Ceramic susceptor

Abstract

To provide a ceramic susceptor.SOLUTION: The susceptor includes an insulating plate in which a heating element is disposed, and a shaft joined to a bottom portion of the insulating plate. The heating element includes a first heating element pattern including a first resistance section and a first connecting section connected between a first pair of terminals. In a plan view of the first resistance section projected onto the insulating plate, the first resistance section includes a first central resistance section disposed within a smaller diameter region than a joint portion between the insulating plate and the shaft.SELECTED DRAWING: Figure 3A

Description

Technical Field

[0001] The present invention relates to a ceramic susceptor, and particularly to a ceramic susceptor for improving temperature uniformity and enhancing the lifespan of a heater pattern.

Background Art

[0002] Generally, semiconductor devices or display devices are manufactured by a method of 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 them. These thin film layers are sequentially deposited on the substrate by a Chemical Vapor Deposition (CVD) process or a Physical Vapor Deposition (PVD) process. The CVD process includes a Low Pressure CVD (LPCVD) process, a Plasma Enhanced CVD (PECVD) process, a Metal Organic CVD (MOCVD) process, and the like. Such CVD devices and PVD devices are provided with a ceramic susceptor for supporting a glass substrate, a flexible substrate, a semiconductor wafer substrate, etc., and generating predetermined heat or generating plasma by a radio frequency (RF) electrode. The ceramic susceptor is widely used in a plasma deposition process or the like in accordance with accurate temperature control and heat treatment requirements for high-precision processes such as wiring miniaturization of semiconductor elements, and is also used for plasma formation and substrate heating in an etching process of a thin film layer formed on a semiconductor wafer substrate or a baking process of a photoresist.

[0003] A general ceramic susceptor includes a heating element for heater function disposed between ceramic materials. In a ceramic susceptor structure, when the heating element receives power supply and generates heat to heat a semiconductor wafer substrate or the like, the temperature uniformity of the substrate is important for improving the yield by a stable semiconductor process.

[0004] Figure 1 illustrates a typical heating element pattern for a conventional ceramic susceptor.

[0005] Referring to Figure 1, conventional ceramic susceptors generally include a heating element pattern 10 that extends in an arc from a central terminal pair 10a, 10b on the same plane. Conventional heating element patterns 10 include a hairpin section 20, which is a section that bends sharply due to bending in a narrow central area. That is, the radius of curvature of the hairpin section 20 near the terminal pair 10a, 10b is smaller than the radius of curvature of the adjacent bent section, resulting in a sharp curve.

[0006] However, these hairpin sections 20 are regions with high pattern density and high heat generation density per unit area, making them prone to cracking after prolonged use. This is due to thermal stress caused by the difference in thermal expansion coefficients of the heating elements embedded in the ceramic material. Ceramic susceptors used in semiconductor processes, particularly in the vapor deposition process, are exposed to repeated heat cycle environments, causing cracks to continuously develop on the surface of the ceramic susceptor, leading to a decrease in its function and rendering it unusable. [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, the present invention was devised to solve the above-mentioned problems, and the object of the present invention is to provide a ceramic susceptor that improves temperature uniformity over the entire surface of the susceptor and improves the lifespan of the heater pattern by forming a heating element pattern without hairpin sections in the central part of the susceptor plate where the density of embedded heating elements is high. [Means for solving the problem]

[0008] First, to summarize the features of the present invention, a susceptor according to one aspect of the present invention for achieving the above objective includes an insulating plate on which a heating element is arranged; and a shaft joined to the lower part of the insulating plate, wherein the heating element includes a first heating element pattern including a first resistive portion and a first connecting portion connected between a first pair of terminals, and the first resistive portion may include a first central resistive portion located in a diameter region smaller than the joint portion between the insulating plate and the shaft in a plan view when the insulating plate is projected onto the first resistive portion.

[0009] The first resistive section includes a plurality of circular arc sections connected in the circumferential direction and a plurality of bent sections connecting the circular arc sections, and the curve of the first central resistive section may be formed to intersect with the extension of a virtual straight line passing through the spaced-out area between adjacent bent sections.

[0010] The first resistive section includes a plurality of circular arc sections connected in the circumferential direction and a plurality of bent sections connecting the circular arc sections, and the curve of the first central resistive section may be formed to meet a virtual extension line extending from the bent section closest to the first central resistive section.

[0011] The curve of the first central resistor may be formed such that the radius of curvature of a portion close to one of the first terminal pairs is larger than the radius of curvature at the bent portion of the first resistor.

[0012] The radius of curvature of a portion of the first terminal pair closest to any one of them may be twice or more the maximum radius of curvature of the bent portion of the first resistor.

[0013] The curve of the first central resistance portion may be formed such that the radius of curvature of a portion close to one of the first terminal pairs is larger than the radius of curvature of the nearest adjacent bent portion of the first resistance portion.

[0014] The curve of the first central resistance section may be formed such that the radius of curvature of a portion close to one of the first terminal pairs is larger than the radius of curvature of the nearest adjacent bent portion of the first resistance section, and the curve of the second central resistance section may be formed such that the radius of curvature of a portion close to one of the second terminal pairs is larger than the radius of curvature of the nearest adjacent bent portion of the second resistance section.

[0015] The first terminal pair may be positioned within a diameter region smaller than the joint between the insulating plate and the shaft.

[0016] The heating element includes a second heating element pattern comprising a second resistive portion and a second connecting portion connected between a second pair of terminals, and may include a second central resistive portion of the second resistive portion, which is arranged in a plan view when the insulating plate is projected onto the first resistive portion and the second resistive portion within a diameter region smaller than the joint portion between the insulating plate and the shaft.

[0017] The second resistive section includes a plurality of circular arc sections connected in the circumferential direction and a plurality of bent sections connecting the circular arc sections, and one or more of the curves of the first central resistive section and the curves of the second central resistive section may be formed to intersect with the extension of a virtual straight line passing through the spaced-out area between adjacent bent sections.

[0018] The adjacent bent portions may include bent portions adjacent to the bent portion of the first resistor and the bent portion of the second resistor.

[0019] The second resistive section includes a plurality of circular arc sections connected in the circumferential direction and a plurality of bent sections connecting the circular arc sections, and one or more of the curves of the first central resistive section and the curves of the second central resistive section may be formed to meet a virtual extension line extending from the bent section of the first central resistive section that is closest to the first central resistive section or the second central resistive section.

[0020] The second resistance part includes a plurality of arc parts connected in the circumferential direction and a plurality of bending parts connecting the arc parts, and one or more of the curves of the first central resistance part and the curve of the second central resistance part may be formed so as to meet a virtual extension line extending from the bending part of the second central resistance part closest to the first central resistance part or the second central resistance part.

[0021] The second resistance part includes a plurality of arc parts connected in the circumferential direction and a plurality of bending parts connecting the arc parts, and one or more of the curves of the first central resistance part and the curve of the second central resistance part may be formed so as to meet the respective virtual extension lines extending from the bending parts of the first central resistance part and the second central resistance part closest to the first central resistance part and the second central resistance part, respectively.

[0022] The curves of the first central resistance part and the curve of the second central resistance part may be formed such that the radius of curvature of a part close to any one of the respective terminal pairs is larger than the radius of curvature at the bending parts of the first resistance part and the second resistance part, respectively.

[0023] The radius of curvature of a part close to any one of the respective terminal pairs may be at least twice the maximum radius of curvature of the bending parts of the first resistance part and the second resistance part.

[0024] The second terminal pair may be arranged in a diameter region smaller than the joint part of the insulating plate and the shaft.

Advantages of the Invention

[0025] According to the ceramic susceptor of the present invention, by forming a heating element pattern without a hairpin section in the central part of the susceptor plate with a high embedding density of the heating element, the temperature uniformity can be improved in the entire area of the upper surface of the susceptor, and the life of the heater pattern can be extended very much.

Brief Description of the Drawings

[0026] The accompanying drawings, which are included as a part of the detailed description to assist in understanding the present invention, provide examples of embodiments according to the present invention and explain the technical idea of the present invention together with the detailed description.

[0027] [Figure 1] It is a diagram illustrating a heating element pattern of a conventional ceramic susceptor. [Figure 2] It is a schematic cross-sectional view showing a ceramic susceptor according to an embodiment of the present invention. [Figure 3A] It is an example of a heating element pattern of the ceramic susceptor of the present invention. [Figure 3B] It is a diagram for explaining a sharp curve portion of the curve of the conventional resistance portion in FIG. 1. [Figure 3C] It is a diagram for explaining a change in the curve of the central resistance portion (910) of the present invention. [Figure 4A] It is an example of a two-zone arrangement structure of a heating element pattern of the ceramic susceptor of the present invention. [Figure 4B] It is another example of a two-zone arrangement structure of a heating element pattern of the ceramic susceptor of the present invention. [Figure 5A] It is an enlarged view of the PP1 portion in FIG. 4A. [Figure 5B] It is an enlarged view of the PP2 portion in FIG. 4B.

Mode for Carrying Out the Invention

[0028] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Here, the same reference numerals are given to 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 explaining the necessary parts for understanding the operations according to various embodiments, and omits explanations of elements that may obscure the gist of the explanation. In addition, some components in the drawings can be illustrated exaggeratedly, omitted, or schematically. The sizes of the components do not fully reflect the actual sizes, and therefore the content described here is not limited by the relative sizes and intervals of the components depicted in each figure.

[0029] When describing embodiments of the present invention, detailed descriptions of prior art related to the present invention will be omitted if it is determined that such descriptions may obscure the gist of the invention. Furthermore, the terms described below are defined in consideration of the function in the present invention and are subject to change depending on the intent or convention of the user or operator. Therefore, their definitions should be based on the content throughout this specification. The terms used in the detailed description are solely for the purpose of describing embodiments of the present invention and should not be restrictive. Unless otherwise specified, singular expressions include the meaning of plural expressions. In this description, expressions such as "includes" or "equip" are intended to indicate a certain characteristic, number, stage, operation, element, part thereof or combination thereof, and should not be construed as excluding the existence or possibility of one or more other characteristics, numbers, stages, operations, elements, part thereof or combination thereof that are not described.

[0030] Furthermore, terms such as "first," "second," etc., may be used to describe various components, but these terms do not limit the various components mentioned above; rather, they are used solely to distinguish one component from others.

[0031] Figure 2 is a schematic cross-sectional view showing a ceramic susceptor 100 according to one embodiment of the present invention.

[0032] Referring to Figure 2, an embodiment of the present invention, a (ceramic) susceptor 100, includes an insulating plate 110 and a shaft 120.

[0033] A ceramic susceptor 100 according to one embodiment of the present invention is a semiconductor device for supporting a substrate to be processed for various purposes, such as a semiconductor wafer, a glass substrate, or a flexible substrate, and for use in semiconductor processes that heat the substrate to be processed to a predetermined temperature or use plasma for plasma-enhanced chemical vapor deposition or dry etching.

[0034] The insulating plate 110 may be configured such that electrodes 112 for plasma generation and electrostatic chuck function and / or heating elements (electrodes) 114 for substrate heating are arranged (embedded) at predetermined intervals between ceramic materials. The insulating plate 110 is configured to stably support the substrate to be processed while enabling semiconductor processes using substrate heating by the heating elements 114 and / or plasma from the electrodes 112.

[0035] In the ceramic susceptor 100 of the present invention, although not shown in the figures, the electrode 112 may be used for plasma generation, and additionally, a chuck electrode with an electrostatic chuck function may be further arranged to support the substrate 11 placed on the insulating plate 110. For example, the chuck electrode may be further configured to be positioned (embedded) at a predetermined distance above or below the electrode 112 or the heating element 114.

[0036] The insulating plate 110 may be formed as a plate-like structure having a predetermined shape. For example, the insulating plate 110 may be formed as a circular plate-like structure, and is not necessarily limited to this. Here, the ceramic material is Al2O3, Y2O3, Al2O3 / Y2O3, ZrO2, AlC (Autoclaved lightweight concrete), TiN, AlN, TiC, MgO, CaO, CeO2, TiO2, B x C y The material may be at least one of the following: BN, SiO2, SiC, YAG, mullite, or AlF3, preferably aluminum nitride (AlN). Each ceramic powder may selectively contain about 0.1 to 10%, preferably about 1 to 5%, of yttrium oxide powder.

[0037] The shaft 120 is hollow with a through hole and is joined or bonded to the lower surface of the insulating plate 110. The shaft 120 may be formed from the same ceramic material as the insulating plate 110 and joined or bonded to it.

[0038] The electrode 112 or chuck electrode may be made of tungsten (W), molybdenum (Mo), silver (Ag), gold (Au), niobium (Nb), titanium (Ti), aluminum nitride (AlN), or an alloy thereof, preferably molybdenum (Mo). The electrode 112 may be connected to an RF (Radio) power supply or to ground via a connecting rod 121 embedded in the hollow shaft 120, and the chuck electrode may be connected to a power supply (DC or AC power supply) for driving the chuck electrode via another connecting rod embedded in the hollow shaft 120. The electrode 112 may have a wire type or sheet type mesh structure. Here, the mesh structure is a network-like structure formed in which a plurality of metals arranged in a first direction and a plurality of metals arranged in a second direction intersect each other with a staggered appearance.

[0039] The heating element 114 is made of tungsten (W), molybdenum (Mo), or alloys or carbides thereof, and has a high melting point and high resistance. The heating element 114 may be formed in the form of a plate-shaped coil using heating wires (or resistance wires or heating electrodes). The heating element 114 may also be formed in a multilayer structure for precise temperature control. Such a heating element 114 is connected to a power supply via a connecting rod 123 embedded in a hollow shaft 120 during the semiconductor manufacturing process, and can perform the function of heating the substrate to be processed on the insulating plate 110 to a predetermined constant temperature in order to carry out smooth deposition and etching processes.

[0040] In one embodiment of the present invention, the ceramic susceptor 100 has a heating element 114 made of a heating wire (or resistance wire) that forms a heating element pattern without hairpin sections as shown in Figure 1 in the central portion SR of the susceptor plate with a high embedding density, that is, in a diameter region SR smaller than the joint portion between the insulating plate 110 and the shaft 120, as shown in Figures 3A to 5B. This improves temperature uniformity across the entire upper surface of the susceptor and makes it possible to greatly extend the life of the heater pattern.

[0041] In other words, the heating element pattern, which is positioned in a diameter region SR smaller than the joint between the insulating plate 110 and the shaft 120, consists of curves that bend at 90° or more (for example, 90 to 270°) without sharp curves. Here, sharp curves may include cases where the radius of curvature decreases and then increases, or increases and then decreases.

[0042] The configuration of this invention will be described in detail below with reference to Figures 3A to 4B.

[0043] Figure 3A shows an example of the pattern of the heating element 114 of the ceramic susceptor 100 of the present invention.

[0044] Referring to Figure 3A, the heating element 114 may include a heating element pattern that includes a first resistive portion 91 and a first connecting portion 92 connected between the first terminal pair 71a and 71b. The resistive portion 91 may include a plurality of arc portions 85 connected in the circumferential direction and a plurality of bent portions 86 connecting the arc portions to each other.

[0045] The first connecting portion 92 is a connecting wire portion for electrically connecting the first terminal pair 71a, 71b at both ends of the first resistive portion 91. The first resistive portion 91 and the first connecting portion 92 are made of a material with high resistance, such as tungsten (W), molybdenum (Mo), or alloys or carbides thereof. The resistive portion 91 is a part in which the above material is processed into a coil shape (a sawtooth zigzag shape is also possible in some cases) to increase the distance electrons can travel, thereby increasing its resistance.

[0046] In a plan view of the first resistor 91 with the insulating plate 110 projected onto it, the first central resistor 910, which is positioned within a diameter region SR smaller than the joint between the insulating plate 110 and the shaft 120, may consist of a curve that bends at 90° or more (for example, 90 to 270°) without sharp curves. The first terminal pair 71a and 71b are also preferably positioned within a diameter region SR smaller than the joint between the insulating plate 110 and the shaft 120, but may be positioned in other regions if necessary.

[0047] In other words, the curve of the first central resistance section 910 means a curve without sharp curves in the pattern of the first resistance section 91, which is located within a region SR smaller than the joint portion of the shaft 120. If such sharp curve sections appear, it will create hairpin sections like those shown in Figure 1, which is detrimental to temperature uniformity and the lifespan of the heating element pattern. Therefore, the curve of the first central resistance section 910 does not have sharp curves, that is, if it includes bending points B1 and B2 of the curve, it may consist of a portion where the extensions before and after the bending points B1 and B2 of the curve bend at an angle of 90° or more (for example, 90 to 270°).

[0048] Figure 3B is a diagram illustrating the sharp curve portion of the conventional resistor section shown in Figure 1. Referring to Figure 3B, the conventional resistor section in the center of the plate, as shown in Figure 1, has a sharp curve shape in which the radius of curvature at the bending point A1 of the hairpin section of the curve near terminal pairs 10a and 10b is smaller than the radius of curvature of the adjacent bent section. Such a sharp curve shape can result in, for example, the extensions A1-1 and A1-2 before and after the bending point A1 being bent at less than 90°. This is a region where the pattern density per unit area is high and the heat generation density is high, making it prone to cracking after long-term use.

[0049] Figure 3C is a diagram illustrating the change in the curve of the central resistance section 910 of the present invention. Referring to Figure 3C, the curve of the first central resistance section 910 of the present invention consists of a portion where, at one or more bending points B1, B2, the extensions before and after the bending point intersect at an angle of 90° or more (for example, 90 to 270°), so that it can be designed without any sharp curve sections. For example, at bending point B1, the extensions before and after may be a first extension connecting a terminal (for example, 71a) or a previous bending point (not shown) to bending point B1, and a second extension connecting bending points B1 and B2. Also, at bending point B2, the extensions before and after may be a first extension connecting bending points B1 and B2, and a second extension connecting bending point B2 to the next bending point (not shown).

[0050] Furthermore, it is preferable that the curve of the first central resistance section 910, which is located within a region SR smaller than the joint portion of the shaft 120, is formed to intersect at least once with the extension of a virtual straight line LL that passes through the spaced-out area between adjacent bent sections 86 of the resistance section 91, as shown by point PL in Figure 3A. The spaced-out area between adjacent bent sections 86 includes the spaced-out area between at least one pair of opposing bent sections 86; however, the opposing bent sections 86 do not necessarily need to be formed symmetrically as shown in the drawing, as long as they are spaced out. In Figure 3A, the spaced-out area between adjacent bent sections 86 is assumed to be the spaced-out area between three pairs of opposing bent sections 86.

[0051] Thus, when the meeting points PL / PL1 / PL2 exist, the empty space between the bent portions 86 where there is no resistance portion 91 pattern is not extended into a region SR smaller than the joint portion of the shaft 120. In this case, the resistance portion 91 pattern at the meeting points PL / PL1 / PL2 makes it possible to improve the temperature uniformity around that portion.

[0052] Figure 4A shows an example of a two-zone arrangement structure of the heating element 114 pattern of the ceramic susceptor 100 of the present invention.

[0053] Figure 4B shows another example of a two-zone arrangement structure of the heating element 114 pattern of the ceramic susceptor 100 of the present invention.

[0054] In Figures 4A and 4B, the central resistors 910-1 and 910-2 are positioned differently.

[0055] Referring to Figures 4A and 4B, the heating element 114 may include a first heating element pattern 411 including a first resistive portion 91-1 and a first connecting portion 92-1 connected between a first terminal pair 81a and 81b, and a second heating element pattern 412 including a second resistive portion 91-2 and a second connecting portion 92-2 connected between a second terminal pair 82a and 82b. Each of the resistive portions 91-1 / 91-2 may include a plurality of arc portions 85-1 / 85-2 connected in the circumferential direction and a plurality of bent portions 86-1 / 86-2 connecting the arc portions to each other.

[0056] Each of the connecting sections 92-1 / 92-2 is a connecting wire portion for electrically connecting to the terminal pairs 81a,81b / 82a,82b at both ends of the resistive sections 91-1 / 91-2, respectively. The first resistive section 91 and the first connecting section 92 are made of a material with high resistance, such as tungsten (W), molybdenum (Mo), or their alloys or carbides. The resistive section 91 is a part in which the resistance is increased by processing the above material into a coil shape (a sawtooth zigzag shape is also possible in some cases) to increase the distance electrons can travel.

[0057] In a plan view of the first resistor 91-1 and the second resistor 91-2, respectively, with the insulating plate 110 projected onto them, the first central resistor 910-1 of the first resistor 91-1 and the second central resistor 910-2 of the second resistor 91-2, which are located within a diameter region SR smaller than the joint between the insulating plate 110 and the shaft 120, may each consist only of curves without sharp curves or straight sections. The first terminal pair 81a, 81b and the second terminal pair 82a, 82b are preferably located within a diameter region SR smaller than the joint between the insulating plate 110 and the shaft 120, but may be located in other regions if necessary.

[0058] In other words, the curves of the central resistance sections 910-1 and 910-2 may consist of curves in which the respective resistance section patterns 91-1 / 91-2, which are located within a region SR smaller than the joint portion of the shaft 120, bend at an angle of 90° or more (for example, 90 to 270°) without any sharp curves.

[0059] Furthermore, it is preferable that the curve of one or more of the central resistance sections 910-1 and 910-2 (for example, 910-2) located within a region SR smaller than the joint portion of the shaft 120 is formed to intersect at least once with the extension of a virtual straight line LL passing through the spaced-out area between adjacent bent sections 86-1 and 86-2 of the resistance sections 91-1 and 91-2, as shown at point PL in Figure 4A. The spaced-out area between adjacent bent sections 86-1 and 86-2 of the resistance sections 91-1 and 91-2 includes at least one spaced-out area between a pair of opposing bent sections 86-1 of the first resistance section 91-1 and 86-2 of the second resistance section 91-2; however, the opposing bent sections 86-1 and 86-2 do not necessarily need to be formed symmetrically as shown in the drawing, as long as they are spaced out. Figure 4A shows that the space between the adjacent bent portions 86-1 and 86-2 is the space between the three pairs of opposing bent portions 86.

[0060] Figure 5A is an enlarged view of the PP1 portion of Figure 4A.

[0061] Referring to Figure 5A, one or more of the curves of the central resistance sections 910-1 and 910-2, which are located within a region SR smaller than the joint portion of the shaft 120, may be formed to meet a virtual extension line LL1 extending from the bent portion 86-11 of the first central resistance section 910-1 that is closest to the first central resistance section 910-1 or the second central resistance section 910-2, as shown at point PL1. Alternatively, one or more of the curves of the central resistance sections 910-1 and 910-2, which are located within a region SR smaller than the joint portion of the shaft 120, may be formed to meet a virtual extension line LL2 extending from the bent portion 86-21 of the second central resistance section 910-2 that is closest to the first central resistance section 910-1 or the second central resistance section 910-2, as shown at point PL2.

[0062] Figure 5B is an enlarged view of the PP2 portion of Figure 4B.

[0063] Referring to Figure 5B, one or more of the curves of the central resistance sections 910-1 and 910-2, which are located within a region SR smaller than the joint portion of the shaft 120, may be formed such that they meet virtual extension lines LL1 and LL2, respectively, which extend from the bent portion 86-11 of the first central resistance section 910-1 and the bent portion 86-21 of the second central resistance section 910-2, which are closest to the first central resistance section 910-1 and the second central resistance section 910-2, respectively, as shown at points PL1 and PL2.

[0064] As described above, when the meeting points PL / PL1 / PL2 exist, the empty space between the bent portions 86 where there is no resistance portion 91 pattern is not extended into a region SR smaller than the joint portion of the shaft 120. In this case, the pattern of the resistance portion 91 at the meeting points PL / PL1 / PL2 makes it possible to improve the temperature uniformity around that area.

[0065] Furthermore, in Figures 5A and 5B, the respective curves of the central resistance sections 910-1 and 910-2, which are located within a region SR smaller than the joint portion of the shaft 120, include a radius of curvature RC1 (e.g., R7) section near the terminal side of the central resistance section, a radius of curvature RC2 (e.g., R2.5) section between the central resistance section and the bent section 86-1, and a radius of curvature RC3 (e.g., R3.5) section between the other arc section 85 and the bent section 86-1. Here, the units of the radius of curvature values ​​for R7, R3.5, and R2.5 are mm.

[0066] Here, for convenience, the radius of curvature for the first resistance section 91-1 and the first central resistance section 910-1 is illustrated as an example, but such a relationship may also be applied to the radius of curvature for the second resistance section 91-2 and the second central resistance section 910-2. Furthermore, such a relationship may be applied to both the first resistance section 91-1 and the first central resistance section 910-1, and the second resistance section 91-2 and the second central resistance section 910-2.

[0067] Similarly, this relationship may also apply to the first resistive section 91 and the first central resistive section 910 in Figure 3A. That is, in Figure 3A, one or more of the curves of the central resistive section 910 connected to the first terminal pair 71a, 71b within a region SR smaller than the joint portion of the shaft 120 include a radius of curvature RC1 (e.g., R7) section near the terminal side (e.g., 71a) of the central resistive section 910, a radius of curvature RC2 (e.g., R2.5) section between the central resistive section 910 and the bent section 86, a radius of curvature RC3 (e.g., R3.5) section between the other arc section 85 and the bent section 86, and so on.

[0068] In other words, the curves of the central resistance sections 910-1 and 910-2, which are located within a region SR smaller than the joint portion of the shaft 120, may have a radius of curvature (e.g., R7) in a portion close to one of the terminal pairs 81a, 81b / 82a, 82b that is larger than the radii of curvature in all other bent sections 86-1 and 86-2 (e.g., R2.5, R3.5, etc.). In this case, the radius of curvature (e.g., R7) in a portion close to one of the terminal pairs 81a, 81b / 82a, 82b may be formed to be more than twice as large as the maximum radius of curvature (e.g., R3.5) in all other bent sections 86-1 and 86-2.

[0069] Furthermore, the curve of the first central resistor 910-1 may be formed such that the radius of curvature of a portion close to one of the first terminal pairs 81a and 81b (for example, RC1=R7) is larger than the radius of curvature of the nearest adjacent bent portion of the first resistor 91-1 (for example, RC2=R2.5). Similarly, the curve of the second central resistor 910-2 may be formed such that the radius of curvature of a portion close to one of the second terminal pairs 82a and 82b (for example, RC1=R7) is larger than the radius of curvature of the nearest adjacent bent portion of the second resistor 91-2 (for example, RC2=R2.5).

[0070] As described above, the ceramic susceptor 100 of the present invention improves temperature uniformity across the entire surface of the susceptor by forming a heating element pattern without hairpin sections in the central part of the susceptor plate 110 where the embedding density of heating elements 114 is high, thereby significantly extending the lifespan of the heater pattern.

[0071] As described above, the present invention has been explained with specific details such as concrete components, limited embodiments, and drawings. These are provided only to aid in a more general understanding of the present invention, and the present invention is not limited to the above embodiments. A person with ordinary skill in the art to which the present invention belongs can make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the idea of ​​the present invention should not be limited to the embodiments described, and any technical idea that is equivalent to or has an equivalent variation to the claims described below should be interpreted as being included within the scope of the rights of the present invention. [Explanation of Symbols]

[0072] 110 Insulating Plate 114 Heating element 71a, 71b, 81a, 81b, 82a, 82b terminal pairs 85 Arc section 86 Folding section 91,91-1,91-2 Resistance section 92,92-1,92-2 Connection part 910,910-1,910-2 Central resistance section

Claims

1. An insulating plate on which a heating element is placed, The insulating plate includes a shaft joined to the lower part of the insulating plate, The heating element includes a first heating element pattern including a first resistor and a first connecting portion connected between a first pair of terminals, and a second heating element pattern including a second resistor and a second connecting portion connected between a second pair of terminals. In a plan view of the first resistive portion as seen by projecting the insulating plate, the first resistive portion includes a first central resistive portion arranged within a diameter region smaller than the joint portion between the insulating plate and the shaft, In a plan view of the second resistive portion as seen by projecting the insulating plate, the second resistive portion includes a second central resistive portion located within a diameter region smaller than the joint portion between the insulating plate and the shaft. The first central resistance section and the second central resistance section each consist of curves connected to the corresponding first connecting section and the second connecting section, and continue to a portion not exceeding the first bend. A susceptor in which the curve includes one or more bending points that form sharp curves toward the terminals of each terminal pair, and the radius of curvature of the curve at the bending points is formed to be greater than the radius of curvature of the first bend.

2. The first resistive section includes a plurality of arc sections connected in the circumferential direction and a plurality of bent sections connecting the arc sections to each other. The susceptor according to claim 1, wherein the curve of the first central resistance portion is formed to meet the extension of a hypothetical straight line passing through a spaced-out area between adjacent bent portions.

3. The first resistive section includes a plurality of arc sections connected in the circumferential direction and a plurality of bent sections connecting the arc sections to each other. The susceptor according to claim 1, wherein the curve of the first central resistance portion is formed to meet a virtual extension line extending from the bending portion closest to the first central resistance portion.

4. The susceptor according to claim 1, wherein the curve of the first central resistive portion is formed such that the radius of curvature of a portion close to one of the first terminal pairs is larger than the radius of curvature at the bent portion of the first resistive portion.

5. The susceptor according to claim 4, wherein the radius of curvature of a portion close to any one of the first terminal pairs is at least twice the maximum radius of curvature of the bent portion of the first resistor.

6. The susceptor according to claim 1, wherein the curve of the first central resistive portion is formed such that the radius of curvature of a portion close to any one of the first terminal pairs is larger than the radius of curvature of the nearest adjacent bent portion of the first resistive portion.

7. The susceptor according to claim 1, wherein the first terminal pair is arranged within a diameter region smaller than the joint portion between the insulating plate and the shaft.

8. The second resistive section includes a plurality of arc sections connected in the circumferential direction and a plurality of bent sections connecting the arc sections to each other. The susceptor according to claim 1, wherein one or more of the curves of the first central resistance portion and the curves of the second central resistance portion are formed to intersect with the extension of a virtual straight line passing through a spaced-out area between adjacent bent portions.

9. The susceptor according to claim 8, wherein the adjacent bent portions include adjacent bent portions of the first resistive portion and the second resistive portion.

10. The second resistive section includes a plurality of arc sections connected in the circumferential direction and a plurality of bent sections connecting the arc sections to each other. The susceptor according to claim 1, wherein one or more of the curves of the first central resistance portion and the curves of the second central resistance portion are formed to meet a virtual extension line extending from the bent portion of the first central resistance portion that is closest to the first central resistance portion or the second central resistance portion.

11. The second resistive section includes a plurality of arc sections connected in the circumferential direction and a plurality of bent sections connecting the arc sections to each other. The susceptor according to claim 1, wherein one or more of the curves of the first central resistance portion and the curves of the second central resistance portion are formed to meet a virtual extension line extending from the bent portion of the second central resistance portion that is closest to the first central resistance portion or the second central resistance portion.

12. The second resistive section includes a plurality of arc sections connected in the circumferential direction and a plurality of bent sections connecting the arc sections to each other. The susceptor according to claim 1, wherein one or more of the curves of the first central resistance portion and the curves of the second central resistance portion are formed to meet virtual extension lines extending from the bent portion of the first central resistance portion and the bent portion of the second central resistance portion that are closest to the first central resistance portion and the second central resistance portion, respectively.

13. The susceptor according to claim 1, wherein the curve of the first central resistive section and the curve of the second central resistive section have a radius of curvature of a portion close to either one of their respective terminal pairs that is larger than the radius of curvature at the bent portion of the first resistive section and the second resistive section, respectively.

14. The susceptor according to claim 13, wherein the radius of curvature of a portion close to any one of the respective terminal pairs is at least twice the maximum radius of curvature of the bent portions of the first and second resistive portions.

15. The curve of the first central resistance section is formed such that the radius of curvature of a portion close to one of the first terminal pairs is larger than the radius of curvature of the nearest adjacent bent portion of the first resistance section. The susceptor according to claim 1, wherein the curve of the second central resistive portion is formed such that the radius of curvature of a portion close to any one of the second terminal pairs is larger than the radius of curvature of the most adjacent bent portion of the second resistive portion.

16. The susceptor according to claim 1, wherein the second pair of terminals is arranged within a diameter region smaller than the joint between the insulating plate and the shaft.

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