Substrate processing apparatus

Abstract

A substrate processing device capable of locally controlling plasma intensity and improving the uniformity of thin film characteristics and thickness comprises a power supply unit, a processing unit electrically connected to the power supply unit, and a substrate support unit disposed below the processing unit, wherein the substrate support unit comprises a first ground electrode and a second ground electrode.

Description

Technology Field

[0001] The present invention relates to a substrate processing apparatus, and more particularly to a substrate processing apparatus configured to process a substrate by supplying plasma power through a processing unit disposed on the substrate. Background Technology

[0002] It includes a heating block used in a substrate processing device, and the heating block heats the mounted substrate to enable processing on the substrate. The substrate support unit including the heating block can also function as an electrode during a plasma process. For example, during an in-situ plasma process, a shower head facing the heating block and the reaction space functions as a lower electrode and an upper electrode, respectively.

[0003] As the size of the substrate to be processed increases, localized concentration of plasma density occurs, which may result in a decrease in the uniformity of thin film characteristics and thickness at the center and edges of the substrate. This problem of reduced plasma uniformity is also mentioned in Japanese Patent Publication No. 2004-363552. Specifically, the paragraph of the said document

[0004] It mentions that non-uniformity of plasma density occurs at the center and edges of the electrode. The problem to be solved

[0004] One of the problems that the present invention aims to solve is to provide a substrate processing apparatus capable of improving the non-uniformity of plasma on a substrate. means of solving the problem

[0005] Additional aspects will be partially described in the following description, partially apparent from the description, and can be learned by practicing the embodiments presented in this disclosure.

[0006] According to one aspect of embodiments based on the technical concept of the present invention, a substrate processing device comprises: a power supply unit; a processing unit electrically connected to the power supply unit; and a substrate support unit disposed below the processing unit, wherein the substrate support unit may include a first ground electrode and a second ground electrode.

[0007] According to one example of the above-described substrate processing device, the processing unit may be configured to function as an electrode that supplies power to the reaction space.

[0008] According to another example of the above-described substrate processing device, the second ground electrode may be spaced apart from the first ground electrode and arranged to surround the first ground electrode.

[0009] According to another example of the above substrate processing device, the first ground electrode and the second ground electrode are electrically connected to ground, and the substrate processing device may include at least one of a first plasma intensity control unit connected between the first ground electrode and ground; and a second plasma intensity control unit connected between the second ground electrode and ground.

[0010] According to another example of the above substrate processing device, at least one of the first plasma intensity control unit and the second plasma intensity control unit may include an LC circuit comprising an inductor, a capacitor, and a variable capacitor.

[0011] According to another example of the above-described substrate processing device, at least one of the first ground electrode and the second ground electrode may include a plate-type ground electrode.

[0012] According to another example of the above-described substrate processing device, at least one of the first ground electrode and the second ground electrode may include a mesh ground electrode.

[0013] According to another example of the above-described substrate processing device, the mesh grounding electrode comprises a first grounding line extending in a first direction; and a second grounding line extending in a second direction different from the first direction, and the first grounding line and the second grounding line may be electrically connected.

[0014] According to another example of the above-described substrate processing device, the first ground line and the second ground line come into contact at the point where the first ground line and the second ground line intersect, and through said contact, the first ground line and the second ground line can be electrically connected.

[0015] According to another example of the above-described substrate processing device, the first ground line and the second ground line are spaced apart at the point where the first ground line and the second ground line intersect, and the first ground line and the second ground line can be electrically connected by a conductive member connecting the end of the first ground line and the end of the second ground line.

[0016] According to another example of the above-described substrate processing device, in a plurality of first portions where the first ground line and the second ground line intersect, the distance between the upper surface of the substrate support unit and the first ground line is greater than the distance between the upper surface of the substrate support unit and the second ground line, and in a second portion other than the first portion, the distance between the upper surface of the substrate support unit and the first ground line may be equal to the distance between the upper surface of the substrate support unit and the second ground line.

[0017] According to another example of the above-described substrate processing device, the first ground electrode includes a first mesh ground electrode and the second ground electrode includes a second mesh ground electrode, and the first mesh ground electrode and the second mesh ground electrode may have different mesh densities.

[0018] According to another example of the above-described substrate processing device, the first ground electrode may be placed at a different level from the second ground electrode.

[0019] According to another example of the above-described substrate processing device, the first ground electrode and the second ground electrode may partially overlap.

[0020] According to another example of the above substrate processing device, the substrate processing device may further include a first electrode rod in contact with the first ground electrode; and a first connecting rod electrically connecting the first electrode rod and ground.

[0021] According to another example of the above substrate processing device, the substrate processing device may further include a first buffer rod disposed between the first electrode rod and the first connection rod.

[0022] According to another example of the above-described substrate processing device, the first electrode rod comprises a first metal component, the first connecting rod comprises a second metal component different from the first metal component, and the first buffer rod may comprise an alloy component of the first metal component and the second metal component.

[0023] According to another example of the above substrate processing device, the substrate support unit further comprises a first heating unit disposed below the first ground electrode; and a second heating unit disposed below the second ground electrode, wherein the first heating unit and the second heating unit can be controlled independently.

[0024] According to another aspect of embodiments of the technical concept of the present invention, a substrate processing device comprises: a power supply unit; a showerhead electrode electrically connected to the power supply unit; and a heating block disposed below the showerhead electrode, wherein the heating block comprises a first ground electrode in the form of a disc and a second ground electrode in the form of a ring spaced apart from the first ground electrode and surrounding the first ground electrode, and at least one of the first ground electrode and the second ground electrode is connected to an LC circuit comprising an inductor, a capacitor, and a variable capacitor, and the LC circuit is connected to ground, and through parameter control of the LC circuit, at least one of the density and intensity of the plasma in the reaction space can be controlled.

[0025] According to another aspect of embodiments based on the technical concept of the present invention, a substrate processing device may include a first ground electrode connected to ground; and a second ground electrode spaced apart from the first ground electrode and connected to ground. Brief explanation of the drawing

[0026] The above and other aspects, features, and advantages of specific embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings. FIG. 1 is a schematic diagram showing a substrate processing apparatus according to embodiments based on the technical concept of the present invention. FIGS. 2 and FIGS. 3 illustrate embodiments related to a mesh grounding electrode. FIG. 4 schematically illustrates a substrate processing apparatus according to embodiments based on the technical concept of the present invention. Figure 5 illustrates an RF ground electrode within a heating block. Figure 6 shows a case where the distance from the RF ground electrode to the surface of the heating block varies by location. FIG. 7 shows an example of an arrangement of RF ground wires according to the present invention. FIG. 8 shows another embodiment of a substrate processing apparatus according to the present invention. FIG. 9 shows a cross-sectional view of a heating block according to the present invention viewed from different directions. Figure 10 shows the connection structure between the RF ground electrode and the RF electrode rod. Figure 11 illustrates the arrangement of the RF ground electrode and the heating wire. Figure 12 shows the distribution of plasma intensity in a reactor equipped with a heating block according to the present invention. Specific details for implementing the invention

[0027] References to embodiments will now be made in detail, examples of which are illustrated in the accompanying drawings, and similar reference numbers refer to similar elements throughout. In this regard, the embodiments may take different forms and are not limited to the descriptions given herein. Accordingly, embodiments are described below with reference to the drawings merely to illustrate aspects of the description. As used herein, the term "and / or" includes any and all combinations of one or more associated listed items. Expressions such as "at least one" modify the entire list of elements when preceding a list of elements, and do not modify individual elements of the list.

[0028] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0029] The embodiments of the present invention are provided to more fully explain the invention to those skilled in the art, and the following embodiments may be modified in various different forms, and the scope of the invention is not limited to the following embodiments. Rather, these embodiments are provided to make the disclosure more faithful and complete and to fully convey the spirit of the invention to those skilled in the art.

[0030] The terms used herein are for describing specific embodiments and are not intended to limit the invention. As used herein, the singular form may include the plural form unless the context clearly indicates otherwise. Additionally, as used herein, “comprise” and / or “comprising” specify the presence of the mentioned features, numbers, steps, actions, parts, elements, and / or groups thereof, and do not exclude the presence or addition of one or more other features, numbers, actions, parts, elements, and / or groups. As used herein, the term “and / or” includes any one of the listed items and all combinations of one or more of them.

[0031] Although terms such as "first," "second," etc. are used in this specification to describe various components, regions, and / or parts, it is obvious that these components, parts, regions, layers, and / or parts should not be limited by these terms. These terms do not imply a specific order, hierarchy, or superiority, and are used solely to distinguish one component, region, or part from another. Accordingly, the first component, region, or part described below may refer to the second component, region, or part without departing from the teachings of the present invention.

[0032] Hereinafter, embodiments of the present invention are described with reference to drawings that schematically illustrate ideal embodiments of the present invention. In the drawings, variations of the illustrated shapes may be expected, for example, depending on manufacturing techniques and / or tolerances. Accordingly, embodiments of the present invention should not be interpreted as being limited to specific shapes of the areas illustrated herein, but should include, for example, variations in shape resulting from manufacturing.

[0033] FIG. 1 is a schematic diagram showing a substrate processing apparatus according to embodiments based on the technical concept of the present invention.

[0034] Referring to FIG. 1, the substrate processing device may include a power supply unit (PWR), a processing unit (110), and a substrate support unit (150).

[0035] A power supply unit (PWR) may be configured to generate power. The power may be, for example, electrical energy for generating plasma, or in other examples, the plasma itself. The generated power may be transferred to a processing unit (110). For example, the power supply unit (PWR) may be electrically connected to the processing unit (110) via an RF load, and thus the power generated in the power supply (e.g., RF power) may be transferred to the processing unit (110) by the RF load.

[0036] The processing unit (110) may be positioned on a substrate support unit (150) configured to support a substrate. A reaction space (51) may be defined between the substrate support unit (150) and the processing unit (110). The processing unit (110) may be a conductor and may be used as an electrode to generate plasma. That is, the processing unit (110) itself may function as an electrode to generate plasma. Plasma may be generated in the reaction space (51) by the processing unit (110) which is electrically connected to a power supply unit (PWR). In other words, the processing unit (110) may function as a plasma electrode to supply power to the reaction space (51).

[0037] The processing unit (110) may include components that perform appropriate functions depending on the function of the substrate processing device. For example, if the substrate processing device performs a deposition function, the processing unit (110) may include a reaction material supply unit (e.g., a showerhead assembly). In another embodiment, if the reactor performs a polishing function, the processing unit (110) may include a polishing pad. In some embodiments, if the processing unit (110) itself is used as an electrode and performs the function of a showerhead assembly, the processing unit (110) may be referred to as a showerhead electrode.

[0038] The substrate support unit (150) may be configured to provide an area on which a substrate (S) (e.g., a semiconductor substrate or a display substrate) to be processed is placed. The substrate support unit (150) may be positioned below the processing unit (110). The substrate support unit (150) may be supported by a support (not shown) capable of vertical and rotational movement. Additionally, the substrate support unit (150) may include a conductor, and the substrate support unit (150) may function as an electrode (i.e., an electrode opposite to a gas supply electrode) that generates plasma using the conductor.

[0039] The substrate support unit (150) may include a first ground electrode (GE1), a second ground electrode (GE2), a first heating unit (HU1), a second heating unit (HU2), a first plasma intensity control unit (PC1), and a second plasma intensity control unit (PC2). A structure including these ground electrodes and heating units may also be referred to as a heating block in this specification.

[0040] The first ground electrode (GE1) and the second ground electrode (GE2) may be spaced apart from each other. For example, the first ground electrode (GE1) may be positioned at the center of the substrate support unit (150), and the second ground electrode (GE2) may be positioned to surround the first ground electrode (GE1). In one example, the first ground electrode (GE1) may be in the shape of a disc (e.g., a circular or square disc), and the second ground electrode (GE2) may be in the shape of a ring (e.g., a circular ring or a square ring) surrounding the first ground electrode (GE1).

[0041] In some embodiments, the substrate support unit (150) may include three or more ground electrodes. For example, the three or more ground electrodes may include a central electrode positioned in the center, a first ring electrode surrounding the central electrode, and a second ring electrode surrounding the first ring electrode.

[0042] The first ground electrode (GE1) and the second ground electrode (GE2) can each be electrically connected to ground (GND). That is, the ground electrodes (GE1, GE2) within the substrate support unit (150) are not connected to a power supply unit (PWR) that supplies power, but are connected to ground (GND). Accordingly, the path through which power (e.g. RF power) supplied through the processing unit (110) travels to ground (GND) may include a first channel through the first ground electrode (GE1) and a second channel through the second ground electrode (GE2).

[0043] At least one of the first channel and the second channel may be implemented as a rod. For example, if the first channel is implemented as a rod, the first channel may be implemented as a single rod. In some embodiments, the first channel may be implemented as a plurality of rods. The second channel may also be implemented as a rod, and in some examples, the first channel and the second channel may each be implemented as separate rods.

[0044] When the first channel is implemented with a plurality of rods, the first channel may include a first electrode rod and a first connection rod. The first electrode rod may be in contact with a first ground electrode (GE1). The first connection rod may electrically connect the first electrode rod and ground (GND). In some embodiments, a first buffer rod may be placed between the first electrode rod and the first connection rod.

[0045] In an additional embodiment, the first buffer rod may include a metal component of the first electrode rod and an alloy component of the first connecting rod. For example, if the first electrode rod is implemented with molybdenum (Mo) and the first connecting rod is implemented with nickel (Ni), the first buffer rod may be implemented with a Mo-Ni alloy.

[0046] The first plasma intensity control unit (PC1) can be connected between the first ground electrode (GE1) and ground (GND). Thus, the power moving to ground (GND) through the first channel can be controlled by the first plasma intensity control unit (PC1). The second plasma intensity control unit (PC2) can be connected between the second ground electrode (GE2) and ground (GND). Thus, the power moving to ground (GND) through the second channel can be controlled by the second plasma intensity control unit (PC2).

[0047] In some embodiments, the plasma intensity control unit (i.e., the first and / or second plasma intensity control unit (PC1, PC2)) may include an LC circuit comprising an inductor, a capacitor, and a variable capacitor. In some embodiments, the LC circuit may be included only in the first plasma intensity control unit (PC1), and in other embodiments, the LC circuit may be included only in the second plasma intensity control unit (PC2). In yet another embodiment, the LC circuit may be included in both the first plasma intensity control unit (PC1) and the second plasma intensity control unit (PC2).

[0048] The first plasma intensity control unit (PC1) and the second plasma intensity control unit (PC2) may have different parameters. By controlling these parameters, at least one of the density and intensity of the plasma in the reaction space can be adjusted. In an additional example, the plasma intensity control unit may include a circuit configuration other than an LC circuit (e.g., a band-pass filter).

[0049] In some embodiments, the first ground electrode (GE1) and the second ground electrode (GE2) (or either one thereof) may be implemented as plate-shaped ground electrodes. For example, the first ground electrode (GE1) may be in the form of a circular or square plate, and the second ground electrode (GE2) may be a ring-shaped circular or square plate surrounding the first ground electrode (GE1).

[0050] In some other embodiments, the first ground electrode (GE1) and the second ground electrode (GE2) (or either one thereof) may be implemented as mesh ground electrodes. For example, the first ground electrode (GE1) may be a disk-shaped mesh ground electrode with multiple intersecting wires, and the second ground electrode (GE2) may be a ring-shaped mesh ground electrode with multiple intersecting wires. In one example where the first ground electrode (GE1) is implemented to include the first mesh ground electrode and the second ground electrode (GE2) is implemented to include the second mesh ground electrode, the first mesh ground electrode and the second mesh ground electrode may have different mesh densities. Due to this difference in mesh density, the plasma density or intensity on the substrate may be controlled.

[0051] In some embodiments relating to a mesh grounding electrode, with reference to FIGS. 2 and FIGS. 3, the mesh grounding electrode may include a first grounding line (C1) extending in a first direction and a second grounding line (C2) extending in a second direction different from the first direction. The first grounding line (C1) and the second grounding line (C2) may be electrically connected. The first grounding line (C1) and the second grounding line (C2) may be arranged to be inserted into a substrate support unit (150).

[0052] In some examples, referring to FIG. 2, the first grounding line (C1) and the second grounding line (C2) may come into contact at the intersection (P) where the first grounding line (C1) and the second grounding line (C2) intersect. Through contact at the intersection, a mesh grounding electrode in which the first grounding line (C1) and the second grounding line (C2) are electrically connected may be realized.

[0053] In another example, referring to FIG. 3, the first grounding line (C1) and the second grounding line (C2) may be spaced apart at the intersection (P') of the first grounding line (C1) and the second grounding line (C2). In this case, the first grounding line (C1) and the second grounding line (C2) may come into contact at the edge portion. For example, a conductive member (C3) may connect the end of the first grounding line (C1) and the end of the second grounding line (C2). Through this contact at the edge portion, a mesh grounding electrode in which the first grounding line (C1) and the second grounding line (C2) are electrically connected may be realized.

[0054] As shown in FIGS. 2 and 3, in a plurality of first portions where the first ground line (C1) and the second ground line (C2) intersect, the distance (F1) between the upper surface of the substrate support unit (150) and the first ground line (C1) may be greater than the distance (F2) between the upper surface of the substrate support unit (150) and the second ground line (C2). On the other hand, in a second portion other than the first portion, the distance (F2') between the upper surface of the substrate support unit (150) and the first ground line (C1) may be equal to the distance (F2'') between the upper surface of the substrate support unit (150) and the second ground line (C2). Thus, in the entire area of ​​the mesh grounding electrode, the distance between the upper surface of the substrate support unit (150) and the ground lines (i.e., the first ground line (C1) and the second ground line (C2)) can be maintained constant.

[0055] Although the first ground electrode (GE1) and the second ground electrode (GE2) are shown in FIG. 1 at the same height, the first ground electrode (GE1) may be placed at a different level from the second ground electrode (GE2). In other words, the distance between the upper surface of the substrate support unit (150) and the first ground electrode (GE1) may be different from the distance between the upper surface of the substrate support unit (150) and the second ground electrode (GE2).

[0056] Due to the level difference between the first ground electrode (GE1) and the second ground electrode (GE2), the density or intensity of the plasma can be controlled according to the location of the reaction space. For example, if the first ground electrode (GE1) placed at the center of the reaction space is placed at a higher level than the second ground electrode (GE2) placed at the edge of the reaction space, plasma with greater intensity can be applied to the center or the edge of the reaction space.

[0057] When the first grounding electrode (GE1) is placed at a different height from the second grounding electrode (GE2), the distance between the first grounding electrode (GE1) and the second grounding electrode (GE2) in the horizontal direction (i.e., the extension direction of the first grounding electrode (GE1) and the second grounding electrode (GE2)) may be zero. Furthermore, in some other embodiments, the first grounding electrode (GE1) and the second grounding electrode (GE2) may partially overlap in the horizontal direction.

[0058] Referring again to FIG. 1, the first heating unit (HU1) may be placed below the first ground electrode (GE1), and the second heating unit (HU2) may be placed below the second ground electrode (GE2). The first heating unit (HU1) may have a shape corresponding to the first ground electrode (GE1), and the second heating unit (HU2) may have a shape corresponding to the second ground electrode (GE2). For example, if the first ground electrode (GE1) is a disc-shaped electrode, the first heating unit (HU1) may also be implemented in a disc shape. Additionally, if the second ground electrode (GE2) is a ring-shaped electrode, the second heating unit (HU2) may also be implemented in a ring shape.

[0059] The first heating unit (HU1) and the second heating unit (HU2) can be controlled independently. For example, a control unit (CON) may be electrically connected to the first heating unit (HU1) and the second heating unit (HU2), and a first signal for controlling the first heating unit (HU1) and a second signal for controlling the second heating unit (HU2) may be generated from the control unit (CON). The first signal and the second signal may be transmitted to the first heating unit (HU1) and the second heating unit (HU2), respectively, through different channels. Although a plurality of heating units are disclosed in the above embodiment, they are not limited thereto and may be configured as a single unit. In this case, the control unit (CON) may generate a single signal and transmit it to the heating unit.

[0060] FIG. 4 shows a substrate processing apparatus according to embodiments based on the technical concept of the present invention, with a heating wire omitted for the sake of understanding. The substrate processing apparatus according to these embodiments may be a modified example of the substrate processing apparatus according to the aforementioned embodiments. Descriptions that overlap between the embodiments below will be omitted.

[0061] Referring to FIGS. 4a and 4b, the heating block (1) includes an RF ground electrode inside, and the RF ground electrode is composed of a plurality of RF ground electrodes and is arranged independently of each other. The RF ground electrode consists of a first RF ground electrode (2) and a second RF ground electrode (3), and the second RF ground electrode (3) is configured to surround the first RF ground electrode (2). In FIG. 4a, the first RF ground rod (4) is connected to the first RF ground electrode (2) and the second RF ground rod (5) is connected to the second RF ground electrode (3), and the first RF ground electrode (2) and the second RF ground electrode (3) are each connected to ground through the first RF ground rod (4) and the second RF ground rod (5).

[0062] In the case of a heating block containing internal plate electrodes, the characteristics of the electrodes become process variables that affect the substrate process. For instance, during high-temperature processes, differences in the coefficients of thermal expansion between the electrodes and the heating block, as well as the detailed shape of the plate electrodes, affect the reproducibility and uniformity of the substrate process. In the case of thin film processes, this influences the uniformity of the deposited film and the plasma uniformity on the heating block. Generally, the plate electrodes within the heating block are composed of single-layer plate electrodes to ensure plasma uniformity on the substrate. However, in practice, problems arise where the uniformity of the substrate process is degraded due to heat loss and non-uniformity of the gas flow supplied to the substrate. For instance, non-uniform gas distribution on the substrate can lead to localized concentrations of plasma density, potentially degrading the uniformity of film characteristics and thickness between the center and edges of the substrate. However, the substrate processing device according to the embodiments of the technical concept of the present invention can individually control the non-uniformity of plasma at the center and edge portions of the substrate by arranging the first RF ground electrode (2) and the second RF ground electrode (3) apart, and thus the uniformity of the thin film characteristics and thickness of the substrate can be improved.

[0063] The first grounding electrode (2) and the second grounding electrode (3) are formed in a mesh shape and are spaced apart from each other by a spacing d1. Typically, the RF grounding electrode embedded in the heating block is manufactured by printing and is formed in the shape of an integrated plate. However, in high-temperature processes, a stress difference occurs due to the difference in thermal expansion coefficient between the heating block and the embedded RF grounding electrode, which can cause the heating block to break. For example, the thermal expansion coefficient of a heating block made of AlN material is 4.5 x 10⁻⁶ -6The coefficient of thermal expansion of an RF ground electrode made of Mo material is 4.8 x 10⁻⁶ / ℃. -6 Since it is / ℃, the heating block may separate or break due to stress differences at high temperatures.

[0064] In contrast, in the present invention, the RF ground electrode is formed in a mesh shape, so that the constituent material of the heating block, such as AlN, fills the space between the electrode wires, thereby minimizing the destruction of the heating block due to stress differences. More specifically, as shown in FIG. 5a, which illustrates an integrated RF ground electrode (2) within a conventional heating block, the heating block (1) is separated into an upper part (A) and a lower part (B) by the RF ground electrode (2). In a high-temperature process, the upper and lower parts of the heating block may separate or crack due to a stress difference (arrow) between the heating block (1) and the RF ground electrode (2). However, in the structure of FIG. 5b according to the present invention, the upper part (A) and the lower part (B) of the heating block are connected through the area (C) between the mesh of the RF ground electrode, thereby providing a technical feature that can suppress separation or cracking during a high-temperature process.

[0065] Referring again to FIG. 4, the first RF grounding rod (4) is connected to the first LC resonance circuit (7), and the second RF grounding rod (5) is connected to the second LC resonance circuit (8). The LC circuit includes an inductor (L), a capacitor (C), and a variable capacitor (Cvar), and serves to control the plasma intensity on the RF grounding electrode. In addition to the LC circuit, a circuit that controls the plasma intensity on the RF grounding electrode may be applied. As an example of the technical features of this configuration, the thickness and characteristics of the thin film on the substrate can be controlled locally. In the case of a heating block, the temperature of the peripheral area may be lower than that of the center, and the characteristics or thickness of the thin film in the peripheral area may not be the same as those in the center. Alternatively, if the exhaust port of a substrate processing device equipped with multiple reactors is arranged asymmetrically, the characteristics or thickness of the thin film at a specific location on the substrate may not be the same as those in the center. Therefore, through the configuration of the heating block according to the present invention, the uniformity of the characteristics and thickness of the thin film can be controlled and improved.

[0066] In FIG. 4a, the first LC resonance circuit (7) and the second LC resonance circuit (8) are shown to be grounded (i.e. connected to ground), but in other embodiments, they may be connected to a control system (controller, not shown). The control system transmits plasma intensity information measured through a plasma probe capable of monitoring the plasma in the reactor in real time to the control system, and the control system can control the plasma intensity on the substrate in real time by controlling the first or second LC resonance circuit.

[0067] As shown in FIG. 4b, the first RF ground electrode (2) and the second RF ground electrode (3) are spaced apart by a distance d1, making it easier to control the plasma at the center and edge of the substrate individually. The distance d1 has a technical feature that prevents the first RF ground electrode (2) and the second RF ground electrode (3) from coming into contact due to thermal expansion. Preferably, the separation distance d1 is configured to be at least 5 mm.

[0068] Also, in FIG. 4a, the diameter of the first RF ground electrode (2) is smaller than the diameter of the substrate (6). Thus, plasma control of the inner portion excluding the edge portion of the substrate (6) is facilitated. The second RF ground electrode (3) has an inner diameter that is at least larger than the diameter of the substrate. Thus, plasma control of the edge portion of the substrate (6) is facilitated.

[0069] In FIG. 4a, the distance (d2) from the RF ground electrodes (2, 3) to the upper surface of the heating block (1) is preferably maintained at 1 mm. If the distance d2 is less than 1 mm, damage to the heating block (1) may occur due to deformation caused by thermal expansion of the RF ground electrodes at high temperatures, and if it is more than 1 mm, the plasma intensity on the substrate may decrease, so more RF power must be supplied to maintain process uniformity.

[0070] The distance (d2) between the RF ground electrode (2, 3) and the upper surface of the heating block (1) affects the distribution of plasma on the substrate and the plasma intensity. The RF ground electrode according to the present invention is configured in a mesh form, and since the parts where the electrode wires in the horizontal and vertical directions (XY axis) intersect are protruding, the distance d2 between the intersecting parts and the surface of the heating block (1) may be different from the distance d2 between the non-intersecting parts and the surface of the heating block (1).

[0071] FIG. 6 shows a case where the distance from the RF ground electrode to the surface of the heating block varies by location. In FIG. 6a and FIG. 6b, the distance to the upper surface of the heating block (1) is different at the location where the RF ground electrode line (W2) arranged in the X-axis direction and the RF ground electrode line (W3) arranged in the Y-axis direction intersect and at the location where they do not intersect (d3≠Therefore, it is necessary to arrange the RF ground lines so that the distance to the upper surface of the heating block is constant regardless of whether the RF ground lines intersect.

[0072] FIG. 7 shows an embodiment of the arrangement of RF ground lines according to the present invention. In FIG. 7, the distance to the upper surface of the heater block (1) is constant (d3=d4) at the intersection and non-intersection of the RF ground lines (W2, W3) arranged in the X and Y axis directions. Therefore, it has the technical feature of making precise control of plasma on the substrate easier.

[0073] FIG. 8 illustrates another embodiment according to the present invention. Referring to FIG. 8, the distance d5 from the first RF ground electrode (2) to the surface of the heating block and the distance d6 from the second RF ground electrode (3) to the surface of the heating block are different (d5≠

[0074] According to the embodiment of FIG. 8, unlike in FIG. 4, there is a technical feature that allows the plasma intensity of the center and periphery of the substrate to be individually controlled by utilizing the difference in distance between each RF ground electrode and the upper surface of the heating block, even when a single LC resonance circuit is applied. In addition, unlike FIG. 4, since the two RF ground electrodes are not on the same plane, there is no need to set a separation distance considering thermal expansion (g=0).

[0075] FIG. 9 shows a cross-sectional view of a heating block according to the present invention viewed from different directions.

[0076] Referring to FIG. 9, RF ground electrodes (2, 3) are located between the heating element (9) and the upper surface of the heating block (1). The first RF ground electrode (2) and the second RF ground electrode (3) are each connected to the first RF ground rod (4) and the second RF ground rod (5), respectively, and the power rod (10) of the heating block (1) supplies power to the heating element (9).

[0077] Figure 10 shows the connection structure between the RF ground electrode and the RF electrode rod.

[0078] Referring to FIG. 10, the RF ground electrode (11) is formed in a mesh shape. In FIG. 8, the RF ground electrode (11) and the RF ground electrode rod (12) are made of the same material, such as Mo, and the RF ground rod (14) is made of a conductive material, such as Ni. The buffer electrode rod (13) connects the RF ground electrode rod (12) and the RF ground rod (14) and includes the constituent materials of the RF ground electrode rod (12) and the RF ground rod (14). For example, if the RF ground electrode rod (12) is made of Mo and the RF ground rod (14) is made of Ni, the buffer electrode rod (13) is made of a Mo-Ni alloy. By doing so, the RF ground electrode rod (12) and the RF ground rod (14), which are made of metal materials having different coefficients of thermal expansion, have a technical feature that prevents them from becoming misaligned or separated from each other at high temperatures.

[0079] FIG. 11 shows the upper surface of the heating block of FIG. 9 and illustrates the arrangement of RF ground electrodes (2, 3) and heating wires (9). As described above, the RF ground electrodes (2, 3) each form a mesh shape, and the heating wires (9) are arranged to form two-zone heating areas independently provided to the center and periphery of the heating block (1), forming concentric circles with respect to the center of the heating block. The second boundary line (B2) dividing the aforementioned two-zone heating areas corresponds to the first boundary line (B1) dividing the first RF ground electrode (2) and the second RF ground electrode (3). The first boundary line (B1) and the second boundary line (B2) may be symmetrical to each other. For example, if the first boundary line (B1) and the second boundary line (B2) are implemented as circles, they may have the same diameter.

[0080] FIG. 12 shows the distribution of plasma intensity in a reactor equipped with a heating block according to the present invention. It shows that the plasma intensity is individually controlled by RF ground electrodes placed in the center and periphery, and the uniformity of the plasma intensity may be the same or different depending on the purpose of substrate processing.

[0081] In this way, according to embodiments based on the technical concept of the present invention, by placing mesh-shaped RF ground electrodes in the center and periphery of the heating block respectively and connecting an LC resonance circuit to each ground electrode, the plasma intensity on the substrate during the plasma process can be locally controlled and the uniformity of the thin film characteristics or thickness can be improved.

[0082] To ensure a clear understanding of the present invention, the shapes of each part in the attached drawings should be understood as exemplary. It should be noted that various shapes other than those depicted may be modified.

[0083] It will be obvious to those skilled in the art that the present invention described above is not limited to the aforementioned embodiments and attached drawings, and that various substitutions, modifications, and changes are possible within the scope of the technical concept of the present invention.

Claims

Claim 1 A substrate processing device comprising: a power supply unit; a processing unit electrically connected to the power supply unit; and a substrate support unit disposed below the processing unit, wherein the substrate support unit comprises a first ground electrode, a second ground electrode, and a third ground electrode, wherein the third ground electrode comprises a central electrode disposed at the center of the substrate support unit, the first ground electrode comprises a first ring electrode surrounding the central electrode, and the second ground electrode comprises a second ring electrode surrounding the first ring electrode. Claim 2 A substrate processing apparatus according to claim 1, wherein the second ground electrode is spaced apart from the first ground electrode and arranged to surround the first ground electrode. Claim 3 A substrate processing device according to claim 1, wherein the first ground electrode and the second ground electrode are electrically connected to ground, and the substrate processing device comprises at least one of a first plasma intensity control unit connected between the first ground electrode and the ground; and a second plasma intensity control unit connected between the second ground electrode and the ground. Claim 4 A substrate processing apparatus according to claim 3, wherein at least one of the first plasma intensity control unit and the second plasma intensity control unit comprises an LC circuit including an inductor, a capacitor, and a variable capacitor. Claim 5 A substrate processing apparatus according to claim 4, wherein at least one of the first plasma intensity control unit and the second plasma intensity control unit comprises a band-pass filter. Claim 6 A substrate processing apparatus according to claim 1, wherein at least one of the first ground electrode and the second ground electrode comprises a plate-type ground electrode. Claim 7 A substrate processing apparatus according to claim 1, wherein at least one of the first ground electrode and the second ground electrode comprises a mesh ground electrode. Claim 8 A substrate processing apparatus according to claim 7, wherein the mesh grounding electrode comprises: a first grounding line extending in a first direction; and a second grounding line extending in a second direction different from the first direction, and the first grounding line and the second grounding line are electrically connected. Claim 9 A substrate processing apparatus according to claim 8, wherein the first grounding line and the second grounding line come into contact with each other at the portion where the first grounding line and the second grounding line intersect each other, and the first grounding line and the second grounding line are electrically connected at the contact portion between them. Claim 10 A substrate processing apparatus according to claim 8, wherein the first ground line and the second ground line are spaced apart from each other at the portion where the first ground line and the second ground line intersect, and the first ground line and the second ground line are electrically connected to each other by a conductive member that connects the end of the first ground to the end of the second ground line. Claim 11 A substrate processing apparatus according to claim 8, wherein in a plurality of first portions where the first ground line and the second ground line intersect each other, the distance between the upper surface of the substrate support unit and the first ground line is greater than the distance between the upper surface of the substrate support unit and the second ground line, and in a second portion other than the first portion, the distance between the upper surface of the substrate support unit and the first ground line is the same as the distance between the upper surface of the substrate support unit and the second ground line. Claim 12 A substrate processing apparatus according to claim 7, wherein the first ground electrode comprises a first mesh ground electrode and the second ground electrode comprises a second mesh ground electrode, and the first mesh ground electrode and the second mesh ground electrode have different mesh densities. Claim 13 A substrate processing apparatus according to claim 1, wherein the substrate support unit further comprises a first heating unit disposed below the first ground electrode; and a second heating unit disposed below the second ground electrode, wherein the first heating unit and the second heating unit are independently controlled. Claim 14 A substrate processing apparatus according to claim 2, wherein the first ground electrode and the second ground electrode are spaced apart by at least 5 mm in the lateral direction. Claim 15 A substrate processing apparatus according to claim 1, wherein at least one of the first ground electrode and the second ground electrode comprises a first wire and a second wire, and the first wire and the second wire are configured to intersect in the X direction and the Y direction, such that the distance from the upper surface of the substrate support unit to the first wire and the distance from the upper surface of the substrate support unit to the second wire are the same. Claim 16 A substrate processing apparatus according to claim 1, wherein the first ground electrode and the second ground electrode are not spaced apart laterally but are spaced apart vertically. Claim 17 A substrate processing apparatus according to claim 1, wherein the first ground electrode and the second ground electrode comprise molybdenum (Mo). Claim 18 A substrate processing device comprising: a power supply unit; a processing unit electrically connected to the power supply unit; and a substrate support unit disposed below the processing unit, wherein the substrate support unit comprises a first ground electrode and a second ground electrode, wherein the first ground electrode comprises a first mesh ground electrode and the second ground electrode comprises a second mesh ground electrode, and the first mesh ground electrode and the second mesh ground electrode have different mesh densities. Claim 19 A substrate processing apparatus according to claim 18, wherein the plasma density or plasma intensity on the substrate is locally controlled. Claim 20 A substrate processing device comprising: a power supply unit; a processing unit electrically connected to the power supply unit; and a substrate support unit disposed below the processing unit, wherein the substrate support unit comprises a first ground electrode and a second ground electrode, and the substrate support unit further comprises a first heating unit disposed below the first ground electrode; and a second heating unit disposed below the second ground electrode, wherein the first heating unit and the second heating unit are independently controlled.

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