Plasma processing device

Abstract

The present invention relates to a plasma processing apparatus. According to an embodiment of the present invention, the plasma processing apparatus comprises: a cavity having a processing space inside; a substrate support unit disposed in the processing space and used to support a substrate; a gas supply unit for supplying gas to the processing space; a plasma generation unit for plasmaifying the supplied gas; and an electric field measuring unit for measuring the electric field generated in the processing space inside the cavity.

Description

Technical Field

[0001] This invention relates to a plasma processing apparatus. More specifically, it relates to a plasma processing apparatus for measuring changes in the electric field generated inside a cavity. Background Technology

[0002] Commonly used processes for manufacturing semiconductor devices include vapor deposition processes for forming films on semiconductor substrates, chemical / mechanical polishing processes for planarizing films, photoresist processes for forming photoresist patterns on films, etching processes for forming films with electrically conductive patterns using photoresist patterns, ion implantation processes for implanting specific ions into predetermined areas of a substrate, cleaning processes for removing impurities from a substrate, and inspection processes for inspecting the surface of a substrate with films or patterns formed.

[0003] During the plasma etching process described above, as the process time and number of cycles increase, consumable components inside the cavity, such as nozzles and ring assemblies, may be partially etched due to the plasma. This alters the electric field generated inside the cavity, thus changing the incident angle of ions incident on the substrate. Consequently, the pattern formed on the substrate is etched unevenly, resulting in a decrease in semiconductor device yield. Summary of the Invention

[0004] This invention addresses the problems of the prior art and relates to a plasma processing device for measuring changes in the electric field inside a cavity.

[0005] The problems to be solved by the present invention are not limited to those mentioned above, and another problem not mentioned can be clearly understood by those skilled in the art from the following description.

[0006] The plasma processing apparatus according to an embodiment of the present invention may include: a cavity having a processing space inside; a substrate support unit disposed in the processing space and used to support a substrate; a gas supply unit for supplying gas to the processing space; a plasma generation unit for plasmaifying the supplied gas; and an electric field measuring unit for measuring the electric field generated in the processing space inside the cavity.

[0007] A plasma processing apparatus according to an embodiment of the present invention may include: a cavity having a processing space inside; a substrate support unit disposed in the processing space and used to support a substrate; a gas supply unit for supplying gas to the processing space; a plasma generation unit for plasmaifying the supplied gas; and an electric field measuring unit for measuring an electric field generated by the plasma generation unit in the processing space inside the cavity, the electric field measuring unit including: a liquid crystal; a plurality of optical sensors disposed below the liquid crystal; a detection unit connected to the optical sensors to receive optical signals from the optical sensors; and a processing module for converting the optical signals into electrical signals, wherein liquid crystal dipoles inside the liquid crystal are randomly arranged and then aligned by the electric field generated by the plasma generation unit.

[0008] Alternatively, a plasma processing apparatus according to another embodiment of the present invention may include: a cavity having a processing space inside; a substrate support unit disposed in the processing space and used to support a substrate; a gas supply unit for supplying gas to the processing space; a plasma generation unit for plasmaifying the supplied gas; an electric field measuring unit for measuring the electric field generated by the plasma generation unit; at least one light source unit for applying light to the electric field measuring unit; and a light source driving unit for adjusting the direction and angle of the light source unit. The electric field measuring unit includes: a liquid crystal; a plurality of optical sensors disposed below the liquid crystal; a detection unit connected to the optical sensors to receive optical signals from the optical sensors; and a processing module for converting the optical signals into electrical signals. The liquid crystal dipoles inside the liquid crystal are aligned by the electric field generated by the plasma generation unit, and the alignment angle of the liquid crystal dipoles is confirmed by the light source unit.

[0009] According to the present invention, the change in electric field generated inside the cavity can be measured by using an electric field measuring unit.

[0010] The electric field change inside the cavity is measured by using an electric field measurement unit, thus saving time and cost by eliminating the need for a patterned substrate, and the replacement time point for the internal components can be set.

[0011] However, the effects of the present invention are not limited to those mentioned above, and another effect not mentioned can be clearly understood by those skilled in the art from the following drawings. Attached Figure Description

[0012] Figure 1 This is a diagram illustrating a plasma processing apparatus according to an embodiment of the present invention.

[0013] Figure 2 This is an enlarged view of an electric field measuring unit according to an embodiment of the present invention.

[0014] Figures 3 to 5 This is a diagram illustrating the arrangement and transmittance of liquid crystal dipoles according to an embodiment of the present invention.

[0015] Figure 6 This is a diagram illustrating a plasma processing apparatus according to yet another embodiment of the present invention.

[0016] Figure 7 This is a graph showing the alignment angle of liquid crystal dipoles determined by measuring the transmittance of the liquid crystal based on the incident angle of the light source, according to yet another embodiment of the present invention.

[0017] Figure 8 This is a diagram illustrating the distortion linewidth SCD according to the tilt of the liquid crystal dipole according to an embodiment of the present invention.

[0018] (Explanation of reference numerals in the attached diagram)

[0019] 10: Plasma processing device

[0020] 100: Cavity

[0021] 200: Substrate support unit

[0022] 300: Gas supply unit

[0023] 400: Plasma Generating Unit

[0024] 500: Electric Field Measurement Unit

[0025] 600: Light source unit

[0026] 700: Control Unit Detailed Implementation

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art to which this invention pertains can readily implement it. However, the present invention can be implemented in various different ways and is not limited to the embodiments described herein.

[0028] When describing embodiments of the present invention, specific descriptions of known functions or structures are omitted when it is determined that such specific descriptions would unnecessarily obscure the spirit of the invention. Parts that perform similar functions and effects are referred to by the same reference numerals in all drawings.

[0029] At least some of the terminology used in this specification is defined with consideration of its function in this invention, and therefore may vary depending on the user's or operator's intent, conventions, etc. Consequently, the terminology should be interpreted based on the entire content of this specification.

[0030] Furthermore, in this specification, unless otherwise specified in the statements, the singular also includes the plural. In this specification, when a statement refers to the inclusion of a certain constituent element, unless specifically contradicted, it means that other constituent elements may be included, rather than excluding them.

[0031] On the other hand, in the accompanying drawings, for ease of understanding, the size or shape of the constituent elements, the thickness of the lines, etc., may be presented in a more or less enlarged manner.

[0032] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When describing with reference to the accompanying drawings, the same or corresponding components are marked with the same reference numerals, regardless of the drawing numbers, and repeated descriptions of them are omitted.

[0033] Figure 1 This is a diagram illustrating a plasma processing apparatus according to an embodiment of the present invention.

[0034] Reference Figure 1 The plasma processing device 10 may include a cavity 100, a substrate support unit 200, a gas supply unit 300, a plasma generation unit 400, an electric field measurement unit 500, and a control unit 700.

[0035] The cavity 100 has a processing space for performing the process. The cavity 100 may have an exhaust port 102 at its lower part, which can be connected to an exhaust line equipped with a pump P. The exhaust port 102 can discharge reaction byproducts generated during the process and residual gases inside the cavity 100 to the outside of the cavity 100 via the exhaust line. In this case, the internal space of the cavity 100 can be depressurized to a predetermined pressure.

[0036] The cavity 100 may have an opening 104 formed in its sidewall. The opening 104 may function as a passage for the substrate W to enter and exit the interior of the cavity 100. Such an opening 104 may be configured to be opened and closed by a door assembly.

[0037] The baffle unit 106 can perform the function of venting plasma process byproducts, unreacted gases, etc. The baffle unit 106 can be disposed between the inner wall of the cavity 100 and the substrate support unit 200 (described later). The baffle unit 106 can be provided in an annular shape and can have multiple through holes extending in the vertical direction. The flow of process gas can be controlled according to the number and shape of the through holes in the baffle unit 106.

[0038] The substrate support unit 200 can be disposed in the lower region inside the cavity 100. The substrate support unit 200 can support the substrate W by electrostatic force. However, this embodiment is not limited to this, and the substrate W can be supported by various methods such as mechanical clamping or vacuum.

[0039] The substrate support unit 200 may include a support body 220 and an electrostatic chuck 240 disposed on the support body 220. The electrostatic chuck 240 may be configured as an electrostatic adsorption substrate W and may include a ceramic layer with electrodes inserted therein.

[0040] According to one embodiment of the present invention, although not shown, a heating element and a cooling element for maintaining the substrate at the process temperature can be provided inside the substrate support unit 200. The heating element may be a heating coil, and the cooling element may be a cooling line for refrigerant flow.

[0041] Below the support body 220, a support member 260 may be provided for supporting the support body 220 and the electrostatic chuck 240. The support member 260 is cylindrical in shape with a predetermined height and may have space inside.

[0042] The ring assembly 280 can be disposed at the edge region of the substrate support unit 200. The ring assembly 280 can have a ring shape and be disposed along the periphery of the electrostatic chuck 240. The ring assembly 280 can have a focusing ring 282 and an insulating ring 284. The focusing ring 282 can be provided to surround the electrostatic chuck 240, concentrating plasma towards the substrate W. The insulating ring 284 can be provided to surround the focusing ring 282. Optionally, the ring assembly 280 may include an edge ring (not shown) provided close to the periphery of the focusing ring 282 to prevent damage to the sides of the electrostatic chuck 240 by plasma. The focusing ring 282 can be made of silicon, and the insulating ring 284 can be made of quartz. Unlike the above, the structure of the ring assembly 280 can be modified in various ways.

[0043] The gas supply unit 300 can supply the process gas to the cavity 100. Such a gas supply unit 300 may include a gas supply source 302, a gas supply line 304, and a gas injection nozzle (not shown). The gas supply line 304 connects the gas supply source 302 and the gas injection nozzle (not shown). The gas supply line 304 supplies gas stored in the gas supply source 302 to the gas injection nozzle. A valve 306 may be provided on the gas supply line 304 for opening and closing its passage or regulating the flow rate of fluid flowing through its passage.

[0044] exist Figure 1Only one of the gas supply source 302, gas supply line 304 and gas supply valve 306 is shown, but the gas supply unit 300 of the present invention may include multiple gas supply sources to supply multiple gases to the cavity 100 and multiple gas supply valves to allow independent control of the supply of each gas.

[0045] The plasma generation unit 400 can generate plasma within the processing space of the cavity 100. The plasma can be formed within the cavity 100 in the region above the substrate support unit 200. According to one embodiment of the present invention, the plasma generation unit 400 can generate plasma within the processing space inside the cavity 100 using a capacitively coupled plasma (CCP) source.

[0046] However, this embodiment is not limited to this. It is also possible for the plasma generation unit 400 to generate plasma in the processing space inside the cavity 100 using an inductively coupled plasma (ICP) source or other plasma sources such as microwave.

[0047] The plasma generation unit 400 may include a high-frequency power supply 402 and a matching unit 404. The high-frequency power supply 402 can supply high-frequency power to either the upper or lower electrode to generate a potential difference between the upper and lower electrodes. Here, the upper electrode may be the nozzle 420, and the lower electrode may be the substrate support unit 200. Figure 1 The example shown is of a high-frequency power supply 402 connected to the lower electrode and the upper electrode grounded, but it is also possible for the high-frequency power supply to be connected to the upper electrode and the lower electrode grounded.

[0048] The nozzle 420 can be formed inside the cavity 100, vertically opposite to the substrate support unit 200. Such a nozzle 420 can have multiple gas injection holes to uniformly inject gas into the cavity 100. On the other hand, the nozzle 420 can be made of silicon or metal.

[0049] The electric field measuring unit 500 can measure changes in the electric field occurring inside the cavity 100. According to the present invention, the electric field measuring unit 500 can be disposed above the substrate support unit 200, but is not limited thereto; it can also be disposed above the substrate W disposed on the substrate support unit 200. Alternatively, the electric field measuring unit 500 can be disposed inside the cavity 100 only when measuring changes in the electric field.

[0050] Figure 2 This is an enlarged view of an electric field measuring unit according to an embodiment of the present invention.

[0051] Reference Figure 2 The electric field measurement unit 500 may include a liquid crystal 520, an optical sensor 540, a detection unit 560, and a processing module 580.

[0052] A coating 522 for protecting the liquid crystal 520 can be formed along the outer peripheral surface of the liquid crystal 520. According to one embodiment of the invention, the coating 522 can be made of glass. The shape of the liquid crystal 520 can be maintained by the coating 522 formed on the outer peripheral surface of the liquid crystal 520; for example, the liquid crystal 520 can be disk-shaped. The liquid crystal dipoles 524 inside the liquid crystal 520 can be randomly arranged.

[0053] Multiple optical sensors 540 can be arranged below the liquid crystal 520 to measure light passing through the liquid crystal 520. The optical sensors 540 can be arranged radially with respect to the center of the liquid crystal 520. However, this embodiment is not limited to this, and the arrangement of the optical sensors 540 can be changed. As an example, the optical sensors 540 can also be arranged along the edge region of the liquid crystal 520.

[0054] The detection unit 560 can be connected to the optical sensor 540 and receive optical signals from the optical sensor 540. The optical signal detected by the detection unit 560 can have information about the electric field formed inside the cavity 100. According to the present invention, the detection unit 560 can detect the amount of light that enters the optical sensor 540 through the liquid crystal 520 from light formed by plasma.

[0055] The processing module 580 can be connected to the detection unit 560 to receive information about the electric field detected in the detection unit 560. The processing module 580 can convert the optical signal detected in the detection unit 560 into an electrical signal.

[0056] Figures 3 to 5 This is a diagram illustrating the arrangement of liquid crystal dipoles inside a liquid crystal according to an embodiment of the present invention.

[0057] Reference Figures 3 to 5 The liquid crystal dipoles 524 can be aligned by an electric field generated inside the cavity 100, and can be aligned tilted or vertically. Specifically, the randomly arranged liquid crystal dipoles 524 can be aligned by an electric field, and can be configured such that the negative pole of the liquid crystal dipole 524 faces the top of the liquid crystal 520 and the positive pole faces the bottom of the liquid crystal 520.

[0058] exist Figure 3 In this case, the liquid crystal dipoles 524 are vertically aligned through an electric field. Figure 4 as well as Figure 5 In this case, the liquid crystal dipole 524 is tilted by an electric field.

[0059] When Figure 3 When the liquid crystal dipoles 524 are aligned vertically by an electric field, the light generated by the plasma needs to pass through the long axis M of the liquid crystal dipoles 524. In this case, the light cannot pass through the liquid crystal dipoles 524, so the light transmittance is 0. When the liquid crystal dipoles 524 are not tilted as described above, it means that the electric field inside the cavity 100 does not change.

[0060] exist Figure 4 as well as Figure 5 In this case, the liquid crystal dipole 524 at the edge region of the liquid crystal 520 can be tilted by the electric field.

[0061] exist Figure 4 In the case of liquid crystal dipoles 524 adjacent to the center C of liquid crystal 520, they can be vertically aligned. Liquid crystal dipoles 524 adjacent to the edge of liquid crystal 520 can be aligned such that the circumference formed by the positive pole is larger than the circumference formed by the negative pole (outward tilt). For vertically aligned liquid crystal dipoles 524, light generated by plasma is introduced along the long axis M but cannot pass through them, therefore the light transmittance is 0. For tilted liquid crystal dipoles 524, light generated by plasma can be introduced along the short axis and pass through them, thus the light transmittance can be detected.

[0062] exist Figure 5 In the case of liquid crystal dipoles 524 adjacent to the center C of liquid crystal 520, they can be vertically aligned. Liquid crystal dipoles 524 adjacent to the edge of liquid crystal 520 can be aligned such that the circumference formed by the negative pole is larger than the circumference formed by the positive pole (inward tilt). For vertically aligned liquid crystal dipoles 524, light generated by plasma is introduced along the long axis M but cannot pass through them, therefore the light transmittance is 0. For tilted liquid crystal dipoles 524, light generated by plasma can be introduced along the short axis and pass through them, thus the light transmittance can be detected.

[0063] like Figure 4 as well as Figure 5In this case, when the liquid crystal dipole 524 adjacent to the edge of the liquid crystal 520 is tilted, light is transmitted along the short axis of the liquid crystal dipole 524. Therefore, the transmittance of light can be detected, and the change in the electric field generated inside the cavity 100 can be determined based on this. The change in the electric field inside the cavity 100 means that a part of the consumable parts inside the cavity 100 (for example, ring assembly, nozzle, etc.) is etched as the etching process proceeds. Therefore, it can be used to determine whether the parts are abnormal. Thus, the replacement time point of the consumable parts inside the cavity 100 can be set by detecting the change in the electric field. In addition, the change in the electric field inside the cavity 100 is measured by the electric field measuring unit 500 instead of by the pattern substrate, thus saving costs and time. The alignment direction and transmittance of the liquid crystal dipole 524 can be changed according to the type of liquid crystal 520.

[0064] Refer again Figure 1 The control unit 700 can comprehensively control the operation of the plasma processing apparatus 10 configured as described above. The control unit 700 can be, for example, a computer, and may include a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and auxiliary storage devices. The CPU can operate based on programs or processing conditions stored in the ROM or auxiliary storage devices, controlling the overall operation of the plasma processing apparatus 10. Furthermore, the computer-readable program required for control can also be stored on a storage medium. The storage medium can be, for example, a flexible optical disc, a CD (Compact Disc), a CD-ROM, a hard disk, flash memory, or a DVD. The control unit 700 can be located inside or outside the plasma processing apparatus 10. When the control unit 700 is located externally, it can control the plasma processing apparatus 10 via wired or wireless communication methods.

[0065] According to an embodiment of the present invention, the control unit 700 can control the gas supply unit 300 and the plasma generation unit 400 to plasmaize the supplied gas. Furthermore, the control unit 700 can be connected to the processing module 580 to receive electrical signals converted by the processing module 580. Based on the received electrical signals, the control unit 700 can calculate the transmittance of light through the liquid crystal 520, thereby confirming the change in the electric field of the processing space inside the cavity 100 and setting the replacement time for consumable parts inside the cavity 100.

[0066] Figure 6 This is a figure illustrating a plasma processing apparatus 10 according to yet another embodiment of the present invention. Figure 6The plasma processing device 10 can be connected with Figure 1 The plasma processing device differs in that the cavity 100 also includes a viewport 120 and a light source unit 600.

[0067] Reference Figure 6 The plasma processing apparatus 10 may include a viewport 120, a light source unit 600, and a light source driving unit 620.

[0068] At least one viewing port 120 may be formed in the wall of the cavity 100. The viewing port 120 may be formed to illuminate the interior of the cavity 100 with the light source of the light source unit 600 (described later). Specifically, the viewing port 120 may be formed with a predetermined angle to apply the light source to the electric field measuring unit 500. In this invention, the viewing port 120 is shown to be formed along the wall of the cavity 100, but it is not limited thereto; multiple viewing ports may also be formed at certain intervals along the periphery of the cavity 100. The viewing port 120 may be formed of a quartz material.

[0069] The liquid crystal dipoles 524 inside the liquid crystal 520 can be aligned by the plasma generation unit 400. The liquid crystal 520 can be cured by applying UV generated by plasma to the liquid crystal 520, which is in a state of alignment of the liquid crystal dipoles 524 through an electric field. At this time, the UV generated by plasma can be generated by a specific gas; for example, the specific gas could be HBr.

[0070] The light source unit 600 may be formed outside the cavity 100. At least one light source unit 600 may be formed to supply light to the electric field measuring unit 500 disposed on the substrate support unit 200 at multiple angles. As an example, the light source unit 600 may be an LED, but is not limited thereto.

[0071] The light source driving unit 620 can be connected to the light source unit 600 to move the light source unit 600. The light source driving unit 620 can change the direction and angle of the light source unit 600 outside the cavity 100 in order to apply light to the liquid crystal 520 at multiple angles. The light source driving unit 620 can change the direction of the light source unit 600 via the guide rail 622, and the angle of the light source unit 600 can be adjusted using the angle adjustment unit 624. According to the present invention, the guide rail 622 can be formed along the outer peripheral surface of the cavity 100.

[0072] By applying light sources to the liquid crystal 520, which is fixed in the direction of the liquid crystal dipole 524, using the light source unit 600, at multiple angles, the fixed direction and angle of the liquid crystal dipole 524 can be determined.

[0073] Figure 7 This is a graph showing the alignment angle of liquid crystal dipoles determined by measuring the transmittance of the liquid crystal based on the incident angle of the light source, according to yet another embodiment of the present invention.

[0074] Reference Figure 7 A light source unit 600 can be moved by the light source driving unit 620, and can be used to apply light to the liquid crystal 520 at multiple angles.

[0075] The liquid crystal dipoles 524 inside the liquid crystal 520 have a fixed orientation. Therefore, by adjusting the angle of the light source unit 600 applied to the liquid crystal 520, the alignment angle of the liquid crystal dipoles 524 can be detected. Specifically, if the light source unit 600 is irradiated into the liquid crystal 520 at multiple angles, the transmittance of the light source passing through the liquid crystal dipoles 524 can change depending on the angle applied by the light source unit 600. The transmittance measured based on the angle applied by the light source unit 600 can be transmitted to the processing module 580, which compares the measured transmittance with stored data to confirm the alignment angle of the liquid crystal dipoles 524. The stored data, used as a comparison reference, can be transmittance data based on the alignment angle of the liquid crystal dipoles 524. The stored data can be stored in a storage medium provided in the plasma processing apparatus 10. The alignment angle of the liquid crystal dipoles 524 can be detected by comparing the measured transmittance with the stored data.

[0076] Figure 8 This is a diagram illustrating the distortion linewidth SCD according to the tilt of the liquid crystal dipole according to an embodiment of the present invention.

[0077] Reference Figure 8 The degree of distortion can be determined by comparing the measured alignment angle of the liquid crystal dipole 524 with the distortion linewidth SCD (Skew Critical Dimension).

[0078] When the liquid crystal dipole 524 is not tilted, the distortion linewidth is 0, which means that there is no change in the electric field inside the cavity 100. When the liquid crystal dipole 524 is tilted, the distortion linewidth is above or below 0, which means that the electric field inside the cavity 100 has changed. By using the electric field measuring unit 500 to detect the alignment angle of the liquid crystal dipole 524, the change in the electric field inside the cavity 100 can be determined without consuming the pattern substrate, thus reducing time and cost.

[0079] The above description is merely an illustrative account of the technical concept of the present invention. Those skilled in the art can make various modifications and variations without departing from the essential characteristics of the invention. Therefore, the embodiments described herein are for illustrating the technical concept of the invention and are not intended to limit it. The technical concept of the invention is not limited to such embodiments. The scope of protection of the present invention should be interpreted through the appended claims, and all technical concepts within the same scope should be included within the scope of the claims.

Claims

1. A plasma processing apparatus, comprising: The cavity has processing space inside; A substrate support unit is disposed in the processing space and is used to support the substrate; A gas supply unit for supplying gas to the processing space; A plasma generation unit for plasmaifying the supplied gas; as well as An electric field measurement unit is used to measure the electric field generated in the processing space inside the cavity.

2. The plasma processing apparatus according to claim 1, wherein, The electric field measurement unit includes: liquid crystal; Multiple optical sensors are disposed below the liquid crystal; The detection unit is connected to the optical sensor and receives optical signals from the optical sensor; and The processing module converts the optical signal into an electrical signal.

3. The plasma processing apparatus according to claim 2, wherein, A coating is formed along the outer peripheral surface of the liquid crystal to protect it.

4. The plasma processing apparatus according to claim 3, wherein, The coating is made of glass.

5. The plasma processing apparatus according to claim 3, wherein, The liquid crystal has a disk shape due to the coating.

6. The plasma processing apparatus according to claim 2, wherein, The optical sensors are arranged radially with respect to the center of the liquid crystal.

7. The plasma processing apparatus according to claim 1, wherein, The electric field measuring unit is positioned above the substrate support unit.

8. A plasma processing apparatus, comprising: The cavity has processing space inside; A substrate support unit is disposed in the processing space and is used to support the substrate; A gas supply unit for supplying gas to the processing space; A plasma generation unit for plasmaifying the supplied gas; as well as An electric field measurement unit is used to measure the electric field generated by the plasma generation unit in the processing space inside the cavity. The electric field measurement unit includes: liquid crystal; Multiple optical sensors are disposed below the liquid crystal; The detection unit is connected to the optical sensor and receives optical signals from the optical sensor; and The processing module converts the optical signal into an electrical signal. The liquid crystal dipoles inside the liquid crystal are randomly arranged and then aligned by an electric field generated by the plasma generation unit.

9. The plasma processing apparatus according to claim 8, wherein, The liquid crystal dipole is tilted by the electric field.

10. The plasma processing apparatus according to claim 8, wherein, The optical sensor measures the light generated from the plasma.

11. The plasma processing apparatus according to claim 8, wherein, The plasma processing device also includes a control unit. The control unit receives optical signals from the optical sensor to determine the transmittance of the liquid crystal.

12. The plasma processing apparatus according to claim 11, wherein, The control unit measures the transmittance of the liquid crystal to understand the change in the electric field inside the cavity and thus determine the abnormality of the components inside the cavity.

13. The plasma processing apparatus according to claim 11, wherein, After determining the change in the electric field inside the cavity, the control unit sets the replacement time point for the accessories inside the cavity.

14. A plasma processing apparatus, comprising: The cavity has processing space inside; A substrate support unit is disposed in the processing space and is used to support the substrate; A gas supply unit for supplying gas to the processing space; A plasma generation unit for plasmaifying the supplied gas; An electric field measurement unit is used to measure the electric field generated by the plasma generation unit. At least one light source unit is provided for applying light to the electric field measuring unit; as well as The light source driving unit is used to adjust the direction and angle of the light source unit. The electric field measurement unit includes: liquid crystal; Multiple optical sensors are disposed below the liquid crystal; The detection unit is connected to the optical sensor and receives optical signals from the optical sensor; and The processing module converts the optical signal into an electrical signal. The liquid crystal dipoles inside the liquid crystal are aligned by the electric field generated by the plasma generation unit, and the alignment angle of the liquid crystal dipoles is determined by the light source unit.

15. The plasma processing apparatus according to claim 14, wherein, The aligned dipoles are in a fixed state by UV curing of the liquid crystal.

16. The plasma processing apparatus according to claim 15, wherein, The UV is generated by plasmaizing a specific gas. The specific gas is HBr.

17. The plasma processing apparatus according to claim 14, wherein, At least one viewport is formed in the cavity. Light emitted from the light source unit passes through the viewport and illuminates the liquid crystal at multiple angles.

18. The plasma processing apparatus according to claim 14, wherein, The optical sensor measures the light supplied from the light source unit.

19. The plasma processing apparatus according to claim 14, wherein, The plasma processing device also includes a control unit. The control unit receives optical signals from the optical sensor to determine the transmittance of the liquid crystal.

20. The plasma processing apparatus according to claim 19, wherein, The control unit measures the transmittance of the liquid crystal to determine the alignment angle of the liquid crystal dipoles.

Images