Substrate processing apparatus and substrate processing method

Abstract

To provide a substrate processing apparatus.SOLUTION: A substrate processing apparatus can include a chamber having an interior space, a support unit that supports the substrate in the interior space, a ring unit that is placed in the edge area of the support unit when viewed from the top, an impedance control unit electrically coupled to the ring unit and configured to regulate the flow or density of the plasma in the edge region of the substrate, and a filter unit disposed between the ring unit and the impedance control unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a substrate processing apparatus and a substrate processing method. [Background technology]

[0002] To manufacture semiconductor devices, desired patterns are formed on substrates through various processes, including photolithography, etching, ashing, ion implantation, thin film deposition, and cleaning. The etching process involves removing selected heated regions of a film formed on a substrate, and can involve wet etching or dry etching. For dry etching, a plasma etching system is used. Plasma refers to an ionized gas state consisting of ions, electrons, and radicals. Plasma is generated by very high temperatures and strong RF electromagnetic fields. The RF field consists of opposing electrodes (referring to multiple electrodes; hereafter, the term "electrodes" after a component refers to multiple components), and an RF generator applies an RF voltage to one of these electrodes. The RF power applied by the RF generator excites the process gas supplied to the chamber, generating plasma.

[0003] Meanwhile, uniform delivery of plasma onto a substrate, such as a wafer, is important for uniformly removing a film formed on the substrate. That is, it is necessary to uniformly control the plasma density above the substrate. To this end, an impedance control unit controls the plasma density above the substrate by transmitting an RF signal to a conductive component (e.g., a coupling ring disposed below the edge region of the substrate) that can adjust the plasma density within the chamber. The impedance control unit also includes a variable capacitor, and the plasma density is controlled by adjusting the capacitance of the variable capacitor.

[0004] However, in this case, harmonics generated by the impedance control unit may affect the plasma density in the chamber through conductive components. That is, the harmonics may cause deterioration in the processing uniformity of the substrate. Furthermore, the impedance of the cable electrically connecting the impedance control unit and the coupling ring may change due to deterioration as the process progresses. The changed cable impedance may cause deterioration in the processing uniformity of the substrate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Korean Patent Publication No. 10-2020-0135114 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a substrate processing apparatus and a substrate processing method that can process substrates efficiently.

[0007] Another object of the present invention is to provide a substrate processing apparatus and a substrate processing method that can improve the uniformity of substrate processing by plasma.

[0008] Another object of the present invention is to provide a substrate processing apparatus and a substrate processing method that can match substrate processing levels between substrate processing apparatuses.

[0009] Another object of the present invention is to provide a substrate processing apparatus and a substrate processing method that can improve processing uniformity for a substrate even if the impedance of a cable changes.

[0010] The problems to be solved by the present invention are not limited to those described above, and problems not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from this specification and the accompanying drawings. [Means for solving the problem]

[0011] The present invention provides a substrate processing apparatus, including a chamber having an internal space, a support unit that supports a substrate in the internal space, a ring unit disposed at an edge region of the support unit when viewed from above, an impedance control unit electrically connected to the ring unit and configured to adjust plasma flow or density at the edge region of the substrate, and a filter unit disposed between the ring unit and the impedance control unit.

[0012] According to an embodiment, the filter unit and the impedance control unit may further include a cable electrically connecting the filter unit and the impedance control unit.

[0013] According to an embodiment, the filter unit may be configured to filter harmonics generated by the impedance control unit from being transmitted to the ring unit.

[0014] According to an embodiment, the filter unit may be configured to filter out a third harmonic from among the harmonics generated by the impedance control unit from being transmitted to the ring unit.

[0015] According to an embodiment, the filter unit may include a housing having an accommodation space, and a filter provided in the accommodation space to filter the harmonics.

[0016] According to an embodiment, the housing may have at least one heat dissipation hole formed therein to dissipate heat generated in the internal space.

[0017] According to one embodiment, the impedance control unit may include an RF power supply that transmits an RF signal 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.

[0018] According to one embodiment, the ring unit includes an edge ring configured to be disposed under the edge region of the substrate and / or on the outer periphery of the edge region of the substrate, and a coupling ring disposed under the edge ring, and the impedance control unit may be electrically connected to the coupling ring.

[0019] According to one embodiment, the coupling ring may include a ring electrode electrically connected to the impedance control unit, and an insulating body configured to surround the ring electrode and made of an insulating material.

[0020] The present invention also provides an apparatus for processing a substrate using plasma, the substrate processing apparatus including a chamber having an internal space, a support unit for supporting a substrate in the internal space, a power supply unit for generating plasma in the internal space, a conductive component for adjusting a flow or density of the plasma delivered to the substrate, an impedance control unit electrically connected to the conductive component for adjusting an impedance for adjusting the flow or density of the plasma delivered to the substrate, and a filter unit disposed between the impedance control unit and the conductive component.

[0021] According to one embodiment, the impedance control unit may include an RF power supply that delivers an RF signal to the conductive component, and an impedance control circuit for adjusting the density of the plasma delivered to the substrate.

[0022] According to one embodiment, the filter unit may be configured to filter a signal having a frequency that is a constant multiple of the RF signal transmitted by the RF power source.

[0023] According to one embodiment, the filter unit may be configured to filter a signal having a frequency three times that of the RF signal delivered by the RF power source.

[0024] According to an embodiment, the amplifier may further include an RF cable that electrically connects the filter unit and the impedance control unit.

[0025] According to one embodiment, the filter unit may include a housing having an accommodating space, and a filter provided in the accommodating space to filter harmonics generated by the impedance control unit from being transmitted to the conductive component.

[0026] According to an embodiment, the housing may be formed with at least one heat dissipation hole for dissipating heat generated by the filter to the outside.

[0027] According to an embodiment, the support unit may further include a ring unit disposed at an edge region of the support unit and having the conductive component.

[0028] According to one embodiment, the ring unit includes an edge ring configured to surround the edge region of the substrate or the outer periphery of the edge region of the substrate when viewed from above, and the conductive component has a ring shape but can be arranged below the edge ring.

[0029] The present invention also provides a method for processing a substrate, which includes supplying a process gas to an internal space of a chamber and exciting the process gas to generate plasma to process the substrate, adjusting a variable capacitor of an impedance control unit electrically connected to a ring unit disposed under an edge region of the substrate to adjust the density or flow of the plasma transmitted to the substrate, and a filter disposed between the impedance control unit and the ring unit to filter harmonics generated by the impedance control unit from being transmitted to the ring unit.

[0030] According to one embodiment, the filter and the impedance control unit are connected to each other by an RF cable, and the harmonics filtered by the filter may have three times the frequency of the RF signal generated by the impedance control unit. [Effects of the Invention]

[0031] According to one embodiment of the present invention, substrates can be processed efficiently.

[0032] Furthermore, according to an embodiment of the present invention, the uniformity of plasma substrate processing can be improved.

[0033] Furthermore, according to an embodiment of the present invention, substrate processing levels can be matched among substrate processing apparatuses.

[0034] Furthermore, according to an embodiment of the present invention, it is possible to improve the processing uniformity for the substrate even when the impedance of the cable changes.

[0035] The effects of the present invention are not limited to the effects described above, and effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from this specification and the accompanying drawings. [Brief explanation of the drawings]

[0036] [Figure 1] 1 is a view showing a substrate processing apparatus according to an embodiment of the present invention; [Figure 2] 2 is a diagram illustrating an impedance control unit and a filter unit of FIG. 1; [Figure 3] 3 is a diagram schematically illustrating a housing of the filter unit of FIG. 2. [Figure 4] 3 is a diagram illustrating an impedance control circuit of the filter unit of FIG. 2. [Figure 5] 10 is a graph showing the degree of substrate treatment depending on the degree of cable deterioration when a filter unit according to an embodiment of the present invention is not installed. [Figure 6] 10 is a graph showing the degree of substrate treatment depending on the degree of cable deterioration when a filter unit according to an embodiment of the present invention is installed; DETAILED DESCRIPTION OF THE INVENTION

[0037] Other advantages and features of the present invention, and methods for achieving them, will become apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. These embodiments are provided solely to ensure that the disclosure of the present invention is complete and to fully convey the scope of the invention to those skilled in the art. The present invention is defined only by the scope of the claims.

[0038] Even if not defined, all terms (including technical or scientific terms) used herein have the same meaning as commonly accepted by the art in which this invention pertains. Terms defined by common dictionaries may be interpreted to have the same meaning as in the relevant art and / or the body of this application, and even if not expressly defined herein, they will not be conceptualized or interpreted excessively formally.

[0039] The terms used in this specification are for the purpose of describing the embodiments and are not intended to limit the present invention. In this specification, the singular includes the plural unless otherwise specifically stated in the context of the phrase. As used in this specification, the term "comprises" and / or its various conjugations, such as "comprises," "includes," "includes," "comprises," etc., do not preclude the presence or addition of one or more other compositions, components, elements, steps, acts, and / or elements to a stated composition, component, component, step, act, and / or element. As used herein, the term "and / or" refers to each of the listed components or various combinations thereof.

[0040] Terms such as "first" and "second" may be used to describe various components, but the components should not be limited by these terms. These terms may be used to distinguish one component from another. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component, without departing from the scope of the present invention.

[0041] The singular expression includes the plural expression unless the context clearly dictates otherwise. Also, in the drawings, the shapes and sizes of elements may be exaggerated for clearer explanation.

[0042] As used throughout this specification, 'unit' and 'module' may refer to a unit that processes at least one function or operation, for example, software or a hardware component such as an FPGA or ASIC. However, 'unit' and 'module' are not limited to software or hardware. 'Unit' and 'module' may be configured to reside on an addressable storage medium, or may be configured to execute one or more processors.

[0043] For example, a 'module' and a 'module' may include components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, routines, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided by the components and modules may be performed separately by multiple components and modules, or may be integrated with other additional components.

[0044] Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

[0045] FIG. 1 is a schematic view of a substrate processing apparatus according to an embodiment of the present invention.

[0046] 1, a substrate processing apparatus 10 processes a substrate (W) using plasma. For example, the substrate processing apparatus 10 can perform an etching process on the substrate (W). The substrate processing apparatus 10 can include a chamber 100, a support unit 200 (an example of a lower electrode unit), a gas supply unit 300, an upper electrode unit 400, a temperature control unit 500, a power supply unit 600, a ring unit 700, a harmonic control unit 800, a filter unit (F), and a controller 900.

[0047] The chamber 100 may have an internal space 101. A substrate (W) may be processed in the internal space 101. The substrate (W) may be processed by plasma in the internal space 101. The substrate (W) may be etched by plasma. The plasma may be transferred to the substrate (W) to etch a film formed on the substrate (W).

[0048] The inner wall of the chamber 100 may be coated with a material having excellent plasma resistance. The chamber 100 may be grounded. A loading / unloading port (not shown) may be formed in the chamber 100, through which the substrate (W) can be loaded or unloaded. The loading / unloading port may be selectively opened or closed by a door (not shown). While the substrate (W) is being processed, the internal space 101 may be closed by the loading / unloading port. Furthermore, while the substrate (W) is being processed, the internal space 101 may have a vacuum pressure atmosphere.

[0049] An exhaust hole 102 may be formed at the bottom of the chamber 100. The atmosphere in the internal space 101 may be exhausted through the exhaust hole 102. The exhaust hole 102 may be connected to an exhaust line (VL) that provides a reduced pressure to the internal space 101. The process gas, plasma, process by-products, etc. supplied to the internal space 101 may be exhausted to the outside of the substrate processing apparatus 10 through the exhaust hole 102 and the exhaust line (VL). The pressure in the internal space 101 may be adjusted by the reduced pressure provided by the exhaust line (VL). For example, the pressure in the internal space 101 may be adjusted by the reduced pressure provided by the gas supply unit 300 and the exhaust line (VL), which will be described later. To further reduce the pressure in the internal space 101, the reduced pressure provided by the exhaust line (VL) may be increased, or the amount of process gas supplied per unit time by the gas supply unit 300 may be reduced. Conversely, if the pressure in the internal space 101 is to be further increased, the vacuum provided by the exhaust line (VL) can be reduced, or the amount of process gas supplied by the gas supply unit 300 per unit time can be increased.

[0050] 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 any one of 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 adsorb and fix the substrate (W) using electrostatic force.

[0051] 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 .

[0052] The dielectric plate 210 may be provided on the upper part of 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 mounting surface that supports the substrate (W). When viewed from above, the mounting surface of the dielectric plate 210 may have a smaller area than the lower 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.

[0053] A first supply channel 211 is formed in the dielectric plate 210. The first supply channel 211 may extend from the top surface to the bottom surface of the dielectric plate 210. A plurality of first supply channels 211 may be formed spaced apart from each other and may serve as a passage through which a heat transfer medium is supplied to the bottom surface of the substrate (W). For example, the first supply channel 211 may be fluidly connected to a first circulation channel 241 and a second supply channel 243, which will be described later.

[0054] In addition, a separate electrode (not shown) may be embedded in the dielectric plate 210 to attract the substrate (W) to the dielectric plate 210. A direct current may be applied to the electrode. The applied current causes an electrostatic force to act between the electrode and the substrate, and the substrate (W) may be attracted to the dielectric plate 210 by the electrostatic force.

[0055] The electrostatic electrode 220 can generate an electrostatic force to chuck the substrate (W). The electrostatic electrode 220 can be provided within the dielectric plate 210. The electrostatic electrode 220 can be embedded within the dielectric plate 210. The electrostatic electrode 220 can be electrically connected to an electrostatic power source 221. The electrostatic power source 221 can apply power to the electrostatic electrode 220 to selectively chuck the substrate (W).

[0056] The heater 230 is electrically connected to an external power source (not shown). The heater 230 generates heat by resisting a current applied from the external power source. The generated heat is transferred to the substrate (W) through the dielectric plate 210. The substrate (W) is maintained at a predetermined temperature by the heat generated by the heater 230. The heater 230 includes a spiral-shaped coil. The heater 230 may be embedded in the dielectric plate 210 at uniform intervals.

[0057] A lower electrode 240 is positioned below the dielectric plate 210. The lower electrode 240 may be an electrode that forms an electric field in the internal space 101. The lower electrode 240 may be one of the opposing electrodes that form an electric field in the internal space 101. The lower electrode 240 may be provided to face the other opposing electrode, an upper electrode 420 (described later). The electric field formed in the internal space 101 by the lower electrode 240 may excite a process gas supplied by a gas supply unit 300 (described later) to generate plasma. The lower electrode 240 may be provided within the dielectric plate 210.

[0058] The top surface of the lower electrode 240 may have a stepped shape such that the central region is higher than the edge regions. The central region of the top surface of the lower electrode 240 has an area corresponding to the bottom surface of the dielectric plate 210 and is bonded to the bottom surface of the dielectric plate 210. The lower electrode 240 may have a first circulation channel 241, a second circulation channel 242, and a second supply channel 243 formed therein.

[0059] The first circulation flow path 241 is provided as a path through which the heat transfer medium circulates. The heat transfer medium stored in the heat transfer medium storage unit GS can be supplied to the first circulation flow path 241 through the medium supply line GL. A medium supply valve GB can be installed in the medium supply line GL. By turning the medium supply valve GB on / off or changing the opening rate, the heat transfer medium can be supplied to the first circulation flow path 241 or the supply flow rate per unit time of the heat transfer medium supplied to the first circulation flow path 241 can be adjusted. The heat transfer medium can include helium (He) gas.

[0060] The first circulation channels 241 may be formed in a spiral shape inside the lower electrode 240. Alternatively, the first circulation channels 241 may be arranged such that ring-shaped channels with different radii have the same center. The first circulation channels 241 may be connected to each other. The first circulation channels 241 are formed at the same height.

[0061] The second circulation channel 242 is provided as a passage through which a cooling fluid circulates. The 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). By turning the fluid supply valve (CB) on / off or changing its opening rate, the cooling fluid can be supplied to the second circulation channel 242 or the supply flow rate per unit time of the cooling fluid supplied to the second circulation channel 242 can be adjusted. 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 a predetermined temperature can maintain the temperature of the dielectric plate 210 and / or the substrate (W) at a predetermined temperature.

[0062] The second circulation channel 242 may be formed in a spiral shape inside the lower electrode 240. Alternatively, the second circulation channel 242 may be arranged such that ring-shaped channels with different radii have the same center. The second circulation channels 242 may be connected to each other. The second circulation channel 242 may have a larger cross-sectional area than the first circulation channel 241. The second circulation channels 242 may be formed at the same height. The second circulation channel 242 may be located below the first circulation channel 241.

[0063] The second supply channels 243 extend upward from the first circulation channels 241 and are provided on the upper surface of the lower electrode 240. The number of the second supply channels 243 corresponds to the number of the first supply channels 211, and the first circulation channels 241 and the first supply channels 211 can be fluidly connected to each other.

[0064] An insulating plate 250 is provided below the lower electrode 240. The insulating plate 250 is provided to have a size corresponding to the lower electrode 240. The insulating plate 250 is located between the lower electrode 240 and the bottom surface of the chamber 100. The insulating plate 250 is made of an insulating material and can electrically insulate the lower electrode 240 from the chamber 100.

[0065] The gas supply unit 300 supplies a process gas to the chamber 100. The gas supply unit 300 includes a gas storage unit 310, a gas supply line 320, and a gas inlet port 330. The gas supply line 320 connects the gas storage unit 310 to the gas inlet port 330 and supplies the process gas stored in the gas storage unit 310 to the gas inlet port 330. The gas inlet port 330 may be installed in a gas supply hole 422 formed in the upper electrode 420.

[0066] The upper electrode unit 400 may have an upper electrode 420 facing the lower electrode 240. The gas supply unit 300 is connected to the upper electrode unit 400, and may provide a portion of a supply path for the process gas supplied by the gas supply unit 300. The upper electrode unit 400 may include a support body 410, an upper electrode 420, and a distribution plate 430.

[0067] The support body 410 may be fastened to the chamber 100. The support body 410 may be a body to which the upper electrode 420 and the distribution plate 430 of the upper electrode unit 400 are fastened. The support body 410 may be a medium that allows the upper electrode 420 and the distribution plate 430 to be installed in the chamber 100.

[0068] The upper electrode 420 may be an electrode facing the lower electrode 240. The upper electrode 420 may be provided to face the lower electrode 240. An electric field may be formed in the space between the upper electrode 420 and the lower electrode 240. The formed electric field may excite the process gas supplied to the internal space 101 to generate plasma. The upper electrode 420 may be provided in a disk shape. The upper electrode 420 may include an upper plate 410a and a lower plate 410b. The upper electrode 420 may be grounded. However, the present invention is not limited thereto, and an RF power source (not shown) may be connected to the upper electrode 420 to apply an RF voltage.

[0069] The bottom surface of the upper plate 412a is stepped so that the central region is higher than the edge regions. Gas supply holes 422 are formed in the central region of the upper plate 420a. The gas supply holes 422 are connected to the gas inlet port 330 and supply process gas to the buffer space 424. A cooling channel 421 may be formed inside the upper plate 410a. The cooling channel 421 may be formed in a spiral shape. Alternatively, the cooling channel 421 may be arranged such that ring-shaped channels with different radii share the same center. A temperature control unit 500 (described below) supplies cooling fluid to the cooling channel 421. The supplied cooling fluid circulates along the cooling channel 421 to cool the upper plate 420a.

[0070] The lower plate 420b is positioned below the upper plate 420a. The lower plate 420b is provided with a size corresponding to the upper plate 420a and is positioned opposite the upper plate 420a. The upper surface of the lower plate 420b is stepped so that the central region is lower than the edge regions. The upper surface of the lower plate 420b and the bottom surface of the upper plate 420a combine to form a buffer space 424. The buffer space 424 is provided as a space where gas supplied through the gas supply holes 422 temporarily stays before being supplied into the chamber 100. Gas supply holes 423 are formed in the central region of the lower plate 420b. A plurality of gas supply holes 423 are formed and spaced apart at regular intervals. The gas supply holes 423 are connected to the buffer space 424.

[0071] The distribution plate 430 is located below the lower plate 420b. The distribution plate 430 is disk-shaped. Distribution holes 431 are formed in the distribution plate 430. The distribution holes 431 are provided from the top to the bottom of the distribution plate 430. The number of distribution holes 431 corresponds to the number of gas supply holes 423, and they are positioned corresponding to the fulcrums where the gas supply holes 423 are positioned. The process gas remaining in the buffer space 424 is uniformly distributed inside the chamber 100 through the gas supply holes 423 and the distribution holes 431.

[0072] The temperature control unit 500 can control the temperature of the upper electrode 420. The temperature control unit 500 can include a heating element 511, a heating power supply 513, a filter 515, a cooling fluid supply 521, a fluid supply channel 523, and a valve 525.

[0073] The heating element 511 can heat the lower plate 420b. The heating element 511 can be a heater. The heating element 511 can be a resistive heater. The heating element 511 can be embedded in the lower plate 420b. The heating power source 513 can generate power for heating the heating element 511. The heating power source 513 can heat the heating element 511 to heat the lower plate 420b. The heating power source 513 can be a DC power source. The filter 515 can block the RF voltage (power) applied by the power supply unit 600 (described later) from being transmitted to the heating power source 513.

[0074] The cooling fluid supply unit 521 may store a cooling fluid for cooling the upper plate 520a. The cooling fluid supply unit 521 may supply the cooling fluid to the cooling passage 421 through the fluid supply channel 523. The cooling fluid supplied to the cooling passage 421 may flow along the cooling passage 421 to reduce the temperature of the upper plate 420a. In addition, a fluid valve 525 may be installed in the fluid supply channel 523 to control the amount of cooling fluid supplied by the cooling fluid supply unit 521 or the amount of cooling fluid supplied per unit time. The fluid valve 525 may be an on / off valve or a flow rate control valve.

[0075] The power supply unit 600 can apply an RF (Radio Frequency) voltage to the lower electrode 240. The power supply unit 600 can apply the RF voltage to the lower electrode 240 to form an electric field in the internal space 101. The electric field formed in the internal space 101 can excite the process gas supplied to the internal space 101 to generate plasma. The power supply unit 600 can include a first power source 610, a second power source 620, a third power source 630, and a matching member 640.

[0076] The first power source 610 may apply a voltage having a first frequency to the lower electrode 240. The first frequency of the voltage generated by the first power source 610 may be higher than second and third frequencies (described later) of the voltages generated by the second and third power sources 620 and 630. The first power source 610 may be a source RF that generates plasma in the internal space 101. The first frequency may be 60 MHz.

[0077] The first power supply 610 may be configured to apply a first sustained voltage having a first frequency or a first pulsed voltage having a first frequency to the lower electrode 240. The first sustained voltage may be a CW (Continuous wave) RF power source, and the first pulsed voltage may be a Pulsed RF power source.

[0078] The second power source 620 may apply a voltage having a second frequency to the lower electrode 240. The second frequency of the voltage generated by the second power source 620 may be lower than the first frequency of the voltage generated by the first power source 610 and higher than the third frequency of the voltage generated by the third power source 630. The second power source 620 may be a source RF that generates plasma in the internal space 101 together with the first power source 610. The second frequency may be between 2 MHz and 9.8 MHz.

[0079] The second power supply 620 may be configured to apply a second sustained voltage having a second frequency or a second pulsed voltage having a second frequency to the lower electrode 240. The second sustained voltage may be a CW (Continuous wave) RF, and the second pulsed voltage may be a Pulsed RF.

[0080] The third power supply 630 may apply a voltage having a third frequency to the lower electrode 240. The third frequency of the voltage generated by the third power supply 630 may be lower than the first frequency of the voltage generated by the first power supply 610 and the second frequency generated by the second power supply 620. The second power supply 620 may be a bias RF used together with the first power supply 610 to accelerate plasma ions in the internal space 101. The third frequency may be 400 kHz.

[0081] The third power supply 630 may be configured to apply a third sustained voltage having a third frequency or a third pulsed voltage having a third frequency to the lower electrode 240. The third sustained voltage may be a CW (Continuous wave) RF power source, and the third pulsed voltage may be a Pulsed RF power source.

[0082] The matching member 640 may perform impedance matching. The matching member 640 is connected to the first power source 610, the second power source 620, and the third power source 630, and may perform impedance matching for the voltages applied to the lower electrode 240 by the first power source 610, the second power source 620, and the third power source 630.

[0083] The ring unit 700 may be disposed in an edge region of the support unit 200. The ring unit 700 may include an edge ring 710, an insulating body 720, and a coupling ring 730.

[0084] The 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 ring shape. When viewed from above, the edge ring 710 may be configured such that a portion overlaps the edge region of the substrate (W) and another portion 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 a surface adjacent to the central region of the substrate (W). The outer upper surface may be a surface farther from the central region of the substrate (W) than the inner upper surface. The inclined upper surface may be a surface provided between the inner upper surface and the outer upper surface. The inclined upper surface may be a surface inclined upward in a direction away from the center of the substrate (W). The edge ring 710 may expand the electric field generation region so that the substrate (W) is positioned at the center of the plasma generation region. The edge ring 710 may be a focus ring. The edge ring 710 can be made of a material including Si or SiC.

[0085] The insulating body 720 may be configured to surround the edge ring 710 when viewed from above. The insulating body 720 may be made of an insulating material such as quartz or ceramics.

[0086] An electric line (EL) may be connected to the coupling ring 730. The electric line (EL) may be connected to a filter unit (F) described below. The filter unit (F) may be connected to the impedance control unit 800 via an RF cable (CA). That is, the coupling ring 730 may be connected to the impedance control unit 800 via the electric line (EL) and the RF cable (CA).

[0087] The coupling ring 730 may be disposed below the edge ring 710 and the insulating body 720. The coupling ring 730 may be surrounded by the edge ring 710, the insulating body 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 example 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 such as quartz or ceramics. The ring body 731 may be configured to surround the ring electrode 732. The ring electrode 732 may be made of a conductive material, such as a material containing metal.

[0088] 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 so as to perform a harmonic control method, which will be described later.

[0089] The control device 900 may include a process controller implemented by a microprocessor (computer) that controls the substrate processing apparatus 10; a user interface implemented by a keyboard through which an operator inputs commands to manage the substrate processing apparatus 10 and a display that visualizes the operating status of the substrate processing apparatus; and a memory unit that stores a control program for controlling the processes performed by the substrate processing apparatus 10 under the control of the process controller and a program for causing each component to execute a process according to various data and processing conditions, i.e., a process recipe. The user interface and memory unit may be connected to the process controller. The process recipe may be stored in a storage medium within the memory unit, which may be a hard disk, a portable disk such as a CD-ROM or DVD, or a semiconductor memory such as a flash memory.

[0090] Figure 2 is a diagram schematically illustrating the impedance control unit and filter unit of Figure 1. Referring to Figure 2, an impedance control unit 800 according to an embodiment of the present invention may include an impedance control circuit 810 and an RF power supply 820. The impedance control unit 800 may be electrically connected to the filter unit (F) via an RF cable (CA). The filter unit (F) may be electrically connected to the ring electrode 732 of the coupling ring 730 via an electrical line (EL). That is, the impedance control unit 800 may be electrically connected to the ring unit 700.

[0091] 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, for example, a 60 MHz RF voltage to the ring electrode 732. The density of plasma above the edge region of the substrate (W) can be controlled by the strength or frequency of the voltage applied by the RF power supply 820. For example, if the strength or frequency of the voltage applied by the RF power supply 820 is increased, the plasma density can be further increased.

[0092] The impedance control unit 800 may also include an impedance control circuit 810. The impedance control circuit 810 may include a variable capacitor. Adjusting the capacitance of the variable capacitor may adjust the upper voltage of the edge ring 710. Adjusting the upper voltage of the edge ring 710 may adjust the incident angle of ions of the plasma at the edge region of the W substrate. That is, the flow of plasma may be adjusted. The incident angle of ions of the plasma may be determined by the potential difference between the upper potential of the edge ring 710 and the upper potential of the W substrate, and the potential of the upper potential of the W substrate may be determined by the RF voltage applied by the power supply unit 600. The impedance control circuit 810 may adjust the incident angle of plasma ions at the edge region of the W substrate by adjusting the potential of the upper potential of the edge ring 710. That is, the impedance control unit 800 may be electrically connected to the ring unit 700 and configured to adjust the plasma flow or plasma density at the edge region of the W substrate supported by the support unit 200.

[0093] The filter unit (F) can block harmonic components that can be 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 a signal having a frequency that is a constant multiple of the RF signal transmitted by the RF power supply 820 of the impedance control unit 800. The filter unit (F) can be configured to filter a signal having a frequency that is three times the frequency of the RF signal transmitted by the RF power supply 820, i.e., the third harmonic among the harmonic components that can be generated by the impedance control unit 800. For example, if the signal generated by the RF 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 a harmonic having a frequency of 180 MHz.

[0094] The filter unit (F) may include a housing (HU) having an accommodation space and a filter (C) provided in the accommodation space of the housing (HU). The housing (HU) may have at least one heat dissipation hole (HO) formed therein as shown in FIG. 3. A plurality of heat dissipation holes (HO) may be formed. When harmonics are filtered by the filter (C), the filter (C) may generate heat, and the heat dissipation holes (HO) can help to discharge the heat generated by the filter (C) to the outside. The housing (HU) may also play a role in protecting the filter (C) from the outside.

[0095] Furthermore, filter (C) of filter unit (F) may be implemented by combining at least one filter selected from the group consisting of a band pass filter, a band reject filter, a low pass filter, a low reject filter, a high pass filter, and a high reject filter. Filter (C) may have a rejection band capable of filtering out harmonic components generated by impedance control unit 800. As shown in FIG. 4, filter (C) may be a circuit including an inductor and a variable capacitor, and may be configured to reject, via ground, n-th harmonics (120 MHz for the second harmonic and 180 MHz for the third harmonic), which are constant multiples of 60 MHz generated by impedance control unit 800. In other words, filter (C) may filter out harmonics generated by impedance control unit 800 from being transmitted to ring electrode 732, which is a conductive component. In addition, the filter (C) may be configured to filter at least one harmonic component out of the second harmonic and the third harmonic. For example, the filter (C) may be configured to filter the second harmonic, or the third harmonic, or the second and third harmonics. This is because harmonic components of the fourth harmonic or higher may have very little effect on the density or flow of the plasma.

[0096] That is, by providing the filter unit F according to an embodiment of the present invention, harmonic components generated by the impedance control unit 800 can be filtered from being transmitted to the ring electrode 732, minimizing the influence on controlling the plasma density or flow, thereby minimizing the problem of poor processing uniformity on the substrate W.

[0097] As explained above, as the plasma treatment process for the substrate (W) progresses, the impedance of the coaxial cable, RF cable (CA), changes due to deterioration. Generally, the impedance of RF cable (CA) refers to the reactance of the RF cable (CA) at a frequency of 180MHz (the third harmonic of 60MHz). As explained above, this is because harmonics above the fourth harmonic have little effect on the density or flow of plasma.

[0098] Table 1 below compares the impedance (more specifically, reactance) of the RF cable (CA) at the frequency of the third harmonic (180 MHz) when the filter unit (F) of the present invention is not installed, and the impedance (more specifically, reactance) of the RF cable (CA) and filter (C) at the frequency of the third harmonic (180 MHz) when the filter unit (F) of the present invention is installed.

[0099] [Table 1]

[0100] If a filter unit (F) is not installed, the RF cables (CA) may have different impedances depending on the degree of degradation. For example, if multiple substrate processing apparatuses 10 are provided, the impedance of the RF cable (CA) installed in one of the substrate processing apparatuses 10 may be 112 Ohm, the impedance of the RF cable (CA) installed in another of the substrate processing apparatuses 10 may be 311 Ohm, and the impedance of the RF cable (CA) installed in yet another of the substrate processing apparatuses 10 may be 470 Ohm. In this case, the etch rates of the substrate processing apparatuses 10 may differ from each other, as shown in FIG. 5. In FIG. 5, the X-axis represents the distance from the center of the substrate (W), and the Y-axis represents the etch rate for the film on the substrate (W). PA indicates the etching rate in the substrate processing apparatus 10 equipped with an RF cable (CA) having an impedance of 112 Ohms, PB indicates the etching rate in the substrate processing apparatus 10 equipped with an RF cable (CA) having an impedance of 311 Ohms, and PC indicates the etching rate in the substrate processing apparatus 10 equipped with an RF cable (CA) having an impedance of 470 Ohms. When a filter unit (F) is installed, even if the impedance of the RF cables (CA) varies depending on the degree of degradation, the deviation between the filter (C) and the RF cable (CA) as viewed from the ring electrode 732 can be very small. This is because the third harmonic component is removed. For example, if multiple substrate processing apparatuses 10 are provided, the impedance of the RF cable (CA) + filter (C) installed in one of the substrate processing apparatuses 10 may be 55.08 Ohm, the impedance of the RF cable (CA) + filter (C) installed in another of the substrate processing apparatuses 10 may be 55.43 Ohm, and the impedance of the RF cable (CA) + filter (C) installed in yet another of the substrate processing apparatuses 10 may be 55.18 Ohm. In this case, the difference in etch rate between the substrate processing apparatuses 10 may be very small, as shown in FIG. 6.6, the X-axis represents the distance from the center of the substrate (W), and the Y-axis represents the etching rate for the film on the substrate (W). RA represents the etching rate for the substrate processing apparatus 10 equipped with an RF cable (CA) and filter (C) with an impedance of 112 Ohms, RB represents the etching rate for the substrate processing apparatus 10 equipped with an RF cable (CA) and filter (C) with an impedance of 311 Ohms, and RC represents the etching rate for the substrate processing apparatus 10 equipped with an RF cable (CA) and filter (C) with an impedance of 470 Ohms. In other words, by installing the filter (C), it is possible to minimize variations in etching rates between substrate processing apparatuses 10, even if the degree of degradation of the RF cable (CA) differs from one substrate processing apparatus 10 to another.

[0101] A substrate processing method according to an embodiment of the present invention may be implemented by a controller 900 controlling components of the substrate processing apparatus 10. The substrate processing method may include supplying a process gas to an inner space 101 of a chamber 100 using a gas supply unit 300, and exciting the process gas to generate plasma to process a substrate (W).

[0102] At this time, the density or flow of the plasma transmitted to the substrate (W) is adjusted by adjusting the variable capacitor of the impedance control unit 800 electrically connected to the ring unit 700 arranged under the edge region of the substrate (W), and the filter unit (F) arranged between the impedance control unit 800 and the ring unit 700 can filter out harmonics generated by the impedance control unit 800 from being transmitted to the ring electrode 732 of the ring unit 700.

[0103] In addition, the filter (C) and the impedance control unit 800 are electrically connected to each other by an RF cable (CA), and the harmonics filtered by the filter (C) may have a frequency three times that of the RF signal generated by the impedance control unit 800.

[0104] In the above example, the conductive component is the ring electrode 732 of the ring unit 700, but is not limited thereto. For example, the conductive component can be modified into various configurations that can be used to adjust the flow or density of plasma delivered to the substrate (W).

[0105] The above embodiments are presented to aid in understanding the present invention and do not limit the scope of the present invention, and it should be understood that various modified embodiments are also within the scope of the present invention. The drawings provided in this specification merely illustrate the best embodiment of the present invention. It should be understood that the technical scope of protection of the present invention should be determined by the technical ideas of the claims, and is not limited to the literal recitation of the claims themselves, but should substantially extend to inventions of equivalent technical value. [Explanation of symbols]

[0106] 100 Chambers 101 Interior Space 102 Exhaust hole VL exhaust line 200 Lower electrode unit 210 Dielectric plate 211 First supply channel 220 Electrostatic Electrode 221 Electrostatic Power Supply 230 Heater 240 Lower electrode 241 First circulation channel 242 Second circulation channel 243 Second supply channel 250 Insulating plate 260 Ring member 270 Insulated fuselage 280 Coupling Ring GS Heat Transfer Medium Storage Unit GL media supply line GB Medium Supply Valve CS Cooling Fluid Reservoir CL Fluid supply line CB fluid supply valve 300 Gas Supply Unit 310 Gas storage unit 320 Gas Supply Line 330 Gas inlet port 400 Upper electrode unit 410 Support fuselage 420 Upper electrode 420a Upper plate 420b lower plate 430 Distribution plate 440 Upper power supply section 500 Temperature Control Unit 511 Heating element 513 Heating power supply 515 filters 521 Cooling fluid supply section 523 Fluid Supply Channel 525 Fluid Valve 600 Power Supply Unit 610 1st power supply 620 2nd power supply 630 3rd power supply 640 Alignment member 800 Impedance Control Unit 810 Impedance control circuit 820 RF Power Supply F Filter unit C Filter HU Housing HO heat dissipation hole CA Cable EL Electric Line 900 Controller

Claims

1. In an apparatus for processing a substrate, a chamber having an interior space; a support unit that supports 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 and configured to adjust the flow or density of plasma in the edge region of the substrate; a filter unit disposed between the ring unit and the impedance control unit; a cable electrically connecting the filter unit and the impedance control unit; The impedance control unit an RF power supply for transmitting an RF signal to the ring unit; 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 comprises: a filter configured to prevent harmonics generated by the impedance control unit from being transmitted to the ring unit; The filter is The substrate processing apparatus is configured to filter a third harmonic of the harmonics generated by the impedance control unit from being transmitted to the ring unit.

2. The filter unit further comprises: a housing having a storage space; The substrate processing apparatus of claim 1 , wherein the filter is provided in the accommodation space.

3. The housing includes:

3. The substrate processing apparatus of claim 2, wherein at least one heat dissipation hole is formed to dissipate heat generated in the internal space.

4. The ring unit is an edge ring configured to be positioned below an edge region of the substrate and / or around an edge region of the substrate; a coupling ring disposed below the edge ring; The impedance control unit The substrate processing apparatus of claim 1 , wherein the coupling ring is electrically connected to the coupling ring.

5. The coupling ring is a ring electrode electrically connected to the impedance control unit; The substrate processing apparatus of claim 4 , further comprising: an insulating body configured to surround the ring electrode and made of an insulating material.

6. In an apparatus for processing a substrate using plasma, a chamber having an interior space; a support unit that supports a substrate in the internal space; a power supply unit that generates plasma in the internal space; a conductive component that adjusts the flow or density of the plasma delivered to the substrate; an impedance control unit electrically connected to the conductive component to adjust impedance to adjust the flow or density of the plasma transferred to the substrate; a filter unit disposed between the impedance control unit and the conductive component; a cable electrically connecting the filter unit and the impedance control unit; The impedance control unit an RF power source that transmits an RF signal to the conductive component; an impedance control circuit having a variable capacitor for adjusting the density of the plasma delivered to the substrate; The filter unit comprises: a filter configured to prevent harmonics generated by the impedance control unit from being transmitted to the conductive component; The filter is The substrate processing apparatus is configured to filter a signal having three times the frequency of the RF signal transmitted by the RF power supply.

7. The filter unit comprises: a housing having a storage space; The substrate processing apparatus of claim 6 , wherein the filter is provided in the accommodation space.

8. The housing includes:

8. The substrate processing apparatus of claim 7, further comprising at least one heat dissipation hole for dissipating heat generated by the filter to the outside.

9. The substrate processing apparatus of claim 6 , further comprising a ring unit disposed at an edge region of the support unit and having the conductive component.

10. The ring unit is When viewed from above, the substrate includes an edge ring configured to surround an edge region of the substrate or an outer periphery of the edge region of the substrate; The conductive component is The substrate processing apparatus of claim 9 , having a ring shape but positioned below the edge ring.

11. 1. A method for processing a substrate, comprising: A process gas is supplied to an internal space of the chamber, and the process gas is excited to generate plasma to process the substrate. adjusting a variable capacitor of an impedance control unit electrically connected to a ring unit disposed under an edge region of the substrate to adjust the density or flow of plasma delivered to the substrate; a filter of a filter unit disposed between the impedance control unit and the ring unit filters out a third harmonic among the harmonics generated by the impedance control unit from being transmitted to the ring unit; The filter and the impedance control unit are connected to each other by an RF cable.

Images