Plasma processing device

Abstract

Provided is a technique for improving the accuracy of an electrical parameter determined using a sensor in a plasma processing device. The plasma processing device comprises a plasma processing chamber, a substrate supporting unit which is disposed within the plasma processing chamber and which includes an electrically conductive base and an electrostatic chuck disposed on the electrically conductive base, an RF power source which is electrically connected to the electrically conductive base via an RF transmission line, a sensor which is configured to detect at least one first electrical parameter at a node on the RF transmission line, a first storage unit which is configured to store a measurement result obtained by measuring the capacitance of the electrostatic chuck, and a control unit, wherein the control unit is configured to determine at least one second electrical parameter of a substrate on a substrate supporting surface on the basis of the at least one first electrical parameter detected by the sensor and the measurement result of the capacitance stored in the first storage unit.

Description

Plasma processing equipment

[0001] SUMMARY OF THE INVENTION An exemplary embodiment of the present disclosure relates to a plasma processing apparatus.

[0002] Patent Document 1 discloses a technique for providing a measurement system having an RF sensor in a plasma processing system, and Patent Document 2 discloses a technique for determining wafer bias in a plasma system.

[0003] US Patent Application Publication No. 2021 / 0407771 JP 2014-195044 A

[0004] The present disclosure provides techniques for improving the accuracy of electrical parameters determined using sensors in plasma processing equipment.

[0005] In one exemplary embodiment of the present disclosure, a plasma processing apparatus includes: a plasma processing chamber; a substrate support disposed within the plasma processing chamber, the substrate support having a conductive base and an electrostatic chuck disposed on the conductive base, the electrostatic chuck having a substrate support surface; an RF power supply electrically connected to the conductive base via an RF transmission line; a sensor configured to detect at least one first electrical parameter at a node on the RF transmission line; a first storage unit configured to store measurement results of measuring the capacitance of the electrostatic chuck; and a controller, wherein the controller is configured to determine at least one second electrical parameter of a substrate on the substrate support surface based on the at least one first electrical parameter detected by the sensor and the capacitance measurement results stored in the first storage unit.

[0006] According to one exemplary embodiment of the present disclosure, a technique for improving the accuracy of electrical parameters determined using sensors in a plasma processing apparatus can be provided.

[0007] FIG. 1 is a diagram for explaining an example of the configuration of a plasma processing system; FIG. 2 is a diagram for explaining an example of the configuration of a plasma processing apparatus; FIG. 3 is a diagram for explaining an example of the configuration of a sensor and a control unit; FIG. 4 is a diagram for explaining an example of a conversion coefficient; FIG. 5 is a flowchart for explaining an example of a measurement process by a sensor; and FIG. 6 is a flowchart for explaining an example of a process for updating measurement results of the capacitance of an electrostatic chuck.

[0008] Hereinafter, each embodiment of the present disclosure will be described.

[0009] In one exemplary embodiment, a plasma processing apparatus is provided, comprising: a plasma processing chamber; a substrate support disposed within the plasma processing chamber, the substrate support having a conductive base and an electrostatic chuck disposed on the conductive base, the electrostatic chuck having a substrate support surface; an RF power source electrically connected to the conductive base via an RF transmission line; a sensor configured to detect at least one first electrical parameter at a node on the RF transmission line; a first storage unit configured to store measurements of the capacitance of the electrostatic chuck; and a controller, wherein the controller is configured to determine at least one second electrical parameter of a substrate on the substrate support surface based on the at least one first electrical parameter detected by the sensor and the capacitance measurements stored in the first storage unit.

[0010] In one exemplary embodiment, the first storage unit is configured to store a table of measured capacitances for each of a plurality of electrostatic chucks.

[0011] In one exemplary embodiment, the at least one first electrical parameter includes a first voltage and a first current, and the at least one second electrical parameter includes a second voltage and a second current.

[0012] In one exemplary embodiment, the RF power source is configured to supply RF power having a frequency in the range of 100 kHz to 20 MHz to the conductive base via an RF transmission line.

[0013] In one exemplary embodiment, the capacitance is in the range of 2000 pF to 20000 pF.

[0014] In one exemplary embodiment, the control unit is configured to perform the steps of determining a conversion coefficient based on the capacitance measurement results stored in the first storage unit, and determining at least one second electrical parameter based on the at least one first electrical parameter detected by the sensor and the determined conversion coefficient.

[0015] In one exemplary embodiment, the method further comprises a second storage unit configured to store the determined transformation coefficients.

[0016] In one exemplary embodiment, the control unit includes a circuit board and the second housing unit is disposed on the circuit board.

[0017] In one exemplary embodiment, the controller is configured to perform the steps of: performing a plasma processing operation based on a first recipe; and determining whether at least one second electrical parameter determined during the plasma processing operation is within a predetermined range.

[0018] In one exemplary embodiment, the control unit is configured to perform the steps of: modifying the capacitance measurement results stored in the first storage unit when it determines that the at least one second electrical parameter determined during the plasma processing operation is not within a predetermined range; and determining a conversion coefficient based on the modified capacitance measurement results.

[0019] In one exemplary embodiment, a plasma processing apparatus is provided, comprising: a plasma processing chamber; a substrate support disposed within the plasma processing chamber, the substrate support having an electrode and an electrostatic chuck, the electrostatic chuck having a substrate support surface; an RF power source electrically connected to the electrode via an RF transmission line; a sensor configured to detect at least one first electrical parameter at a node on the RF transmission line; a first storage unit configured to store measurements of the capacitance of the electrostatic chuck; and a controller, wherein the controller is configured to determine at least one second electrical parameter of a substrate on the substrate support surface based on the at least one first electrical parameter detected by the sensor and the capacitance measurements stored in the first storage unit.

[0020] In one exemplary embodiment, the electrode is disposed within an electrostatic chuck.

[0021] In one exemplary embodiment, the at least one first electrical parameter includes a first voltage and a first current, and the at least one second electrical parameter includes a second voltage and a second current.

[0022] In one exemplary embodiment, the RF power source is configured to supply RF power having a frequency in the range of 100 kHz to 20 MHz to the electrode via an RF transmission line.

[0023] In one exemplary embodiment, the capacitance is in the range of 2000 pF to 20000 pF.

[0024] In one exemplary embodiment, the control unit is configured to perform the steps of determining a conversion coefficient based on the capacitance measurement results stored in the first storage unit, and determining at least one second electrical parameter based on the at least one first electrical parameter detected by the sensor and the determined conversion coefficient.

[0025] In one exemplary embodiment, the method further comprises a second storage unit configured to store the determined transformation coefficients.

[0026] In one exemplary embodiment, the control unit includes a circuit board and the second housing unit is disposed on the circuit board.

[0027] In one exemplary embodiment, the controller is configured to perform the steps of: performing a plasma processing operation based on a first recipe; and determining whether at least one second electrical parameter determined during the plasma processing operation is within a predetermined range.

[0028] In one exemplary embodiment, the control unit is configured to perform the steps of: modifying the capacitance measurements stored in the first storage unit when it determines that the at least one second electrical parameter determined during the plasma processing operation is not within a predetermined range; and determining a conversion coefficient based on the modified capacitance measurements.

[0029] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings. In each drawing, the same or similar elements are designated by the same reference numerals, and redundant explanations will be omitted. Unless otherwise specified, the positional relationships, such as up, down, left, and right, will be described based on the positional relationships shown in the drawings. The dimensional ratios in the drawings do not represent actual ratios, and the actual ratios are not limited to the ratios shown in the drawings.

[0030] <Example of Plasma Processing System> FIG. 1 is a diagram illustrating an example of the configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust port is connected to an exhaust system 40 (described later). The substrate support 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0031] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma generated in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR plasma), helicon wave plasma (HWP), surface wave plasma (SWP), or the like. Various types of plasma generators may be used, including alternating current (AC) plasma generators and direct current (DC) plasma generators. In one embodiment, the AC signal (AC power) used in the AC plasma generator has a frequency in the range of 100 kHz to 10 GHz. Thus, AC signals include radio frequency (RF) signals and microwave signals. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0032] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform various processes 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 may be implemented by, for example, a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. This program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. 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 random access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0033] The following describes a configuration example of a capacitively coupled plasma processing apparatus as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

[0034] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10 (also simply referred to as the "chamber"), a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one process gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms at least a portion 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, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0035] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also called a substrate support surface for supporting the substrate W, and the annular region 111b is also called a ring support surface for supporting the ring assembly 112.

[0036] In one embodiment, the main body 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. Note that the annular region 111b may also be provided by another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member. 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. Furthermore, at least one RF / DC electrode coupled to an RF power supply 31 and / or a DC power supply 32, which will be 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, which will be described later, is supplied to the at least one RF / DC electrode, the RF / DC electrode is also called a bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as multiple lower electrodes. Furthermore, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0037] 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 rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0038] The substrate support 11 may also 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 passage 1110a, or a combination thereof. A heat transfer fluid such as brine or a gas flows through the flow passage 1110a. In one embodiment, the flow passage 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a.

[0039] The showerhead 13 is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The process gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas inlet may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0040] 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 a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of the at least one process gas.

[0041] 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 power) to at least one lower electrode and / or at least one upper electrode. This generates a plasma 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 the plasma generation unit 12. Furthermore, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, thereby attracting ion components in the formed plasma to the substrate W.

[0042] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating 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 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 generating unit 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0043] The second RF generator 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 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 generator 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0044] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to the at least one lower electrode and configured to generate a first DC signal. The generated first DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to the at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0045] In various embodiments, the first and second DC signals 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 rectangular, trapezoidal, triangular, or combination thereof pulse waveform. In one embodiment, a waveform generator for generating the sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one period. The first and second DC generating units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0046] The exhaust system 40 may be connected to, for example, a gas exhaust 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 is regulated by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0047] 3, in one embodiment, the RF power supply 31 is electrically connected to the conductive base 1110 via an RF transmission line 200. In one embodiment, the RF power supply 31 is configured to supply RF power having a frequency in the range of 100 kHz to 20 MHz to the base 1110 via the RF transmission line 200. The RF power supply 31 is connected to the base 1110 via a matching circuit 210 in the RF transmission line 200. The matching circuit 210 may include an impedance matching circuit.

[0048] In one embodiment, the plasma processing apparatus 1 includes a sensor 250 .

[0049] Sensor 250 is configured to detect at least one first electrical parameter at a node on RF transmission line 200. In one embodiment, the at least one first electrical parameter includes a voltage and a current. That is, sensor 250 can detect the voltage and current of an RF signal at a node on RF transmission line 200. In one embodiment, sensor 250 may be connected to a node on RF transmission line 200 between matching circuit 210 and base 1110. Sensor 250 may also be connected to a node on RF transmission line 200 between matching circuit 210 and RF power source 31.

[0050] In one embodiment, the control unit 2 includes a circuit board 300. The circuit board 300 includes a first storage unit 260 and a second storage unit 261. The first storage unit 260 and the second storage unit 261 may be disposed in the memory unit 2a2 of the control unit 2 shown in FIG.

[0051] 3 is configured to store measurement results of the capacitance of the electrostatic chuck 1111. The measurement results of the capacitance are the results of measuring the capacitance of each individual electrostatic chuck 1111. The measurement results of the capacitance of the electrostatic chuck 1111 may be measured before the electrostatic chuck 1111 is placed on the base 1110 of the substrate support unit 11, or may be measured after the electrostatic chuck 1111 is placed on the base 1110 of the substrate support unit 11. The measurement results of the capacitance of the electrostatic chuck 1111 may be measured with the electrostatic chuck 1111 removed from the chamber 10, or may be measured with the electrostatic chuck 1111 placed in the chamber 10.

[0052] The control unit 2 is configured to determine a conversion coefficient A based on the capacitance measurement results stored in the first storage unit 260. The control unit 2 is also configured to determine at least one second electrical parameter of the substrate on the substrate support surface based on the voltage and current of the RF signal detected by the sensor 250 and the determined conversion coefficient A. The at least one second electrical parameter includes the voltage and the current. That is, the control unit 2 is configured to determine the voltage and the current of the substrate on the substrate support surface.

[0053] 4 , the conversion coefficient A may be a conversion matrix that converts the voltage Vs and current Is detected by the sensor 250 into the voltage Vw and current Iw at the substrate on the substrate support surface. The conversion coefficient A includes a conversion coefficient derived from an equivalent circuit that includes the chamber 10, the substrate support 11, the RF transmission line 200, the matching circuit 210, the sensor 250, and the circuit board 300 of the control unit 2, and may be determined by inputting the measurement results of the capacitance of the electrostatic chuck 1111.

[0054] The second storage unit 261 is configured to store the conversion coefficient A determined in the control unit 2 .

[0055] <Example of Measurement Process by Sensor> FIG. 5 is a flowchart for explaining an example of a measurement process by the sensor 250.

[0056] In the measurement process, first, the measurement result of the capacitance of the electrostatic chuck 1111 is stored in the first storage unit 260 (step ST1 in FIG. 5 ). The capacitance of the electrostatic chuck 1111 may be measured before the electrostatic chuck 1111 is placed on the substrate support unit 11. The measurement result of the capacitance of the electrostatic chuck 1111 may be input from the communication interface 2a3 or an input unit of the control unit 2 and stored in the first storage unit 260. The capacitance of the electrostatic chuck 1111 may be in the range of 2000 pF to 20000 pF.

[0057] Next, the control unit 2 determines a conversion coefficient A based on the capacitance measurement results stored in the first storage unit 260 (step ST2 in FIG. 5 ). The control unit 2 may determine the conversion coefficient A using a calculation tool that calculates the conversion coefficient A by inputting the capacitance measurement results. The calculation tool may be stored in advance in the control unit 2. The determined conversion coefficient A is stored in the second storage unit 261.

[0058] Next, the sensor 250 detects the voltage Vs and current Is of the RF signal at a node on the RF transmission line 200 (step ST3 in FIG. 5 ). The detection of the voltage Vs and current Is of the RF signal is performed while the RF signal is being transmitted from the RF power supply 31 to the base 1110. The detection of the voltage and current of the RF signal may be performed at least one of before the start of plasma processing, during plasma processing, and after plasma processing. At this time, the RF power supply 31 may supply RF power having a frequency in the range of 100 kHz to 20 MHz to the base 1110 via the RF transmission line 200.

[0059] The control unit 2 determines the voltage Vw and current Iw at the substrate on the substrate support surface based on the voltage Vs and current Is of the RF signal detected by the sensor 250 and the determined conversion coefficient A (step ST4 in FIG. 5). The voltage Vw and current Iw may be determined using the formulas shown in FIG. 4. The conversion coefficient A stored in the second storage unit 261 is used.

[0060] According to this exemplary embodiment, the plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support 11, an RF power supply 31, a sensor 250, a first storage unit 260, and a controller 2, and the controller 2 is configured to determine at least one second electrical parameter of a substrate on a substrate support surface based on at least one first electrical parameter detected by the sensor 250 and measurement results of the capacitance of the electrostatic chuck 1111 stored in the first storage unit 260. Generally, the capacitance of an electrostatic chuck varies greatly from one individual to another. However, according to this exemplary embodiment, the plasma processing apparatus 1 determines the electrical parameter taking into account the measurement results of the capacitance of the electrostatic chuck, thereby improving the accuracy of the electrical parameter determined using the sensor.

[0061] <Example of Process for Updating Measurement Results of Capacitance> The measurement results of the capacitance of the electrostatic chuck 1111 may be updated. Fig. 6 is a flowchart for explaining an example of a process for updating the measurement results of the capacitance of the electrostatic chuck 1111. The process for updating the measurement results of the capacitance of the electrostatic chuck 1111 may be executed by the control unit 2.

[0062] First, a plasma processing operation is performed based on a first recipe (step ST10 in FIG. 6 ). The first recipe is a recipe in which the correct voltage and current values ​​(true values) at the substrate on the substrate support surface when the RF power supply 31 supplies an RF signal to the base 1110 via the RF transmission line 200 are known.

[0063] The plasma processing operation includes an operation during an etching process in which a film on the substrate W is etched using plasma. The plasma processing operation is executed by the control unit 2. In the plasma processing operation, a source RF signal for generating plasma is supplied to the base 1110, which is the lower electrode. A bias signal for attracting ions may be supplied to the lower electrode. At this time, a processing gas may be supplied from the shower head 13 to the plasma processing space 10s. The atmosphere in the plasma processing space 10s may be exhausted from the gas exhaust port 10e, and the pressure in the plasma processing space 10s may be reduced to a predetermined pressure. Plasma may be generated in the plasma processing space 10s.

[0064] Next, during the plasma processing operation, the voltage Vw and current Iw of the substrate on the substrate support surface are determined by the sensor 250 and the control unit 2 (step ST11 in FIG. 6 ). As in steps ST3 and ST4 described above, the voltage Vw and current Iw are determined by the sensor 250 detecting the voltage Vs and current Is of the RF signal at a node on the RF transmission line 200, and then the control unit 2 determines the voltage Vw and current Iw of the substrate on the substrate support surface based on the voltage Vs and current Is of the RF signal detected by the sensor 250 and the conversion coefficient A.

[0065] Next, the control unit 2 determines whether the voltage Vw and current Iw of the substrate on the substrate support surface determined during the plasma processing operation are within a predetermined range (step ST12 in FIG. 6 ), which is set based on the correct voltage and current values ​​in the first recipe.

[0066] Next, if the control unit 2 determines that the voltage Vw and current Iw of the substrate on the substrate support surface determined during the plasma processing operation are within the predetermined ranges, the update process is terminated. If the control unit 2 determines that the voltage Vw and current Iw of the substrate on the substrate support surface determined during the plasma processing operation are not within the predetermined ranges, the capacitance measurement results stored in the first storage unit 260 are changed (step ST13 in FIG. 6 ).

[0067] The control unit 2 determines and changes the conversion coefficient A based on the changed capacitance measurement result (step ST14 in FIG. 6 ). As in step ST2 described above, the conversion coefficient A may be determined by using a calculation tool in the control unit 2 that calculates the conversion coefficient A by inputting the capacitance measurement result. The determined conversion coefficient A is stored in the second storage unit 261. Then, in the next measurement process using the sensor, the changed conversion coefficient stored in the second storage unit 261 is used.

[0068] According to this exemplary embodiment, the accuracy of the electrical parameters determined using the sensors can be improved even when the capacitance of the electrostatic chuck 1111 changes over time.

[0069] The first storage unit 260 may be configured to store a table of measured capacitances for a plurality of electrostatic chucks. The plurality of electrostatic chucks may be used in the same plasma processing apparatus 1 or may be used in different plasma processing apparatuses 1.

[0070] In the above embodiments, the substrate support includes a conductive base and an electrostatic chuck, and the RF power supply is electrically connected to the conductive base via an RF transmission line. However, the substrate support may include an electrode and an electrostatic chuck, and the RF power supply may be electrically connected to the electrode via an RF transmission line. That is, the plasma processing apparatus may include a plasma processing chamber, a substrate support disposed in the plasma processing chamber and having an electrode and an electrostatic chuck, an RF power supply electrically connected to the electrode via an RF transmission line, a sensor configured to detect at least one first electrical parameter at a node on the RF transmission line, a first storage unit configured to store measurement results of the capacitance of the electrostatic chuck, and a controller. The controller may be configured to determine at least one second electrical parameter of a substrate on a substrate support surface based on the at least one first electrical parameter detected by the sensor and the capacitance measurement results stored in the first storage unit. In this example, the electrode may be disposed within the electrostatic chuck or may be disposed separately from the electrostatic chuck.

[0071] Embodiments of the present disclosure further include the following aspects.

[0072] (Supplementary Note 1) A plasma processing apparatus comprising: a plasma processing chamber; a substrate support disposed within the plasma processing chamber, the substrate support having a conductive base and an electrostatic chuck disposed on the conductive base, the electrostatic chuck having a substrate support surface; an RF power source electrically connected to the conductive base via an RF transmission line; a sensor configured to detect at least one first electrical parameter at a node on the RF transmission line; a first storage unit configured to store measurement results of a capacitance of the electrostatic chuck; and a controller, wherein the controller is configured to determine at least one second electrical parameter of a substrate on the substrate support surface based on the at least one first electrical parameter detected by the sensor and the capacitance measurement results stored in the first storage unit.

[0073] (Supplementary Note 2) The plasma processing apparatus according to Supplementary Note 1, wherein the first storage unit is configured to store a table of electrostatic capacitances measured for each of a plurality of electrostatic chucks.

[0074] (Supplementary Note 3) The plasma processing apparatus according to Supplementary Note 1 or 2, wherein the at least one first electrical parameter includes a first voltage and a first current, and the at least one second electrical parameter includes a second voltage and a second current.

[0075] (Supplementary Note 4) The plasma processing apparatus according to any one of Supplementary Notes 1 to 3, wherein the RF power source is configured to supply RF power having a frequency in a range of 100 kHz to 20 MHz to the conductive base via the RF transmission line.

[0076] (Supplementary Note 5) The plasma processing apparatus according to any one of Supplementary Notes 1 to 4, wherein the capacitance is in a range of 2000 pF to 20000 pF.

[0077] (Supplementary Note 6) The plasma processing apparatus according to any one of Supplementary Notes 1 to 5, wherein the control unit is configured to execute the steps of: determining a conversion coefficient based on the measurement results of the capacitance stored in the first storage unit; and determining the at least one second electrical parameter based on the at least one first electrical parameter detected by the sensor and the determined conversion coefficient.

[0078] (Supplementary Note 7) The plasma processing apparatus according to Supplementary Note 6, further comprising: a second storage unit configured to store the determined conversion coefficient.

[0079] (Supplementary Note 8) The plasma processing apparatus according to Supplementary Note 7, wherein the control unit includes a circuit board, and the second storage unit is disposed on the circuit board.

[0080] (Supplementary Note 9) The plasma processing apparatus according to any one of Supplementary Notes 6 to 8, wherein the control unit is configured to perform the steps of: performing a plasma processing operation based on a first recipe; and determining whether the at least one second electrical parameter determined during the plasma processing operation is within a predetermined range.

[0081] (Supplementary Note 10) The plasma processing apparatus according to Supplementary Note 9, wherein the control unit is configured to execute the steps of: changing the capacitance measurement results stored in the first storage unit when it is determined that the at least one second electrical parameter determined during the plasma processing operation is not within a predetermined range; and determining a conversion coefficient based on the changed capacitance measurement results.

[0082] (Supplementary Note 11) A plasma processing apparatus comprising: a plasma processing chamber; a substrate support disposed within the plasma processing chamber, the substrate support having an electrode and an electrostatic chuck, the electrostatic chuck having a substrate support surface; an RF power supply electrically connected to the electrode via an RF transmission line; a sensor configured to detect at least one first electrical parameter at a node on the RF transmission line; a first storage unit configured to store measurement results of a capacitance of the electrostatic chuck; and a controller, wherein the controller is configured to determine at least one second electrical parameter of a substrate on the substrate support surface based on the at least one first electrical parameter detected by the sensor and the capacitance measurement results stored in the first storage unit.

[0083] (Supplementary Note 12) The plasma processing apparatus according to Supplementary Note 11, wherein the electrode is disposed within the electrostatic chuck.

[0084] (Supplementary Note 13) The plasma processing apparatus according to Supplementary Note 11 or 12, wherein the at least one first electrical parameter includes a first voltage and a first current, and the at least one second electrical parameter includes a second voltage and a second current.

[0085] (Supplementary Note 14) The plasma processing apparatus according to any one of Supplementary Notes 11 to 13, wherein the RF power supply is configured to supply RF power having a frequency in a range of 100 kHz to 20 MHz to the electrode via the RF transmission line.

[0086] (Supplementary Note 15) The plasma processing apparatus according to any one of Supplementary Notes 11 to 14, wherein the capacitance is in a range of 2000 pF to 20000 pF.

[0087] (Supplementary Note 16) The plasma processing apparatus according to any one of Supplementary Notes 11 to 15, wherein the control unit is configured to execute the steps of: determining a conversion coefficient based on the measurement results of the capacitance stored in the first storage unit; and determining the at least one second electrical parameter based on the at least one first electrical parameter detected by the sensor and the determined conversion coefficient.

[0088] (Supplementary Note 17) The plasma processing apparatus according to Supplementary Note 16, further comprising: a second storage unit configured to store the determined conversion coefficient.

[0089] (Supplementary Note 18) The plasma processing apparatus according to Supplementary Note 17, wherein the control unit includes a circuit board, and the second storage unit is disposed on the circuit board.

[0090] (Supplementary Note 19) The plasma processing apparatus according to any one of Supplementary Notes 16 to 18, wherein the control unit is configured to perform the steps of: performing a plasma processing operation based on a first recipe; and determining whether the at least one second electrical parameter determined during the plasma processing operation is within a predetermined range.

[0091] (Supplementary Note 20) The plasma processing apparatus according to Supplementary Note 19, wherein the control unit is configured to execute the steps of: modifying the capacitance measurement results stored in the first storage unit when it is determined that the at least one second electrical parameter determined during the plasma processing operation is not within a predetermined range; and determining a conversion coefficient based on the modified capacitance measurement results.

[0092] The above embodiments are described for the purpose of explanation and are not intended to limit the scope of the present disclosure. Various modifications can be made to the above embodiments without departing from the scope and spirit of the present disclosure. For example, some components in one embodiment can be added to other embodiments. Also, some components in one embodiment can be replaced with corresponding components in other embodiments.

[0093] REFERENCE SIGNS LIST 1: plasma processing apparatus, 2: control unit, 10: chamber, 11: substrate support unit, 31: RF power supply, 1110: base, 1111: electrostatic chuck, 200: RF transmission line, 250: sensor, 260: first storage unit, 261: second storage unit, W: substrate

Claims

1. A plasma processing apparatus comprising: a plasma processing chamber; a substrate support disposed within the plasma processing chamber, the substrate support having a conductive base and an electrostatic chuck disposed on the conductive base, the electrostatic chuck having a substrate support surface; an RF power source electrically connected to the conductive base via an RF transmission line; a sensor configured to detect at least one first electrical parameter at a node on the RF transmission line; a first storage unit configured to store measurements of the capacitance of the electrostatic chuck; and a controller, wherein the controller is configured to determine at least one second electrical parameter of a substrate on the substrate support surface based on the at least one first electrical parameter detected by the sensor and the capacitance measurements stored in the first storage unit.

2. The plasma processing apparatus according to claim 1, wherein the first storage unit is configured to store a table of capacitances measured for each of a plurality of electrostatic chucks.

3. The plasma processing apparatus of claim 1, wherein the at least one first electrical parameter comprises a first voltage and a first current, and the at least one second electrical parameter comprises a second voltage and a second current.

4. The plasma processing apparatus of claim 3, wherein the RF power source is configured to supply RF power having a frequency in the range of 100 kHz to 20 MHz to the conductive base via the RF transmission line.

5. The plasma processing apparatus according to claim 4, wherein the capacitance is in the range of 2000 pF to 20000 pF.

6. A plasma processing apparatus according to any one of claims 1 to 5, wherein the control unit is configured to execute the steps of: determining a conversion coefficient based on the measurement results of the capacitance stored in the first storage unit; and determining the at least one second electrical parameter based on the at least one first electrical parameter detected by the sensor and the determined conversion coefficient.

7. The plasma processing apparatus according to claim 6, further comprising: a second storage unit configured to store the determined conversion coefficient.

8. The plasma processing apparatus according to claim 7, wherein the control unit includes a circuit board, and the second storage unit is disposed on the circuit board.

9. The plasma processing apparatus of claim 6, wherein the control unit is configured to perform the steps of: performing a plasma processing operation based on a first recipe; and determining whether the at least one second electrical parameter determined during the plasma processing operation is within a predetermined range.

10. The plasma processing apparatus of claim 9, wherein the control unit is configured to execute the steps of: modifying the capacitance measurement results stored in the first storage unit when it is determined that the at least one second electrical parameter determined during the plasma processing operation is not within a predetermined range; and determining a conversion coefficient based on the modified capacitance measurement results.

11. A plasma processing apparatus comprising: a plasma processing chamber; a substrate support disposed within the plasma processing chamber, the substrate support having an electrode and an electrostatic chuck, the electrostatic chuck having a substrate support surface; an RF power source electrically connected to the electrode via an RF transmission line; a sensor configured to detect at least one first electrical parameter at a node on the RF transmission line; a first storage unit configured to store measurements of the capacitance of the electrostatic chuck; and a controller, wherein the controller is configured to determine at least one second electrical parameter of a substrate on the substrate support surface based on the at least one first electrical parameter detected by the sensor and the capacitance measurements stored in the first storage unit.

12. The plasma processing apparatus according to claim 11, wherein the electrode is disposed within the electrostatic chuck.

13. The plasma processing apparatus of claim 11, wherein the at least one first electrical parameter comprises a first voltage and a first current, and the at least one second electrical parameter comprises a second voltage and a second current.

14. The plasma processing apparatus of claim 13, wherein the RF power source is configured to supply RF power having a frequency in the range of 100 kHz to 20 MHz to the electrode via the RF transmission line.

15. The plasma processing apparatus according to claim 14, wherein the capacitance is in the range of 2000 pF to 20000 pF.

16. A plasma processing apparatus according to any one of claims 11 to 15, wherein the control unit is configured to execute the steps of: determining a conversion coefficient based on the measurement results of the capacitance stored in the first storage unit; and determining the at least one second electrical parameter based on the at least one first electrical parameter detected by the sensor and the determined conversion coefficient.

17. The plasma processing apparatus of claim 16, further comprising: a second storage unit configured to store the determined conversion coefficient.

18. The plasma processing apparatus according to claim 17, wherein the control unit includes a circuit board, and the second storage unit is disposed on the circuit board.

19. The plasma processing apparatus of claim 16, wherein the controller is configured to: perform a plasma processing operation based on a first recipe; and determine whether the at least one second electrical parameter determined during the plasma processing operation is within a predetermined range.

20. The plasma processing apparatus of claim 19, wherein the control unit is configured to execute the steps of: modifying the capacitance measurement results stored in the first storage unit when it is determined that the at least one second electrical parameter determined during the plasma processing operation is not within a predetermined range; and determining a conversion coefficient based on the modified capacitance measurement results.

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