Retaining member

Abstract

To provide a holding member that can improve the uniformity of heat distribution on the surface that holds the object. [Solution] In one aspect of the present disclosure, in an electrostatic chuck 1, the heating element 41 is a pair of heating elements It comprises an in 43, a first folded portion 45a, and a second folded portion 45b, and the first folded portion The circumferential pitch width δC, which is the distance between section 45a and the second folded section 45b, is the heat generation of a pair The radial pitch width δR, which is the distance between the two heating lines 42 that make up line 43, is greater than big.

Description

Technical Field

[0001] This disclosure relates to a holding member for holding an object.

Background Art

[0002] As a document related to a holding member, Patent Document 1 discloses a wafer heating device used in a film forming apparatus or an etching apparatus in a semiconductor device manufacturing process. And, the wafer heating device disclosed in this Patent Document 1 has a heater pattern formed by heating lines for heating a wafer inside a ceramic member (ceramic substrate) having a holding surface (a support surface of the wafer).

Prior Art Documents

[0003]

Patent Documents

Patent Document 1

Summary of the Invention

[0004]

Problems to be Solved by the Invention

[0005] Therefore, this disclosure was made to solve the above-mentioned problems, and to hold the object The objective is to provide a retaining member that can improve the uniformity of heat distribution on the surface. [Means for solving the problem]

[0006] One form of this disclosure made to solve the above problem is a first aspect and the first aspect is A first plate-like member having a second surface provided on the opposite side, a third surface, and the third surface The first plate has a second plate-like member having a fourth surface provided on the opposite side, and the first plate The second surface of the plate-shaped member and the third surface of the second plate-shaped member are thermally connected. Furthermore, in a holding member that holds an object on the first surface, the inside of the first plate-shaped member Alternatively, the heating element has linear heating lines formed in substantially concentric circles on the second surface, When viewed from the direction of arrangement of the first plate-shaped member and the second plate-shaped member, the heating element is the A pair of heating lines is formed from two heating lines that are adjacent to each other in the radial direction of the heating element. The first pair of heating lines are arranged separately in the circumferential direction of the heating element, separated by a predetermined separation region. and a second pair of heating lines and the two heating lines that constitute the first pair of heating lines The first folded portion connects the ends on the separated region side, and the second heating line pair It comprises a second folded portion that connects the ends of the two heating lines on the separated region side. The circumferential pitch width, which is the distance between the first folded portion and the second folded portion, The radial pitch width is the distance between the two heating lines that make up a pair of heating lines. It is also characterized by its large size.

[0007] According to this embodiment, by increasing the circumferential pitch width, the first folded portion and the second folded portion This suppresses the temperature rise in the separation region caused by heat generation in the return section. Therefore, it can hold the object. On the surface, that is, on the first surface of the first plate-like member, at the position corresponding to the separation region, A tosspot (i.e., a temperature singularity, a region where the temperature is higher than other parts) occurs. This can suppress the occurrence of heat generation. Therefore, it is possible to improve the uniformity of heat distribution on the surface that holds the object. ru.

[0008] In the above embodiment, the circumferential pitch width is 4 times or less the radial pitch width. It is preferable that...

[0009] According to this embodiment, the circumferential pitch width does not become too large, so the first folded portion and the second This can suppress insufficient temperature rise in the separated region due to heat generation at the folded portion. Therefore, on the surface that holds the object, a cold spot (sand) is located at the position corresponding to the separation region. This suppresses the occurrence of temperature singularities (areas where the temperature is lower than other parts). Yes, it is possible. Therefore, it is possible to more reliably improve the uniformity of the heat distribution on the surface that holds the object. ru.

[0010] In the above aspect, the resistance value per unit length of the heating line is preferably greater than the resistance value per unit length of the heating lines forming the pair of heating lines.

[0011] According to this aspect, the calorific value in the first folded portion and the second folded portion becomes large, so that generation of a cold spot at a position corresponding to the separation region on the surface holding the object can be suppressed. Therefore, furthermore, the heat uniformity of the surface holding the object can be improved.

[0012] In the above aspect, at least one of the first plate-like member and the second plate-like member has a through hole formed therein, and when viewed from the arrangement direction, the through hole is formed at the position of the separation region between the first folded portion and the second folded portion, and the circumferential pitch width is preferably greater than or equal to the circumferential width of the through hole.

[0013] According to this aspect, since the through hole is formed at the position of the separation region, the temperature easily rises in this separation region, but since the circumferential pitch width is greater than or equal to the circumferential width of the through hole, the distance between the first folded portion and the second folded portion becomes large, and an increase in temperature in the separation region can be suppressed.

[0014] Also, when a through hole is formed in the first plate-like member, by setting the circumferential pitch width to be greater than or equal to the circumferential width of the through hole, structurally, it is possible to prevent the heating element (the first folded portion and the second folded portion) from being formed in the portion of the through hole, and the portion inserted into the through hole This ensures sufficient insulation distance between the product and the heating element.

[0015] In the above embodiment, the holding member generates an electrostatic attractive force for holding the object. It is preferable that the electrostatic chuck has chuck electrodes that allow it to operate.

[0016] According to this embodiment, the uniformity of heat is improved on the surface that holds the object in the electrostatic chuck. It is possible. [Effects of the Invention]

[0017] The holding member of this disclosure can improve the uniformity of heat distribution on the surface that holds the object. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic perspective view of the electrostatic chuck of this embodiment. [Figure 2] This is an XY plan view of the electrostatic chuck of this embodiment. [Figure 3] This is an XZ cross-sectional view of the ceramic member of this embodiment. [Figure 4] This is a top view of the heating element of this embodiment. [Figure 5] This is an enlarged view of the pair of folded portions of the heating element in this embodiment and the surrounding area (an enlarged view of the area α in Figure 4). [Figure 6] This diagram shows a pair of folded portions of a heating element and its surrounding area, with a circumferential pitch width of 2.5 mm. [Figure 7] This is an evaluation result of the temperature distribution in a portion of the holding surface (i.e., the position on the holding surface corresponding to the hole in the base member and the surrounding area) when the circumferential pitch width is set to 2.5 mm. [Figure 8] This diagram shows a pair of folded portions of a heating element and its surrounding area, with a circumferential pitch width of 5.0 mm. [Figure 9]This is an evaluation result of the temperature distribution in a portion of the holding surface when the circumferential pitch width is 5.0 mm. [Figure 10] This diagram shows a pair of folded sections of a heating element and their surroundings, with a circumferential pitch width of 6.0 mm. [Figure 11] This is an evaluation result of the temperature distribution in a portion of the holding surface when the circumferential pitch width is 6.0 mm. [Figure 12] This diagram shows a pair of folded portions of a heating element and their surroundings, with a circumferential pitch width of 8.0 mm (and a line width ratio of 100%). [Figure 13] This is an evaluation result of the temperature distribution of a portion of the holding surface when the circumferential pitch width is 8.0 mm (and the line width ratio is 100%). [Figure 14] This graph shows the evaluation results of the temperature difference on the holding surface with respect to the circumferential pitch width. [Figure 15] This is a table showing the evaluation results of the temperature difference of the holding surface with respect to the circumferential pitch width. [Figure 16] This diagram shows a pair of folded sections of a heating element and their surroundings, with the line width ratio set to 75%. [Figure 17] This figure shows the evaluation results of the temperature distribution in a portion of the holding surface when the line width ratio is set to 75%. [Figure 18] This diagram shows a pair of folded sections of a heating element and their surroundings, with the line width ratio set to 50%. [Figure 19] This figure shows the evaluation results of the temperature distribution in a portion of the holding surface when the line width ratio is set to 50%. [Figure 20] This diagram shows a pair of folded sections of a heating element and their surroundings, with the line width ratio set to 25%. [Figure 21] This figure shows the evaluation results of a portion of the temperature distribution on the holding surface when the line width ratio is set to 25%. [Figure 22] This graph shows the evaluation results of the temperature difference on the holding surface in relation to the ratio of line width. [Figure 23]This is a table showing the evaluation results of the temperature difference on the holding surface in relation to the ratio of line width. [Figure 24] This is a diagram showing the first modified example. [Figure 25] This figure shows a second modified example. [Modes for carrying out the invention]

[0019] Embodiments of the retaining member of this disclosure will be described. In this embodiment, the retaining member is electrostatic I will explain using Chuck 1 as an example.

[0020] <Overall explanation of electrostatic chucks> The electrostatic chuck 1 of this embodiment is a device that holds a semiconductor wafer W by attracting it with electrostatic force. For example, to fix a semiconductor wafer W in a vacuum chamber of a semiconductor manufacturing apparatus. It is used. Note that the semiconductor wafer W is an example of the "subject matter" in this disclosure.

[0021] As shown in Figure 1, the electrostatic chuck 1 comprises a ceramic member 10 and a base member 20. It has a bonding layer 30 that joins the ceramic member 10 and the base member 20. Mixed member 10 is an example of the “first plate-like member” of this disclosure, and base member 20 is the same as the present disclosure This is an example of the "second plate-like member".

[0022] For the purposes of the following explanation, the XYZ axes will be defined as shown in Figure 1. Here, the Z-axis is the axis in the direction of the central axis Ca of the electrostatic chuck 1 (vertical direction in Figure 1). The X and Y axes are the radial axes of the electrostatic chuck 1.

[0023] As shown in Figure 1, the ceramic member 10 is plate-shaped, more specifically, disc-shaped. It is formed from ceramics (ceramic substrate). Specifically, the ceramic part Material 10 consists of two disks of different diameters that overlap with a common central axis Ca (see Figure 2) (details On top of the larger diameter disc-shaped lower section 10b, there is a smaller diameter disc-shaped upper section. It has a stepped disc shape (in which the stepped portions 10a overlap).

[0024] Various ceramics are used, but they have different strengths, wear resistances, and plastic resistances. From the viewpoint of zumminess, for example, aluminum oxide (alumina, Al2O3) or aluminum nitride It is preferable to use ceramics whose main component is luminium (AlN). The term "main component" here refers to the component that makes up the largest proportion (for example, a component with a volume content of 90 vol% or more). This refers to the above components.

[0025] As shown in Figures 1 to 3, the ceramic member 10 is a holding surface that holds the semiconductor wafer W. 11 (top surface) and the ceramic member 10 are held in the thickness direction (i.e., the Z-axis direction). It comprises a lower surface 12 provided on the opposite side of surface 11. Note that the retaining surface 11 is as described in this disclosure. The lower surface 12 is an example of the "first surface" of this disclosure.

[0026] Furthermore, the diameter of the ceramic member 10 is such that the lower section 10b is larger than the upper section 10a. The stepped section 10a is, for example, about 150-300 mm, and the lower stepped section 10b is, for example, 180-40 It is approximately 0 mm. The thickness of the ceramic component 10 is, for example, approximately 2 to 6 mm. The thermal conductivity of the ceramic member 10 is 10 to 50 W / mK (more preferably 18 to 3 A range of 0 W / mK is desirable.

[0027] Furthermore, the ceramic member 10 is equipped with a chuck electrode (adsorption electrode) (not shown) inside. It is. When a voltage is applied to this chuck electrode from a power source (not shown), the chuck An electrostatic attraction is generated at the electrode, and this electrostatic attraction causes the semiconductor wafer W to adhere to the holding surface 11. It is held and retained.

[0028] The base member 20 is positioned on the opposite side of the ceramic member 10 from the holding surface 11 side. It is. This base member 20 is formed in the shape of a cylinder, for example. Also, the base member 20 is For example, it is formed from a metal (for example, aluminum or aluminum alloy, etc.), It doesn't have to be metal.

[0029] Then, as shown in Figure 1, the base member 20 has an upper surface 21 and a thickness of the base member 20. It comprises a lower surface 22 provided on the opposite side of the upper surface 21 in the direction (i.e., the Z-axis direction), The upper surface 21 of the base member 20 is connected to the lower surface 12 of the ceramic member 10, and the bonding layer It is thermally connected via 30. Note that the upper surface 21 is an example of the “third surface” of this disclosure. Yes, the lower surface 22 is an example of the “fourth surface” of this disclosure.

[0030] The diameter of the base member 20 is, for example, about 180 to 400 mm. The thickness of 0 (dimension in the Z-axis direction) is, for example, about 20-50 mm. Note that base member 2 The thermal conductivity of 0 (assuming aluminum) is 160-250 W / mK (preferably 230 A range of approximately W / mK is desirable.

[0031] The bonding layer 30 is located between the lower surface 12 of the ceramic member 10 and the upper surface 21 of the base member 20. The components are positioned to join the ceramic member 10 and the base member 20 in a way that allows for heat transfer.

[0032] This bonding layer 30 is made of a resin containing a thermally conductive filler (silicone-based resin or acrylic resin). It is composed of adhesives such as epoxy resins and epoxy resins. The dimension in the Z-axis direction is, for example, about 0.1 to 1.5 mm. Also, the heat transfer of the bonding layer 30 The conductivity is, for example, 1.0 W / mK. Note that the bonding layer 30 (assuming a silicone-based resin) The thermal conductivity is within the range of 0.1 to 2.0 W / mK (preferably 0.5 to 1.5 W / mK). That is preferable.

[0033] In the electrostatic chuck 1 described above, the refrigerant flow path (not shown) provided in the base member 20 By flowing a refrigerant through it, the base member 20 is cooled, and as a result, through the bonding layer 30 Heat is transferred from the ceramic member 10 to the base member 20, and the ceramic member 10 cools down. And as the ceramic member 10 is cooled, it is held in place by the holding surface 11. It is designed to cool the semiconductor wafer W.

[0034] <About the heating element> In this embodiment, as shown in Figure 3, inside the upper portion 10a of the ceramic member 10, A heating element 41 is provided. That is, the heating element 41 is located in the upper part of the ceramic member 10. It is embedded in 10a. The heating element 41 generates heat to heat the semiconductor wafer W. The heating element 41 is formed of, for example, tungsten or a molybdenum alloy. However, other metals may also be used. Also, the heating element 41 is located below the ceramic member 10. It may also be embedded in the stepped portion 10b. Furthermore, the heating element 41 is located below the ceramic member 10. It may also be formed on surface 12.

[0035] As shown in Figure 4, the heating element 41 is located in the thickness direction of the ceramic member 10 (i.e., Figure 1 When viewed from the Z-axis direction, the linear heating lines 42 are formed in a substantially concentric manner. The line width LW of the heating line 42 is approximately 0.1 mm to 1.0 mm, and the diameter of the heating element 41 From two heating lines 42 that are arranged adjacent to each other (at least in part) in the opposite direction, It is equipped with a pair of heating lines 43. The two components that make up this pair of heating lines 43 The heating line 42 is formed in the same circular shape. The heating element 41 is an example shown in Figure 4. It has a number of pairs of heating lines 43, but at least two pairs of heating lines 4 It is sufficient if it has 3. Note that "approximately concentric circles" means that some of the circles in the circumferential direction are not connected. This includes circular shapes (for example, shapes where multiple elements are arranged in a fan shape).

[0036] As shown in Figure 5 (an enlarged view of region α in Figure 4), the heating element 41 is a pair of heating elements. Line 43 includes a first heating line pair 43a and a second heating line pair 43b. The first pair of heating lines 43a and the second pair of heating lines 43b are arranged in the circumferential direction of the heating element 41. They are arranged separately, separated by a predetermined separation region 44.

[0037] Furthermore, the heating element 41 has a pair of folded portions 45, namely a first folded portion 45a and a second folded portion 45a. It is equipped with a folded portion 45b. This first folded portion 45a and second folded portion 45b These are arranged separately from the heating element 41 in the circumferential direction, with a predetermined separation region 44 in between. The return section 45a is the separation region of the two heating lines 42 that constitute the first heating line pair 43a. The ends 42a on the 44 side are connected. The second folded portion 45b is connected to the second heating line 43b The ends 42b of the two heat lines 42 that make up the system are connected to each other on the side of the separation region 44.

[0038] <Means for improving heat uniformity of the holding surface> The base member 20 has holes Ho for inserting, for example, power supply terminals or temperature sensors. An example of a "through hole" in this disclosure is formed. And, as the hole Ho is formed in this way, In the area where it is located, the volume of the base member 20 decreases, so the ceramic member 10 is reduced to the base Therefore, heat is less likely to be drawn to member 20, and the holes in the holding surface 11 of the ceramic member 10 At the location corresponding to Ho, the temperature tends to rise easily.

[0039] In this embodiment, as shown in Figure 5, the arrangement of the ceramic member 10 and the base member 20 When viewed from the direction (i.e., the Z-axis direction in Figure 1), the first folded portion 45a and the second folded portion A hole Ho is formed at the location of the separation region 44 between part 45b and part 45b. In region 44, heat is less likely to be drawn from the ceramic member 10 to the base member 20. Therefore, the temperature is more likely to rise. In the example shown in Figure 5, the center of hole Ho is separated. It is formed so as to be located at the center of region 44.

[0040] And in this case, when the circumferential pitch width δC (see Figure 5) is small and the separation region 44 is narrow In this case, the heat generated by the first folded portion 45a and the second folded portion 45b causes odor in the separated region 44. The temperature rises significantly, and at the position corresponding to the separation region 44 on the holding surface 11, that is, At the location corresponding to hole Ho, there is a hot spot HS (i.e., a temperature singularity, and other There is a risk that areas may become hotter than the surrounding areas.

[0041] The "circumferential pitch width δC" refers to the first folded portion 45a and the second folded portion 45b. This is the distance between the first folded portion 45a and the second folded portion 45b. This is the maximum length in the circumferential direction.

[0042] In this embodiment, the circumferential pitch width δC is made larger than the radial pitch width δR, and further More specifically, the hole Ho is set to be at least as large as the diameter Dh (circumferential width). In this way, In this embodiment, the circumferential pitch width δC is increased, so the separation region 44 becomes wider. Due to the heat generated by the first folded portion 45a and the second folded portion 45b, the temperature in the separation region 44 It becomes difficult to raise. Therefore, at the position corresponding to the hole Ho on the holding surface 11, hot spoil This can suppress the occurrence of HS (Heatstroke Prevention).

[0043] Here, "radial pitch width δR" refers to the two heating elements that make up the pair of heating lines 43. This is the distance between in 42, and more specifically, the center of the retaining surface 11, which is formed to have a circular outer shape. This is the distance between two heat-generating lines 42 on a straight line La extending radially from the point. The radial pitch width δR is approximately constant throughout the heating element 41, for example, 1.5 mm~ It is 3.5 mm.

[0044] Here, we evaluate the relationship between the circumferential pitch width δC and the temperature distribution of the holding surface 11. This was done. Specifically, the diameter Dh of hole Ho was set to 5.0 mm, and the radial pitch width δR was set to 2. Under the conditions of a 5mm diameter and a line width LW of 0.5mm, the circumferential pitch width δC is 2.5mm. (See Figure 6), 5.0 mm (See Figure 8), 6.0 mm (See Figure 10), 8.0 mm (See Figure 1) (See reference 2) The temperature distribution of the holding surface 11 was evaluated.

[0045] As an evaluation result, first, when the circumferential pitch width δC was set to 2.5 mm (see Figure 6), In other words, if the circumferential pitch width δC is equal to the radial pitch width δR, then it will look like Figure 7. In addition, a hot spot HS occurred on the holding surface 11 at a position corresponding to the hole Ho. As shown in Figures 14 and 15, the temperature difference ΔT of the holding surface 11 was 15.7°C.

[0046] Note that the "temperature difference ΔT of the holding surface 11" corresponds to the center of the hole Ho on the holding surface 11. This is the temperature difference between one location and other locations (i.e., locations that do not correspond to hole Ho).

[0047] Furthermore, when the circumferential pitch width δC is set to 5.0 mm (see Figure 8), that is, the circumferential pitch If the pitch width δC is made larger than the radial pitch width δR and equal to the diameter Dh of the hole Ho, In combination, the results shown in Figure 9 were obtained. As shown in Figure 9, the hole H in the holding surface 11 The size of the hot spot HS that occurred at the position corresponding to o is 2 times the circumferential pitch width δC. It became smaller than when it was set to 5mm (see Figure 7). And as shown in Figures 14 and 15... The temperature difference ΔT of the holding surface 11 was 2.7℃. In this way, the circumferential pitch width δC was By making the radial pitch width greater than δR, hot spots H are created on the holding surface 11. We were able to obtain results that suppressed the generation of S.

[0048] Furthermore, when the circumferential pitch width δC is set to 6.0 mm (see Figure 10), that is, circumferential When the pitch width δC is greater than the diameter Dh of the hole Ho, the results shown in Figure 11 are obtained. As shown in Figure 11, a small amount of material was found on the holding surface 11 at the position corresponding to hole Ho. A temperature singularity CS (i.e., a part where the temperature is lower than other parts) Although a (minute) occurred, no hotspot HS occurred. And as shown in Figures 14 and 15. Thus, the temperature difference ΔT of the holding surface 11 was -0.9℃. If δC is made larger than the diameter Dh of the hole Ho, hot spots will appear on the holding surface 11. We were able to obtain results in which HS (High Stress Factor) did not occur.

[0049] Furthermore, when the circumferential pitch width δC is set to 8.0 mm (see Figure 12), that is, circumferential If the pitch width δC is even larger than the diameter Dh of the hole Ho, then the following configuration is possible, as shown in Figure 13. The result was obtained. As shown in Figure 13, a small Cold spots (CS) occurred, but hot spots (HS) did not. And, As shown in Figures 14 and 15, the temperature difference ΔT of the holding surface 11 was -5.1°C. Furthermore, if the circumferential pitch width δC is made even larger than the diameter Dh of the hole Ho, the retaining surface 1 In case 1, we were able to obtain the result that no hotspots (HS) occurred.

[0050] Here, when the circumferential pitch width δC is set to 8.0 mm (see Figure 12), the result is shown in Figure 13. As a result, small cold spots CS occurred on the holding surface 11. If the width δC is increased beyond 8.0 mm, an even larger cold spot CS will be created. There is a risk that this may occur.

[0051] Therefore, in this embodiment, the circumferential pitch width δC is set to be 4 times or less the radial pitch width δR. This suppresses the occurrence of cold spots CS on the holding surface 11.

[0052] Furthermore, if the line width LW of the heating line 42 is reduced, its resistance increases. The amount of heat generated increases. Therefore, if cold spots (CS) are likely to occur, a pair of folding... The line width LW1 of the return section 45 may be smaller than the line width LW of the pair of heating lines 43. And in this way, the unit length of the heating line 42 that forms a pair of folded portions 45 The resistance value per unit length of the heating line 42 that forms a pair of heating lines 43 is the resistance It may be made larger than the resistance value. This results in the first folded portion 45a and the second folded portion 45 By increasing the heat generated by b, the occurrence of cold spots CS on the holding surface 11 can be suppressed. .

[0053] Note that "the line width LW1 of the pair of folded portions 45" refers to the first folded portion 45a and the second This is the line width of the heating line 42 that forms the folded portion 45b. Also, "a pair of heating lines 4 "Line width LW of 3" is the line width of the two heating lines 42 that form a pair of heating lines 43. ru.

[0054] Furthermore, the resistance value per unit length of the heating line 42 that forms the pair of folded portions 45 is The resistance per unit length of the heating line 42 that forms the pair of heating lines 43 is greater than the resistance per unit length of the heating line 42. Another method involves reducing the thickness of the heating line 42 that forms a pair of folded portions 45. Making it smaller than the thickness of the heating line 42 that forms the pair of heating lines 43, or folding a pair The material of the heating line 42 that forms the return section 45 is the heating element that forms the pair of heating lines 43 It is also possible to use a material with a higher resistivity than the material used for IN42.

[0055] Here, we discuss the relationship between the line width LW1 of the pair of folded portions 45 and the temperature distribution of the holding surface 11. The evaluation was performed. Specifically, the radial pitch width δR was set to 2.5 mm, and the circumferential pitch width δ Under the condition that C is 8.0 mm, the line width LW1 of the pair of folded parts 45 is changed, and the holding surface We evaluated the temperature distribution of 11 samples. More specifically, under the condition that the line width LW is 0.5 mm. The ratio LR of the line width, which represents the size of the line width LW1 of the pair of folded portions 45, is set to 100% (the above (See Figure 12), 75% (See Figure 16), 50% (See Figure 18), 25% (See Figure 20) The evaluation was conducted as follows. Note that "line width ratio LR" refers to the line width LW of a pair of heating lines 43. This is the ratio of the line width LW1 of the pair of folded sections 45 to (LW1 / LW) × 100%. This is shown by the following formula:

[0056] As an evaluation result, first, when the line width ratio LR is set to 100% (see Figure 12 above) As shown in Figure 13 above, in the holding surface 11, at the position corresponding to the hole Ho, Spot CS occurred. And, as shown in Figures 22 and 23, the temperature difference of the holding surface 11 ΔT was -5.1℃.

[0057] Furthermore, when the line width ratio LR is set to 75% (see Figure 16), that is, a pair of folds If the line width LW1 of section 45 is made smaller than the line width LW of the pair of heating lines 43, then Figure 1 As shown in 7, a cold spot occurred on the holding surface 11 at a position corresponding to hole Ho. CS became smaller than when the line width ratio LR was set to 100% (see Figure 13). As shown in Figures 22 and 23, the temperature difference ΔT of the holding surface 11 was -2.2°C. Thus, the line width LW1 of the pair of folded sections 45 is smaller than the line width LW of the pair of heating lines 43. This results in the suppression of cold spot CS on the holding surface 11. And it was done.

[0058] Furthermore, when the line width ratio LR is set to 50% (see Figure 18), and when the line width ratio LR is set When set to 25% (see Figure 20), that is, the line width LW1 of a pair of folded sections 45 is one pair If the line width LW of the heating line 43 is made even smaller, as shown in Figures 19 and 21. However, a hot spot HS occurred at the position corresponding to the hole Ho on the holding surface 11. No cold spots (CS) occurred. And, as shown in Figures 22 and 23, The temperature differences ΔT on surface 11 were 1.7°C and 16.0°C.

[0059] As a first modified example, as shown in Figure 24, the pair of folded portions 45 are separated into a separation region 44 It is formed in a curved arc shape, moving away from (away from hole Ho). This is also acceptable. In this case, the circumferential pitch width δC is the radial center of the first folded portion 45a This is the straight-line distance between the radial central portion 45c of section 45c and the second folded portion 45b. In other words, the vertex of the arc of the first folded portion 45a and the vertex of the arc of the second folded portion 45b This is the straight-line distance between two points.

[0060] Furthermore, if a hole Ho is formed in the ceramic member 10, the part inserted into the hole Ho is In order to ensure an insulating distance between the component and the pair of folded portions 45 of the heating element 41, the circumferential pitch The width δC is made larger than the diameter Dh of the hole Ho, with a margin of safety. In this case, for example, hole H If the diameter Dh of o is 5 mm, the circumferential pitch width δC should be 7 mm or more.

[0061] Furthermore, when a hole Ho is formed in the ceramic member 10, in this manner the circumferential direction Even if the pitch width δC is increased, hot spots will still form on the holding surface 11 at the position corresponding to the hole Ho. If the generation of HS cannot be suppressed, as a second modification, as shown in Figure 25, a pair The line width LW1 of the folded portion 45 may be made larger than the line width LW of the pair of heating lines 43. And this reduces the resistance value of the heating line 42 that forms the pair of folded portions 45. Thus, by reducing the amount of heat generated by the pair of folded portions 45, holes are formed in the holding surface 11. The generation of hotspots (HS) can be suppressed at the location corresponding to Ho.

[0062] <Effects of this embodiment> As described above, in the electrostatic chuck 1 of this embodiment, the heating element 41 of the ceramic member 10 In this context, the circumferential pitch is the distance between the first folded portion 45a and the second folded portion 45b. The width δC is the radial distance between the two heating lines 42 that make up the pair of heating lines 43. It is larger than the pitch width δR.

[0063] In this way, by increasing the circumferential pitch width δC, the first folded portion 45a This suppresses the temperature rise in the separation region 44 caused by heat generation in the second folded portion 45b. Therefore, if a hole Ho is formed in the base member 20 at a position corresponding to the separation region 44, However, the temperature rise in the separation region 44 can be suppressed. Therefore, on the holding surface 11 Hot spot HS is located at a position corresponding to the separation region 44, that is, at a position corresponding to hole Ho. This can suppress the occurrence of this phenomenon. Therefore, the uniformity of the heat distribution on the holding surface 11 can be improved.

[0064] Furthermore, since the hole Ho is formed at the location of the separation region 44, the temperature in this separation region 44 This makes it easier for the temperature to rise. However, in this embodiment, the circumferential pitch width δC is the straight of the hole Ho The diameter is set to be greater than or equal to the size between the first folded portion 45a and the second folded portion 45b. This increases the distance between the two regions, which helps to suppress the temperature rise in the separation region 44.

[0065] Furthermore, if a hole Ho is formed in the ceramic member 10, the circumferential pitch width δC By making the diameter of the hole Ho greater than or equal to the diameter Dh, the heating element 41 (first fold) is structurally defined. This prevents the formation of part 45a and the second folded part 45b in the hole Ho. This ensures sufficient insulation distance between the component inserted into hole Ho and the heating element 41.

[0066] Furthermore, the circumferential pitch width δC is less than or equal to four times the radial pitch width δR.

[0067] In this way, the circumferential pitch width δC does not become too large, so the first folded portion 45 The temperature rise in the separation region 44 due to the heat generated by a and the second folded portion 45b is insufficient. This can be suppressed. Therefore, on the holding surface 11, at a position corresponding to the separation region 44, i.e., a hole This can suppress the occurrence of cold spots CS at the location corresponding to Ho. Therefore, This makes it possible to more reliably improve the uniformity of the heat distribution on the holding surface 11.

[0068] Furthermore, a cold spot CS occurs on the holding surface 11 at a position corresponding to the hole Ho. If so, the line width LW1 of the pair of folded sections 45 is the line width of the pair of heating lines 43 It may be smaller than LW. And in this way, a pair of folded portions 45 are formed. The resistance value per unit length of the heating line 42 is determined by the heating lines forming a pair of heating lines 43. The resistance per unit length may be greater than that of IN42.

[0069] This increases the amount of heat generated in the first folded portion 45a and the second folded portion 45b. Thus, by increasing the temperature rise in the separation region 44, holes are formed in the holding surface 11. This can suppress the occurrence of cold spots (CS) at the location corresponding to Ho.

[0070] The embodiments described above are merely illustrative and do not limit the present disclosure in any way. Of course, various improvements and modifications are possible within the bounds of not deviating from its essence.

[0071] For example, the invention of this disclosure can also be applied when the outer shape of hole Ho is not circular. In addition, the circumferential pitch width δC should be greater than or equal to the circumferential width of the hole Ho.

[0072] Furthermore, the hole Ho is formed in at least one of the ceramic member 10 and the base member 20. It is sufficient if it is formed on both the ceramic member 10 and the base member 20. It's okay to be there. [Explanation of Symbols]

[0073] 1. Electrostatic Chuck 10 Ceramic components 11 Holding surface 12 Bottom side 20 Base members 21 Top side 22 Bottom side 41 Heating element 42 Heating lines 42a end 42b End 43 Pair of heating lines 43a First heat line pair 43b Second heating line pair 44 Separation area 45 A pair of folded sections 45a First Fold-Over Section 45b Second Fold-Over Section 45c central part W Semiconductor wafer LW line width Ho Hole δC circumferential pitch width HS hotspot δR radial pitch width Dh (hole) diameter ΔT (temperature difference of the holding surface) CS Cold Spot LW1 (line width of the first and second folds) LR line width ratio

Claims

1. A first plate-like portion comprising a first surface and a second surface provided on the opposite side of the first surface. Materials and, A second plate-like portion comprising a third surface and a fourth surface provided on the opposite side of the third surface. Materials and, It has, The second surface of the first plate-like member and the third surface of the second plate-like member are thermal It is connected, In the holding member that holds an object on the first surface, Within the first plate-shaped member or on the second surface, linear heating lines are arranged in substantially concentric circles. Having a heat-generating element, When viewed from the direction of arrangement of the first plate-like member and the second plate-like member, The aforementioned heating element is A pair of heating elements, each consisting of two adjacent heating lines in the radial direction of the heating element. As a line, the first heating element is arranged separately in the circumferential direction of the heating element, separated by a predetermined separation region. A pair of heat lines and a second pair of heat lines, The ends of the two heating lines constituting the first heating line pair on the separation region side The first folding section that connects the two parts, The ends of the two heating lines constituting the second pair of heating lines on the separation region side The second folding section that connects the two parts, Equipped with, The circumferential pitch width, which is the distance between the first folded portion and the second folded portion, The radial pitch width is the distance between the two heating lines that make up the pair of heating lines. It's even bigger, A retaining member characterized by the following.

2. In the retaining member of claim 1, The circumferential pitch width is no more than four times the radial pitch width. A retaining member characterized by the following.

3. In the retaining member of claim 1 or 2, The unit length of the heating line forming the first folded portion and the second folded portion The resistance value per unit length of the heating line forming the pair of heating lines is the resistance per unit length of the heating line. It must be greater than the resistance value. A retaining member characterized by the following.

4. In any one of the holding members of claims 1 to 3, A through hole is formed in at least one of the first plate-like member and the second plate-like member. Re, When viewed from the aforementioned arrangement direction, The through hole is the separation region between the first folded portion and the second folded portion. It is formed at the position, The circumferential pitch width is greater than or equal to the circumferential width of the through hole. A retaining member characterized by the following.

5. In any one of the holding members from claim 1 to 4, The holding member has a chuck electrode that generates an electrostatic attractive force for holding the object. It is an electrostatic chuck. A retaining member characterized by the following.

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