Plasma processing method and plasma processing apparatus

Abstract

A plasma processing method according to an exemplary embodiment includes a step of preparing a substrate in a chamber of a plasma processing apparatus. The substrate is disposed on the substrate support in the chamber. The substrate support includes a lower electrode and an electrostatic chuck. The electrostatic chuck is disposed over the lower electrode. The plasma processing method further includes a step of applying a positive polarity voltage to the conductive member when plasma has been generated in the chamber in order to perform plasma processing on the substrate. The conductive member extends in the vicinity of a grounded side wall closer to the chamber than the substrate.

Description

[0001] This application is a divisional application of an application with a filing date of July 6, 2020, application number 202010640097.8, and invention name “Plasma processing method and plasma processing device”. Technical Field

[0002] Exemplary embodiments of the present invention relate to a plasma processing method and a plasma processing apparatus. Background Art

[0003] A plasma processing device is used for plasma processing of a substrate. As one type of plasma processing device, there is known a plasma processing device described in Japanese Patent Publication No. 2003-297810 (hereinafter referred to as "Patent Document 1"). The plasma processing device described in Patent Document 1 includes a chamber, a lower electrode, and an upper electrode. The lower electrode is disposed in the chamber. The substrate is placed on the lower electrode. The upper electrode is disposed above the lower electrode. In the plasma processing device described in Patent Document 1, the upper electrode is formed into a dome shape in order to make the plasma density uniform. Summary of the invention

[0004] The present invention provides a technique for adjusting the ion density near the edge of a substrate.

[0005] In one exemplary embodiment, a plasma processing method is provided. The plasma processing method includes a step of preparing a substrate in a chamber of a plasma processing apparatus. The substrate is arranged on a substrate support in the chamber. The substrate support includes a lower electrode and an electrostatic chuck. The electrostatic chuck is arranged on the lower electrode. The plasma processing method also includes a step of applying a positive polarity voltage to a conductive component when plasma has been generated in the chamber in order to perform plasma processing relative to the substrate. The conductive component extends near a grounded side wall of the chamber that is closer to the substrate.

[0006] According to an exemplary embodiment, the ion density near the edge of the substrate can be adjusted. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a flow chart of a plasma processing method according to an exemplary embodiment.

[0008] Figure 2 FIG. 1 is a diagram schematically showing a plasma processing apparatus according to an exemplary embodiment.

[0009] Figure 3 middle, Figure 3 (a) is a diagram showing an example of bias voltage, Figure 3 (b) represents the potential of the substrate

[0010] A timing diagram showing an example of the potential of a conductive component.

[0011] Figure 4 This is a diagram showing another example of bias voltage.

[0012] Figure 5 FIG. 1 is a diagram schematically showing a plasma processing apparatus according to another exemplary embodiment.

[0013] Figure 6 FIG. 1 is a diagram schematically showing a plasma processing apparatus according to another exemplary embodiment.

[0014] Figure 7 This is a timing diagram showing an example of the potential of the substrate and the potential of the conductive component.

[0015] Figure 8 This is another example of a timing diagram showing the potential of a substrate and the potential of a conductive component.

[0016] Fig. 9 This is a timing chart showing another example of the potential of the substrate and the potential of the conductive component.

[0017] Fig.10 This is a timing chart showing another example of the potential of the substrate and the potential of the conductive component.

[0018] Fig.11 FIG. 1 is a diagram schematically showing a plasma processing apparatus according to another exemplary embodiment.

[0019] Fig.12 This is a timing chart showing an example of the potential of the substrate, the potential of the conductive component, and the potential of the edge ring.

[0020] Fig.13 FIG. 1 is a diagram schematically showing a plasma processing apparatus according to another exemplary embodiment.

[0021] Fig.14 FIG. 1 is a diagram schematically showing a plasma processing apparatus according to another exemplary embodiment. DETAILED DESCRIPTION

[0022] Various exemplary embodiments are described below.

[0023] In one exemplary embodiment, a plasma processing method is provided. The plasma processing method includes a step of preparing a substrate in a chamber of a plasma processing apparatus. The substrate is arranged on a substrate support in the chamber. The substrate support includes a lower electrode and an electrostatic chuck. The electrostatic chuck is arranged on the lower electrode. The plasma processing method also includes a step of applying a positive polarity voltage to a conductive component when plasma has been generated in the chamber in order to perform plasma processing relative to the substrate. The conductive component extends near a grounded side wall of the chamber that is closer to the substrate.

[0024] In the above embodiment, by applying a positive polarity voltage to the conductive component, the density of negative ions increases near the edge of the substrate. The density of positive ions in the plasma is represented by the sum of the density of negative ions and the density of electrons. Therefore, by applying a positive polarity voltage to the conductive component, the density of positive ions near the edge of the substrate can be adjusted.

[0025] In an exemplary embodiment, the substrate is arranged on a substrate support and in an area surrounded by an edge ring. The edge ring is a conductive component. The plasma processing method also includes a step of supplying a bias voltage to the lower electrode when plasma has been generated in the chamber in order to perform plasma processing relative to the substrate. The bias voltage is a high-frequency bias power or a pulsed negative polarity voltage periodically applied to the lower electrode. The positive polarity voltage is applied to the edge ring during a period when the potential of the substrate is above 0, and the potential of the edge ring is set to be higher than the potential of the substrate during this period.

[0026] In an exemplary embodiment, the substrate is disposed on a substrate support and in an area surrounded by an edge ring. The conductive component is electrically isolated from the edge ring and extends near a side wall of the chamber closer to the edge ring. The plasma processing method also includes a step of supplying a bias voltage to the lower electrode when plasma has been generated in the chamber in order to perform plasma processing relative to the substrate. The bias voltage is a high-frequency bias power or a pulsed negative polarity voltage periodically applied to the lower electrode. The positive polarity voltage is applied to the conductive component during a period when the potential of the substrate is negative.

[0027] In one exemplary embodiment, a positive polarity voltage may be applied to the conductive member even during a period in which the potential of the substrate is equal to or greater than 0.

[0028] In an exemplary embodiment, the positive polarity voltage may be a DC voltage continuously applied to the conductive member during both a period when the potential of the substrate is negative and a period when the potential of the substrate is equal to or greater than 0.

[0029] In an exemplary embodiment, a positive polarity voltage applied to the conductive member during a period when the potential of the substrate is negative may be higher than a positive polarity voltage applied to the conductive member during a period when the potential of the substrate is zero or higher.

[0030] In an exemplary embodiment, a positive polarity voltage may be applied to the edge ring in such a manner that the potential of the edge ring is set higher than the potential of the substrate during a period in which the potential of the substrate is equal to or greater than 0.

[0031] In one exemplary embodiment, the plasma treatment may be plasma etching with respect to the substrate.

[0032] In another exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, and a power supply device. The substrate support is disposed in the chamber. The substrate support includes a lower electrode and an electrostatic chuck. The electrostatic chuck is disposed on the lower electrode. The power supply device is configured to apply a positive polarity voltage to a conductive component. The conductive component extends near a grounded side wall of the chamber closer to a substrate placed on the substrate support.

[0033] In an exemplary embodiment, the plasma processing apparatus further includes a bias power supply. The bias power supply is configured to supply a bias voltage to the lower electrode when plasma is generated in the chamber in order to perform plasma processing relative to the substrate. The bias voltage is a high-frequency bias power or a pulsed negative voltage periodically applied to the lower electrode. The conductive component is an edge ring extending in a manner surrounding the substrate. The power supply device is configured to apply a positive polarity voltage to the edge ring during a period when the potential of the substrate is above 0, and set the potential of the edge ring to be higher than the potential of the substrate during this period.

[0034] In an exemplary embodiment, the conductive component extends closer to the side wall of the chamber than the edge ring extending in a manner to surround the substrate placed on the substrate support. The plasma processing apparatus further includes a bias power supply. The bias power supply is configured to supply a bias voltage to the lower electrode when plasma has been generated in the chamber in order to perform plasma processing relative to the substrate. The bias voltage is a high-frequency bias power or a pulsed negative polarity voltage periodically applied to the lower electrode. The power supply device is configured to apply a positive polarity voltage to the conductive component during a period when the potential of the substrate is negative.

[0035] In one exemplary embodiment, the power supply device may be configured to apply a positive polarity voltage to the conductive member even when the potential of the substrate is equal to or greater than 0.

[0036] In one exemplary embodiment, the power supply device may be configured to continuously apply the DC voltage as a positive polarity voltage to the conductive member during both a period when the potential of the substrate is negative and a period when the potential of the substrate is equal to or greater than 0.

[0037] In an exemplary embodiment, a positive polarity voltage applied to the conductive member during a period when the potential of the substrate is negative may be higher than a positive polarity voltage applied to the conductive member during a period when the potential of the substrate is zero or higher.

[0038] In one exemplary embodiment, the plasma processing apparatus may further include another power supply device configured to set the potential of the edge ring to be higher than the potential of the substrate during a period when the potential of the substrate is equal to or greater than 0, thereby applying a positive polarity voltage to the edge ring during a period when the potential of the substrate is equal to or greater than 0.

[0039] Hereinafter, various exemplary embodiments will be described in detail with reference to the accompanying drawings. In addition, in each of the drawings, the same or corresponding parts are marked with the same symbols.

[0040] Figure 1 is a flow chart of a plasma processing method according to an exemplary embodiment. Figure 1 The plasma treatment method (hereinafter referred to as "method MT") shown is applied to a substrate. The plasma treatment of method MT is, for example, plasma etching of the substrate. Method MT includes step ST1 and step ST2. In one embodiment, method MT may further include step STb.

[0041] In step ST1, a substrate is prepared in a chamber of a plasma processing device. The substrate may be formed into a disc shape. The substrate is arranged substantially horizontally on a substrate support in the chamber. In one embodiment, the substrate support includes a lower electrode and an electrostatic chuck. The electrostatic chuck is disposed on the lower electrode. The substrate is held by the electrostatic chuck.

[0042] In method MT, in order to perform plasma processing on a substrate, plasma is generated in a chamber while the substrate is disposed in the chamber. When plasma is generated in the chamber, step STb is performed. In step STb, a bias voltage is supplied to the lower electrode. The bias voltage is a high-frequency bias power or a pulsed negative polarity voltage periodically applied to the lower electrode.

[0043] When plasma is generated in the chamber, step ST2 is performed. In step ST2, a positive voltage is applied to the conductive member. The conductive member extends near the grounded side wall of the chamber closer to the substrate.

[0044] By applying a positive polarity voltage to the conductive component, the density of negative ions near the edge of the substrate increases. The density of positive ions in the plasma is represented by the sum of the density of negative ions and the density of electrons. Therefore, by applying a positive polarity voltage to the conductive component, the density of positive ions near the edge of the substrate can be adjusted.

[0045] Hereinafter, various plasma processing apparatuses according to exemplary embodiments that can be used when executing method MT will be described. Also, step ST2 that is executed using the plasma processing apparatuses according to the various exemplary embodiments will be described.

[0046] Figure 2FIG. 1 is a diagram schematically showing a plasma processing apparatus according to an exemplary embodiment. Figure 2 The plasma processing apparatus 1A shown is a capacitively coupled plasma processing apparatus. The plasma processing apparatus 1A includes a chamber 10. The chamber 10 provides an internal space 10s therein. The central axis of the internal space 10s is an axis AX extending in the vertical direction.

[0047] In one embodiment, the chamber 10 includes a chamber body 12. The chamber body 12 is formed in a substantially cylindrical shape. The internal space 10s is provided in the chamber body 12. The chamber body 12 is made of, for example, aluminum. The chamber body 12 is electrically grounded. That is, the chamber body 12 provides a grounded side wall of the chamber 10. A plasma-resistant film is formed on the inner wall surface of the chamber body 12, i.e., the wall surface defining the internal space 10s. The film may be a ceramic film such as a film formed by anodizing or a film formed of yttrium oxide.

[0048] A passage 12p is formed in the side wall of the chamber body 12. The substrate W passes through the passage 12p when being transferred between the internal space 10s and the outside of the chamber 10. A gate valve 12g is provided along the side wall of the chamber body 12 to open / close the passage 12p.

[0049] The plasma processing apparatus 1A further includes a substrate support 16. The substrate support 16 is configured to support a substrate W disposed thereon in the chamber 10. The substrate W is formed in a substantially disk shape. The substrate support 16 is supported by a support portion 17. The support portion 17 extends upward from the bottom of the chamber 10. The support portion 17 is formed in a substantially cylindrical shape. The support portion 17 is formed of an insulating material such as quartz.

[0050] The substrate support 16 includes a lower electrode 18 and an electrostatic chuck 20. The lower electrode 18 and the electrostatic chuck 20 are provided in the chamber 10. The lower electrode 18 is formed of a conductive material such as aluminum and is formed in a substantially disk shape.

[0051] A flow path 18f is formed in the lower electrode 18. The flow path 18f is a flow path for a heat exchange medium. As the heat exchange medium, a liquid refrigerant or a refrigerant (e.g., Freon) that cools the lower electrode 18 by gasification is used. A heat exchange medium supply device (e.g., a cooling unit) is connected to the flow path 18f. The supply device is provided outside the chamber 10. The heat exchange medium is supplied from the supply device to the flow path 18f via the pipe 23a. The heat exchange medium supplied to the flow path 18f is returned to the supply device via the pipe 23b.

[0052] The electrostatic chuck 20 is provided on the lower electrode 18. When the substrate W is processed in the internal space 10s, it is placed on the electrostatic chuck 20 and is held by the electrostatic chuck 20.

[0053] The electrostatic chuck 20 has a main body and an electrode. The main body of the electrostatic chuck 20 is formed of a dielectric such as aluminum oxide or aluminum nitride. The main body of the electrostatic chuck 20 is formed in a roughly disc shape. The central axis of the electrostatic chuck 20 is roughly consistent with the axis AX. The electrode of the electrostatic chuck 20 is arranged in the main body. The electrode of the electrostatic chuck 20 has a membrane shape. The electrode of the electrostatic chuck 20 is electrically connected to a DC power supply via a switch. If a voltage from the DC power supply is applied to the electrode of the electrostatic chuck 20, an electrostatic attraction will be generated between the electrostatic chuck 20 and the substrate W. Through the generated electrostatic attraction, the substrate W is attracted to the electrostatic chuck 20 and held by the electrostatic chuck 20.

[0054] The electrostatic chuck 20 includes a substrate mounting region. The substrate mounting region is a region formed in a substantially disk shape. The central axis of the substrate mounting region is substantially consistent with the axis AX. When a substrate W is processed in the chamber 10, it is mounted on the substrate mounting region.

[0055] In one embodiment, the electrostatic chuck 20 may further include an edge ring mounting area. The edge ring mounting area extends circumferentially in a manner surrounding the substrate mounting area around the central axis of the electrostatic chuck 20. An edge ring ER is mounted on the upper surface of the edge ring mounting area. The edge ring ER is substantially plate-shaped and formed in a ring shape. The edge ring ER is mounted on the edge ring mounting area in a manner such that its central axis is consistent with the axis AX. The substrate W is arranged in the area surrounded by the edge ring ER. That is, the edge ring ER is arranged in a manner surrounding the edge of the substrate W. The edge ring ER may have conductivity. The edge ring ER is formed, for example, of silicon or silicon carbide.

[0056] The plasma processing apparatus 1A may further include a gas supply line 25. The gas supply line 25 supplies a heat transfer gas (eg, He gas) from a gas supply mechanism to a gap between the upper surface of the electrostatic chuck 20 and the back surface (lower surface) of the substrate W.

[0057] The plasma processing apparatus 1A may further include an insulating region 27. The insulating region 27 extends circumferentially on the radially outer side relative to the substrate support 16 in a manner of surrounding the substrate support 16. The insulating region 27 may extend circumferentially on the radially outer side relative to the support portion 17 in a manner of surrounding the support portion 17. The insulating region 27 is formed of an insulator such as quartz. The edge ring ER is disposed on the insulating region 27 and the edge ring mounting region of the electrostatic chuck 20.

[0058] The plasma processing apparatus 1A further includes an upper electrode 30 . The upper electrode 30 is provided above the substrate support 16 . The upper electrode 30 closes the upper opening of the chamber body 12 together with a member 32 . The member 32 has insulating properties. The upper electrode 30 is supported on the upper portion of the chamber body 12 via the member 32 .

[0059] The upper electrode 30 includes a top plate 34 and a support body 36. The lower surface of the top plate 34 defines an internal space 10s. A plurality of gas ejection holes 34a are formed in the top plate 34. The plurality of gas ejection holes 34a penetrate the top plate 34 in the plate thickness direction (vertical direction). The top plate 34 is not defined and is formed, for example, of silicon. Alternatively, the top plate 34 may have a structure in which a plasma-resistant film is provided on the surface of an aluminum component. The film may be a ceramic film such as a film formed by anodizing or a film formed of yttrium oxide.

[0060] The support body 36 supports the top plate 34 in a detachable manner. The support body 36 is formed of a conductive material such as aluminum. A gas diffusion chamber 36a is provided inside the support body 36. A plurality of gas holes 36b extend downward from the gas diffusion chamber 36a. The plurality of gas holes 36b are respectively connected to the plurality of gas discharge holes 34a. A gas inlet 36c is formed in the support body 36. The gas inlet 36c is connected to the gas diffusion chamber 36a. A gas supply pipe 38 is connected to the gas inlet 36c.

[0061] The gas source group 40 is connected to the gas supply pipe 38 via the valve group 41, the flow controller group 42 and the valve group 43. The gas source group 40, the valve group 41, the flow controller group 42 and the valve group 43 constitute a gas supply unit. The gas source group 40 includes a plurality of gas sources. The valve group 41 and the valve group 43 each include a plurality of valves (e.g., on-off valves). The flow controller group 42 includes a plurality of flow controllers. The plurality of flow controllers of the flow controller group 42 are respectively mass flow controllers or pressure-controlled flow controllers. The plurality of gas sources of the gas source group 40 are connected to the gas supply pipe 38 via the corresponding valve of the valve group 41, the corresponding flow controller of the flow controller group 42 and the corresponding valve of the valve group 43. The plasma processing device 1A can supply gas from one or more gas sources selected from the plurality of gas sources of the gas source group 40 to the internal space 10s at an independently adjusted flow rate.

[0062] A partition 48 is provided between the substrate support 16 or the support portion 17 and the side wall of the chamber 10. The partition 48 can be formed, for example, by covering a ceramic such as yttrium oxide on an aluminum member. A plurality of through holes are formed in the partition 48. Below the partition 48, an exhaust pipe 52 is connected to the bottom of the chamber 10. An exhaust device 50 is connected to the exhaust pipe 52. The exhaust device 50 has a pressure regulating valve such as an automatic pressure control valve and a vacuum pump such as a turbomolecular pump, so that the pressure of the internal space 10s can be reduced.

[0063] The plasma processing apparatus 1A further includes a high-frequency power supply 61. The high-frequency power supply 61 is a power supply for generating high-frequency power HF. The high-frequency power HF is used to generate plasma from the gas in the chamber 10. The high-frequency power HF has a first frequency. The first frequency is a frequency in the range of 27 to 100 MHz, for example, 40 MHz or 60 MHz. In order to supply high-frequency power HF to the lower electrode 18, the high-frequency power supply 61 is connected to the lower electrode 18 via a matching circuit 63. The matching circuit 63 is configured to match the output impedance of the high-frequency power supply 61 with the impedance of the load side (lower electrode 18 side). In addition, in an embodiment in which the high-frequency power supply 61 is electrically connected to the lower electrode 18, the upper electrode 30 is electrically grounded.

[0064] The plasma processing apparatus 1A further includes a bias power supply 62. The bias power supply 62 is configured to supply a bias voltage BE to the lower electrode 18 when plasma is generated in the chamber 10 in order to perform plasma processing on the substrate W. The bias power supply 62 is electrically connected to the lower electrode 18 via a matching circuit 64. The matching circuit 64 is configured to match the output impedance of the bias power supply 62 with the impedance of the load side (lower electrode 18 side).

[0065] The bias voltage BE is used to introduce ions onto the substrate W. The bias voltage BE has a second frequency. The bias voltage BE is set to change the potential of the substrate W placed on the electrostatic chuck 20 within a period specified by the second frequency. The second frequency is lower than the first frequency. The second frequency is, for example, a frequency in the range of 50 kHz to 27 MHz.

[0066] Figure 3 (a) is a diagram showing an example of bias voltage. Figure 3 As shown in (a), the bias voltage BE can be a high-frequency bias power having a second frequency. Figure 4 is a diagram showing another example of bias voltage. Figure 4 As shown, the bias voltage BE may be a pulsed negative voltage periodically applied to the lower electrode 18 at a second frequency.

[0067] The plasma processing apparatus 1A further includes a power supply device 70. The power supply device 70 is configured to apply a positive voltage to the conductive member. The conductive member extends closer to the side wall of the chamber 10 than the substrate W placed on the substrate support 16. In one embodiment, the conductive member is an edge ring ER.

[0068] Figure 3 (b) is a timing diagram showing an example of the potential of the substrate and the potential of the conductive component. Figure 3As shown in (b), when the bias voltage BE is supplied to the lower electrode 18, the potential of the substrate W changes within a period specified by the second frequency. That is, the period specified by the second frequency includes a period when the potential of the substrate W is negative and a period when the potential of the substrate W is greater than 0. The period when the potential of the substrate W is negative and the period when the potential of the substrate W is positive are repeated alternately.

[0069] The power supply device 70 is configured to apply a positive polarity voltage to the edge ring ER during a period when the potential of the substrate W is equal to or greater than 0, and to set the potential of the edge ring ER during this period to be higher than the potential V of the substrate W. W Potential V A (>V W ). In one embodiment, the power supply device 70 has a DC power supply 70a and a switch 70b. The DC power supply 70a can be a variable DC power supply. The DC power supply 70a is connected to the edge ring ER via the switch 70b. If the switch 70b is turned on, the voltage from the DC power supply 70a is applied to the edge ring ER. The level of the positive polarity voltage applied to the edge ring ER and the period of applying the positive polarity voltage to the edge ring ER are specified by the control unit MC. The level of the positive polarity voltage applied to the edge ring ER and the period of applying the positive polarity voltage to the edge ring ER can be predetermined.

[0070] The plasma processing apparatus 1A may further include a control unit MC. The control unit MC is a computer including a processor, a storage device, an input device, a display device, etc., and controls each unit of the plasma processing apparatus 1A. The control unit MC executes a control program stored in the storage device, and controls each unit of the plasma processing apparatus 1A according to the recipe data stored in the storage device. Through the control by the control unit MC, the process specified by the recipe data is executed in the plasma processing apparatus 1A. When using the plasma processing apparatus 1A, the method MT can be executed by controlling each unit of the plasma processing apparatus 1A by the control unit MC.

[0071] Step ST2 is performed in a state where plasma has been generated in the chamber 10. In order to generate plasma, gas is supplied from the gas supply unit to the chamber 10. Furthermore, the exhaust device 50 operates in a manner to set the pressure in the chamber 10 to a specified pressure. Furthermore, high-frequency power HF is supplied. As a result, the gas in the chamber 10 is excited and plasma is generated from the gas. As described above, step STb is performed in a state where plasma has been generated. In step STb, bias voltage BE is supplied from the bias power supply 62 to the lower electrode 18. As a result, Figure 3As shown in (b), the potential of the substrate W changes periodically. When the plasma processing apparatus 1A is used, in step ST2, a positive polarity voltage is applied to the edge ring ER from the power supply device 70. Specifically, the positive polarity voltage is applied to the edge ring ER during the period when the potential of the substrate W is 0 or above. The positive polarity voltage increases the potential V of the edge ring ER by 0. A is set to be higher than the potential V of the substrate W W .

[0072] The following references Figure 5 . Figure 5 1A is a diagram schematically showing a plasma processing apparatus according to another exemplary embodiment. Figure 5 The plasma processing apparatus 1B shown in FIG. 1 is described. The plasma processing apparatus 1B does not include the power supply device 70. In the plasma processing apparatus 1B, the bias power supply 62 also serves as a power supply device for applying a voltage to the edge ring ER. In the plasma processing apparatus 1B, the bias power supply 62 supplies high-frequency bias power to the lower electrode 18. The lower electrode 18 is connected to the edge ring ER via a variable impedance circuit 72. The variable impedance circuit 72 may include, for example, a variable capacitor.

[0073] In the plasma processing apparatus 1B, the high-frequency bias power supplied to the lower electrode 18 is branched into a first path from the lower electrode 18 to the substrate W via the electrostatic chuck 20 and a second path from the lower electrode 18 to the edge ring ER via the variable impedance circuit 72. Therefore, during a period when the potential of the substrate W is equal to or greater than 0, the voltage applied to the edge ring ER may also have a positive polarity. In addition, in the plasma processing apparatus 1B, the distribution ratio of the high-frequency bias power between the first path and the second path is adjusted by adjusting the impedance of the variable impedance circuit 72. The impedance of the variable impedance circuit 72 is set so that the potential V of the edge ring ER is equal to or greater than 0 during a period when the potential of the substrate W is equal to or greater than 0. A becomes higher than the potential V of the substrate W W The impedance of the variable impedance circuit 72 may be specified by the control unit MC. The impedance of the variable impedance circuit 72 may be predetermined.

[0074] The following references Figure 6 . Figure 6 1A is a diagram schematically showing a plasma processing apparatus according to another exemplary embodiment. Figure 6The plasma processing apparatus 1C shown in the figure is explained. The plasma processing apparatus 1C also has a conductive component 74. The conductive component 74 is a component different from the edge ring ER. The conductive component 74 is formed of a conductive material such as silicon. The conductive component 74 is formed in a ring shape. The conductive component 74 extends near the side wall of the chamber 10 compared to the substrate W placed on the substrate support 16. Specifically, the conductive component 74 extends circumferentially on the radial outside relative to the edge ring ER. The conductive component 74 is mounted on the insulating area 27. In the plasma processing apparatus 1C, the height direction position of the upper surface of the conductive component 74 is approximately the same as the height direction position of the upper surface of the edge ring ER. The conductive component 74 is separated from the edge ring ER. That is, the conductive component 74 is electrically isolated from the edge ring ER.

[0075] The plasma processing apparatus 1C includes a power supply device 76 instead of the power supply device 70 . The power supply device 76 is configured to apply a positive polarity voltage to the conductive member 74 . Figure 7 74 is a timing diagram showing an example of the potential of the substrate and the potential of the conductive member. The power supply device 76 is configured to apply a positive polarity voltage to the conductive member 74 during a period when the potential of the substrate W is negative. Therefore, during a period when the potential of the substrate W is negative, the potential of the conductive member 74 becomes a positive potential V C . In one embodiment, the power supply device 76 has a DC power supply 76a and a switch 76b. The DC power supply 76a can be a variable DC power supply. The DC power supply 76a is connected to the conductive component 74 via the switch 76b. If the switch 76b is turned on, the voltage from the DC power supply 76a is applied to the conductive component 74. The level of the positive polarity voltage applied to the conductive component 74 and the period of applying the positive polarity voltage to the conductive component 74 are specified by the control unit MC. The level of the positive polarity voltage applied to the conductive component 74 and the period of applying the positive polarity voltage to the conductive component 74 can be predetermined.

[0076] As described above, step STb and step ST2 are performed in a state where plasma is generated in the chamber 10. In step STb, bias voltage BE is supplied to the lower electrode 18 from the bias power supply 62. As a result, Figure 7 As shown, the potential of the substrate W changes periodically. When the plasma processing apparatus 1C is used, in step ST2, a positive voltage is applied from the power supply device 76 to the conductive member 74. Specifically, the positive voltage is applied to the conductive member 74 while the potential of the substrate W is negative.

[0077] Figure 8 2 is a timing diagram showing another example of the potential of the substrate and the potential of the conductive component. Figure 8As shown, in one embodiment, the power supply device 76 of the plasma processing apparatus 1C can apply a positive polarity voltage to the conductive component 74 during two periods, when the potential of the substrate W is negative and when the potential of the substrate W is greater than 0. When executing step ST2, the power supply device 76 of the plasma processing apparatus 1C can apply a positive polarity DC voltage to the conductive component 74 continuously, for example, during two periods, when the potential of the substrate W is negative and when the potential of the substrate W is greater than 0.

[0078] Fig. 9 FIG. 1 is a timing diagram showing another example of the potential of the substrate and the potential of the conductive component. Fig. 9 As shown in FIG. 1 , in one embodiment, the power supply device 76 of the plasma processing apparatus 1C can apply a positive polarity voltage to the conductive component 74 during a period when the potential of the substrate W is negative, which is higher than the positive polarity voltage applied to the conductive component 74 during a period when the potential of the substrate W is 0 or higher. In this example, the positive potential V of the conductive component 74 during a period when the potential of the substrate W is negative is C becomes higher than the positive potential V of the conductive member 74 during the period when the potential of the substrate W is 0 or above. D .

[0079] Fig.10 FIG. 1 is a timing diagram showing another example of the potential of the substrate and the potential of the conductive component. Fig.10 As shown, in one embodiment, the power supply device 76 of the plasma processing apparatus 1C can periodically or continuously apply a pulsed positive polarity voltage to the conductive member 74 during a period when the potential of the substrate W is negative.

[0080] The following references Fig.11 . Fig.11 FIG. 1 is a diagram schematically showing a plasma processing apparatus according to another exemplary embodiment. Fig.11 The plasma processing apparatus 1D shown in FIG. 1 is further provided with a power supply device 70 as another power supply device. The power supply device 70 has the same structure as the power supply device 70 of the plasma processing apparatus 1A. Specifically, the power supply device 70 of the plasma processing apparatus 1D applies a positive polarity voltage to the edge ring ER during a period when the potential of the substrate W is 0 or above, and during this period, the potential V of the edge ring ER is lowered to 0. A is set to be higher than the potential V of the substrate W W .

[0081] Fig.12 FIG. 1 is a timing diagram showing an example of the potential of the substrate, the potential of the conductive component, and the potential of the edge ring. Fig.12As shown, when the method MT is performed using the plasma processing apparatus 1D, in step ST2, a positive polarity voltage is applied from the power supply device 76 to the conductive member 74. When the plasma processing apparatus 1D is used, the positive polarity voltage from the power supply device 76 is also the same as the reference voltage. Figure 7 to Figure 10 The positive polarity voltage described above is applied to the conductive member 74. That is, the positive polarity voltage from the power supply device 76 is applied to the conductive member 74 at least during the period when the potential of the substrate W is negative. As a result, during the period when the potential of the substrate W is negative, the potential of the conductive member 74 becomes a positive potential V C When the plasma processing apparatus 1D is used, in step ST2, a positive voltage from the power supply device 70 is applied to the edge ring ER. The positive voltage from the power supply device 70 is applied to the edge ring ER while the potential of the substrate W is 0 or above. The positive voltage applied to the edge ring ER raises the potential V of the edge ring ER to 0. A is set to be higher than the potential V of the substrate W W .

[0082] The following references Fig.13 . Fig.13 FIG. 1 is a diagram schematically showing a plasma processing apparatus according to another exemplary embodiment. Fig.13 The plasma processing apparatus 1E shown in FIG. 1 is described. In the plasma processing apparatus 1E, the insulating region 27 has a raised portion raised upward relative to the edge ring ER on the radially outer side relative to the edge ring ER. The conductive component 74 is mounted on the raised portion. Therefore, the height direction position of the conductive component 74 is higher than the height direction position of the edge ring ER and the height direction position of the substrate W.

[0083] The following references Fig.14 . Fig.14 FIG. 1 is a diagram schematically showing a plasma processing apparatus according to another exemplary embodiment. Fig.14 The plasma processing apparatus 1F shown in FIG. 1F is described below. In the plasma processing apparatus 1F, the conductive member 74 extends in the circumferential direction radially outside the upper electrode 30 . The conductive member 74 is embedded in the member 32 . The member 32 extends between the upper electrode 30 and the side wall of the chamber 10 .

[0084] In addition, similarly to the plasma processing apparatus 1D, the plasma processing apparatus 1E and the plasma processing apparatus 1F may each include a power supply device 70 as another power supply device. The power supply device 70 applies a positive polarity voltage to the edge ring ER while the potential of the substrate W is equal to or greater than 0, thereby raising the potential V of the edge ring ER to 0. Ais set to be higher than the potential V of the substrate W W .

[0085] Various exemplary embodiments have been described above, but the present invention is not limited to the exemplary embodiments described above, and various omissions, substitutions, and changes may be made. Furthermore, elements in different embodiments may be combined to form other embodiments.

[0086] For example, the high frequency power supply 61 may be connected to the upper electrode 30 via the matching circuit 63, but may not be connected to the lower electrode 18. Furthermore, in another embodiment, if the plasma processing device can apply a positive polarity voltage to the edge ring ER and / or the conductive component 74 as described above, it may be any type of plasma processing device such as an inductively coupled plasma processing device. Furthermore, as the positive polarity voltage applied to the edge ring ER and / or the conductive component 74 when plasma is generated, a pulsed or continuous positive polarity DC voltage is exemplified, but it is not particularly limited to the positive polarity voltage. For example, the positive polarity voltage may be a voltage having any waveform such as a waveform obtained by synthesizing a triangular wave or the like with the positive polarity DC voltage. Furthermore, when plasma is not generated, a negative polarity voltage may be applied to the edge ring ER and / or the conductive component 74.

[0087] As can be seen from the above description, various embodiments of the present invention are described in this specification for the purpose of illustration, and various changes can be made without departing from the scope and gist of the present invention. Therefore, the various embodiments disclosed in this specification are not intended to be limiting, and the true scope and gist are shown by the scope of the additional technical solutions.

Claims

1. A plasma treatment method, comprising: The step of preparing a substrate in a chamber of a plasma processing apparatus, wherein the substrate is disposed on a substrate support in the chamber, the substrate support including a lower electrode and an electrostatic chuck disposed on the lower electrode; and A step of applying a positive polarity voltage to a conductive member extending near a grounded side wall of the chamber closer to the substrate when plasma is generated in the chamber in order to perform plasma processing on the substrate.

2. The plasma processing method according to claim 1, wherein: The substrate is disposed on the substrate supporter within a region surrounded by an edge ring, The plasma processing method further includes the step of supplying a bias voltage to the lower electrode when the plasma is generated in the chamber in order to perform the plasma processing on the substrate. The edge ring is the conductive component, The bias voltage is a high frequency bias power or a pulsed negative voltage periodically applied to the lower electrode. The positive polarity voltage is applied to the edge ring during a period in which the potential of the substrate is equal to or greater than 0, and during this period, the potential of the edge ring is set higher than the potential of the substrate.

3. The plasma processing method according to claim 1, wherein: The substrate is disposed on the substrate support and in an area surrounded by an edge ring, The conductive member is electrically isolated from the edge ring and extends closer to the sidewall of the chamber than the edge ring, The plasma processing method further includes the step of supplying a bias voltage to the lower electrode when the plasma is generated in the chamber in order to perform the plasma processing on the substrate. The bias voltage is a high frequency bias power or a pulsed negative voltage periodically applied to the lower electrode. The positive polarity voltage is applied to the conductive component during a period when the potential of the substrate is negative.

4. The plasma processing method according to claim 3, wherein: The positive polarity voltage is also applied to the conductive component during a period when the potential of the substrate is equal to or greater than 0.

5. The plasma processing method according to claim 4, wherein: The positive polarity voltage is a DC voltage that is continuously applied to the conductive member during both the period when the potential of the substrate is negative and the period when the potential of the substrate is equal to or greater than 0.

6. The plasma processing method according to claim 4, wherein: The positive polarity voltage applied to the conductive component during the period when the potential of the substrate is negative is higher than the positive polarity voltage applied to the conductive component during the period when the potential of the substrate is equal to or greater than 0.

7. The plasma processing method according to claim 3, wherein: A positive polarity voltage is applied to the edge ring so that the potential of the edge ring is set higher than the potential of the substrate while the potential of the substrate is equal to or greater than 0.

8. The plasma processing method according to any one of claims 1 to 7, wherein: The plasma processing is plasma etching with respect to the substrate.

9. A plasma processing device, comprising: Chamber; a substrate supporter disposed in the chamber and comprising a lower electrode and an electrostatic chuck disposed on the lower electrode; The power supply device is configured to apply a positive polarity voltage to a conductive member extending near a grounded side wall of the chamber closer to the substrate disposed on the substrate support.

10. The plasma processing apparatus according to claim 9, further comprising: a bias power supply configured to supply a bias voltage to the lower electrode when plasma is generated in the chamber in order to perform plasma processing on the substrate, The bias voltage is a high frequency bias power or a pulsed negative voltage periodically applied to the lower electrode. The conductive component is an edge ring extending so as to surround the substrate, The power supply device is configured to apply the positive polarity voltage to the edge ring while the potential of the substrate is equal to or greater than 0, and to set the potential of the edge ring to be higher than the potential of the substrate during the period.

11. The plasma processing apparatus according to claim 9, further comprising: The conductive member extends closer to the side wall of the chamber than an edge ring extending to surround the substrate placed on the substrate supporter; and a bias power supply configured to supply a bias voltage to the lower electrode when plasma is generated in the chamber in order to perform plasma processing on the substrate, The bias voltage is a high frequency bias power or a pulsed negative voltage periodically applied to the lower electrode. The power supply device is configured to apply the positive polarity voltage to the conductive member while the potential of the substrate is negative.

12. The plasma processing apparatus according to claim 11, wherein: The power supply device is configured to apply the positive polarity voltage to the conductive member even while the potential of the substrate is equal to or greater than 0.

13. The plasma processing apparatus according to claim 12, wherein: The power supply device is configured to continuously apply a DC voltage as the positive polarity voltage to the conductive member during both the period when the potential of the substrate is negative and the period when the potential of the substrate is equal to or greater than 0.

14. The plasma processing apparatus according to claim 12, wherein: The positive polarity voltage applied to the conductive member during the period when the potential of the substrate is negative is higher than the positive polarity voltage applied to the conductive member during the period when the potential of the substrate is equal to or greater than 0.

15. The plasma processing apparatus according to claim 11, further comprising: Another power supply device is configured to set the potential of the edge ring to be higher than the potential of the substrate during a period when the potential of the substrate is equal to or greater than 0, and to apply a positive polarity voltage to the edge ring during the period when the potential of the substrate is equal to or greater than 0.

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