Ceramic heater

Abstract

The ceramic heater comprises a ceramic plate (20) having a wafer loading surface on its upper surface, a plurality of zones (Z1 to Z6) provided on the wafer loading surface, a zone heater embedded in the ceramic plate (20) corresponding to each of the plurality of zones (Z1 to Z6), a single temperature measuring member passage (30) provided in the ceramic plate (20), and a single temperature measuring member (multi TC (40)) disposed in the temperature measuring member passage (30). The temperature measuring member passage (30) is provided to pass through each of the plurality of zones (Z1 to Z6) from an inlet (32) provided on the lower surface of the ceramic plate (20). The multi TC (40) has a plurality of temperature measuring sections (41m to 46m). The plurality of temperature measuring sections (41m to 46m) are disposed at measurement positions (P1 to P6) corresponding to each of the plurality of zones (Z1 to Z6).

Description

Technology Field

[0001] The present invention relates to a ceramic heater. Background Technology

[0002] In semiconductor manufacturing equipment, ceramic heaters are employed to heat wafers. As such ceramic heaters, so-called multi-zone heaters are known. As disclosed in Patent Document 1, a multi-zone heater of this type is disclosed to have a heating element capable of partially heating each of a plurality of zones within a ceramic plate, and a temperature sensor disposed in close proximity to each of the heating elements. The temperature sensor transmits temperature feedback information to an external controller. The controller controls the power applied to the heating element of each zone using the temperature feedback information. Prior art literature

[0003] Japanese Patent Publication No. 2023-55790 The problem to be solved

[0004] However, in the multi-zone heater of Patent Document 1, it was necessary to provide a plurality of holes in the ceramic plate to pass the wiring of each of the plurality of temperature sensors.

[0005] The present invention was made to solve such problems, and its main objective is to simplify the configuration of the ceramic plate in a ceramic heater capable of measuring the temperature of each of a plurality of zones. means of solving the problem

[0006] [1] The ceramic heater of the present invention is,

[0007] A ceramic plate having a wafer loading surface on its upper surface, and

[0008] A plurality of zones provided on the wafer loading surface, and

[0009] A zone heater embedded in the ceramic plate corresponding to each of the plurality of zones, and

[0010] A single temperature measuring member passage provided in the ceramic plate, and

[0011] A single temperature measuring member placed in the above temperature measuring member passage

[0012] Equipped with,

[0013] The above temperature measuring member passage is provided to pass through each of the plurality of zones from an inlet provided on the lower surface of the ceramic plate, and

[0014] The above temperature measuring member has a plurality of temperature measuring parts, and the plurality of temperature measuring parts are disposed at measurement positions corresponding to each of the plurality of zones.

[0015] It is.

[0016] In the ceramic heater of the present invention, the passage of the temperature measuring member is provided to pass through each of the plurality of zones from an inlet provided on the lower surface of the ceramic plate. In addition, a single temperature measuring member has a plurality of temperature measuring parts, and the plurality of temperature measuring parts are arranged at measurement positions corresponding to each of the plurality of zones. Therefore, as in the conventional method, there is no need to provide holes corresponding to each of the plurality of temperature sensors in the ceramic plate (20), so the configuration of the ceramic plate (20) can be simplified.

[0017] [2] The ceramic heater of the present invention (the ceramic heater described in [1]) may further comprise a hollow shaft provided on the lower surface of the ceramic plate and a shaft interior area surrounded by the hollow shaft on the lower surface of the ceramic plate, and the entrance of the temperature measuring member passage may be provided in the shaft interior area. In the ceramic heater having a hollow shaft, various components (e.g., power supply members of each zone heater, etc.) are placed in a relatively narrow shaft interior area on the lower surface of the ceramic plate, but since there is no need to provide a hole corresponding to each of the multiple temperature sensors in the shaft interior area, the shaft interior area can be effectively utilized.

[0018] [3] In the ceramic heater of the present invention (the ceramic heater described in [1] or [2]), the temperature measuring member passage may be provided in a curved shape. In this way, when inserting the temperature measuring member into the temperature measuring member passage, the temperature measuring member passage can be inserted smoothly because the temperature measuring member passage is in a curved shape.

[0019] [4] In the ceramic heater of the present invention (the ceramic heater described in any one of [1] to [3]), the plurality of zones may include a circular center zone that is smaller than the diameter of the ceramic plate, and a plurality of divided outer zones that are circular in shape with an outer diameter equal to the diameter of the ceramic plate and an inner diameter equal to or larger than the diameter of the center zone, and the outermost outer zone may be divided. The temperature measuring member passage may be provided in a spiral shape so as to pass through a measurement position corresponding to the center zone from the entrance and then sequentially pass through each of the measurement positions of the plurality of divided outer zones. In this way, since the shape of the temperature measuring member passage is a spiral shape rather than a meandering shape, the length of the temperature measuring member passage can be made relatively short.

[0020] [5] In the ceramic heater of the present invention (the ceramic heater described in any one of [1] to [4]), the temperature measuring member may be provided with a plurality of thermocouples of different lengths within a single flexible protective tube, and the temperature measuring part may be provided at the tip of the thermocouple, and the wiring connected to each of the plurality of thermocouples may be gathered into a single wiring assembly at the end of the temperature measuring member. In this way, each temperature measuring part of the temperature measuring member can be simply connected to an external device through the wiring assembly.

[0021] [6] In the ceramic heater of the present invention (ceramic heater described in any of [1] to [5]), the width and height of the temperature measuring member passage may be 1.5 mm to 3.0 mm. Brief explanation of the drawing

[0022] FIG. 1 is a perspective view of a ceramic heater (10). FIG. 2 is a cross-sectional view of AA of FIG. 1. FIG. 3 is a cross-sectional view taken from above by cutting the ceramic plate (20) horizontally along the center zone heater forming surface. FIG. 4 is a cross-sectional view taken from above by cutting the ceramic plate (20) horizontally along the temperature measuring member passage (30). FIG. 5 is a front view of the multi TC (40). Fig. 6 is a cross-sectional view of the BB in Fig. 5. FIG. 7 is a block diagram showing the connection relationship between the controller (80) and the ceramic heater (10). Specific details for implementing the invention

[0023] Suitable embodiments of the present invention are described below with reference to the drawings. FIG. 1 is a perspective view of a ceramic heater (10), FIG. 2 is a cross-sectional view AA of FIG. 1, FIG. 3 is a cross-sectional view taken from above by cutting the ceramic plate (20) horizontally along the center zone heater forming surface, FIG. 4 is a cross-sectional view taken from above by cutting the ceramic plate (20) horizontally along the temperature measuring member passage (30), FIG. 5 is a front view of a multi TC (40), FIG. 6 is a cross-sectional view BB of FIG. 5, and FIG. 7 is a block diagram showing the connection relationship between the controller (80) and the ceramic heater (10). Additionally, in FIG. 2, for convenience of explanation, jumpers (22c, 22d, 25c, 26c) are shown as solid lines. In FIG. 3, for convenience of explanation, the hatching indicating the cut surface is omitted, and the cross-section of the tubular shaft (50) is shown.

[0024] The ceramic heater (10) is used to heat a wafer on which etching or CVD processing is performed and is installed in a vacuum chamber not shown. The ceramic heater (10) has a disc-shaped ceramic plate (20) having a wafer loading surface (20a) on its upper surface and a hollow tubular shaft (50) joined to a surface (bottom surface) (20b) opposite to the wafer loading surface (20a) of the ceramic plate (20).

[0025] The ceramic plate (20) is a disc-shaped plate containing ceramics such as aluminum nitride or alumina. The wafer loading surface (20a) of the ceramic plate (20) is divided into a circular center zone (Z1), an annular middle zone (Z2), and an annular outer zone by two virtual circles that are concentric with the ceramic plate (20) and have different diameters. The outer zone is divided into four fan-shaped zones (first to fourth divided outer zones (Z3 to Z6)) by four radial line segments of the ceramic plate (20).

[0026] In the ceramic plate (20), zone heaters are embedded corresponding to each of the plurality of zones (Z1 to Z6). Specifically, as shown in FIG. 3, a center zone heater (21) is embedded in the ceramic plate (20) corresponding to the center zone (Z1), a middle zone heater (22) is embedded corresponding to the middle zone (Z2), a first divided outer zone heater (23) is embedded corresponding to the first divided outer zone (Z3), a second divided outer zone heater (24) is embedded corresponding to the second divided outer zone (Z4), a third divided outer zone heater (25) is embedded corresponding to the third divided outer zone (Z5), and a fourth divided outer zone heater (26) is embedded corresponding to the fourth divided outer zone (Z6). These heaters (21 to 26) are composed of resistance heating elements that generate heat when current is passed through them. Examples of resistance heating elements include coils, printed electrodes, or ribbons made primarily of molybdenum, tungsten, or tungsten carbide.

[0027] The center zone heater (21) is provided on the center zone heater forming surface (a surface parallel to the wafer loading surface (20a)) inside the ceramic plate (20). The center zone heater (21) is formed such that it extends from a terminal (21a) provided near the center of the ceramic plate (20) to the terminal (21b), and then extends across almost the entire center zone (Z1) in a continuous, uninterrupted manner.

[0028] The middle zone heater (22) is provided on a middle zone heater forming surface (a surface parallel to the wafer loading surface (20a)) different from the center zone heater forming surface. The middle zone heater (22) is wired in a continuous, uninterrupted manner across almost the entire middle zone (Z2). Both ends of the middle zone heater (22) are connected to jumpers (22c, 22d) provided on the middle zone heater forming surface. The jumpers (22c, 22d) are connected to terminals (22a, 22b) provided near the center of the ceramic plate (20).

[0029] The first to fourth divided outer zone heaters (23 to 26) are provided on an outer zone heater forming surface (a surface parallel to the wafer loading surface (20a)) that is different from the center zone heater forming surface or the middle zone heater forming surface. The first divided outer zone heater (23) is wired in a continuous, uninterrupted manner across almost the entire first divided outer zone (Z3). Both ends of the first divided outer zone heater (23) are connected to jumpers (23c, 23d) provided on the outer zone heater forming surface. The jumpers (23c, 23d) are connected to terminals (23a, 23b) provided near the center of the ceramic plate (20).

[0030] The second divided outer zone heater (24) is wired in a continuous, continuous manner across almost the entire second divided outer zone (Z4). Both ends of the second divided outer zone heater (24) are connected to jumpers (24c, 24d) provided on the outer zone heater forming surface. The jumpers (24c, 24d) are connected to terminals (24a, 24b) provided near the center of the ceramic plate (20).

[0031] The third divided outer zone heater (25) is wired in a continuous, continuous manner across almost the entire third divided outer zone (Z5). Both ends of the third divided outer zone heater (25) are connected to jumpers (25c, 25d) provided on the outer zone heater forming surface. The jumpers (25c, 25d) are connected to terminals (25a, 25b) provided near the center of the ceramic plate (20).

[0032] The fourth divided outer zone heater (26) is wired in a continuous, continuous manner across almost the entire fourth divided outer zone (Z6). Both ends of the fourth divided outer zone heater (26) are connected to jumpers (26c, 26d) provided on the outer zone heater forming surface. The jumpers (26c, 26d) are connected to terminals (26a, 26b) provided near the center of the ceramic plate (20).

[0033] Inside the ceramic plate (20), as shown in FIG. 4, a single temperature measuring member passage (30) is provided on a surface parallel to the wafer loading surface (20a) (e.g., a surface lower than each heater forming surface). The temperature measuring member passage (30) is provided to pass through each of the plurality of zones (Z1 to Z6) from an inlet (32) extending in the vertical direction formed in the shaft inner region (20c) (see FIG. 2) surrounded by a tubular shaft (50) on the lower surface (20b) of the ceramic plate (20). The inlet (32) is provided to bend from the vertical direction to the horizontal direction. Specifically, the temperature measuring member passage (30) passes through the center zone (Z1), middle zone (Z2), first divided outer zone (Z3), second divided outer zone (Z4), third divided outer zone (Z5), and fourth divided outer zone (Z6) in this order from the inlet (32). The width of the temperature measuring member passage (30) is, for example, 1.5 to 3.0 mm in the direction parallel to the wafer loading surface (20a). The height of the temperature measuring member passage (30) is, for example, 1.5 to 3.0 mm in the direction perpendicular to the wafer loading surface (20a). The temperature measuring member passage (30) is formed in a spiral shape (a type of curved shape) along the horizontal direction. In the temperature measuring member passage (30), measurement positions (P1 to P6) corresponding to each of a plurality of zones (Z1 to Z6) are provided. In FIG. 4, the measurement positions (P1 to P6) are shown as dotted star shapes.

[0034] In the temperature measuring member passage (30), a multi-TC (40) as a single temperature measuring member is disposed. TC represents a thermocouple. The multi-TC (40) has a plurality of temperature measuring members (41m to 46m). As shown in FIGS. 5 and 6, the multi-TC (40) is provided with a plurality of sheath TCs (41 to 46) of different lengths inside a single flexible protective tube (47). The material of the protective tube (47) is, for example, metal (SUS316, etc.), the thickness of the protective tube (47) is, for example, 0.1 to 0.3 mm, and the tube diameter of the protective tube (47) is, for example, about 1.0 mm. The material of the sheath in the sheath TCs (41 to 46) is, for example, metal (SUS316, etc.), and the thickness of the sheath is, for example, 0.1 to 0.3 mm. The interior of the sheath is filled with an insulating material (e.g., MgO), and the TC body is embedded therein. Additionally, the interior of the protective tube (47) is not filled with an insulating material. The temperature measuring section (41m to 46m) is the tip of the sheath TC (41 to 46) (the tip of the TC body inside the sheath TC (41 to 46)). The end of the sheath TC (41 to 46) is fixed to a sleeve (48) provided at the end of the protective tube (47). The wiring connected to each of the plurality of sheath TCs (41 to 46) is bundled by a flat cable (49), which is a wiring assembly installed in the sleeve (48). As shown in FIG. 2, the sleeve (48) is installed on a support (60) installed at the bottom of a tubular shaft (50).

[0035] Multi TC (40) inserts the protective tube (47) from the inlet (32) of the ceramic plate (20) into the temperature measuring member passage (30), and when the tip of the protective tube (47) reaches the contact part of the temperature measuring member passage (30), the temperature measuring parts (41m to 46m) of the six sheath TCs (41 to 46) embedded in the protective tube (47) of the multi TC (40) are each placed at a predetermined measurement position. Specifically, the temperature measuring part (41m) of the sheath TC (41) is placed at a measurement position (P1) corresponding to the center zone (Z1). The temperature measuring part (42m) of the sheath TC (42) is placed at a measurement position (P2) corresponding to the middle zone (Z2). The temperature measuring part (43m) of the sheath TC (43) is placed at a measurement position (P3) corresponding to the first divided outer zone (Z3). The temperature measuring part (44m) of the sheath TC (44) is placed at a measurement position (P4) corresponding to the second divided outer zone (Z4). The temperature measuring part (45m) of the sheath TC (45) is placed at a measurement position (P5) corresponding to the third divided outer zone (Z5). The temperature measuring part (46m) of the sheath TC (46) is placed at a measurement position (P6) corresponding to the fourth divided outer zone (Z6).

[0036] The cylindrical shaft (50) is formed of a ceramic material, such as aluminum nitride or alumina, just like the ceramic plate (20). As shown in FIG. 2, the upper end of the cylindrical shaft (50) is joined to the ceramic plate (20), and the lower end is hermetically connected to a support (60) through an O-ring (62). Inside the tubular shaft (50), a power supply rod (51a, 51b) connected to each of a pair of terminals (21a, 21b) of a center zone heater (21), a power supply rod connected to each of a pair of terminals (22a, 22b) of a middle zone heater (22), a power supply rod connected to each of a pair of terminals (23a, 23b) of a first divided outer zone heater (23), a power supply rod connected to each of a pair of terminals (24a, 24b) of a second divided outer zone heater (24), a power supply rod connected to each of a pair of terminals (25a, 25b) of a third divided outer zone heater (25), and a power supply rod connected to each of a pair of terminals (26a, 26b) of a fourth divided outer zone heater (26) are arranged. These power supply rods penetrate the support (60) in the vertical direction. A multi-TC (40) is also arranged inside the tubular shaft (50). The multi-TC (40) has a sleeve (48) supported by the support (60). The protective tube (47) and the plurality of sheath TCs (41 to 46) inside it extend vertically inside the tubular shaft (50), but extend horizontally inside the temperature measuring member passage (30).

[0037] As shown in FIG. 7, the controller (80) is configured as a microprocessor centered on a CPU and is equipped with memory that stores various processing programs and various data. The controller (80) is connected to the flat cable (49) of the multi-TC (40) (i.e., each signal line of the sheath TC (41 to 46)) and is capable of inputting temperature signals from these. The controller (80) is connected to the center zone power supply (81) connected to the center zone heater (21), the middle zone power supply (82) connected to the middle zone heater (22), and the first to fourth divided outer zone power supplies (83 to 86) connected to the first to fourth divided outer zone heaters (23 to 26), and is capable of outputting control signals to these. The controller (80) performs feedback control by inputting temperature signals from each sys TC (41 to 46) and outputting control signals to each power supply (81 to 86) so that each zone (Z1 to Z6) becomes a preset target temperature.

[0038] Next, an example of using the ceramic heater (10) is described. First, the ceramic heater (10) is installed in a vacuum chamber not shown, and a wafer is loaded onto the wafer loading surface (20a) of the ceramic heater (10). Then, the power supply (81 to 86) for each zone is controlled so that the temperature detected by each sheath TC (41 to 46) becomes the predetermined target temperature for each zone. By doing so, the temperature of the wafer is controlled to become the desired temperature. Then, the inside of the vacuum chamber is set to a vacuum atmosphere or a reduced pressure atmosphere, and plasma is generated inside the vacuum chamber, and CVD film deposition or etching is performed on the wafer using the plasma.

[0039] In the ceramic heater (10) of the present embodiment described above, the temperature measuring member passage (30) is configured to pass through each of the plurality of zones (Z1 to Z6) from an inlet (32) provided on the lower surface of the ceramic plate (20). In addition, the multi-TC (40) as a single temperature measuring member has a plurality of temperature measuring sections (41m to 46m), and the plurality of temperature measuring sections (41m to 46m) are arranged at measurement positions (P1 to P6) corresponding to each of the plurality of zones (Z1 to Z6). Therefore, as in the conventional method, there is no need to provide holes corresponding to each of the plurality of temperature sensors in the ceramic plate (20), so the configuration of the ceramic plate (20) can be simplified.

[0040] In addition, in a ceramic heater (10) equipped with a hollow tubular shaft (50), various components (e.g., power supply members of each zone heater (21 to 26) or multi-TC (40), etc.) are placed in a relatively narrow shaft area (20c) on the lower surface of the ceramic plate (20), but since there is no need to provide a hole corresponding to each of the multiple temperature sensors in the shaft area (20c), the shaft area (20c) can be effectively utilized.

[0041] In addition, the temperature measuring member passage (30) is provided in a curved shape. Therefore, when inserting the multi TC (40) into the temperature measuring member passage (30), it can be inserted smoothly.

[0042] Additionally, the plurality of zones (Z1 to Z6) have a circular center zone (Z1) smaller than the diameter of the ceramic plate (20), a toroidal middle zone (Z2) provided on the outer side of the center zone (Z1), and first to fourth divided outer zones (Z3 to Z6) that divide a toroidal area into multiple parts, wherein the outer diameter is equal to the diameter of the ceramic plate (20) and the inner diameter is larger than the diameter of the center zone (Z1) (wherein the inner diameter is equal to the outer diameter of the middle zone (Z2)). The temperature measuring member passage (30) is provided in a spiral shape so as to pass through the center zone (Z1) from the entrance (32), pass through the middle zone (Z2), and then sequentially pass through each of the plurality of first to fourth divided outer zones (Z3 to Z6). Since the shape of the temperature measuring member passage (30) is a spiral shape rather than a meandering shape, the length of the temperature measuring member passage (30) can be made relatively short.

[0043] In addition, the multi-TC (40) is equipped with multiple sheathed TCs (41 to 46) of different lengths within a single flexible protective tube (47), and the temperature measuring section (41m to 46m) is provided at the leading end of the sheathed TCs (41 to 46). The wiring connected to each of the multiple sheathed TCs (41 to 46) is gathered into a single flat cable (49) at the end of the multi-TC (40). Therefore, each temperature measuring section (41m to 46m) of the multi-TC (40) can be easily connected to an external device (controller (80)) through the flat cable (49).

[0044] Furthermore, the present invention is not limited in any way to the embodiments described above, and it is obvious that it can be implemented in various forms as long as they fall within the technical scope of the present invention.

[0045] For example, in the above-described embodiment, six zones are provided on the wafer loading surface (20a): a center zone (Z1), a middle zone (Z2), and first to fourth divided outer zones (Z3 to Z6), but the shape of the zones is not limited to this, and the number of zones may be two or more. For example, the wafer loading surface (20a) may be divided into two or more zones (circular zones and one or more annular zones) by circles of different diameters that form concentric circles with the ceramic plate (20). Alternatively, the wafer loading surface (20a) of the ceramic plate (20) may be divided into two or more zones by radial lines.

[0046] In the above-described embodiment, a plurality of zone heaters (center zone heater (21), middle zone heater (22), and first to fourth divided outer zone heaters (23 to 26)) embedded in the ceramic plate (20) are each formed as heater forming surfaces at different heights from the wafer loading surface (20a), but are not particularly limited thereto. For example, the plurality of zone heaters may be formed as heater forming surfaces at the same height from the wafer loading surface (20a), or some may be formed as heater forming surfaces at the same height and the rest as heater forming surfaces at different heights.

[0047] In the above-described embodiment, a jumper (22c, 22d) connecting the middle zone heater (22) and the terminals (22a, 22b) is provided on the middle zone heater forming surface, but it is not particularly limited to this. For example, the heater forming surface and the jumper forming surface may be separate surfaces. This point applies equally to the jumper (23c, 23d, 24c, 24d, 25c, 25d, 26c, 26d).

[0048] In the above-described embodiment, as a multi-TC (40), the longest sheath TC (46) is arranged along the central axis of the protective tube (47), and other sheath TCs (41 to 45) are arranged around it, but it is not particularly limited to this. For example, sheath TCs (41 to 46) may be randomly arranged inside the protective tube (47).

[0049] In the above-described embodiment, an electrostatic electrode may be embedded in the ceramic plate (20). In this way, after loading a wafer onto the wafer loading surface (20a), the wafer can be electrostatically adsorbed to the wafer loading surface (20a) by applying voltage to the electrostatic electrode. Alternatively, an RF electrode may be embedded in the ceramic plate (20). In that case, a shower head (not shown) is placed above the wafer loading surface (20a) with a space, and high-frequency power is supplied between the shower head and a parallel plate electrode including the RF electrode. By doing so, plasma is generated, and the plasma can be used to perform CVD film deposition or etching on the wafer. Additionally, the electrostatic electrode may be used in combination with the RF electrode. Industrial applicability

[0050] The present invention can be used in a semiconductor manufacturing apparatus that performs processing on a wafer. Explanation of the symbols

[0051] 10: Ceramic heater 20: Ceramic plate 20a: Wafer loading surface 20b: If 20c: Area within the shaft 21: Center Zone Heater 22: Middle Zone Heater 23 to 26: 1st to 4th divided outer zone heaters 21a, 21b, 22a, 22b, 23a, 23b, 24a, 24b, 25a, 25b, 26a, 26b: terminal 22c, 22d, 23c, 23d, 24c, 24d, 25c, 25d, 26c, 26d: Jumper 30: Temperature measuring member passage 32: Entrance 40: Multi TC 41 to 46: Cis TC 41m to 46m: Temperature measuring section 47: Protector 48: Sleeve 49: Flat cable 50: Tubular shaft 51a, 52b: Feed rods 60: Support 62: O-ring 80: Controller 81: Center Zone All 82: All Middle Zone players 83 to 86: 1st to 4th divided outer zone power P1 to P6: Measurement positions Z1: Center Zone Z2: Middle Zone Z3 to Z6: 1st to 4th divided outer zones

Claims

Claim 1 A ceramic heater comprising a ceramic plate having a wafer loading surface on its upper surface, a plurality of zones provided on the wafer loading surface, a zone heater embedded in the ceramic plate corresponding to each of the plurality of zones, a single temperature measuring member passage provided in the ceramic plate, and a single temperature measuring member disposed in the temperature measuring member passage, wherein the temperature measuring member passage is provided to pass through each of the plurality of zones from an inlet provided on the lower surface of the ceramic plate, the temperature measuring member has a plurality of temperature measuring parts, the plurality of temperature measuring parts are disposed at measurement positions corresponding to each of the plurality of zones, and the temperature measuring member has a plurality of thermocouples of different lengths provided within a single flexible protective tube. Claim 2 A ceramic heater according to claim 1, comprising a hollow shaft provided on the lower surface of the ceramic plate and a shaft inner region surrounded by the hollow shaft on the lower surface of the ceramic plate, wherein the inlet of the temperature measuring member passage is provided in the shaft inner region. Claim 3 A ceramic heater according to claim 1 or 2, wherein the temperature measuring member passage is provided in a curved shape. Claim 4 A ceramic heater according to claim 1 or 2, wherein the plurality of zones comprises a circular center zone smaller than the diameter of the ceramic plate and a plurality of divided outer zones having an outer diameter equal to the diameter of the ceramic plate and an inner diameter equal to or larger than the diameter of the center zone, and the outermost outer zone is divided, and the temperature measuring member passage is provided in a spiral shape to pass through a measuring position corresponding to the center zone from the inlet and then sequentially pass through each of the measuring positions of the plurality of divided outer zones. Claim 5 A ceramic heater according to claim 1 or 2, wherein the temperature measuring member is provided at the tip of the thermocouple, and the wiring connected to each of the plurality of thermocouples is gathered into a single wiring assembly at the end of the temperature measuring member. Claim 6 A ceramic heater according to claim 1 or 2, wherein the width and height of the temperature measuring member passage are 1.5 mm to 3.0 mm.

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