Substrate processing apparatus and system, control method of substrate processing apparatus and system

Abstract

A substrate processing apparatus and system, and a control method of the substrate processing apparatus and system are provided. The substrate processing apparatus includes a substrate stage for placing a substrate, a first high-frequency power source for outputting a first high-frequency power of a first frequency to the substrate stage, a second high-frequency power source for outputting a second high-frequency power of a second frequency lower than the first frequency to the substrate stage, and a control section for controlling the first high-frequency power source. The first high-frequency power source includes a reflected wave detector for detecting a reflected wave input from the substrate stage. The control section decides a set value according to a processing content, and controls the first high-frequency power source so that an effective power becomes the set value. The effective power is a difference between an output power of the first high-frequency power source and a power of the reflected wave detected by the reflected wave detector.

Description

TECHNICAL FIELD

[0001] The present application relates to a substrate processing apparatus, a substrate processing system, a control method of a substrate processing apparatus, and a control method of a substrate processing system. BACKGROUND

[0002] For example, Patent Document 1 discloses a plasma etching apparatus capable of stably controlling load power in a high-frequency power source.

[0003] Prior art documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-090770 SUMMARY

[0006] Problem to be solved by the invention

[0007] A technique is sought for processing with desired processing characteristics according to processing contents in a plasma etching apparatus.

[0008] Solution to the problem

[0009] According to one embodiment of the present disclosure, a substrate processing apparatus is provided, including: a substrate stage for placing a substrate; a first high-frequency power source that outputs first high-frequency power of a first frequency to the substrate stage; a second high-frequency power source that outputs second high-frequency power of a second frequency lower than the first frequency to the substrate stage; and a control section that controls the first high-frequency power source, wherein the first high-frequency power source includes a reflected wave detector that detects a reflected wave input from the substrate stage, the control section decides a set value according to processing contents, and controls the first high-frequency power source so that an effective power becomes the set value, the effective power being a difference obtained by subtracting power of the reflected wave detected by the reflected wave detector from output power of the first high-frequency power source.

[0010] Effects of the invention

[0011] The present disclosure provides a technique for processing with desired processing characteristics according to processing contents in a plasma etching apparatus. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a cross-sectional view showing an outline structure of a substrate processing apparatus according to the present embodiment.

[0013] Figure 2is a block diagram showing a structure of a high-frequency power source and a matcher for generating plasma of a substrate processing apparatus according to the present embodiment.

[0014] Figure 3 is a block diagram showing a structure of a high-frequency power source and a matcher for attracting ions of a substrate processing apparatus according to the present embodiment.

[0015] Figure 4 is a flowchart illustrating a process of a control section of a substrate processing apparatus according to the present embodiment.

[0016] Figure 5 is a graph illustrating a plasma electron density when high-frequency electric power is supplied in a substrate processing apparatus according to the present embodiment.

[0017] Figure 6 is a graph illustrating a result of frequency analysis of a reflected wave in a substrate processing apparatus according to the present embodiment.

[0018] Figure 7 is a graph illustrating a plasma electron density when high-frequency electric power is supplied in a substrate processing apparatus according to the present embodiment.

[0019] Figure 8 is a graph illustrating adjustment of a plasma electron density between apparatuses in a substrate processing apparatus according to the present embodiment.

[0020] Explanation of reference numerals

[0021] 1: substrate processing apparatus; 1A: substrate processing apparatus; 1B: substrate processing apparatus; 1S: substrate processing system; 10: stage; 21a: first high-frequency power source; 21b: second high-frequency power source; 43: control section; 66a: power monitor. DETAILED DESCRIPTION

[0022] Hereinafter, a mode for carrying out the present disclosure will be described with reference to the drawings. Furthermore, in the present specification and drawings, repeated description will be omitted by assigning the same symbol to substantially the same structure.

[0023] <Overall structure of substrate processing apparatus 1>

[0024] First, with reference to Figure 1 An example of the overall structure of the substrate processing apparatus 1 will be described. Figure 1is a cross-sectional view showing a schematic configuration of a substrate processing apparatus 1 according to the present embodiment. In addition, in the present embodiment, an example of the substrate processing apparatus 1 being a RIE (Reactive Ion Etching) type substrate processing apparatus is described. However, the substrate processing apparatus 1 can also be a plasma etching apparatus, a plasma CVD (Chemical Vapor Deposition) apparatus, or the like.

[0025] In Figure 1 the substrate processing apparatus 1 has a cylindrical processing container 2 made of metal, for example, aluminum or stainless steel, in which a circular plate-shaped stage 10 for placing a substrate W is provided. The stage 10 has a base 11 and an electrostatic chuck 25. The base 11 (stage 10) functions as a lower electrode. The base 11 is formed of, for example, aluminum. The base 11 is supported by a cylindrical support portion 13 extending vertically upward from the bottom of the processing container 2 via an insulating cylindrical holding member 12. In addition, the stage 10 is an example of a substrate stage.

[0026] An exhaust passage 14 is formed between the side wall of the processing container 2 and the cylindrical support portion 13, a ring-shaped partition 15 is provided at the inlet or midway of the exhaust passage 14, and an exhaust port 16 is provided at the bottom of the exhaust passage 14, which is connected to an exhaust device 18 via an exhaust pipe 17. Here, the exhaust device 18 has a dry pump and a vacuum pump, and reduces the pressure in the processing space in the processing container 2 to a predetermined vacuum degree. In addition, the exhaust pipe 17 has an automatic pressure control valve (hereinafter referred to as "APC") as an adjustable butterfly valve, which automatically controls the pressure in the processing container 2. Further, a gate valve 20 that opens and closes a substrate W in / out port 19 is installed in the side wall of the processing container 2.

[0027] The base 11 is connected to a first high-frequency power source 21a via a first matcher 22a. In addition, the base 11 is connected to a second high-frequency power source 21b via a second matcher 22b. The first high-frequency power source 21a supplies high-frequency power for generating plasma at a predetermined frequency (for example, 40 MHz) to the base 11 (stage 10). The second high-frequency power source 21b supplies high-frequency power for attracting ions at a predetermined frequency (for example, 400 kHz) lower than that of the first high-frequency power source 21a to the base 11 (stage 10).

[0028] A shower head 24 is provided at the top of the processing container 2, and functions as an upper electrode. High-frequency electric power of two frequencies from the first high-frequency power source 21a and the second high-frequency power source 21b is supplied between the stage 11 (mounting table 10) and the shower head 24.

[0029] An electrostatic chuck 25 that attracts the substrate W by electrostatic attraction force is provided on the upper surface of the stage 11. The electrostatic chuck 25 has a center portion 25a that is a circular plate that mounts the substrate W, and a peripheral portion 25b that is a ring that is formed so as to surround the center portion 25a. The center portion 25a protrudes upward in the drawing with respect to the peripheral portion 25b. The upper surface of the center portion 25a is a substrate mounting surface 25al for mounting the substrate W. The upper surface of the peripheral portion 25b is an edge ring mounting surface 25bl for mounting the edge ring 30. The edge ring mounting surface 25bl is formed so as to mount the edge ring 30 around the substrate mounting surface 25al. The edge ring 30 is also called a focus ring. In addition, the center portion 25a is configured by sandwiching an electrode plate 26 that includes a conductive film between a pair of dielectric films. The electrode plate 26 is electrically connected to a direct-current power source 27. The peripheral portion 25b is configured by sandwiching an electrode plate 29 that includes a conductive film between a pair of dielectric films. The electrode plate 29 is electrically connected to a direct-current power source 28.

[0030] The direct-current power sources 27 and 28 can change the level and polarity of the direct-current voltage that is supplied. The direct-current power source 27 applies a direct-current voltage to the electrode plate 26 under the control of a control section 43 that will be described later. The direct-current power source 28 applies a direct-current voltage to the electrode plate 29 under the control of the control section 43. The electrostatic chuck 25 generates electrostatic force such as a Coulomb force by the voltage applied to the electrode plate 26 from the direct-current power source 27, and holds the substrate W by electrostatic force to the electrostatic chuck 25. In addition, the electrostatic chuck 25 generates electrostatic force such as a Coulomb force by the voltage applied to the electrode plate 29 from the direct-current power source 28, and holds the edge ring 30 by electrostatic force to the electrostatic chuck 25.

[0031] Furthermore, in the electrostatic chuck 25 of the present embodiment, the electrostatic chuck for the substrate W and the electrostatic chuck for the edge ring 30 are formed in one body, but the electrostatic chuck for the substrate W and the electrostatic chuck for the edge ring 30 can be separate electrostatic chucks. That is, the electrode plate 26 and the electrode plate 29 can be sandwiched between separate dielectric films. In addition, the electrode plate 29 of the present embodiment is shown as an example of a unipolar electrode, but can be a bipolar electrode. Furthermore, in the case of a bipolar electrode, the edge ring 30 can be attracted even when plasma is not generated.

[0032] A refrigerant chamber 31 in the shape of a ring extending in the circumferential direction is provided inside the base 11, for example. From the cooling unit 32, a refrigerant such as cooling water at a prescribed temperature is circulated to the refrigerant chamber 31 via pipes 33, 34, and the temperature of the refrigerant is used to control the processing temperature of the substrate W on the electrostatic chuck 25. In addition, the refrigerant is a medium for adjusting the temperature that is circulated to the pipes 33, 34. The medium for adjusting the temperature can not only cool the base 11 and the substrate W but also heat them.

[0033] In addition, the electrostatic chuck 25 is connected to a heat transfer gas supply portion 35 via a gas supply line 36. The heat transfer gas supply portion 35 supplies heat transfer gas to the space between the center portion 25a of the electrostatic chuck 25 and the substrate W using the gas supply line 36. As the heat transfer gas, a gas having heat transfer properties, such as He gas, is preferably used.

[0034] The shower head 24 of the top portion has an electrode plate 37 having a plurality of air holes 37a in the lower surface and an electrode support 38 that supports the electrode plate 37 in a detachable manner. A buffer chamber 39 is provided inside the electrode support 38, and a gas introduction port 38a that communicates with the buffer chamber 39 is connected to a processing gas supply portion 40 via a gas supply pipe 41.

[0035] The respective constituent elements of the substrate processing apparatus 1 are connected to a control portion 43. For example, the exhaust device 18, the first high-frequency power supply 21a, the second high-frequency power supply 21b, the first matcher 22a, the second matcher 22b, the direct-current power supply 27, the direct-current power supply 28, the cooling unit 32, the heat transfer gas supply portion 35, and the processing gas supply portion 40 are connected to the control portion 43. The control portion 43 controls the respective constituent elements of the substrate processing apparatus 1.

[0036] The control portion 43 has a central processing device (CPU) and a storage device such as a memory, not shown, and causes the substrate processing apparatus 1 to perform desired processing by reading and executing a program and processing stored in the storage device. In addition, the control portion 43 performs electrostatic chucking processing for electrostatically chucking the edge ring 30.

[0037] In the substrate processing apparatus 1, first, the gate valve 20 is set to an open state, and a substrate W that is a processing target is carried into the processing container 2 and placed on the electrostatic chuck 25. Then, in the substrate processing apparatus 1, a processing gas (for example, a mixed gas including C4F8 gas, O2 gas, and Ar gas) is introduced into the processing container 2 at a prescribed flow rate and flow rate ratio by the processing gas supply portion 40, and the pressure in the processing container 2 is set to a prescribed value by the exhaust device 18 and the like.

[0038] Also, in the substrate processing apparatus 1, the first high-frequency power supply 21a and the second high-frequency power supply 21b supply high-frequency electric power of different frequencies to the base 11 (the mounting table 10) respectively. In addition, in the substrate processing apparatus 1, the DC power supply 27 applies a direct-current voltage to the electrode plate 26 of the electrostatic chuck 25 to attract the substrate W to the electrostatic chuck 25. In addition, in the substrate processing apparatus 1, the DC power supply 28 applies a direct-current voltage to the electrode plate 29 of the electrostatic chuck 25 to attract the edge ring 30 to the electrostatic chuck 25. The processing gas sprayed from the shower head 24 is plasma-ized, and radicals and ions in the plasma are used to perform etching processing on the substrate W.

[0039] <Structure of the first high-frequency power supply 21a and the first matcher 22a for generating plasma>

[0040] Figure 2 is a block diagram showing the structure of the first high-frequency power supply 21a and the first matcher 22a for generating plasma of the substrate processing apparatus 1 of the present embodiment.

[0041] The first high-frequency power supply 21a outputs first high-frequency electric power HF of a first frequency (for example, 40 MHz) to the first matcher 22a via the high-frequency power supply line 23a. The first high-frequency power supply 21a includes a high-frequency oscillator 60a, a power amplifier 62a, a power supply control section 64a, and a power monitor 66a.

[0042] The high-frequency oscillator 60a is a signal generator that generates a sine wave or a fundamental wave of a fixed frequency (for example, 40 MHz) suitable for generating plasma by high-frequency discharge. The power amplifier 62a is an amplifier that amplifies the power of the fundamental wave output from the high-frequency oscillator 60a with a variable and controllable gain or amplification rate. The power supply control section 64a is a control section that directly controls the high-frequency oscillator 60a and the power amplifier 62a in accordance with a control signal from the control section 43.

[0043] The first high-frequency power supply 21a also includes the power monitor 66a. The power monitor 66a includes a directional coupler on the high-frequency power supply line 23a. The power monitor 66a detects the power PF1 of a traveling wave propagating in the forward direction, that is, from the first high-frequency power supply 21a to the first matcher 22a, on the high-frequency power supply line 23a. In addition, the power monitor 66a detects the power RF1 of a reflected wave propagating in the reverse direction, that is, from the first matcher 22a to the first high-frequency power supply 21a, on the high-frequency power supply line 23a. Furthermore, the power monitor 66a outputs the detection results to the power supply control section 64a and the control section 43. The power supply control section 64a uses the detection results for power feedback control. Moreover, the power monitor 66a is an example of a reflected wave detector.

[0044] The first matcher 22a matches the impedance of the first high-frequency power supply 21a to the impedance of the base 11 (the mounting table 10). The first matcher 22a includes an impedance sensor 70a, a matching circuit 72a, and a matching controller 74a. The impedance sensor 70a is a detector that measures the impedance on the load side including the impedance of the matching circuit 72a on the high-frequency power supply line 23a. The matching circuit 72a is a circuit including a plurality of, for example, two controllable reactance elements (for example, a variable capacitor or a variable inductor) X H1 and X H2 connected to the high-frequency power supply line 23a. The matching controller 74a controls the reactance elements X H1 and X H2 via motors (M) 76a and 78a, respectively. The matching controller 74a controls the motors 76a and 78a so that the output impedance of the first high-frequency power supply 21a matches the impedance detected by the impedance sensor 70a.

[0045] <Structure of second high-frequency power supply 21b and second matcher 22b for attracting ions>

[0046] Figure 3 is a block diagram showing the structure of the second high-frequency power supply 21b and the second matcher 22b for attracting ions of the substrate processing apparatus 1 of the present embodiment.

[0047] The second high-frequency power supply 21b outputs second high-frequency power LF of a second frequency (for example, 400 kHz) lower than the first frequency (for example, 40 MHz) to the second matcher 22b via a high-frequency power supply line 23b. The second high-frequency power supply 21b includes a high-frequency oscillator 60b, a power amplifier 62b, a power supply control section 64b, and a power monitor 66b.

[0048] The high-frequency oscillator 60b is a signal generator that generates a sine wave or a fundamental wave of a fixed frequency (for example, 400 kHz) suitable for attracting ions. The power amplifier 62b is an amplifier that amplifies the power of the fundamental wave output from the high-frequency oscillator 60b with a variable controllable gain or amplification rate. The power supply control section 64b is a control section that directly controls the high-frequency oscillator 60b and the power amplifier 62b according to a control signal from the control section 43.

[0049] The second high-frequency power source 21b also has a power monitor 66b. The power monitor 66b has a directional coupler on the high-frequency supply line 23b. The power monitor 66b detects the power PF2 of a traveling wave propagating in the forward direction, that is, from the second high-frequency power source 21b toward the second matching unit 22b, on the high-frequency supply line 23b. In addition, the power monitor 66b detects the power RF2 of a reflected wave propagating in the reverse direction, that is, from the second matching unit 22b toward the second high-frequency power source 21b, on the high-frequency supply line 23b. Furthermore, the power monitor 66b outputs the detection results to the power control section 64b and the control section 43. The power control section 64b uses the detection results for power feedback control.

[0050] The second matching unit 22b matches the impedance of the second high-frequency power source 21b to the impedance of the base 11 (mounting table 10). The second matching unit 22b has an impedance sensor 70b, a matching circuit 72b, and a matching controller 74b. The impedance sensor 70b is a detector that measures the impedance on the load side including the impedance of the matching circuit 72b on the high-frequency supply line 23b. The matching circuit 72b is a circuit that has a plurality of, for example, two controllable reactance elements (for example, variable capacitance or variable inductance) X L1 and X L2 connected to the high-frequency supply line 23b. The matching controller 74b is a control section that controls the reactance elements X L1 and X L2 via motors (M) 76b, 78b, respectively. The matching controller 74b controls the motors 76b, 78b so that the output impedance of the second high-frequency power source 21b matches the impedance detected by the impedance sensor 70b.

[0051] <Control according to processing content of substrate processing apparatus 1>

[0052] A control according to the processing content of the substrate processing apparatus 1 of the present embodiment will be described. In the substrate processing apparatus 1 of the present embodiment, the output power of the first high-frequency power source 21a is controlled according to the processing content.

[0053] Figure 4 is a flowchart illustrating the control of the control section 43 of the substrate processing apparatus 1 of the present embodiment. The control method of the control section 43 of the substrate processing apparatus 1 will be described with reference to Figure 4

[0054] ​(Step S10) The control section 43 performs a process of deciding a set value of the effective power required in the substrate processing by the substrate processing apparatus 1. For example, when a certain substrate processing is selected by an operator from an input unit such as a keyboard, the set value of the effective power required is decided. That is, the set value of the effective power is decided in accordance with the contents of the processing by the substrate processing apparatus 1. For example, the set value can be the effective power by which a desired etching shape can be obtained based on an experiment that has been performed. Further, in the substrate processing system having a plurality of substrate processing apparatuses described later, a desired value can be input as the set value of the effective power. The control section 43 controls the first high-frequency power supply 21a so as to oscillate at the effective power set. Then, the substrate processing apparatus 1 performs the desired substrate processing.

[0055] (Step S20) The control section 43 calculates the power P HF of the first high-frequency power HF output from the first high-frequency power supply 21a. Specifically, the control section 43 receives the power PF1 of the forward traveling wave on the high-frequency power supply line 23a detected by the power monitor 66a. Then, the control section 43 calculates the power P HF of the first high-frequency power HF using the received power PF1 of the forward traveling wave. HF Further, as the power P R of the first high-frequency power HF, a set value of the output power of the high-frequency oscillator 60a set by the power control section 64a can be used for the calculation.

[0056] (Step S30) The control section 43 calculates the power P R of the reflected wave. Specifically, the control section 43 receives the power RF1 of the reflected wave in the reverse direction on the high-frequency power supply line 23a detected by the power monitor 66a. Then, the power P R of the reflected wave is calculated using the received power RF1 of the reflected wave.

[0057] In the substrate processing apparatus 1 of the present embodiment, since the first matching section 22a is used, the reflected wave of which the power RF1 is detected by the power monitor 66a does not include the reflected wave of the first frequency component, or even if it includes the reflected wave of the first frequency component, it is small to the extent that it can be ignored. Therefore, in the case where the power P R of the reflected wave is calculated using the power RF1 of the reflected wave, the power of the reflected wave of a frequency different from the first frequency, which does not include the reflected wave of the first frequency component, is calculated.

[0058] Further, in the calculation of the power P RAlternatively, the control unit 43 can use a portion of the frequency components from the detection results detected by the power monitor 66a for calculation. For example, if the first frequency is set to F1 (Hz) and the second frequency is set to F2 (Hz), the power P of the reflected wave can be calculated by integrating the power RF1 of the reflected wave over the frequency range F (Hz) of Equation 1. R .

[0059] F1-F2×n≤F≤F1+F2×n…(Equation 2)

[0060] Where n is an integer.

[0061] n is, for example, 2. That is, the control unit 43 can use the power RF1 of the reflected wave within the range to calculate the power P. R The range is the range from the frequency obtained by subtracting the second frequency by 2 from the first frequency to the frequency obtained by adding the second frequency by 2 to the first frequency.

[0062] Furthermore, F2×n in Equation 2 is an example of obtaining the third frequency by multiplying the second frequency by an integer. Therefore, the control unit 43 can use the power RF1 of the reflected wave within the following range to calculate the power P. R The range is the range from the frequency obtained by subtracting the third frequency from the first frequency to the frequency obtained by adding the first frequency and the third frequency.

[0063] (Step S40) The control unit 43 uses the power P of the first high-frequency power HF calculated in step S10. HF and the power P of the reflected wave calculated in step S20 R To calculate the effective power P E Specifically, as shown in Equation 2, based on the power P of the first high-frequency power HF... HF With the power P of the reflected wave R The difference is used to calculate the effective power P. E .

[0064] P E =P HF -P R …(Equation 2)

[0065] (Step S50) Control unit 43 controls the first high-frequency power supply 21a to make the effective power P obtained in step S30... E This becomes the setpoint determined in step S10. Specifically, in the effective power P E If the value is less than the set value, the control unit 43 controls the output of the first high-frequency power supply 21a to increase the effective power P. E This becomes the set value. Additionally, in the effective power P...E When the effective power P is less than the set value, the control section 43 controls the output of the first high-frequency power source 21a to be reduced, so that the effective power P becomes the set value. The output of the first high-frequency power source 21a is controlled, for example, by changing the gain of the power amplifier 62a. E

[0066] <Plasma electron density at the time when high-frequency electric power is supplied in the substrate processing apparatus 1>

[0067] The results obtained by measuring the plasma electron density at the time when the first high-frequency electric power HF and the second high-frequency electric power LF are supplied to the susceptor 11 (the mounting table 10) in the substrate processing apparatus 1 of Embodiment 1 will be described.

[0068] In the substrate processing apparatus 1 according to the present embodiment, the power of each of the first high-frequency electric power HF and the second high-frequency electric power LF, and the plasma electron density at the time when the first high-frequency electric power HF and the second high-frequency electric power are supplied were measured. In the measurement, the power of the first high-frequency electric power HF was set to 1000 W, 2000 W, 3000 W, and 4000 W. In addition, in each case where the first high-frequency electric power HF was set to the above conditions, the second high-frequency electric power LF was set to 2000 W, 4000 W, 6000 W, and 8000 W.

[0069] In Figure 5 the plasma electron density at the time when the first high-frequency electric power HF and the second high-frequency electric power LF were set as described above is shown.

[0070] When the first high-frequency electric power HF is increased, the plasma electron density increases. On the other hand, when the second high-frequency electric power LF is increased at the same first high-frequency electric power HF, the plasma electron density decreases.

[0071] Here, the reflected wave from the susceptor 11 (the mounting table 10) to the first high-frequency power source 21a will be described. Figure 6 ​is a graph showing a result of frequency analysis of a reflected wave in the substrate processing apparatus 1 according to the present embodiment. The first high frequency power HF generated by the first high frequency power source 21a is supplied to the pedestal 11 (mounting table 10) via the first matching device 22a. The impedance is matched by the first matching device 22a, and the reflected wave is small to the extent that it can be ignored at the frequency of the first high frequency power HF (fundamental wave), that is, the first frequency of 40 MHz (specifically, 40.68 MHz). On the other hand, in a case where the first high frequency power HF and the second high frequency power LF are supplied at the same time, a waveform at a frequency obtained by adding or subtracting an integer multiple of the frequency of the second high frequency power to or from the frequency of the first high frequency power HF (hereinafter referred to as intermodulation distortion (IMD)) is generated. Therefore, at the frequency obtained by adding or subtracting an integer multiple of the frequency of the second high frequency power to or from the frequency of the first high frequency power HF, the reflected wave corresponding to the intermodulation distortion (IMD) is observed.

[0072] The intermodulation distortion (IMD) does not contribute to generation of plasma. In addition, the generation condition of the intermodulation distortion (IMD) differs for each substrate processing apparatus, and it is difficult to control the generation of the intermodulation distortion (IMD).

[0073] Therefore, in the substrate processing apparatus 1 according to the present embodiment, the magnitude of the generated intermodulation distortion (IMD) is detected by the power monitor 66a, and control is performed to correct an amount corresponding to the power of the intermodulation distortion (IMD) that does not contribute to generation of plasma.

[0074] In the substrate processing apparatus 1 according to the present embodiment, the effective power P E is used to perform control. In Figure 7 , a result obtained by measuring the electron density when the control is performed using (referencing) the effective power P E is shown. Figure 7 The electron density of the generated plasma with respect to the effective power is shown. According to this, the electron density of the plasma can be approximated as a first function of the effective power. By using the effective power P E , the electron density of the generated plasma can be set to a desired density. For example, even if the intermodulation distortion (IMD) changes over time, the effective power P E can be used to suppress changes in characteristics of substrate processing over time.

[0075] <Substrate processing system>

[0076] By using the substrate processing apparatus 1 of the present embodiment, for example, in a case where the same processing is performed in multiple paths in parallel, it is possible to make the characteristics of the plasma processing in each path the same. That is, in a substrate processing system provided with a plurality of substrate processing apparatuses 1, it is possible to make the characteristics of the processing performed by each substrate processing apparatus 1 consistent.

[0077] Figure 8 is a diagram explaining a method of adjusting the characteristics of processing in the presence of a substrate processing system 1S including a substrate processing apparatus 1A and a substrate processing apparatus 1B that perform the same processing.

[0078] For example, the substrate processing apparatus 1A sets the first high-frequency power HF to 4000 W. On the other hand, the substrate processing apparatus 1B sets the first high-frequency power HF to 4000 W, to be the same processing conditions as the substrate processing apparatus 1A.

[0079] However, in the substrate processing apparatus 1A, due to the influence of intermodulation distortion (IMD), the power of the reflected wave is 1665 W. On the other hand, in the substrate processing apparatus 1B, the power of the reflected wave is 1720 W. Therefore, the effective power is 2335 W in the substrate processing apparatus 1A, and 2280 W in the substrate processing apparatus 1B. In this way, the electron density of the plasma on the side of the substrate processing apparatus 1B becomes small. That is, even if the power of the first high-frequency power HF of the substrate processing apparatus 1A and the substrate processing apparatus 1B is made the same, the electron density of the plasma differs between the devices, and the characteristics of the processing differ. Due to the difference in the electron density of the plasma, the characteristics of the processing in the substrate processing apparatus 1A and the substrate processing apparatus 1B also differ.

[0080] In the substrate processing apparatus 1 of the present embodiment, control is performed using the effective power. Therefore, for example, in the substrate processing apparatus 1B, control is performed so that the effective power is equal to that of the substrate processing apparatus 1A, whereby it is possible to make the electron density of the plasma consistent between the devices. That is, by making the set value of the effective power common in the substrate processing apparatus 1A and the substrate processing apparatus 1B, it is possible to make the characteristics of the substrate processing consistent between the devices.

[0081] <Effects / Advantages>

[0082] With the substrate processing apparatus 1 of the present embodiment, it is possible to control according to the processing contents of the substrate processing apparatus 1. When the first high-frequency power HF for generating plasma and the second high-frequency power LF for attracting ions are supplied to the stage 10, intermodulation distortion (IMD) occurs, and the effective power supplied to the plasma decreases. Also, it is not possible to control the occurrence of intermodulation distortion (IMD), and the occurrence of intermodulation distortion (IMD) differs for each substrate processing apparatus. Therefore, the processing characteristics of the plasma of each substrate processing apparatus change due to intermodulation distortion (IMD). In the substrate processing apparatus 1 of the present embodiment, the power of the reflected wave due to intermodulation distortion (IMD) is used to calculate the effective power. Also, control is performed using the effective power, and thus it is possible to achieve desired processing characteristics according to the processing contents.

[0083] Also, the substrate processing apparatus 1 of the present embodiment uses the effective power, and thus it is possible to suppress changes in the processing characteristics over time even if the state of intermodulation distortion (IMD) changes over time.

[0084] In addition, with the substrate processing apparatus 1 of the present embodiment, it is possible to make the electron density of the plasma uniform between substrate processing apparatuses in a substrate processing system having a plurality of substrate processing apparatuses 1. The substrate processing apparatus 1 of the present embodiment is able to control the electron density of the plasma by using the effective power. Therefore, even if intermodulation distortion (IMD) occurs, it is possible to set the electron density of the plasma between a plurality of substrate processing apparatuses to the same electron density. By making the electron density the same, it is possible to suppress differences in the processing characteristics between substrate processing apparatuses during plasma processing.

[0085] It should be considered that the substrate processing apparatus according to the present embodiment disclosed this time is illustrative in all respects and is not restrictive. The above-described embodiments can be modified and improved in various ways without departing from the scope of the appended claims and the spirit thereof. The matters described in the above-described embodiments can also be adopted in other structures within a range not causing contradiction, and combinations can also be made within a range not causing contradiction.

[0086] The substrate processing apparatus of the present disclosure is a device that generates plasma by Capacitively Coupled Plasma (CCP), Inductively Coupled Plasma (ICP), microwaves, for example, and can also be applied to any type such as plasma generated by Radial Line Slot Antenna (RLSA), Electron Cyclotron Resonance Plasma (ECR), and Helicon Wave Plasma (HWP).

Claims

1. A substrate processing apparatus that performs the same processing as another substrate processing apparatus, the substrate processing apparatus comprising: a substrate stage configured to hold a substrate; a first high-frequency power source configured to output first high-frequency power of a first frequency to the substrate stage; a second high-frequency power source configured to output second high-frequency power of a second frequency lower than the first frequency to the substrate stage; a matching circuit configured to match an output impedance of the first high-frequency power source to an impedance on a load side detected; and a control unit configured to control the first high-frequency power source, the first high-frequency power source including a reflected wave detector configured to detect a reflected wave input from the substrate stage, the control unit configured to decide a set value in accordance with a processing content, and control the first high-frequency power source such that an effective power, which is a difference between an output power of the first high-frequency power source and a power of the reflected wave detected by the reflected wave detector, becomes the set value, the control unit configured to calculate the effective power by integrating the power of the reflected wave in a range from a frequency obtained by subtracting a third frequency, which is an integral multiple of the second frequency, from the first frequency to a frequency obtained by adding the third frequency to the first frequency, when the first high-frequency power and the second high-frequency power are supplied at the same time, an intermodulation distortion in the reflected wave of the substrate processing apparatus is different from an intermodulation distortion in the reflected wave of the another substrate processing apparatus, and the control unit is configured to perform control such that the effective power of the substrate processing apparatus becomes equal to the effective power of the another substrate processing apparatus.

2. The substrate processing apparatus according to claim 1, wherein the first frequency is 40 MHz, and the second frequency is 400 kHz.

3. The substrate processing apparatus according to claim 1, wherein the integral multiple is 2.

4. A substrate processing system including a plurality of substrate processing apparatuses each configured to perform the same processing, each of the substrate processing apparatuses comprising: a substrate stage configured to hold a substrate; a first high-frequency power source configured to output first high-frequency power of a first frequency to the substrate stage; a second high-frequency power source configured to output second high-frequency power of a second frequency lower than the first frequency to the substrate stage; a matching circuit configured to match an output impedance of the first high-frequency power source to an impedance on a load side detected; and a control unit configured to control the first high-frequency power source, the first high-frequency power source including a reflected wave detector configured to detect a reflected wave input from the substrate stage, the control unit configured to control the first high-frequency power source such that an effective power, which is a difference between an output power of the first high-frequency power source and a power of the reflected wave detected by the reflected wave detector, becomes a set value, in the substrate processing system, the set value of each of the substrate processing apparatuses is a common value among the substrate processing apparatuses. ​ ​ wherein ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ wherein ​ ​ ​ ​ the control section calculates the effective power by integrating the power of the reflected wave in a range from a frequency obtained by subtracting a third frequency from the first frequency to a frequency obtained by adding the third frequency to the first frequency, the third frequency being an integral multiple of the second frequency, when the first high-frequency power and the second high-frequency power are supplied at the same time, the intermodulation distortion in the reflected wave of each of the substrate processing apparatuses is different from each other, and the control section is configured to control so that the effective power of each of the substrate processing apparatuses is equal.

5. A control method of a substrate processing apparatus that performs the same processing as another substrate processing apparatus, the substrate processing apparatus including: a substrate stage for placing a substrate; a first high-frequency power source that generates first high-frequency power of a first frequency and outputs the first high-frequency power to the substrate stage; a second high-frequency power source that generates second high-frequency power of a second frequency lower than the first frequency and outputs the second high-frequency power to the substrate stage; a matching circuit that matches an output impedance of the first high-frequency power source with an impedance on a load side detected; and a control section that controls the first high-frequency power source, wherein the first high-frequency power source includes a reflected wave detector that detects a reflected wave input from the substrate stage, the control method of the substrate processing apparatus including: the control section decides a set value according to the processing content; the control section controls the first high-frequency power source so that an effective power, which is a difference obtained by subtracting a power of the reflected wave detected by the reflected wave detector from an output power of the first high-frequency power source, becomes the set value, wherein the control section calculates the effective power by integrating the power of the reflected wave in a range from a frequency obtained by subtracting a third frequency from the first frequency to a frequency obtained by adding the third frequency to the first frequency, the third frequency being an integral multiple of the second frequency, when the first high-frequency power and the second high-frequency power are supplied at the same time, the intermodulation distortion in the reflected wave of the substrate processing apparatus is different from the intermodulation distortion in the reflected wave of the another substrate processing apparatus, and the control section is configured to control so that the effective power of the substrate processing apparatus is equal to the effective power of the another substrate processing apparatus.

6. A control method of a substrate processing system including a plurality of substrate processing apparatuses, each of the substrate processing apparatuses performing the same processing, the substrate processing apparatus including: a substrate stage for placing a substrate; a first high-frequency power source that outputs first high-frequency power of a first frequency to the substrate stage; a second high-frequency power source that outputs second high-frequency power of a second frequency lower than the first frequency to the substrate stage; a matching circuit that matches an output impedance of the first high-frequency power source with an impedance on a load side detected; and a control section that controls the first high-frequency power source, wherein the control section is configured to control so that the effective power of each of the substrate processing apparatuses is equal. ​ ​ ​ ​ ​ ​ ​ ​ ​ wherein The first high-frequency power source includes a reflected wave detector that detects a reflected wave input from the substrate mounting table, The control method of the substrate processing system includes the steps of: The control section of each of the substrate processing apparatuses controls each of the first high-frequency power sources so that an effective power, which is a difference between an output power of the first high-frequency power source and a power of the reflected wave of a different frequency from the first frequency, becomes a set value common among the substrate processing apparatuses, wherein the control section calculates the effective power by integrating the power of the reflected wave in a range from a frequency obtained by subtracting a third frequency, which is an integer multiple of the second frequency, from the first frequency to a frequency obtained by adding the third frequency to the first frequency, while the first high-frequency power and the second high-frequency power are supplied at the same time, intermodulation distortions in the reflected waves of the respective substrate processing apparatuses are different from each other, and the control section is configured to control so that the effective powers of the respective substrate processing apparatuses are equalized.

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