Plasma processing apparatus, method of operating plasma processing apparatus, inspection apparatus, and inspection method

Abstract

The present application aims to provide a technique for evaluating the state of a member for a plasma processing apparatus in a non-destructive and non-contact manner and showing the evaluation result to a user of the plasma processing apparatus. A plasma processing apparatus of the present application has a member having a coating film containing Y and O provided on a surface thereof in a processing chamber in which a wafer is processed using plasma, and has a control unit that notifies that damage or consumption of the coating film has reached a certain value or the lifetime of the member when a value of an absorption intensity of infrared rays of a prescribed wavelength detected from the surface of the coating film of the member becomes a minimum.

Description

Technical Field

[0001] The present invention relates to a plasma processing apparatus, a method for operating the plasma processing apparatus, an inspection apparatus, and an inspection method for forming plasma in a processing chamber inside a vacuum container and processing a sample of a processing object such as a semiconductor wafer disposed in the processing chamber. Background Technology

[0002] In the process of manufacturing electronic devices and magnetic storage devices by processing semiconductor wafers (hereinafter also referred to as "wafers"), plasma etching (hereinafter also referred to as "plasma etching") is used in the fine processing to form circuit structures on the surface of the wafer. Such plasma etching-based processing requires increasingly higher precision and yield as devices become more integrated.

[0003] The inner wall of the plasma processing apparatus used for plasma etching is exposed to high-frequency plasma and etching gas during the etching process, thus forming a protective film with excellent plasma resistance on the inner wall surface. Prior art related to materials for such plasma-resistant films includes the following techniques.

[0004] Patent Document 1 discloses the following: the material constituting the surface of the grounding portion arranged inside the plasma etching apparatus contains a Group IIIA element (with at least one selected from Sm, Eu, Gd, Tb, Dy, Ho, Er, Y, Tm, Yb, and Lu as the main component) and fluorine, and contains a Group IIIA fluoride phase, wherein the fluoride phase is orthorhombic and contains more than 50% of the crystalline phase belonging to the space group Pnma. Specifically, Patent Document 1 discloses the following as an invention for forming a fluoride film, a coated component, and a method for forming a fluoride film. "A fluoride film containing group IIIA elements is a film containing at least group IIIA elements and fluorine, wherein the film contains a group IIIA fluoride phase, and the fluoride phase is orthorhombic, containing more than 50% of a crystalline phase belonging to space group Pnma. According to the present invention, for the purpose of imparting corrosion resistance to components exposed to an atmosphere containing corrosive halogen species, by controlling the state of the crystalline phase in the group IIIA fluoride film on its surface, color changes caused by corrosion can be suppressed. By containing a crystalline phase in the group IIIA fluoride film in this way, corrosion resistance can be improved. Furthermore, by making the crystalline phase orthorhombic, which is essentially a single phase, color changes of the film can also be suppressed. In addition, by making the hardness of the film Hv100 or higher based on the micro-Vickers hardness method, the amount of film wear can be reduced and suppressed."

[0005] Patent Document 2 describes a film made of one or more materials selected from Al2O3, YAG, Y2O3, Gd2O3, Yb2O3, or YF3, disposed on the surface of the grounding portion inside a plasma etching apparatus. Patent Document 3 describes a film made of materials selected from Y3Al5O3. 12 , Y4Al2O9, Er2O3, Gd2O3, Y2O3, Er3Al5O 12 Gd3Al5O 12 Materials such as YF3 or Nd2O3, Y4Al2O9, and Y2O3-ZrO2 solid solutions constitute a film on the surface of the grounding portion disposed inside the plasma etching apparatus. Specifically, Patent Document 2, with the subject matter of "providing an etching processing apparatus that suppresses the generation of foreign matter and improves the yield of the process," discloses the following as an invention of an etching processing apparatus and a component for an etching processing chamber: "An etching processing apparatus that uses plasma to etch a sample disposed in a processing chamber disposed inside a vacuum container, wherein the etching processing apparatus includes: a component disposed inside the processing chamber; and a coating formed by spraying a prescribed material, covering the surface of the component and facing the plasma, the surface of the coating being sealed with the same material as the material." Furthermore, Patent Document 3, as an invention for strengthening a plasma-sprayed coating using plasma flame heat treatment, discloses the following. "A method for forming a plasma-resistant ceramic coating on an article includes a step of arranging the article within a chamber or a plating unit of a plasma plating system. Then, ceramic powder is supplied to the plasma plating system at a given powder supply rate, and the plasma-resistant ceramic coating is deposited on at least one surface of the article within the plasma plating process. Subsequently, the plasma plating system performs in-situ plasma flame heat treatment of the plasma-resistant ceramic coating to form a crust on the coating."

[0006] Patent Document 4 describes that the material of the film on the surface of the grounding part of the plasma etching device includes yttrium fluoride and yttrium fluoride oxide. Patent Document 4 discloses the following invention as a plasma processing apparatus and plasma processing method, with the subject matter of "suppressing the generation of fine particles in a plasma process that introduces a gas containing halogen gas and oxygen". "A plasma processing apparatus 10 is provided, comprising: a processing container 12 capable of depressurization; a lower electrode that also serves as a stage 20 for mounting a wafer W in the processing container; an upper electrode or an antenna electrode arranged opposite to the lower electrode; a gas supply source 32 for introducing a gas containing halogen gas and oxygen into the processing container; a high-frequency power source 18 for applying high-frequency power for plasma generation to at least one of the upper electrode, antenna electrode, and lower electrode; and a unit for plasma processing of the wafer on the stage by plasma generation using the high-frequency power for plasma generation, wherein a portion or all of the surface of the processing container exposed to plasma, at least at a height above the wafer mounting position relative to the upper electrode side, antenna electrode side, or lower electrode side, is covered with fluoride."

[0007] Patent documents 5, 6, and 7 describe a film material for a grounding portion disposed inside a plasma etching apparatus, which is formed by aerosol deposition of yttrium oxide, yttrium fluoride, and yttrium fluoride with an average crystallite size of less than 100 nm. Aerosol deposition is also known to reduce surface unevenness compared to the aforementioned atmospheric pressure plasma spraying method. Specifically, Patent document 5, with the subject matter of "providing a plasma-resistant component that can improve the adhesion strength or adhesion force of a coating covering the inner wall of a chamber, or that can reduce particle size," discloses the following invention as a plasma-resistant component: "A plasma-resistant component is provided, comprising a substrate and a layered structure formed on the surface of the substrate, containing yttrium oxide polycrystals and having plasma resistance, the layered structure having a first uneven structure and a second uneven structure, the second uneven structure being formed by overlapping the first uneven structure and having finer unevenness than the first uneven structure." Furthermore, Patent Document 6, with the subject matter of "Providing a plasma-resistant component capable of reducing particle size and stably maintaining chamber conditions," discloses the following as an invention concerning a plasma-resistant component and its manufacturing method: "A plasma-resistant component is provided, comprising a substrate and a layered structure containing yttrium oxide polycrystals and possessing plasma resistance, formed on the surface of the substrate by an aerosol deposition method. The yttrium oxide polycrystals constituting the layered structure have a crystal structure in which cubic and monoclinic crystals coexist. The proportion of monoclinic crystals to cubic crystals in the yttrium oxide polycrystals constituting the layered structure is 0% or more and 60% or less, and the crystallite size of the yttrium oxide polycrystals constituting the layered structure is 8 nm or more and 50 nm or less." Additionally, Patent Document 7, with the subject matter of "Providing a structure capable of improving plasma resistance," discloses the following as an invention concerning a structure. "A structure is provided which is mainly composed of a polycrystalline form of yttrium oxyfluoride with an orthorhombic crystal structure, wherein the average crystallite size in the polycrystalline form is less than 100 nanometers, wherein when the peak intensity detected by X-ray diffraction near a diffraction angle of 2θ = 32.0° is defined as γ and the peak intensity detected near a diffraction angle of 2θ = 32.8° is defined as δ, the peak intensity ratio γ / δ is greater than 0% and less than 150%."

[0008] On the other hand, Non-Patent Document 1 discloses that increasing the average crystallite size leads to more foreign matter generation.

[0009] Patent Document 9 discloses a range of values ​​for a specific mixing ratio of yttrium fluoride granulated powder to yttrium oxide granulated powder as a spraying material capable of obtaining a yttrium-based fluoride spray coating that exhibits sufficient corrosion resistance to plasma and effectively prevents damage to the base material due to acid penetration during acid cleaning. Furthermore, Patent Document 10 discloses a process for manufacturing a yttrium fluoride spray coating capable of suppressing particle generation, in which a slurry containing yttrium fluoride particles with a specific range of average particle size is supplied to a position downstream of the nozzle of a spraying gun that emits a flame in a high-speed flame spraying method or to the tip of the nozzle of a spraying gun that emits a plasma jet in an atmospheric pressure plasma spraying method, along the central axis of the nozzle of the spraying gun. Specifically, Patent Document 9 discloses the following as an invention for a yttrium-based fluoride spray coating and a corrosion-resistant coating comprising the spray coating. "A yttrium-based fluoride sprayed film, wherein the film has a thickness of 10-500 μm and is formed on the surface of a substrate, with an oxygen concentration of 1-6% by mass and a hardness of 350 HV or higher. It exhibits excellent corrosion resistance in halogen-based gas atmospheres or halogen-based gas plasma atmospheres, and can effectively prevent substrate damage caused by acid penetration during acid cleaning, and can minimize the generation of particles caused by reaction products and granulation from the film."

[0010] Patent Document 11 discloses the following: A spray-coated film, formed within a plasma etching apparatus for components, parts, etc., is deposited using a suspension plasma spraying (SPS, also known as suspended plasma spraying or suspension liquid plasma spraying) method. This method uses rare-earth aluminum monoclinic crystal (R4Al2O9), where a portion of the Al atom sites are replaced by rare-earth (R) atoms, as a raw material. The film is sprayed in the form of a slurry dispersed in a dispersion solvent. Specifically, Patent Document 11 discloses the following invention as a spray-coating material, its manufacturing method, and a method for forming a spray-coated film. "A spray-coated film comprising a crystalline phase of a composite oxide containing rare earth elements (R), aluminum, and oxygen, wherein the crystalline phase of the composite oxide containing rare earth elements and aluminum comprises a composition in which a portion of the sites of Al atoms in rare earth-aluminum-monoclinic crystal (R4Al2O9) are replaced by rare earth elements (R) atoms, resulting in a composition richer in rare earth elements than the stoichiometric composition of rare earth-aluminum-monoclinic crystal (R4Al2O9). The film exhibits low particle content due to the reaction with halogen-based gas plasma, enabling the formation of a highly corrosion-resistant spray-coated film with excellent plasma etching resistance. Such a spray-coated film is excellent for forming on components and parts within plasma etching apparatus used in semiconductor manufacturing processes."

[0011] Existing technical documents

[0012] Patent documents

[0013] Patent Document 1: Japanese Patent Application Publication No. 2004-197181

[0014] Patent Document 2: Japanese Patent Application Publication No. 2009-176787

[0015] Patent Document 3: Japanese Patent Publication No. 2016-539250

[0016] Patent Document 4: Japanese Patent Application Publication No. 2013-140950

[0017] Patent Document 5: Japanese Patent Application Publication No. 2014-141390

[0018] Patent Document 6: Japanese Patent Application Publication No. 2016-27624

[0019] Patent Document 7: Japanese Patent Application Publication No. 2018-82154

[0020] Patent Document 9: Japanese Patent Application Publication No. 2017-190475

[0021] Patent Document 10: Japanese Patent Application Publication No. 2017-150085

[0022] Patent Document 11: Japanese Patent Application Publication No. 2020-172702

[0023] Non-patent literature

[0024] Non-Patent Literature 1: Kazuhiro Ueda, Kazuyuki Ikenaga, Tomoyuki Tamura, Hiroshi Kakuya, "Study on Crystal Structure and Foreign Matter Generation Mechanism of Yttrium-Based Materials for Plasma Etching Apparatus", Japan Society for Analytical Chemistry X-ray Analysis Research Symposium (Editor), Advances in X-ray Analysis 50, Agine Technology Center, Issued: April 1, 2019, pp. 197-205 Summary of the Invention

[0025] The problem that the invention aims to solve

[0026] When plasma processing devices are used for extended periods, the surface of the inner wall material is exposed to plasmas containing N, O, F, H, Cl, and Br. Due to collisions with low-velocity ions, the surface of the inner wall material becomes amorphous, or it is sputtered, and atoms of the sputtered material re-attach to the surface. The surface of the inner wall material corrodes due to plasma reactions, leading to degradation of the plasma-resistant coating and sometimes becoming a source of foreign matter. Even if the average crystallite size of the inner wall material is reduced, large crystals may remain on the surface due to the removal of microcrystals through plasma reactions, thus sometimes making the inner wall material surface a source of foreign matter.

[0027] Furthermore, in the case of grounding components installed in plasma processing equipment, it is impossible to evaluate the surface degradation of the grounding component in a non-destructive and non-contact manner. Therefore, in order to suppress the generation of foreign matter, it is necessary to replace the grounding component after a certain operating time. However, the situation of generating a large amount of foreign matter before replacement is not fully considered, and if the degradation of the grounding component after replacement is evaluated, it is determined that there is still excess material before the generation of foreign matter. The degradation condition varies depending on the quality of the component when it is new and the operating conditions.

[0028] Therefore, the object of the present invention is to provide a technique for evaluating the condition of components used in a plasma processing apparatus in a non-destructive and non-contact manner and to display the evaluation results to the user of the plasma processing apparatus.

[0029] Methods for solving problems

[0030] To address the aforementioned issues, one representative plasma processing apparatus of the present invention is a plasma processing apparatus that includes a component having a coating containing Y and O on its surface within a processing chamber for processing a wafer using plasma. This plasma processing apparatus includes a control unit that, when the absorption intensity of infrared light of a predetermined wavelength detected from the surface of the coating of the component becomes extremely low, notifies that damage or consumption of the coating has reached a certain value, or the lifespan of the component.

[0031] Invention Effects

[0032] According to the present invention, the condition of components used in plasma processing apparatus can be evaluated in a non-destructive and non-contact manner, and the evaluation results can be shown to the user of the plasma processing apparatus.

[0033] Other issues, structures, and effects not described above become clear through the following detailed descriptions. Attached Figure Description

[0034] Figure 1 This is a longitudinal sectional view schematically illustrating the structure of the plasma processing apparatus of Embodiment 1 of the present invention.

[0035] Figure 2 This is a longitudinal sectional view showing the outline of the plasma processing device during vacuum release.

[0036] Figure 3 This is a diagram showing an example of the spectrum representing the measured absorption intensity of infrared radiation.

[0037] Figure 4 This is an enlarged representation of 1300cm. -1 Up to 1800cm -1 A diagram of the wavenumber region.

[0038] Figure 5 This indicates from 1300cm -1 Up to 1800cm -1 The image shows the result obtained by interpolating the background based on the difference in the absorption intensity of infrared radiation in the wavenumber region.

[0039] Figure 6 This is a graph summarizing the infrared absorption intensity of YO binding in samples from different manufacturers and under different plasma treatment conditions.

[0040] Figure 7 It means to Figure 5 A diagram illustrating the application of clustering.

[0041] Figure 8 This is a graph showing the relationship between the peak value of infrared absorption intensity and the standardized lifetime of past data.

[0042] Figure 9 This means at 1300cm -1 Up to 1800cm -1 A graph showing the correlation between the peak value of infrared absorption intensity and normalized lifetime for wavenumber region clustering.

[0043] Figure 10 This means at 1300cm -1 Up to 1800cm -1 A graph showing the correlation between the peak value of infrared absorption intensity and normalized lifetime for wavenumber region clustering.

[0044] Figure 11 It is a diagram showing the line profile of the cross-section of the coating, STEM-EDX.

[0045] Figure 12 This is a diagram representing a STEM image of the coating.

[0046] Figure 13 This is an example diagram representing a model of a coating.

[0047] Figure 14This is a diagram illustrating an example of the structure of the control unit of a plasma processing device.

[0048] Figure 15 It is a flowchart illustrating the operation method of a plasma processing device.

[0049] Figure 16 This is a longitudinal sectional view showing the outline of the structure of the plasma processing apparatus of Embodiment 2 of the present invention.

[0050] Figure 17 This is a schematic diagram illustrating the situation where the vacuum in the processing chamber of the plasma processing device is broken, and the grounding electrode is removed to measure the absorption intensity of infrared radiation. Detailed Implementation

[0051] (Example 1)

[0052] (Structure of the plasma processing device)

[0053] use Figures 1 to 6 Embodiment 1 of the present invention will be described.

[0054] Figure 1 This is a schematic longitudinal sectional view illustrating the general structure of the plasma processing apparatus 100 according to Embodiment 1 of the present invention. The plasma processing apparatus 100 includes a component (ground electrode 22) with a coating containing Y and O on its surface within a processing chamber 5 that processes the wafer 3 using plasma 13. Detailed description follows.

[0055] The plasma processing apparatus 100 of Embodiment 1 includes: a vacuum container having a cylindrical portion; a plasma forming section disposed above or around the cylindrical portion surrounding the vacuum container; and a vacuum exhaust section disposed below the vacuum container and including a vacuum pump for venting the interior of the vacuum container. A processing chamber 5, serving as a space for plasma formation, is disposed inside the vacuum container and configured to communicate with the vacuum exhaust section.

[0056] The upper part of the processing chamber 5 is a space surrounded by a cylindrical inner wall, which constitutes the discharge chamber for forming plasma 13.

[0057] Inside the processing chamber 5 below the discharge chamber that generates plasma 13, there is a stage 4 that serves as a sample stage, on which a wafer 3, which is the substrate to be processed, is placed and held on its upper surface.

[0058] The stage 4 in Embodiment 1 is a cylindrical component. Its vertical central axis is positioned concentrically or approximately concentrically with the discharge chamber when viewed from above. A space is formed between the bottom surface of the processing chamber 5, which has an opening communicating with the vacuum exhaust section, and the lower surface of the stage 4. The stage 4 is positioned midway between the upper and lower end surfaces of the processing chamber 5 in the vertical direction. The space inside the processing chamber 5 below the stage 4 communicates with the discharge chamber through the gap between the side wall of the stage 4 and the cylindrical inner wall of the processing chamber 5 surrounding it. This forms the exhaust path for the products generated on the upper surface of the wafer 3 and in the discharge chamber during the processing of the wafer 3 above the upper surface of the stage 4, as well as the plasma and gas particles in the discharge chamber, to pass through and be discharged to the outside of the processing chamber 5 via the vacuum exhaust section.

[0059] The stage 4 in Embodiment 1 is equipped with: a heater (not shown), which includes a substrate as a cylindrical metal component, and a dielectric film disposed inside the substrate covering its upper surface; and a refrigerant flow path (not shown), which is arranged concentrically or spirally multiple times inside the substrate around the central axis. Furthermore, with the wafer 3 placed on the upper surface of the dielectric film on the stage 4, a heat-conducting gas such as He is supplied to the gap between the lower surface of the wafer 3 and the upper surface of the dielectric film. Therefore, piping (not shown) for the flow of the heat-conducting gas is disposed inside the substrate and the dielectric film.

[0060] Furthermore, the substrate of the stage 4 is connected to a high-frequency power supply 12 via an impedance matching device 11 and a coaxial cable. This high-frequency power supply 12 is supplied with high-frequency electricity to generate an electric field during plasma processing of the wafer 3. This electric field is used to induce charged particles in the plasma above the upper surface of the wafer 3. Additionally, a film-shaped electrode is disposed above a heater within a dielectric film above the substrate. This film-shaped electrode is supplied with direct current to generate electrostatic forces within the dielectric film and the wafer 3. These electrostatic forces are used to attract and hold the wafer 3 to the upper surface of the dielectric film. The film-shaped electrodes are arranged radially symmetrically around a central axis in each of multiple regions from the vertical direction of the generally circular upper surface of the wafer 3 or the stage 4, thus enabling the assignment of different polarities to each region.

[0061] Above the upper surface of the stage 4 in the processing chamber 5, there is a window member 2. This window member 2 is arranged opposite to the stage 4 and forms the upper part of the vacuum container, sealing the inside and outside of the processing chamber 5 airtightly. It has a circular plate shape made of dielectric materials such as quartz or ceramic. Furthermore, below the window member 2 and at the position that forms the top surface of the processing chamber 5, there is a cluster plate 1 made of dielectric materials such as quartz with a circular plate shape. The cluster plate 1 is arranged with a gap 6 between it and the lower surface of the window member 2, and has a plurality of through holes 7 in the center.

[0062] Gap 6 is connected to the vacuum container in communication with the processing gas supply pipe 25. A valve 26 is provided at a designated location on the processing gas supply pipe 25 to open or close the interior. The processing gas (processing gas) supplied to the processing chamber 5 has its flow rate or speed regulated by a gas flow control unit (not shown) connected to one end of the processing gas supply pipe 25. After flowing into gap 6 through the processing gas supply pipe 25 opened by valve 26, it diffuses inside gap 6 and is supplied to the processing chamber 5 from above through the through hole 7.

[0063] Below the vacuum container, directly below the stage 4 on the bottom surface of the processing chamber 5, is a vacuum exhaust section. This vacuum exhaust section discharges the gas and particles inside the processing chamber 5 through an exhaust port, which is an exhaust opening arranged so that its central axis is approximately the same in the vertical direction. The vacuum exhaust section includes a circular plate-shaped valve, i.e., a pressure regulating plate 14, which moves up and down above the exhaust port to increase or decrease the area of ​​the flow path for gas to flow into the exhaust port, and a turbomolecular pump 10, which serves as a vacuum pump. Furthermore, in the vacuum exhaust section, the outlet of the turbomolecular pump 10 is connected to a dry pump 9, which serves as a roughing pump, via an exhaust pipe, and a valve 16 is provided on the exhaust pipe.

[0064] The pressure regulating plate 14 in Embodiment 1 also functions as a valve for opening and closing the exhaust port. The vacuum container is equipped with a sensor, namely a pressure detector 27, for detecting the pressure inside the processing chamber 5. The signal output from the pressure detector 27 is sent to a control unit (not shown) to detect the pressure value. Based on this value, and according to the command signal output from the control unit, the pressure regulating plate 14 is driven to change its position in the vertical direction, thereby increasing or decreasing the area of ​​the exhaust flow path. The control unit will be described later. Of the valves 15 and 17 connected to the exhaust pipe 8, valve 17 is a slow exhaust valve for slowly exhausting the processing chamber 5 from atmospheric pressure to vacuum using a dry pump 9, and valve 15 is a main exhaust valve for high-speed exhaust using a dry pump 9.

[0065] Above the cylindrical portion of the upper part of the vacuum container constituting the processing chamber 5 and around the surrounding sidewalls, a structure is arranged to generate an electric or magnetic field supplied to the processing chamber 5 for plasma generation. Specifically, above the window member 2, a waveguide 19 is arranged to allow the electric field of microwaves supplied to the interior of the processing chamber 5 to propagate inwards, with a magnetron oscillator 18 at one end to oscillate and output the electric field of the microwaves. The waveguide 19 comprises: a square waveguide section having a rectangular longitudinal section and its axis extending horizontally, with the magnetron oscillator 18 at one end; and a circular waveguide section connected to the other end of the square waveguide section, with its central axis extending vertically and its cross-section circular. The lower end of the circular waveguide section has a large-diameter cylindrical shape, and a cavity is arranged inside to enhance the electric field of a specific mode. A multi-stage solenoid coil 20 and a solenoid coil 21, serving as magnetic field generating units, are arranged around the cavity and its surrounding area, and further around the sides of the processing chamber 5.

[0066] In this plasma processing apparatus 100, an unprocessed wafer 3, placed in a transport chamber inside a vacuum container (not shown) connected to the side wall of a vacuum container, is transported to a processing chamber 5 by the leading end of the arm of a vacuum transport device (not shown), such as a robotic arm, disposed within the transport chamber. The wafer is then transferred to a stage 4 and placed on its upper surface. When the arm of the vacuum transport device withdraws from the processing chamber 5, the interior of the processing chamber 5 is sealed, and the wafer is held in place by electrostatic force generated by applying a DC voltage to electrodes used for electrostatic adsorption within the dielectric film. In this state, a heat-transferring gas, such as He, is supplied to the gap between the wafer 3 and the upper surface of the dielectric film constituting the upper surface of the stage 4 through piping disposed inside the stage 4. Additionally, a refrigerant, the temperature of which is regulated to a predetermined range by a refrigerant temperature regulator (not shown), is supplied to the internal refrigerant flow path. This promotes heat transfer between the temperature-regulated substrate and the wafer 3, adjusting the temperature of the wafer 3 to a value suitable for initiating processing.

[0067] The processing gas, with its flow rate or speed regulated by the gas flow control unit, is supplied to the processing chamber 5 through the processing gas supply pipe 25 from the gap 6 through the through hole 7. Meanwhile, the turbomolecular pump 10 exhausts gas from the exhaust port into the processing chamber 5. By balancing these two processes, the pressure inside the processing chamber 5 is regulated to a value suitable for processing. In this state, the electric field of microwaves oscillating from the magnetron oscillator 18 propagates inside the waveguide 19 and radiates into the processing chamber 5 through the window member 2 and the shower plate 1. Furthermore, the magnetic field generated by the solenoid coils 20 and 21 is supplied to the processing chamber 5. Through the interaction of this magnetic field and the electric field of the microwaves, electron cyclotron resonance (ECR) is generated, exciting the atoms or molecules of the processing gas and generating plasma 13 inside the processing chamber 5 through ionization and dissociation.

[0068] When plasma 13 is formed, high-frequency power from high-frequency power supply 12 is supplied to the substrate to form a bias potential above the upper surface of wafer 3. Charged particles such as ions in plasma 13 are induced to the upper surface of wafer 3, and etching is performed along the pattern shape of the mask layer. This etching process involves a film structure that includes a film layer of the object to be processed pre-formed on the upper surface of wafer 3 and multiple film layers of the mask layer. If the processing of the film layer of the object to be processed is detected by a detector (not shown) to have reached its end point, the supply of high-frequency power from high-frequency power supply 12 is stopped, plasma 13 is digested, and the processing is stopped.

[0069] When the control unit determines that further etching of wafer 3 is not required, high-vacuum exhaust is performed. Then, after removing static electricity and releasing the adsorption of wafer 3, the arm of the vacuum transport device enters the processing chamber 5 and transfers the processed wafer 3. As the arm retracts, wafer 3 is moved out to the vacuum transport chamber outside the processing chamber 5.

[0070] (Treatment of the inner wall surface of treatment chamber 5)

[0071] The inner wall of the processing chamber 5 is the surface facing the plasma 13 and exposed to its particles. On the other hand, in order to stabilize the potential of the plasma 13 as a dielectric, it is necessary to arrange a component facing the plasma and functioning as a grounding electrode in contact with it inside the processing chamber 5.

[0072] In the plasma processing apparatus 100 of Embodiment 1, the annular member, namely the grounding electrode 22, which covers the lower surface of the inner wall of the processing chamber 5 surrounding the discharge chamber and surrounds it above the upper surface of the stage 4, is configured to function as a grounding electrode. This grounding electrode 22 includes a base material 23 made of a conductive material and a coating 24 covering its surface. In Embodiment 1, the base material 23 of the grounding electrode is made of a metal such as a stainless steel alloy or an aluminum alloy.

[0073] Without a coating on the surface of the base material 23, the grounding electrode 22 is exposed to the plasma 13, thus becoming a source of corrosion and foreign matter that can contaminate the wafer 3. Therefore, to suppress contamination, a coating 24 made of a plasma-resistant material is provided on the surface of the base material 23 of the grounding electrode 22. By covering the base material 23 with the coating 24, the grounding electrode 22 can maintain its function as a plasma-resistant electrode and suppress damage caused by the plasma.

[0074] It should be noted that the coating 24 can also be a laminated film. In Example 1, a coating 24 is deposited and formed on the surface of the base material 23 of the grounding electrode 22 using microparticles of yttrium fluoride (YF3) and yttrium fluoride oxyfluoride (YOF) as sputtering materials by atmospheric pressure plasma sputtering. In the following description, the coating 24 is sometimes referred to as the YF inner wall material. It should be noted that the description focuses on the YF inner wall material of the grounding electrode 22, but the present invention is not limited to this case. This disclosure can be applied to components other than the grounding electrode 22 disposed in the processing chamber 5 of the plasma processing apparatus 100. Furthermore, it is not limited to the type of coating and can be applied to coatings used to protect components from the effects of plasma processing.

[0075] On the other hand, in the substrate 28, which does not serve as a grounding function, metal components such as stainless steel alloy and aluminum alloy are also used. In order to suppress corrosion, metal contamination, and foreign matter generation caused by exposure to plasma 13, the surface of the substrate 28 is also subjected to passivation treatment, spraying, physical vapor deposition (PVD), chemical vapor deposition (CVD), and other treatments to improve plasma corrosion resistance and reduce consumption.

[0076] It should be noted that, in order to reduce the aforementioned interaction between the substrate 28 and the plasma 13, a cylindrical cover (not shown) made of ceramic such as yttrium oxide or quartz can be disposed between the inner wall of the cylindrical substrate 28 and the discharge chamber. By disposing such a cover between the substrate 28 and the plasma 13, contact with highly reactive particles and collisions with charged particles within the plasma 13 can be blocked or reduced, thereby suppressing the consumption of the substrate 28.

[0077] (Evaluation of the condition)

[0078] Figure 2 This is a longitudinal sectional view showing the outline of the plasma processing apparatus 100 during vacuum release. During maintenance, nitrogen, inert gas, or atmosphere is introduced into the processing chamber 5 of the plasma processing apparatus 100 to break the vacuum. A crane (not shown) is used to lift the upper components of the processing chamber 5, becoming... Figure 2 The state is shown. At this time, without contact with the coating 24 of the grounding electrode 22, the intensity spectrum of infrared light reflected and scattered on the surface of the coating 24 is measured using a Fourier transform infrared absorption spectrometer 29. The inspection device 30 uses the measured spectrum to evaluate the state of the coating 24 of the grounding electrode 22.

[0079] Reference Figures 3 to 10 This describes the processing steps of the infrared absorption spectrum measured in the inspection device 30. Figure 3 This is a graph representing an example of the spectrum showing the measured absorption intensity of infrared radiation. In Figure 3 In the diagram, the vertical axis represents the absorption intensity (light sensitivity) of infrared radiation, and the horizontal axis represents the wavenumber of infrared radiation. Figure 3 The graph shows the infrared absorption intensity spectra of the coating on new products (chart labeled "New"), coatings used at approximately half of their predicted lifespan (chart labeled "In Use"), and coatings used to the end of their predicted lifespan (chart labeled "Deteriorated"). The transmission absorption spectrum of Y₂O₃, as registered in the Fourier Transform Infrared Spectroscopy (FT-IR) database, is shown at 2930 cm⁻¹. -1 1384cm -1 563cm -1 465cm -1 450cm -1 The absorption, in addition, the transmission absorption spectrum of YF3 at 417 cm⁻¹ -1 and 401cm -1 Absorption. In Figure 3 Middle, 2930cm -1 The absorption of OH bonds and the broad absorption range (3000~3750 cm⁻¹) -1Absorption of CH bonds (2750~3000 cm⁻¹) -1 The overlap makes it undetectable. Additionally, 700cm... -1 The following region exhibits high absorption, with a steeply sloping background, making it impossible to detect absorption peaks. At 1300 cm⁻¹... -1 Up to 1800cm -1 Infrared absorption by YO bonds exists in the wavenumber region. The infrared absorption spectrum of this wavenumber region is obtained by [analysis / analysis]. Figure 4 .

[0080] then, Figure 4 This is an enlarged representation of 1300cm. -1 Up to 1800cm -1 The graph shows the wavenumber region. In the graph, due to differences in background caused by use in different manufacturers and plasma processing chambers, a 1300cm depth is used. -1 The absorption intensity of infrared radiation and 1850cm -1 The background was interpolated using the two points of infrared absorption intensity. The results are also shown in... Figure 4 It should be noted that sometimes "1300cm" is used interchangeably with "1300cm". -1 Up to 1800cm -1 The description is recorded as "1300 to 1800 cm". -1 This also applies to other wavenumber regions.

[0081] then, Figure 5 This indicates from 1300cm -1 Up to 1800cm -1 The graph shows the results obtained by subtracting the interpolated background from the absorption intensity of infrared radiation in the wavenumber region. By subtracting from the background, the peaks contained in the absorption intensity of infrared radiation are highlighted.

[0082] then, Figure 6 This is a graph summarizing the infrared absorption intensity of YO bonds in samples from different manufacturers and under different plasma treatment conditions. Although it varies from sample to sample, it is known that there are 2 to 6 peaks. The peaks were found, and the wavenumber regions containing the peaks were classified into 6 types ((1) to (6)).

[0083] then, Figure 7 It means in Figure 5 The graph shows the peak search results based on clustering. The six vertical lines represent the locations of peaks detected within the clusters. Since the number of peaks detected by the spectrum varies, the spectra of undetected peaks are interpolated using the spectral intensity at the average wavenumber of the wavenumber regions within the clusters.

[0084] then, Figure 8This is a graph showing the relationship between the peak value of infrared absorption intensity and the standardized lifetime of past data. Figure 8 This represents the 1592 cm⁻¹ of YO bonds in samples from different manufacturers and under different plasma treatment conditions. -1 The result is plotted with the infrared absorption intensity as the vertical axis and the normalized lifetime (1 for new product and 0 for no remaining lifetime) as the horizontal axis, relative to the lifetime predicted by the new product and normalized by the remaining lifetime of the coating used. Additionally, Figure 8 The curve shown is a regression curve, which shows that the absorption intensity of infrared radiation is minimized around the standardized lifetime of 0.4. Figure 8 Also shown Figure 7 The result of the coating is shown.

[0085] Figure 9 and Figure 10 This means at 1300cm -1 Up to 1800cm -1 A graph showing the correlation between the peak value of infrared absorption intensity and normalized lifetime for wavenumber region clustering. Figure 9 (a) represents the 1355cm cluster of (1). -1 The correlation between the peak value of the absorption intensity of nearby infrared radiation and the normalized lifetime. Figure 9 (b) represents the 1437cm cluster of (2). -1 The correlation between the peak value of the absorption intensity of nearby infrared radiation and the normalized lifetime. Figure 9 (c) represents the 1536cm cluster of (3). -1 The correlation between the peak value of the absorption intensity of nearby infrared radiation and the normalized lifetime. Figure 10 (a) represents clustering (4) 1592cm -1 The correlation between the peak value of the absorption intensity of nearby infrared radiation and the normalized lifetime. Figure 10 (b) represents the 1641cm cluster of (5). -1 The correlation between the peak value of the absorption intensity of nearby infrared radiation and the normalized lifetime. Figure 10 (c) represents the 1738cm cluster of (6). -1 The correlation between the peak value of the nearby infrared absorption intensity and the normalized lifetime is shown. It can be seen that the peak value has a minimum near a normalized lifetime of 0.4 across the entire wavenumber region after clustering. The time elapsed from newness to the peak value becoming a minimum (usage time) is equivalent to 0.6 of a normalized lifetime of 1. It can be seen that if the previous usage time (0.6) is set to 1, the remaining lifetime is less than 2 / 3 of the usage time. On the other hand, there is a difference in intensity between the newness and minimum values ​​based on the peak value. The largest difference is... Figure 10 (a) 1592cm -1 Nearby peaks.

[0086] (Investigation of the mechanism of infrared absorption peak)

[0087] The degradation model of the YF inner wall material is examined based on the analytical results of the absorption intensity of YO bonds. Here, as a first approximation, it is assumed that when the number of YF bonds and the number of YO bonds on the surface of the YF inner wall material decreases, Figure 9 as well as Figure 10 The peak intensity shown on the vertical axis increases, and conversely, the absorption intensity of YO bonds decreases as the number of YF bonds increases. Figure 9 as well as Figure 10 The peak value of the vertical axis decreases.

[0088] Figure 11 This is a diagram showing the line profile of the cross-section STEM-EDX of the coating 24. The cross-section STEM-EDX represents the resolution results obtained by combining scanning transmission electron microscopy and energy dispersive X-ray spectroscopy. Figure 11 (a) is the line profile of the cross-section STEM-EDX of a new coated sample with a normalized lifetime of 1.0. In the 0.0–0.02 μm region, the O concentration increases, while the Y and F concentrations decrease due to the minor unevenness of the coated surface. The O concentration is considered to be high in the 0.02–0.038 μm region due to natural oxidation. In the 0.04–0.09 μm region, the O and F concentrations vary slightly, but are considered to be similar beyond 0.09 μm, with Y at approximately 25 at%, O at 20 at%, and F at 55 at%.

[0089] Figure 12 This is a diagram showing a STEM image of the coating 24. Figure 12 (a) is equivalent to Figure 11 STEM image of the coating 24 of the new product shown in (a), Figure 12 (a) and (1) are bright field images. Figure 12 (a) and (2) are Z-contrast images. Figure 11 The line profile of (a) is determined Figure 12 The white line portion of (a) is obtained. It shows the uneven state on the surface side of the coating 24.

[0090] Figure 13 This is an example diagram showing a model of the coating 24. The upper side of the paper shows the surface of the base material s of the coating 24, excluding the uneven parts and the naturally oxidized parts, while the lower side of the paper shows the interior of the coating 24. Figure 13 (a) will Figure 11 (a) and Figure 12The state of the base material s shown in (a) is represented by a model diagram. “YO-F3” represents the approximate ratio of the concentration of O to F when the Y contained in the base material s of the coating 24 is set to 1.

[0091] When the surface of the coating 24 is fluorinated by plasma treatment, such as Figure 9 as well as Figure 10 As shown, the absorption strength of the YO bond decreases to around 0.4 normalized lifetime. Figure 13 (b) represents the base material s near the normalized lifetime as a model diagram. It is assumed that the absorption intensity of the YO bonds decreases during the period from surface fluorination of coating 24 to approximately 3 μm. "YO 0.6 "-F5" assumes that on the surface portion of the parent material s, the F concentration increases by approximately 60%, while the O concentration decreases by approximately 40%. Here, the detection depth of FT-IR is considered to be about half the wavelength of the infrared light used in FT-IR (approximately 3 μm). This is because materials constituting the inner wall of YF, such as Y2O3, YF3, and Y5O4F7, are almost transparent to visible to infrared light, but the inner wall surface has several μm of unevenness and contains numerous voids and grain boundaries, resulting in scattering at their boundaries and making specular reflection undetectable. The penetration depth of infrared light is considered to be about the wavelength (approximately 6 μm), but considering the length of the channel escaping to the surface, it is estimated to be about half the wavelength.

[0092] Under repeated plasma treatment, the coating 24 deteriorates and becomes unsuitable for use as a grounding electrode 22. Figure 11 (b) represents the STEM-EDX profile of the sample with normalized lifetime = 0. From the surface of the coating 24 down to a depth of 0.022 μm, the O concentration is high, but beyond 0.022 μm, the O concentration gradually decreases while the F concentration increases. Conversely, the interior becomes the same elemental concentration as the virgin sample, thus the O concentration increases and the F concentration decreases within the interior.

[0093] Figure 12 (b) is equivalent to Figure 11 (b) shows a STEM image of the coating 24 with normalized lifetime = 0. Figure 12 (b)(1) is a bright field image. Figure 12 (b) and (2) are Z-contrast images. Figure 11 The line profile of (b) is determined Figure 12 It was obtained from the white line portion of (b). (Speculation and...) Figure 12 Compared to the state of the new product in (a), no unevenness appears on the surface side of the coating 24, which is a state of surface deterioration due to exposure to plasma.

[0094] Figure 13 (c) will Figure 11(b) and Figure 12 The state of the base material s shown in (b) is represented by a model diagram. That is, it is assumed that during the normalized lifetime of 0.4~0, fluorination proceeds to a region deeper than 3 μm from the inner wall surface (“YO”). 0.6 The "-F5" region is transferred to the interior. Because the fluorine supplied only through diffusion from the surface, the fluorine required for fluorination inside becomes insufficient. The fluorine in the fluorine-rich layer on the surface is replaced by oxygen inside, resulting in surface oxidation ("Y-O3-F"). 2.7 The measurement was performed in a manner that "the area where oxidation occurs is formed on the surface of the base material s".

[0095] Y₂O₃ expands in volume upon fluorination and shrinks in volume upon oxidation of YOF. That is, it is assumed that... Figure 13 The “YO 0.6 The boundaries of the "-F5" area, especially "YO" 0.6 The area of ​​"-F5" and "Y-O3-F" 2.7 Large residual stress (tensile stress in the stacking direction) is generated at the boundary of the region, which causes cracks and foreign matter caused by deterioration.

[0096] (Example of the structure of the control unit)

[0097] Figure 14 This figure shows an example of the structure of the control unit 50 of the plasma processing apparatus 100. The control unit 50 includes a memory 51, a communication device 52, an input / output device 53, and a processor 54.

[0098] The memory 51 contains a set of software programs and / or commands executed by the processor 54. The processor 54 executes the various software programs and / or command sets stored in the memory 51, performs various functions for the plasma processing apparatus 100, and processes data. The memory 51 includes non-volatile storage devices such as random access memory (RAM), disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. It should be noted that the plasma processing apparatus 100 is shown to include one memory 51 and one processor 54, but it may also include two or more. In addition, the plasma processing apparatus 100 may also include storage devices other than the memory 51.

[0099] The communication device 52 is an interface for information communication with the constituent parts of the plasma processing apparatus 100 and external devices. For example, the control unit 50 receives signals output from the pressure detector 27 via the communication device 52 and outputs control signals to drive the pressure adjustment plate 14. Furthermore, the control unit 50 manages the progress of the etching process, and when the etching process is completed, the control unit 50 controls the arm of the vacuum transport device via the communication device 52. Additionally, the control unit 50 can also measure the number of wafers 3 processed in the plasma processing apparatus 100 based on information obtained via the communication device 52, from the time elapsed since the components were placed in the processing chamber 5.

[0100] The input / output device 53 is used when a user inputs or outputs information to the plasma processing apparatus 100. Examples of input / output devices 53 include output devices such as displays, and input devices such as keyboards or mice. Alternatively, it can be a device with both input and output functions, such as a touch panel.

[0101] The memory 51 stores software programs and / or command sets for performing the functions of the plasma processing apparatus 100, and data for performing the functions. The memory 51 includes a plasma processing management unit 510, a spectrometer 511, a background interpolation unit 512, a background difference unit 513, a usage period measurement unit 514, a lifespan determination unit 515, a notification unit 516, an FT-IR database 517, and a component database 518.

[0102] When the plasma processing management unit 510 is executed by the memory 51, the processor 54 manages the plasma processing performed on the wafer 3. For example, the processor 54 operates the plasma processing apparatus 100 according to the plasma processing conditions set by the user of the plasma processing apparatus 100. In addition, the processor 54 can acquire set data, such as the cumulative time for plasma 13 to be generated during plasma processing, the number of wafers 3 processed, and the usage period of the components arranged in the plasma processing apparatus 100.

[0103] When the spectral measurement unit 511 is executed by the processor 54, the processor 54 performs spectral measurement. The processor 54 uses a Fourier transform infrared absorption spectrometer 29 to measure the spectrum of infrared intensity reflected and scattered on the surface of the coating 24 of the ground electrode 22.

[0104] Furthermore, when the background interpolation unit 512 is executed by the processor 54, the processor 54 interpolates the background of infrared absorption intensity. The processor 54 selects a predetermined wavenumber region based on the infrared reflection intensity obtained by the spectral measurement unit 511, selects two points, and interpolates the background. Here, the FT-IR database 517 registers the infrared transmission absorption spectra for various substances. In this disclosure, information related to the transmission absorption spectra of compounds containing any of Y, O, and F is registered, but information related to the transmission absorption spectra of other compounds may also be registered in the FT-IR database 517. Additionally, information corresponding to the material manufacturer and the plasma processing in the plasma processing apparatus 100 may also be registered in the FT-IR database 517. The processor 54 is able to select the wavenumber region and set the background based on the information registered in the FT-IR database 517.

[0105] Furthermore, when the background difference section 513 is executed by the processor 54, the processor 54 interpolates the background difference from the absorption intensity of infrared radiation in a specified wavenumber region. Additionally, the processor 54 clusters the specified wavenumber region to detect the peak value of the absorption intensity of infrared radiation at a specified wavelength. In intervals where the absorption intensity of infrared radiation cannot be measured, the processor 54 interpolates the spectral intensity at the average wavenumber of the clustered wavenumber region. In this disclosure, the specified wavelength is between 1300 and 1850 cm⁻¹. -1 The wavelength at which the reflection intensity reaches its maximum (peak) value is defined. It should be noted that the specified wavelength range can also be determined based on the material of the component being tested.

[0106] Furthermore, when the processor 54 executes the usage period measurement unit 514, the processor 54 measures the usage period elapsed from the time the ground electrode 22 is placed in the plasma processing apparatus 100. Indicators of the usage period include, for example, the number of wafers 3 processed after the ground electrode 22 is placed in the processing chamber 5, or the total time (cumulative time) for plasma 13 to form after the ground electrode 22 is placed in the processing chamber 5. The processor 54 measures the number of wafers 3 that have undergone plasma processing and the cumulative time for plasma 13 to form.

[0107] Furthermore, when the lifetime determination unit 515 is executed by the processor 54, the processor 54 determines that the value of the infrared reflection intensity of a specified wavelength detected from the surface of the coating 24 of the ground electrode 22 is extremely small. The processor 54 repeatedly performs the processing of the spectral measurement unit 511, the background interpolation unit 512, and the background difference unit 513, detects the peak value of the infrared reflection intensity, and detects the case where the peak value is extremely small. For example, if the repeatedly detected peak value changes from decreasing to increasing as the usage period progresses, the extreme smallness of the peak value can be detected. When an extreme smallness is detected, it is determined that the normalized lifetime of the ground electrode 22 is 0.4 or less.

[0108] Furthermore, when the notification unit 516 is executed by the processor 54, if the value of the absorption intensity of infrared light of a specified wavelength detected from the surface of the coating 24 of the ground electrode 22 becomes extremely low, the processor 54 notifies that the damage or consumption of the coating 24 of the ground electrode 22 has reached a certain value, or the usability limit (e.g., lifespan) of the ground electrode 22 has been reached. The notification includes the degree of damage or consumption caused by changes in the composition of Y, O, and F contained in the surface of the coating 24 after the value of the absorption intensity of infrared light of the specified wavelength becomes extremely low. For example, the damage rate, consumption rate, and other indicators compared to the condition of a new ground electrode 22 can also be notified to the user of the plasma processing apparatus 100. Additionally, the processor 54 can output information about the lifespan of the coating 24 or the ground electrode 22 to a display or the like in the input / output device 53. Information about the lifespan will be described later.

[0109] In this way, after the grounding electrode 22 is placed in the processing chamber 5, the user of the plasma processing apparatus 100 can grasp the degree of damage or consumption of the coating 24, or the lifespan of the grounding electrode 22, in the case that damage accumulates on the coating 24 as the number of wafers 3 being processed or the total time of plasma formation 13 increases.

[0110] (Lifespan of components)

[0111] When the peak value of infrared absorption intensity becomes extremely small, the normalized lifetime is around 0.4, leaving the ground electrode 22 with some capacity for plasma processing. In this case, the lifetime of the ground electrode 22 can be expressed, for example, by the number of wafers that can be processed before the maintenance operation of the ground electrode 22, or by the sum of the time that plasma 13 can be formed before the maintenance operation of the ground electrode 22. It should be noted that in this disclosure, the case of damage caused by plasma processing is envisioned, so the case referred to as the lifetime of the ground electrode 22 is the same as the case referred to as the lifetime of the coating 24. In addition, in the case of the maintenance operation referred to as the coating 24, the ground electrode 22 itself can be replaced, or the coating 24 of the ground electrode 22 can be newly changed.

[0112] For example, the number of wafers 3 that can be processed from the start of using the ground electrode 22 until its replacement, as well as the total time for plasma 13 to be formed, are pre-registered in the component database 518. In addition, the control unit 50 pre-measures the number of wafers processed until the minimum peak value of the reflection intensity is detected, as well as the cumulative time of plasma formation.

[0113] When the notification time of step S8 is taken as the starting point, and the lifespan of the component (ground electrode 22) is represented by the number of wafers that can be processed from the notification of step S8 to the maintenance operation of coating 24, the control unit 50 can set the number of wafers based on the lifespan to be smaller than the number of wafers until it is determined that the value of the absorption intensity becomes extremely small. Alternatively, when the lifespan of the component (ground electrode 22) is represented by the sum of the time it takes for plasma 13 to be formed from the notification of step S8 to the maintenance operation of coating 24, the control unit 50 sets the sum of the lifespan time to be less than the sum of the time it takes for plasma 13 to be formed before it is determined that the value of the absorption intensity becomes extremely small.

[0114] Furthermore, when the lifespan of the component (ground electrode 22) is represented by the number of wafers 3 that can be processed from the point when the absorption intensity is determined to be at its minimum until the maintenance operation of coating 24, the control unit 50 sets the number of wafers based on the lifespan to be less than the number of wafers 3 that are processed from the point when the absorption intensity is determined to be at its minimum. Alternatively, when the lifespan of the component (ground electrode 22) is represented by the sum of the time it takes for plasma 13 to be formed from the point when the absorption intensity is determined to be at its minimum until the maintenance operation of coating 24, the control unit 50 sets the sum of the lifespan time to be less than the sum of the time it takes for plasma 13 to be formed before the absorption intensity is determined to be at its minimum.

[0115] In this way, the control unit 50 converts the lifespan of the ground electrode 22 (coating 24) into the remaining number of wafers 3 that can be processed before the period requiring maintenance work, or the remaining time for plasma 13 to be formed, and notifies the user of the plasma processing device 100. The user can intuitively understand the lifespan of the ground electrode 22 (coating 24) and can identify the urgency and importance of the maintenance work.

[0116] As described above, the structure of the control unit 50 has been explained, but the inspection device 30 may also have a structure similar to the control unit 50, including at least a memory 51 and a processor 54. The inspection device 30 may also perform the same processing as the control unit 50 to check the state of the ground electrode 22.

[0117] (Flowchart of the operation method of plasma processing device 100)

[0118] Figure 15 This is a flowchart illustrating the operation method of the plasma processing apparatus 100. As step S1, a component is arranged in the processing chamber 5 of the plasma processing apparatus 100. The processing chamber 5 of the plasma processing apparatus 100 is sealed, and the plasma processing apparatus 100 is configured to perform plasma processing on the wafer 3.

[0119] Next, as step S2, the usage period elapsed from the time the component was placed in the processing chamber 5 is measured. Indicators of the usage period include, for example, the number of wafers that can be processed from the time the ground electrode 22 was placed in the processing chamber 5, or the total time for plasma 13 to be formed from the time the ground electrode 22 was placed in the processing chamber 5. Steps S3 to S6 following step S2 are repeated to measure the usage period.

[0120] Next, as step S3, a spectral measurement is performed. For example, the control unit 50 measures the spectrum of infrared intensity of the grounding electrode 22 disposed in the processing chamber 5.

[0121] Next, as step S4, background interpolation is performed. For example, the control unit 50 interpolates the background of a specific wavelength region in the measured infrared absorption intensity.

[0122] Next, as step S5, background subtraction is performed. For example, the control unit 50 obtains the subtraction of the background interpolated within a specific wavelength region and detects the peak intensity of the infrared absorption intensity.

[0123] Next, as step S6, the minimum value of the peak value is detected. For example, the control unit 50 can detect the minimum value of the peak value when the repeatedly detected peak value changes from decreasing to increasing. If the minimum value of the peak value is not detected ("No" in step S6), the measurements taken during the period (steps S7 and S2) are used to repeatedly detect the peak intensity (steps S3 to S5).

[0124] Next, as step S8, the user of the plasma processing device 100 is notified. For example, if a very small peak value is detected ("Yes" in step S6), the control unit 50 notifies the user of the plasma processing device 100 of the extent of damage or consumption of the coating 24, or the lifespan (usable limit) of the grounding electrode 22 (coating 24).

[0125] This describes the case where the operation method described above is controlled by the control unit 50 of the plasma processing apparatus 100, but the operation method described above can also be performed by the inspection device 30.

[0126] (Function / Effect)

[0127] As described above, in the plasma processing apparatus 100 of Example 1, the infrared radiation scattered and reflected from the components disposed within the processing chamber 5 was measured, including radiation up to 1300 cm⁻¹. -1 Up to 1800cm -1 The infrared absorption spectrum in the wavenumber region, using 1300 cm⁻¹ -1 The absorption intensity of infrared rays and 1800cm -1 The background was interpolated using the two points of infrared absorption intensity. Next, measurements were taken from 1437 cm⁻¹. -1 1536cm -1 1592cm -1 1641cm -1 The infrared absorption intensity obtained by subtracting the interpolated background from the absorption intensity of nearby infrared radiation was detected, and it was found that the absorption intensity of this infrared radiation decreased with increasing plasma processing time. Then, if the peak value of the infrared absorption intensity changed to a minimum or increased, it was determined that the normalized lifetime was 0.4 or less. A normalized lifetime of 0.4 or less means that the remaining time before the inner wall material's lifespan is exhausted and foreign matter is generated is less than 2 / 3 of the current usage time. By informing the user of the plasma processing device 100 of the information related to the remaining lifetime, the user can identify the status of the components arranged in the processing chamber 5.

[0128] It should be noted that the Fourier transform infrared absorption spectrometer 29 can also be configured on the movable arm to evaluate the deviation within the components of the grounding electrode 22 by measuring the absorption and scattering of infrared rays at multiple locations of the inner wall material of the grounding electrode 22, and to detect the location with the most severe deterioration.

[0129] Thus, according to this disclosure, the condition of components used in plasma processing apparatus can be evaluated in a non-destructive and non-contact manner, and the evaluation results can be shown to the user of the plasma processing apparatus.

[0130] (Example 2)

[0131] use Figure 16 Example 2 will be described. Figure 16This is a longitudinal sectional view showing the outline of the structure of the plasma processing apparatus 200 according to Embodiment 2 of the present invention. Embodiment 2 differs from Embodiment 1 in that the infrared absorption intensity can be measured without disrupting the vacuum of the processing chamber 5 of the plasma processing apparatus. In Embodiment 2, the plasma processing apparatus 200 further includes: a first window (window 42) for irradiating infrared light onto a component disposed within the processing chamber 5; a second window (window 43) for exposing infrared light scattered from the component to the outside of the processing chamber 5; and a detector (IR detector 41) for detecting infrared light emitted from the second window (window 43). In the following description, the same or equivalent components as those in Embodiment 1 described above are labeled with the same reference numerals, and their descriptions are simplified or omitted.

[0132] The plasma processing apparatus 200 includes an IR laser source 40 and an IR detector 41. Windows 42 and 43 are formed on the substrate 28. Infrared rays IR emitted from the IR laser source 40 are introduced into the processing chamber 5 through the long-wavelength infrared transmission window 42 (e.g., Ge, Si). Similarly, infrared rays SL scattered by the YF inner wall material are also detected by the IR detector 41 through the long-wavelength infrared transmission window 43 (e.g., Ge, Si). In the case of window materials with low plasma resistance such as Ge or Si, a gate valve (not shown) can be installed between the window material and the processing chamber 5 to isolate the window material from the processing chamber 5, preventing the window material from being exposed to plasma during plasma processing.

[0133] Alternatively, the incident infrared (IR) light can also be continuous light parallelized by an optical system, or 1300 cm⁻¹. -1 1800cm -1 Wavenumbers between, for example, 1592 cm -1 A monochromatic laser with a wavenumber of 3 or higher. Incident infrared IR irradiates the coating 24 on the upper end of the component of ground electrode 22. Infrared SL scattered by ground electrode 22 is detected by IR detector 41 (e.g., deuterated triglycine sulfate: DTGS detector) through the window material of window 43.

[0134] The inspection device 30, in the same manner as in Example 1, detects the minimum peak intensity of the absorbed infrared SL. For example, a background of 1300 cm⁻¹ is used. -1 and 1800cm -1 The absorption intensity of infrared radiation from monochromatic laser light of a specified wavenumber was interpolated. Additionally, infrared radiation at a specified frequency of 1592 cm⁻¹ was measured. -1 The absorption intensity of infrared light from a monochromatic laser of a given wavenumber is used to differentiate the interpolated background. The normalized lifetime is 1592 cm⁻¹. -1 The correlation of peak intensity with Figure 8The correlations shown are the same.

[0135] (Function / Effect)

[0136] By adopting the structure described above, it is possible to evaluate the components inside the processing chamber 5 without damaging the vacuum container of the plasma processing apparatus 200.

[0137] (Example 3)

[0138] use Figure 17 Example 3 will be described. Figure 17 This is a schematic diagram illustrating the situation where the absorption intensity of infrared radiation is measured after the vacuum of the processing chamber of the plasma processing device is broken and the grounding electrode 22 is removed. Figure 17 (a) is a 3D diagram. Figure 17 (b) is a longitudinal sectional view.

[0139] In Example 3, without contact with the coating 24 of the grounding electrode 22, a Fourier transform infrared absorption spectrometer 29 is used to measure the spectrum of infrared intensity reflected and scattered on the surface of the coating 24. In Example 1, as... Figure 2 As shown, the Fourier transform infrared absorption spectrometer 29, when positioned with the movable arm, irradiates infrared light onto the ground electrode 22. On the other hand, in Embodiment 3, as... Figure 17 As shown, the ground electrode 22 is positioned on a stage that can move in the up-down, left-right, and rotational directions. With the Fourier transform infrared absorption spectrometer 29 fixed, the absorption and scattering of infrared radiation at multiple locations on the inner wall material of the ground electrode 22 are measured.

[0140] (Function / Effect)

[0141] Therefore, it is possible to evaluate the spectral deviation of the infrared intensity within the grounding electrode 22, and also to detect the most severely degraded parts within the grounding electrode 22.

[0142] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0143] The following description can be, but is not limited to, the content of this invention.

[0144] (Method 1)

[0145] A plasma processing apparatus includes a component having a coating containing Y and O on its surface within a processing chamber for processing a wafer using plasma.

[0146] The plasma processing apparatus includes a control unit that, when the absorption intensity of infrared light of a predetermined wavelength detected from the surface of the coating of the component becomes extremely low, notifies that the damage or consumption of the coating has reached a certain value, or the lifespan of the component.

[0147] (Method 2)

[0148] According to the plasma processing apparatus of method 1, wherein...

[0149] When the control unit uses the number of wafers that can be processed from the notification to the coating maintenance operation to represent the lifespan of the component, it sets the number of wafers based on the lifespan to be smaller than the number of wafers until it is determined that the value of the absorption intensity becomes extremely small, or...

[0150] When the control unit uses the sum of the time it takes for the plasma to form from the notification to the maintenance operation of the coating to represent the lifespan, it sets the sum of the time based on the lifespan to be smaller than the sum of the time it takes for the plasma to form until it is determined that the value of the absorption intensity becomes extremely small.

[0151] (Method 3)

[0152] According to the plasma processing apparatus of method 1 or 2, wherein,

[0153] When the control unit uses the number of wafers that can be processed from the point when the absorption intensity value is determined to be at its minimum until the coating maintenance operation to represent the lifespan of the component, it sets the number of wafers based on the lifespan to be smaller than the number of wafers until the absorption intensity value is determined to be at its minimum, or...

[0154] When the control unit uses the sum of the time from the point when the absorption intensity value becomes minimal to the maintenance operation of the coating to represent the lifespan of the component, it sets the sum of the time based on the lifespan to be smaller than the sum of the time until the absorption intensity value becomes minimal.

[0155] (Method 4)

[0156] The plasma processing apparatus according to any one of methods 1 to 3, wherein...

[0157] The control unit notifies the extent of damage or consumption caused by changes in the composition of Y, O, and F contained in the surface of the coating after the absorption intensity of infrared light at the specified wavelength becomes extremely low.

[0158] (Method 5)

[0159] The plasma processing apparatus according to any one of methods 1 to 4, wherein...

[0160] The specified wavelength is between 1300 and 1850 cm. -1 The value of the absorption intensity within the range becomes the wavelength at which the absorption intensity is maximized.

[0161] (Method 6)

[0162] The plasma processing apparatus according to any one of methods 1 to 5, wherein,

[0163] The plasma processing device also includes:

[0164] The first window allows infrared light to shine onto the component disposed within the processing chamber;

[0165] A second window allows infrared light scattered from the component to escape outside the processing room; and

[0166] The detector detects infrared light emitted from the second window.

[0167] (Method 7)

[0168] A method for operating a plasma processing apparatus, wherein the plasma processing apparatus has a component having a coating comprising Y and O on its surface within a processing chamber for processing a wafer using plasma, wherein...

[0169] The operation method of the plasma processing device includes the following processes:

[0170] When the absorption intensity of infrared light of a specified wavelength detected from the surface of the coating of the component becomes extremely low, it indicates that the damage or wear of the coating has reached a certain value, or the lifespan of the component.

[0171] (Method 8)

[0172] An inspection apparatus for a plasma processing device, wherein the plasma processing device includes a component having a coating containing Y and O on its surface within a processing chamber for processing a wafer using plasma, wherein...

[0173] The inspection device includes a memory and a processor.

[0174] The memory contains processing commands that cause the processor to perform the following processes:

[0175] When the absorption intensity of infrared light of a specified wavelength detected from the surface of the coating of the component becomes extremely low, it indicates that the damage or wear of the coating has reached a certain value, or the lifespan of the component.

[0176] (Method 9)

[0177] An inspection method is provided, which is an inspection method in an inspection apparatus of a plasma processing device. The plasma processing device has a component with a coating containing Y and O on its surface within a processing chamber that processes a wafer using plasma.

[0178] The inspection method includes the following processes:

[0179] The usage period elapsed from the time the component was placed in the processing chamber;

[0180] The infrared reflection intensity of the component was measured.

[0181] Background in a specific wavelength region of the infrared absorption intensity measured by interpolation;

[0182] Obtain the difference of the interpolated background, and detect the peak intensity of the infrared absorption intensity; and

[0183] The minimum value of the peak intensity is detected.

[0184] Explanation of reference numerals in the attached figures:

[0185] 1… Cluster plate, 2… Window component, 3… Wafer, 4… Stage, 5… Processing chamber, 6… Gap, 7… Through hole, 8… Exhaust piping, 9… Dry pump, 10… Turbomolecular pump, 11… Impedance matching device, 12… High-frequency power supply, 13… Plasma, 14… Pressure regulating plate, 15… Valve, 16… Valve, 17… Valve, 18… Magnetron oscillator, 19… Waveguide, 20… Solenoid coil, 21… Solenoid coil, 22… Grounding electrode, 23… Base material, 24… Coating, 25… Processing gas supply piping, 26… Valve, 27… Pressure detector, 28…substrate, 40…IR laser source, 41…IR detector, 42…window, 43…window, 50…processing unit, 51…memory, 52…communication device, 53…input / output device, 54…processor, 56…notification unit, 100, 200…plasma processing device, 511…spectral measurement unit, 512…background interpolation unit, 513…background difference unit, 514…measurement unit during use, 515…lifetime determination unit, 516…notification unit, 517…FT-IR database, 518…component database.

Claims

1. A plasma processing apparatus, wherein a processing chamber for processing a wafer using plasma includes a component having a coating comprising Y and O on its surface, wherein, The plasma processing apparatus includes a control unit that, when the absorption intensity of infrared light of a predetermined wavelength detected from the surface of the coating of the component becomes extremely low, notifies that the damage or consumption of the coating has reached a certain value, or the lifespan of the component.

2. The plasma processing apparatus according to claim 1, wherein, When the control unit uses the number of wafers that can be processed from the notification to the coating maintenance operation to represent the lifespan of the component, it sets the number of wafers based on the lifespan to be smaller than the number of wafers until it is determined that the value of the absorption intensity becomes extremely small, or... When the control unit uses the sum of the time it takes for the plasma to form from the notification to the maintenance operation of the coating to represent the lifespan, it sets the sum of the time based on the lifespan to be smaller than the sum of the time it takes for the plasma to form until it is determined that the value of the absorption intensity becomes extremely small.

3. The plasma processing apparatus according to claim 1, wherein, When the control unit uses the number of wafers that can be processed from the point when the absorption intensity value is determined to be at its minimum until the coating maintenance operation is performed to represent the lifespan of the component, it sets the number of wafers based on the lifespan to be smaller than the number of wafers until the absorption intensity value is determined to be at its minimum, or... When the control unit uses the sum of the time from the point when the absorption intensity value becomes minimal to the maintenance operation of the coating to represent the lifespan of the component, it sets the sum of the time based on the lifespan to be smaller than the sum of the time until the absorption intensity value becomes minimal.

4. The plasma processing apparatus according to claim 1, wherein, The control unit notifies the extent of damage or consumption caused by changes in the composition of Y, O, and F contained in the surface of the coating after the absorption intensity of infrared light at the specified wavelength becomes extremely low.

5. The plasma processing apparatus according to any one of claims 1 to 3, wherein, The specified wavelength is 1300~1850cm. -1 The value of the absorption intensity within the range becomes the wavelength at which the absorption intensity is maximized.

6. The plasma processing apparatus according to claim 1, wherein, The plasma processing device also includes: The first window allows infrared light to shine onto the component disposed within the processing chamber; A second window allows infrared light scattered from the component to escape outside the processing room; as well as The detector detects infrared light emitted from the second window.

7. A method of operating a plasma processing apparatus, wherein the plasma processing apparatus includes a component having a coating comprising Y and O on its surface within a processing chamber for processing a wafer using plasma, wherein... The operation method of the plasma processing device includes the following processes: When the absorption intensity of infrared light of a specified wavelength detected from the surface of the coating of the component becomes extremely low, it indicates that the damage or wear of the coating has reached a certain value, or the lifespan of the component.

8. An inspection apparatus for a plasma processing device, wherein the plasma processing device includes a component having a coating comprising Y and O on its surface within a processing chamber for processing a wafer using plasma, wherein, The inspection device includes a memory and a processor. The memory contains processing commands that cause the processor to perform the following processes: When the absorption intensity of infrared light of a specified wavelength detected from the surface of the coating of the component becomes extremely low, it indicates that the damage or wear of the coating has reached a certain value, or the lifespan of the component.

9. An inspection method, which is an inspection method in an inspection apparatus of a plasma processing apparatus, wherein the plasma processing apparatus has a member having a coating comprising Y and O on its surface in a processing chamber for processing a wafer using plasma, wherein, The inspection method includes the following processes: The usage period elapsed from the time the component was placed in the processing chamber; The infrared reflection intensity of the component was measured. Background in a specific wavelength region of the infrared absorption intensity measured by interpolation; Obtain the difference of the interpolated background and detect the peak intensity of the infrared absorption intensity; as well as The minimum value of the peak intensity is detected.

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