Substrate holding member and method for manufacturing substrate holding member

Abstract

To provide a technique for sufficiently loading an RF electrode with RF power while suppressing a leakage current between electrodes in a substrate holding member in which two layers of electrodes including the RF electrode are embedded.SOLUTION: The substrate holding member 100 includes an upper ceramic substrate 110U, a middle ceramic substrate 110M, and a lower ceramic substrate 110D. Electrostatic chuck electrodes 124 are arranged between the upper ceramic base material 110U and the intermediate ceramic base material 110M, and RF electrodes 126 are arranged between the intermediate ceramic base material 110M and the lower ceramic base material 110D. The resistance value R (Ω) and the electrostatic capacitance C (F) between the electrode for electrostatic attraction 124 and the RF electrode 126 satisfy the relational expression 1.0 * 1021 (Ω / F) ≤ R / C ≤ 1.0 * 1023 (Ω / F).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a substrate holding member and a method for manufacturing a substrate holding member. [Background technology]

[0002] Patent Document 1 discloses an electrostatic chuck as an example of a substrate holding member having a wafer mounting surface for holding a substrate such as a wafer. The electrostatic chuck described in Patent Document 1 has an electrostatic attraction electrode and an RF electrode embedded in two layers in the thickness direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2024-026298 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors of the present invention have found that the following problem may occur in an electrostatic chuck in which two layers of electrodes including an RF electrode are embedded, as in the electrostatic chuck described in Patent Document 1. When the resistance R between the two electrodes becomes small, the leakage current between the two electrodes becomes large. Furthermore, when the capacitance C between the two electrodes becomes small, the combined impedance between the two electrodes becomes small depending on the resistance between the two electrodes, making it impossible to load sufficient RF power.

[0005] In response to this problem, the inventors discovered that the above-mentioned inconveniences could be resolved by adjusting the ratio R / C of the resistance R to the capacitance C between the two layers of electrodes within a predetermined range, and thus arrived at the present invention.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a technique for applying sufficient RF power to an RF electrode while suppressing leakage current between the electrodes in a substrate holding member in which two layers of electrodes, including an RF electrode, are embedded. [Means for solving the problem]

[0007] According to an aspect of the present invention, there is provided a ceramic substrate having a plate-like upper ceramic base member and a main surface for holding a substrate; a plate-shaped intermediate ceramic substrate located below the upper ceramic substrate in a vertical direction perpendicular to the main surface; a plate-shaped lower ceramic substrate located below the intermediate ceramic substrate in the vertical direction; an upper intermediate electrode located between the upper ceramic substrate and the intermediate ceramic substrate in the vertical direction; a lower intermediate electrode located between the intermediate ceramic substrate and the lower ceramic substrate in the vertical direction, The resistance R (Ω) between the upper intermediate electrode and the lower intermediate electrode, and the capacitance C (F) between the upper intermediate electrode and the lower intermediate electrode are 1.0×10 21 (Ω / F)≦ R / C ≦ 1.0×10 23 (Ω / F) The present invention provides a substrate holding member that satisfies the following conditions: [Effects of the Invention]

[0008] According to the above configuration, the substrate holding member includes a plate-shaped upper ceramic substrate having a main surface for holding a substrate, a plate-shaped intermediate ceramic substrate located below the upper ceramic substrate in the vertical direction, a plate-shaped lower ceramic substrate located below the intermediate ceramic substrate in the vertical direction, an upper intermediate electrode located between the upper ceramic substrate and the intermediate ceramic substrate in the vertical direction, and a lower intermediate electrode located between the intermediate ceramic substrate and the lower ceramic substrate. The ratio R / C of the resistance R (Ω) between the upper intermediate electrode and the lower intermediate electrode to the capacitance C (F) between the upper intermediate electrode and the lower intermediate electrode is 1.0×10 21 (Ω / F)≦ R / C ≦ 1.0×10 23 (Ω / F) When the condition (1) is satisfied, the high frequency power applied to the upper intermediate electrode or the lower intermediate electrode can be sufficiently applied while suppressing the leakage current between the upper intermediate electrode and the lower intermediate electrode. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a substrate holding member 100. FIG. [Figure 2] FIG. 2 is a schematic explanatory diagram of a substrate holding member 100 including an electrostatic attraction electrode 124 and an RF electrode 126. As shown in FIG. [Figure 3] FIG. 3 is a schematic explanatory diagram showing the shapes of the electrostatic attraction electrode 124 and the RF electrode 126. As shown in FIG. [Figure 4] FIG. 4 is a flowchart illustrating the flow of a manufacturing method for the substrate holding member 100. [Figure 5] 1(a) to 1(c) are diagrams showing the flow of a method for manufacturing the ceramic base 110. FIG. [Figure 6] FIG. 6 is a table summarizing the results of Examples 1 to 4. [Figure 7] FIG. 7 is a table summarizing the results of Examples 5 to 8. [Figure 8] FIG. 8 is a table summarizing the results of Examples 9 to 12. [Figure 9] FIG. 9 is a table summarizing the results of Examples 13 to 15. [Figure 10] FIG. 10 is a table summarizing the results of Comparative Examples 1 to 4. [Figure 11] FIG. 11 is a table summarizing the results of Comparative Examples 5 and 6. [Figure 12] FIG. 12 is an explanatory diagram for illustrating a substrate holding member 100 of Example 15, in which a plurality of protrusions 118 are provided on the upper surface of a lower ceramic base 110D. DETAILED DESCRIPTION OF THE INVENTION

[0010] <Substrate holding member 100> A substrate holding member 100 according to this embodiment will be described with reference to FIGS. 1 and 2. The substrate holding member 100 according to this embodiment is an example of a substrate holding member for attracting and holding a semiconductor wafer such as a silicon wafer (hereinafter simply referred to as a wafer 10). In the following description, the up-down direction 5 is defined based on the state in which the substrate holding member 100 is installed and ready for use (the state shown in FIG. 1). As shown in FIG. 1, the substrate holding member 100 according to this embodiment mainly includes a ceramic base 110, an electrostatic attraction electrode 124 (see FIG. 2), and an RF electrode 126 (see FIG. 2).

[0011] The ceramic substrate 110 is a circular, plate-like member with a diameter of 12 inches (approximately 300 mm) and includes two main surfaces (an upper surface 111 and a lower surface 113) facing each other in the vertical direction 5. The upper surface 111 of the ceramic substrate 110 (the upper surface of an upper ceramic substrate 110U described below) corresponds to the main surface of the present invention. A wafer 10 to be held is placed on the upper surface 111 of the ceramic substrate 110. Note that in FIG. 1, the wafer 10 and the ceramic substrate 110 are shown separated from each other for ease of viewing. In this embodiment, the ceramic substrate 110 is formed of an AlN ceramic sintered body. For example, the AlN content can be 90% or more. Note that the ceramic substrate 110 does not necessarily have to be formed of an AlN ceramic. For example, the ceramic substrate 110 may be formed of a ceramic sintered body containing Al2O3 (referred to as an Al2O3 ceramic).

[0012] In this embodiment, the ceramic substrate 110 is a ceramic material including an upper ceramic substrate 110U, an intermediate ceramic substrate 110M, and a lower ceramic substrate 110D. The upper ceramic substrate 110U, the intermediate ceramic substrate 110M, and the lower ceramic substrate 110D are stacked in this order from top to bottom in the vertical direction 5. The thickness d1 (length in the vertical direction 5) of the upper ceramic substrate 110U is preferably 50 μm to 2000 μm. For example, the thickness of the upper ceramic substrate 110U can be set to 300 μm. The thickness d2 of the intermediate ceramic substrate 110M is adjusted so that the value R2 / C2, described below, falls within a predetermined range. The thickness d3 of the third ceramic substrate 100C is preferably 5 mm to 20 mm in order to ensure the strength of the substrate holding member 100. For example, the thickness of the lower ceramic substrate 110D can be set to 15 mm.

[0013] The average grain size of the AlN ceramic in the intermediate ceramic substrate 110M is larger than the average grain size of the AlN ceramic in the upper ceramic substrate 110U. The average grain size of the AlN ceramic in the lower ceramic substrate 110D is also larger than the average grain size of the AlN ceramic in the intermediate ceramic substrate 110M. The average grain size of the AlN ceramic can be measured by observing the cross section of each layer with a scanning electron microscope (SEM) and using an intercept method. The average grain size of the upper ceramic substrate 110U is 1.5 μm to 3.2 μm, the average grain size of the intermediate ceramic substrate 110M is 2.5 μm to 4.2 μm, and the average grain size of the lower ceramic substrate 110D is 3.5 μm to 6.0 μm.

[0014] Although not shown, the upper surface 111 of the ceramic substrate 110 can be provided with a ring-shaped protrusion arranged on the outer periphery (outer edge) and multiple cylindrical protrusions arranged inside the ring-shaped protrusion.

[0015] 2, an electrostatic attraction electrode 124 is disposed as an upper intermediate electrode between the upper ceramic substrate 110U and the intermediate ceramic substrate 110M. As described above, the thickness d1 (length in the up-down direction 5) of the upper ceramic substrate 110U can be set to 50 μm to 2000 μm. In this case, the electrostatic attraction electrode 124 is embedded at a position 50 μm to 2000 μm below the upper surface 111 of the ceramic substrate 110. In other words, the thickness of the ceramic insulating layer from the upper surface 111 of the ceramic substrate 110 to the electrostatic attraction electrode 124 can be set to 50 μm to 2000 μm.

[0016] As shown in FIG. 3 , the electrostatic attraction electrode 124 has two semicircular electrodes 124a and 124b arranged facing each other at a predetermined distance, resulting in a generally circular shape. In this embodiment, the outer diameter of the electrostatic attraction electrode 124 is 292 mm. The electrostatic attraction electrode 124 can electrostatically attract the wafer 10 by applying a predetermined voltage (e.g., ±500 V) to the electrodes 124a and 124b, respectively. In this embodiment, the ceramic substrate 110 and the electrostatic attraction electrode 124 form an electrostatic chuck. As described below, the electrostatic attraction electrode 124 may be a printed electrode formed by printing and firing a metal paste, such as molybdenum paste, on the upper surface of the intermediate ceramic substrate 110M. In this case, the thickness of the electrostatic attraction electrode 124 is preferably 15 μm or more. Alternatively, the electrostatic attraction electrode 124 may be a mesh-like electrode formed by etching, mechanically processing, or laser processing a molybdenum foil or thin plate with multiple holes. The mesh electrode can also be formed by plain weaving molybdenum wire. When the electrostatic attraction electrode 124 is a mesh electrode, the opening ratio is preferably 40% to 70%. For example, the opening ratio of the electrostatic attraction electrode 124 can be set to 65%.

[0017] As shown in FIG. 2, an RF (radio frequency power) electrode 126 is disposed between the intermediate ceramic substrate 110M and the lower ceramic substrate 110D as a lower intermediate electrode. As shown in FIG. 3, the RF electrode 126 is a circular electrode. Like the electrostatic attraction electrode 124, the RF electrode 126 may be a printed electrode formed by printing and firing a metal paste such as molybdenum paste on the upper surface of the lower ceramic substrate 110D. Alternatively, the RF electrode 126 may be a mesh electrode in which a plurality of holes are formed in a molybdenum foil or thin plate by etching, mechanical processing, or laser processing, or a mesh electrode formed by plain weaving molybdenum wire.

[0018] It is possible to arrange a heater electrode (not shown) as the lower intermediate electrode and an RF electrode 126 as the upper intermediate electrode. Conversely, it is also possible to arrange an RF electrode 126 as the lower intermediate electrode and a heater electrode (not shown) as the upper intermediate electrode. In either case, the vertical distance d between the upper intermediate electrode and the lower intermediate electrode (thickness d2 of the intermediate ceramic substrate 110M) and the parallelism p between the upper intermediate electrode and the lower intermediate electrode are each d≧750×10 -6 (m), p ≤ 100 × 10 -6 It is preferable that (m) is satisfied.

[0019] In this embodiment, the resistance R (Ω) between the upper intermediate electrode (for example, the electrostatic chucking electrode 124) and the lower intermediate electrode (for example, the RF electrode 126) and the capacitance C (F) between the upper intermediate electrode (for example, the electrostatic chucking electrode 124) and the lower intermediate electrode (for example, the RF electrode 126) are expressed by the following relational expression: 1.0×10 21 (Ω / F)≦ R / C ≦ 1.0×10 23 (Ω / F) It meets the following criteria.

[0020] A gas flow path (not shown) can be formed inside the ceramic base 110. The gas flow path can be used as a flow path for supplying gas to a space (gap) defined by the upper surface 111 of the ceramic base 110 and the lower surface of the wafer 10. Conversely, gas can be exhausted from the space (gap) defined by the upper surface 111 of the ceramic base 110 and the lower surface of the wafer 10 via the gas flow path. In this case, the pressure difference between the pressure outside the gap and the pressure inside the gap can be adjusted by adjusting the exhaust pressure. This allows the wafer 10 to be adsorbed toward the upper surface of the ceramic base 110.

[0021] Next, a method for manufacturing the substrate holding member 100 will be described. In the following, an example will be described in which the ceramic base 110 is made of AlN ceramic. The AlN ceramic is made of AlN ceramic containing AlN as a main component. Here, AlN ceramic containing AlN as a main component refers to a ceramic sintered body containing 50 wt% or more of AlN.

[0022] First, the lower ceramic substrate 110D is fabricated (S101 in FIG. 4). The lower ceramic substrate 110D can be fabricated using known methods such as powder hot pressing and green sheet lamination and firing. Here, the powder hot pressing method will be described as an example. As shown in FIG. 5(a), granulated powder P, primarily composed of AlN powder, is placed in a carbon mold 601 with a bed and pre-pressed with a punch 602. The granulated powder P preferably contains 7 wt% or less of a sintering aid (e.g., YO). Next, the granulated powder P is fired in a pressed state to fabricate the lower ceramic substrate 110D. The pressure applied during firing is preferably 1 MPa or more. Furthermore, firing is preferably performed at a temperature of 1800°C or higher.

[0023] Next, the upper surface of the lower ceramic substrate 110D is processed to form an RF electrode 126 on the upper surface of the lower ceramic substrate 110D (see S102 in FIG. 4 and FIG. 5(b)). At this time, a recess for disposing the RF electrode 126 can be formed on the upper surface of the lower ceramic substrate 110D by machining. The RF electrode 126 can be disposed on the upper surface of the lower ceramic substrate 110D by printing a metal paste such as molybdenum paste. Alternatively, a mesh-like electrode formed by etching, mechanically processing, or laser processing a molybdenum foil or thin plate with multiple holes, or a mesh-like electrode formed by plain-weaving molybdenum wire, can be disposed on the upper surface of the lower ceramic substrate 110D. In addition to molybdenum, for example, a tungsten paste or foil can also be used.

[0024] Next, granulated powder P is placed on top of lower ceramic substrate 110D so as to cover RF electrode 126, and then fired to produce intermediate ceramic substrate 110M (S103 in FIG. 4). Specifically, as shown in FIG. 5(c), further granulated powder P is placed in bed-type mold 601 so as to cover RF electrode 126, and pressed and molded with punch 602. Alternatively, instead of granulated powder P, a ceramic green sheet can be placed so as to cover RF electrode 126, and then fired to produce intermediate ceramic substrate 110M. The firing conditions may be the same as those in step S101, or the firing temperature and pressure may be increased.

[0025] Next, the upper surface of the intermediate ceramic substrate 110M is processed, and the electrostatic attraction electrode 124 is disposed on the upper surface of the intermediate ceramic substrate 110M (S104 in FIG. 4). At this time, a recess for disposing the electrostatic attraction electrode 124 can be formed on the upper surface of the intermediate ceramic substrate 110M by machining according to the shape of the electrode. The electrostatic attraction electrode 124 can be disposed on the upper surface of the intermediate ceramic substrate 110M by printing a metal paste such as molybdenum paste. Alternatively, a mesh electrode formed by etching, mechanically processing, or laser processing a molybdenum foil or thin plate with multiple holes, or a mesh electrode formed by plain-weaving molybdenum wire, can be disposed on the upper surface of the intermediate ceramic substrate 110M.

[0026] Next, granulated powder P is placed on the intermediate ceramic substrate 110M so as to cover the electrostatic attraction electrode 124, and then fired to produce the upper ceramic substrate 110U (S105 in FIG. 4). As described above, additional granulated powder P is added to the bed mold 601 so as to cover the electrostatic attraction electrode 124, and then pressed and molded using the punch 602. Alternatively, instead of the granulated powder P, a ceramic green sheet can be placed so as to cover the electrostatic attraction electrode 124, and then fired to produce the upper ceramic substrate 110U. Using a ceramic green sheet can homogenize the vertical distance between the upper intermediate electrode (e.g., the electrostatic attraction electrode 124) and the lower intermediate electrode (e.g., the RF electrode 126). This stabilizes the resistance and capacitance of the intermediate ceramic substrate 110M. The firing conditions may be the same as those in step S102, or the firing temperature and pressure may be increased.

[0027] The upper surface 111 and the lower surface 113 of the ceramic base 110 thus formed are ground, and further polished as necessary. At this time, the distance in the vertical direction 5 from the upper surface 111 of the ceramic base 110 to the electrostatic attraction electrode 124 can be adjusted. Furthermore, by sandblasting the upper surface 111, it is possible to form a plurality of convex portions and an annular convex portion on the upper surface 111. Note that although sandblasting is a suitable processing method for forming the plurality of convex portions and the annular convex portion, other processing methods can also be used. [Example]

[0028] The present invention will be further described below using Examples 1 to 15 and Comparative Examples 1 to 6. However, the present invention is not limited to the Examples described below. Fig. 6 shows a table summarizing the results of Examples 1 to 4, Fig. 7 shows a table summarizing the results of Examples 5 to 8, Fig. 8 shows a table summarizing the results of Examples 9 to 12, Fig. 9 shows a table summarizing the results of Examples 13 to 15, Fig. 10 shows a table summarizing the results of Comparative Examples 1 to 4, and Fig. 11 shows a table summarizing the results of Comparative Examples 5 and 6.

[0029] Example 1 The substrate holder 100 of Example 1 (see FIG. 2) will be described. In Example 1, aluminum nitride (AlN) doped with 5 wt% Y2O3 was used as the raw material (referred to as AlN-1 in the table of FIG. 6), and a disk-shaped AlN ceramic substrate 110 having a diameter of 300 mm was fabricated by the above-described manufacturing method. That is, the upper ceramic substrate 110U, the intermediate ceramic substrate 110M, and the lower ceramic substrate 110D had the same composition. The cross sections of the upper ceramic substrate 110U, the intermediate ceramic substrate 110M, and the lower ceramic substrate 110D were observed using an SEM, and the average grain diameters of the AlN ceramics were measured using an intercept method. The average grain diameter of the upper ceramic substrate 110U was 1.9 μm, the average grain diameter of the intermediate ceramic substrate 110M was 2.7 μm, and the average grain diameter of the lower ceramic substrate 110D was 3.7 μm. In Example 1, the volume resistivity ρ of the material of the intermediate ceramic substrate 110M is 2.49 × 1014 The volume resistivity ρ was measured in a state where the AlN ceramic substrate 110 was heated to 100° C. using a hot plate or an oven.

[0030] In Examples 1 to 15, the thickness (length in the vertical direction 5) of the upper ceramic substrate 110U was set to 300 μm, and the thickness of the lower ceramic substrate 110D was set to 15 mm. In Example 1, the thickness d of the intermediate ceramic substrate 110M was set to 1.0 mm (1.0×10 -3 m).

[0031] In Example 1, the upper intermediate electrode was an electrostatic attraction electrode 124 disposed between the upper ceramic substrate 110U and the intermediate ceramic substrate 110M. The lower intermediate electrode was an RF electrode 126 disposed between the intermediate ceramic substrate 110M and the lower ceramic substrate 110D. The electrostatic attraction electrode 124 and the RF electrode 126 were formed using a mesh electrode material (opening ratio 65%) made by plain weaving molybdenum wire with a wire diameter of 0.1 mm and a mesh size of #50. The electrostatic attraction electrode 124 is a pair of electrodes formed by circularly arranging two mesh electrode materials cut into a crescent shape. The RF electrode 126 is an electrode formed by cutting a mesh electrode material into a circle. In this specification, the value obtained by multiplying the outer area of ​​the electrode material constituting the electrode by the opening ratio of the electrode material is defined as the equivalent area of ​​the electrode. Furthermore, when two electrodes are arranged parallel to each other, the area of ​​the overlapping region of the two electrodes is defined as the equivalent facing area S. In Example 1, the outer diameter area of ​​the electrostatic attraction electrode 124 is 0.0664 m 2 and the outer diameter area of ​​the RF electrode 126 is 0.0679 m 2 The opposing equivalent area S is 0.0235m 2 In addition, in Examples 1 to 14, the parallelism p between the upper intermediate electrode (for example, the electrostatic attraction electrode 124) and the lower intermediate electrode (for example, the RF electrode 126) was p≦100×10 -6 (m) is satisfied.

[0032] The resistance value R between the electrostatic chucking electrode 124 and the RF electrode 126 was measured using an ultra-high resistance meter. The applied voltage was 500 V, and the measurement temperature was 100° C. In Example 1, the resistance value R between the electrostatic chucking electrode 124 and the RF electrode 126 was 1.06×10 13 Ω. The capacitance C between the electrostatic chucking electrode 124 and the RF electrode 126 was measured using an LCR meter. An impedance analyzer can also be used to measure the capacitance C. In Example 1, the capacitance C between the electrostatic chucking electrode 124 and the RF electrode 126 was 4.87×10 -9 F. At this time, the ratio of resistance R to capacitance C, R / C, is 2.18 × 10 21 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 17.65. Note that f is the frequency of the high frequency voltage applied to the RF electrode 126, and in Example 1, the frequency f was 13.56 MHz.

[0033] In Example 1, a process test was performed by placing a wafer 10 on the substrate holding member 100 and applying predetermined voltages to the electrostatic chucking electrode 124 and the RF electrode 126. The results of the process test were favorable. That is, the electrostatic chucking voltage applied to the electrostatic chucking electrode 124 was maintained, and the high-frequency power applied to the RF electrode 126 was successfully applied. "Maintaining the electrostatic chucking voltage" means that the current value of the DC power supply connected to the electrostatic chucking electrode 124 was 2 mA or less. "Successfully applying the high-frequency power" means that a plasma process test was performed using high-frequency power with a frequency of 13.56 MHz, and the reflection coefficient of the power from the load was low relative to the input power, resulting in a reflection coefficient of 0.3 or less. A reflection coefficient of 0.3 or less is preferable, and 0.2 or less is more preferable. In the evaluation items for high-frequency power load in the tables of Figures 6 to 11, a reflection coefficient of 0.2 or less is represented by ◎, a reflection coefficient of more than 0.2 and less than 0.3 is represented by ○, and a reflection coefficient of more than 0.3 is represented by ×.

[0034] <Example 2> The substrate holding member 100 of Example 2 has a thickness d of the intermediate ceramic substrate 110M of 7.5×10 -4 This is the same as the substrate holding member 100 of the first embodiment, except that the thickness is set to mm.

[0035] In the second embodiment, the resistance value R between the electrostatic chucking electrode 124 and the RF electrode 126 is 7.95×10 12 Ω and the capacitance C is 6.49×10 -9 F. At this time, the ratio of resistance R to capacitance C, R / C, is 1.22 × 10 21 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 23.53.

[0036] In Example 2, a process test similar to that in Example 1 was performed. A plasma process test was performed in Example 2. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 was 2 mA or less, which indicated good electrostatic attraction of the substrate, and the reflection coefficient was 0.2 or less, which indicated good high-frequency power load.

[0037] Example 3 The substrate holding member 100 of Example 3 is the same as the substrate holding member 100 of Example 1, except that the electrostatic attraction electrode 124 serving as the upper intermediate electrode is a printed electrode prepared by printing molybdenum paste. The opening ratio of the electrostatic attraction electrode 124 is 0%, and the opposing equivalent area S between the electrostatic attraction electrode 124 and the RF electrode 126 is 0.0237 m 2 It was.

[0038] In the third embodiment, the resistance R between the electrostatic chucking electrode 124 and the RF electrode 126 is 1.05×10 13 Ω and the capacitance C is 4.92×10 -9 F. At this time, the ratio of resistance R to capacitance C, R / C, is 2.13 × 10 21 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 )1 / 2 / S was 17.65.

[0039] In Example 3, a process test similar to that in Example 1 was performed. A plasma process test was performed in Example 3. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 was 2 mA or less, which indicated good electrostatic attraction of the substrate, and the reflection coefficient was 0.2 or less, which indicated good high-frequency power load.

[0040] Example 4 The substrate holding member 100 of Example 4 is the same as the substrate holding member 100 of Example 1, except that the RF electrode 126 serving as the lower intermediate electrode is a printed electrode prepared by printing molybdenum paste. The opening ratio of the RF electrode 126 is 0%, and the opposing equivalent area S of the electrostatic attraction electrode 124 and the RF electrode 126 is 0.0232 m 2 It was.

[0041] In the fourth embodiment, the resistance R between the electrostatic chucking electrode 124 and the RF electrode 126 is 8.04×10 12 Ω and the capacitance C is 6.42×10 -9 F. At this time, the ratio of resistance R to capacitance C, R / C, is 1.25 × 10 21 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 23.53.

[0042] In Example 4, a process test similar to that in Example 1 was performed. A plasma process test was performed in Example 4. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 was 2 mA or less, which indicated good electrostatic attraction of the substrate, and the reflection coefficient was 0.2 or less, which indicated good high-frequency power load.

[0043] <Example 5> The substrate holding member 100 of Example 5 is the same as the substrate holding member 100 of Example 1, except that the electrostatic attraction electrode 124 serving as the upper intermediate electrode and the RF electrode 126 serving as the lower intermediate electrode are printed electrodes prepared by printing molybdenum paste. The opening ratio of the electrostatic attraction electrode 124 is set to 0%, and the opening ratio of the RF electrode 126 is set to 65%, the same as in Example 1. The opposing equivalent area S of the electrostatic attraction electrode 124 and the RF electrode 126 is 0.0237 m 2 It was.

[0044] In the fifth embodiment, the resistance R between the electrostatic chucking electrode 124 and the RF electrode 126 is 1.05×10 13 Ω and the capacitance C is 4.92×10 -9 F. At this time, the ratio of resistance R to capacitance C, R / C, is 2.13 × 10 21 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 17.65.

[0045] In Example 5, a process test similar to that in Example 1 was performed. A plasma process test was performed in Example 5. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 was 2 mA or less, which indicated good electrostatic attraction of the substrate, and the reflection coefficient was 0.2 or less, which indicated good high-frequency power load.

[0046] Example 6 The substrate holding member 100 of Example 6 has a thickness d of the intermediate ceramic substrate 110M of 2.0×10 -3 mm, and the opening ratios of the electrostatic chucking electrode 124 and the RF electrode 126 are both 0%. In Example 6, the equivalent opposing area S of the electrostatic chucking electrode 124 and the RF electrode 126 is 0.0664 m 2 It was.

[0047] In the sixth embodiment, the resistance R between the electrostatic chucking electrode 124 and the RF electrode 126 is 7.50×10 12 Ω and the capacitance C is 6.88×10-9 F. At this time, the ratio of resistance R to capacitance C, R / C, is 1.09 × 10 21 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 8.83.

[0048] In Example 6, a process test similar to that in Example 1 was performed. A plasma process test was performed in Example 6. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 was 2 mA or less, which indicated good electrostatic attraction of the substrate, and the reflection coefficient was 0.2 or less, which indicated good high-frequency power load.

[0049] Example 7 The substrate holding member 100 of Example 7 has a thickness d of the intermediate ceramic substrate 110M of 5.0×10 -3 This is the same as the substrate holding member 100 of Example 6, except that the thickness is set to mm.

[0050] In the seventh embodiment, the resistance value R between the electrostatic chucking electrode 124 and the RF electrode 126 is 1.88×10 13 Ω and the capacitance C is 2.75×10 -9 F. At this time, the ratio of resistance R to capacitance C, R / C, is 6.82 × 10 21 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 3.53.

[0051] In Example 7, a process test similar to that in Example 1 was performed. A plasma process test was performed in Example 7. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 was 2 mA or less, which indicated good electrostatic attraction of the substrate, and the reflection coefficient was 0.2 or less, which indicated good high-frequency power load.

[0052] Example 8 The substrate holder 100 of Example 8 has a thickness d of the intermediate ceramic substrate 110M of 1.0×10 -2This is the same as the substrate holding member 100 of Example 6, except that the thickness is set to mm.

[0053] In the eighth embodiment, the resistance R between the electrostatic chucking electrode 124 and the RF electrode 126 is 3.75×10 13 Ω and the capacitance C is 1.38×10 -9 F. At this time, the ratio of resistance R to capacitance C, R / C, is 2.73 × 10 22 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 1.77.

[0054] In Example 8, a process test similar to that in Example 1 was performed. In Example 8, a plasma process test was performed. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 was 2 mA or less, and the electrostatic attraction of the substrate was good. The reflection coefficient was 0.25, and the high-frequency power was applied well but not optimal.

[0055] Example 9 The substrate holder 100 of Example 9 was manufactured by the above-described manufacturing method using aluminum nitride (AlN) to which 6 wt % of a titanium compound and 1 wt % of Y2O3 had been added (referred to as AlN-2 in the table of FIG. 8) as a raw material, and the thickness d of the intermediate ceramic substrate 110M was 5.0 × 10 -3 In Example 9, the volume resistivity ρ of the material of the intermediate ceramic substrate 110M was 7.80×10 12 The volume resistivity ρ was measured in the same state as in Example 1, with the AlN ceramic substrate 110 heated to 100° C. using a hot plate or an oven.

[0056] In Example 9, the resistance value R between the electrostatic attraction electrode 124 and the RF electrode 126 is 1.68×10 12 Ω and the capacitance C is 9.63×10 -10F. At this time, the ratio of resistance R to capacitance C, R / C, is 1.74 × 10 21 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 3.53.

[0057] In Example 9, a process test similar to that in Example 1 was performed. A plasma process test was performed in Example 9. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 was 2 mA or less, which indicated good electrostatic attraction of the substrate, and the reflection coefficient was 0.2 or less, which indicated good high-frequency power load.

[0058] Example 10 The substrate holding member 100 of Example 10 has a thickness d of the intermediate ceramic substrate 110M of 1.0×10 -2 This is the same as the substrate holding member 100 of Example 9, except that the thickness is set to mm.

[0059] In the tenth embodiment, the resistance R between the electrostatic chucking electrode 124 and the RF electrode 126 is 3.36×10 12 Ω and the capacitance C is 4.82×10 -10 F. At this time, the ratio of resistance R to capacitance C, R / C, is 6.97 × 10 21 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 1.77.

[0060] In Example 10, a process test similar to that in Example 1 was performed. A plasma process test was also performed in Example 10. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 was 2 mA or less, and the electrostatic attraction of the substrate was good. The reflection coefficient was 0.26, and the high-frequency power was applied well but not optimal.

[0061] Example 11 The substrate holding member 100 of Example 11 is the same as the substrate holding member 100 of Example 4, except that the diameter of the ceramic base 110 is 200 mm. The outer diameter area of ​​the electrostatic attraction electrode 124 in Example 11 is 0.0286 m 2 and the outer diameter area of ​​the RF electrode 126 is 0.0295 m 2 The opposing equivalent area S is 0.0101m 2 It was.

[0062] In the eleventh embodiment, the resistance R between the electrostatic chucking electrode 124 and the RF electrode 126 is 1.85×10 13 Ω and the capacitance C is 2.80×10 -9 F. At this time, the ratio of resistance R to capacitance C, R / C, is 6.60 × 10 21 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 23.53.

[0063] In Example 11, a process test similar to that in Example 1 was performed. A plasma process test was performed in Example 11. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 was 2 mA or less, which indicated good electrostatic attraction of the substrate, and the reflection coefficient was 0.2 or less, which indicated good high-frequency power load.

[0064] Example 12 The substrate holding member 100 of Example 12 is the same as the substrate holding member 100 of Example 1, except that the upper ceramic substrate 110U is produced by the above-mentioned manufacturing method using aluminum nitride (AlN) to which 6 wt % of a titanium compound and 1 wt % of Y2O3 are added as the raw material (AlN-2). The compositions of the intermediate ceramic substrate 110M and the lower ceramic substrate 110D are the same as those of Example 1.

[0065] In the twelfth embodiment, the resistance R between the electrostatic chucking electrode 124 and the RF electrode 126 is 1.06×10 13 Ω and the capacitance C is 4.87×10 -9F. At this time, the ratio of resistance R to capacitance C, R / C, is 2.18 × 10 21 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 17.65.

[0066] In Example 12, a process test similar to that in Example 1 was performed. A plasma process test was performed in Example 12. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 was 2 mA or less, which indicated good electrostatic attraction of the substrate, and the reflection coefficient was 0.2 or less, which indicated good high-frequency power load.

[0067] Example 13 The substrate holding member 100 of Example 13 is the same as the substrate holding member 100 of Example 1, except that the upper ceramic substrate 110U is produced by the above-described manufacturing method using aluminum nitride (AlN) to which 1.5 wt % of a titanium compound and 1 wt % of a rare earth oxide are added as the raw material (AlN-3). The compositions of the intermediate ceramic substrate 110M and the lower ceramic substrate 110D are the same as those of Example 1.

[0068] In the thirteenth embodiment, the resistance R between the electrostatic chucking electrode 124 and the RF electrode 126 is 1.06×10 13 Ω and the capacitance C is 4.87×10 -9 F. At this time, the ratio of resistance R to capacitance C, R / C, is 2.18 × 10 21 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 17.65.

[0069] In Example 13, a process test similar to that in Example 1 was performed. A plasma process test was performed in Example 13. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 was 2 mA or less, which indicated good electrostatic attraction of the substrate, and the reflection coefficient was 0.2 or less, which indicated good high-frequency power load.

[0070] Example 14 The substrate holding member 100 of Example 14 is the same as the substrate holding member 100 of Example 1, except that an RF electrode 126 is disposed as an upper intermediate electrode between the upper ceramic substrate 110U and the intermediate ceramic substrate 110M, and a heater electrode (not shown) is disposed as a lower intermediate electrode between the intermediate ceramic substrate 110M and the lower ceramic substrate 110D. The heater electrode is an electrode in which molybdenum mesh cut into strips is spirally arranged so as to form a substantially circular shape overall. In Example 14, the heater electrode is formed using a mesh electrode material (opening ratio 65%) in which molybdenum wire with a wire diameter of 0.1 mm and a mesh size of #50 is plain woven. In Example 14, the outer diameter area of ​​the RF electrode 126 is 0.0679 m 2 The outer diameter of the heater electrode is 0.0637 m 2 The opposing equivalent area S is 0.0225m 2 It was.

[0071] In Example 14, the resistance R between the RF electrode 126 and the heater electrode is 3.31×10 13 Ω and the capacitance C is 1.56×10 -9 F. At this time, the ratio of resistance R to capacitance C, R / C, is 2.13 × 10 22 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 5.58.

[0072] In Example 14, a process test similar to that in Example 1 was performed. Although the substrate holding member 100 in Example 14 was not provided with an electrostatic attraction electrode 124, when a predetermined high-frequency voltage was applied to the RF electrode 126, a DC voltage was generated between the plasma potential and the potential of the RF electrode 126 due to a self-bias. As a result, even when the electrostatic attraction electrode 124 was not provided, the RF electrode 126 could electrostatically attract the wafer 10 placed on the upper surface 111 of the substrate holding member 100. A plasma process test was performed in Example 14. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 was 2 mA or less, indicating good electrostatic attraction of the substrate, and the reflection coefficient was 0.2 or less, indicating good high-frequency power load.

[0073] Example 15 The substrate holding member 100 of Example 15 was the same as the substrate holding member 100 of Example 1, except that a plurality of protrusions 118 (see FIG. 12) were formed by machining on the upper surface of the lower ceramic base 110D. The flatness of the top surfaces 118a of the protrusions 118 was 1 μm or less.

[0074] In the fifteenth embodiment, the resistance value R between the electrostatic chucking electrode 124 and the RF electrode 126 is 1.06×10 13 Ω and the capacitance C is 4.87×10 -9 F. At this time, the ratio of resistance R to capacitance C, R / C, is 2.18 × 10 21 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 17.65.

[0075] In Example 15, a process test similar to that in Example 1 was performed. In Example 15, a plasma process test was performed. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 was 2 mA or less, which indicated good electrostatic attraction of the substrate, and the reflection coefficient was 0.2 or less, which indicated good high-frequency power load.

[0076] In Example 15, the flatness of the top surface 118a of the convex portion 118 could be reduced to 1 μm or less, thereby suppressing the thickness distribution of the intermediate ceramic substrate 110M formed thereon to 100 μm or less. This improved the in-plane uniformity of the characteristics of the substrate holding member 100. Furthermore, when the intermediate ceramic substrate 110M was fabricated by filling the granulated powder P so as to cover the RF electrode 126 arranged on the lower ceramic substrate 110D, the granulated powder P was able to penetrate into the gaps between the convex portions 118 through the voids in the mesh. This enabled the intermediate ceramic substrate 110M and the electrostatic attraction electrode 124 formed from a mesh-like metal to be firmly attached to each other.

[0077] <Comparative Example 1> The substrate holding member 100 of Comparative Example 1 has a thickness d of the intermediate ceramic substrate 110M of 6.0×10 -4 This is the same as the substrate holding member 100 of the first embodiment, except that the thickness is set to mm.

[0078] In Comparative Example 1, the resistance value R between the electrostatic chucking electrode 124 and the RF electrode 126 is 6.36×10 12 Ω and the capacitance C is 8.12×10 -9 F. At this time, the ratio of resistance R to capacitance C, R / C, is 7.83 × 10 20 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 29.42.

[0079] In Comparative Example 1, a process test similar to that in Example 1 was performed. A plasma process test was performed in Comparative Example 1. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 exceeded 2 mA, and the electrostatic attraction voltage applied to the electrostatic attraction electrode 124 could not be maintained, and the wafer 10 could not be electrostatically attracted, resulting in poor electrostatic attraction.

[0080] <Comparative Example 2> The substrate holding member 100 of Comparative Example 2 is the same as the substrate holding member 100 of Example 5, except that the opening ratio of the RF electrode 126 is 0%. In Comparative Example 2, the opposing equivalent area S of the electrostatic chucking electrode 124 and the RF electrode 126 is 0.0664 m 2 It was.

[0081] In Comparative Example 2, the resistance value R between the electrostatic chucking electrode 124 and the RF electrode 126 is 3.75×10 12 Ω and the capacitance C is 1.38×10 -8 F. At this time, the ratio of resistance R to capacitance C, R / C, is 2.73 × 10 20 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 17.65.

[0082] In Comparative Example 2, a process test similar to that in Example 1 was performed. A plasma process test was performed in Comparative Example 2. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 exceeded 2 mA, making it impossible to maintain the electrostatic attraction voltage applied to the electrostatic attraction electrode 124, and the wafer 10 could not be electrostatically attracted, resulting in poor electrostatic attraction.

[0083] <Comparative Example 3> The substrate holding member 100 of Comparative Example 3 is the same as the substrate holding member 100 of Example 8, except that the RF electrode 126 is formed using the same mesh electrode material (opening ratio 65%) as in Example 1. In Comparative Example 3, the opposing equivalent area S of the electrostatic attraction electrode 124 and the RF electrode 126 is 0.0237 m 2 It was.

[0084] In Comparative Example 3, the resistance value R between the electrostatic chucking electrode 124 and the RF electrode 126 is 1.05×10 14 Ω and the capacitance C is 4.92×10 -10 F. At this time, the ratio of resistance R to capacitance C, R / C, is 2.13 × 10 23 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 )1 / 2 / S was 1.77.

[0085] In Comparative Example 3, a process test similar to that in Example 1 was performed. A plasma process test was also performed in Comparative Example 3. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 was 2 mA or less, and the electrostatic attraction voltage applied to the electrostatic attraction electrode 124 could be maintained, and the wafer 10 could be electrostatically attracted, and electrostatic attraction was satisfactory. However, the reflection coefficient was 0.31, and high-frequency power could not be applied satisfactorily.

[0086] <Comparative Example 4> The substrate holding member 100 of Comparative Example 4 has a thickness d of the intermediate ceramic substrate 110M of 2.0×10 -3 This is the same as the substrate holding member 100 of Example 9, except that the thickness is set to mm.

[0087] In Comparative Example 4, the resistance value R between the electrostatic chucking electrode 124 and the RF electrode 126 is 6.71×10 11 Ω and the capacitance C is 2.41×10 -9 F. At this time, the ratio of resistance R to capacitance C, R / C, is 2.79 × 10 20 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 8.83.

[0088] In Comparative Example 4, a process test similar to that in Example 1 was performed. A plasma process test was performed in Comparative Example 4. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 exceeded 2 mA, and the electrostatic attraction voltage applied to the electrostatic attraction electrode 124 could not be maintained, and the wafer 10 could not be electrostatically attracted, resulting in poor electrostatic attraction.

[0089] <Comparative Example 5> The substrate holder 100 of Comparative Example 5 was manufactured by the above-described manufacturing method using aluminum nitride (AlN) to which 1.5 wt % of a titanium compound and 1 wt % of a rare earth oxide were added as a raw material (AlN-3), and the thickness d of the intermediate ceramic substrate 110M was 2.0 × 10 -3 In Comparative Example 5, the volume resistivity ρ of the intermediate ceramic substrate 110M was 3.20×10 9 The volume resistivity ρ was measured in the same state as in Example 1, with the AlN ceramic substrate 110 heated to 100° C. using a hot plate or an oven.

[0090] In Comparative Example 5, the resistance value R between the electrostatic chucking electrode 124 and the RF electrode 126 is 2.75×10 8 Ω and the capacitance C is 2.41×10 -9 F. At this time, the ratio of resistance R to capacitance C, R / C, is 1.14 × 10 17 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 8.83.

[0091] In Comparative Example 5, a process test similar to that in Example 1 was performed. A plasma process test was performed in Comparative Example 5. As a result, the current value of the DC power supply connected to the electrostatic attraction electrode 124 exceeded 2 mA, and the electrostatic attraction voltage applied to the electrostatic attraction electrode 124 could not be maintained, and the wafer 10 could not be electrostatically attracted, resulting in poor electrostatic attraction.

[0092] <Comparative Example 6> The substrate holding member 100 of Comparative Example 6 has a thickness d of 1.0×10 -2 The thickness was the same as that of the substrate holding member 100 of Comparative Example 5, except that the thickness was set to mm.

[0093] In Comparative Example 6, the resistance value R between the electrostatic chucking electrode 124 and the RF electrode 126 is 1.38×109 Ω and the capacitance C is 4.82×10 -10 F. At this time, the ratio of resistance R to capacitance C, R / C, is 2.86 × 10 18 Ω / F. Also, the value (1 / R 2 +(2πfC) 2 ) 1 / 2 / S was 1.77.

[0094] In Comparative Example 6, a process test similar to that in Example 1 was performed. A plasma process test was performed in Comparative Example 6. The results were unsatisfactory. Although a sufficient amount of high-frequency power was applied to the RF electrode 126, the electrostatic attraction voltage applied to the electrostatic attraction electrode 124 could not be maintained, and the wafer 10 could not be electrostatically attracted.

[0095] <Effects of the embodiment> In the above embodiment, the substrate holding member 100 includes a plate-shaped upper ceramic substrate 110U having an upper surface 111 for holding a wafer 10, a plate-shaped intermediate ceramic substrate 110M located below the upper ceramic substrate 110U in the vertical direction 5, and a plate-shaped lower ceramic substrate 110D located below the intermediate ceramic substrate 110M in the vertical direction 5. Furthermore, in the above embodiment and Examples 1 to 13, an electrostatic attraction electrode 124 serving as an upper intermediate electrode is disposed between the upper ceramic substrate 110U and the intermediate ceramic substrate 110M, and an RF electrode 126 serving as a lower intermediate electrode is disposed between the intermediate ceramic substrate 110M and the lower ceramic substrate 110D. Furthermore, in Example 14, an RF electrode 126 serving as an upper intermediate electrode is disposed between the upper ceramic substrate 110U and the intermediate ceramic substrate 110M, and a heater electrode (not shown) serving as a lower intermediate electrode is disposed between the intermediate ceramic substrate 110M and the lower ceramic substrate 110D. In the above embodiment and Examples 1 to 14, the resistance R (Ω) between the upper intermediate electrode (for example, the electrostatic chucking electrode 124) and the lower intermediate electrode (for example, the RF electrode 126) and the capacitance C (F) between the upper intermediate electrode (for example, the electrostatic chucking electrode 124) and the lower intermediate electrode (for example, the RF electrode 126) are expressed by the following relational expression: 1.0×10 21 (Ω / F)≦ R / C ≦ 1.0×10 23 (Ω / F) The ratio R / C is 5.0×10 23 (Ω / F) or less, and 3.0×10 23 It is more preferable that the resistance is 0.01Ω / F or less.

[0096] Comparing Examples 1 to 14 with Comparative Examples 1, 2, and 4 to 6, the ratio R / C was 1.0 × 10 21 (Ω / F), it was found that in the above process test, it was not possible to properly apply high frequency power to the RF electrode 126 while maintaining the electrostatic chucking force on the wafer 10. Furthermore, when Examples 1 to 14 were compared with Comparative Example 3, it was found that the value of the ratio R / C was 1.0×10 23 (Ω / F), it was found in the above process test that high frequency power could not be applied to the RF electrode 126 satisfactorily while maintaining the electrostatic adsorption force on the wafer 10.

[0097] Here, as the resistance value R (Ω) between the upper intermediate electrode (e.g., the electrostatic chucking electrode 124) and the lower intermediate electrode (e.g., the RF electrode 126) decreases, the DC leakage current between these two electrodes increases. Therefore, if the resistance value R (Ω) becomes too small, the DC leakage current between the two electrodes makes it impossible to maintain the voltage applied to the electrostatic chucking electrode 124. On the other hand, as the capacitance C (F) between the upper intermediate electrode (e.g., the electrostatic chucking electrode 124) and the lower intermediate electrode (e.g., the RF electrode 126) increases, the composite impedance of the ceramic layer between the upper intermediate electrode and the lower intermediate electrode increases. Therefore, if the capacitance C (F) becomes too large, the RF power is not sufficiently loaded on the RF electrode 126, and the process efficiency decreases. In the present invention, the ratio R / C is set to 1.0×10 21 (Ω / F) or more 1.0×10 23By adjusting the resistance R (Ω) and capacitance C (F) between the upper and lower intermediate electrodes so that the resistance R (Ω) and capacitance C (F) are equal to or less than the resistance R (Ω / F), the DC leakage current between the two electrodes is suppressed, and the electrostatic chucking force to the wafer 10 is maintained, while high frequency power is applied to the RF electrode 126 in an appropriate manner.

[0098] Comparing the above-mentioned Examples 1 to 7, 9, 11 to 14 with Examples 8 and 10, it can be seen that the equivalent opposing area S calculated from the shapes of the upper intermediate electrode (for example, the electrostatic attraction electrode 124) and the lower intermediate electrode (for example, the RF electrode 126) is (1 / R 2 +(2πfC) 2 ) 0.5 / S≧2.0 When the above condition is satisfied, it was found that in a plasma process test using high frequency power with a frequency of 13.56 MHz, the reflection of power from the load can be reduced relative to the input power, and the reflection coefficient can be reduced to 0.3 or less.

[0099] In the above embodiment and Examples 1 to 13, the distance d between the upper intermediate electrode and the lower intermediate electrode in the vertical direction 5 is d≧750×10 -6 (m). Distance d is 750×10 -6 By setting the parallelism between the upper and lower intermediate electrodes to p≦100×10 or more, the risk of dielectric breakdown between the upper and lower intermediate electrodes can be reduced. -6 (m) is satisfied. This makes it possible to make the in-plane distribution of the effects resulting from the upper intermediate electrode and / or the lower intermediate electrode (for example, the in-plane distribution of plasma, the in-plane distribution of electrostatic adsorption force, and the in-plane distribution of the heated region by the heater) more uniform.

[0100] As in the above embodiment and Examples 1 to 13, the upper intermediate electrode can be the electrostatic attraction electrode 124, and the lower intermediate electrode can be the RF electrode 126. Alternatively, as in the above embodiment and Example 14, one of the upper intermediate electrode and the lower intermediate electrode can be the RF electrode 126, and the other can be the electrostatic attraction electrode 124. In this way, a highly functional substrate holder 100 can be produced by allowing the multiple electrodes (upper intermediate electrode and lower intermediate electrode) to perform different functions.

[0101] In the above embodiment, the average particle diameter of the ceramic particles (AlN ceramic particles) constituting the intermediate ceramic substrate 110U is larger than the average particle diameter of the ceramic particles (AlN ceramic particles) constituting the upper ceramic substrate 110U. The average particle diameter of the ceramic particles (AlN ceramic particles) constituting the lower ceramic substrate 110D is larger than the average particle diameter of the ceramic particles (AlN ceramic particles) constituting the intermediate ceramic substrate 110M. In the above-described method for manufacturing the substrate holding member 100, the lower ceramic substrate 110D is fired three times, the intermediate ceramic substrate 110M is fired twice, and the upper ceramic substrate 110U is fired once. Accordingly, the average particle diameter of the ceramic particles in the lower ceramic substrate 110D, which has been fired the most times, is the largest, and the average particle diameter of the ceramic particles in the upper ceramic substrate 110U, which has been fired the least times, is the smallest. The upper ceramic substrate 110U is a component that directly contacts the wafer. Therefore, if ceramic particles fall off, there is a risk that the ceramic particles will adhere to the wafer 10. Since the smaller the average particle diameter of the ceramic particles, the smaller the impact of particle shedding, minimizing the average particle diameter of the upper ceramic base 110U can prevent the shed ceramic particles from adhering to the wafer 10.

[0102] In Examples 12 and 13, the composition of the ceramic constituting the upper ceramic substrate 110U is different from the compositions of the ceramic constituting the middle ceramic substrate 110M and the lower ceramic substrate 110D. Similarly, the composition of the ceramic of any one of these three ceramic substrates can be made different from the composition of the ceramic of the other ceramic substrates. In this case, appropriate additives can be added to each ceramic substrate, allowing the physical properties of each ceramic substrate to be adjusted.

[0103] In the above embodiment, the manufacturing method of the substrate holding member 100 includes a step (S101) of firing a ceramic material to produce a plate-shaped lower ceramic substrate 110D, a step (S102) of arranging a lower intermediate electrode (e.g., RF electrode 126) on the upper surface of the lower ceramic substrate 110D, a step (S103) of arranging granulated powder P of the ceramic material on the lower ceramic substrate 110D so as to cover the lower intermediate electrode (RF electrode 126) and firing the granulated powder to produce an intermediate ceramic substrate 110M, a step (S104) of arranging an upper intermediate electrode (e.g., electrostatic adsorption electrode 124) on the upper surface of the intermediate ceramic substrate 110M, and a step (S105) of arranging granulated powder P of the ceramic material on the intermediate ceramic substrate 110M so as to cover the upper intermediate electrode (electrostatic adsorption electrode 124) and firing the granulated powder P to produce an upper ceramic substrate 110U. When the substrate holding member 100 is produced using this manufacturing method, the lower ceramic substrate 110D is fired three times, the middle ceramic substrate 110M is fired twice, and the upper ceramic substrate 110U is fired once. This minimizes the average particle size of the upper ceramic substrate 110U as described above, and prevents shed ceramic particles from adhering to the wafer 10.

[0104] In the above embodiment, the ceramic material for forming the intermediate ceramic base 110M can be a ceramic green sheet. As described above, when a ceramic green sheet is used, the vertical distance between the upper intermediate electrode (e.g., the electrostatic attraction electrode 124) and the lower intermediate electrode (e.g., the RF electrode 126) can be made uniform. This allows the resistance and capacitance of the intermediate ceramic base 110M to be stabilized.

[0105] In the above embodiment, the upper intermediate electrode (e.g., the electrostatic attraction electrode 124) and the lower intermediate electrode (e.g., the RF electrode 126) can be formed of a metal mesh. In this case, a process can be adopted in which granulated powder P of a ceramic material is filled so as to cover each electrode, and the resulting mixture is subjected to pressure firing. In this process, the granulated powder P can penetrate into the voids in the mesh, thereby firmly adhering the ceramic base material and the electrodes formed of the metal mesh.

[0106] In Example 15, multiple protrusions 118 were formed on the upper surface of lower ceramic substrate 110D by machining. Similarly, multiple protrusions can be formed on the upper surface of intermediate ceramic substrate 110M by machining. In either case, when a ceramic substrate is produced by filling granulated powder of a ceramic material so as to cover an electrode placed on a ceramic substrate on which protrusions have been formed, the granulated powder can penetrate into the gaps between the protrusions through the voids in the mesh that constitutes the electrode. This allows the ceramic substrate and the electrode formed from a mesh-like metal to be firmly attached to each other.

[0107] <Modification form> The above-described embodiment is merely an example and can be modified as appropriate. For example, the ceramic base 110 does not necessarily have to be made of AlN ceramics, and may be made of another ceramic sintered body.

[0108] In the above-described embodiment, the upper intermediate electrode and the lower intermediate electrode are formed using molybdenum. However, the present invention is not limited to this embodiment, and various metal materials such as tungsten, molybdenum alloys, and tungsten alloys can be used.

[0109] Furthermore, the shapes, thicknesses, etc. of the upper ceramic substrate 110U, the middle ceramic substrate 110M, and the lower ceramic substrate 110D that constitute the ceramic substrate 110 can be changed as appropriate.

[0110] Although the present invention has been described above using embodiments and modifications thereof, the technical scope of the present invention is not limited to the scope of the above description. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0111] The order of execution of each process in the manufacturing method shown in the specification and drawings is not particularly specified, and the processes may be executed in any order unless the output of a previous process is used in a subsequent process. For convenience, even if a description is made using "first," "next," etc., it does not mean that the processes must be executed in this order. [Explanation of symbols]

[0112] 100 Substrate holding member 110 Ceramic substrate 110U Upper ceramic substrate 110M Intermediate ceramic substrate 110D Lower ceramic substrate 124 Electrostatic Adsorption Electrode 126 RF electrode

Claims

1. a plate-shaped upper ceramic base having a main surface for holding a substrate; a plate-shaped intermediate ceramic substrate located below the upper ceramic substrate in a vertical direction perpendicular to the main surface; a plate-shaped lower ceramic substrate located below the intermediate ceramic substrate in the vertical direction; an upper intermediate electrode located between the upper ceramic substrate and the intermediate ceramic substrate in the vertical direction; a lower intermediate electrode located between the intermediate ceramic substrate and the lower ceramic substrate in the vertical direction, The resistance R (Ω) between the upper intermediate electrode and the lower intermediate electrode, and the capacitance C (F) between the upper intermediate electrode and the lower intermediate electrode are 1.0×10 ２１ (Ω / F)≦ R / C ≦ 1.0×10 ２３ (Ohm / F) A substrate holding member characterized by satisfying the above.

2. When a high frequency voltage having a frequency f is applied to the upper intermediate electrode or the lower intermediate electrode from a high frequency power supply, An equivalent opposing area S calculated from the shapes of the upper intermediate electrode and the lower intermediate electrode is (1 / R ２ +(2πfC) ２ ) ０．５ / S≧2.0 2. The substrate holder according to claim 1, wherein the following is satisfied:

3. 2. The substrate holding member according to claim 1, wherein one of said upper intermediate electrode and said lower intermediate electrode is an electrode for electrostatic attraction, and the other is an electrode for applying high frequency waves.

4. 2. The substrate holding member according to claim 1, wherein one of said upper intermediate electrode and said lower intermediate electrode is a heater electrode, and the other is a high frequency electrode.

5. The distance d between the upper intermediate electrode and the lower intermediate electrode in the vertical direction and the parallelism p between the upper intermediate electrode and the lower intermediate electrode are respectively: d≧750×10 －６ (m) p≦100×10 －６ (m) The substrate holding member according to claim 1 , wherein the above formula (1) is satisfied.

6. the average particle size of the ceramic particles constituting the lower ceramic substrate is larger than the average particle size of the ceramic particles constituting the intermediate ceramic substrate; 2. The substrate holding member according to claim 1, wherein the average particle size of the ceramic particles constituting the intermediate ceramic substrate is larger than the average particle size of the ceramic particles constituting the upper ceramic substrate.

7. 2. The substrate holding member according to claim 1, wherein one of the ceramic compositions constituting the upper ceramic substrate, the ceramic composition constituting the intermediate ceramic substrate, and the ceramic composition constituting the lower ceramic substrate has a different composition from the others.

8. A step of firing the ceramic material to prepare a plate-shaped lower ceramic substrate; disposing a lower intermediate electrode on an upper surface of the lower ceramic substrate; a step of disposing a ceramic material on the lower ceramic substrate so as to cover the lower intermediate electrode, and firing the ceramic material to form an intermediate ceramic substrate; disposing an upper intermediate electrode on an upper surface of the intermediate ceramic substrate; a step of placing a ceramic material on the intermediate ceramic substrate so as to cover the upper intermediate electrode, and firing the ceramic material to form an upper ceramic substrate.

9. The resistance R (Ω) between the upper intermediate electrode and the lower intermediate electrode, and the capacitance C (F) between the upper intermediate electrode and the lower intermediate electrode are 10 ２１ (Ω / F)≦ R / C ≦ 10 ２３ (Ohm / F) The method for manufacturing a substrate holding member according to claim 8, wherein the above condition is satisfied.

10. 10. The method for manufacturing a substrate holding member according to claim 8 or claim 9, wherein any one of the compositions of the ceramic material for forming the upper ceramic substrate, the ceramic material for forming the intermediate ceramic substrate, and the ceramic material for forming the lower ceramic substrate is different from the other compositions.

11. 10. The method for manufacturing a substrate-holding member according to claim 8, wherein the ceramic material for forming the intermediate ceramic substrate is a ceramic green sheet.

12. 10. The method for manufacturing a substrate holding member according to claim 8, wherein the upper intermediate electrode or the lower intermediate electrode is made of a metal mesh.

13. 10. The method for manufacturing a substrate holder according to claim 8, further comprising the step of forming a plurality of protrusions on the upper surface of the lower ceramic substrate or the intermediate ceramic substrate.

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