Particle monitoring system, particle monitoring method, and monitoring device

Abstract

This particle monitor system comprises: a light-emitting device that emits light into a plasma processing device; and a monitor device mounted on a stage inside the plasma processing device. The monitor device includes: a base substrate; a plurality of imaging devices; and a control device. The base substrate has a plate shape. The plurality of imaging devices each have an optical axis directed upward on the base substrate, are disposed apart from each other, and capture images containing scattered light from particles irradiated with light. The control device identifies particles in the images captured by the plurality of imaging devices.

Description

[Technical field]

[0001] Exemplary embodiments of the present disclosure relate to a particle monitoring system, a particle monitoring method, and a monitoring apparatus. [Background technology]

[0002] Patent Document 1 discloses a technique for measuring the number of particles in a chamber. In this technique, an ISPM (In Situ Particle Monitor) consisting of a laser oscillator and a photodetector is provided in the chamber. The ISPM measures the number of particles moving in the chamber. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-180015 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for acquiring particle distribution data in a plasma processing apparatus. [Means for solving the problem]

[0005] In one exemplary embodiment, a particle monitor system for measuring particles in a plasma processing apparatus is provided. The system includes a light emitting device that irradiates light into the plasma processing apparatus, and a monitor device that is placed on a stage in the plasma processing apparatus. The monitor device includes a base substrate, a plurality of imaging devices, and a control device. The base substrate is plate-shaped. The plurality of imaging devices have optical axes facing upward on the base substrate, are arranged spaced apart from one another, and capture images that include scattered light from particles irradiated with light. The control device identifies particles in images captured by the plurality of imaging devices. Effect of the Invention

[0006] According to one exemplary embodiment, a particle monitor system can obtain data on the distribution of particles in a plasma processing apparatus. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating a processing system. [Diagram 2] FIG. 2 is a perspective view illustrating an aligner. [Diagram 3] FIG. 3 is a diagram showing an example of a plasma processing apparatus. [Figure 4] FIG. 4 is a plan view of an example of a monitor device as viewed from the top side. [Diagram 5] FIG. 5 is a block diagram showing a configuration of an example of a monitor device. [Figure 6] FIG. 6 is a schematic diagram for explaining the imaging range of an imaging device in an example of a monitor device. [Figure 7] FIG. 7 is a diagram illustrating an example of a composite image based on images captured by an imaging device. [Figure 8] FIG. 8 is a flow chart illustrating an example of a method of operation of the monitoring device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Various exemplary embodiments are described below.

[0009] In one exemplary embodiment, a particle monitor system for measuring particles in a plasma processing apparatus is provided. The system includes a light emitting device that irradiates light into the plasma processing apparatus, and a monitor device that is placed on a stage in the plasma processing apparatus. The monitor device includes a base substrate, a plurality of imaging devices, and a control device. The base substrate is plate-shaped. The plurality of imaging devices have optical axes facing upward on the base substrate, are arranged spaced apart from one another, and capture images that include scattered light from particles irradiated with light. The control device identifies particles in images captured by the plurality of imaging devices.

[0010] In one exemplary embodiment, a particle monitoring method is provided for measuring particles in a plasma processing apparatus using a monitoring device. The monitoring device includes a plate-shaped base substrate and a plurality of imaging devices arranged spaced apart from each other on the base substrate, with optical axes facing upward. The method includes a step of placing the monitoring device on a stage in a chamber of the plasma processing apparatus. The method includes a step of irradiating light into the chamber of the plasma processing apparatus. The method includes a step of capturing images of scattered light from particles irradiated with the light by the plurality of imaging devices. The method includes a step of identifying particles in images captured by the plurality of imaging devices.

[0011] In the particle monitor system and particle monitor method of the above embodiment, particles in the plasma processing apparatus are imaged by a plurality of imaging devices of a monitor device mounted on a stage. The plurality of imaging devices are arranged spaced apart from each other on a base substrate. Therefore, the imaging ranges imaged by each imaging device are different from each other. That is, each imaging device can image particles in different regions in the plasma processing apparatus. Therefore, in the particle monitor system and particle monitor method, the particle distribution in the plasma processing apparatus can be obtained by identifying particles in images imaged by the plurality of imaging devices.

[0012] In one exemplary embodiment, the light emitting device may be a laser oscillator that radiates laser light as the light.

[0013] In one exemplary embodiment, the controller may count particles in images captured by multiple imaging devices.

[0014] In one exemplary embodiment, the control device may obtain the positions of particles within images captured by multiple image capture devices, in which case a more detailed distribution of particles may be obtained.

[0015] In one exemplary embodiment, the controller may obtain particle sizes from images captured by multiple imaging devices.

[0016] In one exemplary embodiment, the imaging ranges of the multiple imaging devices in the plasma processing apparatus may not include overlapping areas, which can prevent particles from being counted in duplicate.

[0017] In one exemplary embodiment, the step of imaging with the multiple imaging devices may be performed in a state where gas is supplied into the chamber, in which case particles may be counted in an environment where gas is supplied into the chamber.

[0018] In one exemplary embodiment, the step of imaging with the multiple imagers may be performed with a plasma being generated in the chamber, such that particles in the plasma-generated environment may be counted.

[0019] Various embodiments will be described in detail below with reference to the drawings, in which the same or corresponding parts are designated by the same reference numerals.

[0020] The monitor device 100 according to an exemplary embodiment cooperates with a processing system 1 having a function as a semiconductor manufacturing device S1 to configure a particle monitor system. First, a processing system having a processing device for processing a workpiece and a transport device for transporting the workpiece to the processing device will be described. FIG. 1 is a diagram illustrating an example of the processing system. The processing system 1 includes stages 2a-2d, containers 4a-4d, a loader module LM, an aligner AN, load lock modules LL1 and LL2, process modules PM1-PM5, a transfer module TF, and a controller MC. Note that the number of stages 2a-2d, the number of containers 4a-4d, the number of load lock modules LL1 and LL2, and the number of process modules PM1-PM5 are not limited and may be any number equal to or greater than one.

[0021] The stages 2a to 2d are arranged along one edge of the loader module LM. The containers 4a to 4d are mounted on the stages 2a to 2d, respectively. Each of the containers 4a to 4d is, for example, a container called a FOUP (Front Opening Unified Pod). Each of the containers 4a to 4d can be configured to accommodate a workpiece W. The workpiece W has a substantially disk shape, such as a wafer.

[0022] The loader module LM has a chamber wall that defines a transfer space therein under atmospheric pressure. A transfer device TU1 is provided in this transfer space. The transfer device TU1 is, for example, an articulated robot, and is controlled by a control unit MC. The transfer device TU1 is configured to transfer the workpiece W between the containers 4a-4d and the aligner AN, between the aligner AN and the load lock modules LL1-LL2, and between the load lock modules LL1-LL2 and the containers 4a-4d.

[0023] The aligner AN is connected to the loader module LM. The aligner AN is configured to adjust (calibrate) the position of the workpiece W. FIG. 2 is a perspective view illustrating the aligner. The aligner AN has a support table 6T, a drive unit 6D, and a sensor 6S. The support table 6T is a table that can rotate about an axis extending in the vertical direction, and is configured to support the workpiece W thereon. The support table 6T is rotated by the drive unit 6D. The drive unit 6D is controlled by the control unit MC. When the support table 6T rotates by the power from the drive unit 6D, the workpiece W placed on the support table 6T also rotates.

[0024] The sensor 6S is an optical sensor, and detects the edge of the workpiece W while the workpiece W is being rotated. From the edge detection result, the sensor 6S detects the amount of deviation of the angular position of the notch WN (or another marker) of the workpiece W relative to the reference angular position, and the amount of deviation of the center position of the workpiece W relative to the reference position. The sensor 6S outputs the amount of deviation of the angular position of the notch WN and the amount of deviation of the center position of the workpiece W to the control unit MC. Based on the amount of deviation of the angular position of the notch WN, the control unit MC calculates the amount of rotation of the support table 6T for correcting the angular position of the notch WN to the reference angular position. The control unit MC controls the drive unit 6D to rotate the support table 6T by this amount of rotation. This allows the angular position of the notch WN to be corrected to the reference angular position. The control unit MC may also correct the angular position of the notch WN to an arbitrary angular position. In addition, the control unit MC controls the position of the end effector of the transport device TU1 when receiving the workpiece W from the aligner AN, based on the deviation of the center position of the workpiece W. This causes the center position of the workpiece W to coincide with a predetermined position on the end effector of the transport device TU1.

[0025] 1, each of the load lock modules LL1 and LL2 is provided between the loader module LM and the transfer module TF. Each of the load lock modules LL1 and LL2 provides a preliminary reduced pressure chamber.

[0026] The transfer module TF is airtightly connected to the load lock modules LL1 and LL2 via gate valves. The transfer module TF provides a decompression chamber capable of reducing pressure. A transfer device TU2 is provided in this decompression chamber. The transfer device TU2 is, for example, an articulated robot having a transfer arm TUa, and is controlled by a control unit MC. The transfer device TU2 is configured to transfer a workpiece W between the load lock modules LL1-LL2 and the process modules PM1-PM5, and between any two of the process modules PM1-PM5.

[0027] The process modules PM1 to PM5 are airtightly connected to the transfer module TF via gate valves. Each of the process modules PM1 to PM5 is a processing device configured to perform a dedicated process such as a plasma process on the workpiece W.

[0028] A series of operations when the workpiece W is processed in the processing system 1 is exemplified as follows. The transfer device TU1 of the loader module LM takes out the workpiece W from one of the containers 4a to 4d and transfers the workpiece W to the aligner AN. Then, the transfer device TU1 takes out the workpiece W whose position has been adjusted from the aligner AN and transfers the workpiece W to one of the load lock modules LL1 and LL2. Then, one of the load lock modules reduces the pressure in the preliminary decompression chamber to a predetermined pressure. Then, the transfer device TU2 of the transfer module TF takes out the workpiece W from one of the load lock modules and transfers the workpiece W to one of the process modules PM1 to PM5. Then, one or more of the process modules PM1 to PM5 process the workpiece W. Then, the transfer device TU2 transfers the processed workpiece W from the process module to one of the load lock modules LL1 and LL2. Next, the transfer device TU1 transfers the workpiece W from one of the load lock modules to any one of the containers 4a to 4d.

[0029] As described above, the processing system 1 includes a control unit MC. The control unit MC may be a computer including a processor, a storage device such as a memory, a display device, an input / output device, a communication device, etc. The series of operations of the processing system 1 described above are realized by the control unit MC controlling each part of the processing system 1 according to a program stored in the storage device.

[0030] Fig. 3 is a diagram showing an example of a plasma processing apparatus that can be employed as any one of the process modules PM1 to PM5. The plasma processing apparatus 10 shown in Fig. 3 is a capacitively coupled plasma etching apparatus. The plasma processing apparatus 10 includes a chamber body 12 having a substantially cylindrical shape. The chamber body 12 is made of, for example, aluminum, and an inner wall surface thereof may be anodized. The chamber body 12 is safety grounded.

[0031] A substantially cylindrical support 14 is provided on the bottom of the chamber body 12. The support 14 is made of, for example, an insulating material. The support 14 is provided within the chamber body 12 and extends upward from the bottom of the chamber body 12. A stage ST is provided within a chamber S provided by the chamber body 12. The stage ST is supported by the support 14.

[0032] The stage ST has a lower electrode LE and an electrostatic chuck ESC. The lower electrode LE includes a first plate 18a and a second plate 18b. The first plate 18a and the second plate 18b are made of a metal such as aluminum and have a substantially disk shape. The second plate 18b is provided on the first plate 18a and is electrically connected to the first plate 18a.

[0033] An electrostatic chuck ESC is provided on the second plate 18b. The electrostatic chuck ESC has a structure in which an electrode, which is a conductive film, is disposed between a pair of insulating layers or insulating sheets, and has a substantially disk shape. A DC power supply 22 is electrically connected to the electrode of the electrostatic chuck ESC via a switch 23. The electrostatic chuck ESC attracts the workpiece W by electrostatic force such as Coulomb force generated by a DC voltage from the DC power supply 22. This allows the electrostatic chuck ESC to hold the workpiece W.

[0034] A focus ring FR is provided on the peripheral portion of the second plate 18b so as to surround the edge of the workpiece W and the electrostatic chuck ESC. The focus ring FR may be made of any of a variety of materials, such as silicon, silicon carbide, or silicon oxide.

[0035] A coolant flow passage 24 is provided inside the second plate 18b. The coolant flow passage 24 constitutes a temperature adjustment mechanism. A coolant is supplied to the coolant flow passage 24 from a chiller unit provided outside the chamber body 12 via a pipe 26a. The coolant supplied to the coolant flow passage 24 is returned to the chiller unit via a pipe 26b. In this manner, the coolant is circulated between the coolant flow passage 24 and the chiller unit. By controlling the temperature of this coolant, the temperature of the workpiece W supported by the electrostatic chuck ESC is controlled.

[0036] A plurality of (for example, three) through holes 25 are formed in the stage ST and pass through the stage ST. The plurality of through holes 25 are formed inside the electrostatic chuck ESC in a plan view. A lift pin 25a is inserted into each of the through holes 25. Note that FIG. 3 illustrates one through hole 25 into which one lift pin 25a is inserted. The lift pin 25a is provided so as to be movable up and down within the through hole 25. As the lift pin 25a rises, the workpiece W supported on the electrostatic chuck ESC rises.

[0037] A plurality of (e.g., three) through holes 27 penetrating the stage ST (lower electrode LE) are formed in the stage ST at positions outside the electrostatic chuck ESC in a plan view. A lift pin 27a is inserted into each of the through holes 27. Note that FIG. 3 illustrates one through hole 27 into which one lift pin 27a is inserted. The lift pin 27a is provided so as to be movable up and down within the through hole 27. As the lift pin 27a rises, the focus ring FR supported on the second plate 18b rises.

[0038] The plasma processing apparatus 10 is also provided with a gas supply line 28. The gas supply line 28 supplies a heat transfer gas, for example, He gas, from a heat transfer gas supply mechanism to between the upper surface of the electrostatic chuck ESC and the back surface of the workpiece W.

[0039] The plasma processing apparatus 10 also includes an upper electrode 30. The upper electrode 30 is disposed above the stage ST and faces the stage ST. The upper electrode 30 is supported on the upper part of the chamber body 12 via an insulating shielding member 32. The upper electrode 30 may include a top plate 34 and a support 36. The top plate 34 faces the chamber S, and is provided with a plurality of gas ejection holes 34a. The top plate 34 may be made of silicon or quartz. Alternatively, the top plate 34 may be formed by forming a plasma-resistant film such as yttrium oxide on the surface of an aluminum base material.

[0040] The support 36 detachably supports the top plate 34 and may be made of a conductive material such as aluminum. The support 36 may have a water-cooled structure. A gas diffusion chamber 36a is provided inside the support 36. A plurality of gas flow holes 36b that communicate with the gas discharge holes 34a extend downward from the gas diffusion chamber 36a. The support 36 is also formed with a gas inlet 36c that introduces a process gas into the gas diffusion chamber 36a, and a gas supply pipe 38 is connected to the gas inlet 36c.

[0041] A gas source group 40 is connected to the gas supply pipe 38 via a valve group 42 and a flow rate controller group 44. The gas source group 40 includes a plurality of gas sources for a plurality of types of gas. The valve group 42 includes a plurality of valves, and the flow rate controller group 44 includes a plurality of flow rate controllers such as mass flow controllers. The plurality of gas sources in the gas source group 40 are connected to the gas supply pipe 38 via the corresponding valves in the valve group 42 and the corresponding flow rate controllers in the flow rate controller group 44.

[0042] Furthermore, in the plasma processing apparatus 10, a deposit shield 46 is detachably provided along the inner wall of the chamber body 12. The deposit shield 46 is also provided on the outer periphery of the support part 14. The deposit shield 46 prevents etching by-products (deposits) from adhering to the chamber body 12, and may be formed by coating an aluminum material with ceramics such as yttrium oxide.

[0043] An exhaust plate 48 is provided on the bottom side of the chamber body 12 and between the support 14 and the side wall of the chamber body 12. The exhaust plate 48 can be made, for example, by coating ceramics such as yttrium oxide on an aluminum material. A plurality of holes are formed in the exhaust plate 48, penetrating in the plate thickness direction. An exhaust port 12e is provided below the exhaust plate 48 and in the chamber body 12. An exhaust device 50 is connected to the exhaust port 12e via an exhaust pipe 52. The exhaust device 50 has a pressure adjustment valve and a vacuum pump such as a turbo molecular pump, and can reduce the pressure of the space in the chamber body 12 to a desired vacuum level. In addition, a load / unload port 12g for the workpiece W is provided on the side wall of the chamber body 12, and the load / unload port 12g can be opened and closed by a gate valve 54.

[0044] The plasma processing apparatus 10 further includes a first high frequency power supply 62 and a second high frequency power supply 64. The first high frequency power supply 62 is a power supply that generates a first high frequency for generating plasma, and generates a high frequency having a frequency of, for example, 27 to 100 MHz. The first high frequency power supply 62 is connected to the upper electrode 30 via a matching device 66. The matching device 66 has a circuit for matching the output impedance of the first high frequency power supply 62 with the input impedance on the load side (upper electrode 30 side). The first high frequency power supply 62 may be connected to the lower electrode LE via the matching device 66.

[0045] The second high frequency power supply 64 is a power supply that generates a second high frequency for attracting ions into the workpiece W, and generates a high frequency with a frequency within a range of, for example, 400 kHz to 13.56 MHz. The second high frequency power supply 64 is connected to the lower electrode LE via a matching device 68. The matching device 68 has a circuit for matching the output impedance of the second high frequency power supply 64 with the input impedance on the load side (the lower electrode LE side).

[0046] In the plasma processing apparatus 10, gas is supplied to the chamber S from one or more selected gas sources among a plurality of gas sources. The pressure in the chamber S is set to a predetermined pressure by the exhaust device 50. The gas in the chamber S is excited by a first high frequency wave from the first high frequency power supply 62. This generates plasma. The workpiece W is then processed by the generated activated species. If necessary, ions may be attracted to the workpiece W by a bias based on the second high frequency wave from the second high frequency power supply 64.

[0047] A window 12w that transmits light is provided in the peripheral wall of the chamber body 12. The window 12w is provided at a position above the stage ST in the up-down direction. A laser oscillator 70 (light emitting device) that emits laser light 70L may be arranged outside the window 12w. The laser oscillator 70 is arranged outside the chamber body 12 so that the laser light 70L is irradiated into the chamber S from the window 12w. Various optical components may be arranged on the optical path between the window 12w and the laser oscillator 70. The laser oscillator 70 irradiates the laser light 70L into the chamber body 12 through the window 12w. The optical axis of the laser light 70L irradiated from the laser oscillator 70 may be parallel to the stage ST above the stage ST.

[0048] The laser oscillator 70 scans the inside of the chamber body in the horizontal direction, for example, with a pulsed laser beam 70L. That is, a horizontal plane that is a predetermined height higher than the stage ST is scanned with the laser beam 70L. In one example, the wavelength of the laser beam 70L may be about 532 nm, but the wavelength of the laser beam 70L is not limited to this. For example, the laser oscillator 70 may be connected to a computer 88 described later, and the operation of the laser oscillator 70 may be controlled by the computer 88.

[0049] Next, a description will be given of the monitor device 100. The monitor device 100 captures images of particles in the chamber body 12 of the plasma processing device 10. The monitor device 100, as an example, is a device for placing an image capturing device at a predetermined position on a stage ST in a process module PM (plasma processing device 10), and may therefore be referred to as a jig.

[0050] FIG. 4 is a schematic plan view of an example of the monitoring device 100 seen from the top side. FIG. 5 is a block diagram showing an example of the monitoring device 100. FIG. 5 also shows a schematic view of a dedicated FOUP 4F used when using the monitoring device 100. The FOUP 4F may be any one of the containers 4a to 4d. The monitoring device 100 has a base substrate 110, a control substrate 120, and a battery 140. The monitoring device 100 can be transported from the FOUP 4F to above the stage ST (i.e., above the electrostatic chuck ESC) by the transport devices TU1 and TU2 of the processing system 1.

[0051] That is, the transfer device TU1 takes out the monitor device 100 from the FOUP 4F and transfers it to the aligner AN. Next, the transfer device TU1 takes out the monitor device 100 whose position has been adjusted from the aligner AN and transfers the monitor device 100 to one of the load lock modules LL1 and LL2. Next, the transfer device TU2 of the transfer module TF takes out the monitor device 100 from one of the load lock modules and transfers the monitor device 100 onto a stage ST of one of the process modules PM1 to PM5.

[0052] The base substrate 110 may be a substrate, such as a disk-shaped wafer, similar to the workpiece W, so that it can be transported by the transport devices TU1 and TU2 of the processing system 1. However, the base substrate 110 is not limited to a disk shape, and is not limited to a polygonal, elliptical, or other shape, as long as it can be transported by the transport devices TU1 and TU2 that transport the workpiece W. A notch 110N is formed on the edge of the base substrate 110. Therefore, the rotational position of the monitor device 100 when transported onto the stage ST can be controlled to be constant. Examples of materials for the base substrate 110 include silicon, carbon fiber, quartz glass, silicon carbide, silicon nitride, and alumina.

[0053] The control board 120 is a circuit board provided on the upper surface of the plate-shaped base board 110. The control board 120 includes a plurality of imaging devices 130, a connector pad 160, and a control circuit 170.

[0054] The imaging device 130 is a device for detecting scattered light emitted from a particle by irradiation with the laser light 70L. The imaging device 130 may be an image sensor such as a CCD (Charge Coupled Device). The imaging device 130 can acquire an image in a predetermined imaging range in the optical axis direction of the imaging device 130. The multiple imaging devices 130 have optical axes facing upward on the base substrate 110 in order to image the upper part of the base substrate 110. The optical axis may be defined as the optical central axis of the imaging device 130. On the base substrate 110, the imaging devices 130 are arranged apart from each other. The imaging device 130 can monitor scattered light from a particle irradiated with the laser light 70L in a state where it is placed on the stage ST. In one example, the multiple imaging devices 130 may be arranged so as to be point symmetric on the base substrate 110 in a plan view. Furthermore, the multiple imaging devices 130 may be arranged on the base substrate 110 in line symmetry in a plan view.

[0055] In one example, one of the imaging devices 130 is disposed at the center of the base substrate 110 as shown in FIG. 4. The imaging devices 130 are disposed at a plurality of positions in the radial direction of the base substrate 110. The imaging devices 130 are disposed at equal intervals in the circumferential direction of the base substrate 110. In one example, the imaging devices 130 may be disposed closer together in the radial direction on the peripheral side of the base substrate 110 than on the central side. In the illustrated example, the imaging devices 130 are disposed at eight positions including the center along the radial direction on the disk-shaped base substrate 110. In addition, the imaging devices 130 are disposed at four positions at 90° intervals in the circumferential direction except for the center. That is, in the illustrated example, 29 imaging devices 130 are disposed on the base substrate 110. When the diameter of the base substrate 110 is 300 mm, as an example, the imaging devices 130 may be disposed at positions 3 mm, 5 mm, 10 mm, 15 mm, 20 mm, 50 mm, 100 mm, and 150 mm (center) from the periphery of the base substrate 110.

[0056] The optical axis of each imaging device 130 is, for example, substantially perpendicular to the top surface of the planar base substrate 110. The optical axis may also be obliquely intersecting with the plane of the base substrate 110. The imaging device 130 has a light-transmitting cover 131 for protecting the inside from plasma generated in the plasma processing apparatus 10. The cover 131 may be made of a material such as sapphire.

[0057] FIG. 6 is a diagram for explaining the imaging range 135 of the imaging device 130 in the monitor device 100 of an example, and shows the imaging ranges 135 of the multiple imaging devices 130 when viewed from the side. In FIG. 6, the imaging ranges 135 of five imaging devices are shown typically for ease of understanding. The imaging range 135 of the example may be a range that intersects with the irradiation surface of the laser light 70L in the region 133 along the angle of view of the imaging device 130. The imaging device 130 can capture scattered light from the particle P present in the imaging range 135. In a state in which the monitor device 100 is placed on the stage ST in the chamber body 12, the imaging range 135 of each of the multiple imaging devices 130 may be a region that includes the area directly above each imaging device 130. In an example, the imaging ranges 135 of each of the multiple imaging devices 130 do not include overlapping regions. That is, the imaging ranges 135 of each of the multiple imaging devices 130 may be independent regions that are separated (spaced apart) from each other.

[0058] The connector pad 160 is a connection portion for charging the battery 140, and can be connected to an external power source. With the monitor device 100 placed in the dedicated FOUP 4F, the connector pad 160 is connected to the external power source via a connector 4FC provided on the dedicated FOUP 4F. A plurality of batteries 140 (four in the illustrated example) are arranged on the base substrate 110. The battery 140 supplies power to the imaging device 130 and the control circuit 170. As shown in FIG. 5, a charging circuit 177 is connected between the connector pad 160 and the battery 140, and the charging of the battery 140 is controlled by the charging circuit 177. In addition, a power supply circuit 178 is connected to the battery 140, and power from the battery 140 is supplied to each device via the power supply circuit 178.

[0059] The control circuit 170 is disposed on the control board 120. The control circuit 170 has an arithmetic unit 171 including a processor, a memory 172, a controller 173, etc., and controls the operation of the monitor device 100 based on a program stored in the memory 172. The control circuit 170 functions as a control unit that controls each part of the monitor device 100. For example, the image pickup device 130 captures an image, and the controller 173 controls the image pickup device 130. In addition, a communication device 175 is connected to the control circuit 170 for controlling communication with other external devices. In one example, the communication device 175 is used for connection with an external computer 88. The communication device 175 and the computer 88 may be connected by wire or wirelessly. In one example, the monitor device 100 includes a connector pad 176 connected to the control circuit 170. The connector pad 176 is connected to a switch SW provided on a dedicated FOUP 4F. The control circuit 170 can start controlling the monitor device 100 based on a signal input from the switch SW. In one example, the switch SW and the controller MC are communicatively connected, and the controller MC may start controlling the processing system 1 based on a signal input from the switch SW.

[0060] In one example, the controller 173 executes imaging by the imaging device 130 when the laser oscillator 70 irradiates the inside of the chamber body 12 with the laser light 70L with the monitor device 100 placed on the stage ST. Imaging by the imaging device 130 may be executed in synchronization with the irradiation of the laser light 70L by the laser oscillator 70. In one example, imaging by the imaging device 130 is executed in conjunction with the irradiation of the pulsed laser light 70L that scans within a horizontal plane. The number of times imaging is performed at the same laser irradiation position may be one or multiple times.

[0061] Image data captured by the imaging devices 130 may be stored, for example, in memory 172. After the imaging is completed, the image data stored in memory 172 is transmitted to a computer 88 connected to a communication device 175. The computer 88 (control device) identifies particles P in the image of scattered light captured by the multiple imaging devices 130. For example, the computer 88 identifies particles P in the image and counts the particles P in the image by utilizing an image processing technique.

[0062] The computer 88, as an example, acquires in advance a background image to be captured by the monitor device 100. The background image may be an image captured by the imaging device 130 in a state where the inside of the chamber body 12 in which no particle P exists is irradiated with the laser light 70L. For example, the computer 88 acquires a plurality of types of background images according to the imaging conditions of the particle P. The imaging conditions may include, for example, a state where a gas is supplied into the chamber S and a high frequency is applied to the upper electrode 30 and the lower electrode LE. The imaging conditions may also include, for example, a state where a gas is supplied into the chamber S and a high frequency is applied only to the upper electrode 30. The imaging conditions may also include, for example, a state where a gas is supplied into the chamber S and a high frequency is not applied to the upper electrode 30 and the lower electrode LE. In this way, the background image may correspond to a plurality of imaging conditions, such as a state where plasma emission exists and a state where plasma emission does not exist. A plurality of background images in a state where plasma emission exists may be acquired according to the value of the high frequency voltage.

[0063] The computer 88 compares the image including the scattered light captured by the imaging device 130 with the background image, and when the difference in luminance value between corresponding pixels exceeds a predetermined threshold, counts the area including the pixel as a particle P. The computer 88 may also estimate the size of the particle P based on the luminance value (i.e., the scattered light intensity) of the particle P in the image. For example, the computer 88 may store data indicating the relationship between the scattered light intensity of the particle P and the size (e.g., the diameter) of the particle P, which is created by prior measurement or the like.

[0064] Furthermore, the computer 88 identifies the position of the particle P in the image. That is, the computer 88 acquires the position of the pixel counted as the particle P as the position of the particle P. When a pixel group consisting of a plurality of pixels is determined as one particle P, the center of the pixel group may be identified as the position of the particle P.

[0065] For example, the computer 88 may combine a plurality of images captured by a plurality of imaging devices 130 into one image so as to form a plane facing the stage ST. FIG. 7 is a diagram showing an example of a combined image. In FIG. 7, for ease of understanding, a combined image G based on nine imaging devices is shown typically. In the combined image G in FIG. 7, the area facing the monitor device 100 on the stage ST is shown by a solid line, and the imaging range of each imaging device 130 is shown by a dashed line. As described above, the imaging ranges of the respective imaging devices 130 do not overlap with each other. Therefore, the combined image may be an image in which a plurality of imaging ranges are separated from each other. The computer 88 may identify the position of the particle P in the combined image and display the size, etc. at the position of the particle P.

[0066] Next, a monitoring method for measuring particles using the monitor device 100 will be described. FIG. 8 is a flow chart showing an example of the monitoring method. As shown in FIG. 8, in the monitoring method, the monitor device 100 is transported by the transport devices TU1 and TU2 into the plasma processing device 10 (process module PM) to be monitored (mounting step: step ST1). The plasma processing device 10 may be previously equipped with a laser oscillator 70. When the monitor device 100 is operated, the monitor device 100 mounted in the dedicated FOUP 4F is first started. As described above, the dedicated FOUP 4F is provided with a switch SW for starting the monitor device 100, so that the monitor device 100 can be started by the switch SW. When the monitor device 100 is used to monitor particles P in the chamber body 12, the monitor device 100 is first started by the switch SW. The monitor device 100 is stored in a reduced pressure environment in a decompressible stocker 3 connected to the transport device TU2, and may be transported from the stocker 3 to the plasma processing device 10. 1, for example, a stocker 3 is arranged next to process modules PM1 to PM5. The monitor device 100 may be transported from the stocker 3 to the plasma processing device 10 by a transport device TU2. The stocker 3 may have a switch SW and the like, similar to the FOUP 4F.

[0067] When the switch SW is operated, a signal from the switch SW is also output to the controller MC. The controller MC, which receives the signal from the switch SW, controls the processing system 1 so that the transfer devices TU1 and TU2 transfer the monitor device 100 from the FOUP 4F to above the stage ST in the process module PM. In one example, after transferring the monitor device 100 onto the electrostatic chuck ESC of the stage ST, the controller MC may supply gas to the chamber S and apply high frequency waves to the upper electrode 30 and the lower electrode LE to generate plasma.

[0068] Subsequently, the laser light 70L is irradiated into the plasma processing apparatus 10 (irradiation process: step ST2). In one example, when the monitor apparatus 100 is started by the switch SW, a signal notifying the start of the monitor apparatus 100 is also output to the computer 88. The computer 88 controls the laser oscillator 70 so that the irradiation of the laser light 70L by the laser oscillator 70 is started when it is determined that the monitor apparatus 100 has been transported to the process module PM1. For example, the computer 88 may determine that the monitor apparatus 100 has been transported to the process module PM1 when a predetermined time (hereinafter, referred to as a first time) has elapsed since the signal notifying the start of the monitor apparatus 100 was input. The irradiation of the laser light 70L by the laser oscillator 70 may be ended after a predetermined time has elapsed since the start of the irradiation.

[0069] Next, the scattered light from the particle P irradiated with the laser light 70L is imaged by the imaging device 130 (imaging process: step ST3). When it is determined that the monitor device 100 has been transported onto the electrostatic chuck ESC, the controller 173 controls the imaging device 130 so that the imaging operation of the particle P by the imaging device 130 is started. For example, the controller 173 may determine that the monitor device 100 has been placed on the electrostatic chuck ESC when a predetermined time (hereinafter, referred to as the second time) has elapsed since the signal of the switch SW was input. In one example, the first time and the second time may be the same length. That is, the imaging device 130 may start imaging when the laser oscillator 70 starts irradiating the laser light 70L.

[0070] For example, the controller 173 controls the imaging device 130 so that the timing of imaging is synchronized with the irradiation timing of the pulsed laser light 70L that scans within a horizontal plane. The imaging operation by the imaging device 130 ends a predetermined time after the start of imaging. The imaging time by the imaging device 130 may match the irradiation time of the laser light 70L by the laser oscillator 70. The imaging operation continues until the scanning within the horizontal plane by the laser light 70L is completed.

[0071] The controller MC controls the processing system 1 so that, after the imaging by the monitor apparatus 100 is completed, the transfer apparatus TU1, TU2 transfer the monitor apparatus 100 from the stage ST to the FOUP4F. That is, the transfer apparatus TU2 takes out the monitor apparatus 100 from the process module and transfers it to one of the load lock modules LL1 and LL2. Next, the transfer apparatus TU1 takes out the monitor apparatus 100 from the one load lock module and transfers it to the FOUP4F. For example, the controller MC may determine that the imaging by the monitor apparatus 100 is completed when a predetermined time has elapsed since the monitor apparatus 100 was transferred onto the stage ST.

[0072] Next, the particles P in the image are identified (measurement step: step ST4). In one example, when the monitor device 100 returns to the FOUP 4F, the image data stored in the memory 172 of the monitor device 100 is transmitted to the computer 88. The computer 88 measures the particles P based on the acquired image data. In one example, the computer 88 combines a plurality of images captured by a plurality of imaging devices 130. Then, the computer 88 identifies the positions of the particles P in the combined image and counts the particles P. The computer 88 also estimates the size of each of the identified particles P. The computer 88 may display the combined image by superimposing the positions of the identified particles P. The computer 88 may also output the number of particles P and the size of each particle P together with the combined image.

[0073] As described above, in one exemplary embodiment, a particle monitor system for measuring particles P in a plasma processing apparatus 10 is provided. The system includes a laser oscillator 70 for irradiating a laser beam 70L into the plasma processing apparatus 10, and a monitor apparatus 100 placed on a stage ST in the plasma processing apparatus 10. The monitor apparatus 100 includes a base substrate 110, a plurality of imaging devices 130, and a computer 88. The plurality of imaging devices 130 are disposed spaced apart from each other on the base substrate 110 so as to image an upward direction, and capture an image including scattered light from particles P irradiated with the laser beam 70L. The computer 88 identifies particles P in the images captured by the plurality of imaging devices 130.

[0074] In the particle monitor system, particles P in the plasma processing apparatus 10 are imaged by a plurality of imaging devices 130 of a monitor device 100 mounted on a stage ST. The plurality of imaging devices 130 are arranged spaced apart from one another on a base substrate 110. Therefore, imaging ranges 135 imaged by the respective imaging devices 130 are different from one another. That is, each imaging device 130 can image particles P in different regions in the plasma processing apparatus 10. Therefore, in the particle monitor system, the distribution of particles P in the plasma processing apparatus 10 can be obtained by distinguishing particles P in images imaged by the plurality of imaging devices 130.

[0075] In one exemplary embodiment, the computer 88 may count the particles P in the images captured by the multiple imaging devices 130. In this configuration, the distribution pattern of the particles P can be quantitatively obtained.

[0076] In one exemplary embodiment, the computer 88 may obtain the positions of the particles P in the images captured by the multiple imaging devices 130. In this configuration, a more detailed distribution pattern of the particles P can be obtained.

[0077] In one exemplary embodiment, the computer 88 may obtain the sizes of the particles P in the images captured by the multiple imaging devices 130. In this configuration, the distribution of the sizes of the particles P can be obtained.

[0078] In one exemplary embodiment, the imaging ranges 135 of the imaging devices 130 in the plasma processing device 10 do not include overlapping regions. In this configuration, overlapping counting of particles P is suppressed.

[0079] In one exemplary embodiment, the imaging devices 130 may be arranged more densely in the radial direction on the periphery side of the base substrate 110 than on the center side. In this configuration, particles above the periphery of the base substrate 110 are easier to observe.

[0080] In one exemplary embodiment, the imaging step (step ST3) may be performed in a state where gas is supplied into the chamber S. In this configuration, particles in an environment where gas is supplied into the chamber S can be counted.

[0081] In one exemplary embodiment, the imaging step (step ST3) may be performed in a state where plasma is generated in the chamber S. In this configuration, particles in an environment where plasma is generated can be counted.

[0082] Although various exemplary embodiments have been described above, various omissions, substitutions, and modifications may be made without being limited to the above-described exemplary embodiments.

[0083] Although a capacitively coupled plasma processing apparatus has been exemplified as the plasma processing apparatus, the form of the plasma processing apparatus is not limited thereto. For example, the plasma processing apparatus may be an inductively coupled plasma processing apparatus. Furthermore, the plasma processing apparatus may be a plasma processing apparatus that generates plasma using surface waves such as microwaves.

[0084] Although an example has been shown in which the imaging devices are arranged evenly in the circumferential direction at predetermined radial positions on the base substrate, the arrangement of the imaging devices is not limited to this. For example, the number of imaging devices arranged in the circumferential direction may be increased as the distance from the center in the radial direction increases. Furthermore, the imaging devices may be arranged evenly in the X and Y directions on the base substrate as an XY plane so as to be arranged in a lattice pattern.

[0085] Although an example in which the captured image data is transmitted to the computer 88 after all the images are captured has been shown, for example, the captured image data may be transmitted to the computer 88 in real time by wireless communication or the like when the image capturing device 130 is capturing images. In this case, the computer 88 may count particles in real time. Also, the captured image data may be transmitted to the computer 88 by wireless communication or the like when the transport devices TU1 and TU2 transport the monitor device 100 from the stage ST to the FOUP4F after the image capturing by the monitor device 100 is completed. Also, for example, a transmitter may be provided in the monitor device 100, a receiver may be provided in the stage ST, and the image data stored in the memory 172 of the monitor device 100 may be transmitted from the transmitter of the monitor device 100 to the receiver of the stage ST by wire or wireless. In this case, the receiver of the stage ST may be connected to an external computer.

[0086] Although an example has been shown in which scattered light from particles P is identified by comparing it with a previously acquired background image, imaging may also be performed using an imaging device equipped with a wavelength filter that passes light of the wavelength of laser light but does not pass light of the wavelength of plasma emission.

[0087] For example, the imaging device 130 may be an image sensor such as a CCD built into the control board 120. That is, the imaging device 130 may be built into the control board 120 by a semiconductor manufacturing process including a lithography process.

[0088] Although an example has been shown in which the computer 88 counts particles in the image captured by the imaging device 130, for example, the particles in the image may be counted by the arithmetic device 171 of the monitor device 100.

[0089] Although the laser oscillator 70 has been exemplified as a light-emitting device that irradiates light, the light-emitting device may be, for example, an LED (Light-Emitting Diode) light source or the like. In this case, the LED light source may be provided on the upper surface of the monitor device 100 and configured to be capable of irradiating the inside of the chamber S.

[0090] Various exemplary embodiments included in the present disclosure are now described in [E1] to [E5] below.

[0091] [E1] A system for measuring particles in a plasma processing apparatus, comprising: a light emitting device that irradiates light into the plasma processing apparatus; A monitor device is placed on a stage in a plasma processing apparatus, the monitor device including a plate-shaped base substrate, and a plurality of image capturing devices each having an optical axis facing upward on the base substrate and spaced apart from one another, the image capturing devices capturing an image including scattered light from the particles irradiated with the light; a control device that identifies the particles in the images captured by the multiple imaging devices.

[0092] [E2] The particle monitor system according to E1, wherein the light emitting device is a laser oscillator that irradiates laser light as the light.

[0093] [E3] The particle monitor system according to E1 or E2, wherein the control device counts the particles in the images captured by the multiple imaging devices.

[0094] [E4] The particle monitor system according to any one of E1 to E3, wherein the control device acquires positions of the particles in the images captured by the multiple imaging devices.

[0095] [E5] The particle monitor system according to any one of E1 to E4, wherein the control device acquires sizes of the particles in the images captured by the multiple imaging devices.

[0096] [E6] The particle monitor system according to any one of E1 to E5, wherein the imaging ranges of the plurality of imaging devices in the plasma processing apparatus do not include overlapping regions.

[0097] [E7] A method for measuring particles in a plasma processing apparatus using a monitor device, comprising: The monitor device includes: A plate-shaped base substrate; a plurality of imaging devices arranged on the base substrate at a distance from each other and having optical axes facing upward; The method comprises: placing a monitor device on a stage in a chamber of the plasma processing apparatus; irradiating a chamber of the plasma processing apparatus with light; capturing images of scattered light from the particles irradiated with the light by the plurality of imaging devices; and identifying the particles in the images captured by the plurality of imaging devices.

[0098] [E8] The particle monitoring method according to E7, wherein the step of irradiating light irradiates laser light as the light.

[0099] [E9] The particle monitoring method according to E7 or E8, wherein the step of capturing images using the multiple imaging devices is performed in a state in which gas is being supplied into the chamber.

[0100] [E10] The particle monitoring method according to E7 or E8, wherein the step of capturing images using the multiple imaging devices is performed while plasma is being generated in the chamber.

[0101] [E11] A monitor device for measuring particles in a plasma processing apparatus, comprising: a light emitting device that irradiates light into the plasma processing apparatus; A plate-shaped base substrate placed on a stage in a plasma processing apparatus; a plurality of imaging devices each having an optical axis facing upward on the base substrate and spaced apart from one another, for capturing an image including scattered light from the particles irradiated with light incident into the plasma processing apparatus; a control device that identifies the particles in the images captured by the plurality of imaging devices.

[0102] From the foregoing, it will be understood that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the appended claims. [Explanation of symbols]

[0103] 10: plasma processing apparatus, 70: laser oscillator, 88: computer (control device), 100: monitor device, 110: base substrate, 130: imaging device.

Claims

1. A system for measuring particles in a plasma processing apparatus, comprising: a light emitting device that irradiates light into the plasma processing apparatus; A monitor device is placed on a stage in a plasma processing apparatus, the monitor device including: a plate-shaped base substrate; and a plurality of image capturing devices each having an optical axis facing upward on the base substrate so as to capture an image above the base substrate, the image capturing devices being spaced apart from each other and capturing an image including scattered light from the particles irradiated with the light; a control device that identifies the particles in the images captured by the multiple imaging devices.

2. 2. The particle monitor system according to claim 1, wherein the light emitting device is a laser oscillator that irradiates a laser beam as the light.

3. The particle monitor system according to claim 1 , wherein the control device counts the particles in the images captured by the multiple imaging devices.

4. The particle monitor system according to claim 1 , wherein the control device acquires positions of the particles in the images captured by the multiple imaging devices.

5. The particle monitor system according to claim 1 , wherein the control device acquires sizes of the particles in the images captured by the multiple imaging devices.

6. 2. The particle monitor system according to claim 1, wherein the imaging ranges of the plurality of imaging devices in the plasma processing apparatus do not include any overlapping areas.

7. A method for measuring particles in a plasma processing apparatus using a monitor device, comprising: The monitor device includes: A plate-shaped base substrate; a plurality of imaging devices arranged apart from each other and having optical axes facing upward on the base substrate so as to capture an image above the base substrate; The method comprises: placing a monitor device on a stage in a chamber of the plasma processing apparatus; irradiating a chamber of the plasma processing apparatus with light; capturing images of scattered light from the particles irradiated with the light by the plurality of imaging devices; and identifying the particles in the images captured by the plurality of imaging devices.

8. 8. The particle monitoring method according to claim 7, wherein the step of irradiating with light irradiates a laser beam as the light.

9. 8. The particle monitoring method according to claim 7, wherein the step of capturing images by the plurality of image capturing devices is performed in a state where a gas is being supplied into the chamber.

10. 8. The particle monitoring method according to claim 7, wherein the step of capturing images by the plurality of image capturing devices is performed in a state where plasma is generated in the chamber.

11. A monitor device for measuring particles in a plasma processing apparatus, comprising: a light emitting device that irradiates light into the plasma processing apparatus; A plate-shaped base substrate placed on a stage in a plasma processing apparatus; a plurality of imaging devices each having an optical axis facing upward on the base substrate so as to image an area above the base substrate, the imaging devices being spaced apart from one another and configured to capture an image including scattered light from the particles irradiated with light incident into the plasma processing apparatus; a control device that identifies the particles in the images captured by the plurality of imaging devices.

Images