Ceramic Susceptor

Abstract

To provide a susceptor with an electrode rod having a high frequency transmission characteristic excellent for a low impedance to an RF current.SOLUTION: A ceramic susceptor 100 according to the present invention includes a ceramic plate 110, on which an electrode 111 is arranged. The ceramic plate includes an electrode pad 112 connected to the electrode, and an electrode rod coupled with an electrode pad at one side end and supplying power to the electrode. The electrode rod may include an extension part 130 coupled to the electrode pad, and a power source coupling part 133 provided at an end of a tapered portion of the extension part.SELECTED DRAWING: Figure 10A

Description

[Technical Field]

[0001] The present invention relates to a susceptor, and more particularly to a susceptor in which an electrode rod material is applied to a ceramic-based susceptor to reduce impedance.

[0002] The present invention also relates to a susceptor, and more particularly to a ceramic susceptor in which the durability of the electrode rod is improved. [Background technology]

[0003] Generally, semiconductor devices or display devices are manufactured by sequentially stacking a plurality of thin film layers, including dielectric layers and metal layers, on a glass substrate, a flexible substrate, or a semiconductor wafer substrate, followed by patterning. In semiconductor manufacturing processes, susceptors are used as a holding structure for holding the substrate. Susceptors are widely used in plasma deposition processes and other processes that require precise temperature control and heat treatment for precision processes such as finer wiring on semiconductor devices. They are also used to generate plasma or heat the substrate during etching processes of thin film layers formed on semiconductor wafer substrates.

[0004] Fig. 1 is a diagram illustrating an electrode portion of a conventional susceptor. Referring to Fig. 1, the conventional susceptor has a conductive pad 36 inside a ceramic plate 30 for connection to electrode rods 31 and 32. An RF electrode 35 having various two-dimensional shapes, such as a circular or crescent shape, is embedded in the ceramic plate 30. Also embedded is a conductive pad 36 electrically connected to the RF electrode 35.

[0005] The eyelet-shaped support 34, which accommodates the electrode rods 31 and 32, is screwed into the ceramic plate 30 via threads formed in the openings of the ceramic plate 30. A brazing filler 37 may be provided between the upper electrode rod 31 and the lower electrode rod 32 and between the lower electrode rod 32 and the conductive pad 36. The brazing filler 37 electrically connects the electrode rods 31 and 32 to the RF electrode 35 through a joining process such as brazing. In conventional susceptors, the gap between the support 34 and the lower electrode rod 32 or the gap between the support 34 and the ceramic plate 30 acts as a path through which oxygen can penetrate in a high-temperature atmosphere, potentially oxidizing the upper electrode rod 31 and the lower electrode rod 32. This oxidation reduces the electrical conductivity of the electrode rods, thereby reducing power transmission efficiency and potentially reducing the reliability of the electrode unit and the lifespan of the susceptor.

[0006] Due to this oxidation problem, conventional electrode rods have mainly been made of heat-resistant and oxidation-resistant materials such as Ni and Ni alloys. However, when the Ni-based heat-resistant materials used in conventional electrode rods are used as power transmission lines in the high-frequency range, the impedance of the electrode rod increases due to the skin effect, where current flows along the surface of the electrode rod, resulting in heat generation.

[0007] Furthermore, with the development of semiconductor processes, there is a demand for susceptors that can operate at higher temperatures and that can apply high-power radio frequency waves to have better plasma characteristics. As a result, the skin effect in the electrode rods becomes more pronounced, and problems of short circuits due to heat generation and oxidation occur frequently.

[0008] To improve this, attempts have been made to reduce heat generation or thermal conduction by coating a Ni or Ti rod base material with Au, Ag, Al, or Cu, as in Korean Patent Publication No. 10-2018-0121662 (November 7, 2018), or by coating a Mo, Ni, or Ti rod base material with an alumina thin film, as in Korean Patent Publication No. 10-2021-0139368 (November 22, 2021).However, even in these cases, the problem of increased impedance of electrode rod materials due to increased frequency in high-frequency power transmission has not been fundamentally resolved.

[0009] FIG. 9 is a diagram illustrating another electrode portion of a conventional ceramic susceptor.

[0010] 9, a conventional ceramic susceptor has an electrode portion in the center of a ceramic plate 30 for connection to external electrode rods 31 and 32. An electrode 35, which can be a heating element (electrode) or an RF (radio frequency) electrode, is embedded in the ceramic plate 30 in a ring or circle shape, and a conductive pad 36, which serves as an electrode base material and is electrically connected to the electrode 35, is also embedded. An eyelet-shaped support 34 is screwed onto threads formed in the opening, and brazing is performed between the upper electrode rod 31 and the lower electrode rod 32, and between the lower electrode rod 32 and the conductive pad 36, electrically connecting the electrode rods 31 and 32 and the electrode 35 for power supply. In such conventional ceramic susceptors, the gap between the support 34 and the lower electrode rod 32 or the gap between the support 34 and the ceramic plate 30 creates a path through which oxygen can penetrate in a high-temperature atmosphere, oxidizing the brazing filler 37 formed at the interface between the conductive pad 36 (the electrode base material) and the lower electrode rod 32, or the conductive pad 36 and the lower electrode rod 32. The brazing filler formed at the interface between the upper electrode rod 31 and the lower electrode rod 32 can also be oxidized by oxygen penetration. If such oxidation reduces electrical conductivity and power transmission efficiency, it can lead to a decrease in the reliability of the electrode portion and shorten the life of the ceramic susceptor.

[0011] To overcome these reliability issues, conventional electrode rods have primarily been made of heat-resistant and oxidation-resistant materials such as Ni or Ni alloys. However, because the Ni material used in conventional electrode rods is a ferromagnetic material, when used as a power transmission line in a high-frequency range, such as in an electrode, the skin effect reduces the skin depth in the line through which electrons move, making it difficult for electrons to move. This creates impedance and heat, which can lead to short circuits with the ceramic plate 30, etc.

[0012] To address this issue, conventional electrode rods have been made of a material with low magnetic permeability, such as Mo, or a coating film has been applied to prevent oxidation of the rod material. However, even in these cases, thermal stress at the interface between the electrode rod metal material (e.g., Mo) and the coating film, or the brittleness of the coating material itself, can cause the coating film to crack during use in semiconductor processes, resulting in oxygen penetration into the electrode rod metal, and accelerating oxidation of the electrode rod metal. Summary of the Invention [Problem to be solved by the invention]

[0013] The inventors of the present invention found that because Ni or Ni alloy materials are ferromagnetic and have high relative permeability (<600), when used as RF (radio frequency) rods, the skin effect causes the skin depth within the electrode rod to become extremely small, making it difficult for electrons to move, resulting in an increase in impedance. This increase in electrode rod impedance not only reduces plasma efficiency by converting electrical energy that should be consumed for plasma discharge into thermal energy at the end of the electrode rod, but also reduces plasma efficiency by causing hot spots on the upper surface of the ceramic plate that holds the substrate. This can lead to variations in the thickness and quality of thin films deposited on the substrate, resulting in reduced yields.

[0014] In addition, the temperature of the ceramic portion where the electrode rod is attached rises rapidly in a localized area, which can lead to destruction of the susceptor due to thermal shock and damage to the brazing joint, resulting in the generation of an arc. Therefore, the impedance problem of the electrode rod must be resolved in order to increase the yield of semiconductor devices and improve the durability of the susceptor.

[0015] Therefore, an object of the present invention is to provide a susceptor having an electrode rod that has low impedance to RF current and good high frequency transmission characteristics.

[0016] Another object of the present invention is to provide an electrode rod having the above-mentioned surface coating structure suitable for RF power transmission.

[0017] Another object of the present invention is to provide an electrode rod having a surface coating structure that is resistant to heat generation due to the skin effect.

[0018] Another object of the present invention is to provide an electrode rod having a surface coating structure that exhibits good brazing properties.

[0019] Another object of the present invention is to provide a method for manufacturing the above-mentioned electrode rod.

[0020] Another object of the present invention is to provide a susceptor including the above-mentioned electrode rod for RF power transmission.

[0021] Another object of the present invention is to provide a susceptor having a surface coating structure and an integral electrode rod.

[0022] Furthermore, even when the material of the electrode rod for the electrode is selected from Mo, W, or alloys thereof, and a material with high resistivity such as TiN, TiAlCrN, TiAlN, or AlCrN is used for the coating film, as shown in Figure 9, at the joint along the extension line of the electrode rod where there are steps or corners, cracks in the coating film cause oxygen to penetrate into the metal material of the electrode rod, oxidizing the metal material of the electrode rod and generating oxides intensively.This is an attempt to improve this problem.

[0023] An object of the present invention to achieve the above improvements is to provide a ceramic susceptor having a unique position and structure of the joint portion on the extension line of the electrode rod, in order to provide an electrode rod structure of a ceramic susceptor having improved durability so as to have good high-frequency transmission characteristics in oxidation-resistant and corrosion-resistant environments. [Means for solving the problem]

[0024] In order to achieve the above technical objectives, the present invention provides a susceptor including a ceramic plate on which an electrode is disposed, and an electrode rod having one end electrically connected to the electrode and the other end electrically connected to a power source for supplying power to the electrode, the electrode rod including a base material made of Mo, W, or an alloy of these metals, and a metal nitride film covering the surface of the base material. Furthermore, in the present invention, one end of the electrode rod includes an exposed surface of the base material that is not covered by the metal nitride film.

[0025] In the present invention, the metal nitride film may include an AlCrN film, in which the Cr / (Al+Cr) molar ratio may be 0.1 to 0.9.

[0026] The metal nitride film may include at least one nitride film selected from the group consisting of AlCrSiN, AlCrSiWN, and AlTiCrN.

[0027] In the present invention, the ratio of the resistivity of the metal nitride film to the resistivity of the base material is 10 2 That's it, 10 3 or more, or 10 4 It is preferable that this is equal to or greater than this.

[0028] In the present invention, a CrN underlayer may be further included between the base material and the metal nitride film.

[0029] In the present invention, the thickness of the metal nitride film may be 1.0 to 10.0 μm.

[0030] In order to achieve the above technical objectives, the present invention provides a susceptor including a ceramic plate on which an electrode is disposed, and an electrode rod assembly having one end electrically connected to the electrode and the other end electrically connected to a power source to supply power to the electrode, the electrode rod assembly including a first rod and a second rod connected in series, the first rod including a base material made of Mo, W or an alloy of these metals, and a metal nitride film covering the surface of the base material.

[0031] In the present invention, the first rod and the second rod may be joined by a joining material.

[0032] Preferably, the bonding surfaces of the first rod and the second rod are exposed surfaces of the base material that are not covered with a metal nitride film.

[0033] In the present invention, the first rod may include a base material made of Kovar.

[0034] In accordance with another aspect of the present invention for achieving the above object, a susceptor including a ceramic plate on which an electrode is disposed includes an electrode pad connected to the electrode, and an electrode rod having one end connected to the electrode pad for supplying power to the electrode, the electrode rod including an extension connected to the electrode pad and a power connector provided at an end of a tapered portion of the extension.

[0035] The electrode rod may include a metal nitride film on the surface of the base material.

[0036] The tapered portion may be formed by tapering using a machine tool so that the tapered portion is included between the extension portion and the power supply connection portion, which have different diameters.

[0037] The tapered portion of the extension may have an inclination angle of 10° to 80° with respect to the longitudinal direction of the extension.

[0038] The tapered portion of the extension may have a length of 1.0 mm to 10.0 mm in the longitudinal direction of the extension.

[0039] The tapered portion of the extension may have a smaller diameter end at a position that is 10% or more lower than the temperature of the lowermost surface of the ceramic plate.

[0040] Preferably, the position of the end of the tapered portion of the extension portion where the diameter is smaller may be at a position that is 20% or more lower than the temperature of the lowermost end surface of the ceramic plate.

[0041] The electrode rod may have a base material of Mo, W or an alloy thereof.

[0042] The extension of the electrode rod may include a second rod brazed to the electrode pad and a first rod brazed to the second rod.

[0043] The second rod is preferably made of a metal material having a thermal expansion coefficient difference of 3 or less with respect to the material of the electrode pad.

[0044] The electrode may be a radio frequency electrode, an electrostatic chuck electrode, or a heating element. [Effects of the Invention]

[0045] According to a first aspect of the present invention, it is possible to provide a susceptor including an electrode rod having low impedance to RF current and good high frequency transmission characteristics.

[0046] According to a second aspect of the present invention, the electrode rod is provided with a resistive surface coating, and when RF power is transmitted through the electrode rod, RF current flows through the base material within the surface coating, causing the heat generating portion to penetrate inside the surface coating of the electrode rod, thereby moving the heat generating portion away from the surface of the electrode rod and reducing the possibility of it reacting with oxygen in the atmosphere.

[0047] Furthermore, according to the third aspect of the present invention, it is possible to provide an electrode rod with a surface coating structure suitable for RF power transmission.

[0048] Furthermore, according to the fourth aspect of the present invention, it is possible to provide an electrode rod having a surface-coated structure that is resistant to heat generation due to the skin effect.

[0049] Furthermore, according to the fifth aspect of the present invention, it is possible to provide an electrode rod having a surface coating structure that exhibits good brazing properties.

[0050] Furthermore, according to a sixth aspect of the present invention, it is possible to provide a susceptor including an RF power transmission electrode rod having the above-mentioned characteristics.

[0051] Furthermore, according to the seventh aspect of the present invention, it is possible to provide a susceptor that is provided with a surface coating structure and an integrated electrode rod.

[0052] According to an eighth aspect of the present invention, a tapered portion AA is positioned at a position where the electrode rod is separated from the ceramic plate to receive power, particularly at a position where the temperature drops significantly during semiconductor processing, and the shape of the joint is designed to be streamlined, such as trapezoidal, so as to avoid forming a steeply inclined edge, thereby providing a ceramic susceptor with improved durability and lifespan so as to have good high-frequency transmission characteristics for a long period of time even in oxidation-resistant and corrosion-resistant environments.

[0053] The accompanying drawings, which are included as part of the detailed description to aid in understanding the present invention, provide examples of the present invention and, together with the detailed description, explain the technical concept of the present invention. [Brief explanation of the drawings]

[0054] [Figure 1] FIG. 10 is a diagram illustrating an electrode portion of a conventional susceptor. [Figure 2A] 1 is a perspective view schematically showing the outer shape of an electrode rod according to an embodiment of the present invention. [Figure 2B] 1 is a cross-sectional view schematically showing the outer shape of an electrode rod according to an embodiment of the present invention. [Figure 3] FIG. 10 is a diagram schematically showing a cross section of an electrode rod structure according to another embodiment of the present invention. [Figure 4] FIG. 2 is a cross-sectional view schematically showing a part of a susceptor according to an embodiment of the present invention. [Figure 5] FIG. 10 is a cross-sectional view schematically showing the structure of a susceptor according to another embodiment of the present invention. [Figure 6] 5A to 5C are diagrams showing the steps of forming a metal nitride film on an electrode rod of a susceptor according to an embodiment of the present invention. [Figure 7] FIG. 10 is a diagram showing the results of power loss measurements. [Figure 8] 1 is a graph plotting the resistance measurement results before and after oxidation treatment for each rod material. [Figure 9] FIG. 10 is a diagram illustrating another electrode portion of a conventional ceramic susceptor. [Figure 10A] 10A and 10B are diagrams illustrating the structure of a ceramic susceptor according to still another embodiment of the present invention. [Figure 10B] 10A and 10B are diagrams illustrating the structure of a ceramic susceptor according to still another embodiment of the present invention. [Figure 11] 10C is an enlarged view of the peripheral portion including the tapered portion (AA) between the extension portion and the power connection portion of the present invention of FIGS. 10A and 10B. FIG. [Figure 12] 1 is a view showing an embodiment in which a ceramic susceptor according to the present invention is installed in a process chamber of a semiconductor device. [Figure 13] 4 is a flowchart illustrating a process for forming a coating on an electrode rod of a ceramic susceptor according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0055] The present invention will be described in detail below with reference to the accompanying drawings. Here, identical components in each drawing are designated by the same reference numerals whenever possible. Detailed descriptions of already known functions and / or configurations will be omitted. The following disclosure will focus on the parts necessary for understanding the operation of various embodiments, and descriptions of elements that may obscure the gist of the description will be omitted. Some components in the drawings may be exaggerated, omitted, or illustrated in outline. The size of each component does not fully reflect the actual size, and therefore, the content described herein should not be construed as limited by the relative sizes and spacing of the components depicted in each drawing.

[0056] When describing embodiments of the present invention, if a detailed description of known technologies related to the present invention is deemed to obscure the gist of the present invention, that detailed description will be omitted. Furthermore, the terms used below are defined in consideration of their functions in the present invention and may be changed based on the intentions or practices of users and operators. Therefore, their definitions should be based on the entire content of this specification. Terms used in the detailed description are intended solely to describe embodiments of the present invention and should not be considered limiting. Unless otherwise specified, singular expressions include plural meanings. In this description, terms such as "comprise" or "comprises" are intended to indicate certain features, numbers, steps, operations, elements, parts thereof, or combinations thereof, and should not be interpreted as excluding the presence or possibility of one or more features, numbers, steps, operations, elements, parts thereof, or combinations other than those stated.

[0057] It should be noted that terms such as "first" and "second" may be used to describe various components, but these terms do not limit the various components, and are used only to distinguish one component from another.

[0058] In the present specification, the nitride film in the term "nitride film" or "metal nitride film" may be a nitride film of one metal element or a nitride film of two or more metal elements. In the present specification, a nitride film of metal element A may be expressed as an A nitride film or AN. In this case, the expression A nitride film or AN may refer to a nitride film of a binary metal element in which part of metal element A is replaced or substituted with another metal element, or a nitride film of a multi-component metal element containing yet another metal element. Similarly, a nitride film of a binary metal element may be expressed as an "A and B nitride film," (A,B)N, or ABN, and this expression may refer to a nitride film of a ternary metal element containing an additional metal element in addition to A or B, or a multi-component metal nitride film of ternary or higher elements. For example, in the present specification, AlCrN may be used to mean not only a binary nitride film but also a ternary metal nitride film such as AlCrTiN.

[0059] In the present specification, "electrical connection" of two components includes whether the two components are electrically connected through direct contact or via one or more other components therebetween.

[0060] In addition, in the specification of the present invention, terms such as "above" or "on" of an object are used to refer not only to a position that is in direct contact with the surface of the object, but also to a position that is not in direct contact with the surface of the object through another component.

[0061] 2A and 2B are a perspective view and a cross-sectional view, respectively, that schematically show the outer shape of an electrode rod according to one embodiment of the present invention.

[0062] 2A and 2B, the electrode rod 10 has the shape of a long, thin pillar extending in the longitudinal direction. The shape of the electrode rod shown here is merely illustrative, and the present invention is not limited thereto. The electrode rod may have any shape, such as a triangular prism or a rectangular prism, in addition to a cylindrical shape. Also, while the ends of the electrode rod in the figures are flat, the present invention is not limited thereto, and at least one of the ends of the electrode rod may, of course, have a curved shape.

[0063] The electrode rod 10 includes a base material 12 and a metal nitride film 14 on the surface of the base material 12. In the present invention, the metal nitride film 14 may be in direct contact with the base material, or an additional material layer may be interposed between the base material and the metal nitride film 14.

[0064] In the present invention, the base material 12 preferably has low impedance and is a paramagnetic material, for example, Mo, W, or an alloy thereof, which are paramagnetic materials.

[0065] As shown in the figure, a metal nitride film 14 is formed on the surface of the base material 12. The metal nitride film 14 extends along the outer peripheral surface in the longitudinal direction of the base material.

[0066] Meanwhile, in the present invention, since the metal nitride film 14 of the electrode rod has a higher impedance than the base material, a connection design for smooth connection of RF current between the electrode rod and other components may be required. To this end, in the present invention, one end of the electrode rod 10 may include an exposed surface E1 that is not covered with the metal nitride film 14. In addition, the other end of the electrode rod 10 may include an exposed surface E2 that is not covered with the metal nitride film 14.

[0067] In the present invention, the exposed surfaces E1 and E2 of the electrode rod 10 can provide better electrical connection with adjacent components. For example, as described below, the exposed surface E1 can be in direct contact with a conductive pad of the electrode or can be electrically connected to the conductive pad via a conductive material layer such as an adhesive. The other exposed surface E2 can be electrically connected to an external power source.

[0068] In the present invention, the exposed surfaces E1 and E2 for electrical connection at one end of the electrode rod 10 may extend from the bottom surface to the side surface of the cylinder. In this case, the extension width w of the exposed surfaces may be appropriately designed. Of course, such an extension of the exposed surfaces may be provided at the other end of the electrode rod 10. Of course, the extension of the exposed surfaces may be realized by chamfering the end of the electrode rod.

[0069] In the present invention, the metal nitride film may preferably include a metal nitride film containing Cr. More preferably, the metal nitride film may be a binary or ternary or higher-component metal nitride film containing Al and Cr. For example, the metal nitride film may include at least one nitride film selected from the group consisting of AlCrN, AlCrSiN, AlCrSiWN, AlTiCrN, etc. Furthermore, in the present invention, the metal nitride film may be a multilayer film in which layers of different compositions are stacked.

[0070] In the present invention, the metal nitride film has a higher resistance than the base material. In the present invention, the resistivities of Mo and W as the base materials are as shown in the table below.

[0071] [Table 1]

[0072] In the present invention, the resistivity (@20°C) of the metal nitride film is preferably 1*10 -4 Ω cm or less, 1*10 -3 Ω cm or less, 1*10 -2 Ω cm or less, 1*10 -1 It is preferably Ω·cm or less, 1 Ω·cm or less, 1.5 Ω·cm or less, 2 Ω·cm or less, 5 Ω·cm or less, 10 Ω·cm or less, or 20 Ω·cm or less.

[0073] On the other hand, the ratio of the resistivity of the metal nitride film to the resistivity of the base material is 10 2 That's it, 10 3 That's it, 10 4 or more, or 105 It may be more than that.

[0074] In the present specification, the resistivity may be calculated by multiplying the surface resistivity obtained by multiplying the resistance of the film measured by the 4-point probe method by a correction factor (CF) and then multiplying the result by the thickness of the film.

[0075] In the present invention, the metal nitride film may further include one or more underlayers, for example, a CrN underlayer.

[0076] In the present invention, when the metal nitride film is embodied by AlCrN, the resistivity of the metal nitride film may be controlled by the relative content of Al and Cr.

[0077] For example, Al 1-x Cr x The resistivity of the metal nitride film may be controlled by controlling the atomic ratio (x) of Cr in the composition of the metal nitride film expressed by N (where x is the atomic ratio), i.e., Cr / (Al+Cr).

[0078] The CrN film formed by arc ion plating is 3*10 -4 The resistivity is shown in Ωcm. 1-x Cr x The resistivity may vary depending on the Al and Cr contents in the N and the nitrogen concentration during the film formation process. An AlCrN film formed by arc ion plating with x ≈ 0.2 to 0.8 may have a resistivity of 1 to 15 Ω cm, and an AlCrN film with x ≈ 0.5 may have a resistivity of approximately 7 to 9 Ω cm. In the present invention, it is possible to adjust the resistivity by changing the ratio of Al to Cr.

[0079] In the present invention, in order to achieve a preferable resistivity value, Al 1-x Cr xThe x value of the N film is preferably 0.1 or more, 0.15 or more, 0.2 or more, or 0.25 or more, and is preferably 0.9 or less, 0.8 or less, 0.75 or less, 0.70 or less, 0.65 or less, 0.6 or less, 0.55 or less, or 0.5 or less.

[0080] In addition, the measured resistivity values ​​of various metal nitride films formed on Al2O3 substrates are summarized in Table 2 below.

[0081] [Table 2]

[0082] FIG. 3 is a diagram schematically showing a cross section of an electrode rod structure according to another embodiment of the present invention.

[0083] Referring to Figure 3, the electrode rod assembly 1 includes a first rod 10'. The first rod 10' includes a base material 12' and a metal nitride film 14' covering the surface of the base material. In addition, both ends of the first rod 10' form exposed base material surfaces on which no metal nitride film is formed. The base material 12' and the metal nitride film 14' may be made of the same material as the electrode rod 10 described with reference to Figure 2.

[0084] Meanwhile, a second rod 20 is connected to the front end of the first rod 10'. The first rod 10' and the second rod 20 may be connected by a joint S. The joint S may be provided by soldering or brazing an Au-Ni alloy joint material or an alloy joint material containing Ti at an appropriate temperature.

[0085] In the present invention, the second rod 20 may include a second base material 22 and a second metal nitride film 24 covering the second base material. In addition, it is preferable that the second base material 22 at both ends of the second rod 20 is exposed.

[0086] In the present invention, the second base material 22 and the second metal nitride film 24 may be made of the same material as the first base material 12' and the first metal nitride film 14'.

[0087] Alternatively, the second base material 22 may include a metal different from that of the first base material 12'. In this case, the second base material 22 may include a metal or alloy having a similar thermal expansion coefficient to that of the electrode pad. For example, when Mo, W, or an alloy thereof is used for the electrode pad, an alloy having a low thermal expansion coefficient, such as Kovar, may be used for the second base material 22. In this case, when a nickel-based alloy, such as Kovar, is used for the second base material 22, the second metal nitride film 24 of FIG. 3 may not be provided.

[0088] 3, the second rod 20 of the assembly 1 may be electrically connected to an electrode pad, and the first rod 10' of the assembly 1 may be electrically connected to an external power source, although the reverse connection is also possible.

[0089] While the electrode rod assembly has been described above with reference to Fig. 3 in which two electrode rods are connected in series, the present invention is not limited thereto, and an electrode rod assembly having, for example, three or more electrode rods may also be used. Some or all of the electrode rods constituting such an electrode rod assembly may have the electrode rod structure described in relation to Fig. 2.

[0090] FIG. 4 is a cross-sectional view schematically showing a part of a susceptor according to an embodiment of the present invention.

[0091] 4, a (ceramic) susceptor 100 includes a ceramic plate 110, an electrode 111 embedded in the ceramic plate 110, and an electrode pad 112 for electrical connection of the electrode. The ceramic plate 110 has an opening 190 that exposes the electrode pad, and an electrode rod 10 is coupled to the opening. The electrode rod 10 supplies power (e.g., RF (Radio Frequency) power) to the electrode 111.

[0092] Meanwhile, a support eyelet 120 for supporting the electrode rod 10 within the opening may be further provided on the outer periphery of the electrode rod 10. The support eyelet 120 may be screwed into the opening. To this end, a thread 191 may be formed on a portion of the inner periphery of the opening 190, and a corresponding coupling structure (e.g., male thread) for fastening with the thread 191 (e.g., female thread) may be provided on the outer side of the support eyelet 120.

[0093] Meanwhile, although not shown, in the present invention, the ceramic plate 110 may further include a heating element (not shown) for heating a substrate placed on the ceramic plate and an electrode pad for supplying power to the heating element in addition to the electrode 111. Therefore, although the structure of the electrode rod 10 of the electrode 111 will be described in this specification, this structure may also be applied to an electrode rod for connecting the heating element (not shown) to the electrode rod.

[0094] In the present invention, the ceramic plate 110 may be configured such that electrodes 111 and / or heating elements (not shown) are disposed (embedded) at predetermined intervals between ceramic materials. The ceramic plate 110 may be configured to stably hold a substrate to be processed and to perform heating using a heating element (not shown) and / or plasma enhanced chemical vapor deposition (PECVD) using the electrodes 111. The ceramic plate 110 may be formed as a plate-like structure having a predetermined shape. For example, the ceramic plate 110 may be formed as a circular plate-like structure, but is not limited thereto. Here, the ceramic material may be at least one of Al2O3, Y2O3, Al2O3 / Y2O3, ZrO2, AlC (autoclaved lightweight concrete), TiN, AlN, TiC, MgO, CaO, CeO2, TiO2, BxCy, BN, SiO2, SiC, YAG, mullite, and AlF3, and may be preferably aluminum nitride (AlN).

[0095] An electrode pad 112 electrically connected to the electrode 111 is exposed in the opening 190 of the ceramic plate 110. The end connection surface of the electrode rod 10 and the electrode pad 112 are electrically connected by joining such as soldering or brazing.

[0096] In the present invention, the electrodes 111, the electrode pads 112, the support eyelets 120, and the heating element (not shown) may be made of a conductive material, such as tungsten (W), molybdenum (Mo), silver (Ag), copper (Cu), nickel (Ni), gold (Au), platinum (Pt), niobium (Nb), titanium (Ti), or an alloy thereof.

[0097] In the present invention, the electrode rod 10 has low resistance, i.e., low impedance, and is embodied as a paramagnetic material. Since the base material of the electrode rod 10 is made of paramagnetic materials such as Mo, W, or an alloy thereof, the electrode rod 10 has a larger skin depth than Ni or a Ni alloy, and as a result, exhibits improved impedance characteristics.

[0098] On the other hand, the base materials of the electrode rods, molybdenum, tungsten, and their alloys, react with oxygen and oxidize more easily than Ni or Ni alloys. Therefore, when the base materials are heated by the application of RF current, the electrode rods are oxidized and deteriorated.

[0099] To solve this problem, the present invention provides a metal nitride film on the surface of the base material of the electrode rod 10. In addition, in the present invention, a metal nitride film is formed on the outer circumferential surface of the electrode rod, but not on the end where the electrode rod connects to other components. This allows the electrode rod to provide good electrical connection with adjacent components while complementing the oxidation resistance of the base material.

[0100] In the present invention, the electrode rod has controlled electrical characteristics. In the present invention, the resistivity and ratio of the metal nitride film and the metal base material may be controlled to be within an appropriate range.

[0101] In addition, in the present invention, the metal nitride film may be appropriately designed depending on the frequency and power of the RF current drawn into the electrode rod. When the RF power frequency increases, the skin depth of the workpiece decreases and the amount of heat generated on the workpiece surface may increase. In this case, it is preferable to increase the thickness of the metal nitride film.

[0102] For example, when the RF power frequency drawn into the electrode rod is 10 MHz, the skin depth of the Mo base material is approximately 38 μm, and when the RF power frequency is 100 MHz, the skin depth of the Mo base material is 12 μm.

[0103] In the present invention, the thickness of the metal nitride film is preferably in the range of 4 to 10 μm in an environment where an RF power frequency of 10 to 40 MHz is used (for example, 13.56 MHz, 27.12 MHz, etc.).

[0104] In the present invention, one end of the electrode rod 10 may be joined to the electrode pad 112 by soldering or brazing. To this end, a first conductive filler 151 for joining to the electrode pad 112 may be provided at one end of the electrode rod 10.

[0105] Additionally, a second conductive filler 152 may be provided around the electrode rod 10 inserted inside the support eyelet 120 to fill the space between the support eyelet 120 and the electrode rod 10. The first and second conductive fillers 151 and 152 may be provided by soldering or brazing an Au-Ni alloy bonding material or an alloy bonding material containing Ti at an appropriate temperature.

[0106] In the present invention, the amounts of the first and second conductive fillers may be appropriately controlled.

[0107] FIG. 5 is a cross-sectional view schematically showing the structure of a susceptor according to another embodiment of the present invention.

[0108] 5, the susceptor has substantially the same configuration as that of FIG. 3, except that the electrode rod 10 of FIG. 3 is replaced with the electrode rod assembly 1 described in relation to FIG. 2. The electrode rod assembly 1 includes a first rod 10′ and a second rod 20 that are brazed and joined by the brazing joint 162 described in relation to FIG. 2, and the respective components have been described in relation to FIG. 2, so further description thereof will be omitted. Meanwhile, as described above, the second rod 20 does not need to be provided with the metal nitride film 24.

[0109] 6 is a flow chart showing a process for forming a metal nitride film on an electrode rod of a susceptor according to one embodiment of the present invention. In this embodiment, an AlCrN film is formed as the metal nitride film.

[0110] Referring to FIG. 6, in the present invention, various deposition methods, for example, a PVD (Physical Vapor Deposition) method such as arc ion plating, may be applied to the AlCrN formation process.

[0111] As shown in the figure, the coating of the electrode rod 10 may be formed by including a plasma pretreatment step (S110), an adhesive layer formation step (S120), and a reactive vapor deposition step (S130).

[0112] First, the surface of a base material made of Mo, W, or an alloy thereof is plasma pretreated (S110). In the plasma pretreatment step (S110), the base material 12 of an electrode rod is loaded into an arc ion plating device or a sputtering device, and a 1×10 -5 Torr (133.3 × 10 -5 The surface of the base material 12 of the electrode rod is cleaned by plasma pretreatment at a vacuum level of 1000 Pa or less. This is to ensure that the adhesion layer and metal nitride film are optimally coated in the subsequent process.

[0113] Next, the adhesion layer forming step (S120) is performed to reduce the internal stress of the metal nitride film to be formed and to improve adhesion. The adhesion layer may contain a metal such as Cr or its alloy. Preferably, the adhesion layer may contain Cr nitride or a nitride of a Cr alloy.

[0114] In the present invention, the adhesive layer may be formed by arc ion plating or sputtering. For example, a CrN layer may be deposited as an adhesive layer on the surface of the base material 12 of each electrode rod to a thickness of 0.1 to 4.0 μm using arc ion plating or sputtering equipment. In this case, a Cr target may be pre-loaded into the arc ion plating or sputtering equipment, and the CrN layer may be formed on the surface of the base material 12 of the electrode rod at a predetermined vacuum level using a PVD method while injecting nitrogen into the reactor.

[0115] In the reactive deposition process (S130), Al and Cr targets or Al-Cr alloy targets are loaded into the arc ion plating equipment, and 1×10 -2 Torr (133.3 × 10 -2 The AlCrN is formed to a thickness of 1.0 to 10.0 μm at a vacuum of about 1000 Pa. The AlCr alloy target may be an AlCr alloy target containing aluminum (Al) and chromium (Cr) at a predetermined ratio (e.g., 7:3 at%). In contrast, when an Al target and a Cr target are used, the Al / Cr ratio can be adjusted by changing the current of each target.

[0116] As described above, the ends of the base material may be appropriately masked to prevent the formation of a metal nitride film on the ends of the electrode rods 10, 10'. For example, the ends of the base material may be masked by applying adhesive tape or a photoresist film to the ends, or by using a jig. Alternatively, the exposed surface of the electrode rod may be realized by processing the end of the electrode rod 10 on which the metal nitride film is formed to expose the base material.

[0117] <Experimental Example 1: Resistivity measurement experiment of AlCrN film> Using alloy targets with different Al and Cr contents, AlCrN films measuring 30mm x 30mm and 5-7μm thick were formed on the surface of an Al2O3 substrate by arc ion plating. The Al:Cr ratio of the AlCrN film formed for each target was analyzed by EDS, and the resistivity of the AlCrN film was measured using a four-point wire method with a Mitsubishi Chemical Loresta-GP instrument. The resistivity of the AlCrN film was 1-15 Ω·cm.

[0118] As a result of EDS analysis of each composition, the composition ratio (at%) was as shown in Table 3 below.

[0119] [Table 3]

[0120] <Experimental Example 2: Measurement of RF power loss in electrode rod> The RF power loss was measured for Φ4×330 mm rods with different materials and coating compositions. The rods used for measurement were Ni rods, Mo rods, AlCrN / Mo rods, W rods, and AlCrN / W rods, and the composition of the AlCrN film was the composition of #2 in Experimental Example 1.

[0121] Figure 7 shows the results of power loss measurements. As shown in Figure 6, in the RF (Radio Frequency) power loss rate calculated based on the measured impedance values, it can be seen that, with the loss rate of Ni as the reference, the loss rates of Mo, AlCrN / Mo having an AlCrN film on its surface, W, and AlCrN / W having an AlCrN film on its surface are reduced by about 40% compared to Ni. These results show that in terms of power loss, the Mo, W, AlCrN / Mo, and AlCrN / W electrode rods exhibit superior properties compared to Ni.

[0122] <Experimental Example 3: Oxidation resistance of electrode rod> The oxidation resistance characteristics of the electrode rod, Φ2×330mm, were confirmed based on the material and coating composition.

[0123] The electrode rods used were Mo, MoW, AlCrN / Mo, and AlCrN / MoW rods. The AlCrN film had the composition of #2 in Experimental Example 1.

[0124] Each rod was oxidized in a box furnace at 700°C for 10 hours. The resistance of each rod was measured before and after the oxidation treatment. The measurement was performed using a HIOKI Resistance Meter (RM3545) under the condition of IN 10mΩ.

[0125] FIG. 8 is a graph plotting the results of measuring the resistance value before and after oxidation treatment for each rod material.

[0126] It can be seen from Figure 8 that the resistance of each rod material increased due to the oxidation treatment. However, in the case of the rod with the AlCrN film formed, it can be seen that the rate of change in resistance before and after the heat treatment was low, and the resistance value was also low.

[0127] In the present invention, the susceptor is a semiconductor device for processing various substrates to be processed, such as semiconductor wafers, glass substrates, and flexible substrates, and includes an electrode 111 that functions as a high-frequency electrode for processing the substrate to be processed, such as plasma-based dry etching or plasma-enhanced chemical vapor deposition, as described below. Alternatively, the electrode 111 may be used as a chuck electrode for use in an electrostatic chuck to support the substrate to be processed. In the present invention, the susceptor may further include a heating wire (or a heating element / heating electrode) for heating the substrate to a predetermined temperature.

[0128] The electrode (or conductor) 111, such as a radio frequency electrode, electrostatic chuck electrode, or heating wire, may be made of a conductive metal material such as silver (Ag), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), tungsten (W), molybdenum (Mo), or titanium (Ti), or an alloy thereof. The radio frequency electrode may be supplied with power in a semiconductor manufacturing process to perform processes such as plasma enhanced chemical vapor deposition on a substrate positioned on the upper surface of a susceptor. The electrostatic chuck electrode may receive a bias from a power source to generate an electrostatic force to chuck a substrate positioned on the upper surface of a susceptor, and when unloading the substrate, an opposite bias may be applied to discharge the electrostatic force to dechuck the substrate. The heating wire (or heating element / heating electrode) may be formed in the form of a plate-shaped coil or a flat plate using a resistance wire having a predetermined resistance, or may be formed in a multi-layer structure for precise temperature control. The heating wire (or heating element / heating electrode) may be supplied with power and have the function of heating a substrate placed on the upper surface of the susceptor to a certain temperature in order to perform smooth deposition and etching processes in a semiconductor manufacturing process.

[0129] Therefore, in the following description of the present invention, the electrode 111 of the ceramic susceptor will be described as functioning as a high-frequency electrode to which radio frequency (RF) power is supplied via an electrode rod. However, the present invention is not limited to this, and it should be made clear in advance that the relevant description can be similarly applied to the case in which the electrode of the ceramic susceptor functions as a chuck electrode for electrostatic chuck function or an additional heating element receives power via an electrode rod.

[0130] Hereinafter, other aspects of the present invention will be described with reference to the accompanying Figures 10A to 13. In this case, the same components in the drawings will be assigned the same reference numerals. Furthermore, even if the reference numerals are not the same, as long as the names of the components are the same, the components may have the same structure and the same function. In particular, the same components in the description of Figures 2A to 8 can also be applied to Figures 10A to 13, and detailed description of the same functions and / or configurations described above will be omitted. Furthermore, the same components in the description of Figures 10A to 13 can also be applied to Figures 2A to 8.

[0131] FIG. 10A is a diagram illustrating the structure of a ceramic susceptor 100 according to still another embodiment of the present invention.

[0132] 10A, a ceramic susceptor 100 according to yet another embodiment of the present invention may include a ceramic plate 110 on which an electrode 111 is disposed. Here, the ceramic plate 110 may include an electrode pad 112 connected to the electrode 111, and an electrode rod assembly 150 having one end connected to the electrode pad 112 and for supplying power to the electrode 112. In this case, the electrode rod assembly 150 includes an extension portion 130 including a first rod 131 and a second rod 132.

[0133] 10A, the electrode rod assembly 150 may include an extension 130 connected to the electrode pad 112 and a power connector 133 provided at an end of a tapered portion AA of the extension 130. That is, the electrode rod assembly 150 includes the extension 130 including a first rod 131 and a second rod 132, and includes a tapered portion AA and a power connector 133 at the end of the extension 130.

[0134] In this case, the extension portion 130 may include a first rod 131 and a second rod 132 brazed to the first rod 131 by brazing 162. The second rod 132 may be made of a metal material having a thermal expansion coefficient difference of 3 or less from that of the material of the electrode pad 112. For example, the electrode pad 112, the first rod 131, and the power connector 133 may have a thermal expansion coefficient of 4.5 to 5.6 μm / °C and may be made of Mo, W, or an alloy thereof (MoW). The second rod 132 may have a thermal expansion coefficient of 4.9 to 6.2 μm / °C and may be made of an Fe-Ni-Co alloy (e.g., Kovar). It is preferable that the thermal expansion coefficient of the second rod 132 differs from that of the first rod 131, including the power connector 133, by 3 or less.

[0135] 10B is a view illustrating the structure of a ceramic susceptor 200 according to yet another embodiment of the present invention. In this case, one rod is connected to the electrode pad 112 and extends to the power connector 133.

[0136] 10B, a ceramic susceptor 200 according to another embodiment of the present invention may include a ceramic plate 110 on which an electrode 111 is disposed. Here, the ceramic plate 110 may include an electrode pad 112 connected to the electrode 111, and an electrode rod assembly 150 having one end connected to the electrode pad 112 to supply power to the electrode 112.

[0137] In this case, the electrode rod assembly 150 may include a first rod or extension 131 connected to the electrode pad 112, and a power connector 133 provided at an end of a tapered portion AA of the extension 131. That is, the electrode rod assembly 150 includes the extension 131 made of a single rod, and includes the tapered portion AA and the power connector 133 at the end of the extension 131. Here, for example, the extension 131 including the power connector 133 may have a thermal expansion coefficient of 4.5 to 5.6 μm / °C and may be made of Mo, W, or an alloy thereof.

[0138] That is, as shown in Figures 10A and 10B, the electrode rod assembly 150 of the present invention may include an extension portion 130 / 131 connected to the electrode pad 112 and a power connection portion 133 provided at the end of the tapered portion AA of the extension portion 130 / 131.

[0139] The ceramic susceptor 100 may also include a support eyelet 120 that couples with the electrode rod assembly 150. For example, the electrode rod assembly 150 may couple with the support eyelet 120 that is fastened to the electrode 111 by threads 191 on the ceramic plate 110.

[0140] Meanwhile, as mentioned above, although not shown, in the present invention, the ceramic plate 110 may further include a heating element (electrode) (not shown) and the electrode rod. Therefore, in the present invention, a structure related to the electrode rod assembly 150 of the electrode 111 will be described, but it is clear that such a structure may also be applied to the heating element (electrode) (not shown) and the electrode rod.

[0141] That is, the ceramic plate 110 may be configured such that the electrodes 111 and / or heating elements (electrodes) are disposed (embedded) at predetermined intervals between the ceramic materials. The ceramic plate 110 is configured to stably hold the substrate to be processed placed on the upper surface SS, and to perform heating using the heating elements (electrodes) and / or electrostatic chucking using the electrodes 111, or semiconductor processes using plasma. The ceramic plate 110 may be formed as a plate-like structure having a predetermined shape. For example, the ceramic plate 110 may be formed as a circular plate-like structure, but is not necessarily limited thereto. Here, the ceramic material may be Al2O3, Y2O3, Al2O3 / Y2O3, ZrO2, AlC (autoclaved lightweight concrete), TiN, AlN, TiC, MgO, CaO, CeO2, TiO2, B x C yThe ceramic powder may be at least one of BN, SiO2, SiC, YAG, mullite, and AlF3, and preferably aluminum nitride (AlN). Each ceramic powder may optionally contain about 0.1 to 10%, preferably about 1 to 5%, of yttrium oxide, MgO, TiO2 powder, etc.

[0142] The electrode pad 112 is embedded in the ceramic plate 110 so as to be partially exposed at the bottom surface of a predetermined aperture of the ceramic plate 110. The end surface of the electrode rod assembly 150 and the electrode pad 112 may be electrically connected by brazing.

[0143] The electrode 111, electrode pad 112, electrode rod assembly 150, support eyelet 120, etc. may be made of a conductive material, such as tungsten (W), molybdenum (Mo), silver (Ag), platinum (Pt), palladium (Pd), nickel (Ni), gold (Au), niobium (Nb), titanium (Ti), or an alloy thereof.

[0144] In particular, in the present invention, the electrode rod assembly 150 preferably has low impedance and is a paramagnetic material. For example, the electrode rod assembly 150 may be made of a base material such as Mo, W, or an alloy thereof, and an oxidation-resistant coating may be provided on the surface of the base material of the electrode rod assembly 150. As described above, for example, in FIG. 10A, the first rod 131 including the electrode pad 112 and the power connection portion 133 may be made of Mo, W, or an alloy thereof, and the second rod 132 may be made of an Fe-Ni-Co alloy (e.g., Kovar). Also, for example, in FIG. 10B, the extension portion 131 including the power connection portion 133 may have a thermal expansion coefficient of 4.5 to 5.6 μm / °C and may be made of Mo, W, or an alloy thereof.

[0145] In the present invention, the oxidation-resistant coating preferably includes metal nitride films 141, 142. For example, the metal nitride film may include AlN, more preferably TiN, TiAlCrN, TiAlN, or AlCrN. This makes it possible to provide a ceramic susceptor 100 that has all the thermal, electrical (magnetic), and mechanical properties required in the manufacturing and processing environments of the ceramic susceptor 100 and is advantageous in terms of processability and material cost.

[0146] In the ceramic susceptor 100 of the present invention having the structure shown in FIG. 10A , one side of the electrode rod assembly 150 may be joined inside the support eyelet 120 and may include a first rod 131 and a second rod 132 connected by brazing. The first rod 131 and the second rod 132 may be integrated into a single rod as the extension portion 130, or may have a structure in which the first rod 131 and the second rod 132 are joined together. One end surface of the second rod 132 may be brazed to the electrode pad 112 using a first conductive filler 151, and the first rod 131 may be brazed to the other end surface of the second rod 132 using a second conductive filler 162. For example, an Au-Ni metal filler may be used as the conductive fillers 151 and 162. A conductive filler 152 may be provided around the rods 131 and 132 inserted inside the support eyelet 120 to fill the space between the support eyelet 120 and the rods 131 and 132 .

[0147] The electrode pad 112 may be made of Mo, W, or an alloy thereof. Since the second rod 132 is located close to the electrode 111, heat loss and thermal stress may occur. Therefore, in order to prevent heat loss and reduce cracks due to thermal stress, as described above, the second rod 132 is preferably made of a metal material having a thermal expansion coefficient difference of 3 or less with the material of the electrode pad 112. In particular, in the present invention, metal nitride films 141 and 142 may be formed on the surface of the electrode rod assembly 150 to protect against oxidation (corrosion). That is, the metal nitride film 141 may be formed on the surface of the second rod 132, and the metal nitride film 142 may be formed on the surface of the first rod 131. In some cases, the metal nitride film 141 may not be necessary on the surface of the second rod 132, but the metal nitride film 141 may be formed on the surface of the second rod 132 if necessary.

[0148] In addition, the electrode rod assembly 150 includes a power supply connection portion 133 that has a diameter different from that of the extension portions 131, 132 (130), extends to the end of the extension portion 130, and is formed by tapering.

[0149] To bond each of the brazing processes, first, first conductive filler 151 is injected into the bottom of opening 190, i.e., around the exposed portion of electrode pad 112, and second rod 132 is pressed into support eyelet 120 to bring one end surface of second rod 132 into close contact with electrode pad 112. Next, second conductive filler 162 is injected sufficiently onto the other end surface of second rod 132, and one end surface of first rod 131 is brought into close contact with the injected second conductive filler 162, heated at a high temperature, and then cooled.

[0150] 10B , except that the second rod 132 is omitted, one end surface of the first rod or extension 131 consisting of a single first rod 131 may be brazed to the electrode pad 112 using the first conductive filler 151 in a similar manner to the above method. A conductive filler 152 may be provided around the rod 131 inserted inside the support eyelet 120 to fill the space between the support eyelet 120 and the rod 131.

[0151] By using such ceramic susceptor 100 / 200 of the present invention, and connecting the power connector 133 of the electrode rod assembly 150 to a power source and supplying power to the electrode 111 via the electrode pad 112, it can perform semiconductor processes such as plasma-based dry etching and plasma-enhanced chemical vapor deposition, or function as an electrostatic chuck. Heat (or high frequency waves) generated from the heating element (electrode) can be used to heat a substrate to be processed (e.g., a semiconductor wafer, a glass substrate, a flexible substrate, etc.) in a semiconductor process, etc.

[0152] In particular, the electrode rod assembly 150 may be made of Mo, W, or an alloy containing one or more of these metals at a greater weight percentage (wt%) than other metals (e.g., MoW, MoNi, WNi, etc.). Metal nitride films 141, 142 are included on the surface of the electrode rod assembly 150 to protect against oxidation (corrosion), thereby effectively preventing oxidation of the electrode rod assembly 150 and eliminating factors that increase impedance with use. By reducing changes such as an increase in impedance of the electrode rod assembly 150 and eliminating energy loss converted to heat energy in the electrode rod assembly 150, electrical energy can be efficiently consumed in plasma discharge. Furthermore, by reducing the heat generated by the electrode rod assembly 150, hot spots are not formed on the upper surface of the ceramic plate 110 that holds the substrate. This improves the uniformity of the thickness and quality of the thin film deposited on the substrate, thereby increasing yield. In addition, the temperature rise of the ceramic portion that contacts the portion where the electrode rod assembly 150 is fastened is eliminated, thereby reducing the damage to the ceramic susceptor 100 due to thermal shock and reducing the occurrence of arcs at the brazing joint. Therefore, the reduction in impedance change of the electrode rod assembly 150 in the present invention provides a ceramic susceptor 100 with improved durability, which can contribute to an increase in the yield of semiconductor devices.

[0153] FIG. 11 is an enlarged view of the peripheral portion 200 including the tapered portion AA between the extension portion 130 / 131 and the power connection portion 133 of the present invention of FIGS. 10A and 10B.

[0154] 11, as described above, the power supply connection portion 133 is provided at the end of the tapered portion AA of the extension portion 130 / 131 of the electrode rod assembly 150. That is, the tapered portion AA may be formed by tapering using a machine tool so that the tapered portion AA is included between the extension portion 130 / 131 and the power supply connection portion 133, which have different diameters. The machine tool may include a processing device using various methods such as a milling machine, a lathe, a machining center (MCT), a computer numerical control (CNC), a laser, etc.

[0155] In the present invention, the tapered portion AA of the electrode rod assembly 150 may be formed by processing the cylindrical rod 130 / 131 at the same inclination angle θ along the circumference thereof. The electrode rod assembly 150 may have a total length of, for example, 250 to 400 mm, of which the length LL of the tapered end AA, which gradually narrows from the extension portion 130 / 131 toward the power connection portion 133, is preferably 1.0 mm to 10.0 mm in the longitudinal direction of the extension portion 130 / 131.

[0156] The inclination angle θ of the tapered portion AA of the extension portion 130 / 131 may be 10° to 80° with respect to the longitudinal direction of the extension portion 130, and may be 45° or less, 40° or less, 35° or less, 30° or less, 25° or less, or 20° or less for a smoother, more streamlined connection. More preferably, the inclination angle θ may be 12° to 16°. This may result in the longitudinal cross section of the tapered portion AA of the extension portion 130 / 131 being trapezoidal.

[0157] The position of the smaller diameter end of the tapered portion AA of the extension portion 130 / 131 may be determined to be a predetermined position for improving oxidation resistance and corrosion resistance. For example, the position of the smaller diameter end of the tapered portion AA of the extension portion 130 / 131 may be a position that is 10% or more lower, and preferably 20% or more lower, than the temperature of the ceramic plate 110, i.e., the temperature of the lowermost surface of the ceramic plate 110 (see BB in FIG. 12 ) (e.g., 650° C., 550° C., 450° C., etc.) when the ceramic plate 110 is started, i.e., when the heating element (electrode) is activated (or an external heater can be used if no heating element is present).

[0158] In the following example, the total length of the electrode rod assembly 150 is about 330 mm, the diameter of the extensions 131 and 132 is 4.6 mm, the diameter of the power connection portion 133 is 4 mm, the length LL of the tapered end AA is 2.5 mm, and the inclination angle θ is 13.7°. In this case, it was confirmed that the position where the temperature of the lowermost surface of the ceramic plate 110 (see BB in FIG. 12) is 80% or less of the temperature (e.g., 650°C, 550°C, 450°C, etc.) of the ceramic plate 110 is 5 mm or more away from the lowermost surface of the ceramic plate 110 (see BB in FIG. 12).

[0159] That is, the tapered portion AA is placed at a position away from the ceramic plate 110 where the temperature drops significantly during the semiconductor process, thereby preventing oxidation or corrosion of that portion due to high temperatures that may occur during use in the brazing or deposition process.

[0160] FIG. 12 shows an embodiment in which the ceramic susceptor 100 of the present invention is installed in a process chamber 300 of a semiconductor equipment.

[0161] Referring to FIG. 12, a ceramic susceptor 100 / 200 may be installed inside a process chamber 300 of semiconductor equipment for performing a semiconductor process such as plasma-enhanced chemical vapor deposition, and the ceramic susceptor 100 / 200 may be installed so as to be supported by a shaft 310 having a through hole therein and a predetermined connecting mount 320.

[0162] In the ceramic susceptor 100 / 200, the electrode rods 130 / 132 connected to the electrode pads 112 of the ceramic plates 110 may pass through the inside of the shaft 310, pass through the connection mount 320, and extend to the outside of the chamber 300. That is, the power connection portions 133 of the electrode rods 130 / 132 extend to the outside of the chamber 300, and the periphery of the end PP of the power connection portion 133 is connected to a connecting means of a power source, so that the necessary power supply can be received.

[0163] In this chamber 300, the heating elements of the ceramic plate 110 were activated to raise the temperatures of the ceramic plate 110 to 650°C, 550°C, and 450°C, respectively. The temperature was measured at positions A, B, C, D, E, and F, moving downward at predetermined intervals from an outer position A of the shaft 310 aligned with the bottom surface BB of the ceramic plate 110. The temperature was confirmed to decrease linearly as shown in Table 4 below. The susceptor sample used here had an electrode rod assembly 150 with a total length of approximately 330 mm, extensions 131 and 132 with a diameter of 4.6 mm, and a power connection portion 133 with a diameter of 4 mm. The tapered end AA had a length LL of 2.5 mm and an inclination angle θ of 13.7°.

[0164] [Table 4]

[0165] As can be seen in the table above, when the temperature at position A on the bottom surface BB of the ceramic plate 110 is 650°C, 550°C, and 450°C, respectively, all positions that are 10% or more lower than that temperature are position C, and all positions that are 20% or more lower than that temperature are position D.

[0166] Therefore, in the above case, the position of the end with the smaller diameter in the tapered portion AA of the extension portion 130 / 131 may be located at C, D, E, or F, and preferably at D, E, or F.

[0167] This allows the tapered portion AA to be located at a position at a temperature 10% or more lower than the temperature of the ceramic plate 110, thereby improving the oxidation resistance and corrosion resistance of the electrode rod assembly 150.

[0168] As described above, the ceramic susceptor 100 according to the present invention has the tapered portion AA located at a position where the electrode rod assembly 150 is separated from the ceramic plate 110 to receive power, particularly at a position where the temperature drops significantly during semiconductor processing. The tapered portion AA is designed to have a streamlined shape such as a trapezoidal shape to avoid forming a steeply inclined edge, thereby improving durability and ensuring a long lifespan so that the ceramic susceptor 100 has good high frequency transmission characteristics for a long period of time even in oxidation-resistant and corrosion-resistant environments.

[0169] FIG. 13 is a flowchart illustrating a process for forming a film on the electrode rod assembly 150 of the ceramic susceptor 100 according to an embodiment of the present invention.

[0170] 13, first, a physical vapor deposition (PVD) method such as arc ion plating may be applied to form metal nitride films 141, 142 on the surface of the base material of the electrode rod assembly 150, which may be made of Mo, W, or an alloy thereof, to form coatings on the electrode rod assembly 150. As shown in the figure, the coatings on the electrode rod assembly 150 may be formed by a plasma pretreatment process (S110), a process of forming an adhesive layer 145 (S120), and a reactive deposition process (S130).

[0171] First, in the plasma pre-treatment process (S110), the base material of the electrode rod assembly 150 is loaded into an arc ion plating device or a sputtering device before the adhesive layer 145 is formed. -5 The base material surface of the electrode rod assembly 150 is cleaned by plasma pretreatment at a vacuum level of Torr or less. This is to optimally coat the adhesion layer 145 and the metal nitride films 141 and 142 in subsequent processes. Here, the electrode rod assembly 150 may be a rod on which the extension portions 130 / 131, the tapered portion AA, and the power connection portion 133 are pre-formed.

[0172] Next, the adhesion layer formation step (S120) is a step for reducing internal stress and improving adhesion of the metal nitride films 141 and 142. The adhesion layer 145 may include a metal such as Cr or its alloy. Preferably, the adhesion layer may include Cr nitride or a nitride of a Cr alloy.

[0173] In the present invention, the adhesive layer 145 may be formed by arc ion plating or sputtering. For example, a CrN layer may be deposited to a thickness of 0.1 to 4.0 μm as the adhesive layer 145 on the base metal surface of the extension portion 130 / 131 of each electrode rod assembly 150 using arc ion plating or sputtering equipment. In this case, a Cr target is first loaded into the arc ion plating or sputtering equipment, and nitrogen is injected into the reactor. The CrN layer can be formed on the base metal surface of the extension portion 130 / 131 of the electrode rod assembly 150, i.e., on the extension portion 130 / 131 including the tapered portion AA and the power connection portion 133 of the electrode rod assembly 150, at a predetermined vacuum level using a PVD method.

[0174] In the reactive deposition process (S130), an Al target and a Cr target are loaded into the arc ion plating or sputtering equipment in advance, or an AlCr alloy target is loaded, and then 1×10 Cr is deposited by PVD while injecting nitrogen into the reactor of the arc ion plating or sputtering equipment. -2 The metal nitride films 141 and 142 are formed to a thickness of 1.0 to 10.0 μm at a vacuum of about Torr. The AlCr alloy target may be an AlCr alloy target in which aluminum (Al) and chromium (Cr) are alloyed at a predetermined ratio (e.g., 7:3 at%). Alternatively, when an Al target and a Cr target are used, the ratio of Al to Cr required for forming the metal nitride films 141 and 142 can be adjusted by changing the current for each target.

[0175] As described above, the ceramic susceptor 100 / 200 according to the present invention has the tapered portion AA located at a position where the electrode rod assembly 150 is separated from the ceramic plate 110 to receive power, particularly at a position where the temperature drops significantly during semiconductor processing, and is designed to have a streamlined shape such as a trapezoidal shape to avoid forming sharply inclined edges, thereby improving durability and ensuring a long life so that the ceramic susceptor 100 / 200 has good high-frequency transmission characteristics for a long period of time even in oxidation-resistant and corrosion-resistant environments.

[0176] As described above, the present invention has been described using specific details such as specific components, limited embodiments, and drawings, but these are provided merely to facilitate a more comprehensive understanding of the present invention, and the present invention is not limited to the above embodiments, and various modifications and variations may be made by a person skilled in the art to which the present invention pertains without departing from the essential characteristics of the present invention. Therefore, the concept of the present invention should not be limited to the described embodiments, and should be construed as falling within the scope of the claims below, as well as any technical concepts that are equivalent to or have been modified in a similar manner to the claims. [Explanation of symbols]

[0177] 1,150 Electrode Rod Assembly 10,10' electrode rod 12,12', 22 Base material 14,14',24,141,142 Metal nitride films 100 susceptors 110 Ceramic Plate 111 Electrode 112 electrode pads 120 support eyelet

Claims

1. A susceptor including a ceramic plate on which an electrode is disposed, the ceramic plate includes an electrode pad connected to the electrode, and an electrode rod having one end connected to the electrode pad for supplying power to the electrode; the electrode rod includes an extension connected to the electrode pad and a power connector provided at an end of a tapered portion of the extension; the electrode rod is made of a base material of Mo, W, or an alloy thereof; the electrode rod, including the extension portion, the tapered portion, and the power supply connection portion extending from the tapered portion, is formed of the same material; The electrode rod includes a metal nitride film on a surface of a base material. Susceptor.

2. A susceptor including a ceramic plate on which an electrode is disposed, the ceramic plate includes an electrode pad connected to the electrode, and an electrode rod having one end connected to the electrode pad for supplying power to the electrode; the electrode rod includes an extension connected to the electrode pad and a power connector provided at an end of a tapered portion of the extension; the electrode rod is made of a base material of Mo, W, or an alloy thereof; the extension portion of the electrode rod includes a second rod brazed to the electrode pad and a first rod brazed to the second rod, the tapered portion of the first rod and the power connection portion extending from the tapered portion are formed of the same material; The electrode rod includes a metal nitride film on a surface of a base material. Susceptor.

3. A susceptor including a ceramic plate on which an electrode is disposed, the ceramic plate includes an electrode pad connected to the electrode, and an electrode rod having one end connected to the electrode pad for supplying power to the electrode; the electrode rod includes an extension connected to the electrode pad and a power connector provided at an end of a tapered portion of the extension; the tapered portion is formed on the exterior of the ceramic plate; the electrode rod is made of a base material of Mo, W, or an alloy thereof; the electrode rod, including the extension portion, the tapered portion, and the power supply connection portion extending from the tapered portion, is formed of the same material; Susceptor.

4. The susceptor according to claim 3 , wherein the electrode rod includes a metal nitride film on a surface of a base material thereof.

5. 4. The susceptor according to claim 1, wherein the tapered portion of the extension has an inclination angle of 10° to 80° with respect to the longitudinal direction of the extension.

6. 4. The susceptor according to claim 1, wherein the tapered portion of the extension has a length of 1.0 mm to 10.0 mm in the longitudinal direction of the extension.

7. 4. The susceptor according to claim 1, wherein the end of the tapered portion of the extension having a smaller diameter is positioned at a distance of 5 mm or more from the lowermost surface of the ceramic plate.

8. The susceptor according to claim 2 , wherein the second rod is made of a metal material having a thermal expansion coefficient difference of 3 or less with respect to a material of the electrode pad.

9. The susceptor according to claim 1 , wherein the electrode is a high-frequency electrode, an electrostatic chuck electrode, or a heating element.

10. A susceptor as described in claim 2, wherein the first rod and the second rod are formed from different materials.

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