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 to which a material of an electrode rod for reducing impedance is applied to a ceramic-based susceptor.

[0002] Further, the present invention relates to a susceptor, and more particularly to a ceramic susceptor with improved durability of an electrode rod.

Background Art

[0003] Generally, a semiconductor device or a display device is manufactured by sequentially laminating a plurality of thin film layers including a dielectric layer and a metal layer on a glass substrate, a flexible substrate, or a semiconductor wafer substrate, and then patterning. A susceptor is used as a holding structure for holding a substrate in such a semiconductor manufacturing process. The susceptor is widely used in a plasma deposition process or the like for precise processes such as wiring miniaturization of semiconductor elements in accordance with requirements such as accurate temperature control and heat treatment, and is also used for plasma formation or substrate heating in an etching process of a thin film layer formed on a semiconductor wafer substrate.

[0004] FIG. 1 is a diagram for explaining an electrode portion of a conventional susceptor. Referring to FIG. 1, a conventional susceptor has conductive pads 36 for connection with electrode rods 31 and 32 inside a ceramic plate 30. The ceramic plate 30 has RF electrodes 35 of various two-dimensional shapes such as circular or semi-circular embedded therein. Further, conductive pads 36 electrically connected to the RF electrodes 35 are embedded.

[0005] The support 34 in the form of an eyelet that houses the electrode rods 31 and 32 is screwed onto the ceramic plate with a thread formed in the opening of the ceramic plate 30. At this time, 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 can electrically connect the electrode rods 31 and 32 and the RF electrode 35 by a joining process such as brazing. In such a conventional susceptor, 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, and may oxidize the upper electrode rod 31 and the lower electrode rod 32. When the electrical conductivity of the electrode rod decreases due to such oxidation and the power transmission efficiency decreases, it may lead to a decrease in the reliability of the electrode part, and there is a problem of shortening the life of the susceptor.

[0006] Due to such oxidation problems, heat-resistant and oxidation-resistant materials such as Ni or Ni alloy materials have mainly been used for conventional electrode rods. However, when the Ni-based heat-resistant material applied to the conventional electrode rod is used as a power transmission line in a high-frequency region, the impedance of the electrode rod increases due to the skin effect in which the current flows along the surface of the electrode rod, accompanied by heat generation.

[0007] Moreover, with the development of semiconductor processes, there is a demand for a susceptor that can operate at a higher temperature and can apply a high-power high-frequency to have higher plasma characteristics. Therefore, the skin effect in the electrode rod is more prominent, and problems of short circuits due to heat generation and oxidation frequently occur.

[0008] To improve this, conventionally, a rod base material of Ni or Ti is coated with Au, Ag, Al, Cu, etc., as in Korean Patent Publication No. 10-2018-0121662 (November 7, 2018), or an alumina thin film is coated on a rod base material of Mo, Ni, Ti, as in Korean Patent Publication No. 10-2021-0139368 (November 22, 2021), in an attempt to reduce heat generation or decrease heat conduction. However, even in such cases, the problem of increased impedance of the electrode rod material due to an increase in frequency in power transmission in the high-frequency region has not been fundamentally solved.

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

[0010] Referring to FIG. 9, a conventional ceramic susceptor has an electrode portion for coupling with external electrode rods 31 and 32 at the central portion of a ceramic plate 30. In the ceramic plate 30, an electrode 35 that can be a heating element (electrode) or an RF (radio frequency) electrode is embedded in a ring shape, circular shape, etc., and a conductive pad 36, which is an electrode base material electrically connected to the electrode 35, is also embedded. A support 34 in the form of an eyelet is screwed with a thread formed in an opening, and brazing joints are made between the upper electrode rod 31 and the lower electrode rod 32 and between the lower electrode rod 32 and the conductive pad 36 to electrically connect the electrode rods 31 and 32 for power supply and the electrode 35. In such a conventional ceramic susceptor, 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, which is an 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 may also be oxidized due to oxygen penetration. Such oxidation reduces the electrical conductivity and the power transmission efficiency, which may lead to a decrease in the reliability of the electrode portion and shorten the life of the ceramic susceptor.

[0011] To overcome such reliability problems, heat-resistant and oxidation-resistant materials such as Ni or Ni alloys have been mainly used for conventional electrode rods. Since the Ni material applied to conventional electrode rods is a ferromagnetic material, when used as a high-power transmission line in a high-frequency region such as for electrodes, the skin depth becomes small due to the skin effect in the path where electrons move, making it difficult for electrons to move. Therefore, there is a problem of generating impedance and heat and causing a short circuit with the ceramic plate 30, etc.

[0012] In addition, as a conventional electrode rod for improving this, a material with a low magnetic permeability such as Mo may be used, or a coating film for preventing oxidation of the rod material may be applied. However, even in such a case, due to the thermal stress at the interface between the electrode rod metal material such as Mo and the coating film, and the brittle characteristics of the coating material itself, etc., during use in the semiconductor process, the coating film may break (crack), and oxygen may penetrate into the electrode rod metal material due to this, resulting in the problem of promoting the oxidation of the electrode rod metal material.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0013] The inventors of the present invention noted that since Ni or Ni alloy materials are ferromagnetic and have a high relative magnetic permeability (<600), when used as RF (Radio Frequency) rods, as the power and frequency increase, the skin depth in the electrode rod becomes extremely small due to the skin effect, making it difficult for electrons to move, and as a result, it becomes a factor in increasing impedance. Such an increase in the impedance of the electrode rod not only causes a decrease in plasma efficiency because the electrical energy to be consumed in plasma discharge is converted into thermal energy and consumed at the end of the electrode rod, but also the heat generated from the electrode rod forms a hot-spot zone on the surface of the upper end of the ceramic plate holding the substrate, leading to variations in the thickness and thin film quality of the thin film deposited on the substrate, and may become a factor in reducing the yield.

[0014] In addition, the temperature of the ceramic part corresponding to the part where the electrode rod is attached rises locally and suddenly, becoming a decisive factor for the occurrence of an arc due to the breakage of the susceptor and damage to the brazing joint due to thermal shock. Therefore, the impedance problem of the electrode rod must be solved necessarily for increasing the yield of semiconductor elements and improving the durability of the susceptor.

[0015] Accordingly, an object of the present invention is to provide a susceptor including an electrode rod having a low impedance and good high-frequency transmission characteristics with respect to RF current.

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

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

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

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

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

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

[0022] Further, in the present invention, when the material of the electrode rod for the electrode is selected from Mo, W, or their alloys, and a substance having a high specific resistance such as TiN, TiAlCrN, TiAlN, or AlCrN is used for the coating film, as shown in FIG. 9, at a portion where a step portion or a corner portion exists in the joint portion on the extension line of the electrode rod, oxygen penetration into the electrode rod metal material occurs due to cracking of the coating film, and oxidation of the electrode rod metal material progresses, and oxides are concentratedly generated. Focusing on this point, an attempt was made to improve it.

[0023] For the above improvement, an object of the present invention is to provide an electrode rod structure of a ceramic susceptor with improved durability so as to have good high-frequency transmission characteristics in an oxidation-resistant and corrosion-resistant environment, and to provide a ceramic susceptor with a unique position and structure of a joint portion on the extension line of the electrode rod.

Means for Solving the Problems

[0024] To achieve the above technical problems, the present invention provides a susceptor including a ceramic plate on which an electrode is disposed, and including an electrode rod 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 includes a base material of Mo, W or an alloy of these metals, and a metal nitride film covering the surface of the base material. Further, in the present invention, one end of the electrode rod may include a base material exposed surface not covered by the metal nitride film.

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

[0026] Further, 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 specific resistance of the metal nitride film to the specific resistance of the base material is 10 2 or more, 10 3 or more, or 10 4 or more, which is preferable.

[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 problem, 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 includes a first rod and a second rod connected in series. The first rod includes a base material 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] Further, the joint surface of the first rod and the second rod is preferably an exposed surface of the base material not covered by the metal nitride film.

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

[0034] In addition, a susceptor according to another aspect of the present invention for achieving the above object and including a ceramic plate on which an electrode is disposed includes an electrode pad connected to the electrode, and an electrode rod having one side end connected to the electrode pad to supply power to the electrode. The electrode rod includes an extending portion connected to the electrode pad, and a power source connection portion provided at an end of the tapered portion of the extending portion.

[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 taper processing with a machine tool so as to include the tapered portion between the extending portion and the power source connection portion having different diameters.

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

[0038] The length of the tapered portion of the extending portion may be 1.0 mm to 10.0 mm in the longitudinal direction of the extending portion.

[0039] In the tapered portion of the extending portion, the position of the end with the smaller diameter may be a position that is 10% or more lower than the temperature of the lowermost end surface of the ceramic plate.

[0040] Preferably, in the tapered portion of the extending portion, the position of the end with the smaller diameter may be 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 be made of Mo, W, or an alloy thereof as a base material.

[0042] The extending portion 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 formed of a metal material having a thermal expansion coefficient difference of 3 or less from the material of the electrode pad.

[0044] The electrode may be a high-frequency electrode, an electrostatic chuck electrode, or a heating element.

Advantages of the Invention

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

[0046] Further, according to the second aspect of the present invention, since the electrode rod is provided with a resistive surface coating, when RF power is transmitted through the electrode rod, the RF current flows through the base material in the surface coating, so that the heating portion penetrates inside the surface coating of the electrode rod. As a result, the heating portion moves away from the surface of the electrode rod, and the possibility of reacting with oxygen in the atmosphere is reduced.

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

[0048] Moreover, according to the fourth aspect of the present invention, it becomes possible to provide an electrode rod having a surface coating structure that has resistance to heat generation caused by the skin effect.

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

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

[0051] Moreover, according to the seventh aspect of the present invention, it becomes possible to provide a susceptor including a surface coating structure and an integral electrode rod.

[0052] Moreover, according to the eighth aspect of the present invention, among the positions where the electrode rod is separated from the ceramic plate to receive power supply, particularly at the position where the temperature drops significantly during the semiconductor process, a tapered portion AA is positioned, and the shape of the joint is designed to be streamline such as a trapezoid so as not to form a sharp edge, thereby providing a ceramic susceptor with improved durability and lifespan so as to have good high-frequency transmission characteristics for a long time even in an oxidation-resistant and corrosion-resistant environment.

[0053] The accompanying drawings, which are included as a part of the detailed description to assist in understanding the present invention, provide examples of embodiments of the present invention and explain the technical idea of the present invention together with the detailed description.

Brief Description of the Drawings

[0054]

Figure 1

Figure 2A

Figure 2B

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10A

Figure 10B

Figure 11

Figure 12

Figure 13

Mode for Carrying Out the Invention

[0055] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Here, the same reference numerals are used for the same components in each figure as much as possible. Also, detailed descriptions of already known functions and / or configurations are omitted. The content disclosed below focuses on the parts necessary for understanding the operations according to various embodiments, and descriptions of elements that may obscure the gist of the description are omitted. Also, some components of the drawings may be illustrated exaggeratedly, omitted, or schematically. The size of each component does not entirely reflect the actual size, and thus, the content described herein is not limited by the relative sizes and intervals of the components depicted in each figure.

[0056] When describing embodiments of the present invention, if it is determined that specific descriptions of known technologies related to the present invention may obscure the gist of the present invention, the detailed descriptions thereof are omitted. And the terms described below are terms defined in consideration of the functions in the present invention, and they can be changed depending on the intention or convention of the user, operator, etc. Therefore, the definitions should be made based on the content throughout this specification. The terms used in the detailed description are merely for describing the embodiments of the present invention and should never be restrictive. Unless otherwise specified, the singular form expressions include the meanings of the plural forms. In this description, expressions such as "including" or "comprising" are for indicating a certain characteristic, number, step, operation, element, part thereof, or combination, and should not be construed as excluding the existence or possibility of one or more other characteristics, numbers, steps, operations, elements, part thereof, or combination other than those described.

[0057] Note that terms such as first and second may be used to describe various components, but these components are not limited by these terms, and these terms are only used for the purpose of distinguishing one component from another.

[0058] In the specification of the present invention, the nitride film in the "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. Also, in the specification of the present invention, the nitride film of metal element A may be expressed as A nitride film or AN. At this time, the expression A nitride film or AN can refer to a binary metal element nitride film in which a part of metal element A is replaced or substituted with another metal element, or a multi-component metal element nitride film containing still other metal elements. Similarly, the binary metal element nitride film may be expressed as "nitride film of A and B", (A,B)N or ABN, and this expression can refer to a ternary metal element nitride film or a multi-component metal nitride film of ternary or higher containing additional metal elements in addition to A or B. For example, in the specification of the present invention, AlCrN may be used in the sense of including ternary metal nitride films such as AlCrTiN in addition to binary nitride films.

[0059] In the specification of the present invention, the "electrical connection" of two components includes that the two components are directly in contact and electrically connected, or are electrically connected with one or more other components intervening therebetween.

[0060] Also, in the specification of the present invention, terms such as "above" or "on" of an object are used not only to refer to a position in direct contact with the surface of the object, but also to refer to a position where direct contact is not made with other components intervening therebetween.

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

[0062] Referring to FIGS. 2A and 2B, the electrode rod 10 has the shape of an elongated column extending in the longitudinal direction. Here, the shape of the electrode rod is exemplary, and the present invention is not limited thereto, and electrode rods of any shape such as a triangular prism or a quadrangular prism are also possible in addition to a circular column. Also, in the figure, the ends of the electrode rod are flat, but the present invention is not limited thereto, and of course, at least one of the ends of the electrode rod may have a curved surface 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 a low impedance and is paramagnetic. For example, the base material 12 may be composed of paramagnetic Mo, W, or an alloy thereof.

[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] On the other hand, in the present invention, since the metal nitride film 14 of the electrode rod has a higher impedance than the base material, the design of a connection portion for smooth connection of RF current between the electrode rod and other components may be required. For this purpose, in the present invention, one end portion of the electrode rod 10 may include an exposed surface E1 not covered with the metal nitride film 14. Further, the other end portion of the electrode rod 10 may include an exposed surface E2 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 will be described later, the exposed surface E1 can be in direct contact with the conductive pad of the electrode or provide electrical connection to the conductive pad through a conductive material layer such as a bonding material. Further, the other exposed surface E2 can provide electrical connection 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. At this time, the extension width w of the exposed surface may be appropriately designed. Such an extension of the exposed surface may of course be provided at the other end of the electrode rod 10. Of course, the above-described extension of the exposed surface may also 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 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, and the like. In the present invention, the metal nitride film may also be a multilayer film in which layers having different compositions are laminated.

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

[0071]

Table 1

[0072] In the present invention, the specific resistance (@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 Ω·cm or less, 1Ω·cm or less, 1.5Ω·cm or less, 2Ω·cm or less, 5Ω·cm or less, 10Ω·cm or less, or 20Ω·cm or less.

[0073] On the other hand, the ratio of the specific resistance of the metal nitride film to the specific resistance of the base material is 10 2 or more, 10 3 or more, 10 4 or more, or 105 It may be as described above.

[0074] In the specification of the present invention, the specific resistance may be calculated by multiplying the surface resistance value obtained by multiplying the resistance value of the film measured by the four-point probe method by the correction factor (C.F) by the thickness of the film.

[0075] In the present invention, the metal nitride film may further include one or more underlying layers. For example, the underlying layer may be a CrN underlying layer.

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

[0077] For example, Al 1-x Cr x By controlling the atomic ratio of Cr, that is, Cr / (Al + Cr), in the composition of the metal nitride film represented by N (where x is the atomic ratio), the specific resistance of the metal nitride film may be controlled.

[0078] The CrN film formed by arc ion plating exhibits a specific resistance of 3*10 -4 Ωcm. The specific resistance value may vary depending on the content of Al and Cr in Al 1-x Cr x N and the nitrogen concentration during the film formation process. The AlCrN film with x ≒ 0.2 to 0.8 formed by arc ion plating may have a value of 1 to 15 Ω·cm, and the AlCrN film with x ≒ 0.5 may have a value of about 7 to 9 Ω·cm. In the present invention, it is possible to adjust the specific resistance according to the ratio of Al and Cr.

[0079] In the present invention, in order to achieve a preferable specific resistance 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. Further, the x value 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, when summarizing and showing the resistivity measurement values of various metal nitride films formed on the Al2O3 substrate, it is as shown 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 FIG. 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. Further, at both ends of the first rod 10', a base material exposed surface where no metal nitride film is formed is formed. The base material 12' and the metal nitride film 14' may be formed of the same material as the electrode rod 10 described with reference to FIG. 2.

[0084] On the other hand, a second rod 20 is coupled to the front end of the first rod 10'. The first rod 10' and the second rod 20 may be coupled by a joint portion S. The joint portion S may be provided by soldering or brazing an Au-Ni alloy bonding material or an alloy bonding 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. Further, 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 materials as the first base material 12' and the first metal nitride film 14'.

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

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

[0089] As described above with reference to FIG. 3, the case where two electrode rods are connected in series to form an electrode rod assembly has been described. However, the present invention is not limited thereto. For example, an electrode rod assembly composed of three or more electrode rods is also possible. Some or all of the electrode rods constituting these electrode rod assemblies 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] Referring to FIG. 4, the (ceramic) susceptor 100 includes a ceramic plate 110, electrodes 111 embedded in the ceramic plate 110, and electrode pads 112 for electrical connection of the electrodes. The ceramic plate 110 is provided with an opening 190 for exposing the electrode pads, and an electrode rod 10 is coupled to the opening. The electrode rod 10 supplies power (for example, RF (Radio Frequency) power) to the electrodes 111.

[0092] On the other hand, a support eyelet 120 for supporting 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. For this purpose, a thread 191 is formed on a part of the inner peripheral surface of the opening 190, and correspondingly, a coupling structure (for example, a male thread) for fastening with the thread 191 (for example, a female thread) may be provided on the outside of the support eyelet 120.

[0093] On the other hand, although not shown, in the present invention, the ceramic plate 110 may further include, in addition to the electrodes 111, 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. Therefore, in this specification, the structure of the electrode rod 10 of the electrodes 111 will be described, but this structure may be directly applied to the electrode rod for connection between the heating element (not shown) and the electrode rod as well.

[0094] In the present invention, the ceramic plate 110 may be configured such that electrodes 111 and / or a heating element (not shown) are arranged (embedded) at a predetermined interval between ceramic materials. The ceramic plate 110 may be configured to enable heating using a heating element (not shown) and / or a plasma enhanced chemical vapor deposition process using the electrodes 111 while stably holding a substrate to be processed. The ceramic plate 110 may be formed of a plate-like structure having a predetermined shape. As an example, the ceramic plate 110 may be formed of a circular plate-like structure, but is not necessarily limited thereto. Here, the ceramic material may be at least one substance among 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 preferably may be 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 bonding such as soldering or brazing.

[0096] In the present invention, the electrodes 111, the electrode pads 112, the support eyelets 120, the heating element (not shown), etc. may be formed 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 alloys thereof.

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

[0098] On the other hand, molybdenum, tungsten, and alloys thereof, which are the base materials of the electrode rod, exhibit characteristics of easily reacting with oxygen and oxidizing compared to Ni or Ni alloys. For this reason, when the base material generates heat due to the application of an RF current, the electrode rod oxidizes and deteriorates.

[0099] To solve such problems, the present invention provides a metal nitride film on the surface of the base material of the electrode rod 10. Also, in the present invention, a metal nitride film is formed on the outer peripheral surface of the electrode rod, but not on the end portion where the electrode rod is connected to other components. Thereby, the electrode rod can provide a good electrical connection with adjacent components and at the same time complement the oxidation resistance characteristics of the base material.

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

[0101] Also, in the present invention, the metal nitride film may be appropriately designed according to the frequency and power of the RF current drawn into the electrode rod. When the RF power frequency increases, the skin depth of the base material decreases, and the amount of heat generated on the surface of the base material 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 about 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, in an environment where an RF power frequency of 10 to 40 MHz is used (for example, 13.56 MHz, 27.12 MHz, etc.), the thickness of the metal nitride film is preferably in the range of 4 to 10 μm.

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

[0105] Further, a second conductive filler 152 for filling the space between the support eyelet 120 and the electrode rod 10 may be provided around the electrode rod 10 inserted inside the support eyelet 120. The first and second conductive fillers 151, 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] Referring to FIG. 5, the susceptor has substantially the same configuration except that the electrode rod 10 in FIG. 3 is the electrode rod assembly 10 described in connection with FIG. 2. The electrode rod assembly 1 includes the first rod 10' and the second rod 20 joined by brazing 162 described in connection with FIG. 2. Since each configuration has been described in FIG. 2, the description thereof is omitted. On the other hand, as described above, the second rod 20 does not necessarily need to be provided with the metal nitride film 24.

[0109] Figure 6 is a flowchart of a metal nitride film forming process for an electrode rod of a susceptor according to an embodiment of the present invention. In this embodiment, the case of forming an AlCrN film as the metal nitride film is illustrated.

[0110] Referring to Figure 6, in the present invention, various deposition methods, such as PVD (Physical Vapor Deposition) methods like arc ion plating, may be applied to the AlCrN forming process.

[0111] As shown in the figure, the film of the electrode rod 10 may be formed including a plasma pretreatment step (S110), an adhesion layer forming step (S120), and a reactive 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 the electrode rod is loaded into arc ion plating equipment or sputtering equipment, and the surface of the base material 12 of the electrode rod is cleaned by plasma pretreatment at a vacuum degree of 1x10 -5 Torr (133.3×10 -5 Pa) or less. This is to ensure that the adhesion layer and the metal nitride film are optimally coated in subsequent steps.

[0113] Next, the adhesion layer forming step (S120) is for reducing the internal stress of the formed metal nitride film and achieving good adhesion. The adhesion layer may include a metal such as Cr or an alloy thereof. Preferably, the adhesion layer may include 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, in arc ion plating or sputtering equipment, a CrN layer may be deposited on the surface of the base material 12 of each electrode rod as an adhesive layer with a thickness of 0.1 to 4.0 μm. At this time, a Cr target may be pre-loaded into the arc ion plating or sputtering equipment, and while injecting nitrogen into the reactor, the CrN layer may be formed on the surface of the base material 12 of the electrode rod in a PVD method at a predetermined degree of vacuum.

[0115] In the reactive evaporation process (S130), an Al and Cr target or an Al-Cr alloy target is loaded into the arc ion plating equipment, and while injecting nitrogen into the reactor, in a PVD method at a vacuum degree of about 1×10 -2 Torr (133.3×10 -2 Pa), AlCrN is formed to a thickness of 1.0 to 10.0 μm. In the case of an AlCr alloy target, it may be an AlCr alloy target containing aluminum (Al) and chromium (Cr) in predetermined ratios (for example, 7:3 at%). In contrast, when using an Al target and a Cr target, the Al / Cr ratio can be adjusted by changing the current of each target.

[0116] As described above, the ends of the base materials may be appropriately masked so that the metal nitride film is not formed at the ends of the electrode rods 10, 10'. For example, the ends of the base materials may be masked by providing an adhesive tape or a photoresist film on the ends of the base materials or by using a jig. In contrast, it goes without saying that the exposed surface of the electrode rod can 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: Specific Resistance Measurement Experiment of AlCrN Film> Using alloy targets with different Al and Cr contents, an AlCrN film with an area of 30 mm × 30 mm and a thickness of 5 - 7 μm was formed on the surface of an Al2O3 substrate by arc ion plating. The ratios of Al and Cr in the AlCrN films formed for each target were analyzed by EDS, and the resistivity of the AlCrN films was measured by the four-point probe method using the Loresta-GP equipment of Mitsubishi Chemical. The resistivity of the AlCrN films showed 1 - 15 Ω·cm.

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

[0119]

Table 3

[0120] <Experimental Example 2: Experiment on Measuring RF Power Loss of Electrode Rods> RF power losses were measured for rods with a diameter of Φ4 × 330 mm having different materials and film compositions. As the rods to be measured, Ni rods, Mo rods, AlCrN / Mo rods with an AlCrN film on their surfaces, W rods, and AlCrN / W rods with an AlCrN film on their surfaces were used. The composition of the AlCrN film was the same as that of #2 in Experimental Example 1.

[0121] Figure 7 is a diagram showing the results of the power loss measurement. As shown in Figure 6, in the RF (Radio Frequency) power loss rate calculated based on the actually measured impedance values, taking the loss rate of Ni as a reference, it can be confirmed that for Mo or AlCrN / Mo having an AlCrN film on its surface, W or AlCrN / W having an AlCrN film on its surface, the loss rate is reduced by about 40% compared to Ni. From such results, it can be seen that in terms of power loss, the electrode rods of Mo, W, AlCrN / Mo, and AlCrN / W show excellent characteristics compared to Ni.

[0122] <Experimental Example 3: Oxidation Resistance Characteristics of Electrode Rods> The oxidation resistance characteristics of electrode rods with a diameter of Φ2 × 330 mm were confirmed according to their materials and film compositions.

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

[0124] Each rod was subjected to an oxidation treatment at 700 °C for 10 hours in a box furnace. The resistance values of each rod were measured before and after the oxidation treatment. The measurement was performed under the condition of INT10mΩ using a measurement equipment of Resistance Meter (RM3545) manufactured by HIOKI.

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

[0126] From Figure 8, it can be confirmed 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 confirmed that the resistance change rate before and after the heat treatment is low and the resistance value is also low.

[0127] On the other hand, in the present invention, the susceptor is a semiconductor device for processing various target substrates for processing purposes such as semiconductor wafers, glass substrates, and flexible substrates. As described below, the target substrate is provided with an electrode 111 that functions as a high-frequency electrode for process treatments such as dry etching using plasma or plasma-enhanced chemical vapor deposition. In addition, the electrode 111 may also be used as a chuck electrode for use in an electrostatic chuck to support the target substrate. In the present invention, the susceptor may further include a heating wire (or, a heating element / heating electrode) for heating the target substrate to a predetermined temperature.

[0128] As the electrode (or conductor) 111, a high-frequency electrode, an electrostatic chuck electrode, a heating wire, etc. may be made of a conductive metal material such as silver (Ag), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), tungsten (W), molybdenum (Mo), and titanium (Ti), or an alloy thereof. The electrode as the high-frequency electrode may be supplied with power in a semiconductor manufacturing process to enable process treatment such as plasma-enhanced chemical vapor deposition on a substrate located on the upper surface of the susceptor. Further, the electrode as the electrostatic chuck electrode may receive a bias of power in a semiconductor manufacturing process to generate an electrostatic force, and can chuck a substrate located on the upper surface of the susceptor. When unloading the substrate, an opposite bias may be applied to cause discharge so that de-chucking is performed. Further, the heating wire (or heating element / heating electrode) may be formed in a plate-like coil form or a flat plate form by a resistance wire having a predetermined resistance, and may be formed in a multilayer structure for precise temperature control. Such a heating wire (or heating element / heating electrode) may be supplied with power and have a function of heating a substrate located on the upper surface of the susceptor to a constant temperature in order to perform a smooth deposition process and etching process in a semiconductor manufacturing process.

[0129] Therefore, hereinafter, in the present invention, the case where the electrode 111 of the ceramic susceptor functions as the high-frequency electrode to which high-frequency (RF) power is supplied via the electrode rod will be taken up and described. However, the present invention is not limited thereto. In the present invention, it is clarified in advance that when the electrode of the ceramic susceptor is a chuck electrode having an electrostatic chuck function, or when power is supplied to an additional heating element via the electrode rod, related explanations can be similarly applied.

[0130] Hereinafter, another aspect of the present invention will be described with reference to the attached FIGS. 10A to 13. At this time, in the drawings, the same reference numerals are assigned to the same components. Also, even if the reference numerals are not the same, if the names of the components are the same, the components may be the same structure and may have the same function. In particular, the same components in the descriptions regarding FIGS. 2A to 8 are further applicable to FIGS. 10A to 13, and detailed descriptions of the same functions and / or configurations described above will be omitted. Also, the same components in the descriptions regarding FIGS. 10A to 13 may be further applied to FIGS. 2A to 8.

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

[0132] Referring to FIG. 10A, a ceramic susceptor 100 according to still 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 extending portion 130 including a first rod 131 and a second rod 132.

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

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

[0135] FIG. 10B is a diagram for explaining the structure of the ceramic susceptor 200 according to still another embodiment of the present invention. In this case, it is a case where one rod is connected to the electrode pad 112 and extends to the power supply connection portion 133.

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

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

[0138] That is, as shown in FIGS. 10A and 10B, the electrode rod assembly 150 of the present invention may include an extension 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 130 / 131.

[0139] In addition, the ceramic susceptor 100 may include a support eyelet 120 that couples to the electrode rod assembly 150. For example, the electrode rod assembly 150 may be coupled to a support eyelet 120 fastened to the threads 191 of the ceramic plate 110 at the electrode 111.

[0140] On the other hand, as described above, although not shown in the drawings, 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, the structure related to the electrode rod assembly 150 of the electrode 111 will be described, but it is clear that such a structure may be directly 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 electrode 111 and / or the heating element (electrode) are arranged (embedded) at a predetermined interval between the ceramic materials. The ceramic plate 110 is configured to enable heating using the heating element (electrode) and / or an electrostatic chuck function using the electrode 111 and semiconductor processes using plasma while stably holding the substrate to be processed placed on the upper surface SS. The ceramic plate 110 may be formed as a plate-like structure having a predetermined shape. As an example, the ceramic plate 110 may be formed as a circular plate-like structure, but is not necessarily limited thereto. Here, the ceramic materials are Al2O3, Y2O3, Al2O3 / Y2O3, ZrO2, AlC (Autoclaved lightweight concrete), TiN, AlN, TiC, MgO, CaO, CeO2, TiO2, B x C yIt may be at least one of BN, SiO2, SiC, YAG, mullite, AlF3, and preferably may be aluminum nitride (AlN). Each ceramic powder may selectively contain about 0.1 to 10%, preferably about 1 to 5% of yttrium oxide or MgO, TiO2 powder, etc.

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

[0143] The electrode 111, the electrode pad 112, the electrode rod assembly 150, the support eyelet 120, etc. may be made of a conductor, for example, formed of tungsten (W), molybdenum (Mo), silver (Ag), platinum (Pt), palladium (Pd), nickel (Ni), gold (Au), niobium (Nb), titanium (Ti) or their alloys.

[0144] In particular, in the present invention, the electrode rod assembly 150 preferably has a low impedance and is paramagnetic. For example, the electrode rod assembly 150 may be made of a base material of Mo, W or their alloys, and an oxidation-resistant film is 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 a Mo, W or their alloy material, and the second rod 132 may be made of an Fe-Ni-Co alloy (for example, a Kovar product) material. Also, for example, in FIG. 10B, the extending 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 a Mo, W or their alloy material.

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

[0146] In the ceramic susceptor 100 of the present invention having the structure of 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 that are connected by brazing. The first rod 131 and the second rod 132 may be formed as an integrated single rod as the extending portion 130, or may have a structure in which the first rod 131 and the second rod 132 are joined in this way. One end face of the second rod 132 may be brazed to the electrode pad 112 and the first conductive filler 151, and the first rod 131 may be brazed to the other end face of the second rod 132 and the second conductive filler 162. For example, an Au-Ni metal filler or the like may be used as the conductive fillers 151 and 162. A conductive filler 152 for filling the space between the support eyelet 120 and the rods 131 and 132 may be provided around the rods 131 and 132 inserted inside the support eyelet 120.

[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, it may cause heat loss and thermal stress. Therefore, in order to prevent heat loss and reduce the occurrence of cracks due to thermal stress, as described above, it is preferable that the difference in the coefficient of thermal expansion from the material of the electrode pad 112 is 3 or less for the metal material. In particular, in the present invention, in preparation for oxidation (corrosion), a metal nitride film 141, 142 may be included on the surface of the electrode rod assembly 150, that is, a metal nitride film 141 on the surface of the second rod 132 and a metal nitride film 142 on the surface of the first rod 131. In some cases, the metal nitride film 141 on the surface of the second rod 132 may not be necessary, but if necessary, the metal nitride film 141 can also be formed on the surface of the second rod 132.

[0148] In addition to this, the electrode rod assembly 150 has different diameters from the extending portions 131, 132 (130), extends to the end of the extending portion 130, and includes a power supply connection portion 133 formed by taper processing.

[0149] For each brazing joint as described above, first, the first conductive filler 151 is pre-injected around the bottom surface of the opening 190, that is, around the exposed portion of the electrode pad 112, and the second rod 132 is pushed into the inside of the support eyelet 120 to bring the one-side end surface of the second rod 132 into close contact with the electrode pad 112. Next, the second conductive filler 162 is sufficiently injected onto the other-side end surface of the second rod 132, and after the one-side end surface of the first rod 131 is brought into close contact with the injected second conductive filler 162 and heated at a high temperature, it is cooled.

[0150] Also in the ceramic susceptor 200 of the present invention having the structure of FIG. 10B, except that the second rod 132 is omitted, in a similar manner to the above method, the one-side end surface of the first rod or the extending portion 131 composed of a single first rod 131 may be brazed to the electrode pad 112 by the first conductive filler 151. A conductive filler 152 for filling the space between the support eyelet 120 and the rod 131 may be provided around the rod 131 inserted inside the support eyelet 120.

[0151] Using such a ceramic susceptor 100 / 200 of the present invention, the power connection part 133 of the electrode rod assembly 150 is connected to a power source, and power is supplied to the electrode 111 via the electrode pad 112, so that semiconductor processes such as dry etching using plasma or plasma-enhanced chemical vapor deposition, or the function of an electrostatic chuck can be achieved, and a substrate to be processed (for example, a semiconductor wafer, a glass substrate, a flexible substrate, etc.) can be heated in a semiconductor process using heat (or high frequency) generated from a heating element (electrode).

[0152] In particular, the electrode rod assembly 150 may be made of Mo, W, or an alloy containing one or more of these in a weight ratio (wt%) larger than other metal substances (for example, MoW, MoNi, WNi, etc.). By including metal nitride films 141, 142 on the surface of the electrode rod assembly 150 in preparation for oxidation (corrosion), oxidation of the electrode rod assembly 150 can be effectively prevented, and factors causing an increase in impedance as it is used are removed. By reducing changes such as an increase in the impedance of such an electrode rod assembly 150 and removing energy loss converted into thermal energy in the electrode rod assembly 150, electrical energy can be efficiently consumed in plasma discharge. Also, by reducing the heat generated from the electrode rod assembly 150, a hot-spot zone is not formed on the upper end surface of the ceramic plate 110 that holds the substrate. Therefore, the thickness and thin film quality uniformity of the thin film deposited on the substrate can be improved, and the yield can be increased. Also, by removing the temperature rise of the ceramic part in contact with the part where the electrode rod assembly 150 is tightened, breakage of the ceramic susceptor 100 due to thermal shock can be reduced, and arc generation at the brazing joint can be reduced. Therefore, the reduction in impedance change of the electrode rod assembly 150 in the present invention can provide a ceramic susceptor 100 with improved durability and contribute to an increase in the yield of semiconductor elements.

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

[0154] Referring to FIG. 11, as described above, the power connection portion 133 is provided at the end of the tapered portion AA of the extending portion 130 / 131 of the electrode rod assembly 150. That is, the tapered portion AA may be formed by taper processing with a machine tool so as to include the tapered portion AA between the extending portions 130 / 131 and the power connection portion 133 having different diameters. The machine tool may include a processing device using various methods such as milling, lathe, MCT (Machining CenTer), CNC (Computer Numerical Control), and laser.

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

[0156] Also, the inclination angle θ of the tapered portion AA of the extending portion 130 / 131 may be 10° to 80° with respect to the longitudinal direction of the extending 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 streamline connection. More preferably, the inclination angle θ may be 12° to 16°. Thereby, the cross section in the longitudinal direction of the tapered portion AA of the extending portion 130 / 131 may be trapezoidal.

[0157] Also, the position of the end with the smaller diameter in the tapered portion AA of the extending portion 130 / 131 may be determined at a predetermined position for improving oxidation resistance and corrosion resistance. The position of the end with the smaller diameter in the tapered portion AA of the extending portion 130 / 131 is, for example, when starting the ceramic plate 110, that is, when operating the heating element (electrode) (or when there is no heating element, an external heater can be used), it may be a position that is 10% or more lower compared to the temperature of the ceramic plate 110, that is, the temperature of the lowermost end surface (see BB in FIG. 12) of the ceramic plate 110 (for example, 650 °C, 550 °C, 450 °C, etc.), and preferably a position that is 20% or more lower.

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

[0159] That is, among the positions separated from the ceramic plate 110, the tapered portion AA is placed at a position where the temperature drops significantly during the semiconductor process, and it is possible to prevent oxidation or corrosion due to the high temperature that may occur during use in the brazing joining or vapor deposition process at this portion.

[0160] FIG. 12 shows an example in which the ceramic susceptor 100 of the present invention is installed in the process chamber 300 of 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 semiconductor processes such as plasma enhanced chemical vapor deposition. The ceramic susceptor 100 / 200 may be installed to be supported by a shaft 310 having through holes inside and a predetermined connection mount 320.

[0162] In the ceramic susceptor 100 / 200, electrode rods 130 / 132 connected to the electrode pads 112 of the ceramic plate 110 may penetrate through the inside of the shaft 310, penetrate through the connection mount 320, and extend to the outside of the chamber 300. That is, the power connection portion 133 of the electrode rod 130 / 132 extends to the outside of the chamber 300, and the periphery of the end PP of the power connection portion 133 is connected to the connecting means of the power supply, and can receive the supply of the required power.

[0163] In such a chamber 300, the heating elements and the like of the ceramic plate 110 described above operate, and the ceramic plate 110 is started so that the temperatures become 650 °C, 550 °C, and 450 °C respectively. As a result of measuring the temperature at positions A, B, C, D, E, and F while descending at predetermined intervals downward from the outer position A of the shaft 310 aligned with the lowermost end surface BB, it was confirmed that a linear temperature decrease was shown as in Table 4 below. The susceptor sample used here had a total length of the electrode rod assembly 150 of about 330 mm, a diameter of the extending portions 131, 132 of 4.6 mm, and a diameter of the power connection portion 133 of 4 mm. Also, the length LL of the tapered end AA was 2.5 mm, and the inclination angle θ was 13.7°.

[0164]

Table 4

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

[0166] Therefore, in the above cases, the position of the smaller-diameter end in the tapered portion AA of the extension part 130 / 131 may be arranged at positions C, D, E, and F, and preferably at positions D, E, and F.

[0167] Thereby, the tapered portion AA is arranged at a position where the temperature is 10% or more lower than the temperature of the ceramic plate 110, and the oxidation resistance and corrosion resistance of the electrode rod assembly 150 can be improved.

[0168] In this way, in the ceramic susceptor 100 according to the present invention, the tapered portion AA is positioned at a position where the temperature drops significantly during the semiconductor process, particularly at a position where the electrode rod assembly 150 is separated from the ceramic plate 110 to receive power supply. By designing the shape of the tapered portion AA to be streamline such as a trapezoid so as not to form a sharp inclined edge, the durability is improved so as to have good high-frequency transmission characteristics for a long time even in an oxidation-resistant and corrosion-resistant environment, and a long service life can be guaranteed.

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

[0170] Referring to FIG. 13, first, in order to form films on the electrode rod assemblies 150 respectively, a PVD (Physical Vapor Deposition) method such as arc ion plating may be applied to the surface of the base material of the electrode rod assemblies 150 made of Mo, W or their alloys to form the respective metal nitride films 141, 142. As shown in the figure, the film of the electrode rod assembly 150 may be formed including a plasma pretreatment step (S110), a step of forming an adhesive layer 145 (S120), and a reactive evaporation step (S130).

[0171] First, in the plasma pretreatment step (S110), the base material of the electrode rod assembly 150 is loaded into an arc ion plating equipment or a sputtering equipment before the adhesive layer 145 is formed, and the surface of the base material of the electrode rod assembly 150 is cleaned by plasma pretreatment at a vacuum degree of 1×10 -5 Torr or less. This is to optimally coat the adhesive layer 145 and the metal nitride films 141, 142 in subsequent steps. Here, the electrode rod assembly 150 may be a rod in which the extending portions 130 / 131, the tapered portion AA, and the power connection portion 133 are previously formed.

[0172] Next, the adhesive layer forming step (S120) is a step for reducing the internal stress of the metal nitride films 141, 142 and for good adhesion. The adhesive layer 145 may include a metal such as Cr or its alloy. Preferably, the adhesive 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 as the adhesive layer 145 on the base material surface of the extending portions 130 / 131 of each electrode rod assembly 150 with a thickness of 0.1 to 4.0 μm by arc ion plating or sputtering equipment. At this time, a Cr target is pre-loaded into the arc ion plating or sputtering equipment, and while nitrogen is injected into the reactor, the CrN layer is formed on the base material surface of the extending portions 130 / 131 of the electrode rod assembly 150, that is, the tapered portion AA of the electrode rod assembly 150 and the extending portions 130 / 131 including the power supply connection portion 133, by PVD method at a predetermined degree of vacuum.

[0174] In the reactive vapor deposition step (S130), an Al target and a Cr target are pre-loaded into the arc ion plating equipment or sputtering equipment, or an AlCr alloy target or the like is loaded, and while nitrogen is injected into the reactor of the arc ion plating equipment or sputtering equipment, the metal nitride films 141, 142 are formed to a thickness of 1.0 to 10.0 μm by PVD method at a degree of vacuum of about 1×10 -2 Torr. The AlCr alloy target may be an AlCr alloy target in which aluminum (Al) and chromium (Cr) are alloyed at a predetermined ratio (for example, 7:3 at%). In contrast, when using an Al target and a Cr target, the ratio of Al and Cr required for the formation of the metal nitride films 141, 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 positions the tapered portion AA at a position where the electrode rod assembly 150 is separated from the ceramic plate 110, particularly at a position where the temperature drops significantly during the semiconductor process. It is designed in a streamline shape such as a trapezoid so as not to form an edge with a steep slope, improving durability so as to have good high-frequency transmission characteristics for a long time even in an oxidation-resistant and corrosion-resistant environment, and enabling a long life to be guaranteed.

[0176] As described above, the present invention has been described with specific matters such as specific components, limited embodiments, and drawings, but this is only provided to assist in a more general understanding of the present invention. The present invention is not limited to the above embodiments, and those with ordinary knowledge in the field to which the present invention pertains can make various modifications and deformations without departing from the essential characteristics of the present invention. Therefore, the idea of the present invention should not be defined only by the described embodiments, and not only the scope of the following claims, but also any technical idea with a modification equivalent or equivalent to this scope of claims should be interpreted as being included in the scope of rights of the present invention.

Explanation of Reference Numerals

[0177] 1,150 Electrode rod assembly 10,10’ Electrode rod 12,12’,22 Base material 14,14’,24,141,142 Metal nitride film 100 Susceptor 110 Ceramic plate 111 Electrode 112 Electrode pad 120 Support eyelet

Claims

1. A susceptor including a ceramic plate on which a high-frequency electrode is disposed, comprising an electrode rod having one end electrically connected to the high-frequency electrode and the other end electrically connected to a power source to supply power to the high-frequency electrode, wherein the electrode rod comprises a base material of Mo, W, or an alloy of these metals, and a metal nitride film covering the surface of the base material, and one end of the electrode rod includes an exposed surface of the base material not covered by the metal nitride film.

2. The susceptor according to claim 1, wherein the metal nitride film includes an AlCrN film.

3. The susceptor according to claim 2, wherein the atomic ratio of Cr / (Al + Cr) in the AlCrN film is 0.1 to 0.

9.

4. The susceptor according to claim 1, wherein the metal nitride film includes at least one nitride film selected from the group consisting of AlCrSiN, AlCrSiWN, and AlTiCrN.

5. The ratio of the specific resistance of the metal nitride film to the specific resistance of the base material is 10 ２ or more. The susceptor according to claim 1.

6. The ratio of the specific resistance of the metal nitride film to the specific resistance of the base material is 10 ３ or more. The susceptor according to claim 1.

7. The ratio of the resistivity of the metal nitride film to the resistivity of the base material is 10 ４ or more. The susceptor according to claim 1.

8. The susceptor according to claim 1, further including a CrN underlayer between the base material and the metal nitride film.

9. The susceptor according to claim 1, wherein the thickness of the metal nitride film is 1.0 to 10.0 μm.

10. A susceptor including a ceramic plate on which a high-frequency electrode is disposed, comprising an electrode rod assembly having one end electrically connected to the high-frequency electrode and the other end electrically connected to a power source to supply power to the high-frequency electrode, wherein the electrode rod assembly includes a first electrode rod and a second electrode rod connected in series, wherein the first electrode rod comprises a base material of Mo, W, or an alloy of these metals, and a metal nitride film covering the surface of the base material, and one end of the first electrode rod is an exposed surface of the base material not covered by the metal nitride film.

11. The susceptor according to claim 10, wherein the first electrode rod and the second electrode rod are joined by a joining material.

12. The susceptor according to claim 11, wherein the joining surface of the first electrode rod and the second electrode rod is an exposed surface of the base material not covered by the metal nitride film.

13. The susceptor according to claim 10, wherein the second electrode rod includes a base material made of Kovar.

14. The susceptor according to claim 10, wherein the metal nitride film includes an AlCrN film.

15. The susceptor according to claim 14, wherein the atomic ratio of Cr / (Al + Cr) of the AlCrN film is 0.1 to 0.

9.

16. The susceptor according to claim 10, wherein the metal nitride film contains at least one nitride film selected from the group consisting of AlCrSiN, AlCrSiWN, and AlTiCrN.

17. The ratio of the specific resistance of the metal nitride film to the specific resistance of the base material is 10 ２ or more. The susceptor according to claim 10.

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