Holding device
The holding device addresses non-uniform heat distribution by using a parallel-connected heater configuration with annular regions to ensure consistent temperature across the mounting surface, despite manufacturing-induced thickness variations.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- NITERRA CO LTD
- Filing Date
- 2024-08-23
- Publication Date
- 2026-07-07
AI Technical Summary
Existing holding devices suffer from non-uniform heat distribution on their placement surfaces, which can be exacerbated by variations in heater thickness due to manufacturing methods.
The holding device incorporates a heater configuration with multiple regions arranged in annular shapes, where heaters within each region are connected in parallel, ensuring the same voltage is applied to each, thereby inversely proportional to their electrical resistance, thus reducing temperature variations.
This configuration significantly improves heat uniformity on the mounting surface by compensating for thickness variations in the heaters, resulting in more consistent temperature distribution.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a holding device.
Background Art
[0002] Conventionally, a holding device including a heater for heating an object placed on a placement surface has been known (for example, Patent Document 1).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, even with the prior art such as Patent Document 1, there is still room for improvement in the technology for improving the heat uniformity of the placement surface in the holding device.
[0005] An object of the present invention is to provide a technology for improving the heat uniformity of a placement surface in a holding device.
Means for Solving the Problems
[0006] The present invention has been made to solve at least a part of the above problems and can be realized in the following forms.
[0007] (1) According to one embodiment of the present invention, a holding device is provided. The holding device comprises a plate-shaped portion having a mounting surface on which an object is placed, and a heater portion disposed inside the plate-shaped portion so as to face the mounting surface, wherein the heater portion has a first region, a second region and a third region arranged to form at least a part of an annular shape in a plan view of the mounting surface of the plate-shaped portion, and each of the first heater disposed in the first region, the second heater disposed in the second region and the third heater disposed in the third region are connected in parallel to each other.
[0008] In this configuration, the plate-like portion having a mounting surface on which an object is placed is equipped with a heater portion positioned opposite the mounting surface. The heater portion has a first region, a second region, and a third region arranged in a plan view of the mounting surface of the plate-like portion so as to form at least a part of an annular shape. A first heater, a second heater, and a third heater are arranged in parallel with each other in each of the first, second, and third regions. As a result, the same voltage is applied to each of the first, second, and third heaters, and the relationship between the amount of heat generated by each heater is inversely proportional to the electrical resistance of each heater. Therefore, even if there is variation in the thickness of the heaters, the temperature distribution on the mounting surface can be reduced, thereby improving the uniformity of the heat distribution on the mounting surface.
[0009] (2) In the above-described form of the holding device, the heater section has a fourth region located inside the ring shape formed by the first region, the second region and the third region in a plan view of the mounting surface of the plate-shaped section, and the fourth heater arranged in the fourth region may consist of a heating wire and a pair of pad portions connected to each of the ends of the heating wire. With this configuration, in the heater section, the fourth region located inside the ring shape formed by the first region, the second region and the third region is arranged, and a fourth heater consisting of a heating wire and a pair of pad portions connected to each of the ends of the heating wire is arranged. With such a configuration, for example, even if the thickness of the heater has directionality due to the manufacturing method of the holding device, the temperature distribution on the mounting surface can be reduced by connecting the first heater, the second heater and the third heater, which are arranged to surround the fourth region, in parallel with each other.Therefore, the uniformity of the heat distribution on the mounting surface can be improved.
[0010] (3) In the above-described form of the holding device, the heater section has, in a plan view of the mounting surface of the plate-like portion, a fourth region having an annular shape located inside the annular shape formed by the first region, the second region and the third region, and a fifth region located inside the fourth region in a plan view of the mounting surface of the plate-like portion, and the fourth heater located in the fourth region and the fifth heater located in the fifth region may be connected in parallel with each other. With this configuration, the heater section has a fourth region having an annular shape where the fourth heater is located, located inside the annular shape formed by the first region, the second region and the third region, and a fifth region where the fifth heater is located, located inside the fourth region. Since the fourth heater and the fifth heater are connected in parallel with each other, the same magnitude of voltage is applied to them. As a result, the relationship of the amount of heat generated in each heater is inversely proportional to the magnitude of the electrical resistance of each heater, so that the uniformity of the heat on the mounting surface can be further improved.
[0011] (4) In the above-described form of the holding device, the heater section has, in a plan view of the mounting surface of the plate-like portion, a sixth region having an annular shape located outside the annular shape formed by the first region, the second region and the third region, and a seventh region having an annular shape located outside the sixth region in a plan view of the mounting surface of the plate-like portion, and the sixth heater located in the sixth region and the seventh heater located in the seventh region may be connected in parallel to each other. With this configuration, the heater section has a sixth region having an annular shape where the sixth heater is located, located outside the annular shape formed by the first region, the second region and the third region, and a seventh region where the seventh heater is located, located outside the sixth region. Since the sixth heater and the seventh heater are connected in parallel to each other, the same magnitude of voltage is applied to them. As a result, the relationship of the amount of heat generated in each heater is inversely proportional to the magnitude of the electrical resistance of each heater, so that uniform heating can be improved even if the mounting surface is large.
[0012] Furthermore, the present invention can be realized in various forms, for example, in the form of a method for manufacturing a holding device, a system including a holding device, a method for controlling these devices and systems, a computer program that causes these devices and systems to perform the holding of an object, a server device for distributing the computer program, a non-temporary storage medium storing the computer program, and so on. [Brief explanation of the drawing]
[0013] [Figure 1] This is a perspective view of the holding device of the first embodiment. [Figure 2] This is a cross-sectional view of the holding device according to the first embodiment. [Figure 3] This is a diagram illustrating the heater section of the holding device according to the first embodiment. [Figure 4] This diagram illustrates the connection relationships of the heaters in the heater section of the first embodiment. [Figure 5] This is a diagram illustrating the manufacturing method of the holding device according to the first embodiment. [Figure 6]This diagram illustrates the amount of heat generated in the heater section of the comparative example holding device. [Figure 7] This figure illustrates the amount of heat generated in the heater section of the holding device according to the first embodiment. [Figure 8] This diagram illustrates the configuration of the heater section of the holding device according to the second embodiment. [Figure 9] This diagram illustrates the connection relationships of the heaters in the heater section of the second embodiment. [Figure 10] This is a diagram illustrating the heater section of the holding device according to the third embodiment. [Figure 11] This diagram illustrates the connection relationships of the heaters in the heater section of the third embodiment. [Figure 12] This is a diagram illustrating the heater section of the holding device according to the fourth embodiment. [Modes for carrying out the invention]
[0014] <First Embodiment> Figure 1 is a perspective view of the holding device 1 of this embodiment. Figure 2 is a cross-sectional view of the holding device 1 of this embodiment. The holding device 1 of this embodiment is an electrostatic chuck that holds an object, such as a wafer W, by electrostatic attraction. The electrostatic chuck is used, for example, as a table on which a wafer W (object) is placed in a chamber. The holding device 1 comprises a ceramic part 10, a base part 20, and a joint part 30. In the holding device 1 of this embodiment, as shown in Figure 1, the ceramic part 10, the joint part 30, and the base part 20 are stacked in that order. For convenience, in Figures 1 and 2, the stacking direction of the ceramic part 10, the joint part 30, and the base part 20 is shown as the z-axis direction, the x-axis is perpendicular to the z-axis, and the y-axis is perpendicular to the z-axis and x-axis.
[0015] The ceramic part 10 is a part having a substantially disc shape with ceramic as the main component. Here, the "main component" means the component with the highest content ratio. The ceramic part 10 of this embodiment has alumina (Al2O3) as the main component. The ceramic part 10 includes a plate-like part 11, a heater part 12, and a chuck electrode 13.
[0016] The plate-like part 11 is a part having a substantially disc shape formed of ceramic. The plate-like part 11 of this embodiment is formed of alumina and has substantially the same shape as the ceramic part 10. Note that the material forming the plate-like part 11 may be other ceramic materials such as aluminum nitride (AlN) and silicon carbide (SiC). The plate-like part 11 has a mounting surface 11a on which the wafer W is mounted.
[0017] The heater part 12 is disposed inside the plate-like part 11 so as to face the mounting surface 11a. The heater part 12 of this embodiment has a plurality of heaters H12. The plurality of heaters H12 are connected to an external power source via a power supply terminal 12a for the heater H12. When power is supplied from an external power source to the heater part 12, it generates heat capable of heating the wafer W mounted on the mounting surface 11a. Details of the heater part 12 will be described later.
[0018] The chuck electrode 13 is located inside the plate-shaped portion 11. The chuck electrode 13 is made of a conductive material such as tungsten (W), molybdenum (Mo), or platinum (Pt). The chuck electrode 13 is connected to an external power source via a chuck electrode terminal 13a. When power is supplied from the external power source, the chuck electrode 13 generates an electrostatic attractive force capable of adsorbing and holding the wafer W to the mounting surface 11a of the plate-shaped portion 11. In this embodiment, as shown in Figure 2, the chuck electrode 13 is located further from the mounting surface 11a than the heater portion 12, but the positional relationship between the heater portion 12 and the chuck electrode 13 inside the plate-shaped portion 11 is not limited to this. The chuck electrode 13 may be closer to the mounting surface 11a than the heater portion 12. In addition to the heater portion 12 and the chuck electrode 13, high-frequency electrodes and the like may also be located inside the ceramic portion 10.
[0019] The base portion 20 is a substantially disc-shaped component mainly composed of a metal such as aluminum or an aluminum alloy, a metal matrix composite such as an Al-SiC composite material, or a ceramic such as silicon carbide (SiC). In this embodiment, the base portion 20 is made of aluminum. In this embodiment, the base portion 20 is larger than the ceramic portion 10. For example, if the diameter of the ceramic portion 10 is 300 mm, the diameter of the base portion 20 will be 340 mm. However, the size relationship between the ceramic portion 10 and the base portion 20 is not limited to this. They may be the same size.
[0020] Multiple refrigerant channels 21 are formed inside the base portion 20. A refrigerant such as a fluorine-based inert liquid or water flows through the refrigerant channels 21. As a result, the base portion 20 is cooled, and the ceramic portion 10 is cooled via the joint portion 30.
[0021] The joint 30 joins the ceramic part 10 and the base part 20. The joint 30 is, for example, a bonding sheet containing a silicone-based organic adhesive, an inorganic adhesive, or an Al-based metal adhesive. The joint 30 should preferably have high adhesive strength to both the ceramic part 10 and the base part 20, as well as high pressure resistance and high thermal conductivity.
[0022] Next, the features of the holding device 1 of this embodiment will be described. The heater portion 12 of the holding device 1 has a circular shape in plan view of the mounting surface 11a of the plate-shaped portion 11. The heater portion 12 has a first region, a second region, and a third region that are arranged to form at least a part of an annular shape in plan view of the mounting surface 11a of the plate-shaped portion 11.
[0023] Figure 3 is a diagram illustrating the configuration of the heater section 12 of the holding device 1 of this embodiment. Figure 3 shows a plan view of the ceramic section 10, specifically the mounting surface 11a of the plate-shaped section 11, that is, a view from the positive side in the z-axis direction. The heater section 12 of this embodiment has a first region R1, a second region R2, and a third region R3. In Figure 3, each of the first region R1, the second region R2, and the third region R3 is shown as a region enclosed by a dashed line. The first region R1, the second region R2, and the third region R3 are arranged to form the outer periphery of the circular heater section 12. The first region R1, the second region R2, and the third region R3 form a first annular region Rc1 in the heater section 12, which has an annular shape centered on the central axis C1 of the holding device 1.
[0024] The heater portion 12 of the ceramic portion 10 of the holding device 1 of this embodiment has a central region Rc0 located inside the ring shape formed by the first region R1, the second region R2, and the third region R3 in a plan view of the mounting surface 11a of the plate-shaped portion 11. The central region Rc0 has a circular shape centered on the central axis C1 of the holding device 1 and is located inside the first ring region Rc1.
[0025] The holding device 1 of this embodiment has a plurality of heaters H12, namely a first heater H1, a second heater H2, a third heater H3, and a central heater H0. In the holding device 1 of this embodiment, one heater is arranged in each region. Specifically, the first heater H1 is arranged in the first region R1, the second heater H2 is arranged in the second region R2, the third heater H3 is arranged in the third region R3, and the central heater H0 is arranged in the central region Rc0.
[0026] In the holding device 1 of this embodiment, each heater consists of a heating wire and a pair of pads connected to each end of the heating wire. Specifically, the first heater H1 consists of a heating wire E1 and a pair of pads P1a and P1b connected to each end of the heating wire E1. The second heater H2 consists of a heating wire E2 and a pair of pads P2a and P2b connected to each end of the heating wire E2. The third heater H3 consists of a heating wire E3 and a pair of pads P3a and P3b connected to each end of the heating wire E3. The central heater H0 consists of a heating wire E0 and a pair of pads P0a and P0b connected to each end of the heating wire E0.
[0027] Figure 4 is a diagram illustrating the connection relationships of the heaters in the heater section of the first embodiment. Next, the connection relationships between each of the heaters H1, H2, H3, and H0 in the heater section 12 and the power supply will be explained. In Figure 4, two power supplies PSc and PS1 are shown to supply power to the heaters in the central region Rc0 and the first annular region Rc1, respectively, in order to make the connection relationships of the multiple heaters H1, H2, H3, and H0 easier to understand, but one power supply may be used to supply power to one holding device.
[0028] The first heater H1, second heater H2, and third heater H3, each located in the first, second, and third regions R1, which form the first annular region Rc1, are connected in parallel to the power supply PS1, as shown in Figure 4. Specifically, the pads P1a and P1b of the first heater H1 are directly connected to the power supply PS1, the pads P2a and P2b of the second heater H2 are directly connected to the power supply PS1, and the pads P3a and P3b of the third heater H3 are directly connected to the power supply PS1. The central heater H0, located in the central region Rc0, is connected one-to-one with the power supply PSc.
[0029] Next, the manufacturing method of the holding device 1 will be described. In the manufacturing method of the holding device 1, the ceramic part 10 and the base part 20 are manufactured separately, and the separately manufactured ceramic part 10 and base part 20 are joined together by a joint part 30.
[0030] In the manufacturing method for the ceramic part 10, first, a slurry for the green sheet and a metallization paste are prepared. The slurry for the green sheet is prepared by mixing a mixture containing, for example, alumina powder, an acrylic binder, a dispersant, and a plasticizer with an organic solvent using a ball mill. The metallization paste is prepared by mixing a mixture of alumina powder, an acrylic binder, and an organic solvent with conductive powder such as tungsten or molybdenum.
[0031] The prepared slurry for the green sheet is formed into a sheet using a casting device, and the resulting molded product is dried. This yields a green sheet. On a specific green sheet from among several green sheets, the portions that will become heaters H1, H2, H3, and H0 of the heater portion 12 are printed using a metallizing paste, for example, by a screen printing device. Subsequently, a laminate of green sheets is manufactured by laminating multiple green sheets, including the specific green sheet on which the metallizing paste has been printed. The ceramic portion 10 is manufactured by firing the laminate of green sheets in an electric furnace. In the manufacturing method of the base portion 20, multiple metal plates, each with a processed portion that will become the refrigerant flow path 21, are laminated. Note that the manufacturing methods for the ceramic portion 10 and the base portion 20 are not limited to these.
[0032] In the manufacturing method of the holding device 1, a bonding sheet, which will form the bonding portion 30, is placed on the surface of either the separately manufactured ceramic portion 10 or the base portion 20. For example, the bonding sheet is placed on the surface of the base portion 20, the bonding sheet is sandwiched between the ceramic portion 10 and the base portion 20, and the entire assembly is heated so that the ceramic portion 10 and the base portion 20 are joined by the bonding portion 30. In this way, the holding device 1 is manufactured. However, the manufacturing method of the holding device 1 is not limited to this.
[0033] In the manufacturing method of the holding device 1 described above, heaters H1, H2, H3, and H0 are formed by printing on a green sheet using a screen printing device with metallized paste. In the method of forming the heater portion using a screen printing device, a certain directionality may occur in the thickness of the heater portion due to the direction of printing.
[0034] Figure 5 illustrates the manufacturing method of the holding device 1 of this embodiment. Figure 5 shows a schematic diagram e10 showing a plan view of the ceramic component and a graph g5 showing an example of the change in the thickness of the heater formed by the screen printing device. Schematic diagram e10 shows the x, y, and z axes representing the direction of the ceramic component. The ceramic component shown in schematic diagram e10 has a circular region Re0 where the heater is located.
[0035] In graph g5 shown in Figure 5, the vertical axis p1 indicates the position on the ceramic component shown in schematic diagram e10, and the horizontal axis t1 indicates the thickness of the heater portion formed on the green sheet by a screen printing device using metallizing paste. In screen printing using metallizing paste, for example, as shown in Figure 5, the metallizing paste is printed on the ceramic component along the direction of the white arrow F1, from the most positive point Pa in the y-axis direction to the most negative point Pb in the y-axis direction. When metallizing paste is printed in this way, due to the characteristics of screen printing, as shown in graph g5 in Figure 5, the thickness of the heater portion has a directionality, gradually decreasing from point Pa where screen printing started to point Pb. When the thickness of the heater portion has a directionality, the distribution of electrical resistance as a heater also has a directionality. Specifically, as shown in Figure 5, if we assume that virtual heaters Ha, Hb, Hc, and Hd are formed sequentially from point Pa to point Pb, and that the thickness of the heater portion has a directionality as shown in graph g5 of Figure 5, then the thickness of the metallized paste that forms the heater will decrease in the order of heater Ha, heater Hb, heater Hc, and heater Hd, and therefore the electrical resistance will increase in the order of heater Ha, heater Hb, heater Hc, and heater Hd.
[0036] Figure 6 is a diagram illustrating the amount of heat generated in the heater section of the comparative example holding device. The comparative example holding device 1s shown in Figure 6 comprises a ceramic section 90, a base section 20, and a joint section (not shown). The ceramic section 90 comprises a plate-shaped section 91 having a substantially disc shape and made of ceramic, a heater section 92, and a chuck electrode (not shown). The heater section 92 has a plurality of heaters H91, H92, and H93. The heater section 92 has a circular central region R91 included by the central axis C1s of the holding device 1s, an annular-shaped region R92 located outside the central region R91, and an annular-shaped region R93 located outside the annular-shaped region R92. The annular-shaped regions R92 and R93 of the heater section 92 of the comparative example holding device 1s correspond to the first annular region Rc1 of the heater section 12 of the holding device 1 of this embodiment. A heater H91 is located in the central region R91, a heater H92 is located in the ring-shaped region R92, and a heater H93 is located in the ring-shaped region R93. In the comparative example holding device 1s, as shown in Figure 6, the heater H92 in the ring-shaped region R92 and the heater H93 in the ring-shaped region R93 are connected in series to the power supply PS1.
[0037] Figure 6 shows how the ranges corresponding to heaters Ha, Hb, Hc, and Hd shown in Figure 5 overlap with the heater section 92 of the comparative example holding device 1s. In Figure 6, the amount of heat generated for each range corresponding to heaters Ha, Hb, Hc, and Hd is indicated by the density of dots used in the hatching, with a higher density indicating a greater amount of heat generated. In the configuration of the comparative example holding device 1s shown in Figure 6, if there is a directionality in the thickness of the heater part as explained in Figure 5, the ranges corresponding to heater Ha and heater H93 overlap, resulting in significantly different electrical resistances within the heaters. Since heaters H92 and H93 are connected in series, the same current flows through them. Therefore, the amount of heat generated by the product of electrical resistance and the square of the current differs significantly between the portion corresponding to heater Ha and the portion corresponding to heater Hd in heaters H92 and H93. Specifically, the amount of heat generated in the portion corresponding to heater Hd is greater than the amount of heat generated in the portion corresponding to heater Ha. Similarly, in heater H91, the amount of heat generated in the portion corresponding to heater Hc is greater than the amount of heat generated in the portion corresponding to heater Hb. As a result, in the comparative example holding device 1s, the negative side in the y-axis direction tends to become hotter, and the positive side in the y-axis direction tends to become colder. Furthermore, in the negative side in the y-axis direction, which tends to become hotter, the electrical resistance of the heater increases even more due to the effect of temperature, so the temperature difference between the negative side and the positive side in the y-axis direction tends to become even larger. Thus, in the comparative example holding device 1, if the heater portion is formed by screen printing using metallized paste, for example, the temperature distribution on the mounting surface tends to be large. In other words, the uniformity of the mounting surface of the comparative example holding device 1s tends to decrease.
[0038] Figure 7 illustrates the amount of heat generated in the heater section of the holding device of this embodiment. In the holding device 1 of this embodiment, the first annular region Rc1 of the heater section 12 comprises a first region R1 where the first heater H1 is located, a second region R2 where the second heater H2 is located, and a third region R3 where the third heater H3 is located. As shown in Figure 7, the first heater H1, the second heater H2, and the third heater H3 are each connected in parallel to the power supply PS1. As a result, the relationship between the amount of heat generated by the first heater H1, the second heater H2, and the third heater H3 is calculated by dividing the square of the voltage by the electrical resistance, and is therefore inversely proportional to the magnitude of the electrical resistance. Therefore, in the holding device 1 of this embodiment, even if the amount of heat generated by the central heater H0 in the central region Rc0 has the same directionality as the heater H91 in the central region R91 of the comparative example holding device 1s, as shown in Figure 7, in the first annular region Rc1, the relatively high temperature portion of the central heater H0 (the range corresponding to heater Hc) is adjacent to the relatively low temperature portion (the range corresponding to heater Hd), and the relatively low temperature portion of the central heater H0 (the range corresponding to heater Hb) is adjacent to the relatively high temperature portion (the range corresponding to heater Ha). This improves the uniformity of heat on the mounting surface 10a.
[0039] In the holding device 1 of this embodiment, the area of the first annular region Rc1 corresponding to heater Ha becomes relatively hot, so the portion of the second heater H2 corresponding to heater Ha has a relatively large electrical resistance. However, since the first heater H1, the second heater H2, and the third heater H3, each located in the first annular region Rc1, are connected in parallel to the power supply PS1, the amount of heat generated in the portion of the second heater H2 corresponding to heater Ha is suppressed to be excessively large. This further improves the uniformity of heat on the mounting surface 10a.
[0040] As described above, according to the holding device 1 of this embodiment, the plate-shaped portion 11 having a mounting surface 11a on which the wafer W is placed is equipped with a heater portion 12 arranged opposite to the mounting surface 11a. The heater portion 12 has a first region R1, a second region R2, and a third region R3 arranged in a plan view of the mounting surface 11a of the plate-shaped portion 11 so as to form at least a part of an annular shape. A first heater H1, a second heater H2, and a third heater H3 are arranged in parallel with each other in the first region R1, the second region R2, and the third region R3, respectively. As a result, the same magnitude of voltage is applied to each of the first heater H1, the second heater H2, and the third heater H3, so the relationship of the amount of heat generated in each heater is inversely proportional to the magnitude of the electrical resistance of each heater. Therefore, even if there is variation in the thickness of the heater, the temperature distribution on the mounting surface 11a can be reduced, thereby improving the uniformity of the heat distribution on the mounting surface 11a.
[0041] Furthermore, according to the holding device 1 of this embodiment, in the heater section 12, the central region Rc0 located inside the ring shape formed by the first region R1, the second region R2, and the third region R3 is equipped with a central heater H0 consisting of a heating wire E0 and a pair of pad sections P0a and P0b connected to each end of the heating wire E0. As a result, even if the thickness of the heater is directional due to the manufacturing method of the holding device 1, the first heater H1, the second heater H2, and the third heater H3, each located in the first region R1, the second region R2, and the third region R3 that surround the central region Rc0, are connected in parallel to each other, thereby reducing the temperature distribution on the mounting surface 11a. Therefore, the uniformity of the heat distribution on the mounting surface 11a can be improved.
[0042] <Second Embodiment> Figure 8 is a diagram illustrating the configuration of the heater section of the holding device 2 of the second embodiment. Compared with the holding device 1 of the first embodiment (Figure 3), the holding device 2 of the second embodiment differs in the shape of the region located inside the first annular region Rc1, and in the way the heater located inside the first annular region Rc1 is connected to the power supply.
[0043] The holding device 2 of the second embodiment comprises a ceramic part 40, a base part 20, and a joining part 30. The holding device 2 of this embodiment is an electrostatic chuck that holds an object such as a wafer W by electrostatic attraction.
[0044] The ceramic part 40 is a component having a roughly disc shape, with alumina as its main component. The ceramic part 40 comprises a plate-shaped part 11, a heater part 42, and a chuck electrode 13. The heater part 42 is arranged inside the plate-shaped part 11 so as to face the mounting surface 11a. The heater part 42 in this embodiment has a plurality of heaters H42. The plurality of heaters H42 are connected to an external power supply via a power supply terminal 12a for the heaters H42. When power is supplied from the external power supply, the heater part 42 generates heat capable of heating the wafer W placed on the mounting surface 11a.
[0045] The heater section 42 has a circular shape in plan view of the mounting surface 11a of the plate-shaped section 11. The heater section 42 is located inside the ring shape formed by the first region R1, second region R2, and third region R3 that form the first annular region Rc1, and has a fourth region R4 which also has a ring shape, and a fifth region R5 which is located inside the fourth region R4. The fifth region R5 has a circular shape centered on the central axis C2 of the holding device 2.
[0046] The holding device 2 of this embodiment has a plurality of heaters H42, namely a first heater H1, a second heater H2, a third heater H3, a fourth heater H4, and a fifth heater H5. In the holding device 2 of this embodiment, one heater is arranged in each region. Specifically, the first heater H1 is arranged in the first region R1, the second heater H2 is arranged in the second region R2, the third heater H3 is arranged in the third region R3, the fourth heater H4 is arranged in the fourth region R4, and the fifth heater H5 is arranged in the fifth region R5.
[0047] In the holding device 2 of this embodiment, one heater consists of a heating wire and a pair of pad portions connected to each end of the heating wire. The first heater H1, the second heater H2, and the third heater H3 are the same as in the first embodiment. The fourth heater H4 consists of a heating wire E4 and a pair of pad portions P4a and P4b connected to each end of the heating wire E4. The fifth heater H5 consists of a heating wire E5 and a pair of pad portions P5a and P5b connected to each end of the heating wire E5.
[0048] Figure 9 is a diagram illustrating the connection relationships of the heaters in the heater section 42 of this embodiment. The first heater H1, second heater H2, and third heater H3, each located in the first, second, and third regions R1, which form the first annular region Rc1, are connected in parallel to the power supply PS1. The fourth heater H4, located in the fourth region R4, and the fifth heater H5, located in the fifth region R5, are connected in parallel to the power supply PSc. Specifically, the pad sections P4a and P4b of the fourth heater H4 are directly connected to the power supply PSc, and the pad sections P5a and P5b of the fifth heater H5 are directly connected to the power supply PSc.
[0049] As described above, according to the holding device 2 of this embodiment, the first region R1, the second region R2, and the third region R3 of the heater section 42 are each arranged in parallel with a first heater H1, a second heater H2, and a third heater H3. As a result, the same voltage is applied to each of the first heater H1, the second heater H2, and the third heater H3, so that even if there is variation in the thickness of the heaters, the temperature distribution on the mounting surface 11a can be reduced. Therefore, the uniformity of the heat on the mounting surface 11a can be improved.
[0050] Furthermore, according to the holding device 2 of this embodiment, in the heater section 42, the fourth region R4, which has a ring shape in which the fourth heater H4 is located, is located inside the ring shape formed by the first region R1, the second region R2, and the third region R3, and the fifth region R5, which has the fifth heater H5 located inside the fourth region R4. Since the fourth heater H4 and the fifth heater H5 are connected in parallel to each other, the same magnitude of voltage is applied to them. As a result, the relationship between the amount of heat generated by the fourth heater H4 and the fifth heater H5 is inversely proportional to the magnitude of the electrical resistance of the fourth heater H4 and the fifth heater H5, so that the uniformity of the heat distribution on the mounting surface 11a can be further improved.
[0051] <Third Embodiment> Figure 10 is a diagram illustrating the heater section of the holding device 3 of the third embodiment. The holding device 3 of the third embodiment differs from the holding device 2 of the second embodiment (Figure 8) in that the heater section has a region where the heater is located outside the first annular region Rc1.
[0052] The holding device 3 of the third embodiment comprises a ceramic part 50, a base part 20, and a joint part 30. The holding device 3 of this embodiment is an electrostatic chuck that holds an object, such as a wafer W, by electrostatic attraction.
[0053] The ceramic part 50 is a component with a roughly disc shape, mainly composed of alumina. The ceramic part 50 comprises a plate-shaped part 11, a heater part 52, and a chuck electrode 13. The heater part 52 is positioned inside the plate-shaped part 11 so as to face the mounting surface 11a. The heater part 52 in this embodiment has a plurality of heaters H52. The plurality of heaters H52 are connected to an external power source via a power supply terminal 12a for the heaters H52. When power is supplied from the external power source, the heater part 52 generates enough heat to heat the wafer W placed on the mounting surface 11a. Note that in Figure 10, which shows a schematic plan view of the mounting surface 11a of the plate-shaped part 11, the base part 20 is omitted to avoid making the drawing too complex.
[0054] The heater section 52 has a circular shape in plan view of the mounting surface 11a of the plate-shaped section 11. In plan view of the mounting surface 11a of the plate-shaped section 11, the heater section 52 has a sixth region R6 located outside the ring shape formed by the first region R1, the second region R2, and the third region R3, and a seventh region R7 located outside the sixth region R6, which also has a ring shape. In the heater section 52, the sixth region R6 and the seventh region R7 form a second annular region Rc2 having a ring shape centered on the central axis C3 of the holding device 3. In the heater section 52 of this embodiment, the fourth region R4 having a ring shape is located inside the ring shape formed by the first region R1, the second region R2, and the third region R3, and a fifth region R5 is located inside the fourth region R4.
[0055] The holding device 3 of this embodiment has a plurality of heaters H52, namely a first heater H1, a second heater H2, a third heater H3, a fourth heater H4, a fifth heater H5, a sixth heater H6, and a seventh heater H7. In the holding device 3 of this embodiment, one heater is arranged in each region. Specifically, the first heater H1 is arranged in the first region R1, the second heater H2 is arranged in the second region R2, and the third heater H3 is arranged in the third region R3. The fourth heater H4 is arranged in the fourth region R4, and the fifth heater H5 is arranged in the fifth region R5. The sixth heater H6 is arranged in the sixth region R6, and the seventh heater H7 is arranged in the seventh region R7.
[0056] In the holding device 3 of this embodiment, one heater consists of a heating wire and a pair of pad portions connected to each end of the heating wire. The first heater H1, the second heater H2, and the third heater H3 are the same as in the first embodiment. The fourth heater H4 and the fifth heater H5 are the same as in the second embodiment. The sixth heater H6 consists of a heating wire E6 and a pair of pad portions P6a and P6b connected to each end of the heating wire E6. The seventh heater H7 consists of a heating wire E7 and a pair of pad portions P7a and P7b connected to each end of the heating wire E7.
[0057] Figure 11 is a diagram illustrating the connection relationships of the heaters in the heater unit 52 of this embodiment. In the heater unit 52, the first heater H1, the second heater H2, and the third heater H3, each located in the first region R1, the second region R2, and the third region R3 that form the first annular region Rc1, are connected in parallel to the power supply PS1. The fourth heater H4, located in the fourth region R4 which is inside the first annular region Rc1, and the fifth heater H5, located in the fifth region R5, are connected in parallel to the power supply PSc. The sixth heater H6, located in the sixth region R6, and the seventh heater H7, located in the seventh region R7, are connected in parallel to the power supply PS2. Specifically, the pads P6a and P6b of the sixth heater H6 are directly connected to the power supply PS2, and the pads P7a and P7b of the seventh heater H7 are directly connected to the power supply PS2. Note that in Figure 11, three power supplies PSc, PS1, and PS2 are shown to supply power to the heaters in the central region Rc0, the first annular region Rc1, and the second annular region Rc2, respectively, in order to make the connection relationships of the multiple heaters H52 easier to understand. However, one power supply may be used to power a single holding device.
[0058] As described above, according to the holding device 3 of this embodiment, the first region R1, the second region R2, and the third region R3 of the heater section 52 are each equipped with a first heater H1, a second heater H2, and a third heater H3 connected in parallel to each other. As a result, the same voltage is applied to each of the first heater H1, the second heater H2, and the third heater H3, so even if there is variation in the thickness of the heaters, the temperature distribution on the mounting surface 11a can be reduced. Therefore, the uniformity of the heat on the mounting surface 11a can be improved.
[0059] Furthermore, according to the holding device 3 of this embodiment, the heater section 52 has a sixth region R6 located outside the ring shape formed by the first region R1, the second region R2, and the third region R3, where the sixth heater H6 is located, and a seventh region R7 located outside the sixth region R6 where the seventh heater H7 is located. Since the sixth heater H6 and the seventh heater H7 are connected in parallel to each other, the same magnitude of voltage is applied to them. As a result, the relationship between the amount of heat generated by the sixth heater H6 and the seventh heater H7 is inversely proportional to the magnitude of their respective electrical resistances, so that uniform heating can be improved even if the mounting surface 11a is large.
[0060] <Fourth Embodiment> Figure 12 is a diagram illustrating the heater section of the holding device 4 of the fourth embodiment. The holding device 4 of the fourth embodiment differs from the holding device 3 of the third embodiment (Figure 10) in that the heater section has a region in which the heater is located outside the second annular region Rc2 which has an annular shape.
[0061] The holding device 4 of the fourth embodiment comprises a ceramic part 60, a base part 20, and a joint part 30. The holding device 3 of this embodiment is an electrostatic chuck that holds an object such as a wafer W by electrostatic attraction.
[0062] The ceramic part 60 is a component with a roughly disc shape, mainly composed of alumina. The ceramic part 60 comprises a plate-shaped part 11, a heater part 62, and a chuck electrode 13. The heater part 62 is positioned inside the plate-shaped part 11 so as to face the mounting surface 11a. The heater part 62 in this embodiment has multiple heaters. The multiple heaters are connected to an external power source via a power supply terminal 12a. When power is supplied from the external power source, the heater part 62 generates enough heat to heat the wafer W placed on the mounting surface 11a. Note that in Figure 12, which shows a schematic plan view of the mounting surface 11a of the plate-shaped part 11, the shapes of the base part 20 and the multiple heaters of the heater part 62 are omitted to avoid making the drawing too complex.
[0063] The heater section 62 has a circular shape in plan view of the mounting surface 11a of the plate-shaped section 11. The heater section 62 has an eighth region R8, a ninth region R9, a tenth region R10, and an eleventh region R11 that are arranged to form an annular shape in plan view of the mounting surface 11a of the plate-shaped section 11. The eighth region R8, the ninth region R9, the tenth region R10, and the eleventh region R11 form a third annular region Rc3 located outside the seventh region R7. Inside the seventh region R7 is a sixth region R6 which has an annular shape, and inside the sixth region R6 is a first annular region Rc1 formed by the first region R1, the second region R2, and the third region R3. Inside the first annular region Rc1 is a fourth region R4 which has an annular shape, and a fifth region R5 located inside the fourth region R4.
[0064] In the holding device 4 of this embodiment, one heater is arranged in each region. The heaters located in the eighth region R8, the ninth region R9, the tenth region R10, and the eleventh region R11 are connected in parallel to each other to an external power supply (not shown).
[0065] As described above, with respect to the holding device 4 of this embodiment, the heaters located in the eighth region R8, the ninth region R9, the tenth region R10, and the eleventh region R11 of the heater section 62 are connected in parallel with each other. As a result, the same voltage is applied to the heaters located in the eighth region R8, the ninth region R9, the tenth region R10, and the eleventh region R11, so that even if there is variation in the thickness of the heaters, the temperature distribution on the mounting surface 11a can be reduced. Therefore, the uniformity of the heat distribution on the mounting surface 11a can be improved.
[0066] <Modified form of this embodiment> The present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit, for example, the following modifications are also possible.
[0067] [Example 1] In the above-described embodiment, the first, second, and third regions of the heater section are arranged to form an annular shape in a plan view of the mounting surface 11a of the plate-like portion 11. The three regions may be arranged to form at least a part of the annular shape. For example, the first annular region Rc1 may be formed by four or more regions, including the first, second, and third regions.
[0068] [Differentiation 2] In the embodiment described above, each heater located in one of the multiple regions consists of a heating wire and a pair of pad portions connected to each end of the heating wire. The configuration of the heater is not limited to this. For example, the first heater located in the first region R1 may have multiple heating wires and multiple pairs of pad portions connected to each end of the multiple heating wires, provided that each of the multiple heating wires is connected to the power supply in parallel with each other.
[0069] [Difference 3] In the third embodiment, the heater section 52 includes a fourth ring-shaped region R4, a fifth region R5 located inside the fourth region R4, a first annular region Rc1 located outside the fourth region R4, and a second annular region Rc2 located outside the first annular region Rc1. The fourth region R4 and the fifth region R5 do not necessarily exist inside the first annular region Rc1, and a circular central region Rc0 may be located inside, as in the first embodiment.
[0070] [Differentiation Example 4] In the above-described embodiment, the holding device comprises a ceramic part mainly composed of ceramic, a base part made of metal, and a joint part that joins the ceramic part and the base part. The configuration of the holding device is not limited to this. The entire device may be made of ceramic, or it may be made of a composite material of ceramic and metal.
[0071] The embodiments of this specification have been described above based on the embodiments and modifications described above. The embodiments described above are for the purpose of facilitating understanding of this specification and do not limit it. This specification may be modified and improved without departing from its spirit and the scope of the claims, and equivalents thereof are included in this specification. Furthermore, any technical features that are not described as essential in this specification may be deleted as appropriate.
[0072] <Application Example 1> A holding device, A plate-shaped part having a mounting surface on which an object is placed, The plate-like portion comprises a heater portion arranged inside the plate-like portion so as to face the aforementioned mounting surface, The heater section is, In a plan view of the surface on which the plate-like portion is placed, it has a first region, a second region, and a third region arranged to form at least a part of an annular shape. The first heater located in the first region, the second heater located in the second region, and the third heater located in the third region are each connected in parallel to one another. holding device. <Application Example 2> The holding device described in Application Example 1, The heater portion has a fourth region located inside the ring shape formed by the first region, the second region and the third region in a plan view of the mounting surface of the plate-like portion. The fourth heater located in the fourth region is, Heating wire and It is characterized by comprising a pair of pad portions connected to each end of the heating element. holding device. <Application Example 3> A holding device as described in Application Example 1 or Application Example 2, The heater section is, In a plan view of the aforementioned surface of the plate-like portion, a fourth region having an annular shape is located inside the annular shape formed by the first region, the second region, and the third region, In a plan view of the aforementioned mounting surface of the plate-like portion, it has a fifth region located inside the fourth region, The fourth heater located in the fourth region and the fifth heater located in the fifth region are connected in parallel to each other, holding device. <Application Example 4> The holding device described in any one of the examples from Application Example 1 to Application Example 3 further, The heater section is, In a plan view of the aforementioned surface of the plate-like portion, a sixth region having an annular shape is located outside the annular shape formed by the first region, the second region, and the third region, In a plan view of the aforementioned mounting surface of the plate-like portion, it has a seventh region located outside the sixth region and having an annular shape, The sixth heater located in the sixth region and the seventh heater located in the seventh region are connected in parallel to each other, holding device. [Explanation of Symbols]
[0073] 1,2,3,4…holding device 11…Plate-like part 11a... Mounting surface 12, 42, 52, 62… Heater section E0,E1,E2,E3,E4,E5,E6,E7…heating wire P0a, P0b, P1a, P1b, P2a, P2b, P3a, P3b, P4a, P4b, P5a, P5b, P6a, P6b, P7a, P7b... Pad section H0...Central heater H1...First heater H2...Second heater H3...Third heater H4...4th heater H5...5th heater H6...6th heater H7...7th heater R1…first area R2…Second area R3...Third area R4…4th area R5…The 5th Domain R6…The 6th Domain R7…7th Domain W…ウェハ
Claims
1. A holding device, A plate-like portion having a disc shape and a mounting surface on which an object is placed, The plate-like portion comprises a heater portion arranged inside the plate-like portion so as to face the aforementioned mounting surface, The heater portion has a first region, a second region, and a third region arranged in a plan view of the mounting surface of the plate-like portion to form at least a part of an annular shape. The first heater located in the first region, the second heater located in the second region, and the third heater located in the third region are each connected in parallel to one another. The first heater, the second heater, and the third heater are formed such that their thickness changes along the radial direction of the plate-like portion from one side to the other, and they are characterized by having different electrical resistances from one another. holding device.
2. A holding device according to claim 1, The heater portion has a fourth region located inside the ring shape formed by the first region, the second region and the third region in a plan view of the mounting surface of the plate-like portion. The fourth heater located in the fourth region is Heating wire and It is characterized by comprising a pair of pad portions connected to each end of the heating element. holding device.
3. A holding device according to claim 1, The heater section is, In a plan view of the aforementioned surface of the plate-like portion, a fourth region having an annular shape is located inside the annular shape formed by the first region, the second region, and the third region, In a plan view of the aforementioned mounting surface of the plate-like portion, it has a fifth region located inside the fourth region, The fourth heater located in the fourth region and the fifth heater located in the fifth region are connected in parallel to each other, holding device.
4. The holding device described in claim 3 further, The heater section is, In a plan view of the aforementioned surface of the plate-like portion, a sixth region having an annular shape is located outside the annular shape formed by the first region, the second region, and the third region, In a plan view of the aforementioned mounting surface of the plate-like portion, it has a seventh region located outside the sixth region and having an annular shape, The sixth heater located in the sixth region and the seventh heater located in the seventh region are connected in parallel to each other, holding device.