Plasma Processing Apparatus and Endpoint Detection Method

Abstract

To accurately detect the end point of plasma processing.SOLUTION: A measurement unit is provided on an electrode arranged in a chamber or on wiring connected to the electrode, and measures either voltage or current. A gas supply unit supplies a gas to be converted into plasma into the chamber. A high-frequency power source supplies high-frequency power to the chamber in a pulsed manner to convert the gas supplied into the chamber into plasma. A detection unit detects the end point of the plasma processing from any change in the voltage, current, or phase difference between the voltage and the current measured by the measurement unit at timing synchronized with the cycle of the high-frequency power pulse.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a plasma processing apparatus and an endpoint detection method.

Background Art

[0002] Patent Document 1 discloses a technique for detecting an etching endpoint (endpoint) from a signal measured by a VI probe during plasma etching.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique for accurately detecting the endpoint of plasma processing.

Means for Solving the Problems

[0005] A plasma processing apparatus according to an aspect of the present disclosure includes a chamber, an electrode, a measurement unit, a gas supply unit, a high-frequency power source, and a detection unit. The chamber is provided with a mounting table on which a substrate is mounted inside. The electrode is disposed inside the chamber. The measurement unit is provided on the electrode or a wiring connected to the electrode and measures either voltage or current. The gas supply unit supplies a gas to be plasmaized into the chamber. The high-frequency power source supplies high-frequency power for plasmaizing the gas supplied into the chamber to the chamber in a pulsed manner. The detection unit detects the endpoint of plasma processing from a change in any of the voltage, current, and phase difference between voltage and current measured by the measurement unit at a timing synchronized with the period of the pulse of the high-frequency power.

Effects of the Invention

[0006] According to the present disclosure, the end point of plasma processing can be accurately detected.

Brief Description of the Drawings

[0007]

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[0008] Hereinafter, embodiments of the plasma processing apparatus and the endpoint detection method disclosed in the present application will be described in detail with reference to the drawings. Note that the plasma processing apparatus and the endpoint detection method disclosed are not limited by the present embodiment.

[0009] In plasma etching, in order to prevent excessive etching and suppress fluctuations in the pattern shape, a method of detecting the endpoint of etching in real time and stopping the etching process is applied. As a conventional method for detecting the endpoint of etching, for example, there is a method of detecting the endpoint of etching from a change in the emission intensity of plasma during etching using an OES (Optical Emission Sensor). In addition, there is a method of detecting the endpoint of etching from a signal measured by a VI probe during plasma etching.

[0010] By the way, compared with conventional etching in which a high-frequency (RF) power of constant power is applied over time, cycle etching in which RF power is repeatedly applied in a pulsed manner is effective in improving processing accuracy. Cycle etching is becoming the mainstream of etching, starting from processes with strict processing accuracy. However, with conventional methods for detecting the endpoint of etching, the endpoint of etching cannot be detected accurately. Therefore, a technique for accurately detecting the endpoint of etching is expected.

[0011] In addition, in a plasma processing apparatus, cleaning is performed to remove depositions adhering in a plasma processing chamber using plasma. Even in such cleaning, a technique of repeatedly applying RF power in a pulsed manner is effective for removing depositions. In order to prevent excessive etching in the plasma processing chamber by plasma even during cleaning, a technique for accurately detecting the end point of cleaning is expected.

[0012] As described above, a technique for accurately detecting the end point of plasma processing such as etching and cleaning is expected.

[0013] [First Embodiment] [Apparatus Configuration] In the first embodiment, a case of detecting the end point of plasma processing for etching a substrate will be described. An example of the plasma processing apparatus of the present disclosure will be described. FIG. 1 is a diagram showing an example of a schematic configuration of a plasma processing apparatus 1 according to the first embodiment.

[0014] Hereinafter, a configuration example of a capacitively coupled plasma processing apparatus as an example of the plasma processing apparatus 1 will be described. 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. Further, the plasma processing apparatus 1 includes a substrate support unit 11 and a gas introduction unit. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes a shower head 13. The substrate support unit 11 is disposed in the plasma processing chamber 10. The shower head 13 is disposed above the substrate support unit 11. In one embodiment, the shower head 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 shower head 13, the side wall 10a of the plasma processing chamber 10, and the substrate support unit 11. The side wall 10a is grounded. The shower head 13 and the substrate support unit 11 are electrically insulated from the plasma processing chamber 10 housing.

[0015] 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 (substrate support surface) 111a for supporting a substrate (wafer) W and an annular region (ring support surface) 111b for supporting the ring assembly 112. The annular region 111b of the main body portion 111 surrounds the central region 111a of the main body portion 111 in a plan 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. In one embodiment, the main body portion 111 includes a base and an electrostatic chuck. The base includes a conductive member. The conductive member of the base functions as a lower electrode. The electrostatic chuck is disposed on the base. The upper surface of the electrostatic chuck has the substrate support surface 111a. The ring assembly 112 includes one or more annular members. At least one of the one or more annular members is an edge ring. Also, although not shown, the substrate support portion 11 may include a temperature control module configured to adjust at least one of the electrostatic chuck, the ring assembly 112, and the substrate to a target temperature. The temperature control module may include a heater, a heat transfer medium, a flow path, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path. Further, the substrate support portion 11 may include a heat transfer gas supply portion configured to supply a heat transfer gas between the back surface of the substrate W and the substrate support surface 111a.

[0016] 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 a plurality of gas introduction ports 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 plurality of gas introduction ports 13c. Further, the showerhead 13 includes a conductive member. The conductive member of the showerhead 13 functions as an upper electrode. Note that the gas introduction unit may include, in addition to the showerhead 13, one or more side gas injectors (SGI) attached to one or more openings formed in the sidewall 10a.

[0017] 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 corresponding gas source 21 to the showerhead 13 via the corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Further, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of at least one process gas.

[0018] 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) such as a source RF signal and a bias RF signal to the conductive member of the substrate support 11 and / or the conductive member of the showerhead 13. Thereby, plasma is formed from at least one process 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. Further, by supplying a bias RF signal to the conductive member of the substrate support 11, a bias potential is generated on the substrate W, and the ion component in the formed plasma can be drawn into the substrate W.

[0019] 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 the conductive member of the substrate support unit 11 and / or the conductive member of the shower head 13 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 13 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 generated one or more source RF signals are supplied to the conductive member of the substrate support unit 11 and / or the conductive member of the shower head 13. The second RF generation unit 31b is coupled to the conductive member of the substrate support unit 11 via at least one impedance matching circuit, and is configured to generate a bias RF signal (bias RF power). In one embodiment, the bias RF signal has the same frequency as the source RF signal or a frequency lower than the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 400 kHz to 50 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 generated one or more bias RF signals are supplied to the conductive member of the substrate support unit 11. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0020] For example, the first RF generation unit 31a is electrically connected to the conductive member of the shower head 13 via a conductive part 33a such as a wiring. An impedance matching circuit 34a is provided in the conductive part 33a. The impedance matching circuit 34a matches the output impedance of the first RF generation unit 31a and the input impedance on the load side (the shower head 13 side). The first RF generation unit 31a supplies the first high-frequency power of the first frequency for generating plasma to the conductive member of the shower head 13. For example, the first RF generation unit 31a supplies the above-described source RF signal as the first high-frequency power to the conductive member of the shower head 13 via the conductive part 33a and the impedance matching circuit 34a. The source RF signal is, for example, 60 MHz. The conductive member of the shower head 13 functions as an electrode. When the source RF signal is supplied, high-density plasma is generated in the plasma processing chamber 10.

[0021] Also, for example, the second RF generation unit 31b is electrically connected to the conductive member of the base of the substrate support unit 11 via a conductive part 33b such as a wiring. An impedance matching circuit 34b is provided in the conductive part 33b. The impedance matching circuit 34b matches the output impedance of the second RF generation unit 31b and the input impedance on the load side (the substrate support unit 11 side). The second RF generation unit 31b supplies the second high-frequency power of a second frequency lower than the first frequency for drawing the ion component in the plasma to the substrate W to the conductive member of the substrate support unit 11. For example, the second RF generation unit 31b supplies the above-described bias RF signal as the second high-frequency power to the conductive member of the substrate support unit 11 via the conductive part 33b and the impedance matching circuit 34b. The bias RF signal is, for example, 40 MHz. The conductive member of the substrate support unit 11 functions as an electrode. When the bias RF signal is supplied, the ion component in the plasma generated in the plasma processing chamber 10 is drawn to the substrate W.

[0022] The plasma processing apparatus 1 according to the present embodiment supplies high-frequency power from the RF power source 31 to the plasma processing chamber 10 in a pulsed manner in order to perform cycle etching. For example, at least one of the first RF generation unit 31a and the second RF generation unit 31b of the RF power source 31 supplies high-frequency power in a pulsed manner.

[0023] The plasma processing apparatus 1 is provided with a measurement unit 35 that measures either voltage or current on an electrode disposed in the plasma processing chamber 10 or a wiring connected to the electrode. In the present embodiment, the measurement unit 35 is provided on a conductive portion 33b connected to the conductive member of the substrate support unit 11. The measurement unit 35 includes a probe that detects current and voltage, and measures the voltage and current. The measurement unit 35 measures the voltage and current of the conductive portion 33b through which the bias RF signal flows, and outputs a signal indicating the measured voltage and current to a control unit 100 described later.

[0024] Further, the power source 30 may include a DC power source 32 coupled to the plasma processing chamber 10. The DC power source 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 the conductive member of the substrate support unit 11 and is configured to generate a first DC signal. The generated first DC signal is applied to the conductive member of the substrate support unit 11. In one embodiment, the first DC signal may be applied to another electrode such as an electrode in the electrostatic chuck. In one embodiment, the second DC generation unit 32b is connected to the conductive member of the shower head 13 and is configured to generate a second DC signal. The generated second DC signal is applied to the conductive member of the shower head 13. In various embodiments, the first and second DC signals may be pulsed. Note that the first and second DC generation units 32a and 32b may be provided in addition to the RF power source 31, or the first DC generation unit 32a may be provided in place of the second RF generation unit 31b.

[0025] The exhaust system 40 can be connected to, for example, 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 is adjusted by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0026] The plasma processing apparatus 1 configured as described above further includes a control unit 100 described later. FIG. 2 is a block diagram showing an example of the schematic configuration of the control unit 100 according to the first embodiment. The operation of the plasma processing apparatus 1 shown in FIG. 1 is comprehensively controlled by the control unit 100.

[0027] The control unit 100 is, for example, a computer and controls each part of the plasma processing apparatus 1. The operation of the plasma processing apparatus 1 is comprehensively controlled by the control unit 100. The control unit 100 performs control to cause the plasma processing apparatus 1 to execute various processes described in the present disclosure. The control unit 100 is provided with an external interface 101, a process controller 102, a user interface 103, and a storage unit 104.

[0028] The external interface 101 is capable of communicating with each part of the plasma processing apparatus 1 and inputs and outputs various data. For example, signals indicating the voltage and current measured by the measurement unit 35 are input to the external interface 101.

[0029] The process controller 102 includes a CPU (Central Processing Unit) and controls each part of the plasma processing apparatus 1.

[0030] The user interface 103 is composed of a keyboard for a process manager to input commands for managing the plasma processing apparatus 1, a display for visualizing and displaying the operating status of the plasma processing apparatus 1, and the like.

[0031] The storage unit 104 stores a control program (software) for realizing various processes executed by the plasma processing apparatus 1 under the control of the process controller 102, and a recipe in which processing condition data and the like are stored. Note that the control program and the recipe may be in a state stored in a computer-readable recording medium (for example, an optical disk such as a hard disk or a DVD, a flexible disk, a semiconductor memory, etc.). Further, the control program and the recipe can be transmitted from other devices at any time via, for example, a dedicated line and used online.

[0032] The process controller 102 has an internal memory for storing programs and data, reads out the control program stored in the storage unit 104, and executes the processing of the read control program. The process controller 102 functions as various processing units when the control program operates. For example, the process controller 102 has the functions of a plasma control unit 102a and a detection unit 102b. In this embodiment, a case where the process controller 102 has the functions of the plasma control unit 102a and the detection unit 102b will be described as an example. However, the functions of the plasma control unit 102a and the detection unit 102b may be realized in a distributed manner by a plurality of controllers.

[0033] The plasma control unit 102a controls plasma processing. For example, the plasma control unit 102a controls the exhaust system 40 to exhaust the inside of the plasma processing chamber 10 to a predetermined degree of vacuum. The plasma control unit 102a controls the gas supply unit 20 to introduce a processing gas from the gas supply unit 20 into the plasma processing space 10s. The plasma control unit 102a controls the power supply 30, and in accordance with the introduction of the processing gas, supplies a source RF signal and a bias RF signal from the first RF generation unit 31a and the second RF generation unit 31b to generate plasma in the plasma processing chamber 10.

[0034] The plasma processing apparatus 1 according to this embodiment performs cycle etching. The plasma control unit 102a controls the RF power supply 31 and supplies high-frequency power from the RF power supply 31 in a pulsed manner. The RF power supply 31 supplies at least one of a source RF signal and a bias RF signal in a pulsed manner. For example, the plasma control unit 102a controls the RF power supply 31 to supply the source RF signal and the bias RF signal from the first RF generation unit 31a and the second RF generation unit 31b in a pulsed manner, respectively. The frequency of the pulses for turning on and off the supply of the source RF signal and the bias RF signal is set to 100 Hz to 10 kHz. Hereinafter, among the source RF signal and the bias RF signal, the source RF signal with a higher frequency is also referred to as HF (High Frequency), and the bias RF signal with a lower frequency is also referred to as LF (Low Frequency).

[0035] The detection unit 102b detects the end point of the plasma process from the voltage and current of the signal input from the measurement unit 35. For example, the detection unit 102b detects the end point of the plasma process from a change in any of the voltage, current, and the phase difference between the voltage and current measured by the measurement unit 35 at a timing synchronized with the period of the pulse of the high-frequency power. In this embodiment, the detection unit 102b detects the end point of the etching from a change in any of the voltage, current, and the phase difference between the voltage and current measured by the measurement unit 35 at a timing synchronized with the period of the pulse of the high-frequency power. The detection unit 102b detects the end point of the etching from a change in any of the voltage, current, and the phase difference between the voltage and current measured by the measurement unit 35 at a timing when the combination of the supplied source RF signal and bias RF signal contributes most to the etching and the selectivity. For example, in this embodiment, the period during which the bias RF signal is supplied contributes most to the etching and the selectivity. The detection unit 102b detects the end point of the etching from a change in any of the voltage, current, and the phase difference between the voltage and current measured by the measurement unit 35 during the period when the bias RF signal is supplied.

[0036] Based on the detection result of the detector 102b, the plasma control unit 102a controls the plasma process. For example, when the detector 102b detects the end point of etching, the plasma control unit 102a terminates the plasma etching.

[0037] Here, the detection of the end point of etching will be specifically described. FIG. 3 is a diagram for explaining the detection of the end point of etching according to the first embodiment. FIG. 3 shows the periods during which the source RF signal and the bias RF signal are supplied. "HF" indicates the period during which the source RF signal is supplied. "LF" indicates the period during which the bias RF signal is supplied. The source RF signal and the bias RF signal are each supplied during the On period. In FIG. 3, the source RF signal and the bias RF signal are each supplied in a pulsed manner without overlapping periods. In FIG. 3, the frequencies of the pulses for turning the source RF signal and the bias RF signal On and Off are set to 1 kHz, and the source RF signal and the bias RF signal are turned On and Off at a period of 1 ms to perform cycle etching.

[0038] FIG. 3 shows the follow-up characteristics of radicals, ions, and electrons included in the plasma. The follow-up of radicals to the on and off of the high-frequency power is 1 ms or more. For this reason, during one cycle of on and off, radicals generated at different pulse levels are mixed. For example, during the On period of LF, radicals generated during the previous On period of HF and radicals generated when LF becomes On are mixed. Therefore, when detecting the end point of etching for radicals such as by-products generated at a specific pulse level, radicals generated at other pulse levels and the trailing near their signal wavelengths become noise. For example, during the On period of LF, radicals generated during the previous On period of HF become noise.

[0039] On the other hand, the follow-up of ions and electrons to the on and off of the high-frequency power is 0.1 ms or less. For this reason, in cycle etching using RF pulses of 100 Hz to 10 kHz, interference due to different pulse levels does not occur.

[0040] FIG. 4 is a diagram for explaining the detection of the end point of conventional etching. In the case of cycle etching, the plasma contains radicals generated at different pulse levels as described above. For this reason, even if the emission intensity of the plasma during etching is detected by OES and the end point of etching is detected from the change in the detected emission intensity, the end point of etching cannot be accurately detected. For example, even if an attempt is made to detect the end point of etching from the change in the emission intensity of the plasma during the LF on period, since the emission due to the radicals during the HF on period is mixed during the LF on period, the end point of etching cannot be accurately detected.

[0041] Here, an example of detecting the end point of etching will be described. FIG. 5 is a diagram showing an example of a substrate W to be etched according to the first embodiment. The case where the SAC (Self-Aligned Contact) process is performed on the substrate W is shown. The substrate W has a plurality of transistors 120 formed thereon. An oxide film 121 such as a SiO2 film is formed on the transistor 120. A pattern 122 is formed on the oxide film 121. In the SAC process, the oxide film 121 is etched using the pattern 122 as a mask. For example, the plasma processing apparatus 1 performs etching of the oxide film 121 in the SAC process by cycle etching using a processing gas containing C4F6 gas, Ar gas, and O2 gas as the etching gas. During etching, the components of the etched oxide film 121 are continuously released into the plasma, but when the etching of the oxide film 121 ends, the release of the components of the oxide film 121 disappears and the characteristics of the plasma change. The detection unit 102b detects the end of etching from any change in the voltage, current, or phase difference between the voltage and current measured by the measurement unit 35.

[0042] FIG. 6 is a diagram for explaining the detection of the end point of etching according to the first embodiment. FIG. 6 schematically shows the change in the emission intensity measured by OES in the period before just-etch when the etching of the oxide film 121 is just about to end and the period after just-etch. Since the signals of HF on and LF on overlap in the signal measured by OES, the end point of etching cannot be accurately detected. Further, FIG. 6 schematically shows the change in the signal (VI signal) measured by the measuring unit 35 in each period when HF and LF are supplied in the period before just-etch and the period after just-etch. The signal (VI signal) roughly shows the change in the voltage and current measured by the measuring unit 35, and the signal is divided into "HF" and "LF" corresponding to the periods when HF and LF are respectively supplied. The "HF" signal changes little before and after just-etch. On the other hand, the "LF" signal changes greatly before and after just-etch. FIG. 7 is a diagram for explaining an example of the detection of the end of etching according to the first embodiment. FIG. 7 shows the change in the "LF" signal (VI signal) during the etching of the oxide film 121. The "LF" signal changes greatly before and after the timing of just-etch of the oxide film 121. Therefore, by measuring the change in the voltage and current during the period when LF is supplied, the end of etching can be accurately detected.

[0043] The detection unit 102b detects the etching status from the voltage and current of the signal input from the measurement unit 35. For example, the detection unit 102b detects the end of the etching of the oxide film 121 as the etching status from any change in the voltage, current, or phase difference between the voltage and current measured by the measurement unit 35 during the period when the bias RF signal is supplied. The detection unit 102b monitors the voltage, current, and phase difference between the voltage and current measured by the measurement unit 35 in real time, and regards the moment when a significant change occurs as the end point of the etching. General mathematical methods for reducing noise, such as moving average and time differentiation, may be applied to the data processing for detecting the end point by the detection unit 102b. The measurement unit 35 may extract a signal of a specific frequency by passing the voltage and current signals through a frequency filter.

[0044] Here, during cycle etching, for example, when the end point of the etching is detected from the moving average of the signal continuously measured by a VI probe as in the prior art, the signal during the period other than the period when LF is supplied becomes noise, and the end point of the etching cannot be accurately detected.

[0045] On the other hand, in the cycle etching of the present embodiment shown in FIG. 3, the period when the bias RF signal is supplied contributes most to the etching and the selectivity. Therefore, the detection unit 102b can accurately detect the end of the etching by detecting the end of the etching of the oxide film 121 from any change in the voltage, current, or phase difference between the voltage and current measured by the measurement unit 35 during the period when the bias RF signal is supplied.

[0046] Incidentally, as semiconductor devices are miniaturized, the proportion of the area of the substrate W to be etched is decreasing. For example, in the substrate W shown in FIG. 5, as the miniaturization progresses, the diameter of the opening of the pattern 122 to be used as a mask becomes smaller, and the proportion of the area where the oxide film 121 is exposed is decreasing. Therefore, the accuracy of endpoint detection of etching when the proportion of the area of the substrate W to be etched changes will be described. FIGS. 8A and 8B are diagrams showing an example of the substrate W according to the first embodiment. FIG. 8A is a top view of the substrate W. FIG. 8B is a side view of the substrate W. The substrate W has a chip 131 provided on a bare wafer 130. The chip 131 has an oxide film 133 such as a SiO2 film formed on a silicon film 132. The substrate W can change the proportion of the area of the oxide film 133 to the surface area of the substrate W by changing the surface area of the chip 131. Substrates W with the proportion of the area of the oxide film 133 to the surface area of the substrate W being 0%, 0.04%, 0.1%, 0.6%, 1%, and 4% were prepared respectively. Then, the plasma processing apparatus 1 according to the present embodiment performed cycle etching on the oxide film 133 of each substrate W, and the measurement unit 35 measured the voltage and current during the period when the bias RF signal was supplied.

[0047] FIG. 9 is a diagram for explaining an example of the measurement results by the measurement unit 35 according to the first embodiment. FIG. 9 shows the measurement results of the voltage and current measured by the measurement unit 35 when cycle etching was performed on substrates W with the proportion of the area of the oxide film 133 to the surface area of the substrate W being 0%, 0.04%, 0.1%, 0.6%, 1%, and 4% respectively. In FIG. 9, the peak-to-peak value V PP of the voltage V measured by the measurement unit 35 is divided by the peak-to-peak value I PP of the current I to obtain V PP / I PPThe waveform of the change in the value of is shown as the measurement result. That is, FIG. 9 shows the change in the resistance value in the measurement unit 35. Also, on the right side of FIG. 9, enlarged views of the waveforms of the substrate W at 0%, 0.04%, 0.1%, and 0.6% are shown. Further, FIG. 9 shows the just-etch timing T1 of the oxide film 133. As shown in FIG. 9, in the substrates W of 0.04%, 0.1%, 0.6%, 1%, and 4%, the waveform changes before and after the just-etch timing T1, and particularly at 0.6% or more, the waveform changes significantly. From this, the end point of etching can be detected.

[0048] Here, as a comparative example, the change in the emission intensity measured by OES will be described. FIG. 10 is a diagram for explaining an example of the measurement result by OES of the comparative example. FIG. 10 shows the waveforms of the change in the emission intensity measured by OES when the above-described substrates W of 0%, 0.04%, 0.1%, 0.6%, 1%, and 4% are each subjected to cycle etching. Further, FIG. 10 shows the just-etch timing T2 of the oxide film 133. When comparing FIGS. 9 and 10, the change in the waveform before and after just-etch is larger in the measurement result by the measurement unit 35 according to the embodiment than in the comparative example, and the S / n ratio for detecting the end point of etching is better. Therefore, the measurement unit 35 according to the embodiment can detect the end point of etching with higher accuracy than the comparative example.

[0049] In FIG. 9, the voltage and current V measured by the measurement unit 35 PP / I PPThe case where the end point of etching is detected from the change in the value of

[0050] has been described by taking as an example the case where the measurement unit 35 is provided in the conductive part 33b connected to the substrate support part 11 in the first embodiment. However, the present invention is not limited to this. Since the measurement unit 35 measures the state of the plasma in the plasma processing chamber 10, it may be provided in an electrode arranged in the plasma processing chamber 10 or in a wiring connected to the electrode. For example, the measurement unit 35 may be provided in the conductive part 33a connected to the conductive member of the shower head 13. Further, a measurement electrode may be arranged in the plasma processing chamber 10, and the measurement unit 35 may be provided in the electrode or in a wiring connected to the electrode. Further, in the present embodiment, the measurement unit 35 is provided on the substrate support part 11 side rather than the impedance matching circuit 34b of the conductive part 33b. Thereby, the measurement unit 35 can measure the state of the plasma in the plasma processing chamber 10.

[0051] In addition, in the first embodiment, the case where the source RF signal and the bias RF signal are each supplied in a pulsed manner without overlapping periods was described as an example. However, the present invention is not limited to this. The RF power supply 31 may supply at least one of the source RF signal and the bias RF signal in a pulsed manner. Further, the RF power supply 31 may change the power of the source RF signal and the bias RF signal. The detection unit 102b may detect the end point of the etching from a change in any of the voltage, current, and phase difference between the voltage and the current measured by the measurement unit 35 at the timing when the combination of the source RF signal and the bias RF signal contributes most to the etching and the selection ratio. FIGS. 11A to 11E are diagrams showing an example of the source RF signal and the bias RF signal according to the first embodiment and the period for detecting the end point of the etching. "HF" indicates the period during which the source RF signal is supplied. "LF" indicates the period during which the bias RF signal is supplied. FIG. 11A shows the case where the source RF signal and the bias RF signal are each supplied in a pulsed manner from the RF power supply 31 without overlapping periods, as in the above-described embodiment. In this case, the detection unit 102b may detect the end point of the etching from a change in any of the voltage, current, and phase difference between the voltage and the current measured by the measurement unit 35 during the period T3 when the bias RF signal is supplied. FIG. 11B shows the case where the source RF signal and the bias RF signal are each supplied in a pulsed manner from the RF power supply 31 with a partial overlap in periods. In this case, the detection unit 102b may detect the end point of the etching from a change in any of the voltage, current, and phase difference between the voltage and the current measured by the measurement unit 35 during the period T4 when only the bias RF signal is supplied. In FIG. 11B, the detection unit 102b sets the period T4, which is the period T3 during which the bias RF signal is supplied excluding the overlapping period T5 with the source RF signal, as the period for detecting the end point of the etching. FIG. 11C shows the case where the bias RF signal is supplied in a pulsed manner while the source RF signal is continuously supplied from the RF power supply 31. In this case, the detection unit 102b detects the end point of the etching from a change in any of the voltage, current, and phase difference between the voltage and the current measured by the measurement unit 35 during the period T3 when the bias RF signal is supplied.FIG. 11D shows a case where a source RF signal is supplied in a pulsed manner while a bias RF signal is continuously supplied from the RF power supply 31. In this case, the detection unit 102b detects the end point of etching from any change in the voltage, current, or phase difference between the voltage and the current measured by the measurement unit 35 during the period T6 when the source RF signal is off and only the bias RF signal is supplied. FIG. 11E shows a case where the source RF signal and the bias RF signal are each supplied in a pulsed manner with a part of the period overlapping from the RF power supply 31. Also, the power during the on period of the source RF signal and the bias RF signal is changing. In this case, the detection unit 102b detects the end point of etching from any change in the voltage, current, or phase difference between the voltage and the current measured by the measurement unit 35 during the period T7 when only the bias RF signal is supplied.

[0052] Also, in the first embodiment, the end point detection when the SAC process is performed by cycle etching in FIG. 5 was described as an example. However, it is not limited to this. It can be applied to the end point detection in any cycle etching process. For example, it can also be applied to the end point detection when the BEOL (back end of line) process or the MOL (Middle Of the Line) process is performed by cycle etching.

[0053] Next, the processing flow of the end point detection method performed by the plasma processing apparatus 1 according to the first embodiment will be described. FIG. 12 is a diagram for explaining an example of the processing order of the end point detection method according to the first embodiment. In the first embodiment, the end point of etching is detected by the end point detection method. The processing of the end point detection method shown in FIG. 12 is executed when the substrate W on which the film to be etched is formed is placed on the substrate support unit 11 and cycle etching is performed.

[0054] The plasma control unit 102a starts cycle etching (S10). For example, the plasma control unit 102a controls the exhaust system 40 to evacuate the inside of the plasma processing chamber 10 to a predetermined degree of vacuum. The plasma control unit 102a controls the gas supply unit 20 to introduce a processing gas from the gas supply unit 20 into the plasma processing space 10s. The plasma control unit 102a controls the power supply 30 and, in accordance with the introduction of the processing gas, supplies at least one of a source RF signal and a bias RF signal in a pulsed manner from the first RF generation unit 31a and the second RF generation unit 31b to start cycle etching.

[0055] The detection unit 102b detects the end point of etching (S11) from a change in any of the voltage, current, and phase difference between voltage and current measured by the measurement unit 35 during the period when the bias RF signal is supplied. For example, the detection unit 102b detects the end of etching of the film to be etched from a change in any of the voltage, current, and phase difference between voltage and current measured by the measurement unit 35. The detection unit 102b monitors the voltage, current, and phase difference between voltage and current measured by the measurement unit 35 in real time and regards the moment when a significant change occurs as the end point of etching.

[0056] The plasma control unit 102a determines whether the end point of etching has been detected by the detection unit 102b (S12). If the end point of etching has not been detected (S12: No), the process proceeds to S11.

[0057] On the other hand, if the end point of etching has been detected (S12: Yes), the plasma control unit 102a ends cycle etching (S13) and ends the process.

[0058] As described above, the plasma processing apparatus 1 according to the first embodiment includes a plasma processing chamber 10, a conductive member (electrode) of the substrate support portion 11, a measurement unit 35, a gas supply unit 20, an RF power supply 31 (high-frequency power supply), and a detection unit 102b. The plasma processing chamber 10 is provided therein with a substrate support portion 11 (mounting table) on which a substrate W is placed. The conductive member of the substrate support portion 11 is disposed within the plasma processing chamber 10. The measurement unit 35 is provided on the conductive member of the substrate support portion 11 or a conductive portion 33b (wiring) connected to the conductive member of the substrate support portion 11, and measures either voltage or current. The gas supply unit 20 supplies a gas to be plasmaized into the plasma processing chamber 10. The RF power supply 31 supplies high-frequency power for plasmaizing the gas supplied into the plasma processing chamber 10 to the plasma processing chamber 10 in a pulsed manner. The detection unit 102b detects the end point of plasma processing from a change in any one of the voltage, current, and phase difference between voltage and current measured by the measurement unit 35 at a timing synchronized with the period of the pulse of the high-frequency power. Thereby, the plasma processing apparatus 1 can accurately detect the end point of plasma processing.

[0059] Further, the gas supply unit 20 supplies an etching gas as the gas to be plasmaized. The detection unit 102b detects the end point of etching from a change in any one of the voltage, current, and phase difference between voltage and current measured by the measurement unit 35 at a timing synchronized with the period of the pulse of the high-frequency power. Thereby, the plasma processing apparatus 1 can accurately detect the end point of etching.

[0060] Further, the RF power supply 31 supplies at least one of a source RF signal (first high-frequency power) for generating plasma and a bias RF signal (second high-frequency power) for attracting ion components in the plasma to the substrate in a pulsed manner. The detection unit 102b detects the end point of etching from a change in any one of the voltage, current, and phase difference between voltage and current measured by the measurement unit 35 at a timing when the combination of the supplied source RF signal and bias RF signal contributes most to etching and the selectivity ratio. Thereby, the plasma processing apparatus 1 can accurately detect the end point of etching.

[0061] Further, the detection unit 102b detects the end point of the etching from any change in the voltage, current, or phase difference between the voltage and the current measured by the measurement unit 35 during the period when the bias RF signal is supplied. Thereby, the plasma processing apparatus 1 can accurately detect the end point of the etching.

[0062] Further, the RF power supply 31 supplies the source RF signal and the bias RF signal in a pulsed manner, either with a partial overlap in the supply period or without overlapping the supply periods. The detection unit 102b detects the end point of the etching from any change in the voltage, current, or phase difference between the voltage and the current measured by the measurement unit 35 during the period when only the bias RF signal is supplied. Thereby, the plasma processing apparatus 1 can accurately detect the end point of the etching.

[0063] Further, the RF power supply 31 supplies high-frequency power in a pulsed manner at a frequency of 100 Hz to 10 kHz. Thereby, the plasma processing apparatus 1 can detect the end point of the etching with higher accuracy than when detecting the end point of the etching by OES.

[0064] Further, the electrode is provided on the substrate support unit 11. The conductive part 33b connected to the electrode is provided with an impedance matching circuit 34b, and high-frequency power is supplied from the RF power supply 31. The measurement unit 35 is provided on the electrode side of the impedance matching circuit 34b of the conductive part 33b. Thereby, the plasma processing apparatus 1 can accurately measure the state of the plasma from the voltage and current measured by the measurement unit 35, and thus can accurately detect the end point of the etching.

[0065] Further, the substrate W has a film to be etched (oxide film 121) formed thereon. The detection unit 102b detects the end of the etching of the film (oxide film 121). Thereby, the plasma processing apparatus 1 can accurately detect the end point of the etching of the film to be etched.

[0066] [Second Embodiment] Next, the second embodiment will be described. In the second embodiment, a case of detecting the end point of plasma processing for cleaning the inside of the plasma processing chamber will be described. FIG. 13 is a diagram showing an example of a schematic configuration of a plasma processing apparatus 1 according to the second embodiment. Since the plasma processing apparatus 1 according to the second embodiment has a configuration partly similar to that of the plasma processing apparatus 1 according to the first embodiment shown in FIG. 1, the same reference numerals are given to the same parts and the description thereof is omitted, and mainly the different parts will be described.

[0067] The plasma processing apparatus 1 is provided with a measurement unit 35 that measures either voltage or current on an electrode disposed in the plasma processing chamber 10 or a wiring connected to the electrode. In the plasma processing apparatus 1 according to the second embodiment, a measurement unit 35a is provided in a conductive part 33a connected to a conductive member of the shower head 13. Further, in the plasma processing apparatus 1 according to the second embodiment, a measurement unit 35b is provided in a conductive part 33b connected to a conductive member of the substrate support unit 11. The measurement units 35a and 35b are configured to include probes that detect current and voltage. The measurement units 35a and 35b measure voltage and current. The measurement unit 35a measures the voltage and current of the conductive part 33a through which the source RF signal flows. The measurement unit 35a outputs a signal indicating the measured voltage and current to the control unit 100. The measurement unit 35b measures the voltage and current of the conductive part 33b through which the bias RF signal flows. The measurement unit 35b outputs a signal indicating the measured voltage and current to the control unit 100.

[0068] FIG. 14 is a block diagram showing an example of a schematic configuration of the control unit 100 according to the second embodiment. Since the control unit 100 according to the second embodiment has a configuration partly similar to that of the control unit 100 according to the first embodiment shown in FIG. 2, the same reference numerals are given to the same parts and the description thereof is omitted, and mainly the different parts will be described. The plasma processing apparatus 1 shown in FIG. 14 is overall controlled in its operation by the control unit 100.

[0069] The external interface 101 is capable of communicating with each part of the plasma processing apparatus 1 and inputs and outputs various types of data. For example, signals indicating the voltage and current measured by the measurement units 35a and 35b are input to the external interface 101.

[0070] The plasma control unit 102a controls the plasma processing. For example, the plasma control unit 102a controls plasma cleaning for removing depositions adhering to the inside of the plasma processing chamber 10. The plasma control unit 102a controls the exhaust system 40 to exhaust the inside of the plasma processing chamber 10 to a predetermined degree of vacuum. The plasma control unit 102a controls the gas supply unit 20 to introduce a cleaning gas from the gas supply unit 20 into the plasma processing space 10s. The cleaning gas may be any gas capable of removing depositions and the like adhering to the inside of the plasma processing chamber 10. Examples of the cleaning gas include oxygen-containing gases such as O2 gas. The plasma control unit 102a controls the power supply 30 and, in accordance with the introduction of the cleaning gas, supplies a source RF signal and a bias RF signal from the first RF generation unit 31a and the second RF generation unit 31b to generate plasma inside the plasma processing chamber 10. The frequency of the source RF signal is in the range of 40 MHz to 130 MHz. The frequency of the bias RF signal is lower than the first frequency of the source RF signal and is in the range of 400 kHz to 40 MHz.

[0071] The plasma processing apparatus 1 according to the second embodiment performs plasma cleaning by repeatedly supplying RF power in a pulsed manner. The plasma control unit 102a controls the RF power supply 31 to supply high-frequency power from the RF power supply 31 in a pulsed manner. The RF power supply 31 supplies at least one of a source RF signal and a bias RF signal in a pulsed manner. For example, the plasma control unit 102a controls the RF power supply 31 to supply the source RF signal and the bias RF signal from the first RF generation unit 31a and the second RF generation unit 31b in a pulsed manner, respectively. The frequency of the pulses for turning on and off the supply of the source RF signal and the bias RF signal is set to 100 Hz to 10 kHz. Hereinafter, among the source RF signal and the bias RF signal, the source RF signal with a higher frequency is also referred to as HF (High Frequency), and the bias RF signal with a lower frequency is also referred to as LF (Low Frequency).

[0072] FIG. 15 is a diagram showing an example of the supply of high-frequency power according to the second embodiment. FIG. 15 shows the periods during which the source RF signal and the bias RF signal are supplied and the supply power (Power). "HF" indicates the period during which the source RF signal is supplied. "LF" indicates the period during which the bias RF signal is supplied. The source RF signal and the bias RF signal are each supplied during the On period. In FIG. 15, the source RF signal and the bias RF signal are each supplied in a pulsed manner without overlapping periods. In FIG. 15, the frequency of the pulses for turning the source RF signal and the bias RF signal On and Off is set to 1 kHz, and the source RF signal and the bias RF signal are turned On and Off at a cycle of 1 ms to perform cleaning.

[0073] The detection unit 102b detects the end point of the plasma process from the voltage and current of the signals input from the measurement units 35a and 35b. For example, the detection unit 102b detects the end point of the plasma process from a change in any of the voltage, current, and phase difference between the voltage and current measured by the measurement units 35a and 35b at a timing synchronized with the period of the pulse of the high-frequency power. In the present embodiment, the detection unit 102b detects the end point of the cleaning from a change in any of the voltage, current, and phase difference between the voltage and current measured by the measurement units 35a and 35b at a timing synchronized with the period of the pulse of the high-frequency power. The detection unit 102b detects the end point of the cleaning from a change in any of the voltage, current, and phase difference between the voltage and current measured by the measurement units 35a and 35b at a timing when the combination of the supplied source RF signal and bias RF signal contributes most to the cleaning. For example, when the source RF signal is supplied, in the plasma processing chamber 10, a path through which the source RF signal flows is formed near the upper electrode (for example, the shower head 13), and plasma is generated near the upper part inside. Therefore, the period during which the source RF signal is supplied contributes most to the cleaning near the upper electrode (for example, the shower head 13) in the plasma processing chamber 10. The detection unit 102b detects the end point of the cleaning near the upper electrode in the plasma processing chamber 10 from a change in any of the voltage, current, and phase difference between the voltage and current measured by the measurement unit 35a during the period when the source RF signal is supplied. Also, when the bias RF signal is supplied, in the plasma processing chamber 10, a path through which the bias RF signal flows is formed near the lower electrode (for example, the substrate support part 11), and plasma is generated near the lower electrode. Therefore, the period during which the bias RF signal is supplied contributes most to the cleaning near the lower electrode (for example, the substrate support part 11) in the plasma processing chamber 10. The detection unit 102b detects the end point of the cleaning near the lower electrode in the plasma processing chamber 10 from a change in any of the voltage, current, and phase difference between the voltage and current measured by the measurement unit 35b during the period when the bias RF signal is supplied.

[0074] The plasma control unit 102a controls the plasma process based on the detection result of the detection unit 102b. For example, when the detection unit 102b detects the end point of cleaning, the plasma control unit 102a ends the cleaning.

[0075] Here, the detection of the end point of cleaning will be specifically described. FIG. 16 is a diagram for explaining the detection of the end point of cleaning according to the second embodiment. FIG. 16 schematically shows the change in the signal (VI signal) measured by the measurement units 35a and 35b. FIG. 16 schematically shows the change in the signal (VI signal) in the state where deposition adheres in the plasma processing chamber 10 (Dirty) and in the state where the deposition in the plasma processing chamber 10 is removed (Clean). The signal (VI signal) schematically shows the change in the voltage and current measured by the measurement units 35a and 35b, and the signal is divided into "HF" and "LF" corresponding to the periods during which HF and LF are respectively supplied. In FIG. 16, the signal (VI signal) indicates the voltage. "HF" schematically shows the change in the voltage measured by the measurement unit 35a by the source RF signal. "LF" schematically shows the change in the voltage measured by the measurement unit 35b by the bias RF signal. The source RF signal and the bias RF signal are supplied during their respective On periods. FIG. 16 shows the On periods of the source RF signal and the bias RF signal respectively. For "HF", the change in the voltage increases corresponding to the period when the source RF signal is On. For "LF", the change in the voltage increases corresponding to the period when the bias RF signal is On.

[0076] The voltages measured by the measurement units 35a and 35b during the On periods of the source RF signal and the bias RF signal respectively change when the deposition in the plasma processing chamber 10 is removed. For example, as shown in FIG. 16, the voltages measured by the measurement units 35a and 35b during the On periods of the source RF signal and the bias RF signal respectively increase when the inside of the plasma processing chamber 10 changes from Dirty to Clean.

[0077] Near the upper electrode in the plasma processing chamber 10, it is cleaned by the plasma generated by the source RF signal. The plasma near the upper electrode is affected by depositions near the upper electrode and the like. Therefore, the voltage measured by the measurement unit 35a during the period when the source RF signal is On changes depending on the cleaning status of the deposition near the upper electrode. For example, as shown in FIG. 16, the voltage measured by the measurement unit 35a during the period when the source RF signal is On increases when the deposition on the shower head 13 in the plasma processing chamber 10 is removed. Therefore, the end point of cleaning of the shower head 13 can be detected from the change in the voltage measured by the measurement unit 35a during the period when the source RF signal is On.

[0078] Also, near the lower electrode in the plasma processing chamber 10, it is cleaned by the plasma generated by the bias RF signal. The plasma near the lower electrode is affected by depositions near the lower electrode and the like. Therefore, the voltage measured by the measurement unit 35b during the period when the bias RF signal is On changes depending on the cleaning status of the deposition near the lower electrode. For example, as shown in FIG. 16, the voltage measured by the measurement unit 35b during the period when the bias RF signal is On increases when the deposition on the substrate support 11 in the plasma processing chamber 10 is removed. Therefore, the end point of cleaning of the substrate support 11 can be detected from the change in the voltage measured by the measurement unit 35b during the period when the bias RF signal is On.

[0079] In the present embodiment, the detection unit 102b detects the end point of cleaning of the shower head 13 portion in the plasma processing chamber 10 from the change in the voltage measured by the measurement unit 35a during the period when the source RF signal is On. Also, the detection unit 102b detects the end point of cleaning of the substrate support 11 portion in the plasma processing chamber 10 from the change in the voltage measured by the measurement unit 35b during the period when the bias RF signal is On.

[0080] Note that the voltage change during the period when the bias RF signal and the source RF signal shown in FIG. 16 are On is an example, and the voltage change is not limited thereto. For example, depending on the configuration of the plasma processing apparatus 1 and the like, there may be a case where the voltage decreases due to the removal of the deposition. Even in such a case, the end point of cleaning can be detected from the voltage change.

[0081] Also, the current, voltage, and the phase difference between the current measured by the measurement units 35a and 35b during the period when the bias RF signal and the source RF signal are On change due to the removal of the deposition, similar to the voltage. Therefore, the detection unit 102b can detect the end point of cleaning in the plasma processing chamber 10 from the changes in the voltage, current, and the phase difference between the voltage and the current measured by the measurement units 35a and 35b during the period when the bias RF signal and the source RF signal are On. For example, the detection unit 102b may monitor the voltage, current, and the phase difference between the voltage and the current measured by the measurement units 35a and 35b in real time, and regard the moment when a significant change occurs that can be considered as the removal of the deposition as the end point of cleaning.

[0082] Next, the process of the plasma processing apparatus 1 according to the second embodiment for cleaning the inside of the plasma processing chamber 10 will be briefly described. When cleaning is performed, a cleaning dummy wafer DW is placed on the substrate support portion 11 as the substrate W. The dummy wafer DW is appropriately replaced during cleaning. The plasma processing apparatus 1 performs exhaust by the exhaust system 40 and exhausts the inside of the plasma processing chamber 10 to a predetermined degree of vacuum. Then, the plasma processing apparatus 1 introduces a cleaning gas from the gas supply unit 20 into the plasma processing space 10s. The plasma processing apparatus 1 supplies a source RF signal and a bias RF signal in a pulsed manner from the first RF generation unit 31a and the second RF generation unit 31b in accordance with the introduction of the cleaning gas to generate plasma in the plasma processing chamber 10 and perform cleaning. The plasma processing apparatus 1 detects the end point of cleaning from a change in any of the voltage, current, and phase difference between the voltage and the current measured by the measurement units 35a and 35b at a timing synchronized with the pulse period of the source RF signal and the bias RF signal. For example, the plasma processing apparatus 1 detects the end point of cleaning from the change in the voltage measured by the measurement units 35a and 35b during the periods when the source RF signal and the bias RF signal are each On.

[0083] FIG. 17 is a diagram for explaining the cleaning process according to the second embodiment. FIG. 17 schematically shows the change in the signal (VI signal) measured by the measurement units 35a and 35b. The signal (VI signal) schematically shows the change in voltage and current measured by the measurement units 35a and 35b, and the signal is divided into "HF" and "LF" corresponding to the periods during which HF and LF are respectively supplied. In FIG. 17, the signal (VI signal) represents voltage. "HF" schematically shows the change in voltage measured by the measurement unit 35a by the source RF signal. "LF" schematically shows the change in voltage measured by the measurement unit 35b by the bias RF signal. Further, FIG. 17 shows the deposition states near the upper electrode (e.g., shower head 13) and near the lower electrode (e.g., substrate support 11) in the plasma processing chamber 10. Dirty indicates the state where deposition has adhered. Clean indicates the state where the deposition has been removed. In FIG. 17, both near the upper electrode and near the lower electrode are Dirty, but through cleaning, near the upper electrode becomes Clean, and then near the lower electrode becomes Clean. The voltage measured by the measurement unit 35a during the period when the source RF signal is On increases when near the upper electrode becomes Clean. Also, the voltage measured by the measurement unit 35b during the period when the bias RF signal is On increases when near the lower electrode becomes Clean.

[0084] The plasma processing apparatus 1 detects the end points of cleaning near the upper electrode and near the lower electrode respectively from the changes in the voltages measured by the measurement units 35a and 35b during the periods when the source RF signal and the bias RF signal are respectively On. For example, the plasma processing apparatus 1 detects the end point of cleaning of the shower head 13 from the change in the voltage measured by the measurement unit 35a during the period when the source RF signal is On. Also, the plasma processing apparatus 1 detects the end point of cleaning near the substrate support 11 from the change in the voltage measured by the measurement unit 35b during the period when the bias RF signal is On.

[0085] When the plasma processing apparatus 1 detects the end point of cleaning near the upper electrode, it stops the supply of the source RF signal. As a result, the plasma near the upper electrode disappears, and the cleaning near the upper electrode stops. Further, when the plasma processing apparatus 1 detects the end point of cleaning near the lower electrode, it stops the supply of the bias RF signal. As a result, the plasma near the lower electrode disappears, and the cleaning near the lower electrode stops.

[0086] FIG. 18 is a diagram for explaining an example of the flow of detecting the end point of cleaning according to the second embodiment. In FIG. 18, a line L1 schematically showing the change in the signal (VI signal) measured by the measuring unit 35a during the period when the source RF signal is On, and a line L2 schematically showing the change in the signal (VI signal) measured by the measuring unit 35b during the period when the bias RF signal is On are shown. The lines L1 and L2 show, for example, the change in the average value of the voltage during the On period, respectively. Further, in FIG. 18, a line L3 showing the time derivative of the line L1 and a line L4 showing the time derivative of the line L2 are shown. The line L3 shows the amount of change per unit time of the line L1. The line L4 shows the amount of change per unit time of the line L2.

[0087] When the vicinity of the upper electrode becomes Clean, as shown by the line L1, the voltage during the period when the source RF signal is On increases. The plasma processing apparatus 1 detects the end point of cleaning near the upper electrode from the change in the voltage shown by the line L1. For example, the plasma processing apparatus 1 differentiates the voltage shown by the line L1 with respect to time to obtain the amount of change per unit time shown by the line L3, and detects the end point of cleaning near the upper electrode based on the timing T11 at which the amount of change peaks. For example, the plasma processing apparatus 1 detects the timing when a predetermined margin time MT1 has elapsed from the timing T11 as the end point of cleaning near the upper electrode. The margin time MT1 is the elapsed time that can be considered when the deposition near the upper electrode has been removed and it has become Clean, starting from the timing T11. The margin time MT1 is determined, for example, by experiments or simulations.

[0088] In addition, when the vicinity of the lower electrode becomes clean, as shown by line L2, the voltage during the period when the bias RF signal is On increases. The plasma processing apparatus 1 detects the end point of the cleaning near the lower electrode from the change in the voltage shown by line L2. For example, the plasma processing apparatus 1 differentiates the voltage shown by line L2 with respect to time to obtain the amount of change per unit time shown by line L4, and detects the end point of the cleaning near the lower electrode based on the timing T12 at which the amount of change peaks. For example, the plasma processing apparatus 1 detects the timing when a predetermined margin time MT2 has elapsed from the timing T12 as the end point of the cleaning near the lower electrode. The margin time MT2 is the elapsed time that can be considered when the deposition near the lower electrode has been removed and it has become clean. The margin time MT2 is also determined by, for example, experiments or simulations.

[0089] Note that the detection unit 102b may detect the timing when the increase in the voltage shown by line L1 saturates as the end point of the cleaning near the upper electrode. Further, the detection unit 102b may detect the timing when the increase in the voltage shown by line L2 saturates as the end point of the cleaning near the lower electrode.

[0090] Next, the processing flow of the end point detection method performed by the plasma processing apparatus 1 according to the second embodiment will be described. In the second embodiment, the end point of the cleaning is detected by the end point detection method. FIG. 19 is a diagram for explaining an example of the processing order of the end point detection method according to the second embodiment. The processing of the end point detection method shown in FIG. 19 is executed when the dummy wafer DW is placed on the substrate support unit 11 and cleaning is performed in the plasma processing chamber 10.

[0091] The plasma control unit 102a initializes the first flag and the second flag to 0 respectively (S20). The first flag is a flag indicating whether the cleaning near the upper electrode has ended. The second flag is a flag indicating whether the cleaning near the lower electrode has ended. When the cleaning has not ended, 0 is set in the first flag and the second flag, and when the cleaning has ended, 1 is set.

[0092] The plasma control unit 102a starts the cleaning (S21). For example, the plasma control unit 102a controls the exhaust system 40 to exhaust the inside of the plasma processing chamber 10 to a predetermined degree of vacuum. The plasma control unit 102a controls the gas supply unit 20 to introduce a cleaning gas from the gas supply unit 20 into the plasma processing space 10s. The plasma control unit 102a controls the power supply 30 and, in accordance with the introduction of the cleaning gas, supplies a source RF signal and a bias RF signal in a pulsed manner from the first RF generation unit 31a and the second RF generation unit 31b to start the cleaning.

[0093] The detection unit 102b determines whether the value of the first flag is 1 (S22). That is, the detection unit 102b determines whether the cleaning near the upper electrode has been completed.

[0094] When the value of the first flag is 1 (S22: Yes), the process proceeds to S27 described later. That is, when the cleaning near the upper electrode has been completed, the process proceeds to S27.

[0095] On the other hand, when the value of the first flag is not 1 (S22: No), the detection unit 102b detects the end point of the cleaning near the upper electrode from any change in the voltage, current, or phase difference between the voltage and current measured by the measurement unit 35a during the period when the source RF signal is On (S23).

[0096] The plasma control unit 102a determines whether the detection unit 102b has detected the end point of the cleaning near the upper electrode (S24). When the end point of the cleaning near the upper electrode has not been detected (S24: No), the process proceeds to S27 described later.

[0097] On the other hand, when the end point of the cleaning near the upper electrode is detected (S24: Yes), the plasma control unit 102a controls the power supply 30 to stop the supply of the source RF signal from the first RF generation unit 31a (S25). Then, the plasma control unit 102a sets 1, which indicates the end of the cleaning near the upper electrode, to the first flag (S26).

[0098] The detection unit 102b determines whether the value of the second flag is 1 (S27). That is, the detection unit 102b determines whether the cleaning near the lower electrode has been completed.

[0099] When the value of the second flag is 1 (S27: Yes), the process proceeds to S32, which will be described later. That is, when the cleaning near the lower electrode has been completed, the process proceeds to S32.

[0100] On the other hand, when the value of the second flag is not 1 (S27: No), the detection unit 102b detects the end point of the cleaning near the lower electrode from any change in the voltage, current, or phase difference between the voltage and current measured by the measurement unit 35b during the period when the bias RF signal is On (S28).

[0101] The plasma control unit 102a determines whether the detection unit 102b has detected the end point of the cleaning near the lower electrode (S29). When the end point of the cleaning near the lower electrode has not been detected (S29: No), the process proceeds to S32, which will be described later.

[0102] On the other hand, when the end point of the cleaning near the lower electrode has been detected (S29: Yes), the plasma control unit 102a controls the power supply 30 to stop the supply of the bias RF signal from the second RF generation unit 31b (S30). Then, the plasma control unit 102a sets 1, which indicates the end of the cleaning near the lower electrode, to the second flag (S31).

[0103] The plasma control unit 102a determines whether the values of the first flag and the second flag are both 1 (S32). That is, the plasma control unit 102a determines whether the cleaning near the upper electrode and the cleaning near the lower electrode have been completed. When the values of the first flag and the second flag are not both 1 (S32: No), the process proceeds to S22 described above. That is, when the cleaning near the upper electrode and the cleaning near the lower electrode have not been completed, the process proceeds to S22 to continue the cleaning.

[0104] On the other hand, when the values of the first flag and the second flag are both 1 (S32: Yes), the process ends.

[0105] In the second embodiment described above, as shown in FIG. 15, an example was described in which the supply of the source RF signal and the bias RF signal from the RF power supply 31 was turned on and off without overlapping the on periods. However, the present invention is not limited to this. Among the source RF signal and the bias RF signal, at least one of them does not necessarily have to set the supply power to 0 W when it is turned off. FIG. 20 is a diagram showing another example of the supply of high-frequency power according to the second embodiment. FIG. 20 shows the periods during which the source RF signal and the bias RF signal are supplied and the supply power (Power). "HF" indicates the period during which the source RF signal is supplied and the supply power. "LF" indicates the period during which the bias RF signal is supplied and the supply power. In FIG. 20, the source RF signal is supplied in a pulsed manner by alternately switching the supply power between two states of high power and low power. Also, in FIG. 20, the bias RF signal is supplied in a pulsed manner during the period when the supply power of the source RF signal is low power. In this case, the period during which the high-power source RF signal is supplied contributes most to the cleaning near the upper electrode (for example, the shower head 13) in the plasma processing chamber 10. The detection unit 102b can detect the end point of the cleaning near the upper electrode in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and the current measured by the measurement unit 35a during the period when the high-power source RF signal is supplied. Also, during the period when the bias RF signal is supplied, the low-power source RF signal is also supplied. When the bias RF signal and the low-power source RF signal are supplied, plasma is generated near the inner side wall and the lower electrode in the plasma processing chamber 10. Therefore, the period during which the bias RF signal and the low-power source RF signal are supplied contributes most to the cleaning near the side wall and the lower electrode (for example, the substrate support portion 11) in the plasma processing chamber 10. The detection unit 102b can detect the end point of the cleaning near the side wall and the lower electrode in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and the current measured by the measurement units 35a and 35b during the period when the bias RF signal and the low-power source RF signal are supplied.

[0106] Further, the source RF signal and the bias RF signal may be supplied while gradually changing the supply power. FIG. 21 is a diagram showing another example of the supply of high-frequency power according to the second embodiment. FIG. 21 shows the periods during which the source RF signal and the bias RF signal are supplied and the supply power (Power). "HF" indicates the period during which the source RF signal is supplied and the supply power. "LF" indicates the period during which the bias RF signal is supplied and the supply power. In FIG. 21, the source RF signal is repeatedly supplied while sequentially switching the supply power among three states: high power, low power, and 0 W. Also, in FIG. 21, in synchronization with the switching of the source RF signal, the source RF signal is repeatedly supplied while sequentially switching the supply power among three states: high power, low power, and 0 W. In FIG. 21, the bias RF signal is set to 0 W during the period when the source RF signal is at high power. Also, the bias RF signal is supplied at high power during the period when the source RF signal is 0 W. Further, the bias RF signal is supplied at low power during the period when the source RF signal is at low power. In this case, the period during which the high-power source RF signal is supplied contributes most to the cleaning near the upper electrode (e.g., the shower head 13) in the plasma processing chamber 10. The detection unit 102b can detect the end point of the cleaning near the upper electrode in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and current measured by the measurement unit 35a during the period when the high-power source RF signal is supplied. Also, the period during which the high-power bias RF signal is supplied contributes most to the cleaning near the lower electrode (e.g., the substrate support 11) in the plasma processing chamber 10. The detection unit 102b can detect the end point of the cleaning near the lower electrode in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and current measured by the measurement unit 35b during the period when the high-power bias RF signal is supplied. Also, during the period when the low-power bias RF signal is supplied, the low-power source RF signal is also supplied. When the low-power bias RF signal and the low-power source RF signal are supplied, plasma is generated near the inner sidewall of the plasma processing chamber 10. Therefore, the period during which the low-power bias RF signal and the low-power source RF signal are supplied contributes most to the cleaning near the sidewall in the plasma processing chamber 10.The detection unit 102b can detect the endpoint of the cleaning of the sidewall in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and the current measured by the measurement units 35a and 35b during the period when the low-power bias RF signal and the low-power source RF signal are supplied.

[0107] Also, the plasma processing apparatus 1 has been described by taking as an example the case where a source RF signal is supplied from the first RF generation unit 31a to the shower head 13 and a bias RF signal is supplied from the second RF generation unit 31b to the substrate support unit 11. FIG. 22 is a diagram schematically showing an example of the supply path of the RF signal in the plasma processing apparatus 1 according to the second embodiment. FIG. 22 schematically shows the supply path of the RF signal in the plasma processing apparatus 1 shown in FIG. 13. The first RF generation unit 31a supplies a source RF signal to the conductive member of the shower head 13 via the conductive part 33a and the impedance matching circuit 34a. The second RF generation unit 31b supplies a bias RF signal to the conductive member of the substrate support unit 11 via the conductive part 33b and the impedance matching circuit 34b. However, the supply path of the RF signal is not limited to this. For example, both the source RF signal and the bias RF signal may be supplied to the substrate support unit 11. FIG. 23 is a diagram schematically showing another example of the supply path of the RF signal in the plasma processing apparatus 1 according to the second embodiment. The conductive part 33a is grounded via a capacitor 37. Also, the conductive part 33b branches and is connected to the first RF generation unit 31a and the second RF generation unit 31b. The first RF generation unit 31a supplies a source RF signal to the conductive member of the substrate support unit 11 via the conductive part 33b and the impedance matching circuit 34b. The second RF generation unit 31b supplies a bias RF signal to the conductive member of the substrate support unit 11 via the conductive part 33b and the impedance matching circuit 34b. Even when the source RF signal is supplied to the substrate support unit 11 in this way, when the source RF signal is supplied, a path through which the source RF signal flows is formed near the upper electrode in the plasma processing chamber 10, and plasma is generated near the upper part inside. Therefore, the detection unit 102b can detect the end point of cleaning near the upper electrode in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and the current measured by the measurement unit 35b during the period when the source RF signal is supplied. Also, the detection unit 102b can detect the end point of cleaning near the lower electrode in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and the current measured by the measurement unit 35b during the period when the bias RF signal is supplied.

[0108] Alternatively, the plasma processing apparatus 1 may supply a third RF signal to the substrate support portion 11 or the shower head 13. The frequency of the third RF signal shall be lower than the frequency of the source RF signal and higher than the frequency of the bias RF signal. For example, the frequency of the source RF signal shall be in the range of 40 MHz to 130 MHz. The frequency of the bias RF signal shall be lower than the frequency of the source RF signal and in the range of 400 kHz to 40 MHz. The frequency of the third RF signal shall be lower than the frequency of the source RF signal, higher than the frequency of the bias RF signal, and in the range of 13 MHz to 60 MHz. FIG. 24 is a diagram schematically showing another example of the supply path of the RF signal in the plasma processing apparatus 1 according to the second embodiment. The conductive portion 33b is branched and connected to the second RF generation portion 31b and the third RF generation portion 31c. The first RF generation portion 31a supplies the source RF signal to the conductive member of the shower head 13 via the conductive portion 33a and the impedance matching circuit 34a. The second RF generation portion 31b supplies the bias RF signal to the conductive member of the substrate support portion 11 via the conductive portion 33b and the impedance matching circuit 34b. The third RF generation portion 31c supplies the third RF signal to the conductive member of the substrate support portion 11 via the conductive portion 33b and the impedance matching circuit 34b. For example, the first RF generation portion 31a, the second RF generation portion 31b, and the third RF generation portion 31c supply the source RF signal, the bias RF signal, and the third RF signal in a pulsed manner without overlapping periods. When the third RF signal is supplied, plasma is generated near the inner sidewall of the plasma processing chamber 10. Therefore, the period during which the third RF signal is supplied contributes most to the cleaning near the sidewall in the plasma processing chamber 10. Thus, the detection unit 102b can detect the end point of the cleaning near the sidewall in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and current measured by the measurement unit 35b during the period when the third RF signal is supplied. Further, the detection unit 102b can detect the end point of the cleaning near the upper electrode in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and current measured by the measurement unit 35b during the period when the source RF signal is supplied.Further, the detection unit 102b can detect the end point of cleaning near the lower electrode in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and current measured by the measurement unit 35b during the period when the bias RF signal is supplied.

[0109] Alternatively, a source RF signal, a bias RF signal, and a third RF signal may be supplied to the substrate support unit 11. FIG. 25 is a diagram schematically showing another example of the RF signal supply path in the plasma processing apparatus 1 according to the second embodiment. The conductive part 33a is grounded via a capacitor 37. Further, the conductive part 33b branches and is connected to a first RF generation unit 31a, a second RF generation unit 31b, and a third RF generation unit 31c. The first RF generation unit 31a supplies a source RF signal to the conductive member of the substrate support unit 11 via the conductive part 33b and the impedance matching circuit 34b. The second RF generation unit 31b supplies a bias RF signal to the conductive member of the substrate support unit 11 via the conductive part 33b and the impedance matching circuit 34b. The third RF generation unit 31c supplies a third RF signal to the conductive member of the substrate support unit 11 via the conductive part 33b and the impedance matching circuit 34b. For example, the first RF generation unit 31a, the second RF generation unit 31b, and the third RF generation unit 31c supply the source RF signal, the bias RF signal, and the third RF signal in a pulsed manner without overlapping periods. Even in such a configuration, the detection unit 102b can detect the end point of cleaning near the upper electrode in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and current measured by the measurement unit 35b during the period when the source RF signal is supplied. Further, the detection unit 102b can detect the end point of cleaning near the lower electrode in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and current measured by the measurement unit 35b during the period when the bias RF signal is supplied. Further, the detection unit 102b can detect the end point of cleaning near the side wall in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and current measured by the measurement unit 35b during the period when the third RF signal is supplied.

[0110] As described above, the plasma processing apparatus 1 according to the second embodiment includes a plasma processing chamber 10, a conductive member (electrode) of the substrate support portion 11, measurement units 35a and 35b, a gas supply unit 20, an RF power supply 31 (high-frequency power supply), and a detection unit 102b. The plasma processing chamber 10 is provided therein with a substrate support portion 11 (mounting table) on which a substrate W is placed. The conductive member of the substrate support portion 11 is disposed within the plasma processing chamber 10. The measurement units 35a and 35b are provided on the conductive member of the substrate support portion 11 or on conductive portions 33a and 33b (wiring) connected to the conductive member of the substrate support portion 11, and measure either voltage or current. The gas supply unit 20 supplies a gas to be turned into plasma into the plasma processing chamber 10. The RF power supply 31 supplies, in a pulsed manner, high-frequency power for turning the gas supplied into the plasma processing chamber 10 into plasma to the plasma processing chamber 10. The detection unit 102b detects the end point of plasma processing from a change in any of the voltage, current, and phase difference between voltage and current measured by the measurement units 35a and 35b at a timing synchronized with the period of the pulse of the high-frequency power. Thereby, the plasma processing apparatus 1 can accurately detect the end point of plasma processing.

[0111] Further, the gas supply unit 20 supplies a cleaning gas as the gas to be turned into plasma. The detection unit 102b detects the end point of cleaning from a change in any of the voltage, current, and phase difference between voltage and current measured by the measurement unit 35 at a timing synchronized with the period of the pulse of the high-frequency power. Thereby, the plasma processing apparatus 1 can accurately detect the end point of cleaning.

[0112] Further, the RF power supply 31 supplies, in a pulsed manner, at least one of a source RF signal (first high-frequency power) for generating plasma and a bias RF signal (second high-frequency power) for attracting ion components in the plasma to the substrate. The detection unit 102b detects the end point of cleaning from a change in any of the voltage, current, and phase difference between voltage and current measured by the measurement unit 35 at a timing when the combination of the supplied source RF signal and bias RF signal contributes most to cleaning. Thereby, the plasma processing apparatus 1 can accurately detect the end point of cleaning.

[0113] Further, the RF power supply 31 supplies a source RF signal to the substrate support portion 11 or the top portion (shower head 13) of the plasma processing chamber 10, and supplies a bias RF signal to the substrate support portion 11. The detection unit 102b detects the end point of the cleaning of the top portion in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and the current measured by the measurement unit 35a or the measurement unit 35b during the period when the source RF signal is supplied. Further, the detection unit 102b detects the end point of the cleaning of the substrate support portion 11 from any change in the voltage, current, or phase difference between the voltage and the current measured by the measurement unit 35b during the period when the bias RF signal is supplied. Thereby, the plasma processing apparatus 1 can accurately detect the end points of the cleaning of the top portion in the plasma processing chamber 10 and the substrate support portion 11 individually.

[0114] Further, the detection unit 102b detects the end point of the cleaning of the side wall portion in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and the current measured by the measurement unit 35a or the measurement unit 35b during the period when the source RF signal and the bias RF signal are supplied. Thereby, the plasma processing apparatus 1 can accurately detect the end point of the cleaning of the side wall portion in the plasma processing chamber 10.

[0115] Further, the frequency of the source RF signal is set to a frequency in the range of 40 MHz to 130 MHz. The frequency of the bias RF signal is set to a frequency lower than the frequency of the source RF signal and in the range of 400 kHz to 40 MHz. Thereby, the plasma processing apparatus 1 can clean the top portion in the plasma processing chamber 10 with the source RF signal and can clean the substrate support portion 11 with the bias RF signal.

[0116] Further, the third RF generation unit 31c supplies a third RF signal (third high-frequency power) having a third frequency between the frequency of the source RF signal and the frequency of the bias RF signal in a pulsed manner. The detection unit 102b detects the end point of the cleaning of the side wall portion in the plasma processing chamber 10 from any change in the voltage, current, or phase difference between the voltage and current measured by the measurement unit 35b during the period when the third RF signal is supplied. Thereby, the plasma processing apparatus 1 can accurately detect the end point of the cleaning of the side wall portion in the plasma processing chamber 10.

[0117] Further, the frequency of the third RF signal is set to be lower than the frequency of the source RF signal, higher than the frequency of the bias RF signal, and in the range of 13 MHz to 60 MHz. Thereby, the plasma processing apparatus 1 can clean the side wall portion in the plasma processing chamber 10 with the third RF signal.

[0118] Further, the detection unit 102b obtains the amount of change per unit time of the voltage measured by the measurement units 35a and 35b at a timing synchronized with the period of the high-frequency power pulse, and detects the end point of the cleaning based on the timing at which the amount of change peaks. Further, the detection unit 102b detects the timing when a predetermined margin time has elapsed from the timing at which the amount of change peaks as the end point of the cleaning. Thereby, the plasma processing apparatus 1 can accurately detect the end point of the cleaning.

[0119] As described above, the embodiments have been described. However, the embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. In fact, the above-described embodiments can be embodied in various forms. Further, the above-described embodiments may be omitted, substituted, or changed in various forms without departing from the scope of the claims and the gist thereof.

[0120] For example, in the above embodiment, the case where plasma processing is performed on a semiconductor wafer as the substrate W has been described as an example, but it is not limited thereto. The substrate W can be any one.

[0121] It should be noted that the embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. In fact, the above-described embodiments can be embodied in various forms. Also, the above embodiments may be omitted, replaced, or changed in various forms without departing from the scope and spirit of the appended claims.

Explanation of Reference Numerals

[0122] 1 Plasma processing apparatus 10 Plasma processing chamber 11 Substrate support part 13 Shower head 20 Gas supply part 30 Power supply 31 RF power supply 32 DC power supply 32a First DC generation part 32b Second DC generation part 31a First RF generation part 31b Second RF generation part 31c Third RF generation part 33a, 33b Conductive part 34a, 34b Impedance matching circuit 35, 35a, 35b Measuring part 40 Exhaust system 100 Control part 101 External interface 102 Process controller 102a Plasma control part 102b Detection part 103 User interface 104 Storage part W Substrate

Claims

1. A chamber provided internally with a mounting table on which a substrate is mounted, an electrode disposed within the chamber, a measuring unit provided on the electrode or a wiring connected to the electrode for measuring either voltage or current, a gas supply unit for supplying gas into the chamber, a first high-frequency power supply for supplying first high-frequency power having a first frequency for generating plasma from the gas supplied into the chamber to the chamber, a second high-frequency power supply for supplying second high-frequency power having a second frequency lower than the first frequency for drawing ions in the plasma into the substrate to the electrode, a detection unit for detecting an end point of plasma processing by the plasma generated within the chamber, having, at least one of the first high-frequency power and the second high-frequency power is supplied in a pulsed manner at a frequency of 100 Hz to 10 kHz, the detection unit detects an end point of plasma processing by the plasma generated within the chamber from a change in any one of the voltage, current, and phase difference between voltage and current measured by the measuring unit during a period in which the second high-frequency power is supplied, a plasma processing apparatus.

2. The gas is an etching gas, and the plasma processing is an etching process, The plasma processing apparatus according to Claim 1.

3. The gas is a cleaning gas, and the plasma processing is a cleaning process, The plasma processing apparatus according to Claim 1.

4. The detection unit detects an end point of etching at a timing when the combination of the supplied first high-frequency power and the second high-frequency power contributes most to etching and selectivity ratio The plasma processing apparatus according to Claim 2.

5. A chamber provided therein with a mounting table on which a substrate is mounted, electrodes disposed in the chamber, a measuring unit provided on the electrodes or wiring connected to the electrodes for measuring either voltage or current, a gas supply unit for supplying an etching gas into the chamber, a high-frequency power supply that supplies, in a pulsed manner, a first high-frequency power of a first frequency for plasmaizing the etching gas supplied into the chamber and a second high-frequency power of a second frequency lower than the first frequency for attracting ion components in the plasma to the mounting table, either with a part of the supply periods overlapping or without overlapping the supply periods, a detection unit that detects an end point of etching from a change in any of voltage, current, and the phase difference between voltage and current measured by the measuring unit during a period when only the second high-frequency power is supplied, and a plasma processing apparatus having the same.

6. The substrate has a film to be etched, The plasma processing apparatus according to any one of Claims 2, 4, and 5.

7. The first high-frequency power and the second high-frequency power are supplied in a pulsed manner at frequencies of 100 Hz to 10 kHz The plasma processing apparatus according to Claim 5.

8. The apparatus further includes a matching circuit provided in the wiring connected to the electrodes, The electrodes are provided on the mounting table, The second high-frequency power is supplied to the electrodes, The measuring unit is provided on the electrode side of the matching circuit in the wiring, The plasma processing apparatus according to any one of Claims 1 to 7.

9. The detection unit detects an end point of cleaning at a timing when the combination of the supplied first high-frequency power and second high-frequency power most contributes to cleaning The plasma processing apparatus according to Claim 3.

10. A chamber provided internally with a mounting table on which a substrate is placed, electrodes disposed within the chamber, a measuring unit provided on the electrodes or wiring connected to the electrodes for measuring either voltage or current, a gas supply unit for supplying a cleaning gas into the chamber, at least one of a first high-frequency power of a first frequency for plasmaizing the cleaning gas supplied into the chamber and a second high-frequency power of a second frequency lower than the first frequency for attracting ion components in the plasma to the mounting table is in a pulsed form, the first high-frequency power is supplied to the mounting table or the top of the chamber, and the second high-frequency power is supplied to the mounting table; a high-frequency power supply, a detection unit that detects an end point of cleaning of the top portion within the chamber from a change in any of voltage, current, and the phase difference between voltage and current measured by the measuring unit during a period when the first high-frequency power is supplied, and detects an end point of cleaning of the mounting table portion from a change in any of voltage, current, and the phase difference between voltage and current measured by the measuring unit during a period when the second high-frequency power is supplied; A plasma processing apparatus having the same.

11. The detection unit detects an end point of cleaning of a side wall portion within the chamber during a period when the first high-frequency power and the second high-frequency power are supplied. The plasma processing apparatus according to claim 9 or 10.

12. The first frequency is a frequency in the range of 40 MHz to 130 MHz, The second frequency is lower than the first frequency and is a frequency in the range of 400 kHz to 40 MHz, The plasma processing apparatus according to any one of claims 9 to 11.

13. The high-frequency power supply supplies a third high-frequency power having a third frequency between the first frequency and the second frequency in a pulsed form, The detection unit detects the end point of the cleaning of the side wall portion in the chamber during the period when the third high-frequency power is supplied. The plasma processing apparatus according to claim 10.

14. The third frequency is a frequency lower than the first frequency and higher than the second frequency, and is a frequency in the range of 13 MHz to 60 MHz. The plasma processing apparatus according to claim 13.

15. The detection unit obtains the amount of change per unit time of the voltage measured by the measurement unit during the period, and detects the end point of the cleaning based on the timing at which the amount of change peaks. The plasma processing apparatus according to any one of claims 1, 3, 9 to 14.

16. The detection unit detects the timing when a predetermined margin time has elapsed from the timing at which the amount of change peaks as the end point of the cleaning. The plasma processing apparatus according to claim 15.

17. A step of supplying gas into a chamber provided therein with a mounting table on which a substrate is mounted; Together with the supply of the gas, a first high-frequency power having a first frequency for generating plasma from the gas supplied into the chamber and a second high-frequency power having a second frequency lower than the first frequency for drawing ion components in the plasma into the substrate are supplied to the chamber; A step of detecting the end point of plasma processing by the plasma generated in the chamber; and At least one of the first high-frequency power and the second high-frequency power is supplied in a pulsed manner at a frequency of 100 Hz to 10 kHz. In the step of detecting, the end point of plasma processing by the plasma generated in the chamber is detected from any change in voltage, current, or phase difference between voltage and current during the period when the second high-frequency power is supplied. End point detection method.

18. The gas is an etching gas, The plasma treatment is etching, The endpoint detection method according to claim 17.

19. The gas is a cleaning gas, The plasma treatment is cleaning, The endpoint detection method according to claim 17.

20. A step of supplying an etching gas to a chamber in which a mounting table on which a substrate is mounted is provided inside and an electrode is disposed inside; Along with the supply of the etching gas, a first high-frequency power of a first frequency for plasmaizing the etching gas supplied into the chamber and a second high-frequency power of a second frequency lower than the first frequency for drawing ion components in the plasma into the mounting table are each supplied in a pulsed manner with a part of the supply periods overlapping or without overlapping the supply periods; A step of detecting an endpoint of etching from a change in any of a voltage, a current, and a phase difference between the voltage and the current measured during a period in which only the second high-frequency power is supplied by a measuring unit provided on the electrode or a wiring connected to the electrode and measuring any of the voltage, the current; An endpoint detection method having the above.

21. A step of supplying a cleaning gas into a chamber in which a mounting table on which a substrate is mounted is provided inside and an electrode is disposed inside; Along with the supply of the cleaning gas, at least one of a first high-frequency power of a first frequency for plasmaizing the cleaning gas supplied into the chamber and a second high-frequency power of a second frequency lower than the first frequency for drawing ion components in the plasma into the mounting table is made pulsed, the first high-frequency power is supplied to the mounting table or the top of the chamber, and the second high-frequency power is supplied to the mounting table; Provided in the electrode or the wiring connected to the electrode, from a change in any of voltage, current, or the phase difference between voltage and current measured by a measurement unit that measures any of voltage, current, a step of detecting an end point of cleaning of the top portion in the chamber from a change in any of voltage, current, or the phase difference between voltage and current measured during a period in which the second high-frequency power is supplied, and detecting an end point of cleaning of the mounting table portion; An end point detection method having the above.

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