JP2006228966A - Plasma treatment apparatus, its component, and lifetime detecting method of component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a component hardly generating a crack extending from an identification marker as a start point and in a plasma treatment apparatus, and to provide a method capable of detecting the lifetime of the component utilizing the identification marker. <P>SOLUTION: In the plasma treatment apparatus 1, plasma is produced in a treatment container 10 containing a substrate W to apply plasma treatment to the substrate W. The identification markers 20, 21 are labelled on the surface of the component 17 disposed in the treatment container 10. Each marker has one or two or more of symbols 21 in combination, and each symbol has a substantially circular shape as viewed in a plane and being formed by arranging a plurality of dotted holes 22 each having a substantially U shape in its longitudinal cross sectional shape. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plasma processing apparatus, and more particularly, to a component disposed in a processing container of a plasma processing apparatus and a life detection method thereof.

  In a manufacturing process of an electronic device such as a semiconductor device or a liquid crystal display device, for example, an etching process for etching a film on a substrate into a predetermined shape is performed in order to form a predetermined circuit pattern on the substrate. A plasma processing apparatus is widely used for this etching process. The plasma processing apparatus has, for example, a lower electrode on which a substrate is placed and a shower head serving as an upper electrode that ejects a predetermined gas to the substrate on the lower electrode in a processing chamber. The etching process is performed by etching the film on the substrate by applying a high frequency between the upper and lower electrodes and generating plasma in the processing chamber in a state where a predetermined mixed gas is jetted from the shower head into the processing chamber, for example. Yes.

  Here, as described above, when plasma is generated in the processing chamber and the substrate in the processing chamber is etched, the etching characteristics such as the etching rate and the etching selectivity vary between the central portion and the outer peripheral portion of the substrate. there were. One possible cause is that the plasma density generated in the processing chamber is non-uniform between the vicinity of the central portion and the vicinity of the outer peripheral portion. Therefore, a so-called focus ring is arranged around the substrate placed on the lower electrode, and the plasma generation range is extended to the periphery of the substrate, thereby averaging the plasma density on the substrate and making the etching process uniform. (For example, refer to Patent Documents 1 and 2).

JP-A-9-45624 JP 2002-184664 A

  By the way, some focus rings and other parts arranged in the processing container of the plasma processing apparatus are provided with identification marks such as a production number for parts management. By managing with this identification mark, it is possible to determine the replacement time of a part or to follow up the manufacturing process of a part in which a defect has occurred. Conventionally, when an identification mark is attached to a part of a plasma processing apparatus, a so-called laser marking method is used, and an identification mark such as a number or a letter is formed by marking a continuous groove on the surface of the part.

  However, since the parts placed in the processing vessel of the plasma processing apparatus are exposed to high temperatures during processing, the parts with such identification marks are treated as starting points by the thermal stress applied during each plasma treatment. There was a case where cracking occurred. In particular, cracks starting from identification marks were likely to occur in parts made of Si such as a focus ring and parts made of so-called brittle materials such as quartz, alumina ceramics, yttria ceramics, and SiC.

  The present invention has been made in view of the above points. In the plasma processing apparatus, the present invention provides a component in which cracks starting from an identification mark are unlikely to occur, and uses the identification mark to prolong the life of the component. It aims to provide a method that can be detected.

  In order to achieve the above object, according to the present invention, in a plasma processing apparatus for generating plasma in a processing container containing a substrate and subjecting the substrate to plasma processing, the components are arranged in the processing container. In addition, the surface of the component has a substantially circular shape in plan view, and an identification mark formed by combining one or more symbols indicated by arranging a plurality of dot holes having a substantially U-shaped longitudinal section. A part of a plasma processing apparatus is provided, characterized in that

  In this component, for example, the diameter D of the dot hole is 0.1 mm or less, and the shortest distance L between the center axes of the dot holes is 3 times or more of the diameter D. In this case, it is preferable that the diameter D of the dot hole is narrower than the sheath thickness during plasma processing. In order to indicate the symbol, when a dot row in which a plurality of dot holes are arranged in a line and another dot row in which a plurality of dot holes are arranged in a line contact with each other, The angle formed by the dot rows may not be less than 25 °.

  Further, the surface of the part exposed in the processing container is provided with an identification mark that is a combination of two or more symbols, and in each of the two or more symbols, the depth of the dot hole is different for each symbol. May be. Further, the identification mark may be attached to a surface of the component that is not exposed in the processing container.

  The component may be made of any one of Si, quartz, alumina ceramics, yttria ceramics, and SiC.

  The dot holes can be formed by laser processing, for example. The dot holes can be formed by wet etching, for example.

  According to the present invention, there is provided a plasma processing apparatus for generating plasma in a processing container containing a substrate and performing plasma processing on the substrate, wherein the components are arranged in the processing container. A plasma processing apparatus is provided.

  According to the present invention, there is provided a method for detecting the lifetime of a component disposed in the processing container in a plasma processing apparatus for generating plasma in a processing container containing a substrate and performing plasma processing on the substrate. The surface of the component is provided with an identification mark formed by combining one or more symbols indicated by arranging a plurality of dot holes having a substantially circular shape in a plan view and a substantially U-shaped longitudinal section. In addition, there is provided a component lifetime detection method in a plasma processing apparatus, wherein the component lifetime is detected according to the state of the identification mark.

  In this case, for example, the diameter D of the dot hole is 0.1 mm or less, and the shortest distance L between the central axes of the dot holes is 3 times or more of the diameter D. Moreover, it is preferable that the diameter D of the dot hole is smaller than the sheath thickness at the time of plasma processing. In addition, an identification mark combining two or more symbols having different dot hole depths for each symbol is attached to the surface exposed in the processing container of the component. The life may be detected.

  According to the present invention, it is possible to suppress the occurrence of cracks starting from an identification mark in a component disposed in a processing container of a plasma processing apparatus. Further, according to the present invention, the life of the part can be detected by using the identification mark attached to the surface of the part.

  Hereinafter, preferred embodiments of the present invention will be described. FIG. 1 is a longitudinal sectional view for explaining a schematic configuration of a plasma processing apparatus 1 according to the present embodiment. The plasma processing apparatus 1 is configured to perform, for example, a plasma etching process on a substrate W such as a Si wafer.

  The plasma processing apparatus 1 is configured as a capacitive coupling type having a so-called parallel plate electrode structure. The plasma processing apparatus 1 includes, for example, a substantially cylindrical processing container 10 in which a processing chamber S is formed. The processing vessel 10 is formed of, for example, an aluminum alloy, and the inner wall surface is covered with an alumina film or an yttrium oxide film. Further, the processing container 10 is grounded.

  A cylindrical susceptor support 12 is provided at the center bottom in the processing vessel 10 with an insulating plate 11 interposed. On the susceptor support 12, a susceptor 13 is supported as a placement portion on which the substrate W is placed. The susceptor 13 constitutes a lower electrode having a parallel plate electrode structure. The susceptor 13 is made of, for example, an aluminum alloy.

  An electrostatic chuck 14 that holds the substrate W is provided on the susceptor 13. The electrostatic chuck 14 has an electrode 15 inside. A DC power supply 16 is electrically connected to the electrode 15. By applying a DC voltage from the DC power source 16 to the electrode 15, a Coulomb force can be generated and the substrate W can be attracted to the upper surface of the susceptor 13.

  A focus ring 17 is arranged on the upper surface of the susceptor 13 around the electrostatic chuck 14 so as to surround the substrate W adsorbed on the upper surface of the susceptor 13. The focus ring 17 is made of the same Si as the substrate W. A cylindrical insulator member 18 made of, for example, quartz is attached to the outer peripheral surfaces of the susceptor 13 and the susceptor support 12. The focus ring 17 is placed on the susceptor 13 and the insulator member 18 so that the upper surface of the focus ring 17 is exposed in the processing container 10 and the lower surface of the focus ring 17 is not exposed in the processing container 10. ing. Further, the height of the upper surface of the focus ring 17 is set to be the same as the height of the upper surface of the substrate W adsorbed on the upper surface of the susceptor 13.

  2 and 3 are a top view and a bottom view of the focus ring 17 used in the plasma processing apparatus 1. As shown in FIGS. 2 and 3, a predetermined identification mark 20 is attached to the upper surface of the focus ring 17, and similarly, another predetermined identification mark 21 is attached to the lower surface of the focus ring 17. In this embodiment, the identification mark 20 attached to the upper surface of the focus ring 17 is a combination of three symbols 20a, 20b, and 20c. Similarly, the identification mark attached to the lower surface of the focus ring 17 is used. 21 also has a configuration in which three symbols 21a, 21b, and 21c are combined.

  4 is an enlarged view of the identification mark 20 attached to the upper surface of the focus ring 17, and FIG. 5 is an enlarged view of the identification mark 21 attached to the lower surface of the focus ring 17. As shown in FIG. 4, the identification mark 20 attached to the upper surface of the focus ring 17 represents the symbol 20a representing the number “1”, the symbol 20b representing the number “2”, and the number “3”. By arranging the symbols 20c, a three-digit number “123” is shown as a whole. As shown in FIG. 5, the identification mark 21 attached to the lower surface of the focus ring 17 includes a symbol 21 a representing the number “4”, a symbol 21 b representing the number “5”, and a number “6”. By arranging the symbols 21c to represent, the whole number “456” is shown.

  Each of the symbols 20a, 20b, 20c, 21a, 21b, and 21c has a configuration in which a plurality of dot holes 22 formed on the surface (upper surface or lower surface) of the focus ring 17 are arranged. FIG. 6 is an enlarged plan view showing a state in which the dot hole 22 is viewed from above or below. As shown in FIG. 6, each dot hole 22 has a substantially circular shape in plan view. FIG. 7 is an enlarged longitudinal sectional view showing the surface (upper surface or lower surface) of the focus ring 17 cut at the dot hole 22. As shown in FIG. 7, each dot hole 22 has a hemispherical bottom in the longitudinal section, and an entrance near the surface of the focus ring 17 is formed in a cylindrical shape. Thereby, the longitudinal shape of each dot hole 22 is substantially U-shaped.

  Further, the diameter D of each dot hole 22 is formed to be narrower than the thickness of the sheath of the plasma generated in the processing container 10 during the plasma processing in the plasma processing apparatus 1. The plasma sheath thickness varies depending on various factors such as plasma generation conditions and processing gas. Specifically, the diameter D of each dot hole 22 is, for example, 0.1 mm or less, preferably each dot. The diameter D of the hole 22 is 0.05 mm or less.

  A plurality of dot holes 22 arranged in a line to represent each symbol 20a, 20b, 20c, 21a, 21b, 21c are arranged at a predetermined distance from each other. In the adjacent dot holes 22, the shortest distance L between the central axes of the dot holes 22 is set to, for example, three times or more the diameter D of the dot holes 22 (ie, L ≧ 3D). Specifically, this shortest distance L is, for example, 0.15 mm or more.

  Further, in showing each symbol 20a, 20b, 20c, 21a, 21b, 21c, a dot row in which a plurality of dot holes 22 are arranged in a line and another dot line in which a plurality of dot holes are arranged in a line are shown. When the dot rows touch each other, the angle formed by the dot rows is set so as not to be less than 25 ° at the position where the dot rows touch each other. That is, for example, based on the symbol 21a representing the numeral “4” in the identification mark 21 shown in FIG. 5, the symbol 21a is arranged by arranging a plurality of dot holes 22 in an L-shaped line. The first dot row 22a and a second dot row 22b in which a plurality of dot holes 22 are arranged in a straight line in the vertical axis direction. Then, one end portion of the first dot row 22a arranged in an L shape is connected to substantially the center of the second dot row 22b arranged in a vertical row. Taking this symbol 21a as an example, the position 22c where the first dot row 22a and the second dot row 22b are in contact (that is, the position 22c of one end of the first dot row 22a arranged in an L shape) = In the substantially central position 22c) of the second dot row 22b arranged in a vertical row, the angles θa and θb formed by the first dot row 22a and the second dot row 22b are not less than 25 °. Is set as follows. In the example of the symbol 21a, the angles θa and θb formed by the first dot row 22a and the second dot row 22b at the position 22c are both approximately 90 °. Although the symbol 21a representing the numeral “4” has been described, in the other symbols 20a, 20b, 20c, 21b, and 21c, the angle formed by the dot rows at which the dot rows are in contact with each other In this case, the angle is set so as not to be less than 25 °.

  In addition, the depth d of each dot hole 22 is prepared with different depths in several stages. That is, in this embodiment, as shown in FIG. 8A, the dot hole 22 having a relatively shallow depth d1, and as shown in FIG. 8B, the dot hole 22 having a medium depth d2. As shown in FIG. 8C, there is a dot hole 22 having a relatively deep depth d3. And about the identification mark 20 attached | subjected to the upper surface of the focus ring 17, it sets so that the depth of the dot hole 22 may differ for each symbol 20a, 20b, 20c.

  In this embodiment, in the identification mark 20 shown in FIG. 4, the symbol 20a representing the numeral “1” is indicated by using a dot hole 22 having a relatively shallow depth d1. A symbol 20b representing the numeral “2” is shown using a dot hole 22 having a medium depth d2, and a symbol 20c representing the numeral “3” is a relatively deep depth d3. The dot holes 22 are shown.

  On the other hand, for the identification mark 21 attached to the lower surface of the focus ring 17, the symbols 21a, 21b, and 21c are all shown using dot holes 22 having the same depth. In this case, each symbol 21a, 21b, 21c is constituted by only the dot hole 22 having a relatively shallow depth d1, for example.

  Each dot hole 22 as described above is formed by, for example, a laser processing apparatus 23 as shown in FIG. According to this laser processing apparatus 23, a desired diameter D and depth can be obtained by irradiating the surface of the focus ring 17 with laser light emitted from the laser oscillator 24 via optical means such as a scanning mechanism 25 and a lens 26. It is possible to form a dot hole 22 having d. In this laser processing device 23, for example, the diameter D of the dot hole 22 can be set to an arbitrary size by adjusting the irradiation range of the laser beam by the scanning mechanism 25. Further, for example, by adjusting the number of shots of the laser beam applied to the surface of the focus ring 17, the depth d of the dot hole 22 can be made arbitrary. For example, the number of shots of the laser beam is moderate. By reducing the number of times of forming the dot hole 22 having the depth d2, the dot hole 22 having the relatively shallow depth d1 can be formed. Conversely, by increasing the number of shots of the laser light more than the number of times of forming the dot hole 22 having the medium depth d2, the dot hole 22 having the relatively deep depth d3 can be formed.

  Each dot hole 22 can be formed by wet etching in which an etching droplet 27 is brought into contact with the surface of the focus ring 17 as shown in FIG. In this case, for example, the diameter D and the depth d of the dot hole 22 can be set to arbitrary sizes by adjusting the etching processing time. Alternatively, the dot holes 22 may be formed by performing an etching process using masking. For example, a mixed solution of hydrofluoric acid and nitric acid can be used as the etching solution.

  As shown in FIG. 1, a ring-shaped refrigerant chamber 28 is formed inside the susceptor support 12. The refrigerant chamber 28 communicates with a chiller unit (not shown) installed outside the processing container 10 through the pipes 29a and 20b. Refrigerant or cooling water is circulated and supplied to the refrigerant chamber 28 through the pipes 29a and 29b, and the temperature of the substrate W on the susceptor 13 can be controlled by this circulation supply. A gas supply line 29 c passing through the susceptor 13 and the susceptor support 12 is connected to the upper surface of the electrostatic chuck 14, and a heat transfer gas such as He gas can be supplied between the substrate W and the electrostatic chuck 14.

  Above the susceptor 13, an upper electrode 30 facing the susceptor 13 in parallel is provided. A plasma generation space is formed between the susceptor 13 and the upper electrode 30.

  The upper electrode 30 includes a ring-shaped outer upper electrode 31 and a disk-shaped inner upper electrode 32 inside thereof. A ring-shaped dielectric 33 is interposed between the outer upper electrode 31 and the inner upper electrode 32. A ring-shaped insulating shielding member 34 made of alumina, for example, is airtightly interposed between the outer upper electrode 31 and the inner peripheral wall of the processing container 10.

  A first high frequency power supply 44 is electrically connected to the outer upper electrode 31 via a matching unit 40, an upper power feed rod 41, a connector 42, and a power feed cylinder 43. The first high frequency power supply 44 can output a high frequency voltage having a frequency of 40 MHz or more, for example, 60 MHz.

  The power supply cylinder 43 is formed in, for example, a substantially cylindrical shape having an open bottom surface, and a lower end portion is connected to the outer upper electrode 31. The lower end portion of the upper power supply rod 41 is electrically connected to the center portion of the upper surface of the power supply tube 43 by a connector 42. The upper end of the upper power feed rod 41 is connected to the output side of the matching unit 40. The matching unit 40 is connected to the first high-frequency power supply 44 and can match the internal impedance of the first high-frequency power supply 44 with the load impedance. The outside of the power supply cylinder 43 is covered with a cylindrical ground conductor 10 a having a side wall with the same diameter as the processing container 10. The lower end of the ground conductor 10 a is connected to the upper part of the side wall of the processing container 10. The upper power feed rod 41 described above passes through the center portion of the upper surface of the ground conductor 10a, and an insulating member 45 is interposed at the contact portion between the ground conductor 10a and the upper power feed rod 41.

  The inner upper electrode 32 constitutes a shower head that ejects a predetermined mixed gas onto the substrate W placed on the susceptor 13. The inner upper electrode 32 includes a circular electrode plate 50 having a large number of gas ejection holes 50a, and an electrode support 52 that detachably supports the upper surface side of the electrode plate 50. The electrode support 52 is formed in a disk shape having the same diameter as the electrode plate 50, and a circular buffer chamber 53 is formed therein.

  In the buffer chamber 53, for example, as shown in FIG. 11, an annular partition member 54 made of an O-ring is provided, and the buffer chamber 53 has a first buffer chamber 53a on the central side and a second buffer chamber on the outer peripheral side. It is divided into 53b. The first buffer chamber 53 a faces the center of the substrate W on the susceptor 13, and the second buffer chamber 53 b faces the outer periphery of the substrate W on the susceptor 13. Gas ejection holes 50a communicate with the lower surfaces of the buffer chambers 53a and 53b. From the first buffer chamber 53a to the center of the substrate W and from the second buffer chamber 53b to the outer periphery of the substrate W. A predetermined mixed gas can be ejected toward the portion. A gas supply system for supplying a predetermined mixed gas to each buffer chamber 53 will be described later.

  As shown in FIG. 1, a lower power supply cylinder 60 connected to the upper power supply rod 41 is electrically connected to the upper surface of the electrode support 52. A variable capacitor 61 is provided in the lower feed cylinder 60. The variable capacitor 61 can adjust the relative ratio between the electric field strength formed immediately below the outer upper electrode 31 and the electric field strength formed immediately below the inner upper electrode 32 by the high-frequency voltage from the first high-frequency power supply 44. .

  An exhaust port 70 is formed at the bottom of the processing container 10. The exhaust port 70 is connected through an exhaust pipe 71 to an exhaust device 72 having a vacuum pump or the like. The exhaust device 72 can reduce the pressure in the processing container 10 to a desired degree of vacuum.

  A second high frequency power supply 81 is electrically connected to the susceptor 13 via a matching unit 80. The second high frequency power supply 81 can output a high frequency voltage having a frequency in the range of 2 MHz to 20 MHz, for example, 20 MHz.

  The inner upper electrode 32 is electrically connected to a low-pass filter 82 for cutting off the high frequency from the first high frequency power supply 44 and passing the high frequency from the second high frequency power supply 81 to the ground. The susceptor 13 is electrically connected to a high-pass filter 83 for passing a high frequency from the first high frequency power supply 44 to the ground.

  The plasma processing apparatus 1 is provided with a device control unit 90 that controls operations of various specifications for performing an etching process such as the DC power supply 16, the first high-frequency power supply 44, and the second high-frequency power supply 81. .

  Next, a mixed gas supply system for the inner upper electrode 32 will be described. As shown in FIG. 12, the inner upper electrode 32 is connected to two gas boxes 100 and 101 set outside the processing container 10. The first buffer chamber 53 a on the center side of the inner upper electrode 32 is connected to the first gas box 100 by the first gas supply pipe 102. The first gas box 100 accommodates three gas supply sources 103a, 103b, and 103c. The first gas supply pipe 102 extends from the first buffer chamber 53a toward the first gas box 100, branches in the middle, and communicates with the gas supply sources 103a to 103c of the first gas box 100. ing. Each branch pipe of the first gas supply pipe 102 is provided with a mass flow controller 104. The mass flow controller 104 can mix the gases from the gas supply sources 103a to 103c at a predetermined mixing ratio and supply them to the first buffer chamber 53a. The first gas supply pipe 102 is provided with a flow rate adjustment valve 105, and a mixed gas having a predetermined flow rate can be supplied to the first buffer chamber 53a.

In the present embodiment, for example, the gas supply source 103a is filled with, for example, a fluorocarbon-based fluorine compound, for example, C _X F _Y gas such as CF ₄ , C ₄ F ₆ , C ₄ F ₈ , C ₅ F _8. The gas supply source 103b is filled with, for example, O ₂ gas as a gas for controlling the deposition of a CF-based reaction product. For example, a rare gas as a carrier gas, for example, Ar gas is sealed in the gas supply source 103c.

  Similarly, the second buffer chamber 53 b on the outer peripheral side of the inner upper electrode 32 is connected to the second gas box 101 by the second gas supply pipe 110. In the second gas box 101, for example, three gas supply sources 111a, 111b, and 111c are accommodated. The second gas supply pipe 102 extends from the second buffer chamber 53b toward the second gas box 101, branches in the middle, and communicates with the gas supply sources 111a to 111c of the second gas box 101. ing. Each branch pipe of the second gas supply pipe 110 is provided with a mass flow controller 112. The mass flow controller 112 can mix the gases of the gas supply sources 111a to 111c at a predetermined mixing ratio and supply the mixed gas to the second buffer chamber 53b. The second gas supply pipe 110 is provided with a flow rate adjustment valve 113, and a mixed gas having a predetermined flow rate can be supplied to the second buffer chamber 53b.

In the present embodiment, for example, like the gas supply sources 103a to 103c of the first gas box 100, the gas supply source 111a is filled with, for example, C _X F _Y gas as a main etching gas. 111b is filled with, for example, O ₂ gas as a removal gas for deposits of CF-based reaction products. For example, Ar gas as a dilution gas is sealed in the gas supply source 111c.

  The operations of the mass flow controller 104 and the flow rate control valve 105 on the first gas supply pipe 102 side, and the mass flow controller 112 and the flow rate control valve 113 on the second gas supply pipe 110 side are, for example, the device control unit 90 of the plasma processing apparatus 1. It is controlled by. The apparatus control unit 90 is set with the mixture ratio and flow rate of the mixed gas supplied to the first buffer chamber 53a and the mixture ratio and flow rate of the mixed gas supplied to the second buffer chamber 53b. The controller 90 can control the operations of the mass flow controllers 104 and 112 and the flow rate control valves 105 and 113 according to various settings of the mixed gas.

  The plasma processing apparatus 1 is provided with a gas setting device 120 for setting each mixed gas supplied to the first buffer chamber 53a and the second buffer chamber 53b. The gas setting device 120 is constituted by a general-purpose computer, for example. The gas setting device 120 can communicate with, for example, the device control unit 90, and can output setting information to the device control unit 90 and make various settings related to the mixed gas in the device control unit 90.

In the etching process in the plasma processing apparatus 1 configured as described above, the substrate W is first placed on the susceptor 13. Next, the processing chamber S is adjusted to a predetermined pressure by the exhaust from the exhaust pipe 90. From the inner upper electrode 32, for example, a mixed gas as an etching gas composed of C _X F _Y gas, O ₂ gas, and Ar gas is supplied into the processing chamber S. At this time, the mixed gas is supplied from the first buffer chamber 53a to the central portion side of the substrate W, and the mixed gas is supplied from the second buffer chamber 53b to the outer peripheral portion side of the substrate W. The In addition, a high frequency is applied to the susceptor 13 by the high frequency power supply 81, and the gas in the processing chamber S is turned into plasma. The film on the substrate W is etched into a predetermined shape by the action of the plasma.

  Here, when the plasma etching process is performed on the substrate W in the processing chamber S as described above, since the focus ring 17 is disposed around the substrate W placed on the susceptor 13, the plasma generation range is set to the substrate. It can be spread to the periphery of W, and the plasma density on the substrate W can be averaged to make the etching process uniform. And after completion | finish of an etching process, the board | substrate W in which the uniform etching process was performed in this way is carried out from the inside of the processing container 10. FIG.

  By the way, during such a plasma etching process, the focus ring 17 exposed in the processing container 10 is exposed to a high temperature, and the focus ring 17 repeatedly expands and contracts every time the process is performed. A thermal stress is applied to the focus ring 17 every time the expansion / contraction is repeated.

  However, according to the focus ring 17 described in this embodiment, as described above, the identification marks 20, 21 attached to the surface (upper surface and lower surface) of the focus ring 17 are formed of fine circular dot holes 22. Since it consists of symbols 20a, 20b, 20c, 21a, 21b, and 21c, it is difficult for cracks to start from the identification mark. For this reason, the focus ring 17 can be used for a longer period of time than before. In this case, for example, in the case of the focus ring 17 made of Si, if the diameter D of each dot hole 22 is 0.1 mm or less and the shortest distance L between the central axes of the dot holes 22 is three times or more of the diameter D, It is possible to effectively prevent cracking starting from the identification mark. Further, as described with reference to the symbol 21a (numeral “4”) shown in FIG. 5, in order to indicate each symbol 20a, 20b, 20c, 21a, 21b, 21c, a plurality of dot holes 22 are linearly formed. When dot rows arranged side by side are in contact with each other, if the angles formed by the dot rows are not set to be less than 25 °, a plurality of dot holes 22 will not concentrate at a specific location. , It is possible to more effectively prevent cracks starting from the identification marks 20 and 21. If the diameter D of the dot hole 22 is smaller than the sheath thickness at the time of plasma processing, plasma does not enter the dot hole 22 at the time of plasma processing, and the dot hole 22 is dug by the plasma processing. Such problems can be almost avoided.

  On the other hand, when such a plasma etching process is repeatedly performed, the upper surface of the focus ring 17 exposed in the processing vessel 10 is sputtered by the attack received from plasma ions, and the focus ring 17 becomes gradually thinner. However, according to the focus ring 17 described in this embodiment, the identification mark 20 attached to the upper surface of the focus ring 17 as described above is the depth of the dot hole 22 for each symbol 20a, 20b, 20c. Since the symbols 20a, 20b, and 20c are set to be different from each other, the symbols 20a, 20b, and 20c act as indicators that indicate how much the focus ring 17 is reduced, and the lifetime of the focus ring 17 is known using the symbols 20a, 20b, and 20c. be able to.

  That is, since the depths d1, d2, and d3 of the symbols 20a constituting the identification mark 20 are different, the upper surface of the focus ring 17 exposed in the processing vessel 10 is gradually reduced by plasma ion attack. First, the symbol 20a (the numeral “1”) indicated by using the dot hole 22 having the relatively shallow depth d1 disappears, so that the upper surface of the focus ring 17 is substantially at the depth d1. It can be detected that the amount has been reduced to. If the upper surface of the focus ring 17 is further reduced by plasma ion attack, and the symbol 20b (numeral “2”) indicated by using the dot hole 22 having a medium depth d2 disappears, Thus, it can be detected that the upper surface of the focus ring 17 has decreased to substantially the depth d2. Furthermore, when the upper surface of the focus ring 17 is further reduced by the plasma ion attack, the symbol 20c (the numeral “3”) indicated by using the dot hole 22 having a relatively deep depth d3 disappears. Thereby, it can be detected that the upper surface of the focus ring 17 has decreased to substantially the depth d3. In this way, by using the symbols 20a, 20b, and 20c as indicators, the life of the focus ring 17 can be known in stages. If the diameter D of the dot hole 22 is smaller than the sheath thickness at the time of plasma processing, plasma will not enter the dot hole 22 at the time of plasma processing. For this reason, since there are few problems that the dot hole 22 is dug by the plasma processing, each dot hole 22 serves as an accurate indicator.

  Since the lower surface of the focus ring 17 that is not directly exposed in the container 10 is substantially not subjected to plasma ion attack, it is not necessary to detect the decrease as the upper surface of the focus ring 17. The identification mark 21 attached to the lower surface of the focus ring 17 only needs to be indicated by a dot hole 22 of the minimum necessary size that can be visually observed. Therefore, it may be constituted by only the dot hole 22 having a relatively shallow depth d1. Absent. Thus, the identification mark 21 attached to the lower surface of the focus ring 17 that is not directly exposed in the container 10 is optimal for, for example, a manufacturing number used for parts management.

  The example of the embodiment of the present invention has been described above, but the present invention is not limited to this example and can take various forms. For example, the example in which the depth of the dot hole 22 is different for each of the symbols 20a, 20b, and 20c has been described for the identification mark 20 attached to the upper surface of the focus ring 17. However, the symbols 20a, 20b, and 20c are described. The depths of the dot holes 22 may be equal. Even in such a case, it is possible to detect the life of the focus ring 17 depending on the state of the identification mark 20 being reduced.

  In this embodiment, the identification marks 20 and 21 attached to the upper and lower surfaces of the focus ring 17 are all indicated by three-digit numbers. However, the identification mark may be indicated by only one symbol. Alternatively, a plurality of symbols other than three may be combined. Further, the identification mark is not limited to numerals, and can be indicated by using various symbols such as letters and other arbitrary patterns.

  In addition, when attaching the identification marks 20 and 21 to the surface of the focus ring 17 or the like, the dot hole 22 can be formed by using the laser processing described in FIG. 9 or the wet etching described in FIG. In this case, if wet etching is used, it is easy to form a smooth dot hole 22 having a hemispherical bottom surface without sharp edges. In addition, wet etching is advantageous in that crystal defects are less likely to occur.

  Further, although the focus ring 17 has been described as an example, the present invention can be widely applied to various components arranged in the processing container of the plasma processing apparatus. The present invention is particularly effective for parts made of brittle materials such as Si, quartz, alumina ceramics, yttria ceramics, and SiC. Examples of other parts to which the present invention is applied include an upper electrode and a deposition shield.

  Although an example of performing a plasma etching process has been described as an example of a plasma processing apparatus, the present invention can be applied to a plasma processing apparatus that performs various film forming processes, a CVD process, and the like in addition to a plasma etching process.

  FIG. 13 shows a test piece 200 used as an example of the present invention, and FIG. 14 shows a test piece 210 used as a comparative example. Each of these test pieces 200 and 210 is a 30 mm × 30 mm square plate material. On the surface of the test piece 200 of the embodiment shown in FIG. 13, symbols 201 representing the number “4” are formed in a horizontal row by arranging a plurality of dots in the same manner as the symbol 21a described above with reference to FIG. On the other hand, on the surface of the test piece 210 of the comparative example shown in FIG. 14, symbols 211 representing the numeral “4” were formed in a horizontal row by imprinting continuous grooves by a laser marking method. As shown in FIG. 15, the center of these test pieces 200 and 210 was pressed from the surface opposite to the symbols 201 and 211, and the fracture strength F was measured. When the thickness t (mm) of the test pieces 200 and 210 was changed and the relationship between the thickness t and the fracture strength F was examined, FIG. 16 was obtained. In the examples of the present invention, the fracture strength was much improved as compared with the comparative examples.

  The present invention can be applied to a plasma processing apparatus.

It is a longitudinal cross-sectional view for demonstrating the schematic structure of the plasma processing apparatus concerning this Embodiment. It is a top view of a focus ring. It is a bottom view of a focus ring. It is an enlarged view of the identification mark attached | subjected to the upper surface of a focus ring. It is an enlarged view of the identification mark attached | subjected to the lower surface of a focus ring. It is an enlarged plan view which shows the state which looked at the dot hole from the top or the bottom. It is the expanded longitudinal cross-sectional view which cut and showed the surface of the focus ring in the location of a dot hole. It is explanatory drawing of the depth of a dot hole. It is explanatory drawing of a laser processing apparatus. It is explanatory drawing of wet etching. It is a cross-sectional view of an inner upper electrode. It is explanatory drawing which shows the schematic structure of a gas supply type. It is explanatory drawing of the test piece of the Example of this invention. It is explanatory drawing of the test piece of a comparative example. It is explanatory drawing of a destructive test. It is a graph which shows the relationship between thickness and fracture strength about the test piece of the Example of this invention, and the test piece of a comparative example.

Explanation of symbols

S processing chamber W substrate 1 plasma processing apparatus 10 processing vessel 11 insulating plate 12 susceptor support 13 susceptor 14 electrostatic chuck 15 electrode 16 DC power supply 17 focus ring 18 insulator member 20, 21 identification mark 20a, 20b, 20c, 21a, 21b , 21c Symbol 22 Dot hole 23 Laser processing device 24 Laser oscillator 25 Scanning mechanism 26 Lens 27 Etching droplet 28 Refrigerant chamber 29a29b Piping 29c Gas supply line 30 Upper electrode 31 Outer upper electrode 32 Inner upper electrode 33 Dielectric 34 Insulating shielding member DESCRIPTION OF SYMBOLS 40 Matching device 41 Upper feed rod 42 Connector 43 Feed cylinder 44 1 High frequency power supply 45 Insulation member 50 Electrode plate 50a Gas ejection hole 52 Electrode support 53 Buffer chamber 54 Annular partition member 53a First buffer chamber 5 b Second buffer chamber 60 Lower feed cylinder 61 Variable capacitor 70 Exhaust port 71 Exhaust pipe 72 Exhaust device 80 Matching device 81 Second high frequency power source 82 Low pass filter 83 High pass filter 90 Device control unit 100, 101 Gas box 102 First Gas supply pipe 104 Mass flow controller 105 Flow control valve 110 Second gas supply pipe 112 Mass flow controller 113 Flow control valve 120 Gas setting device

Claims (14)

In a plasma processing apparatus for generating plasma in a processing container containing a substrate and performing plasma processing on the substrate, the component is disposed in the processing container,
The surface of the component is provided with an identification mark formed by combining one or more symbols indicated by arranging a plurality of dot holes having a substantially circular shape in a plan view and a substantially U-shaped longitudinal section. Parts of plasma processing equipment, characterized by   2. The plasma processing apparatus according to claim 1, wherein a diameter D of the dot hole is 0.1 mm or less, and a shortest distance L between central axes of the dot holes is three times or more of the diameter D. 3. parts.   The component of the plasma processing apparatus according to claim 2, wherein a diameter D of the dot hole is smaller than a sheath thickness at the time of plasma processing.   In indicating the symbol, when a dot row in which a plurality of dot holes are arranged in a line and another dot row in which a plurality of dot holes are arranged in a line contact with each other, the dots are arranged at the contact position. The part of the plasma processing apparatus according to any one of claims 1 to 3, wherein an angle formed by the rows does not become less than 25 °.   An identification mark combining two or more symbols is attached to the surface exposed in the processing container of the component, and the depth of the dot hole is different for each symbol in the two or more symbols. The parts of the plasma processing apparatus according to claim 1.   The component of the plasma processing apparatus according to claim 1, wherein the identification mark is attached to a surface of the component that is not exposed in the processing container.   The component of the plasma processing apparatus according to claim 1, wherein the component is made of any one of Si, quartz, alumina ceramics, yttria ceramics, and SiC.   The component of the plasma processing apparatus according to claim 1, wherein the dot hole is formed by laser processing.   The component of the plasma processing apparatus according to claim 1, wherein the dot hole is formed by wet etching. A plasma processing apparatus for generating plasma in a processing container containing a substrate and performing plasma processing on the substrate,
A plasma processing apparatus, wherein the component according to any one of claims 1 to 9 is disposed in the processing container. In a plasma processing apparatus for generating plasma in a processing container containing a substrate and performing plasma processing on the substrate, a method for detecting the lifetime of components arranged in the processing container,
An identification mark formed by combining one or more symbols indicated by arranging a plurality of dot holes having a substantially circular shape in a plan view and a substantially U-shaped longitudinal section on the surface of the component is attached to the surface of the component. A method for detecting the lifetime of a component in a plasma processing apparatus, wherein the lifetime of the component is detected based on the state of the identification mark.   A method for detecting the life of a component in a plasma processing apparatus, wherein the diameter D of the dot hole is 0.1 mm or less, and the shortest distance L between the center axes of the dot holes is three times or more of the diameter D.   13. The method for detecting the life of a component in a plasma processing apparatus according to claim 12, wherein the diameter D of the dot hole is narrower than the sheath thickness during plasma processing.   An identification mark that combines two or more symbols having different dot hole depths for each symbol is attached to the surface exposed in the processing container of the component, and the lifetime of the component is increased by the disappearance of each symbol. The method of detecting a lifetime of a part in a plasma processing apparatus according to any one of claims 11 to 13, wherein detection is performed.

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