Substrate processing apparatus and substrate processing method

Abstract

The present inventive concept provides a substrate processing apparatus. The substrate processing apparatus can include a chamber having an internal space; a support unit to support a substrate in the internal space; a ring unit disposed on an edge region of the support unit when viewed from above; an impedance control unit electrically connected to the ring unit to control a flow or a density of plasma in an edge region of the substrate; and a filter unit disposed between the ring unit and the impedance control unit.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2021-0192279, filed with the Korean Intellectual Property Office on December 30, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The embodiments of the inventive concept described herein relate to substrate processing apparatus and substrate processing method. Background Technology

[0004] To manufacture semiconductor devices, various processes (e.g., photolithography, etching, ashing, ion implantation, thin film deposition, and cleaning) are performed on a substrate to form desired patterns on the substrate. Among these processes, etching is the process of removing selected hot regions of the film formed on the substrate, and includes wet etching and dry etching. For dry etching, etching equipment utilizing plasma is used. Plasma refers to an ionized gas state composed of ions, electrons, or groups. Plasma is generated at very high temperatures or under strong radio frequency (RF) electromagnetic fields. For RF electromagnetic fields, an RF generator applies an RF voltage to one of two opposing electrodes. The RF power applied by the RF generator excites the process gas supplied to the space within the chamber to generate plasma.

[0005] On the other hand, in order to uniformly remove the film formed on the substrate (e.g., a wafer), it is important to uniformly deliver plasma to the substrate. That is, the plasma density on the top surface of the substrate must be uniformly adjusted. For this purpose, an impedance control unit transmits a radio frequency signal to a conductive component (e.g., a coupling ring disposed below the edge region of the substrate) capable of adjusting the plasma density in the chamber, thereby controlling the plasma density on the top surface of the substrate. Furthermore, the impedance control unit includes a variable capacitor, and the plasma density can be controlled by adjusting the capacitance of this variable capacitor.

[0006] However, in this scenario, harmonics generated by the impedance control unit may affect the plasma density within the chamber via conductive components. In other words, harmonics can degrade the uniformity of substrate processing. Furthermore, as the process progresses, the impedance of the cable electrically connecting the impedance control unit and the coupling loop may change due to degradation. Depending on the altered cable impedance, the uniformity of substrate processing may deteriorate. Summary of the Invention

[0007] The embodiments of the present invention provide a substrate processing apparatus and a substrate processing method that can effectively process substrates.

[0008] Furthermore, embodiments of the present invention provide a substrate processing apparatus and a substrate processing method that can effectively improve the uniformity of substrate processing by means of a uniform substrate.

[0009] Furthermore, embodiments of the present invention provide a substrate processing apparatus and a substrate processing method capable of increasing the degree of substrate processing between matching substrate processing apparatuses.

[0010] Furthermore, embodiments of the present invention provide a substrate processing apparatus and a substrate processing method that can improve the uniformity of substrate processing even when the impedance of the cable changes.

[0011] The problems to be solved by the present invention are not limited to those described above, and those skilled in the art will clearly understand from this specification and the accompanying drawings any problems not mentioned.

[0012] The present invention provides a substrate processing apparatus. The substrate processing apparatus may include: a chamber having an internal space; a support unit supporting a substrate within the internal space; a ring unit disposed on an edge region of the support unit when viewed from above; an impedance control unit electrically connected to the ring unit to control the flow or density of plasma in the edge region of the substrate; and a filter unit disposed between the ring unit and the impedance control unit.

[0013] According to the implementation scheme, the substrate processing apparatus may also include a cable that electrically connects the filter unit and the impedance control unit.

[0014] According to the implementation scheme, the filter unit can filter out harmonics generated by the impedance control unit to prevent harmonics from being transmitted to the ring unit.

[0015] According to the implementation scheme, the filter unit can filter out the third harmonic in the harmonics generated by the impedance control unit to prevent the third harmonic from being transmitted to the ring unit.

[0016] According to the implementation scheme, the filter unit may include a housing and a filter, the housing having a receiving space, and the filter being disposed in the receiving space to filter out harmonics.

[0017] According to the implementation plan, the shell may have at least one heat dissipation hole to dissipate heat generated in the internal space.

[0018] According to the implementation scheme, the impedance control unit may include a radio frequency power supply and an impedance control circuit, the radio frequency power supply transmitting radio frequency signals to the ring unit, and the impedance control circuit having a variable capacitor for controlling the flow or density of plasma generated above the ring unit.

[0019] According to the implementation scheme, the ring unit may include an edge ring and a coupling ring. The edge ring is disposed below the edge region of the substrate and / or in the outer periphery of the edge region of the substrate. The coupling ring is disposed below the edge ring, and the impedance control unit may be electrically connected to the coupling ring.

[0020] According to the implementation scheme, the coupling ring may include a ring electrode and an insulator, the ring electrode being electrically connected to the impedance control unit, and the insulator surrounding the ring electrode and being made of an insulating material.

[0021] The present invention provides a substrate processing apparatus using plasma. This plasma-using substrate processing apparatus may include: a chamber having an internal space; a support unit supporting a substrate within the internal space; a power supply unit generating plasma within the internal space; a conductive component regulating the flow or density of plasma delivered to the substrate; an impedance control unit electrically connected to the conductive component to regulate the impedance for controlling the flow or density of plasma delivered to the substrate; and a filter unit disposed between the impedance control unit and the conductive component.

[0022] According to the implementation scheme, the impedance control unit may include a radio frequency power supply and an impedance control circuit, wherein the radio frequency power supply transmits radio frequency signals to the conductive component and the impedance control circuit adjusts the density of plasma transmitted to the substrate.

[0023] According to the implementation scheme, the filter unit can filter out a signal whose frequency is an integer multiple of the frequency of the radio frequency signal emitted by the radio frequency power supply.

[0024] According to the implementation scheme, the filter unit can filter out a signal with a frequency three times that of the radio frequency signal emitted by the radio frequency power supply.

[0025] According to the implementation plan, the substrate processing apparatus also includes an RF cable that electrically connects the filter unit and the impedance control unit.

[0026] According to the implementation scheme, the filter unit may include a housing and a filter, the housing having a receiving space, the filter being disposed in the receiving space to filter harmonics generated by the impedance control unit so that they are not transmitted to conductive components.

[0027] According to the implementation scheme, the housing may have at least one heat dissipation hole to dissipate the heat generated by the filter to the outside.

[0028] According to the implementation scheme, the substrate processing apparatus may further include a ring unit disposed on the edge region of the support unit and having conductive components.

[0029] According to the implementation scheme, the ring unit may include an edge ring that, when viewed from above, surrounds the edge region of the substrate or the outer periphery of the edge region of the substrate, and the conductive component may have an annular shape and be disposed below the edge ring.

[0030] The present invention provides a substrate processing method. This substrate processing method may include: supplying a process gas to the interior space of a chamber and generating plasma by exciting the process gas to process the substrate; adjusting the density or flow of plasma delivered to the substrate by adjusting a variable capacitor of an impedance control unit, the impedance control unit being electrically connected to a ring unit disposed below an edge region of the substrate; and filtering out harmonics generated by the impedance control unit to prevent harmonics from being transmitted to the ring unit, the filter being disposed between the impedance control unit and the ring unit.

[0031] According to the implementation plan, the filter and the impedance control unit can be connected to each other via an RF cable, and the frequency of the harmonics filtered out by the filter can be three times the frequency of the RF signal generated by the impedance control unit. Attached Figure Description

[0032] Referring to the following figures, the above and other objects and features will become apparent from the following description, unless otherwise stated, the same reference numerals throughout the figures refer to the same parts, and in the figures:

[0033] Figure 1 A substrate processing apparatus according to an embodiment of the present invention is shown;

[0034] Figure 2 For illustrative purposes only Figure 1 A schematic diagram of the impedance control unit and filter unit in the diagram;

[0035] Figure 3 for Figure 2 A schematic diagram of the housing of the filter unit in the diagram;

[0036] Figure 4 For illustrative purposes only Figure 2 A schematic diagram of the impedance control circuit of the filter unit in the diagram;

[0037] Figure 5 A graph showing the degree of cable degradation versus the degree of substrate treatment when the filter unit of the embodiment according to the present invention is not installed;

[0038] Figure 6 A graph showing the degree of cable degradation versus the degree of substrate treatment during the installation of a filter unit according to an embodiment of the present invention. Detailed Implementation

[0039] Other advantages and features of the inventive concept, as well as methods of implementing them, will become apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the inventive concept is not limited to the embodiments disclosed below, but can be implemented in various forms, and these embodiments will make the disclosure of the inventive concept complete and are provided so that this disclosure is thorough and complete, and will fully convey the scope of the invention to those skilled in the art, the scope of which is defined only by the scope of the claims.

[0040] Unless otherwise defined herein, all terms used herein (including technical or scientific terms) have the same meaning as commonly accepted in the prior art to which this invention pertains. Terms defined in general dictionaries are to be understood to have the same meaning as terms used in the relevant field and / or the text of this application, and even if some terms are not explicitly defined, they should not be construed as conceptual or overly formal.

[0041] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the inventive concept. Singular expressions include plural expressions unless the context clearly indicates otherwise. Throughout the description and claims, the term “comprising” and variations thereof, such as “including,” specify the presence of the described composition, ingredient, component, step, operation, and / or element, and do not exclude the presence or addition of one or more other compositions, ingredients, components, steps, operations, and / or elements. In the specification, the term “and / or” refers to the listed components or various combinations thereof.

[0042] Terms such as "first," "second," etc., may be used to describe different components, but the component should not be limited by these terms. These terms are only used to distinguish one component from another. For example, without departing from the scope of this disclosure, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.

[0043] As used herein, the singular form includes the plural form unless the context clearly indicates otherwise. Furthermore, for clarity, the shape and size of elements in the figures may be exaggerated.

[0044] As used throughout this specification, "~cell" or "module" is a unit that performs at least one function or operation, and may refer to a software component or a hardware component, such as a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC). However, "~cell" or "module" is not intended to be limited to software or hardware. A "~cell" or "module" may be configured to be located in an addressable storage medium or may be configured to reproduce one or more processors.

[0045] As an example, a "~unit" or "module" can include various components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, programs, subroutines, fragments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided by components and "~units" or "modules" can be performed separately by multiple components and "~units" or "modules," or can be integrated with other additional components.

[0046] In the following text, reference will be made to Figures 1 to 6 The embodiments of the present invention are described in detail.

[0047] Figure 1 A substrate processing apparatus according to an embodiment of the present invention is illustrated schematically.

[0048] refer to Figure 1 The substrate processing apparatus 10 can use plasma to process the substrate "W". For example, the substrate processing apparatus 10 can perform an etching process on the substrate "W". The substrate processing apparatus 10 may include a chamber 100, a support unit 200 (an embodiment of the lower electrode unit), a gas supply unit 300, an upper electrode unit 400, a temperature control unit 500, a power supply unit 600, a loop unit 700, an impedance control unit 800, a filter unit "F" and a controller 900.

[0049] The chamber 100 may have an internal space 101. A substrate "W" may be processed within the internal space 101. Within the internal space 101, the substrate "W" may be processed by plasma. The substrate "W" may be etched using plasma. Plasma may be delivered to the substrate "W" to etch a film formed on the substrate "W".

[0050] The inner wall of chamber 100 may be coated with a material having excellent plasma resistance. Chamber 100 may be grounded. An inlet / outlet port (not shown) may be formed in chamber 100, through which the substrate "W" can be transported in or out. The inlet / outlet port may be selectively opened and closed by a door (not shown). When processing substrate "W", the internal space 101 may be closed by the inlet / outlet port. In addition, when processing substrate "W", the internal space 101 may have a vacuum pressure atmosphere.

[0051] A vent 102 can be formed at the bottom of chamber 100. The atmosphere of the internal space 101 can be discharged through the vent 102. The vent 102 can be connected to a discharge line VL, which provides reduced pressure in the internal space 101. Process gases, plasma, processing byproducts, etc., supplied to the internal space 101 can be discharged to the outside of the substrate processing apparatus 10 through the vent 102 and the discharge line VL. Furthermore, the pressure in the internal space 101 can be regulated by the reduced pressure provided by the discharge line VL. For example, the pressure in the internal space 101 can be regulated by the gas supply unit 300 and the reduced pressure provided by the discharge line VL, which will be described later. When the pressure in the internal space 101 needs to be reduced, the reduced pressure provided by the discharge line VL can be increased, or the supply amount of process gas supplied by the gas supply unit 300 per unit time can be reduced. Conversely, when the pressure in the internal space 101 increases further, the pressure reduction provided by the discharge line VL can be reduced, or the supply of process gas per unit time by the gas supply unit 300 can be increased.

[0052] The support unit 200 can support the substrate "W". The support unit 200 can support the substrate "W" in the internal space 101. The support unit 200 can have one of the opposing electrodes that form an electric field in the internal space 101. In addition, the support unit 200 can be an electrostatic chuck (ESC) that can use electrostatic force to attract and fix the substrate "W".

[0053] The support unit 200 may include a dielectric plate 210, an electrostatic electrode 220, a heater 230, a lower electrode 240, and an insulating plate 250.

[0054] The dielectric plate 210 may be disposed above the support unit 200. The dielectric plate 210 may be made of an insulating material. For example, the dielectric plate 210 may be made of a material including ceramic or quartz. The dielectric plate 210 may have a seat surface supporting the substrate "W". When viewed from above, the dielectric plate 210 may have a seat surface smaller than the bottom surface of the substrate "W". The lower surface of the edge region of the substrate "W" placed on the dielectric plate 210 may face the upper surface of the edge ring 710, which will be described later.

[0055] A first supply channel 211 may be formed in the dielectric plate 210. The first supply channel 211 may be formed to extend from the upper surface of the dielectric plate 210 to the lower surface of the dielectric plate 210. A plurality of first supply channels 211 may be formed to be spaced apart from each other and may be configured to supply heat transfer medium to the lower surface of the substrate "W" through them. For example, the first supply channel 211 may be in fluid communication with the first circulation channel 241 and the second supply channel 243, which will be described later.

[0056] Furthermore, a separate electrode (not shown) for adsorbing the substrate "W" onto the dielectric plate 210 can be embedded in the dielectric plate 210. A direct current can be applied to this electrode. By applying the current, an electrostatic force can be formed between the electrode and the substrate "W", and the substrate "W" can be adsorbed onto the dielectric plate 210 by the electrostatic force.

[0057] The electrostatic electrode 220 clamps the substrate "W" by generating electrostatic force. The electrostatic electrode 220 may be disposed inside the dielectric plate 210. The electrostatic electrode 220 may be embedded in the dielectric plate 210. The electrostatic electrode 220 may be electrically connected to the electrostatic power supply 221. The electrostatic power supply 221 may selectively clamp the substrate "W" by applying power to the electrostatic electrode 220.

[0058] Heater 230 is electrically connected to an external power source (not shown). Heater 230 generates heat by resisting current applied from the external power source. The generated heat can be transferred to substrate "W" through dielectric plate 210. Substrate "W" can be maintained at a predetermined temperature by the heat generated by heater 230. Heater 230 may include a helical coil. Heater 230 may be embedded in dielectric plate 210 at fixed intervals.

[0059] The lower electrode 240 is disposed below the dielectric plate 210. The lower electrode 240 can be an electrode that forms an electric field in the internal space 101. The lower electrode 240 can be any of the opposing electrodes that form an electric field in the internal space 101. The lower electrode 240 can be configured to face the upper electrode 420, which is described later, and the upper electrode 420 is another opposing electrode. The electric field formed in the internal space 101 by the lower electrode 240 can excite the process gas supplied from the gas supply unit 300, described later, to generate plasma. The lower electrode 240 can be disposed inside the dielectric plate 210.

[0060] The upper surface of the lower electrode 240 can be stepped, allowing the central region to be positioned higher than the edge regions. The central region of the upper surface of the lower electrode 240 can have a region corresponding to the lower surface of the dielectric plate 210, and can be bonded to the lower surface of the dielectric plate 210. A first circulation channel 241, a second circulation channel 242, and a second supply channel 243 can be formed in the lower electrode 240.

[0061] The first circulation channel 241 is configured as the channel through which the heat transfer medium circulates. The heat transfer medium stored in the heat transfer medium reservoir GS can be supplied to the first circulation channel 241 via the medium supply line GL. A medium supply valve GB can be installed in the medium supply line GL. The heat transfer medium can be supplied to the first circulation channel 241 according to the opening / closing of the medium supply valve GB, or the change in the opening rate of the medium supply valve GB, or the supply flow rate of the heat transfer medium supplied to the first circulation channel 241 per unit time can be controlled. The heat transfer medium may include helium (He).

[0062] The first circulation channel 241 may be formed in a spiral shape within the lower electrode 240. Alternatively, annular channels with different radii may be arranged in the first circulation channel 241 to have the same center. The first circulation channels 241 may be interconnected. The first circulation channels 241 may be formed at the same height.

[0063] The second circulation channel 242 can be used as a channel for cooling fluid circulation. Cooling fluid stored in the cooling fluid reservoir CS can be supplied to the second circulation channel 242 through the fluid supply line CL. A fluid supply valve CB can be installed in the fluid supply line CL. Cooling fluid can be supplied to the second circulation channel 242 according to the opening / closing of the fluid supply valve CB, or the change in the opening rate of the fluid supply valve CB, or the supply flow rate of cooling fluid supplied to the second circulation channel 242 per unit time can be controlled. The cooling fluid can be cooling water or cooling gas. The cooling fluid supplied to the second circulation channel 242 can cool the lower electrode 240 to a predetermined temperature. The lower electrode 240 cooled to the predetermined temperature can maintain the temperature of the dielectric plate 210 and / or the substrate "W" at the predetermined temperature.

[0064] The second circulation channel 242 may be formed in a spiral shape inside the lower electrode 240. Alternatively, in the second circulation channel 242, annular channels with different radii may be arranged to have the same center. The second circulation channels 242 may be interconnected. The second circulation channel 242 may have a larger cross-sectional area than the first circulation channel 241. The second circulation channels 242 are formed at the same height. The second circulation channel 242 may be located below the first circulation channel 241.

[0065] The second supply channel 243 may extend upward from the first circulation channel 241 and be disposed on the upper surface of the lower electrode 240. The number of the second supply channels 243 may be set to correspond to the number of the first supply channels 211, and the first circulation channel 241 and the first supply channel 211 may be in fluid communication with each other.

[0066] An insulating plate 250 may be disposed below the lower electrode 240. The dimensions of the insulating plate 250 may correspond to the dimensions of the lower electrode 240. The insulating plate 250 may be arranged between the lower electrode 240 and the bottom surface of the chamber 100. The insulating plate 250 may be made of an insulating material and electrically insulates the lower electrode 240 from the chamber 100.

[0067] The gas supply unit 300 supplies process gas to the chamber 100. The gas supply unit 300 may include a gas reservoir 310, a gas supply line 320, and a gas inlet port 330. The gas supply line 320 connects the gas reservoir 310 and the gas inlet port 330, and supplies the process gas stored in the gas reservoir 310 to the gas inlet port 330. The gas inlet port 330 may be installed at a gas supply hole 422 formed in the upper electrode 420.

[0068] The upper electrode unit 400 may have an upper electrode 420 facing the lower electrode 240. Furthermore, the aforementioned gas supply unit 300 may be connected to the upper electrode unit 400 to provide part of the supply path for the process gas supplied by the gas supply unit 300. The upper electrode unit 400 may include a support body 410, the upper electrode 420, and a distribution plate 430.

[0069] The support body 410 can be fastened to the chamber 100. The support body 410 can be the body that fastens the upper electrode 420 and the distribution plate 430 of the upper electrode unit 400. The support body 410 can be the medium in which the upper electrode 420 and the distribution plate 430 are installed in the chamber 100.

[0070] The upper electrode 420 can be an electrode facing the lower electrode 240. The upper electrode 420 can be configured to face the lower electrode 240. An electric field can be formed in the space between the upper electrode 420 and the lower electrode 240. The formed electric field can generate plasma by exciting the process gas supplied to the internal space 101. The upper electrode 420 can be disk-shaped. The upper electrode 420 can include an upper plate 420a and a lower plate 420b. The upper electrode 420 can be grounded. However, it is not limited to this; a radio frequency power supply (not shown) can be connected to the upper electrode 420 to apply a radio frequency voltage.

[0071] The bottom surface of the upper plate 420a can be stepped, allowing its central region to be positioned higher than the edge regions. A gas supply port 422 is formed in the central region of the upper plate 420a. The gas supply port 422 can be connected to a gas inlet port 330 to supply process gas to the buffer space 424. A cooling channel 421 can be formed inside the upper plate 420a. The cooling channel 421 can be formed in a spiral shape. Alternatively, the cooling channel 421 can be arranged such that annular channels with different radii have the same center. A temperature control unit 500, described later, can supply cooling fluid to the cooling channel 421. The supplied cooling fluid can circulate along the cooling channel 421 and cool the upper plate 420a.

[0072] A lower plate 420b can be arranged below an upper plate 420a. The dimensions of the lower plate 420b can be set to correspond to the dimensions of the upper plate 420a, and it is positioned facing the upper plate 420a. The upper surface of the lower plate 420b can be stepped, such that its central region is positioned lower than the edge region. The upper surface of the lower plate 420b and the lower surface of the upper plate 420a can be joined together to form a buffer space 424. The buffer space 424 can be configured as a space in which process gas supplied through the gas supply port 422 temporarily resides before being supplied to the chamber 100. A gas supply port 423 can be formed in the central region of the lower plate 420b. Multiple gas supply ports 423 can be spaced apart at fixed intervals. The gas supply ports 423 can be connected to the buffer space 424.

[0073] The distribution plate 430 can be arranged below the lower plate 420b. The distribution plate 430 can be disc-shaped. Distribution holes 431 can be formed in the distribution plate 430. The distribution holes 431 can be configured to extend from the upper surface to the lower surface of the distribution plate 430. The number of distribution holes 431 can be set to correspond to the number of gas supply holes 423, and can be positioned according to the location of the gas supply holes 423. The process gas remaining in the buffer space 424 can be uniformly supplied to the chamber 100 through the gas supply holes 423 and the distribution holes 431.

[0074] The temperature control unit 500 can control the temperature of the upper electrode 420. The temperature control unit 500 may include a heating element 511, a heating power supply 513, a filter 515, a cooling fluid supply unit 521, a fluid supply channel 523, and a valve 525.

[0075] Heating element 511 can heat lower plate 420b. Heating element 511 can be a heater. Heating element 511 can be a resistance heater. Heating element 511 can be embedded in lower plate 420b. Heating power supply 513 can generate power for heating heating element 511. Heating power supply 513 can heat lower plate 420b by heating heating element 511. Heating power supply 513 can be a direct current (DC) power supply. Filter 515 can prevent the radio frequency voltage (power) applied by power supply unit 600 from being transmitted to heating power supply 513, which will be described later.

[0076] The cooling fluid supply unit 521 can store cooling fluid for cooling the upper plate 420a. The cooling fluid supply unit 521 can supply cooling fluid to the cooling channel 421 via the fluid supply channel 523. The cooling fluid supplied to the cooling channel 421 can reduce the temperature of the upper plate 420a as it flows along the cooling channel 421. Furthermore, a fluid valve 525 can be installed in the fluid supply channel 523 to control whether cooling fluid is supplied to the cooling fluid supply unit 521 or the amount of cooling fluid supplied per unit time. The fluid valve 525 can be configured as an on / off valve or a flow control valve.

[0077] The power supply unit 600 can apply a radio frequency (RF) voltage to the lower electrode 240. The power supply unit 600 can apply the RF voltage to the lower electrode 240 to create an electric field in the internal space 101. The electric field created in the internal space 101 can generate plasma by exciting the process gas supplied to the internal space 101. The power supply unit 600 may include a first power supply 610, a second power supply 620, a third power supply 630, and a matching component 640.

[0078] The first power supply 610 can apply a voltage with a first frequency to the lower electrode 240. The first frequency of the voltage generated by the first power supply 610 can be higher than the second and third frequencies of the voltages generated by the second power supply 620 and the third power supply 630 described below. The first power supply 610 can be a radio frequency source for generating plasma in the internal space 101. The first frequency can be 60 MHz.

[0079] The first power supply 610 can be configured to apply a first sustaining voltage having a first frequency or a first pulse voltage having a first frequency to the lower electrode 240. The first sustaining voltage can be continuous wave (CW) radio frequency. Alternatively, the first pulse voltage can be pulsed radio frequency.

[0080] The second power supply 620 can apply a voltage with a second frequency to the lower electrode 240. The second frequency of the voltage generated by the second power supply 620 can be less than the first frequency of the voltage generated by the first power supply 610, and greater than the third frequency of the voltage generated by the third power supply 630. The second power supply 620 can be a source radio frequency that cooperates with the first power supply 610 to generate plasma in the internal space 101. The second frequency can be from 2 MHz to 9.8 MHz.

[0081] The second power supply 620 can be configured to apply a second sustaining voltage having a second frequency or a second pulse voltage having a second frequency to the lower electrode 240. The second sustaining voltage can be continuous wave (CW) radio frequency. Alternatively, the second pulse voltage can be pulsed radio frequency.

[0082] The third power supply 630 can apply a voltage with a third frequency to the lower electrode 240. The third frequency of the voltage generated by the third power supply 630 can be lower than the first frequency of the voltage generated by the first power supply 610 and the second frequency of the voltage generated by the second power supply 620. The third power supply 630 can be a bias radio frequency that cooperates with the first power supply 610 to accelerate plasma ions in the internal space 101. The third frequency can be 400 kHz.

[0083] The third power supply 630 can be configured to apply a third sustaining voltage with a third frequency or a third pulse voltage with a third frequency to the lower electrode 240. The third sustaining voltage can be continuous wave (CW) radio frequency. Alternatively, the third pulse voltage can be pulsed radio frequency.

[0084] Matching member 640 can perform impedance matching. Matching member 640 is connected to a first power supply 610, a second power supply 620 and a third power supply 630 to perform impedance matching relative to the voltage applied to the lower electrode 240 by the first power supply 610, the second power supply 620 and the third power supply 630.

[0085] The ring unit 700 may be disposed on the edge region of the support unit 200. The ring unit 700 may include an edge ring 710, an insulator 720, and a coupling ring 730.

[0086] An edge ring 710 may be disposed below the edge region of the substrate "W". At least a portion of the edge ring 710 may be configured to be disposed below the edge region of the substrate "W". The edge ring 710 may have an overall annular shape. When viewed from above, the edge ring 710 may be configured such that a portion of the edge ring 710 overlaps with the edge region of the substrate "W", and another portion of the edge ring 710 surrounds the outer periphery of the substrate "W". The upper surface of the edge ring 710 may include an inner upper surface, an outer upper surface, and an inclined upper surface. The inner upper surface may be an upper surface adjacent to the central region of the substrate "W". The outer upper surface may be an upper surface further away from the central region of the substrate "W" than the inner upper surface. The inclined upper surface may be an upper surface disposed between the inner and outer upper surfaces. The inclined upper surface may be an upper surface inclined upward in a direction away from the center of the substrate "W". The edge ring 710 may expand the electric field forming region, such that the substrate "W" is positioned at the center of the plasma forming region. The edge ring 710 may be a focusing ring. The edge ring 710 may be formed of a material comprising Si or SiC.

[0087] The insulator 720 can be configured to surround the edge ring 710 when viewed from above. The insulator 720 can be made of an insulating material. The insulator 720 can be configured to contain an insulating material, such as quartz or ceramic.

[0088] The electric line EL can be connected to the coupling ring 730. The electric line EL can be connected to the filter unit "F", which will be described later. The filter unit "F" can be connected to the impedance control unit 800 via the RF cable CA. That is, the coupling ring 730 can be connected to the impedance control unit 800 via the electric line EL and the RF cable CA.

[0089] A coupling ring 730 may be disposed below the edge ring 710 and the insulator 720. The coupling ring 730 may be surrounded by the edge ring 710, the insulator 720, the lower electrode 240, and the dielectric plate 210. The coupling ring 730 may include a ring body 731 and a ring electrode 732 (an embodiment of a conductive component). The ring body 731 may be made of an insulating material. For example, the ring body 731 may be made of an insulating material (e.g., quartz or ceramic). The ring body 731 may be configured to surround the ring electrode 732. The ring electrode 732 may be made of a conductive material, for example, a material comprising metal.

[0090] The controller 900 can control the substrate processing apparatus 10. The controller 900 can control the components of the substrate processing apparatus 10. The controller 900 can control the substrate processing apparatus 10 to execute the harmonic control method described later.

[0091] The controller 900 may include a process controller comprising: a microprocessor (computer) that performs control on the substrate processing apparatus 10; a user interface including a keyboard through which an operator inputs commands to manage the substrate processing apparatus 10, etc.; a display that visualizes and displays the operating status of the substrate processing apparatus, etc.; and a memory storing programs that execute in the substrate processing apparatus 10 under the control of the process controller, or programs that cause each component to perform a process according to various data and process conditions (i.e., process recipes). Additionally, the user interface and the memory may be connected to the process controller. The process recipes may be stored in a storage medium of the memory, and the storage medium may be a hard disk, a portable disk (e.g., CD-ROM or DVD), or semiconductor memory (e.g., flash memory).

[0092] Figure 2 For illustrative purposes only Figure 1 A diagram of the impedance control unit and filter unit. (Reference) Figure 2 According to an embodiment of the present invention, the impedance control unit 800 may include an impedance control circuit 810 and an RF power supply 820. Furthermore, the impedance control unit 800 can be electrically connected to the filter unit "F" via an RF cable CA. Additionally, the filter unit "F" can be electrically connected to the ring electrode 732 of the coupling ring 730 via a wire EL. That is, the impedance control unit 800 can be electrically connected to the ring unit 700.

[0093] The RF power supply 820 of the impedance control unit 800 can apply an RF signal (RF voltage) to the ring electrode 732. The RF power supply 820 can apply an RF voltage (e.g., 60 MHz) to the ring electrode 732. The plasma density above the edge region of the substrate "W" can be controlled according to the intensity or frequency of the voltage applied by the RF power supply 820. For example, the plasma density can increase when the intensity or frequency of the voltage applied by the RF power supply 820 increases.

[0094] Additionally, the impedance control unit 800 may include an impedance control circuit 810. The impedance control circuit 810 may include a variable capacitor. When the capacitance of the variable capacitor is adjusted, the voltage at the upper end of the edge ring 710 can be adjusted. When the voltage at the upper end of the edge ring 710 is adjusted, the incident angle of plasma ions in the edge region of the substrate "W" can be adjusted. That is, the flow of plasma can be controlled. The incident angle of plasma ions can be determined by the difference between the upper end of the edge ring 710 and the upper end of the substrate "W". The potential at the upper end of the substrate "W" can be determined by the radio frequency voltage applied by the power supply unit 600. The impedance control circuit 810 can adjust the incident angle of plasma ions in the edge region of the substrate "W" by adjusting the potential at the upper end of the edge ring 710. In other words, the impedance control unit 800 can be electrically connected to the ring unit 700 to adjust the flow or density of plasma in the edge region of the substrate "W" supported on the support unit 200.

[0095] The filter unit "F" can prevent harmonics generated by the impedance control unit 800 from being transmitted to the ring electrode 732 of the ring unit 700. The filter unit "F" can be configured to filter signals having a frequency that is an integer multiple of the frequency of the radio frequency signal emitted by the radio frequency power supply 820 of the impedance control unit 800. The filter unit "F" can be configured to filter signals having a frequency that is three times the frequency of the radio frequency signal emitted by the radio frequency power supply 820 (i.e., the third harmonic in the harmonics generated by the impedance control unit 800). For example, when the signal generated by the radio frequency power supply 820 of the impedance control unit 800 has a frequency of 60 MHz, the impedance control unit 800 can be configured to filter harmonics with a frequency of 180 MHz.

[0096] The filter unit "F" may include a housing HU with a receiving space and a filter "C" disposed within the receiving space of the housing HU. For example... Figure 3 As shown, at least one heat dissipation hole HO can be formed in the housing HU. Multiple heat dissipation holes HO can be formed. When harmonics are filtered by the filter "C", the filter "C" can generate heat, and the heat dissipation hole HO can help dissipate the heat generated by the filter "C" to the outside. Moreover, the housing HU can be used to protect the filter "C" from external influences.

[0097] Furthermore, the filter "C" of the filter unit "F" can be provided as a combination of at least one or more of the following: bandpass filter, bandstop filter, low-pass filter, low-impedance filter, high-pass filter, and high-impedance filter. The filter "C" can have a cutoff band capable of filtering out harmonic components generated by the impedance control unit 800. For example... Figure 4As shown, filter "C" can be a circuit consisting of an inductor and a variable capacitor, and can be configured to remove the nth harmonic (120MHz for the second harmonic and 180MHz for the third harmonic) by grounding. The nth harmonic can be an integer multiple of 60MHz generated by the impedance control unit 800. That is, filter "C" can filter out the harmonics generated by the impedance control unit 800 to prevent harmonics from being transmitted to the ring electrode 732, which is a conductive component. Furthermore, filter "C" can be configured to filter out at least one of the second and third harmonic components. For example, filter "C" can be configured to filter out the second or third harmonic, or simultaneously filter out both the second and third harmonics. This is because the harmonic components of the fourth or higher harmonics have very little effect on the density or flow of the plasma.

[0098] In other words, since the filter unit "F" according to the embodiment of the present invention is provided, harmonic components that may be generated by the impedance control unit 800 can be filtered out and not transmitted to the ring electrode 732, thereby minimizing the impact on the density or flow of the controlled plasma. Therefore, the problem of deterioration of the processing uniformity of the substrate "W" can be minimized.

[0099] Furthermore, as mentioned above, the impedance of the RF cable CA, which is a coaxial cable, may change due to degradation as the substrate "W" undergoes plasma treatment. Typically, the impedance of the RF cable CA can refer to its reactance at a frequency of 180MHz (the third harmonic of 60MHz). This is because, as mentioned above, fourth harmonics or higher have almost no effect on plasma density or flow.

[0100] Table 1 below shows a comparison of the impedance (more specifically, reactance) of the RF cable CA at the third harmonic (180MHz) frequency without the filter unit "F" of the present invention installed, and the impedance (more specifically, reactance) of the RF cable CA and filter "C" at the third harmonic (180MHz) frequency with the filter unit "F" of the present invention installed.

[0101] Table 1

[0102]

[0103] When the filter unit "F" is not installed, the RF cable CA can have different impedances depending on the degree of degradation. For example, multiple substrate processing units 10 can be provided. The impedance of the RF cable CA installed in one of the multiple substrate processing units 10 can be 112 ohms, the impedance of the RF cable CA installed in another of the multiple substrate processing units 10 can be 311 ohms, and the impedance of the RF cable CA installed in yet another of the multiple substrate processing units 10 can be 470 ohms. In this case, as... Figure 5 As shown, the etching rates of the substrate processing apparatuses 10 can be different from each other. Figure 5 In the diagram, the X-axis represents the distance from the center of the substrate "W", and the Y-axis represents the etching rate of the film on the substrate "W". PA represents the etching rate in the substrate processing apparatus 10 with an RF cable CA having an impedance of 112 ohms, PB represents the etching rate in the substrate processing apparatus 10 with an RF cable CA having an impedance of 311 ohms, and PC represents the etching rate in the substrate processing apparatus 10 with an RF cable CA having an impedance of 470 ohms. When the filter unit "F" is installed, viewed from the ring electrode 732, even if the impedance of the RF cable CA changes according to the degree of degradation, the difference between the filter "C" and the RF cable CA can be very small. This is because the third harmonic component is removed. For example, multiple substrate processing apparatuses 10 are provided, and the impedance of the RF cable CA+ filter "C" installed in any one of the substrate processing apparatuses 10 can be 55.08 ohms, the impedance of the RF cable CA+ filter "C" installed in another of the multiple substrate processing apparatuses 10 can be 55.43 ohms, and the impedance of the RF cable CA+ filter "C" installed in yet another of the multiple substrate processing apparatuses 10 can be 55.18 ohms. In this case, as... Figure 6 As shown, the difference in etching rates between the substrate processing apparatuses 10 can be very small. Figure 6 In the diagram, the X-axis represents the distance from the center of the substrate "W", and the Y-axis represents the etching rate of the film on the substrate "W". RA represents the etching rate in the substrate processing apparatus 10 with a 12-ohm impedance filter "C" and an RF cable CA, RB represents the etching rate in the substrate processing apparatus 10 with a 311-ohm impedance filter "C" and an RF cable CA, and RC represents the etching rate in the substrate processing apparatus 10 with a 470-ohm impedance filter "C" and an RF cable CA. In other words, due to the installation of the filter "C", even if there are differences in the degree of degradation of the RF cables CA between the substrate processing apparatuses 10, the deviation in etching rate between the substrate processing apparatuses 10 can be minimized.

[0104] The substrate processing method according to an embodiment of the present invention can be implemented by controlling the components of the substrate processing apparatus 10 with a controller 900. The substrate processing method may include: supplying process gas to the internal space 101 of the chamber 100 through a gas supply unit 300, and generating plasma by exciting the process gas to process the substrate "W".

[0105] In this case, by adjusting the variable capacitor of the impedance control unit 800 which is electrically connected to the ring unit 700 located below the edge region of the substrate "W", the density or flow of the plasma delivered to the substrate "W" can be adjusted, and the filter unit "F" located between the impedance control unit 800 and the ring unit 700 can filter out the harmonics generated by the impedance control unit 800 to prevent the harmonics from being transmitted to the ring electrode 732 of the ring unit 700.

[0106] Furthermore, the filter "C" and the impedance control unit 800 can be electrically connected to each other via the radio frequency cable CA, and the harmonics filtered out by the filter "C" can be three times the frequency of the radio frequency signal generated by the impedance control unit 800.

[0107] In the above embodiments, the conductive component has been described as a ring electrode 732 of the ring unit 700, but this is not the only example. For instance, the conductive component can be configured in various ways to regulate the flow or density of plasma delivered to the substrate "W".

[0108] The above embodiments are presented to aid in understanding the inventive concept and do not limit the scope of the invention. It should be understood that various modifications to the above embodiments are also included within the scope of the inventive concept. The accompanying drawings provided in this invention are merely the preferred embodiments of the inventive concept. It should be understood that the technical protection scope of this invention should be determined by the technical concept of the claims and is not limited to the textual description of the claims, but actually extends to equivalent inventive concepts of technical value.

[0109] According to the embodiments of the present invention, the substrate can be processed efficiently.

[0110] Furthermore, according to the embodiments conceived in this invention, the uniformity of processing the substrate by plasma can be improved.

[0111] Furthermore, according to the embodiments conceived in this invention, it is possible to match the degree of substrate processing between substrate processing apparatuses.

[0112] Furthermore, according to the embodiments of the present invention, even when the impedance of the cable changes, the uniformity of the substrate processing can be improved.

[0113] The effects of this invention are not limited to those described above, and those skilled in the art will clearly understand any effects not mentioned from the present specification and drawings.

[0114] Although the inventive concept has been described with reference to embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the inventive concept. Therefore, it should be understood that the above embodiments are not restrictive but illustrative.

Claims

1. A substrate processing apparatus, the substrate processing apparatus comprising: A chamber having an internal space; A support unit configured to support a substrate in the internal space; A ring unit, when viewed from above, is disposed on the edge region of the support unit; An impedance control unit, electrically connected to the ring unit, controls the flow or density of plasma in the edge region of the substrate; A filter unit is disposed between the loop unit and the impedance control unit; as well as A cable configured to electrically connect the filter unit and the impedance control unit; The impedance control unit includes: Radio frequency (RF) power supply, configured to transmit RF signals to the ring unit; and An impedance control circuit having a variable capacitor for controlling the flow or density of the plasma generated above the ring unit; The filter unit is configured to filter out the third harmonic from the harmonics generated by the radio frequency power supply, so as to prevent the third harmonic from being transmitted to the ring unit.

2. The substrate processing apparatus according to claim 1, wherein, The filter unit includes: A housing having a receiving space; and A filter, disposed within the accommodating space, is used to filter out the harmonics.

3. The substrate processing apparatus according to claim 2, wherein, The housing has at least one heat dissipation hole to dissipate heat generated in the internal space.

4. The substrate processing apparatus according to claim 1, wherein, The ring unit includes: An edge ring, the edge ring being disposed below the edge region of the substrate and / or in the outer periphery of the edge region of the substrate; and A coupling ring, wherein the coupling ring is disposed below the edge ring; The impedance control unit is electrically connected to the coupling ring.

5. The substrate processing apparatus according to claim 4, wherein, The coupling ring includes: A ring electrode, electrically connected to the impedance control unit; and An insulator configured to surround the ring electrode and made of an insulating material.

6. A substrate processing apparatus using plasma, the substrate processing apparatus comprising: A chamber having an internal space; A support unit configured to support the substrate in the internal space; A power supply unit configured to generate the plasma in the internal space; A conductive component configured to regulate the flow or density of the plasma delivered to the substrate; An impedance control unit, electrically connected to the conductive component, adjusts the impedance for controlling the flow or density of the plasma delivered to the substrate; A filter unit is disposed between the impedance control unit and the conductive component; A radio frequency cable configured to electrically connect the filter unit and the impedance control unit; as well as A ring unit, wherein the ring unit is disposed in the edge region of the support unit and has the conductive component; The impedance control unit includes: Radio frequency (RF) power supply, configured to transmit RF signals to the ring unit; and An impedance control circuit having a variable capacitor for controlling the flow or density of the plasma generated above the ring unit; The filter unit is configured to filter out a signal whose frequency is three times that of the radio frequency signal emitted by the radio frequency power supply.

7. The substrate processing apparatus according to claim 6, wherein, The filter unit includes: A housing having a receiving space; and A filter, disposed in the receiving space, is provided to filter out harmonics generated by the impedance control unit so that they are not transmitted to the conductive component.

8. The substrate processing apparatus according to claim 7, wherein, The housing has at least one heat dissipation hole to dissipate the heat generated by the filter to the outside.

9. The substrate processing apparatus according to claim 6, wherein, The ring unit includes an edge ring configured to surround an edge region of the substrate or the outer periphery of the edge region of the substrate when viewed from above; The conductive component has an annular shape and is disposed below the edge ring.

10. A substrate processing method, the substrate processing method comprising: Process gas is supplied to the interior space of the chamber, and plasma is generated by exciting the process gas to process the substrate; The density or flow of the plasma delivered to the substrate is adjusted by adjusting the variable capacitor of the impedance control unit, which is electrically connected to a ring unit disposed below the edge region of the substrate. The impedance control unit includes a radio frequency power supply configured to transmit radio frequency signals to the ring unit. The harmonics generated by the radio frequency power supply are filtered out by a filter to prevent the harmonics from being transmitted to the loop unit. The filter is disposed between the impedance control unit and the loop unit. Wherein, the frequency of the harmonics filtered out by the filter is three times the frequency of the radio frequency signal generated by the radio frequency power supply; The filter and the impedance control unit are connected to each other via an RF cable.

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