Plasma processing apparatus and control method

Abstract

The invention relates to a plasma processing apparatus and a control method. The plasma processing apparatus includes a chamber, a substrate support portion, and an upper electrode. The substrate supporting part is arranged in the chamber. The upper electrode has a plurality of gas holes, and is provided above the substrate support part. During an ON period, a high-frequency power supply supplies a high-frequency generation source electric power to the high-frequency electrode, and a first bias power supply supplies an electric bias to the substrate supporting part. During a first period including a start time point of the ON period, a negative voltage having a voltage level having a first absolute value is applied from the second bias power supply to the upper electrode. In a second period following the first period within the ON period, a negative voltage having a voltage level having a second absolute value is applied from a second bias power supply to the upper electrode. The first absolute value is less than the second absolute value.

Description

Technical Field

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

[0002] A plasma processing apparatus is used in plasma processing of a substrate. A capacitively coupled plasma processing apparatus is known as one type of plasma processing apparatus. The capacitively coupled plasma processing apparatus includes a chamber, a substrate support portion, and an upper electrode. The substrate support portion is disposed in the chamber. The upper electrode is disposed above the substrate support portion. The plasma processing apparatus described in Patent Document 1 supplies a generation source high-frequency electric power for generating plasma and a bias high-frequency electric power (also referred to as bias high-frequency power) for attracting ions to the substrate support portion in a pulsed manner, and applies a negative voltage to the upper electrode.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2010-171320 Summary of the Invention

[0006] Technical Problem to be Solved by the Invention

[0007] The present invention provides a technique capable of suppressing discharge in an upper electrode of a plasma processing apparatus.

[0008] Technical Means for Solving the Technical Problem

[0009] In an exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, an upper electrode, a high-frequency power supply, a first bias power supply, a second bias power supply, and a control unit. The substrate support is disposed in the chamber. The upper electrode is disposed above the substrate support. A plurality of gas holes for introducing gas into the chamber are formed in the upper electrode. The high-frequency power supply is electrically coupled to the substrate support or the upper electrode as a high-frequency electrode, and is configured to be capable of generating a high-frequency power for generating plasma from gas in the chamber (also referred to as a high-frequency power for a generation source). The first bias power supply is electrically coupled to the substrate support, and is configured to be capable of generating an electrical bias for attracting ions in the chamber to the substrate on the substrate support. The second bias power supply is configured to be capable of applying a negative voltage to the upper electrode. The control unit controls the high-frequency power supply to supply the high-frequency power for the generation source to the high-frequency electrode during an ON period (also referred to as an activation period). The control unit controls the first bias power supply to supply an electrical bias to the substrate support during the ON period. The control unit controls the second bias power supply to apply a negative voltage having a first absolute value to the upper electrode during a first period including a start time point during the ON period. The control unit controls the second bias power supply to apply a negative voltage having a second absolute value to the upper electrode during a second period after the first period during the ON period. The first absolute value is smaller than the second absolute value.

[0010] Effects of the Invention

[0011] According to an exemplary embodiment, a technique for suppressing discharge in the upper electrode of a plasma processing apparatus can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a diagram for explaining a structural example of a capacitively coupled plasma processing apparatus.

[0013] Figure 2 is a diagram schematically showing a plasma processing apparatus according to an exemplary embodiment.

[0014] Figure 3 (a) of Figure 3 and (b) of

[0015] Figure 4 are diagrams each showing an example of a waveform of an electrical bias.

[0016] Figure 5 is a flowchart of a control method of a plasma processing apparatus according to an exemplary embodiment.

[0017] Figure 6 is a diagram schematically showing a plasma processing apparatus according to another exemplary embodiment.

[0018] Figure 7 It is a timing chart of a plasma processing apparatus according to another exemplary embodiment.

[0019] Figure 8 It is a flowchart of a control method of a plasma processing apparatus according to another exemplary embodiment. Detailed Embodiments

[0020] Hereinafter, each exemplary embodiment will be described in detail with reference to the drawings. In addition, in each drawing, the same or corresponding parts are given the same reference numerals.

[0021] Hereinafter, a structural example of the plasma processing system will be described. Figure 1 It is a diagram for explaining a structural example of a capacitively coupled plasma processing apparatus.

[0022] The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a control unit 2. The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. In addition, the plasma processing apparatus 1 includes a substrate support unit 11 and a gas introduction unit. The gas introduction unit is configured to be able to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes a showerhead 13. The substrate support unit 11 is disposed in the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support unit 11. In one embodiment, the showerhead 13 constitutes at least a part of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, the sidewall 10a of the plasma processing chamber 10, and the substrate support unit 11. The plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space 10s; and at least one gas discharge port for discharging gas from the plasma processing space. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support unit 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0023] The substrate support portion 11 includes a main body portion 111 and a ring assembly 112. The main body portion 111 has: a central region 111a for supporting the substrate W; and an annular region 111b for supporting the ring assembly 112. A wafer is an example of the substrate W. The annular region 111b of the main body portion 111 surrounds the central region 111a of the main body portion 111 in a top view. The substrate W is disposed on the central region 111a of the main body portion 111, and the ring assembly 112 is disposed on the annular region 111b of the main body portion 111 so as to surround the substrate W on the central region 111a of the main body portion 111. Therefore, the central region 111a is also referred to as a substrate support surface for supporting the substrate W, and the annular region 111b is also referred to as a ring support surface for supporting the ring assembly 112.

[0024] In one embodiment, the main body portion 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Alternatively, other components surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck and an annular insulating member, may have the annular region 111b. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. In addition, at least one RF / DC electrode coupled to an RF (Radio Frequency) power supply 31 and / or a DC (Direct Current) power supply 32 described later may be disposed within the ceramic member 1111a. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal described later is supplied to the at least one RF / DC electrode, the RF / DC electrode is also referred to as a bias electrode. Alternatively, the conductive member of the base 1110 and the at least one RF / DC electrode may function as a plurality of lower electrodes. In addition, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support portion 11 includes at least one lower electrode.

[0025] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge ring is formed of a conductive material or an insulating material, and the cover ring is formed of an insulating material.

[0026] In addition, the substrate support portion 11 may include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. A heat transfer fluid such as brine or gas flows in the flow path 1110a. In one embodiment, the flow path 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. In addition, the substrate support portion 11 may include a heat transfer gas supply portion configured to supply a heat transfer gas to a gap between the back surface of the substrate W and the central region 111a.

[0027] The shower head 13 is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. The shower head 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas introduction ports 13c. The process gas supplied to the gas supply port 13a is introduced into the plasma processing space 10s from the plurality of gas introduction ports 13c through the gas diffusion chamber 13b. In addition, the shower head 13 includes at least one upper electrode. Further, the gas introduction unit may include, in addition to the shower head 13, one or more side gas injectors (SGIs) mounted in one or more openings formed in the side wall 10a.

[0028] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from the respective corresponding gas source 21 to the shower head 13 via the respective corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Moreover, the gas supply unit 20 may include one or more flow modulation devices for modulating or pulsing the flow rate of at least one process gas.

[0029] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF electric power) to at least one lower electrode and / or at least one upper electrode. Thereby, plasma can be formed from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of a plasma generation unit configured to generate plasma from one or more processing gases in the plasma processing chamber 10. In addition, by supplying a bias RF signal to at least one lower electrode, a bias potential can be generated on the substrate W, and the ion component in the formed plasma can be introduced into the substrate W.

[0030] In one embodiment, the RF power supply 31 includes a first RF generation unit 31a and a second RF generation unit 31b. The first RF generation unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit, and is configured to generate a source RF signal (source RF electric power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generation unit 31a may be configured to generate a plurality of source RF signals having different frequencies. The one or more generated source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0031] The second RF generation unit 31b is coupled to at least one lower electrode via at least one impedance matching circuit, and is configured to generate a bias RF signal (bias RF electric power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generation unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. The one or more generated bias RF signals are supplied to at least one lower electrode. In addition, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0032] In addition, the power supply 30 may include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generation unit 32a and a second DC generation unit 32b. In one embodiment, the first DC generation unit 32a is connected to at least one lower electrode and configured to generate a first DC signal. The generated first bias DC signal is applied to at least one lower electrode. In one embodiment, the second DC generation unit 32b is connected to at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to at least one upper electrode.

[0033] In various embodiments, at least one of the first DC signal and the second DC signal may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a pulse waveform of a rectangle, a trapezoid, a triangle, or a combination thereof. In one embodiment, a waveform generation unit for generating a sequence of voltage pulses from the DC signal is connected between the first DC generation unit 32a and at least one lower electrode. Accordingly, the first DC generation unit 32a and the waveform generation unit constitute a voltage pulse generation unit. In the case where the second DC generation unit 32b and the waveform generation unit constitute a voltage pulse generation unit, the voltage pulse generation unit is connected to at least one upper electrode. The voltage pulses may have a positive polarity or a negative polarity. In addition, the sequence of voltage pulses may include one or more positive-polarity voltage pulses and one or more negative-polarity voltage pulses within one cycle. Further, it may be that in addition to providing the RF power supply 31, the first DC generation unit 32a and the second DC generation unit 32b are also provided, or it may be that the first DC generation unit 32a is provided in place of the second RF generation unit 31b.

[0034] The exhaust system 40 can be connected, for example, to a gas discharge port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 10s can be regulated using the pressure regulating valve. The vacuum pump may include a turbo molecular pump, a dry pump, or a combination thereof.

[0035] The control unit 2 can process computer-executable commands for causing the plasma processing apparatus 1 to execute the respective steps (also referred to as "processes") described in the present invention. The control unit 2 is configured to be able to control the respective elements of the plasma processing apparatus 1 to execute the respective steps described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 is implemented by a computer 2a, for example. The processing unit 2a1 can read a program from the storage unit 2a2 and perform various control actions by executing the read program. The program may be pre-stored in the storage unit 2a2 or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read and executed by the processing unit 2a1 from the storage unit 2a2. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 can communicate with the plasma processing apparatus 1 via a communication line such as a LAN (Local Area Network).

[0036] Hereinafter, with reference to Figure 2 . Figure 2 is a diagram schematically showing a plasma processing apparatus according to an exemplary embodiment. As Figure 2 shown, the plasma processing apparatus 1 includes the above-described upper electrode 14. In one embodiment, the upper electrode 14 includes a top plate 141 and a cooling plate 142.

[0037] The top plate 141 is in contact with the plasma processing space 10s and defines the plasma processing space 10s from above. The top plate 141 is formed of a conductive material. The top plate 141 is formed of silicon, for example. The cooling plate 142 is provided on the top plate 141 and supports the top plate 141. The cooling plate 142 is formed, for example, by forming a dielectric film such as alumina on the surface of a base material formed of aluminum. The cooling plate 142 has a refrigerant flow path 142f formed therein. Refrigerant is supplied from a cooling unit 60 provided outside the chamber 10 to the refrigerant flow path 142f. The refrigerant supplied to the refrigerant flow path 142f is returned to the cooling unit 60. The top plate 141 is cooled by supplying refrigerant to the refrigerant flow path 142f.

[0038] The cooling plate 142 provides the gas diffusion chamber 13b. The top plate 141 and the cooling plate 142 provide a plurality of gas holes as the plurality of gas introduction ports 13c described above. The plurality of gas holes extend from the gas diffusion chamber 13b through the cooling plate 142 and the top plate 141 and open to the plasma processing space 10s.

[0039] The plasma processing apparatus 1 includes a high-frequency power supply 50, a first bias power supply 51, and a second bias power supply 52. The high-frequency power supply 50 is a first RF generation unit 31a and is electrically coupled to the high-frequency electrode. The high-frequency electrode is the lower electrode of the substrate support unit 11 described above or the upper electrode 14. The high-frequency power supply 50 is configured to be able to generate a high-frequency electric power as a generation source RF signal for generating plasma from a gas in the chamber 10. The high-frequency power supply 50 is electrically connected to the high-frequency electrode via a matcher 50m. The matcher 50m includes a matching circuit for matching the impedance of the load of the high-frequency power supply 50 with the output impedance of the high-frequency power supply 50.

[0040] The first bias power supply 51 is electrically coupled to the substrate support unit 11 (for example, the lower electrode described above). The first bias power supply 51 is configured to be able to generate an electric bias EB for attracting ions in the plasma in the chamber 10 to the substrate W on the substrate support unit 11. The electric bias EB has a bias frequency. The bias frequency has a frequency in the range of 100 kHz or more and 60 MHz or less. The bias frequency is, for example, 400 kHz.

[0041] The first bias power supply 51 may also be the second RF generation unit 31b described above. In this case, the first bias power supply 51 is configured to be able to generate a bias high-frequency electric power LF as the bias RF signal as the electric bias EB. In this case, the first bias power supply 51 is electrically connected to the substrate support unit 11 via a matcher 51m. The matcher 51m includes a matching circuit for matching the impedance of the load of the first bias power supply 51 with the output impedance of the first bias power supply 51. The bias high-frequency electric power LF, as Figure 3 shown in (a) of, is an electric power presenting a sine wave shape having a bias frequency and is generated periodically. The waveform period CY of the bias high-frequency electric power LF has a time length that is the reciprocal of the bias frequency.

[0042] Alternatively, the first bias power supply 51 may also include the first DC generation unit 32a described above. In this case, the first bias power supply 51 is configured to be able to periodically generate a voltage pulse VP as the first DC signal as the electric bias EB. In this case, the plasma processing apparatus 1 may not have a matcher 51m, and the first bias power supply 51 may be electrically connected to the substrate support unit 11 (for example, the lower electrode) without passing through the matcher 51m. The voltage pulse VP, as Figure 3As shown in (b), it is generated periodically at time intervals of the waveform period CY. Figure 3 In the example of (b), the voltage pulse VP is a pulse of a negative voltage or a negative DC voltage. However, as long as ions can be attracted from the plasma to the substrate W, the polarity of the voltage pulse VP is not limited to the negative polarity.

[0043] The second bias power supply 52 includes the second DC generating unit 32b described above, and is electrically coupled to the upper electrode 14. The second bias power supply 52 is configured to be able to apply a negative voltage UEV to the upper electrode 14. The second bias power supply 52 may include a variable DC power supply.

[0044] The following, with Figure 2 and Figure 3 Refer to Figure 4 . Figure 4 FIG. 2 is a timing chart of a plasma processing apparatus according to an exemplary embodiment. The control unit 2 controls the high frequency power source 50 so that during the ON period (ie, the opening period or the connected period) P ON The high frequency electrode is supplied with the generated high frequency electric power HF. ON The power level of the high frequency electric power HF generated by the generator is, for example, 1000 W or more.

[0045] In addition, the control unit 2 controls the first bias power supply 51 so that during the ON period P ON The electric bias EB is supplied to the substrate support portion 11 (for example, the lower electrode). When the electric bias EB is a bias high frequency electric power LF, the ON period P ON The power level of the bias high frequency electric power LF is, for example, 3000 W or more and 100000 W or less. When the electric bias EB includes a voltage pulse VP, the ON period P ON The voltage level of the voltage pulse VP is, for example, a level in the range between -3000V and -10000V.

[0046] like Figure 4 As shown, the control unit 2 controls the second bias power supply 52 to ON The first period P including the start time point 1 A voltage level V is applied to the upper electrode 14. 1 With the first absolute value |V 1 |Negative voltage UEV. |V 1 |For example, it is greater than 0V and is 300V or less. |V 1 |For example, 200V. The first period P 1 It may also have a time length of more than 4 times the waveform period CY. 1 It may also have a time length of less than 8 times or less than 10 times the waveform period CY.1 It can start at the start time point of P during ON, ON or can also start from a time point before or just before the start time point of P during ON. ON

[0047] In addition, the control unit 2 controls the second bias power supply 52 to apply a voltage level V ON with a second absolute value |V 1 | to the upper electrode 14 during a second period P 2 after a first period P 2 within the ON period P. Here, the first absolute value |V 2 | is smaller than the second absolute value |V 1 |. |V 2 | is, for example, 100 V or more and 1000 V or less. |V 2 | is, for example, 500 V. 2

[0048] In one embodiment, the ON period P ON can also appear alternately with the OFF period (also referred to as the turn-off period) P OFF The control unit 2 controls the high-frequency power supply 50 and the first bias power supply 51 to stop supplying the generated source high-frequency electric power HF and the electric bias EB during the OFF period P OFF . That is, in one embodiment, the high-frequency power supply 50 periodically supplies pulses of the generated source high-frequency electric power HF under the control of the control unit 2, and the first bias power supply 51 periodically supplies pulses of the electric bias EB under the control of the control unit 2. The pulses of the generated source high-frequency electric power HF and the pulses of the electric bias EB are periodically supplied, for example, at a pulse frequency of 1 kHz or more and 20 kHz or less. That is, the ON period P ON appears periodically at time intervals that are the reciprocal of the pulse frequency.

[0049] The control unit 2 can also control the second bias power supply 52 to apply a negative voltage UEV to the upper electrode 14 during the OFF period P OFF . The voltage level V OFF of the negative voltage UEV during the OFF period P 3 and the third absolute value |V 3 | can also be larger than the second absolute value |V 2 |. |V 3 | is, for example, 300 V or more and 1000 V or less. |V 3 | is, for example, 1000 V.

[0050] In the above-described plasma processing apparatus 1, during the ON period P ONA negative voltage UEV is applied to the upper electrode 14. As a result, the distance between the plasma and the upper electrode 14 becomes larger, and an increase in the temperature of the upper electrode 14 can be suppressed.

[0051] In addition, during the first period P 1 the first absolute value |V 1 | of the voltage level of the negative voltage UEV can also be smaller than the second absolute value |V 2 | of the voltage level of the negative voltage UEV during the second period P 2 . Therefore, it is possible to suppress abnormal discharges in a plurality of gas holes of the upper electrode 14 that may occur if the voltage level of the negative voltage UEV during the first period P 1 is not small at the start of the ON period P ON .

[0052] In addition, since a negative voltage UEV is applied to the upper electrode 14 also during the OFF period P OFF , the upper electrode 14 is discharged during the OFF period P OFF .

[0053] Hereinafter, with reference to Figure 5 , a control method for a plasma processing apparatus according to an exemplary embodiment will be described. Figure 5 is a flowchart of a control method for a plasma processing apparatus according to an exemplary embodiment. Figure 5 The control method (hereinafter referred to as "method MT") shown includes steps STa to STd.

[0054] Step STa is performed during the ON period P ON (throughout the ON period P ON ). In step STa, in order to generate plasma from the gas in the chamber 10 of the plasma processing apparatus 1, a high-frequency power generation source high-frequency electric power HF is supplied from the high-frequency power supply 50 to the high-frequency electrode.

[0055] Step STb is performed during the ON period P ON (throughout the ON period P ON ). In step STb, in order to attract ions in the chamber 10 to the substrate W on the substrate support portion 11, an electric bias EB is supplied from the first bias power supply 51 to the substrate support portion 11 (for example, the lower electrode).

[0056] Step STc is performed during the above-described first period P 1 . In step STc, a negative voltage UEV having a voltage level V 1 with a first absolute value |V 1 | is applied from the second bias power supply 52 to the upper electrode 14.

[0057] Step STd is performed during the above-described second period P2 is carried out. In step STd, a voltage level V is applied from the second bias power supply 52 to the upper electrode 14 2 with a negative voltage UEV having a second absolute value |V 2 |. As described above, the first absolute value |V 1 | is smaller than the second absolute value |V 2 |.

[0058] In the method MT, it can also be that P during the ON period ON and P during the OFF period OFF are alternately repeated. In this case, the method MT further includes step STe, step STf, and step STJ.

[0059] Step STe and step STf are carried out during the OFF period P OFF (during the entire OFF period P OFF ). In step STe, the supply of the source high-frequency electric power HF and the electric bias EB is stopped. In step STf, a negative voltage UEV is applied from the second bias power supply 52 to the upper electrode 14. The voltage level V of the negative voltage UEV in step STf 3 with a third absolute value |V 3 |, as described above, can be larger than the second absolute value |V 2 |.

[0060] In step STJ, it is judged whether the stop condition is satisfied. The stop condition is satisfied, for example, when the number of repetitions of steps STa to STf reaches a specified number. When it is judged in step STJ that the stop condition is not satisfied, the processing starting from step STa is repeated again. When it is judged in step STJ that the stop condition is satisfied, the method MT ends.

[0061] Hereinafter, with reference to Figure 6 , a plasma processing apparatus according to another exemplary embodiment will be described. Figure 6 is a diagram schematically showing a plasma processing apparatus according to another exemplary embodiment. Hereinafter, for Figure 6 the plasma processing apparatus 1B shown, an explanation will be given from the viewpoint of differences from the plasma processing apparatus 1.

[0062] The plasma processing apparatus 1B further includes a detector 70. The detector 70 is configured to be able to obtain a detection signal that changes in magnitude from the normal value when there is a possibility of discharge in the upper electrode 14. The detection period of the detection signal may include the entire ON period P ON or a part thereof. As a part of the ON period P of the detection period of the detection signal ON may include the ON period P ONThe start time point. The detection period of the detection signal may also include the OFF period P OFF At least a part of. The detection signal is input to the control unit 2.

[0063] The detection signal may be a signal representing the light emission intensity of a monitoring gas hole among a plurality of gas holes (i.e., a plurality of gas inlets 13c) of the upper electrode 14. In this case, the detector 70 includes: an optical sensor 71s configured to be able to measure the light emission intensity (hereinafter referred to as "light emission intensity") of the monitoring gas hole. An optical fiber extends between the optical sensor 71s and the monitoring gas hole, optically connecting the optical sensor 71s and the monitoring gas hole.

[0064] Alternatively, the detection signal may also be a signal representing the potential or current value of the upper electrode 14. In this case, the detector 70 includes: an electrical sensor 72s configured to be able to measure the potential or current value of the upper electrode 14. The electrical sensor 72s is electrically connected to the upper electrode 14.

[0065] In the plasma processing apparatus 1B, when the control unit 2 determines from the detection signal that there is no possibility of discharge of the upper electrode 14, the first control is executed, and when it determines from the detection signal that there is a possibility of discharge of the upper electrode 14, the second control is executed.

[0066] Alternatively, when the light emission intensity of the monitoring gas hole, the potential of the upper electrode 14, or the current value of the upper electrode 14 is equal to or greater than a threshold value, the control unit 2 determines that there is a possibility of discharge of the upper electrode 14 and executes the second control. The control unit 2 executes the first control in other cases.

[0067] Alternatively, when the difference between the light emission intensity of the monitoring gas hole, the potential of the upper electrode 14, or the current value of the upper electrode 14 and the corresponding value in the normal state is equal to or greater than a threshold value, the control unit 2 determines that there is a possibility of discharge of the upper electrode 14 and executes the second control. The control unit 2 executes the first control in other cases.

[0068] The first control executed by the control unit 2 includes, as Figure 7 shown, controlling the second bias power supply 52 so that during the ON period P ON (during the entire ON period P ON ) a voltage level V is applied to the upper electrode 14 2 having the above-mentioned second absolute value |V 2 | of the negative voltage UEV.

[0069] The second control executed by the control unit 2 includes: as Figure 4 shown, controlling the second bias power supply 52 so that during the first period P1 Apply a voltage level V to the upper electrode 14 1 A negative voltage UEV having the first absolute value |V 1 | as described above. In addition, the second control executed by the control unit 2 includes: as Figure 4 shown, control the second bias power supply 52 to apply a voltage level V to the upper electrode 14 during the second period P 2 Apply a voltage level V to the upper electrode 14 2 A negative voltage UEV having the second absolute value |V 2 | as described above.

[0070] According to the plasma processing apparatus 1B, the second control that is not required when there is no possibility of discharging the upper electrode 14 is not performed, and the voltage applied to the upper electrode 14 can be controlled by the first control.

[0071] Hereinafter, with reference to Figure 8 , a control method of a plasma processing apparatus according to another exemplary embodiment will be described. Figure 8 is a flowchart of a control method of a plasma processing apparatus according to another exemplary embodiment. Hereinafter, for Figure 8 the control method shown (hereinafter referred to as "method MTB"), an explanation will be given from the viewpoint of differences from method MT.

[0072] Method MTB further includes step STJB. Step STJB is used by the control unit 2 to determine whether there is a possibility of discharging the upper electrode 14 based on the detection signal acquired by the detector 70. For the determination of the possibility of discharging the upper electrode 14, refer to the above description of the plasma processing apparatus 1B.

[0073] When it is determined in step STJB that there is no possibility of discharging the upper electrode 14, the above-described first control is executed in step ST1. After step ST1, the process may transfer to step STe.

[0074] When it is determined in step STJB that there is a possibility of discharging the upper electrode 14, the above-described second control is executed in step ST2. The second control includes step STc and step STd of method MT. After step ST2, the process may transfer to step STe.

[0075] As described above, each exemplary embodiment has been described, but it is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and changes can be made. In addition, elements of different embodiments can be combined to form other embodiments.

[0076] Here, each exemplary embodiment included in the present invention is described in the following [E1] to [E18].

[0077] [E1]

[0078] A plasma processing apparatus, comprising:

[0079] A chamber;

[0080] A substrate support disposed in the chamber;

[0081] An upper electrode disposed above the substrate support, and a plurality of gas holes for introducing gas into the chamber are formed in the upper electrode;

[0082] A high-frequency power supply electrically coupled to the substrate support or the upper electrode as a high-frequency electrode, the high-frequency power supply being configured to be able to generate a high-frequency electric power of a generation source for generating plasma from gas in the chamber;

[0083] A first bias power supply electrically coupled to the substrate support, the first bias power supply being configured to be able to generate an electrical bias for attracting ions in the chamber to the substrate on the substrate support;

[0084] A second bias power supply configured to be able to apply a negative voltage to the upper electrode; and

[0085] A control unit,

[0086] The control unit is configured to,

[0087] Be able to control the high-frequency power supply to supply the high-frequency electric power of the generation source to the high-frequency electrode during the ON period,

[0088] Be able to control the first bias power supply to supply the electrical bias to the substrate support during the ON period,

[0089] Be able to control the second bias power supply to apply the negative voltage having a first absolute value to the upper electrode during a first period including a start time point during the ON period, and

[0090] Be able to control the second bias power supply to apply the negative voltage having a second absolute value to the upper electrode during a second period after the first period during the ON period,

[0091] The first absolute value is smaller than the second absolute value.

[0092] [E2]

[0093] The plasma processing apparatus according to E1, wherein,

[0094] The electrical bias is a bias high-frequency electric power having a bias frequency, or a voltage pulse periodically generated at a time interval of the reciprocal of the bias frequency,

[0095] The first period has a length that is more than four times the following period, which is the time length of the reciprocal of the bias frequency starting from the start time point.

[0096] [E3]

[0097] The plasma processing apparatus according to E2, wherein

[0098] The first period has a length that is eight times or less or ten times or less the period.

[0099] [E4]

[0100] The plasma processing apparatus according to any one of E1 to E3, wherein

[0101] The ON period and the OFF period appear alternately,

[0102] The control unit is configured to be able to control the high-frequency power supply and the first bias power supply to stop the supply of the high-frequency electric power and the supply of the electric bias during the OFF period.

[0103] [E5]

[0104] The plasma processing apparatus according to E4, wherein

[0105] The control unit is configured to be able to control the second bias power supply to apply a negative voltage having a third absolute value greater than the second absolute value to the upper electrode during the OFF period.

[0106] [E6]

[0107] The plasma processing apparatus according to any one of E1 to E5, wherein

[0108] The upper electrode includes:

[0109] A top plate in contact with the plasma processing space in the chamber; and

[0110] A cooling plate provided on the top plate, in which a refrigerant flow path is provided.

[0111] [E7]

[0112] The plasma processing apparatus according to E6, wherein

[0113] The top plate is formed of silicon.

[0114] [E8]

[0115] A control method, comprising:

[0116] A step of supplying high-frequency electric power for a generation source from a high-frequency power supply to a high-frequency electrode to generate plasma from a gas in a chamber during an ON period, wherein the high-frequency electrode is a substrate support portion in the chamber or an upper electrode disposed above the substrate support portion;

[0117] A step of supplying an electrical bias from a first bias power supply to the substrate support portion during the ON period to attract ions in the chamber to a substrate on the substrate support portion;

[0118] A step of applying a negative voltage having a first absolute value to the upper electrode from a second bias power supply during a first period including a start time point during the ON period; and

[0119] A step of applying the negative voltage having a second absolute value to the upper electrode from the second bias power supply during a second period after the first period during the ON period,

[0120] The first absolute value is less than the second absolute value.

[0121] [E9]

[0122] A plasma processing apparatus, comprising:

[0123] A chamber;

[0124] A substrate support portion disposed in the chamber;

[0125] An upper electrode disposed above the substrate support portion, and a plurality of gas holes for introducing a gas into the chamber are formed in the upper electrode;

[0126] A high-frequency power supply electrically coupled to the substrate support portion or the upper electrode as a high-frequency electrode, the high-frequency power supply being configured to generate high-frequency electric power for a generation source for generating plasma from a gas in the chamber;

[0127] A first bias power supply electrically coupled to the substrate support portion, the first bias power supply being configured to generate an electrical bias for attracting ions in the chamber to a substrate on the substrate support portion;

[0128] A second bias power supply configured to apply a negative voltage to the upper electrode;

[0129] A detector configured to acquire a signal representing the light emission intensity of a monitoring gas hole among the plurality of gas holes or a signal representing the potential or current value of the upper electrode as a detection signal; and

[0130] A control unit,

[0131] The control unit is configured such that,

[0132] It is possible to control the high-frequency power supply to supply the high-frequency electric power of the generation source to the high-frequency electrode during the ON period.

[0133] It is possible to control the first bias power supply to supply the electric bias to the substrate support portion during the ON period.

[0134] Execute the first control when it is determined from the detection signal that there is no possibility of discharge of the upper electrode.

[0135] Execute the second control when it is determined from the detection signal that there is a possibility of discharge of the upper electrode, where

[0136] The second control includes:

[0137] Control the second bias power supply to apply the negative voltage having the first absolute value to the upper electrode during the first period including the start time point during the ON period, and

[0138] Control the second bias power supply to apply the negative voltage having the second absolute value to the upper electrode during the second period after the first period during the ON period.

[0139] The first control includes:

[0140] Control the second bias power supply to apply the negative voltage having the second absolute value to the upper electrode during the entire ON period.

[0141] The first absolute value is smaller than the second absolute value.

[0142] [E10]

[0143] The plasma processing apparatus according to E9, where

[0144] The electric bias is a bias high-frequency electric power having a bias frequency, or a voltage pulse periodically generated at a time interval of the reciprocal of the bias frequency.

[0145] The first period has a length of 4 times or more of the following period, and this period has a time length of the reciprocal of the bias frequency from the start time point.

[0146] [E11]

[0147] The plasma processing apparatus according to E10, where

[0148] The first period has a length of 8 times or less or 10 times or less of the period.

[0149] [E12]

[0150] The plasma processing apparatus according to any one of E9 to E11, wherein

[0151] the ON period and the OFF period appear alternately,

[0152] the control unit is configured to be able to control the high-frequency power supply and the first bias power supply to stop the supply of the high-frequency electric power and the supply of the electric bias during the OFF period.

[0153] [E13]

[0154] The plasma processing apparatus according to E12, wherein

[0155] the control unit is configured to be able to control the second bias power supply to apply, during the OFF period, the negative voltage having a third absolute value larger than the second absolute value to the upper electrode.

[0156] [E14]

[0157] The plasma processing apparatus according to any one of E9 to E13, wherein

[0158] the upper electrode includes:

[0159] a top plate in contact with the plasma processing space in the chamber; and

[0160] a cooling plate provided on the top plate, and a refrigerant flow path is provided in the cooling plate.

[0161] [E15]

[0162] The plasma processing apparatus according to E14, wherein

[0163] the top plate is formed of silicon.

[0164] [E16]

[0165] The plasma processing apparatus according to any one of E9 to E15, wherein

[0166] the control unit is configured to perform the second control when the light emission intensity, the potential, or the current value determined according to the detection signal is equal to or greater than a threshold value.

[0167] [E17]

[0168] The plasma processing apparatus according to any one of E9 to E15, wherein

[0169] The control unit is configured to perform the second control when the difference between the light emission intensity, the potential, or the current value determined based on the detection signal and the normal value of the light emission intensity, the potential, or the current value is equal to or greater than a threshold value.

[0170] [E18]

[0171] A control method, comprising:

[0172] A step of supplying high-frequency electric power of a generation source from a high-frequency power supply to a high-frequency electrode to generate plasma from a gas in a chamber of a plasma processing apparatus during an ON period, wherein the high-frequency electrode is a substrate support portion in the chamber or an upper electrode disposed above the substrate support portion;

[0173] A step of supplying an electrical bias from a first bias power supply to the substrate support portion during the ON period to attract ions in the chamber to a substrate on the substrate support portion;

[0174] A step of performing a first control when it is determined based on a detection signal that there is no possibility of discharge of the upper electrode, wherein the detection signal is a signal indicating the light emission intensity of a monitoring gas hole among a plurality of gas holes of the upper electrode for introducing gas into the chamber or a signal indicating the potential or current value of the upper electrode; and

[0175] A step of performing a second control when it is determined based on the detection signal that there is a possibility of discharge of the upper electrode,

[0176] The second control includes:

[0177] A step of applying a negative voltage having a first absolute value to the upper electrode from a second bias power supply during a first period including a start time point during the ON period; and

[0178] A step of applying the negative voltage having a second absolute value to the upper electrode from the second bias power supply during a second period after the first period during the ON period,

[0179] The first control includes: a step of applying the negative voltage having the second absolute value to the upper electrode from the second bias power supply throughout the ON period,

[0180] The first absolute value is smaller than the second absolute value.

[0181] As should be understood from the above description, the various embodiments of the present invention are described in this specification for illustrative purposes, and various changes can be made without exceeding the scope and gist of the present invention. Therefore, each embodiment described in this specification is not a limitation on the present invention, and the scope and gist of the present invention are represented by the claims.

[0182] Description of Reference Numerals

[0183] 1... Plasma processing apparatus, 2... Control unit, 10... Chamber, 11... Substrate support portion, 14... Upper electrode, 50... High-frequency power supply, 51... First bias power supply, 52... Second bias power supply.

Claims

1. A plasma processing device, characterized in that: include: Chamber; a substrate support portion disposed in the chamber; an upper electrode disposed above the substrate support portion, wherein a plurality of gas holes for introducing gas into the chamber are formed on the upper electrode; a high-frequency power source electrically coupled to the substrate support portion or the upper electrode as a high-frequency electrode, the high-frequency power source being configured to generate a generation source high-frequency electric power for generating plasma from a gas in the chamber; a first bias power supply electrically coupled to the substrate support, the first bias power supply being configured to generate an electrical bias for attracting ions in the chamber to the substrate on the substrate support; a second bias power supply configured to apply a negative voltage to the upper electrode; and Control Department, The control unit is configured as follows: The high frequency power source can be controlled to supply the generating source high frequency electric power to the high frequency electrode during the ON period, capable of controlling the first bias power supply to supply the electrical bias to the substrate support portion during the ON period, The second bias power supply can be controlled to apply the negative voltage having a first absolute value in a first period including a start time point of the ON period to the upper electrode, and The second bias power supply can be controlled to apply the negative voltage having a second absolute value in voltage level to the upper electrode during a second period after the first period within the ON period, The first absolute value is smaller than the second absolute value.

2. The plasma processing device according to claim 1, wherein: The electric bias is a bias high frequency electric power having a bias frequency, or a voltage pulse periodically generated at a time interval of the inverse of the bias frequency. The first period has a length that is four times or more as long as a period having a time length that is a reciprocal of the bias frequency from the start time point.

3. The plasma processing device according to claim 2, wherein: The first period has a length that is less than or equal to 8 times or less than or equal to 10 times the period.

4. The plasma processing apparatus according to any one of claims 1 to 3, characterized in that: The ON period and the OFF period appear alternately. The control unit is configured to be able to control the high-frequency power supply and the first bias power supply so as to stop supply of the high-frequency electric power and supply of the electric bias during the OFF period.

5. The plasma processing device according to claim 4, characterized in that: The control unit is configured to be capable of controlling the second bias power supply so as to apply the negative voltage having a third absolute value greater than the second absolute value to the upper electrode during the OFF period.

6. The plasma processing apparatus according to any one of claims 1 to 3, characterized in that: The upper electrode comprises: a top plate in contact with the plasma processing space within the chamber; and The cooling plate is provided on the top plate and has a cooling medium flow path in the cooling plate.

7. The plasma processing apparatus according to claim 6, wherein: The top plate is formed of silicon.

8. A control method, characterized in that: include: A step of supplying a generation source high frequency electric power from a high frequency power supply to a high frequency electrode to generate plasma from a gas in a chamber of a plasma processing device during an ON period, wherein the high frequency electrode is a substrate support portion in the chamber or an upper electrode arranged above the substrate support portion; During the ON period, supplying an electrical bias from a first bias power source to the substrate support portion to attract ions in the chamber to the substrate on the substrate support portion; A step of applying a negative voltage having a first absolute value in voltage level to the upper electrode from a second bias power source during a first period including a start time point of the ON period; and a step of applying the negative voltage having a second absolute value in voltage level to the upper electrode from the second bias power supply during a second period after the first period within the ON period, The first absolute value is smaller than the second absolute value.

9. A plasma processing device, characterized in that: include: Chamber; a substrate support portion disposed in the chamber; an upper electrode disposed above the substrate support portion, wherein a plurality of gas holes for introducing gas into the chamber are formed on the upper electrode; a high-frequency power source electrically coupled to the substrate support portion or the upper electrode as a high-frequency electrode, the high-frequency power source being configured to generate a generation source high-frequency electric power for generating plasma from a gas in the chamber; a first bias power supply electrically coupled to the substrate support, the first bias power supply being configured to generate an electrical bias for attracting ions in the chamber to the substrate on the substrate support; a second bias power supply configured to apply a negative voltage to the upper electrode; a detector configured to acquire, as a detection signal, a signal indicating the luminescence intensity of the monitoring gas hole among the plurality of gas holes or a signal indicating the potential or current value of the upper electrode; and Control Department, The control unit is configured as follows: The high frequency power source can be controlled to supply the generating source high frequency electric power to the high frequency electrode during the ON period, capable of controlling the first bias power supply to supply the electrical bias to the substrate support portion during the ON period, When it is determined based on the detection signal that there is no possibility of discharge of the upper electrode, a first control is executed; When it is determined based on the detection signal that there is a possibility of discharge of the upper electrode, a second control is performed, wherein: The second control includes: controlling the second bias power supply to apply the negative voltage having a first absolute value in voltage level to the upper electrode during a first period including a start time point of the ON period, and controlling the second bias power supply to apply the negative voltage having a second absolute value in voltage level to the upper electrode during a second period after the first period within the ON period, The first control includes: controlling the second bias power supply to apply the negative voltage having the second absolute value to the upper electrode during the ON period, The first absolute value is smaller than the second absolute value.

10. The plasma processing apparatus according to claim 9, wherein: The electric bias is a bias high frequency electric power having a bias frequency, or a voltage pulse periodically generated at a time interval of the inverse of the bias frequency. The first period has a length that is four times or more as long as a period having a time length that is a reciprocal of the bias frequency from the start time point.

11. The plasma processing apparatus according to claim 10, wherein: The first period has a length that is less than or equal to 8 times or less than or equal to 10 times the period.

12. The plasma processing apparatus according to any one of claims 9 to 11, characterized in that: The ON period and the OFF period appear alternately. The control unit is configured to be able to control the high-frequency power supply and the first bias power supply so as to stop supply of the high-frequency electric power and supply of the electric bias during the OFF period.

13. The plasma processing apparatus according to claim 12, wherein: The control unit is configured to be capable of controlling the second bias power supply so as to apply the negative voltage having a third absolute value greater than the second absolute value to the upper electrode during the OFF period.

14. The plasma processing apparatus according to any one of claims 9 to 11, characterized in that: The upper electrode comprises: a top plate in contact with the plasma processing space within the chamber; and The cooling plate is provided on the top plate and has a cooling medium flow path in the cooling plate.

15. The plasma processing apparatus according to claim 14, wherein: The top plate is formed of silicon.

16. The plasma processing apparatus according to any one of claims 9 to 11, characterized in that: The control unit is configured to execute the second control when the light emission intensity, the potential, or the current value determined based on the detection signal is equal to or greater than a threshold value.

17. The plasma processing apparatus according to any one of claims 9 to 11, characterized in that: The control unit is configured to execute the second control when the difference between the luminous intensity, the potential or the current value determined based on the detection signal and a normal value of the luminous intensity, the potential or the current value is greater than a threshold value or greater than a threshold value.

18. A control method, characterized in that: include: A step of supplying a generation source high frequency electric power from a high frequency power supply to a high frequency electrode to generate plasma from a gas in a chamber of a plasma processing device during an ON period, wherein the high frequency electrode is a substrate support portion in the chamber or an upper electrode arranged above the substrate support portion; During the ON period, supplying an electrical bias from a first bias power source to the substrate support portion to attract ions in the chamber to the substrate on the substrate support portion; A step of performing a first control when it is determined based on a detection signal that there is no possibility of discharge of the upper electrode, wherein the detection signal is a signal indicating the luminous intensity of a monitoring gas hole among a plurality of gas holes of the upper electrode for introducing gas into the chamber, or a signal indicating a potential or current value of the upper electrode; and a step of executing a second control when it is determined based on the detection signal that there is a possibility of discharge of the upper electrode; The second control includes: A step of applying a negative voltage having a first absolute value in voltage level to the upper electrode from a second bias power source during a first period including a start time point of the ON period; and a step of applying the negative voltage having a second absolute value in voltage level to the upper electrode from the second bias power supply during a second period after the first period within the ON period, The first control includes the step of applying the negative voltage having the second absolute value in voltage level to the upper electrode from the second bias power supply during the ON period, The first absolute value is smaller than the second absolute value.

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