JP7722211B2 - Apparatus for performing plasma processing and method for performing plasma processing - Google Patents

Description

This disclosure relates to an apparatus for performing plasma processing and a method for performing plasma processing.

CVD (Chemical Vapor Deposition) and ALD (Atomic Layer Deposition) are well-known methods for depositing films on semiconductor wafers (hereafter referred to as "wafers") during the semiconductor device manufacturing process. These film deposition processes use source gases containing film precursors and reactive gases that oxidize or reduce the source gases (hereafter collectively referred to as "film deposition gases").

In a film formation process, highly reactive activated species obtained by converting a film formation gas into plasma may be used.
For example, Patent Document 1 describes a plasma CVD apparatus in which a needle-shaped metal electrode (cathode) is arranged at the center of a plurality of cylindrical metal electrodes (anodes) that are formed to protrude and face a substrate supported on a support stand. This plasma CVD apparatus obtains radicals and ions by introducing a source gas into the cylindrical metal electrodes and forming a glow discharge between the cylindrical metal electrodes and the needle-shaped metal electrodes.

Furthermore, Patent Document 2 describes a technology in which two plates with multiple through holes are placed one on top of the other between a space where microwave plasma is generated and a wafer placed on a susceptor. By shifting the positions of the through holes in the upper and lower plates so that they do not overlap, ions in the plasma are blocked and hydrogen radicals are selectively allowed to pass through.
In addition to film formation processes, etching processes, modification processes, and the like also use activated species in plasma-converted gases.

Japanese Unexamined Patent Publication No. 60-262972 Japanese Patent Application Laid-Open No. 2006-86449

This disclosure provides a technology for plasma processing by supplying low-energy charged particles, neutral particles, or radicals to a substrate from a processing gas that has been converted into plasma.

The present disclosure provides an apparatus for performing plasma processing by supplying a processing gas converted into plasma to a substrate in a processing chamber,
a mounting table provided in the processing chamber for mounting the substrate thereon;
a plurality of plasma generation spaces, each of which is provided above the mounting table and is a cylindrical space formed between tubular wall surfaces arranged opposite to each other in a double-tubular configuration, and each of which is provided with a plasma generation mechanism for generating plasma from the processing gas;
a processing gas supply unit for supplying the processing gas to a position upstream of a flow of the processing gas so that the processing gas flows along an axial direction of the cylindrical plasma generation space;
The device comprises a ring-shaped regulating member that is provided at a position where the processing gas flows out from each of the plasma formation spaces, and that regulates the flow of the processing gas so that the flow direction is toward the radial direction of the cylindrical plasma formation space, and that forms a throttle flow path with a flow path area smaller than that of the plasma formation space between it and a member that constitutes one side of the tubular wall surface.

According to the present disclosure, plasma processing can be performed by supplying low-energy charged particles, neutral particles, or radicals to a substrate from a processing gas that has been converted into plasma.

1 illustrates an example of the configuration of a film forming apparatus equipped with a gas supply mechanism according to the present disclosure. FIG. 2 is a vertical sectional side view of the gas supply mechanism according to the first embodiment. FIG. 2 is an enlarged vertical cross-sectional view of the gas supply mechanism according to the first embodiment. FIG. 2 is a plan view of the gas supply mechanism according to the first embodiment, as viewed from the top or bottom side. FIG. 10 is an enlarged vertical cross-sectional view of a gas supply mechanism according to a modified example. FIG. 10 is a vertical sectional side view of a gas supply mechanism according to a second embodiment. FIG. 11 is a first enlarged vertical cross-sectional view of a gas supply mechanism according to a second embodiment. FIG. 10 is a second enlarged vertical cross-sectional view of the gas supply mechanism according to the second embodiment. FIG. 10 is a partially cutaway plan view of a gas supply mechanism according to a second embodiment. 10 illustrates a configuration example of a microwave supply mechanism of a gas supply mechanism according to a third embodiment. FIG. 11 is a vertical sectional side view of a gas supply mechanism according to a third embodiment. FIG. 10 is an enlarged vertical cross-sectional view of a gas supply mechanism according to a third embodiment. FIG. 10 is a vertical sectional side view of a gas supply mechanism according to a fourth embodiment. FIG. 10 is a first enlarged vertical cross-sectional view of a gas supply mechanism according to a fourth embodiment. FIG. 10 is a second enlarged vertical cross-sectional view of the gas supply mechanism according to the fourth embodiment. FIG. 11 is an enlarged vertical cross-sectional view of a gas supply mechanism according to a fifth embodiment. FIG. 11 is a plan view of a gas supply mechanism according to a fifth embodiment. 13A and 13B are explanatory views of the operation of magnets provided in the gas supply mechanism according to the fifth embodiment.

<Film forming equipment>
First, an example of the overall configuration of a film formation apparatus 1, which is one embodiment of the "plasma processing apparatus" according to the present disclosure, will be described with reference to FIG. 1 . The film formation apparatus 1 of this example is configured to supply a film formation gas, such as a source gas containing a film raw material or a reactive gas, as a process gas to a wafer W to form a film of a desired substance on the surface of the wafer W. There are no particular limitations on the film formed on the wafer W, and it may be a metal oxide film or a metal nitride film for forming an insulating film, or a metal film for forming a wiring layer. In addition, the film formation apparatus 1 is configured to be able to supply low-energy particles, neutral particles, or radicals at a high concentration by controlling the flow of plasma of the film formation gas generated in a cylindrical plasma generation space 7, which will be described later.

This film formation apparatus 1 is configured to supply film formation gases, such as source gases containing film raw materials such as metal compounds and reactive gases, into a processing chamber 11 that accommodates and processes wafers W, and form a film of the desired material on the surface of the wafer W. The film formation method may be a CVD method in which film formation gases are continuously supplied and a film material is deposited on the surface of the wafer W. Alternatively, an ALD method may be used in which the supply and exhaust of source gases and the supply and exhaust of reactive gases are alternately performed, and the adsorption and reaction of the source gases on the wafer W are repeated, depositing a thin film of the film material.

In this example, the processing vessel 11 is made of a flat, cylindrical metal and is grounded. A loading/unloading port 12 for loading and unloading wafers W and a gate valve 13 for opening and closing the loading/unloading port 12 are provided in the sidewall of the processing vessel 11. An exhaust duct 14, which is annular in plan view, is provided above the loading/unloading port 12. A slit-shaped exhaust port 141 extending circumferentially is formed in the inner peripheral surface of the exhaust duct 14. An opening 15 is formed in the sidewall of the exhaust duct 14, and one end of an exhaust pipe 16 is connected through this opening 15. The other end of the exhaust pipe 16 is connected to an exhaust mechanism 17, which includes a pressure adjustment mechanism and a vacuum pump.

A mounting table 31 is provided within the processing vessel 11 for horizontally mounting a wafer W. A heater 311 is provided inside the mounting table 31 for heating the wafer W. The upper end of a rod-shaped support member 34, which extends vertically and penetrates the bottom of the processing vessel 11, is connected to the center of the underside of the mounting table 31. An elevation mechanism 35 is connected to the lower end of the support member 34, and this elevation mechanism 35 enables the mounting table 31 to move up and down between a lower position indicated by a dashed line in FIG. 1 and an upper position indicated by a solid line in the same figure. The lower position is a transfer position for transferring the wafer W to and from a transfer mechanism (not shown) for the wafer W entering the processing vessel 11 through the loading/unloading port 12. The upper position is a processing position where a film formation process is performed on the wafer W.

In addition, multiple support pins 38 are arranged below the mounting table 31, and are configured to be freely raised and lowered by a lifting mechanism 381. When the mounting table 31 is positioned at the transfer position, raising and lowering the support pins 38 causes the support pins 38 to protrude and retract from the top surface of the mounting table 31 through through holes 39 provided in the mounting table 31. This action allows the wafer W to be transferred between the mounting table 31 and the transfer mechanism.

<Gas supply system 4>
The gas supply mechanism 2 having the plasma generation space 7 is provided inside the annular exhaust duct 14, i.e., above the mounting table 31. The detailed configuration of the gas supply mechanism 2 will be described in FIG. 2 and subsequent drawings. Therefore, an example configuration of the gas supply system 4 that supplies various film formation gases to the gas supply mechanism 2 will be described first.

The gas supply system 4 in this example includes a source gas supply unit 41 that supplies a source gas containing a precursor (film raw material) that serves as a raw material for the film material to be formed on the wafer W, a reactive gas supply unit 42 that supplies a reactive gas that reacts with the precursor to obtain the film material, and an auxiliary gas supply unit 43 that supplies an auxiliary gas such as argon gas that is added to assist in generating plasma from the film-forming gas (the reactive gas in the example described below). When forming a film containing titanium as the film material, a source gas containing _TiCl4 can be used, for example. Examples of reactive gases include oxygen gas or ozone gas when forming an oxide film, ammonia gas when forming a nitride film, and hydrogen gas, which is a reducing gas when reducing the precursor to form a metal film.

One end of a raw material gas supply line 412 is connected to the raw material gas supply unit 41, and a flow rate regulator 411 and a valve V1 are installed on this raw material gas supply line 412, in that order from the upstream side. One end of a reactive gas supply line 422 is connected to the reactive gas supply unit 42, and a flow rate regulator 421 and a valve V2 are installed on this reactive gas supply line 422, in that order from the upstream side. Furthermore, when forming a film by ALD, for example, storage tanks 413 and 423 for each gas may be installed upstream of valves V1 and V2 to supply sufficient amounts of raw material gas and reactive gas in a short period of time.

Furthermore, one end of an auxiliary gas supply line 432 is connected to the auxiliary gas supply unit 43, and a flow rate regulator 431 and a valve V3 are provided in this auxiliary gas supply line 432 in this order from the upstream side.
The configuration of the gas supply system 4 is not limited to this example, and for example, a purge gas supply line for supplying a purge gas that promotes the discharge of film forming gas from the processing vessel 11 may be joined to each of the gas supply lines 412, 422, and 432. Examples of the purge gas include an inert gas such as argon gas or nitrogen gas.

The other end of each of the gas supply lines 412, 422, 432 is connected to a connection port 21 provided in the gas supply mechanism 2. The specific configuration of the connection port 21 will be described together with the description of the gas supply mechanism 2 from FIG. 2 onwards, so FIG. 1 comprehensively shows the areas to which the gas supply lines 412, 422, 432 are connected.
A high frequency power supply 52 that applies high frequency power for plasma generation is connected to the gas supply mechanism 2 via a matching box 51, and a ground terminal is also connected to the gas supply mechanism 2. The configuration relating to the connection state of the high frequency power supply 52 and the ground terminal will also be described in the description of the gas supply mechanism 2 from FIG. 2 onwards.

<Gas supply mechanism 2 of first embodiment>
Next, a configuration example (first embodiment) of the gas supply mechanism 2 that converts a film formation gas into plasma and supplies activated species contained in the plasma toward the wafer W placed on the mounting table 31 will be described with reference to FIGS. 2 to 4.

The gas supply mechanism 2 in this example generates a capacitively coupled plasma of a film formation gas containing a reactive gas supplied from a reactive gas supply unit 42 in a plasma formation space 7, which is a cylindrical space. It is then configured to supply activated species contained in the plasma toward the wafer W. At this time, the gas supply mechanism 2 removes high-energy charged particles (ions) contained in the plasma and supplies activated species with an increased concentration of low-energy charged particles, neutral particles, or radicals. As a result, film formation processing can be performed with minimal damage to the wafer W.

Fig. 2 shows a partially cutaway side view of the gas supply mechanism 2 of this example, and Fig. 3 shows an enlarged longitudinal cross-sectional view thereof. Fig. 4(a) shows a plan view of the gas supply mechanism 2 as seen from above, and Fig. 4(b) shows a plan view of the gas supply mechanism 2 as seen from below.
2, the gas supply mechanism 2 has a plurality of plasma generation spaces 7 arranged side by side in the lateral direction. A gas shower head (hereinafter simply referred to as "shower head") 22 is provided below the area where the plasma generation spaces 7 are arranged, for dispersing and supplying various film formation gases toward the wafer W on the mounting table 31. Since the configuration of each plasma generation space 7 is common to all of them, an example of the configuration of the plasma generation space 7 will be described in detail with reference to FIG.

As shown in Figure 3, the gas supply mechanism 2 has an outer cell 643 and an inner cell 63 nested on the underside of a dielectric plate 601 made of a dielectric material. The outer cell 643 and the inner cell 63 are each made of a cylindrical dielectric material, and the inner diameter of the outer cell 643 is larger than the outer diameter of the inner cell 63.

The outer cell 643 and the inner cell 63 are connected to the lower surface of the dielectric plate 601 with their central axes aligned and facing the vertical direction. Each dielectric member is made of, for example, quartz (hereinafter, the same applies unless otherwise specified).
With the above-described configuration, the outer peripheral wall surface (tubular wall surface) of the inner cell 63 and the inner peripheral wall surface (tubular wall surface) of the outer cell 643, both of which are made of a dielectric material, are arranged in a double-tube shape, and a cylindrical plasma generation space 7 is formed between these wall surfaces. In Fig. 4(a), the positions of the wall surfaces of the inner cell 63 and the outer cell 643 are indicated by dashed lines.

A cylindrical metal electrode 612 is provided inside the inner cell 63. A rod-thread-shaped electrode terminal 611 is inserted into the electrode 612, penetrating a metal plate provided on the upper surface. A high-frequency power source 52 is connected to the upper end of the electrode terminal 611 via a matching box 51.

The upper portion of the electrode terminal 611 is held in place by an upper nut 621 made of a dielectric material attached to the dielectric plate 601. The lower end of this upper nut 621 protrudes from the underside of the dielectric plate 601 and is inserted into the inner cell 63.

Furthermore, a lower nut 622 made of a dielectric material is inserted from the underside of the inner cell 63 so as to fit into the cylindrical electrode 612. An opening is formed on the upper surface of the lower nut 622, and the lower end of the electrode terminal 611 is inserted into this opening. In addition, a flange is formed on the lower end of the lower nut 622, and this flange closes the opening on the lower side of the inner cell 63.

On the other hand, a groove opening toward the upper surface is formed in the outer cell 643 along the circumferential direction. A roughly cylindrical metal electrode 642 is inserted into this groove, except for the position where the source gas flow path 65 (described below) passes through. A rod-thread-shaped electrode terminal 641 is inserted into the electrode 642. A ground terminal is connected to the upper end of the electrode terminal 641.

With the configuration described above, the electrodes 612, 642 arranged inside the inner cell 63 and outer cell 643, which form the plasma generation space 7, respectively, serve as opposing electrodes. When high-frequency power is supplied from the high-frequency power supply 52 to the electrode 612, which serves as the cathode electrode, capacitive coupling is formed within the plasma generation space 7 between the electrode 612, which serves as the grounded anode electrode, and the electrode 642.

Next, a description will be given of a configuration for supplying a film formation gas to the plasma generation space 7 where capacitive coupling is formed. In the gas supply mechanism 2 of this example, an example will be shown in which a reactive gas and an auxiliary gas that assists in generating plasma from the reactive gas are supplied into the plasma generation space 7.
3 , a connection port 211 connected to a reactive gas supply line 422 that supplies a reactive gas, and a connection port 212 connected to an auxiliary gas supply line 432 that supplies an auxiliary gas, are provided on the upper surface of the dielectric plate 601. The connection ports 211 and 212 are respectively connected to a reactive gas flow path 671 and an auxiliary gas flow path 672 that vertically penetrate the dielectric plate 601. A plurality of connection ports 211 and 212 are provided on the upper surface of the dielectric plate 601, and the downstream ends of the reactive gas supply line 422 and the auxiliary gas supply line 432 branch out and are connected to the respective connection ports 211 and 212.
The connection port portion 21 shown in FIG. 1 collectively represents the connection ports 211 and 212 with the above-mentioned reaction gas supply line 422 and auxiliary gas supply line 432, and the connection port 213 with the raw material gas supply line 412 described below.

Meanwhile, a flange portion 631 with a diameter larger than the main body of the inner cell 63 is provided at the upper end of the inner cell 63 provided on the underside of the dielectric plate 601. The lower ends of the previously mentioned reaction gas flow path 671 and auxiliary gas flow path 672 open toward the upper surface of this flange portion 631. Furthermore, in an area radially outward from the opening positions of the reaction gas flow path 671 and auxiliary gas flow path 672, a gap is formed between the upper surface of the flange portion 631 and the lower surface of the dielectric plate 601. This gap serves as an introduction flow path 72, through which the reaction gas supplied from the reaction gas supply line 422 and the auxiliary gas supplied from the auxiliary gas supply line 432 flow into the plasma generation space 7.

The film-forming gas formed by mixing the reactive gas and auxiliary gas flowing into the plasma-forming space 7 flows axially from the upper side to the lower side of the plasma-forming space 7 and is converted into plasma by the capacitive coupling between the electrodes 612 and 642.
From this perspective, the devices (reactive gas supply unit 42, auxiliary gas supply unit 43, flow rate adjusters 421, 431, etc.) upstream of the reactive gas supply line 422 and the auxiliary gas supply line 432, the connection ports 211, 212, the reactive gas flow path 671, the auxiliary gas flow path 672, and the introduction flow path 72 correspond to the process gas supply unit in this example. In addition, the electrodes 612, 642 constituting the counter electrode, the matching box 51, and the high-frequency power supply 52 correspond to a plasma generation mechanism provided in the plasma generation space 7 for generating plasma from the film formation gases (reactive gas and auxiliary gas).

Meanwhile, a regulating member is provided at the lower end of the plasma formation space 7, where the film formation gas flows out, to remove high-energy charged particles contained in the plasma-converted film formation gas. In this example, the regulating member comprises a ring-shaped support portion 661 that protrudes radially inward of the plasma formation space 7 from the lower end of the outer cell 643 toward the inner cell 63, and a ring member 662 positioned on the inner peripheral edge of the support portion 661. The support portion 661 and ring member 662 may be made of a dielectric member, or may be made of a metal member whose surface is coated with a dielectric film. Examples of dielectric materials that make up these members or that coat the metal members include silicon dioxide (quartz) and yttria oxide.

The ring member 662 supported by the support portion 661 is positioned below the inner cell 63 and lower nut 622, and is configured to cover the entire lower surface of the inner cell 63 and part of the lower surface of the lower nut 622 when viewed from the mounting table 31. A gap is formed between the upper surface of the ring member 662 and the lower surfaces of the inner cell 63 and lower nut 622. This gap serves as a throttle channel 71, through which film formation gas flowing out of the plasma formation space 7 flows into the shower head 22 below via the throttle channel 71 and an opening 73 on the central side of the ring member 662. For ease of illustration, the introduction channel 72 and throttle channel 71 are omitted from Figure 2.

The support member 661 and ring member 662 are positioned at a position where the film formation gas flows out of the plasma formation space 7, and regulate the flow direction of the film formation gas along the axial direction of the plasma formation space 7 so that it flows radially through the cylindrical plasma formation space 7. Furthermore, the flow area (cross-sectional area of the flow path intersecting the flow direction) of the throttle flow path 71 formed between the upper surface of the ring member 662 and the lower surface of the inner cell 63 and lower nut 622 is smaller than that of the plasma formation space 7.

The support portion 661 and the ring member 662 constitute the restricting member of this example. The inner cell 63 and the lower nut 622 correspond to the first member, and the outer cell 643 located at the starting point of the restricting member (support portion 661) arranged to protrude downward from the first member corresponds to the second member.
As described above, the support portion 661 and the ring member 662, both of which are restricting members, are configured as separate bodies. Therefore, by replacing the ring member 662 with one having a different opening diameter of the opening 73, the flow path length of the throttle flow path 71 can be changed.

The shower head 22 is located at the position where the film formation gas flows out through the opening 73 of the ring member 662. The shower head 22 is divided into multiple gas diffusion chambers 222a corresponding to each of the plasma formation spaces 7 provided in the gas supply mechanism 2, for diffusing the film formation gas flowing out from the plasma formation spaces 7. The gas diffusion chambers 222a are formed by placing a gas dispersion plate 221 below the support member 661 and the ring member 662, which serve as a regulating member. The gas dispersion plate 221 has multiple gas supply holes 223 formed therein for supplying the film formation gas toward the processing vessel 11. Figure 4(b) schematically illustrates the formation of multiple gas supply holes 223 in the gas diffusion chambers 222a by applying a dot pattern corresponding to the area where the gas diffusion chambers 222a are formed. As shown in Figure 4(b), each gas diffusion chamber 222a has a circular planar shape.

The gas supply mechanism 2 also has the function of supplying a source gas containing a precursor into the processing vessel 11. In this example, the source gas is supplied into the processing vessel 11 as an "other film formation gas (processing gas)" that has not been converted into plasma, without passing through the plasma formation space 7.

For example, as shown in FIG. 4(a), a connection port 213 is provided on the upper surface of the dielectric plate 601, positioned above the cylindrical outer cell 643. Multiple connection ports 213 are provided on the upper surface of the dielectric plate 601, and the downstream end of the raw material gas supply line 412 that supplies the raw material gas branches and is connected to each connection port 213. As shown in FIG. 3, a raw material gas flow path 65 made of a metal piping member is provided in the connection port 213, penetrating the dielectric plate 601 and the outer cell 643 in the vertical direction. The raw material gas flow path 65 is electrically connected to an electrode 642 arranged in the outer cell 643 and is in a grounded state.

The lower end of the source gas flow path 65 is connected to the gas diffusion chamber 222b, which is formed to separate it from the gas diffusion chamber 222a described above. The gas diffusion chamber 222b is formed in an annular shape so as to surround each gas diffusion chamber 222a, which has a circular planar shape. The gas dispersion plate 221 on the lower surface of the gas diffusion chamber 222b also has a large number of gas supply holes 223 formed therein for supplying film formation gas toward the processing vessel 11. Figure 4(b) schematically shows the large number of gas supply holes 223 formed in the annular region where the gas diffusion chamber 222b is formed, by adding a dot pattern corresponding to that region.

In this example, the gas supply mechanism 2 is provided with multiple units of plasma generation space 7, each unit consisting of the related components of the plasma generation space 7 described using Figure 3 (inner cell 63, outer cell 643, support member 661, ring member 662, gas diffusion chamber 222a, etc.). In this case, as shown in Figures 2, 4(a), and 4(b), the units that make up the plasma generation space 7 are packed and arranged adjacent to each other within the plane of the gas supply mechanism 2, which is circular in plan view.

<Control Unit 100>
Returning to the explanation of FIG. 1 , the film forming apparatus 1 includes a control unit 100. The control unit 100 is configured with a computer including a storage unit, a memory, and a CPU that stores a program. The program contains instructions (steps) for outputting control signals from the control unit 100 to each unit of the film forming apparatus 1 and for carrying in and out wafers W and for executing film forming processes. The program is stored in a storage unit of the computer, such as a flexible disk, compact disk, hard disk, MO (magneto-optical disk), or nonvolatile memory, and is read from the storage unit and installed in the control unit 100.

<Film formation process>
Next, an operation of performing a film forming process on a wafer W as a plasma process using the film forming apparatus 1 having the above-described configuration will be described.
When the wafer W to be processed is transferred to the external vacuum transfer chamber, the gate valve 13 is opened, and a transfer mechanism (not shown) holding the wafer W is introduced into the processing vessel 11 through the transfer port 12. Then, the wafer W is transferred to the mounting table 31 waiting at a lower position using the support pins 38.

Thereafter, the transfer mechanism is withdrawn from the processing chamber 11, the gate valve 13 is closed, and the pressure in the processing chamber 11 and the temperature of the wafer W are adjusted. Next, reactive gas and auxiliary gas are supplied to each plasma generation space 7, and high-frequency power is applied from the high-frequency power supply 52 to the electrode 612. The film-forming gas (reactive gas, auxiliary gas) supplied to the plasma generation space 7 is converted into plasma by capacitive coupling with the electrode 642. Note that, in the following explanation of the operation, for convenience of explanation, only reactive gas may be referred to; however, the auxiliary gas is also supplied simultaneously with the reactive gas to be converted into plasma. The converted reactive gas passes through the plasma generation space 7, flows into the gas diffusion chamber 222a, and is then supplied into the processing chamber 11.
Furthermore, the source gas flowing into the gas diffusion chamber 222 b through the source gas flow passage 65 is also supplied into the processing vessel 11 .

At this time, when forming a film by CVD, the supply of the reactive gas through the plasma generating space 7 and the supply of the raw material gas through the raw material gas flow passage 65 may be carried out in parallel.
Furthermore, when forming a film by the ALD method, for example, a cycle of "supply of raw material gas via the raw material gas flow path 65 (adsorption of precursor onto the wafer W) → supply of purge gas via the plasma forming space 7 and the raw material gas flow path 65 → supply of reactive gas into the plasma forming space 7 (reaction with the precursor adsorbed onto the wafer W) → supply of purge gas via the plasma forming space 7 and the raw material gas flow path 65" is repeated a predetermined number of times. In this case, plasma of the gas supplied via the plasma forming space 7 is formed only when the reactive gas is supplied.

<Action of the Restricting Member>
Here, the action of the regulating members (supporting portion 661, ring member 662) on the plasma generation of the reactive gas in the plasma generation space 7 and the flow of the plasma-generated reactive gas will be described.
The reactive gas that flows into the plasma-forming space 7 from the inlet flow path 72 on the upper side of the inner cell 63 flows downward from the upper side to the lower side within the plasma-forming space 7. At this time, the reactive gas is converted into plasma by the action of capacitive coupling between the electrodes 612 and 642, and activated species of the reactive gas (ions, electrons, radicals) are generated.

Here, the plasma generation space 7 is configured as a cylindrical space formed between the tubular walls of the inner cell 63 and outer cell 643, which are arranged facing each other in a double-tubular configuration. The cylindrical plasma generation space 7 allows the plasma generation space 7 to be efficiently positioned within a limited area while preventing the separation distance between the electrodes 612, 642 from increasing. Therefore, compared to, for example, when the electrodes 612, 642 are positioned across a cylindrical space of the same volume and capacitively coupled plasma is generated, energy can be supplied to the reactive gas more efficiently and active species can be generated.

The activated species generated in the plasma generation space 7 are supplied to the wafer W in the form of ions, electrons, or radicals alone, and react with the source gas on or near the wafer W to form a film.

On the other hand, some of the active species generated in the plasma generation space 7 have relatively high energy. For example, if ions (charged particles) with a high valence are supplied to the wafer W at high density, there is a risk that the device structure being manufactured will be electrically damaged. Furthermore, if the charged particles have a large amount of kinetic energy in the direction toward the surface of the wafer W, the physical damage caused by the collision of the active species with the wafer W will be significant.

Regarding these points, if the activated species of the reactive gas flowing out from the plasma generation space 7 are supplied directly to the wafer W, ions with high valences will be supplied to the wafer W with large velocity components, which may cause electrical and physical damage.
Therefore, in the gas supply mechanism 2 of this example, a support portion 661 and a ring member 662 serving as restricting members are provided at a position where the reactive gas flows out from the plasma generating space 7 .

By providing the support portion 661 and ring member 662 at the exit position of the plasma generation space 7, a sufficient amount of activated species can be generated without impeding the plasma generation of the reactive gas within the plasma generation space 7. After a sufficient amount of activated species has been obtained, the flow direction of the reactive gas is regulated so that it flows radially within the plasma generation space 7, thereby preventing ions with large velocity components from colliding with the wafer W.

As mentioned above, the support portion 661 and ring member 662 are made of a dielectric material such as silicon dioxide (quartz), or are metal members coated with a dielectric film. Dielectric materials have the property of being less likely to deactivate radicals or neutral particles even when they come into contact with these active species.

On the other hand, when the high-energy charged particles (ions) reach the positions of the support member 661 and ring member 662 at the exit of the plasma generation space 7, their flow direction changes and the velocity component toward the wafer W decreases. Furthermore, some of the high-energy charged particles collide with the support member 661 and ring member 662, and some of them are deactivated due to the transfer of charge upon contact with these members 661 and 662.

Furthermore, the flow area of the throttle channel 71 formed between the upper surface of the ring member 662 and the lower surfaces of the inner cell 63 and lower nut 622 is smaller than that of the plasma generation space 7. As already mentioned, the inner cell 63 and lower nut 622 are also made of dielectric materials, and charged particles flowing through the throttle channel 71 are deactivated when they come into contact with the surfaces of the ring member 662, inner cell 63, or lower nut 622. In the throttle channel 71 with its small flow area, the probability of charged particles coming into contact with these dielectric materials increases, allowing the charged particles to be deactivated efficiently.

As described above, the regulating members (supporting member 661, ring member 662) have the function of regulating the flow direction of the reactive gas flowing out of the plasma generation space 7, and the function of suppressing the deactivation of radicals and neutral particles while promoting the deactivation of charged particles. Due to these functions, high-energy charged particles contained in the activated species generated in the plasma generation space 7 are deactivated by contact with the dielectric member, and the velocity component of the remaining charged particles that are not deactivated, moving toward the wafer W, is reduced.
By these actions, a reaction gas containing activated species from which high-energy charged particles have been selectively removed can be obtained.

The reaction gas that passes through the throttle flow path 71 flows into the gas diffusion chamber 222a through the opening 73, spreads within the gas diffusion chamber 222a, and is then supplied into the processing vessel 11 through the numerous gas supply holes 223 formed in the gas dispersion plate 221. This reaction gas contains a reduced concentration of high-energy charged particles and a high concentration of low-energy charged particles, neutral particles, and radicals, allowing the film formation process to proceed while minimizing damage to the wafer W.

After film formation by CVD or ALD has been performed for a preset period of time, the supply of various film formation gases from the plasma formation space 7 and the source gas flow path 65, as well as the supply of high-frequency power to the electrode terminal 611, is stopped. The wafer W on which film formation has been performed is then unloaded from the processing chamber 11 in the reverse order of the loading procedure.

<Effects>
The film forming apparatus 1 according to this embodiment has the following advantages: High-energy charged particles contained in the plasma-converted film forming gas (reactive gas) are removed by the restricting members (supporting portion 661, ring member 662). As a result, low-energy charged particles, neutral particles, or radicals can be supplied to the wafer W at a high concentration to perform the film forming process.

Here, the regulating member is not limited to being arranged so as to protrude from the outer cell 643 side toward the inner cell 63 side, as in the example shown in Figure 3, and to form a throttle flow path 71 between it and the inner cell 63 or the lower nut 622.
5, a restricting member (a support portion 661a and a ring member 662a) may be provided so as to protrude from the inner cell 63 toward the outer cell 643. In this case, for example, a gap between the upper surface of the ring member 662a and the lower surface of the electrode 642 serves as the throttle flow path 71a. In this example, the outer cell 643 corresponds to the first member, and the inner cell 63 located at the starting point of the support portion 661a corresponds to the second member.

<Gas supply mechanism 2b of second embodiment>
Next, a configuration example of a gas supply mechanism 2b according to the second embodiment will be described with reference to Figures 6 to 8. In each of the configurations shown in Figures 5 to 16, including the gas supply mechanism 2a shown in Figure 5 already described, components common to those described using Figures 1 to 4 are denoted by the same reference numerals as those used in these figures.
Fig. 6 is a diagram showing longitudinal cross-sectional views of gas supply mechanism 2b as viewed from two mutually orthogonal directions on the same screen, Fig. 7A and Fig. 7B are enlarged longitudinal cross-sectional views of the central region of gas supply mechanism 2b as viewed from the above two directions, and Fig. 8 is a partially cutaway plan view of gas supply mechanism 2b as viewed from above.

The gas supply mechanism 2 according to the first embodiment is different in that a plurality of cylindrical plasma formation spaces 7 are arranged adjacent to each other, whereas the gas supply mechanism 2b according to the second embodiment is different in that a plurality of plasma formation spaces 7 are arranged in a multiple concentric circle pattern.
6 and 8, a cylindrical inner cell 63 made of a dielectric material and containing a cylindrical electrode 612a is provided in the center of the gas supply mechanism 2b. As shown in FIGS. 7A and 7B, a high-frequency power supply 52 is connected to the electrode 612a.

Anode cells 643a and cathode cells 63a, made of flat, annular dielectric materials, are alternately arranged at intervals on the outer side of the inner cell 63. Each anode cell 643a and cathode cell 63a has a groove that opens toward the top and extends circumferentially.

As shown in Figures 7A, 7B, and 8, roughly cylindrical metal electrodes 642 are inserted into the grooves of the anode cell 643a, except for the position where the source gas flow path 65 passes through. The upper ends of these electrodes 642 are arranged to contact the metal lid 23 and are grounded via the lid 23.

Meanwhile, a cylindrical metal electrode 612b is inserted into the groove of the cathode cell 63a. The high-frequency power supply 52 is connected to these electrodes 612b via electrode terminals 611. A quartz cap 663 made of a circular dielectric material is provided between the upper surface of the electrode 612 and the lower surface of the lid 23, along the opening of the groove in the electrode 612b, to prevent contact between the grounded lid 23 and the electrode 612b.

With the above-described configuration, electrodes 612a and 612b connected to the high-frequency power supply 52 serve as cathode electrodes, and the grounded electrode 642 serves as an anode electrode, forming opposing electrodes. When high-frequency power is supplied from the high-frequency power supply 52 to electrode 612, which serves as the cathode electrode, capacitive coupling is formed within the plasma generation space 7 between electrode 612 and the grounded anode electrode 642.

Other features of the gas supply mechanism 2 according to the first embodiment are as follows: a reactive gas and an auxiliary gas are supplied to the plasma generation space 7 via a reactive gas flow path 671 and an auxiliary gas flow path 672; support members 661, 661a and ring members 662, 662a, which serve as regulating members, are provided at a position where the plasmatized reactive gas flows out of the plasma generation space 7, thereby forming a throttle flow path 71; a shower head 22, in which gas diffusion chambers 222a, 222b, and 222c are formed, is provided on the underside of the support members 661, 661a and ring members 662, 662a; and a source gas flow path 65 is formed so as to vertically penetrate the anode cell 643a, and its lower end is connected to the gas diffusion chamber 222b formed in the shower head 22.
However, the planar shapes of the centrally located support portion 661, the support portion 661a other than the gas diffusion chamber 222a, the regulating member 662b, and the gas diffusion chambers 222b and 222c are annular corresponding to the planar shapes of each plasma formation space 7, which is different from the gas supply mechanism 2 according to the first embodiment.

The gas supply mechanism 2b configured as described above can also remove high-energy charged particles contained in the plasma-converted film formation gas (reaction gas) using the regulating members (supports 661, 661a, ring members 662, 662b). As a result, a reaction gas containing a high concentration of low-energy charged particles, neutral particles, or radicals can be supplied to the wafer W, allowing for film formation processing with minimal damage to the wafer W.

<Gas supply mechanism 2c of third embodiment>
Next, an embodiment using a different plasma formation method will be described with reference to FIGS.
The third to fifth embodiments described below show examples in which various technical configurations are applied to gas supply mechanisms 2c to 2e in which multiple plasma generation spaces 7 are arranged in a multiple concentric pattern, similar to the second embodiment described using Figures 6 to 8.

The gas supply mechanism 2c according to the third embodiment differs from the gas supply mechanisms 2, 2a, and 2b according to the first and second embodiments, which form capacitively coupled plasma, in that it uses microwaves to form surface wave plasma of the film forming gas.
9 shows a partially cutaway side view of the upper portion of the processing vessel 11 of the film forming apparatus 1. A microwave introduction unit 535 is provided on the top surface of the gas supply mechanism 2c provided on the exhaust duct 14, and a microwave generation unit 531 is connected to this microwave introduction unit 535 via a coaxial waveguide 534, a mode converter 533, and a waveguide 532. A cover 18 is provided on the top surface of the gas supply mechanism 2c to prevent microwave leakage.

10 and 11, the gas supply mechanism 2c has a configuration in which, from the top, dielectric plates 601 and 602 and dielectric members 603 and 604 are stacked. As shown in the enlarged vertical cross-sectional view of Fig. 11, microwaves supplied to a microwave introduction part 535 propagate through the lower surface of a microwave propagation plate 536 arranged between the topmost and second-highest dielectric plates 601 and 602, and are supplied to the dielectric plate 602 on the lower surface side thereof.
The microwave generator 531, the waveguide 532, the mode converter 533, the coaxial waveguide 534, the microwave introduction part 535, and the microwave propagation plate 536 correspond to the microwave supply mechanism of this example. The microwave supply mechanism constitutes a plasma generation mechanism for generating surface wave plasma of the reactive gas.

The dielectric plate 602 is made of a dielectric material that transmits microwaves, such as quartz, and has multiple concentric grooves formed on the bottom surface of the dielectric plate 602.
The third and fourth rows of dielectric members 603 and 604 from the top are configured so that a disk-shaped dielectric member in the central region and multiple ring-shaped dielectric members in the outer region are arranged in multiple concentric circles with spaces between them so that annular openings are formed at positions that communicate with these grooves.

By vertically connecting the grooves in the dielectric plate 602 and the openings in the dielectric members 603 and 604, multiple plasma generation spaces 7 are formed that open toward the underside of the gas supply mechanism 2c, as shown in Figures 10 and 11. These multiple plasma generation spaces 7 are arranged in multiple concentric circles when viewed from above, similar to the plasma generation spaces 7 of the gas supply mechanism 2b according to the second embodiment shown in Figure 8.

As shown in Figures 10 and 11, a reactive gas flow path member 671a is provided inside the third-stage dielectric member 603. Each reactive gas flow path member 671a is made of a dielectric member. A flat, circular flow path space is formed within the central region reactive gas flow path member 671a, while an annular flow path space is formed within the outer region reactive gas flow path member 671a. As shown in Figure 11, a plurality of gas supply holes 671b are formed in the upper surface of the reactive gas flow path member 671a along the edge of the flow path space. Each gas supply hole 671b is connected to the plasma generation space 7 via an introduction flow path 72 consisting of a gap formed between the lower surface of the dielectric plate 602 and the upper surface of the dielectric member 603.

Furthermore, as shown in FIG. 10, a reactive gas flow path 671 is formed within the outermost reactive gas flow path member 671a. The upstream end of this reactive gas flow path 671 is connected to the reactive gas supply line 422 shown in FIG. 1 (connection not shown). The downstream end of the reactive gas flow path 671 is connected to the flow path space of the outermost reactive gas flow path member 671a. Furthermore, the auxiliary gas supply line 432 shown in FIG. 1 joins the upstream end of the reactive gas flow path 671, so that an auxiliary gas for plasma formation is premixed and supplied together with the reactive gas. Hereinafter, in the explanations of FIGS. 10 and 11, the premixed mixture of reactive gas and auxiliary gas will be simply referred to as the "reactive gas."

Furthermore, the flow path spaces of each reactant gas flow path member 671a are connected to each other by connecting pipes (not shown) made of a dielectric material that are arranged to radially penetrate the reactant gas flow path member 671a and the dielectric member 603. With this configuration, reactant gas supplied to the flow path space of the outermost reactant gas flow path member 671a via the reactant gas flow path 671 flows into the flow path spaces of other reactant gas flow path members 671a arranged radially inward. The reactant gas supplied to the flow path space of each reactant gas flow path member 671a then flows into each plasma generation space 7 via the gas supply holes 671b and the introduction flow paths 72.

10 and 11, a raw material gas flow path member 65a is provided inside the fourth-stage dielectric member 604. Each raw material gas flow path member 65a is made of a dielectric member. A flat, circular flow path space is formed within the raw material gas flow path member 65a in the central region, and an annular flow path space is formed within the raw material gas flow path member 65a in the outer region. As shown in FIG. 11, the shower head 22 is partitioned into gas diffusion chambers 222a and 222c for reactant gas and a gas diffusion chamber 222b for raw material gas. A gas supply hole 65b is formed in the lower surface of the raw material gas flow path member 65a located above the gas diffusion chamber 222b for raw material gas. On the other hand, no gas supply hole 65b is formed in the remaining raw material gas flow path members 65a located above the gas diffusion chambers 222a and 222c for reactant gas.

10, a raw gas flow channel 672c is formed within the outermost raw gas flow channel member 65a. The upstream end of the raw gas flow channel 672c is connected to the downstream end of the raw gas supply line 412 shown in FIG. 1. The flow channel spaces of each raw gas flow channel member 65a are connected to each other by connecting pipes (not shown) made of a dielectric material that are arranged to radially penetrate the raw gas flow channel member 65a and the dielectric member 604. With this configuration, the raw gas supplied via the raw gas flow channel 672c flows into the flow channel spaces of each raw gas flow channel member 65a arranged radially inward. The raw gas supplied to each raw gas flow channel member 65a is then supplied to the raw gas gas diffusion chamber 222b via the raw gas supply holes 65b.

In the gas supply mechanism 2c according to the third embodiment, which has the configuration described above, a regulating member 662b is also provided at the lower end of the plasma formation space 7, where the film formation gas (reaction gas) flows out of the plasma formation space 7. As shown in FIG. 11 , the regulating member 662b in this example is made of a dielectric member and is a ring-shaped member that protrudes laterally from the lower end of the dielectric member 604, from the gas diffusion chamber 222b for the source gas toward the gas diffusion chambers 222a and 222c for the reaction gas.

The tip of the regulating member 662b is positioned below the dielectric member 604, which is provided on the gas diffusion chambers 222a and 222c for the reactive gas. Therefore, the regulating member 662b is provided so as to cover part of the lower surface of the dielectric member 604 when viewed from the mounting table 31 side. The gap between the upper surface of the regulating member 662b and the lower surface of the dielectric member 604 forms a throttle flow path 71 through which the reactive gas flows out of the plasma generation space 7.

The regulating member 662b is also similar to the gas supply mechanism 2 according to the first embodiment in that (1) it is positioned at a position where the reactive gas flows out of the plasma generation space 7 and regulates the flow direction of the reactive gas along the axial direction of the plasma generation space 7 so that it flows in the radial direction of the cylindrical plasma generation space 7, and (2) the throttle flow path 71 has a flow path area smaller than that of the plasma generation space 7.

The operation of the gas supply mechanism 2c according to the third embodiment, which has the configuration described above, will now be described. Reactive gas is supplied from the reactive gas flow path member 671a to each plasma formation space 7 via the inlet flow path 72, and microwaves are supplied from the microwave generator 531 to the uppermost dielectric plate 601. As a result, surface wave plasma (SWP) of the reactive gas is formed along the wall surface of the plasma formation space 7, which is the tubular wall surface through which microwaves propagate within the plasma formation space 7.

When the plasma-converted reactive gas flows out of the plasma generation space 7, its flow direction is restricted by the restricting member 662b. Because the restricting member 662b is made of a dielectric material, deactivation of radicals and neutral particles is suppressed. Meanwhile, high-energy charged particles contained in the activated species generated in the plasma generation space 7 are deactivated upon contact with the dielectric material, and the velocity component of the remaining charged particles moving toward the wafer W is reduced. As a result, the function of obtaining a reactive gas containing activated species from which high-energy charged particles have been selectively removed is the same as in the first embodiment described above.

The reaction gas that passes through the throttle flow path 71 flows into the gas diffusion chambers 222a and 222c through the openings 73 and is supplied into the processing vessel 11 through the numerous gas supply holes 223 formed in the gas dispersion plate 221. The source gas that flows into the gas diffusion chamber 222b through the source gas flow path member 65a is also supplied into the processing vessel 11. The concentration of high-energy charged particles is reduced, and the reaction gas contains a high concentration of low-energy charged particles, neutral particles, and radicals, allowing the film formation process to proceed while minimizing damage to the wafer W.

<Gas supply mechanism 2d of fourth embodiment>
A gas supply mechanism 2d according to the fourth embodiment shown in FIGS. 12 to 13B differs from the gas supply mechanisms 2, 2a, and 2b according to the first and second embodiments in that it uses a coil 54 to form inductively coupled plasma of the reactive gas, which forms capacitively coupled plasma.
FIG. 12 is a vertical cross-sectional side view of the entire gas supply mechanism 2d, and FIGS. 13A and 13B are enlarged vertical cross-sectional views of the central region of the gas supply mechanism 2d as viewed from two directions perpendicular to each other.

As shown in these longitudinal side views, a cylindrical inner cell 63 made of a dielectric material is provided in the center of the gas supply mechanism 2d according to the fourth embodiment. Ground electrode cells 643b and coil cells 63b made of flat, annular dielectric material are alternately provided at intervals on the outer side of this inner cell 63. The configurations of these inner cells 63, ground electrode cells 643b, and coil cells 63b are substantially similar to the configurations of the inner cells 63, anode cells 643a, and cathode cells 63a of the gas supply mechanism 2b according to the second embodiment, as described using Figures 6, 7A, and 7B.

A cylindrically wound coil 54 is provided within the central inner cell 63. Furthermore, a coil 54 wound along the annular groove of the coil cell 63b is provided within the groove of the annular coil cell 63b. One end of each coil 54 is connected to the high-frequency power supply 52 via a matching unit 51, and the other end is grounded. Furthermore, the electrode 642 provided within the ground electrode cell 643b is grounded via the lid 23. The coil 54 connected to the high-frequency power supply 52 and the grounded electrode 642 constitute the plasma generation mechanism of this example.

Other than that, the configurations of the support member 661 and ring member 662, which are restricting members, the configurations of the reactive gas flow path 671 and auxiliary gas flow path 672 that supply reactive gas and auxiliary gas to the plasma formation space 7, the configuration of the shower head unit 22, and the configuration of the raw material gas flow path 65 that supplies raw material gas are substantially the same as those of the gas supply mechanism 2b according to the second embodiment, and therefore will not be described again.

The gas supply mechanism 2d according to the fourth embodiment, which has the configuration described above, supplies reactive gas and auxiliary gas to each plasma formation space 7. High-frequency power is then applied from the high-frequency power supply 52 to the coil 54, and the reactive gas supplied to the plasma formation space 7 is converted into plasma by inductive coupling.

The flow of the plasma-converted reactive gas and the functions of the support member 661 and ring member 662, which serve as restricting members, are the same as those of the gas supply mechanism 2b according to the second embodiment. That is, as the reactive gas passes through the throttle flow path 71, the concentration of high-energy charged particles is reduced and the concentration of low-energy charged particles, neutral particles, and radicals is increased. As a result, the film formation process can proceed while minimizing damage to the wafer W.

<Gas supply mechanism 2e of fifth embodiment>
14 to 16 show an example of a gas supply mechanism 2e provided with a magnet 644 for reducing the kinetic energy of the charged particles toward the surface of the wafer W to generate low-energy charged particles. Similar to the gas supply mechanism 2d according to the fourth embodiment, the gas supply mechanism 2e according to the fifth embodiment is an example of a configuration in which, among the inner cell 63, coil cell 63b, and ground electrode cell 643b that constitute the multiple concentric plasma generation space 7, the coil 54 is disposed in the inner cell 63 and the coil cell 63b.

However, when viewed from the mounting table 31 side, the end of the restricting member 662b, which is provided so as to protrude from the ground electrode cell 643b side, does not cover the lower surfaces of the inner cell 63 and the coil cell 63b, which is different from the gas supply mechanism 2d according to the fourth embodiment. Furthermore, the gas supply mechanism 2e of this example does not have a shower head unit 22.

As shown in the enlarged longitudinal cross-sectional view of Figure 14, a magnet 644 is provided at the lower end of the groove of the ground electrode cell 643b in which the electrode 642 is provided. As shown schematically in the transverse plan view of Figure 15, multiple magnets 644 are arranged circumferentially at intervals within the groove of the ground electrode cell 643b in which the electrode 642 is provided. Note that the gray areas in Figure 15 indicate the space within the grooves of the inner cell 63 and coil cell 63b, within which the coil 54 is disposed. The dashed-dotted lines in the figure indicate the positions of the wall surfaces (tubular wall surfaces) of the inner cell 63, coil cell 63b, and ground electrode cell 643b that constitute the plasma generation space 7.

As shown in the enlarged schematic view of Figure 16, multiple magnets 644 are arranged in the groove of the electrode 642 so that the line connecting the north and south poles faces in a direction that intersects with the circumferential direction of the plasma generation space 7. Furthermore, these magnets 644 are arranged so that the north and south poles of adjacent magnets 644 face in opposite directions.

With this arrangement, the magnets 644 can form magnetic field lines in each plasma generation space 7 that act in a direction that intersects with the flow direction of the reactive gas containing active species. The action of these magnetic field lines causes the high-energy charged particles contained in the active species to move along the magnetic field lines. As a result, the kinetic energy of the high-energy charged particles toward the surface of the wafer W is reduced, and combined with the action of the regulating member 662b, it becomes possible to supply the charged particles to the wafer W in a low-energy state.

In addition, the gas supply mechanism 2e shown in FIG. 14 is provided with a magnet 644 that reduces the kinetic energy of charged particles, and therefore the flow path area of the throttle flow path 71 is larger than that of the gas supply mechanisms 2, 2b, and 2c according to other embodiments shown in, for example, FIGS. 3, 7A, and 11 (however, the requirement that "the flow path area of the throttle flow path 71 is smaller than that of the plasma generation space 7" remains unchanged). In this way, by widening the flow path area of the throttle flow path 71, it is possible to suppress the increase in pressure loss that would otherwise occur if a regulating member 662b were provided.

As mentioned above, the gas supply mechanism 2e of this example does not include a shower head 22. The shower head 22 diffuses the reaction gas flowing out from the throttle flow path 71 within the gas diffusion chambers 222a, 222c before supplying it toward the wafer W, thereby preventing charged particles from colliding with the wafer W at high speeds. In this regard, the provision of a magnet 644, which acts to reduce the kinetic energy of the charged particles, eliminates the need for a shower head 22, suppresses the increase in pressure loss that would otherwise occur if a regulating member 662b were provided, and simplifies the device configuration.

<Other variations>
Each of the configurations described above in the gas supply mechanisms 2, 2a to 2e according to the first to fifth embodiments can be appropriately combined with the configurations described in other embodiments.
For example, the plasma generation mechanisms according to the second to fourth embodiments may be applied to the gas supply mechanisms 2 and 2a illustrated in the first embodiment, in which multiple plasma generation spaces 7 are arranged side by side. Regarding the arrangement and configuration of the regulating member, the arrangement and configuration of the regulating member (support member 661a, ring member 662a) according to the modified example of the first embodiment described with reference to FIG. 5 may be applied to the gas supply mechanisms 2b to 2e according to the second to fifth embodiments. Furthermore, the regulating member 662b according to the third and fifth embodiments, which does not include the ring member 662 for adjusting the diameter of the opening 73, may be applied to the gas supply mechanisms 2, 2a, 2b, and 2d according to the first, second, and fourth embodiments. Conversely, the gas supply mechanisms 2c and 2e according to the third and fifth embodiments may be provided with a regulating member consisting of the support member 661 and the ring member 662. Furthermore, the shower head 22 may be omitted from the gas supply mechanisms 2, 2a to 2d according to the first to fourth embodiments.

In each embodiment, the protruding direction of the regulating members (supporting portions 661, 661a, ring members 662, 662a, regulating members 662b) is not limited to the horizontal direction, and they may be configured to protrude diagonally downward or diagonally upward. Furthermore, it is not an essential requirement that these regulating members cover the entire outlet for the processing gas from the plasma generation space 7 when viewed from the mounting table 31 side. As long as the plasma formed in the plasma generation space 7 is hidden by the regulating members when viewed from the mounting table 31 side, part of the outlet may be visible.

Furthermore, in each of the gas supply mechanisms 2, 2a to 2e, the plasma generation space 7 does not have to be configured as an integrated space. For example, partition walls made of a dielectric material may be provided at intervals along the circumferential direction of the cylindrical space, and the cylindrical plasma generation space 7 may be configured as a whole by a plurality of mutually partitioned partial spaces.
Furthermore, the planar shape of each plasma generating space 7 as viewed from the mounting table 31 side is not limited to a circular ring shape, but may be, for example, a polygonal ring shape or an elliptical ring shape.

The above-described gas supply mechanisms 2, 2a-2e are not limited to application to the film formation apparatus 1 that forms films on wafers W. A gas supply mechanism equipped with the plasma formation space 7 and regulating member configured as described above may be provided to supply various gases into the processing chamber 11 of an etching processing apparatus that supplies plasma-converted etching gas to wafers W to etch a film formed on the wafers W, or a modifying apparatus that performs a modification process that modifies a substance on the wafers W using plasma-converted modifying gas. In these cases, the etching gas and modifying gas each correspond to the processing gas disclosed herein.

The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

W wafer 1 film forming device 11 processing vessel 2, 2a to 2e
Gas supply mechanism 52 High frequency power supply 531 Microwave generating units 661, 661a
Support parts 662, 662a
Ring member 671 Reaction gas flow path 672 Auxiliary gas flow paths 71, 71a
Restricted flow channel

Claims (13)

An apparatus for performing plasma processing by supplying a processing gas that has been converted into plasma to a substrate in a processing container,
a mounting table provided in the processing chamber for mounting the substrate thereon;
a plurality of plasma generation spaces, each of which is provided above the mounting table and is a cylindrical space formed between tubular wall surfaces arranged opposite to each other in a double-tubular configuration, and each of which is provided with a plasma generation mechanism for generating plasma from the processing gas;
a processing gas supply unit for supplying the processing gas to a position upstream of a flow of the processing gas so that the processing gas flows along an axial direction of the cylindrical plasma generation space;
a ring-shaped regulating member that is provided at a position where the processing gas flows out from each of the plasma formation spaces, and that regulates the flow of the processing gas so that the flow direction is toward the radial direction of the cylindrical plasma formation space, and that forms a throttle flow path with a flow path area smaller than that of the plasma formation space between itself and a member that constitutes one side of the tubular wall surface. The device described in claim 1, wherein the tubular wall surface is made of a dielectric material. When a member constituting one side of the tubular wall surface is referred to as a first member and a member constituting the other side of the tubular wall surface is referred to as a second member,
The device according to claim 1 or 2, wherein the restricting member is provided so as to protrude downward from the second member as a starting point thereof toward a lower side of the first member. The device described in claim 3, wherein the regulating member is arranged to cover a portion of the underside of the first member when viewed from the mounting table side, and the throttle flow path is formed between the first member and the regulating member. An apparatus according to any one of claims 1 to 4, wherein the multiple plasma formation spaces are arranged adjacent to each other in the lateral direction. The apparatus described in any one of claims 1 to 4, wherein the multiple plasma formation spaces are arranged in a multi-concentric pattern. The apparatus described in any one of claims 1 to 6, further comprising: a gas shower head unit in which a plate-shaped gas dispersion plate having a large number of gas supply holes is disposed below the regulating member; and a gas diffusion chamber is formed between the regulating member and the gas dispersion plate for diffusing the processing gas that has passed through the throttle flow path. The apparatus described in claim 7, wherein the gas diffusion chamber is partitioned into multiple spaces, and other processing gases that have not been converted into plasma are supplied to some of these spaces via flow paths other than the plasma formation space. The apparatus described in any one of claims 1 to 8, wherein the plasma generation mechanism includes a high-frequency power source for supplying high-frequency power from one side of the tubular wall surface to form a capacitively coupled plasma between the other side and the grounded tubular wall surface. The apparatus described in any one of claims 1 to 8, wherein the plasma formation mechanism includes a microwave supply mechanism that supplies microwaves to form plasma along the tubular wall surface. The apparatus described in any one of claims 1 to 8, wherein the plasma formation mechanism includes a coil connected to a high-frequency power source for forming an inductively coupled plasma within the plasma formation space. The apparatus described in any one of claims 1 to 11, further comprising a magnet for forming magnetic field lines that exert a magnetic force in a direction intersecting the flow direction of the processing gas flowing through the plasma generation space. A method for performing plasma processing by supplying a processing gas converted into plasma to a substrate in a processing container, comprising:
a plurality of plasma generation spaces, each of which is provided with a plasma generation mechanism for generating plasma from the processing gas; and a ring-shaped regulating member, which is provided at a position where the processing gas flows out from each of the plasma generation spaces, for regulating the flow direction of the processing gas so that the flow direction is in the radial direction of the cylindrical plasma generation space, and which forms a throttle flow path having a flow path area smaller than that of the plasma generation space between a member constituting one side of the tubular wall and the ring-shaped regulating member.
supplying the processing gas to the plurality of plasma generation spaces and causing the processing gas to flow along the axial direction of the cylindrical plasma generation spaces;
generating plasma from the processing gas flowing in each of the plasma generation spaces by the plasma generation mechanism;
and a step of using the regulating member to regulate the flow of the processing gas flowing out of each of the plasma generation spaces so that it is directed in the radial direction, and after passing through the throttle flow path, supplying the processing gas to the substrate on the mounting table.