Plasma processing apparatus and plasma state detection method

Abstract

The invention provides a plasma processing apparatus for detecting the state of plasma and a plasma state detection method. The plasma processing apparatus includes: a processing container having an internal space; a substrate support part provided in the internal space of the processing container; a gas supply unit that supplies a processing gas into the internal space of the processing container; a plasma generation unit that generates plasma in the internal space of the processing container; a vibration detection sensor provided outside the internal space of the processing container; and a control unit that detects the state of the plasma on the basis of the vibration detected by the vibration detection sensor.

Description

TECHNICAL FIELD

[0001] The present application relates to a plasma processing apparatus and a plasma state detection method. BACKGROUND

[0002] A plasma processing apparatus is disclosed in Patent Literature 1, which includes a housing chamber that houses a substrate, an electrode that is disposed in the housing chamber and applies high-frequency electric power to the housing chamber, and a pipe that introduces a processing gas to the housing chamber, and includes a potential variation detection mechanism that detects a potential variation, an ultrasonic wave detection mechanism that detects an ultrasonic wave, and an abnormal discharge determination unit that determines that abnormal discharge has occurred when the potential variation is detected and the ultrasonic wave is detected.

[0003] Patent Literature 2 discloses an abnormality detection system that detects an abnormality generated in a processing apparatus, which includes a plurality of ultrasonic wave sensors that detect acoustic emissions generated in the processing apparatus, a distribution unit that distributes each output signal of the plurality of ultrasonic wave sensors into a first signal and a second signal, a trigger generation unit that samples the first signal at a first frequency and generates a trigger signal when a prescribed feature is detected, a trigger generation time determination unit that receives the trigger signal and determines a trigger generation time, a data generation unit that generates sampling data obtained by sampling the second signal at a second frequency that is higher than the first frequency, and a data processing unit that performs waveform analysis on data corresponding to a period of time from the trigger generation time determined by the trigger generation time determination unit in the sampling data to analyze an abnormality generated in the processing apparatus.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Publication No. 2006-128304

[0007] Patent Literature 2: Japanese Patent Application Publication No. 2011-014608 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] In one aspect, the present application provides a plasma processing apparatus and a plasma state detection method that detect a state of a plasma.

[0010] TECHNICAL SOLUTION FOR SOLVING THE PROBLEMS

[0011] To solve the above-described technical problem, according to one embodiment, there is provided a plasma processing apparatus including: a processing vessel having an internal space; a substrate support portion provided in the internal space of the processing vessel; a gas supply portion that supplies a processing gas into the internal space of the processing vessel; a plasma generation portion that generates plasma in the internal space of the processing vessel; a vibration detection sensor provided outside the internal space of the processing vessel; and a control portion that detects a state of the plasma based on a vibration detected by the vibration detection sensor.

[0012] Effects of Invention

[0013] According to one aspect, it is possible to provide a plasma processing apparatus and a reaction tube wall protection member that suppress consumption of a reaction tube. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 FIG. 1 is an example of a longitudinal cross-sectional side view showing a plasma processing apparatus of one embodiment.

[0015] Figure 2 FIG. 2 is an example of a horizontal cross-sectional top view showing a plasma processing apparatus of one embodiment.

[0016] Figure 3 FIG. 3 is an example of a block diagram showing a functional structure of a control portion.

[0017] Figure 4 FIG. 4 is an example of a flowchart showing a plasma state detection method.

[0018] Figure 5 FIG. 5 is a chart showing an example of a detection result and an analysis result of a vibration.

[0019] REFERENCE NUMERALS

[0020] W wafer

[0021] 1 plasma processing apparatus (film formation apparatus)

[0022] 2 rotary table (substrate support portion)

[0023] 11 vacuum vessel

[0024] 12 vessel top plate

[0025] 13 vessel main body

[0026] 19 opening portion

[0027] 24 wafer holder (substrate support portion)

[0028] 51 to 55 gas nozzles (gas supply portion)

[0029] 61 Antenna ceiling (ceiling member)

[0030] 65 Antenna (plasma generation section)

[0031] 66 High-frequency power source (plasma generation section)

[0032] 68 Pressing ring

[0033] 69a Sealing member

[0034] 69b Sealing member

[0035] 69c Fastening member

[0036] 70 Vibration detection sensor

[0037] 100 Control section

[0038] 110 Vibration acquisition section

[0039] 120 Analysis section

[0040] 130 Plasma state determination section

[0041] R Prescribed high-frequency band DETAILED DESCRIPTION

[0042] Hereinafter, a mode for carrying out the present application will be described with reference to the accompanying drawings. In each drawing, the same reference numerals are assigned to the same components, and sometimes repeated description is omitted.

[0043] [Plasma processing apparatus]

[0044] Referring to Figure 1 and Figure 2 , a plasma processing apparatus (film forming apparatus) 1 of an embodiment of the present application will be described. Figure 1 is an example of a longitudinal sectional side view of the plasma processing apparatus 1 of one embodiment. Figure 2 is an example of a transverse sectional plan view of the plasma processing apparatus 1 of one embodiment. The plasma processing apparatus 1 is a substrate processing apparatus that generates plasma in a vacuum container 11 to perform substrate processing (plasma processing) on a wafer W as an example of a substrate.

[0045] In the following description, we will take the case where the plasma processing apparatus 1 is a film deposition apparatus that uses ALD (Atomic Layer Deposition) to deposit a film on a wafer W as an example. The plasma processing apparatus (film deposition apparatus) 1 forms a film on the wafer W by repeatedly performing the following steps: supplying a raw material gas to the wafer W to adsorb the raw material gas onto the wafer W; supplying a reactive gas to the wafer W to react the raw material gas adsorbed on the wafer W to form a molecular layer; and generating a plasma of a modified gas to expose the wafer W to the generated plasma to modify the molecular layer formed on the wafer W. In the following description, we will take the case where BTBAS (di-tert-butylaminosilane) gas, which is a processing gas containing silicon (Si), is used as the raw material gas, ozone (O3) gas, which is an oxidizing gas (a processing gas containing oxygen (O),) is used as the reactive gas, and a mixture of argon (Ar) gas and oxygen (O2) gas is used as the modified gas (plasma generation gas) to form a silicon oxide film (SiO2) as the film formed on the wafer W as an example.

[0046] The plasma processing apparatus 1 includes a generally circular, flat vacuum container 11 and a horizontal, plate-shaped rotary table (substrate support) 2 disposed within the vacuum container 11. The vacuum container 11 has a top plate 12 and a container body 13. The container body 13 has an opening at the top, forming the side walls and bottom of the vacuum container 11. The top plate 12 closes the opening formed at the top of the container body 13, constituting the top wall of the vacuum container 11.

[0047] A central shaft 21 extending vertically downward from the center of the rotating platform 2 is disposed at the center of the vacuum container 11. The central shaft 21 is connected to a rotary drive unit 22, which is configured to close an opening 14 formed at the bottom of the container body 13. The rotating platform 2 is supported within the vacuum container 11 via the central shaft 21 and the rotary drive unit 22. The rotating platform 2 rotates clockwise or counterclockwise when viewed from above the plasma processing apparatus 1. The rotary drive unit 22 is, for example, an electric actuator such as a motor. A gas supply pipe 15 discharges N2 (nitrogen) gas into the gap between the central shaft 21 and the container body 13, thereby preventing the raw material gas and oxidizing gas from spreading from the front to the back of the rotating platform 2.

[0048] Additionally, on the lower surface of the container top plate 12 of the vacuum container 11, there is a central region forming portion C that protrudes in a manner opposite to the center portion of the rotating platform 2 and appears circular when viewed from above, and two convex portions 17 that extend outward from the central region forming portion C toward the outside of the rotating platform 2 (see reference). Figure 2 The two convex portions 17 have a roughly fan-shaped planar shape with their tops cut into an arc shape.

[0049] These central region forming portions C and convex portions 17 constitute a top surface that is lower than their outer regions. The gap between the central region forming portion C and the center of the rotating platform 2 constitutes the flow path 18 for N2 gas (see reference). Figure 1 In the processing of wafer W, N2 gas is supplied from a gas supply pipe connected to the top plate 12 of the container to the flow path 18, and flows circumferentially from the flow path 18 toward the outside of the rotary table 2. This N2 gas prevents the raw material gas and the oxidizing gas from coming into contact at the center of the rotary table 2.

[0050] At the bottom of the container body 13, below the rotary table 2, a flat, annular recess 31 is formed along the circumference of the rotary table 2. An annular slit 32 is formed on the bottom surface of the recess 31, extending along the circumference of the recess 31 and penetrating the bottom of the container body 13 in the thickness direction. Furthermore, on the bottom surface of the recess 31, seven heaters 33 are arranged in a ring for heating the wafer W placed on the rotary table 2.

[0051] The heaters 33 are arranged concentrically around the rotation center of the rotary table 2. Four of the seven heaters 33 are located inside the slit 32, and the other three are located outside the slit 32. A shield 34 is provided to cover the top of each heater 33 and close the upper side of the recess 31. An annular slit 37 is provided on the shield 34, overlapping the slit 32, and the support column 41 passes through the slits 32 and 37. Furthermore, at the bottom of the container body 13, exhaust ports 35 and 36 are provided on the outer side of the recess 31 for venting exhaust from the vacuum container 11 (see reference). Figure 1 , Figure 2 Exhaust ports 35 and 36 are connected to an exhaust mechanism (not shown) consisting of a vacuum pump or the like.

[0052] like Figure 2 As shown, five circular recesses 23 are formed on the front surface of the rotary table 2 along the rotation direction of the rotary table 2, and a circular wafer holder (substrate support) 24 is provided in each recess 23. Figure 1 As shown, a recess 25 is formed on the surface of the wafer holder 24, and the wafer W can be horizontally housed within the recess 25. Therefore, the bottom surface of the recess 25 constitutes a mounting surface capable of holding the wafer W. In this example, the height of the sidewall of the recess 25 is the same as the thickness of the wafer W, for example, it is configured to be 1 mm.

[0053] Three support pillars 41 extend vertically downwards from the back of the rotating platform 2 at circumferentially spaced intervals. Figure 1As shown, each support column 41 passes through the bottom of the container body 13 via gaps 32 and 37 and is connected to a support ring 42, which is located below the container body 13 and serves as a connecting part. The support ring 42 is formed along the rotation direction of the rotating platform 2 and is horizontally arranged so as to be suspended from the container body 13 by the support column 41, and rotates together with the rotating platform 2.

[0054] Furthermore, the rotation shaft 26, serving as a rotation axis for self-rotation, extends vertically downward from the lower center of the wafer holder 24. The lower end of the rotation shaft 26 passes through the rotary table 2, through the bottom of the container body 13 via the slit 32, and through the support ring 42 and the magnetic sealing unit 20 disposed on the lower side of the support ring 42, thus connecting with the rotation drive unit 27 for self-rotation. The magnetic sealing unit 20 consists of a bearing and a magnetic seal (magnetic fluid seal). The bearing supports the rotation shaft 26 in such a way that it can rotate relative to the support ring 42, and the magnetic seal seals the gaps around the rotation shaft 26.

[0055] The aforementioned magnetic seal is configured to suppress the diffusion of particles generated from the bearing, such as lubricating oil used in the bearing, into the vacuum atmosphere outside the magnetic seal unit 20. Furthermore, by supporting the rotating shaft 26 using the bearing, the wafer holder 24 is positioned, for example, slightly suspended from the rotary table 2. Additionally, a rotation drive 27 is provided below the support ring 42, supported via the magnetic seal unit 20, causing the rotating shaft 26 to rotate about its axis. The rotation drive 27 is, for example, an electric actuator such as a motor. In the plasma processing apparatus 1, the wafer W revolves around the rotating table 2, and rotates on its own axis by the wafer holder 24 rotating in parallel with the rotation of the rotating table 2.

[0056] like Figure 1 As shown, the shielding ring 44 is configured to close the gap 32 of the container body 13 from the lower side, and is thus able to rotate together with the turntable 2. Therefore, the aforementioned rotating shaft 26 and support column 41 are arranged to pass through the shielding ring 44. The shielding ring 44 serves to prevent the rotation drive unit 27 from being exposed to the gases and the overheated heat insulation plate.

[0057] Additionally, a lower wall portion 45 is formed below the container body 13. This lower wall portion 45 is concave in cross-section and surrounds the support ring 42, the rotation drive unit 27, and the shielding ring 44. The lower wall portion 45 is annular along the rotation direction of the rotary table 2. Furthermore, at the bottom of the lower wall portion 45, five (in) spaced apart in the circumferential direction are provided. Figure 1(Only one charging mechanism 46 is shown in the figure) When the wafer W is not being processed, the rotary table 2 is stationary with its rotation drive unit 27 positioned directly below the charging mechanism 46. Charging of the respective rotation drive units 27 is achieved through contactless power supply from the charging mechanism 46. The gas supply path 47 has an opening in the space surrounded by the lower wall 45. For example, during the processing of the wafer W, the gas nozzle 48 supplies N2 gas to the space surrounded by the lower wall 45 via the gas supply path 47 to purge the space. For example, this space is connected to an exhaust path connecting the exhaust ports 35 and 36 and the aforementioned exhaust mechanism (not shown), so even if particles are generated in this space, they are removed by the N2 gas purging.

[0058] A wafer W delivery port 38 and a gate 39 for opening and closing the delivery port 38 are provided on the side wall of the container body 13 (see reference). Figure 2 The wafer W is transferred between the conveying device, which enters the vacuum container 11 through the conveying port 38, and the recess 25. Specifically, through holes are formed at corresponding positions on the bottom surface of the recess 25, the bottom of the container body 13, and the rotary table 2, and the tip of a pin moves up and down through each through hole. The transfer of the wafer W is carried out using this pin. The diagram of the pin and the through holes it passes through is omitted.

[0059] In addition, such as Figure 2 As shown, on the rotating platform 2, a raw material gas nozzle 51, a separation gas nozzle 52, an oxidation gas nozzle 53, a plasma generating gas nozzle 54, and a separation gas nozzle 55 are arranged sequentially at intervals along the rotation direction of the rotating platform 2. Each gas nozzle 51 to 55 is formed as a rod extending horizontally from the side wall of the vacuum container 11 towards the center along the diameter of the rotating platform 2, and gas is discharged downward from multiple outlets 56 formed along this diameter. Each gas nozzle (gas supply section) 51 to 55 is an example of a gas supply section that supplies gas into the vacuum container 11.

[0060] The raw material gas nozzle 51, constituting the processing gas supply mechanism, emits the aforementioned BTBAS (di-tert-butylaminosilane) gas. A nozzle cover 57 covers the raw material gas nozzle 51 and is formed in a fan shape extending upstream and downstream of the raw material gas nozzle 51 in the rotational direction of the rotary table 2. The nozzle cover 57 increases the concentration of BTBAS gas below it, thereby improving the adsorption of BTBAS gas onto the wafer W. Additionally, the oxidation gas nozzle 53 emits the aforementioned ozone (O3) gas. Separation gas nozzles 52 and 55 are gas nozzles for emitting N2 gas, arranged such that the fan-shaped protrusions 17 of the container top plate 12 are respectively divided circumferentially. The plasma generation gas nozzle 54 emits a plasma generation gas, for example, a mixture of argon (Ar) and oxygen (O2).

[0061] A fan-shaped opening 19 along the rotation direction of the rotary table 2 is provided on the top plate 12 of the container. A cup-shaped antenna top plate (top plate component) 61 made of a dielectric such as quartz, corresponding to the shape of the opening 19, is provided to close the opening 19. Figure 1 , Figure 2 When viewed along the rotation direction of the rotary table 2, the antenna top plate 61 is positioned between the oxidizing gas nozzle 53 and the protrusion 17. Figure 2 In the diagram, the location of the antenna top plate 61 is indicated by a dashed line.

[0062] A protrusion 62 is provided along the periphery of the lower surface of the antenna top plate 61. A plasma generation region is formed within the area surrounded by the protrusion 62 and between the antenna top plate 61 and the rotary table 2 (wafer holder 24). The front end of the plasma generating gas nozzle 54 extends through the protrusion 62 from the outer periphery of the rotary table 2 in a manner that allows gas to be discharged into the plasma generation region surrounded by the protrusion 62. The protrusion 62 serves to suppress the entry of N2 gas, ozone (O3) gas, and BTBAS gas below the antenna top plate 61 and to suppress the decrease in the concentration of plasma generating gas.

[0063] A recess is formed on the upper side of the antenna top plate 61, and a box-shaped Faraday shield 63 with an upward opening is disposed in the recess. An antenna 65 is mounted on the bottom surface of the Faraday shield 63 via an insulating plate member 64. The antenna 65 has a structure in which a metal wire is wound into a coil shape around a vertical axis. The antenna 65 is connected to a high-frequency power supply 66. A slit 67 (see reference) is formed on the bottom surface of the Faraday shield 63. Figure 2 The slit 67 serves to prevent the electric field component of the electromagnetic field generated in the antenna 65 when a high frequency is applied to it from moving downwards, and also serves to allow the magnetic field component to move downwards. Multiple slits 67 extend in a direction orthogonal (intersecting) to the winding direction of the antenna 65, and are formed along the winding direction of the antenna 65. By configuring these components in this way, the antenna 65 is configured to couple with the vacuum container 11, enabling the generation of plasma within the vacuum container 11. When the high-frequency power supply 66 is switched on and high-frequency electrical power is applied to the antenna 65, the plasma supplied to the area below the antenna top plate 61 can be plasmaized using gas plasma generation. Furthermore, the antenna 65 and the high-frequency power supply 66 constitute a plasma generation unit for generating plasma within the vacuum container 11.

[0064] The protrusion 62 of the antenna top plate 61 and the portion inside the protrusion 62 are inserted into the opening 19 of the container top plate 12. The antenna top plate 61 has a flange that extends further outward in the horizontal direction than the protrusion 62. The lower peripheral surface of the flange is secured by the container top plate 12, and the upper peripheral surface of the flange is pressed and fixed by a pressing ring 68. That is, the flange of the antenna top plate 61 is clamped by the container top plate 12 and the pressing ring 68. A sealing member 69a is disposed and clamped between the lower peripheral surface of the flange of the antenna top plate 61 and the container top plate 12. A sealing member 69b is disposed and clamped between the upper peripheral surface of the flange of the antenna top plate 61 and the pressing ring 68. Furthermore, the pressing ring 68 is fixed to the container top plate 12 by fastening members 69c (not shown) such as bolts.

[0065] In addition, the plasma processing apparatus 1 is equipped with a vibration detection sensor 70 for detecting high-frequency vibrations of the plasma processing apparatus 1. As the vibration detection sensor 70, vibration sensors such as AE (Acoustic Emission) sensors, piezoelectric elements, and SAW (Surface Acoustic Wave) sensors can be widely used.

[0066] In particular, the vibration detection sensor 70 is preferably a sensor using a sheet-like piezoelectric element that can detect vibrations at frequencies with a wide frequency band (e.g., a band from 0.01 Hz to 1000 kHz). This results in high sensitivity and a high signal-to-noise ratio, enabling the appropriate detection of minute vibrations at a specified high frequency band (e.g., around 500 kHz, specifically 450 kHz to 550 kHz). Furthermore, by using the vibration detection sensor 70 capable of detecting vibrations at frequencies with a wide frequency band, transient phenomena during plasma ignition can be detected.

[0067] The vibration detection sensor 70 is preferably located near the plasma generation region. Specifically, the vibration detection sensor 70 is provided on the pressing ring 68 of the antenna top plate 61 that presses against the top wall of the plasma generation region. Thus, the vibration detection sensor 70 detects high-frequency vibrations of the antenna top plate 61. Alternatively, the vibration detection sensor 70 may be directly mounted on the antenna top plate 61.

[0068] In addition, for Figure 1 and Figure 2 The plasma processing device 1 shown has been described with a single plasma generation region, but is not limited to this structure. The plasma processing device 1 may also have a structure with multiple plasma generation regions. In this case, a vibration detection sensor 70 may be provided on the pressing ring 68 of the antenna top plate 61 corresponding to each plasma generation region.

[0069] On the rotary table 2, the area below the nozzle cover 57 of the raw material gas nozzle 51 is designated as an adsorption region R1 for adsorbing BTBAS gas, which is used as the raw material gas, and the area below the oxidizing gas nozzle 53 is designated as an oxidation region R2 for oxidizing BTBAS gas using ozone (O3) gas. Additionally, the area below the antenna top plate 61 is designated as a plasma formation region R3 for modifying the SiO2 film using plasma. The areas below the convex portion 17 are respectively configured as separation regions D and D, which are used to separate the adsorption region R1 and the oxidation region R2 from each other using N2 gas emitted from the separation gas nozzles 52 and 55 to prevent the raw material gas and the oxidizing gas from mixing.

[0070] The aforementioned exhaust port 35 has an opening on the outer side between the adsorption region R1 and the separation region D adjacent to the adsorption region R1 on the downstream side of the rotation direction, for discharging the remaining BTBAS gas. The exhaust port 36 has an opening on the outer side near the boundary between the plasma formation region R3 and the separation region D adjacent to the plasma formation region R3 on the downstream side of the rotation direction, for discharging the remaining O3 gas and plasma generation gas. N2 gas supplied from each separation region D, the gas supply pipe 15 below the rotating stage 2, and the central region forming section C of the rotating stage 2 is also discharged from each exhaust port 35 and 36.

[0071] The plasma processing device 1 is equipped with a control unit 100 that controls the operation of the entire control device (see reference). Figure 1 The control unit 100 is, for example, configured as a computer. The control unit 100 stores a program for executing the substrate processing method. The program sends control signals to each part of the plasma processing apparatus 1 to control the operation of each part. For example, the control signals control the gas flow rate supplied from each gas nozzle 51-55, the temperature of the wafer W generated by the heater 33, the flow rate of N2 gas supplied from the gas supply pipe 15 and the central region forming section C, the rotational speed of the rotary table 2, and the rotational speed of the wafer holder 24. Furthermore, the scheme (program) sets the process conditions for executing the substrate processing method for each step. The scheme and other programs are installed in the control unit 100 from storage media such as hard disks, optical disks, optical discs, memory cards, and floppy disks.

[0072] In this plasma processing apparatus 1, the wafer W revolves and passes through the adsorption region R1, separation region D, oxidation region R2, plasma formation region R3, and separation region D in sequence as the rotary stage 2 rotates, thereby performing an ALD-based film formation process. As described above, the wafer W rotates in parallel with the rotation of the rotary stage 2 by rotating the wafer holder 24, but the rotation of the rotary stage 2 and the rotation of the wafer holder 24 are not synchronized. However, the rotation of the rotary stage 2 and the rotation of the wafer holder 24 can also be synchronized. Specifically, when the rotary stage 2 rotates one revolution from a predetermined position in the vacuum container 11 toward a first orientation and returns to the predetermined position, the wafer W rotates at a rotational speed (rotational speed) that is a second orientation different from the first orientation. The setting of the rotational speed (unit: rpm) of the wafer W, as described later, is performed by the control unit 100 based on parameters set by the operator from a specific setting screen.

[0073] [Plasma State Detection Methods]

[0074] Next, use Figures 3 to 4 This describes the plasma state detection method. Figure 3 This is an example of a block diagram showing the functional structure of the control unit 100.

[0075] The control unit 100 includes a vibration acquisition unit 110, an analysis unit 120, and a plasma state determination unit 130.

[0076] The vibration acquisition unit 110 acquires the detection signal from the vibration detection sensor 70.

[0077] The analysis unit 120 analyzes the vibration acquired by the vibration acquisition unit 110. Here, the analysis unit 120 performs frequency analysis on the vibration, for example, using Fourier analysis.

[0078] The plasma state determination unit 130 determines the plasma state based on the analysis results of the analysis unit 120. Specifically, based on the analysis results of the analysis unit 120, the plasma state determination unit 130 determines at least one of the following: plasma ignition, ignition delay, and extinguishment.

[0079] Figure 4 This is an example of a flowchart illustrating a plasma state detection method.

[0080] In step S101, the high-frequency electrical power applied to the antenna 65 is controlled. Here, the control unit 100 controls the high-frequency power supply 66 to control the high-frequency electrical power applied to the antenna 65. Furthermore, the control of the high-frequency electrical power applied to the antenna 65 includes starting and ending the application of high-frequency electrical power to the antenna 65.

[0081] In step S102, vibration of the pressing ring 68 (antenna top plate 61) is detected. Here, the vibration detection sensor 70 detects the vibration of the pressing ring 68 (antenna top plate 61) and outputs the detection signal to the vibration acquisition unit 110. Then, the vibration acquisition unit 110 acquires the detection signal from the vibration detection sensor 70.

[0082] In step S103, the plasma state is detected. The control unit 100 determines the plasma state (at least one of plasma ignition, ignition delay, and extinction) based on the vibration of the pressing ring 68 (antenna top plate 61) acquired by the vibration acquisition unit 110. Specifically, the analysis unit 120 performs frequency analysis on the vibration acquired by the vibration acquisition unit 110, for example, using Fourier analysis. Then, the plasma state determination unit 130 determines the plasma state in a predetermined high-frequency band R (see below). Figure 5 (c) Figure 5 (d). For example, the frequency band around 500kHz. Specifically, the frequency band from 450kHz to 550kHz. If the spectral intensity in the specified high-frequency band R exceeds a predetermined threshold, the plasma is determined to be in a state of ignition. On the other hand, if the spectral intensity in the specified high-frequency band R does not exceed the predetermined threshold, the plasma is determined to be in a state of extinction.

[0083] Figure 5 This is a graph representing an example of vibration detection and analysis results.

[0084] Figure 5 (a) shows the vibration (original waveform) of the pressing ring 68 (antenna top plate 61) detected by the vibration detection sensor 70 and acquired by the vibration acquisition unit 110. The horizontal axis represents time. The vertical axis represents the amplitude of the vibration. In addition, hollow arrows indicate the moment when high-frequency electrical power (Plasma On) is applied to the antenna 65 and the moment when high-frequency electrical power (Plasma Off) is applied to the antenna 65.

[0085] like Figure 5 As shown in (a), the amplitude of the vibration is represented before plasma generation (before Plasma On), during plasma generation (between Plasma On and Plasma Off), and after plasma generation (after Plasma Off).

[0086] Figure 5 (b) is a graph showing the frequency at which the spectral intensity reaches its peak after frequency analysis of the vibration using Fourier analysis. The horizontal axis represents time. The vertical axis represents the frequency of the vibration at which the spectral intensity reaches its peak. Here, the analysis unit 120 performs Fourier analysis on the vibration (refer to...) Figure 5 Frequency analysis is performed on (a) to calculate the spectral intensity for each frequency. Furthermore, inFigure 5 (b) shows a graph plotting the frequency of vibrations where the spectral intensity reaches its peak (maximum).

[0087] Figure 5 (c) is a graph showing the relationship between the frequency of the vibration and the spectral intensity when the plasma is extinguished (A-A' or C-C'). Figure 5 (d) is a graph showing the relationship between the frequency and spectral intensity of the vibration (B-B') during plasma ignition. Figure 5 (c) and Figure 5 In (d), the vertical axis represents the frequency of vibration, and the horizontal axis represents the spectral intensity corresponding to the frequency of vibration.

[0088] like Figure 5 (b) and Figure 5 As shown in (c), no peak in spectral intensity was observed before plasma generation (before Plasma On).

[0089] like Figure 5 As shown in (b), when high-frequency electrical power (Plasma On) is first applied to antenna 65, the frequency at which the spectral intensity peaks changes transiently. That is, when high-frequency electrical power (Plasma On) is first applied to antenna 65, the frequency at which the spectral intensity peaks increases. By using a vibration detection sensor 70 capable of detecting a wide bandwidth, such as... Figure 5 As shown in (b), it is possible to detect transient changes in the vibration. In other words, it is possible to detect transient changes in the state of the plasma.

[0090] like Figure 5 (b) and Figure 5 As shown in (d), after plasma ignition, when the plasma state becomes stable, a peak value of the spectral intensity appears in a predetermined high-frequency band R. That is, the plasma state determination unit 130 can determine whether the plasma has been ignited based on whether a peak value of the spectral intensity appears in the predetermined high-frequency band R. In other words, if the spectral intensity in the predetermined high-frequency band R is above a predetermined threshold, the plasma state determination unit 130 can determine that the plasma has been ignited. Furthermore, if the time difference from the start of applying high-frequency electrical power (Plasma On) to the moment when plasma ignition is determined exceeds a predetermined threshold time, it can be determined that an ignition delay has occurred.

[0091] like Figure 5 (b) and Figure 5As shown in (c), when the application of high-frequency electrical power (Plasma Off) to antenna 65 is stopped, no peak appears in the spectral intensity. That is, when the spectral intensity in the specified high-frequency band R is less than a specified threshold, the plasma state determination unit 130 can determine that the plasma is extinguished.

[0092] Thus, the analysis unit 120 analyzes the vibration detected by the vibration detection sensor 70 (e.g., Fourier analysis) and determines the amplitude of the detected vibration (refer to...). Figure 5 (a)) Calculates the spectral intensity of each frequency. Then, the plasma state determination unit 130 can determine the transient changes in the frequency at which the spectral intensity peaks (refer to...). Figure 1 (b) is used to detect transient changes in the state of the plasma.

[0093] Furthermore, when the spectral intensity of the plasma state determination unit 130 in the specified high-frequency band R is above a specified threshold (see reference...), Figure 2 (d) indicates that the plasma has been ignited. On the other hand, if the spectral intensity of the plasma state determination unit 130 in the specified high-frequency band R is not above a specified threshold (refer to...). ​ (c) is used to determine the state of plasma extinction. In addition, even in the case of unexpected plasma extinction, plasma extinction can be detected by determining that the spectral intensity in the specified high-frequency band R is not above the specified threshold.

[0094] Furthermore, the specified high-frequency band R can also be a band that includes the inherent vibration frequencies of the antenna top plate 61 and / or the pressing ring 68 that vibrate due to plasma generation. Additionally, the peak value and bandwidth of the detected spectrum vary depending on the inherent vibration frequency and rigidity of the object on which the sensor is mounted.

[0095] Furthermore, plasma processing apparatuses are known to have sapphire glass windows on the side walls of the container body, and plasma emission within the vacuum container is detected via the sapphire glass windows using an optical detector located outside the container body, thereby detecting the state of the plasma. Compared to such plasma processing apparatuses, the plasma processing apparatus 1 of this embodiment does not require expensive sapphire glass windows, thus reducing apparatus costs. Additionally, the elimination of windows on the side walls of the container body prevents leakage.

[0096] In addition, by providing a vibration detection sensor 70 on the outside of the processing space (the internal space of the vacuum container 11) of the plasma processing device 1 (for example, on the upper surface of the pressing ring 68), the state of the plasma can be detected.

[0097] Furthermore, the plasma processing device 1, which detects the state of the plasma based on the vibration detected by the vibration detection sensor 70, ... ​ and ​ The structure shown is an example, but it is not limited to this structure. In inductively coupled plasma (ICP) devices, capacitively coupled plasma (CCP) devices, and microwave plasma (MP) devices, it can also be applied to structures that detect the state of plasma based on vibrations detected by vibration detection sensors. Furthermore, the case where plasma processing apparatus 1 is used as a film-forming apparatus is illustrated as an example, but it is not limited to this and can also be applied to plasma etching apparatuses.

[0098] Furthermore, the present invention is not limited to the structures exemplified in the above embodiments, or combinations of other elements shown herein. Modifications can be made in these aspects without departing from the spirit of the invention, and can be appropriately determined depending on its application.

Claims

1. A plasma processing device, characterized in that, include: A processing container with internal space; A substrate support portion disposed within the internal space of the processing container; A gas supply unit that supplies processing gas to the internal space of the processing container; A plasma generation unit that generates plasma within the internal space of the processing container; Vibration detection sensors disposed outside the internal space of the processing container; and Control Department The control unit detects the state of the plasma based on the vibration detected by the vibration detection sensor.

2. The plasma processing apparatus according to claim 1, characterized in that: The control unit analyzes the vibration detected by the vibration detection sensor to calculate the spectral intensity corresponding to the frequency. The control unit detects the state of the plasma based on the transient changes in the peak value of the spectral intensity.

3. The plasma processing apparatus according to claim 1, characterized in that: The control unit analyzes the vibration detected by the vibration detection sensor to calculate the spectral intensity corresponding to the frequency. The control unit detects at least one of the following: ignition, ignition delay, and extinguishing of the plasma, based on the spectral intensity in a specified frequency band.

4. The plasma processing apparatus according to claim 3, characterized in that: The processing container includes: The container body has an opening at the top; The container top plate that closes the opening; A top plate component, disposed at the opening of the container top plate and positioned above the plasma generation region; and A pressing ring secures the top plate component to the top plate of the container. The vibration detection sensor is disposed on the top plate component or the pressing ring.

5. The plasma processing apparatus according to claim 4, characterized in that: The specified frequency band is the frequency band that includes the inherent vibration frequency of the top plate component or the pressing ring.

6. A method for detecting the plasma state of a plasma processing device, characterized in that: The plasma processing device includes: A processing container with internal space; A substrate support portion disposed within the internal space of the processing container; A gas supply unit that supplies processing gas to the internal space of the processing container; A plasma generating unit that generates plasma within the internal space of the processing container; and Vibration detection sensors are disposed outside the internal space of the processing container. The plasma state detection method detects the state of the plasma based on the vibration detected by the vibration detection sensor.

7. The plasma state detection method according to claim 6, characterized in that: The vibrations detected by the vibration detection sensor are analyzed to calculate the spectral intensity corresponding to the frequency. The state of the plasma is detected based on the transient changes in the peak value of the spectral intensity.

8. The plasma state detection method according to claim 6, characterized in that: The vibrations detected by the vibration detection sensor are analyzed to calculate the spectral intensity corresponding to the frequency. The ignition or extinguishing of the plasma is detected based on the spectral intensity within a specified frequency band.

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