Plasma processing apparatus

Abstract

To provide a technique which suppresses the fluctuation of the spread in the radial direction of plasma in a cycle of electric bias energy supplied to a bias electrode of a substrate support unit of a plasma processing apparatus.SOLUTION: In the disclosed plasma processing apparatus, an edge ring is arranged so as to surround a substrate on a substrate support unit in a plasma processing chamber. A ring electrode is arranged so as to surround the edge ring. A first bias RF power source is configured to supply a first bias RF power to the bias electrode. The first bias RF power has a first frequency and a first power level. A second bias RF power source is configured to supply a second bias RF power to the ring electrode. The second bias RF power has the first frequency and a second power level and is synchronized with the first bias RF power.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE Exemplary embodiments of the present disclosure relate to a plasma processing apparatus and a plasma processing method. [Background technology]

[0002] A plasma processing apparatus is used for plasma processing of a substrate. The plasma processing apparatus includes a chamber, an electrostatic chuck, and a lower electrode. The electrostatic chuck and the lower electrode are provided in the chamber. The electrostatic chuck is provided on the lower electrode. The electrostatic chuck supports an edge ring placed thereon. The edge ring is sometimes called a focus ring. The electrostatic chuck supports a substrate placed in a region surrounded by the edge ring. When plasma processing is performed in the plasma processing apparatus, a gas is supplied into the chamber. Also, high frequency power is supplied to the lower electrode. A plasma is formed from the gas in the chamber. The substrate is processed by chemical species such as ions and radicals from the plasma.

[0003] When plasma processing is performed, the edge ring is consumed and the thickness of the edge ring is reduced. When the thickness of the edge ring is reduced, the position of the upper end of the plasma sheath (hereinafter referred to as the "sheath") above the edge ring is lowered. The vertical position of the upper end of the sheath above the edge ring and the vertical position of the upper end of the sheath above the substrate should be equal. Japanese Patent Laid-Open Publication No. 2008-227063 (hereinafter referred to as "Patent Document 1") discloses a plasma processing apparatus that makes it possible to adjust the vertical position of the upper end of the sheath above the edge ring. The plasma processing apparatus described in Patent Document 1 is configured to apply a DC voltage to the edge ring. In addition, the plasma processing apparatus described in Patent Document 1 is configured to adjust the power level of the high frequency power supplied to the lower electrode when the DC voltage is applied to the edge ring. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-227063 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a technique for suppressing variations in radial expansion of plasma within a period of electrical bias energy supplied to a bias electrode of a substrate support of a plasma processing apparatus. [Means for solving the problem]

[0006] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a plasma processing chamber, a substrate support, an RF power supply, an edge ring, a ring electrode, a first bias RF power supply, and a second bias RF power supply. The substrate support is disposed within the plasma processing chamber and includes a bias electrode. The RF power supply is configured to generate RF power to generate a plasma within the chamber. The edge ring is disposed to surround a substrate on the substrate support. The ring electrode is disposed to surround the edge ring. The first bias RF power supply is configured to supply a first bias RF power to the bias electrode. The first bias RF power has a first frequency and a first power level. The second bias RF power supply is configured to supply a second bias RF power to the ring electrode. The second bias RF power has a first frequency and a second power level. The second bias RF power is synchronized with the first bias RF power. Effect of the Invention

[0007] According to one exemplary embodiment, it is possible to suppress the fluctuation in the radial expansion of plasma within a period of electrical bias energy supplied to a bias electrode of a substrate support of a plasma processing apparatus. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram illustrating a plasma processing apparatus according to an exemplary embodiment; [Diagram 2] FIG. 2 illustrates a substrate support and multiple power supplies in a plasma processing apparatus according to an exemplary embodiment. [Diagram 3] FIGS. 3(a) and 3(b) are diagrams showing examples of electrical bias energy supplied to the bias electrode and the ring electrode, respectively. [Figure 4] FIG. 13 illustrates a substrate support and multiple power supplies according to another exemplary embodiment. [Diagram 5] 1 illustrates a substrate support and multiple power supplies in accordance with yet another exemplary embodiment. [Figure 6] 1 illustrates a substrate support and multiple power supplies in accordance with yet another exemplary embodiment. [Figure 7] 1 illustrates a substrate support and multiple power supplies in accordance with yet another exemplary embodiment. [Figure 8] 1 illustrates a substrate support and multiple power supplies in accordance with yet another exemplary embodiment. [Figure 9] 1 illustrates a substrate support and multiple power supplies in accordance with yet another exemplary embodiment. [Figure 10] 1 illustrates a substrate support and multiple power supplies in accordance with yet another exemplary embodiment. [Figure 11] 1 illustrates a substrate support and multiple power supplies in accordance with yet another exemplary embodiment. [Figure 12] 1 illustrates a substrate support and multiple power supplies in accordance with yet another exemplary embodiment. [Figure 13] 1 illustrates a substrate support and multiple power supplies in accordance with yet another exemplary embodiment. [Figure 14] 1 is a flow diagram of a plasma processing method according to an exemplary embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Various exemplary embodiments will now be described in detail with reference to the drawings, in which the same or corresponding parts are designated by the same reference numerals.

[0010] FIG. 1 is a schematic diagram of a plasma processing apparatus according to an exemplary embodiment. FIG. 2 is a diagram showing a substrate support and a plurality of power supplies of the plasma processing apparatus according to an exemplary embodiment. The plasma processing apparatus 1 shown in FIG. 1 is a capacitively coupled plasma processing apparatus. The plasma processing apparatus 1 includes a chamber 10 (plasma processing chamber). 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.

[0011] In one embodiment, the chamber 10 may include a chamber body 12. The chamber body 12 has a generally cylindrical shape. An 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. 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. This film may be a ceramic film, such as a film formed by anodization or a film formed from yttrium oxide.

[0012] The sidewall of the chamber body 12 provides a passage 12p. 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 sidewall of the chamber body 12 to open and close the passage 12p.

[0013] 1 and 2, the plasma processing apparatus 1 further includes a substrate support 16. The substrate support 16 is surrounded by a dielectric portion 17. The dielectric portion 17 extends in a circumferential direction outside the substrate support 16 in a radial direction with respect to the axis line AX. The dielectric portion 17 is made of a dielectric material such as quartz. The dielectric portion 17 may support the substrate support 16.

[0014] The substrate support 16 is configured to support the substrate W placed thereon in the chamber 10. The substrate W has a substantially disk shape. The substrate W is placed on the substrate support 16 so that its center is located on the axis AX. The substrate support 16 is configured to further support an edge ring ER. The edge ring ER has an annular shape. The edge ring ER is made of a material selected according to the plasma processing performed in the plasma processing apparatus 1. The edge ring ER is made of, for example, silicon or silicon carbide. The edge ring ER is placed on the substrate support 16 so that its central axis coincides with the axis AX. The substrate W is placed on the substrate support 16 and in a region surrounded by the edge ring ER. That is, the edge ring ER is placed so as to surround the substrate W. The outer edge portion of the edge ring ER may be placed on the dielectric portion 17.

[0015] The substrate support 16 may include a base 18 and an electrostatic chuck 20. The base 18 and the electrostatic chuck 20 are provided in the chamber 10. The base 18 is made of a conductive material such as aluminum, and has a substantially disk shape. The central axis of the base 18 is an axis line AX.

[0016] The base 18 provides a flow passage 18f therein. The flow passage 18f is a flow passage for a heat exchange medium. The heat exchange medium is, for example, a refrigerant. The flow passage 18f is connected to a supply device 22 for the heat exchange medium. The supply device 22 is provided outside the chamber 10. The flow passage 18f receives the heat exchange medium supplied from the supply device 22. The heat exchange medium supplied to the flow passage 18f is returned to the supply device 22.

[0017] The electrostatic chuck 20 is provided on a base 18. The electrostatic chuck 20 may be fixed to the base 18 via a bonding member 19 such as an adhesive. The electrostatic chuck 20 includes a first region 20R1 and a second region 20R2. The first region 20R1 is a region for holding a substrate W placed thereon and has a substantially disk shape. The central axis of the first region 20R1 substantially coincides with the axis AX. The second region 20R2 is a region for holding an edge ring ER placed thereon. The second region 20R2 has a substantially annular shape in a plan view and extends in the circumferential direction radially outward of the first region 20R1. The upper surface of the first region 20R1 extends at a position higher in the height direction than the position of the upper surface of the second region 20R2 in the height direction.

[0018] The electrostatic chuck 20 has a body 20m and a chuck electrode 20a. The body 20m is made of a dielectric material such as aluminum oxide or aluminum nitride. The body 20m has a substantially disk shape. The central axis of the electrostatic chuck 20 and the body 20m is the axis AX. The chuck electrode 20a is provided in the body 20m in the first region 20R1. The chuck electrode 20a is a film made of a conductive material. The chuck electrode 20a may have a substantially circular planar shape. The center of the chuck electrode 20a may be located on the axis AX. The chuck electrode 20a is electrically connected to a DC power supply 50p via a switch 50s. When a voltage from the DC power supply 50p is applied to the chuck electrode 20a, an electrostatic attractive force is generated between the electrostatic chuck 20 and the substrate W. The generated electrostatic attractive force attracts the substrate W to the electrostatic chuck 20 and the substrate W is held by the electrostatic chuck 20.

[0019] The electrostatic chuck 20 may further include chuck electrodes 20b and 20c. The chuck electrodes 20b and 20c are provided in the body 20m in the second region 20R2. Each of the chuck electrodes 20b and 20c is a film formed of a conductive material. The chuck electrodes 20b and 20c extend in a circumferential direction around the axis line AX. The chuck electrode 20c extends radially outward relative to the chuck electrode 20b. Each of the chuck electrodes 20b and 20c may have an annular shape. The chuck electrode 20b is electrically connected to a DC power supply 51p via a switch 51s. The chuck electrode 20c is electrically connected to a DC power supply 52p via a switch 52s. When the voltages from the DC power supplies 51p and 52p are applied to the chuck electrodes 20b and 20c, respectively, an electrostatic attraction force is generated between the electrostatic chuck 20 and the edge ring ER. The edge ring ER is attracted to the electrostatic chuck 20 by the generated electrostatic attractive force and is held by the electrostatic chuck 20.

[0020] The plasma processing apparatus 1 further includes a ring electrode DR. The ring electrode DR extends radially outward relative to the edge ring ER. The ring electrode DR may have a substantially annular shape in a plan view. In the embodiment of FIG. 2, the ring electrode DR extends so as to surround the edge ring ER. The ring electrode DR may be disposed on the dielectric portion 17. In the embodiment of FIG. 2, the ring electrode DR is formed of a conductive material such as silicon, silicon carbide, nickel, Hastelloy, or the like.

[0021] 1, the plasma processing apparatus 1 may be provided with a gas supply line 24. The gas supply line 24 supplies a heat transfer gas, for example, He gas, from a gas supply mechanism to a gap between the upper surface of the electrostatic chuck 20 and the rear surface (lower surface) of the substrate W.

[0022] The plasma processing apparatus 1 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 by the upper part of the chamber body 12 via the member 32.

[0023] The upper electrode 30 may include a top plate 34 and a support 36. The lower surface of the top plate 34 defines an internal space 10s. The top plate 34 provides a plurality of gas holes 34a. Each of the plurality of gas holes 34a penetrates the top plate 34 in the thickness direction (vertical direction). The top plate 34 is made of, for example, silicon. Alternatively, the top plate 34 may have a structure in which a plasma-resistant film is provided on the surface of an aluminum member. This film may be a ceramic film, such as a film formed by anodizing or a film formed of yttrium oxide.

[0024] The support 36 detachably supports the top plate 34. The support 36 is formed of a conductive material such as aluminum. The support 36 provides a gas diffusion chamber 36a therein. The support 36 further provides a plurality of gas holes 36b. The plurality of gas holes 36b extend downward from the gas diffusion chamber 36a and communicate with the plurality of gas holes 34a, respectively. The support 36 further provides a gas introduction port 36c. The gas introduction port 36c is connected to the gas diffusion chamber 36a. A gas supply pipe 38 is connected to the gas introduction port 36c.

[0025] The gas source group 40 is connected to the gas supply pipe 38 via the valve group 41, the flow rate controller group 42, and the valve group 43. The gas source group 40, the valve group 41, the flow rate controller group 42, and the valve group 43 configure a gas supply unit. The gas source group 40 includes a plurality of gas sources. Each of the valve group 41 and the valve group 43 includes a plurality of valves (e.g., on-off valves). The flow rate controller group 42 includes a plurality of flow rate controllers. Each of the plurality of flow rate controllers of the flow rate controller group 42 is a mass flow controller or a pressure control type flow rate controller. Each of the plurality of gas sources of the gas source group 40 is connected to the gas supply pipe 38 via a corresponding valve of the valve group 41, a corresponding flow rate controller of the flow rate controller group 42, and a corresponding valve of the valve group 43. The plasma processing apparatus 1 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 individually adjusted flow rates.

[0026] The plasma processing apparatus 1 may further include a baffle member 48. The baffle member 48 extends between the dielectric portion 17 and the side wall of the chamber body 12. The baffle member 48 may be formed, for example, by coating an aluminum member with a ceramic such as yttrium oxide. The baffle member 48 provides a plurality of through holes. The space above the baffle member 48 and the space below the baffle member 48 are connected via the plurality of through holes in the baffle member 48.

[0027] The plasma processing apparatus 1 may further include an exhaust device 50. The exhaust device 50 is connected to the bottom of the chamber body 12 below the baffle member 48 via an exhaust pipe 52. The exhaust device 50 has a pressure controller such as an automatic pressure control valve and a vacuum pump such as a turbomolecular pump, and can reduce the pressure in the internal space 10s.

[0028] 1 and 2, the plasma processing apparatus 1 further includes a high-frequency power supply 61 (RF power supply). The high-frequency power supply 61 generates high-frequency power RF (RF power) to be supplied to a high-frequency electrode to generate plasma above the substrate support 16. The high-frequency power RF has a frequency in the range of 27 to 100 MHz, for example, a frequency of 40 MHz or 60 MHz. In one embodiment, the high-frequency electrode is the base 18. That is, in one embodiment, the base 18 provides a lower electrode that is a high-frequency electrode.

[0029] The high frequency power supply 61 is connected to the base 18 via a matching device 61m. The matching device 61m has a matching circuit configured to match the impedance of the load side (base 18 side) of the high frequency power supply 61 to the output impedance of the high frequency power supply 61. In one embodiment, the high frequency power supply 61 may be connected to the base 18 via the matching device 61m and a filter 61f. The filter 61f is a filter having a frequency characteristic that selectively passes high frequency power RF, and has a characteristic of blocking or reducing electric bias energy described later. The high frequency power supply 61 may be electrically connected to the upper electrode 30 instead of the high frequency electrode of the substrate support 16. That is, in another embodiment, the high frequency electrode may be the upper electrode 30.

[0030] The plasma processing apparatus 1 further includes a bias power supply 62 (first bias power supply). The bias power supply 62 is electrically coupled to the bias electrode of the substrate support 16 and is configured to generate an electric bias energy BE to be applied to the bias electrode of the substrate support 16. In the embodiment of FIG. 2, the bias electrode of the substrate support 16 is the base 18. The electric bias energy BE is used to attract ions to the substrate W. The electric bias energy BE has a bias frequency. The bias frequency may be different from or the same as the frequency of the high frequency power RF. The bias frequency may be lower than the frequency of the high frequency power RF. In one embodiment, the bias frequency is a frequency in the range of 50 kHz to 27 MHz, for example, 400 kHz.

[0031] Please refer to Figures 3(a) and 3(b) below in conjunction with Figures 1 and 2. Figures 3(a) and 3(b) each show an example of electrical bias energy supplied to a bias electrode and an example of electrical bias energy supplied to a ring electrode.

[0032] In one embodiment, the bias power supply 62 (first bias power supply or first bias RF power supply) may generate high frequency power, i.e., high frequency bias power (first bias RF power), as the electrical bias energy BE, as shown in FIG. 3(a). The high frequency bias power (and its voltage waveform) as the electrical bias energy BE is a sine wave having a bias frequency. The inverse of the bias frequency is the time length of the cycle CP (repetition period).

[0033] The bias power supply 62 (first bias power supply or first bias RF power supply) is connected to the bias electrode (the base 18 in the embodiment of FIG. 2) via a matching device 62m and a filter 62f in order to supply high frequency bias power to the bias electrode. The matching device 62m has a matching circuit configured to match the impedance on the load side of the bias power supply 62 to the output impedance of the bias power supply 62. The filter 62f has a frequency characteristic that selectively passes the electric bias energy BE, and has a characteristic that blocks or reduces the high frequency power RF.

[0034] In another embodiment, the bias power supply 62 (first bias power supply or first voltage pulse power supply) may be configured to periodically apply a voltage pulse as the electrical bias energy BE to the bias electrode (base 18 in the embodiment of FIG. 2) as shown in FIG. 3(b). That is, the electrical bias energy BE may be a first DC pulse signal or a sequence of DC voltage pulses. The voltage pulse is applied to the bias electrode (base 18 in the embodiment of FIG. 2) at a time interval (i.e., period CP) that is the inverse of the bias frequency. The voltage pulse may be a negative voltage pulse or a negative DC voltage pulse. The voltage pulse may have any waveform, such as a triangular wave, a square wave, etc.

[0035] The plasma processing apparatus 1 may further include a high-frequency power supply 63 (RF power supply). The high-frequency power supply 63 generates high-frequency power RF2 (RF power) to generate plasma above the substrate support 16. The high-frequency power RF2 may have the same frequency as the frequency of the high-frequency power RF. The high-frequency power supply 63 is electrically connected to the ring electrode DR via a matching device 63m and a filter 63f. The matching device 63m has a matching circuit configured to match the impedance of the load side of the high-frequency power supply 63 to the output impedance of the high-frequency power supply 63. The filter 63f has a characteristic of selectively passing the high-frequency power RF2 and has a characteristic of blocking or reducing the electric bias energy BE2 described later.

[0036] The plasma processing apparatus 1 further includes a bias power supply 64 (second bias power supply). The bias power supply 64 is electrically coupled to the ring electrode DR and configured to generate an electric bias energy BE2 to be applied to the ring electrode DR. The electric bias energy BE2 has the same bias frequency as the bias frequency of the electric bias energy BE.

[0037] As shown in (a) of Fig. 3, the electric bias energy BE2 may be high-frequency bias power (second bias RF power) like the electric bias energy BE. In this case, the bias power supply 64 (second bias power supply or second bias RF power supply) is connected to the ring electrode DR via a matching device 64m and a filter 64f. The matching device 64m has a matching circuit configured to match the impedance of the load side of the bias power supply 64 to the output impedance of the bias power supply 64. The filter 64f has a frequency characteristic that selectively passes the electric bias energy BE2 and has a characteristic that blocks or reduces the high-frequency power RF2.

[0038] As shown in FIG. 3(b), the electrical bias energy BE2 may be a sequence of voltage pulses similar to the electrical bias energy BE. That is, the electrical bias energy BE2 generated by the bias power supply 64 (second bias power supply or second voltage pulse power supply) may be a second DC pulse signal or a sequence of DC voltage pulses. The voltage pulses of the electrical bias energy BE2 are periodically applied to the ring electrode DR with a time interval (i.e., period CP) that is the inverse of the bias frequency. The voltage pulses may be negative voltage pulses or negative DC voltage pulses. The voltage pulses may have any waveform, such as a triangular wave, a square wave, etc.

[0039] As shown in FIG. 3(a) and FIG. 3(b), one period (period CP or repeating period) of the electrical bias energy BE is composed of a positive phase period PP (second period) and a negative phase period PN (first period). Also, one period (period CP or repeating period) of the electrical bias energy BE2 is composed of a positive phase period PP (fourth period) and a negative phase period PN (third period). In the negative phase period PN, each of the electrical bias energies BE and BE2 has a voltage lower than its average voltage in one period (period CP). In the positive phase period PP, each of the electrical bias energies BE and BE2 has a voltage equal to or higher than its average voltage in one period (period CP).

[0040] The negative phase period PN of the electrical bias energy BE2 generated by the bias power supply 64 at least partially overlaps with the negative phase period PN of the electrical bias energy BE generated by the bias power supply 62. As shown in Figures 3(a) and 3(b), the negative phase period PN of the electrical bias energy BE2 may coincide with the negative phase period PN of the electrical bias energy BE. That is, the phase of the electrical bias energy BE2 may be synchronized with the phase of the electrical bias energy BE.

[0041] It should be noted that when the electrical bias energies BE and BE2 are first and second bias RF powers, respectively, the first and second power levels of the first and second bias RF powers may be the same as each other or may be different from each other, and the second power level may be greater or less than the first power level.

[0042] When the electrical bias energy BE is a first voltage pulse signal, the first voltage pulse signal has a first voltage level in a first period and a second voltage level in a second period. The absolute value of the first voltage level is greater than the absolute value of the second voltage level. When the electrical bias energy BE2 is a second voltage pulse signal, the second voltage pulse signal has a third voltage level in a third period and a second voltage level in a fourth period. The absolute value of the third voltage level is greater than the absolute value of the fourth voltage level. The first voltage level and the third voltage level may be negative levels. The third voltage level may be the same as the first voltage level, and the fourth voltage level may be the same as the second voltage level. Alternatively, the third voltage level may be different from the first voltage level.

[0043] When the electrical bias energies BE and BE2 are first and second voltage pulse signals, respectively, the first period may have the same length as the second period. Alternatively, the first period may have a different length than the second period. The length of the first period may be longer or shorter than the length of the second period.

[0044] In one embodiment, the plasma processing apparatus 1 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 part of the plasma processing apparatus 1. Specifically, the control unit MC executes a control program stored in the storage device, and controls each part of the plasma processing apparatus 1 based on recipe data stored in the storage device. Under the control of the control unit MC, a process specified by the recipe data is executed in the plasma processing apparatus 1.

[0045] During the above-mentioned positive phase period PP, the thickness of the sheath on the substrate W is small, and the impedance between the substrate W and the plasma is small, so that a relatively large amount of high frequency power RF is coupled to the plasma above the substrate W. On the other hand, during the negative phase period PN, the thickness of the sheath on the substrate W is large, and the impedance between the substrate W and the plasma is large. In the plasma processing apparatus 1, in order to increase the thickness of the sheath on the radial outside of the edge of the substrate W during the negative phase period PN and to increase the impedance between the ring electrode DR and the plasma, electric bias energy BE2 is supplied to the ring electrode DR. Therefore, the high frequency power RF coupled to the plasma above the ring electrode DR during the negative phase period PN is suppressed. As a result, the fluctuation of the radial spread of the plasma within the period CP of the electric bias energy BE supplied to the bias electrode is suppressed. In addition, it is possible to suppress the abnormal shape formed at the edge of the substrate W and its vicinity by etching.

[0046] Reference is now made to Figure 4, which illustrates a substrate support and a number of power supplies according to another exemplary embodiment. Differences between the embodiment of Figure 4 and the embodiment of Figure 2 will now be described.

[0047] The substrate support 16B of the embodiment of FIG. 4 can be employed as a substrate support of the plasma processing apparatus 1. In the embodiment of FIG. 4, the ring electrode DRB extends radially outward relative to the edge ring ER. The ring electrode DRB may have a substantially annular shape in a plan view. The ring electrode DRB extends so as to surround the edge ring ER and is disposed on the dielectric portion 17. The ring electrode DRB is formed of a conductive material such as silicon or silicon carbide.

[0048] In the substrate support 16B, an auxiliary electrode 71 is provided in the dielectric portion 17 below the ring electrode DRB. The auxiliary electrode 71 may have an annular shape and extend in a circumferential direction around the axis line AX. Other configurations of the substrate support 16B are the same as the corresponding configurations of the substrate support 16 shown in Fig. 2. In the embodiment of Fig. 4, the high frequency power supply 63 and the bias power supply 64 are electrically connected to the auxiliary electrode 71 and are capacitively coupled to the ring electrode DRB via the auxiliary electrode 71.

[0049] Reference is now made to Figure 5, which illustrates a substrate support and a number of power supplies according to yet another exemplary embodiment. The differences between the embodiment of Figure 4 and the embodiment of Figure 3 will now be described.

[0050] The substrate support 16C of the embodiment of Fig. 5 can be employed as a substrate support of the plasma processing apparatus 1. In the embodiment of Fig. 5, a ring member 72 extends radially outward from the edge ring ER. The ring member 72 may have a substantially annular shape in a plan view. The ring member 72 extends so as to surround the edge ring ER, and is disposed on the dielectric portion 17. The ring member 72 is formed of a dielectric material such as quartz or aluminum oxide.

[0051] In the substrate support 16C, the ring electrode DRC is provided in the ring member 72. The ring electrode DRC may have an annular shape and extend in a circumferential direction around the axis line AX. Other configurations of the substrate support 16C are the same as the corresponding configurations of the substrate support 16B. In the embodiment of FIG. 5, the high frequency power supply 63 and the bias power supply 64 are electrically connected to the ring electrode DRC. Note that the ring electrode DRC may be provided in a region away from the ring member 72, for example, in the dielectric portion 17.

[0052] Reference is now made to Figure 6, which illustrates a substrate support and a number of power supplies according to yet another exemplary embodiment. The differences between the embodiment of Figure 6 and the embodiment of Figure 2 will now be described.

[0053] 6, the plasma processing apparatus 1 further includes a bias power supply 66. The bias power supply 66 is electrically coupled to the edge ring ER and configured to generate an electrical bias energy BE3 that is applied to the edge ring ER. The electrical bias energy BE3 may have the same bias frequency as the bias frequency of the electrical bias energy BE.

[0054] The electric bias energy BE3 may be high-frequency bias power (third bias RF power) like the electric bias energy BE. In this case, the bias power supply 66 is connected to the edge ring ER via a matching device 66m and a filter 66f. The matching device 66m has a matching circuit configured to match the impedance of the load side of the bias power supply 66 to the output impedance of the bias power supply 66 (third bias RF power supply). The filter 66f has a frequency characteristic that selectively passes the electric bias energy BE3, and has a characteristic that blocks or reduces the high-frequency power RF.

[0055] Alternatively, the electrical bias energy BE3 may be a sequence of voltage pulses similar to the electrical bias energy BE or a third voltage pulse signal. The voltage pulses of the electrical bias energy BE3 are applied to the ring electrode DR periodically with a time interval (i.e., period CP) that is the inverse of the bias frequency.

[0056] 6, the electrical bias energy applied to the edge ring ER can be independently controlled to independently control the thickness of the sheath on the edge ring ER. Note that a bias power supply 66 may also be electrically coupled to the edge ring ER in each of the substrate support 16B and the substrate support 16C.

[0057] Reference is now made to Figure 7, which illustrates a substrate support and a number of power supplies according to yet another exemplary embodiment. The differences between the embodiment of Figure 7 and the embodiment of Figure 6 will now be described.

[0058] The substrate support 16D shown in FIG. 7 can be employed as the substrate support of the plasma processing apparatus 1. The electrostatic chuck 20D of the substrate support 16D further includes an electrode 20e. The other configurations of the substrate support 16D are the same as the corresponding configurations of the substrate support 16 shown in FIG. 6. The electrode 20e is a film made of a conductive material and is provided in the body 20m in the second region 20R2. The electrode 20e may have a ring shape and may extend in a circumferential direction around the axis line AX. In the embodiment of FIG. 7, the bias power supply 66 is electrically connected to the electrode 20e and is capacitively coupled to the edge ring ER via the electrode 20e.

[0059] In each of the substrate support 16B and the substrate support 16C, the bias power supply 66 may be electrically coupled to the edge ring ER via the electrode 20e. The bias power supply 66 may be electrically connected to the chuck electrode 20b and the chuck electrode 20c. In this case, the substrate support does not need to include the electrode 20e.

[0060] Reference is now made to Figure 8, which illustrates a substrate support and a number of power supplies according to yet another exemplary embodiment. Differences between the embodiment of Figure 8 and the embodiment of Figure 7 will now be described.

[0061] The substrate support 16E shown in FIG. 8 can be used as the substrate support of the plasma processing apparatus 1. The electrostatic chuck 20E of the substrate support 16E further includes an electrode 20f. The other configurations of the substrate support 16E are the same as the corresponding configurations of the substrate support 16D. The electrode 20f is a film made of a conductive material and is provided in the body 20m in the first region 20R1. The electrode 20f may have a substantially circular shape, and its center may be located on the axis line AX. In the embodiment of FIG. 8, the bias power supply 62 is electrically connected to the electrode 20f. That is, the electrode 20f constitutes a bias electrode in the substrate support 16E.

[0062] In addition, in each of the substrate support 16B and the substrate support 16C, the bias power supply 62 may be electrically connected to the electrode 20f. The bias power supply 62 may be electrically connected to the chuck electrode 20a. In this case, the chuck electrode 20a constitutes the bias electrode. In this case, the substrate support does not need to include the electrode 20f.

[0063] Reference is now made to Figure 9, which illustrates a substrate support and a number of power supplies according to yet another exemplary embodiment. Differences between the embodiment of Figure 9 and the embodiment of Figure 8 will now be described.

[0064] 9, the high frequency power supply 61 and the bias power supply 62 are electrically connected to the electrode 20f. That is, the electrode 20f constitutes a high frequency electrode and a bias electrode in the substrate support 16E.

[0065] In the embodiment of FIG. 9, the plasma processing apparatus 1 further includes a high-frequency power supply 65. The high-frequency power supply 65 generates high-frequency power RF3 (RF power) to generate plasma above the substrate support 16. The high-frequency power RF3 may have the same frequency as the frequency of the high-frequency power RF. The high-frequency power supply 65 is electrically connected to the electrode 20e via a matching device 65m and a filter 65f. The matching device 65m has a matching circuit configured to match the impedance of the load side of the high-frequency power supply 65 to the output impedance of the high-frequency power supply 65. The filter 65f has a characteristic of selectively passing the high-frequency power RF3 and a characteristic of blocking or reducing the electrical bias energy BE3.

[0066] In addition, in each of the substrate support 16B and the substrate support 16C, the high frequency power supply 61 and the bias power supply 62 may be electrically connected to the electrode 20f. In addition, in each of the substrate support 16B and the substrate support 16C, the high frequency power supply 65 and the bias power supply 66 may be electrically connected to the electrode 20e.

[0067] Reference is now made to Figure 10, which illustrates a substrate support and a number of power supplies according to yet another exemplary embodiment. The differences of the embodiment of Figure 10 relative to the embodiment of Figure 2 will now be described.

[0068] In the embodiment of FIG. 10, the plasma processing apparatus 1 does not include a high frequency power supply 63 and a bias power supply 64. In the embodiment of FIG. 10, the high frequency power supply 61 is electrically connected to the ring electrode DR in addition to the high frequency electrode of the substrate support 16 (the base 18 in the embodiment of FIG. 10). In the embodiment of FIG. 10, the high frequency power RF is distributed to the high frequency electrode of the substrate support 16 and the ring electrode DR. The distribution ratio of the high frequency power RF between the high frequency electrode of the substrate support 16 and the ring electrode DR is adjusted by an impedance adjuster 61i. The impedance adjuster 61i is connected between the ring electrode DR and a node on the electrical path connecting the high frequency power supply 61 and the high frequency electrode of the substrate support 16. The impedance adjuster 61i has a variable impedance. The impedance adjuster 61i may include, for example, a variable capacitance capacitor.

[0069] In the embodiment of FIG. 10, the bias power supply 62 is electrically connected to the ring electrode DR in addition to the bias electrode of the substrate support 16 (the base 18 in the embodiment of FIG. 10). That is, in the embodiment of FIG. 10, the single bias RF power supply 62 serves as both the first bias RF power supply and the second bias RF power supply. In the embodiment of FIG. 10, the electric bias energy BE is distributed to the bias electrode of the substrate support 16 and the ring electrode DR. The distribution ratio of the electric bias energy BE between the bias electrode of the substrate support 16 and the ring electrode DR is adjusted by an impedance adjuster 62i. The impedance adjuster 62i is connected between a node on the electrical path connecting the bias power supply 62 and the bias electrode of the substrate support 16 and the ring electrode DR. The impedance adjuster 62i has a variable impedance. The impedance adjuster 62i may include, for example, a variable capacitance capacitor.

[0070] In the embodiment of Fig. 10, the electric bias energy BE from a single bias power supply 62 is distributed to the bias electrode of the substrate support 16 and the ring electrode DR. Therefore, the phase of the electric bias energy provided to the bias electrode of the substrate support 16 and the phase of the electric bias energy provided to the ring electrode DR are synchronized with each other. Therefore, the high frequency power RF coupled to the plasma above the ring electrode DR during the negative phase period PN is suppressed. As a result, the variation in the radial spread of the plasma within the period of the electric bias energy BE supplied to the bias electrode of the substrate support 16 is suppressed.

[0071] 10, the high frequency power RF from the high frequency power supply 61 may be distributed to the high frequency electrode and the ring electrode DRB of the substrate support 16 in the substrate support 16B as well. Also, as in the embodiment of FIG. 10, the electric bias energy BE from the bias power supply 62 may be distributed to the bias electrode and the ring electrode DRB of the substrate support 16 in the substrate support 16B as well. Also, as in the embodiment of FIG. 10, the high frequency power RF from the high frequency power supply 61 may be distributed to the high frequency electrode and the ring electrode DRC of the substrate support 16 in the substrate support 16C as well. Also, as in the embodiment of FIG. 10, the electric bias energy BE from the bias power supply 62 may be distributed to the bias electrode and the ring electrode DRC of the substrate support 16 in the substrate support 16C as well.

[0072] Reference is now made to Figure 11, which illustrates a substrate support and a number of power supplies according to yet another exemplary embodiment. Differences between the embodiment of Figure 11 and the embodiment of Figure 10 will now be described.

[0073] In the embodiment shown in FIG. 11, the plasma processing apparatus 1 includes a substrate support 16D. The substrate support 16D is the same as the substrate support 16D shown in FIG. 7. In the embodiment shown in FIG. 11, the bias power supply 62 is further electrically connected to the electrode 20e. In the embodiment shown in FIG. 11, the electric bias energy BE is distributed to the bias electrode of the substrate support 16, the ring electrode DR, and the electrode 20e. The distribution ratio of the electric bias energy BE to the bias electrode of the substrate support 16, the ring electrode DR, and the electrode 20e is adjusted by the impedance adjuster 62i and the impedance adjuster 62j. The impedance adjuster 62j is connected between the electrode 20e and a node on the electrical path connecting the bias power supply 62 and the bias electrode of the substrate support 16. The impedance adjuster 62j has a variable impedance. The impedance adjuster 62j may include, for example, a variable capacitance capacitor.

[0074] 11, the high frequency power RF from the high frequency power supply 61 may be distributed to the high frequency electrode and the ring electrode DRB of the substrate support 16 in the substrate support 16B as well. Also, as in the embodiment of FIG. 11, the electric bias energy BE from the bias power supply 62 may be distributed to the bias electrode, the ring electrode DRB, and the electrode 20e of the substrate support 16 in the substrate support 16B as well. Also, as in the embodiment of FIG. 11, the high frequency power RF from the high frequency power supply 61 may be distributed to the high frequency electrode and the ring electrode DRC of the substrate support 16 in the substrate support 16C as well. Also, as in the embodiment of FIG. 11, the electric bias energy BE from the bias power supply 62 may be distributed to the bias electrode, the ring electrode DRC, and the electrode 20e of the substrate support 16 in the substrate support 16C as well.

[0075] Reference is now made to Figure 12, which illustrates a substrate support and a number of power supplies according to yet another exemplary embodiment. Differences between the embodiment of Figure 12 and the embodiment of Figure 11 will now be described.

[0076] In the embodiment shown in Fig. 12, the plasma processing apparatus 1 includes a substrate support 16E. The substrate support 16E is the same as the substrate support 16E shown in Fig. 8. In the embodiment shown in Fig. 12, a bias power supply 62 is electrically connected to the electrode 20f.

[0077] 12, the high frequency power RF from the high frequency power supply 61 may be distributed to the high frequency electrode and the ring electrode DRB of the substrate support 16 in the substrate support 16B as well. Also, as in the embodiment of FIG. 12, the electric bias energy BE from the bias power supply 62 may be distributed to the electrode 20f, the ring electrode DRB, and the electrode 20e in the substrate support 16B as well. Also, as in the embodiment of FIG. 12, the high frequency power RF from the high frequency power supply 61 may be distributed to the high frequency electrode and the ring electrode DRC of the substrate support 16 in the substrate support 16C as well. Also, as in the embodiment of FIG. 11, the electric bias energy BE from the bias power supply 62 may be distributed to the electrode 20f, the ring electrode DRC, and the electrode 20e in the substrate support 16C as well.

[0078] Reference is now made to Figure 13, which illustrates a substrate support and a number of power supplies according to yet another exemplary embodiment. Differences between the embodiment of Figure 13 and the embodiment of Figure 12 will now be described.

[0079] In the embodiment shown in FIG. 13, the high frequency power supply 61 is electrically connected to the electrode 20f and further electrically connected to the electrode 20e. In the embodiment of FIG. 13, the high frequency power RF is distributed to the electrode 20f, the ring electrode DR, and the electrode 20e. The distribution ratio of the high frequency power RF to the electrode 20f, the ring electrode DR, and the electrode 20e is adjusted by the impedance adjuster 61i and the impedance adjuster 61j. The impedance adjuster 61j is connected between the electrode 20e and a node on the electrical path connecting the high frequency power supply 61 and the electrode 20f. The impedance adjuster 61j has a variable impedance. The impedance adjuster 61j may include, for example, a variable capacitance capacitor.

[0080] 13, the high frequency power RF from the high frequency power supply 61 may be distributed to the electrode 20f, the ring electrode DRB, and the electrode 20e in the substrate support 16B as well. Also, as in the embodiment of FIG. 13, the electric bias energy BE from the bias power supply 62 may be distributed to the electrode 20f, the ring electrode DRB, and the electrode 20e in the substrate support 16B as well. Also, as in the embodiment of FIG. 13, the high frequency power RF from the high frequency power supply 61 may be distributed to the electrode 20f, the ring electrode DRC, and the electrode 20e in the substrate support 16C as well. Also, as in the embodiment of FIG. 13, the electric bias energy BE from the bias power supply 62 ...

[0081] Reference is now made to Fig. 14. Fig. 14 is a flow chart of a plasma processing method according to one exemplary embodiment. The plasma processing method shown in Fig. 14 (hereinafter, referred to as "method MT") can be performed using any of the various plasma processing apparatuses described above.

[0082] The method MT starts with step STa. In step STa, the substrate W is placed on a substrate support of the plasma processing apparatus 1. In step STa, the substrate W is disposed in an area surrounded by an edge ring ER. The method MT further includes steps STb to STd. The steps STb to STd are performed in a state in which the substrate W is placed on the substrate support.

[0083] In step STb, high frequency power RF is supplied to generate plasma above the substrate support. In the plasma processing apparatus 1 including the high frequency power supply 63, high frequency power RF2 may be further supplied. In the plasma processing apparatus 1 including the high frequency power supply 65, high frequency power RF3 may be further supplied. In the method MT, steps STc and STd are performed during the period in which step STb is performed, i.e., during the period in which plasma is generated in the chamber 10.

[0084] In step STc, an electric bias energy BE is supplied to the bias electrode (the base 18, the electrode 20f, or the chuck electrode 20a) of the substrate support. In step STd, an electric bias energy (BE or BE2) is supplied to the ring electrode (DR, DRB, or DRC).

[0085] In one embodiment, in step STd, an electric bias energy BE2 is supplied to the ring electrode. A negative phase period PN of the electric bias energy BE2 at least partially overlaps with a negative phase period PN of the electric bias energy BE supplied to the bias electrode of the substrate support. The negative phase period PN of the electric bias energy BE2 may coincide with the negative phase period PN of the electric bias energy BE supplied to the bias electrode of the substrate support. The phase of the electric bias energy BE2 may be synchronized with the phase of the electric bias energy BE supplied to the bias electrode of the substrate support.

[0086] In another embodiment, steps STc and STd, electrical bias energy BE from a single bias power supply 62 is distributed to the bias electrode of the substrate support and the ring electrode. Thus, the negative phase period PN of the electrical bias energy supplied to the ring electrode coincides with the negative phase period PN of the electrical bias energy supplied to the bias electrode of the substrate support. That is, the phase of the electrical bias energy supplied to the ring electrode coincides with the phase of the electrical bias energy supplied to the bias electrode of the substrate support.

[0087] Various exemplary embodiments included in the present disclosure are described below in [E1] to [E12] and [F1] to [F19].

[0088] [E1] A chamber; a substrate support disposed within the chamber and configured to support a substrate and an edge ring disposed thereon to surround the substrate, the substrate support including a bias electrode; a radio frequency power source configured to generate radio frequency power to generate a plasma above the substrate support; a ring electrode extending radially outwardly from the edge ring; a first bias power supply electrically coupled to the bias electrode; a second bias power supply electrically coupled to the ring electrode; Equipped with each of the first bias power supply and the second bias power supply configured to generate electrical bias energy having a bias frequency; a period of the electrical bias energy having a time length that is the inverse of the bias frequency includes a negative phase period during which the electrical bias energy has a voltage that is lower than its average voltage during the period; the negative phase period of the electrical bias energy generated by the second bias power supply at least partially overlaps with the negative phase period of the electrical bias energy generated by the first bias power supply; Plasma processing equipment.

[0089] One period of the electric bias energy includes the negative phase period and the positive phase period described above. In the positive phase period, the electric bias energy has a voltage equal to or greater than its average voltage in one period. In the positive phase period, the thickness of the sheath on the substrate is small and the impedance between the substrate and the plasma is small, so that a relatively large amount of high frequency power is coupled to the plasma above the substrate. On the other hand, in the negative phase period, the thickness of the sheath on the substrate is large and the impedance between the substrate and the plasma is large. In the above embodiment, the electric bias energy generated by the second bias power supply is supplied to the ring electrode in order to increase the thickness of the sheath on the radial outer side of the edge of the substrate in the negative phase period and to increase the impedance between the ring electrode and the plasma. Therefore, the high frequency power coupled to the plasma above the ring electrode in the negative phase period is suppressed. As a result, according to the above embodiment, the fluctuation in the radial spread of the plasma within the period of the electric bias energy supplied to the bias electrode is suppressed.

[0090] [E2] The plasma processing apparatus according to [E1], wherein a phase of the electrical bias energy generated by the second bias power supply is synchronized with a phase of the electrical bias energy generated by the first bias power supply.

[0091] [E3] The plasma processing apparatus of [E1] or [E2], wherein the electrical bias energy generated by each of the first bias power supply and the second bias power supply is high-frequency power having the bias frequency, or is a voltage pulse generated periodically at a time interval that is the inverse of the bias frequency.

[0092] [E4] The plasma processing apparatus described in any one of [E1] to [E3], wherein the first bias power supply, the second bias power supply, or another bias power supply generating electrical bias energy having the bias frequency is electrically coupled to the edge ring.

[0093] [E5] A chamber; a substrate support disposed within the chamber and configured to support a substrate and an edge ring disposed thereon to surround the substrate, the substrate support including a bias electrode; a radio frequency power source configured to generate radio frequency power to generate a plasma above the substrate support; a ring electrode extending radially outwardly from the edge ring; a bias power supply electrically coupled to the bias electrode and the ring electrode to generate electrical bias energy having a bias frequency and deliver the electrical bias energy to the bias electrode and the ring electrode; A plasma processing apparatus comprising:

[0094] In the above embodiment, the electric bias energy from a single bias power supply is distributed to the bias electrode and the ring electrode of the substrate support. Therefore, the phase of the electric bias energy provided to the bias electrode of the substrate support and the phase of the electric bias energy provided to the ring electrode are synchronized with each other. Therefore, the high frequency power coupled to the plasma above the ring electrode during the negative phase is suppressed. As a result, according to the above embodiment, the variation in the radial spread of the plasma within the period of the electric bias energy supplied to the bias electrode is suppressed.

[0095] [E6] The plasma processing apparatus according to [E5], wherein the electrical bias energy is high-frequency power having the bias frequency or is a voltage pulse generated periodically at a time interval that is the inverse of the bias frequency.

[0096] [E7] The plasma processing apparatus of [E5] or [E6], wherein the bias power supply or another bias power supply generating electrical bias energy having the bias frequency is electrically coupled to the edge ring.

[0097] [E8] The plasma processing apparatus according to any one of [E1] to [E7], wherein the high frequency power supply is electrically connected to the bias electrode or another electrode provided in the substrate support and configured to supply the high frequency power to the bias electrode or the other electrode.

[0098] [E9] The plasma processing apparatus described in any one of [E1] to [E8], wherein the high frequency power supply or another high frequency power supply configured to generate high frequency power to generate plasma above the substrate support is electrically coupled to the ring electrode.

[0099] [E10] The plasma processing apparatus according to any one of [E1] to [E9], wherein the ring electrode extends so as to surround the edge ring.

[0100] [E11] (a) placing a substrate on a substrate support provided in a chamber of a plasma processing apparatus, the substrate support including a bias electrode, the substrate being disposed within a region surrounded by an edge ring disposed on the substrate support; (b) providing radio frequency power to generate a plasma above the substrate support; (c) supplying electrical bias energy from a first bias power supply to the bias electrode; (d) supplying electrical bias energy from a second bias power supply to a ring electrode, the ring electrode extending radially outward of the edge ring; Including, the electrical bias energy generated by each of the first bias power supply and the second bias power supply has a bias frequency; one period of the electrical bias energy generated by each of the first bias power supply and the second bias power supply has a time length that is the inverse of the bias frequency and includes a negative phase period during which the electrical bias energy has a voltage that is lower than its average voltage within the one period; the negative phase period of the electrical bias energy generated by the second bias power supply at least partially overlaps with the negative phase period of the electrical bias energy generated by the first bias power supply; Plasma treatment method.

[0101] [E12] (a) placing a substrate on a substrate support provided in a chamber of a plasma processing apparatus, the substrate support including a bias electrode, the substrate being disposed within a region surrounded by an edge ring disposed on the substrate support; (b) providing radio frequency power to generate a plasma above the substrate support; (c) providing electrical bias energy to the bias electrode; (d) applying electrical bias energy to a ring electrode, the ring electrode extending radially outward of the edge ring; Including, In the plasma processing methods (c) and (d), electrical bias energy generated by a single bias power supply is distributed to the bias electrode and the ring electrode.

[0102] [F1] a plasma processing chamber; a substrate support disposed within the plasma processing chamber and including a bias electrode; an RF power source configured to generate RF power to generate a plasma in the chamber; an edge ring disposed to surround the substrate on the substrate support; a ring electrode disposed to surround the edge ring; a first bias RF power supply configured to supply a first bias RF power to the bias electrode, the first bias RF power having a first frequency and a first power level; a second bias RF power supply configured to supply a second bias RF power to the ring electrode, the second bias RF power having the first frequency and a second power level, the second bias RF power being synchronous with the first bias RF power; A plasma processing apparatus comprising:

[0103] [F2] The plasma processing apparatus according to [F1], wherein the second power level is the same as the first power level.

[0104] [F3] The plasma processing apparatus according to [F1], wherein the second power level is different from the first power level.

[0105] [F4] The plasma processing apparatus according to [F3], wherein the second power level is greater than the first power level.

[0106] [F5] The plasma processing apparatus according to [F3], wherein the second power level is lower than the first power level.

[0107] [F6] The plasma processing apparatus according to any one of [F1] to [F5], wherein a single bias RF power supply serves as both the first bias RF power supply and the second bias RF power supply.

[0108] [F7] a plasma processing chamber; a substrate support disposed within the plasma processing chamber and including a bias electrode; an RF power source configured to generate RF power to generate a plasma in the chamber; an edge ring disposed to surround the substrate on the substrate support; a ring electrode disposed to surround the edge ring; a first voltage pulse power supply configured to apply a first voltage pulse signal to the bias electrode, the first voltage pulse signal having a first voltage level during a first period within a repetition period that is lower than a first average voltage of the first voltage pulse signal during the repetition period and a second voltage level during a second period within the repetition period that is higher than the first average voltage, the absolute value of the first voltage level being greater than the absolute value of the second voltage level; a second voltage pulse power supply configured to apply a second voltage pulse signal to the ring electrode, the second voltage pulse signal having a third voltage level during the first period that is lower than a second average voltage of the second voltage pulse signal and a fourth voltage level during the second period that is higher than the second average voltage, the absolute value of the third voltage level being greater than the absolute value of the fourth voltage level; A plasma processing apparatus comprising:

[0109] [F8] The plasma processing apparatus according to [F7], wherein the first voltage level and the third voltage level have negative polarity.

[0110] [F9] The plasma processing apparatus according to [F7] or [F8], wherein the third voltage level is the same as the first voltage level, and the fourth voltage level is the same as the second voltage level.

[0111] [F10] The plasma processing apparatus according to [F9], wherein a single voltage pulse power supply serves as both the first voltage pulse power supply and the second voltage pulse power supply.

[0112] [F11] The plasma processing apparatus according to [F7] or [F8], wherein the third voltage level is different from the first voltage level.

[0113] [F12] The plasma processing apparatus according to any one of [F7] to [F11], wherein the first period has the same length as the second period.

[0114] [F13] The plasma processing apparatus according to any one of [F7] to [F11], wherein the first period has a length different from a length of the second period.

[0115] [F14] The plasma processing apparatus according to any one of [F7] to [F11], wherein the first period is longer than the second period.

[0116] [F15] The plasma processing apparatus according to any one of [F7] to [F11], wherein the first period is shorter than the second period.

[0117] [F16] A chamber; a substrate support disposed within the chamber and including a bias electrode; an RF power source configured to generate RF power to generate a plasma in the chamber; an edge ring disposed to surround the substrate on the substrate support; a ring electrode disposed to surround the edge ring; a first bias power supply electrically connected to the bias electrode; a second bias power supply electrically connected to the ring electrode; Equipped with each of the first bias power supply and the second bias power supply configured to generate electrical bias energy having a bias frequency; a period of the electrical bias energy having a time length that is the inverse of the bias frequency includes a negative phase period during which the electrical bias energy has a voltage that is lower than its average voltage during the period; the negative phase period of the electrical bias energy generated by the second bias power supply at least partially overlaps with the negative phase period of the electrical bias energy generated by the first bias power supply; Plasma processing equipment.

[0118] [F17] The plasma processing apparatus according to [F16], wherein a phase of the electrical bias energy generated by the second bias power supply is synchronized with a phase of the electrical bias energy generated by the first bias power supply.

[0119] [F18] The plasma processing apparatus of [F16] or [F17], wherein the electrical bias energy generated by each of the first bias power supply and the second bias power supply is RF power having the bias frequency or is a sequence of DC voltage pulses generated periodically at a time interval that is the inverse of the bias frequency.

[0120] [F19] The plasma processing apparatus according to any one of [F16] to [F18], wherein the first bias power supply, the second bias power supply, or another bias power supply configured to generate electrical bias energy having the bias frequency is coupled to the edge ring.

[0121] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and modifications may be made. In addition, elements in different embodiments can be combined to form other embodiments.

[0122] From the foregoing, it will be understood that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the appended claims. [Explanation of symbols]

[0123] Reference Signs List 1: plasma processing apparatus, 10: chamber, 16: substrate support, 18: base, 20: electrostatic chuck, 61, 63: high frequency power supplies, 62, 64: bias power supplies, W: substrate, ER: edge ring, DR: ring electrode.

Claims

1. A plasma processing chamber; a substrate support disposed within the plasma processing chamber and including a bias electrode; an RF power source configured to generate RF power to generate a plasma in the plasma processing chamber; an edge ring disposed to surround the substrate on the substrate support; a ring electrode disposed to surround the edge ring; a first bias RF power source configured to supply a first bias RF power having a first frequency and a first power level to the bias electrode; a second bias RF power supply configured to supply a second bias RF power having the first frequency and a second power level to the ring electrode; a third bias RF power supply configured to supply a third bias RF power to the edge ring; Equipped with the second bias RF power and the RF power for generating the plasma are applied to the ring electrode; the third bias RF power applied to the edge ring is different from the second bias RF power applied to the ring electrode; Plasma processing equipment.

2. A plasma processing apparatus as described in claim 1, wherein the second power level is the same as the first power level.

3. A plasma processing apparatus as described in claim 2, wherein a single bias RF power supply functions as both the first bias RF power supply and the second bias RF power supply.

4. A plasma processing apparatus as described in claim 1, wherein the second power level is different from the first power level.

5. A plasma processing apparatus as described in claim 4, wherein the second power level is greater than the first power level.

6. A plasma processing apparatus as described in claim 4, wherein the second power level is less than the first power level.

7. A plasma processing chamber; a substrate support disposed within the plasma processing chamber and including a bias electrode; an RF power source configured to generate RF power to generate a plasma in the plasma processing chamber; an edge ring disposed to surround the substrate on the substrate support; a ring electrode disposed to surround the edge ring; a first voltage pulse power supply configured to apply a first voltage pulse signal to the bias electrode, the first voltage pulse signal having a first average voltage in a period, the first voltage pulse signal having a first voltage level during a first time period within the period that is lower than the first average voltage and a second voltage level during a second time period within the period that is higher than the first average voltage; a second voltage pulse power supply configured to apply a second voltage pulse signal to the ring electrode, the second voltage pulse signal having a second average voltage during the period, the second voltage pulse signal having a third voltage level during the first period that is lower than the second average voltage and a fourth voltage level during the second period that is higher than the second average voltage, the absolute value of the third voltage level being greater than the absolute value of the fourth voltage level; A plasma processing apparatus comprising:

8. The plasma processing apparatus of claim 7, wherein the first voltage level and the third voltage level have negative polarity.

9. The plasma processing apparatus of claim 8, wherein the third voltage level is the same as the first voltage level, and the fourth voltage level is the same as the second voltage level.

10. The plasma processing apparatus of claim 9, wherein a single voltage pulse power supply functions as both the first voltage pulse power supply and the second voltage pulse power supply.

11. The plasma processing apparatus of claim 7, wherein the first period has the same length as the second period.

12. The plasma processing apparatus of claim 7, wherein the first period has a length different from that of the second period.

13. The plasma processing apparatus of claim 7, wherein the first period has a length longer than the second period.

14. The plasma processing apparatus of claim 7, wherein the first period has a length shorter than the second period.

15. The plasma processing apparatus of claim 7, wherein the third voltage level is different from the first voltage level.

16. A plasma processing chamber; a substrate support disposed within the plasma processing chamber and including a bias electrode; an RF power source configured to generate RF power to generate a plasma in the plasma processing chamber; an edge ring disposed to surround the substrate on the substrate support; a ring electrode disposed to surround the edge ring; a first bias power supply electrically connected to the bias electrode; a second bias power supply electrically connected to the ring electrode; Equipped with each of the first bias power supply and the second bias power supply configured to generate electrical bias energy having a bias frequency; a period of the electrical bias energy having a time length that is the inverse of the bias frequency includes a negative phase period during which the electrical bias energy has a voltage that is lower than an average voltage of the electrical bias energy during the period; the negative phase duration of the electrical bias energy generated by the second bias power supply at least partially overlaps with the negative phase duration of the electrical bias energy generated by the first bias power supply; Plasma processing equipment.

17. A plasma processing apparatus as described in claim 16, wherein the phase of the electrical bias energy generated by the second bias power supply is synchronized with the phase of the electrical bias energy generated by the first bias power supply.

18. A plasma processing apparatus as described in claim 16, wherein the electrical bias energy generated by each of the first bias power supply and the second bias power supply is RF power having the bias frequency, or a sequence of DC voltage pulses generated periodically at a time interval that is the reciprocal of the bias frequency.

19. A plasma processing apparatus as described in claim 16, wherein the first bias power supply, the second bias power supply, or an additional bias power supply that generates the electrical bias energy having the bias frequency is electrically coupled to the edge ring.

20. A plasma processing apparatus as described in claim 1, wherein the first bias RF power and RF power applied to the substrate are different from the second bias RF power and RF power applied to the ring electrode.

21. The plasma processing apparatus of claim 1, wherein the ring electrode is located on a dielectric component.

22. The plasma processing apparatus of claim 1, wherein the ring electrode is directly connected to the second bias RF power supply and the RF power supply.

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