electrostatic chuck

Abstract

To provide an electrostatic chuck capable of improving uniformity of a temperature distribution of an in-plane of a processing object.SOLUTION: An electrostatic chuck comprises: a ceramic dielectric substrate onto which a processing object is mounted; a base plate that supports the ceramic dielectric substrate; and a heater part that heats the ceramic dielectric substrate. The heater part includes: at least one heater layer containing a first heater layer; and a first bypass part as a power supply path to the heater layer. The first heater layer includes a plurality of first zones, and each of the plurality of first zones includes: two first power supply parts; and a first heater line electrically connecting the two first power supply parts. One of the first zones is adjacent to another one of the first zones via a first inter-zone region. The first bypass part includes a liner part that overlaps with the first inter-zone region in a Z direction, and is extended along the first inter-zone region.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] Aspects of the present invention generally relate to electrostatic chucks.

Background Art

[0002] Electrostatic chucks on which objects to be processed such as semiconductor wafers and glass substrates are placed are known. An electrostatic chuck is used as a means for adsorbing and holding an object to be processed in a plasma processing chamber of a semiconductor manufacturing apparatus that performs, for example, etching, CVD (Chemical Vapor Deposition), sputtering, ion implantation, or ashing. An electrostatic chuck adsorbs a substrate such as a silicon wafer by applying electrostatic adsorption power to a built-in electrode, for example.

[0003] In an electrostatic chuck, it is required to control the in-plane temperature distribution of an object to be processed such as a wafer. Therefore, for example, providing a heater divided into a plurality of zones has been considered. By independently adjusting the output of each zone, the in-plane temperature distribution of the object to be processed can be controlled. For example, by increasing the number of zones, the in-plane temperature distribution can be controlled more finely. The number of such zones has been increasing in recent years and may exceed 100, for example.

[0004] For example, a heating resistor is provided corresponding to each zone, and a conduction part that serves as a path for flowing a current from a power source to the heating resistor is connected to the heating resistor. However, there has been a risk that the heat uniformity of the sample holding surface may deteriorate due to heat generation of the conduction part (Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] This invention was made based on the recognition of the above problems, and aims to provide an electrostatic chuck that can improve the uniformity of the in-plane temperature distribution of an object being processed. [Means for solving the problem]

[0007] The first invention is an electrostatic chuck comprising: a ceramic dielectric substrate having a first main surface on which an object to be processed is placed and a second main surface opposite to the first main surface; a base plate supporting the ceramic dielectric substrate; and a heater section for heating the ceramic dielectric substrate, wherein the heater section has at least one heater layer including a first heater layer and a first bypass section which is a power supply path to the at least one heater layer, the first heater layer has a plurality of first zones, each of the plurality of first zones has two first power supply sections and a first heater line electrically connecting the two first power supply sections, one of the plurality of first zones is adjacent to another of the plurality of first zones via an inter-zone region, and the first bypass section overlaps with the inter-zone region in the Z direction perpendicular to the first main surface and has a linear portion extending along the inter-zone region.

[0008] The inter-zone region between adjacent first zones is a cool spot with a low temperature because the first heater line is not located there, making it prone to uneven temperature distribution within the surface. On the other hand, although the amount of heat generated is smaller than that of the heater layer, heat is also generated in the first bypass section due to the flow of current. In particular, the amount of heat generated increases when the current is concentrated in the linear portion. With this electrostatic chuck, the linear portion of the first bypass section overlaps with the inter-zone region and extends along the inter-zone region, so that the heat generated in the linear portion can suppress the uneven temperature distribution within the surface caused by the inter-zone region. This makes it possible to improve the uniformity of the temperature distribution within the surface of the object being processed.

[0009] The second invention is an electrostatic chuck in which, in the first invention, the heater portion has a central region located in the center of the heater portion when viewed along the Z direction, and an outer peripheral region located outside the central region and including the outer peripheral end of the heater portion, and the linear portion overlaps with at least the first inter-zone region located in the outer peripheral region and extends along at least the first inter-zone region located in the outer peripheral region.

[0010] In the heater section, temperature distribution variations in the outer periphery tend to be greater than those in the central region. To address this, a linear bypass section is provided along the first zone inter-zone region of the outer periphery, thereby suppressing temperature distribution variations in the outer periphery.

[0011] The third invention is an electrostatic chuck in the first or second invention, wherein, in a plan view, the width of the linear portion is the same as or narrower than the width of the first interzone region.

[0012] With this electrostatic chuck, the width of the linear portion is less than or equal to the width of the region between the first zones, thereby suppressing the overlap between the linear portion and the first zone. This reduces the influence of heat generation from the linear portion on the temperature of the first zone, and suppresses temperature variations across the entire surface on which the object to be processed is placed.

[0013] The fourth invention is an electrostatic chuck in the first or second invention, wherein, in plan view, the width of the linear portion is wider than the minimum distance between a portion of the first heater line and another portion of the first heater line in one of the plurality of first zones.

[0014] This electrostatic chuck reduces the width of the linear portion, thereby suppressing the generation of excessive heat in the linear portion.

[0015] The fifth invention is an electrostatic chuck in the first or second invention, wherein, in a plan view, the width of the first heater line in one of the plurality of first zones is narrower than the width of the region between the first zones.

[0016] This electrostatic chuck reduces the width of the linear portion, thereby suppressing the generation of excessive heat in the linear portion.

[0017] The sixth invention is an electrostatic chuck in the first or second invention, wherein the number of the plurality of first zones included in the first heater layer is 50 or more.

[0018] This electrostatic chuck allows for fine-tuning of the temperature of the surface on which the object being processed is placed (and consequently, the temperature within the surface of the object being processed) by dividing the first heater layer into more than 50 first zones. On the other hand, increasing the number of first zones also increases the area between the first zones. In response to this, the linear portion of the first bypass is positioned so as to overlap with the area between the first zones. Therefore, even when the first zones are subdivided, the uniformity of the temperature distribution within the surface of the object being processed can be improved.

[0019] The seventh invention is an electrostatic chuck in which, in the sixth invention, the heater portion further comprises a second heater layer having a plurality of second zones, each of the plurality of second zones having two second power supply units and a second heater line electrically connecting the two second power supply units, the number of the plurality of second zones is less than the number of the plurality of first zones, one of the plurality of second zones is adjacent to another of the plurality of second zones via an inter-second zone region, the inter-first zone region has an overlapping region that overlaps with the inter-second zone region in the Z direction, and the linear portion is an electrostatic chuck that overlaps with the overlapping region in the Z direction.

[0020] The region between adjacent second zones, where no second heater line is arranged, becomes a cool spot with a low temperature, and unevenness in the in-plane temperature distribution is likely to occur. For example, an overlapping region where the first-zone region and the second-zone region overlap is likely to become a cool spot. In contrast, according to this electrostatic chuck, the linear portion of the first bypass portion overlaps with the overlapping region, and the heat generation of the linear portion can suppress the unevenness in the in-plane temperature distribution caused by the overlapping region. Thereby, the uniformity of the in-plane temperature distribution of the object to be processed can be improved.

Advantages of the Invention

[0021] According to an aspect of the present invention, an electrostatic chuck is provided that can improve the uniformity of the in-plane temperature distribution of an object to be processed.

Brief Description of the Drawings

[0022] [Figure 1] FIG. 1 is a perspective view schematically showing an electrostatic chuck according to an embodiment. [Figure 2] FIGS. 2(a) and 2(b) are cross-sectional views schematically showing a part of the electrostatic chuck according to the embodiment. [Figure 3] FIGS. 3(a) and 3(b) are cross-sectional views schematically showing a part of the electrostatic chuck according to a modification of the embodiment. [Figure 4] FIG. 4 is a cross-sectional view schematically showing a part of the electrostatic chuck according to the embodiment. [Figure 5] FIG. 5 is a plan view schematically showing a main zone of a second heater element according to the embodiment. [Figure 6] FIG. 6 is a plan view schematically showing a subzone of a first heater element according to the embodiment. [Figure 7] FIG. 7 is a plan view schematically showing a second heater element according to the embodiment. [Figure 8] FIG. 8 is a plan view schematically showing a part of a subzone of a first heater element according to the embodiment. [Figure 9]Figure 9 is a plan view illustrating the bypass portion of the bypass layer according to the embodiment. [Figure 10] Figure 10(a) is a schematic perspective view showing the connection between the bypass portion of the bypass layer according to the embodiment and the first heater element, and Figure 10(b) is a schematic plan view showing a modified example of the bypass portion. [Figure 11] Figure 11 is a plan view illustrating a modified example of the bypass portion of the bypass layer according to the embodiment. [Figure 12] Figure 12 is a schematic cross-sectional view showing a wafer processing apparatus according to an embodiment. [Modes for carrying out the invention]

[0023] Embodiments of the present invention will be described below with reference to the drawings. In each drawing, similar components are denoted by the same reference numerals, and detailed descriptions are omitted as appropriate. Figure 1 is a schematic perspective view of an electrostatic chuck according to an embodiment. Figures 2(a) and 2(b) are schematic cross-sectional views showing a part of the electrostatic chuck according to the embodiment. Figure 1 shows a cross-sectional view of a portion of the electrostatic chuck for illustrative purposes. Figure 2(a) is a cross-sectional view taken along the line A1-A1 shown in Figure 1. Figure 2(b) is an enlarged view of region B1 shown in Figure 2(a). Note that the object to be processed W is omitted in Figure 2(b). As shown in Figures 1, 2(a), and 2(b), the electrostatic chuck 10 according to this embodiment comprises a ceramic dielectric substrate 100, a heater section 200, and a base plate 300.

[0024] The ceramic dielectric substrate 100 is, for example, a flat substrate made of a polycrystalline ceramic sintered body, and has a first main surface 101 on which a workpiece W such as a semiconductor wafer is placed, and a second main surface 102 on the opposite side of the first main surface 101.

[0025] In this specification, the direction perpendicular to the first main surface 101 is defined as the Z direction. In other words, the Z direction is the direction connecting the first main surface 101 and the second main surface 102. In other words, the Z direction is the direction from the base plate 300 toward the ceramic dielectric substrate 100. Furthermore, one of the directions perpendicular to the Z direction is defined as the X direction, and the direction perpendicular to both the Z direction and the X direction is defined as the Y direction. In this specification, "in-plane" refers to, for example, the XY plane. Also, in this specification, "plan view" refers to the view along the Z direction.

[0026] Examples of crystal materials included in the ceramic dielectric substrate 100 include Al2O3 and Y2O 3、 Examples include YAG. By using such materials, the infrared transmittance, dielectric strength, and plasma durability of the ceramic dielectric substrate 100 can be improved. Alternatively, the material may be SiC or AlN.

[0027] An electrode layer 111 is provided inside the ceramic dielectric substrate 100. The electrode layer 111 is interposed between the first main surface 101 and the second main surface 102. In other words, the electrode layer 111 is formed to be inserted into the ceramic dielectric substrate 100. The electrode layer 111 is integrally sintered into the ceramic dielectric substrate 100.

[0028] Furthermore, the electrode layer 111 is not limited to being interposed between the first main surface 101 and the second main surface 102, but may also be attached to the second main surface 102.

[0029] The electrostatic chuck 10 generates an electric charge on the first main surface 101 side of the electrode layer 111 by applying an adsorption and holding voltage to the electrode layer 111, and adsorbs and holds the object to be processed W by electrostatic force.

[0030] The electrode layer 111 is provided along the first main surface 101 and the second main surface 102. The electrode layer 111 is an adsorption electrode for adsorbing and holding the object to be processed W. The electrode layer 111 may be unipolar or bipolar. Furthermore, the electrode layer 111 may be tripolar or other multipolar. The number and arrangement of the electrode layers 111 are selected as appropriate.

[0031] The base plate 300 is provided on the second main surface 102 side of the ceramic dielectric substrate 100 and supports the ceramic dielectric substrate 100. A communication passage 301 is provided in the base plate 300. In other words, the communication passage 301 is provided inside the base plate 300. Aluminum is one example of a material for the base plate 300.

[0032] The base plate 300 plays a role in regulating the temperature of the ceramic dielectric substrate 100. For example, when cooling the ceramic dielectric substrate 100, a cooling medium is introduced into the communication passage 301, passes through the communication passage 301, and then flows out from the communication passage 301. In this way, the cooling medium absorbs the heat of the base plate 300, thereby cooling the ceramic dielectric substrate 100 mounted on it.

[0033] Furthermore, protrusions 113 are provided on the first main surface 101 side of the ceramic dielectric substrate 100 as needed. Grooves 115 are provided between adjacent protrusions 113. The grooves 115 are in communication with each other. A space is formed between the back surface of the object to be processed W mounted on the electrostatic chuck 10 and the grooves 115.

[0034] An introduction channel 321 is connected to the groove 115, penetrating the base plate 300 and the ceramic dielectric substrate 100. When a transfer gas such as helium (He) is introduced through the introduction channel 321 while the object to be processed W is adsorbed and held, the transfer gas flows into the space between the object to be processed W and the groove 115, allowing the object to be directly heated or cooled by the transfer gas.

[0035] The heater unit 200 heats the ceramic dielectric substrate 100. By heating the ceramic dielectric substrate 100, the heater unit 200 heats the object to be processed W through the ceramic dielectric substrate 100. In this example, the heater unit 200 is separate from the ceramic dielectric substrate 100 and is located outside of the ceramic dielectric substrate 100. More specifically, the heater unit 200 is located between the ceramic dielectric substrate 100 and the base plate 300.

[0036] An adhesive layer 403 is provided between the base plate 300 and the heater unit 200. An adhesive layer 403 is also provided between the heater unit 200 and the ceramic dielectric substrate 100. Examples of materials for the adhesive layer 403 include heat-resistant resins such as silicone, which have relatively high thermal conductivity. The thickness of the adhesive layer 403 is, for example, about 0.1 millimeters (mm) or more and 1.0 mm or less.

[0037] Figures 3(a) and 3(b) are schematic cross-sectional views showing a part of an electrostatic chuck according to a modified embodiment. Figure 3(b) is an enlarged view of region B2 shown in Figure 3(a). Note that the object W to be processed is omitted in Figure 3(b). As shown in Figures 3(a) and 3(b), in this example, the heater portion 200 is provided between the first main surface 101 and the second main surface 102. That is, the heater portion 200 may be formed to be inserted into the ceramic dielectric substrate 100. In other words, the heater portion 200 may be built into the ceramic dielectric substrate 100. In this case, the adhesive layer 403 is omitted.

[0038] Figure 4 is a schematic cross-sectional view showing a part of the electrostatic chuck according to the embodiment. In Figure 4, the heater unit 200 is provided on the ceramic dielectric substrate 100, but in an embodiment, at least a portion of the heater unit 200 may be provided between the ceramic dielectric substrate 100 and the base plate 300.

[0039] The heater unit 200 has at least one heater element (heater layer), including a first heater element 231 (e.g., a first heater layer). Each heater element heats the ceramic dielectric substrate 100. For example, the heater unit 200 has a first heater element 231 and a second heater element 232 (e.g., a second heater layer). Furthermore, the heater unit 200 is provided with a bypass layer 250. The bypass layer 250 becomes part of the power supply path to the multiple heater elements. The heater unit 200 may be provided with support plates for supporting the heater elements as appropriate. Insulating layers may be provided to insulate between the support plates and the heater elements, between the heater elements themselves, and between the bypass layer 250 and the heater elements. The bypass layer 250 may be provided separately from the heater unit 200. For example, the bypass layer 250 is built into the ceramic dielectric substrate 100. In this case, the distance between the bypass layer 250 and the first heater element 231 and the second heater element 232 can be reduced, thereby further enhancing the effect of uniformizing the in-plane temperature. Alternatively, in the heater section 200, the first heater element 231 and the second heater element 232 can be embedded in the ceramic dielectric substrate 100, and the bypass layer 250 can be provided outside the ceramic dielectric substrate 100. Specifically, the bypass layer 250 may be positioned below the second main surface 102 of the ceramic dielectric substrate 100. This makes it easier to route the power supply mechanism of the heater section 200.

[0040] The first heater element 231 and the second heater element 232 are separated in the Z direction. That is, the second heater element 232 is located in a different layer from the layer on which the first heater element 231 is located. For example, the first heater element 231 is insulated from the second heater element 232 and is electrically independent. In this example, the second heater element 232 is located above the first heater element 231. At least a portion of the second heater element 232 may overlap with the first heater element 231 in the Z direction.

[0041] The second heater element 232 has a plurality of main zones 600. Each main zone 600 has a main heater line 232c (see Figure 7 below). The first heater element 231 has a plurality of subzones 700. Each subzone 700 has a subheater line 231c (see Figure 8 below).

[0042] When the first heater element 231 is embedded in the ceramic dielectric substrate 100, the material of the first heater element 231 (subheater line 231c) may include, for example, a metal containing at least one of titanium, chromium, nickel, copper, aluminum, molybdenum, tungsten, palladium, platinum, silver, tantalum, molybdenum carbide, and tungsten carbide. It is preferable that the material of the first heater element 231 includes both the above metal and a ceramic material. Examples of ceramic materials include aluminum oxide (Al2O3), yttrium oxide (Y2O3), and yttrium aluminum garnet (YAG_Y3Al5O 12Examples include aluminum nitride (AlN), silicon carbide (SiC), etc. Preferably, the ceramic material included in the first heater element 231 is the same as the components of the ceramic dielectric substrate 100. When the first heater element 231 is provided outside the ceramic dielectric substrate 100, examples of materials for the first heater element 231 include metals containing at least one of stainless steel, titanium, chromium, nickel, copper, aluminum, Inconel®, molybdenum, tungsten, palladium, platinum, silver, tantalum, molybdenum carbide, and tungsten carbide. The thickness (length in the Z direction) of the first heater element 231 is, for example, about 0.01 mm or more and 0.20 mm or less. The material and thickness of the second heater element 232 (main heater line 232c) are the same as the material and thickness of the first heater element 231. For example, when the second heater element 232 is provided inside the ceramic dielectric substrate 100, the material of the second heater element 232 may be the same as the material of the first heater element 231 when the first heater element 231 is provided inside the ceramic dielectric substrate 100. For example, when the second heater element 232 is provided outside the ceramic dielectric substrate 100, the material of the second heater element 232 may be the same as the material of the first heater element 231 when the first heater element 231 is provided outside the ceramic dielectric substrate 100. The material and thickness of the second heater element 232 may differ from the material and thickness of the first heater element 231.

[0043] At least one of the first heater element 231 and the second heater element 232 is electrically connected to the bypass layer 250. For example, the first heater element 231 and the second heater element 232 are each electrically connected to the bypass layer 250.

[0044] The first heater element 231 and the second heater element 232 each generate heat when current flows through them. By generating heat, the first heater element 231 and the second heater element 232 heat the ceramic dielectric substrate 100. The first heater element 231 and the second heater element 232, for example, heat the object W to be processed via the ceramic dielectric substrate 100, thereby making the temperature distribution in the plane of the object W uniform. Alternatively, the first heater element 231 and the second heater element 232 can, for example, intentionally create a temperature difference in the plane of the object W by heating the object W via the ceramic dielectric substrate 100.

[0045] Specifically, the heater unit 200 has a plurality of power supply terminals (not shown) that are electrically connected to the first heater element 231 and the second heater element 232, respectively. The power supply terminals supply power supplied from outside the electrostatic chuck 10 to the first heater element 231 and the second heater element 232. That is, an external current flows through the power supply terminals to the main heater line 232c (e.g., the second heater line). As a result, the main heater line 232c generates heat. Similarly, an external current flows through the power supply terminals to the sub-heater line 231c (e.g., the first heater line). As a result, the sub-heater line 231c generates heat.

[0046] The bypass layer 250 is conductive and, for example, has a plate-like shape. The bypass layer 250 is electrically connected to, for example, the first heater element 231 and the second heater element 232, and is the power supply path for the first heater element 231 and the second heater element 232. For example, the bypass layer 250 is a conductive part that electrically connects the main heater line 232c and the power supply terminal. For example, the bypass layer is a conductive part that electrically connects the sub-heater line 231c and the power supply terminal. The power supply terminal may be directly connected to the first heater element 231 and the second heater element 232. In this case, a part of the bypass layer 250 can be omitted.

[0047] The thickness (length in the Z direction) of the bypass layer 250 is, for example, approximately 0.03 mm or more and 0.30 mm or less.

[0048] For example, when the bypass layer 250 is provided outside the ceramic dielectric substrate 100, the material of the bypass layer 250 may include metals containing at least one of stainless steel, titanium, chromium, nickel, copper, aluminum, Inconel®, molybdenum, tungsten, palladium, platinum, silver, tantalum, molybdenum carbide, and tungsten carbide. For example, when the heater section 200 (bypass layer 250, first heater element 231, and second heater element 232) is embedded in the ceramic dielectric substrate 100, the material of the bypass layer 250 is the same as the material of the first heater element 231 and the second heater element 232. On the other hand, the thickness of the bypass layer 250 is greater than the thickness of the first heater element 231 and greater than the thickness of the second heater element 232. Therefore, the electrical resistance of the bypass layer 250 is lower than the electrical resistance of the first heater element 231 and lower than the electrical resistance of the second heater element 232. This makes it possible to suppress the heat generation of the bypass layer 250, even when the material of the bypass layer 250 is the same as that of the first heater element 231 and the second heater element 232. In other words, it is possible to reduce the electrical resistance of the bypass layer 250 and reduce the amount of heat generated by the bypass layer 250.

[0049] Furthermore, the means of suppressing the electrical resistance of the bypass layer 250 and the amount of heat generated by the bypass layer 250 may be achieved not by the thickness of the bypass layer 250, but by using a material with a relatively low volume resistivity. In other words, the material of the bypass layer 250 may be different from the material of the first heater element 231 and the second heater element 232. Examples of materials for the bypass layer 250 include metals containing at least one of stainless steel, titanium, chromium, nickel, copper, aluminum, Inconel®, molybdenum, tungsten, palladium, platinum, silver, tantalum, molybdenum carbide, and tungsten carbide.

[0050] For example, when the bypass layer 250 is provided inside the ceramic dielectric substrate 100, the material of the bypass layer 250 is the same as the material of the first heater element 231 when the first heater element 231 is provided inside the ceramic dielectric substrate 100. For example, when the bypass layer 250 is provided outside the ceramic dielectric substrate 100, the material of the bypass layer 250 is the same as the material of the first heater element 231 when the first heater element 231 is provided outside the ceramic dielectric substrate 100.

[0051] The bypass layer 250 includes a plurality of bypass sections 251. Each bypass section 251 is part of the power supply path to one of the heater elements. For example, one of the heater elements is electrically connected to a bypass section 251. A power supply terminal for supplying external power to that bypass section 251 is connected to it. In other words, the bypass section 251 is located between the heater element and the power supply terminal in the current path, electrically connecting the power supply terminal and the heater element. To put it another way, the heater element is electrically connected to the power supply terminal via the bypass section 251.

[0052] For example, the bypass layer 250 has a first sub-bypass section 251a (e.g., a first bypass section) which is part of the power supply path to the first heater element 231. The first heater element 231 is electrically connected to the power supply terminal via the first sub-bypass section 251a.

[0053] Although not shown in the diagram, for example, the multiple bypass sections 251 may further include a second sub-bypass section, a first main bypass section, and a second main bypass section. The second sub-bypass section (e.g., the second bypass section) is electrically connected to the first heater element 231 and forms another part of the power supply path to the first heater element 231. The first main bypass section (e.g., the third bypass section) is electrically connected to the second heater element 232 and forms another part of the power supply path to the second heater element 232. The second main bypass section (e.g., the fourth bypass section) is electrically connected to the second heater element 232 and forms another part of the power supply path to the second heater element 232. The number of bypass sections is not particularly limited and may be one or more. In this embodiment, it is sufficient to provide at least the first bypass section.

[0054] When the first heater element 231 and / or the second heater element 232 have a large number of zones, for example, 20 or more, or 50 or more, or 100 or more, it may be difficult to arrange power supply terminals corresponding to each zone. By providing a bypass layer 250, the degree of freedom in arranging power supply terminals is improved compared to when they are arranged for each zone.

[0055] For example, the current flowing through the first heater element 231 and the current flowing through the second heater element 232 are controlled separately. For example, the bypass section 251 connected to the first heater element 231 (the first sub-power supply section 231a and the second sub-power supply section 231b described later) is different from the bypass section 251 connected to the second heater element 232 (the first main power supply section 232a and the second main power supply section 232b described later). However, the bypass section 251 connected to the first heater element 231 may be the same as the bypass section 251 connected to the second heater element 232.

[0056] The first heater element 231 generates less heat than the second heater element 232. In other words, the first heater element 231 is a low-power sub-heater, and the second heater element 232 is a high-power main heater.

[0057] In this way, the first heater element 231 generates less heat than the second heater element 232, thereby suppressing temperature unevenness within the surface of the object W being processed, which is caused by the pattern of the second heater element 232. Therefore, the uniformity of the temperature distribution within the surface of the object W being processed can be improved.

[0058] The volume resistivity of the first heater element 231 is higher than, for example, the volume resistivity of the second heater element 232. The volume resistivity of the first heater element 231 is the volume resistivity of the sub-heater line 231c. In other words, the volume resistivity of the first heater element 231 is the volume resistivity between one end of the sub-heater line 231c (the first sub-power supply section 231a, described later) and the other end (the second sub-power supply section 231b, described later). To put it another way, the volume resistivity of the first heater element 231 is the volume resistivity in the current path from the first sub-power supply section 231a through the sub-heater line 231c to the second sub-power supply section 231b. Similarly, the volume resistivity of the second heater element 232 is the volume resistivity of the main heater line 232c. In other words, the volume resistivity of the second heater element 232 is the volume resistivity between one end of the main heater line 232c (the first main power supply section 232a, described later) and the other end (the second main power supply section 232b, described later). To put it another way, the volume resistivity of the second heater element 232 is the volume resistivity in the current path from the first main power supply section 232a through the main heater line 232c to the second main power supply section 232b.

[0059] In this way, by making the volume resistivity of the first heater element 231 higher than that of the second heater element 232, the output (heat generation, power consumption) of the first heater element 231 can be made lower than the output (heat generation, power consumption) of the second heater element 232. As a result, the temperature unevenness within the surface of the object being processed, caused by the pattern of the second heater element, can be suppressed by the first heater element. Therefore, the uniformity of the temperature distribution within the surface of the object being processed can be improved.

[0060] Alternatively, the volume resistivity of the subheater line 231c may be lower than, for example, the volume resistivity of the main heater line 232c. For example, the electrical resistance from one end to the other of the subheater line 231c may be lower than the electrical resistance from one end to the other of the main heater line 232c. Even in this case, the output (heat generation) of the second heater element 232 (e.g., the second heater layer) is configured to be greater than that of the first heater element 231 (e.g., the first heater layer).

[0061] The area around the power supply terminals is prone to becoming a temperature singularity (a point where the temperature differs relatively significantly from the surrounding area). By providing the bypass layer 250, the degree of freedom in the placement of the power supply terminals can be increased. For example, power supply terminals that are prone to becoming temperature singularities can be dispersed, allowing heat to dissipate more easily around these singularities. This improves the uniformity of the in-plane temperature distribution of the object W being processed.

[0062] The provision of the bypass layer 250 allows for a configuration in which the power supply terminals, which have a large heat capacity, are not directly connected to the first heater element 231 and the second heater element 232. This improves the uniformity of the in-plane temperature distribution of the object W being processed. Furthermore, the provision of the bypass layer 250 eliminates the need to directly connect the power supply terminals to the relatively thin first heater element 231 and the second heater element 232. This improves the reliability of the heater unit 200.

[0063] The power supply terminals are provided extending from the heater unit 200 toward the base plate 300. Therefore, power can be supplied to the power supply terminals from the lower surface 303 of the base plate 300 (see Figures 2(a) and 2(b)) via a component called a socket or the like. This allows for heater wiring while preventing the power supply terminals from being exposed inside the chamber where the electrostatic chuck 10 is installed.

[0064] In this example, the second heater element 232 is located above the first heater element 231. However, the second heater element 232 may be located below the first heater element 231.

[0065] When the first heater element 231 is positioned above the second heater element 232, the first heater element 231 is relatively close to the object W being processed, making it easier to control the temperature of the object W using the first heater element 231. In other words, the first heater element 231 can more easily suppress temperature unevenness within the surface of the object W caused by the pattern of the second heater element 232. Therefore, the uniformity of the temperature distribution within the surface of the object W can be improved.

[0066] On the other hand, when the second heater element 232 is located above the first heater element 231, the high-output second heater element 232 is relatively close to the object W being processed. This improves the temperature responsiveness (heating rate and cooling rate) of the object W being processed.

[0067] In this example, the first heater element 231 is located between the bypass layer 250 and the second heater element 232 in the Z direction. That is, the bypass layer 250 is located below the first heater element 231 and the second heater element 232. This allows the power supply terminals to be connected to the bypass layer 250 from the opposite side from the first heater element 231 and the second heater element 232. Therefore, there is no need to provide holes in the first heater element 231 and the second heater element 232 for passing the power supply terminals, which reduces temperature singularities on the heater pattern and improves the uniformity of the in-plane temperature distribution of the first heater element 231 and the second heater element 232.

[0068] The bypass layer 250 may be located above the first heater element 231 and the second heater element 232. Alternatively, the bypass layer 250 may be located between the first heater element 231 and the second heater element 232.

[0069] Furthermore, the number of heater elements in the heater unit 200 is not limited to "2". In other words, the heater unit 200 may have additional heater elements provided in layers different from the first heater element 231 and the second heater element 232.

[0070] Figure 5 is a schematic plan view showing the main zone of the second heater element according to the embodiment. Figure 5 shows the second heater element 232 projected onto a plane perpendicular to the Z direction. As shown in Figure 5, the second heater element 232 has multiple main zones 600 (e.g., the second zone) divided radially in the Dr direction. In the second heater element 232, independent temperature control is performed in each main zone 600.

[0071] In this specification, "radial direction Dr" refers to the direction from the center of the heater element (heater portion) towards the outer circumference along the radius. "Circumferential direction Dc" refers to the direction along the outer circumference of the heater element. The circumferential direction Dc may be substantially the same as, for example, the direction along the outer circumference of the ceramic dielectric substrate 100 in a plan view, or the direction along the outer circumference of the base plate 300 in a plan view.

[0072] In this example, the multiple main zones 600 have three main zones 601 to 603 aligned radially in the Dr. That is, for example, the second heater element 232 is divided into three parts radially in the Dr. Each main zone 600 is arranged in the order of main zone 601, main zone 602, and main zone 603, moving outward radially from the center CT2 of the second heater element 232 in the Dr.

[0073] Main zone 601 is circular in shape with center CT2 in a plan view. Main zone 602 is located outside main zone 601 and is ring-shaped with center CT2 in a plan view. Main zone 603 is located outside main zone 602 and is ring-shaped with center CT2 in a plan view.

[0074] The number of main zones 600 and their shape in plan view are arbitrary. For example, in the example in Figure 4, four main zones 600 are shown. Furthermore, the main zones 600 may be divided in the circumferential direction Dc, or divided in the circumferential direction Dc and the radial direction Dr. The configuration within each main zone 600 will be described later.

[0075] The main heater lines 232c that make up each main zone 600 are independent of each other. This allows a different voltage to be applied to each main zone 600 (main heater line 232c). Therefore, the output (amount of heat generated) can be controlled independently for each main zone 600. In other words, each main zone 600 is a heater unit that can perform independent temperature control, and the second heater element 232 is an assembly of heater units having multiple such heater units.

[0076] Each main zone 600 is arranged at a predetermined interval from adjacent main zones 600. That is, the second heater element 232 has an inter-main zone region 650 (for example, a second inter-zone region). The inter-main zone region 650 is provided between two adjacent main zones 600. The inter-main zone region 650 is a region that separates two adjacent zones. That is, one main zone 600 is adjacent to another main zone 600 via the inter-main zone region 650. The inter-main zone region 650 includes the region from the main heater line 232c in one main zone 600 to the main heater line 232c in another main zone 600 adjacent to that main zone 600 (the region between the main heater lines 232c). For example, insulating material is appropriately placed in the inter-main zone region 650.

[0077] Specifically, the inter-main-zone region 650 comprises the inter-main-zone region 651 and the inter-main-zone region 652. The inter-main-zone region 651 is a predetermined interval provided between main zone 601 and main zone 602. That is, the inter-main-zone region 651 includes the interval from the main heater line 232c of main zone 601 to the main heater line 232c of main zone 602. The inter-main-zone region 652 is a predetermined interval provided between main zone 602 and main zone 603. That is, the inter-main-zone region 652 includes the interval from the main heater line 232c of main zone 602 to the main heater line 232c of main zone 603. In plan view, the inter-main-zone region 651 and the inter-main-zone region 652 are annular with center CT2. For example, the inter-main-zone region 650 curves along the circumferential direction Dc. However, not only is a curve along the circumferential direction Dc possible; at least a portion of the area 650 between the main zones may curve in a direction different from the circumferential direction Dc, or it may be straight.

[0078] The radial width LMa of the inter-main-zone region 651 may be narrower than the radial width LM1 (radius) of the main zone 601 and the radial width LM2 of the main zone 602. The radial width LMb of the inter-main-zone region 652 may be narrower than the width LM2 and the radial width LM3 of the main zone 602. Note that the width in plan view of a linear or strip-extending element is, in other words, the thickness in plan view, and is the length along the direction perpendicular to its extension direction. In an annular shape, the width is the distance from the inner edge to the outer edge (half the difference between the inner diameter and the outer diameter).

[0079] The width of the main zone inter-zone region 650 in a plan view (e.g., width LMa or width LMb) is arbitrary, but as an example, it is 0.5 mm or more and 4 mm or less, preferably 1 mm or more and 3 mm or less. The width of the main zone inter-zone region 650 in a plan view may be constant or may vary along its extension direction.

[0080] Figure 6 is a schematic plan view showing a subzone of the first heater element according to the embodiment. Figure 6 shows the first heater element 231 projected onto a plane perpendicular to the Z direction. As shown in Figure 6, in this example, the first heater element 231 has a plurality of subzones 700 (e.g., the first zone) divided into radial Dr and circumferential Dc directions. In the first heater element 231, independent temperature control is performed in each subzone 700.

[0081] In this example, the multiple subzones 700 include the first region 701 to the third region 703. The first region 701 is circular in shape with the center CT1 of the first heater element 231 at its center. The second region 702 and the third region 703 are annular in shape with the center CT1 at their center. In plan view, the first region 701 to the third region 703 are arranged in the order of the first region 701, the second region 702, and the third region 703, moving outward radially from the center CT1 in the direction Dr.

[0082] The first region 701 to the third region 703 each have multiple subzones 700 arranged in the circumferential direction Dc. The planar shape of each subzone 700 in the first region 701 is fan-shaped. The planar shape of each subzone 700 in the second region 702 and the third region 703 is part of an annular shape.

[0083] Thus, for example, the second heater element 232 is divided into three parts in the radial direction Dr. Furthermore, the first region 701 to the third region 703 are each divided into multiple parts in the circumferential direction Dc.

[0084] Specifically, in the example shown in Figure 6, the first region 701 has eight subzones 700 aligned in the circumferential direction Dc. The second region 702 has ten subzones 700 aligned in the circumferential direction Dc. The third region 703 has twelve subzones 700 aligned in the circumferential direction Dc.

[0085] In this example, the radial width LS1 (radius) of the first region 701 is wider than the radial width LS2 of the second region 702. Also, in this example, the radial width LS3 of the third region 703 is the same as width LS2. However, the widths of each region may be different from each other.

[0086] The number of subzones 700 is greater than the number of mainzones 600. In other words, the first heater element 231 is divided into more zones than the second heater element 232.

[0087] By increasing the number of subzones 700 in the first heater element 231 compared to the number of main zones 600 in the second heater element 232, the first heater element 231 can control the temperature of a narrower area than the second heater element 232. This allows for finer temperature adjustment by the first heater element 231, improving the uniformity of the temperature distribution within the surface of the object W being processed.

[0088] The number of subzones 700 and their shapes in plan view are arbitrary. Furthermore, the subzones 700 do not necessarily have to be divided along the circumferential direction Dc. In other words, the first region 701 and the second region 702 do not necessarily have to contain multiple subzones 700 divided along the circumferential direction Dc. The configuration within each subzone 700 will be described later.

[0089] The subheater lines 231c that make up each subzone 700 are independent of each other. This allows a different voltage to be applied to each subzone 700 (subheater line 231c). Therefore, the output (amount of heat generated) can be controlled independently for each subzone 700. In other words, each subzone 700 is a heater unit that can perform independent temperature control, and the first heater element 231 is an assembly of heater units having multiple such heater units.

[0090] Each subzone 700 is arranged at a predetermined interval from adjacent subzones 700. The second heater element 232 has an inter-subzone region 750 (for example, a first inter-zone region). The inter-subzone region 750 is provided between adjacent subzones 700. The inter-subzone region 750 is a region that separates two adjacent zones. That is, one subzone 700 is adjacent to another subzone 700 via the inter-subzone region 750. The inter-subzone region 750 includes the region from a subheater line 231c in one subzone 700 to a subheater line 231c in another subzone 700 adjacent to that subzone 700 (the region between subheater lines 231c). For example, insulating material is appropriately placed in the inter-subzone region 750.

[0091] The subzone region 750 has a plurality of curved regions 750c (curved region 751c and curved region 752c) that are curved in a plan view. The curved region 750c is, for example, a predetermined interval provided between adjacent subzones 700 in the radial direction Dr. That is, the curved region 750c includes the interval from the subheater line 231c of one subzone 700 to the subheater line 231c of the subzone 700 adjacent to that subzone 700 in the radial direction Dr. The curved region 750c curves along the circumferential direction Dc and extends in the circumferential direction Dc. In a plan view, the curved region 750c is an annular shape centered on the center CT1.

[0092] Specifically, the curved region 751c is provided between the first region 701 and the second region 702, and the curved region 752c is provided between the second region 702 and the third region 703. At least a portion of the inter-subzone region 750 located between adjacent subzones 700 in the radial direction Dr is not limited to a curve along the circumferential direction Dc, but may also curve along a direction different from the circumferential direction Dc, or may be straight.

[0093] The inter-subzone region 750 further comprises a plurality of linear regions 750r (linear regions 751r to 753r). A linear region 750r is a predetermined interval provided between adjacent subzones 700 in the circumferential direction Dc. That is, a linear region 750r includes the interval from the subheater line 231c of one subzone 700 to the subheater line 231c of the subzone 700 adjacent to that subzone 700 in the circumferential direction Dc. In a plan view, a linear region 750r is a straight line extending in the radial direction Dr.

[0094] Specifically, the straight region 751r is provided between the subzones 700 of the first region 701, the straight region 752r is provided between the subzones 700 of the second region 702, and the straight region 753r is provided between the subzones 700 of the third region 703. At least a portion of the inter-subzone region 750 located between adjacent subzones 700 in the circumferential direction Dc is not limited to being a straight line extending in the radial direction Dr, but may also extend along a direction different from the radial direction Dr, or may be curved.

[0095] The width of the subzone region 750 in a plan view is, for example, 0.5 mm or more and 3 mm or less. The width L750c of the curved region 750c (length along the radial direction Dr of the curved region 750c) is, for example, 0.5 mm or more and 3 mm or less. The width L750r of the straight region 750r (length along the circumferential direction Dc of the straight region 750r) is, for example, 0.5 mm or more and 3 mm or less. The width of the subzone region 750 in a plan view may be constant or may vary along its extension direction.

[0096] Figure 7 is a schematic plan view of the second heater element according to the embodiment. As shown in Figure 7, one main zone 600 has two main power supply units (one first main power supply unit 232a and one second main power supply unit 232b) and one main heater line 232c. The main heater line 232c electrically connects the two main power supply units (for example, the second power supply unit). The main zone 600 is a region composed of a continuous main heater line 232c connecting the first main power supply unit 232a and the second main power supply unit 232b.

[0097] One first main power supply unit 232a is provided at one end of one main heater line 232c and is electrically connected to a power supply terminal. The first main power supply unit 232a may be connected to the power supply terminal via a bypass unit 251 (first main bypass unit), or it may be connected to the power supply terminal without the bypass unit 251. One second main power supply unit 232b is provided at the other end of the main heater line 232c and is electrically connected to another power supply terminal. The second main power supply unit 232b may be connected to the power supply terminal via a bypass unit 251 (second main bypass unit), or it may be connected to the power supply terminal without the bypass unit 251. Current from an external source flows from the power supply terminal connected to the second main power supply unit 232b to the main heater line 232c via the second main power supply unit 232b. The current flowing through the main heater line 232c flows from the first main power supply unit 232a to the outside via another power supply terminal connected to the first main power supply unit 232a. The main heater line 232c generates heat due to the flow of current.

[0098] The width of the main heater line 232c in a plan view is, for example, 0.5 mm or more and 5 mm or less, preferably 0.8 mm or more and 3 mm or less. The width of the main heater line 232c in a plan view may be constant or may vary along its extending direction.

[0099] In the example shown in Figure 7, the main heater line 232c is not located between the two main power supply units, and the two main power supply units are in close proximity to each other. However, the arrangement of the main power supply units is not limited to this and can be changed as appropriate. For example, as in the example shown in Figure 5, the two main power supply units may be far apart from each other.

[0100] Figure 8 is a schematic plan view showing a portion of the subzone of the first heater element according to the embodiment. As shown in Figure 8, one subzone 700 has two sub-power supply units (one first sub-power supply unit 231a and one second sub-power supply unit 231b) and one sub-heater line 231c. The sub-heater line 231c electrically connects the two sub-power supply units (for example, the first power supply unit). Subzone 700 is a region composed of a continuous sub-heater line 231c connecting the first sub-power supply unit 231a and the second sub-power supply unit 231b. In Figure 8, the extent of each subzone 700 is represented by a dashed line.

[0101] One first sub-power supply unit 231a is provided at one end of one sub-heater line 231c and is electrically connected to a power supply terminal. The first sub-power supply unit 231a may be connected to the power supply terminal via a bypass unit 251 (e.g., a first sub-bypass unit), or it may be connected to the power supply terminal without a bypass unit 251. One second sub-power supply unit 231b is provided at the other end of the sub-heater line 231c and is electrically connected to another power supply terminal. The second sub-power supply unit 231b may be connected to the power supply terminal via a bypass unit 251 (e.g., a second sub-bypass unit), or it may be connected to the power supply terminal without a bypass unit 251. Current from an external source flows from the power supply terminal connected to the second sub-power supply unit 231b through the second sub-power supply unit 231b to the sub-heater line 231c. The current flowing through the sub-heater line 231c flows from the first sub-power supply unit 231a to the outside via another power supply terminal connected to the first sub-power supply unit 231a. The sub-heater line 231c generates heat due to the flow of current.

[0102] The width t4 of the subheater line 231c in a plan view is, for example, 0.1 mm or more and 2 mm or less, preferably 0.3 mm or more and 1.5 mm or less. The width of the subheater line 231c in a plan view may be constant or may vary along its extending direction.

[0103] In the example shown in Figure 8, the two sub-power supply units are located in the center of the sub-zone 700. However, the arrangement of the sub-power supply units is not limited to this and can be changed as appropriate. For example, as shown in Figure 6, the two sub-power supply units may be located on the outer periphery of the sub-zone 700 and separated from each other.

[0104] Figure 9 is a plan view illustrating the bypass portion of the bypass layer according to the embodiment. Figure 10(a) is a schematic perspective view showing the connection between the bypass portion of the bypass layer according to the embodiment and the first heater element, and Figure 10(b) is a schematic plan view showing a modified example of the bypass portion. In the examples shown in Figures 9 and 10(a), the bypass section 251 is a first sub-bypass section 251a that is electrically connected to the subzone 700 of the first heater element 231.

[0105] As shown by the dashed line in Figure 10(a), in this example, the first sub-bypass section 251a is electrically connected to the first sub-power supply sections 231a of multiple sub-zones 700. That is, one bypass section 251 is connected to multiple first sub-power supply sections 231a. However, this is not the only option; multiple first sub-bypass sections 251a may be provided, and each first sub-bypass section 251a may be connected to each first sub-power supply section 231a. The number of first sub-power supply sections 231a (number of sub-zones) to which one first sub-bypass section 251a is connected is arbitrary. For example, as shown in Figure 10(b), the first sub-bypass section 251a may be divided into eight bypass sections 251. In this way, multiple bypass sections 251 may be provided, and multiple first sub-power supply sections 231a may be electrically connected to each bypass section 251. By dividing the bypass section 251, it is possible to suppress the excessive current flowing through one bypass section 251, which would cause excessive heat generation in the bypass section 251. Although not shown in the diagram, in this example, each of the second sub-power supply sections 231b of the multiple sub-zones 700 is connected to each of the multiple power supply terminals.

[0106] For example, the first sub-bypass section 251a is a mesh structure provided according to the arrangement of the inter-subzone region 750. The first sub-bypass section 251a has a linear portion 280 that overlaps with the inter-subzone region 750 in the Z direction. The linear portion 280 extends along the inter-subzone region 750.

[0107] In this example, the linear portion 280 has a plurality of curved portions 280c (curved portions 281c and 282c) that are curved in a plan view. The curved portions 280c curve, for example, along the circumferential direction Dc and extend in the circumferential direction Dc. In a plan view, the curved portions 280c are annular with center CT1. Note that the curved portions 280c are not limited to curves along the circumferential direction Dc, but may also curve along directions different from the circumferential direction Dc.

[0108] The linear portion 280 further comprises a plurality of straight portions 280r (straight portions 281r to 283r). In a plan view, the straight portions 280r are straight lines extending in the radial direction Dr and are connected to the curved portion 280c. The straight portions 280r may extend in a direction different from the radial direction Dr.

[0109] The width of the linear portion 280 in plan view is, for example, 0.5 mm or more and 3 mm or less, preferably 1 mm or more and 2 mm or less. The width L280c of the curved portion 280c (length along the radial direction Dr of the curved portion 280c) and the width L280r of the straight portion 280r (length along the circumferential direction Dc of the straight portion 280r) shown in Figure 9 are, for example, 0.5 mm or more and 3 mm or less, preferably 1 mm or more and 2 mm or less. The width of the linear portion 280 in plan view may be constant or may vary along its extension direction.

[0110] For example, as shown in Figure 10(a), the curved portion 280c of the bypass overlaps with the curved portion 750c of the subzone region 750 in the Z direction. The curved portion 280c extends along the curved portion 750c in a plan view. More specifically, in a plan view, the curved portion 281c overlaps with the curved portion 751c and extends along the curved portion 751c. The curved portion 282c overlaps with the curved portion 752c and extends along the curved portion 752c.

[0111] For example, in a plan view, the curvature of the curved portion 280c is the same as the curvature of the curved region 750c. Note that curvature refers to, for example, the curvature of the outer edge (inner or outer edge) in a plan view. The curvature may also be the curvature of the center line in the width direction (radial direction Dr). For example, the outer edge or center line of the curved portion 280c and the outer edge or center line of the curved region 750c are curves that run parallel to each other along the XY plane while maintaining a constant distance from each other, and may have the same shape.

[0112] Furthermore, for example, the straight section 280r of the bypass overlaps with the straight section 750r of the subzone region 750 in the Z direction. The straight section 280r extends along the straight section 750r in a plan view. More specifically, in a plan view, the straight section 281r overlaps with the straight section 751r and extends along the straight section 751r. The straight section 282r overlaps with the straight section 752r and extends along the straight section 752r. The straight section 283r overlaps with the straight section 753r and extends along the straight section 753r.

[0113] For example, the outer edge or center line in the width direction (circumferential direction Dc) of the straight portion 280r and the outer edge or center line in the width direction (circumferential direction Dc) of the straight region 750r are parallel lines that extend along the XY plane while maintaining a constant distance from each other.

[0114] For example, to prevent short circuits between adjacent subzones 700, a subzone region 750 is provided between subzones 700 at a predetermined interval. Since the subheater line 231c is not located in the subzone region 750 between adjacent subzones 700, it becomes a cool spot with a low temperature, making it prone to uneven temperature distribution within the plane. On the other hand, although the amount of heat generated is smaller than that of the heater layer, heat is also generated in the bypass section 251 when current flows through it. In particular, the amount of heat generated increases when current is concentrated in the linear section 280. In contrast, the linear section 280 of the bypass section 251 overlaps with the subzone region 750 and extends along the subzone region 750, so that the heat generated by the linear section 280 can suppress the uneven temperature distribution within the plane caused by the subzone region 750. This makes it possible to improve the uniformity of the temperature distribution within the plane of the object being processed. For example, a portion of the cool spot formed by the subzone region 750 is offset and equalized by a portion of the heat generated (hot spot) in the linear portion of the bypass section 251.

[0115] Furthermore, as shown in Figure 6 or Figure 9, the heater unit 200 has a central region 200C and an outer peripheral region 200D located outside the central region. The central region 200C is a circular region with radius RC centered on the center CT1 in a plan view. Radius RC is half the length of the radius of the heater unit 200 in a plan view. The outer peripheral region 200D is an annular region that is tangent to the outer peripheral edge 200Cp of the central region 200C and surrounds the central region 200C. The outer peripheral region 200D includes the outer peripheral edge 200p of the heater unit 200.

[0116] Preferably, the linear portion 280 of the bypass portion 251 overlaps with at least the subzone inter-region 750 located in the outer peripheral region 200D in the Z direction and extends along at least the subzone inter-region 750 located in the outer peripheral region 200D. For example, the straight portion 283r of the linear portion 280 overlaps with the straight portion 753r of the subzone inter-region 750 located in the outer peripheral region 200D and extends along the straight portion 753r. For example, the curved portion 282c of the linear portion 280 overlaps with the curved portion 752c of the subzone inter-region 750 located in the outer peripheral region 200D and extends along the curved portion 752c.

[0117] In the heater section 200, the temperature distribution variation in the outer peripheral region 200D tends to be greater than the temperature distribution variation in the central region 200C. Electrostatic chucks are subjected to two main types of heat: heat from the outside and heat from the electrostatic chuck itself. External heat, for example, when an electrostatic chuck is placed in an etching apparatus, includes heat input from plasma, etc. This external heat causes the outer peripheral region 200D of the electrostatic chuck to generate heat (so-called edge hotting). On the other hand, when an electrostatic chuck is equipped with a heater section 200, there is no heater (heating element) outside the outer peripheral region, resulting in a lower temperature in the outer peripheral region than other regions. Depending on the balance between this external heat input and the heat from the electrostatic chuck itself, the temperature of the outer peripheral region 200D may vary. In particular, in electrostatic chucks equipped with a heater, the effect of external heat input (edge ​​hotting) can be canceled out by the heater, but in that case, the temperature in the outer peripheral region 200D may become even lower. In contrast, by providing a linear portion 280 of the bypass portion 251 along the subzone inter-zone region 750 of the outer peripheral region 200D, variations in the temperature distribution in the outer peripheral region 200D can be suppressed.

[0118] For example, in Figure 8, the position of the linear portion 280 of the bypass section 251 in a plan view is schematically represented by a dashed line, superimposed on the first heater element 231. As shown in Figure 8, the width t1 of the linear portion 280 is the same as, or narrower than, the width t2 of the subzone region 750.

[0119] If the width t1 of the linear portion 280 is wider than the width t2 of the subzone region 750, the heat generated by the linear portion 280 will have a greater impact on the temperature of the subzone 700, which may complicate the temperature design. For example, if the width of the linear portion 280 is wide, the heat-generating linear portion 280 and the subheater line 231c will overlap, potentially leading to the formation of hot spots. In contrast, by keeping the width t1 of the linear portion 280 less than or equal to the width t2 of the subzone region 750, overlap between the linear portion 280 and the subzone 700 is suppressed. This reduces the impact of the heat generated by the linear portion 280 on the temperature of the subzone 700, thereby suppressing temperature variations across the entire surface on which the object to be processed is placed.

[0120] For example, the width L280c of the curved portion 280c of the linear portion 280 (see Figure 9) is the same as, or narrower than, the width L750c of the curved portion 750c of the subzone region 750 (see Figure 6). For example, the width L280r of the straight portion 280r of the linear portion 280 (see Figure 9) is the same as, or narrower than, the width L750r of the straight portion 750r of the subzone region 750 (see Figure 6).

[0121] Furthermore, as shown in Figure 8, in a plan view, the width t1 of the linear portion 280 is wider than the width t3. The width t3 is the minimum distance between a part of the subheater line 231c in one of the subzones 700 and another part of the same subheater line 231c in a plan view. This narrows the width t1 of the linear portion 280, thereby suppressing the generation of excessive heat in the linear portion 280.

[0122] Furthermore, as shown in Figure 8, for example, in a plan view, the width t4 of the subheater line 231c in one of the subzones 700 is narrower than the width t1 of the linear portion 280. This narrows the width t1 of the linear portion 280, thereby suppressing the generation of excessive heat in the linear portion 280.

[0123] Note that the width of a certain part (for example, width t1, width t2, or width t4) is the shortest distance between two opposing sides of that part (two sides that extend along the direction of extension of that part and are far apart from each other) in a plan view. If the width of the linear part 280 changes along the direction of extension of the linear part 280, width t1 is the minimum width of the linear part 280. Similarly, if the width of the subzone region 750 changes along the direction of extension of the subzone region 750, width t2 is the minimum width of the subzone region 750. If the width of the subheater line 231c changes along the direction of extension of the subheater line 231c, width t4 is the minimum width of the subheater line 231c.

[0124] The number of subzones 700 (first zones) is, for example, 50 or more. By finely dividing the first heater element 231 to create 50 or more subzones 700, the temperature of the surface on which the object to be processed is placed (and consequently the temperature within the surface of the object to be processed) can be finely adjusted. On the other hand, as the number of subzones 700 increases, the inter-subzone regions 750 also increase. In this embodiment, however, the linear portion 280 of the bypass portion 251 is arranged to overlap with the inter-subzone regions 750. Therefore, even when the subzones 700 are subdivided, the uniformity of the temperature distribution within the surface of the object to be processed can be improved. The number of first zones is, for example, around 200 zones, but there is no particular upper limit.

[0125] Furthermore, as shown in Figure 4, for example, the subzone region 750 has an overlapping region 760 that overlaps with the main zone region 650 in the Z direction. For example, a part of the subzone region 750 (the overlapping region 760) overlaps with the main zone region 650 in the Z direction and extends along the main zone region 650. More specifically, for example, the curved region 752c (see Figure 6) of the subzone region 750 overlaps with the main zone region 652 (see Figure 5) in the Z direction. For example, in a plan view, the curvature of the curved region 752c is the same as the curvature of the main zone region 652. For example, the outer edge or center line of the curved region 752c and the outer edge or center line of the main zone region 652 are curves that run parallel to each other along the XY plane while maintaining a constant distance from each other, and may have the same shape. Similarly, for example, the curved region 751c (see Figure 6) of the subzone region 750 overlaps with the main zone region 651 (see Figure 5) in the Z direction.

[0126] The linear portion 280 of the bypass portion 251 overlaps with the overlapping region 760 in the Z direction. For example, the linear portion 280 extends along the overlapping region 760. More specifically, for example, the curved portion 282c of the linear portion 280 (see Figure 10(a)) overlaps with a part of the overlapping region 760 (a part of the curved region 752c) in the Z direction. For example, in a plan view, the curvature of the curved portion 282c is the same as the curvature of that part of the overlapping region 760. For example, the outer edge or center line of the curved portion 282c and the outer edge or center line of that part of the overlapping region 760 are curves that run parallel to each other along the XY plane while maintaining a constant distance from each other, and may have the same shape. Similarly, for example, the curved portion 281c of the linear portion 280 (see Figure 10(a)) overlaps with a part of the overlapping region 760 (a part of the curved region 751c) in the Z direction.

[0127] In the inter-main-zone region 650 between adjacent main-zone regions 600, the main heater line 232c is not located, resulting in a cool spot with a low temperature and making it prone to uneven temperature distribution within the plane. For example, the overlapping region where the inter-sub-zone region 750 and the inter-main-zone region 650 overlap is prone to becoming a cool spot. In contrast, the linear portion 280 of the bypass section 251 overlaps with the overlapping region 760, and the heat generated by the linear portion 280 can suppress the uneven temperature distribution within the plane caused by the overlapping region 760. This improves the uniformity of the temperature distribution within the plane of the object being processed.

[0128] Figure 11 is a plan view illustrating a modified example of the bypass portion of the bypass layer according to the embodiment. . In the example shown in Figure 11, the linear portion 280 of the bypass section 251 is located in the outer peripheral region 200D. The portion 285 of the bypass section 251 located in the central region 200C is circular in shape (like a membrane) when viewed from above. Thus, it is sufficient for a portion of the bypass section 251 to be the linear portion 280, and the bypass section 251 may also have a wide plate-like portion.

[0129] As described above, in the embodiment, the first bypass portion (e.g., the first sub-bypass portion 251a) overlaps with the first inter-zone region (e.g., the sub-zone region 750) of the first heater element in the Z direction and has a linear portion that extends along the first inter-zone region. In the above explanation, the first bypass section was described as a bypass section 251 connected to the subzone 700, i.e., the first sub-bypass section 251a. However, the first bypass section is not necessarily limited to the first sub-bypass section 251a. For example, although not shown in the diagram, any number of second sub-bypass sections, any number of first main bypass sections, and any number of second main bypass sections may be provided, similar to the first sub-bypass section 251a. Each second sub-bypass section is connected to any number of second sub-power supply sections 231b. Each first main bypass section is connected to any number of first main power supply sections 232a. Each second main bypass section is connected to any number of second main power supply sections 232b. Multiple bypass sections 251 may be arranged side by side in the same XY plane, or they may be divided and arranged in multiple layers as appropriate. The first bypass section may be a second sub-bypass section, a first main bypass section, or a second main bypass section. In other words, the linear portion that overlaps with the first zone inter-zone region may be provided, for example, in the bypass section 251 connected to the main zone 600.

[0130] Furthermore, although the above explanation used the example where the first heater layer is the first heater element 231, the first zone is the subzone 700, and the inter-zone region is the inter-subzone region 750, the first heater layer may be the second heater element 232, the first zone may be the main zone 600, and the inter-zone region may be the inter-main zone region 650. In other words, the linear portion of the first bypass may, for example, overlap with the inter-main zone region 650 and extend along the inter-main zone region 650.

[0131] Figure 12 is a schematic cross-sectional view showing a wafer processing apparatus according to an embodiment. As shown in Figure 12, the wafer processing apparatus 500 according to this embodiment includes a processing container 501, an upper electrode 510, and an electrostatic chuck 10. The ceiling of the processing container 501 is provided with a processing gas inlet 502 for introducing a processing gas into the interior. The bottom plate of the processing container 501 is provided with an exhaust port 503 for depressurizing and exhausting the interior. A high-frequency power supply 504 is connected to the upper electrode 510 and the electrostatic chuck 10, and the pair of electrodes, the upper electrode 510 and the electrostatic chuck 10, are arranged to face each other in parallel at a predetermined distance.

[0132] In the wafer processing apparatus 500, when a high-frequency voltage is applied between the upper electrode 510 and the electrostatic chuck 10, a high-frequency discharge occurs, and the processing gas introduced into the processing container 501 is excited and activated by the plasma, thereby processing the object to be processed W. The object to be processed W can be exemplified by a semiconductor substrate (wafer). However, the object to be processed W is not limited to a semiconductor substrate (wafer), and may be, for example, a glass substrate used in a liquid crystal display device.

[0133] The high-frequency power supply 504 is electrically connected to the base plate 300 of the electrostatic chuck 10. As mentioned above, the base plate 300 is made of a metal material such as aluminum. That is, the base plate 300 is conductive. As a result, the high-frequency voltage is applied between the upper electrode 410 and the base plate 300.

[0134] In this example, the heater section 200 is constructed by stacking the first support plate 210, the first insulating layer 220, the first heater element 231, the second insulating layer 240, the second heater element 232, the third insulating layer 245, the bypass layer 250, the fourth insulating layer 260, and the second support plate 270 in that order. The base plate 300 is electrically connected to the first support plate 210 and the second support plate 270. As a result, in the wafer processing apparatus 500, a high-frequency voltage is applied between the first support plate 210 and the upper electrode 510, and between the second support plate 270 and the upper electrode 510.

[0135] In this way, a high-frequency voltage is applied between each support plate 210, 270 and the upper electrode 510. This allows the location where the high-frequency voltage is applied to be closer to the object W being processed compared to the case where the high-frequency voltage is applied only between the base plate 300 and the upper electrode 510. As a result, for example, plasma can be generated more efficiently and at a lower potential.

[0136] A wafer processing apparatus with a configuration like the 500 is generally called a parallel-plate type RIE (Reactive Ion Etching) apparatus, but the electrostatic chuck 10 according to this embodiment is not limited to application to this apparatus. For example, it can be widely applied to so-called vacuum processing apparatuses such as ECR (Electron Cyclotron Resonance) etching apparatuses, dielectric coupling plasma processing apparatuses, helicon wave plasma processing apparatuses, plasma separation type plasma processing apparatuses, surface wave plasma processing apparatuses, and plasma CVD (Chemical Vapor Deposition) apparatuses. Such a wafer processing apparatus 500 is used, for example, in the manufacture of semiconductor devices. The wafer processing apparatus 500 is used, for example, as semiconductor manufacturing equipment.

[0137] Furthermore, the electrostatic chuck 10 according to this embodiment can be widely applied to substrate processing equipment in which processing and inspection are performed under atmospheric pressure, such as exposure equipment and inspection equipment. However, considering the high plasma resistance of the electrostatic chuck 10 according to this embodiment, it is preferable to apply the electrostatic chuck 10 to a plasma processing equipment. Note that known configurations can be applied to the parts of these devices other than the electrostatic chuck 10 according to this embodiment, so their description will be omitted.

[0138] According to the wafer processing apparatus 500 (semiconductor manufacturing apparatus) according to the embodiment, by providing the electrostatic chuck 10 described above, the uniformity of the in-plane temperature distribution of the heater section 200 can be improved. This makes it possible to improve the uniformity of the in-plane temperature distribution of the object to be processed W.

[0139] In this specification, "electrically connected" includes not only cases where the connection is made by direct contact, but also cases where the connection is made via other conductive members or the like. In this specification, "same" and "constant" do not mean strictly the same and constant, but rather that they be approximately the same and approximately constant. For example, "same" and "constant" may include the range of variations in the manufacturing process. In this specification, "perpendicular" and "parallel" do not mean strictly perpendicular and strictly parallel, but also include variations in the manufacturing process, for example, and it is sufficient if they are substantially perpendicular and substantially parallel.

[0140] The embodiment may include the following configurations. (Composition 1) A ceramic dielectric substrate having a first main surface on which the object to be processed is placed, and a second main surface opposite to the first main surface, A base plate supporting the ceramic dielectric substrate, A heater section for heating the ceramic dielectric substrate, Equipped with, The heater section includes at least one heater layer including a first heater layer, and a first bypass section which is a power supply path to the at least one heater layer. The first heater layer has a plurality of first zones, Each of the plurality of first zones has two first power supply units and a first heater line that electrically connects the two first power supply units. One of the plurality of first zones is adjacent to another of the plurality of first zones via an inter-first-zone region. The electrostatic chuck wherein the first bypass portion overlaps with the first interzone region in the Z direction perpendicular to the first main surface and has a linear portion extending along the first interzone region. (Configuration 2) The heater portion, when viewed along the Z-direction, has a central region located in the center of the heater portion and an outer peripheral region located outside the central region and including the outer peripheral end of the heater portion. The electrostatic chuck according to configuration 1, wherein the linear portion overlaps with at least the first interzone region located in the outer peripheral region and extends along the first interzone region located in the outer peripheral region. (Composition 3) In a plan view, the width of the linear portion is the same as, or narrower than, the width of the first inter-zone region, according to configuration 1 or 2 of the electrostatic chuck. (Composition 4) An electrostatic chuck according to any one of configurations 1 to 3, wherein, in a plan view, the width of the linear portion is wider than the minimum distance between one part of the first heater line and another part of the first heater line in one of the plurality of first zones. (Composition 5) An electrostatic chuck according to any one of configurations 1 to 4, wherein, in a plan view, the width of the first heater line in one of the plurality of first zones is narrower than the width of the region between the first zones. (Composition 6) The electrostatic chuck according to any one of configurations 1 to 5, wherein the number of the plurality of first zones included in the first heater layer is 50 or more. (Composition 7) The heater section further comprises a second heater layer having a plurality of second zones, Each of the plurality of second zones has two second power supply units and a second heater line that electrically connects the two second power supply units. The number of the aforementioned multiple second zones is less than the number of the aforementioned multiple first zones. One of the plurality of second zones is adjacent to another of the plurality of second zones via an inter-second zone region, The first interzone region has an overlapping region that overlaps with the second interzone region in the Z direction. The linear portion is an electrostatic chuck according to any one of configurations 1 to 6, which overlaps with the overlapping region in the Z direction.

[0141] Embodiments of the present invention have been described above. However, the present invention is not limited to these descriptions. Modifications made by those skilled in the art to the above-described embodiments are also included within the scope of the present invention, as long as they retain the features of the present invention. For example, the shape, dimensions, material, arrangement, and installation configuration of each element are not limited to those exemplified and can be modified as appropriate. Furthermore, the elements of each of the embodiments described above can be combined to the extent technically possible, and these combinations are also included within the scope of the present invention insofar as they include the features of the present invention. [Explanation of symbols]

[0142] 10 Electrostatic Chuck 100 Ceramic dielectric substrates 101 First Main Surface 102 Second Main Surface 111 Electrode layer 113 Convex part 115 Groove 200 Heater section 200C central area 200Cp outer edge 200D outer area 200p outer edge 210 Support plate 220 Insulating layer 231 First heater element 231a First Sub-Power Supply Unit 231b Second Sub-Power Supply Unit 231c Sub-heater line 232 Second Heater Element 232a First Main Power Supply Section 232b Second Main Power Supply Unit 232c Main heater line 240 Second insulating layer 245 Third insulating layer 250 Bypass Layer 251 Bypass section 251a First Sub-Bypass Section 260 Insulating layer 270 Support plate 280 Linear part 280c curved section 280r straight section 281c Curved section 281r Straight section 282c Curved section 282r Straight section 283r Straight section 300 base plate 301 Communication path 303 Bottom surface 321 Introductory path 403 Adhesive layer 410 Upper electrode 500 wafer processing equipment 501 Processing container 502 Processing gas inlet 503 Exhaust vent 504 High frequency power supply 510 Upper electrode 600, 601-603 Main Zone 650651652 Inter-mainzone area 700 subzones 701~703 1st area~3rd area 750 Inter-subzone regions 750c curve region 750r straight line area 751c curve region 751r linear region 752c curve region 752r linear region 753r linear region 760 Duplicate area B1, B2 area CT1, CT2 center Dc circumferential direction Dr radial direction L280c width L280r width L750c width L750r width LM1 width LM2 width LM3 width LMa width LMb width LS1 width LS2 width LS3 width RC radius W - Items to be processed t1 width t2 width t3 width t4 width

Claims

1. A ceramic dielectric substrate having a first main surface on which the object to be processed is placed, and a second main surface opposite to the first main surface, A base plate supporting the ceramic dielectric substrate, A heater section for heating the ceramic dielectric substrate, Equipped with, The heater section includes at least one heater layer including a first heater layer, and a first bypass section which is a power supply path to the at least one heater layer. The first heater layer has a plurality of first zones, Each of the plurality of first zones has two first power supply units and a first heater line that electrically connects the two first power supply units. One of the plurality of first zones is adjacent to another of the plurality of first zones via an inter-zone region. The electrostatic chuck wherein the first bypass portion overlaps with the first interzone region in the Z direction perpendicular to the first main surface and has a linear portion that extends along the first interzone region when viewed along the Z direction.

2. The heater portion, when viewed along the Z-direction, has a central region located in the center of the heater portion and an outer peripheral region located outside the central region and including the outer peripheral end of the heater portion. The electrostatic chuck according to claim 1, wherein the linear portion overlaps with at least the first interzone region located in the outer peripheral region and extends along the first interzone region located in the outer peripheral region.

3. The electrostatic chuck according to claim 1 or 2, wherein, in a plan view, the width of the linear portion is the same as, or narrower than, the width of the first interzone region.

4. The electrostatic chuck according to claim 1 or 2, wherein, in a plan view, the width of the linear portion is wider than the minimum distance between one portion of the first heater line and another portion of the first heater line in one of the plurality of first zones.

5. The electrostatic chuck according to claim 1 or 2, wherein, in a plan view, the width of the first heater line in one of the plurality of first zones is narrower than the width of the region between the first zones.

6. The electrostatic chuck according to claim 1 or 2, wherein the number of the plurality of first zones included in the first heater layer is 50 or more.

7. The heater section further comprises a second heater layer having a plurality of second zones, Each of the plurality of second zones has two second power supply units and a second heater line that electrically connects the two second power supply units. The number of the aforementioned multiple second zones is less than the number of the aforementioned multiple first zones. One of the plurality of second zones is adjacent to another of the plurality of second zones via an inter-second zone region. The first interzone region has an overlapping region that overlaps with the second interzone region in the Z direction. The electrostatic chuck according to claim 6, wherein the linear portion overlaps with the overlapping region in the Z direction.

8. The first interzone region includes a curved region that extends in the circumferential direction of the heater portion when viewed along the Z direction, The linear portion includes a curved portion that extends in the circumferential direction when viewed along the Z direction, The electrostatic chuck according to claim 1, wherein the outer edge of the curved portion and the outer edge of the curved region extend parallel to each other along a plane perpendicular to the Z direction, while maintaining a constant distance between them.

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