KR20230144962A - Shower plate and plasma processing apparatus - Google Patents

Abstract

The present invention relates to shower plates and plasma processing devices. The shower plate of the present invention includes a plasma formation surface, a gas supply surface, a plurality of gas flow paths, a plurality of hollow cathode slits formed on the plasma formation surface, and a plurality of hollow cathode slits disposed inside each of the plurality of hollow cathode slits. It has a gas outlet. The plurality of hollow cathode slits are arranged so as not to intersect each other. The plurality of gas flow paths are opened inside each of the plurality of hollow cathode slits. The plasma formation surface has a plurality of depth setting areas. In each of the plurality of depth setting regions, each depth of the plurality of hollow cathode slits in the thickness direction is set to be large. Boundaries of two adjacent depth setting areas among the plurality of depth setting areas and each of the plurality of hollow cathode slits do not intersect each other.

Description

SHOWER PLATE AND PLASMA PROCESSING APPARATUS}

The present invention relates to shower plates and plasma processing devices.

Conventionally, plasma processing devices are known that use plasma to decompose raw material gas and form a thin film on, for example, a film-forming surface of a substrate. In this plasma processing apparatus, for example, as shown in Patent Documents 1 and 2, a processing chamber is comprised of 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).

In the processing chamber, a susceptor on which a shower plate and a substrate are placed is installed. The shower plate is connected to the electrode flange and has a plurality of jet outlets. A space is formed between the shower plate and the electrode flange. This space is a gas supply space into which raw material gas is introduced. That is, the shower plate divides the space within the processing chamber into a film formation space where a film is formed on the substrate and a gas supply space.

Here, in the manufacture of flat panel displays (FPDs) such as liquid crystal displays and organic EL displays, processes such as plasma CVD are performed on substrates having a large area. In plasma processing of such a substrate, it is difficult to control the film thickness distribution of the film formed on the substrate. It is necessary to precisely control the electron density, plasma density, and radical density on the surface of the substrate.

In order to perform such control, it is known to install a cathode cavity in the shower plate that becomes the cathode and use the hollow cathode effect. Specifically, a shower plate having a cathode cavity is known. A method of forming a cathode cavity in such a shower plate is disclosed, for example, in Patent Document 1. Patent Document 1 discloses a method of providing a deep hole or groove having a concave shape on the substrate-facing surface of a shower plate facing the substrate, and simultaneously increasing the depth of the hole or groove. Additionally, a method of enlarging the opening of a hole or groove on the outside of the substrate along the opposing surface of the substrate has also been disclosed.

Similarly, a method of forming grooves on the surface of a shower plate is known (Patent Document 2).

[Patent Document 1] US Patent No. 10262837 Specification [Patent Document 2] Japanese Patent Application Publication No. 2002-025984

However, in the conventional technology, the control of the plasma generation density is not sufficient, and the accuracy of the film thickness distribution of the film formed on the substrate is not sufficient. For this reason, there has been a desire to improve the control of plasma generation density and the accuracy of film thickness distribution. In addition, if a slit (groove) is formed in a shower plate with a large area and the shower plate is designed to ensure good film thickness distribution, protrusions, acute angles, and steps will appear within the slit, causing abnormal discharge. There was.

The present invention has been made in consideration of the above circumstances, and seeks to achieve the following objectives.

1. To improve the film thickness distribution of the film formed on the substrate.

2. Enables plasma generation at high density.

3. Stabilize the plasma distribution density along the processing surface of the substrate and improve the uniformity of plasma processing.

4. Suppressing the occurrence of abnormal discharge.

A shower plate according to an embodiment of the present invention supplies a processing gas uniformly from the gas supply space to the plasma formation space within the chamber of the plasma processing apparatus, and serves as a cathode electrode disposed opposite to the anode electrode. A shower plate, comprising: a plasma formation surface facing the anode electrode and in contact with the plasma formation space; a gas supply surface on a side opposite to the plasma formation surface and in contact with the gas supply space; and a thickness of the shower plate. In the direction, a plurality of gas flow paths communicating from the gas supply surface to the plasma formation surface, a plurality of hollow cathodal slits formed in the plasma formation surface, and each interior of the plurality of hollow cathode slits is disposed in and has a plurality of gas jets that evenly supply the processing gas to the entire area of the plasma formation surface, and the plurality of hollow cathode slits are arranged to cover the plasma formation surface and not to intersect each other. The plurality of gas flow paths are opened inside each of the plurality of hollow cathode slits, and the plurality of gas ejection ports are formed in a row along the longitudinal direction of each of the plurality of hollow cathode slits, The plurality of gas jets are capable of supplying the processing gas equally to each of the plurality of hollow cathode slits in each longitudinal direction of the plurality of hollow cathode slits, and the plasma formation surface has a central region and , an edge region, and a plurality of depth setting regions divided into each other along a direction from the center region to the edge region, and in each of the plurality of depth setting regions, the plurality of hollow cathode slits in the thickness direction. Each depth is set to be large, and the boundaries of two adjacent depth setting areas among the plurality of depth setting areas and each of the plurality of hollow cathode slits do not intersect. In this way, the above problem was solved.

In the shower plate according to one embodiment of the present invention, the distance between two gas jets that are adjacent to each other among the plurality of gas jets may be set uniformly in plan view.

In the shower plate according to one embodiment of the present invention, each of the plurality of hollow cathode slits may be formed to extend in a straight line when viewed in plan view.

In the shower plate according to an embodiment of the present invention, the long sides of two adjacent hollow cathode slits among the plurality of hollow cathode slits may be parallel to each other.

In the shower plate according to an embodiment of the present invention, the boundaries of the two adjacent depth setting areas may be arranged along the long side of the hollow cathode slit.

In the shower plate according to an embodiment of the present invention, each of the plurality of depth setting regions is configured so that the positions of the plurality of gas jets in the thickness direction are the same and the plasma formation surface is formed curved. The depth of each of the plurality of hollow cathode slits may be set.

In the shower plate according to an embodiment of the present invention, in each of the plurality of depth setting regions, the positions of the plurality of gas jets in the thickness direction change and the plasma formation surface has a flat surface. The depth of each of the plurality of hollow cathode slits may be set.

In the shower plate according to an embodiment of the present invention, each of the plurality of depth setting regions has a plurality of circumferential regions, and each of the plurality of circumferential regions is divided in the circumferential direction, In each of the plurality of circumferential regions, all of the plurality of hollow cathode slits are arranged in parallel and facing the same direction, and each of the plurality of hollow cathode slits in the central region is adjacent to the central region. It may be arranged parallel to the hollow cathode slit in a circumferential region of one of the depth setting regions and facing in the same direction.

In the shower plate according to an embodiment of the present invention, in each of the plurality of depth setting regions, at the boundary of two adjacent circumferential regions, an end of the hollow cathode slit of one circumferential region is formed. , the ends of the hollow cathode slits in the other circumferential region may be arranged differently.

In the shower plate according to one embodiment of the present invention, the plurality of gas flow paths are formed to extend from the gas outlet toward the gas supply surface, and a plurality of orifices correspond one to one to the plurality of gas flow paths. (orifice), and in all of the plurality of gas flow paths, the lengths of the plurality of orifices in the thickness direction may be the same.

In the shower plate according to one embodiment of the present invention, in plan view, the distance between two gas jets that are adjacent to each other among the plurality of gas jets is 2, which forms plasma while sandwiching the plasma formation space between them. It may be smaller than the distance between two electrodes.

A plasma processing device according to an embodiment of the present invention includes an electrode flange connected to a high-frequency power source, a chamber having a side wall and a bottom, an insulating flange disposed between the chamber and the electrode flange, and the chamber and the electrode flange. It has a processing chamber having a plasma formation space surrounded by an electrode flange and the insulating flange, a substrate accommodated in the processing chamber and having a processing surface is placed, a support portion serving as an anode electrode, and a shower plate according to the above-described embodiment. , the shower plate faces away from the electrode flange to form the gas supply space, and faces away from the support to form the plasma formation space.

A shower plate according to an embodiment of the present invention supplies a processing gas uniformly from the gas supply space to the plasma formation space within the chamber of the plasma processing apparatus, and serves as a cathode electrode disposed opposite to the anode electrode. A shower plate, comprising: a plasma formation surface facing the anode electrode and in contact with the plasma formation space; a gas supply surface on a side opposite to the plasma formation surface and in contact with the gas supply space; and a thickness of the shower plate. In the direction, a plurality of gas flow paths communicating from the gas supply surface to the plasma formation surface, a plurality of hollow cathode slits formed in the plasma formation surface, and a plurality of hollow cathode slits are disposed inside each of the plurality of hollow cathode slits, It has a plurality of gas jets that evenly supply the processing gas to the entire plasma formation surface, and the plurality of hollow cathode slits are arranged so as to cover the plasma formation surface and do not intersect each other, and the plurality of hollow cathode slits are arranged so as to cover the plasma formation surface and do not intersect each other. Inside each hollow cathode slit, the plurality of gas flow paths are opened, the plurality of gas jets are formed in a row along each longitudinal direction of the plurality of hollow cathode slits, and the plurality of gas jets are formed in a row. It is possible to evenly supply the processing gas to each of the plurality of hollow cathode slits in the longitudinal direction of each of the plurality of hollow cathode slits, and the plasma formation surface has a center area and an edge area, and It has a plurality of depth setting areas divided into each other along a direction from the center area to the edge area, and in each of the plurality of depth setting areas, the depth of each of the plurality of hollow cathode slits in the thickness direction is not large. is set so that the boundaries of two adjacent depth setting areas among the plurality of depth setting areas and each of the plurality of hollow cathode slits do not intersect each other.

According to the above configuration, the entire plasma formation surface of the shower plate exposed to the plasma formation space can be covered with hollow cathode slits that do not intersect each other. Compared to a conventional sharp rate having a flat plasma formation surface, plasma processing can be performed with increased plasma density, radical density, and electron density.

Additionally, a single gas jet is formed in the width direction of the hollow cathode slit. A plurality of gas jets are formed in the longitudinal direction of the hollow cathode slit. In the longitudinal direction of the hollow cathode slit, a plurality of gas jets can equally supply processing gas to the hollow cathode slit. A plurality of gas jets are arranged inside the hollow cathode slit. As a result, within each of the plurality of hollow cathode slits, the plurality of gas jets can uniformly supply the processing gas in the longitudinal direction of the hollow cathode slit. In addition, over the entire plasma formation surface, a plurality of gas jets are arranged to enable uniform supply of processing gas. For this reason, it is possible to realize a state in which the plasma density is uniform throughout the plasma formation space.

Moreover, in each of the plurality of depth setting areas divided into each other along the direction from the center area to the edge area, the depth of the hollow cathode slit in the thickness direction is set to be large. For this reason, unlike a conventional shower plate having a flat plasma forming surface, it is possible to prevent the plasma density from decreasing in the edge area (peripheral area) compared to the center area. It becomes possible to realize uniform plasma density across the entire plasma formation surface.

Moreover, the boundaries of two adjacent depth setting areas and each of the plurality of hollow cathode slits do not intersect. For this reason, protruding portions such as steps and protrusions are not formed inside each of the plurality of hollow cathode slits and on the surface exposed to the plasma formation space. Therefore, it is possible to prevent abnormal discharge from occurring during plasma generation.

Through the above-described action, it becomes possible to achieve uniformity in the two-dimensional distribution of plasma processing characteristics along the processing surface of the substrate and to improve the stability of plasma processing characteristics.

Here, the phrase “a plurality of hollow cathode slits cover the plasma formation surface” means that the openings of the plurality of hollow cathode slits on the plasma formation surface are arranged close to each other with a predetermined distance apart, and , This means that a plurality of hollow cathode slits are arranged throughout the plasma formation surface in a state where the distance between the openings of two neighboring hollow cathode slits does not change.

For example, the openings of the plurality of hollow cathode slits may be arranged parallel to each other so that each of the longitudinal directions in which the plurality of hollow cathode slits extend is in the same direction. In this case, in plan view, the hollow cathode is formed so that a plurality of gas jets equally arranged in each of the plurality of hollow cathode slits open along the longitudinal direction at the central position in the width direction of the hollow cathode slit. The opening of the slit can be arranged.

Additionally, the phrase “a plurality of hollow cathode slits are arranged so as not to intersect” means that the opening of the hollow cathode slit on the plasma formation surface does not form a curved corner at either an acute or obtuse angle. do. For example, the openings of a plurality of hollow cathode slits may be arranged to be parallel to each other in the longitudinal direction. Alternatively, this phrase means that when the openings of two hollow cathode slits that are adjacent to each other while running in different directions are close to each other, the opening end of one hollow cathode slit is not at any part of the opening of the other hollow cathode slit. It means the state of not being connected. In other words, in the longitudinal direction of the opening edge of the hollow cathode slit, the opposing distance between parallel opposing sides does not change. Alternatively, this phrase means that the hollow cathode slits are arranged so that when two adjacent hollow cathode slits intersect each other in the longitudinal direction, the respective openings of the plurality of hollow cathode slits are not connected. .

In the shower plate according to one embodiment of the present invention, in plan view, the distance between two gas jets that are adjacent to each other among the plurality of gas jets is set to be uniform.

According to the above configuration, gas can be supplied in uniform distribution to the plasma formation space. As a result, plasma processing can be performed with uniform plasma density distribution, radical density distribution, and electron density distribution. Therefore, it becomes possible to achieve uniformity in the two-dimensional distribution of plasma processing characteristics along the processing surface of the substrate and to improve the stability of plasma processing characteristics.

In the shower plate according to one embodiment of the present invention, each of the plurality of hollow cathode slits is formed to extend in a straight line when viewed in plan view.

According to the above configuration, it becomes possible to easily arrange a plurality of hollow cathode slits so that they are parallel to the longitudinal direction. At the same time, it becomes easy to arrange the boundary of the depth setting area and the hollow cathode slit in parallel. This makes it easy to realize uniform plasma density distribution, uniform radical density distribution, and uniform electron density distribution while preventing the occurrence of abnormal discharge. Therefore, it becomes possible to achieve uniformity in the two-dimensional distribution of plasma processing characteristics along the processing surface of the substrate and to improve the stability of plasma processing characteristics.

In the shower plate according to an embodiment of the present invention, the long sides of two adjacent hollow cathode slits among the plurality of hollow cathode slits are parallel to each other.

According to the above configuration, it becomes easy to arrange the hollow cathode slits at uniform intervals, and it becomes easy to arrange the hollow cathode slits at a uniform density within the depth setting area. This makes it easy to realize uniform plasma density distribution, uniform radical density distribution, and uniform electron density distribution while preventing the occurrence of abnormal discharge. Therefore, it becomes possible to achieve uniformity in the two-dimensional distribution of plasma processing characteristics along the processing surface of the substrate and to improve the stability of plasma processing characteristics.

In the shower plate according to one embodiment of the present invention, the boundaries of the two adjacent depth setting regions are arranged along the long side of the hollow cathode slit.

According to the above configuration, it becomes easy to arrange the border of the depth setting area and the hollow cathode slit in parallel. This makes it easy to realize uniform plasma density distribution, uniform radical density distribution, and uniform electron density distribution while preventing the occurrence of abnormal discharge. Therefore, it becomes possible to achieve uniformity in the two-dimensional distribution of plasma processing characteristics along the processing surface of the substrate and to improve the stability of plasma processing characteristics.

In the shower plate according to an embodiment of the present invention, each of the plurality of depth setting regions is configured so that the positions of the plurality of gas jets in the thickness direction are the same and the plasma formation surface is formed curved. The depth of each of the plurality of hollow cathode slits is set.

The method for setting each depth of a plurality of hollow cathode slits is as follows. When changing the depth of the hollow cathode slit depending on the plasma formation surface (according to the longitudinal or width direction of the plasma formation surface), a hollow cathode slit of the same depth is formed on the entire surface of the plasma formation surface. After that, the depths of each of the plurality of hollow cathode slits are set according to the depth of the hollow cathode slit set in each of the plurality of depth setting areas. Specifically, the hollow cathode slit is formed so that the hollow cathode slit becomes deeper in the central area of the plasma formation surface. In addition, the plasma formation surface is removed so that the hollow cathode slit becomes shallow as it goes from the center region of the plasma formation surface to the edge region, forming a hollow cathode slit. This makes it possible to easily form a hollow cathode slit with a predetermined depth. Additionally, a plurality of hollow cathode slits of different depths can be formed with high precision on the entire surface simply by shaving the surface of the flat plate. It becomes possible to reduce the number of steps in the manufacturing process, shorten the manufacturing time, and reduce manufacturing costs. At the same time, it becomes possible to manufacture shower plates with high processing precision. For this reason, it becomes possible to easily obtain uniformity in the two-dimensional distribution of plasma processing characteristics along the processing surface of the substrate and improve the stability of plasma processing characteristics.

In the shower plate according to an embodiment of the present invention, in each of the plurality of depth setting regions, the positions of the plurality of gas jets in the thickness direction change and the plasma formation surface has a flat surface. The depth of each of the plurality of hollow cathode slits may be set.

The method for setting each depth of a plurality of hollow cathode slits is as follows. Depending on the plasma formation surface (along the longitudinal or width direction of the plasma formation surface), the depth of the hollow cathode slit is changed to a value set in the depth setting area to form a hollow cathode slit. In addition, a gas outlet and a gas flow path are formed corresponding to the bottom position in the hollow cathode slit that changes in the thickness direction. This makes it possible to easily form a hollow cathode slit with a predetermined depth. At the same time, it is possible to maintain the planar shape of the plasma forming surface, which is the cathode electrode. For this reason, it becomes easy to reduce the influence on plasma processing characteristics by varying the distance between the two electrodes that form plasma.

In the shower plate according to an embodiment of the present invention, each of the plurality of depth setting regions has a plurality of circumferential regions, and each of the plurality of circumferential regions is divided in the circumferential direction, In each of the plurality of circumferential regions, all of the plurality of hollow cathode slits are arranged in parallel and facing the same direction, and each of the plurality of hollow cathode slits in the central region is adjacent to the central region. It is arranged parallel to the hollow cathode slit in a circumferential region of one of the depth setting regions and facing the same direction.

According to the above configuration, all hollow cathode slits are arranged in parallel and facing the same direction in each of the plurality of circumferential regions in the plurality of depth setting regions. For this reason, uniform gas supply can be easily performed in each of the plurality of circumferential regions. It becomes easy to realize uniform plasma density distribution, uniform radical density distribution, and uniform electron density distribution in each of the plurality of circumferential regions. At the same time, it becomes easy to uniformly arrange the hollow cathode slits even in the central area. For this reason, it becomes easy to realize uniform plasma density distribution, uniform radical density distribution, and uniform electron density distribution while preventing the occurrence of abnormal discharge.

In the shower plate according to an embodiment of the present invention, in each of the plurality of depth setting regions, at the boundary of two adjacent circumferential regions, an end of the hollow cathode slit of one circumferential region is formed. , the ends of the hollow cathode slits in the other circumferential regions are arranged differently.

According to the above configuration, in the plasma formation space, the processing gas flows radially from the center along the plasma formation surface. At this time, it is possible to prevent the processing gas from reaching the edge of the plasma formation surface without crossing the hollow cathode slit during the flow of the processing gas. That is, in hollow cathode slits arranged so that their ends are different from each other at the boundary of two adjacent circumferential regions, a configuration in which the hollow cathode slit intersects with the flow of the processing gas flowing along the plasma formation surface can be easily realized. It can be. Thereby, the hollow cathode effect can be fully exhibited. Moreover, it becomes easy to realize the required plasma density distribution, radical density distribution, and electron density distribution over the entire length of the flow of the processing gas along the radial direction.

In the shower plate according to one embodiment of the present invention, the plurality of gas flow paths are formed to extend from the gas outlet toward the gas supply surface, and a plurality of orifices correspond one to one to the plurality of gas flow paths. In all of the plurality of gas flow paths, the lengths of the plurality of orifices in the thickness direction are equal to each other.

According to the above configuration, the flow rate of the processing gas ejected from the gas ejection port into the hollow cathode slit is controlled by the orifice. As a result, the flow rate of the processing gas at each of the plurality of gas jets can be made uniform. Moreover, even in a plurality of hollow cathode slits of different depths, the length of the orifices is the same for all orifices. For this reason, the flow rate of the processing gas can be controlled.

In the shower plate according to one embodiment of the present invention, in plan view, the distance between two gas jets that are adjacent to each other among the plurality of gas jets is 2, which forms plasma while sandwiching the plasma formation space between them. is less than the distance between the two electrodes.

In order to obtain the desired plasma density, radical density, and electron density required for plasma processing performed in the plasma formation space, it becomes possible to supply the necessary processing gas to the plasma formation space evenly along the plasma formation surface.

A plasma processing device according to an embodiment of the present invention includes an electrode flange connected to a high-frequency power source, a chamber having a side wall and a bottom, an insulating flange disposed between the chamber and the electrode flange, and the chamber and the electrode flange. It has a processing chamber having a plasma formation space surrounded by an electrode flange and the insulating flange, a substrate accommodated in the processing chamber and having a processing surface is placed, a support portion serving as an anode electrode, and a shower plate according to the above-described embodiment. , the shower plate faces away from the electrode flange to form the gas supply space, and faces away from the support to form the plasma formation space.

According to the above configuration, the entire plasma formation surface of the shower plate exposed to the plasma formation space can be covered with a plurality of hollow cathode slits that do not intersect each other. Plasma treatment, such as film formation by plasma CVD, can be performed on a substrate supported on a supporter with increased plasma density, radical density, and electron density compared to the conventional sharp rate with a flat plasma formation surface. .

In addition, a single gas outlet is formed in the width direction of the hollow cathode slit. A plurality of gas jets are formed in the longitudinal direction of the hollow cathode slit. In the longitudinal direction of the hollow cathode slit, a plurality of gas jets can equally supply processing gas to the hollow cathode slit. A plurality of gas jets are arranged inside the hollow cathode slit. As a result, within each of the plurality of hollow cathode slits, the plurality of gas jets can supply the processing gas uniformly in the longitudinal direction of the hollow cathode slit. In addition, on the entire surface of the plasma formation surface and the entire surface of the substrate, a plurality of gas jets are arranged to enable uniform supply of processing gas. For this reason, it is possible to realize a state in which the plasma density is uniform throughout the plasma formation space. Therefore, uniform film formation, etc. can be realized.

Additionally, in each of the plurality of depth setting regions facing outward in the longitudinal or width direction of the plasma formation surface, the depth of the hollow cathode slit in the thickness direction is set to be large. For this reason, it is possible to prevent the plasma density from decreasing at the periphery compared to the center, as in the conventional sharp rate having a flat plasma formation surface without a hollow cathode slit. According to the above configuration, it becomes possible to realize uniform plasma density over the entire plasma formation surface and perform uniform film formation, etc.

Additionally, the boundary of the depth setting area and the hollow cathode slit do not intersect each other. For this reason, protruding portions such as steps and protrusions are not formed on the inside of the hollow cathode slit and on the surface exposed to the plasma formation space. Therefore, it is possible to prevent abnormal discharge from occurring during plasma generation.

This makes it possible to achieve uniformity in the two-dimensional distribution of plasma processing characteristics along the processing surface of the substrate, and to prevent deterioration of film formation characteristics due to abnormal discharge and improve its stability.

According to the shower plate and plasma processing device according to an embodiment of the present invention, the film thickness distribution of the film formed on the substrate can be improved. High plasma density can improve processing uniformity. The plasma distribution density can be stabilized along the processing surface of the substrate, and the uniformity of plasma processing can be improved.

[Figure 1] A schematic longitudinal cross-sectional view showing a plasma processing apparatus according to a first embodiment of the present invention.
[FIG. 2] A schematic plan view showing a gas jet port of a shower plate in the plasma processing device according to the first embodiment of the present invention.
[FIG. 3] is a perspective view showing the shower plate in the plasma processing device according to the first embodiment of the present invention, and showing parts of the gas flow path, gas jet outlet, and hollow cathode slit.
[FIG. 4] is a perspective view of the shower plate in the plasma processing device according to the first embodiment of the present invention, and is a perspective view showing another example of the gas flow path, gas jet outlet, and hollow cathode slit.
[FIG. 5] A plan view showing the opening of the hollow cathode slit and the gas jet port of the shower plate in the plasma processing device according to the first embodiment of the present invention.
[FIG. 6] A plan view showing another example of the opening of the hollow cathode slit of the shower plate and the gas jet port in the plasma processing device according to the first embodiment of the present invention.
[FIG. 7] A plan view showing another example of the opening of the hollow cathode slit of the shower plate and the gas jet port in the plasma processing device according to the first embodiment of the present invention.
[FIG. 8] A perspective view showing a hollow cathode slit in an area near the edge area of a shower plate in the plasma processing apparatus according to the first embodiment of the present invention.
[FIG. 9] A perspective view showing a hollow cathode slit in an area near the center area of the shower plate in the plasma processing device according to the first embodiment of the present invention.
[FIG. 10] A plan view showing the depth setting area of the hollow cathode slit of the shower plate in the plasma processing device according to the first embodiment of the present invention.
[FIG. 11] A cross-sectional view showing the depth setting area of the hollow cathode slit of the shower plate in the plasma processing device according to the first embodiment of the present invention.
[FIG. 12] A cross-sectional view showing the boundary of adjacent depth setting areas of a shower plate in the plasma processing device according to the first embodiment of the present invention.
[FIG. 13] A cross-sectional view showing the relationship between the depth of the hollow cathode slit and the plasma formation surface.
[FIG. 14] A cross-sectional view showing the state of plasma formation in the hollow cathode slit of the shower plate in the plasma processing device according to the first embodiment of the present invention.
[Figure 15] A perspective view showing an example of a hollow cathode slit of a shower plate.
[FIG. 16] A cross-sectional view showing another example of the depth setting area of the hollow cathode slit of the shower plate in the plasma processing device according to the first embodiment of the present invention.
[FIG. 17] A cross-sectional view showing the depth setting area of the hollow cathode slit of the shower plate in the plasma processing device according to the second embodiment of the present invention.
[FIG. 18] A cross-sectional view showing the boundary of adjacent depth setting areas of a shower plate in the plasma processing device according to the second embodiment of the present invention.
[FIG. 19] A cross-sectional view showing the boundary of the depth setting area of the hollow cathode slit of the shower plate in the plasma processing device according to the second embodiment of the present invention.
[FIG. 20] A cross-sectional view showing the state of plasma formation in the plasma processing device according to the second embodiment of the present invention.
[FIG. 21] A plan view showing the depth setting area of the gas jet port of the shower plate and the hollow cathode slit in the plasma processing device according to the third embodiment of the present invention.
[FIG. 22] A plan view showing the depth setting area of the gas jet port of the shower plate and the hollow cathode slit in the plasma processing device according to the fourth embodiment of the present invention.
[FIG. 23] A plan view showing the depth setting area of the gas jet port of the shower plate and the hollow cathode slit in the plasma processing device according to the fifth embodiment of the present invention.
[FIG. 24] A plan view showing the depth setting area of the gas jet port of the shower plate and the hollow cathode slit in the plasma processing device according to the sixth embodiment of the present invention.
[FIG. 25] A plan view showing the depth setting area of the gas jet port of the shower plate and the hollow cathode slit in the plasma processing device according to the seventh embodiment of the present invention.
[FIG. 26] A plan view showing the depth setting area of the gas jet port of the shower plate and the hollow cathode slit in the plasma processing device according to the eighth embodiment of the present invention.
[FIG. 27] A diagram showing an embodiment of a shower plate and a plasma processing device in the present invention.
[FIG. 28] A diagram showing an embodiment of the shower plate and plasma processing device in the present invention.
[FIG. 29] A diagram showing an embodiment of the shower plate and plasma processing device in the present invention.
[FIG. 30] A diagram showing an embodiment of a shower plate and a plasma processing device in the present invention.
[FIG. 31] A diagram showing an embodiment of a shower plate and a plasma processing device in the present invention.
[FIG. 32] A diagram showing an embodiment of the shower plate and plasma processing device in the present invention.
[FIG. 33] A diagram showing an embodiment of a shower plate and a plasma processing device in the present invention.
[FIG. 34] A diagram showing an embodiment of a shower plate and a plasma processing device in the present invention.
[FIG. 35] A diagram showing an embodiment of a shower plate and a plasma processing device in the present invention.
[FIG. 36] A diagram showing an embodiment of the shower plate and plasma processing device in the present invention.

<First embodiment>

Hereinafter, a shower plate and a plasma processing device according to the first embodiment of the present invention will be described based on the drawings.

1 is a schematic cross-sectional view showing a plasma processing device according to this embodiment. In FIG. 1, symbol 1 denotes a plasma processing device.

In addition, in each figure used in the following description, the dimensions and proportions of each component may be appropriately different from the actual ones in order to make each component recognizable on the drawing.

Regarding the definition of direction, “up and down direction” is the same as the direction seen from the vertical direction of the plasma processing device 1. When viewed in an upward and downward direction, it is sometimes referred to as planar vision.

The “lateral direction” is a direction perpendicular to the vertical direction. The up and down direction may be referred to as the Z direction. In this case, the lateral direction includes the X direction and Y direction.

The plasma processing device 1 according to this embodiment is a film forming device using the plasma CVD method. As shown in FIG. 1 , the plasma processing apparatus 1 includes a processing chamber 3 having a plasma formation space 2a (film formation space) that is a reaction chamber.

The processing chamber 3 is composed of a vacuum chamber 2 (chamber), a cathode flange 4 (electrode flange), and an insulating flange 23 held between the vacuum chamber 2 and the cathode flange 4. .

<Vacuum chamber (2)>

The vacuum chamber 2 is built around the bottom 11 (fundus surface), the side wall 24 (wall portion) erected from the periphery of the bottom 11, and the end opening (top opening) of the side wall 24. It has an installed flange (21). The vacuum chamber 2 is made of aluminum and aluminum alloy.

A bottom opening is formed in the bottom 11 of the vacuum chamber 2. A support 16 is inserted into this bottom opening. The support 16 is disposed at the lower part of the vacuum chamber 2.

The tip of the strut 16 is located within the vacuum chamber 2. A plate-shaped susceptor 15 (support portion) is connected to the tip of the strut 16. The susceptor 15 is arranged in parallel with the plasma formation surface 100a, which is the lower surface of the shower plate 100, which will be described later.

The support post 16 is connected to a lifting drive unit 16A (elevating mechanism) installed outside the vacuum chamber 2. The support column 16 is movable in the vertical direction by the lifting drive unit 16A. That is, the susceptor 15 connected to the tip of the strut 16 is configured to be capable of being raised and lowered in the vertical direction.

Outside the vacuum chamber 2, a bellows (not shown) is installed to cover the outer circumference of the support column 16. When the support column 16 moves up and down, the plasma formation space 2a is kept sealed by the bellows.

An exhaust pipe 27 is connected to the vacuum chamber 2 at a position closer to the bottom 11 than the susceptor 15. A vacuum pump 28 is installed at the tip of the exhaust pipe 27. The vacuum pump 28 reduces the pressure so that the inside of the vacuum chamber 2 becomes a vacuum state.

<Installation flange (21)>

An installation flange 21 is installed at the upper end of the side wall 24 of the vacuum chamber 2.

The mounting flange 21 is installed around the side wall 24 so as to protrude from the end opening of the side wall 24 toward the outside of the mounting flange 21 . The side wall 24 and the mounting flange 21 are each made of a conductive material. The side wall 24 and the mounting flange 21 may be integrated or may be separate members. For example, when the side wall 24 and the mounting flange 21 are composed of separate members, a seal member such as an O-ring may be placed between the side wall 24 and the mounting flange 21. The side wall 24 and the mounting flange 21 are formed of aluminum, aluminum alloy, etc. The upper surface 21a of the mounting flange 21 has a substantially horizontal planar shape.

<Cathode flange (4), shower plate (100)>

The cathode flange 4 is mounted on the upper part of the vacuum chamber 2 through the insulating flange 23.

The shape of the cathode flange 4 is substantially flat. The cathode flange 4 covers the end opening of the vacuum chamber 2 formed by the mounting flange 21 . The cathode flange 4 has a peripheral portion 4a. The lower surface of the peripheral portion 4a of the cathode flange 4 faces the upper surface 21a of the mounting flange 21. The lower surface of the peripheral portion 4a of the cathode flange 4 is positioned substantially parallel to the upper surface 21a of the mounting flange 21.

A shield cover may be placed above the cathode flange 4. Below the cathode flange 4, a shower plate 100 is arranged to be spaced apart from the cathode flange 4 in the vertical direction.

The shower plate 100 is located below the cathode flange 4. In the transverse direction of the cathode flange 4, the shower plate 100 is located inside the installation flange 21. The shower plate 100 is arranged parallel to the lower surface of the cathode flange 4. The gas supply surface 100b, which is the upper surface of the shower plate 100, is arranged parallel to the lower surface of the cathode flange 4. The shower plate 100 hangs from the cathode flange 4. The shower plate 100 is supported by a support column 4b extending downward from the lower surface of the cathode flange 4. The support member 4b is made of a conductor. The number of supporting parts 4b is plural. The supporting main portion 4b does not need to be composed of a plurality of members. For example, the shape of the support portion 4b may be a frame shape in the plan view of the cathode flange 4. In this case, the frame-shaped support portion 4b is disposed inside the insulating support portion 8.

The cathode flange 4 and the shower plate 100 are electrically connected to each other by the support member 4b. An insulating support portion 8 is disposed outside the periphery of the shower plate 100. The insulating support portion 8 is disposed outside the shower plate 100 in the horizontal direction. The insulating support portion 8 is located inside the mounting flange 21 in the transverse direction. The insulating support portion 8 and the mounting flange 21 are spaced apart from each other in the horizontal direction. The upper end of the insulating support portion (8) hangs from the cathode flange (4).

A shower plate 100 is in contact with the inside of the insulating support portion 8 in the horizontal direction. The lateral inner contour at the lower end of the insulating support portion 8 is set to limit the extent to which the cathode flange 4 and the shower plate 100 are exposed to the plasma formation space 2a. The insulating support portion 8 functions as an electrode insulating cover.

The cathode flange 4 and the shower plate 100 are spaced apart in the vertical direction and are arranged substantially parallel to each other. As a result, the gas supply space 2c is formed between the cathode flange 4 and the shower plate 100.

The lower surface 4c of the cathode flange 4 faces the shower plate 100. A gas introduction port 7a is provided through the cathode flange 4.

Additionally, a gas introduction pipe 7 is installed between the process gas supply unit 7b installed outside the processing chamber 3 and the gas introduction port 7a.

One end of the gas introduction pipe 7 is connected to the gas introduction port 7a. The other end of the gas introduction pipe 7 is connected to the process gas supply unit 7b.

The gas introduction pipe 7 penetrates the shield cover. Process gas (process gas) is supplied from the process gas supply part 7b to the gas supply space 2c through the gas introduction pipe 7.

The gas supply space 2c functions as a space to stabilize the gas flow, gas composition, gas pressure, etc. into which the process gas is introduced.

In the shower plate 100, a plurality of gas ejection ports 102 and hollow cathode slits 110, as described later, are formed.

The process gas introduced into the gas supply space 2c is ejected from the gas ejection port 102 into the plasma formation space 2a within the vacuum chamber 2.

The cathode flange 4 and the shower plate 100 are each made of a conductive material. A shield cover may be installed around the cathode flange 4 to cover the cathode flange 4. In this case, the shield cover is not in contact with the cathode flange 4. The shield cover is arranged to be electrically connected to the vacuum chamber 2.

A high-frequency power source 9 (high-frequency power source) installed outside the vacuum chamber 2 is connected to the cathode flange 4 through a matching box 12.

The matching box 12 is mounted on the shield cover.

The cathode flange 4 and shower plate 100 constitute a cathode electrode.

The vacuum chamber 2 is grounded through a shield cover. The lower peripheral edge of the shield cover may be mounted in contact with the outer peripheral portion of the installation flange 21.

<Susceptor (15)>

The susceptor 15 is a plate-shaped member with 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 have a built-in heater 14. The susceptor 15 may enable heating and temperature control of the mounted substrate 10 using the heater 14.

The susceptor 15 functions as a ground electrode, that is, an anode electrode. For this reason, the susceptor 15 is formed of a conductive metal or the like. For example, the susceptor 15 is made of aluminum, aluminum alloy, etc.

The susceptor 15 is a member whose surface is made of aluminum or aluminum alloy and whose surface has been subjected to alumite treatment.

When the substrate 10 is placed on the susceptor 15, the substrate 10 and the shower plate 100 are positioned close to and parallel to each other.

The upper surface of the susceptor 15 is maintained parallel to the upper surface 21a of the mounting flange 21. The upper surface of the susceptor 15 maintains a state parallel to the upper surface 21a of the mounting flange 21 even when the height position changes due to movement in the vertical direction by the lifting drive unit 16A.

With the substrate 10 placed on the susceptor 15, if the process gas is ejected from the gas inlet 7a, the process gas is supplied to the gas supply space 2c. The process gas supplied to the gas supply space 2c is supplied to the plasma formation space 2a on the processing surface 10a of the substrate 10 through the shower plate 100.

The susceptor 15 and the substrate 10 are heated by the heater 14 inside the susceptor 15. As a result, the temperature of the substrate 10 is adjusted to a predetermined temperature.

The heater 14 is connected to a power source 14b outside the vacuum chamber 2 by a heater wire 14a inserted into a through hole formed in the approximately central portion of the susceptor 15 and the support 16. there is. The heater wire protrudes downward from the rear surface of the approximately central portion of the susceptor 15 as seen in the vertical direction of the susceptor 15. The power source 14b adjusts the temperatures of the susceptor 15 and the substrate 10 according to the power supplied to the heater 14.

A substrate insulating cover may be installed on the upper surface of the susceptor 15 at a position adjacent to the outside of the substrate 10 in the horizontal direction. The substrate insulating cover surrounds the substrate 10 . The substrate insulating cover is installed around the entire circumference of the substrate 10. The height of the substrate insulating cover may protrude upward from the processing surface 10a of the substrate 10. The height of the substrate insulating cover is, for example, the same as the processing surface 10a of the substrate 10. The height of the substrate insulating cover can be lower than the processing surface 10a of the substrate 10.

<Door valve (26a)>

On the side wall 24 of the vacuum chamber 2, a carrying-in/out portion 26 (carry-out inlet) used to carry out or load the substrate 10 is formed.

A door valve 26a is installed on the outer surface of the side wall 24 of the vacuum chamber 2 to open and close the loading/unloading portion 26. The door valve 26a can slide in the up and down direction, for example.

When the door valve 26a slides downward (in the direction toward the bottom 11 of the vacuum chamber 2), the loading and unloading portion 26 opens. In this state, the substrate 10 can be carried out or brought into the vacuum chamber 2.

Additionally, when the door valve 26a slides upward (in the direction toward the cathode flange 4), the loading/unloading portion 26 closes. In this state, processing (film formation processing) of the substrate 10 can be performed.

<Specific configuration of shower plate 100>

FIG. 2 is a plan view showing the arrangement of gas jets in the shower plate of the plasma processing device according to the present embodiment. FIG. 3 is a perspective view showing the shower plate of the plasma processing device according to the present embodiment, showing the gas flow path and the hollow cathode slit.

In the shower plate 100, a plurality of gas flow paths 101 are formed that communicate in the thickness direction from the gas supply surface 100b to the plasma formation surface 100a.

A part of the gas flow path 101 is a gas outlet 102. The gas jet port 102 opens on the plasma formation surface 100a. As shown in FIG. 2 , the plurality of gas jet ports 102 are evenly arranged on the plasma formation surface 100a of the shower plate 100 in plan view. In other words, in the plurality of gas jets 102, the distance between two adjacent gas jets 102 is the same across the entire plasma formation surface 100a in plan view. Here, the “two gas outlets 102 adjacent to each other” may be referred to as the “closest adjacent gas outlets 102.” That is, two gas jet ports 102 that are adjacent to each other in the plurality of gas jet ports 102 are spaced apart by the same distance. The arrangement spacing, or pitch, of the gas jet nozzles 102 is set to be the same across the entire surface of the plasma formation surface 100a.

In this embodiment, each of the plurality of gas jets 102 is arranged at a position that is the vertex of an equilateral triangle arranged without a gap on the plasma formation surface 100a. In other words, the line connecting the two adjacent gas outlets 102 constitutes one side of an equilateral triangle. That is, the angle formed by two sides of an equilateral triangle with three sides is 60°. In addition, the arrangement of the plurality of gas jets 102 includes a first array in which the plurality of gas jets 102 are lined up in a straight line, and a second array in which the plurality of gas jets 102 are lined up in a straight line while being inclined to the first array. It has an array. The first arrangement and the second arrangement are inclined at 60° or 120°.

Here, in the equilateral triangle in which the gas jet nozzle 102 is arranged, the side extending in the longitudinal direction of the paper in FIG. 2 is parallel to the longitudinal side in the short direction of the outline of the plasma formation surface 100a.

The plurality of gas jets 102 are all located within the hollow cathode slit 110 formed on the plasma formation surface 100a. That is, the gas jet port 102 is not formed to open directly to the plasma formation surface 100a and is located outside the hollow cathode slit 110. Additionally, in FIG. 2, the hollow cathode slit 110 is not shown, and the arrangement of the gas outlet 102 is given priority.

An orifice 102a is formed in the gas flow path 101 at a position close to the gas ejection port 102, that is, at a position close to the plasma formation space 2a. The orifice 102a controls the gas flow from the gas supply space 2c to the plasma formation space 2a. That is, the thickness of the gas flow path 101 at the position close to the gas outlet 102 is becoming thinner. In other words, a plurality of orifices 102a are formed in the shower plate 100. The length of the orifice 102a is set to be the same in any gas flow path 101. As a result, the plurality of orifices 102a are configured so that the gas flow ejected from each of the plurality of gas ejection ports 102 is the same. The thickness of the orifice 102a and the length of the orifice 102a are both set according to the processing conditions specified for the plasma processing performed in the plasma processing apparatus 1.

The orifice 102a extends in the thickness direction of the shower plate 100. The orifice 102a is formed to connect to the hollow cathode slit 110. The lower end opening of the orifice 102a constitutes the gas outlet 102. One orifice 102a is formed corresponding to one gas flow path 101.

The hollow cathode slit 110 is a groove-shaped recess formed in the plasma formation surface 100a. Regarding the shape of the groove-shaped concave portion, the dimension of the hollow cathode slit 110 in the longitudinal direction (110L) is longer than the dimension of the hollow cathode slit 110 in the width direction (110W). Additionally, a plurality of hollow cathode slits 110, as described later, are arranged to cover the entire surface of the plasma formation surface 100a. For this reason, the shape of the groove-shaped recess in the hollow cathode slit 110 is not limited to this embodiment. The dimensions in the width direction (110W) and the dimensions in the longitudinal direction (110L) may be about the same. The shape of the hollow cathode slit 110 is set to obtain the following two, for example.

- The hollow cathode effect can be exerted evenly on the entire surface of the plasma formation surface (100a).

- Do not generate abnormal discharge in front of the plasma formation surface (100a).

The opening position where the gas jet port 102 opens in the hollow cathode slit 110 will be described. As shown in FIG. 3 , the opening position is located at the center of the top surface 111 of the hollow cathode slit 110 in the width direction 110W. That is, as shown in FIG. 3, the gas outlet 102 is exactly at the center between the opposing side wall surfaces 112 where the hollow cathode slit 110 extends in the longitudinal direction 110L (longitudinal direction). Open in Jeongbu-myeon (111).

Moreover, as shown in FIG. 3, the opening position of the gas outlet 102 within the hollow cathode slit 110 is substantially equal in the longitudinal direction 110L on the top surface 111 of the hollow cathode slit 110. They are separated by one interval.

In addition, the opening position of the gas jet port 102 preferably gives priority to the uniformity of gas supply on the plasma formation surface 100a over the arrangement of the hollow cathode slit 110 on the plasma formation surface 100a. For this reason, as long as the opening position of the gas jet port 102 is open to the hollow cathode slit 110, a configuration other than the above arrangement may be adopted.

As shown in FIG. 3, the top surface 111 of the hollow cathode slit 110 may be inclined on both sides toward the center of the width direction 110W. That is, in the top surface 111, the center of the width direction 110W becomes the uppermost position along the longitudinal direction 110L. The hollow cathode slit 110 may have a pentagonal cross-sectional shape along the width direction (110W). In the hollow cathode slit 110 whose cross-sectional shape in the width direction (110W) is pentagonal, it is preferable that all of the gas jet ports 102 open at the vertex, which is the uppermost position.

FIG. 4 is a perspective view of the shower plate of the plasma processing device according to the present embodiment and shows another example of a gas flow path and a hollow cathode slit.

Unlike the structure shown in FIG. 3, the top surface 111 of the hollow cathode slit 110 may be a plane parallel to the plasma formation surface 100a, as shown in FIG. 4. That is, the center of the top surface 111 in the width direction 110W becomes the uppermost position along the longitudinal direction 110L. The hollow cathode slit 110 may have a square cross-sectional shape in the width direction (110W). In this case, basically, the gas jet port 102 can be opened in a rectangular exterior parallel to the plasma formation surface 100a. In addition, the gas jet port 102 is preferably opened at a central position of 110 W in the width direction of the rectangular exterior, but the position of the gas jet port 102 may be slightly shifted in the width direction 110 W.

However, in both cases of FIGS. 3 and 4 , a single gas outlet 102 is formed in the width direction (110W) of the hollow cathode slit 110. The gas jet port 102 is arranged so that the hollow cathode slit formation density in the longitudinal direction 110L is uniform. That is, it is not preferable that a plurality of gas ejection ports 102 are formed in the width direction (110W) of the hollow cathode slit. This is to make the amount of gas ejected into the hollow cathode slit 110 uniform in the width direction (110W) and the longitudinal direction (110L) of the hollow cathode slit 110.

FIG. 5 is a plan view showing the opening of the hollow cathode slit and the gas jet port in the shower plate of the plasma processing device according to the present embodiment.

The hollow cathode slit 110 has an opening 113 having a predetermined shape.

As shown in FIG. 5 , the opening 113 may have a rectangular shape in plan view. The long sides of the opening 113 are arranged parallel to each other.

The opening 113 has the same dimension of 110 W in the width direction. That is, the opening 113 has a shape corresponding to the distance between the side wall surfaces 112 that extend in the longitudinal direction 110L and face each other in parallel.

3 and 4, the depth 110D of the hollow cathode slit 110 is uniform in the longitudinal direction 110L. That is, the dimension from the top surface 111 of the hollow cathode slit 110 to the opening 113 is uniform in the longitudinal direction 110L. Basically, in one hollow cathode slit 110, the depth 110D of the hollow cathode slit 110 is set uniformly and does not change.

3 and 4, the side wall surfaces 112 of the hollow cathode slit 110 in the width direction 110W are parallel to each other in the thickness direction of the shower plate 100. Alternatively, the side wall surface 112 of the hollow cathode slit 110 in the width direction 110W is directed from the top surface 111 to the opening 113 in the thickness direction of the shower plate 100, and the distance between them is apart. It is okay to incline it so that it is outside the base.

FIG. 6 is a plan view showing another example of an opening of a hollow cathode slit and a gas jet port in the shower plate of the plasma processing device according to the present embodiment. Fig. 7 is a plan view showing another example of an opening of a hollow cathode slit and a gas jet port in the shower plate of the plasma processing device according to the present embodiment. As shown in FIG. 6 , the opening 113 may have a rectangular shape with rounded angles in plan view. As shown in FIG. 7 , the opening 113 may have an elliptical shape in plan view.

Fig. 8 is a perspective view showing a hollow cathode slit in a region near an edge region of the shower plate of the plasma processing device according to the present embodiment. Fig. 9 is a perspective view showing a hollow cathode slit in a region near the center region of the shower plate of the plasma processing device according to the present embodiment.

As shown in FIG. 8, the plurality of hollow cathode slits 110 are formed to cover the entire plasma formation surface 100a. Here, “the plurality of hollow cathode slits 110 cover the entire plasma formation surface 100a” means that the arrangement pitch of the hollow cathode slits 110 arranged adjacent to each other in parallel is the pitch of the gas jet port 102. is the same as , and also means that the arrangement pitch of the hollow cathode slits 110 does not change throughout the plasma formation surface 100a.

Alternatively, "the plurality of hollow cathode slits 110 cover the entire plasma formation surface 100a" means that, in the plasma formation surface 100a of the shower plate 100, from the center of the plasma formation surface 100a This means that there is no place where the gas flowing toward the edge does not cross the hollow cathode slit 110. Here, in the plasma formation surface 100a of the shower plate 100, as long as the gas flowing from the center toward the edge does not cross the hollow cathode slit 110, there may be a place where it terminates at a part of the plasma forming surface 100a.

A plurality of hollow cathode slits 110 cover the plasma formation surface 100a and are arranged so as not to intersect each other.

As shown in FIG. 8, the hollow cathode slits 110 that "do not intersect each other" are basically arranged so that the hollow cathode slits 110 adjacent to each other in the width direction 110W are parallel to each other in the longitudinal direction. It means that it has been done.

In addition, the plurality of hollow cathode slits 110 are divided throughout the plasma formation surface 100a without intersecting each other. That is, on the entire surface of the plasma formation surface 100a, each of the plurality of hollow cathode slits 110 is formed in a straight line. Even when the linear hollow cathode slits 110 have different lengths, the plurality of hollow cathode slits 110 are arranged adjacent to each other in parallel.

That is, as shown in FIG. 9, when the longitudinal directions in which the plurality of hollow cathode slits 110 extend are different, the hollow cathode slits 110 do not intersect and all parts maintain a straight shape, so that the hollow cathode slits (110) are 110) is being divided.

The direction of the hollow cathode slit 110 is set for each depth setting area and each circumferential area into which the depth setting area is divided in the circumferential direction. Here, the circumferential direction is a direction along the periphery (outer periphery) of the center region R01, which will be described later.

<Depth setting area, circumferential area>

Hereinafter, the depth setting area and the circumferential direction area will be described.

FIG. 10 is a plan view showing a plurality of depth setting regions of hollow cathode slits in the shower plate of the plasma processing device according to the present embodiment. FIG. 11 is a cross-sectional view showing each of a plurality of depth setting regions of the hollow cathode slit in the shower plate of the plasma processing device according to the present embodiment.

In this embodiment, depth setting areas R01 to R20 are set on the plasma formation surface 100a of the shower plate 100. The depth setting regions R01 to R20 are each set in a ring shape from the center to the periphery of the plasma formation surface 100a of the shower plate 100.

As shown in FIGS. 10 and 11, the depth setting areas R01 to R20 are roughly divided into two depth setting areas. The first depth setting area (first depth setting area) is a central area R01 including the center of the plasma formation surface 100a of the shower plate 100. The second depth setting area (second depth setting area) is a plurality of depth setting areas from the area R02 located next to the center area R01 to the peripheral area R20 located at the edge of the plasma formation surface 100a.

Among the plurality of depth setting areas R02 to R20, area R20 is an area located on the outermost side of the shower plate 100. In the following description, the area R20 may be referred to as the edge area R20. The edge region R20 is in contact with the edge of the plasma formation surface 100a. Additionally, there are cases where the depth setting area is simply referred to as an area. The areas indicated by symbols R01 to R20 may be referred to as the first to twentieth areas indicated by ordinal numbers, respectively.

In this embodiment, 20 depth setting areas R01 to R20 are set, but the number of areas set is not limited to 20. Other setting numbers may be adopted. As long as uniform plasma density can be realized throughout the plasma formation surface 100a, the number of settings for the depth setting areas R01 to R20 is not limited.

The direction from the central region R01 located at the center of the plasma formation surface 100a to the edge region R20 located at the periphery of the plasma formation surface 100a is sometimes referred to as “radially outward.” The direction opposite to the “radial outside” may be referred to as “radial inside.” When “outer” and “inner” are not distinguished, “radial outer” and “radial inner” may simply be referred to as “radial direction.”

For example, the plurality of depth setting areas R02 to R20 are located radially outside the center area R01. Among the plurality of depth setting areas R02 to R20, area R02 is located adjacent to the center area R01 on the outer radial direction. Area R19 is located adjacent to edge area R20 on the radial inner side.

The depth setting regions R01 to R20 are set so that the depth 110D of the hollow cathode slit 110 is different in the thickness direction of the shower plate 100. Within each of the depth setting areas R01 to R20, the hollow cathode slit 110 is set to have the same depth 110D.

In the depth setting areas R01 to R20, the depth of the hollow cathode slit 110 is set to become deeper as the numbers R01 to R20 increase from the center area R01 to the edge area R20. That is, the depth 110D of the hollow cathode slit 110 in the depth setting area R02 adjacent to the outer side in the radial direction is larger than that in the depth setting area R01 (center area).

The depth 110D of the hollow cathode slit 110 in the depth setting area R03 adjacent to the outer side in the radial direction is larger than that in the depth setting area R02. Hereinafter, as the area numbers R03 to R17 increase from the depth setting area R03 to the depth setting area R17, the depth 110D of the hollow cathode slit 110 increases. Moreover, the depth 110D of the hollow cathode slit 110 in the depth setting area R19 adjacent to the outer side in the radial direction is larger than that in the depth setting area R18. The depth 110D of the hollow cathode slit 110 in the depth setting area R20 adjacent to the outer side in the radial direction is larger than that in the depth setting area R19.

Additionally, as shown in FIG. 10, in the depth setting areas R08 to R20, only a part of the ring-shaped area is set. The depth setting regions R08 to R20 are formed in a state in which only a portion of the ring-shaped region is cut by the plasma forming surface 100a having a square outline.

The outer outline shape of the depth setting areas R01 to R20 is set according to a straight line connecting the gas jet ports 102. For this reason, in this embodiment, the outer outline shape of the depth setting areas R01 to R20 is set to a hexagon. In particular, the outer outline shape of the center region R01 is set to a regular hexagon. That is, the outer outline shape of the depth setting areas R01 to R20 is defined by the arrangement of the gas jet port 102.

The hollow cathode slits 110 are arranged along each of the plurality of boundaries RR of the depth setting regions R01 to R20. In other words, each shape of the plurality of boundaries RR of the depth setting areas R01 to R20, that is, the outer outline shape of the depth setting areas R01 to R20, is arranged along the long side of the hollow cathode slit 110.

Each of the depth setting areas R02 to R20 has a plurality of circumferential areas. The plurality of circumferential regions are divided in the circumferential direction. For example, in the depth setting area R03, circumferential areas R03a to R03f divided in the circumferential direction are formed. In the circumferential regions R03a to R03f, the hollow cathode slits 110 are all set to have the same depth. Similarly, in the depth setting area R06, circumferential areas R06a to R06f divided in the circumferential direction are formed. In the circumferential regions R06a to R06f, the depth 110D of the hollow cathode slit 110 is set to be the same.

Inside each of the circumferential regions R02a to R20f, all hollow cathode slits 110 are arranged in parallel and facing the same direction. At the same time, inside each of the circumferential regions R02a to R20f, all hollow cathode slits 110 are arranged facing in the same direction parallel to the outer outline of the circumferential regions R02a to R20f.

For example, the depth setting region R03 shown in FIG. 10 has a plurality of circumferential regions R03a to R03f arranged in order in a counterclockwise direction in the circumferential direction. The circumferential areas R03a to R03f are areas in which the depth setting area R03 is divided into six. The circumferential regions R03a to R03f are divided by parallel lines parallel to each side of the hexagon and boundaries Rab, Rbc, Rcd, Rde, Ref, and Rfa. Here, the boundaries Rab, Rbc, Rcd, Rde, Ref, and Rfa are straight lines passing through the center of the plasma formation surface 100a.

In the circumferential area R03a shown at the central position in the longitudinal direction on the right side of the page of FIG. 10, a straight line serving as the outer boundary RR of the depth setting area R03 extends in the longitudinal direction of the page of FIG. 10. Accordingly, all hollow cathode slits 110 arranged in the area of the circumferential region R03a are parallel to each other and are arranged toward the longitudinal direction of the page of FIG. 10 .

In the circumferential area R03b, which is shown at a position above the circumferential area R03a on the upper right side of the drawing of FIG. 10, the straight line that becomes the outer boundary RR of the depth setting area R03 extends from the center to the right in the left and right direction of the drawing of FIG. 10 rather than the horizontal direction. It is serialized in a direction inclined downward at 60°. Therefore, all hollow cathode slits 110 arranged in the area of the circumferential area R03b are parallel to each other and are inclined 60° downward from the horizontal direction toward the right from the center in the left and right direction of the page of FIG. 10. It is placed towards.

In the circumferential area R03c shown at a position to the left of the circumferential area R03b on the upper left side of the paper in FIG. 10, the straight line that becomes the outer boundary RR of the depth setting area R03 extends from the center to the left in the left and right directions of the paper in FIG. 10 rather than the horizontal direction. It is serialized in a direction inclined downward at 60°. Therefore, all hollow cathode slits 110 arranged in the area of the circumferential area R03c are parallel to each other and are inclined 60° downward from the horizontal direction toward the left from the center in the left and right direction of the page of FIG. 10. It is placed towards.

In the circumferential area R03d shown at the central position in the longitudinal direction on the left side of the page of FIG. 10, a straight line serving as the outer boundary RR of the depth setting area R03 extends in the longitudinal direction of the page of FIG. 10. Accordingly, all hollow cathode slits 110 arranged in the area of the circumferential area R03d are parallel to each other and are arranged toward the longitudinal direction of the page of FIG. 10.

In the circumferential area R03e shown at a position lower than the circumferential area R03d on the lower left side of the drawing of FIG. 10, the straight line that becomes the outer boundary RR of the depth setting area R03 extends from the center to the left in the horizontal direction of the drawing of FIG. 10. It is serialized in a direction inclined upward at 60°. Therefore, all hollow cathode slits 110 arranged in the area of the circumferential area R03e are parallel to each other and are inclined 60° above the horizontal direction toward the left from the center in the left and right direction of the page of FIG. 10. It is placed towards.

In the circumferential area R03f, which is located at a position to the right of the circumferential area R03e and lower than the circumferential area R03a in the lower right side of the drawing of FIG. It is serialized in a direction slanting 60° upward from the horizontal direction toward the right from the center. Therefore, all hollow cathode slits 110 arranged in the area of the circumferential area R03f are parallel to each other and are inclined 60° upward from the horizontal direction toward the right from the center in the left and right direction of the page of FIG. 10. It is placed towards.

In each of the depth setting areas R02 and R04 to R07 other than the depth setting area R03 in FIG. 10, the circumferential areas R02a to R02f, R04a to R04f, R05a to R05f, R06a to R06f, and R07a to R07f are set similarly. . In each of these circumferential regions, all hollow cathode slits 110 are arranged in parallel with each other along the outer peripheral boundaries of the depth setting regions R02 and R04 to R07.

In addition, the depth setting regions R08 to R20 do not have a ring-shaped shape with a hexagonal circumferential shape, but have a shape in which the ring-shaped shape is partially missing. In the depth setting areas R08 to R20, the circumferential areas R08b to R20f are set similarly. In each of the circumferential regions R08b to R20f, all hollow cathode slits 110 are arranged in parallel with each other along the outer boundary RR of the depth setting regions R08 to R20.

In the central region R01 according to the present embodiment, the hollow cathode slits 110 are parallel to each other and are arranged toward the longitudinal direction of the page of FIG. 10 .

In the central region R01, all hollow cathode slits 110 are arranged in parallel with each other along the outer boundary RR of the central region R01. In other words, in the central region R01, one side of the regular hexagonal outer boundary RR is selected, and all hollow cathode slits 110 in the central region R01 are arranged parallel to the selected side.

In the present embodiment, the hollow cathode slits 110 in the central region R01 are arranged to line up in the longitudinal direction of the paper, as shown in FIG. 9 . In the central region R01 of this embodiment, all hollow cathode slits 110 are arranged parallel to each other. Moreover, the hollow cathode slit 110 in the central area R01 is parallel to the hollow cathode slit 110 in the circumferential area R02a and the circumferential area R02d, respectively. Additionally, in the central region R01, the hollow cathode slit 110 of the central region R01 may be arranged so as to be parallel to any one of the circumferential regions R02a to R02f of the depth setting region R02 adjacent to the central region R01.

The reason for adopting the arrangement of the hollow cathode slit 110 in the central region R01 in this way is that if a circumferential region is set for each regular hexagonal outer boundary RR in the central region R01, the straight hollow cathode slit 110 has a length of This is because the dimension in direction 110L becomes too short, which is not desirable. Also, in the center region R01, all hollow cathode slits 110 need to be arranged parallel to each other.

In other words, all hollow cathode slits 110 in the central region R01 are oriented in the same direction parallel to the hollow cathode slits 110 in the circumferential region R02a or circumferential region R02d of the depth setting region adjacent to the central region R01. It is placed towards.

Additionally, the outer boundaries RR of the plurality of circumferential regions R02a to R20f have the same direction in the circumferential direction. Specifically, in the depth setting area R02, there is a boundary Rab between the circumferential area R02a and the circumferential area R02b, which are adjacent to each other in the circumferential direction. In the depth setting area R03 adjacent to the radial outer side of the depth setting area R02, there is a boundary Rab between the circumferential area R03a and the circumferential area R03b, which are adjacent to each other in the circumferential direction. The border Rab in the depth setting area R02 coincides with the border Rab in the depth setting area R03.

Similarly, the boundary Rbc between the circumferential area R02b and the circumferential area R02c coincides with the boundary Rbc between the circumferential area R03b and the circumferential area R03c. The boundary Rcd between the circumferential area R02c and the circumferential area R02d coincides with the boundary Rcd between the circumferential area R03c and the circumferential area R03d. The boundary Rde between the circumferential area R02d and the circumferential area R02e coincides with the boundary Rde between the circumferential area R03d and the circumferential area R03e.

The boundary Ref between the circumferential area R02e and the circumferential area R02f coincides with the boundary Ref between the circumferential area R03e and the circumferential area R03f. The boundary Rfa between the circumferential area R02f and the circumferential area R02a coincides with the boundary Rfa between the circumferential area R03f and the circumferential area R03a.

In this way, in all of the depth setting areas R02 to R20, as shown in Figs. 9 and 10, the boundaries of adjacent circumferential areas coincide at corresponding positions in the circumferential direction.

In the depth setting regions R02 to R20, a plurality of hollow cathode slits 110 in each of a plurality of circumferential regions adjacent to each other face the same direction and are arranged in parallel. For example, even at the border RR between the circumferential region R02a and the circumferential region R03a, the hollow cathode slit 110 in the depth setting region R02 and the hollow cathode slit 110 in the depth setting region R03 face in the same direction. They are arranged in parallel.

In relation to this, in each of the plurality of depth setting regions R02 to R20, at the boundary of two circumferential regions adjacent to each other in the circumferential direction, a hollow cathode slit 110 in one circumferential region and a circumferential edge in the other The hollow cathode slits 110 in the direction area are arranged to face in different directions. For example, in the depth setting region R02, at the boundary Rab between the circumferential region R02a and the circumferential region R02b, which are adjacent to each other in the circumferential direction, the hollow cathode slit 110 of the circumferential region R02a and the circumferential region R02b The hollow cathode slits 110 are arranged facing different directions, as shown in FIG. 9 . Similarly, at the boundary Rbc, the extending direction of the hollow cathode slit 110 in the circumferential region R02b and the extending direction of the hollow cathode slit 110 in the circumferential region R02c are 60° or 120°, as shown in FIG. 9. They are inclined toward each other to form an angle of .

Here, in each of the plurality of depth setting regions R02 to R20, at the boundary of two circumferential regions adjacent to each other in the circumferential direction, the end portion 115 of the hollow cathode slit 110 of one circumferential region is , the end portions 115 of the hollow cathode slits 110 in the other circumferential region are arranged differently along the radial direction.

At the boundary of these two circumferential regions adjacent to each other in the circumferential direction, as shown in FIG. 9, the end portion 115 of the hollow cathode slit 110 of the other circumferential region protrudes into the other circumferential region. In addition, they are arranged so that they are not connected to each other.

That is, as shown in FIG. 9, the following effects can be obtained by the end portion 115 of the hollow cathode slit 110 disposed at the boundary of two circumferential regions adjacent to each other in the circumferential direction. The process gas flows radially outward from the center of the plasma formation space 2a along the plasma formation surface 100a. At this time, during the flow of the process gas, it is arranged to prevent the process gas from reaching the edge of the plasma formation surface 100a without crossing the hollow cathode slit 110.

For example, here, the boundary Rbc between the circumferential area R03b and the circumferential area R03c in the depth setting area R03 will be described. As shown in Fig. 9, consider the case where the end 115 of the hollow cathode slit 110 located in an arbitrary radial direction protrudes leftward from the circumferential region R03b toward the circumferential region R03c rather than the boundary Rbc. In this case, in the circumferential region R03b, the end 115 of the hollow cathode slit 110 adjacent to the radial outer side is drawn to the right of the boundary Rbc toward the circumferential region R03b.

At the same time, at the border Rbc, as shown in FIG. 9, the end 115 of the hollow cathode slit 110 located in an arbitrary radial direction protrudes in the right direction from the circumferential region R03c toward the circumferential region R03b beyond the border Rbc. Consider one case. In this case, in the circumferential region R03c, the end 115 of the hollow cathode slit 110 adjacent to the radial outer side enters the circumferential region R03c to the left of the boundary Rbc.

Here, the hollow cathode slit 110 is provided with an end portion 115 that protrudes in a right direction from the circumferential region R03c toward the circumferential region R03b rather than the boundary Rbc. The hollow cathode slit 110 is provided with an end portion 115 that protrudes in the left direction from the circumferential region R03b toward the circumferential region R03c beyond the boundary Rbc. The end portion 115 protruding to the right and the end portion 115 protruding to the left are arranged at approximately the same position in the circumferential direction.

That is, the end 115 protruding in the right direction and the end 115 protruding in the left direction are arranged on the same straight line from the center of the plasma formation surface 100a toward the outer edge along the radial direction. .

Additionally, the end portions 115 protruding to the right are all arranged at substantially the same position in the circumferential direction. That is, the end portions 115 disposed at different positions in the radial direction and each protruding in the right direction are all disposed on the same straight line from the center of the plasma formation surface 100a to the outer edge along the radial direction.

Additionally, the end portions 115 protruding to the left are all arranged at substantially the same position in the circumferential direction. That is, the end portions 115 disposed at different positions in the radial direction and each protruding in the left direction are all disposed on the same straight line from the center of the plasma formation surface 100a toward the outer edge along the radial direction.

Additionally, the end portions 115 leading in the right direction are all arranged at substantially the same position in the circumferential direction. That is, the ends 115 arranged at different positions in the radial direction and each leading in the right direction are all arranged on the same straight line from the center of the plasma formation surface 100a to the outer edge along the radial direction.

Additionally, the end portions 115 that lead in to the left are all arranged at substantially the same position in the circumferential direction. That is, the ends 115 arranged at different positions in the radial direction and each leading in the left direction are all arranged on the same straight line from the center of the plasma formation surface 100a to the outer edge along the radial direction.

That is, the end portions 115 that protrude or retract in the circumferential direction are respectively located on substantially straight lines in the radial direction in the depth setting regions R02 to R20.

That is, the hollow cathode slits 110 are arranged so that the end portions 115 of the hollow cathode slits 110 are different from each other at the boundary between one circumferential region and the other circumferential region. For this reason, the hollow cathode slit 110 is positioned to intersect the flow of process gas flowing along the plasma formation surface 100a.

At this time, the end portion 115 of one hollow cathode slit 110 approaches the other side wall surface 112, but does not contact it. That is, all hollow cathode slits 110 maintain a straight shape.

FIG. 12 is a cross-sectional view showing the boundary of two depth setting regions adjacent to each other in the shower plate of the plasma processing device according to the present embodiment.

In this embodiment, the depth 110D is changed at the border RR of two adjacent depth setting areas among the depth setting areas R01 to R20, as shown in FIG. 12. That is, the depth 110D of the hollow cathode slit 110 located in one depth setting area is different from the depth 110D of the hollow cathode slit 110 located in the other depth setting area.

Here, in the hollow cathode slit 110 according to the present embodiment, the positions of the plurality of gas jets 102 in the thickness direction of the shower plate 100 do not change throughout the plasma formation surface 100a. Therefore, in each of the depth setting regions R01 to R20, by changing the position of the opening 113 of the plasma formation surface 100a in the thickness direction of the shower plate 100, the depth of the hollow cathode slit 110 ( 110D) is changing.

That is, as shown in FIG. 12, with respect to the depth 110D at a position closer to the center area R01 shown on the left side of FIG. 12 than the border RR, at a position closer to the edge area R20 shown on the right side of FIG. 12 than the border RR. The depth (110D) is large. 12 schematically shows the change in depth 110D on both sides of the boundary RR, but in reality, abnormal discharge such as steps and convexities occurs inside the hollow cathode slit 110. Avoid shapes that do this.

That is, the portion DD such as a step shown in FIG. 13 is not formed on the plasma formation surface 100a corresponding to the boundary RR. At the position corresponding to the boundary RR, the shape of the smooth plasma formation surface 100a changes. Here, the area DD corresponds to the area that causes abnormal discharge to occur.

Therefore, as shown in FIG. 11, a curved surface is formed on the plasma formation surface 100a. This curved surface is loose and concave at the center of the plasma formation surface 100a, and has a concave shape in which the lower profile of the cross-section in the thickness direction is curved in an arc shape toward the outer periphery of the shower plate 100. An opening 113 is formed in the plasma forming surface 100a having this curved surface. For this reason, the depth 110D of the hollow cathode slit 110 is changed and set.

Specifically, the plasma formation surface 100a has a rectangular outline with a side length of 1000 mm or more in plan view. In contrast, the depth of the concave portion of the plasma formation surface 100a in the thickness direction is about several mm.

<Method of manufacturing shower plate 100>

When manufacturing the shower plate 100 according to this embodiment, first, a plate body having a uniform thickness is prepared. A plurality of grooves for forming a plurality of gas flow paths 101, an orifice 102a, a gas outlet 102, and a hollow cathode slit are formed in the plate body. At this time, the length of the orifice 102a in the thickness direction, the position of the gas outlet 102 in the thickness direction, and the depth of the plurality of grooves for forming the hollow cathode slit are all uniform. do. Thereafter, the plasma formation surface 100a is deepened from the center or removed corresponding to the preset depth setting areas R01 to R20. This makes it possible to realize the distribution of the depth 110D of the hollow cathode slit 110 having a predetermined state.

Next, the operation when forming a film on the processing surface 10a of the substrate 10 using the plasma processing device 1 will be explained.

<Plasma treatment process>

When starting processing, first, the vacuum pump 28 is driven and the pressure inside the vacuum chamber 2 is reduced. With the inside of the vacuum chamber 2 maintained at a vacuum, the door valve 26a opens, and the plasma formation space 2a enters the plasma formation space 2a from the outside of the vacuum chamber 2 through the loading/unloading portion 26 of the vacuum chamber 2. The substrate 10 is being brought in. The substrate 10 is placed on the susceptor 15. The substrate 10 is aligned by defining a placement position on the susceptor 15 using a substrate insulating cover or other configuration.

After loading the substrate 10, the door valve 26a is closed (closing operation).

Before placing the substrate 10, the susceptor 15 is located in the lower part of the vacuum chamber 2. Additionally, before placing the substrate 10, the susceptor 15 is located lower than the loading/unloading section 26.

That is, since the gap between the susceptor 15 and the shower plate 100 is widened, 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 lifting drive unit 16A is activated to raise the support column 16. The substrate 10 placed on the susceptor 15 pushed upward also moves upward. As a result, the distance between the shower plate 100 and the substrate 10 is determined to be a desired value so as to be the distance necessary for proper film formation, and this distance is maintained. The distance between the plasma formation surface 100a of the shower plate 100 and the processing surface 10a of the substrate 10 is the distance between the plasma formation electrodes in the plasma formation space 2a (100T) (see FIG. 18). . The distance (100T) is set according to processing conditions.

Furthermore, the susceptor 15 on which the substrate 10 is placed is heated by the heater 14 supplied with power from the power source 14b through the heater wire 14a. The temperature of the substrate 10 is maintained at a predetermined temperature.

Afterwards, the process gas is introduced from the process gas supply unit 7b into the gas supply space 2c through the gas introduction pipe 7 and the gas introduction port 7a. Then, the process gas is ejected into the plasma formation space 2a, which is the film formation space, through the gas ejection port 102 of the shower plate 100 and the hollow cathode slit 110.

FIG. 14 is a cross-sectional view showing the state of plasma formation in the shower plate of the plasma processing device according to the present embodiment.

Next, the high-frequency power supply 9 is started to apply high-frequency power to the cathode flange 4.

Then, a high-frequency current flows from the surface of the cathode flange 4 along the surface of the shower plate 100, and a discharge is generated between the shower plate 100 and the susceptor 15. Then, plasma is generated between the shower plate 100 and the processing surface 10a of the substrate 10.

At the same time, as shown in FIG. 14, plasma is generated at a higher plasma density than that of a flat electrode due to the hollow cathode effect also inside the hollow cathode slit 110.

In the plasma generated in this way, the process gas is decomposed, the process gas in a plasma state can be 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. there is.

The high-frequency current transmitted to the susceptor 15 is returned through the side wall 24 and the shield cover (return current).

In the plasma processing apparatus 1 according to the present embodiment, the interval between adjacent hollow cathode slits 110 is defined by the opening distribution of the gas jet port 102. The distance between the two adjacent gas jets 102 is the distance between the plasma formation surface 100a of the shower plate 100 and the processing surface 10a of the substrate 10 (100T). It is set smaller. For this reason, the process gas is uniformly supplied into the plasma formation space 2a, which is the film formation space. At the same time, it is possible to realize high plasma density, high radical density, and high electron density due to the hollow cathode effect.

In particular, conventionally, a hole-type configuration is known in which the opening of the gas flow path to the plasma formation surface 100a is expanded for each of a plurality of gas flow paths. In this configuration, a hollow cathode effect can be obtained. Compared to such a conventional configuration, according to the present embodiment, not only can the hollow cathode effect be obtained, but it is also possible to realize high plasma density, high radical density, and high electron density. It becomes possible to obtain more suitable plasma processing characteristics and film forming characteristics.

Furthermore, in the plasma processing device 1 according to the present embodiment, the distribution of the depth 110D of the hollow cathode slit 110 is set to be larger toward the outer periphery than the center, according to the depth setting regions R01 to R20. Normally, the plasma density, radical density, and electron density are small in the outer frame, but according to this embodiment, they can be distributed and formed uniformly in the radial direction of the plasma formation surface 100a.

Here, as the depth 110D of the hollow cathode slit 110 is large (deep), the electron density increases. This is because the space volume inside the hollow cathode slit 110 increases for each unit length of the hollow cathode slit 110. When the dimension of the hollow cathode slit 110 in the width direction (110W) is large, the electron density becomes high.

This makes it possible to easily realize uniform distribution of plasma processing characteristics, that is, uniform film thickness distribution during film formation. Moreover, depending on the composition of the film being formed, it can be easily controlled to suppress variations in characteristic distribution.

In addition, the configuration of this embodiment is different from the configuration of having corners within the hollow cathode slit that is curved in plan view, as shown in FIG. 15 . In the plasma processing device 1 according to the present embodiment, all hollow cathode slits 110 are formed in a straight line. The plurality of hollow cathode slits 110 do not intersect each other. In that state, a plurality of hollow cathode slits 110 are arranged to cover the entire plasma forming surface 100a of the shower plate 100. Therefore, the area DD that causes abnormal discharge such as convexities, protrusions, and steps is not formed in the slit that causes the hollow cathode effect. For this reason, it becomes possible to avoid the occurrence of abnormal discharge that adversely affects film formation characteristics. As a result, there is no deterioration in film formation characteristics.

Furthermore, according to the depth setting areas R01 to R20, the depth 110D of the hollow cathode slit 110 is set to increase from the center toward the outer periphery along the radial direction of the plasma formation surface 100a. This makes it easy to control the plasma density, radical density, and electron density to a desired state while setting the plasma density, radical density, and electron density uniformly.

In this embodiment, corresponding to the depth setting regions R01 to R20, the plasma formation surface 100a is processed so that the center of the plasma formation surface 100a is concave compared to the outer periphery. Only through this processing, the depth 110D of the hollow cathode slit 110 can be formed to vary along the radial direction of the plasma formation surface 100a. Therefore, it becomes easy to set the depth 110D of the hollow cathode slit 110 with good processing precision.

At the same time, a configuration is obtained in which the depth setting regions R01 to R20 and the hollow cathode slit 110 do not intersect. For this reason, it is possible to uniformly realize high plasma density, high radical density, and high electron density without forming a site DD that causes abnormal discharge.

At the same time, in the plasma processing device 1 according to the present embodiment, it is possible to easily control the characteristic distribution fluctuations according to the composition of the film to be formed.

Here, both type of film formation in which the characteristic change due to the plasma formation power is large and type of film formation in which the characteristic change in the distance (100T) between the plasma formation electrodes is large can be performed satisfactorily. Plasma treatment can be performed so that there is no difference in the characteristics of the two.

The composition of the film formed on the substrate 10 changes depending on the process gas supplied to the plasma formation space 2a, but at the same time, the processing characteristics also change due to changes in the type of gas. In other words, when forming a film with a different composition, the behavior, especially the sensitivity, changes with respect to changes in power and distance between electrodes.

In contrast, according to the present embodiment, it is easy to change the density while maintaining the uniformity of the density distribution using the depth setting areas R01 to R20. For this reason, even if the plasma power fluctuates, it becomes possible to maintain the characteristic distribution along the plasma formation surface 100a. Additionally, when the distance 100T between the plasma forming electrodes is changed, it is possible to maintain the characteristic distribution along the plasma forming surface 100a. Therefore, it becomes possible to effectively utilize the characteristics resulting from changes in the distance between electrodes for film formation.

This makes it possible to provide a plasma processing device 1 equipped with a shower plate 100 that can realize good film thickness distribution without abnormal discharge by using the hollow cathode slit 110 with high plasma density.

FIG. 16 is a cross-sectional view showing another example of the depth setting area of the hollow cathode slit in the shower plate of the plasma processing device according to the present embodiment.

Furthermore, compared to the example shown in FIG. 11, in the example shown in FIG. 16, the plasma formation surface 100a is processed so that the center is more concave than the outer periphery to correspond to the depth setting regions R01 to R20. The plasma formation surface 100a may be formed such that the depth 110D of the hollow cathode slit 110 varies greatly along the radial direction of the plasma formation surface 100a.

As a result, even when forming a film with a large difference in film thickness distribution in the radial direction of the plasma formation surface 100a, film formation with a uniform film thickness distribution can be realized.

<Second Embodiment>

Hereinafter, a shower plate and a plasma processing device according to a second embodiment of the present invention will be described based on the drawings.

FIG. 17 is a cross-sectional view showing the depth setting area of the hollow cathode slit in the shower plate of the plasma processing device according to the present embodiment. FIG. 18 is a cross-sectional view showing the boundary of adjacent depth setting areas in the shower plate of the plasma processing device according to the present embodiment. This embodiment differs from the above-described first embodiment in that the depth 110D of the hollow cathode slit 110 is set. Other components corresponding to the above-described first embodiment are assigned the same reference numerals and their descriptions are omitted.

In the plasma processing device 1 according to the present embodiment, as shown in FIGS. 17 and 18, the plasma formation surface 100a of the shower plate 100 is formed to have a flat surface. Additionally, the plasma formation surface 100a is formed so that the position of the gas jet port 102 in the thickness direction of the shower plate 100 changes.

By this, the depth 110D of the hollow cathode slit 110 in the depth setting region R01 to R20 is set.

In this embodiment, the depth 110D is changed at the boundary RR of two adjacent depth setting areas among the depth setting areas R01 to R20, as shown in FIG. 18. That is, the depth 110D of the hollow cathode slit 110 located in one depth setting area is different from the depth 110D of the hollow cathode slit 110 located in the other depth setting area.

Here, in the hollow cathode slit 110 according to the present embodiment, the position of the opening 113 in the thickness direction of the shower plate 100 does not change throughout the plasma formation surface 100a. That is, the entire surface of the plasma formation surface 100a is flat.

In contrast, the position of the gas outlet 102 in the thickness direction of the shower plate 100 is displaced in the thickness direction of the shower plate 100 depending on each of the depth setting regions R01 to R20. As a result, the depth 110D of the hollow cathode slit 110 is changing.

Here, when the thickness dimension of the shower plate 100 is set uniformly, the shape of the gas flow path 101 in each of the depth setting regions R01 to R20 is changed. The gas flow path 101 is closer to the gas supply surface 100b than the orifice 102a. This gas flow path 101 changes corresponding to the depth 110D of the hollow cathode slit 110.

That is, as shown in FIG. 18, with respect to the depth 110D at a position closer to the center area R01 shown on the left side of FIG. 18 than the border RR, at a position closer to the edge area R20 shown on the right side of FIG. 18 than the border RR. The depth (110D) is large. 18 schematically shows the change in depth 110D on both sides of the boundary RR, but in reality, abnormal discharge such as steps and convexities occurs inside the hollow cathode slit 110. Avoid shapes that do this.

Here, the top surface 111 of the plurality of hollow cathode slits 110 is formed along a spherical surface 100d that protrudes convexly downward, as shown in FIG. 17 .

This spherical surface 100d is formed by tying the gas outlet 102 of the top surface 111 across a plurality of hollow cathode slits 110. This spherical surface 100d corresponds to the plasma formation surface 100a formed as a curved surface protruding in a convex shape toward the upward direction described in the above-described first embodiment. That is, the depth 110D of the hollow cathode slit 110 is set according to the position of the spherical surface 100d in the thickness direction of the shower plate 100.

Here, the portion DD that causes abnormal discharge such as a step shown in FIG. 19 is not formed on the top surface 111 of the hollow cathode slit 110. Additionally, each of the plurality of hollow cathode slits 110 does not exceed the boundary RR of the depth setting area. For this reason, the step shown in Fig. 19 is not formed on the top surface 111 of one hollow cathode slit 110.

With respect to the flat plasma formation surface 100a, the positions of the plurality of gas jets 102 in the thickness direction are changing. In particular, the position of the gas outlet 102 is loosely close to the center of the plasma formation surface 100a. In addition, the position of the gas jet port 102 is set to be away from the plasma formation surface 100a along the curved surface curved in an arc shape toward the outer periphery of the shower plate 100. As a result, the depth 110D of the hollow cathode slit 110 is changed and set.

Specifically, the plasma formation surface 100a has a rectangular outline with a side length of 1000 mm or more in plan view. In contrast, the difference in distance from the flat plasma formation surface 100a to the position of the gas jet port 102 in the thickness direction is about several mm.

In this embodiment, similarly to the first embodiment, the depth 110D of the hollow cathode slit 110 is set corresponding to the depth setting regions R01 to R20. Additionally, the plasma formation surface 100a is planar. As a result, as shown in FIG. 18, the distance 100T between the plasma forming electrodes can be maintained uniform throughout the plasma forming space 2a. This makes it possible to perform uniform plasma processing, for example, film formation processing, over the entire plasma formation surface 100a, even for plasma processing that is sensitive to variations in the distance 100T between electrodes.

<Method of manufacturing shower plate 100>

When manufacturing the shower plate 100 according to this embodiment, a plate body having a uniform thickness is prepared. A plurality of gas flow paths 101, orifices 102a, gas outlets 102, and hollow cathode slits each changed in the thickness direction of the shower plate 100 in correspondence with the preset depth setting areas R01 to R20. (110) is formed on the plate body. At this time, the length of the orifice 102a in the thickness direction is formed to be uniform. This makes it possible to realize the distribution of the depth 110D of the hollow cathode slit 110 having a predetermined state with respect to the planar plasma formation surface 100a.

Figure 20 is a cross-sectional view showing the state of plasma formation in the shower plate of the plasma processing device according to the present embodiment.

Also in this embodiment, when the high-frequency power supply 9 is activated and high-frequency power is applied to the cathode flange 4, a discharge occurs between the shower plate 100 and the susceptor 15. Then, plasma is generated between the shower plate 100 and the processing surface 10a of the substrate 10.

At the same time, as shown in FIG. 20, plasma is generated at a higher plasma density than that of a flat electrode due to the hollow cathode effect, even inside the hollow cathode slit 110.

In this embodiment, the same effect as the above-described embodiment can be produced.

<Third embodiment>

Hereinafter, a shower plate and a plasma processing device according to a third embodiment of the present invention will be described based on the drawings.

FIG. 21 is a plan view showing the arrangement pattern of the gas jet port of the shower plate of the plasma processing apparatus according to the present embodiment and the boundary arrangement pattern of the depth setting area of the hollow cathode slit.

This embodiment differs from the above-described first and second embodiments in that it relates to the arrangement pattern of the gas jet outlet and the depth setting area. Other components corresponding to the first and second embodiments described above are assigned the same reference numerals and their descriptions are omitted.

In the plasma processing apparatus 1 according to the present embodiment, as shown in FIG. 21, an arrangement pattern of the gas jet nozzles 102 on the plasma formation surface 100a of the shower plate 100 is obtained. In this arrangement pattern, the gas jet nozzle 102 is disposed at the vertex of an equilateral triangle arranged without gaps on the plasma formation surface 100a. This configuration is the same as the above-described embodiment. Additionally, the direction of the arrangement pattern of the gas jet nozzle 102 relative to the outline of the rectangular plasma formation surface 100a is different.

That is, with respect to the equilateral triangle in which the gas jet port 102 is arranged at the vertex, the lower side of the equilateral triangle extending in the left and right directions in FIG. 21 is parallel to the longitudinal side of the outline of the plasma formation surface 100a.

In the depth setting area of the present embodiment, as shown in FIG. 21, the boundary RR of the depth setting area is set so that the side of the equilateral triangle at which the gas outlet 102 is arranged at the vertex and the side of the hexagon of the depth setting area are parallel. there is. At this time, the boundary RR of the depth setting area has a side parallel to the longitudinal side of the outline of the plasma formation surface 100a.

Additionally, the width direction dimension of the depth setting area in this embodiment is set smaller than that in the first and second embodiments. That is, the number of divisions of the depth setting area of the present embodiment is set to be smaller than the number of divisions of the depth setting area of the first and second embodiments. Additionally, the boundary RR of the depth setting area of this embodiment has a substantially equal radial separation distance. Additionally, depending on the plasma processing conditions, the boundary RR of the depth setting region may have a different radial separation distance depending on the position in the radial direction.

In this embodiment, the same effect as the above-described embodiment can be produced.

<Fourth Embodiment>

Hereinafter, a shower plate and a plasma processing device according to a fourth embodiment of the present invention will be described based on the drawings.

FIG. 22 is a plan view showing the arrangement pattern of the gas jet port of the shower plate of the plasma processing apparatus according to the present embodiment and the boundary arrangement pattern of the depth setting area of the hollow cathode slit.

This embodiment differs from the above-described third embodiment in that it relates to the arrangement pattern of the gas jet outlet and the depth setting area. Other components corresponding to the third embodiment described above are assigned the same reference numerals and their descriptions are omitted.

In the plasma processing apparatus 1 according to the present embodiment, as shown in FIG. 22, an arrangement pattern of the gas jet ports 102 on the plasma formation surface 100a of the shower plate 100 is obtained. In this arrangement pattern, the gas jet nozzle 102 is disposed at the vertex of an equilateral triangle arranged without gaps on the plasma formation surface 100a. This configuration is the same as the third embodiment. Additionally, the direction of the arrangement pattern of the gas jet nozzles 102 with respect to the outline of the rectangular plasma formation surface 100a is the same as that of the first embodiment.

That is, with respect to the equilateral triangle in which the gas jet port 102 is arranged at the vertex, the side extending in the longitudinal direction in FIG. 22 is parallel to the side extending in the longitudinal direction in the short direction of the outline of the plasma formation surface 100a.

In the depth setting area of the present embodiment, as shown in FIG. 22, the boundary RR of the depth setting area is set so that the side of the equilateral triangle at which the gas outlet 102 is arranged at the vertex and the side of the hexagon of the depth setting area are parallel. there is. At this time, the boundary RR of the depth setting area has a side parallel to the short side of the outline of the plasma formation surface 100a.

Additionally, the width direction dimension of the depth setting area in this embodiment is set smaller than that in the first to third embodiments. That is, the number of divisions of the depth setting area in this embodiment is set to be smaller than the number of divisions in the depth setting area in the first to third embodiments. Additionally, the boundary RR of the depth setting area of this embodiment has a substantially equal radial separation distance. Additionally, depending on the plasma processing conditions, the boundary RR of the depth setting region may have a different radial separation distance depending on the position in the radial direction.

In this embodiment, the same effect as the above-described embodiment can be produced.

<Fifth Embodiment>

Hereinafter, a shower plate and a plasma processing device according to a fifth embodiment of the present invention will be described based on the drawings.

FIG. 23 is a plan view showing the arrangement pattern of the gas jet port of the shower plate of the plasma processing apparatus according to the present embodiment and the boundary arrangement pattern of the depth setting area of the hollow cathode slit.

This embodiment differs from the fourth embodiment described above in terms of the arrangement pattern of the gas jet outlet and the depth setting area. Other components corresponding to the above-described fourth embodiment are assigned the same reference numerals and their descriptions are omitted.

In the plasma processing apparatus 1 according to the present embodiment, as shown in FIG. 23, an arrangement pattern of the gas jet nozzles 102 on the plasma formation surface 100a of the shower plate 100 is obtained. In this arrangement pattern, the gas jet nozzle 102 is disposed at the vertex of an equilateral triangle arranged without gaps on the plasma formation surface 100a. This configuration is the same as the fourth embodiment. Additionally, the direction of the arrangement pattern of the gas jet nozzles 102 with respect to the outline of the square plasma formation surface 100a is also the same as that of the fourth embodiment.

That is, with respect to the equilateral triangle in which the gas jet nozzle 102 is arranged at the vertex, the side extending in the longitudinal direction in FIG. 23 is parallel to the side extending in the longitudinal direction in the short direction of the outline of the plasma formation surface 100a.

In the depth setting area of the present embodiment, as shown in FIG. 23, the boundary RR of the depth setting area is set so that the side of the equilateral triangle at which the gas outlet 102 is arranged at the vertex is parallel to the side of the hexagon of the depth setting area. there is. At this time, the boundary RR of the depth setting area has a side parallel to the short side of the outline of the plasma formation surface 100a.

Additionally, the width direction dimension of the depth setting area in this embodiment is set smaller than that in the fourth embodiment. That is, the number of divisions of the depth setting area in the present embodiment is set to be smaller than the number of divisions in the depth setting area in the fourth embodiment. Specifically, the boundary RR of the depth setting area is set only in the area near the edge of the outline of the plasma formation surface 100a.

Additionally, the boundary RR of the depth setting area in the area near the corner of the outline of the plasma formation surface 100a may have a substantially equal radial separation distance. Additionally, depending on the plasma processing conditions, the boundary RR of the depth setting region may have a different radial separation distance depending on the position in the radial direction.

In this embodiment, the same effect as the above-described embodiment can be produced.

<Sixth Embodiment>

Hereinafter, a shower plate and a plasma processing device according to a sixth embodiment of the present invention will be described based on the drawings.

FIG. 24 is a plan view showing the arrangement pattern of the gas jet port of the shower plate of the plasma processing apparatus according to the present embodiment and the boundary arrangement pattern of the depth setting area of the hollow cathode slit.

This embodiment differs from the fourth and fifth embodiments described above in terms of the arrangement pattern of the gas outlet and the depth setting area. Other components corresponding to the fourth and fifth embodiments described above are assigned the same reference numerals and their descriptions are omitted.

In the plasma processing apparatus 1 according to the present embodiment, as shown in FIG. 24, an arrangement pattern of the gas jet nozzles 102 on the plasma formation surface 100a of the shower plate 100 is obtained. In this arrangement pattern, the gas jet nozzle 102 is disposed at the vertex of an equilateral triangle arranged without gaps on the plasma formation surface 100a. This configuration is the same as the fourth and fifth embodiments. Additionally, the direction of the arrangement pattern of the gas jet nozzles 102 with respect to the outline of the square plasma formation surface 100a is also the same as that of the fourth and fifth embodiments.

That is, with respect to the equilateral triangle in which the gas jet nozzle 102 is arranged at the vertex, the side extending in the longitudinal direction in FIG. 23 is parallel to the side extending in the longitudinal direction in the short direction of the outline of the plasma formation surface 100a.

As shown in FIG. 24, the boundary RR of the depth setting area of the present embodiment is set so that the sides of the hexagon of the depth setting area are parallel to the equilateral triangle with the gas outlet 102 arranged at its vertex. At this time, the boundary RR of the depth setting area has a side parallel to the short side of the outline of the plasma formation surface 100a. In a part of the depth setting area of the present embodiment, the sides of the equilateral triangle at which the gas outlet 102 is arranged at the vertex are parallel to the sides of the quadrangle having the boundary RR. This square is a rhombus.

Additionally, the width direction dimension of the depth setting area in this embodiment is set to be almost the same as that in the fourth embodiment. That is, the number of divisions of the depth setting area in the present embodiment is set to be almost the same as the number of divisions in the depth setting area in the fourth embodiment. Specifically, as in the fifth embodiment, the boundary RR of the depth setting area is set near the edge of the outline of the plasma formation surface 100a. In addition, the boundary RR of the depth setting area with a rectangular outline and the boundary RR of the depth setting area with a hexagonal outline are set in the vicinity of the center area R01.

Additionally, the boundary RR of the depth setting area of this embodiment may have a substantially equal radial separation distance. Additionally, depending on the plasma processing conditions, the boundary RR of the depth setting region may have a different radial separation distance depending on the position in the radial direction.

In this embodiment, the same effect as the above-described embodiment can be produced.

<Seventh embodiment>

Hereinafter, a shower plate and a plasma processing device according to a seventh embodiment of the present invention will be described based on the drawings.

Fig. 25 is a plan view showing the arrangement pattern of the gas jet port of the shower plate of the plasma processing apparatus according to the present embodiment and the boundary arrangement pattern of the depth setting area of the hollow cathode slit.

This embodiment differs from the above-described first to sixth embodiments in that it relates to the arrangement pattern of the gas jet outlet and the depth setting area. Other components corresponding to the first to sixth embodiments described above are assigned the same reference numerals and their descriptions are omitted.

In the plasma processing apparatus 1 according to the present embodiment, as shown in FIG. 25, an arrangement pattern of the gas jet nozzles 102 on the plasma formation surface 100a of the shower plate 100 is obtained. In this arrangement pattern, unlike the first to sixth embodiments, the gas jet nozzle 102 is disposed at the vertex of a square arranged without gaps on the plasma formation surface 100a. This configuration is different from the first to sixth embodiments. In other words, the line connecting two adjacent gas outlets 102 constitutes one side of a square. That is, the angle formed by two orthogonal sides of a square with four sides is 90°. In addition, the arrangement of the plurality of gas jets 102 includes a first array in which the plurality of gas jets 102 are lined up in a straight line, and a second array in which the plurality of gas jets 102 are lined up in a straight line at a right angle to the first array. It has an array. The first arrangement and the second arrangement are inclined at 90°. In addition, each of the first array and the second array is inclined at 45° with respect to the contour edge of the square plasma formation surface 100a.

That is, each of the four sides forming a square with the gas jet nozzle 102 positioned at the vertex is all inclined at 45° with respect to the side of the outline of the plasma formation surface 100a extending in the longitudinal direction in FIG. 25. do.

In the depth setting area of this embodiment, as shown in FIG. 25, the boundary RR of the depth setting area is set so that the sides of the square where the gas outlet 102 is arranged at the vertex are parallel to the sides of the square of the depth setting area. It is done. At this time, the boundary RR of the depth setting area has a side inclined at 45° with respect to the side of the outline of the plasma formation surface 100a. In addition, a plurality of concentric squares are set by the border RR of the depth setting area of this embodiment. Each side of the plurality of squares is parallel to the side of the square at which the gas outlet 102 is located at the vertex.

Additionally, the boundary RR of the depth setting area in this embodiment is set to have substantially the same separation distance, unlike the first to sixth embodiments. The number of divisions of the depth setting area of the present embodiment is set to be approximately the same as the number of divisions of the depth setting area of the sixth embodiment. Specifically, unlike the first to sixth embodiments, the boundary RR of the depth setting region is set with an equal radial distance throughout the plasma formation surface 100a.

Additionally, the boundary RR of the depth setting area of this embodiment may have a substantially equal radial separation distance. Additionally, depending on the plasma processing conditions, the boundary RR of the depth setting region may have a different radial separation distance depending on the position in the radial direction.

In this embodiment, the same effect as the above-described embodiment can be produced.

<Eighth embodiment>

Hereinafter, a shower plate and a plasma processing device according to an eighth embodiment of the present invention will be described based on the drawings.

FIG. 26 is a plan view showing the arrangement pattern of the gas jet port of the shower plate of the plasma processing apparatus according to the present embodiment and the boundary arrangement pattern of the depth setting area of the hollow cathode slit.

This embodiment differs from the above-described first to seventh embodiments in that it relates to the arrangement pattern of the gas jet outlet and the depth setting area. Other components corresponding to the first to seventh embodiments described above are assigned the same reference numerals and their descriptions are omitted.

In the plasma processing apparatus 1 according to the present embodiment, as shown in FIG. 26, an arrangement pattern of the gas jet nozzles 102 on the plasma formation surface 100a of the shower plate 100 is obtained. This arrangement pattern, unlike the first to seventh embodiments, is arranged spaced apart in a plurality of concentric circles. Also, like the first to seventh embodiments, the outline center of the plasma formation surface 100a and the center of the circle where the gas jet port 102 is arranged are set to coincide.

In the depth setting area of this embodiment, as shown in FIG. 26, the border RR is a concentric circle corresponding to the circle in which the gas jet nozzles 102 are arranged concentrically. At this time, since the boundary RR of the depth setting area is circular, it does not match the outline of the plasma formation surface 100a. In addition, the hollow cathode slits 110 inside the depth setting area of the present embodiment are also formed in a plurality of circles arranged concentrically with the boundary RR of the depth setting area. In this arrangement, the hollow cathode slit 110 does not intersect the boundary RR of the depth setting area.

Additionally, the boundary RR of the depth setting area in this embodiment is set to have substantially the same separation distance as in the seventh embodiment. The number of divisions of the depth setting area of the present embodiment is set to be smaller than the number of divisions of the depth setting area of the seventh embodiment.

Additionally, the boundary RR of the depth setting area of this embodiment may have a substantially equal radial separation distance. Additionally, depending on the plasma processing conditions, the boundary RR of the depth setting region may have a different radial separation distance depending on the position in the radial direction.

In this embodiment, the same effect as the above-described embodiment can be produced.

In addition, it is possible to create a configuration by appropriately selecting and combining the individual configurations described in each of the above embodiments.

Moreover, among the embodiments disclosed in this specification, those composed of a plurality of elements may integrate the plurality of elements, and conversely, those composed of a single element may be divided into a plurality of elements. Regardless of whether it is integrated or not, it is okay as long as it is configured to achieve the purpose of the invention.

[Example]

Hereinafter, embodiments according to the present invention will be described.

Here, an experiment was conducted using the shower plate and plasma processing device of the present invention as specific examples. A test to confirm the film formation characteristics obtained through this experiment will be explained.

<Experimental Example 1>

First, as Experimental Example 1, a test was conducted to confirm the increase in electron density on the shower plate 100 on which the hollow cathode slit 110 of the present invention was formed.

First, the change in electron density when changing the depth 110D of the hollow cathode slit 110 was obtained through simulation.

Here, as shown in FIGS. 8 to 10, with respect to the shower plate 100 on which the hollow cathode slit 110 is formed, the change in electron density when the depth 110D of the hollow cathode slit 110 is changed is confirmed. A test was conducted. The specifications in Experimental Example 1 are shown below.

- Shower plate dimensions; 1978mm*1628mm

- Dimensions in the hollow cathode slit width direction (110W); 5.7mm~6.7mm

- Hollow cathode slit depth 110D; 3mm~8mm

- Arrangement spacing (pitch) of a plurality of gas outlets (102); An equilateral triangle with a side of 7 mm

- Distance between plasma forming electrodes (100T); 18mm

- supply power; 9kW

- High power frequency; 13.56 MHz

- pressure in the vacuum chamber; 120Pa

The results of Experimental Example 1 are shown as Slit in FIG. 27.

Using a shower plate that induces the same hole-type hollow cathode effect, the same changes in depth and electron density were calculated.

Here, in the shower plate that induces the hole-type hollow cathode effect, like the hollow cathode slit of the present invention, the spacing between the plurality of gas jets is an equilateral triangle with a side of 7 mm. A plurality of circular concave portions were formed on the side of the plasma formation surface rather than each orifice of the plurality of gas jets. Each of the plurality of circular recesses is individually separated. The diameter of each of the plurality of circular concave portions was set to be the same as that of the hollow cathode slit of the present invention, the dimension in the width direction (110W) (5.7 mm to 6.7 mm). This result is shown as Hole in FIG. 27.

As a result shown in FIG. 27, with respect to the change in electron density when the depth 110D is changed, the amount of change in electron density of the hollow cathode slit 110 (Slit) according to the present invention compared to the hole type (Hole) You can see this big thing.

<Experimental Example 2>

Next, as Experimental Example 2, based on the difference in the amount of change in electron density obtained in Experimental Example 1, the degree to which the shape difference occurs between the two types of shower plates in order to maintain in-plane uniformity is compared. did. Here, the comparison was performed using the conditions described above.

In order to realize uniform electron density distribution using a shower plate that induces a hole-type hollow cathode effect, the following dimensions are required.

- The depth from the center of the shower plate is set to 3.0 mm, the smallest of the above depths.

- The depth at the outer edge of the shower plate is set to 7.5 mm, which is the largest of the above depths.

- In other words, it is necessary to set the difference in hole depth, ΔHole, in the shower plate, which causes the hole-type hollow cathode effect, to 4.5 mm.

Regarding this, a case where the shower plate 100 having the hollow cathode slit 110 of the present invention is used will be described.

Consider the case where, at the center of the shower plate 100, the depth 110D of the hollow cathode slit 110 is set to 3.0 mm, which is the smallest. In this case, in order to realize uniform electron density distribution, the depth 110D of the hollow cathode slit 110 necessary to obtain the same uniform electron density at the outer edge of the shower plate 100 was calculated.

Here, in each of the shower plate causing the hole-type hollow cathode effect and the shower plate 100 with the hollow cathode slit 110 of the present invention, in order to change all the depths, the plasma forming surface 100a A shower plate having a curved surface with a concave portion formed at the center was used.

As a result, from the results shown in FIG. 27, it was found that in order to equalize the electron density, the depth 110D of the hollow cathode slit 110 needed to be 4.5 mm. In other words, it was found that the difference ΔSlit in depth (110D) was required to be 3.5 mm.

In other words, it can be seen that in the Slit type, the change in electron density with respect to depth is greater than in the Hole type. In addition, in the case of a structure in which the plasma formation surface 100a is curved, ΔSlit requires a curve of 3.5 mm, while ΔHole requires a curve of 4.5 mm. That is, it can be seen that the shower plate 100 having the hollow cathode slit 110 of the present invention has a structure that can reduce the curvature of the plasma forming surface 100a of the shower plate 100.

That is, in the shower plate 100 having the hollow cathode slit 110 of the present invention, compared to the shower plate causing the hole-type hollow cathode effect, the distance between the plasma forming electrodes along the plasma forming surface 100a (100T) It becomes possible to reduce the difference.

Likewise, in the case of a flat structure in which hollow cathode slits 110 with different depths 110D are formed on the flat plasma formation surface 100a, there is a difference in depth compared to the hole type, that is, the gas outlet 102 It can be seen that the change in formation position is small.

Additionally, in a shower plate having a plasma formation surface that is formed as a plane and does not have a hollow cathode effect, the difference in electron density depending on the plasma formation surface becomes even larger than in the hole type. This difference in electron density cannot be resolved.

<Experimental Example 3>

Next, as Experimental Example 3, the parameter dependence of each type of shower plate when films with different compositions were deposited was verified.

Here, as an example, the difference in film formation speed and dependence of parameters between SiN (silicon nitride) and SiO (silicon oxide) is shown.

Here, the film formation conditions for SiN and SiO film formation are shown in Figure 28, respectively.

In the film formation of SiN and SiO, the amount of change in the film deposition rate (Deposition rate) when the distance between electrodes (100T) was changed as a parameter is shown in Figure 29. Each of the change amounts shown in Figure 29 is standardized.

Similarly, in the film formation of SiN and SiO, the amount of change in the film deposition rate (Deposition rate) when the RF power was changed as a parameter is shown in FIG. 30. Each of the change amounts shown in Figure 30 is standardized.

Here, RF power is the plasma formation power applied between electrodes. As a film formation condition, RF power corresponds to changes in plasma density and electron density.

From the results in Figure 29, when comparing the film formation speed of SiN and the film formation speed of SiO, the change in the film formation speed on the vertical axis with respect to the change in the distance between electrodes on the horizontal axis is smaller than that of SiO. In other words, it can be seen that the dependence of the SiN film formation speed on the distance between electrodes is smaller than that of SiO. In other words, the dependence of the SiO film formation speed on the distance between electrodes is greater than that of SiN.

From the results in Figure 30, when comparing the film formation speed of SiN and the film formation speed of SiO, the change in film formation speed on the vertical axis with respect to the change in RF power on the horizontal axis is smaller than that of SiN. In other words, it can be seen that the dependence of the SiO film formation speed on RF power is smaller than that of SiN. In other words, the SiN film formation speed is more dependent on RF power than the SiO film formation speed.

In other words, it can be seen that the SiN film formation speed depends on the plasma density and electron density compared to the SiO film formation.

Here, an examination is conducted based on the results in FIG. 29 and the results in FIG. 30. Specifically, in the film formation of SiN and SiO, as in Experimental Examples 1 and 2, the slit type shower plate 100 is used to consider the effect on the film formation speed when the electron density is increased. Additionally, the slit type shower plate 100 has a structure in which the plasma formation surface 100a is curved. Furthermore, in this slit type shower plate 100, the depth 110D of the hollow cathode slit 110 on the outer peripheral side is deeper than the center.

Here, the depth 110D of the hollow cathode slit 110 was set to each of the depth setting areas R01 to R20 shown in FIG. 10. The depth 110D of the hollow cathode slit 110 in the depth setting region R01 to R20 is shown in FIG. 31.

Here, depth setting areas R01 to R20 are indicated as areas 1 to 19. Additionally, since the depth setting area R19 and the depth setting area R20 are set to the same depth (110D), they are indicated as area 19.

Then, in the case of a shower plate with a curved plasma forming surface 100a, the distance between the outer electrodes (100T) close to the periphery becomes relatively closer than the distance between the inner electrodes (100T) close to the center.

Similarly, based on the results of FIG. 29 and FIG. 30, in the film formation of SiN and SiO, a hole-type shower plate with a structure in which the plasma formation surface is curved and the hole depth on the outer periphery is deeper than the center is used. By using it, the effect on the film formation speed when the electron density is increased is considered.

As an object of comparison, the effect on the film formation speed when forming a SiN and SiO film using a flat type shower plate with a flat plasma formation surface without holes or slits is considered.

In this case, as shown in FIG. 32, the change in film formation speed ΔFlat-SiN at the position in the substrate plane of the normalized film formation speed in SiN film formation was 22.6%. Similarly, the change in substrate in-plane position ΔFlat-SiO at the normalized film formation speed in SiO film formation was 3.3%.

Here, the substrate position (mm), which is the horizontal axis of Figure 32 and Figures 34 and 35 described later, represents the value at each point on the diagonal of a square glass substrate, as shown in Figure 33.

When a hole-type shower plate is used, the change in film formation speed is as shown in FIG. 34, and the change ΔHole-SiN at the position in the substrate plane at the standardized film formation speed in SiN film formation was 2.8%. In other words, when a hole-type shower plate was used, the change in film formation speed during SiN film formation at a position within the substrate surface was able to be greatly suppressed compared to when a flat-type shower plate was used. When a hole-type shower plate was used, the change in film formation speed during SiN film formation at a position within the substrate surface was reduced by one order of magnitude compared to when a flat-type shower plate was used.

Additionally, when a hole-type shower plate is used, the change in film formation speed is as shown in FIG. 34, and the change ΔHole-SiO at the position in the substrate plane of the standardized film formation speed in SiO film formation was 5.7%. When a hole-type shower plate was used, the change in film formation speed during SiO film formation at the position within the substrate surface could not be suppressed compared to when a flat-type shower plate was used.

In contrast, when a slit type shower plate is used, the change in film formation speed is as shown in Figure 35. The change in the substrate in-plane position ΔSlit-SiN at the standardized film formation speed for SiN film formation is 2.5%. It has been done. In other words, when a slit type shower plate was used, the change in film formation speed during SiN film formation at a position within the substrate surface could be greatly suppressed compared to when a flat type shower plate was used. At the same time, when a slit-type shower plate was used, the change in film formation speed during SiN film formation at a position within the substrate surface could be reduced compared to when a hole-type shower plate was used.

In addition, when using a slit type shower plate, the change in film formation speed is as shown in Figure 35, the change ΔSlit-SiO at the position in the substrate plane of the standardized film formation speed in SiO film formation was 2.0%. In other words, when a slit type shower plate was used, the change in film formation speed during SiO film formation at a position within the substrate surface could be suppressed compared to when a flat type shower plate was used. When a slit-type shower plate was used, the change in film formation speed during SiO film formation at a position within the substrate surface was significantly reduced compared to when a hole-type shower plate was used.

In other words, it was found that when a slit type shower plate was used, in addition to the change in SiN ΔSlit-SiN, the change in SiO ΔSlit-SiO could also be suppressed to 3% or less to the same degree.

Let's consider this result.

By curving the plasma formation surface 100a, the distance between the outer electrodes (100T) near the periphery became relatively closer than the distance between the inner electrodes (100T) closer to the center. For this reason, while the SiO film thickness distribution deteriorates in the Hole type, the curvature of the plasma formation surface can be reduced in the Slit type compared to the Hole type. Therefore, in the Slit type, it can be considered that the SiO film thickness distribution is good.

In addition, in the type of structure in which the position of the gas jet port 102 in the thickness direction is changed, there is no curvature of the plasma formation surface, so there is almost no influence of SiO due to the curved structure.

In addition, each numerical value in the graphs shown in Fig. 32, Fig. 34, and Fig. 35 is again posted as data in Fig. 36.

<Experimental Example 4>

Next, as Experimental Example 4, suppression of abnormal discharge was confirmed.

In Experimental Example 4, the occurrence of abnormal discharge in the following two shower plates was compared.

- As shown in FIGS. 8 to 10, a shower plate 100 in which only straight hollow cathode slits 110 are formed.

- As shown in Fig. 15, a shower plate in which hexagonal hollow cathode slits of different diameter dimensions are formed concentrically, and a region DD (corner portion) is formed within the slit where the hollow cathode slits are bent.

Conditions such as supply power are as follows.

- Arrangement spacing (pitch) of a plurality of gas outlets (102); An equilateral triangle with a side of 7 mm

- frequency ; 13.56 MHz

- supply power; 9kW

- supply power; 13kW

In the straight hollow cathode slit 110, no abnormal discharge occurred regardless of the power supplied. In contrast, abnormal discharge was observed in the shower plate where site DD was formed under some conditions.

From these results, it was found that in the shower plate 100 formed only with the linear hollow cathode slit 110 of the present invention, it was possible to substantially suppress the occurrence of abnormal discharge.

Additionally, the type of processing gas supplied was changed and the occurrence of abnormal discharge was verified.

The conditions are shown below. Additionally, the power conditions are the same as above.

-Ar only

- SiH ₄ , N ₂ O, Ar

- SiH ₄ , NH ₃ , N ₂

From these results, it was found that, depending on the type of gas, it was possible to substantially suppress the occurrence of abnormal discharge in the shower plate 100 in which only the linear hollow cathode slit 110 of the present invention was formed.

One… plasma processing device
2a… plasma formation space
2c… gas supply space
100… shower plate
100a… plasma formation surface
100b… gas supply surface
101… gas euro
102… gas vent
102a… orifice
110… hollow cathode slit
110D… depth
R01~R20… Depth setting area

Claims (12)

A shower plate that uniformly supplies processing gas from the gas supply space to the plasma formation space within the chamber of a plasma processing device and serves as a cathode electrode disposed opposite to the anode electrode,
a plasma formation surface facing the anode electrode and in contact with the plasma formation space;
a gas supply surface on a side opposite to the plasma formation surface and in contact with the gas supply space;
a plurality of gas flow paths communicating from the gas supply surface to the plasma formation surface in the thickness direction of the shower plate;
a plurality of hollow cathode slits formed on the plasma formation surface;
A plurality of gas jets disposed inside each of the plurality of hollow cathode slits and supplying the processing gas evenly throughout the plasma formation surface.
With
The plurality of hollow cathode slits are arranged to cover the plasma formation surface and do not intersect each other,
Inside each of the plurality of hollow cathode slits, the plurality of gas flow paths are opened,
The plurality of gas ejection ports are formed in a row along each longitudinal direction of the plurality of hollow cathode slits,
The plurality of gas jets are capable of equally supplying the processing gas to each of the plurality of hollow cathode slits in each longitudinal direction of the plurality of hollow cathode slits,
The plasma formation surface has a center region, an edge region, and a plurality of depth setting regions divided into each other along a direction from the center region to the edge region,
In each of the plurality of depth setting regions, each depth of the plurality of hollow cathode slits in the thickness direction is set to be large,
Boundaries of two adjacent depth setting areas among the plurality of depth setting areas and each of the plurality of hollow cathode slits do not intersect each other.
shower plate. According to paragraph 1,
In plan view, the distance between two gas jets that are adjacent to each other among the plurality of gas jets is set uniformly.
shower plate. According to claim 1 or 2,
In plan view, each of the plurality of hollow cathode slits is formed to extend in a straight line,
shower plate. According to claim 1 or 2,
Among the plurality of hollow cathode slits, the long sides of two adjacent hollow cathode slits are parallel to each other,
shower plate. According to claim 1 or 2,
The boundaries of the two adjacent depth setting regions are arranged along the long side of the hollow cathode slit.
shower plate. According to claim 1 or 2,
The respective depths of the plurality of hollow cathode slits in each of the plurality of depth setting regions are set such that the positions of the plurality of gas jets in the thickness direction are the same and the plasma formation surface is formed curved. set,
shower plate. According to claim 1 or 2,
The respective depths of the plurality of hollow cathode slits in each of the plurality of depth setting regions are set so that the positions of the plurality of gas jets in the thickness direction change and the plasma formation surface has a flat surface. It is done,
shower plate. According to claim 1 or 2,
Each of the plurality of depth setting areas has a plurality of circumferential areas,
Each of the plurality of circumferential regions is divided in the circumferential direction,
In each of the plurality of circumferential regions, all of the plurality of hollow cathode slits are arranged in parallel and facing the same direction,
Each of the plurality of hollow cathode slits in the central region is arranged parallel to and facing the same direction as the hollow cathode slit in a circumferential region of one of the depth setting regions adjacent to the central region.
shower plate. According to clause 8,
In each of the plurality of depth setting regions, at a boundary between two adjacent circumferential regions, an end of the hollow cathode slit in one circumferential region and an end of the hollow cathode slit in the other circumferential region are arranged differently,
shower plate. According to claim 1 or 2,
The plurality of gas passages are formed to extend from the gas outlet toward the gas supply surface, and have a plurality of orifices corresponding one to one to the plurality of gas passages,
In all of the plurality of gas flow paths, the lengths of the plurality of orifices in the thickness direction are the same,
shower plate. According to claim 1 or 2,
In plan view, the distance between two gas jets that are adjacent to each other among the plurality of gas jets is such that the plasma formation space is sandwiched between them and the plasma is formed at the same time.
shower plate. An electrode flange connected to a high-frequency power source,
a chamber having side walls and a bottom;
an insulating flange disposed between the chamber and the electrode flange;
a processing chamber having a plasma formation space surrounded by the chamber, the electrode flange, and the insulating flange;
a support portion accommodated in the processing chamber, on which a substrate having a processing surface is placed, and serving as an anode electrode;
Shower plate of claim 1 or 2
With
The shower plate is,
forming the gas supply space facing away from the electrode flange,
Forming the plasma formation space by facing away from the support,
Plasma processing device.

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