Holding member and holding device

Abstract

To provide a holding member which can improve the thermal uniformity of the surface of a plate-like member, and a holding device having the holding member.SOLUTION: A ceramic member 10 includes heat generation circuits 43 in a second zone ZO2, which are an inner heat generation circuit 62 and an external heat generation circuit 61 arranged in the outer peripheral side of the heater electrode 41 than the inner heat generation circuit 62. An outside heater line length L1, which is the length of the heater line 42 of the external heat generation circuit 61, is larger than an inner heater line length L2, which is the length of the heater line 42 of the inner heat generation circuit 62. Also, an outside heater line width b1 as the line width of the heater line 42 of the external side heat generation circuit 61 is larger than an inner heater line width b2, as the line width of the heater line 42 of the inner side heat generation circuit 62.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a holding member and a holding device for holding an object. [Background technology]

[0002] Patent Document 1 discloses a ceramic heater (holding member) having heater electrodes that are embedded in a disk-shaped ceramic substrate (plate-shaped member) and formed concentrically. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-126770 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the ceramic heater disclosed in Patent Document 1, the heater electrode is divided into multiple zones (i.e., two zones, an inner periphery zone and an outer periphery zone). When the heater electrode is divided into multiple zones in this way, if multiple heater circuits are provided in one zone, temperature variations will occur if the heat generation density of each heater circuit differs. This causes temperature variations on the surface of the ceramic substrate, and there is a risk that the thermal uniformity of the surface of the ceramic substrate will decrease.

[0005] Therefore, the present disclosure has been made to solve the above-mentioned problems, and aims to provide a holding member that improves thermal uniformity on the surface of a plate-shaped member, and a holding device having this holding member. [Means for solving the problem]

[0006] One form of the present disclosure made to solve the above problems is characterized in that, in a holding member having a plate-shaped member and a heating element embedded in the plate-shaped member, the heating element has a plurality of heating circuits formed by linear heating lines, the plurality of heating circuits are arranged in a plurality of zones for each power source to which they are connected, and in at least one of the zones, the heating circuits include an inner heating circuit and an outer heating circuit arranged on the outer periphery of the heating element relative to the inner heating circuit, and a length of the heating line of one of the inner heating circuit and the outer heating circuit is greater than a length of the heating line of the other heating circuit, and a line width of the heating line of the one heating circuit is greater than a line width of the heating line of the other heating circuit.

[0007] According to this embodiment, one of the inner and outer heating circuits has a larger heating line length and a larger line width than the other heating circuit. This makes it possible to suppress the difference in heat density between the inner and outer heating circuits. Therefore, it is possible to suppress the temperature variation within one zone. Therefore, it is possible to suppress the temperature variation on the surface of the plate-like member and improve the thermal uniformity of the surface of the plate-like member.

[0008] If the line width of the heating line becomes too large, the resistance value of the heating line becomes very small, and the heat density of the heating line may be excessively reduced. Therefore, in the above aspect, it is preferable that the line width of the heat generating line of the one heat generating circuit is five times or less the line width of the heat generating line of the other heat generating circuit.

[0009] According to this embodiment, the line width of the heat generating line of one heat generating circuit is kept to 5 times or less the line width of the heat generating line of the other heat generating circuit. This makes it possible to suppress an excessive decrease in heat density of one heat generating circuit. Therefore, it is possible to more effectively suppress the difference in heat density between the inner heat generating circuit and the outer heat generating circuit.

[0010] If the length of the heat generating line is too large, the heat density of the heat generating line may increase excessively. Therefore, in the above aspect, it is preferable that the length of the heat generating line of the one heat generating circuit is 5 times or less the length of the heat generating line of the other heat generating circuit.

[0011] According to this embodiment, the length of the heat generating line of one heat generating circuit is kept to 5 times or less the length of the heat generating line of the other heat generating circuit. This makes it possible to suppress an excessive increase in heat density of one heat generating circuit. Therefore, it is possible to more effectively suppress the difference in heat density between the inner heat generating circuit and the outer heat generating circuit.

[0012] In the above aspect, it is preferable that the one heating circuit is the outer heating circuit, and the other heating circuit is the inner heating circuit.

[0013] According to this aspect, the outer heat generating circuit has a larger heat generating line length and a larger line width than the inner heat generating circuit, thereby making it possible to suppress the difference in heat density between the inner heat generating circuit and the outer heat generating circuit.

[0014] In the above aspect, it is preferable that the one heating circuit is the inner heating circuit, and the other heating circuit is the outer heating circuit.

[0015] According to this aspect, the inner heating circuit has a heating line that is longer in length and has a larger line width than the outer heating circuit, thereby making it possible to reduce the difference in heat density between the inner heating circuit and the outer heating circuit.

[0016] Another aspect of the present disclosure made to solve the above problem is characterized in that a holding device has the holding member of the above aspect.

[0017] According to this aspect, the temperature uniformity on the surface of the plate-like member that holds the object is improved. Effect of the Invention

[0018] According to the holding member and holding device of the present disclosure, the thermal uniformity of the surface of the plate-like member is improved. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic perspective view of an electrostatic chuck according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an XZ cross-sectional view of the ceramic member of the present embodiment. [Diagram 3] FIG. 2 is a top view of a heater electrode according to the present embodiment. [Figure 4] FIG. 1 is a diagram showing the relationship between power sources and zones. [Diagram 5] FIG. 13 is a top view of a heater electrode according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] An embodiment of a holding member and a holding device according to the present disclosure will be described. In this embodiment, a ceramic member 10 is exemplified as the holding member, and an electrostatic chuck 1 is exemplified as the holding device. The electrostatic chuck 1 is used in semiconductor manufacturing equipment such as a film forming apparatus (such as a CVD film forming apparatus or a sputtering film forming apparatus) or an etching apparatus (such as a plasma etching apparatus).

[0021] <Overall explanation of electrostatic chuck> The electrostatic chuck 1 of the present embodiment is a device that attracts and holds a semiconductor wafer W by electrostatic attraction, and is used, for example, to fix the semiconductor wafer W in a vacuum chamber of a semiconductor manufacturing device. The semiconductor wafer W is an example of an "object" in the present disclosure.

[0022] 1, the electrostatic chuck 1 includes a ceramic member 10, a base member 20, and a bonding layer 30 that bonds the ceramic member 10 to the base member 20. The ceramic member 10 is an example of the "holding member" of the present disclosure.

[0023] In the following description, for convenience of explanation, the X, Y and Z axes are defined as shown in Fig. 1. Here, the Z axis is an axis in the central axis direction of the electrostatic chuck 1 (the vertical direction in Fig. 1), and the X and Y axes are axes in the radial directions of the electrostatic chuck 1.

[0024] 1 and 2, the ceramic member 10 is a plate-like, more specifically, disk-like member, and is formed of a ceramic substrate 40. The ceramic member 10 has a stepped disk shape in which two disks of different diameters are overlapped with a common central axis (more specifically, a disk-shaped upper stage portion 10a having a smaller diameter is overlapped on a disk-shaped lower stage portion 10b having a larger diameter).

[0025] Although various ceramics are used as the ceramics forming the ceramic member 10, it is preferable to use ceramics containing aluminum oxide (alumina, Al2O3) or aluminum nitride (AlN) as the main component from the viewpoints of strength, wear resistance, plasma resistance, etc. Here, the main component means the component with the highest content (for example, a component with a volume content of 90 vol% or more).

[0026] 1 and 2, the ceramic member 10 has a holding surface 11 (upper surface) that holds a semiconductor wafer W, and a lower surface 12 that is provided on the opposite side to the holding surface 11 in the thickness direction (i.e., the Z-axis direction) of the ceramic member 10. The holding surface 11 is an example of a surface of a "holding member" in the present disclosure.

[0027] The upper portion 10a of the ceramic member 10 has a diameter of, for example, about 150 to 300 mm, and the lower portion 10b has a diameter of, for example, about 180 to 400 mm. The thickness of the ceramic member 10 is, for example, about 2 to 6 mm. The thermal conductivity of the ceramic member 10 is preferably within a range of 10 to 50 W / mK (more preferably, 18 to 30 W / mK).

[0028] The ceramic member 10 also has a chuck electrode (adsorption electrode) (not shown) inside it. When a voltage is applied to the chuck electrode from a power source (not shown), an electrostatic force of attraction is generated in the chuck electrode, and the semiconductor wafer W is attracted to and held on the holding surface 11 by the electrostatic force of attraction.

[0029] The base member 20 is disposed on the opposite side of the ceramic member 10 from the holding surface 11. The base member 20 is formed, for example, in a cylindrical shape. The base member 20 is formed, for example, from a metal (for example, aluminum or an aluminum alloy), but may be formed from a material other than metal.

[0030] 1, the base member 20 has an upper surface 21 and a lower surface 22 provided on the opposite side to the upper surface 21 in the thickness direction (i.e., the Z-axis direction) of the base member 20. The upper surface 21 of the base member 20 is thermally connected to the lower surface 12 of the ceramic member 10 via a bonding layer 30.

[0031] The diameter of the base member 20 is, for example, about 180 to 400 mm. The thickness (dimension in the Z-axis direction) of the base member 20 is, for example, about 20 to 50 mm. The thermal conductivity of the base member 20 (assumed to be aluminum) is desirably within a range of 160 to 250 W / mK (preferably, about 230 W / mK).

[0032] The bonding layer 30 is disposed between the lower surface 12 of the ceramic member 10 and the upper surface 21 of the base member 20, and bonds the ceramic member 10 and the base member 20 in a heat-transferable manner.

[0033] The bonding layer 30 is made of an adhesive material of resin (such as silicone resin, acrylic resin, or epoxy resin) containing a thermally conductive filler. The thickness (dimension in the Z-axis direction) of the bonding layer 30 is, for example, about 0.1 to 1.5 mm. The thermal conductivity of the bonding layer 30 is, for example, 1.0 W / mK. The thermal conductivity of the bonding layer 30 (assuming a silicone resin) is desirably within a range of 0.1 to 2.0 W / mK (preferably 0.5 to 1.5 W / mK).

[0034] <About the heater electrode> In this embodiment, as shown in Fig. 2, the ceramic member 10 has a heater electrode 41. The heater electrode 41 is embedded inside the ceramic substrate 40 that forms the ceramic member 10, and generates heat to heat the semiconductor wafer W held on the holding surface 11. The heater electrode 41 is formed of, for example, tungsten or a molybdenum alloy, but may be formed of other metals. The heater electrode 41 is an example of a "heating element" in the present disclosure.

[0035] The heater electrode 41 has linear heater lines 42 formed in a substantially concentric shape as shown in Fig. 3 when viewed in the thickness direction of the ceramic member 10, and the heater lines 42 have a line width of about 0.1 mm to 1.0 mm. The heater lines 42 are an example of a "heating line" in the present disclosure.

[0036] In this embodiment, the heater electrode 41 includes a plurality of heater circuits 43 formed by heater lines 42. The plurality of heater circuits 43 are arranged in a plurality of zones ZO for each power source 50 to be connected. The heater circuits 43 are an example of a "heat generating circuit" in the present disclosure.

[0037] For example, as shown in Figures 3 and 4, a plurality of zones ZO are formed, including a first zone ZO1 (the region on the inner side of the dashed dotted line on the inner side shown in Figure 3) in which a heater circuit 43 connected to a first power source 51 is arranged, and a second zone ZO2 (the region between the dashed dotted line on the inner side and the dashed dotted line on the outer side shown in Figure 3) in which a heater circuit 43 connected to a second power source 52 is arranged.

[0038] The first power source 51 is connected to the power supply portion 43a (see FIG. 3) of the heater circuit 43 in the first zone ZO1. The second power source 52 is connected to the power supply portion 43a of the heater circuit 43 in the second zone ZO2 (i.e., the power supply portion 61a (see FIG. 3) of the outer heater circuit 61 described later and the power supply portion 62a (see FIG. 3) of the inner heater circuit 62 described later).

[0039] In addition, although three heater circuits 43 and two zones ZO are illustrated in Figures 3 and 4, the number of heater circuits 43 and zones ZO is not limited to this, and four or more heater circuits 43 may be arranged, and three or more zones ZO may be formed.

[0040] <Measures to improve the temperature uniformity of the holding surface> 3, in the second zone ZO2, the heater circuit 43 includes an inner heater circuit 62 and an outer heater circuit 61 that is disposed closer to the outer periphery of the heater electrode 41 than the inner heater circuit 62. The outer heater circuit 61 is an example of an "outer heat generating circuit" in the present disclosure, and the inner heater circuit 62 is an example of an "inner heat generating circuit" in the present disclosure.

[0041] In this embodiment, the relationship between the length and line width of the heater lines 42 of the outer heater circuit 61 and the inner heater circuit 62 arranged in the same second zone ZO2 is specified to suppress the difference in heat generation density between the outer heater circuit 61 and the inner heater circuit 62.

[0042] Specifically, the outer heater wire length L1 is greater than the inner heater wire length L2 (i.e., L1>L2), and the outer heater wire width b1 is greater than the inner heater wire width b2 (i.e., b1>b2).

[0043] It should be noted that the "outer heater wire length L1" is the length of the heater line 42 of the outer heater circuit 61. Also, the "inner heater wire length L2" is the length of the heater line 42 of the inner heater circuit 62. Also, the "outer heater wire width b1" is the line width of the heater line 42 of the outer heater circuit 61. Also, the "inner heater wire width b2" is the line width of the heater line 42 of the inner heater circuit 62.

[0044] Here, the heat density of the heater line 42 increases as its length increases, whereas the heat density decreases as its line width increases. Therefore, in this embodiment, as described above, the outer heater line length L1 is made larger than the inner heater line length L2, and the outer heater line width b1 is made larger than the inner heater line width b2.

[0045] In this way, the outer heater circuit 61 is adjusted so that the heat density of the outer heater circuit 61 is equivalent to that of the inner heater circuit 62 by making the heater line 42 longer in length and wider in width than the inner heater circuit 62. On the other hand, the inner heater circuit 62 is adjusted so that the heat density of the inner heater circuit 62 is equivalent to that of the outer heater circuit 61 by making the heater line 42 shorter in length and narrower in width than the outer heater circuit 61. This suppresses the difference in heat density between the outer heater circuit 61 and the inner heater circuit 62. Therefore, it is possible to suppress the temperature variation in the second zone ZO2. Therefore, it is possible to suppress the temperature variation of the holding surface 11, and the temperature uniformity of the holding surface 11 is improved.

[0046] Furthermore, as described above, the outer heater wire width b1 is made larger than the inner heater wire width b2. However, if the outer heater wire width b1 becomes too large, the resistance value of the heater line 42 of the outer heater circuit 61 becomes very small, which may result in an excessive reduction in the heat generation density of the outer heater circuit 61.

[0047] Therefore, in this embodiment, the outer heater line width b1 is larger than the inner heater line width b2, but is kept to be 5 times or less than the inner heater line width b2.

[0048] This ensures the resistance value of the heater line 42 in the outer heater circuit 61, thereby suppressing an excessive decrease in heat generation density. Therefore, the difference in heat generation density between the outer heater circuit 61 and the inner heater circuit 62 can be more effectively suppressed.

[0049] Furthermore, as described above, the outer heater wire length L1 is made greater than the inner heater wire length L2. However, if the outer heater wire length L1 is too large, the heat density of the outer heater circuit 61 may increase excessively.

[0050] Therefore, in this embodiment, the outer heater wire length L1 is greater than the inner heater wire length L2, but is kept to be 5 times or less than the inner heater wire length L2.

[0051] This makes it possible to suppress an excessive increase in the heat generation density in the outer heater circuit 61. Therefore, the difference in heat generation density between the outer heater circuit 61 and the inner heater circuit 62 can be suppressed more effectively.

[0052] As a modified example, as shown in FIG. 5, the inner heater wire length L2 may be larger than the outer heater wire length L1 (i.e., L2>L1), and the inner heater wire width b2 may be larger than the outer heater wire width b1 (i.e., b2>b1).

[0053] In this case, the inner heater wire width b2 is preferably kept to 5 times or less the outer heater wire width b1, and the inner heater wire length L2 is preferably kept to 5 times or less the outer heater wire length L1.

[0054] It should be noted that the above-described embodiments are merely examples and do not limit the present disclosure in any way. Needless to say, various improvements and modifications are possible without departing from the spirit and scope of the present disclosure.

[0055] For example, the above description exemplifies an outer heater circuit 61 and an inner heater circuit 62 in the second zone ZO2, but this is not limited to this, and the outer heater circuit 61 and the inner heater circuit 62 may be provided in the first zone ZO1, or in both the first zone ZO1 and the second zone ZO2.

[0056] Further, in the above description, two zones ZO, a first zone ZO1 and a second zone ZO2, are provided as the multiple zones ZO, but the present invention is not limited to this, and three or more zones ZO may be provided. [Explanation of symbols]

[0057] 1. Electrostatic chuck 10 Ceramic materials 11 Holding surface 20 Base material 30 Bonding layer 40 Ceramic Substrate 41 Heater electrode 42 Heater Line 43 Heater Circuit 50 power supply 51 1st power supply 52 2nd power supply 61 Outside heater circuit 62 Inner heater circuit W Semiconductor wafer ZO Zone ZO1 1st Zone ZO2 Second Zone L1 Outer heater wire length L2 Inner heater wire length b1 Outer heater wire width b2 Inner heater line width

Claims

1. A plate-like member; A heating element embedded in the plate-shaped member; In a holding member having The heating element includes a plurality of heating circuits formed by linear heating lines, The plurality of heat generating circuits are arranged in a plurality of zones for each power source to which they are connected, In at least one of the zones, the heat generating circuit includes an inner heat generating circuit and an outer heat generating circuit disposed on an outer circumferential side of the heat generating body relative to the inner heat generating circuit, a length of the heat generating line of one of the inner heat generating circuit and the outer heat generating circuit is greater than a length of the heat generating line of the other heat generating circuit; and, a line width of the heat generating line of the one heat generating circuit is larger than a line width of the heat generating line of the other heat generating circuit; A holding member comprising:

2. The holding member according to claim 1, the line width of the heat generating line of the one heat generating circuit is 5 times or less the line width of the heat generating line of the other heat generating circuit; A holding member comprising:

3. The holding member according to claim 1 or 2, The length of the heat generating line of the one heat generating circuit is 5 times or less than the length of the heat generating line of the other heat generating circuit; A holding member comprising:

4. The holding member according to claim 1 or 2, the one heating circuit is the outer heating circuit, the other heating circuit is the inner heating circuit; A holding member comprising:

5. The holding member according to claim 1 or 2, the one heating circuit is the inner heating circuit, the other heating circuit is the outer heating circuit; A holding member comprising:

6. A holding device for holding an object, comprising the holding member according to claim 1 or 2.

Images