formed on the upper surface of the base plate 17, the conductive band portion 31 and the conductive band portion facing the conductive band portion 31 are formed in the same manner as in the first embodiment. 35 can form a capacitor in the path of the high frequency return current.

In this embodiment, the same effects as those of the above-described first embodiment can be obtained.

Furthermore, in this embodiment, the width dimension of the conductive band portion 35 can be set by the insulating film 36a and the insulating film 37a.
That is, the width dimension of the conductive band portion 35 can be set by the insulating films 36a and 37a, and the size of the capacitor in the path of the high-frequency return current can be set by the conductive band portions 31 and 35. . In this case, it is possible to set the width dimension of the conductive band portion 31 and the conductive band portion 35 to be equal, or set the width dimension of the conductive band portion 31 and the conductive band portion 35 to be different.

Other examples of embodiments of the present invention will be described below with reference to the drawings.
FIG. 7 is a top view showing an example of arranging the conductive band portion on the upper surface of the base plate 17 in the embodiment of the present invention.
Note that the ground plate 19, the board insulating cover 82, and the like are omitted in the figure.

In this example, the conductive band portion 31a is provided on the upper surface of the base plate 17 up to the outer periphery of the contour.
Accordingly, the insulating film 33 is not provided on the upper surface of the base plate 17 .

In this example, the same effects as those of the above-described embodiments can be obtained.

Other examples of embodiments of the present invention will be described below with reference to the drawings.
FIG. 8 is a top view showing an example of arranging the conductive band portion on the upper surface of the base plate 17 in the embodiment of the present invention.
Note that the ground plate 19, the board insulating cover 82, and the like are omitted in the figure.

In this example, the conductive band portion 31 b and the conductive band portion 31 c are double provided on the upper surface of the base plate 17 so as to be concentric with the contour of the base plate 17 .
That is, the conductive band portion 31b and the conductive band portion 31c are provided parallel to each other.
An insulating film 32a is provided between the conductive band portion 31b and the conductive band portion 31c.
Thereby, the width dimension of the insulating film 33 in the radial direction of the base plate 17 is reduced.

In this example, the same effects as those of the above-described embodiments can be obtained.

Other examples of embodiments of the present invention will be described below with reference to the drawings.
FIG. 9 is a top view showing an example of arranging the conductive band portion on the upper surface of the base plate 17 in the embodiment of the present invention.
Note that the ground plate 19, the board insulating cover 82, and the like are omitted in the figure.

In this example, the conductive band portion 31d is intermittently provided around the upper surface of the base plate 17 in the form of a broken line. The conductive band portions 31d are arranged so that the lengths of the line segments at the breaking lines are substantially equal.
Thus, the insulating films 32 and 33 have continuous portions.

In this example, the same effects as those of the above-described embodiments can be obtained.

Other examples of embodiments of the present invention will be described below with reference to the drawings.
FIG. 10 is a top view showing an example of arranging the conductive band portion on the top surface of the base plate 17 in the embodiment of the present invention.
Note that the ground plate 19, the board insulating cover 82, and the like are omitted in the figure.

In this example, the conductive band portion 31 e is provided intermittently around the upper surface of the base plate 17 . The conductive band portions 31e are arranged as four straight lines corresponding to each side of the contour shape of the rectangular base plate 17 . The conductive band portion 31 e is not continuous in the circumferential direction of the base plate 17 at portions corresponding to corners of the contour shape of the rectangular base plate 17 .

Thus, the insulating films 32 and 33 have continuous portions at portions corresponding to corners of the contour shape of the rectangular base plate 17 .

In this example, the same effects as those of the above-described embodiments can be obtained.

Other examples of embodiments of the present invention will be described below with reference to the drawings.
FIG. 11 is a top view showing an example of arranging the conductive band portion on the top surface of the base plate 17 in the embodiment of the present invention.
Note that the ground plate 19, the board insulating cover 82, and the like are omitted in the figure.

In this example, the conductive band portion 31f is intermittently provided around the upper surface of the base plate 17 . The conductive band portions 31f are arranged as four straight lines corresponding to each side of the contour shape of the rectangular base plate 17 . The conductive band portion 31f is not continuous in the circumferential direction of the base plate 17 at portions corresponding to the central portions of the four sides of the outline shape of the rectangular base plate 17 . The conductive band portion 31f is formed in a continuous L shape at portions corresponding to corners of the contour shape of the rectangular base plate 17 .
Thus, the insulating films 32 and 33 have continuous portions at portions corresponding to the central portions of the four sides of the contour shape of the rectangular base plate 17 .

In this example, the same effects as those of the above-described embodiments can be obtained.

It is preferable that the capacitance of the capacitor formed in the capacitor forming portion 30 is 100 pF or more.
The width of the conductive band portion 31 in the capacitor forming portion 30 is preferably 10 mm or more, more preferably 20 mm or more.
A gap G between the step portion 25 and the base plate 17 is preferably 0.1 mm or more and 10 mm or less, and more preferably 0.5 mm or more and 5 mm or less.

Application examples of the present invention include a plasma CVD apparatus, a plasma etching apparatus, a plasma doping apparatus, and the like.

1... Plasma processing apparatus 2... Vacuum chamber (chamber)
2a Film-forming space 4 Electrode flange 5 Shower plate 6 Gas ejection port 7 Gas introduction pipe 9 High-frequency power supply 10 Substrate 10a Processing surface 11 Bottom (inner bottom)
12... Matching box 13... Shield cover 14... Space 15... Susceptor (support part)
16... Column 16A... Base lifting drive section (lifting drive section)
DESCRIPTION OF SYMBOLS 17... Base plate 18... Support|pillar 19... Earth plate 23... High frequency electrode support part 24... Wall part (side wall)
25 Stepped portion 26 Loading/unloading portion 26a Door valve 27 Exhaust pipe 28 Vacuum pump 30 Capacitor forming portion 31 Conductive band portions 31a, 31b, 31c, 31d, 31e, 31f, 35 Conductive band portions 32, 32a, 33, 36a, 37a... Insulating film 41... Upper plate 42... Gas introduction port 43... Peripheral wall 81... Insulating flange 82... Substrate insulating cover 101... Processing chamber G... Gap
G... Gap P... Plasma

Claims (12)

A plasma processing apparatus,
an electrode flange;
a chamber having sidewalls and a bottom;
an insulating flange positioned between the chamber and the electrode flange;
a processing chamber comprising the chamber, the electrode flange, and the insulating flange and having a reaction chamber;
a support unit on which a substrate having a processing surface is placed in the reaction chamber and capable of controlling the temperature of the substrate;
an elevation drive unit that drives the support unit up and down;
a high-frequency power source connected to the electrode flange and applying a high-frequency voltage;
a base plate having an upper surface electrically connected to the lower surface of the support and positioned radially outward of the support;
a base elevation driving unit that vertically drives the base plate independently of the support;
a capacitor forming portion provided around the edge of the upper surface of the base plate;
a capacitor forming portion formed on the side wall of the chamber and circumferentially arranged at a position facing the capacitor forming portion of the base plate on a lower surface facing the bottom;
has
elevating the base plate by the base elevating drive unit to form a gap between the upper surface of the base plate and the lower surface of the chamber;
A plasma processing apparatus according to claim 1, wherein a capacitor for a high-frequency return current during plasma formation is formed at a position corresponding to the entire circumference of the substrate between the capacitor forming portions facing each other. The capacitor forming portion is provided around the edge of the upper surface of the base plate, and the lower surface formed on the side wall of the chamber and facing the bottom portion is provided around the base plate at a position facing the capacitor forming portion. 2. The plasma processing apparatus according to claim 1, wherein said capacitor forming portion has a substantially uniform width dimension in a radial direction of said substrate in a circumferential direction of said substrate. The capacitor forming portion is provided around the edge of the upper surface of the base plate, and the lower surface formed on the side wall of the chamber and facing the bottom portion is provided around the base plate at a position facing the capacitor forming portion. 3. The plasma processing apparatus according to claim 1, wherein said capacitor forming portion is formed continuously or intermittently in the circumferential direction of said substrate. 4. The plasma processing apparatus according to any one of claims 1 to 3, wherein an insulating member is arranged on at least one of the upper surface of the base plate and the lower surface of the chamber, which face each other. At least the capacitor forming portion peripherally provided on the edge of the upper surface of the base plate is formed to be more concave than the insulating member on the upper surface of the adjacent base plate ,
The capacitor forming portion formed on the side wall of the chamber and circumferentially arranged at a position facing the capacitor forming portion of the base plate on the lower surface toward the bottom is positioned higher than the insulating member on the lower surface of the adjacent chamber. Concavely formed or flush and continuous with an adjacent region of the lower surface
5. The plasma processing apparatus according to claim 4, wherein: 6. The plasma processing apparatus according to any one of claims 1 to 5, wherein an insulating member is arranged radially outward of the substrate on the upper surface of the supporting portion. 7. The plasma processing apparatus according to any one of claims 1 to 6, wherein said base plate and said support are electrically connected by an earth plate. The processing chamber is provided with a shower plate electrically connected to the electrode flange and positioned above the reaction chamber,
7. The plasma processing apparatus according to any one of claims 1 to 6, wherein an inner peripheral contour of said capacitor forming portion of said base plate is larger than an outer peripheral contour of said shower plate exposed to said reaction chamber. The side wall of the chamber is provided with a stepped portion so that the diameter of the reaction chamber is larger at a position closer to the bottom than at a position closer to the electrode flange,
8. The plasma processing apparatus according to any one of claims 1 to 7, wherein the capacitor forming portion is formed on the lower surface of the stepped portion facing the bottom portion. 10. The plasma processing apparatus according to claim 9, wherein the inner peripheral contour of said stepped portion is larger than the outer peripheral contour of said support portion. The side wall of the chamber is provided with a loading/unloading part used for loading/unloading the substrate into/from the reaction chamber,
11. The plasma processing apparatus according to claim 9, wherein the lower surface of the stepped portion is provided at a position closer to the electrode flange than the loading/unloading portion. 3. The capacitor forming portion on the upper surface of the base plate facing the lower surface of the chamber is electrically connected to the capacitor forming portion on the lower surface facing the upper surface of the base plate. 12. The plasma processing apparatus according to any one of 1 to 11.

Images