Abnormal Detection Method of Plasma Processing Apparatus and Plasma Processing Apparatus

Abstract

The present disclosure relates to a method for detecting an abnormality in a plasma processing device and a plasma processing device. The plasma processing device includes a plurality of antenna coils arranged along a virtual rectangular plane corresponding to a window member, one end of each of the plurality of antenna coils being connected to a high-frequency power supply and the other end being connected to a ground potential via an ammeter. At least a portion of the virtual rectangular plane is divided into a plurality of regions, each of which is respectively arranged with any of the plurality of antenna coils. The virtual rectangular plane includes a portion divided into a plurality of merged regions, each of which is formed by combining regions arranged symmetrically in the virtual rectangular plane. The method for detecting an abnormality in a plasma processing device includes the following steps: comparing evaluation values of the antenna coils arranged in each region included in each of the plurality of merged regions, calculating a difference between a maximum value and a minimum value, and detecting an abnormality based on the difference.

Description

Technical Field

[0001] The present disclosure relates to an abnormality detection method for a plasma processing device and the plasma processing device. Background Art

[0002] Patent Document 1 discloses a plasma processing apparatus that stops the output of at least one high-frequency power source when an excessively large reflected wave is generated in the high-frequency power source, and also instantly stops the output of the other high-frequency power sources.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2009-070844 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] The present disclosure provides a technology for detecting an abnormality occurring in a plasma processing apparatus.

[0008] Solutions for solving problems

[0009] According to one embodiment of the present disclosure, a method for detecting an abnormality of a plasma processing device is provided, wherein the plasma processing device includes a plurality of antenna coils arranged along a virtual rectangular plane corresponding to a rectangular planar window member, the window member facing a loading surface of a loading table on which the substrate is loaded inside a processing chamber for processing the substrate, and dividing the interior of the processing chamber into an upper part and a lower part, one end of each of the plurality of antenna coils is connected to a high-frequency power supply, and the other end is connected to a ground potential via an ammeter, and at least a portion of the virtual rectangular plane is divided into a plurality of areas where any one of the plurality of antenna coils is respectively arranged, The virtual rectangular plane has a portion divided into multiple merged areas, each of the merged areas is formed by combining the areas arranged at symmetrical positions in the virtual rectangular plane, and the abnormality detection method of the plasma processing device includes the following steps: measuring the change of the current of each antenna coil of the multiple antenna coils over time by the ammeter; calculating an evaluation value based on the change of the current over time for each antenna coil of the multiple antenna coils; and calculating the difference between the maximum and minimum values of the evaluation values of the antenna coils arranged in each of the areas included in each merged area of the multiple merged areas, and detecting abnormalities based on the difference.

[0010] Effects of the Invention

[0011] According to the present disclosure, it is possible to detect abnormality occurring in a plasma processing apparatus. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a plan view showing an example of a substrate processing system 500 according to this embodiment.

[0013] Figure 2 1 is a cross-sectional view showing an inductively coupled plasma processing apparatus 100 according to this embodiment.

[0014] Figure 3 This is a diagram showing an example of the antenna segment 121.

[0015] Figure 4 This is a diagram showing an example of the area of the high-frequency antenna 120 and the integrated area.

[0016] Figure 5 1 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.

[0017] Figure 6 1 is a block diagram showing an example of processing performed by the inductively coupled plasma processing apparatus 100 according to the present embodiment.

[0018] Figure 7 1 is a diagram illustrating an example of processing performed by the inductively coupled plasma processing apparatus 100 according to the present embodiment.

[0019] Figure 8 FIG. 1 is a diagram illustrating an example of processing performed by the inductively coupled plasma processing apparatus 100 according to the present embodiment.

[0020] Figure 9 FIG. 1 is a diagram illustrating an example of processing performed by the inductively coupled plasma processing apparatus 100 according to the present embodiment.

[0021] Figure 10 It is a plan view showing an example of a helical antenna according to another embodiment. DETAILED DESCRIPTION

[0022] <Implementation Method>

[0023] Hereinafter, the mode for implementing the present disclosure will be described with reference to the accompanying drawings. In addition, in this specification and the accompanying drawings, substantially the same structure is denoted by the same reference numerals, and thus repeated description may be omitted.

[0024] <Substrate Processing System According to Embodiment>

[0025] Figure 1FIG1 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.

[0026] The substrate processing system 500 is a system that performs various substrate processing operations on a rectangular substrate G, such as one used in a flat panel display (FPD) when viewed from above. Substrate G is, for example, a transparent glass plate or a transparent synthetic resin plate. Electronic circuits, such as light-emitting elements and thin film transistors (TFTs) for driving the light-emitting elements, are formed on the surface of substrate G.

[0027] Substrate processing performed in the substrate processing system 500 includes plasma processing (plasma processes) such as dry etching (plasma etching), plasma CVD (Chemical Vapor Deposition), or plasma PVD (Physical Vapor Deposition). Substrate processing may also include processing (processes) that does not use plasma, such as post-processing.

[0028] The FPD is, for example, a liquid crystal display (LCD), an organic EL (ElectroLuminescence) panel, or a plasma display panel (PDP).

[0029] The planar dimensions of FPD substrates G have become increasingly larger with each generation. The planar dimensions of substrates G processed by the substrate processing system 500 can range from approximately 1500 mm x 1800 mm for at least the 6th generation to approximately 3000 mm x 3400 mm for the 10.5th generation. Furthermore, the thickness of substrates G can range from, for example, 0.2 mm to several millimeters. By singulating a single substrate G, multiple FPDs can be obtained.

[0030] When plasma processing is performed on a substrate G for FPD having a large planar size to be processed by the substrate processing system 500 , uniformity of plasma density in a large area corresponding to the planar size of the substrate G is required.

[0031] The substrate processing system 500 is a multi-chamber cluster tool and is configured to be capable of performing serial processing in a vacuum atmosphere.

[0032] In substrate processing system 500, a load-lock chamber 510 is mounted on one side of a centrally located hexagonal transfer apparatus 520 (including a transfer chamber, also called a transfer module) via a gate valve 512. Furthermore, five process chambers 530A, 530B, 530C, 530D, and 530E are mounted on the other five sides of transfer apparatus 520 via gate valves 522. Transfer apparatus 520 is not limited to a hexagonal shape when viewed from above; it may also be a quadrilateral or polygonal shape with another number of sides.

[0033] Each chamber is controlled to have the same vacuum atmosphere. When the gate valve 522 is opened to transfer the substrate G between the transfer chamber of the transfer device 520 and each process chamber 530A to 530E, the pressure is adjusted so as not to cause pressure fluctuations between the chambers.

[0034] A load 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 load module. A large number of substrates G are housed in a cassette (not shown) located at a different location on the load module than the location where the load lock chamber 510 is connected. The load lock chamber 510 is configured to switch the internal pressure atmosphere between normal pressure and vacuum. Substrates G are transferred between the load lock chamber 510 and the load module.

[0035] The load lock chambers 510 are stacked in two layers, for example. Each load lock chamber 510 is provided with a holder 514 for holding a substrate G and a positioner 513 for adjusting the position of the substrate G. After the load lock chamber 510 is controlled to a vacuum atmosphere, the gate valve 512 is opened to connect the load lock chamber 510 to the transfer device 520, which is also controlled to a vacuum atmosphere. The substrate G is then transferred from the load lock chamber 510 to the transfer device 520 in the direction of arrow D2.

[0036] The transport mechanism 521 is mounted within the transport apparatus 520. It is rotatable in the direction indicated by arrow D1 and slidable toward each process chamber 530A through 530E. The direction indicated by arrow D1 represents the circumferential direction. The transport mechanism 521 transports substrates G received from the load lock chamber 510 to the desired process chamber (any of the process chambers 530A through 530E). Furthermore, by opening a gate valve 522, the transport mechanism 521 delivers substrates G to each process chamber 530A through 530E, which has been adjusted to a vacuum atmosphere comparable to that of the transport apparatus 520.

[0037] The substrate G is transferred between the transport apparatus 520 and the process chamber 530A along the direction of arrow D3. Similarly, the substrate G is transferred between the transport apparatus 520 and the process chamber 530B along the direction of arrow D4. The substrate G is transferred between the transport apparatus 520 and the process chamber 530C along the direction of arrow D5. The substrate G is transferred between the transport apparatus 520 and the process chamber 530D along the direction of arrow D6. The substrate G is transferred between the transport apparatus 520 and the process chamber 530E along the direction of arrow D7. The substrate G is transferred to the process chambers 530A to 530E according to the process steps for plasma processing and other processes.

[0038] One or more of the process chambers 530A to 530E may, for example, be chambers for performing plasma processing, such as dry etching (plasma etching) using a halogen-based etching gas (e.g., a fluorine-based or chlorine-based etching gas), plasma CVD, or plasma PVD. Furthermore, the process chambers 530A to 530E may include, for example, a chamber for performing post-treatment (post-processing) to remove chlorine or chlorine-based compounds from the substrate G. The portion of the substrate processing system 500 that includes the chambers for performing plasma processing is an inductively coupled plasma processing apparatus according to an embodiment.

[0039] Achieving uniform plasma density in the plasma processing chambers among process chambers 530A to 530E is crucial. Substrate G is very large in planar dimensions, and multiple FPDs are produced from a single substrate G. Therefore, low plasma density uniformity degrades the distribution of film quality formed on substrate G, hindering the production of FPDs with high image quality. From this perspective, improving plasma density uniformity during the plasma processing included in the manufacturing process for FPD substrates G is crucial.

[0040] Figure 2 1 is a cross-sectional view showing an inductively coupled plasma processing apparatus 100 according to this embodiment. The inductively coupled plasma processing apparatus 100 includes a process chamber 530. The process chamber 530 is Figure 1 The process chambers 530A to 530E shown are chambers for performing plasma processing. Specifically, plasma processing includes, for example, etching of silicon oxide films, silicon nitride films, metal films, etc., forming of silicon oxide films and silicon nitride films to protect metal films, ITO (Indium Tin Oxide) films when forming thin-film transistors on the surface of substrate G, or ashing of resist films.

[0041] Process chamber 530 is an airtight, rectangular cylindrical chamber made of a conductive material, such as anodized aluminum, with its inner walls treated. Process chamber 530 is assembled in a removable manner and electrically grounded via a ground wire 1a. Process chamber 530 is divided vertically into an antenna chamber 3 and a processing chamber 4 by a dielectric wall (dielectric window) 2. Thus, dielectric wall 2 functions as the ceiling of the processing chamber 4, which is divided into upper and lower sections. Dielectric wall 2 has a rectangular planar shape when viewed from above. Dielectric wall 2 is composed of ceramics such as Al2O3, quartz, or other materials.

[0042] A spray housing 11 for supplying process gases is embedded in the lower portion of the dielectric wall 2. The spray housing 11 is, for example, arranged in a cross shape. The spray housing 11 functions as a beam supporting the dielectric wall 2 from below. The dielectric wall 2 can be divided into four sections corresponding to the cross-shaped spray housing 11. Furthermore, the spray housing 11, which supports the dielectric wall 2, is suspended from the ceiling of the process chamber 530 by multiple suspenders (not shown).

[0043] The shower housing 11 is made of a conductive material, preferably metal. The shower housing 11 is made of, for example, aluminum with an anodized inner or outer surface to prevent contamination. The shower housing 11 is electrically grounded.

[0044] A horizontally extending gas flow path 12 is formed in the shower housing 11. The gas flow path 12 communicates with a plurality of downwardly extending gas ejection holes 12a. A gas supply pipe 20a, connected to the gas flow path 12, is provided in the center of the upper surface of the dielectric wall 2. The gas supply pipe 20a extends through the top of the process chamber 530 and outward, connecting to a process gas supply system 20 comprising a process gas supply source and a valve system. Therefore, during plasma processing, process gas supplied from the process gas supply system 20 is supplied into the shower housing 11 via the gas supply pipe 20a and ejected from the gas ejection holes 12a into the processing chamber 4.

[0045] A support frame 5 protruding inward is provided between the side wall 3a of the antenna chamber 3 and the side wall 4a of the treatment chamber 4 in the process chamber 530. The dielectric wall 2 is placed on the support frame 5.

[0046] Inductively coupled plasma processing apparatus 100 also includes an antenna unit 50 having a radio frequency (RF) antenna 120. RF antenna 120 is connected to RF power supply 15 via power supply unit 51, power supply line 19, and matching unit 14. RF antenna 120 is isolated from dielectric wall 2 by spacer 17, which is an insulating member. RF power, for example, having a frequency of 13.56 MHz, is supplied from RF power supply 15 to RF antenna 120, generating an induced electric field within processing chamber 4. The induced electric field generated within processing chamber 4 by RF antenna 120 converts processing gas supplied from shower housing 11 into plasma.

[0047] The antenna unit 50 includes a radio frequency antenna 120 and a power supply unit 51 that supplies radio frequency power to the radio frequency antenna 120 via the matching unit 14 . The radio frequency antenna 120 is provided on the upper surface of the dielectric wall 2 .

[0048] The high-frequency antenna 120 has a plurality of antenna segments. Figure 3 As shown in FIG, each antenna segment is formed by winding an antenna wire made of copper wire, etc. Details of the antenna segment will be described later.

[0049] The planar portions of the multiple antenna segments of the radio frequency antenna 120 are positioned downward on the upper surface 2A side of the dielectric wall 2, facing the upper surface of the substrate G across the dielectric wall 2, which functions as a dielectric window for high-frequency power. The planar portions of the multiple antenna segments of the radio frequency antenna 120 are arranged in concentric rectangular rings, forming a rectangular plane corresponding to the substrate G. The planar portions of the multiple antenna segments of the radio frequency antenna 120 form a rectangular ring shape as a whole, for example, a multi-segmented ring antenna such as a concentric three-ring antenna consisting of an outer ring antenna, a middle ring antenna, and an inner ring antenna, generating an induced electric field that contributes to plasma generation.

[0050] Furthermore, process chamber 530 is an example of a processing chamber, dielectric wall 2 is an example of a window member, and upper surface 2A of dielectric wall 2 is an example of a virtual rectangular plane. For example, a metal wall (metal window) may be used in place of dielectric wall 2 to partition process chamber 530 into antenna chamber 3 and processing chamber 4. In this case, if high-frequency antenna 120 induces a current in the metal wall, the induced current in the metal wall generates an induced electric field within processing chamber 4 that contributes to plasma generation. Furthermore, the metal wall may also serve as a shower housing.

[0051] The high frequency antenna 120 is divided into a plurality of regions, each of which has one or more antenna segments supplying high frequency power, so as to control the plasma density distribution of the plasma generated in the process chamber 530 in the plurality of regions.

[0052] A mounting table 23 for mounting a substrate G is provided at the bottom of the processing chamber 4, facing the high-frequency antenna 120 across the dielectric wall 2. The substrate G is mounted on a mounting surface 23A. The mounting table 23 is made of a conductive material, such as anodized aluminum. The substrate G mounted on the mounting table 23 is held by an electrostatic chuck (not shown).

[0053] The mounting table 23 is housed within an insulating frame 24 and supported by the bottom of the process chamber 530. The mounting table 23 is equipped with lift pins (not shown). The lift pins vertically raise and lower the substrates G during loading and unloading. Furthermore, a loading / unloading port 27a for loading and unloading substrates G and a gate valve 512 for opening and closing the loading / unloading port 27a are provided on the side wall 4a of the processing chamber 4.

[0054] The mounting table 23 is connected to a high-frequency power supply 29 via a power supply line 25a through a matching box 28. During plasma processing, the high-frequency power supply 29 applies high-frequency bias power, for example, a high-frequency power having a frequency of 3.2 MHz, to the mounting table 23. The self-bias voltage generated by the high-frequency bias power effectively attracts ions in the plasma generated in the processing chamber 4 to the substrate G.

[0055] Furthermore, a temperature control mechanism including a heating unit such as a ceramic heater, a refrigerant flow path, and a temperature sensor (not shown) is provided within the mounting table 23 to control the temperature of the substrate G. Pipes and wiring of these mechanisms and components are led out of the process chamber 530 .

[0056] An exhaust device 30 including a vacuum pump is connected to the bottom of the processing chamber 4 via an exhaust pipe 31. The exhaust device 30 exhausts the processing chamber 4 to set and maintain a predetermined vacuum atmosphere (eg, 1.33 Pa) in the processing chamber 4 during plasma processing.

[0057] A He gas flow path 41 is provided for supplying heat transfer gas (He gas) at a constant pressure to the minute gap between the upper surface of the mounting table 23 and the back surface of the substrate G, thereby improving the temperature controllability of the substrate G by the temperature control mechanism provided on the mounting table 23. By supplying heat transfer gas to the back surface of the substrate G in this manner, it is possible to prevent temperature increases and temperature fluctuations of the substrate G under vacuum.

[0058] The inductively coupled plasma processing apparatus 100 includes a control device 110. The control device 110 is implemented, for example, by a computer. The computer includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), a HDD (Hard Disk Drive), input / output interfaces, and an internal bus.

[0059] The control device 110 includes a main control unit 111, a plasma generation processing unit 112, an abnormality detection and determination unit 113, and a memory 115. The functions (utilities) of the programs executed by the control device 110 are represented as functional blocks of the main control unit 111, the plasma generation processing unit 112, and the abnormality detection and determination unit 113. The memory 115 functionally represents the memory of the control device 110.

[0060] Each component of the inductively coupled plasma processing apparatus 100 is connected to a control device 110 . Each component of the inductively coupled plasma processing apparatus 100 is controlled by a main control unit 111 , a plasma generation processing unit 112 , and an abnormality detection and determination unit 113 of the control device 110 .

[0061] The control device 110 is connected to a user interface 101 including a keyboard for an operator to input commands for managing the inductively coupled plasma processing apparatus 100 and a display for visually displaying the operating status of the inductively coupled plasma processing apparatus 100 .

[0062] The operator is not limited to an operator in a factory equipped with the inductively coupled plasma processing apparatus 100, but also includes an operator who operates the inductively coupled plasma processing apparatus 100 in the assembly stage before shipment at a manufacturing plant of the inductively coupled plasma processing apparatus 100.

[0063] The main control unit 111 is a processing unit that centrally controls the control device 110 and executes processes other than those performed by the plasma generation unit 112 and the abnormality detection and determination unit 113. For example, the main control unit 111 controls the transport of the substrate G and controls etching and film formation processes according to the process recipe.

[0064] The plasma generation processing unit 112 performs plasma generation processing to generate plasma by supplying high-frequency power to a plurality of regions of the high-frequency antenna 120. The plasma generation processing unit 112 also adjusts the output of the high-frequency power output by the power supply unit 51, and the like.

[0065] The abnormality detection and determination unit 113 detects abnormality in the inductively coupled plasma processing apparatus 100. The details of the abnormality detection and determination unit 113 will be described later.

[0066] The memory 115 stores (or retains) control programs for implementing various processes performed by the inductively coupled plasma processing apparatus 100, and programs (process recipes) for causing various components of the inductively coupled plasma processing apparatus 100 to execute processes according to processing conditions. Furthermore, the process recipes may be transferred from a portable storage medium such as a CDROM, DVD, or flash memory to the control apparatus 110 and stored in the memory 115. Alternatively, the process recipes may be transferred from another device to the control apparatus 110, for example, via a dedicated line. Furthermore, as needed, any process recipe may be retrieved from the memory 115 in accordance with instructions from the user interface 101 and executed by the control apparatus 110, thereby allowing the inductively coupled plasma processing apparatus 100 to perform desired plasma processing, etc., under the control of the control apparatus 110.

[0067] In addition, data indicating the relationship between a plurality of regions and a plurality of integrated regions described later and antenna segments is stored in the memory 115 .

[0068] Furthermore, the control device 110 is connected to an external host computer 200. The host computer 200 obtains the processing results and device status data of the inductively coupled plasma processing apparatus 100 from the control device 110.

[0069] Furthermore, the processing in the control device 110 may be performed by a plurality of devices. Part of the processing in the control device 110, for example, the processing in the abnormality detection and determination unit 113, may be performed by a programmable logic controller or the like.

[0070] Figure 3 1 is a diagram showing an example of an antenna segment 121. The antenna segment 121 is one of the plurality of antenna segments 121 included in the high-frequency antenna 120. Figure 3 The XYZ coordinate system is shown in . The XY plane is parallel to the horizontal plane, and the Z direction is the vertical upward direction.

[0071] Antenna segment 121 is formed by winding an antenna wire 122 made of a conductive material such as copper multiple times in the vertical direction about a horizontally extending winding axis RA. Winding axis RA is, for example, parallel to the X-axis. Antenna wire 122 is not wound horizontally but rather bent in the vertical (longitudinal) direction. Antenna wire 122 is wound in the longitudinal direction to form a rectangular shape when viewed from the YZ plane.

[0072] Antenna wire 122 is wound multiple times between end 122A and end 122B, thus having multiple bottom portions 122C. Bottom portions 122C are the bottom portions of the three-dimensionally wound antenna wire 122. Multiple bottom portions 122C are parallel to the Y-axis, for example, and form a planar portion 125 parallel to the horizontal plane.

[0073] Figure 3 The antenna wire 122 shown has, for example, three bottom portions 122C, and thus the planar portion 125 is constituted by, for example, three bottom portions 122C. The induced electric field generated by the planar portion 125 contributes to the generation of plasma.

[0074] Figure 3 The shape of the antenna segment 121 shown is an example, and the shapes of the multiple antenna segments 121 included in the high-frequency antenna 120 match the shapes of the respective regions. Therefore, the shape of the antenna segment 121 may differ from the shape of the respective regions. Figure 3 The antenna segments 121 shown have different shapes, but all antenna segments 121 have a planar portion 125 formed of a plurality of bottom portions 122C. The planar portion 125 is arranged along the upper surface 2A of the dielectric wall 2 .

[0075] The antenna segment 121 is an example of an antenna coil.

[0076] Figure 4 This diagram shows an example of region A and merged region SA of high-frequency antenna 120. Antenna unit 50 is divided into eighteen regions, region A1 through region A18. Each region A1 through region A18 includes an antenna segment 121. Regions A1 and A2 constitute the inner region corresponding to the inner loop antenna, regions A3 through A6 constitute the middle region corresponding to the middle loop antenna, and regions A7 through A18 constitute the outer region corresponding to the outer loop antenna. The inner, middle, and outer regions are examples of multiple concentric rectangular regions. The outer region is located at the outermost perimeter of the concentric rectangular regions.

[0077] Furthermore, areas A1 to A18 belong to any one of the combined areas SA1 to SA5. The areas included in each of the combined areas SA1 to SA5 are composed of a combination of areas that are point-symmetrical or line-symmetrical when the mounting table 23 is viewed from above.

[0078] For example, regions that are point-symmetrical with respect to the center AC of the mounting table 23 (mounting surface 23A) can be combined. Alternatively, regions that are line-symmetrical with respect to an axis AX passing through the center AC of the mounting table 23 (mounting surface 23A) and perpendicular to the short side of the mounting table 23 (mounting surface 23A) or an axis AY passing through the center AC of the mounting table 23 (mounting surface 23A) and perpendicular to the long side of the mounting table 23 (mounting surface 23A) can be combined. Furthermore, regions that are line-symmetrical with respect to a diagonal line of the mounting table 23 (mounting surface 23A) can be combined.

[0079] Antenna segment 121, disposed on upper surface 2A of dielectric wall 2, is arranged point-symmetrically with respect to the center of upper surface 2A of dielectric wall 2, corresponding to center AC of mounting base 23 (mounting surface 23A). For example, winding axis RA of antenna segment 121 is oriented in a direction parallel to or in a direction toward the center of upper surface 2A of dielectric wall 2, corresponding to center AC of mounting base 23 (mounting surface 23A).

[0080] Therefore, antenna segments 121 arranged in symmetrical areas structurally have the same antenna current. In this embodiment, areas with antenna segments 121 of the same characteristics are combined into a combined area. Furthermore, by making judgments based on the antenna currents of the antenna segments 121 in the combined area, abnormalities can be stably detected.

[0081] Furthermore, the axis AX is an example of a first axis of symmetry, and the axis AY is an example of a second axis of symmetry.

[0082] Specifically, the area included in each of the merged areas SA1 to SA5 will be described.

[0083] The combined area SA1 includes an area A1 and an area A2. The area A1 and the area A2 are point-symmetrical with respect to the center AC of the mounting table 23. The area A1 and the area A2 are also line-symmetrical with respect to the axis AX of the mounting table 23.

[0084] Merged area SA2 includes area A3, area A4, area A5, and area A6. Area A3 and area A5 are point-symmetrical with respect to the center of stage 23. Furthermore, area A4 and area A6 are point-symmetrical with respect to the center of stage 23. Furthermore, area A3 and area 5A are located on the short side, while area A4 and area A6 are located on the long side. Therefore, strictly speaking, the areas on the short side and the areas on the long side are not identical in shape. However, depending on the required accuracy of determination, areas A3, A4, A5, and A6 can be treated as if they are all point-symmetrical with respect to the center of stage 23.

[0085] The merged area SA3 includes the merged area SA3a and the merged area SA3b. The merged area SA3a and the merged area SA3b are respectively a collection of areas that are adjacent to each other in the merged area SA3 and can be regarded as a group. In other words, the merged area SA3 is subdivided according to the groups of areas separated from each other (the same applies below). The merged area SA3a includes areas A7 and A8. The merged area SA3b includes areas A9 and A10. Areas A7 and A10 included in the merged area SA3 are point-symmetrical with respect to the center of the loading platform 23. In addition, areas A8 and A9 included in the merged area SA3 are point-symmetrical with respect to the center of the loading platform 23. And, for example, areas A7 and A9 are respectively linearly symmetrical with respect to the axis AX. In addition, for example, areas A7 and A8 are respectively linearly symmetrical with respect to the axis AY.

[0086] Merged area SA4 includes merged area SA4a and merged area SA4b. Merged area SA4a includes area A11 and area A12. Merged area SA4b includes area A13 and area A14. Areas A11 and A14 included in merged area SA4 are point-symmetrical with respect to the center of stage 23. Furthermore, areas A12 and A13 included in merged area SA4 are point-symmetrical with respect to the center of stage 23. Furthermore, for example, areas A11 and A12 are each line-symmetrical with respect to axis AX. Furthermore, for example, areas A11 and A13 are each line-symmetrical with respect to axis AY.

[0087] The merged area SA5 includes the merged area SA5a, the merged area SA5b, the merged area SA5c, and the merged area SA5d. The merged area SA5a is equal to the area A15. The merged area SA5b is equal to the area A16. The merged area SA5c is equal to the area A17. The merged area SA5d is equal to the area A18. The area A15 and the area A17 included in the merged area SA5 are point-symmetrical with respect to the center of the loading platform 23. In addition, the area A16 and the area A18 included in the merged area SA5 are point-symmetrical with respect to the center of the loading platform 23. Moreover, for example, the area A15 and the area A16 are respectively line-symmetrical with respect to the axis AX. In addition, for example, the area A15 and the area A18 are respectively line-symmetrical with respect to the axis AY. In addition, as in the case of the merged area SA2, the area A15, the area A16, the area A17, and the area A18 can be treated as all being point-symmetrical with respect to the center of the loading platform 23 according to the required judgment accuracy.

[0088] In the case of the above-mentioned specific example of the integrated area, the integrated area SA1 constitutes the inner area, the integrated area SA2 constitutes the middle area, and the integrated areas SA3, SA4, and SA5 constitute the outer area.

[0089] Figure 5 1 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.

[0090] Antenna circuit 150 includes multiple antenna segments 121 corresponding to areas A1 through A18. Antenna circuit 150 also includes multiple ammeters 131, placed between each antenna segment 121 and ground, to measure antenna current. Specifically, one end of antenna segment 121 is connected to high-frequency power supply 15, and the other end is connected to ground potential via ammeter 131.

[0091] The ammeter 131 is, for example, a current transformer and outputs, for example, a voltage based on the current flowing between the antenna section 121 and the ground.

[0092] Figure 6 1 is a block diagram showing an example of processing performed by the inductively coupled plasma processing apparatus 100 according to the present embodiment.

[0093] The inductively coupled plasma processing apparatus 100 includes ammeters 131 corresponding to each of the areas A1 to A18, an input unit 132 connected to each ammeter 131, and an abnormality detection and determination unit 113 for detecting and determining abnormalities. Furthermore, the abnormality detection and determination unit 113 outputs the detection results to the host computer 200.

[0094] The ammeters 131 corresponding to the respective areas A1 to A18 are connected to an input unit 132. The input unit 132 is, for example, an A / D (Analog / Digital) converter that converts analog signals corresponding to the current values measured by the ammeters 131 into digital signals.

[0095] The abnormality detection and determination unit 113 determines whether an abnormality has occurred in each of the merged areas SA1 to SA5. The abnormality detection and determination unit 113 determines whether an abnormality has occurred based on the current values measured in the areas A1 to A18 included in any of the merged areas SA1 to SA5.

[0096] The abnormality detection process in the abnormality detection and determination unit 113 will be described. The abnormality detection process in the abnormality detection and determination unit 113 will be described to explain the abnormality detection method of the inductively coupled plasma processing apparatus 100. Figure 7 1 is a flowchart showing an example of processing performed by the inductively coupled plasma processing apparatus 100 according to the present embodiment.

[0097] The plasma generation processing unit 112 causes the high-frequency power supply 15 to supply rated high-frequency power to the high-frequency antenna 120 (step S10). The abnormality detection and determination unit 113 then begins abnormality detection processing (step S20). The abnormality detection and determination unit 113 receives the temporal changes in the antenna current measured by the ammeter 131 in each of regions A1 to A18. Specifically, the abnormality detection and determination unit 113 uses the ammeter 131 to measure the temporal changes in the current of the coil antenna (antenna segment 121) in each of regions A1 to A18. The abnormality detection and determination unit 113 then generates the measurement results as sampling data (step S30).

[0098] Furthermore, step S30 is an example of a process of measuring a temporal change in the current of each of the plurality of antenna coils (antenna segments 121 ) by the ammeter 131 .

[0099] The abnormality detection and determination unit 113 calculates the current change rate in each of the areas A1 to A18 (step S40 ).

[0100] Here, in the description of the processing in any of the areas A1 to A18 , each of the areas A1 to A18 is referred to as an area An (where n is an integer of 1 to 18).

[0101] The measured value of ammeter 131 in region An at time t is denoted as CT_n(t). The time rate of change of the antenna current is calculated based on the current values of the antenna current measured at one or more time intervals. For example, when the time rate of change of the antenna current is measured for K time intervals (where K is an integer greater than or equal to 1), the K time intervals are represented as time interval Δt_k. Furthermore, k is an integer greater than or equal to 1 and less than or equal to K, for example, 10. Furthermore, it is preferable that time interval Δt_k is an integer multiple of the sampling period of input unit 132.

[0102] By obtaining the measured values of ammeter 131 in area An at time intervals Δt_k, the antenna current values can be measured at discrete points in time. Furthermore, by performing measurements at multiple time intervals Δt_k, this method can be applied even when the antenna current exhibits temporal variations as a background. For example, by performing measurements at multiple time intervals Δt_k, it can accommodate both slowly and rapidly varying antenna currents.

[0103] For example, regarding the time interval Δt_k, the time interval Δt_1 is set to the sampling period of the input unit 132 , the time interval Δt_2 is set to twice the sampling period of the input unit 132 , and the time interval Δt_3 is set to four times the sampling period of the input unit 132 .

[0104] Abnormality detection and determination unit 113 calculates the time rate of change of the antenna current as an evaluation value based on the temporal change of the antenna current in the antenna coil. The time rate of change of the antenna current at time t and time interval Δt_k in region An is referred to as time rate of change ΔCT_n,k(t). Abnormality detection and determination unit 113 calculates time rate of change ΔCT_n,k(t) using Equation 1.

[0105] ΔCT_n,k(t)=(CT_n(t)-CT_n(t-Δt_k))CT_n(t)...(Formula 1)

[0106] When abnormality detection is performed at a plurality of time intervals, the abnormality detection determination unit 113 calculates a plurality of time change rates ΔCT_n,k(t) at a plurality of different time intervals Δt_k.

[0107] 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 an example of the change between the first and second current values. While Equation 1 divides the change between the first and second current values by the first current value, the change between the first and second current values can also be divided by the second current value. Step S40 is an example of a process for calculating an evaluation value based on the temporal change in current for each of the multiple antenna coils (antenna segments 121).

[0108] Next, the abnormality detection and determination unit 113 calculates the time-varying rate difference of the antenna current in each of the merged areas SA1 through SA5 at every time interval Δt_k (step S45). Here, the description of the processing within any of the merged areas SA1 through SA5 is based on the assumption that each of the merged areas SA1 through SA5 is referred to as the merged area SAm (where m is an integer greater than or equal to 1 and less than or equal to 5).

[0109] The abnormality detection and determination unit 113 compares the time change rates of the antenna currents of the areas included in the merged area SAm, and calculates the time change rate difference ΔSA_m,k(t) of the antenna currents of the merged area SAm at time t and time interval Δt_k by using Formula 2. In addition, n represents the number of the area included in the merged area SAm. In addition, max(ΔCT_n,k(t)) represents the maximum value (maximum value) of the time change rates ΔCT_n,k(t) of the areas included in the merged area SAm. min(ΔCT_n,k(t)) represents the minimum value (minimum value) of the time change rates ΔCT_n,k(t) of the areas included in the merged area SAm. In addition, n of max(ΔCT_n,k(t)) and n of min(ΔCT_n,k(t)) represent different area numbers. For convenience, the same n is used here to represent them, and they are set to correspond to the number of the area with the maximum value and the number of the area with the minimum value, respectively.

[0110] ΔSA_m,k(t)=max(ΔCT_n,k(t))-min(ΔCT_n,k(t))…(Formula 2)

[0111] Through the process of step S40 , the abnormality detection and determination unit 113 obtains M (here, 5) time-varying rate differences ΔSA_m,k(t) of the antenna currents at every time interval Δt_k.

[0112] Furthermore, step S45 is an example of a process of calculating the difference between the maximum and minimum evaluation values of the antenna coils (antenna segments 121 ) arranged in each region included in each of the plurality of integrated regions and detecting an abnormality based on the difference.

[0113] Then, the abnormality detection and determination unit 113 determines whether all of the time change rate differences ΔSA_m,k(t) of the M antenna currents are smaller than a threshold value (step S50). The threshold value is a predetermined reference difference value (reference difference value).

[0114] If all of the M antenna current time change rate differences ΔSA_m,k(t) are smaller than the threshold value (Yes in step S50 ), the abnormality detection and determination unit 113 determines that the current is normal. The abnormality detection and determination unit 113 then determines whether to terminate the process (step S60 ).

[0115] If the process is not to be terminated, that is, if the process is to be continued (No in step S60), the process returns to step S30 and the process is repeated. If the process is to be terminated (Yes in step S60), the process is terminated.

[0116] If at least one of the M antenna current time rate of change differences ΔSA_m,k(t) is not less than a threshold value, that is, if it exceeds the threshold value ("No" in step S50), the abnormality detection and determination unit 113 considers a possible abnormality and determines it as a tentative abnormality. The abnormality detection and determination unit 113 counts the number of tentative abnormality determinations. Then, the abnormality detection and determination unit 113 determines whether the number of tentative abnormality determinations is greater than a set number (step S70).

[0117] If the number of assumed abnormalities (number of times exceeding the reference difference (number of times exceeding)) is determined to be greater than the set number (reference number) ("Yes" in step S70), the abnormality detection and determination unit 113 detects the occurrence of an abnormality (step S80). The plasma generation processing unit 112 then deems the occurrence of an abnormality and stops the supply of high-frequency power from the high-frequency power supply 15 to the high-frequency antenna 120. The main control unit 111 then causes the inductively coupled plasma processing apparatus 100 to stop abnormally (step S90).

[0118] In addition, step S90 is an example of a process of stopping the high-frequency power supply.

[0119] If it is determined that the number of assumed abnormalities is not equal to or greater than the set number (No in step S70), the abnormality detection determination unit 113 returns to step S30 and continues the measurement. The above-described process is performed for each of K time intervals.

[0120] Figure 8 Indicates an example of specific processing. Figure 8 1 is a diagram illustrating the process of the inductively coupled plasma processing apparatus 100 according to this embodiment. Figure 8 In the following, the processing in the merge area SA5 is described. Figure 8 In the example, a time interval Δt is described. In addition, Figure 8 The waveforms are simulated for illustration purposes.

[0121] Figure 8 The horizontal axis represents time. Figure 8 The vertical axis represents the value equivalent to the current value. Figure 8 Graph Frf represents the current value supplied from high-frequency power supply 15. Graphs F1, F2, F3, and F4 represent the current measurement values in regions A15, A16, A17, and A18, respectively. Graph Fv represents the time-dependent rate of change of the antenna current. Fth represents the threshold value of the difference (reference difference). The reference number of times, or threshold value, is set to five.

[0122] The current value at time T2 in area A15 shown in graph F1 fluctuates relative to the current value at time T1. Meanwhile, graphs F2, F3, and F4 at time T2 remain unchanged relative to time T1. Because the current value changes in area A15, the difference in the time rate of change of the antenna current, graph Fv, increases at time T2 relative to time T1. However, at time T2, it is less than the threshold, graph Fth, and therefore not detected as an abnormality.

[0123] At time T4, the graph Fv is larger than the graph Fth, so a tentative abnormality is determined. However, since the number of times is only one, compared to the threshold value of five (the reference number of times), processing continues. Furthermore, the numbers shown in the graph indicate the number of times the reference difference value has been exceeded (the number of times exceeded).

[0124] Similarly, tentative abnormalities are detected at time T5, time T8, time T11, and time T12. At time T12, the number of times reaches five, which is the reference number. Therefore, after determining that the reference number has been reached at time T12, the current supplied from the high-frequency power supply 15 is stopped.

[0125] Specifically, the results of operating the inductively coupled plasma processing apparatus 100 will be described. Figure 9 FIG. 1 is a diagram showing an example of a process when operating the inductively coupled plasma processing apparatus 100 according to the present embodiment.

[0126] Figure 9 (a) shows a time waveform of a current value measured in the inductively coupled plasma processing apparatus 100 . Figure 9 The horizontal axis of (a) represents time. Figure 9 The vertical axis of (a) represents the current value. Figure 9 The graph Grf of (a) shows the current value supplied from the high-frequency power supply 15. The graph G shows the current measurement values of the areas A15, A16, A17, and A18, respectively.

[0127] Figure 9 (b) shows the time rate of change difference calculated in the inductively coupled plasma processing apparatus 100 . Figure 9 The horizontal axis of (b) represents time. Figure 9 (b) The horizontal axis of time and Figure 9 The time on the horizontal axis of (a) is consistent. Figure 9 The vertical axis of (b) represents the time change rate difference. Figure 9 The graph Gv in (b) represents the time rate of change difference of the antenna current, and Gth represents a threshold value.

[0128] exist Figure 9In (b), an abnormality is detected at a point indicated by P. Then, when the abnormality is detected five times, the current supplied from the high-frequency power supply 15 is stopped.

[0129] <Other Implementations>

[0130] In the above embodiment, the following example is shown: the loop antennas in any of the outer area, the middle area, and the inner area are formed by Figure 3 The antenna segment 121 shown as an example in FIG. 1 is formed by a longitudinally wound antenna coil. In contrast, as another embodiment, only the outer loop antenna in the outer region may be formed by an antenna segment formed by a longitudinally wound antenna coil. In this case, for example, the middle region and the inner region may be configured with Figure 10 The helical antenna 160 shown here constitutes a loop antenna. Figure 10 The helical antenna 160 is formed by winding four antenna wires 16 at 90° intervals, but is not limited to this. For example, two antenna wires may be wound at 180° intervals, or a single antenna wire may be wound, so long as the overall configuration is helical. In this other embodiment, abnormality detection is performed on an antenna segment basis in the outer region, while abnormalities are detected on the helical antenna itself in the middle and inner regions. When abnormality detection is performed only in the outer region, the device structure becomes simpler, thus reducing costs. Therefore, this embodiment is advantageous when abnormality detection is sufficient only at the outer edge of the plasma. Alternatively, a configuration may be employed in which antenna segments with longitudinally wound antenna coils are used in the outer and middle regions, while the helical antenna 160 is positioned in the inner region. Alternatively, a configuration may be employed in which the helical antenna 160 is positioned in the outer region, and antenna segments with longitudinally wound antenna coils are positioned in either the middle or inner region, or both. In other words, a configuration is possible in which abnormality detection is performed specifically in the portion of the plasma to be monitored.

[0131] While embodiments of the abnormality detection method and inductively coupled plasma processing apparatus disclosed herein have been described above, the present disclosure is not limited to the aforementioned embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. Such changes are naturally within the technical scope of the present disclosure.

[0132] Description of Reference Numerals

[0133] 1a: Ground wire; 2: Dielectric wall (dielectric window); 3: Antenna chamber; 3a: Side wall; 4: Processing chamber; 4a: Side wall; 5: Support frame; 11: Spray housing; 12: Gas flow path; 14: Matching element; 15: High-frequency power supply; 17: Isolator; 19: Power supply line; 20: Processing gas supply system; 23: Loading table; 24: Insulator frame; 29: High-frequency power supply; 30: Exhaust device; 31: Exhaust pipe; 41: He gas flow path; 50: Antenna unit; 51: Power supply unit; 100: Inductively coupled plasma processing apparatus; 101: User interface; 110: Control device; 111: Main control unit; 112: Plasma generation processing unit; 113: Abnormality detection and determination unit; 115: Memory; 120: Radio frequency (RF) Frequency) antenna; 121: Antenna segment; 131: Amperemeter; 132: Intake unit; 150: Antenna circuit; 500: Substrate processing system; 510: Load interlock chamber; 520: Transfer device; 521: Transfer mechanism; 530, 530A, 530B, 530C, 530D, 530E: Process chambers; A1~A18: Areas; G: Substrate; SA, SA1, SA2, SA3, SA4, SA5: Merged areas.

Claims

1. A method for detecting abnormality in a plasma processing device, The plasma processing apparatus includes a plurality of antenna coils arranged along a virtual rectangular plane corresponding to a rectangular planar window member, the window member facing a mounting surface of a mounting table on which a substrate is mounted within a processing chamber for processing a substrate, and dividing the interior of the processing chamber into an upper portion and a lower portion. One end of each of the plurality of antenna coils is connected to a high-frequency power supply, and the other end is connected to a ground potential via an ammeter. At least a portion of the virtual rectangular plane is divided into a plurality of regions in which any one of the plurality of antenna coils is respectively arranged. The virtual rectangular plane has a portion divided into a plurality of merged regions, each of the merged regions being a combination of the regions arranged at symmetrical positions in the virtual rectangular plane. The abnormality detection method of the plasma processing device includes the following steps: measuring, by the ammeter, a change in a current of each of the plurality of antenna coils over time; calculating, for each of the plurality of antenna coils, an evaluation value based on a change in the current over time; as well as A difference between a maximum value and a minimum value of the evaluation values of the antenna coils arranged in each of the regions included in each of the plurality of integrated regions is calculated, and an abnormality is detected based on the difference.

2. The abnormality detection method for a plasma processing device according to claim 1, wherein: The virtual rectangular plane is divided into a plurality of concentric rectangular areas, and the plurality of merged areas are divided at least from outermost areas of the plurality of concentric rectangular areas.

3. The abnormality detection method for a plasma processing device according to claim 2, wherein: The plurality of merged areas are divided from all of the plurality of concentric rectangular areas.

4. The abnormality detection method for a plasma processing apparatus according to any one of claims 1 to 3, wherein: The method further includes comparing the difference with a predetermined reference difference value, and stopping the high-frequency power supply when the difference exceeds the reference difference value during the temporal change.

5. The abnormality detection method for a plasma processing device according to claim 4, wherein: In the step of stopping the high frequency power supply, the number of times the difference exceeds the reference difference value during the temporal change is counted, and the high frequency power supply is stopped when the number of times reaches a predetermined reference number.

6. The abnormality detection method for a plasma processing apparatus according to any one of claims 1 to 3, wherein: The symmetry is symmetry about at least any one of the face center of the virtual rectangular plane, the first symmetry axis passing through the face center and orthogonal to the short side of the virtual rectangular plane, the second symmetry axis passing through the face center and orthogonal to the long side of the virtual rectangular plane, and the diagonal of the virtual rectangular plane.

7. The abnormality detection method for a plasma processing apparatus according to any one of claims 1 to 3, wherein: The evaluation value is a current change rate obtained by dividing the change between the first current value and the second current value in the temporal change process of the current by the first current value or the second current value.

8. The abnormality detection method for a plasma processing device according to claim 7, wherein: The first current value and the second current value are values of the current measured at time points separated by a predetermined time.

9. The abnormality detection method for a plasma processing apparatus according to any one of claims 1 to 3, wherein: In the step of calculating the evaluation value, a plurality of evaluation values based on temporal changes of the current at a plurality of different time intervals are calculated. 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 the calculated plurality of differences.

10. A plasma processing apparatus comprising: a mounting table for mounting the substrate inside a processing chamber for processing the substrate; a rectangular planar window member facing the mounting 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 arranged along a virtual rectangular plane corresponding to the window member; and The control unit detects abnormalities, in, One end of each of the plurality of antenna coils is connected to a high-frequency power supply, and the other end is connected to a ground potential via an ammeter. At least a portion of the virtual rectangular plane is divided into a plurality of regions in which any one of the plurality of antenna coils is respectively arranged. The virtual rectangular plane has a portion divided into a plurality of merged regions, each of the merged regions being a combination of the regions arranged at symmetrical positions in the virtual rectangular plane. The control unit detects an abnormality based on a current value measured by the ammeter for the antenna coil disposed in each of the regions included in each of the plurality of integrated regions.

11. The plasma processing apparatus according to claim 10, wherein: The virtual rectangular plane is divided into a plurality of concentric rectangular areas, and the plurality of merged areas are divided at least from outermost areas of the plurality of concentric rectangular areas.

12. The plasma processing apparatus according to claim 11, wherein: The plurality of merged areas are divided from all of the plurality of concentric rectangular areas.

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