JP7131916B2 - Plasma processing equipment - Google Patents

Description

The present invention relates to a plasma processing apparatus.

2. Description of the Related Art In manufacturing processes for various products such as semiconductor devices, liquid crystal displays, and optical discs, thin films such as optical films are sometimes formed on workpieces such as wafers and glass substrates. A thin film can be produced by forming a film of metal or the like on a workpiece, or by performing film processing such as etching, oxidation, or nitridation on the formed film.

Film formation or film processing can be performed by various methods, one of which is a method using plasma. In film formation, an inert gas is introduced into a chamber in which a target is placed, and a DC voltage is applied. Plasma inert gas ions are made to collide with the target, and the material ejected from the target is deposited on the workpiece to form a film. In film processing, a process gas is introduced into a chamber in which electrodes are arranged, and a high frequency voltage is applied to the electrodes. Film processing is performed by colliding active species such as ions and radicals of the plasmatized process gas against the film on the workpiece.

In order to continuously perform such film formation and film processing, a rotary table, which is a rotating body, is attached inside one chamber, and a unit for film formation and a unit for film processing are arranged in the circumferential direction above the rotary table. There is a plasma processing apparatus in which a plurality of are arranged (see, for example, Patent Document 1). In this way, an optical film or the like is formed by holding the workpiece on the rotary table, conveying it, and passing it directly under the film forming unit and the film processing unit.

2. Description of the Related Art In a plasma processing apparatus using a rotary table, a cylindrical electrode (hereinafter referred to as a “cylindrical electrode”) having a closed upper end and an opening at a lower end is sometimes used as a film processing unit. When using a cylindrical electrode, an opening is provided in the upper part of the chamber, and the upper end of the cylindrical electrode is attached to this opening via an insulator. A side wall of the cylindrical electrode extends into the interior of the chamber, and an opening at the lower end faces the rotary table with a small gap therebetween. The chamber is grounded, the cylindrical electrode serves as the anode, and the chamber and rotary table serve as the cathode. A process gas is introduced into the cylindrical electrode and a high frequency voltage is applied to generate plasma. Electrons contained in the generated plasma flow into the rotating table, which is the cathode. By passing the workpiece held on the rotary table under the opening of the cylindrical electrode, active species such as ions and radicals generated by the plasma collide with the workpiece to perform film processing.

Japanese Patent No. 4428873 Japanese Patent No. 3586198

In recent years, the size of workpieces to be processed has increased, and there has been a demand for improvement in processing efficiency. However, when plasma is generated by applying a voltage to the cylindrical electrode, it may be difficult to generate wide-area, high-density plasma.

Therefore, a plasma processing apparatus has been developed that can generate high-density plasma over a relatively wide area and perform film processing on a large workpiece (see, for example, Patent Document 2). In such a plasma processing apparatus, the antenna is arranged outside the chamber with a window member such as a dielectric interposed between the antenna and the gas space into which the process gas is introduced. Then, by applying a high-frequency voltage to the antenna, plasma is generated by inductive coupling in the gas space to perform film processing.

Consider a case where a film processing unit using inductively coupled plasma is used as a film processing unit in a plasma processing apparatus using a rotary table as described above. In this case, in order to suppress an increase in the weight of the window such as the dielectric, it is conceivable to make the width of the window such as the dielectric uniform in the circumferential direction of the rotary table. Along with this, it is conceivable that the range in which the film processing is performed in the circumferential direction of the turntable, that is, the width of the processing area is formed parallel to the direction along the radial direction of the turntable. By the way, the inner peripheral side and the outer peripheral side of the turntable have different velocities passing through the processing area on the surface of the turntable. That is, the passing speed within the same distance is faster on the outer peripheral side of the rotary table and slower on the inner peripheral side. When the width of the processing area is parallel to the radial direction of the rotary table as described above, the surface of the rotary table passes through the processing area in a shorter time on the outer peripheral side than on the inner peripheral side. It will be. Therefore, the film processing rate after processing for a certain period of time is low on the outer peripheral side and high on the inner peripheral side.

Then, for example, when oxidizing or nitriding the niobium or silicon film formed in the film forming section to form a compound film, the niobium or silicon film is formed on the inner peripheral side and the outer peripheral side of the rotary table. The degree of oxidization or nitridation of the film is greatly different. Therefore, it is difficult to uniformly process the entire work or to change the degree of processing at a desired position of the work.

This problem also occurs, for example, when wafers such as semiconductors as works are arranged in a line in the circumferential direction on a rotary table and subjected to plasma processing. Further, from the viewpoint of processing efficiency, etc., if a plurality of devices are arranged in the radial direction so that plasma processing can be performed, the problem becomes even more pronounced. Specifically, when the radius of the rotary table exceeds 1.0 m and the width of the processing area in the radial direction of the rotary table reaches 0.5 m, the difference in processing rate between the inner and outer circumferences becomes very large. becomes large.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a plasma processing apparatus capable of performing desired plasma processing on a workpiece circulated and transported by a rotating body according to positions on the surface of the rotating body at different passing speeds.

In order to achieve the above object, the plasma processing apparatus of the present invention includes:
a vacuum container whose interior can be evacuated;
a conveying unit provided in the vacuum vessel, having a rotating body on which a work is mounted and rotating, and circulating and conveying the work on a circumferential conveying path by rotating the rotating body;
a cylindrical portion having an opening at one end extending in a direction toward the transfer path inside the vacuum vessel;
a window portion provided in the tubular portion and separating a gas space into which a process gas is introduced between the inside of the tubular portion and the rotating body and the outside of the gas space;
It is arranged outside the gas space and near the window, and when electric power is applied, the process gas in the gas space is inductively coupled plasma for plasma-processing the work passing through the transfer path. an antenna that generates
a supply unit for supplying the process gas from a plurality of supply ports provided in the gas space corresponding to a plurality of locations corresponding to a plurality of locations where the surface of the rotating body passes through the processing region where the plasma processing is performed;
a distribution plate arranged at a position facing the plurality of supply ports with a gap therebetween, and for dispersing the process gas and allowing it to flow into the gas space;
has
The supply unit has an adjustment unit that individually adjusts a supply amount of the process gas per unit time supplied from each of the plurality of supply ports according to the passage time,
The dispersion plate has a surface extending in a direction intersecting with the gas flow of the process gas so that the process gas supplied from the plurality of supply ports collides with each other. and the antenna.

The flow path of the process gas between the dispersion plate and the supply port may be closed on the rotor side and communicated with the gas space on the window side.

The adjustment unit may adjust the supply amount of the process gas introduced from each supply port according to the position in the direction intersecting the transport path.

A film forming unit is provided at a position facing the work circulated and conveyed in the conveying path and deposits a film forming material on the work by sputtering to form a film, and the film is deposited on the work by the film forming unit. The film of the film material may be subjected to the film treatment using the inductively coupled plasma.

The supply port corresponds to a region where the film formation unit forms a film, is provided in an annular film formation region along the transport path, and is also provided outside the film formation region. The supply port provided outside may be excluded from the adjustment target of the supply amount of the process gas by the adjustment unit.

The supply ports may be arranged at opposing positions across the gas space in a direction along the transport path.

The adjustment unit may adjust the supply amount of the process gas introduced from each gas introduction port according to the film thickness to be formed on the workpiece and the passage time.

According to the present invention, a desired plasma treatment can be performed on a workpiece that is circulated and transported by a rotating body according to positions on the surface of the rotating body that pass at different speeds.

1 is a see-through perspective view of a plasma processing apparatus according to an embodiment; FIG. 1 is a perspective plan view of a plasma processing apparatus according to an embodiment; FIG. FIG. 3 is a cross-sectional view taken along line AA of FIG. 2; FIG. 3 is a cross-sectional view taken along line BB of FIG. 2; FIG. 5 is an enlarged view showing details of part A of FIG. 4; It is an exploded perspective view showing a processing unit of an embodiment. It is a perspective plan view showing the processing unit of the embodiment. FIG. 3 is a schematic diagram showing a flow path of process gas; 1 is a perspective view showing an antenna of an embodiment; FIG. It is a block diagram which shows the structure of the control apparatus of embodiment. It is a graph which shows the test result of a comparative example and an Example.

An embodiment of the present invention (hereinafter referred to as the present embodiment) will be specifically described with reference to the drawings.
[Overview]
A plasma processing apparatus 100 shown in FIG. 1 is an apparatus for forming a compound film on the surface of each workpiece W using plasma. That is, in the plasma processing apparatus 100, as shown in FIGS. 1 to 3, when the rotating body 31 rotates, the work W on the tray 34 held by the holding portion 33 moves in a circular locus. Due to this movement, the workpiece W repeatedly passes through the positions facing the film forming units 40A, 40B, or 40C. At each pass, particles of the targets 41A to 41C are caused to adhere to the surface of the workpiece W by sputtering. Moreover, the workpiece W repeatedly passes through the position facing the film processing section 50A or 50B. At each pass, the particles adhering to the surface of the workpiece W combine with substances in the introduced process gas G2 to form a compound film.

[Constitution]
As shown in FIGS. 1 to 3, the plasma processing apparatus 100 includes a vacuum vessel 20, a transport section 30, film forming sections 40A, 40B, and 40C, film processing sections 50A and 50B, a load lock section 60, and a control device. 70.

[Vacuum container]
The vacuum container 20 is a container whose interior can be evacuated, a so-called chamber. A vacuum chamber 21 is formed inside the vacuum container 20 . The vacuum chamber 21 is a cylindrical closed space surrounded by a ceiling 20a, an inner bottom surface 20b, and an inner peripheral surface 20c inside the vacuum vessel 20. As shown in FIG. The vacuum chamber 21 is airtight and can be evacuated by decompression. In addition, the ceiling 20a of the vacuum vessel 20 is configured to be openable and closable.

A reaction gas G is introduced into a predetermined region inside the vacuum chamber 21 . The reaction gas G includes a sputtering gas G1 for film formation and a process gas G2 for film processing (see FIG. 3). In the following description, the sputtering gas G1 and the process gas G2 may be referred to as the reaction gas G when not distinguished from each other. The sputtering gas G1 is a gas for depositing the material of the targets 41A to 41C on the surface of the workpiece W by colliding the ions generated by the plasma generated by the application of electric power against the targets 41A to 41C. For example, an inert gas such as argon gas can be used as the sputtering gas G1.

The process gas G2 is a gas for forming a compound film by allowing active species generated by plasma generated by inductive coupling to permeate the film deposited on the surface of the workpiece W. As shown in FIG. Hereinafter, such surface treatment using plasma, which does not use the targets 41A to 41C, may be referred to as reverse sputtering. The process gas G2 can be appropriately changed depending on the purpose of processing. For example, when oxynitriding a film, a mixed gas of oxygen O ₂ and nitrogen N ₂ is used.

The vacuum container 20 has an exhaust port 22 and an inlet port 24, as shown in FIG. The exhaust port 22 is an opening for ensuring gas flow between the vacuum chamber 21 and the outside to perform exhaust E. As shown in FIG. This exhaust port 22 is formed, for example, at the bottom of the vacuum vessel 20 . An exhaust portion 23 is connected to the exhaust port 22 . The exhaust unit 23 has a pipe, a pump (not shown), a valve, and the like. The inside of the vacuum chamber 21 is decompressed by the evacuation process by the evacuation unit 23 .

The introduction port 24 is an opening for introducing the sputtering gas G1 into each of the film forming portions 40A, 40B, and 40C. This introduction port 24 is provided, for example, in the upper portion of the vacuum vessel 20 . A gas supply unit 25 is connected to the introduction port 24 . The gas supply unit 25 has a gas supply source of the reaction gas G, a pump, a valve, etc. (not shown) in addition to the piping. The sputtering gas G<b>1 is introduced into the vacuum chamber 21 through the introduction port 24 by the gas supply unit 25 . An opening 21a into which the film processing units 50A and 50B are inserted is provided in the upper portion of the vacuum vessel 20, as will be described later.

[Conveyor]
An outline of the transport section 30 will be described. The transfer section 30 has a rotating body 31 provided inside the vacuum vessel 20 . A workpiece W is mounted on the rotating body 31 . The transport unit 30 is a device that circulates and transports the work W along a circumferential transport path T by rotating a rotating body 31 . Circulating transport means that the workpiece W is repeatedly circulated along a circumferential locus. The transport path T is a trajectory along which the workpiece W or a later-described tray 34 is moved by the transport unit 30, and is a doughnut-shaped wide ring. The details of the transport unit 30 will be described below.

The rotary body 31 is a circular plate-like rotary table. The rotating body 31 may be, for example, a stainless steel plate-like member whose surface is thermally sprayed with aluminum oxide. Henceforth, simply referring to the "circumferential direction" means "the circumferential direction of the rotating body 31", and simply referring to the "radial direction" means "the radial direction of the rotating body 31". Further, in this embodiment, a flat substrate is used as an example of the work W, but the type, shape and material of the work W to be plasma-processed are not limited to specific ones. For example, a curved substrate having a concave or convex portion in the center may be used. Also, a material containing a conductive material such as metal or carbon, a material containing an insulator such as glass or rubber, or a material containing a semiconductor such as silicon may be used. Also, the number of works W to be plasma-processed is not limited to a specific number.

The conveying section 30 has a motor 32 and a holding section 33 in addition to the rotating body 31 . The motor 32 is a driving source that applies a driving force to the rotating body 31 and rotates the rotating body 31 about the center of the circle. The holding section 33 is a component that holds the tray 34 transported by the transport section 30 . A plurality of holding portions 33 are arranged on the surface of the rotating body 31 at equidistant positions on the circumference thereof. The surface of the rotating body 31 in the present embodiment is a surface facing upward when the rotating body 31 is horizontal, that is, a top surface. For example, the regions in which the holding portions 33 hold the trays 34 are formed in a direction parallel to the tangent line of the circle in the circumferential direction of the rotating body 31 and are provided at equal intervals in the circumferential direction. More specifically, the holding part 33 is a groove, a hole, a projection, a jig, a holder, or the like for holding the tray 34, and can be configured by a mechanical chuck, an adhesive chuck, or the like.

The tray 34 is a member having a flat mounting surface on which the workpiece W is mounted on one side of a rectangular flat plate. As a material for the tray 34, it is preferable to use a material having high thermal conductivity, such as metal. In this embodiment, the material of the tray 34 is SUS. The material of the tray 34 may be, for example, ceramics or resin with good thermal conductivity, or a composite material thereof. The work W may be directly mounted on the mounting surface of the tray 34, or may be indirectly mounted via a frame or the like having an adhesive sheet. A single work W may be mounted on each tray 34, or a plurality of works W may be mounted.

In this embodiment, since six holding portions 33 are provided, six trays 34 are held on the rotor 31 at intervals of 60°. However, the number of holding portions 33 may be one or plural. The rotating body 31 circulates and conveys the tray 34 on which the work W is mounted, and repeatedly passes through positions facing the film forming units 40A, 40B, 40C and the film processing units 50A, 50B.

[Deposition part]
The film forming units 40A, 40B, and 40C are processing units that are provided at positions facing the work W that is circulated and transported on the transport path T, and that deposit a film forming material on the work W by sputtering to form a film. Hereinafter, the plurality of film forming units 40A, 40B, and 40C will be described as the film forming unit 40 when not distinguished. The film forming section 40 has a sputtering source 4, a dividing section 44, and a power supply section 6, as shown in FIG.

(spatter source)
The sputtering source 4 is a supply source of a film-forming material for forming a film by depositing a film-forming material on the workpiece W by sputtering. The sputtering source 4 has targets 41A, 41B, 41C, a backing plate 42, and an electrode 43, as shown in FIGS. The targets 41A, 41B, and 41C are formed of a film-forming material that is deposited on the workpiece W to form a film, and are arranged at positions facing the transport path T with a gap therebetween.

In this embodiment, three targets 41A, 41B, and 41C are provided at positions aligned on the vertices of a triangle in plan view. Targets 41A, 41B, and 41C are arranged in this order from the side nearer to the center of rotation of the rotating body 31 toward the outer periphery. Hereinafter, the targets 41A, 41B, and 41C will be referred to as the target 41 when not distinguished. The surface of the target 41 faces the workpiece W moved by the transport unit 30 while being separated therefrom. Note that the three targets 41A, 41B, and 41C have a larger area than the size of the tray 34 in the radial direction, to which the film-forming material can be deposited. Thus, the annular area along the transport path T corresponding to the area where the film is formed in the film forming section 40 is defined as the film forming area F (indicated by the dotted line in FIG. 2). The width of the film forming area F in the radial direction is longer than the width of the tray 34 in the radial direction. In addition, in this embodiment, the three targets 41A to 41C are arranged so that the film forming material can adhere to the entire width of the film forming region F in the radial direction without gaps.

Niobium, silicon, or the like, for example, is used as the film-forming material. However, various materials can be applied as long as they are materials that can be deposited by sputtering. Moreover, the target 41 is cylindrical shape, for example. However, other shapes such as an oval columnar shape and a prismatic shape may be used.

The backing plate 42 is a member that individually holds the targets 41A, 41B, and 41C. The electrodes 43 are conductive members for applying power individually to the targets 41A, 41B, and 41C from outside the vacuum vessel 20 . The power applied to each target 41A, 41B, 41C can be individually varied. In addition, the sputtering source 4 is appropriately equipped with a magnet, a cooling mechanism, and the like, as required.

(delimiter)
The partitioning part 44 is a member that partitions the film forming positions M2, M4 and M5 where the workpiece W is formed by the sputtering source 4 and the film processing positions M1 and M3 where the film processing is performed. As shown in FIG. 2 , the dividing section 44 is a square wall plate radially arranged from the center of rotation of the rotating body 31 of the conveying section 30 . For example, as shown in FIG. 1, the partitioning section 44 is provided on the ceiling 20a of the vacuum chamber 21 between the film processing section 50A, the film forming section 40A, the film processing section 50B, the film forming section 40B, and the film forming section 40C. ing. The lower end of the partition 44 faces the rotating body 31 with a gap through which the workpiece W passes. The presence of the dividing portion 44 can suppress diffusion of the reaction gas G and the film-forming material at the film-forming positions M2, M4, and M5 into the vacuum chamber 21. FIG.

The horizontal ranges of the film forming positions M2, M4, and M5 are regions separated by a pair of partitions 44. As shown in FIG. The workpiece W circulated and transported by the rotating body 31 repeatedly passes through the film-forming positions M2, M4, and M5 facing the target 41, thereby depositing the film-forming material on the surface of the workpiece W as a film. The film formation positions M2, M4, and M5 are areas where most of the film formation is performed. However, since the film formation material leaks even in areas outside of these areas, it is not the case that there is no film deposition. . In other words, the region where film formation is performed is a slightly wider region than each of the film formation positions M2, M4, and M5.

(Power supply part)
The power supply unit 6 is a component that applies power to the target 41 . By applying electric power to the target 41 from the power supply unit 6, plasmatized sputtering gas G1 is generated. Then, the ions generated by the plasma collide with the target 41 , so that the film-forming material ejected from the target can be deposited on the workpiece W. As shown in FIG. The power applied to each target 41A, 41B, 41C can be individually varied. In this embodiment, the power supply unit 6 is, for example, a DC power supply that applies a high voltage. In addition, in the case of an apparatus that performs high-frequency sputtering, an RF power supply may be used. Also, the power source section 6 may be provided for each of the film forming sections 40A, 40B, and 40C, or may be provided for only one for the plurality of film forming sections 40A, 40B, and 40C. When only one power supply section 6 is provided, application of electric power is switched for use. The rotor 31 has the same potential as the grounded vacuum vessel 20, and a potential difference is generated by applying a high voltage to the target 41 side.

A plurality of film-forming units 40A, 40B, and 40C simultaneously form films using the same film-forming material, thereby increasing the amount of film-forming within a certain period of time, that is, the film-forming rate. In addition, the film-forming units 40A, 40B, and 40C can use film-forming materials of different types to form a film composed of a plurality of layers of film-forming materials.

In this embodiment, as shown in FIG. 2, three film forming units 40A, 40B, and 40C are arranged between the film processing units 50A and 50B in the transport direction of the transport path T. As shown in FIG. Film-forming positions M2, M4, and M5 correspond to the three film-forming units 40A, 40B, and 40C. The film processing positions M1 and M3 correspond to the two film processing units 50A and 50B.

[Membrane processing section]
The film processing units 50</b>A and 50</b>B are processing units that perform film processing on materials deposited on the work W transported by the transport unit 30 . This film processing is reverse sputtering that does not use the target 41 . In the following description, the film processing units 50A and 50B will be referred to as the film processing unit 50 unless distinguished from each other. The film processing section 50 has a processing unit 5 . A configuration example of the processing unit 5 will be described with reference to FIGS. 3 to 6. FIG.

The processing unit 5 has a cylinder portion H, a window portion 52, a supply portion 53, an adjustment portion 54 (see FIG. 8), and an antenna 55, as shown in FIGS. The cylindrical portion H is a cylindrical structural portion having an opening H о at one end extending in the direction toward the transfer path T inside the vacuum vessel 20 . The tubular portion H has a tubular body 51 , a cooling portion 56 and a dispersion portion 57 . Among the members forming the tubular portion H, the tubular body 51 will be described first, and the cooling portion 56 and the dispersing portion 57 will be described later. The cylindrical body 51 is a cylinder with a rounded rectangular horizontal cross section. The rounded rectangular shape referred to here is the shape of a track used in athletics. The track shape is a shape in which a pair of partial circles are opposed to each other with their convex sides facing in opposite directions, and both ends of the circles are connected by parallel straight lines. The cylindrical body 51 is made of the same material as the rotating body 31 . The tubular body 51 is inserted into the opening 21a provided in the ceiling 20a of the vacuum vessel 20 so that the opening 51a faces the rotating body 31 side with a space therebetween. As a result, most of the side walls of the cylindrical body 51 are accommodated within the vacuum chamber 21 . The cylindrical body 51 is arranged such that its major axis direction is parallel to the radial direction of the rotating body 31 . It should be noted that they do not need to be strictly parallel, and may be slightly inclined. Further, the processing region, which is a region to be plasma-processed, that is, film-processed, has a rectangular shape with rounded corners similar to the opening 51 a of the cylindrical body 51 . That is, the width of the processing area in the rotational direction is the same in the radial direction.

As shown in FIGS. 4 and 5, an inner flange 511 is formed along the entire circumference at one end of the tubular body 51 . The inner flange 511 is a thick portion in which the inner edge of one end of the cylindrical body 51 protrudes over the entire circumference so that the vertical cross section orthogonal to the outer circumference is L-shaped. The innermost edge of the inner flange 511 is a rectangular opening 51a with rounded corners that is substantially similar to the cross section of the tubular body 51 . The inner flange 511 has shelf surfaces 511a, 511b, and 511c that become lower as it goes from the inner wall of the tubular body 51 toward the opening 51a, thereby forming a stepped shape.

As shown in FIGS. 7 and 8, the inner flange 511 is formed with a plurality of supply ports 512A-D and 512a-d. In the following description, the supply ports 512A to 512D and 512a to 512d are referred to as the supply port 512 when they are not distinguished from each other. The supply port 512 is a hole for supplying the process gas G2 into the cylindrical body 51, as shown in FIGS. Each supply port 512 penetrates from the shelf surface 511a to the opening 51a so as to form an L shape as shown in FIG.

Here, when comparing the center side (inner peripheral side) and the outer peripheral side of the rotating body 31 of the work W mounted on the rotating body 31, a difference occurs in the speed of passing a certain distance. That is, in this embodiment, the cylindrical body 51 is arranged so that the major axis direction is parallel to the radial direction of the rotating body 31 . Moreover, the straight portions of the opening 51a in which the plurality of supply ports 512 are formed are parallel to each other in the radial direction. In such a configuration, the time required for the work W to pass through the lower portion of the cylindrical body 51 for a certain distance is shorter on the outer peripheral side of the rotating body 31 than on the inner peripheral side. For this reason, the plurality of supply ports 512 are provided at a plurality of locations where the surface of the rotating body 31 passes through the processing region where the plasma processing is performed. The direction in which the plurality of supply ports 512 are arranged intersects the transport path T. As shown in FIG. Furthermore, the supply ports 512 are arranged at opposite positions with the gas space R interposed therebetween. The direction in which the supply ports 512 facing each other across the gas space R are aligned along the transport path T. As shown in FIG.

More specifically, as shown in FIG. 8, the supply ports 512A to 512D extend in the longitudinal direction of the cylindrical body 51,
That is, they are arranged side by side at regular intervals along one inner wall in the major axis direction. The supply ports 512a to 512d are arranged side by side at equal intervals along the other inner wall of the cylindrical body 51 in the longitudinal direction. The supply ports 512A to 512D are arranged in the order of supply port 512A, supply port 512B, supply port 512C, and supply port 512D from the inner peripheral side to the outer peripheral side. Similarly, the supply ports 512a to 512d are arranged in the order of supply port 512a, supply port 512b, supply port 512c, and supply port 512d. The supply ports 512A to 512D are arranged on the downstream side of the transport path T, and the supply ports 512a to 512d are arranged on the upstream side of the transport path. The supply port 512A and the supply port 512a, the supply port 512B and the supply port 512b, the supply port 512C and the supply port 512c, and the supply port 512D and the supply port 512d face each other on the downstream side and the upstream side.

Furthermore, as shown in FIG. 4, an outer flange 51b is formed at the end of the cylindrical body 51 opposite to the opening 51a. Between the lower surface of the outer flange 51b and the top surface of the vacuum vessel 20, an O-ring 21b is arranged over the entire circumference to hermetically seal the opening 21a.

The window portion 52 is provided in the cylinder portion H and is a member that partitions between the gas space R into which the process gas G2 in the vacuum vessel 20 is introduced and the outside. In this embodiment, the window portion 52 is provided in the tubular body 51 that constitutes the tubular portion H. As shown in FIG. The gas space R is a space formed between the rotor 31 and the inside of the cylindrical portion H in the film processing section 50, and the work W circulated and transported by the rotor 31 repeatedly passes through. The window portion 52 is a dielectric flat plate that fits inside the cylindrical body 51 and has a horizontal cross section that is substantially similar to the horizontal cross section of the cylindrical body 51 . The window portion 52 is mounted on an O-ring 21b fitted in a circumferential groove formed in the shelf surface 511b to hermetically seal the opening 51a. The window 52 may be a dielectric such as alumina, or a semiconductor such as silicon.

The supply unit 53 supplies the process gas G2 to the gas space R, as shown in FIGS. The supply unit 53 is a device that supplies the process gas G2 from a plurality of locations where the surface of the rotating body 31 passes through the processing area at different times. The plurality of locations correspond to the arrangement positions of the supply ports 512 in the longitudinal direction of the tubular body 51 . Specifically, the supply unit 53 has a supply source of the process gas G2 such as a cylinder (not shown) and pipes 53a, 53b, and 53c connected thereto. Process gas G2 is, for example, oxygen and nitrogen. The pipes 53a are a pair of paths from the respective supply sources of the process gas G2. That is, it consists of a line connected to an oxygen supply and a line connected to a nitrogen supply. Four sets of pipes 53 a are provided corresponding to the arrangement positions of the supply ports 512 . The pipe 53b is one route to which the pair of pipes 53a are connected. Each pipe 53b is connected to each supply port 512A-D in one row. A pipe 53c branched from each pipe 53b is connected to each of the supply ports 512a to 512d in the other row.

The ends of the branched pipes 53c extend from the outer flange 51b side along the inner wall of the cylindrical body 51 toward the opening 51a side and are connected to the end portion of the supply port 512 on the shelf surface 511a side. The pipe 53b is similarly connected to the end of the supply port 512 on the shelf surface 511a side. As a result, the supply unit 53 supplies the process gas G2 to the gas space R from a plurality of locations at which the workpieces W pass at different speeds through the supply ports 512A to 512D and the supply ports 512a to 512d arranged side by side as described above. supply. In other words, the supply ports 512A to 512D and the supply ports 512a to 512d are provided corresponding to a plurality of locations to which the supply section 53 supplies the process gas G2. In this embodiment, the innermost peripheral supply ports 512A and 512a and the outermost peripheral supply ports 512D and 512d are located outside the film formation region F. As shown in FIG.

The adjustment unit 54 adjusts the supply amount of the process gas G2 introduced from each supply port 512 according to the position in the direction intersecting the transport path T, as shown in FIG. That is, the adjustment unit 54 individually adjusts the supply amount of the process gas G2 per unit time at a plurality of locations of the supply unit 53 according to the time required for the surface of the rotating body 31 to pass through the processing region. The adjustment unit 54 has mass flow controllers (MFC) 54a respectively provided in a pair of paths of the pipe 53a. The MFC 54a is a member having a mass flow meter for measuring the flow rate of fluid and an electromagnetic valve for controlling the flow rate.

The antenna 55 is a member that generates inductively coupled plasma for processing the workpiece W passing through the transport path T, as shown in FIGS. The antenna 55 is arranged outside the gas space R and near the window 52 . When electric power is applied to the antenna 55, an electric field is generated induced by the magnetic field created by the antenna current, and the process gas G2 in the gas space R becomes plasma. The shape of the antenna 55 can change the distribution shape of the generated inductively coupled plasma. In other words, the shape of the inductively coupled plasma distribution can be determined by the shape of the antenna 55 . In this embodiment, by forming the antenna 55 into the following shape, it is possible to generate an inductively coupled plasma having a shape substantially similar to the horizontal cross section of the gas space R.

Antenna 55 has a plurality of conductors 551 a - 551 d and a capacitor 552 . The plurality of conductors 551 are strip-shaped conductive members, and are connected to each other via capacitors 552 to form a rectangular electrical path with rounded corners when viewed in the planar direction. The outer shape of this antenna 55 is smaller than the opening 51a.

Each capacitor 552 has a substantially cylindrical shape and is connected in series between conductors 551a, 551b, 551c and 551d. If the antenna 55 is composed only of a conductor, the voltage amplitude becomes excessively large at the end on the power supply side, and the window 52 is locally shaved. Therefore, by dividing the conductor and connecting the capacitor 552, a small voltage amplitude is generated at the ends of the conductors 551a, 551b, 551c, and 551d, thereby suppressing the scraping of the window 52. FIG.

However, the continuity of the conductors 551a, 551b, 551c, and 551d is interrupted at the capacitor 552 portion, and the plasma density is lowered. For this reason, the ends of the conductors 551a, 551b, 551c, and 551d facing the window 52 overlap each other in the planar direction, and sandwich the capacitor 552 from above and below. More specifically, the connection ends of the conductors 551a, 551b, 551c, and 551d to the capacitor 552 are bent to have an inverted L-shaped cross section, as shown in FIG. Between the horizontal surfaces of the ends of the adjacent conductors 551a and 551b, gaps are provided to sandwich the capacitor 552 from above and below. Similarly, the horizontal surfaces of the ends of the conductors 551b and 551c and the horizontal surfaces of the ends of the conductors 551c and 551d are provided with gaps for holding the capacitor 552 from above and below.

An RF power supply 55 a for applying high frequency power is connected to the antenna 55 . A matching box 55b, which is a matching circuit, is connected in series to the output side of the RF power supply 55a. For example, one end of the conductor 551d and the RF power supply 55a are connected. In this example, conductor 551a is the ground side. A matching box 55b is connected between the RF power supply 55a and one end of the conductor 551d. The matching box 55b stabilizes the plasma discharge by matching the impedance on the input side and the output side.

As shown in FIGS. 4 to 6, the cooling part 56 is a rectangular cylindrical member with rounded corners having substantially the same outer size as the cylindrical body 51, and its upper surface is in contact with the bottom surface of the cylindrical body 51. are positioned to match A cavity through which cooling water flows is provided inside the cooling part 56, though not shown. A supply port and a drain port connected to a chiller, which is a cooling water circulation device for circulating and supplying cooling water, communicate with the cavity. The cooling water cooled by the chiller is supplied from the supply port, flows through the cavity, and is discharged from the drain port. is suppressed.

The dispersing portion 57 is a rectangular cylindrical member with rounded corners having substantially the same external size as the cylindrical body 51 and the cooling portion 56 , and is provided at a position where the top surface thereof contacts and matches the bottom surface of the cooling portion 56 . , and an opening H.sub.o of the cylindrical portion H is provided on the bottom surface thereof. The dispersion unit 57 is provided with a dispersion plate 57a. The dispersion plate 57a is spaced apart from the supply port 512 and arranged at a position facing the supply port 512, and distributes the process gas G2 introduced from the supply port 512 to flow into the gas space R. The horizontal width of the annular portion of the dispersion portion 57 is larger than that of the cylindrical body 51 by the amount that the dispersion plate 57a is provided inside.

More specifically, the dispersion plate 57 a is raised from the inner edge of the dispersion portion 57 over the entire circumference, extends beyond the cooling portion 56 , and extends to a position close to the bottom surface of the window portion 52 . As shown in FIG. 5, the passage of the process gas G2 between the dispersion plate 57a and the supply port 512 is closed on the rotor 31 side and communicated with the gas space R on the window portion 52 side. In other words, between the inner flange 511 and the dispersion plate 57 a , an annular gap is formed along the lower surface of the window 52 and communicated with the gas space R below the window 52 .

The vertical distance between the bottom surface of the dispersing portion 57 and the surface of the rotating body 31 has a length that allows the work W on the transport path T to pass therethrough. Further, since the dispersion plate 57a enters the gas space R inside the cylindrical body 51, the plasma generation region in the gas space R is the space inside the dispersion plate 57a. The distance between the dispersion plate 57a and the window portion 52 is, for example, 1 mm to 5 mm. If this distance is set to 5 mm or less, it is possible to prevent abnormal discharge from occurring in the gap.

A process gas G2 is introduced into the gas space R from the supply portion 53 through the supply port 512, and a high frequency voltage is applied to the antenna 55 from the RF power source 55a. Then, an electric field is generated in the gas space R through the window portion 52, and the process gas G2 is turned into plasma. As a result, active species such as electrons, ions and radicals are generated.

[Load lock section]
The load lock unit 60 loads the tray 34 loaded with the unprocessed workpieces W from the outside into the vacuum chamber 21 by a transport means (not shown) while maintaining the vacuum in the vacuum chamber 21, and loads the processed workpieces W into the vacuum chamber 21. It is a device for carrying out the mounted tray 34 to the outside of the vacuum chamber 21 . Since the load lock unit 60 can have a well-known structure, the description thereof is omitted.

[Control device]
The control device 70 is a device that controls each part of the plasma processing apparatus 100 . This control device 70 can be configured by, for example, a dedicated electronic circuit or a computer that operates according to a predetermined program. That is, the contents of control are programmed for the control of the introduction and exhaust of the sputtering gas G1 and the process gas G2 into the vacuum chamber 21, the control of the power supply unit 6 and the RF power supply 55a, the control of the rotation of the rotor 31, and the like. . The control device 70 executes this program by a processing device such as a PLC or CPU, and is capable of supporting various specifications of plasma processing.

The objects to be specifically controlled are as follows. That is, the rotation speed of the motor 32, the initial exhaust pressure of the plasma processing apparatus 100, the selection of the sputtering source 4, the power applied to the target 41 and the antenna 55, the flow rates, types, introduction time and exhaust time of the sputtering gas G1 and the process gas G2. , film formation and film processing times, and the like.

In particular, in this embodiment, the control device 70 controls the film formation rate by controlling the application of electric power to the target 41 of the film formation section 40 and the supply amount of the sputtering gas G1 from the gas supply section 25 . Further, the control device 70 controls the film processing rate by controlling the application of electric power to the antenna 55 and the amount of the process gas G2 supplied from the supply unit 53 .

The configuration of the control device 70 for executing the operation of each unit as described above will be described with reference to FIG. 10, which is a virtual functional block diagram. That is, the control device 70 has a mechanism control section 71 , a power supply control section 72 , a gas control section 73 , a storage section 74 , a setting section 75 and an input/output control section 76 .

The mechanism control unit 71 is a processing unit that controls drive sources such as the exhaust unit 23, the gas supply unit 25, the supply unit 53, the adjustment unit 54, the motor 32, the load lock unit 60, electromagnetic valves, switches, power supplies, and the like. The power control unit 72 is a processing unit that controls the power supply unit 6 and the RF power supply 55a. For example, the power control unit 72 individually controls the power applied to the targets 41A, 41B, and 41C. If the film formation rate is to be uniform over the entire workpiece W, the power is increased sequentially such that target 41A<target 41B<target 41C in consideration of the speed difference between the inner and outer peripheral sides. In other words, the electric power should be determined in proportion to the inner and outer velocities. However, the proportional control is only an example, and the higher the speed, the higher the power, and the setting may be made so that the processing rate becomes uniform. Further, the electric power applied to the target 41 may be increased at locations where the film thickness to be formed on the workpiece W is desired to be thickened, and the electric power applied to the target 41 may be decreased at locations where the film thickness is desired to be thinned.

The gas control section 73 is a processing section that controls the introduction amount of the process gas G2 by the adjustment section 54 . For example, the amount of process gas G2 supplied per unit time from each supply port 512 is individually controlled. If it is desired to make the film processing rate uniform over the entire workpiece W, the supply amount from each supply port 512 is directed from the inner peripheral side to the outer peripheral side in consideration of the speed difference between the inner peripheral side and the outer peripheral side. Gradually increase. Specifically, the supply amount is set to supply port 512A<supply port 512B<supply port 512C<supply port 512D and supply port 512a<supply port 512b<supply port 512c<supply port 512d. In other words, the supply amount can be determined in proportion to the inner and outer velocities. In addition, the supply amount of the process gas G2 supplied from each supply port 512 is adjusted according to the film thickness to be formed on the workpiece W. FIG. In other words, the supply amount of the process gas G2 is increased so as to increase the amount of film processing at locations where the film thickness is to be thickened. Then, the supply amount of the process gas G2 is reduced so as to reduce the amount of film processing at the portion where the film thickness is to be thinned. Further, for example, in the case of film processing for a film formed so as to have a thicker film thickness toward the inner circumference, the supply amount of the process gas G2 can be set to increase toward the inner circumference. Combined with the relationship with the speed described above, this may result in uniform supply amounts from the respective supply ports 512 . That is, the adjustment unit 54 may adjust the supply amount of the process gas G2 supplied from each supply port 512 according to the film thickness to be formed on the workpiece W and the time for the rotating body 31 to pass through the processing area. The gas control unit 73 also controls the introduction amount of the sputtering gas G1.

The storage unit 74 is a component that stores information necessary for control of the present embodiment. The information stored in the storage unit 74 includes the exhaust amount of the exhaust unit 23, the power applied to each target 41, the supply amount of the sputtering gas G1, the power applied to the antenna 55, and the supply of the process gas G2 for each supply port 512. Including quantity. The setting unit 75 is a processing unit that sets externally input information in the storage unit 74 . The power applied to the antenna 55 is determined, for example, by the desired film thickness to be formed while the rotor 31 rotates once and the rotational speed (rpm) of the rotor 31 .

Further, the electric power applied to the targets 41A, 41B, 41C and the supply amount of the process gas G2 from the supply ports 512A-D, 512a-d may be linked. In other words, when the power to be applied to the targets 41A, 41B, and 41C is set by the setting unit while the rotational speed (rpm) of the rotating body 31 is constant, the power from each of the supply ports 512A to 512A to 512a to 512d is proportional to this. may be set. Further, when the rotation speed (rpm) of the rotating body 31 is constant and the amount of supply from each of the supply ports 512A to 512A to 512a to 512d is set by the setting unit, each of the targets 41A, 41B and 41C is proportional to this. You may make it set the electric power applied to.

Such settings can be made, for example, as follows. First, the relationship between the film thickness and the corresponding applied power or the amount of supply of the process gas G2, and the relationship between the applied power and the corresponding amount of supply of the process gas G2 are obtained by experiments or the like in advance. At least one of these is tabulated and stored in the storage unit 74 . Then, according to the input film thickness, applied power, or supply amount, the setting unit 75 refers to the table to determine the applied power and supply amount.

The input/output control unit 76 is an interface that controls signal conversion and input/output with each unit to be controlled. Further, an input device 77 and an output device 78 are connected to the control device 70 . The input device 77 is input means such as a switch, a touch panel, a keyboard, and a mouse for the operator to operate the plasma processing apparatus 100 via the control device 70 . For example, the selection of the film forming unit 40 and the film processing unit 50 to be used, the desired film thickness, the power applied to each of the targets 41A to 41C, the supply amount of the process gas G2 from each of the supply ports 512A to 512D and 512a to 512d, etc. It can be input by the input means.

The output device 78 is output means such as a display, a lamp, a meter, etc., for making information for confirming the state of the apparatus visible to the operator. For example, the output device 78 can display a screen for inputting information from the input device 77 . In this case, the targets 41A, 41B, 41C and the supply ports 512A to 512D, 512a to 512d may be displayed in a schematic diagram so that each position can be selected and a numerical value input. Further, the targets 41A, 41B, 41C and the supply ports 512A to 512D, 512a to 512d may be displayed in schematic diagrams, and the values set for each may be displayed numerically.

[motion]
The operation of the present embodiment as described above will be described below with reference to FIGS. 1 to 10 described above. Although not shown, the tray 34 on which the work W is mounted is carried in, carried out, and carried out of the plasma processing apparatus 100 by a carrying means such as a conveyor or a robot arm.

The plurality of trays 34 are sequentially carried into the vacuum container 20 by the transport means of the load lock section 60 . The rotating body 31 sequentially moves the empty holding portions 33 to the carrying-in position from the load lock portion 60 . The holding unit 33 individually holds the trays 34 carried in by the conveying means. In this way, as shown in FIGS. 2 and 3, the tray 34 loaded with the workpieces W to be film-formed is entirely placed on the rotating body 31. As shown in FIG.

The processing for forming a film on the workpiece W introduced into the plasma processing apparatus 100 as described above is performed as follows. The following operation is an example in which film formation and film processing are performed by operating one of the film formation unit 40 and the film processing unit 50, such as only the film formation unit 40A and only the film processing unit 50A. be. However, the processing rate may be increased by operating a plurality of sets of the film forming section 40 and the film processing section 50 . An example of film formation and film processing by the film formation section 40 and the film processing section 50 is processing for forming a silicon oxynitride film. The silicon oxynitride film is formed by repeating the process of impregnating the work W with oxygen ions and nitrogen ions each time silicon is attached to the work W at the atomic level while the work W is circulated.

First, the vacuum chamber 21 is constantly evacuated by the evacuation unit 23 to reduce the pressure. When the vacuum chamber 21 reaches a predetermined pressure, the rotor 31 rotates as shown in FIGS. Thereby, the workpiece W held by the holding section 33 moves along the transport path T and passes under the film forming sections 40A, 40B, 40C and the film processing sections 50A, 50B. When the rotating body 31 reaches a predetermined rotational speed, the gas supply section 25 of the film forming section 40 then supplies the sputtering gas G1 around the target 41 . At this time, the supply unit 53 of the film processing unit 50 also supplies the process gas G2 to the gas space R.

In the film forming section 40, the power supply section 6 applies electric power to each of the targets 41A, 41B, and 41C. As a result, the sputtering gas G1 becomes plasma. In the sputtering source 4, active species such as ions generated by the plasma collide with the target 41 and eject particles of the film-forming material. For this reason, particles of the film-forming material are deposited on the surface of the work W passing through the film-forming section 40 each time it passes through the film-forming section 40 to form a film. In this example a layer of silicon is formed.

The electric power applied to each of the targets 41A, 41B, and 41C by the power supply unit 6 is set in the storage unit 74 so as to increase sequentially from the inner circumference side to the outer circumference side of the rotor 31 . The power supply control unit 72 controls the power supply unit 6 to power each target 4 according to the power set in the storage unit 74 .
1 to control the power applied to it. Because of this control, the amount of film formed per unit time by sputtering increases from the inner circumference to the outer circumference, but the passing speed of the rotor 31 increases from the inner circumference to the outer circumference. As a result, the film thickness of the entire work W becomes uniform.

Even if the work W passes through the film forming section 40 and the film processing section 50 that are not in operation, the work W is not heated because film formation and film processing are not performed. In this unheated area, the workpiece W gives off heat. Note that the non-operating film forming units 40 are, for example, the film forming positions M4 and M5. Further, the film processing unit 50 that is not in operation is, for example, the film processing position M3.

On the other hand, the work W on which the film has been formed passes through a position facing the opening H? of the cylindrical portion H in the processing unit 5. As shown in FIG. In the processing unit 5, as shown in FIG. 8, oxygen and nitrogen, which are the process gas G2, are supplied into the gas space R from the supply part 53 through the supply port 512, and a high frequency voltage is applied to the antenna 55 from the RF power supply 55a. applied. By applying the high-frequency voltage, an electric field is applied to the gas space R through the window 52 to generate plasma. Oxygen ions and nitrogen ions generated by the generated plasma collide with the surface of the workpiece W on which the film is formed, and penetrate the film material.

The flow rate per unit time of the process gas G2 introduced from the supply port 512 is set in the storage unit 74 so that the inner peripheral side of the rotating body 31 is smaller and the outer peripheral side is larger. The gas control unit 73 outputs an instruction so that the adjustment unit 54 controls the flow rate of the process gas G2 flowing through each pipe 53a according to the flow rate set in the storage unit 74 . Therefore, the amount of active species such as ions per unit volume generated in the gas space R is greater on the outer peripheral side than on the inner peripheral side. Therefore, the amount of membrane treatment, which depends on the amount of active species, increases from the inner circumference side to the outer circumference side. However, the processing region to be film-processed has a rectangular shape with rounded corners similar to the opening 51 a of the cylindrical body 51 . Therefore, the width of the processing area, that is, the width in the direction of rotation, is the same in the radial direction. That is, the processing area has a constant width in the radial direction. On the other hand, the workpiece W passes through the processing area at a higher speed from the inner circumference side to the outer circumference side. Therefore, the work W passes through the processing area in a shorter time as it moves from the inner circumference to the outer circumference. By increasing the supply amount of the process gas G2 toward the outer periphery, the film processing amount increases toward the outer periphery, so that the short transit time of the processing region can be compensated for. As a result, the film processing amount of the entire workpiece W becomes uniform.

Also, when film processing is performed using two or more types of process gases G2, such as oxynitriding, the film formed in the film forming unit 40 is completely converted into a compound film while the rotating body rotates once. At the same time, the composition of the film must be uniform over the film formation surface. This embodiment is suitable for a plasma processing apparatus 100 that performs film processing using two or more kinds of process gases G2. For example, suppose we want a film of silicon oxynitride (SiO _x N _y ) with an x:y ratio of 1:1. Then, it is necessary to control both the amount of active species and the ratio of oxygen and nitrogen contained in the active species so that the deposited film becomes a compound film. In this embodiment, the process gas G2 is supplied to a plurality of locations, and the amount of the process gas G2 supplied to each supply location can be adjusted for each type of the process gas G2, so both the amount and the ratio can be controlled. It's easy to do.

Further, as shown in FIG. 5, the process gas G2 supplied from the supply port 512 collides with the dispersion plate 57a, spreads horizontally along the vertical surface of the dispersion plate 57a, and spreads from the upper edge of the dispersion plate 57a. It flows into the gas space R. Since the process gas G2 is dispersed in this way, only the flow rate of the process gas G2 in the vicinity of the supply port 512 does not significantly increase. In other words, the distribution of the gas flow rate from the inner peripheral side to the outer peripheral side is prevented from being locally increased, and rises with a nearly linear gradient. This prevents the film processing rate from partially increasing or decreasing, resulting in variations in processing.

During the process of forming the film as described above, the rotating body 31 continues to rotate and continues to circulate and convey the tray 34 on which the work W is mounted. In this manner, the compound film is formed by circulating the work W and repeating film formation and film processing. In this embodiment, a film of silicon oxynitride is formed on the surface of the workpiece W as the compound film.

After a predetermined processing time has passed for the silicon oxynitride film to have a desired film thickness, the film forming section 40 and the film processing section 50 are stopped. That is, the application of electric power to the target 41 by the power supply unit 6, the supply of the process gas G2 from the supply port 512, the application of voltage by the RF power supply 55a, and the like are stopped.

After the film forming process is completed in this manner, the trays 34 loaded with the works W are sequentially positioned in the load lock section 60 by the rotation of the rotating body 31, and carried out to the outside by the carrying means.

[Results of film formation test]
Film formation test results of an example corresponding to this embodiment and a comparative example will be described with reference to the graph of FIG. 11 . Examples 1 to 3 are test results in which the flow rate per unit time of oxygen and nitrogen from the plurality of supply ports 512 was increased stepwise from the inner peripheral side to the outer peripheral side. Examples 1 and 3 are examples using the dispersion plate 57a, and Example 2 is an example in which the gas is directly supplied from the supply port 512 to the gas space without using the dispersion plate 57a.

However, in Examples 2 and 3, the flow rate of the process gas G2 at the outermost peripheral supply ports 512D and 512d outside the film forming area F is not maximized, but is made lower than that of the supply ports 512B, 512C, 512b and 512c. ing. That is, the flow rate is set so that supply port 512A<supply port 512D<supply port 512B<supply port 512C and supply port 512a<supply port 512d<supply port 512b<supply port 512c.

Since the workpiece W does not pass through a position outside the film forming region F, there is no need to supply the process gas G2. However, as shown in FIG. 7, when the cylindrical body 51 is formed outside the film forming region F with a margin, if the process gas G2 is not supplied to the outside of the film forming region F at all, the film formation Diffusion of the process gas G2 to the outside of the film formation region F occurs in the vicinity of the inner peripheral end and the outer peripheral end of the region F. As shown in FIG. As a result, the processing rate decreases in the vicinity of the inner peripheral edge and the outer peripheral edge of the film formation area F. For this reason, the process gas G2 may be preliminarily supplied outside the film forming region F as well. The amount of the process gas G2 at this time may be sufficient to compensate for the decrease due to diffusion, so the amount may be sufficient to prevent the diffusion in relation to the size of the area serving as the above margin. However, it may be necessary to increase the supply amount from the supply ports 512C and 512c. In this way, the supply ports 512A, 512a, 512D, and 512d positioned outside the film formation region F may be excluded from the targets for adjustment of the process gas G2 by the adjustment unit 54 according to the passage time.

Also, in the comparative example, the process gas G2 is supplied from one place. Other conditions are common to Examples 1 to 3 and Comparative Example. For example, the voltage applied to the target 41 was controlled so that the thickness of the film formed on the workpiece W by the film forming unit 40 was uniform.

In the graph of FIG. 11, the horizontal axis represents the radial distance [mm] from the center of rotation of the rotating body 31 toward the outer circumference, and the vertical axis represents the refractive index Nf of the deposited film. Since the refractive index of the film changes according to the degree of film processing, the degree of film processing can be known by measuring the refractive index. As is clear from this graph, the comparative example had a large variation in the refractive index between the inner and outer circumferences of ±4.17%. On the other hand, Example 1 was ±1.21% and Example 2 was ±1.40%. Example 3 had the smallest variation of ±1.00%.

From this test result, it can be seen that by adjusting the flow rate of the process gas G2 from each supply port 512, variations in film processing from the inner peripheral side to the outer peripheral side can be suppressed. Moreover, it can be seen that the provision of the dispersion plate 57a can make the degree of the entire film processing more uniform.

Furthermore, the supply ports 512D and 512d located outside the film forming area F are less involved in the film processing, and the flow rate of the process gas G2 need not be maximized, but the process gas G2 is supplied even in a small amount. Thus, it can be seen that the degree of film processing can be made more uniform. The same can be considered for the supply ports 512A and 512a on the inner peripheral side. In other words, even by providing the supply port 512 outside the film forming region F, it is possible to obtain the effect of making the degree of film processing uniform.

[Effect]
(1) This embodiment has a vacuum vessel 20 whose interior can be evacuated, and a rotating body 31 provided in the vacuum vessel 20 and rotating with a work W mounted thereon. a conveying portion 30 that circulates and conveys the work W in a circumferential conveying route T by moving a cylindrical portion H having an opening Ho at one end extending in a direction toward the conveying route T inside the vacuum vessel 20; a window portion 52 provided in the cylindrical portion H and the rotating body 31 to separate the gas space R into which the process gas G2 is introduced and the outside of the gas space R; A supply unit 53 that supplies G2 and a work piece that passes through the transfer path T is placed outside the gas space R and near the window 52, and power is applied to the process gas G2 in the gas space R. and an antenna 55 for generating an inductively coupled plasma for plasma processing W. Then, the supply unit 53 supplies the process gas G2 from a plurality of locations at which the surface of the rotating body 31 passes through the processing region where the plasma processing is performed. It has an adjustment unit 54 that individually adjusts the supply amount of G2 according to the time of passage through the processing region.

Therefore, it is possible to adjust the degree of plasma processing for the work W circulated and transported by the rotating body 31 according to the positions on the surface of the rotating body 31 at different passing speeds. Therefore, it is possible to perform desired plasma processing such as making the degree of processing of the workpiece W uniform or changing the degree of processing at a desired position. This is more effective as the diameter of the rotating body 31 is larger and the width of the film formation region F is larger, that is, the difference in circumferential speed between the inner circumference side and the outer circumference side of the film formation region F is larger. In the present embodiment, the shape of the opening 51a of the tubular body 51 into which the process gas G2 is introduced is a rectangular shape with rounded corners similar to that of the antenna 55. The process gas G2 can be supplied, and highly efficient plasma can be obtained.

(2) In addition, in the present embodiment, the supply unit 53 is provided corresponding to a plurality of locations where the process gas G2 is supplied, and a plurality of supply ports 512 for supplying the process gas G2 to the gas space R and the supply ports 512 are provided. A dispersion plate 57a is disposed at a position facing the supply port 512 with an interval therebetween, and distributes the process gas G2 supplied from the supply port 512 to flow into the gas space R.

Therefore, the process gas G2 is dispersed by the dispersion plate 57a, the gas flow is not locally concentrated, and the occurrence of process variations is prevented. Further, the dispersion plate 57a can prevent hollow cathode discharge from occurring at the supply port 512. FIG. For example, in a state where the supply port 512 is exposed to the gas space R without the dispersion plate 57a, hollow cathode discharge may occur at the supply port 512 . When the hollow cathode discharge occurs, it cannot form a uniform plasma by interfering with the inductively coupled plasma. In this embodiment, the dispersion plate 57a is spaced from the supply port 512 and arranged at a position facing the supply port 512, so that hollow cathode discharge is generated between the dispersion plate 57a and the supply port 512. prevent this from happening. Further, the process gas G2 is introduced from the supply port 512 into the gas space R in the vicinity of the window 52 through the dispersion plate 57a. Therefore, the process gas G2 can be more accurately supplied to the gas space R near the antenna 55, and highly efficient plasma can be obtained.

(3) The flow path of the process gas G2 between the dispersion plate 57a and the supply port 512 is closed on the rotor 31 side and communicated with the gas space R on the window portion 52 side.

Therefore, the process gas G2 is supplied along the lower surface of the window 52 in the vicinity of the window 52 where the electric field is generated, so that plasma with high density is formed and the processing efficiency is improved. Furthermore, since the flow path for the process gas G2 between the distribution plate 57a and the supply port 512 is closed on the rotating body 31 side, the process gas G2 accumulates on the lower side of the flow path. The cooling unit 56 cools the dispersion plate 57a through the collected process gas G2. When the dispersion plate 57a is cooled in this way, deactivation of the plasma is suppressed, so plasma can be generated with high efficiency. Such an effect is further enhanced by cooling the upper surface of the dispersing portion 57 in contact with the bottom surface of the cooling portion 56 .

(4) The adjustment unit 54 adjusts the supply amount of the process gas G2 introduced from each supply port 512 according to the position of the rotor 31 in the direction intersecting the transport path T.

Therefore, the supply amount of the process gas G2 from the plurality of supply ports 512 can be individually adjusted according to positions on the surface of the rotating body 31 where the passing speed is different.

(5) A film forming unit 40 is provided at a position facing the work W circulated and conveyed on the transport path T, and deposits a film forming material on the work W by sputtering to form a film, and the film forming unit 40 A film of the film forming material deposited on the workpiece W is subjected to film processing using inductively coupled plasma.

Therefore, the degree of film processing for the formed film can also be adjusted in accordance with positions on the surface of the rotating body 31 at different passing speeds.

(6) The supply port 512 corresponds to the area where the film is formed by the film forming section 40, and is provided within the film forming area F, which is an annular area along the transport path T, and outside the film forming area F. is provided, and the supply port 512 provided outside the film forming area F is not subject to adjustment of the supply amount of the process gas G2 by the adjustment unit 54 .

In this way, by supplying the process gas G2 even outside the film-forming region F, shortage of the flow rate of the process gas G2 at the edge of the film-forming region F can be prevented. For example, even if the outermost peripheral supply port 512 and the innermost peripheral supply port 512 are outside the film formation region F, uniform film processing can be achieved by supplying the process gas G2. However, even if the maximum flow rate is not set outside the outermost film forming region F, the flow rate in the film forming region F does not become insufficient, so the flow rate can be saved. That is, the supply point of the process gas G2 outside the film formation area F functions as an auxiliary supply point and an auxiliary supply port for supplementing the flow rate of the process gas G2 inside the film formation area F.

(7) The supply ports 512 are arranged in a direction along the transport path T at opposing positions with the gas space R interposed therebetween. Therefore, the process gas G2 can be distributed in the gas space R in a short time.

(8) The adjustment unit 54 adjusts the supply amount of the process gas G2 introduced from each supply port 512 according to the film thickness to be formed on the workpiece W and the time for the rotor 31 to pass through the processing area. Therefore, film processing suitable for the film thickness can be performed.

(9) Since the pipes 53b and 53c are connected to the cylindrical body 51 and the process gas G2 is discharged from the cylindrical body 51, removal of the cylindrical part H from the plasma processing apparatus 100 is facilitated. That is, the tubular portion H can be removed while the pipes 53 b and 53 c are connected to the tubular body 51 . For example, when the pipes 53b and 53c are introduced into the vacuum chamber 21 from the side surface of the vacuum chamber 20 and connected to the tubular body 51, the pipes 53b and 53c are removed when the tubular portion H is removed from the plasma processing apparatus 100. and the cylindrical body 51 must be disconnected. Moreover, when the tubular portion H is attached to the plasma processing apparatus 100, the pipes 53b and 53c and the tubular body 51 must be connected again, which complicates the work. Alternatively, when the pipes 53b and 53c are introduced into the vacuum chamber 21 from the side surface of the vacuum vessel 20, it is conceivable to provide a notch in the cylindrical portion H to avoid the pipes 53b and 53c. In this case, it becomes easy to remove the cylindrical portion H from the plasma processing apparatus 100, but most of the process gas G2 dispersed by the dispersion plate 57a leaks from the notch portion. Therefore, since the process gas G2 cannot be introduced into the gas space R near the antenna 55, highly efficient plasma cannot be obtained. Also, the leaked process gas G2 may flow into the film forming section 40 and mix with the sputtering gas G1. If the process gas G2 and the sputtering gas G1 are mixed, the film forming rate of the film forming unit 40 may decrease. When the film forming rate of the film forming unit 40 is lowered, not only is the productivity lowered, but the optimum supply amount determined in advance is no longer optimum, so there is a possibility that the uniformity of the film quality will be deteriorated. On the other hand, in the cylindrical portion H of the present embodiment, the vertical distance between the bottom surface of the dispersing portion 57 and the surface of the rotor 31 is narrowed to a length through which the workpiece W can pass. Therefore, leakage of the process gas G2 from the gas space R is suppressed. In addition, even if a very small amount of liquid leaks, the partition section 44 prevents it from flowing into the film forming section 40 .

(10) Assuming specific conditions, the supply amount of the process gas G2 from a plurality of locations can be calculated. For this reason, the control device 70 may have a supply amount calculator that calculates the supply amount of the process gas G2. The supply amount calculation unit calculates the supply amount of the process gas G2 based on the conditions input from the input device 77 or the conditions stored in the storage unit 74, for example. The calculated supply amount is set in the storage unit 74 . Based on the set supply amount, the adjustment unit 54 adjusts the supply amount of the process gas G2 supplied from each supply port 512 . A more specific example is described below.

(Constitution)
A basic configuration of the plasma processing apparatus 100 is the same as the above embodiment. The control device 70 has a supply amount calculation unit, and a storage unit 74 stores the film thickness of the innermost or outermost circumference, the optimum supply amount for that film thickness, and the distance of each supply port 512 from the rotation center of the rotating body 31. (the radius of a circle passing through the center of each supply port 512).

(arithmetic processing)
When it is desired to form a large-area film with a uniform film thickness and uniform film quality, the following four conditions must be considered when adjusting the amount of supply of the process gas G2.
[1] Film thickness formed in the film forming section during one rotation of the rotating body [2] Thickness distribution of the deposited film in the radial direction of the rotating body [3] Velocity of the inner and outer circumferences of the rotating body Difference [4] Width of plasma generation region (width of processing region)

Here, the condition [2] can be removed from the conditions if power is applied individually to each of the targets 41A, 41B, and 41C of the film forming section 40 to form a uniform film thickness. In addition, as in the above embodiment, the antenna 55 and the gas space R are shaped like a rectangle with rounded corners when viewed from the plane direction, so that the width of the processing area is increased from the innermost circumference to the outermost circumference of the film forming area F. be the same. Therefore, the same plasma density can be obtained within the width range, so the condition [4] can also be removed from the conditions.

Therefore, the supply amount of each supply port 512 can be determined from the conditions [1] and [3]. In other words, as the condition of [1], either the innermost or outermost film thickness of the film forming region F and the optimum supply amount suitable for that film thickness are obtained by preliminary experiments or the like. Since the speed difference between the inner and outer circumferences in [3] is related (proportional) to the radii of the inner and outer circumferences, the radial positions (distances from the center of rotation) of the plurality of supply ports 512 and the above The supply amount of each of the plurality of supply ports 512 can be determined from the film thickness and the optimum supply amount. The thickness of the film formed during one rotation of the rotor 31 on the innermost circumference of the film formation region F and the film thickness of the film formed during one rotation of the rotor 31 on the outermost circumference of the film formation region F The information stored in the storage unit 74 includes the film thickness, the optimum supply amount suitable for the film thickness, and the radial position of each supply port 512 .

For example, the optimum supply amount of the innermost peripheral supply port 512 for a predetermined film thickness of the film formed in the film forming section 40 is a, the innermost peripheral radius is Lin, the outermost peripheral radius is Lu, and the outermost peripheral radius is Let A be the optimum supply amount of the supply port 512 . First, the case where the optimum supply amount a of the innermost peripheral supply port 512 is known will be described. The supply amount calculation unit obtains from the storage unit 74 the optimum supply amount a of the innermost circumference, the radius Lin of the circle passing through the supply port 512 of the innermost circumference, and the radius Lou of the circle passing through the supply port 512 of the outermost circumference. , the optimum supply amount A for the outermost circumference is determined based on the following equation.
A=a×Lou/Lin
Similarly, the optimum supply amount of other supply ports 512 can also be determined according to the radius ratio. That is, assuming that the optimum supply amount of the supply port 512 is Ax and the radius of the circle passing through the supply port 512 is Px, the optimum supply amount Ax can be obtained based on the following equation.
Ax=a×Px/Lin
On the contrary, when the optimum supply amount A of the outermost supply port 512 is known, the optimum supply amount ax of each supply port 512 is calculated from the radius px of the circle passing through the supply port 512 as follows. It can be obtained based on the formula.
ax=A×px/Lou

(effect)
As described above, [1] if the film thickness of the film formed by the film forming unit 40 during one rotation of the rotor is known, the supply amount from the plurality of supply ports 512 is automatically determined. Therefore, the amount of data to be held in the storage unit 74 can be reduced as compared with the case of holding a large number of data as a pattern of expected supply amount from each supply port 512 . For example, in the case of a film such as SiON whose refractive index changes depending on the composition, the supply amount of _each supply port 512 is automatically determined from the innermost or outermost film thickness of the film formation region F. By adjusting the mixing ratio of ₂ , a film with a desired refractive index can be obtained.

[Other embodiments]
The present invention is not limited to the above embodiments, and includes the following aspects.
(1) Various materials that can form a film by sputtering can be used as the film forming material. For example, tantalum, titanium, aluminum, etc. can be applied. Various materials can also be applied to materials for forming compounds.

(2) The number of targets in the film forming section is not limited to three. The number of targets may be one, two, or four or more. By increasing the number of targets and adjusting the applied power, the film thickness can be more precisely controlled. Also, the number of film forming units may be one, two, or four or more. The film formation rate can be improved by increasing the number of film formation units. Accordingly, the film processing rate can be improved by increasing the number of film processing units.

(3) The film formation by the film formation unit may not be necessarily performed, and the film formation unit may not be provided. In other words, the present invention is not limited to a plasma processing apparatus that performs film processing, but can be applied to a plasma processing apparatus that processes an object using active species generated by plasma. For example, the processing unit may be configured as a plasma processing apparatus that generates plasma in the gas space and performs surface modification such as etching and ashing, cleaning, and the like. In this case, for example, an inert gas such as argon may be used as the process gas.

(4) The process gas supply port may not be provided in the cylindrical body. For example, each pipe in the supply section may be extended into the cylindrical body, and the tip of each pipe may be used as the supply port. The tip of the pipe may be shaped like a nozzle by reducing the diameter. Also in this case, pipes may be provided not only in the film formation area but also outside the film formation area to function as auxiliary supply ports and auxiliary nozzles for supplementing the flow rate of the process gas in the film formation area.

(5) The number of locations where the supply unit supplies the process gas and the number of supply ports are not limited to the numbers exemplified in the above embodiments, as long as they are a plurality of locations with different passing speeds on the surface of the rotating body. By arranging three or more in a row in the film formation region, it is possible to perform finer flow rate control according to the processing position. In addition, as the number of supply points and supply ports increases, the distribution of the gas flow rate becomes closer to linear, thereby preventing local variations in processing. The supply ports may not be provided in two rows facing each other in the cylindrical body, but may be arranged in one row. Moreover, the supply ports may not be arranged in a straight line, but may be arranged at positions shifted in the height direction.

(6) The configuration of the adjustment section is not limited to the above example. A manual valve may be provided in each pipe for manual adjustment. Since it is sufficient to adjust the amount of gas supply, the pressure may be kept constant and adjusted by opening and closing a valve, or the pressure may be increased or decreased. The adjustment may be realized by a feed port. For example, supply ports with different diameters may be provided in accordance with positions on the surface of the rotating body where the passing speeds differ to adjust the amount of supply of the process gas. The supply port may be replaceable with nozzles having different diameters. Also, the diameter of the supply port may be changed by a shutter or the like.

(7) Since the speed is the distance traveled per unit time, the amount of process gas supplied from each supply port is set in relation to the time required for passing through the processing area in the radial direction. good too.

(8) The shape of the tubular body, the window, and the antenna are not limited to those exemplified in the above embodiments. The horizontal cross-section may be square, circular or elliptical. However, in the case of a shape in which the interval between the inner circumference and the outer circumference is equal, the passage time of the work W between the inner circumference and the outer circumference is different, so it is difficult to adjust the process gas supply amount according to the difference in processing time. easy. Further, if the space between the inner circumference side and the outer circumference side is equal, for example, a space can be formed between the dividing section 44 that divides the film forming section 40 and the film processing section 50 . Therefore, the effect of preventing the process gas G2 such as oxygen or nitrogen from flowing into the film forming unit 40 is enhanced. Further, for example, the antenna may be formed in a sector shape or the like so that the processing area is fan-shaped. In this case, even if the velocity increases toward the outer periphery, the time required for passing through the processing region is the same or substantially the same, so the amount of process gas supplied may be the same.

(9) The number of trays and works that are simultaneously transported by the transport unit and the number of holding units that hold the same may be at least one, and are not limited to the numbers exemplified in the above embodiments. In other words, one work may be circulated, or two or more works may be circulated. A mode in which the workpieces are arranged in two or more rows in the radial direction and circulated and transported may be used.

(10) In the above embodiments, the rotating body is a rotating table, but the rotating body is not limited to a table shape. It may be a rotator that rotates while holding a tray or a workpiece on an arm that extends radially from the center of rotation. The film forming section and film processing section may be located on the bottom side of the vacuum vessel, and the vertical relationship between the film forming section and film processing section and the rotor may be reversed. In this case, the surface of the rotating body on which the holding portion is arranged is the surface facing downward when the rotating body is horizontal, that is, the lower surface.

(11) Although the embodiments and modifications of each part of the present invention have been described above, these embodiments and modifications of each part are presented as examples, and are not intended to limit the scope of the invention. . These novel embodiments described above can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims.

100 plasma processing apparatus 20 vacuum chamber 20a ceiling 20b inner bottom surface 20c inner peripheral surface 21 vacuum chamber 21a opening 21b O-ring 22 exhaust port 23 exhaust unit 24 introduction port 25 gas supply unit 30 transport unit 31 rotating body 32 motor 33 holding unit 34 tray 40, 40A, 40B, 40C Film forming unit 4 Sputtering sources 41, 41A, 41B, 41C Target 42 Backing plate 43 Electrode 44 Separating unit 5 Processing units 50, 50A, 50B Film processing unit 51 Cylindrical body 51a Opening 51b Outer flange 511 Inner flanges 511a, 511b, 511c Shelf surfaces 512, 512A-D, 512a-d Supply port 52 Window 53 Supply parts 53a, 53b, 53c Pipe 54 Adjusting part 54a MFC
55 Antenna 55a RF power supply 55b Matching box 551, 551a-d Conductor 552 Capacitor 56 Cooling unit 57 Distributing unit 57a Distributing plate 6 Power supply unit 60 Load lock unit 70 Control device 71 Mechanism control unit 72 Power supply control unit 73 Gas control unit 74 Storage unit 75 Setting unit 76 Input/output control unit 77 Input device 78 Output device E Exhaust T Transport paths M1, M3 Film processing positions M2, M4, M5 Film formation position G Reaction gas G1 Sputtering gas G2 Process gas H Cylinder Hо Opening F Film formation Region R gas space

Claims (7)

a vacuum container whose interior can be evacuated;
a conveying unit provided in the vacuum vessel, having a rotating body on which a work is mounted and rotating, and circulating and conveying the work on a circumferential conveying path by rotating the rotating body;
a cylindrical portion having an opening at one end extending in a direction toward the transfer path inside the vacuum vessel;
a window portion provided in the tubular portion and separating a gas space into which a process gas is introduced between the inside of the tubular portion and the rotating body and the outside of the gas space;
It is arranged outside the gas space and near the window, and when electric power is applied, the process gas in the gas space is inductively coupled plasma for plasma-processing the work passing through the transfer path. an antenna that generates
a supply unit for supplying the process gas from a plurality of supply ports provided in the gas space corresponding to a plurality of locations corresponding to a plurality of locations where the surface of the rotating body passes through the processing region where the plasma processing is performed;
a distribution plate arranged at a position facing the plurality of supply ports with a gap therebetween, and for dispersing the process gas and allowing it to flow into the gas space;
has
The supply unit has an adjustment unit that individually adjusts a supply amount of the process gas per unit time supplied from each of the plurality of supply ports according to the passage time,
The dispersion plate has a surface extending in a direction intersecting with the gas flow of the process gas so that the process gas supplied from the plurality of supply ports collides with each other. and the antenna. 2. The process gas flow path according to claim 1, wherein the flow path of the process gas between the dispersion plate and the supply port is closed on the rotating body side and communicates with the gas space on the window side. Plasma processing equipment. 3. The plasma processing apparatus according to claim 1, wherein the adjustment unit adjusts the supply amount of the process gas introduced from each supply port according to the position in the direction intersecting the transfer path. a film-forming unit provided at a position facing the work circulatingly conveyed in the conveying path and depositing a film-forming material on the work by sputtering to form a film;
4. The plasma processing apparatus according to any one of claims 1 to 3, wherein the film of the film-forming material deposited on the workpiece by the film-forming unit is subjected to film processing by the inductively coupled plasma. The supply port corresponds to a region where the film formation unit forms a film, is provided in an annular film formation region along the transport path, and is also provided outside the film formation region,
5. The plasma processing apparatus according to claim 4, wherein said supply port provided outside said film forming area is not subject to adjustment of the supply amount of said process gas by said adjustment unit. 6. The plasma processing apparatus according to claim 4, wherein said supply ports are arranged at opposite positions across said gas space in a direction along said transport path. 6. The plasma according to claim 4, wherein the adjustment unit adjusts the supply amount of the process gas supplied from each supply port according to the film thickness to be formed on the workpiece and the passage time. processing equipment.

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