Sealing member and substrate processing apparturs comprising the same

Abstract

A sealing member according to one embodiment of the present invention is characterized by comprising a matrix made of fluororubber material and a silicon carbide filler added to the matrix. When the sealing member of the present invention is positioned between the lower surface of the dielectric plate of a substrate support unit and the base plate to surround the side of the adhesive layer, it is possible to prevent the adhesive layer from being exposed to processing gas and / or plasma even if the substrate support unit undergoes thermal expansion, and the material stability can be improved.

Description

Technology Field

[0001] The present invention relates to a sealing member and a substrate processing device including the same. Background Technology

[0002] A substrate processing device is generally used to perform specific processing steps on a substrate, such as a semiconductor wafer, for the manufacture of semiconductor devices. Specific processing steps include a deposition process for forming a specific film on the surface of the substrate, an etching process for forming a specific pattern on the film formed on the substrate, and a cleaning process for physically or chemically cleaning the surface of the substrate.

[0003] A substrate processing device includes a substrate support unit that supports the substrate. An electrostatic chuck, which fixes the substrate by electrostatic adsorption, is commonly used as the substrate support unit. The electrostatic chuck includes a dielectric plate that incorporates a chucking electrode and adsorbs and supports the lower surface of the substrate, and a metal base plate positioned beneath the dielectric plate that functions as a lower electrode for plasma generation or as a means for cooling the substrate. The dielectric plate and the base plate are bonded by an adhesive layer. The adhesive layer also plays an important role in heat transfer between the dielectric plate and the base plate.

[0004] Meanwhile, if the adhesive layer between the dielectric plate and the base plate is etched by exposure to processing gas and / or plasma, changes in heat transfer characteristics may cause problems with the uniformity of the substrate processing process. To prevent this problem, a technology has been proposed to protect the adhesive layer using a ring-shaped sealing member.

[0005] The sealing member is positioned to wrap around the perimeter of the adhesive layer so that the adhesive layer is not exposed to processing gas and / or plasma. Patent Document 1 discloses a technique for forming the sealing member from plasma-resistant fluororubber materials such as polytetrafluoroethylene (PTFE), fluoroelastomer (FKM), or perfluoroelastomer (FFKM).

[0006] However, sealing members made of PTFE or fluororubber have room for improvement in terms of resistance to processing gas and / or plasma penetration and material stability. Therefore, sealing members with enhanced performance are required. Prior art literature

[0007] (Patent Document 0001) KR 10-2024-0099069 A (2024.06.28) The problem to be solved

[0008] The present invention aims to provide a sealing member with improved performance in preventing processing gas and / or plasma penetration and material stability, and a substrate processing device including the same.

[0009] In particular, the purpose is to provide a sealing member having excellent material stability against plasma and a substrate processing device including the same, which protects the adhesive layer from being exposed to processing gas and / or plasma even if the substrate support unit undergoes thermal expansion. means of solving the problem

[0010] A sealing member according to one embodiment of the present invention is characterized by comprising a matrix made of fluororubber material and a silicon carbide filler added to the matrix.

[0011] In one embodiment, the matrix may be either a fluoroelastomer (FKM) or a perfluoroelastomer (FFKM).

[0012] In one embodiment, the silicon carbide filler may have a cubic crystal structure, and preferably 3C-SiC.

[0013] A substrate processing device according to one embodiment of the present invention comprises a chamber body that provides a processing space inside, and a substrate support unit disposed inside the chamber body to support a substrate to be processed, wherein the substrate support unit comprises a dielectric plate for adsorbing and fixing a substrate and a base plate disposed below the dielectric plate and bonded to the dielectric plate by an adhesive layer, and a sealing member disposed between the lower surface of the dielectric plate and the base plate to surround the side of the adhesive layer, wherein the sealing member is characterized by having a silicon carbide filler added to a matrix of fluororubber material.

[0014] In one embodiment, the base plate includes a first upper surface that is bonded to the lower surface of the dielectric plate by the adhesive layer, a side surface that extends downward from the first upper surface to form a step, and a second upper surface that is connected by the first upper surface and the side surface and is positioned lower than the first upper surface, and the lower surface of the dielectric plate is formed to extend further in the transverse direction than the adhesive layer and the side surface of the base plate, and the sealing member may be disposed between the lower surface of the dielectric plate and the second upper surface of the base plate.

[0015] In one embodiment, the sealing member may be positioned so as to be in contact with the second upper surface of the base plate at room temperature and not in contact with the lower surface of the dielectric plate.

[0016] In one embodiment, the substrate processing device may further include a gas supply unit for supplying a fluorine (F)-based gas to a processing space and a plasma generation unit for generating plasma in the processing space. Effects of the invention

[0017] According to an embodiment of the present invention, by using a sealing member in which a silicon carbide filler is added to a matrix of fluororubber material, the adhesive layer can be protected from exposure to processing gas and / or plasma even if the substrate support unit undergoes thermal expansion.

[0018] In addition, according to an embodiment of the present invention, by using a silicon carbide filler having a cubic crystal structure, preferably 3C-SiC, it is possible to provide a sealing member with excellent material stability against plasma and a substrate processing apparatus including the same. Brief explanation of the drawing

[0019] FIG. 1 is a schematic diagram of a substrate processing apparatus according to one embodiment of the present invention. FIG. 2 is a drawing for explaining the arrangement structure of a sealing member according to one embodiment of the present invention. Figure 3 shows the plasma exposure test results of the sealing member. Specific details for implementing the invention

[0020] Hereinafter, embodiments of the present invention are described in detail with reference to the attached drawings so that a person skilled in the art can easily implement the present invention. However, the present invention may be embodied in various other forms and is not limited to the embodiments described herein.

[0021] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0022] In addition, in various embodiments, components having the same configuration are described using the same reference numerals only in the representative embodiment, and in other embodiments, only configurations different from the representative embodiment are described.

[0023] Throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0024] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0026] FIG. 1 is a schematic diagram of a substrate processing apparatus according to one embodiment of the present invention.

[0027] Referring to FIG. 1, a substrate processing apparatus (1) according to one embodiment of the present invention includes a processing chamber (100). The processing chamber (100) provides a processing space (S) inside a chamber body (101) where a substrate processing process is performed. The chamber body (101) may be formed of a metal such as aluminum. The substrate processing process may be a plasma processing process. The plasma processing process may be performed in a reduced pressure atmosphere, and for this purpose, an exhaust port (102) may be formed in the processing chamber (100). The exhaust port (102) may be formed on the bottom of the processing chamber. An exhaust pump (P) is connected to the exhaust port (102) through an exhaust line (104) and an exhaust valve (103). By operating the exhaust pump (P) and adjusting the exhaust valve (103), the processing space (S) inside the processing chamber (100) can be adjusted to a predetermined pressure.

[0028] A substrate support unit (110) for supporting a substrate (W) is provided inside the processing chamber (100). The substrate support unit (110) may be configured to include a base plate (111) and a dielectric plate (112) that is supported on the base plate (111) and adsorbs and fixes the substrate (W). The base plate (111) and the dielectric plate (112) may be bonded by an adhesive layer (113), and the adhesive layer (113) may be formed of a silicone adhesive or the like.

[0029] The dielectric plate (112) may be made of a dielectric material such as alumina and may be equipped with a chucking electrode (114) to generate an electrostatic force. When voltage is applied to the chucking electrode (114) by a power source (not shown), an electrostatic force is generated, and the substrate (W) is adsorbed and fixed to the dielectric plate (112). The dielectric plate (112) may be equipped with a heater (115) to control the temperature of the substrate (W), but the heater (115) may not be provided depending on the substrate processing process. The heater (115) may be composed of a plurality of separated zone heaters to independently control the temperature for each region of the substrate (W).

[0030] The base plate (111) is positioned below the dielectric plate (112) and may be made of a metallic material such as aluminum. The base plate (111) has a refrigerant channel (117) formed therein through which a cooling fluid flows, and may function as a cooling means for cooling the substrate (W). The refrigerant channel (117) may be provided as a circulation passage through which the cooling fluid circulates.

[0031] The substrate support unit (110) may include a ring member (116) surrounding a dielectric plate (112). A step may be formed on the upper part of the ring member (116) to support the outer surface of the substrate (W). The ring member (116) may be formed of a ceramic material and may be a focus ring.

[0032] A shower head unit (120) may be provided at the top of the processing chamber (100). The shower head unit (120) may include a shower plate (121) having a plurality of gas supply holes (122), a gas distribution chamber (123), and a gas inlet (127). Gas supplied from the gas supply unit (300) may flow into the gas distribution chamber (123) through the gas inlet (127) and then be supplied to the processing space (S) through the gas supply holes (122).

[0033] The gas supply unit (300) supplies gas required for plasma treatment to the processing space (S). The gas supply unit (300) may include a gas source (310), a gas supply line (320), and a gas flow controller (330). The gas supply line (320) connects the gas source (310) and the gas inlet (127), and the gas flow controller (330) can regulate the flow rate of the gas flowing through the gas supply line (320) or block the gas supply line (320).

[0034] Although only one gas supply source (310), one gas supply line (320), and one gas flow controller (330) are shown in FIG. 1, the gas supply unit (300) of the present invention may include a plurality of gas supply sources and a plurality of gas flow controllers capable of independently controlling the supply of each gas so as to supply a plurality of gases to a processing space (S). The plurality of gases may be etching gases used to etch a processing film formed on a substrate (W). The etching gas may include, for example, a fluorine (F)-based gas. Additionally, the plurality of gases may further include other gases such as a gas containing oxygen (O) or an inert gas.

[0035] The plasma generation unit (130) may include a high-frequency power supply (131) for generating plasma in a processing space (S) by supplying high-frequency power and a matching device (132) for impedance matching. The high-frequency power supply (131) may provide high-frequency power in the range of hundreds of kHz to hundreds of MHz.

[0036] The high-frequency power source (131) can supply high-frequency power to a substrate support unit (110) that functions as a lower electrode, and the showerhead unit (120) that functions as an upper electrode can be grounded. Although FIG. 1 is illustrated with the high-frequency power source (131) connected to the lower electrode, this should be understood as exemplary. High-frequency power is applied to the upper electrode to generate plasma in the processing space (S), and the lower electrode can be grounded. Additionally, high-frequency power may optionally be applied to both the upper electrode and the lower electrode. Multiple high-frequency power sources with different frequencies may be used as the high-frequency power source (131).

[0037] In addition, although the plasma source in FIG. 1 is depicted as a CCP (Capactively Coupled Plasma) source, this should be understood as an example. In addition to CCP, the plasma source of the present invention may be various methods capable of generating plasma in the processing space (S), such as ICP (Inductively Coupled Plasma), remote plasma, and microwave plasma.

[0039] FIG. 2 is a drawing for explaining the arrangement structure of a sealing member according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of one side outer circumference portion of a substrate support unit, and the other outer circumference portion may have a roughly identical structure.

[0040] Referring to FIG. 2, a sealing member (10) is positioned to surround the side exposed portion of the adhesive layer (113) between the dielectric plate (112) and the base plate (111). The sealing member (10) may be positioned between the lower surface (112b) of the dielectric plate (112) and the base plate (111). The sealing member (10) may be in the shape of a ring that surrounds the entire side exposed portion of the adhesive layer (113). The cross-sectional shape of the sealing member (10) may be various shapes, such as a circle, a square, or an ellipse.

[0041] The base plate (111) may include a step on its outer surface. Specifically, the base plate (111) may include a first upper surface (111u) that is bonded to the lower surface (112b) of the dielectric plate (112) by an adhesive layer (113), a side surface (111s) that extends downward (-Z direction) from the first upper surface (111u) to form a step, and a second upper surface (111b) that is connected by the first upper surface (111u) and the side surface (111s) and is located lower than the first upper surface (111u). The lower surface (112b) of the dielectric plate (112) may be formed to extend further in the transverse direction (+X direction in FIG. 2) than the adhesive layer (113) and the side surface (111s) of the base plate (111). As a result, a space for placing a sealing member (10) can be formed between the lower surface (112b) of the dielectric plate (112) and the second upper surface (111b) of the base plate (111). The sealing member (10) can be inserted and placed in the space formed between the lower surface (112b) of the dielectric plate (112) and the second upper surface (111b) of the base plate (111).

[0042] The sealing member (10) may be positioned to contact at least the second upper surface (111b) of the base plate (111). Considering the thermal expansion of the sealing member (10), the height of the sealing member (10) may be formed to be slightly smaller than the distance between the lower surface (112b) of the dielectric plate (112) and the second upper surface (111b) of the base plate (111). That is, when the sealing member (10) is positioned to contact the second upper surface (111b) of the base plate (111), the sealing member (10) and the lower surface (112b) of the dielectric plate (112) may not come into contact at room temperature.

[0043] The sealing member (10) can be formed from a material having excellent plasma resistance, excellent elasticity, and improved material stability. Specifically, the sealing member (10) can be formed from a material in which a silicon carbide (SiC) filler is added to a matrix of fluororubber material. Preferably, the silicon carbide added as a filler may be silicon carbide with a cubic crystal structure. More preferably, it may be 3C-SiC with a stacking pattern period of 3.

[0044] The sealing member (10) is positioned to surround the side of the adhesive layer (113) so that the adhesive layer (113) is not exposed to the processing gas and / or plasma. This prevents the problem of the uniformity of the substrate processing process deteriorating due to the loss of the adhesive layer (113).

[0045] Meanwhile, if the sealing member is formed with PTFE material, it has excellent plasma resistance but lacks elasticity, so the adhesive layer (113) may be exposed to the processing gas and / or plasma during thermal expansion of the substrate support unit (110). Thermal expansion may occur in the substrate support unit (110) during the process of heating the substrate (W) by applying power to the built-in heater (115). Alternatively, even without using the heater (115), thermal expansion may occur due to heat transfer from the substrate (W) heated by the plasma. Thermal expansion may occur more significantly in the base plate (111), which is made of metal, compared to the dielectric plate (112), which is made of ceramic material, and as a result, the distance between the lower surface (112b) of the dielectric plate (112) and the second upper surface (111b) of the base plate (111) may increase. During this process, a gap may form between the sealing member (10) and the lower surface (112b) of the dielectric plate (112), allowing the processing gas and / or plasma to penetrate and cause the adhesive layer (113) to be lost.

[0046] An embodiment of the present invention can solve this problem by using a fluororubber material with relatively excellent elasticity as the material for the sealing member (10). Fluoro-elastomer (FKM) or perfluoroelastomer (FFKM) can be used as the fluororubber.

[0047] The sealing member (10) made of fluororubber has excellent elasticity, so that even when the substrate support unit (10) undergoes thermal expansion, a gap is not formed between the lower surface (112b) of the dielectric plate (112) and the sealing member (10).

[0048] Silicon carbide fillers may be added to the fluororubber matrix to improve the material stability of the fluororubber. If only fluororubber materials such as FKM and FFKM are used, cracks may form in the sealing member (10) when exposed to plasma, and in severe cases, the sealing member (10) may break. This may be because the fluorocarbon components of the fluororubber react with the plasma to generate volatile components. If cracks occur in the sealing member (10), the processing gas and / or plasma may penetrate into the adhesive layer (113) through the cracks.

[0049] This phenomenon can be suppressed by adding silicon carbide fillers to the fluororubber matrix. Silicon carbide can significantly improve the material stability of fluororubber compared to other silicon-based filler materials such as silicon oxide.

[0050] It is preferable to use silicon carbide filler particles with a particle size of 100 nm or less. As the filler particles become smaller, the surface area ratio increases, allowing for a strong interfacial bonding effect with the matrix. This can reduce defects caused by air gaps or impurities at the interface between the filler particles and the fluororubber matrix. The average particle size of the silicon carbide filler particles may be 100 nm or less. Alternatively, D50, which is the particle size corresponding to 50% of the volume accumulation from the smaller particle size side, may be 100 nm or less, and preferably, D90, which is the particle size corresponding to 90% of the volume accumulation from the smaller particle size side, may be 100 nm or less.

[0051] Since the addition of silicon carbide fillers increases material stability against plasma while lowering the coefficient of thermal expansion, it is desirable to control the content of silicon carbide fillers within an appropriate range. To ensure material stability, it is desirable that the content of silicon carbide fillers in the fluororubber matrix be 5 atomic% or more. In addition, to ensure a coefficient of thermal expansion, it is desirable that the content of silicon carbide fillers be 20 atomic% or less.

[0052] In particular, it is desirable to use silicon carbide with a cubic crystal structure for the silicon carbide filler particles. Generally, hexagonal silicon carbide (e.g., 6H-SiC), which has excellent strength, is preferred as silicon carbide; however, in the embodiments of the present invention, it is more desirable to use cubic silicon carbide, which is relatively easy to deform. As cubic silicon carbide, 3C-SiC with a stacking pattern period of 3 can be used.

[0053] 3C-SiC has 12 slip systems, making it easier to deform than 6H-SiC, which has 3 slip systems, so it is relatively suitable for the present invention, which requires that the adhesive layer (113) not be exposed due to deformation caused by thermal expansion. That is, by using 3C-SiC instead of 6H-SiC, the sealing member can be deformed without cracking even when it is deformed.

[0054] To evaluate the material stability of the sealing member (10) according to an embodiment of the present invention, the degree of mass loss and whether cracks occurred were measured after exposure to plasma for a long time. The plasma exposure time was set to 20 hours, and the test was conducted with the matrix of the sealing member being FFKM and only the filler components and content being different.

[0055] FIG. 3 shows the results of a plasma exposure test of a sealing member (10), including the mass reduction rate before and after plasma exposure of each sample, whether surface cracks occurred, and a surface photograph after plasma exposure. In FIG. 3, the filler content is all atomic%.

[0056] Referring to Fig. 3, in Comparative Example 1, which did not add filler, and Comparative Example 2, which added a small amount (1.5%) of silicon oxide filler, the mass loss rate was large, exceeding 10%, and cracks occurred on the surface in both cases. In Comparative Example 3, in which the silicon oxide filler content was increased to 8%, the mass loss rate decreased to less than 10%, but cracks still occurred on the surface, and even the sealing member broke, indicating poor material stability.

[0057] Comparative Example 4 and the Example were prepared by adding silicon carbide fillers. In the case of Comparative Example 4, which added 6H-SiC fillers, the mass loss rate was higher than that of the Example despite the filler content being 20%, and surface cracks were also observed. On the other hand, in the case of the Example, which added 10% 3C-SiC fillers, the mass loss rate was the lowest at 6.1%, and no surface cracks were observed, confirming that the material stability is excellent.

[0059] The embodiments and drawings attached to this specification merely clearly illustrate a part of the technical concept included in the present invention, and it is obvious that variations and specific embodiments that can be easily deduced by a person skilled in the art within the scope of the technical concept included in the specification and drawings of the present invention are all included within the scope of the rights of the present invention.

[0060] Accordingly, the scope of the present invention should not be limited to the described embodiments, and all things equivalent to or having equivalent variations to the claims set forth below, as well as the claims set forth below, shall be considered to fall within the scope of the concept of the present invention. Explanation of the symbols

[0061] 1: Substrate processing device 100: Processing chamber 110: Chamber body 110: Substrate support unit 120: Shower head unit 130: Plasma Generation Unit 300: Gas supply unit 10: Sealing member

Claims

Claim 1 A sealing member comprising: a matrix made of fluororubber material; a silicon carbide filler added to the matrix; wherein the silicon carbide filler is 3C-SiC with a cubic crystal structure. Claim 2 In claim 1, the matrix is ​​a sealing member that is either a fluoroelastomer (FKM) or a perfluoroelastomer (FFKM). Claim 3 delete Claim 4 delete Claim 5 A substrate processing apparatus comprising a chamber body providing a processing space inside, and a substrate support unit disposed inside the chamber body to support a substrate to be processed, wherein the substrate support unit comprises a dielectric plate for adsorbing and fixing a substrate and a base plate disposed below the dielectric plate and bonded to the dielectric plate by an adhesive layer, and a sealing member disposed between the lower surface of the dielectric plate and the base plate to surround the side of the adhesive layer and comprising a silicon carbide filler added to a matrix of fluororubber material, wherein the silicon carbide filler is 3C-SiC having a cubic crystal structure. Claim 6 In claim 5, the matrix is ​​a substrate processing device that is either a fluoroelastomer (FKM) or a perfluoroelastomer (FFKM). Claim 7 delete Claim 8 A substrate processing apparatus according to claim 5, wherein the base plate comprises a first upper surface that is bonded to the lower surface of the dielectric plate by the adhesive layer, a side surface that extends downward from the first upper surface to form a step, and a second upper surface that is connected by the first upper surface and the side surface and is positioned lower than the first upper surface, wherein the lower surface of the dielectric plate is formed to extend further in the transverse direction than the adhesive layer and the side surface of the base plate, and the sealing member is disposed between the lower surface of the dielectric plate and the second upper surface of the base plate. Claim 9 In claim 8, the sealing member is arranged to be in contact with the second upper surface of the base plate at room temperature and not in contact with the lower surface of the dielectric plate. Claim 10 A substrate processing apparatus according to claim 5, further comprising: a gas supply unit for supplying a fluorine (F)-based gas to the processing space; and a plasma generation unit for generating plasma in the processing space.

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