Plasma processing device and plasma processing method

Abstract

The disclosed plasma processing apparatus includes a chamber, a substrate support, a plasma generation unit, a first power supply, and a second power supply. The substrate support has a lower electrode and is disposed within the chamber. The first power supply is configured to generate an electrical bias and is electrically connected to the lower electrode. The second power supply is configured to apply a positive voltage to the component during a first period, a portion of the entire period during which the electrical bias output from the first power supply to the lower electrode has a potential above the average potential of the electrical bias within its cycle. The component is configured to be exposed to the plasma generated within the chamber. The first power supply is configured to output an electrical bias having a positive potential to the lower electrode during a second period following the first period.

Description

Technical Field

[0001] Exemplary embodiments of the present invention relate to a plasma processing apparatus and a plasma processing method. Background Technology

[0002] In plasma processing, ions supplied from plasma are used to process a substrate. Typically, the ions supplied to the substrate are positive ions, but sometimes negative ions are supplied in addition to positive ions. Japanese Patent Application Publication No. 2012-9544 (hereinafter referred to as "Patent Document 1") discloses a technique for supplying negative ions to a substrate in addition to positive ions.

[0003] In the technology of Patent Document 1, when both a high-frequency power pulse wave and a bias high-frequency power pulse wave are supplied to the plasma, positive ions are supplied from the plasma to the substrate. When these pulse waves are stopped, negative ions are generated in the plasma. When the high-frequency power pulse wave of the plasma is stopped and a bias high-frequency power pulse wave is supplied, negative ions are supplied from the plasma to the substrate. Summary of the Invention

[0004] In one exemplary embodiment, a technique is provided for efficiently supplying negative ions from plasma to a substrate.

[0005] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, a plasma generation unit, a first power supply, and a second power supply. The substrate support has a lower electrode and is disposed within the chamber. The plasma generation unit is configured to generate plasma from gas within the chamber. The first power supply is configured to generate an electrical bias and is electrically connected to the lower electrode. The second power supply is configured to apply a positive voltage to a component exposed to the plasma generated within the chamber. The second power supply is configured to apply a positive voltage to the component during a first period, a portion of the entire period during which the electrical bias output from the first power supply to the lower electrode has a potential above the average potential of the electrical bias within its cycle. The first power supply is configured to output an electrical bias having a positive potential to the lower electrode during a second period following the first period.

[0006] According to an exemplary embodiment, negative ions in plasma can be effectively supplied to a substrate. Attached Figure Description

[0007] Figure 1 This is a schematic diagram illustrating a plasma processing apparatus according to an exemplary embodiment.

[0008] Figure 2 This is a timing diagram related to a plasma processing apparatus according to an exemplary embodiment.

[0009] Figure 3 This is a diagram that schematically illustrates the electrical configuration of a plasma processing apparatus according to an exemplary embodiment.

[0010] Figure 4 This is another timing diagram related to a plasma processing apparatus according to an exemplary embodiment.

[0011] Figure 5 This is a diagram that schematically illustrates the electrical configuration of a plasma processing apparatus according to another exemplary embodiment.

[0012] Figure 6 This is a timing diagram related to a plasma processing apparatus according to another exemplary embodiment.

[0013] Figure 7 middle, Figure 7 (a) Figure 7 (b) and Figure 7 (c) These are diagrams that schematically represent a plasma processing apparatus according to yet another exemplary embodiment. Detailed Implementation

[0014] The following describes various exemplary embodiments.

[0015] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, a plasma generation unit, a first power supply, and a second power supply. The substrate support has a lower electrode and is disposed within the chamber. The plasma generation unit is configured to generate plasma from gas within the chamber. The first power supply is configured to generate an electrical bias and is electrically connected to the lower electrode. The second power supply is configured to apply a positive voltage to a component exposed to the plasma generated within the chamber. The second power supply is configured to apply a positive voltage to the component during a first period, a portion of the entire period during which the electrical bias output from the first power supply to the lower electrode has a potential above the average potential of the electrical bias within its cycle. The first power supply is configured to output an electrical bias having a positive potential to the lower electrode during a second period following the first period.

[0016] If a positive electrical bias is applied to the lower electrode when plasma is present in the chamber, electrons in the plasma reach the substrate support faster than ions in the plasma. As a result, the potential of the lower electrode is neutralized, and the strength of the electric field used to introduce negative ions into the substrate support decreases. On the other hand, in the above embodiment, after electrons in the plasma are introduced into the component exposed to the plasma, a positive electrical bias is applied to the lower electrode, so negative ions in the plasma are effectively supplied to the substrate on the substrate support.

[0017] In one exemplary embodiment, the plasma generation unit may be configured to: stop supplying high-frequency power for generating plasma in the chamber or reduce the power level of the high-frequency power during at least the period from the start time of the first period to the time between the start time and the end time of the second period.

[0018] In one exemplary embodiment, the potential of the component during the first period may be higher than the potential of the lower electrode during the first period.

[0019] In one exemplary embodiment, the first power supply may be configured to output an electrical bias to the lower electrode during a second period, having a positive potential that is higher than the electrical bias during the first period.

[0020] In one exemplary embodiment, the plasma processing apparatus may be a capacitively coupled plasma processing apparatus.

[0021] In one exemplary embodiment, the plasma processing apparatus may further include an upper electrode disposed above the substrate support. The aforementioned component may be an upper electrode.

[0022] In one exemplary embodiment, the first power supply may be configured to periodically output a pulsed DC voltage or an arbitrary voltage waveform as an electrical bias.

[0023] In one exemplary embodiment, the first power supply may be configured to output high-frequency power as an electrical bias.

[0024] In another exemplary embodiment, a plasma processing method is provided. The plasma processing method includes a step (a) in which plasma is generated from gas within a chamber of a plasma processing apparatus. The plasma processing apparatus includes a substrate support disposed within the chamber. A first power source is electrically connected to a lower electrode within the substrate support. The plasma processing method further includes a step (b) in which, during a first period, a portion of the entire period during which an electrical bias output from the first power source to the lower electrode has a potential above the average potential of the electrical bias within its cycle, a positive voltage is applied from a second power source to a component exposed to the plasma. The plasma processing method further includes a step (c) in which, during a second period following the first period, an electrical bias having a positive potential is output from the first power source to the lower electrode.

[0025] In one exemplary embodiment, the supply of high-frequency power for generating plasma in the chamber may be stopped or the power level of the high-frequency power may be reduced, at least during the period from the start time of the first period to the time between the start and end time of the second period.

[0026] Hereinafter, various exemplary embodiments will be described in detail with reference to the accompanying drawings. Furthermore, in the drawings, the same or equivalent parts are labeled with the same symbols.

[0027] Figure 1 This is a schematic diagram illustrating a plasma processing apparatus according to an exemplary embodiment. Figure 1 The plasma processing apparatus 1 shown is a capacitively coupled plasma processing apparatus. The plasma processing apparatus 1 includes a chamber 10. An internal space 10s is provided inside the chamber 10. The central axis of the chamber 10 is an axis AX extending vertically.

[0028] In one embodiment, the chamber 10 may include a chamber body 12. The chamber body 12 is generally cylindrical. An internal space 10s is disposed within the chamber body 12. The chamber body 12 is made of, for example, aluminum. The chamber body 12 is electrically grounded. A corrosion-resistant film is provided on the inner wall surface of the chamber body 12. The corrosion-resistant film may be a film formed of ceramics such as alumina or yttrium oxide.

[0029] A channel 12p is provided on the side wall of the chamber body 12. When the substrate W is transported between the internal space 10s and the outside of the chamber 10, the substrate W passes through the channel 12p. The channel 12p can be opened and closed by a gate valve 12g. The gate valve 12g is provided along the side wall of the chamber body 12.

[0030] The plasma processing apparatus 1 also includes a substrate support 16. The substrate support 16 is configured to support a substrate W within the chamber 10. The substrate W may be generally disk-shaped. The substrate support 16 can be supported by a support body 15. The support body 15 extends upward from the bottom of the chamber body 12. The support body 15 is generally cylindrical in shape. The support body 15 is formed of an insulating material such as quartz.

[0031] The substrate support 16 includes a lower electrode 18. The substrate support 16 may also include an electrostatic chuck 20. The substrate support 16 may also include an electrode plate 19. The electrode plate 19 is formed of a conductive material such as aluminum. The electrode plate 19 is generally disk-shaped, with its central axis being axis AX. The lower electrode 18 is disposed on the electrode plate 19. The lower electrode 18 is formed of a conductive material such as aluminum. The lower electrode 18 is generally disk-shaped, with its central axis being axis AX. The lower electrode 18 is electrically connected to the electrode plate 19.

[0032] The lower electrode 18 has a flow path 18f inside. The flow path 18f is connected to a heat exchange medium supply device (e.g., a cooler unit). This supply device is located outside the chamber 10. The flow path 18f receives the heat exchange medium supplied from the supply device via piping 23a. The heat exchange medium flows through the flow path 18f and returns to the supply device via piping 23b. The supply device constitutes the temperature control mechanism of the plasma processing apparatus 1.

[0033] An electrostatic chuck 20 is disposed on the lower electrode 18. A substrate W is mounted on the upper surface of the electrostatic chuck 20. The electrostatic chuck 20 has a main body and electrodes. The main body is formed of a dielectric. The electrostatic chuck 20 and its main body are both generally disk-shaped, with their central axis being axis AX. The electrodes are conductive films and are disposed within the main body. The electrodes are connected to a DC power supply via a switch. When a voltage from the DC power supply is applied to the electrodes, an electrostatic attraction is 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 it.

[0034] The substrate support 16 can support the edge ring ER mounted on its periphery. The edge ring ER can be formed of silicon, silicon carbide, or quartz. The substrate W is disposed on the electrostatic chuck 20 within the area surrounded by the edge ring ER.

[0035] The plasma processing apparatus 1 may also include a gas supply line 25. The gas supply line 25 supplies heat transfer gas (e.g., He gas) from the gas supply mechanism to the gap between the upper surface of the electrostatic chuck 20 and the back surface (lower surface) of the substrate W.

[0036] The plasma processing apparatus 1 may also include a cylindrical portion 28 and an insulating portion 29. The cylindrical portion 28 extends upward from the bottom of the chamber body 12. The cylindrical portion 28 extends along the outer periphery of the support body 15. The cylindrical portion 28 is formed of a conductive material and is generally cylindrical in shape. The cylindrical portion 28 is electrically grounded. The insulating portion 29 is disposed on the cylindrical portion 28. The insulating portion 29 is formed of an insulating material. The insulating portion 29 is formed, for example, of ceramic such as quartz. The insulating portion 29 is generally cylindrical in shape. The insulating portion 29 extends along the outer periphery of the electrode plate 19, the outer periphery of the lower electrode 18, and the outer periphery of the electrostatic chuck 20.

[0037] The plasma processing apparatus 1 also includes an upper electrode 30. The upper electrode 30 is disposed above the substrate support 16. The upper electrode 30 is supported on the upper part of the chamber body 12 via a component 32. The component 32 is formed of an insulating material. The upper electrode 30 and the component 32 close the upper opening of the chamber body 12.

[0038] The upper electrode 30 may include a top plate 34 and a support 36. The lower surface of the top plate 34 is the lower surface of the internal space 10s side, and divides the internal space 10s. The top plate 34 may be formed of a low-resistance conductor or semiconductor with low Joule heating. In one embodiment, the top plate 34 is formed of silicon. The top plate 34 is provided with a plurality of vent holes 34a. The plurality of vent holes 34a penetrate the top plate 34 in the thickness direction of the top plate 34.

[0039] The support body 36 detachably supports the top plate 34. 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. The support body 36 also has multiple gas holes 36b. The multiple gas holes 36b extend downwards from the gas diffusion chamber 36a. The multiple gas holes 36b communicate with multiple exhaust holes 34a. The support body 36 also has a gas inlet 36c. The gas inlet 36c is connected to the gas diffusion chamber 36a. A gas supply pipe 38 is connected to the gas inlet 36c.

[0040] A gas source assembly 40 is connected to the gas supply pipe 38 via a valve assembly 41, a flow controller assembly 42, and a valve assembly 43. The gas supply unit GS is composed of the gas source assembly 40, valve assembly 41, flow controller assembly 42, and valve assembly 43. The gas source assembly 40 includes multiple gas sources. The multiple gas sources in the gas source assembly 40 include multiple gas sources. Valve assemblies 41 and 43 each include multiple on / off valves. The flow controller assembly 42 includes multiple flow controllers. The multiple flow controllers in the flow controller assembly 42 are either mass flow controllers or pressure-controlled flow controllers. The multiple gas sources in the gas source assembly 40 are connected to the gas supply pipe 38 via on / off valves corresponding to valve assembly 41, flow controllers corresponding to flow controller assembly 42, and on / off valves corresponding to valve assembly 43.

[0041] The plasma processing apparatus 1 may also include a baffle member 48. The baffle member 48 is disposed between the cylindrical portion 28 and the side wall of the chamber body 12. The baffle member 48 may be a plate-shaped component. The baffle member 48 may be constructed, for example, by forming a corrosion-resistant film on the surface of a component made of aluminum. The corrosion-resistant film may be a film formed of a ceramic such as yttrium oxide. The baffle member 48 is provided with multiple through holes. An exhaust port is provided below the baffle member 48 at the bottom of the chamber body 12. An exhaust device 50 is connected to the exhaust port via an exhaust pipe 52. The exhaust device 50 includes a pressure regulating valve and a vacuum pump such as a turbomolecular pump.

[0042] The plasma processing apparatus 1 also includes a high-frequency power supply 61. The high-frequency power supply 61 is a power source for generating high-frequency power HF for plasma generation. The high-frequency power HF has a first frequency. The first frequency is, for example, a frequency in the range of 27 to 100 MHz. The high-frequency power supply 61 is connected to the lower electrode 18 via a matching device 61m and an electrode plate 19 to supply the high-frequency power HF to the lower electrode 18. The matching device 61m has a matching circuit. The matching circuit of the matching device 61m has a variable impedance. Adjusting the impedance of the matching circuit of the matching device 61m reduces reflections from the load of the high-frequency power supply 61. Alternatively, the high-frequency power supply 61 may not be electrically connected to the lower electrode 18, or it may be connected to the upper electrode 30 via the matching device 61m. The high-frequency power supply 61 constitutes a plasma generation unit in one embodiment.

[0043] The plasma processing apparatus 1 also includes a bias power supply 62. The bias power supply 62 constitutes a first power supply in one embodiment. The bias power supply 62 is connected to the lower electrode 18 via the electrode plate 19 and is configured to generate an electrical bias EB. The electrical bias EB applied from the bias power supply 62 to the lower electrode 18 causes a change in the potential of the substrate W.

[0044] In one embodiment, the bias power supply 62 is configured to periodically output a pulsed DC voltage or an arbitrary voltage waveform as an electrical bias EB. The period CY of the electrical bias EB is defined (refer to...). Figure 2 The second frequency is lower than the first frequency. The second frequency is the reciprocal of the duration of the period CY. The second frequency is, for example, a frequency in the range of 1 kHz to 27 MHz. In this embodiment, the bias power supply 62 is configured to apply an electrical bias EB, which includes pulses of negative DC voltage and pulses of positive DC voltage, to the lower electrode 18.

[0045] The plasma processing apparatus 1 also includes a power supply 64. The power supply 64 constitutes a second power supply in one embodiment. The power supply 64 is electrically connected to the component 60 and configured to apply voltage to the component 60. The component 60 is configured to be exposed to the plasma generated within the chamber 10. In one embodiment, the component 60 is an upper electrode 30, and the power supply 64 is electrically connected to the upper electrode 30.

[0046] The following, with Figure 1 For reference Figure 2 . Figure 2 This is a timing diagram related to a plasma processing apparatus according to an exemplary embodiment. Figure 2 In the middle, the horizontal axis represents time. When Figure 2 When the vertical axis "HF" is ON, it indicates that high-frequency power HF is supplied. Figure 2 When the vertical axis “HF” is OFF, it indicates that the supply of high-frequency power HF is stopped. Figure 2The vertical axis “PV” represents the voltage applied by power supply 64 to component 60. Figure 2 The vertical axis “EB” represents the electrical bias EB.

[0047] In the plasma processing apparatus 1, plasma is generated from the gas within the chamber 10 during the period when high-frequency power HF is supplied. The bias power supply 62 outputs a negatively biased electrical bias EB to the lower electrode 18 during the period PN of the cycle CY. During the period PN, positive ions from the plasma are supplied to the substrate W.

[0048] Power supply 64 applies a positive voltage to component 60 during period PA (i.e., the first period) within the cycle CY. Period PA is a portion of the entire period during which the electrical bias EB output from bias power supply 62 to lower electrode 18 has a potential higher than the average potential of electrical bias EB within its cycle CY (1 cycle). Period PA, for example, is a period during which the electrical bias EB output from bias power supply 62 to lower electrode 18 has a potential of 0 or positive. In one embodiment, the potential of component 60 during period PA can be set to a potential higher than the potential of lower electrode 18 during period PA. If a positive voltage is applied to component 60 during period PA, electrons in the plasma are attracted to component 60. The duration of period PA is set to attract electrons in the plasma to component 60 and suppress the reduction of the amount of negative ions in the plasma. The duration of period PA can be less than 1 μs or less, or less than 0.2 μs.

[0049] During the period PP (i.e., the second period) following the period PA within the period CY, the bias power supply 62 outputs a positive bias EB to the lower electrode 18. The duration of period PP can be 0.05 μs or more and 5 μs or less. In one embodiment, the bias power supply 62 can output a positive bias EB to the lower electrode 18 having a higher potential than the bias EB during period PA. Electrons in the plasma almost disappear during period PA. Therefore, during period PP, negative ions in the plasma are supplied to the substrate W.

[0050] Furthermore, the high-frequency power supply 61, i.e., the plasma generation unit, can be configured such that, during period PT, the supply of high-frequency power HF used to generate plasma within chamber 10 is stopped or the power level of high-frequency power HF is reduced. Period PT includes at least the time from the start time of period PA to the time between the start and end time of period PP. In one example, period PT is the time from the end time of period PN and the start time of period PA to the time between the start and end time of period PP.

[0051] If a positive electrical bias EB is applied to the lower electrode 18 when plasma is present in the chamber 10, electrons in the plasma reach the substrate support 16 faster than ions in the plasma. As a result, the potential of the lower electrode 18 is neutralized, and the strength of the electric field used to introduce negative ions into the substrate support 16 decreases. On the other hand, in the plasma processing apparatus 1, after electrons in the plasma are introduced into the component 60 exposed to the plasma, a positive electrical bias EB is applied to the lower electrode 18, so negative ions in the plasma are effectively supplied to the substrate W on the substrate support 16.

[0052] like Figure 1 As shown, the plasma processing apparatus 1 also includes a control unit 80. The control unit 80 is a computer equipped with a processor, storage device, input device, display device, etc., and controls each part of the plasma processing apparatus 1. Specifically, the control unit 80 executes a control program stored in the storage device and controls each part of the plasma processing apparatus 1 based on process data stored in the storage device. Through the control of the control unit 80, the process specified by the process data is executed in the plasma processing apparatus 1. Regarding... Figure 2 The timing control of the high-frequency power HF, voltage PV, and electrical bias EB of the timing diagram is executed by controlling the high-frequency power supply 61, power supply 64, and bias power supply 62 based on the control unit 80.

[0053] The following is for reference. Figure 3 . Figure 3 This is a schematic diagram illustrating the electrical configuration of a plasma processing apparatus according to an exemplary embodiment. In one embodiment, the plasma processing apparatus 1 may have... Figure 3 The structure shown is used for timing control, such as Figure 2 The timing diagram shows the high-frequency power HF, voltage PV, and electrical bias EB.

[0054] like Figure 3 As shown, the bias power supply 62 can be connected to the lower electrode 18 via a filter 62f. The filter 62f is a low-pass filter and reduces the high-frequency power HF that can flow into the bias power supply 62.

[0055] The bias power supply 62 may include a DC power supply 62p1, a DC power supply 62p2, a switch 62s1, a switch 62s2, and a switch 62s3. DC power supplies 62p1 and 62p2 may each be variable DC power supplies. The positive terminal of DC power supply 62p1 is connected to the lower electrode 18 via switch 62s1. The negative terminal of DC power supply 62p1 is connected to ground. The negative terminal of DC power supply 62p2 is connected to the lower electrode 18 via switch 62s2. The positive terminal of DC power supply 62p2 is connected to ground. Switch 62s3 is connected between the ground and the lower electrode 18. Furthermore, the variable DC power supplies constituting DC power supplies 62p1 and 62p2 may be variable DC power supplies whose positive and negative terminals can be arbitrarily set. Also, switches 62s1, 62s2, and 62s3 may be connected to the lower electrode 18 via their respective individual filters instead of a single filter 62f.

[0056] The opening and closing of switches 62s1, 62s2, and 62s3 can be controlled by the control unit 80. If switch 62s1 is closed and switches 62s2 and 62s3 are open, a positive voltage from DC power supply 62p1 is output to the lower electrode 18. If switch 62s2 is closed and switches 62s1 and 62s3 are open, a negative voltage from DC power supply 62p2 is output to the lower electrode 18. If switch 62s3 is closed and switches 62s1 and 62s2 are open, the lower electrode 18 is connected to the ground wire.

[0057] like Figure 3 As shown, power supply 64 can be connected to component 60 via filter 64f. Filter 64f is a low-pass filter and reduces the high-frequency power that can flow into power supply 64.

[0058] Power supply 64 may include DC power supply 64p1, DC power supply 64p2, switch 64s1, switch 64s2, and switch 64s3. DC power supply 64p1 and DC power supply 64p2 may each be a variable DC power supply. The positive terminal of DC power supply 64p1 is connected to component 60 via switch 64s1. The negative terminal of DC power supply 64p1 is connected to ground. The negative terminal of DC power supply 64p2 is connected to component 60 via switch 64s2. The positive terminal of DC power supply 64p2 is connected to ground. Switch 64s3 is connected between ground and component 60. Alternatively, power supply 64 may not include DC power supply 64p2 and switch 64s2. Furthermore, the variable DC power supplies constituting DC power supplies 64p1 and 64p2 may be variable DC power supplies whose positive and negative terminals can be arbitrarily set. Also, switches 64s1, 64s2, and 64s3 may be connected to component 60 via their respective individual filters instead of a single filter 64f.

[0059] The opening and closing of switches 64s1, 64s2, and 64s3 can be controlled by the control unit 80. If switch 64s1 is closed and switches 64s2 and 64s3 are open, a positive voltage from DC power supply 64p1 is applied to component 60. If switch 64s2 is closed and switches 64s1 and 64s3 are open, a negative voltage from DC power supply 64p2 is applied to component 60. If switch 64s3 is closed and switches 64s1 and 64s2 are open, component 60 is connected to ground.

[0060] The following is for reference. Figure 4 . Figure 4 This is another timing diagram related to a plasma processing apparatus according to an exemplary embodiment. For example... Figure 4 The timing diagram shown indicates that the plasma processing apparatus 1 can perform timing control of high-frequency power HF, voltage PV, and electrical bias EB. Specifically, the power supply 64 can apply a negative voltage to the component 60 during the period CY, except for the period from the start of period PA to the end of period PP.

[0061] The following is for reference. Figure 5 and Figure 6 . Figure 5 This is a diagram that schematically illustrates the electrical configuration of a plasma processing apparatus according to another exemplary embodiment. Figure 6 This is a timing diagram related to a plasma processing apparatus according to another exemplary embodiment. Figure 5 The plasma processing apparatus 1B shown differs from plasma processing apparatus 1 in that it has a bias power supply 62B instead of a bias power supply 62. Hereinafter, plasma processing apparatus 1B will be described from the viewpoint of its differences from plasma processing apparatus 1. Furthermore, apart from the aspects described below, the structure of plasma processing apparatus 1B can be the same as the corresponding structure of plasma processing apparatus 1.

[0062] The bias power supply 62B can output high-frequency power (i.e., high-frequency bias power) as an electrical bias EB to the lower electrode 18. The electrical bias EB, i.e., the high-frequency power, output by the bias power supply 62B has a second frequency. The second frequency is, for example, a frequency in the range of 100kHz to 27MHz. Figure 6 As shown, the electrical bias EB output from the bias power supply 62B to the lower electrode 18 has a negative potential during the period PN within the period CY, and has a potential of 0 or positive during the periods of the period CY other than the period PN.

[0063] like Figure 5As shown, the bias power supply 62B may have a high-frequency power supply 621 and a power supply 622. The high-frequency power supply 621 is configured to generate high-frequency power with a second frequency. The high-frequency power supply 621 is connected to the lower electrode 18 via a matching device 62m and an electrode plate 19. The matching device 62m has a matching circuit. The matching circuit of the matching device 62m has a variable impedance. Adjusting the impedance of the matching circuit of the matching device 62m reduces reflections from the load of the bias power supply 62.

[0064] like Figure 5 As shown, power supply 622 can be connected to the lower electrode 18 via filter 62f. Filter 62f is a low-pass filter and reduces the high-frequency power HF that can flow into power supply 622.

[0065] The power supply 622 may include a DC power supply 62p1, a switch 62s1, and a switch 62s3. The DC power supply 62p1 may be a variable DC power supply. The positive terminal of the DC power supply 62p1 is connected to the lower electrode 18 via the switch 62s1. The negative terminal of the DC power supply 62p1 is connected to ground. The switch 62s3 is connected between the ground and the lower electrode 18. Furthermore, the variable DC power supply constituting the DC power supply 62p1 may be a variable DC power supply whose positive and negative terminals can be arbitrarily set. Moreover, the switches 62s1 and 62s3 may be connected to the lower electrode 18 via their respective individual filters, rather than a single filter 62f.

[0066] The opening and closing of switches 62s1 and 62s3 can be controlled by the control unit 80. If switch 62s1 is closed and switch 62s3 is open, a positive voltage from the DC power supply 62p1 is output to the lower electrode 18. If switch 62s3 is closed and switch 62s1 is open, the lower electrode 18 is connected to the ground wire.

[0067] During periods other than PP, switches 62s1 and 62s3 are opened to generate... Figure 6 The electrical bias EB is shown. Therefore, during the period other than PP, only the high-frequency power from the high-frequency power supply 621 is supplied to the lower electrode 18 as the electrical bias EB. During PP, switch 62s1 is closed and switch 62s3 is open. Therefore, during PP, the electrical bias EB generated by the overlap of the high-frequency power from the high-frequency power supply 621 and the positive voltage from the power supply 622 is supplied to the lower electrode 18.

[0068] The following is for reference. Figure 7 (a) Figure 7 (b) and Figure 7 (c) Figure 7 middle, Figure 7 (a) Figure 7 (b) and Figure 7(c) These are diagrams that schematically illustrate a plasma processing apparatus according to yet another exemplary embodiment. Figure 7 (a) Figure 7 (b) and Figure 7 As shown in (c), component 60 can be a component different from the upper electrode 30. Figure 7 As shown in (a), component 60 can extend circumferentially around the upper electrode 30. Figure 7 As shown in (b), component 60 can extend circumferentially to surround the plasma generated between the upper electrode 30 and the substrate support 16. Component 60 can be a sidewall of chamber 10 (e.g., a sidewall of chamber body 12) or a portion thereof, or it can be a component different from the sidewall of chamber 10. Figure 7 As shown in (c), component 60 can extend circumferentially in the exhaust path including the space around the substrate support 16. Component 60 can be baffle component 48 or a component different from baffle component 48.

[0069] Hereinafter, the plasma processing method according to the exemplary embodiment will be described using plasma processing apparatus 1 or plasma processing apparatus 1B as an example. In the following description, reference will be made to... Figure 2 , Figure 4 and Figure 6 The plasma processing method includes a step of generating plasma from gas within chamber 10. Regarding the plasma, it is generated from gas within chamber 10 by supplying high-frequency power HF from high-frequency power source 61.

[0070] The plasma processing method also includes a step of applying a positive voltage from the second power supply (power supply 64) during period PA. As described above, period PA is a portion of the entire period during which the electrical bias EB output from the first power supply (bias power supply 62 or bias power supply 62B) to the lower electrode 18 has a potential above the average potential of the electrical bias EB within its period CY. Period PA, for example, is a period during which the electrical bias EB output from the first power supply (bias power supply 62 or bias power supply 62B) to the lower electrode 18 has a potential of 0 or positive.

[0071] The plasma processing method includes a process of outputting an electrical bias EB with a positive potential from the first power supply (bias power supply 62 or bias power supply 62B) to the lower electrode 18 during the period PP after the period PA.

[0072] Additionally, as mentioned above, during the period PT, the supply of high-frequency power HF can be stopped or the power level of high-frequency power HF can be reduced. The period PT includes at least the time from the start time of period PA to the time between the start and end time of period PP.

[0073] The above descriptions have illustrated various exemplary embodiments, but the embodiments are not limited to these exemplary embodiments. Various additions, omissions, substitutions, and modifications can be made. Furthermore, elements from different embodiments can be combined to form other embodiments.

[0074] For example, in another embodiment, the plasma processing apparatus may have a plasma generation unit different from that of a capacitively coupled plasma generation unit. That is, in another embodiment, the plasma processing apparatus may have an inductively coupled plasma generation unit, an electron cyclotron resonance (ECR) plasma generation unit, or a plasma generation unit using surface waves such as microwaves.

[0075] As can be understood from the above description, various embodiments of the present invention have been described in this specification for illustrative purposes, and various modifications can be made without departing from the scope and spirit of the invention. Therefore, the invention is not limited to the various embodiments disclosed in this specification, and the true scope and spirit are indicated by the appended technical solutions.

Claims

1. A plasma processing apparatus, comprising: Chamber; A substrate support having a lower electrode is disposed within the cavity; The plasma generation unit is configured to generate plasma from gas within the chamber; The first power source is configured to generate an electrical bias and is electrically connected to the lower electrode; and The second power source is configured to apply a positive voltage to components exposed to the plasma generated within the chamber. The second power supply is configured such that, during a first period, a positive voltage is applied to the component during a portion of the entire period during which the electrical bias output from the first power supply to the lower electrode has a potential above the average potential of the electrical bias within its cycle. The first power supply is configured to maintain a positive potential electrical bias output to the lower electrode throughout the second period following the first period.

2. The plasma processing apparatus according to claim 1, wherein, The plasma generation unit is configured to: at least during the period from the start time of the first period to the time between the start and end time of the second period, stop the supply of high-frequency power for generating plasma in the chamber or reduce the power level of the high-frequency power.

3. The plasma processing apparatus according to claim 1 or 2, wherein, The potential of the component during the first period is higher than the potential of the lower electrode during the first period.

4. The plasma processing apparatus according to claim 1 or 2, wherein, The first power supply is configured to output an electrical bias to the lower electrode during the second period, having a positive potential that is higher than the electrical bias potential during the first period.

5. The plasma processing apparatus according to claim 1 or 2, wherein it is a capacitively coupled plasma processing apparatus.

6. The plasma processing apparatus according to claim 4, further comprising an upper electrode disposed above the substrate support. The component is the upper electrode.

7. The plasma processing apparatus according to claim 1 or 2, wherein, The first power supply is configured to periodically output a pulsed DC voltage or an arbitrary voltage waveform as the electrical bias.

8. The plasma processing apparatus according to claim 1 or 2, wherein, The first power supply is configured to output high-frequency power as the electrical bias.

9. The plasma processing apparatus according to claim 1 or 2, wherein, The length of the first period is less than 1.0 μs.

10. The plasma processing apparatus according to claim 1 or 2, wherein, The length of the first period is less than 0.2 μs.

11. A plasma processing method, comprising: In step (a), plasma is generated from gas in a chamber of a plasma processing apparatus, the plasma processing apparatus having a substrate support disposed in the chamber, and a first power supply being electrically connected to a lower electrode in the substrate support. In step (b), during a portion of the first period during which the electrical bias output from the first power source to the lower electrode has a potential above the average potential of the electrical bias within its cycle, a positive voltage is applied from the second power source to the component exposed to the plasma. and In step (c), during a second period following the first period, an electrical bias with a positive potential is output from the first power source to the lower electrode. The electrical bias is maintained at a positive potential throughout the second period.

12. The plasma processing method according to claim 11, wherein, for at least a period from the start time of the first period to the time between the start and end time of the second period, the supply of high-frequency power for generating plasma in the chamber is stopped or the power level of the high-frequency power is reduced.

13. The plasma processing method according to claim 11 or 12, wherein, The length of the first period is less than 1.0 μs.

14. The plasma processing method according to claim 11 or 12, wherein, The length of the first period is less than 0.2 μs.

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