JP2004260159A - Plasma treatment apparatus, ring member, and plasma treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To share the use of plasma treatment apparatuses when performing a plurality of processes that are different from one another, in the plasma treatment apparatuses that use plasma, and to provide the apparatuses, ring members and a plasma treatment method that can easily align states of plasma between the apparatuses when performing the same processes by using a plurality of the apparatuses. <P>SOLUTION: A substrate to be treated in a treatment container is surrounded by a ring member made of an insulating material. In this ring member, electrodes are provided to adjust a plasma sheath region. When performing a first process on the substrate to be treated, for example, a first direct-current voltage is applied to the electrodes. When performing a second process on the substrate, a second direct-current voltage is applied to the electrodes. This method is applicable to a suitable direct-current voltage for each process or for each of the apparatuses performing the same processes so that the apparatuses have the same plasma conditions, enabling the shared use of the apparatuses and the easy adjustment of the plasma condition. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a plasma processing apparatus that performs a predetermined process, for example, an etching process on a substrate such as a semiconductor wafer by using plasma.

  2. Description of the Related Art Conventionally, in a manufacturing process of a semiconductor device, dry etching is performed on a substrate, for example, a semiconductor wafer (hereinafter, referred to as a wafer) in order to separate a capacitor or an element or form a contact hole. As one of apparatuses for performing this processing, a single-wafer parallel plate type plasma processing apparatus is known (for example, see Patent Documents 1 and 2).

  Briefly describing the above-described apparatus with reference to FIG. 28, this plasma apparatus is provided with an upper electrode 11 also serving as a gas shower head and a lower electrode 12 also serving as a mounting table on the upper and lower sides of the hermetic container 1, respectively. Further, a silicon ring 13 is provided on the inside to surround the periphery of the wafer W on the mounting table 12, and a quartz ring 14 is provided on the outside. Then, a high-frequency voltage is applied between the upper electrode 11 and the lower electrode 12 by the high-frequency power supply 15 to turn the processing gas from the gas shower head (upper electrode) 11 into plasma, and the high-frequency power supply 16 applies a bias to the lower electrode 12. Is applied, and the wafer W on the mounting table (lower electrode) is etched by evacuating from the exhaust port 17 and maintaining a predetermined pressure.

  Here, the roles of the silicon ring 13 and the quartz ring 14 will be described. Since the processing gas that has reached the vicinity of the surface of the wafer W spreads toward the periphery of the wafer W and is exhausted downward from the outside, the processing gas is located between the periphery of the wafer W (near the periphery) and the region near the center. The gas flow of the processing gas is different, and the balance of a predetermined component ratio in the processing gas is lost at the peripheral portion of the wafer W, and between the region where the wafer W is placed and the outside thereof, the plasma and the lower electrode The values of the impedance component and the conductance component between them are different. For this reason, the state of the plasma is different between the upper portion near the peripheral edge of the wafer and the upper portion inside thereof.

  On the other hand, since there is a strong demand to form devices as close to the periphery of the wafer as possible in order to increase the utilization rate of the wafer, it is necessary to ensure high in-plane uniformity in the etching rate up to the vicinity of the periphery of the wafer W. is there. For this reason, a ring member called a focus ring made of a conductor, a semiconductor, or a dielectric is arranged outside the wafer W to adjust the plasma density above the peripheral portion of the wafer W. Specifically, select the material of the focus ring according to the material of the film to be etched and the magnitude of the supplied power, adjust the ring width and height, etc., and install a focus ring suitable for the processing (For example, see Patent Document 3).

  In the above-mentioned patent document, a silicon ring is used as an example when etching a silicon oxide film, but an insulator such as quartz is used when etching polysilicon, for example.

JP-A-8-335568 (page 3-4, FIG. 2) JP-A-2000-36490 (page 5, FIG. 3) JP-A-8-162444 (page 5, FIG. 2)

  For this reason, in the case of etching a multilayer film formed on the wafer W, the processing gas and the amount of supplied power are different for each layer or between some of the layers. The required focus ring is different for each layer or between some of the layers, and a different number of chambers must be prepared for the different focus rings. In practice, for example, in order to etch five layers of films, two films share a chamber, and the remaining films are processed in the respective chambers. Since the basic components of the etching apparatus are the same even if the type of the film is different, it is advisable to use a common chamber. However, for such a reason, the common chamber is prevented.

  This is one of the factors that make it difficult to reduce the footprint (the occupied area of the device), and increases the variation of the device, which increases the production and operation costs of the device in terms of mass productivity and device management. It is one of the causes.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a plasma processing apparatus and a method thereof that can share an apparatus when performing a plurality of different processes. Another object of the present invention is to provide a plasma processing apparatus that can easily be adjusted to make the state of plasma uniform between apparatuses performing the same process.

A plasma processing apparatus of the present invention is a plasma processing apparatus that performs processing on a substrate to be processed mounted on a mounting table in a processing container using plasma of a processing gas.
A ring member made of an insulating material provided so as to surround the substrate to be processed on the mounting table,
An electrode provided in the ring member along the circumferential direction;
A DC power supply for applying a DC voltage to the electrode to adjust a plasma sheath region above the ring member.

  According to the plasma processing apparatus of the present invention, the thickness of the ion sheath region at the boundary between the surface of the ring member and the plasma is adjusted by applying a predetermined DC voltage to the electrode in the ring member made of an insulator. And the state of plasma can be made uniform for each process. Therefore, a plurality of different process processes can be performed using a common ring member, so that the apparatus can be shared.

  In addition, the present invention applies an applied voltage such that, for example, a first DC voltage is applied to an electrode in a ring member during a first process, and a second DC voltage is applied to an electrode in a ring member during a second process. And means for switching. In this case, the means includes, for example, a storage unit that stores a process condition for performing the first process and a process condition for performing the second process on the substrate to be processed, and stores data in the storage unit. , The applied voltage may be switched. Further, the first process may be, for example, a process of etching a thin film, and the second process may be, for example, a process of etching a thin film of a type different from the thin film. Also, a plurality of electrodes in the ring member may be provided, for example, in the radial direction, and the DC voltage applied to the plurality of electrodes may be adjusted independently of each other.

A ring member according to another aspect of the present invention is configured to surround a substrate to be processed on a mounting table of a plasma processing apparatus that performs processing by a plasma of a processing gas on a substrate to be processed mounted on a mounting table in a processing container. In a ring member made of an insulating material provided in,
An electrode to which a DC voltage is applied for adjusting a plasma sheath region above the ring member is provided inside.

  For example, the ring member is configured such that a first DC voltage is applied to the electrode when a first process is performed on a substrate to be processed, and a second DC voltage is applied to the electrode when a second process is performed on the substrate to be processed. A DC voltage may be applied. In this case, the first process may be a process of etching a thin film, and the second process may be a process of etching a different type of thin film. Further, a plurality of electrodes in the ring member may be provided, for example, in the radial direction, and the DC voltage applied to the plurality of electrodes may be independently adjustable.

The plasma processing method of the present invention is a step of mounting a substrate to be processed on a mounting table in a processing container,
In a state where a first DC voltage is applied to a plasma sheath region adjusting electrode provided along a circumferential direction in a ring member made of an insulating material provided so as to surround a substrate to be processed on the mounting table, Performing a first process on a substrate to be processed by generating plasma in the processing container;
And generating a plasma in the processing vessel and performing a second process on the substrate to be processed in a state in which a second DC voltage is applied to the electrode for adjusting the plasma sheath region. .

  In the above-described ring member, according to a first aspect of the present invention, the substrate has a base material and a coating formed on the surface thereof by thermal spraying of ceramics, and the ceramics forming the coating include B, Mg, Al, A ring member comprising at least one element selected from the group consisting of Si, Ca, Cr, Y, Zr, Ta, Ce and Nd, at least a portion of which is sealed with a resin; provide.

  According to a second aspect of the present invention, there is provided a base material and a coating formed on the surface thereof by spraying ceramics, wherein the coating is made of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta. , A first ceramic layer made of a ceramic containing at least one element selected from the group consisting of Ce and Nd, and B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd. A second ceramics layer made of ceramics containing at least one element selected from the group, wherein at least a part of at least one of the first and second ceramics layers is sealed with a resin. A ring member is provided.

  In the first and second aspects of the present invention, the resin is preferably selected from the group consisting of SI, PTFE, PI, PAI, PEI, PBI, and PFA.

  According to a third aspect of the present invention, there is provided a base material and a coating formed on the surface thereof by spraying ceramics, and the ceramics constituting the coating are B, Mg, Al, Si, Ca, Cr, Y , Zr, Ta, Ce, and Nd. A ring member comprising at least one element selected from the group consisting of, and at least a part of which is subjected to a sealing treatment by a sol-gel method.

  According to a fourth aspect of the present invention, there is provided a base material and a coating formed on the surface thereof by spraying ceramics, wherein the coating is made of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta. , A first ceramic layer made of a ceramic containing at least one element selected from the group consisting of Ce and Nd, and B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd. A second ceramics layer made of ceramics containing at least one element selected from the group, wherein at least a part of at least one of the first and second ceramics layers is sealed by a sol-gel method. A ring member characterized by the following.

  In the third and fourth aspects of the present invention, it is preferable that the sealing treatment is performed using an element selected from elements belonging to Group 3a of the periodic table.

  In the first to fourth aspects of the present invention, the ceramics include B4C, MgO, Al2O3, SiC, Si3N4, SiO2, CaF2, Cr2O3, Y2O3, YF3, ZrO2, TaO2, CeO2, Ce2O3, CeF3, and Nd2O3. At least one selected from the group consisting of:

  According to a fifth aspect of the present invention, there is provided a base material and a coating formed on the surface thereof, wherein the coating includes a main layer formed by spraying ceramics, B, Mg, Al, Si, Ca, A ring member comprising: a barrier coat layer made of a ceramic containing an element selected from the group consisting of Cr, Y, Zr, Ta, Ce, and Nd.

  In the fifth aspect of the present invention, the barrier coat layer includes a group consisting of B4C, MgO, Al2O3, SiC, Si3N4, SiO2, CaF2, Cr2O3, Y2O3, YF3, ZrO2, TaO2, CeO2, Ce2O3, CeF3, and Nd2O3. At least one kind of ceramics selected from the following can be suitably used. Further, as the barrier coat layer, at least a part thereof can be used as a thermal spray coating coated with a resin, and the resin includes SI, PTFE, PI, PAI, PEI, PBI, and PFA. Those selected from the group are preferred. Alternatively, as the barrier coat layer, a thermal spray coating, at least a part of which is subjected to a sealing treatment by a sol-gel method, may be used, wherein the sealing treatment is selected from elements belonging to Group 3a of the periodic table. It is preferable to carry out using.

  According to a sixth aspect of the present invention, there is provided a base material and a coating formed on the surface thereof, wherein the coating is formed between a main layer formed by spraying ceramics and the base material and the main layer. And a barrier coat layer formed of an engineering plastic formed on the ring member.

  In the sixth aspect of the present invention, a plastic selected from the group consisting of PTFE, PI, PAI, PEI, PBI, PFA, PPS, and POM can be suitably used as the engineering plastic.

  In the fifth and sixth aspects of the present invention, the main layer is formed of B4C, MgO, Al2O3, SiC, Si3N4, SiO2, CaF2, Cr2O3, Y2O3, YF3, ZrO2, TaO2, CeO2, Ce2O3, CeF3, and Nd2O3. At least one kind of ceramics selected from the group described above can be suitably used.

  According to a seventh aspect of the present invention, there is provided a base material and a film formed on the surface thereof, wherein the film is made of a ceramic containing at least one element belonging to Group 3a of the periodic table. Characterized in that at least a part of the ring member is hydrated with steam or high-temperature water.

  According to an eighth aspect of the present invention, a first ceramic comprising a substrate and a coating formed on the surface thereof, wherein the coating is made of a ceramic containing at least one element belonging to Group 3a of the periodic table. And a second ceramics layer made of ceramics containing at least one element belonging to Group 3a of the periodic table, wherein at least a part of at least one of the first and second ceramics layers is steam or high-temperature water. A ring member characterized by being subjected to hydration treatment.

  In the seventh and eighth aspects of the present invention, a thermal sprayed coating formed by thermal spraying or a thin film formed by a thin film forming technique can be used as the coating. Further, it is preferable that the ceramic constituting the coating is selected from Y2O3, CeO2, Ce2O3, and Nd2O3.

  According to a ninth aspect of the present invention, there is provided a first ceramic comprising a base material and a coating formed on a surface thereof, wherein the coating is made of a ceramic containing at least one element belonging to Group 3a of the periodic table. A ring member having a layer and a second ceramic layer formed by spraying ceramics, wherein at least a part of the first ceramic layer is hydrated with steam or high-temperature water.

  In the ninth aspect of the present invention, as the first ceramics layer, a thermal sprayed coating formed by thermal spraying or a thin film formed by a thin film forming technique can be used. Further, it is preferable that the ceramics constituting the first ceramics layer is selected from Y2O3, CeO2, Ce2O3, and Nd2O3. Further, as the ceramic constituting the second ceramic layer, selected from the group consisting of B4C, MgO, Al2O3, SiC, Si3N4, SiO2, CaF2, Cr2O3, Y2O3, YF3, ZrO2, TaO2, CeO2, Ce2O3, CeF3 and Nd2O3. At least one of the above is preferred.

  According to a tenth aspect of the present invention, there is provided a base material and a coating formed on a surface thereof, wherein the coating is formed of a hydroxide comprising a hydroxide containing at least one element belonging to Group 3a of the periodic table. A ring member having an oxide layer is provided.

  In the tenth aspect of the present invention, as the hydroxide layer, a thermal spray coating formed by thermal spraying or a thin film formed by a thin film forming technique can be used. The hydroxide constituting the hydroxide layer is preferably selected from Y (OH) 3, Ce (OH) 3 and Nd (OH) 3. Further, at least a part of the hydroxide layer may be subjected to a sealing treatment.

  In the first to tenth aspects of the present invention, an anodic oxide coating may be provided between the base material and the coating. In this case, the anodic oxide coating is sealed with a metal salt aqueous solution. It is preferable that holes have been treated. Further, the anodic oxide film may be one subjected to a sealing treatment with a resin selected from the group consisting of SI, PTFE, PI, PAI, PEI, PBI, and PFA.

  An eleventh aspect of the present invention is characterized in that the ceramic sintered body includes at least one element belonging to Group 3a of the periodic table, and at least a part of the ceramic sintered body has been hydrated with steam or high-temperature water. A ring member is provided. In this case, it is preferable that the ceramic sintered body is obtained by subjecting a ceramic selected from Y2O3, CeO2, Ce2O3, and Nd2O3 to a hydration treatment.

  According to a twelfth aspect of the present invention, there is provided a ring member comprising a ceramic sintered body containing a hydroxide containing at least one element belonging to Group 3a of the periodic table. In this case, the hydroxide contained in the ceramic sintered body is preferably selected from Y (OH) 3, Ce (OH) 3, and Nd (OH) 3.

  According to the present invention, by applying a predetermined DC voltage to the electrode in the ring member made of an insulator, the state of the plasma can be adjusted for each process, so that the apparatus can be shared for a plurality of different process processes. Can be achieved. Further, by setting various DC voltages to be applied to the electrodes, for example, when performing the same process using a plurality of processing vessels, it is possible to easily perform adjustment for aligning the state of plasma between the apparatuses. it can.

  Further, according to the present invention, in the ring member having the structure having the base material and the coating formed by thermal spraying, since various layers functioning as barriers are provided, the base material surface is not exposed to the process gas or the cleaning liquid. And the peeling of the coating formed by thermal spraying can be suppressed.

  Further, according to the present invention, a ceramic containing at least one element belonging to Group 3a of the periodic table is subjected to hydration treatment or a hydroxide containing at least one element belonging to Group 3a of the periodic table is provided. By forming a layer containing a substance or a sintered body, it is possible to obtain a structure in which moisture is hardly adsorbed and hardly desorbed, so that a ring member in which desorption of water hardly occurs during plasma processing can be obtained.

  An embodiment of a plasma processing apparatus according to the present invention will be described with reference to FIG. In the drawing, reference numeral 2 denotes an airtightly formed processing container made of a conductive material such as aluminum, and the processing container 2 is grounded. The processing container 2 includes an upper electrode 3 also serving as a gas shower head which is a gas supply unit for introducing a predetermined processing gas, for example, an etching gas, and a substrate mounting table for mounting a substrate to be processed, for example, a wafer W. The lower electrode 4 also serving as the second electrode is provided so as to face each other. An exhaust port 21 is provided at the bottom of the processing container 2, and a vacuum exhaust unit, for example, a vacuum pump 22 such as a turbo-molecular pump or a dry pump is connected to the exhaust port 21 via an exhaust path 21 a. Further, an opening 24 for loading or unloading the wafer W is provided on the side wall of the processing container 2 and has a gate valve 23 that can be opened and closed.

  A large number of gas diffusion holes 31 are formed on the lower surface side of the upper electrode 3 so as to face the wafer W mounted on the lower electrode 4, and the processing gas from the upper gas supply path 32 is supplied to the gas diffusion holes 31. , And is uniformly supplied to the surface of the wafer W via the gas diffusion holes 31. Further, the gas supply path 32 has a first gas supply system 33 for supplying the first processing gas at the base end side, and a second gas supply system 33 for supplying the second processing gas different in type from the first processing gas. The respective supply systems 33 (34) are connected to a processing gas selected from either the first gas supply system 33 or the second gas supply system 34 by, for example, opening and closing a valve (not shown). Is configured to be supplied. The first gas supply system 33 and the second gas supply system 34 shown here are a first processing gas for performing the first processing and a second processing gas for performing the second processing, respectively. The first processing gas (second processing gas) does not mean one kind of gas, but may be a plurality of kinds of gases. In addition, only one gas supply path 32 is shown for convenience, and a required number of gas supply paths are provided in practice.

  The upper electrode 3 is connected via a low-pass filter 35 to a high-frequency power supply 36 for supplying power having a frequency of, for example, 60 MHz. Further, around the upper electrode 3, an annular shield ring 37 made of quartz is provided so as to be fitted to the outer peripheral portion of the upper electrode 3.

  The lower electrode 4 is connected via a high-pass filter 40 to a high-frequency power supply 41 for applying a bias voltage having a frequency of, for example, 2 MHz. Further, the lower electrode 4 is disposed on an elevating mechanism 42 provided at a lower portion of the processing container 2, thereby being configured to be able to move up and down. Reference numeral 43 denotes a bellows for preventing plasma from entering under the lower electrode 4. Further, on the upper surface of the lower electrode 4, an electrostatic chuck 44 for suction-holding the back surface of the wafer W by an electric suction action is provided. The electrostatic chuck 44 includes a sheet-like chuck electrode 45, an insulating layer 46 made of, for example, polyimide, covering the surface of the chuck electrode 45, and a DC power supply 47 for applying a chuck voltage to the chuck electrode 45. I have. Furthermore, an annular base plate (not shown) made of an insulating material such as quartz is provided around the lower electrode 4 to protect the electrode from plasma.

  Further, the lower electrode 4 is provided with a temperature adjusting means for adjusting the temperature of the wafer W to a predetermined temperature. This temperature adjusting means is for adjusting the temperature of the wafer W from the back side by the refrigerant flow chamber 48, the refrigerant, the gas supply means, the heat transfer gas and the like. Specifically, the lower electrode 4 is provided with a refrigerant flow chamber 48, and the refrigerant is circulated between the refrigerant flow chamber 48 and an external refrigerant temperature control unit (not shown). Further, in a very small gap between the front surface of the electrostatic chuck 44 and the back surface of the wafer W in a vacuum atmosphere (a space formed by unevenness generated due to the limit of processing accuracy of the front surface), it is called a backside gas or the like. A gas supply hole (not shown) for purging a heat transfer gas, for example, a helium gas, is formed in the surface of the electrostatic chuck 44. The gas supply hole is connected to, for example, gas supply means (not shown). ing.

  A focus ring, which is a ring member made of a material selected from an insulator, for example, alumina, quartz, yttrium oxide, etc., is provided around the electrostatic chuck 44 so as to surround the periphery of the wafer W sucked and held by the electrostatic chuck 44. 5 are provided. The focus ring 5 is set to have a width of, for example, 50 mm, and is preferably provided as close as possible to the outer peripheral edge of the wafer W. For example, the focus ring 5 is provided so as to be within 2 mm, preferably 1 mm from the outer peripheral edge of the wafer W. ing. Further, inside the focus ring 5, an electrode 51, for example, a metal foil such as molybdenum (Mo) or aluminum (Al), or a tungsten film is provided in a ring shape over the circumferential direction. Further, a predetermined DC voltage is applied to the electrode 51 for each process, for example, a first DC voltage is applied to the electrode 51 during the first process, and a second DC voltage is applied to the electrode 51 during the second process. Is connected to a DC power supply 52 having an actuator 52a for switching the applied voltage. The focus ring 5 has a role of diffusing plasma, which tends to be concentrated, for example, on the periphery of the wafer W and its vicinity, thereby improving the uniformity of the plasma toward the wafer W.

  Here, a method of manufacturing the focus ring 5 described above will be briefly described, but the invention is not limited by the method of manufacturing. First, for example, a metal foil is formed on the surface of a ring-shaped quartz by screen printing, film formation, or the like, or a metal mesh body is placed to form an electrode 51, and a thin quartz plate is placed thereon. The focus ring 5 is obtained by bonding or welding, or by spraying yttrium oxide or the like. Further, as another method, for example, a metal powder is placed on the surface of a ring-shaped alumina, and the metal powder is solidified by pressing, for example, to form an electrode 51, and the alumina powder is placed thereon and sintered to form the focus ring 5. obtain.

  In FIG. 1, reference numeral 6 denotes a control unit. The control unit 6 has a function of controlling the operations of the high-frequency power supply unit 36, the high-frequency power supply unit 41, the actuator 52a, the first gas supply system 33, and the second gas supply system 34. The control function of the control unit 6 will be further described with reference to FIG. 2. The control unit 6 includes a computer 60, and a storage area 61 of the computer 60 stores a plurality of process recipes. In this process recipe, for example, processing conditions such as the applied voltage of the electrode 51, the process pressure, the wafer W temperature, the type of the processing gas, and the supply flow rate of the processing gas are associated with the type of the film to be processed on the surface of the wafer W. The setting value information is stored. Reference numeral 62 denotes a recipe selection unit for an operator to select a process recipe corresponding to the type of film to be processed, for example. For example, when films having different processing conditions are present on the surface of the wafer W, the first processing and the second processing are determined based on the types and combinations of the films, and the first processing and the second processing are further performed. Is selected by the recipe selection means 62. Although the first processing and the second processing are shown for convenience, the process recipe may be prepared corresponding to the third processing, the fourth processing,... As necessary. Conditions such as the voltage applied to the electrode 51 are determined for each process. The actuator 52a is controlled so that a predetermined DC voltage is applied to the electrode 51 based on the information of the selected process recipe, and a predetermined processing gas is introduced into the processing vessel 2 at a predetermined flow rate. , The supply operation of the first gas supply system 33 and the second gas supply system 34 is controlled. 63 is a CPU, and B is a bus.

  Here, how the state of the plasma is adjusted by applying a DC voltage to the electrode 51 of the focus ring 5 will be described with reference to the schematic diagram shown in FIG. First, as shown in FIG. 3A, when no DC voltage is applied to the electrode 51, when the processing gas in the processing chamber 2 is turned into plasma, a boundary between the surface of the wafer W and the plasma P is formed. In the case, an ion sheath region (plasma sheath region) including the high-density positive ion species 200 is formed due to a higher electron moving speed than the positive ion species. Similarly, an ion sheath region is formed at the boundary between the surface of the focus ring 5 and the plasma P. However, since an insulator is selected as the material of the focus ring 5, the ion sheath region is thicker than the wafer W side. An area is formed. The ion sheath region is formed in various shapes depending on the shape, material and the like of the focus ring 5. If the thickness of the ion sheath region is different as described above, the density of the plasma P varies in the plane of the wafer W, particularly between the central portion and the peripheral portion. For example, when a positive DC voltage is applied, a repulsive force having a strength corresponding to the magnitude of the applied voltage acts between the positive ion species 200 and the electrode 51, and the positive ion species 200 in the ion sheath region is turned into plasma. The density of the plasma P changes as a result of being returned to the P and changing the shape, particularly the thickness, of the ion sheath region.

  More specifically, for example, as shown in FIG. 3B, when the DC voltage applied to the electrode 51 is small, the amount of the positive ion species 200 returned to the plasma P is small, so that the ion sheath region becomes thick, and therefore, the wafer becomes thick. The density of the plasma P near the periphery of W becomes higher than that in the center. On the other hand, as shown in FIG. 3C, when the DC voltage applied to the electrode 51 is large, the positive ion species 200 is returned to the plasma P, and the ion sheath region becomes thin, so that the plasma near the periphery of the wafer W is reduced. P becomes lower in density than the plasma density near the periphery of the wafer W in FIG. Further, as shown in FIG. 3D, when the DC voltage is further increased, the ion sheath region becomes thinner than the wafer W side. Therefore, when a predetermined DC voltage is applied to the electrode 51, the state of the plasma P is adjusted as a result. However, how the DC voltage to be actually applied is set can achieve uniform in-plane processing of the wafer W. It depends on the type of film to be etched, the power supplied to each of the electrodes 3 and 4, and the like, so it is desirable to conduct an experiment in advance to determine the set value for each process. Note that a negative voltage may be applied to the electrode 51.

  Next, a method for processing a wafer W as a substrate to be processed by using the above-described plasma processing apparatus will be described. Here, as an example of different process processing, as shown in FIG. An example will be described in which a wafer W on which a silicon nitride film 65 having different processing conditions from a silicon film is stacked on a silicon film 64 is etched. In this example, as shown in FIG. 4B, a process of etching the upper silicon nitride film 65 is a first process, and as shown in FIG. 4C, the process is performed after the first process. The processing for etching the lower silicon film 64 is a second processing, a process recipe corresponding to these processings is selected by the recipe selecting means 62, and processing conditions are set based on information of the selected process recipe. It will be.

  Then, first, the gate valve 23 is opened, the wafer W is carried into the processing chamber 2 from the load lock chamber (not shown), and the wafer W is placed on the electrostatic chuck 44 of the lower electrode 4 via the substrate elevating pins (not shown). After that, the gate valve 23 is closed to make the processing container 2 airtight. Next, the elevating mechanism 42 is moved up so that the surface of the wafer W is set at a predetermined height position with respect to the upper electrode 3. On the other hand, the surface of the lower electrode 4 is set at a predetermined temperature because the refrigerant circulates in the flow chamber 50. When a gas for heat transfer is supplied to an extremely small gap with the surface of the electrode 4, when plasma is generated as described later, heat transferred from the plasma to the wafer W and gas for heat transfer from the lower electrode 4 are generated. The wafer W is adjusted to a predetermined process temperature by a balance with the heat transferred to the wafer W through the substrate.

Further, while the inside of the processing chamber 2 is evacuated by the vacuum pump 22, a first etching gas such as CHF ₃ from the first gas supply system 33 is introduced at a predetermined flow rate through the gas supply path 32. The liquid is uniformly jetted toward the surface of the wafer W through the diffusion holes 31, and the inside of the processing container 2 is maintained at a vacuum degree of, for example, 30 mTorr to 100 mTorr (about 4-13.3 Pa). The first etching gas forms an airflow that flows radially outward along the surface of the wafer W, and is uniformly exhausted from around the lower electrode 4.

  A first DC voltage, for example, a voltage of 1000 V is applied to the electrode 51, and a high-frequency voltage of, for example, 60 MHz is applied to the upper electrode 3 from the high-frequency power supply unit 34 at, for example, 1800 W. A bias voltage of, for example, 2 MHz is applied to the lower electrode 4 from the high frequency power supply 41 at, for example, 1800 to 2250 W. Thereby, the first etching gas is turned into plasma, and an ion sheath region is formed at the boundary between the plasma and the surface of the wafer W and the focus ring 5. The ion sheath region above the focus ring 5 is formed to have a thickness corresponding to the magnitude of the DC voltage applied to the electrode 51 as described above. Shape. Here, the active species of the plasma move to the ion sheath region, enter the surface of the wafer W to which a high frequency bias is applied with high perpendicularity, and etch the silicon nitride film 65.

  When the etching of the silicon nitride film 65 as the first process is completed, the process recipe of the second process in the storage area 61 is read out, the process conditions are set, and the second process is started. First, the inside of the processing container 2 is cut off, the first etching gas is exhausted, and the applied voltage is switched by the actuator 52 a so that a second DC voltage, for example, a voltage of 100 V is applied to the electrode 51. Further, the high-frequency power supply unit 36 and the high-frequency power supply 41 adjust a high-frequency voltage applied to the upper electrode 3 and the lower electrode 4 according to a process recipe, and a second etching gas such as Cl is supplied from the second gas supply system 34 into the processing chamber 2. If introduced, the second etching gas is turned into plasma. At this time, the thickness of the ion sheath region above the focus ring 5 is adjusted according to the second DC voltage applied to the electrode 51, and a plasma having a shape suitable for etching the silicon film 64 is generated. Will be etched.

  According to the above-described embodiment, by applying a predetermined DC voltage to the electrode 51 of the focus ring 5, the boundary between the surface of the focus ring 5 and the plasma for each process, for example, for each type of film having different processing conditions. The shape of a certain ion sheath region can be adjusted, and an appropriate plasma state in which the wafer W can be uniformly processed in a plane can be formed. Therefore, a plurality of different process processes can be performed using the common focus ring 5, so that the apparatus can be shared. If the apparatus can be shared for a plurality of process processes as described above, the footprint of the apparatus can be reduced, and the production and operation costs of the apparatus can be reduced.

  Further, according to the above-described embodiment, for example, when the same process is performed using a plurality of processing vessels 2, adjustment for making the plasma state uniform among the apparatuses can be easily performed. For example, when a plurality of the above-described plasma processing apparatuses are arranged in a clean room and the same processing is performed between these apparatuses, a slight difference occurs in the processing result of the wafer W because the assembly of the apparatuses is slightly different. However, in this case, by adjusting the voltage applied to the electrode 51, characteristics between devices, that is, processing results can be made uniform, and adjustment between devices is easy. For example, the state of the processed wafer W may be inspected, and the applied voltage may be finely adjusted for each apparatus based on the inspection result. Note that the present invention is not limited to sharing the apparatus, and may be a dedicated apparatus for performing a certain kind of processing, for example, etching a specific film.

  In the plasma processing apparatus of the present invention, the present invention is not limited to the configuration in which two types of process processes are shared as in the first process and the second process. Among them, three, four, or five different processes may be shared depending on the types of films having different processing conditions. Further, six or more different types of processes may be shared. Even with such a configuration, the same effects as those described above can be obtained.

  In the plasma processing apparatus of the present invention, the focus ring 5 made of an insulator is not limited to the configuration arranged close to the periphery of the wafer W. As shown in FIG. Between them, a conductor such as a silicon ring 8 may be provided in the circumferential direction. Even with such a configuration, the same effects as those described above can be obtained.

  In the plasma processing apparatus of the present invention, the number of the electrodes 51 provided on the focus ring 5 is not limited to one, and for example, two ring-shaped electrodes 51a and 51b are provided in the focus ring 5 in the radial direction as shown in FIG. DC power supplies 52A, 52B provided side by side and each provided with an actuator to each of the electrodes 51a, 51b may be connected to each other so that the DC voltage can be adjusted independently. Even with such a configuration, the same effects as those described above can be obtained. Further, in this case, the DC voltage can be set finely in the plane of the focus ring 5 by, for example, applying a DC voltage smaller than the inner electrode 51a to the outer electrode 52b. Can be adjusted with higher precision. The processing container 2 is not symmetrical with respect to the center when viewed in plan view, for example, a transfer port is partially provided. Therefore, the plasma may not be uniform in the circumferential direction. In some cases, in-plane uniformity of processing may be poor in the direction. In this case, the electrode 51 in the focus ring 5 is separated from the electrode in the other part only at a specific part in the circumferential direction, and the uniformity of the plasma in the circumferential direction is achieved by changing the voltage applied to both electrodes. Good.

  In the present invention, the present invention is not limited to the configuration in which the applied voltage is switched by the actuator 52a. For example, a DC power supply 52 for the first processing and a DC power supply 52 for the second processing may be provided and switched by a switch. In this case, the same effect as in the above case can be obtained. Further, in the above-described example, an example is described in which etching is performed as plasma processing. However, other plasma processing can be applied to various plasma processing such as CVD and ashing.

  Finally, an example of a system incorporating the above-described plasma processing apparatus will be described with reference to FIG. In the drawing, reference numeral 90 denotes a first transfer chamber. On both sides of the transfer chamber 90, cassette chambers 92A and 92B into which a cassette 91 capable of storing a large number of wafers W can be loaded from outside are gate valves G1 and G2. Are connected to each other. Further, behind the first transfer chamber 90, preliminary vacuum chambers 93A and 93B are connected via gate valves G3 and G4, respectively. In the first transfer chamber 90, a first transfer means 94 composed of, for example, an articulated arm is provided. A second transfer chamber 95 is connected to the rear side of the preliminary vacuum chambers 93A and 93B via gate valves G5 and G6, and the second transfer chamber 92 is further connected to the left, right, and rear sides, respectively. The processing vessels 2 (2A, 2B, 2C) of the above-described plasma processing apparatus are respectively connected via gate valves G7 to G9 (corresponding to the gate valve 23). Further, in the second transfer chamber 95, a second transfer means 96 composed of, for example, an articulated arm is provided.

  In this system, the wafer W in the cassette 91 is transported along the route of the first transfer chamber 90 → the preliminary vacuum chamber 93A → the second transfer chamber 95. Here, in each of the processing vessels 2A to 2C, for example, three types of films can be etched, and the wafer W on which the three types of films to be etched are formed is a wafer W among the processing vessels 2A to 2C. It is carried into the empty processing container 2A (2B, 2C), and three types of films are etched in the processing container 2A (2B, 2C). Thereafter, the wafer W is unloaded from the processing container 2A (2B, 2C), and the wafer W is returned into the cassette 91 in a flow reverse to the above-described loading operation.

  FIG. 8 is a longitudinal sectional view showing an example of a plasma etching apparatus which is a plasma processing apparatus having a ring member to which the present invention is applied. In the figure, reference numeral 20 denotes a vacuum chamber forming a processing vessel, which is formed of a conductive material such as aluminum so as to form an airtight structure, and the vacuum chamber 20 is grounded for safety. Further, a cylindrical deposition shield 20a is disposed on the inner surface of the vacuum chamber 20 to prevent the inner surface from being damaged by the plasma. In the vacuum chamber 20, a gas shower head 30 also serving as an upper electrode and a mounting table 210 also serving as a lower electrode are provided to face each other. An exhaust pipe 26 is connected as a vacuum exhaust path communicating with the vacuum exhaust means 25 composed of. Further, an opening 27 for carrying in / out an object to be processed, for example, a semiconductor wafer W, is formed in the side wall of the vacuum chamber 20, and can be opened and closed by a gate valve G. Outside the side wall portion, for example, ring-shaped permanent magnets 28 and 29 are provided at positions vertically sandwiching the opening 27, respectively.

  The gas shower head 30 has a large number of holes 38 formed at positions on the mounting table 210 that face the workpiece W, and processes the flow-controlled or pressure-controlled process gas sent from the upper gas supply pipe 39. It is configured to uniformly supply the surface of the workpiece W through the hole 38.

  The mounting table 210 provided below the gas shower head 30 at an interval of about 5 mm to 150 mm is made of, for example, aluminum whose surface is anodized, and is insulated from the vacuum chamber 20 by the insulating member 211a. A pillar-shaped main body portion 211, an electrostatic chuck 212 provided on the upper surface of the main body portion 211, a focus ring 213 as an annular ring member surrounding the periphery of the electrostatic chuck 212, and the focus ring 213 and the main body portion And an insulating ring 213a, which is an annular insulating member provided between the first and second components 211 and 211. The electrostatic chuck 212 includes a sheet-like chuck electrode 216 and an insulating layer 215 made of, for example, polyimide and covering the surface of the chuck electrode 216. The focus ring 213 is made of an insulating or conductive material depending on the process, and acts to confine or diffuse reactive ions as described above. Although not shown, electrodes are provided inside the focus ring 213 in a ring shape, for example, as in the embodiment of FIG. Further, the DC power supply 52, the actuator 52a, and the control unit 6 shown in FIG. 1 are provided, and the first DC voltage and the second DC voltage are applied to the electrodes in the focus ring 213. Similarly, electrodes may be provided in the insulating ring 213a and connected to another DC power supply or the DC power supply to switch the applied voltage.

  A high frequency power supply 200 is connected to, for example, the main body 211 of the mounting table 210 via a capacitor C1 and a coil L1, and high frequency power of, for example, 13.56 MHz to 100 MHz is applied.

  Further, inside the mounting table 210, a temperature adjusting means 314a such as a cooling jacket and a heat transfer gas supplying means 314b for supplying, for example, He gas to the back surface of the processing object W are provided. By activating the 314a and the heat transfer gas supply means 314b, the processing surface temperature of the processing target W held on the mounting table 210 can be set to a desired value. The temperature adjusting means 314a has an inlet pipe 315 and a discharge pipe 316 for circulating the refrigerant through the cooling jacket, and the refrigerant adjusted to an appropriate temperature is supplied into the cooling jacket by the inlet pipe 315, The refrigerant after the exchange is discharged outside through the discharge pipe 316.

  A ring-shaped exhaust plate 214 having a plurality of exhaust holes is provided between the mounting table 210 and the vacuum chamber 20 and below the surface of the mounting table 210 so as to surround the mounting table 210. You. The exhaust plate 214 regulates the flow of the exhaust flow and optimally confines the plasma between the mounting table 210 and the gas shower head 30. Further, in the inside of the mounting table 210, a plurality of, for example, three lifting pins 310 (only two are shown) are lifted and lowered, which are lifting members for transferring the workpiece W to and from a transfer arm (not shown) outside. The lifting pin 310 is provided freely, and is configured to be able to be raised and lowered by a driving mechanism 312 via a connecting member 311. Reference numeral 313 denotes a bellows for maintaining airtightness between the through hole of the elevating pin 310 and the air side.

  In such a plasma etching apparatus, first, the object W is loaded into the vacuum chamber 20 via the gate valve G and the opening 27, placed on the electrostatic chuck 212, and the gate valve G is closed. After that, the inside of the vacuum chamber 20 is evacuated to a predetermined degree of vacuum through the exhaust pipe 26 by the vacuum exhaust means 25. Then, a process gas is supplied into the vacuum chamber 20, and a DC voltage is applied from the DC power supply 217 to the chuck electrode 216 to cause the workpiece W to be electrostatically attracted by the electrostatic chuck 212. A high-frequency electric power of a predetermined frequency is applied to the main body 211 of the mounting table 210 from this, thereby generating a high-frequency electric field between the gas shower head 30 and the mounting table 210, turning the process gas into plasma, and The upper workpiece W is subjected to an etching process. The DC power supply 217 is turned on / off by switching the switch SW1 based on a command from the control unit 80.

  As the process gas, a gas containing a halogen element such as a fluoride such as C4F8 or NF3, a chloride such as BCl3 or SnCl4, or a bromide such as HBr is used. For this reason, the inside of the vacuum chamber 20 becomes an extremely strong corrosive environment. For example, the deposition shield 20a, the exhaust plate 214, the focus ring 213, the shower head 30, the mounting table 210, the electrostatic chuck 212, and the inner wall material of the vacuum chamber 20 The members inside the vacuum chamber 20, that is, the members inside the plasma processing vessel, are required to have high plasma resistance.

  Hereinafter, the above-mentioned ring member will be described in detail. Here, the ring member to which the structure of the present invention is applied corresponds to the focus ring 213 and the insulating ring 213a. Although the insulating ring 213a is laminated below the focus ring 213, the following processing is also preferably performed on the insulating ring 213a because the inner edge thereof comes into contact with a processing gas or a cleaning liquid. In the present invention, the following processing may be performed only on the focus ring 213.

  Conventionally, when a sprayed coating was formed on a base material as a ring member, peeling of the sprayed coating had occurred.According to the results of studies by the present inventors, peeling of the sprayed coating of the ring member was difficult. The process gas or cleaning liquid enters from the through-holes (micropores) of the thermal spray coating, the boundary with the thermal spray coating, or the part damaged by plasma, gas, etc., and reaches the substrate, and the substrate surface is corroded. It is thought that it occurs by doing.

  That is, when a ring member that has been subjected to plasma processing using a process gas containing fluoride is prepared, and an interface (substrate surface) with the sprayed coating is analyzed, F (fluorine) can be confirmed at that portion. From this, it is presumed that this F reacts with water (OH) to form HF, so that the surface of the base material undergoes a corrosion change (corrosion products are generated), leading to peeling of the thermal spray coating. .

  Therefore, it is important that the interface with the thermal spray coating, that is, the substrate surface, is not exposed to the process gas or the cleaning liquid.

  Based on such knowledge, in the ring member in FIG. 8, at any position from the surface of the thermal spray coating to the substrate, it is hardly corroded even when exposed to a process gas or a cleaning solution. A portion having a barrier function that can be prevented from reaching is formed.

  By forming a portion having a barrier function with such a material having excellent corrosion resistance, the surface of the base material is protected against a gas or a cleaning liquid that enters through through pores (micropores) of the thermal spray coating. Is possible. Further, if the portion having the barrier function is brought into contact with the base material, by selecting a material having high adhesion as the material, the process gas from the interface between the portion having the barrier function and the surface of the base material is selected. Alternatively, it is possible to protect the surface of the base material from entering the cleaning liquid.

  Hereinafter, a specific configuration of the ring member will be described in detail. First, as shown in FIG. 9, the first example of the ring member basically includes a substrate 71 and a coating 72 formed on the surface thereof. The coating 72 has a main layer 73 formed by thermal spraying, and a barrier coat layer 74 having a barrier function that is hardly corroded even when exposed to a process gas or a cleaning liquid between the base 71 and the main layer. .

  The base material 71 on which the coating film 72 is applied includes various steels including stainless steel (SUS), Al and Al alloys, W and W alloys, Ti and Ti alloys, Mo and Mo alloys, carbon and oxide-based materials. , A non-oxide ceramic sintered body, and a carbonaceous material are preferably used.

  The material of the barrier coat layer 74 is preferably a ceramic containing at least one element selected from the group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd. More specifically, at least one ceramic selected from the group consisting of B4C, MgO, Al2O3, SiC, Si3N4, SiO2, CaF2, Cr2O3, Y2O3, YF3, ZrO2, TaO2, CeO2, Ce2O3, CeF3 and Nd2O3. Is preferred. For example, “CDC-ZAC” or “Super ZAC” manufactured by Tokaro Corporation can be applied. "CDC-ZAC" is a composite ceramic containing Cr2O3 as a main component, and has properties such as porelessness, high hardness, and high adhesion.

  On the other hand, “Super ZAC” is a composite ceramic containing SiO 2 and Cr 2 O 3 as main components, and is excellent in heat resistance and abrasion resistance in addition to non-porosity, high hardness and high adhesion. This barrier coat layer 74 is preferably formed by a thermal spraying method. The thermal spraying method is a method in which a raw material melted by a heat source such as combustion gas or electricity is sprayed on a base material to form a coating. Further, the barrier coat layer 74 can also be formed by a thin film forming technique such as a PVD method or a CVD method, a dipping method, or a coating method. The PVD method is a method of coating various ceramic films at a low temperature by an ion plating method, while the CVD method is a method of coating a single layer or a multilayer at a high temperature by a thermochemical vapor deposition method. The immersion method is a method in which various materials are immersed in a resin solution and then heat-treated. The coating method is a method in which a resin solution is applied to various materials and heat-treated at a predetermined temperature. The thickness of the barrier coat layer 74 is preferably 50 to 100 μm.

  In this case, at least a part of the barrier coat layer 74, for example, a bonding surface side with the base material 71 or the entirety thereof is preferably subjected to a sealing treatment using a resin. As the resin at that time, a resin selected from the group of SI, PTFE, PI, PAI, PEI, PBI, and PFA is preferable. That is, when the barrier coat layer 74 made of ceramic is formed by the above-described thermal spraying method or the like, the barrier coat layer 74 is formed of a porous material having through-holes (micropores), and at least a part of the micropores of the porous layer is formed of resin. By sealing, the effect of blocking gas or cleaning liquid entering through the fine holes of the main layer 73, which is a thermal spray coating, is enhanced, and the base material 71 can be effectively protected.

  SI is silicone, PTFE is polytetrafluoroethylene, PI is polyimide, PAI is polyamideimide, PEI is polyetherimide, PBI is polybenzimidazole, and PFA is perfluoroalkoxyalkane.

  The sealing treatment can be performed by a sol-gel method. The sealing treatment by the sol-gel method is performed by sealing with a sol (colloid solution) in which ceramics is dispersed in an organic solvent and then gelling by heating. Thereby, sealing with ceramics is realized, and the barrier effect can be improved. In this case, it is preferable to use a material selected from elements belonging to Group 3a of the periodic table for the sealing treatment. Among them, Y2O3 having high corrosion resistance is preferable.

  Further, as another material of the barrier coat layer 74, engineering plastic can be suitably used. Specifically, it is preferably a resin selected from the group of PTFE, PI, PAI, PEI, PBI, PFA, PPS, and POM, such as "Teflon (registered trademark)" (PTFE) manufactured by DuPont. Can be applied. These resins have excellent adhesiveness, are excellent in chemical resistance, and can sufficiently withstand a cleaning liquid at the time of cleaning.

  In addition, PTFE means polytetrafluoroethylene, PI means polyimide, PAI means polyamideimide, PEI means polyetherimide, PBI means polybenzimidazole, PFA means perfluoroalkoxyalkane, PPS means polyphenylene sulfide, and POM means polyacetal.

  Further, an anodic oxide film 75 may be formed between the base material 71 and the barrier coat layer 74 as shown in FIG. In this case, by forming an anodic oxide film with an organic acid such as oxalic acid, chromic acid, phosphoric acid, nitric acid, formic acid, or sulfonic acid, an oxide film having excellent corrosion resistance compared to the case of anodizing treatment with sulfuric acid is formed. The formation is preferable because corrosion by a process gas or a cleaning liquid can be further suppressed. The thickness of the anodic oxide coating 75 is preferably 10 to 200 μm.

  As described above, when the anodic oxide film 75 is formed between the base material 71 and the barrier coat layer 74, the corrosion resistance can be remarkably improved by sealing the fine holes of the anodic oxide film 75. In this case, the material is immersed in hot water containing a metal salt such as Ni, and the metal salt aqueous solution is hydrolyzed in the fine pores of the oxide film and the hydroxide is precipitated, whereby the metal salt is sealed. Holes and the like can be applied.

  Similar effects can be expected even if the micropores of the anodic oxide coating 75 are sealed with a resin. As the resin in this case, a resin selected from the above-mentioned group of SI, PTFE, PI, PAI, PEI, PBI, and PFA is preferable.

  Further, as the anodic oxide film 75 formed on the surface of the base material 71, an anodic oxide film having a porous ceramic layer (KEPLA-COAT: registered trademark) may be used.

  The anodic oxide film (KEPLA-COAT) is formed by immersing the base material as an anode in an alkaline organic electrolyte and discharging oxygen plasma in the alkaline organic electrolyte.

  The main layer 73, which is a thermal spray coating, preferably contains at least one element selected from the group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd. Preferably, at least one ceramic selected from B4C, MgO, Al2O3, SiC, Si3N4, SiO2, CaF2, Cr2O3, Y2O3, YF3, ZrO2, TaO2, CeO2, Ce2O3, CeF3 and Nd2O3. In this case, the main layer 73 preferably has a thickness of 10 μm to 500 μm.

  When manufacturing a ring member having such a structure, first, the surface of the base material 71 is subjected to a blast treatment of spraying particles of Al2O3, SiC, sand, or the like, so that the surface becomes microscopically uneven. It is preferable to improve the adhesion to the barrier coat layer 74 and the anodic oxide film 75 formed thereon. Further, the method for making the surface uneven is not limited to the above blast treatment, and for example, the surface may be etched by being immersed in a predetermined chemical solution.

  Next, the above-described barrier coat layer 74 is formed on the substrate 71 directly or via the anodic oxide film 75 by an appropriate method such as a thermal spraying method. If necessary, the above-described sealing treatment is performed.

  In the sealing treatment, the above resin or ceramic sol is applied to the surface of the barrier coat layer 74, or the base material 71 with the barrier coat layer 74 is immersed in a resin sealing agent or ceramic sol. . When the pores are sealed with a ceramic sol, they are then heated and gelled.

  After the formation of the barrier coat layer 74, subsequently, from the group consisting of B4C, MgO, Al2O3, SiC, Si3N4, SiO2, CaF2, Cr2O3, Y2O3, YF3, ZrO2, TaO2, CeO2, Ce2O3, CeF3 and Nd2O3. The main layer 73, which is a thermal spray coating made of at least one selected ceramic, is formed. The barrier coat layer 74 is selected from those having excellent adhesion. However, in order to further improve the adhesion with the main layer 73, the surface of the barrier coat layer 74 may be subjected to blast treatment or the like.

  As described above, in this example, the barrier coat layer 74 made of a material having excellent corrosion resistance to a process gas or a cleaning liquid containing a halogen element is formed between the main layer 73 which is a thermal spray coating and the base material 71. Since the surface of the substrate 71 is configured not to be exposed to the process gas (halogen element) or the cleaning solution, corrosion products are generated on the surface of the substrate 71, so that the thermal spray coating 72 on the substrate 71 is formed. The problem of peeling can be solved.

  Next, a second example of the ring member will be described. In the second example, as shown in FIGS. 11A, 11B, and 11C, a coating 76 is formed on the surface of the base material 71 by spraying ceramics, and at least a portion of the coating 76 is sealed. The processing section 76a is formed. In the example of FIG. 11A, the sealing portion 76a is formed on the base material 71 side of the coating 76. In the example of FIG. 11B, the sealing portion 76a is formed on the surface side of the coating 76. In the example shown in FIG. 11C, the entire coating 76 is used as the sealing portion 76a.

  The coating 76 contains at least one element selected from the group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce, and Nd. At least one ceramic selected from the group consisting of MgO, Al2O3, SiC, Si3N4, SiO2, CaF2, Cr2O3, Y2O3, YF3, ZrO2, TaO2, CeO2, Ce2O3, CeF3 and Nd2O3 is preferred. In this case, the thickness of the coating 76 is preferably 50 to 300 μm. Note that the same material as in the first example can be used as the base material 71.

  The sealing portion 76a can be formed by completely the same resin sealing or sol-gel sealing as that performed on the barrier layer 74 of the first example described above. By providing the sealing portion 76a in this manner, gas or a cleaning liquid that enters through the fine holes of the coating 76 that is a thermal spray coating can be effectively prevented, and the base material 71 can be sufficiently protected. it can. Since the sealing processing section 76a is for preventing the gas or the cleaning liquid from reaching the base material 71 as described above, the effect is exhibited in any of (a) to (c) of FIG. be able to. However, as shown in FIG. 11A, it is desirable to form a sealing portion 76a on the base material 71 side of the coating film 76. That is, when a ring member obtained by performing a sealing process on a thermal spray coating is used in a plasma atmosphere in which high-frequency power is applied in a high vacuum region (eg, 13.3 Pa), a diluted organic solvent (eg, The pores (micropores) may be formed again in the sprayed coating due to evaporation of the ethyl acetate), corrosion of the sealing agent by plasma, process gas, or the like. Due to the pores, the surface state of the ring member (such as the temperature and the state of adhesion of products) changes over time, which may adversely affect the process in the processing container. Therefore, if the sealing treatment is not performed on the surface side of the coating 76 as shown in FIG. 11A, the surface modification of the coating 76 can be suppressed and the process can be stably performed. The sealing section 76a is not limited to the positions shown in FIGS. 11A to 11C, but may be formed at an intermediate position of the coating 76, for example. The thickness of the sealing portion 76a is preferably 50 to 100 μm.

  Also in this example, as shown in FIG. 12, an anodic oxide film 75 exactly the same as in the first example described above may be formed between the base material 71 and the film 76. Also in this case, it is preferable that the anodic oxide film 75 is sealed. As the sealing process, the same metal salt sealing as described above can be applied.

  Next, a third example of the ring member will be described. In the third example, as shown in FIGS. 13A and 13B, a coating 77 is formed on the surface of the base material 71 by spraying ceramics, and the coating 77 is formed on the first ceramic layer 78 and the first coating. The two ceramic layers 79 have a two-layer structure, and a sealing portion is formed in at least a part of at least one of the two ceramic layers. In the example of FIG. 13A, the sealing portion 78a is formed on the first ceramic layer 78 on the front surface side, and in FIG. 13B, the second ceramic layer 79 on the base material 71 side is formed. A sealing processing part 79a is formed.

  Each of the first ceramic layer 78 and the second ceramic layer 79 constituting the coating 77 is selected from the group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd. It contains at least one element, specifically, a group consisting of B4C, MgO, Al2O3, SiC, Si3N4, SiO2, CaF2, Cr2O3, Y2O3, YF3, ZrO2, TaO2, CeO2, Ce2O3, CeF3, and Nd2O3. At least one ceramic selected from the group consisting of In this case, the thickness of the coating 77 is preferably 50 to 300 μm. Note that the same material as in the first example can be used as the base material 71.

  The sealing portions 78a and 79a can be formed by completely the same resin sealing or sol-gel sealing as that applied to the barrier coat layer 74 of the first example described above. By providing the sealing portions 78a and 79a in this manner, it is possible to effectively prevent gas or cleaning liquid that enters through the fine holes of the first and second ceramic layers 78 and 79, which are the thermal spray coating. In addition, the base material 71 can be sufficiently protected. Since the sealing portions 78a and 79a are for preventing the gas or the cleaning liquid from reaching the base material 71 as described above, the positions of the sealing portions 78a and 79a are as long as their functions can be exhibited. It is not limited, and the entire layer may be used as a sealing treatment section. In addition, a sealing portion may be formed on both the first and second ceramic layers 78 and 79. The thickness of the sealing portions 78a and 79a is preferably 50 to 100 μm.

  Thus, by forming the coating 77 formed on the base material 71 into a two-layer structure, the materials of these two layers can be appropriately set in accordance with the required corrosion resistance and barrier properties, and can be formed at desired positions. By applying the sealing treatment, an extremely flexible application is possible. For example, Y2O3 is used as the first ceramic layer 78 on the front surface side, YF3 or Al2O3 is used as the second ceramic layer 79 on the base material 71, and at least a part of the second ceramic layer 79 is subjected to sealing treatment. If it is, corrosion resistance and barrier properties can be made extremely high.

  Also in this example, as shown in FIG. 14, an anodic oxide film 75 exactly the same as in the first example described above may be formed between the base material 71 and the film 77. Also in this case, it is preferable that the anodic oxide film 75 is sealed. As the sealing process, the same metal salt sealing as described above can be applied.

  In order to confirm the effect of the ring member having such a structure, Sample 1 in which a thermal sprayed coating of Y2O3 was formed on an Al alloy base material, and a resin (PTFE) barrier coat layer on an Al alloy base material Sample 2 in which a thermal sprayed coating of Y2O3 was formed through a substrate, and Sample 3 in which a thermal sprayed coating of Y2O3 was formed on an Al alloy base material and a portion thereof was sealed with a resin, were prepared. The hydrofluoric acid (HF) solution was dropped on the surface of No. 3 and the surface state of the sprayed coating when placed in a plasma environment was compared. More specifically, 10 μL of a 38% hydrofluoric acid solution was dropped on the surface of each sample, heated at 50 ° C. for 3 hours, and then left for 3 minutes in a CF-based gas plasma atmosphere. As a result, in Sample 1 in which no measures were taken against peeling of the thermal spray coating, cracks occurred on the entire surface, whereas Sample 2 in which a barrier coat layer was formed between the base material and the thermal spray coating, Sample 3 in which a part was sealed with a resin did not have any cracks, indicating that the intrusion of the hydrofluoric acid solution was prevented and the surface of the base material was protected.

  When Al2O3 or Y2O3 is used as the ring member, a large amount of moisture is taken in when the vacuum chamber, which is a processing container, is opened to the atmosphere or when the vacuum chamber is wet-cleaned because of high reactivity with moisture in the air. According to the results of studies by the present inventors, ceramics containing an element belonging to Group 3a of the periodic table, such as Y2O3, are subjected to hydration treatment, or hydroxylated containing these elements. It has been found that such an inconvenience is solved by forming an object.

  Based on such knowledge, in the ring member in FIG. 8 (in this example, the focus ring 213 and the insulating ring 213a), a portion obtained by subjecting a ceramic containing an element belonging to Group 3a of the periodic table to a hydration treatment is formed. Alternatively, at least a part thereof is made to be a hydroxide containing the element.

  By doing so, it is possible to obtain a structure in which moisture is hardly adsorbed and hardly desorbed, so that a ring member in which water is hardly desorbed during plasma processing can be obtained.

  First, in a fourth example of the ring member, as shown in FIG. 15, a coating 82 made of ceramics containing an element belonging to Group 3a of the periodic table is formed on a base material 81, and, for example, at least the surface portion thereof is formed. The hydration treatment part 82a is formed.

  As the base material 81, similarly to the base material 71, various steels including stainless steel (SUS), Al and Al alloys, W and W alloys, Ti and Ti alloys, Mo and Mo alloys, carbon and oxide-based materials, A non-oxide ceramic sintered body, a carbonaceous material, and the like are preferably used.

  The coating 82 may be made of a ceramic containing an element belonging to Group 3a of the periodic table, but is preferably an oxide containing an element belonging to Group 3a of the periodic table. Among these, Y2O3, CeO2, Ce2O3, and Nd2O3 are preferable. Among them, Y2O3 is particularly preferable because it has been widely used and has high corrosion resistance.

  This film 82 can be suitably formed by a thin film forming technique such as a thermal spraying method, a PVD method or a CVD method. In addition, it can also be formed by a method such as a dipping method or a coating method.

The hydration treatment section 82a can be formed, for example, by causing a hydration reaction by reacting the coating 82 with steam or high-temperature water. When Y2O3 is used as ceramics, a reaction such as the following equation (1) occurs.
Y2O3 + H2O → Y2O3 · (H2O) n → 2 (YOOH) → Y (OH) 3 (1)
However, the above equation (1) does not consider the valence.
As shown in the formula (1), the hydration treatment finally forms a hydroxide of Y. In the case of other elements belonging to Group 3a of the periodic table, such a hydroxide is formed by a substantially similar reaction. As such a hydroxide, Y (OH) 3, Ce (OH) 3, and Nd (OH) 3 are preferable.

  In order to confirm this, a sample in which a thermal sprayed coating of Y2O3 was formed on a substrate was prepared, immersed in high-temperature water of 80 ° C. for 150 hours, hydrated, and dried at room temperature. An X-ray diffraction measurement was performed on a sample not subjected to such a treatment. As a result, as shown in FIGS. 16A and 16B, Y (OH) 3 was observed only in the sample subjected to the hydration treatment, and it was confirmed that hydroxide was formed by the hydration treatment. Was done.

  Hydroxides of elements belonging to Group 3a of the periodic table are extremely stable, and have characteristics that chemically adsorbed water is hardly desorbed and water is hardly adsorbed. By forming such a hydroxide, inconvenience due to moisture during the process can be avoided.

  In order to confirm the effect of the hydration treatment, a Y2O3 sprayed coating was formed on a substrate to a thickness of about 200 μm, and a sample treated with boiling water for 3 hours and a sample not treated were prepared. Was sprayed with IPA. It should be noted that IPA has higher adsorptivity than water, and therefore, IPA spraying is an accelerated test. As a result of this test, as shown in FIG. 17, IPA was adsorbed on the sample not subjected to hydration treatment, but was not adsorbed on the sample subjected to hydration treatment. From this, it was confirmed that water absorption was extremely unlikely to occur due to the hydration treatment.

  Next, similarly to the above, a Y2O3 thermal spray coating was formed on the base material to a thickness of about 200 μm, a sample treated with boiling water for 3 hours and a sample not treated were prepared, and a resin was applied thereon. , And the cross section was confirmed. As a result, as shown in FIGS. 18A and 18B, in the case of “no treatment”, the coating is entirely transparent and the entire surface is completely in spite of the fact that there is no difference between the surface states. It is recognized that the resin had permeated, whereas in the case of "treated", only a small part of the surface layer was transparent, the inside was white, and it was confirmed that the resin had hardly penetrated. Was. That is, it was found that the hydration treatment resulted in hydrophobicity. In addition, as shown in FIG. 18C, when about 20 μm is removed after the hydration treatment, the portion becomes transparent, and by removing about 20 μm of the hydrated surface layer, the hydrophobicity is reduced. It was confirmed that.

  The effect of H2O on the Y2O3 surface is described in detail in Kuroda et al.'S "Specific Adsorption Behavior of Water on a Y2O3 Surface" described in Langmuir, Vol. 16, No. 17, 2000, pp. 6937-6947.

  Hereinafter, the hydration treatment will be specifically described. The hydration treatment can be performed by heat treatment in an environment rich in steam or by treatment in boiling water. Thereby, for example, several water molecules can be attracted and bound around the yttria (Y2O3) molecule to form one stable molecular population. At this time, the partial pressure of steam, heat treatment temperature, heat treatment time, and the like are parameters. For example, a stable hydroxide can be formed by performing heat treatment for about 24 hours in a furnace at about 100 to 300 ° C. in an environment where the relative humidity is 90% or more. If the relative humidity or the heat treatment temperature is low, the treatment time may be extended. In order to carry out the hydration treatment efficiently, it is preferable to carry out the treatment at high temperature and high pressure. The hydration reaction on the yttria surface basically proceeds sufficiently for a long time even at about room temperature, so that the same final state can be obtained under conditions other than the above. In addition, when the hydration treatment is performed, the hydration treatment using water containing ions (alkaline water having a pH of greater than 7) is more excellent in hydrophobicity than the hydration treatment using pure water. Become.

  The method is not limited to the hydration treatment, and other methods may be adopted as long as the hydroxide is finally formed, for example, a hydroxide at the raw material stage. When the coating is manufactured by the thermal spraying method, since the raw material is exposed to a high temperature, there is a concern that when the raw material is converted into a hydroxide at the raw material stage, the hydroxide is converted into an oxide. A hydroxide film can be formed by spraying underneath. Thus, instead of forming the hydration treatment section, a hydroxide may be directly formed by another method.

  Such a hydrated portion or hydroxide layer needs to be formed on the surface of the coating 82 in order to make the coating 82 hardly adsorb moisture and hardly desorb. In this case, the thickness of the hydration treatment section or the hydroxide film is preferably 100 μm or more, and is preferably set to an optimum thickness according to the place of use.

  Densification is also promoted by hydrating ceramics containing elements belonging to Group 3a of the periodic table. For example, the Y2O3 film formed by thermal spraying, which had a porous state as shown in FIG. 19A before the hydration treatment, was subjected to the hydration treatment, as shown in FIG. 19B. It is densified. Such densification provides the above-described barrier effect as well as the above effect.

  From the viewpoint of obtaining only the barrier effect, the hydration-treated portion 82a converted into a hydroxide by the hydration treatment does not necessarily have to be on the surface, but may be formed at any position of the coating film 82. When forming a hydroxide layer converted into a hydroxide by another method, it is preferable to perform the sealing treatment by the resin or the sol-gel method as described above. In this example, as shown in FIG. 20, a completely similar anodic oxide coating 83 may be formed between the base material 81 and the coating 82 as in the above-described embodiment. Further, it is preferable that the anodic oxide film 83 is subjected to a sealing treatment. As the sealing treatment, the same metal salt sealing as described above can be applied.

  Next, a fifth example of the ring member will be described. In the fifth example, as shown in FIGS. 21A and 21B, a coating 84 is formed on the surface of a base material 81, and the coating 84 is formed by a first ceramic layer 85 and a second ceramic layer. 86, and a hydration treatment part is formed on at least a part of at least one of the two. In the example of FIG. 21A, a hydration treatment portion 85a is formed on the first ceramic layer 85 on the front surface side, and in FIG. 21B, the second ceramic layer 86 on the base material 81 side is formed. The hydration processing part 86a is formed.

  Each of the first ceramic layer 85 and the second ceramic layer constituting the coating 84 is made of a ceramic containing an element belonging to Group 3a of the periodic table, similarly to the fourth example. An oxide containing an element belonging to Group 3a is preferable, and among these, Y2O3, CeO2, Ce2O3, and Nd2O3 are preferable, and Y2O3 is particularly preferable. Note that the same material as that of the fourth example can be used as the base material 81.

  These first and second ceramic layers 85 and 86 can be suitably formed by a thin film forming technique such as a thermal spraying method, a PVD method, or a CVD method, similarly to the coating 82 in the first example. In addition, it can also be formed by a method such as a dipping method or a coating method.

  The hydration units 85a and 86a can be formed in exactly the same manner as the hydration unit 82a in the fourth example. As shown in FIG. 21A, in the case where a hydrated portion is present on the surface of the coating 84, the structure can be made such that moisture is hardly adsorbed and hardly desorbed, as shown in FIG. 21B. As described above, when the hydrated portion is present inside the coating 84, the barrier effect can be effectively exhibited. In order to form the hydrated portion 86a inside the coating 84, the second ceramic layer 86 is manufactured on the base material 81, then hydrated, and then the first ceramic layer 85 may be formed. . It is preferable that the thickness of the hydrated parts 85a and 86a be 100 μm or more.

  In this way, by forming the coating 84 formed on the base material 81 into a two-layer structure, the materials of these two layers and the position of the hydration treatment can be appropriately set according to the required characteristics. Application with a high degree of freedom is possible.

  Also in this example, as shown in FIG. 22, an anodic oxide film 83 exactly the same as in the first example may be formed between the base material 81 and the film 84.

  Next, a sixth example of the ring member will be described. In the sixth example, as shown in FIG. 23, a coating 87 is formed on the surface of a substrate 81, and the coating 87 is formed of a first ceramic made of a ceramic containing at least one element belonging to Group 3a of the periodic table. It has a ceramic layer 88 and a second ceramic layer 89 formed by spraying ceramics, and a hydration treatment section 88 a is formed on the surface of the first ceramic layer 88.

  The ceramic containing an element belonging to Group 3a of the periodic table of the first ceramic layer 88 is preferably an oxide containing an element belonging to Group 3a of the periodic table, and among these, Y2O3, CeO2, and Ce2O3 are preferable. , Nd2O3 are preferred, and Y2O3 is particularly preferred. The thickness of the first ceramics layer 88 is preferably 100 to 300 μm. The first ceramics layer 88 can be suitably formed by a thin film forming technique such as a thermal spraying method, a PVD method, or a CVD method, similarly to the coating 82 in the fourth example. In addition, it can also be formed by a method such as a dipping method or a coating method.

  As the second ceramic layer 89, a layer containing at least one element selected from the group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd is preferable. Specifically, at least one ceramic selected from the group consisting of B4C, MgO, Al2O3, SiC, Si3N4, SiO2, CaF2, Cr2O3, Y2O3, YF3, ZrO2, TaO2, CeO2, Ce2O3, CeF3 and Nd2O3 is preferable. It is. The thickness of the second ceramic layer 89 is preferably 50 to 300 μm. In addition, as the base material 81, exactly the same material as in the fourth example can be used.

  The hydration processing section 88a can be formed in exactly the same way as the hydration processing section 82a in the fourth example. Since the hydrated portion is formed on the surface of the coating 87 as described above, it is possible to obtain a structure in which moisture is hardly adsorbed and hardly desorbed. In addition, the hydration treatment part 88a can be formed inside the first ceramics layer 88 to exert a barrier effect. The thickness of the hydrated portion 88a is preferably 100 μm or more.

  As shown in FIG. 24, it is preferable to form a sealing portion 89a in the second ceramic layer 89. The sealing section 89a can be formed by resin sealing or the sol-gel sealing exactly the same as described in the first to third examples. As described above, by providing the sealing processing portion 89a, gas or cleaning liquid that enters through the fine holes of the second ceramics layer 89, which is a thermal spray coating, can be effectively prevented, and the base material 81 can be sufficiently protected. Can be protected. The sealing section 89a can be formed at an arbitrary position on the second ceramic layer 89.

  With the structure as shown in FIGS. 23 and 24, it is possible to obtain a structure that is excellent in corrosion resistance and hardly adsorbs water and hardly desorbs by the hydration treatment portion 88a of the first ceramic layer 88. Moreover, the base material 81 can be effectively protected by the barrier effect of the second ceramic layer 89. In particular, in the structure of FIG. 24, the barrier effect can be further enhanced by the presence of the sealing section 89a.

  Note that, as shown in FIG. 25, the first ceramic layer 88 and the second ceramic layer 89 may be reversed. In this case, a barrier effect is effectively exerted in the hydration treatment portion 88a of the first ceramics layer 88 on the base material 81 side, and the protection effect of the base material 81 can be enhanced.

  Also in this example, as shown in FIG. 26, an anodic oxide film 83 exactly the same as in the first example may be formed between the base material 81 and the film 87.

  Next, a seventh example of the ring member will be described. In the seventh example, as shown in FIG. 27, the ring member has a hydrated portion 98 formed on the surface of a ceramic sintered body 97 containing an element belonging to Group 3a of the periodic table. The hydration treatment section 98 can be formed in exactly the same manner as in the above-described embodiment, and a hydration treatment forms a hydroxide containing an element belonging to Group 3a of the periodic table.

  By forming the hydration treatment section 98 on the surface in this manner, a structure can be obtained in which moisture is hardly adsorbed and desorbed. In this case, the thickness of the hydration treatment section 98 or the hydroxide film is preferably 100 μm or more.

  Also in the seventh embodiment, as described in the fourth to sixth examples, the ceramic containing an element belonging to Group 3a of the periodic table is an oxide containing an element belonging to Group 3a of the periodic table. Is preferred. Among these, Y2O3, CeO2, Ce2O3, and Nd2O3 are preferable, and Y2O3 is particularly preferable.

  In the above embodiment, the case where the present invention is applied to a ring member (focus ring 213, insulating ring 213a) of a magnetron type parallel plate type plasma etching apparatus using a permanent magnet shown in FIG. Although the present invention has been described above, the present invention is not limited to the apparatus having such a configuration, and is not limited to a parallel plate type plasma etching apparatus without a magnetron, other plasma etching processing apparatuses such as an inductive coupling type and an etching apparatus, as well as an ashing processing. The present invention can also be applied to an apparatus that performs various types of plasma processing other than etching, such as film formation and film formation.

  INDUSTRIAL APPLICABILITY The plasma processing apparatus of the present invention can adjust the state of plasma by applying a predetermined voltage to an electrode in a ring member. Therefore, the present invention is applicable to an apparatus that performs plasma processing such as etching on a semiconductor wafer or the like. Can be. In addition, the ring member of the present invention is particularly suitable for processing by plasma in a highly corrosive atmosphere since the coating formed on the substrate is made of a highly corrosion-resistant ceramic and has a portion functioning as a barrier. Further, the ceramic containing an element belonging to Group 3a of the periodic table is subjected to hydration treatment to obtain a structure that is stable with respect to water, and thus is suitable as a ring member in which moisture is a problem.

It is a longitudinal section showing the plasma processing device concerning an embodiment of the invention. It is an explanatory view showing a control part of the above-mentioned plasma processing device. It is explanatory drawing which shows the state of the plasma when performing plasma processing using the said plasma processing apparatus. It is explanatory drawing which shows the multilayer film etched using the said plasma processing apparatus. It is an explanatory view showing another example of a plasma processing apparatus according to an embodiment of the present invention. FIG. 9 is an explanatory diagram showing still another example of the plasma processing apparatus according to the embodiment of the present invention. FIG. 1 is an explanatory diagram showing a plasma processing system incorporating a plasma processing apparatus according to an embodiment of the present invention. FIG. 1 is a longitudinal sectional view showing a plasma etching apparatus on which a ring member according to an embodiment of the present invention is mounted. FIG. 3 is a cross-sectional view illustrating a layer configuration of a first example of the ring member according to the present invention. Sectional drawing which shows the example which added the anodic oxide film to the structure of FIG. FIG. 6 is a sectional view showing a layer configuration of a second example of the ring member according to the embodiment of the present invention. FIG. 12 is a sectional view showing an example in which an anodic oxide film is added to the configuration of FIG. 11. FIG. 9 is a sectional view showing a layer configuration of a third example of the ring member according to the embodiment of the present invention. FIG. 14 is a sectional view showing an example in which an anodic oxide film is added to the configuration of FIG. 13. FIG. 4 is a cross-sectional view showing a layer configuration of a first example of the ring member according to the embodiment of the present invention. The figure which shows the case where the hydration process is performed to the Y2O3 film | membrane, and the case where it does not perform and shows an X-ray analysis pattern in comparison. The figure which shows comparison of the adsorption | suction of IPA in the case where a hydration process is performed to the Y2O3 film | membrane, and the case where it is not performed. FIG. 4 is a diagram showing a comparison of resin penetration between a case where a hydration treatment is performed on a Y2O3 coating and a case where a hydration treatment is not performed. The scanning electron micrograph which shows the layer state before and after a hydration process in comparison, and shows it. FIG. 16 is a sectional view showing an example in which an anodic oxide film is added to the configuration of FIG. 15. FIG. 6 is a sectional view showing a layer configuration of a second example of the ring member according to the embodiment of the present invention. FIG. 22 is a sectional view showing an example in which an anodic oxide film is added to the configuration of FIG. 21. FIG. 9 is a sectional view showing a layer configuration of a third example of the ring member according to the embodiment of the present invention. FIG. 9 is a sectional view showing a layer configuration of a third example of the ring member according to the embodiment of the present invention. FIG. 9 is a sectional view showing a layer configuration of a third example of the ring member according to the embodiment of the present invention. FIG. 17 is a sectional view showing an example in which an anodic oxide film is added to the configuration of FIG. 16. The schematic diagram which shows the ring member which concerns on embodiment of this invention. It is an explanatory view showing a conventional plasma processing apparatus.

Explanation of reference numerals

2 Processing container 22 Vacuum pump 3 Upper electrode 33 First gas supply system 34 Second gas supply system 4 Lower electrode 44 Electrostatic chuck 5 Focus ring 51 Electrode 52a Actuator 6 Control unit 20 Vacuum chamber 20a Depot shield 30 Gas shower head 210 Mounting table 212 Electrostatic chuck 213 Focus ring 214 Exhaust plate 71, 81 Base material 72, 76, 77, 82, 84, 87 Coating 74 Barrier coating layer 75, 83 Anodized coating 76a, 78a, 79a Sealing section 82a , 86a, 88a, 98 Water treatment section

Claims (44)

In a plasma processing apparatus that performs processing with a plasma of a processing gas on a substrate to be processed mounted on a mounting table in a processing container,
A ring member made of an insulating material provided so as to surround the substrate to be processed on the mounting table,
An electrode provided in the ring member;
And a DC power supply for applying a DC voltage to the electrode to adjust a sheath region of the plasma above the ring member.   When performing the first process on the substrate to be processed, the first DC voltage is applied to the electrode in the ring member. When performing the second process on the substrate to be processed, the second DC voltage is applied to the electrode in the ring member. The plasma processing apparatus according to claim 1, further comprising: means for switching an applied voltage so as to apply a DC voltage.   3. The plasma processing apparatus according to claim 2, wherein the first process is a process for etching a thin film, and the second process is a process for etching a thin film different from the thin film.   2. The plasma processing apparatus according to claim 1, wherein a plurality of electrodes in the ring member are provided in a radial direction, and a DC voltage applied to the plurality of electrodes can be independently adjusted. A ring member made of an insulating material provided so as to surround a substrate to be processed on a mounting table of a plasma processing apparatus for performing processing by a plasma of a processing gas on a substrate to be processed mounted on a mounting table in a processing container. At
A ring member comprising an electrode to which a DC voltage is applied in order to adjust a plasma sheath region above the ring member.   A first DC voltage is applied to the electrodes when performing the first process on the substrate to be processed, and a second DC voltage is applied to the electrodes when performing the second process on the substrate to be processed. The ring member according to claim 5, wherein:   The ring member according to claim 6, wherein the first process is a process of etching a thin film, and the second process is a process of etching a thin film of a type different from the thin film.   The ring member according to claim 5, wherein a plurality of electrodes in the ring member are provided in a radial direction, and a DC voltage applied to the plurality of electrodes can be adjusted independently of each other. A step of mounting the substrate to be processed on a mounting table in the processing container,
A plasma is introduced into a processing vessel in a state where a first DC voltage is applied to a plasma sheath region adjusting electrode provided in a ring member made of an insulating material provided to surround a substrate to be processed on the mounting table. Generating a first process on the substrate to be processed;
And generating a plasma in the processing vessel and performing a second process on the substrate to be processed in a state in which a second DC voltage is applied to the electrode for adjusting the plasma sheath region. Plasma treatment method. Having a substrate and a coating formed on the surface by spraying ceramics,
The ceramic constituting the coating contains at least one element selected from the group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce, and Nd, at least a portion of which is made of resin. The ring member according to claim 5, wherein a sealing process is performed. Having a substrate and a coating formed on the surface by spraying ceramics,
A first ceramic layer made of a ceramic containing at least one element selected from the group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd; A second ceramic layer made of a ceramic containing at least one element selected from the group consisting of Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce, and Nd; The ring member according to claim 5, wherein at least a part of at least one of the ceramic layers (2) is sealed with a resin.   The ring member according to claim 10, wherein the resin is selected from the group consisting of SI, PTFE, PI, PAI, PEI, PBI, and PFA. Having a substrate and a coating formed on the surface by spraying ceramics,
The ceramic constituting the coating contains at least one element selected from the group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd, at least a part of which is a sol-gel method. 6. The ring member according to claim 5, wherein the ring member is sealed. Having a substrate and a coating formed on the surface by spraying ceramics,
A first ceramic layer made of a ceramic containing at least one element selected from the group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd; A second ceramic layer made of a ceramic containing at least one element selected from the group consisting of Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce, and Nd; The ring member according to claim 5, wherein at least a part of at least one of the ceramic layers (2) is sealed by a sol-gel method.   14. The ring member according to claim 13, wherein the sealing treatment is performed using an element selected from elements belonging to Group 3a of the periodic table.   The ceramic is at least one selected from the group consisting of B4C, MgO, Al2O3, SiC, Si3N4, SiO2, CaF2, Cr2O3, Y2O3, YF3, ZrO2, TaO2, CeO2, Ce2O3, CeF3 and Nd2O3. The ring member according to claim 10, wherein Having a substrate and a coating formed on the surface thereof,
The coating comprises a main layer formed by spraying ceramics, and a barrier made of ceramics containing an element selected from the group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd. The ring member according to claim 5, further comprising a coat layer.   The barrier coat layer is made of at least one ceramic selected from the group consisting of B4C, MgO, Al2O3, SiC, Si3N4, SiO2, CaF2, Cr2O3, Y2O3, YF3, ZrO2, TaO2, CeO2, Ce2O3, CeF3 and Nd2O3. The ring member according to claim 17, wherein the ring member is configured.   18. The ring member according to claim 17, wherein at least a part of the barrier coat layer is a thermal spray coating that has been sealed with a resin.   20. The ring member according to claim 19, wherein the resin is selected from the group consisting of SI, PTFE, PI, PAI, PEI, PBI, and PFA.   18. The ring member according to claim 17, wherein at least a part of the barrier coat layer is a thermal spray coating that has been subjected to a sealing treatment by a sol-gel method.   22. The ring member according to claim 21, wherein the sealing treatment is performed using an element selected from elements belonging to Group 3a of the periodic table. Having a substrate and a coating formed on the surface thereof,
The ring according to claim 5, wherein the coating has a main layer formed by spraying ceramics, and a barrier coat layer made of engineering plastic formed between the base material and the main layer. Element.   The ring member according to claim 23, wherein the engineering plastic is a plastic selected from the group consisting of PTFE, PI, PAI, PEI, PBI, PFA, PPS, and POM.   The main layer is composed of at least one ceramic selected from the group consisting of B4C, MgO, Al2O3, SiC, Si3N4, SiO2, CaF2, Cr2O3, Y2O3, YF3, ZrO2, TaO2, CeO2, Ce2O3, CeF3 and Nd2O3. The ring member according to claim 23, wherein the ring member is formed. Having a substrate and a coating formed on the surface thereof,
6. The coating according to claim 5, wherein the coating is made of a ceramic containing at least one element belonging to Group 3a of the periodic table, and at least a part of the coating is hydrated with steam or high-temperature water. Ring member. Having a substrate and a coating formed on the surface thereof,
The coating is a first ceramic layer made of a ceramic containing at least one element belonging to Group 3a of the periodic table, and a second ceramic layer made of a ceramic containing at least one element belonging to Group 3a of the periodic table. 6. The ring member according to claim 5, wherein at least a part of at least one of the first and second ceramic layers is hydrated with steam or high-temperature water. 7.   The ring member according to claim 26, wherein the coating is a thermal spray coating formed by thermal spraying or a thin film formed by a thin film forming technique.   27. The ring member according to claim 26, wherein the ceramic constituting the coating is selected from Y2O3, CeO2, Ce2O3, and Nd2O3. Having a substrate and a coating formed on the surface thereof,
The coating has a first ceramics layer made of ceramics containing at least one element belonging to Group 3a of the periodic table, and a second ceramics layer formed by spraying ceramics. The ring member according to claim 5, wherein at least a part of the ring member is hydrated with steam or high-temperature water.   The ring member according to claim 30, wherein the first ceramics layer is a thermal spray coating formed by thermal spraying or a thin film formed by a thin film forming technique.   31. The ring member according to claim 30, wherein the ceramics forming the first ceramics layer is selected from Y2O3, CeO2, Ce2O3, and Nd2O3.   The second ceramic layer is at least one ceramic selected from the group consisting of B4C, MgO, Al2O3, SiC, Si3N4, SiO2, CaF2, Cr2O3, Y2O3, YF3, ZrO2, TaO2, CeO2, Ce2O3, CeF3, and Nd2O3. 31. The ring member according to claim 30, comprising: Having a substrate and a coating formed on the surface thereof,
The ring member according to claim 5, wherein the coating has a hydroxide layer made of a hydroxide containing at least one element belonging to Group 3a of the periodic table.   35. The ring member according to claim 34, wherein the hydroxide layer is a thermal spray coating formed by thermal spraying or a thin film formed by a thin film forming technique.   35. The ring member according to claim 34, wherein the hydroxide constituting the hydroxide layer is selected from Y (OH) 3, Ce (OH) 3, and Nd (OH) 3.   35. The ring member according to claim 34, wherein at least a part of the hydroxide layer is subjected to a sealing treatment.   The ring member according to claim 10, further comprising an anodic oxide coating between the base material and the coating.   39. The ring member according to claim 38, wherein the anodized film is sealed with an aqueous metal salt solution.   The ring member according to claim 38, wherein the anodic oxide coating is sealed with a resin selected from the group consisting of SI, PTFE, PI, PAI, PEI, PBI, and PFA.   The ring member according to claim 5, comprising a ceramic sintered body containing at least one element belonging to Group 3a of the periodic table, at least a part of which is hydrated with steam or high-temperature water. .   The ring member according to claim 41, wherein the ceramic sintered body is obtained by subjecting a ceramic selected from Y2O3, CeO2, Ce2O3, and Nd2O3 to a hydration treatment.   The ring member according to claim 5, comprising a ceramic sintered body containing a hydroxide containing at least one element belonging to Group 3a of the periodic table. The ring member according to claim 43, wherein the hydroxide contained in the ceramic sintered body is selected from Y (OH) 3, Ce (OH) 3, and Nd (OH) 3. .

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