Plasma analysis apparatus, plasma analysis method, and substrate processing apparatus

Abstract

Disclosed are a plasma analysis apparatus and a plasma analysis method capable of analyzing uniformity of plasma formed in a processing chamber. An apparatus for analyzing plasma in a substrate processing apparatus for processing a substrate using the plasma includes an optical system configured to adjust a path of light incident on the optical system from a processing chamber for processing the substrate; a camera configured to capture an image of the plasma formed in the processing chamber; and an image analyzer configured to analyze a form of the plasma using an image of the plasma captured by the camera. The camera captures an image including a plasma shape in a horizontal direction parallel to a substrate placement direction. The image analyzer evaluates the uniformity of the plasma shape in the image.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2024-0031412, filed on March 5, 2024, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a substrate processing apparatus for processing a substrate using plasma, and more particularly, to a plasma analysis device, a plasma analysis method, and a substrate processing apparatus including the plasma analysis device. Background Art

[0004] The semiconductor (or display) manufacturing process is a process for manufacturing a semiconductor device on a substrate (e.g., a wafer), and includes, for example, exposure, deposition, etching, ion implantation, and cleaning. To perform each manufacturing process, a semiconductor manufacturing device for performing each process is provided in a clean room of a semiconductor manufacturing plant, and each process is performed on a substrate loaded in the semiconductor manufacturing device.

[0005] Plasma-based processes (e.g., etching and deposition) are widely used in semiconductor manufacturing processes. Plasma processing is performed by positioning a substrate in the lower portion of a chamber defining a plasma processing space, supplying a process gas for plasma processing, and applying power via electrodes positioned in the upper and lower portions of the chamber.

[0006] The substrate processing process is significantly affected by the plasma distribution within the processing chamber. Therefore, methods are used to measure plasma distribution and improve its characteristics. In particular, achieving a uniform etch rate across the entire substrate area during dry etching requires uniform plasma formation across the entire substrate area. To achieve this uniform plasma formation, it is necessary to analyze the current state of the plasma within the processing chamber. Summary of the Invention

[0007] The present disclosure provides a plasma analysis apparatus, a plasma analysis method, and a substrate processing device capable of analyzing the uniformity of plasma formed in a processing chamber.

[0008] According to an embodiment of the present disclosure, an apparatus for analyzing plasma in a substrate processing device for processing a substrate using plasma includes: an optical system configured to adjust the path of light incident on the optical system from a processing chamber for processing the substrate; a camera configured to capture an image of plasma formed in the processing chamber; and an image analyzer configured to analyze the form of the plasma using the image of the plasma captured by the camera. The camera captures an image containing the shape of the plasma in a horizontal direction parallel to the direction in which the substrate is placed, and the image analyzer evaluates the uniformity of the plasma shape in the image.

[0009] In an embodiment of the present disclosure, the optical system may be implemented as a viewing port formed in a wall of the process chamber, and the camera may capture an image through the optical system.

[0010] In an embodiment of the present disclosure, an image analyzer may compare the plasma shape to a centerline of an image to assess the uniformity of the plasma shape.

[0011] In an embodiment of the present disclosure, the image analyzer may evaluate the uniformity of the plasma shape based on the distance between the center point of the plasma shape and the center point of the image where center lines intersect perpendicularly with each other.

[0012] In an embodiment of the present disclosure, the image analyzer may evaluate the uniformity of the plasma shape based on ratios of areas of portions of the plasma shape to corresponding areas of the image divided by a center line.

[0013] In an embodiment of the present disclosure, the optical system may adjust the path of light to allow the camera to capture an image containing the plasma shape in a horizontal direction parallel to the placement direction of the substrate.

[0014] In an embodiment of the present disclosure, the camera may include a polarization filter configured to block electromagnetic waves generated from the plasma.

[0015] According to another embodiment of the present disclosure, a plasma analysis method performed by a plasma analysis device in a substrate processing apparatus for processing a substrate using plasma includes: capturing, by a camera, an image including a plasma shape in a horizontal direction parallel to a placement direction of the substrate; and evaluating, by an image analyzer, uniformity of the plasma shape in the image.

[0016] According to another embodiment of the present disclosure, an apparatus for processing a substrate using plasma includes a processing chamber in which a substrate is processed and a plasma analysis device configured to analyze the uniformity of plasma formed in the processing chamber. The plasma analysis device includes an optical system configured to adjust the path of light incident on the optical system from the processing chamber; a camera configured to capture an image of the plasma formed in the processing chamber; and an image analyzer configured to analyze the form of the plasma using the image of the plasma captured by the camera. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings in conjunction with this specification illustrate exemplary embodiments and are used to further illustrate the technical concept of the present disclosure in conjunction with the detailed description of the exemplary embodiments below, and the present disclosure should not be construed as being limited to the contents shown in such drawings. In the drawings:

[0018] Figure 1 The structure of a substrate processing device to which the plasma analysis apparatus according to the present disclosure is applied is shown;

[0019] Figure 2 An example of an image containing plasma shapes is shown;

[0020] Figure 3 An example of an image containing a shape of a non-uniformly formed plasma is shown;

[0021] Figure 4 and Figure 5 is a view of the process used to evaluate plasma uniformity; and

[0022] Figure 6 is a flowchart illustrating a plasma analysis method performed by the plasma analysis apparatus according to the present disclosure. DETAILED DESCRIPTION

[0023] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement these embodiments. However, the present disclosure can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein.

[0024] Parts irrelevant to the description of the present disclosure will be omitted to clearly describe the present disclosure, and the same or similar constituent elements will be designated by the same reference numerals throughout the specification.

[0025] In addition, constituent elements having the same configuration in several embodiments will be assigned the same reference numerals and described only in a representative embodiment, and only constituent elements different from those in the representative embodiment will be described in other embodiments.

[0026] Throughout this specification, when a constituent element is said to be “connected,” “coupled,” or “engaged” to another constituent element, the constituent element and the other constituent element may be “directly connected,” “directly coupled,” or “directly engaged” to each other, or may be “indirectly connected,” “indirectly coupled,” or “indirectly engaged” to each other with one or more intermediate elements interposed therebetween. In addition, throughout this specification, when a constituent element is said to “include,” “comprise,” or “have” another constituent element, as long as there is no particular conflicting description, the constituent element should not be understood as excluding other elements, and the constituent element may include at least one other element.

[0027] Unless otherwise defined, all terms (including technical or scientific terms) used herein have the same meaning as commonly understood by those skilled in the art. Terms such as those defined in commonly used dictionaries should be interpreted as having the same meaning as terms in the context of the relevant technology, and should not be interpreted as having an ideal or overly formal meaning unless clearly defined in this specification.

[0028] Figure 1 The structure of a substrate processing apparatus 1 to which a plasma analysis device 20 according to the present invention is applied is shown. Figure 1 is a cross-sectional view of the substrate processing apparatus 1 when viewed from the side. Figure 1 , horizontal directions X and Y are directions in which the substrate W is placed. The first horizontal direction X and the second horizontal direction Y are orthogonal to each other. The vertical direction Z is a direction orthogonal to the horizontal directions X and Y and refers to a direction perpendicular to the plane on which the substrate W is placed.

[0029] The substrate processing apparatus 1 processes a substrate W using plasma. The substrate processing apparatus 1 includes a processing chamber 10, a plasma analysis device 20, a radio frequency (RF) controller 30, and an RF power supply 40. Figure 1 Although not shown, the substrate processing apparatus 1 may further include a gas supply unit configured to supply gas to the inside of the processing chamber 10 and an exhaust unit configured to exhaust gas from the processing chamber 10 .

[0030] The process chamber 10 is a structure that defines a space for processing a substrate W. A substrate holder 110 and an upper electrode 120 are provided in the process chamber 10 , on which the substrate W is positioned and which serves as a lower electrode.

[0031] The substrate holder 110 supports the substrate W from below. The substrate holder 110 may be configured as an electrostatic chuck (ESC) that chucks the substrate W using electrostatic force. A heater for controlling the temperature of the substrate W and a refrigerant path through which a refrigerant flows may be provided in the substrate holder 110. Furthermore, a flow path for supplying an inert gas (e.g., helium) to uniformly distribute the temperature across the entire area of ​​the substrate W may be formed in the substrate holder 110. Furthermore, the substrate holder 110 may be connected to an RF power supply 40 to receive RF power for generating plasma.

[0032] The upper electrode 120 is located in the upper space of the processing chamber 10. The upper electrode 120 can be connected to the RF power supply 40 to receive RF power for generating plasma. The upper electrode 120 can be an antenna composed of at least one coil. Alternatively, the upper electrode 120 can be a showerhead that sprays the processing gas into the interior of the processing chamber 10. One of the upper electrode 120 and the substrate holder 110 can be grounded, while the other can be connected to the RF power supply 40 to receive RF power.

[0033] The plasma analysis device 20 captures the shape of the plasma formed in the processing chamber 10, analyzes the plasma shape, and provides information regarding plasma uniformity to the RF controller 30. The RF controller 30 can control the RF power supply 40 based on the plasma uniformity information received from the plasma analysis device 20. Furthermore, the RF controller 30 can control the output of a heater provided in the substrate holder 110 based on the plasma uniformity information. The RF controller 30 can control an impedance matching circuit or filter located between the RF power supply 40 and the substrate holder 110 or the upper electrode 120. Alternatively, the RF controller 30 can control a separate RF module to control the distribution of the plasma. The RF controller 30 can control the RF power supply 40 based on the current distribution uniformity of the plasma in the processing chamber 10, so that the plasma is more uniformly distributed across the entire area of ​​the substrate W. The RF power supply 40 supplies RF power to the substrate holder 110 or the upper electrode 120 to generate the plasma.

[0034] The plasma analysis apparatus 20 includes an optical system 210 configured to adjust a path of light incident thereon from the processing chamber 10; a camera 220 configured to capture an image of plasma formed in the processing chamber 10; and an image analyzer 230 configured to analyze the form of the plasma using the image of the plasma captured by the camera 220.

[0035] The optical system 210 forms an optical path through which light from the plasma formed in the processing chamber 10 is incident on the camera 220. The optical system 210 may include at least one lens, a mirror, a filter, and a beam splitter. The optical system 210 may be formed in a wall of the processing chamber 10. The optical system 210 may be implemented as an observation port formed in the wall of the processing chamber 10. The optical system 210 may adjust the optical path so that the camera 220 captures an image of the plasma on a horizontal plane XY parallel to the plane on which the substrate W is placed.

[0036] The camera 220 captures the plasma incident on the optical system through the optical system 210. Specifically, the camera 220 captures an image including the shape of the plasma in a horizontal direction parallel to the direction in which the substrate W is placed. The camera 220 may include one or more image sensors, a lens, a camera controller, an image processing processor, and a flash.

[0037] Camera 220 may include a polarization filter that blocks short-range electromagnetic waves generated from the plasma. Since the short-range electromagnetic waves generated by the plasma are blocked by the polarization filter included in camera 220, the influence of the short-range electromagnetic waves generated by the plasma can be eliminated. For example, noise in images captured by camera 220 or interference between components included in camera 220 due to the short-range electromagnetic waves generated by the plasma can be prevented.

[0038] Image analyzer 230 uses the image of the plasma captured by camera 220 to analyze the form of the plasma. Image analyzer 230 is a device that uses the image of the plasma captured by camera 220 to analyze the characteristics of the plasma in processing chamber 10. Image analyzer 230 can be implemented as one or more computers. Image analyzer 230 may include: a processor, such as a central processing unit (CPU), a graphics processing unit (GPU), or a neural processing unit (NPU); a memory, such as a dynamic random access memory (DRAM), a solid-state drive (SSD), or a hard disk drive (HDD); a communication module, such as a modem or a wireless network adapter; and input / output devices, such as a keyboard, a mouse, a monitor, and a speaker.

[0039] According to the present disclosure, the camera 220 captures an image including the shape of plasma in a horizontal direction parallel to the direction in which the substrate W is placed, and the image analyzer 230 evaluates the uniformity of the shape of the plasma from the image. When the image analyzer 230 evaluates the uniformity of the shape of the plasma from the image including the shape of the plasma in the horizontal direction, the RF controller 30 can control the RF power supply 40 or another device based on the current uniformity of the shape of the plasma so that the plasma is uniformly distributed.

[0040] Figure 2 FIG. 2 shows an example of an image IMG including a plasma shape PL. The camera 220 captures the image IMG including the plasma shape PL through the optical system 210. Figure 2 After capturing the image IMG, the image analyzer 230 checks whether plasma has been normally formed based on the plasma shape PL included in the image IMG.

[0041] The image analyzer 230 can compare the plasma shape PL with the center lines HL and VL of the image IMG to evaluate the uniformity of the plasma shape PL. In the image IMG, the center lines include a horizontal center line HL and a vertical center line VL. The horizontal center line HL and the vertical center line VL are perpendicular to each other. The center point where the horizontal center line HL and the vertical center line VL intersect each other coincides with the center point of the substrate W. The image analyzer 230 evaluates whether the plasma shape PL is uniformly formed based on the horizontal center line HL and the vertical center line VL. Figure 2 As shown, when the horizontal center line HL and the vertical center line VL pass through the horizontal center and the vertical center of the plasma shape PL, the image analyzer 230 may determine that the plasma has been uniformly formed in the processing chamber 10 .

[0042] Figure 3 An example of an image containing the shape of an inhomogeneously formed plasma is shown. Figure 3 (a) in the figure shows the shape PL of the plasma formed centrally in the upper left region of the image IMG. Figure 3 (b) in the image IMG shows the shape PL of the plasma formed in a concentrated manner in the upper right region. Figure 3 (c) in FIG. 1 shows the shape PL of the plasma concentrated in the lower left region of the image IMG, and Figure 3 (d) in FIG. 4 shows the shape PL of the plasma formed in the lower right area of ​​the image IMG. Figure 3 When the plasma shape PL is photographed as shown in (a) to (d) in FIG. 1 , the image analyzer 230 may determine that the plasma has been formed non-uniformly in the processing chamber 10 .

[0043] In an embodiment of the present disclosure, the image analyzer 230 may evaluate the uniformity of the plasma shape PL based on the distance d between the center point CP1 of the plasma shape PL and the image center point CP2 where the center lines HL and VL intersect perpendicularly with each other. Figure 4As shown, the image analyzer 230 can determine that the larger the distance d between the center point CP1 of the plasma shape PL and the center point CP2 of the image where the horizontal center line HL and the vertical center line VL intersect with each other, the lower the uniformity of the plasma shape PL. The image analyzer 230 can determine that the smaller the distance d between the center point CP1 of the plasma shape PL and the center point CP2 of the image where the horizontal center line HL and the vertical center line VL intersect with each other (the closer to zero), the higher the uniformity of the plasma shape PL.

[0044] In an embodiment of the present disclosure, the image analyzer 230 may evaluate the uniformity of the plasma shape PL based on the ratio of the areas R1, R2, R3, and R4 of the portions of the plasma shape PL to the corresponding areas A1, A2, A3, and A4 of the image IMG divided by the center lines HL and VL. Figure 5 As shown, the image IMG is divided into four areas A1, A2, A3, and A4 by a horizontal center line HL and a vertical center line VL, and the areas R1, R2, R3, and R4 of the four portions of the plasma shape PL occupying the four areas A1, A2, A3, and A4 of the image IMG are calculated, respectively. The image analyzer 230 can calculate the ratio of the areas R1, R2, R3, and R4 of the four portions of the plasma shape PL to the corresponding areas A1, A2, A3, and A4 of the image IMG divided by the center lines HL and VL. The image analyzer 230 can determine that the greater the difference between the ratios of the areas R1, R2, R3, and R4 of the four portions of the plasma shape PL to the corresponding areas A1, A2, A3, and A4 of the image IMG, the lower the uniformity of the plasma shape PL. In addition, the image analyzer 230 can determine that the smaller the difference between the ratios of the areas R1, R2, R3 and R4 of the four parts of the plasma shape PL and the corresponding areas A1, A2, A3 and A4 of the image IMG, that is, the more similar the ratios of the areas R1, R2, R3 and R4 of the four parts of the plasma shape PL and the corresponding areas A1, A2, A3 and A4 of the image IMG are to each other, the higher the uniformity of the plasma shape PL.

[0045] Through the above method, the image analyzer 230 can evaluate the uniformity of the plasma shape PL in the image IMG and can send information about the uniformity of the plasma shape PL to the RF controller 30. The RF controller 30 can control the RF power supply 40 or another device based on the information about the uniformity of the plasma shape PL to change the plasma formation conditions, thereby ensuring uniform formation of plasma in the processing chamber 10.

[0046] Figure 62 is a flowchart illustrating a plasma analysis method performed by the plasma analysis apparatus 20 according to the present disclosure. The plasma analysis method according to the present disclosure includes steps S610 and S620. In step S610, the camera 220 captures an image IMG including a plasma shape PL in horizontal directions X and Y parallel to the direction in which the substrate W is placed. In step S620, the image analyzer 230 evaluates the uniformity of the plasma shape PL in the image IMG.

[0047] In an embodiment of the present disclosure, the step S620 of evaluating the uniformity of the plasma shape PL in the image IMG may include a step of comparing the plasma shape PL with the center lines HL and VL of the image IMG to evaluate the uniformity of the plasma shape PL.

[0048] In an embodiment of the present disclosure, step S620 of evaluating the uniformity of the plasma shape PL in the image IMG may include calculating a distance d between the center point CP1 of the plasma shape PL and the image center point CP2 where the center lines HL and VL intersect each other perpendicularly to evaluate the uniformity of the plasma shape PL.

[0049] In an embodiment of the present disclosure, step S620 of evaluating the uniformity of the plasma shape PL in the image IMG may include calculating the ratio of the areas R1, R2, R3 and R4 of the portions of the plasma shape PL to the corresponding areas A1, A2, A3 and A4 of the image IMG divided by the center lines HL and VL to evaluate the uniformity of the plasma shape PL.

[0050] As is apparent from the above description, according to the present disclosure, the uniformity of the plasma shape can be evaluated based on an image containing the plasma shape in the horizontal direction. Accordingly, the uniformity of the plasma formed in the processing chamber can be analyzed, and the plasma can be controlled based on the analyzed uniformity.

[0051] Although the preferred embodiments of the present disclosure have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the disclosure.

[0052] The scope of the present disclosure should be defined only by the appended claims, and all technical concepts within the equivalent scope of the claims should be construed as falling within the scope of the present disclosure.

Claims

1. An apparatus for analyzing plasma in a substrate processing apparatus for processing a substrate using plasma, the apparatus comprising: an optical system configured to adjust a path of light incident on the optical system from a processing chamber for processing the substrate; a camera configured to capture an image of a plasma formed in the processing chamber; as well as an image analyzer configured to analyze a form of the plasma using an image of the plasma captured by the camera, wherein the camera captures an image containing a plasma shape in a horizontal direction parallel to a placement direction of the substrate, and wherein the image analyzer evaluates the uniformity of the plasma shape in the image.

2. The apparatus according to claim 1 , wherein the optical system is implemented as a viewing port formed in a wall of the process chamber, and wherein the camera captures the image through the optical system.

3. The apparatus of claim 1 , wherein the image analyzer compares the plasma shape with a centerline of the image to assess uniformity of the plasma shape.

4. The apparatus of claim 3, wherein the image analyzer evaluates the uniformity of the plasma shape based on a distance between a center point of gravity of the plasma shape and a center point of an image where the center lines intersect each other perpendicularly. 5 . The apparatus of claim 3 , wherein the image analyzer evaluates the uniformity of the plasma shape based on a ratio of areas of a plurality of portions of the plasma shape to corresponding areas of the image divided by the center line. 6 . The apparatus of claim 1 , wherein the optical system adjusts the path of the light to allow the camera to capture an image including a plasma shape in a horizontal direction parallel to a placement direction of the substrate. 7 . The apparatus of claim 1 , wherein the camera comprises a polarization filter configured to block electromagnetic waves generated from the plasma.

8. A plasma analysis method performed by a plasma analysis device in a substrate processing apparatus for processing a substrate using plasma, wherein the plasma analysis device comprises: an optical system configured to adjust a path of light incident on the optical system from a processing chamber for processing the substrate; a camera configured to capture an image of a plasma formed in the processing chamber; as well as an image analyzer configured to analyze a form of the plasma using an image of the plasma captured by the camera, and The plasma analysis method comprises: capturing, by the camera, an image including a plasma shape in a horizontal direction parallel to a placement direction of the substrate; as well as The uniformity of the plasma shape in the image is evaluated by the image analyzer.

9. The plasma analysis method according to claim 8, wherein the optical system is implemented as an observation port formed in a wall of the process chamber, and wherein the camera captures the image through the optical system. 10 . The plasma analysis method of claim 8 , wherein evaluating the uniformity of the plasma shape in the image comprises comparing the plasma shape with a centerline of the image to evaluate the uniformity of the plasma shape.

11. The plasma analysis method according to claim 10, wherein evaluating the uniformity of the plasma shape in the image comprises evaluating the uniformity of the plasma shape based on a distance between a center point of gravity of the plasma shape and a center point of the image where the center lines intersect perpendicularly with each other.

12. The plasma analysis method of claim 10, wherein evaluating the uniformity of the plasma shape in the image comprises evaluating the uniformity of the plasma shape based on a ratio of areas of a plurality of portions of the plasma shape to corresponding areas of the image divided by the center line. 13 . The plasma analysis method according to claim 8 , wherein the optical system adjusts the path of the light to allow the camera to capture an image including a plasma shape in a horizontal direction parallel to a placement direction of the substrate. 14 . The plasma analyzing method according to claim 8 , wherein the camera comprises a polarization filter configured to block electromagnetic waves generated from the plasma.

15. An apparatus for processing a substrate using plasma, the apparatus comprising: a processing chamber in which the substrate is processed; as well as a plasma analysis device configured to analyze uniformity of plasma formed in the processing chamber, Wherein the plasma analysis device comprises: an optical system configured to adjust a path of light incident on the optical system from the processing chamber; a camera configured to capture an image of a plasma formed in the processing chamber; and an image analyzer configured to analyze a form of the plasma using an image of the plasma captured by the camera, wherein the camera captures an image containing a plasma shape in a horizontal direction parallel to a placement direction of the substrate, wherein the image analyzer evaluates the uniformity of the plasma shape in the image, and The optical system adjusts the path of the light to allow the camera to capture an image containing a plasma shape in a horizontal direction parallel to a placement direction of the substrate.

16. The apparatus of claim 15, wherein the optical system is implemented as a viewing port formed in a wall of the process chamber, and wherein the camera captures the image through the optical system.

17. The apparatus of claim 15, wherein the image analyzer compares the plasma shape to a centerline of the image to assess uniformity of the plasma shape.

18. The apparatus of claim 17, wherein the image analyzer evaluates the uniformity of the plasma shape based on a distance between a center point of gravity of the plasma shape and a center point of an image where the center lines intersect each other perpendicularly.

19. The apparatus of claim 17, wherein the image analyzer evaluates the uniformity of the plasma shape based on ratios of areas of portions of the plasma shape to corresponding areas of the image divided by the centerline.

20. The apparatus of claim 15, wherein the camera comprises a polarization filter configured to block electromagnetic waves generated from the plasma.

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