KR20220106688A - Abnormality detection method of plasma processing apparatus and plasma processing apparatus - Google Patents

Abstract

Provided is a technology for detecting an abnormality in a plasma processing apparatus. The plasma processing apparatus is provided with a plurality of antenna coils disposed along a virtual rectangular plane corresponding to a window member partitioning the inside of a processing member. Each of the plurality of antenna coils has one end part connected to a high frequency power source and another end part connected to an amperemeter to be connected to a ground potential. At least a part of the virtual rectangular plane is partitioned into a plurality of areas in which any one of the plurality of antenna coils is disposed for each area. The virtual rectangular plane has a part in which a plurality of combined areas acquired by combining areas disposed on a location opposite to the virtual rectangular plane are partitioned. An abnormality detection method of the plasma processing apparatus includes a process of comparing evaluation values of the antenna coils disposed on each area included in each of the plurality of combined areas to calculate a difference of a maximum value and a minimum value and detecting an abnormality based on the difference. The present invention can detect an abnormality in the plasma processing apparatus.

Description

Abnormality detection method and plasma processing apparatus of a plasma processing apparatus TECHNICAL FIELD

The present disclosure relates to an abnormality detection method of a plasma processing apparatus and a plasma processing apparatus.

Patent Document 1 discloses a plasma processing device that stops the output of the high-frequency power supply when an excessively reflected wave is generated in at least one high-frequency power supply and instantly stops the output of the other high-frequency power supply.

Japanese Patent Laid-Open No. 2009-070844

The present disclosure provides a technique for detecting an abnormality generated in a plasma processing apparatus.

According to an aspect of the present disclosure, in the interior of a processing chamber for processing a substrate, a window member on a rectangular plane that faces a loading surface of a mounting table for loading the substrate and divides the interior of the processing chamber into an upper portion and a lower portion corresponds to a window member. A plurality of antenna coils are provided along a virtual rectangular plane, wherein each of the plurality of antenna coils is connected to a high frequency power supply at one end and to a ground potential through an ammeter at the other end, and the virtual rectangular plane includes at least a part of the antenna coil. wherein each of the plurality of antenna coils is divided into a plurality of areas in which any one of the plurality of antenna coils is arranged, and the virtual rectangular plane is a plurality of integrated areas in which the areas arranged at symmetrical positions in the virtual rectangular plane are combined. A method for detecting an abnormality in a plasma processing apparatus having a partitioned portion, the method comprising the steps of: measuring, with the ammeter, a change in current of each of the plurality of antenna coils with time; a step of calculating an evaluation value based on There is provided an abnormality detection method of a plasma processing apparatus including a step of detecting

ADVANTAGE OF THE INVENTION According to this indication, the abnormality which generate|occur|produced in a plasma processing apparatus can be detected.

1 is a plan view showing an example of a substrate processing system 500 according to the present embodiment.
2 is a cross-sectional view showing the inductively coupled plasma processing apparatus 100 according to the present embodiment.
3 is a diagram showing an example of the antenna segment 121 .
4 : is a figure which shows an example of the area of the high frequency antenna 120, and an integrated area.
5 is a block diagram showing an example of the antenna circuit 150 of the inductively coupled plasma processing apparatus 100 according to the present embodiment.
6 is a block diagram showing an example of processing of the inductively coupled plasma processing apparatus 100 according to the present embodiment.
7 is a view for explaining an example of a process performed by the inductively coupled plasma processing apparatus 100 according to the present embodiment.
FIG. 8 is a diagram showing an example of processing of the inductively coupled plasma processing apparatus 100 according to the present embodiment.
9 is a diagram showing an example of the processing of the inductively coupled plasma processing apparatus 100 according to the present embodiment.
10 is a plan view showing an example of a spiral antenna according to another embodiment.

<Embodiment>

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this indication is demonstrated with reference to drawings. In addition, in this specification and drawing, about the substantially same structure, by attaching|subjecting the same code|symbol, the overlapping description may be abbreviate|omitted.

<Substrate processing system according to the embodiment>

1 is a plan view showing an example of a substrate processing system 500 according to the present embodiment. The substrate processing system 500 includes an inductively coupled plasma (ICP) processing apparatus according to the present embodiment.

The substrate processing system 500 is, as an example, a system that performs various substrate processing on a rectangular substrate G in a planar view for a flat panel display (FPD). The substrate G is, for example, a transparent glass plate or a transparent synthetic resin plate. On the surface of the substrate G, a light-emitting element, an electronic circuit including a TFT (Thin Film Transistor) for driving the light-emitting element, or the like is formed.

The substrate processing performed by the substrate processing system 500 includes a dry etching process (plasma etching process), a plasma chemical vapor deposition (CVD) process, or a plasma process (plasma process) such as a plasma PVD (Physical Vapor Deposition) process. do. Substrate processing may include processing (process) which does not use plasma, for example, post-processing etc.

The FPD is, for example, a liquid crystal display (LCD), an organic EL (Electro Luminescence) panel, or a plasma display panel (PDP).

The plane size of the board|substrate G for FPD is enlarged with the change of generation. The plane size of the substrate G processed by the substrate processing system 500 may be, for example, at least a size of about 1500 mm×1800 mm of the sixth generation to a size of about 3000 mm×3400 mm of the 10.5th generation. In addition, as an example, the thickness of the board|substrate G is about 0.2 mm - several mm. When one board|substrate G is divided into pieces, several FPD will be obtained.

When plasma processing is performed on the substrate G for FPD having a large planar size processed in the substrate processing system 500 , uniformity of plasma density in a large area according to the planar size of the substrate G is required.

The substrate processing system 500 is a cluster tool and is of the multi-chamber type. Further, the substrate processing system 500 is configured as a system in which serial processing can be performed in a vacuum atmosphere.

In the substrate processing system 500 , one side of the hexagonal transfer device 520 (which has a transfer chamber and is also referred to as a transfer module) arranged at the center has a load lock through a gate valve 512 . A chamber 510 is installed. In addition, five process chambers 530A, 530B, 530C, 530D, and 530E are provided on the other five sides of the transfer device 520 via a gate valve 522 , respectively. In addition, the conveying apparatus 520 is not limited to a hexagon in planar view, It may be a quadrangle in planar view, and the polygon which has another number of strokes may be sufficient.

Each chamber is controlled to have the same degree of vacuum atmosphere, so that when the gate valve 522 is opened to transfer the substrate G between the transfer chamber of the transfer apparatus 520 and each process chamber 530A to 530E, It is adjusted so that pressure fluctuations between chambers do not occur.

A loader module (not shown) is connected to the load lock chamber 510 via a gate valve 511 . The load lock chamber 510 is adjacent to the loader module. In the loader module, a plurality of substrates G are accommodated in a cassette (not shown) disposed at a position different from the connection position with the load lock chamber 510 . The load lock chamber 510 is configured to be able to switch the internal pressure atmosphere between the atmospheric pressure atmosphere and the vacuum atmosphere. The load lock chamber 510 transfers the substrate G to and from the loader module.

The load lock chambers 510 are stacked in two stages, for example. In each load lock chamber 510, a rack 514 for holding the substrate G and a positioner 513 for adjusting the position of the substrate G are provided. After the load lock chamber 510 is controlled to the vacuum atmosphere, the gate valve 512 is opened to communicate with the conveying device 520 controlled in the vacuum atmosphere as well, and from the load lock chamber 510 to the conveying device 520 . The substrate G is transferred in the direction of the arrow D2.

In the conveying device 520 , a conveying mechanism 521 that is rotatable in the direction of the arrow D1 and can slide toward each of the process chambers 530A to 530E is mounted. The direction of the arrow D1 is the circumferential direction. The transfer mechanism 521 transfers the substrate G transferred from the load lock chamber 510 to a desired process chamber (any one of the process chambers 530A to 530E). In addition, the transfer mechanism 521 transfers the substrate G to each of the process chambers 530A to 530E adjusted to the same degree of vacuum as that of the transfer apparatus 520 when the gate valve 522 is opened.

Between the transfer apparatus 520 and the process chamber 530A, the substrate G is transferred in the direction of the arrow D3. Similarly, between the transfer device 520 and the process chamber 530B, the substrate G is transferred in the direction of the arrow D4. Between the transfer device 520 and the process chamber 530C, the substrate G is transferred in the direction of the arrow D5. Between the transfer device 520 and the process chamber 530D, the substrate G is transferred in the direction of the arrow D6. Between the transfer device 520 and the process chamber 530E, the substrate G is transferred in the direction of the arrow D7. The substrate G is conveyed to the process chambers 530A to 530E according to the process recipe, and plasma processing or the like is performed.

One or a plurality of the process chambers 530A to 530E are dry etching treatment (plasma etching treatment), plasma CVD treatment in which, for example, a halogen-based etching gas (for example, a fluorine-based or chlorine-based etching gas) is applied. Or the chamber which performs plasma processing, such as a plasma PVD process, may be sufficient. Further, the process chambers 530A to 530E may include, for example, chambers for performing an after-treatment (post-treatment) for removing chlorine and chlorine-based compounds from the substrate G. A part of the substrate processing system 500 including a chamber for performing plasma processing is the inductively coupled plasma processing apparatus of the embodiment.

Among the process chambers 530A to 530E, it is important to equalize the plasma density in the chamber for performing the plasma treatment. The board|substrate G has a very large plane size, and several FPD is obtained from one board|substrate G. For this reason, when the uniformity of plasma density is low, distribution of the film quality formed on the board|substrate G deteriorates, and it becomes impossible to produce an FPD with good image quality. From such a viewpoint, it is very important to make high the uniformity of the plasma density in the plasma process included in the manufacturing process of the board|substrate G for FPD.

2 is a cross-sectional view showing the inductively coupled plasma processing apparatus 100 according to the present embodiment. The inductively coupled plasma processing apparatus 100 includes a process chamber 530 . The process chamber 530 is a chamber in which plasma processing is performed among the process chambers 530A to 530E shown in FIG. 1 . Plasma treatment is, as an example, etching treatment of a silicon oxide film, a silicon nitride film, a metal film, etc., a metal film or an ITO (Indium Tin Oxide) film when forming a thin film transistor on the surface of the substrate G. It is a film forming process of a silicon oxide film or a silicon nitride film, or an ashing process of a resist film, etc.

The process chamber 530 is an airtight chamber in the shape of a square cylinder made of a conductive material, for example, aluminum whose inner wall surface is anodized. The process chamber 530 is disassembled and electrically grounded by a ground wire 1a. The process chamber 530 is divided into an antenna chamber 3 and a processing chamber 4 vertically by a dielectric wall (dielectric window) 2 . Accordingly, the dielectric wall 2 functions as a ceiling wall of the processing chamber 4 divided into an upper portion and a lower portion. The dielectric wall 2 has a rectangular planar shape when viewed from the top. The dielectric wall 2 is made of ceramics such as Al ₂ O ₃ or quartz.

A shower housing 11 for supplying processing gas is fitted in a lower portion of the dielectric wall 2 . The shower housing 11 is provided in a cross shape, for example. The shower housing 11 has a function as a beam supporting the dielectric wall 2 from below. The dielectric wall 2 may be divided into four corresponding to the cross-shaped shower housing 11 . In addition, the shower housing 11 supporting the dielectric wall 2 is suspended from the ceiling of the process chamber 530 by a plurality of suspenders (not shown).

The shower housing 11 is made of a conductive material, preferably metal. The shower housing 11 is made of, for example, anodized aluminum on the inner or outer surface so as not to generate contaminants. The shower housing 11 is electrically grounded.

A gas flow path 12 extending horizontally is formed in the shower housing 11 . A plurality of gas discharge holes 12a extending downward communicate with the gas flow passage 12 . A gas supply pipe 20a communicating with the gas flow passage 12 is provided in the center of the upper surface of the dielectric wall 2 . The gas supply pipe 20a extends outward through the ceiling of the process chamber 530 , and is connected to a process gas supply system 20 including a process gas supply source, a valve system, and the like. Accordingly, in the plasma processing, the processing gas supplied from the processing gas supply system 20 is supplied into the shower housing 11 through the gas supply pipe 20a, and discharged into the processing chamber 4 through the gas discharge hole 12a. .

In the process chamber 530 , a support shelf 5 protruding inward is provided between the side wall 3a of the antenna chamber 3 and the side wall 4a of the processing chamber 4 . A dielectric wall 2 is mounted on the support shelf 5 .

In addition, the inductively coupled plasma processing apparatus 100 includes an antenna unit 50 having a radio frequency (RF) antenna 120 . A high frequency power supply 15 is connected to the high frequency antenna 120 via a power feeding unit 51 , a feeding line 19 , and a matching device 14 . Further, the high-frequency antenna 120 is spaced apart from the dielectric wall 2 by a spacer 17 made of an insulating member. Then, a high-frequency power having a frequency of 13.56 MHz, for example, is supplied to the high-frequency antenna 120 from the high-frequency power supply 15 to generate an induced electric field in the processing chamber 4 . The processing gas supplied from the shower housing 11 is plasmaized by the induced electric field generated in the processing chamber 4 by the high-frequency antenna 120 .

The antenna unit 50 includes a high-frequency antenna 120 and a power supply unit 51 that supplies the high-frequency power that has passed through the matching unit 14 to the high-frequency antenna 120 . The high frequency antenna 120 is provided on the upper surface of the dielectric wall 2 .

The high frequency antenna 120 has a plurality of antenna segments. As shown in Fig. 3, each antenna segment is an antenna wire made of copper wire or the like wound. Details of the antenna segment will be described later.

The planar portion of the plurality of antenna segments of the high frequency antenna 120 is directed downward on the upper surface 2A side of the dielectric wall 2, and passes through the dielectric wall 2 serving as a dielectric window with respect to the high frequency power of the substrate G. It is provided to face the upper surface. The plane portions of the plurality of antenna segments of the high frequency antenna 120 are arranged so as to form a concentric rectangular annular shape, and as a whole constitute a rectangular plane corresponding to the substrate G. As shown in FIG. The planar portion of the plurality of antenna segments of the high-frequency antenna 120 constitutes a multi-segmented annular antenna, which as a whole forms a rectangular annular shape, for example, a concentric three-ring shape of the outer annular antenna, the middle annular antenna, and the inner annular antenna, , create an induced electric field that contributes to the generation of plasma.

Further, the process chamber 530 is an example of a processing chamber, the dielectric wall 2 is an example of a window member, and the upper surface 2A of the dielectric wall 2 is an example of an imaginary rectangular plane. For example, the process chamber 530 may be divided into the antenna chamber 3 and the process chamber 4 by a metal wall (metal window) instead of the dielectric wall 2 . In this case, the high frequency antenna 120 once induces an induced current in the metal wall, and the induced current induced in the metal wall generates an induced electric field that contributes to plasma generation in the processing chamber 4 . Further, the metal wall may also serve as a shower housing.

The high frequency antenna 120 divides the plasma generated in the process chamber 530 into a plurality of areas to which one or two or more antenna segments supplying high frequency power belong in order to divide the plasma into several areas to control the plasma density distribution. is lost

Below the processing chamber 4 , a mounting table 23 for mounting the substrate G is provided so as to face the high frequency antenna 120 with the dielectric wall 2 interposed therebetween. The substrate G is mounted on the mounting surface 23A. The mounting table 23 is made of a conductive material, for example, aluminum whose surface is anodized. The substrate G mounted on the mounting table 23 is adsorbed and held by an electrostatic chuck (not shown).

The mounting table 23 is accommodated in the insulator frame 24 . In addition, the mounting table 23 is supported at the bottom of the process chamber 530 . The mounting table 23 is provided with a lifting pin (not shown). At the time of carrying in/out of the board|substrate G, the board|substrate G is lifted up and down by the raising/lowering pin. Further, on the side wall 4a of the processing chamber 4 , an inlet/outlet 27a for carrying in/out of the substrate G and a gate valve 512 for opening and closing the carry-in/outlet 27a are provided.

A high frequency power supply 29 is connected to the mounting table 23 via a matching device 28 by a power supply line 25a. This high frequency power supply 29 applies high frequency power for bias, for example, high frequency power having a frequency of 3.2 MHz, to the mounting table 23 during plasma processing. Ions in the plasma generated in the processing chamber 4 are effectively drawn into the substrate G by the self-bias generated by the high-frequency power for biasing.

Moreover, in order to control the temperature of the board|substrate G, in the mounting table 23, the temperature control mechanism containing heating means, such as a ceramic heater, a refrigerant flow path, etc., and a temperature sensor are provided (all are not shown). Piping and wiring for these mechanisms and members are led out of the process chamber 530 .

An exhaust device 30 including a vacuum pump or the like is connected to the bottom of the processing chamber 4 through an exhaust pipe 31 . The processing chamber 4 is exhausted by the exhaust device 30 , and the interior of the processing chamber 4 is set and maintained at a predetermined vacuum atmosphere (eg, 1.33 Pa) during plasma processing.

In order to improve the temperature controllability of the substrate G by the temperature control mechanism provided on the mounting table 23, a heat transfer gas (He gas) at a constant pressure is applied to a minute gap between the upper surface of the mounting table 23 and the back surface of the substrate G. A supply He gas flow path 41 is provided. Thus, by supplying the gas for heat transfer to the back surface side of the board|substrate G, it becomes possible to avoid the temperature rise and temperature change of the board|substrate G under vacuum.

The inductively coupled plasma processing apparatus 100 includes a control apparatus 110 . The control device 110 is realized by, for example, a computer. The computer includes a central processing unit (CPU), random access memory (RAM), read only memory (ROM), a hard disk drive (HDD), an input/output interface, an internal bus, and the like.

The control device 110 includes a main control unit 111 , a plasma generation processing unit 112 , an abnormality detection determination unit 113 , and a memory 115 . The main control unit 111 , the plasma generation processing unit 112 , and the abnormality detection determination unit 113 represent functions (functions) of programs executed by the control device 110 as functional blocks. In addition, the memory 115 functionally represents the memory of the control device 110 .

Each component of the inductively coupled plasma processing apparatus 100 is connected to the control apparatus 110 . Each component of the inductively coupled plasma processing apparatus 100 is controlled by the main control unit 111 , the plasma generation processing unit 112 , and the abnormality detection determination unit 113 of the control device 110 .

In addition, in the control device 110 , a keyboard for performing input operations such as a command input for managing the inductively coupled plasma processing device 100 by the operator, and the operation status of the inductively coupled plasma processing device 100 are visualized and displayed. A user interface 101 including a display or the like is connected.

In addition, the operator is not limited to the worker of the factory where the inductively coupled plasma processing apparatus 100 is delivered, etc., in the assembly stage before shipment in the manufacturing plant of the inductively coupled plasma processing apparatus 100, etc. 100), including those who operate it.

The main control unit 111 is a processing unit that generalizes the control processing of the control device 110 , and executes processing other than those performed by the plasma generation processing unit 112 and the abnormality detection determination unit 113 . For example, the main control part 111 performs control processes, such as an etching process and a film-forming process, in accordance with the conveyance control of the board|substrate G and a process recipe.

The plasma generation processing unit 112 performs plasma generation processing for generating plasma by supplying high frequency power to a plurality of areas of the high frequency antenna 120 . The plasma generation processing unit 112 also adjusts the output of the high frequency power output from the power supply unit 51 .

The abnormality detection determination unit 113 detects an abnormality in the inductively coupled plasma processing apparatus 100 . The abnormality detection and determination unit 113 will be described in detail later.

The memory 115 is a control program for realizing various processes executed by the inductively coupled plasma processing device 100, and a program for causing each component unit of the inductively coupled plasma processing device 100 to execute the processing according to processing conditions. (Process recipe) is memorized (stored). The process recipe may be transferred from a portable storage medium such as a CDROM, DVD, or flash memory to the control device 110 and stored in the memory 115 . In addition, you may make it transmit a process recipe to the control apparatus 110 from another apparatus via a dedicated line, for example. Then, if necessary, an arbitrary process recipe is called from the memory 115 by an instruction from the user interface 101 or the like, and the control device 110 executes the inductively coupled plasma processing under the control of the control device 110 . A desired plasma treatment or the like in the apparatus 100 is performed.

In addition, data indicating a relationship between a plurality of areas and a plurality of integrated areas to be described later and an antenna segment is stored in the memory 115 .

In addition, the control device 110 is connected to an external host computer 200 . The host computer 200 acquires the processing result and device state data in the inductively coupled plasma processing device 100 from the control device 110 .

In addition, you may perform the process in the control apparatus 110 by a some apparatus. You may process a part of the process in the control apparatus 110, for example, the process of the abnormality detection determination part 113 by a programmable logic controller etc.

3 is a diagram showing an example of the antenna segment 121 . The antenna segment 121 is one of the plurality of antenna segments 121 included in the high frequency antenna 120 . 3 shows the XYZ coordinate system. The XY plane is parallel to the horizontal plane, and the Z direction is vertically upward.

The antenna segment 121 is formed by three-dimensionally winding the antenna wire 122 made of a conductive material such as copper in the vertical direction a plurality of times, for example, about a winding axis RA extending in the horizontal direction. The winding axis RA is parallel to the X axis as an example. The antenna wire 122 is not wound in a horizontal plane, but is bent and wound in the vertical direction (vertical direction). The antenna wire 122 is wound in the vertical direction in a rectangular shape when viewed from the YZ plane.

Since the antenna wire 122 is wound multiple times between the end 122A and the end 122B, it has a plurality of bottom portions 122C. The bottom 122C is a portion located at the bottom of the three-dimensionally wound antenna wire 122 . The plurality of bottom portions 122C constitute, for example, a flat portion 125 parallel to the Y-axis and parallel to the horizontal plane.

Since the antenna line 122 shown in FIG. 3 has three bottom parts 122C as an example, the flat part 125 is comprised by three bottom parts 122C as an example. The induced electric field generated by the planar portion 125 contributes to the generation of plasma.

The shape of the antenna segment 121 shown in FIG. 3 is an example, and the shape of the plurality of antenna segments 121 included in the high frequency antenna 120 is adapted to the shape of each area or the like. For this reason, depending on the location of each area, the shape of the antenna segment 121 may be different from the shape of the antenna segment 121 shown in FIG. 3, but all the antenna segments 121 have a plurality of bottoms. It has a flat portion 125 constituted by 122C. The flat portion 125 is disposed along the upper surface 2A of the dielectric wall 2 .

The antenna segment 121 is an example of an antenna coil.

4 is a diagram showing an example of an area A and an integrated area SA of the high-frequency antenna 120 . The antenna unit 50 is divided into 18 areas, from area A1 to area A18. Each of the respective areas A1 to A18 includes an antenna segment 121 . Areas A1 and A2 constitute an inner area corresponding to the inner annular antenna, areas A3 to A6 constitute an intermediate area corresponding to the intermediate annular antenna, and areas A7 to A18 correspond to the outer annular antenna. constituting the outer area. The inner area, the middle area, and the outer area are examples of a plurality of concentric rectangular areas. The outer area is located on the outermost periphery of a plurality of concentric rectangular areas.

In addition, each of the areas A1 to A18 belongs to any one of the integrated areas SA1 to SA5. The area included in each of the integrated area SA1 - integrated area SA5 is comprised by the combination of the area which is point symmetry or a line symmetry when the mounting table 23 is viewed from above.

For example, you may combine the area which is point symmetry with respect to the plane center AC of the mounting table 23 (23 A of mounting surfaces). Further, the axis AX or the mounting table 23 (loading surface) passes through the center AC of the mounting table 23 (loading surface 23A) and orthogonal to the short side of the mounting table 23 (loading surface 23A). (23A)) You may combine the area which is line-symmetric with the axis AY which passes through the plane center AC and orthogonal to the long side of the mounting base 23 (23A of mounting surfaces). Furthermore, you may combine the area which is line-symmetric with respect to the diagonal of the mounting table 23 (23 A of mounting surfaces).

The antenna segment 121 disposed on the upper surface 2A of the dielectric wall 2 corresponds to the plane center AC of the mounting table 23 (loading surface 23A) of the upper surface 2A of the dielectric wall 2 . With respect to the center, it is arranged point symmetry. For example, the winding axis RA of the antenna segment 121 is a center direction or a center direction corresponding to the plane center AC of the mounting table 23 (the mounting surface 23A) of the upper surface 2A of the dielectric wall 2 . facing in a direction parallel to

Accordingly, the antenna segments 121 arranged in each of the areas at symmetrical positions have the same antenna current in structure. In this embodiment, the area in which the antenna segments 121 of the same characteristic are arrange|positioned is collectively set as an integrated area. Then, by determining with the antenna current in the antenna segment 121 of the integrated area, abnormality can be detected stably.

In addition, the axis AX is an example of a 1st symmetry axis, and the axis AY is an example of a 2nd symmetry axis.

Specifically, an area included in each of the integrated area SA1 to SA5 will be described.

The integrated area SA1 includes an area A1 and an area A2. The area A1 and the area A2 are point-symmetric with respect to the surface center AC of the mounting table 23. As shown in FIG. In addition, the area A1 and the area A2 are line-symmetrical with respect to the axis|shaft AX of the mounting table 23. As shown in FIG.

Integration area SA2 includes area A3, area A4, area A5, and area A6. The area A3 and the area A5 are point symmetric with respect to the center of the mounting table 23 . In addition, the area A4 and the area A6 are point-symmetric with respect to the center of the mounting table 23. As shown in FIG. In addition, since area A3 and area A5 are on the short side, and area A4 and area A6 are on the long side, these short side areas and long side areas are not strictly the same, but are required for the precision of determination. Accordingly, the area A3, the area A4, the area A5, and the area A6 may all be treated as points symmetric with respect to the center of the mounting table 23 .

Integration area SA3 includes integration area SA3a and integration area SA3b. The integration area SA3a and the integration area SA3b are, respectively, a set of areas which are adjacent to each other in the integration area SA3 and can be viewed as a group. In other words, the integrated area SA3 is subdivided for each chunk of areas spaced apart from each other (the same applies to the following). The integrated area SA3a includes an area A7 and an area A8. The integrated area SA3b includes an area A9 and an area A10. Area A7 and area A10 included in integrated area SA3 are point symmetric with respect to the center of the mounting table 23 . In addition, area A8 and area A9 included in integrated area SA3 are point symmetric with respect to the center of the mounting table 23 . In addition, for example, the area A7 and the area A9 are each line-symmetrical with respect to the axis|shaft AX. In addition, for example, the area A7 and the area A8 are line-symmetric with respect to the axis AY, respectively.

Integration area SA4 includes integration area SA4a and integration area SA4b. The integrated area SA4a includes an area A11 and an area A12. The integrated area SA4b includes an area A13 and an area A14. Area A11 and area A14 included in integrated area SA4 are point symmetric with respect to the center of the mounting table 23 . In addition, the area A12 and the area A13 included in the integrated area SA4 are point-symmetric with respect to the center of the mounting table 23 . In addition, for example, the area A11 and the area A12 are each line-symmetrical with respect to the axis|shaft AX. In addition, for example, the area A11 and the area A13 are line-symmetric with respect to the axis AY, respectively.

Integration area SA5 includes integration area SA5a, integration area SA5b, integration area SA5c, and integration area SA5d. Integrated area SA5a is equivalent to area A15. Integrated area SA5b is equivalent to area A16. Integrated area SA5c is equivalent to area A17. Integrated area SA5d is equivalent to area A18. Area A15 and area A17 included in integrated area SA5 are point symmetric with respect to the center of the mounting table 23 . In addition, the area A16 and the area A18 included in the integrated area SA5 are point-symmetric with respect to the center of the mounting table 23 . In addition, for example, the area A15 and the area A16 are each line-symmetrical with respect to the axis|shaft AX. In addition, for example, the area A15 and the area A18 are line-symmetric with respect to the axis AY, respectively. In addition, similarly to the case of the integrated area SA2, depending on the required precision of determination, the areas A15, A16, A17, and A18 may all be treated as points symmetrical with respect to the center of the mounting table 23.

Moreover, in the case of the specific example regarding the said integration area, integration area SA1 constitutes an inside area, integration area SA2 constitutes an intermediate area, and integration areas SA3, SA4, and SA5 constitute an outer area.

5 is a block diagram showing an example of the antenna circuit 150 of the inductively coupled plasma processing apparatus 100 according to the present embodiment.

The antenna circuit 150 includes a plurality of antenna segments 121 corresponding to each of the areas A1 to A18. The antenna circuit 150 includes a plurality of ammeters 131 for measuring the antenna current provided between each of the antenna segments 121 and the ground. That is, one end of the antenna segment 121 is connected to the high frequency power supply 15 , and the other end is connected to the ground potential through an ammeter 131 .

The ammeter 131 is, for example, a current transformer. The ammeter 131 outputs a voltage based on a current flowing between the antenna segment 121 and the ground, for example.

6 is a block diagram showing an example of processing of the inductively coupled plasma processing apparatus 100 according to the present embodiment.

The inductively coupled plasma processing apparatus 100 includes an ammeter 131 corresponding to each of the areas A1 to A18, an introduction unit 132 connected to each of the ammeters 131 , and abnormality detection for detecting and judging an abnormality. A determination unit 113 is provided. In addition, the abnormality detection and determination unit 113 outputs the detected result to the host computer 200 .

Each of the ammeters 131 corresponding to each of the areas A1 to A18 is connected to the introduction unit 132 . The introduction unit 132 is, for example, an A/D (Analog/Digital) converter that converts an analog signal corresponding to a current value measured by each of the ammeter 131 into a digital signal by analog-digital conversion.

The abnormality detection determination unit 113 determines whether abnormality has occurred in each of the integrated areas SA1 to SA5. The abnormality detection determination unit 113 determines the presence or absence of occurrence of abnormality based on the current values measured in the areas A1 to A18 included in any of the integrated areas SA1 to SA5.

The abnormality detection process in the abnormality detection determination part 113 is demonstrated. The abnormality detection method of the inductively coupled plasma processing apparatus 100 is demonstrated by demonstrating the abnormality detection process in the abnormality detection determination part 113. FIG. 7 is a flowchart showing an example of processing of the inductively coupled plasma processing apparatus 100 according to the present embodiment.

The plasma generation processing unit 112 supplies rated high frequency power from the high frequency power supply 15 to the high frequency antenna 120 (step S10). Then, the abnormality detection determination unit 113 starts the abnormality detection process (step S20). The abnormality detection and determination unit 113 introduces the temporal change of the antenna current measured by the ammeter 131 in each of the areas A1 to A18. That is, the abnormality detection and determination unit 113 measures the change with time of the current of each of the coil antennas (antenna segment 121 ) in the areas A1 to A18 with the ammeter 131 . And the abnormality detection determination part 113 produces|generates the measured result as sampling data (step S30).

In addition, step S30 is an example of a process of measuring the change with time of each electric current of the some antenna coil (antenna segment 121) with the ammeter 131. As shown in FIG.

The abnormality detection determination unit 113 calculates the current change rate in each of the areas A1 to A18 (step S40).

Here, although the process in any one of area A1 - area A18 is demonstrated, each of area A1 - area A18 is demonstrated as an area An (provided that n is an integer of 1 or more and 18 or less), respectively.

Let the measured value of the ammeter 131 in the area An at time t be CT_n(t). The time change rate of the antenna current is calculated based on the current value of the antenna current measured at one or a plurality of time intervals. For example, when measuring the time change rate of the antenna current for K time intervals (provided that K is an integer greater than or equal to 1), the K time intervals are expressed as time intervals Δt_k. In addition, k is an integer of 1 or more and K or less, for example, 10. In addition, it is preferable that the time interval Δt_k is an integer multiple of the sampling period in the introduction unit 132 .

By obtaining the measured value of the ammeter 131 in the area An at the time interval Δt_k, it is possible to measure the current value of the antenna current at the time spaced apart. In addition, by measuring with a plurality of time intervals ?t_k, the present method can be applied even when the antenna current has a temporal change as a background. For example, by measuring with a plurality of time intervals Δt_k, it is possible to respond even when the antenna current changes slowly or rapidly.

For example, the time interval Δt_k is the time interval Δt_1 being the sampling period in the introduction unit 132, the time interval Δt_2 being twice the sampling period in the introduction unit 132, the time interval Δt_3 being the sampling period in the introduction unit ( 132) may be four times the sampling period.

The abnormality detection and determination unit 113 calculates the rate of change of the antenna current with time as an evaluation value based on the temporal change of the antenna current in the antenna coil. Let the time change rate of the antenna current at the time t in the area An and the time interval ?t_k be the time change rate ?CT_n, k(t). The abnormality detection and determination unit 113 calculates the time change rate ΔCT_n, k(t) by the expression (1).

ΔCT_n, k(t)=(CT_n(t)-CT_n(t-Δt_k))/CT_n(t) … (Equation 1)

When abnormality is detected at a plurality of time intervals, the abnormality detection determination unit 113 calculates a plurality of time change rates ΔCT_n, k(t) for a plurality of different time intervals Δt_k.

In Equation 1, CT_n(t) is an example of the first current value, CT_n(t-Δt_k) is an example of the second current value, and CT_n(t)-CT_n(t-Δt_k) is the first current value and the second current value. Incidentally, although the amount of change between the first current value and the second current value is divided by the first current value in Equation 1, it may be divided by the second current value. In addition, step S40 is an example of the process of calculating the evaluation value based on the time-dependent change of electric current with respect to each of the some antenna coil (antenna segment 121).

Next, the abnormality detection and determination unit 113 calculates a time change rate difference of the antenna current for each time interval Δt_k in each of the integrated areas SA1 to SA5 (step S45). Here, the processing in any of the integrated areas SA1 to SA5 will be described. Each of the integrated areas SA1 to SA5 is assumed to be the integrated area SAm (provided that m is an integer of 1 or more and 5 or less). Explain.

The abnormality detection determination unit 113 compares the rate of change of the antenna current in the area included in the integrated area SAm, and the difference in the rate of change in time of the antenna current in the integrated area SAm at the time t and the time interval Δt_k ΔSA_m, k (t) is obtained by Equation 2. In addition, n represents the number of the area included in the integration area SAm. In addition, max(ΔCT_n, k(t)) represents the largest value (maximum value) among the temporal change rates ΔCT_n, k(t) of the area included in the integrated area SAm. min(ΔCT_n, k(t)) represents the smallest value (minimum value) among the temporal change rates ΔCT_n, k(t) of the area included in the integrated area SAm. In addition, although n of max(ΔCT_n, k(t)) and n of min(ΔCT_n, k(t)) indicate different area numbers, it is assumed here that the same n is used for convenience, and the maximum value is It is assumed that it corresponds to the number of the area to be used and the number of the area to be the minimum value.

ΔSA_m, k(t)=max(ΔCT_n, k(t))-min(ΔCT_n, k(t)) … (Equation 2)

By the process of step S40, the abnormality detection and determination unit 113 calculates the time change rate difference ΔSA_m, k(t) of the M antenna currents (here, 5) for each time interval Δt_k.

In step S45, the difference between the maximum value and the minimum value of the evaluation value of the antenna coil (antenna segment 121) disposed in each of the areas included in each of the plurality of integrated areas is calculated, and the abnormality is determined based on the difference. It is an example of the process to detect.

Then, the abnormality detection and determination unit 113 determines whether all of the time change rate differences ?SA_m and k(t) of the M antenna currents are less than a threshold value (step S50). In addition, the said threshold value is the difference value (standard difference value) of a predetermined reference|standard.

When all of the time change rate differences ΔSA_m and k(t) of the M antenna currents are less than the threshold value (YES in step S50), the abnormality detection and determination unit 113 determines that it is normal. Then, the abnormality detection determination unit 113 determines whether or not to end the process (step S60).

If the process is not ended, that is, when the process is continued (No in step S60), the flow returns to step S30 and the process is repeated. In the case of ending the process (Yes in step S60), the process ends.

When at least one of the time change rate differences ΔSA_m, k(t) of the M antenna currents is not less than the threshold, that is, exceeds the threshold (No in step S50), the abnormality detection and determination unit 113 is abnormal. It is judged as a false abnormality as there is a possibility that it will be. The abnormality detection determination unit 113 counts the number of times it has been determined to be a false abnormality. Then, the abnormality detection determination unit 113 determines whether the number of times determined to be a false abnormality is equal to or greater than a set number of times (step S70).

When the number of times (the number of times the reference difference value is exceeded (the number of times)) is greater than or equal to the set number (reference number) (Yes in step S70), the abnormality detection and determination unit 113 determines that an abnormality has occurred. is detected (step S80). Then, the plasma generation processing unit 112 stops the supply of the high frequency power from the high frequency power supply 15 to the high frequency antenna 120 , assuming that an abnormality has occurred. Then, the main control unit 111 abnormally stops the inductively coupled plasma processing apparatus 100 (step S90).

In addition, step S90 is an example of the process of stopping a high frequency power supply.

If the number of times determined to be false is not equal to or greater than the set number of times (NO in step S70), the abnormality detection and determination unit 113 returns to step S30 and continues the measurement again. The above processing is performed for each of the K time intervals.

An example of a specific process is shown in FIG. 8 is a diagram for explaining the processing of the inductively coupled plasma processing apparatus 100 according to the present embodiment. In FIG. 8, the process in integrated area SA5 is demonstrated. In FIG. 8, one time interval Δt will be described. In addition, the waveform of FIG. 8 is created by simulation for description.

The horizontal axis in FIG. 8 represents time. The vertical axis in Fig. 8 indicates a value corresponding to the current value. A graph Frf in FIG. 8 shows a current value supplied from the high frequency power supply 15 . Graphs F1, F2, F3, and F4 show current measured values in areas A15, A16, A17, and A18, respectively. The graph Fv shows the time change rate difference of the antenna current. Fth represents the threshold value (reference difference value) of the difference value. In addition, let the reference frequency|count which is a threshold value of a count be 5 times.

The current value at time T2 in the area A15 shown by the graph F1 fluctuates with respect to the current value at time T1. On the other hand, the graph F2, the graph F3, and the graph F4 in the time T2 do not change with respect to the time T1. Since there is a change in the current value in the area A15, the graph Fv, which is the time change rate difference of the antenna current, is large at the time T2 with respect to the time T1. However, at time T2, since it is smaller than the graph Fth which is a threshold value, abnormality is not detected.

At time T4, since the graph Fv is larger than the graph Fth, it is determined as false. However, with respect to 5 times, which is the threshold value (reference number of times) of the number of times, since the number of times is 1, the process continues as it is. In addition, the number shown in the graph represents the number of times (number of transcendences) exceeding the reference difference value.

Similarly, a pseudo abnormality is detected at time T5, time T8, time T11, and time T12. At time T12, it becomes equal to 5 times of the reference number of times. Therefore, after determining that the reference number of times has been reached at time T12, the current supplied from the high frequency power supply 15 is stopped.

Specifically, the result of operation in the inductively coupled plasma processing apparatus 100 will be described. 9 is a diagram showing an example of processing when the inductively coupled plasma processing apparatus 100 according to the present embodiment is operated.

FIG. 9A shows a time waveform of a current value measured by the inductively coupled plasma processing apparatus 100 . The horizontal axis in FIG. 9A represents time. The vertical axis of FIG. 9A represents the current value. The graph Grf in FIG. 9A shows the current value supplied from the high frequency power supply 15 . Graph G shows current measured values in areas A15, A16, A17, and A18, respectively.

FIG. 9B shows the time change rate difference calculated by the inductively coupled plasma processing apparatus 100 . The horizontal axis of FIG. 9B represents time. In addition, the time on the horizontal axis of FIG.9(b) is making the time and time of the horizontal axis of FIG.9(a) coincide. The vertical axis of FIG. 9B represents the time change rate difference. The graph Gv of FIG. 9B shows the time change rate difference of the antenna current. Gth represents a threshold value.

In Fig. 9B, an abnormality was detected at the point indicated by P. And when 5 or more times are detected, the current supplied from the high frequency power supply 15 is stopped.

<Other embodiment>

In the above embodiment, in any of the annular antennas in the outer area, the middle area, and the inner area, an example in which the antenna segment is formed by a vertically wound antenna coil like the antenna segment 121 shown as an example in FIG. 3 is shown. On the other hand, as another embodiment, only the outer annular antenna in the outer area may be constituted by an antenna segment formed of a vertically wound antenna coil. In this case, in the middle area and the inner area, for example, an annular antenna composed of the spiral antenna 160 as shown in FIG. 10 may be disposed. Although the spiral antenna 160 of FIG. 10 is wound with four antenna wires 161 shifted by 90 degrees, it is not limited to this, and, for example, two antenna wires are wound with 180 degrees shift, and one It may be comprised by winding an antenna wire, and it may be comprised so that it may become a spiral shape as a whole. In such another embodiment, abnormality detection processing is performed in units of antenna segments in the outer area, and abnormality is detected in the spiral antenna alone in the middle area and the inner area. In the case of a configuration in which only the outer area is subjected to anomaly detection processing, the device configuration becomes simpler and costs can be reduced. Therefore, there is an advantage of using this embodiment when it is sufficient if the abnormality detection processing can be performed in the plasma outer edge portion. . Moreover, the antenna segment of a vertically wound antenna coil may be used with respect to an outer side area and an intermediate|middle area, and the structure which arrange|positions the spiral antenna 160 in an inner area may be sufficient. Alternatively, the spiral antenna 160 may be arranged in the outer area, and the antenna segment of the vertically wound antenna coil is arranged in the middle area, the inner area, or both. That is, it can be set as the structure which can perform an abnormality detection process by specializing in the part to be monitored of plasma.

As mentioned above, although embodiment of the abnormality detection method and inductively coupled plasma processing apparatus which concerns on this indication was described, this indication is not limited to the said embodiment etc. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope set forth in the claims. Naturally, they also belong to the technical scope of the present disclosure.

Claims (12)

In the interior of a processing chamber for processing a substrate, a plurality of pluralities disposed along an imaginary rectangular plane corresponding to a window member on a rectangular plane facing a loading surface of a loading table for loading the substrate and dividing the interior of the processing chamber into an upper portion and a lower portion and an antenna coil of
Each of the plurality of antenna coils has one end connected to a high frequency power supply and the other end connected to a ground potential through an ammeter,
The virtual rectangular plane is divided into a plurality of areas in which any one of the plurality of antenna coils is disposed in each of at least a part thereof;
The virtual rectangular plane is an abnormality detection method of a plasma processing apparatus having a portion divided into a plurality of integrated areas in which the areas arranged at symmetrical positions in the virtual rectangular plane are combined;
measuring a change with time of each current of the plurality of antenna coils with the ammeter;
calculating an evaluation value based on the temporal change of the current for each of the plurality of antenna coils;
Plasma processing comprising the step of calculating a difference between a maximum value and a minimum value of the evaluation value of the antenna coil disposed in each of the areas included in each of the plurality of integrated areas, and detecting an abnormality based on the difference How to detect an abnormality in the device. According to claim 1,
The virtual rectangular plane is divided into a plurality of concentric rectangular areas, and at least an outer area located on the outermost periphery of the plurality of concentric rectangular areas. Way. 3. The method of claim 2,
In all of the plurality of concentric rectangular areas, the plurality of integrated areas are partitioned. 4. The method according to any one of claims 1 to 3,
and comparing the difference with a predetermined reference difference value, and stopping the high frequency power supply when the difference exceeds the reference difference value in the time-dependent change. 5. The method of claim 4,
In the step of stopping the high-frequency power supply, the number of times the difference exceeds the reference difference value in the change over time is counted, and when the number of times of exceeding reaches a predetermined reference number of times, the high-frequency power supply is stopped which is an abnormality detection method of a plasma processing apparatus. 6. The method according to any one of claims 1 to 5,
The symmetry includes a plane center of the virtual rectangular plane, a first axis of symmetry passing through the plane center and orthogonal to a short side of the virtual rectangular plane, and a second axis of symmetry passing through the plane center and orthogonal to a long side of the virtual rectangular plane. The abnormality detection method of the plasma processing apparatus which is symmetrical with respect to at least any one of the diagonal of the symmetry axis and the said virtual rectangular plane. 7. The method according to any one of claims 1 to 6,
The evaluation value is a current change rate obtained by dividing an amount of change between a first current value and a second current value in the temporal change of the current by the first current value or the second current value, How to detect anomalies. 8. The method of claim 7,
The first current value and the second current value are the values of the currents respectively measured at time points separated by a predetermined time, the abnormality detection method of the plasma processing apparatus. 8. The method according to any one of claims 1 to 7,
In the step of calculating the evaluation value, a plurality of the evaluation values are calculated based on the temporal change of the current at a plurality of different time intervals,
In the step of detecting the abnormality, the difference is calculated for each of the different time intervals, and the abnormality is detected based on a plurality of the calculated differences. a loading table for loading the substrate in the processing chamber for processing the substrate;
a window member on a rectangular plane facing the loading surface of the mounting table and dividing the interior of the processing chamber into an upper portion and a lower portion;
a plurality of antenna coils disposed along a virtual rectangular plane corresponding to the window member;
A control unit for detecting an abnormality is provided;
Each of the plurality of antenna coils has one end connected to a high frequency power supply and the other end connected to a ground potential through an ammeter,
The virtual rectangular plane is divided into a plurality of areas in which any one of the plurality of antenna coils is disposed in each of at least a part thereof;
The virtual rectangular plane has a portion partitioned into a plurality of integrated areas in which the areas arranged at symmetrical positions in the virtual rectangular plane are combined;
The said control part detects abnormality based on the current value measured by the said ammeter with respect to the said antenna coil arrange|positioned in each of the said area included in each of the said plurality of integration areas. 11. The method of claim 10,
The virtual rectangular plane is divided into a plurality of concentric rectangular areas, and the plurality of integrated areas are partitioned at least in an outer area located on an outermost periphery of the plurality of concentric rectangular areas. 12. The method of claim 11,
In all of the plurality of concentric rectangular areas, the plurality of integrated areas are partitioned.

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