Electrostatic chuck device

Abstract

An electrostatic chuck device is provided with: an electrostatic chuck unit having a dielectric substrate having a placement surface on which a plate-shaped sample is placed, and a suction electrode disposed inside the dielectric substrate; and a base that supports the electrostatic chuck portion from a rear surface side opposite to the mounting surface and is capable of adjusting the temperature of the electrostatic chuck portion, the electrostatic chuck portion having an annular protrusion that protrudes upward from an outer peripheral portion of an upper surface of the dielectric substrate and is formed in an annular shape when viewed from a thickness direction of the electrostatic chuck portion, and the annular protrusion is formed in an annular shape when viewed from the thickness direction. At least a portion of the base is located radially inward of the annular protrusion.

Description

Technical Field

[0001] This invention relates to an electrostatic chuck device.

[0002] This application claims priority based on Japanese Patent Application No. 2023-106628, filed in Japan on June 29, 2023, the contents of which are incorporated herein by reference. Background Technology

[0003] Electrostatic chuck devices for supporting substrates such as semiconductor wafers are known. For example, in Patent Document 1, such an electrostatic chuck device is disclosed with the following structure: an annular protrusion that contacts the substrate is located at the outer periphery of the mounting surface of the substrate (the object being held); gas is supplied between the annular protrusion and the substrate through a through hole provided inside the annular protrusion, and processes such as substrate film formation, etching, and resist film formation are performed.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2006-270084 Summary of the Invention

[0007] The technical problem to be solved by the invention

[0008] In the electrostatic chuck device described above, the heat input generated by the processing performed on the upper surface of the substrate causes the substrate temperature to rise. Through various studies, the inventors have discovered that, in terms of temperature distribution during processing, there is a tendency for a sharp temperature increase, particularly in and around the radial annular protrusions of the substrate, compared to the central portion. Due to this sharp temperature rise near the annular protrusions, strain occurs in the annular protrusions, potentially leading to gas leakage between the substrate and the annular protrusions. Therefore, it is necessary to suppress strain on the annular protrusions during substrate processing and to prevent gas leakage between the substrate and the annular protrusions, i.e., to prevent gas leakage.

[0009] One of the objectives of this invention is to provide an electrostatic chuck device that can suppress strain on the annular protrusion during substrate processing and suppress gas leakage between the substrate and the annular protrusion.

[0010] means for solving technical problems

[0011] The present invention provides the electrostatic chuck device described below.

[0012] The features described below are preferably combined in combination of two or more as needed.

[0013] [1] An electrostatic chuck device comprising: an electrostatic chuck portion having a dielectric substrate and an adsorption electrode, the dielectric substrate having a mounting surface for mounting a plate-shaped sample, the adsorption electrode being disposed inside the dielectric substrate; and a base supporting the electrostatic chuck portion from a back side opposite to the mounting surface and capable of adjusting the temperature of the electrostatic chuck portion, the electrostatic chuck portion having an annular protrusion protruding upward from the outer periphery of the upper surface of the dielectric substrate and forming an annular shape when viewed from the thickness direction of the electrostatic chuck portion, the base having: a mounting surface for mounting the electrostatic chuck portion; and a thermally inhibiting portion disposed on the mounting surface, at least a portion of the thermally inhibiting portion being located radially inward than the annular protrusion when viewed from the thickness direction.

[0014] [2] According to the electrostatic chuck device of [1], the radial width K of the heat-conducting suppression part is greater than the radial width L of the annular protrusion.

[0015] [3] According to the electrostatic chuck device of [1] or [2], wherein, when viewed from the thickness direction, the annular protrusion overlaps with a portion of the thermally conductive suppressing portion.

[0016] [4] According to the electrostatic chuck device of [3], wherein, when viewed from the thickness direction, the radial width d of the portion of the annular protrusion overlapping with a portion of the thermally conductive suppressing portion is relative to the radial width L of the annular protrusion as follows:

[0017] 0 < d < L / 2.

[0018] [5] The electrostatic chuck device according to any one of [1] to [4], wherein the thermal conductivity of the thermally inhibiting part is lower than the thermal conductivity of the base.

[0019] [6] The electrostatic chuck device according to any one of [1] to [5], wherein the heat-conducting suppression portions are provided in a plurality of spaced-apart portions along the circumferential direction of the electrostatic chuck portion around the central axis.

[0020] [7] According to the electrostatic chuck device of [6], the heat-conducting suppression part has an arc shape that is concentrically formed with the annular protrusion.

[0021] [8] According to the electrostatic chuck device of [7], wherein the radius of curvature R2 of the heat-conducting suppression part is smaller than the radius of curvature R1 of the annular protrusion.

[0022] [9] According to the electrostatic chuck device of [6], the heat-conducting suppression part is circular when viewed from the thickness direction and has a radius R3 that is smaller than the radius of curvature R1 of the annular protrusion.

[0023]

[10] The electrostatic chuck device according to any one of [1] to [9], wherein the heat-conducting suppression part is disposed in a hole or recess formed on the mounting surface.

[0024] Invention Effects

[0025] According to the above aspects of the present invention, an electrostatic chuck device is provided, which can suppress strain on the annular protrusion during substrate processing and suppress gas leakage between the substrate and the annular protrusion. Attached Figure Description

[0026] Figure 1 This is a schematic cross-sectional view showing an example of the electrostatic chuck device according to the first embodiment.

[0027] Figure 2 It's enlarged. Figure 1 A partial schematic cross-sectional view of the electrostatic chuck device.

[0028] Figure 3 This is a schematic planar sectional view showing an example of the structure of the heat-conducting suppression part of the electrostatic chuck device.

[0029] Figure 4 This is a diagram illustrating an example of the temperature distribution on the outer periphery of a wafer held by an electrostatic chuck device, caused by the presence or absence of a thermally inhibiting section.

[0030] Figure 5 This is a schematic planar cross-sectional view showing an example of the structure of the heat conduction suppression section in the electrostatic chuck device of the second embodiment.

[0031] Figure 6 This is a schematic planar cross-sectional view showing an example of the structure of the heat conduction suppression section in the electrostatic chuck device of the third embodiment.

[0032] Figure 7 This is a schematic planar cross-sectional view showing an example of the structure of the heat conduction suppression section in the electrostatic chuck device of the fourth embodiment.

[0033] Figure 8 This is a schematic diagram illustrating an example of a semiconductor manufacturing apparatus having the electrostatic chuck device described above. Detailed Implementation

[0034] Hereinafter, preferred embodiments of the electrostatic chuck device of the present invention will be described with reference to the accompanying drawings. Furthermore, in all the following drawings, the dimensions or proportions of the constituent components may be appropriately altered for clarity and ease of understanding.

[0035] Furthermore, this embodiment is a detailed description provided to better understand the spirit of the invention, and is not intended to limit the invention unless otherwise specified. For example, unless otherwise specifically limited, conditions such as materials, quantities, types, quantities, sizes, shapes, positions, ratios, and temperatures can be changed, added, or omitted as needed. As long as there are no problems, the preferred features or conditions of the first to fourth embodiments described below can be shared with each other.

[0036] [First Implementation]

[0037] (The entire electrostatic chuck device)

[0038] Figure 1 This is a schematic cross-sectional view showing an example of the electrostatic chuck device of this embodiment.

[0039] Figure 1 The electrostatic chuck device 100 shown is, for example, arranged in the vacuum container of a plasma processing apparatus with the mounting surface 11a of the wafer (plate-shaped sample) W facing upward.

[0040] Additionally, the Z-axis is shown in each figure to illustrate the reference of the electrostatic chuck device. The Z-axis direction is, for example, the vertical direction. The central axis O of the mounting surface 11a is parallel to the Z-axis. Furthermore, the configuration of the electrostatic chuck device 100 relative to the vertical direction is one example, but other configurations are also possible.

[0041] The electrostatic chuck device 100 includes an electrostatic chuck portion 10 for adsorbing and supporting plate-shaped samples such as wafers W, a base 20 for supporting the electrostatic chuck portion 10, and a thermally inhibiting portion 50A.

[0042] (Electrostatic chuck section)

[0043] The electrostatic chuck portion 10 has a dielectric substrate 11 and an adsorption electrode 30.

[0044] (Dielectric substrate)

[0045] The dielectric substrate 11 is a plate-shaped component that appears circular or approximately circular when viewed from above. In this specification, the thickness direction of the dielectric substrate 11 is sometimes simply referred to as the "thickness direction." Furthermore, in this specification, the side in the thickness direction where the wafer W is mounted is designated as the "upper side," and the opposite side is designated as the "lower side" to describe the electrostatic chuck device. The terms "upper side" and "lower side" in this specification are examples of the posture when using the electrostatic chuck device and are not limited to any particular posture.

[0046] The dielectric substrate 11 is preferably composed of a composite sintered body that has mechanical strength and durability against corrosive gases and their plasmas. As the dielectric material constituting the dielectric substrate 11, ceramics that have mechanical strength and durability against corrosive gases and their plasmas can be suitably used. For example, alumina sintered bodies, aluminum nitride sintered bodies, and alumina-silicon carbide composite sintered bodies can be suitably used as the ceramic constituting the dielectric substrate 11.

[0047] A mounting surface 11a for mounting the wafer W is formed on the upper surface of the dielectric substrate 11. That is, a mounting surface 11a for mounting the wafer W is provided on the dielectric substrate 11. In this embodiment, a plurality of upwardly protruding portions 12 are formed on the upper surface of the dielectric substrate 11 at predetermined intervals.

[0048] Figure 2 It's enlarged. Figure 1 A partial cross-sectional view of the electrostatic chuck device.

[0049] like Figure 1 , Figure 2 As shown, among the plurality of protrusions 12, the protrusion 12 located on the outer periphery of the dielectric substrate 11 is an annular protrusion 12C formed in a ring shape when viewed from the thickness direction. The annular protrusion is preferably a continuous shape, and its upper surface is preferably flat. "Annular" can refer to a circular or substantially circular shape. Preferably, the annular protrusion 12C is integrally formed with the dielectric substrate 11, and it is also preferred that the annular protrusion 12C and the dielectric substrate 11 are formed of the same material, but this is not limited to these examples. Figure 2 As shown, the annular protrusion 12C has an arbitrarily selectable width in the radial direction of the dielectric substrate 11, for example, a width L of 0.5 mm to 5 mm. The width L can be 0.8 mm to 3.5 mm, 1.5 mm to 2.5 mm, etc.

[0050] The front end faces of a plurality of protrusions 12, including annular protrusions 12C, form a mounting surface 11a. The front end face (mounting surface 11a) of the annular protrusions 12C is in continuous contact with the lower surface of the wafer W along its entire circumference. The heights of the annular protrusions 12C and the protrusions 12 are preferably the same or substantially the same. In the dielectric substrate 11, recesses (valve portions) 13 are formed between adjacent plurality of protrusions 12, which are recessed downward relative to the mounting surface 11a. The bottom surface 13b of the recesses 13 faces upward (wafer W side).

[0051] Preferably, vents (not shown) are provided in the dielectric substrate 11. The vents penetrate the dielectric substrate 11 along the thickness direction. The vents are located radially inward relative to the annular protrusion 12C. The vents are connected to a gas supply device (not shown). The vents supply a cooling gas of any choice, such as helium (He), to the space between the wafer W placed on the mounting surface 11a and the bottom surface 13b of the recess 13. The supplied cooling gas cools the wafer W placed on the mounting surface 11a. Since the leading edge of the annular protrusion 12C is in continuous contact with it on the entire circumference of the lower surface of the wafer W, leakage of cooling gas to the radially outward side of the annular protrusion 12C can be suppressed.

[0052] (Adsorption electrode)

[0053] An adsorption electrode 30 is embedded in the dielectric substrate 11. The adsorption electrode 30 is conductive. The adsorption electrode 30 is located inside the dielectric substrate 11. The adsorption electrode 30 extends in a layered manner, for example, along a plane orthogonal to the thickness direction of the dielectric substrate 11. The adsorption electrode 30 is disposed in the dielectric substrate 11, located below the mounting surface 11a and the bottom surface 13b, and at a distance of a predetermined dimension from them.

[0054] The adsorption electrode 30 is connected to a DC power supply (not shown) via a power supply unit (not shown). The adsorption electrode 30 generates electrostatic adsorption force through the DC current supplied from the DC power supply, causing the wafer W to adhere to the mounting surface 11a. Furthermore, the adsorption electrode 30 can have any chosen shape or number; for example, it is not limited to a unipolar adsorption electrode, but can also be a bipolar adsorption electrode consisting of two semi-circular electrodes when viewed from above. Moreover, when viewed in the thickness direction, the adsorption electrode 30 can be provided only in a portion of the circumference of the electrostatic chuck portion 10. Furthermore, when viewed in the thickness direction, multiple adsorption electrodes 30 can be provided at intervals along the circumference of the electrostatic chuck portion 10.

[0055] The adsorption electrode 30 can be formed from any chosen material, such as a composite material of insulating and conductive materials. The insulating material included in the composite material is not particularly limited, but is preferably selected from at least one of the following: alumina (Al₂O₃), aluminum nitride (AlN), silicon nitride (Si₃N₄), yttrium(III) oxide (Y₂O₃), yttrium-aluminum-garnet (YAG), and SmAlO₃. The conductive material included in the composite material is preferably selected from at least one of the following: molybdenum carbide (Mo₂C), molybdenum (Mo), tungsten carbide (WC), tungsten (W), tantalum carbide (TaC), tantalum (Ta), silicon carbide (SiC), carbon black, carbon nanotubes, and carbon nanofibers.

[0056] This adsorption electrode 30 can be an electrode pre-formed into a specified shape, or it can be formed by 3D printing, vapor deposition, or other methods. The adsorption electrode 30 can also be formed by stacking the dielectric substrate 11 in multiple layers, thereby embedding it in the dielectric substrate 11.

[0057] (Base)

[0058] The base 20 of this embodiment is composed of a circular plate-shaped metal component with thickness. The base 20 supports the electrostatic chuck portion 10 from below (opposite to the mounting surface 11a). The material constituting the base 20 can be arbitrarily selected; for example, there are no particular limitations as long as it is a metal or a composite material containing such metal with excellent thermal conductivity, electrical conductivity, and machinability. For example, aluminum, aluminum alloy, copper, copper alloy, stainless steel, etc., can be used appropriately. The features or structure of the base for adjusting the temperature of the electrostatic chuck portion can be arbitrarily selected. For example, the temperature of the electrostatic chuck portion can be effectively adjusted by means of the heat-conducting suppression part described later or the flow path described below. Furthermore, the base 20 of this embodiment preferably has a flow path 21 inside the circular plate-shaped structure for circulating a coolant such as water; in this embodiment, it is a water-cooled base. The coolant circulating in the flow path 21 can be arbitrarily selected and can be a gas such as He gas or N2 gas. This base 20 can cool the electrostatic chuck portion 10 and adjust its temperature by the coolant circulating in the flow path 21.

[0059] The base 20 has an upward-facing mounting surface 20t. The mounting surface 20t of the base 20 is bonded to the lower surface 11b of the dielectric substrate 11 via an adhesive layer 25. The material forming the adhesive layer 25 can be arbitrarily selected, for example, it is composed of heat-resistant resins such as polyimide resin, silicone resin, and epoxy resin, or sheet-like or film-like adhesive resins with insulating properties.

[0060] (Thermal conductivity suppression section)

[0061] In this embodiment, the heat-conducting suppression part 50A is embedded in the base 20. In this embodiment, the heat-conducting suppression part 50A is preferably disposed within a recess 22 formed on the mounting surface 20t of the base 20. The recess 22 is filled or held as a space by a selected material. The heat-conducting suppression part 50A is disposed on the mounting surface 20t. In this embodiment, the upper surface 50a of the heat-conducting suppression part 50A is formed to the same height as the mounting surface 20t of the base 20. The heat-conducting suppression part 50A can be disposed in a hole (bottomed cavity or through hole) formed in the base 20. For example, it can be disposed within the hole. Regarding the recess 22 or hole where the heat-conducting suppression part 50A is disposed, it can also serve other purposes besides disposing of the heat-conducting suppression part 50A, as needed. The bottom surface of the recess 22 can be a plane, but is not limited to this example. The material forming the heat-conducting suppression part 50A is preferably different from the material forming the base 20. Examples of specific materials for forming the thermally inhibiting part 50A include, for example, alumina, yttrium oxide, aluminum nitride, etc., but are not limited to these examples.

[0062] Figure 3 This is a planar sectional view showing the structure of the heat-conducting suppression part of the electrostatic chuck device.

[0063] like Figure 3 As shown, in this embodiment, when viewed from the thickness direction, the thermal conductivity suppression portion 50A is annular. When viewed from the thickness direction, at least a portion of the thermal conductivity suppression portion 50A is located radially inward than the annular protrusion 12C. Figure 2 , Figure 3 As shown, in this embodiment, when viewed from the thickness direction, the outer periphery 50s of the heat-conducting suppression portion 50A is located between the inner periphery 12s and the outer periphery 12t of the annular protrusion 12C. In this embodiment, when viewed from the thickness direction, the inner periphery 50t of the heat-conducting suppression portion 50A is located radially inward than the inner periphery 12s of the annular protrusion 12C. Therefore, in this embodiment, when viewed from the thickness direction, a portion of the radial direction of the heat-conducting suppression portion 50A overlaps with the annular protrusion 12C.

[0064] Furthermore, when viewed from the thickness direction, the outer periphery 50s of the heat-conducting suppression portion 50A can be located radially inward than the inner periphery 12s of the annular protrusion 12C. That is, when viewed from the thickness direction, the heat-conducting suppression portion 50A does not overlap with the annular protrusion 12C, and a radial gap can be formed between the outer periphery 50s of the heat-conducting suppression portion 50A and the inner periphery 12s of the annular protrusion 12C. In this case, the distance between the heat-conducting suppression portion 50A and the inner periphery 12s of the annular protrusion 12C can be arbitrarily selected, for example, it can be 0 to 0.5 times, 0.01 to 0.7 times, 0.05 to 0.8 times, 0.1 to 1.0 times the radial width of the annular protrusion 12C, etc., but is not limited to these examples.

[0065] like Figure 2 As shown, in this embodiment, the radial width K of the thermally inhibiting portion 50A is preferably greater than the radial width L of the annular protrusion 12C to effectively reduce the temperature gradient of the annular protrusion 12C. Furthermore, it is preferably less than the thickness of the base 20 to avoid excessively suppressing the cooling effect of the wafer. The radial width K of the thermally inhibiting portion 50A can be arbitrarily selected; for example, it is preferably 0.5 mm or more and 30 mm or less. Width K can be 1.5 mm or more and 25 mm or less, 3.0 mm or more and 20 mm or less, 7.0 mm or more and 15 mm or less, etc. The depth (thickness) of the thermally inhibiting portion 50A can be arbitrarily selected; for example, it can be 0.1 to 1.0 mm, 0.5 to 3.0 mm, 1.0 to 10.0 mm, but is not limited to these examples. In this embodiment, the width K is constant; however, if the width is not constant, it can refer to the value at the position with the largest radial width.

[0066] Furthermore, when viewed from the thickness direction, the radial width d of the portion where the annular protrusion 12C overlaps with a portion of the thermally inhibiting portion 50A is preferably set as follows, relative to the radial width L of the annular protrusion 12C:

[0067] 0 < d < L / 2.

[0068] With this configuration, the outermost periphery of the wafer, which is prone to becoming hot, can be cooled, and the temperature gradient of the annular protrusion 12C can be suppressed from becoming steeper, which is further preferred.

[0069] The thermal conductivity of the heat-suppressing portion 50A is preferably lower than that of the base 20. The heat-suppressing portion 50A is preferably formed of a material with a thermal conductivity lower than that of the material forming the base 20, such as a metal or a metal-containing composite material. Examples of materials forming the heat-suppressing portion 50A include Teflon (registered trademark) or plastic materials, organic or inorganic adhesives, highly insulating insulators, or ceramic materials. More specifically preferred examples include alumina, yttrium oxide, and aluminum nitride. The heat-suppressing portion 50A may be, for example, a space. The thermal conductivity of the material forming the thermally inhibiting part 50A can be, for example, 0.1–10 W / (m·K), 0.5–20 W / (m·K), 1.0–30 W / (m·K), 5–50 W / (m·K), 10–100 W / (m·K), 100–150 W / (m·K), or 150–200 W / (m·K), but is not limited to these examples. The ratio of the thermal conductivity of the thermally inhibiting part 50A to the thermal conductivity of the base 20 (thermal conductivity of the thermally inhibiting part 50A / thermal conductivity of the base 20) can be arbitrarily selected, for example, it can be 0.01–0.1 times, 0.05–0.5 times, or 0.1–0.9 times, but is not limited to these examples.

[0070] Figure 4 This is a diagram illustrating an example of the temperature distribution on the outer periphery of a wafer held by an electrostatic chuck device, caused by the presence or absence of a thermally inhibiting section.

[0071] Here, we compare the temperature distribution of the annular protrusion 12C on the outer periphery of the electrostatic chuck 10 and its vicinity when plasma processing is performed on the wafer W held by the electrostatic chuck 10 with and without the thermal suppression part 50A.

[0072] like Figure 4 As shown, without the thermal suppression part 50A, compared with the central part of the wafer W, the temperature of the outer periphery of the wafer W, which is in contact with the annular protrusion 12C, rises sharply as it moves radially outward from the wafer W.

[0073] In contrast, as described in the above embodiment, when a thermal suppression portion 50A is provided on the mounting surface 20t of the base 20, compared to the central portion of the wafer W, the temperature of the outer periphery of the wafer W in contact with the annular protrusion 12C rises, but even towards the radially outward side of the wafer W, the temperature gradient, i.e., the temperature rise, becomes gentler. This is because, through the thermal suppression portion 50A, the heat (hot or cold) supplied by the coolant circulating in the flow path 21 of the base 20 for cooling the electrostatic chuck portion 10 is suppressed from being conducted to the annular protrusion 12C and its vicinity of the electrostatic chuck portion 10.

[0074] Thus, by providing the thermal conductivity suppression section 50A, thermal conductivity from the base 20 to the annular protrusion 12C and its vicinity in the electrostatic chuck section 10 is suppressed. As a result, temperature changes become gradual, thereby mitigating the strain generated in the annular protrusion 12C during plasma processing of the wafer W. Through these effects, leakage of cooling gases such as helium (He) from between the wafer W and the annular protrusion 12C to the outside caused by strain in the annular protrusion 12C can be suppressed.

[0075] The electrostatic chuck device 100 of this embodiment includes a heat conduction suppression section 50A, at least a portion of which is located radially inward than the annular protrusion 12C when viewed from the thickness direction. According to this structure, heat conduction to and around the annular protrusion 12C of the electrostatic chuck section 10 can be suppressed. Therefore, during plasma processing of the wafer W, strain generated in the annular protrusion 12C can be mitigated. Consequently, leakage of cooling gases such as helium (He) from between the wafer W and the annular protrusion 12C to the outside can be suppressed.

[0076] In the electrostatic chuck portion 10 of this embodiment, it is preferable that the radial width K of the thermal conductivity suppression portion 50A is greater than the radial width L of the annular protrusion 12C. According to this structure, heat conduction to and around the annular protrusion 12C of the electrostatic chuck portion 10 can be suppressed more effectively. Furthermore, by suppressing the radial width L of the annular protrusion 12C to be smaller than the radial width K of the thermal conductivity suppression portion 50A, i.e., by setting it to be smaller, the yield of the wafer W can be improved. The radial width K of the thermal conductivity suppression portion 50A can be 1.0 to 10 times the radial width L of the annular protrusion 12C, more preferably 1.5 to 9 times, further preferably 2 to 8 times, and particularly preferably 4 to 7 times, but is not limited to these examples. It can also be 1.1 to 1.5 times, 1.3 to 1.8 times, etc.

[0077] In the electrostatic chuck portion 10 of this embodiment, when viewed in the thickness direction, it is preferable that the annular protrusion 12C overlaps with a portion of the heat conduction suppression portion 50A. With this structure, heat conduction from the gap between the annular protrusion 12C and the heat conduction suppression portion 50A can be suppressed. Thus, heat conduction to the vicinity of the annular protrusion 12C of the electrostatic chuck portion 10 can be effectively suppressed.

[0078] In the electrostatic chuck portion 10 of this embodiment, the radial width d of the portion overlapping the annular protrusion 12C and a portion of the heat conduction suppression portion 50A preferably satisfies the relationship 0 < d < L / 2 relative to the radial width L of the annular protrusion 12C. It can be 0 < d < L / 3, 0 < d < L / 4, or 0 < d < L / 6. With this structure, the width d of the portion overlapping the annular protrusion 12C and the heat conduction suppression portion 50A can be suppressed to a small value, and heat conduction to the vicinity of the annular protrusion 12C of the electrostatic chuck portion 10 can be effectively suppressed. d can be selected as needed, for example, 0.01 mm to 5.0 mm, 0.05 mm to 2.5 mm, 0.1 mm to 2.0 mm, 0.3 mm to 1.5 mm, 0.5 mm to 1.0 mm, etc., but is not limited to these examples. Furthermore, in this embodiment, the width d is constant, but if the width is not constant, it can refer to the value at the position with the largest radial width.

[0079] In the electrostatic chuck portion 10 of this embodiment, the thermal conductivity of the heat-suppressing portion 50A is lower than that of the base 20. With this structure, heat conduction to the vicinity of the annular protrusion 12C of the electrostatic chuck portion 10 can be effectively suppressed.

[0080] In the electrostatic chuck portion 10 of this embodiment, the heat conduction suppression portion 50A is disposed in the recess 22 or hole formed on the mounting surface 20t of the base 20. With this structure, the heat conduction suppression portion 50A can be integrated with the base 20, and its installation can be easily performed.

[0081] [Second Implementation]

[0082] Next, the electrostatic chuck device according to the second embodiment of the present invention will be described.

[0083] In the electrostatic chuck device 100 of this embodiment, the structure of the heat conduction suppression part 50B is different from that of the electrostatic chuck device 100 of the first embodiment described above, while the other structures are the same as those of the electrostatic chuck device 100. Therefore, the heat conduction suppression part 50B will be mainly described, while the structures that are the same as those in the electrostatic chuck device 100 will be omitted from the description.

[0084] Figure 5 This is a planar cross-sectional view showing the structure of the heat-conducting suppression section in the electrostatic chuck device of the second embodiment. The electrostatic chuck device 100 includes an electrostatic chuck section 10 and a base 20 (not shown). Furthermore, a heat-conducting suppression section 50B is provided on the mounting surface 20t of the base 20 (not shown).

[0085] In this embodiment, when viewed in the thickness direction, multiple heat-conducting suppression portions 50B are provided at equal intervals along the circumferential direction of the electrostatic chuck portion 10 about its central axis. Each of the multiple heat-conducting suppression portions 50B has an arcuate shape formed concentrically with the annular protrusion 12C. When viewed in the thickness direction, at least a portion of each heat-conducting suppression portion 50B is located radially inward than the annular protrusion 12C. In this embodiment, when viewed in the thickness direction, a radial portion of the heat-conducting suppression portion 50B overlaps with the annular protrusion 12C.

[0086] When viewed from the thickness direction, the width of each heat-suppressing portion 50B, for example, the radial width, is preferably constant or substantially constant. When viewed from the thickness direction, each heat-suppressing portion 50B has no corners and is formed only by curved surfaces. However, it may be made to have corners, for example, a fan-shaped shape, as required. The number of heat-suppressing portions 50B can be arbitrarily chosen; it can be even or odd. Examples include 2 to 200, 3 to 100, 4 to 50, 6 to 30, 8 to 15, 10 to 12, etc., but it is not limited to these examples. When viewed from the thickness direction, the shape or size of the heat-suppressing portions 50B is preferably all the same or substantially the same, but the shape or size may also be different as required. For example, two or more shapes of heat-suppressing portions from the second to fourth embodiments can be selected and combined with each other. Examples include combinations of heat-suppressing portions from the second and third embodiments, combinations of heat-suppressing portions from the third and fourth embodiments, and combinations of heat-suppressing portions from the second and fourth embodiments. The heat-suppressing portions 50B are preferably arranged regularly and evenly. For example, thermally inhibiting portions 50B of different shapes can be alternately arranged with intervals between them along the circumference.

[0087] The electrostatic chuck device 100 of this embodiment includes a heat conduction suppression section 50B, which, when viewed from the thickness direction, is located at least partly radially inward than the annular protrusion 12C. According to this structure, heat conduction to the vicinity of the annular protrusion 12C of the electrostatic chuck section 10 can be suppressed. Therefore, when performing plasma processing on the wafer W, strain generated in the annular protrusion 12C can be mitigated. As a result, leakage of cooling gases such as helium (He) from between the wafer W and the annular protrusion 12C to the outside can be suppressed.

[0088] In the electrostatic chuck device 100 of this embodiment, multiple heat conduction suppression portions 50B are spaced apart from each other along the circumferential direction around the central axis of the electrostatic chuck portion 10. This reduces the suppression of heat conduction between adjacent heat conduction suppression portions 50B in the circumferential direction. Therefore, by means of the heat conduction suppression portions 50B, the area of ​​the region where heat conduction to and around the annular protrusion 12C of the electrostatic chuck portion 10 is suppressed can be reduced, i.e., the area can be minimized.

[0089] Here, the heat conduction suppression section 50B suppresses heat conduction to and around the annular protrusion 12C of the electrostatic chuck section 10, thereby mitigating the strain generated in the annular protrusion 12C. On the other hand, insufficient cooling of the electrostatic chuck section 10 near the annular protrusion 12C may adversely affect the plasma processing of the wafer W. In contrast, in this embodiment, by providing the heat conduction suppression section 50B at intervals along the circumference, the area where insufficient cooling of the electrostatic chuck section 10 near the annular protrusion 12C cannot be achieved can be minimized. As a result, areas that adversely affect the plasma processing of the wafer W can be suppressed, thereby improving product yield.

[0090] In the electrostatic chuck device 100 of this embodiment, the heat-conducting suppression part 50B is an arc shape formed concentrically with the annular protrusion 12C. Therefore, the heat-conducting suppression part 50B can be easily formed.

[0091] [Third Implementation]

[0092] Next, the electrostatic chuck device according to the third embodiment of the present invention will be described.

[0093] In the electrostatic chuck device 100 of this embodiment, the structure of the heat conduction suppression part 50C is different from that of the electrostatic chuck device 100 in the first and second embodiments described above, while the other structures are the same as those of the electrostatic chuck device 100. Therefore, the heat conduction suppression part 50C will be described in detail, while the structures that are the same as those in the electrostatic chuck device 100 will be omitted from the description.

[0094] Figure 6This is a planar cross-sectional view showing the structure of the heat-conducting suppression section in the electrostatic chuck device according to the third embodiment. The electrostatic chuck device 100 includes an electrostatic chuck section 10 and a base 20 (not shown). Furthermore, a heat-conducting suppression section 50C is provided on the mounting surface 20t of the base 20 (not shown).

[0095] In this embodiment, when viewed from the thickness direction, multiple heat-conducting suppression portions 50C are spaced apart from each other circumferentially around the central axis of the electrostatic chuck portion 10. Each of the multiple heat-conducting suppression portions 50C is arc-shaped, and the radius of curvature R2 of the heat-conducting suppression portion 50C is smaller than the radius of curvature R1 of the annular protrusion 12C. When viewed from the thickness direction, the central portion 50r of each heat-conducting suppression portion 50C overlaps with the annular protrusion 12C. When viewed from the thickness direction, the two ends 50p and 50q of each heat-conducting suppression portion 50C are located radially inward than the annular protrusion 12C.

[0096] The electrostatic chuck device 100 of this embodiment includes a heat-conducting suppression section 50C, at least a portion of which, when viewed in the thickness direction, is located radially inward than the annular protrusion 12C. According to this structure, heat conduction to and around the annular protrusion 12C of the electrostatic chuck section 10 can be suppressed. Therefore, during plasma processing of the wafer W, strain generated in the annular protrusion 12C can be mitigated. Consequently, leakage of cooling gases such as helium (He) from between the wafer W and the annular protrusion 12C to the outside can be suppressed.

[0097] In the electrostatic chuck device 100 of this embodiment, multiple heat conduction suppression portions 50C are spaced apart from each other circumferentially along the central axis of the electrostatic chuck portion 10. Therefore, the heat conduction suppression portions 50C can suppress the area of ​​the region where heat conduction to and around the annular protrusion 12C of the electrostatic chuck portion 10 is suppressed, i.e., the area can be reduced. Thus, similar to the second embodiment described above, the area where sufficient cooling of the annular protrusion 12C and the surrounding electrostatic chuck portion 10 cannot be achieved can be minimized. As a result, areas that adversely affect the plasma processing of the wafer W can be suppressed, thereby improving product yield.

[0098] In the electrostatic chuck device 100 of this embodiment, the heat-conducting suppression portion 50C is arc-shaped, and the radius of curvature R2 of the heat-conducting suppression portion 50C is smaller than the radius of curvature R1 of the annular protrusion 12C. Therefore, with respect to the central portion 50r, the two end portions 50p and 50q of each heat-conducting suppression portion 50C are located radially inwards than the annular protrusion 12C. In each heat-conducting suppression portion 50C, the heat-conducting suppression effect and position gradually change from the central portion 50r toward the two end portions 50p and 50q. Therefore, near the boundary between the portion where the heat-conducting suppression portion 50C is provided and the portion where the heat-conducting suppression portion 50C is not provided, abrupt changes in the heat-conducting suppression effect can be suppressed. Thus, strain generated in the annular protrusion 12C can be effectively suppressed. The ratio of the radius of curvature R2 of the heat-conducting suppression part 50C to the radius of curvature R1 of the annular protrusion 12C can be arbitrarily selected. For example, the ratio (R2 / R1) can be 1 / 1 to 1 / 1.5, 1 / 1.5 to 1 / 5, 1 / 5 to 1 / 10, 1 / 10 to 1 / 20, etc., but it is not limited to these examples.

[0099] [Fourth Implementation]

[0100] Next, the electrostatic chuck device according to the fourth embodiment of the present invention will be described.

[0101] In the electrostatic chuck device 100 of this embodiment, the structure of the heat conduction suppression part 50D is different from that of the electrostatic chuck device 100 in the first to third embodiments described above, while the other structures are the same as those of the electrostatic chuck device 100. Therefore, the heat conduction suppression part 50D will be mainly described, while the structures that are the same as those in the electrostatic chuck device 100 will be omitted from the description.

[0102] Figure 7 This is a planar cross-sectional view showing the structure of the heat-conducting suppression section in the electrostatic chuck device according to the fourth embodiment. The electrostatic chuck device 100 includes an electrostatic chuck section 10 and a base 20 (not shown). Furthermore, a heat-conducting suppression section 50D is provided on the mounting surface 20t of the base 20 (not shown).

[0103] In this embodiment, when viewed from the thickness direction, multiple thermally inhibiting portions 50D are provided at intervals along the circumference of the electrostatic chuck portion 10 around its central axis. When viewed from the thickness direction, each of the multiple thermally inhibiting portions 50D is circular and has a radius R3 smaller than the radius of curvature R1 of the annular protrusion 12C. When viewed from the thickness direction, a portion of each thermally inhibiting portion 50D overlaps with the annular protrusion 12C, while the remaining portion is located radially inward than the annular protrusion 12C.

[0104] The electrostatic chuck device 100 of this embodiment includes a heat-conducting suppression section 50D, which, when viewed in the thickness direction, is located at least a portion further radially inward than the annular protrusion 12C. According to this structure, heat conduction to the vicinity of the annular protrusion 12C of the electrostatic chuck section 10 can be suppressed. Therefore, when performing plasma processing on the wafer W, strain generated in the annular protrusion 12C can be mitigated. Consequently, leakage of cooling gases such as helium (He) from between the wafer W and the annular protrusion 12C to the outside can be suppressed.

[0105] In the electrostatic chuck apparatus 100 of this embodiment, multiple heat conduction suppression portions 50D are provided at intervals along the circumferential direction around the central axis of the electrostatic chuck portion 10. Therefore, the area of ​​the region near the annular protrusion 12C of the electrostatic chuck portion 10 where heat conduction is suppressed can be reduced by the heat conduction suppression portions 50D. Thus, similar to the second and third embodiments described above, the area where insufficient cooling of the electrostatic chuck portion 10 near the annular protrusion 12C cannot be achieved can be minimized. As a result, areas that adversely affect the plasma processing of the wafer W can be suppressed, thereby improving product yield.

[0106] In the electrostatic chuck device 100 of this embodiment, when viewed from the thickness direction, the heat-conducting suppression portion 50D is circular and has a radius R3 smaller than the radius of curvature R1 of the annular protrusion 12C. Therefore, regarding each heat-conducting suppression portion 50D, when viewed from the thickness direction, the heat-conducting suppression effect gradually changes from the portion overlapping with the annular protrusion 12C towards both sides of the circumference of the annular protrusion 12C. Thus, near the boundary between the portion where the heat-conducting suppression portion 50D is provided and the portion where the heat-conducting suppression portion 50D is not provided, abrupt changes in the heat-conducting suppression effect can be suppressed. Therefore, strain generated in the annular protrusion 12C can be suppressed. The ratio of the radius of the heat-conducting suppression portion 50D to the radius of the electrostatic chuck portion (radius of the heat-conducting suppression portion 50D / radius of the electrostatic chuck portion) can be arbitrarily selected; for example, 1 / 1.5 to 1 / 5, 1 / 5 to 1 / 10, 1 / 10 to 1 / 20, etc., are examples, but it is not limited to these examples.

[0107] [Semiconductor manufacturing equipment]

[0108] Figure 8 This is a schematic diagram illustrating an example of a semiconductor manufacturing apparatus having the electrostatic chuck device described above. The semiconductor manufacturing apparatus 1000 includes an electrostatic chuck device 100, a vacuum chamber 200, an upper electrode 300, a magnet 400, a gas supply mechanism 500, a vacuum pump 600, and a vacuum stabilization system 700.

[0109] The vacuum chamber 200 houses the electrostatic chuck device 100 and serves as a reaction field for plasma processing within it. The vacuum chamber 200 can employ a known structure used in semiconductor manufacturing apparatuses. The vacuum chamber 200 has a gate (not shown) for loading and unloading plate-shaped samples.

[0110] The upper electrode 300 is a counter electrode housed within the vacuum chamber 200 and used in conjunction with the electrostatic chuck device 100 when plasma is generated within the vacuum chamber 200. The upper electrode 300 is connected to a power source (not shown).

[0111] Magnet 400 is disposed around vacuum chamber 200, generating a longitudinal magnetic field in the space between upper electrode 300 and electrostatic chuck device 100 inside vacuum chamber 200.

[0112] The gas supply mechanism 500 supplies plasma gas G into the vacuum chamber 200. The gas supply mechanism 500 supplies plasma gas G into the vacuum chamber 200, for example, through a gas hole provided on the upper electrode 300.

[0113] Vacuum pump 600 expels gas from vacuum chamber 200 to adjust the atmosphere for plasma generation. Vacuum pump 600 is connected, for example, in vacuum chamber 200 at a position lower than electrostatic chuck device 100.

[0114] The vacuum stabilization system 700 is designed to stabilize the vacuum level within the vacuum chamber 200. The vacuum stabilization system 700 includes a detector 710 and a control unit 720 that controls the semiconductor manufacturing apparatus 1000 based on the detection results from the detector 710.

[0115] Detector 710 detects the vacuum level inside vacuum chamber 200. There can be one detector 710 or multiple detectors.

[0116] The control unit 720 controls the semiconductor manufacturing apparatus 1000 based on the detected value of the vacuum level within the vacuum chamber 200, as detected by the detector 710. The control unit 720 pre-stores the correspondence between the detected values, the supply amount of plasma gas G to the vacuum chamber 200 via the gas supply mechanism 500, and the operation of the vacuum pump 600. Based on the detected values ​​and the aforementioned correspondence, the control unit 720 performs feedback control on the semiconductor manufacturing apparatus 1000 to maintain the vacuum level within the vacuum chamber 200 within a preset range.

[0117] Thus, the vacuum stabilization system 700 suppresses fluctuations in the vacuum level within the vacuum chamber 200 of the semiconductor manufacturing apparatus 1000, thereby stabilizing the state.

[0118] Alternatively, the control unit 720 can be an inherent structure of the vacuum stabilization system 700, or it can be a control device that controls the semiconductor manufacturing apparatus 1000 and also perform this function.

[0119] The semiconductor manufacturing apparatus 1000 according to this embodiment, having the electrostatic chuck device 100 described above, can suppress the leakage of cooling gas from between the wafer W and the annular protrusion 12C into the vacuum chamber 200.

[0120] Furthermore, the semiconductor manufacturing apparatus 1000 suppresses the leakage of cooling gas from between the wafer W and the annular protrusion 12C into the vacuum chamber 200 via the electrostatic chuck device 100, and can suppress fluctuations in the vacuum level within the vacuum chamber 200 via the vacuum level stabilization system 700. Therefore, stable plasma processing can be achieved, and a semiconductor manufacturing apparatus with improved yield can be provided.

[0121] The embodiments and variations of the present invention have been described above. However, each structure and combination thereof in the embodiments and variations are merely examples, and additions, omissions, substitutions, and other changes to the structure can be made without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments.

[0122] For example, in the above embodiment, plasma processing is performed on wafer W, but the processing or apparatus for wafer W may also be other than plasma processing.

[0123] Furthermore, in the above embodiment, the case where a component with a thermal conductivity lower than that of the base is disposed on the mounting surface of the base as a thermally inhibiting part has been described. However, for example, heat transfer to the electrostatic chuck can also be reduced by providing a recess on a portion of the mounting surface of the base, keeping the recess unfilled, and using the internal space as a thermally inhibiting part, thereby reducing the contact area with the adhesive layer 25, etc.

[0124] Label Explanation

[0125] 10-Electrostatic chuck section

[0126] 11-Dielectric substrate

[0127] 11a-Placement Surface

[0128] 11b-lower surface

[0129] 12-Protrusion

[0130] 12C-Annular protrusion

[0131] 12s - Inner peripheral edge of the annular protrusion

[0132] 12t - outer periphery of the annular protrusion

[0133] 13-Concave

[0134] 13b-bottom

[0135] 20-base

[0136] 20t-mounted surface

[0137] 21-Flow path

[0138] 22-concave

[0139] 25-Adhesive layer

[0140] 30-Adsorption Electrode

[0141] 50a-Top Surface

[0142] 50A~50D - Thermal Suppression Section

[0143] 50p, 50q - both ends

[0144] 50r - Central part of the thermally inhibiting section

[0145] 50s - Outer periphery of the thermally conductive suppression section

[0146] 50t - Inner periphery of the thermally conductive suppression section

[0147] 100-Electrostatic Chuck Device

[0148] 200-Vacuum Chamber

[0149] 300-Upper Electrode

[0150] 400-Magnet

[0151] 500-Gas Supply Unit

[0152] 600-Vacuum Pump

[0153] 700-Vacuum Stabilization System

[0154] 710-Detector

[0155] 720-Control Department

[0156] 1000-Semiconductor Manufacturing Equipment

[0157] d-width

[0158] G-plasma gas

[0159] K, L - Width

[0160] O-Central Axis

[0161] R1, R2 - Radius of curvature

[0162] R3 - radius

[0163] W-Wafer (plate-shaped sample)

Claims

1. An electrostatic chuck device, comprising: The electrostatic chuck has a dielectric substrate and an adsorption electrode. The dielectric substrate has a mounting surface for placing a plate-shaped sample, and the adsorption electrode is disposed inside the dielectric substrate. and The base supports the electrostatic chuck from the back side opposite to the mounting surface and allows adjustment of the temperature of the electrostatic chuck. The electrostatic chuck portion has an annular protrusion that protrudes upward from the outer periphery of the upper surface of the dielectric substrate and forms an annular shape when viewed from the thickness direction of the electrostatic chuck portion. The base has: The mounting surface is equipped with the electrostatic chuck portion; and A heat-conducting suppression part is disposed on the mounting surface. When viewed from the thickness direction, at least a portion of the thermally inhibiting portion is located further radially inward than the annular protrusion.

2. The electrostatic chuck device according to claim 1, wherein, The radial width K of the heat-conducting suppression part is greater than the radial width L of the annular protrusion.

3. The electrostatic chuck device according to claim 1, wherein, When viewed from the thickness direction, the annular protrusion overlaps with a portion of the thermally inhibiting portion.

4. The electrostatic chuck device according to claim 3, wherein, When viewed from the thickness direction, the radial width d of the portion where the annular protrusion overlaps with a portion of the thermally inhibiting portion, relative to the radial width L of the annular protrusion, is: 0 < d < L / 2.

5. The electrostatic chuck device according to claim 1, wherein, The thermal conductivity of the heat-suppressing part is lower than that of the base.

6. The electrostatic chuck device according to claim 1, wherein, The thermally conductive suppressing parts are arranged in multiple intervals around the central axis of the electrostatic chuck.

7. The electrostatic chuck device according to claim 6, wherein, The thermally inhibiting portion has an arc shape that is concentrically formed with the annular protrusion.

8. The electrostatic chuck device according to claim 7, wherein, The radius of curvature R2 of the heat-conducting suppression part is smaller than the radius of curvature R1 of the annular protrusion.

9. The electrostatic chuck device according to claim 6, wherein, When viewed from the thickness direction, the thermally inhibiting portion is circular and has a radius R3 that is smaller than the radius of curvature R1 of the annular protrusion.

10. The electrostatic chuck device according to any one of claims 1 to 9, wherein, The thermally conductive suppressing part is disposed in the hole or recess formed on the mounting surface.

Images