Electrostatic chuck component and electrostatic chuck device

Abstract

This electrostatic chuck component is provided with: a base body, one main surface of which is a placement surface on which a plate-shaped sample is placed; and an electrostatic adsorption electrode provided on the opposite side of the mounting surface or inside the base body, the electrostatic adsorption electrode having, on the side peripheral surface of the base body continuous with the mounting surface, at least: a first curved surface that is a convex curved surface provided in the circumferential direction at the peripheral edge of the mounting surface; and a second curved surface provided in the circumferential direction at a position different from the height of the first curved surface, the base body having an annular protrusion provided along the peripheral edge of the placement surface, the outer edge of the electrostatic adsorption electrode overlapping the annular protrusion in plan view, at least a part of the first curved surface being provided on the outer peripheral side of the annular protrusion, and the second curved surface being provided on the outer peripheral side of the annular protrusion. A third curved surface, which is a convex curved surface provided in the circumferential direction of the inner circumference, is provided on the inner circumferential side of the annular protrusion.

Description

Technical Field

[0001] The present invention relates to an electrostatic chuck component and an electrostatic chuck device.

[0002] This application claims priority based on Japanese Patent Application No. 2022-206683 filed on December 23, 2022, and the content thereof is incorporated herein by reference. Background Art

[0003] Conventionally, in a semiconductor manufacturing process for manufacturing semiconductor devices such as ICs, LSIs, and VLSIs, a plate-like specimen such as a silicon wafer is fixed to an electrostatic chuck component having an electrostatic chuck function by electrostatic adsorption and is subjected to a prescribed process. In such a process, for example, after fixing a silicon wafer with an electrostatic chuck device, an etching process or a film-forming process using plasma is performed on the silicon wafer.

[0004] In the manufacturing process as described above, when using an electrostatic chuck device, sometimes particulate foreign matter (hereinafter referred to as foreign matter particles) typified by wafer residues is generated in the electrostatic chuck component. Such foreign matter particles are charged in the semiconductor manufacturing device and adhere to the surface of the electrostatic chuck device. The electrostatic chuck device to which charged foreign matter particles (charged foreign matter particles) adhere may impair the plasma stability in the manufacturing process, resulting in a decrease in productivity. Also, sometimes due to the foreign matter particles, abnormal discharge may occur in the plasma process, disrupting the stabilization of the plasma, thereby leading to a decrease in the yield of components or insulation breakdown of the electrostatic chuck device.

[0005] In response to the above-described problems, in a semiconductor manufacturing process, the following treatment is performed: The electrostatic chuck device contaminated with foreign matter particles is subjected to plasma cleaning to remove the foreign matter particles (for example, refer to Patent Document 1).

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2013-512564 Summary of the Invention

[0009] Technical Problem to be Solved by the Invention

[0010] In recent years, in order to improve the yield of semiconductor chips obtained from silicon wafers, a scheme has been proposed to expand the electrostatic adsorption electrodes provided in the electrostatic chuck component. In the electrostatic chuck component in which the electrostatic adsorption electrodes are expanded, the difference in adsorption force between the center and the periphery of the wafer placement surface becomes smaller, and even in the outer peripheral portion of the silicon wafer, the same processing (etching process) as the central portion can be performed. Thus, even in the outer peripheral portion of the silicon wafer, semiconductor chips can be appropriately manufactured, thereby improving the yield.

[0011] On the other hand, if the electrostatic adsorption electrode is enlarged, the distance between the side surface of the electrostatic chuck member and the electrostatic adsorption electrode becomes closer, and the electric field strength of the side surface of the electrostatic chuck member increases. Therefore, in the electrostatic chuck member with the enlarged electrostatic adsorption electrode, compared with the conventional electrostatic chuck, it has a structure in which charged foreign particles are more likely to be electrostatically adsorbed on the side surface.

[0012] In the electrostatic chuck member described in Patent Document 1, in order to improve the effect of plasma cleaning, an inclined portion is provided around it. However, although this structure can effectively perform cleaning before the wafer process, it cannot suppress the attachment of charged foreign particles to the side surface of the electrostatic chuck member during the manufacturing process. Therefore, there are problems such as a decrease in the yield (productivity decrease) of components caused by abnormal discharge occurring during the wafer process or insulation breakdown of the electrostatic chuck. Therefore, there is a need for an electrostatic chuck member that can reduce the influence of charged foreign particles attached to the side surface of the electrostatic chuck member even during the wafer process and suppress the occurrence of abnormal discharge.

[0013] The present invention has been completed in view of such circumstances, and its object is to provide an electrostatic chuck member that can solve the problems caused by the attachment of charged foreign particles to the side surface, and in particular, can reduce abnormal discharge occurring during the wafer process. Another object of the present invention is to provide an electrostatic chuck device having such an electrostatic chuck member.

[0014] Means for Solving Technical Problems

[0015] In order to solve the above problems, one aspect of the present invention includes the following aspects.

[0016] [1] An electrostatic chuck member having: a base body, one main surface of which is a mounting surface for mounting a plate-shaped specimen; and an electrostatic adsorption electrode provided on the side opposite to the mounting surface or inside the base body. In the side peripheral surface of the base body continuous with the mounting surface, there are at least a first curved surface and a second curved surface. The first curved surface is a convex curved surface provided along the circumferential direction at the peripheral edge of the mounting surface, and the second curved surface is provided along the circumferential direction at a height position different from that of the first curved surface. The base body has an annular protrusion provided along the peripheral edge of the mounting surface. The outer edge of the electrostatic adsorption electrode overlaps with the annular protrusion in a top view. At least a part of the first curved surface is provided on the outer peripheral side of the annular protrusion, and a third curved surface is provided on the inner peripheral side of the annular protrusion. The third curved surface is a convex curved surface provided along the inner circumferential direction.

[0017] [2]The electrostatic chuck component according to [1], wherein the outer edge is located on the outer peripheral side of the center in the width direction of the annular protrusion portion in a plan view, and the radius of curvature of the first curved surface is larger than the radius of curvature of the third curved surface.

[0018] [3]The electrostatic chuck component according to [2], wherein the first curved surface is provided across the annular protrusion portion and below the annular protrusion portion in the base body.

[0019] [4]The electrostatic chuck component according to any one of [1] to [3] satisfies the following formulas (A1) and (A2).

[0020] [Thickness of the electrostatic adsorption electrode] ≤ [Radius of curvature of the first curved surface]... (A1)

[0021] [Thickness of the electrostatic adsorption electrode] ≤ [Radius of curvature of the third curved surface]... (A2)

[0022] [5]The electrostatic chuck component according to any one of [1] to [4], wherein the distance from the outer edge to the side peripheral surface is greater than or equal to the distance from the upper surface of the electrostatic adsorption electrode to the placement surface.

[0023] [6]The electrostatic chuck component according to any one of [1] to [5], wherein the distance from the outer edge to the side peripheral surface is greater than or equal to the distance from the upper surface of the electrostatic adsorption electrode to the placement surface.

[0024] [7]An electrostatic chuck device, comprising: the electrostatic chuck component according to any one of [1] to [6]; and a base component that cools the electrostatic chuck component and adjusts the temperature of the electrostatic chuck component.

[0025] Advantages of the Invention

[0026] According to the present invention, it is possible to provide an electrostatic chuck component capable of reducing problems caused by the attachment of charged foreign particles to the side surface. And it is possible to provide an electrostatic chuck device having such an electrostatic chuck component. Brief Description of the Drawings

[0027] Figure 1 is a schematic perspective view showing an example of the electrostatic chuck component 10 of the first embodiment.

[0028] Figure 2 is a schematic cross-sectional view showing an example of the electrostatic chuck component 10 of the first embodiment.

[0029] Figure 3 is a schematic cross-sectional view showing an example of the electrostatic chuck component 10 of the first embodiment.

[0030] Figure 4 This is a schematic explanatory diagram showing an example of a manufacturing method of the electrostatic chuck member 10 according to the first embodiment.

[0031] Figure 5 This is a schematic explanatory diagram showing an example of the electrostatic chuck member 20 according to the second embodiment.

[0032] Figure 6 This is a schematic explanatory diagram showing an example of the electrostatic chuck member 30 according to the third embodiment.

[0033] Figure 7 This is a schematic explanatory diagram of the electrostatic chuck member 40 according to a modified example of the third embodiment.

[0034] Figure 8 This is a schematic cross-sectional view showing an example of the electrostatic chuck device according to the embodiment.

[0035] Figure 9 This is a schematic explanatory diagram showing an example of a semiconductor manufacturing apparatus having the above-described electrostatic chuck device. Detailed Embodiments

[0036] [First Embodiment]

[0037] Hereinafter, with reference to Figures 1 to 4 an example of the electrostatic chuck member according to the first embodiment of the present invention will be described. In addition, in all the following drawings, in order to easily observe the drawings, the dimensions, ratios, etc. of each component are appropriately changed.

[0038] "Electrostatic Chuck Member"

[0039] Figure 1 This is a schematic perspective view of the electrostatic chuck member 10 of the present embodiment. Figure 2 , Figure 3 This is a cross-sectional view showing the electrostatic chuck member 10 of the present embodiment, and is a cross-sectional view taken along the arrow direction of line II-II in Figure 1 .

[0040] As Figures 1 to 3 shown, the electrostatic chuck member 10 includes a pair of ceramic plates 11 and 12, and an electrostatic adsorption electrode 13 and an insulating layer 15 interposed between the pair of ceramic plates 11 and 12. In the following description, the electrostatic adsorption electrode will be simply referred to as "electrode".

[0041] The structure formed by combining the pair of ceramic plates 11 and 12 and the insulating layer 15 corresponds to the substrate in the present invention. One main surface of the substrate is a mounting surface 10x for mounting a plate-like specimen.

[0042] In the following description, the relative positions between components are sometimes described based on the XY axes in which the plane direction of the mounting surface 10x is the X direction and the normal direction of the mounting surface 10x is the Y direction. Also, on the Y axis, the mounting surface 10x side of the electrostatic chuck component 10 is sometimes referred to as "up", and the side of the electrostatic chuck component 10 opposite to the mounting surface 10x is referred to as "down" to describe the relative positions between components.

[0043] Figure 2 、 Figure 3 The cross-sectional view shown is a cross-section obtained by cutting the electrostatic chuck component with a virtual plane including the center of a circle that is the smallest circle circumscribing the electrostatic chuck component 10 in a plan view. In other words, Figure 2 、 Figure 3 is a cross-sectional view of a cross-section passing through the center C of the base (mounting surface 10x) and including the normal N of the base (mounting surface 10x). When the electrostatic chuck component 10 is substantially circular in a plan view, the center of the above-mentioned circle is substantially the same as the center of the shape of the electrostatic chuck component in a plan view.

[0044] In addition, in this specification, "plan view" means a view from the thickness direction of the electrostatic chuck component, i.e., the Y direction, or a view from the direction of the mounting surface 10x.

[0045] And "cross-section" means a view in the direction orthogonal to the cross-section when cutting along a virtual plane that is perpendicular to the mounting surface and includes the center of a circle that is the smallest circle circumscribing the electrostatic chuck component in a plan view.

[0046] Moreover, in a plan view, the side relatively closer to the center C is sometimes referred to as "inner", and the side farther from the center C is referred to as "outer".

[0047] As Figure 2 shown, a plurality of minute projections 111 are provided on the upper surface of the ceramic plate 11. The minute projections 111 come into contact with the lower surface of the plate-like specimen and support the plate-like specimen when the plate-like specimen is placed on the mounting surface 10x. The minute projections 111 are, for example, in the shape of a cylinder or a frustum of a cone.

[0048] In the space 11x formed around the minute projections 111, a cooling gas such as helium (He) that cools the plate-like specimen heated during plasma processing flows.

[0049] In the ceramic plate 11, a ring-shaped protrusion 112 with a quadrilateral cross-section is provided along the periphery of the placement surface 10x (around the micro-protrusions 111). When a plate-shaped specimen is placed on the placement surface 10x, the ring-shaped protrusion 112 contacts the lower surface of the plate-shaped specimen and functions to seal the space 11x, preventing the cooling gas flowing in the space 11x from leaking to the outside.

[0050] In addition, in this specification, the "ring-shaped protrusion 112" is a structure provided at the peripheral portion of the placement surface 10x in the ceramic plate 11, and refers to the portion above the virtual surface S that contacts the bottom 11y located between the micro-protrusions 111. The virtual surface S is a surface that contacts the bottom 11y and extends in the X-axis direction. When the height positions of the bottom 11y are different at multiple locations (different positions in the Y-axis direction), for the Figure 2 , Figure 3 in the cross-section of the field of view, the average value of the height positions of the multiple bottoms 11y is obtained, and the surface that contacts the point of the obtained height position and extends in the X-axis direction is set as the virtual surface S.

[0051] In the electrostatic chuck member having micro-protrusions 111 on one main surface of the substrate, the virtual surface that contacts the top of each micro-protrusion 111 is set as the placement surface 10x. And when the so-set virtual surface is a concave surface or a convex surface, the least squares plane of the virtual surface is set as the placement surface 10x.

[0052] In the electrostatic chuck member 10, the electrode 13 is provided inside the substrate, but it is not limited to this. In the electrostatic chuck member, the electrode 13 can also be provided on the side opposite to the placement surface 10x.

[0053] In the electrostatic chuck member 10, a ceramic plate 11, an electrode 13, an insulating layer 15, and a ceramic plate 12 are stacked in sequence. That is, the electrostatic chuck member 10 is an assembly in which the ceramic plate 11 and the ceramic plate 12 are joined and integrated via the electrode 13 and the insulating layer 15. And the electrode 13 and the insulating layer 15 are provided in such a way as to contact the joint surface of the ceramic plate 11 facing the ceramic plate 12 and the joint surface of the ceramic plate 12 facing the ceramic plate 11.

[0054] (Ceramic plate)

[0055] The ceramic plates 11 and 12 have the same outer peripheral shape in plan view.

[0056] The ceramic plates 11 and 12 have the same composition or the same main components. The ceramic plates 11 and 12 can be made of an insulating material or a composite of an insulating material and a conductive material.

[0057] The insulating materials contained in the ceramic plates 11 and 12 are not particularly limited, but examples thereof include alumina (Al2O3), aluminum nitride (AlN), yttrium oxide (Y2O3), yttrium aluminum garnet (YAG), etc. Among them, Al2O3 and AlN are preferred.

[0058] The conductive materials contained in the ceramic plates 11 and 12 are not particularly limited, but examples thereof include silicon carbide (SiC), titanium oxide (TiO2), titanium nitride (TiN), titanium carbide (TiC), carbon materials, rare earth oxides, rare earth fluorides, etc. As the carbon materials, carbon nanotubes (CNT) and carbon nanofibers can be cited. Among them, SiC is preferred.

[0059] Regarding the materials of the ceramic plates 11 and 12, as long as the volume resistivity is 10 13 Ω·cm or more and 10 17 Ω·cm or less, and has mechanical strength, and is a material resistant to corrosive gases and their plasmas, there is no particular limitation. As such materials, for example, Al2O3 sintered bodies, AlN sintered bodies, Al2O3-SiC composite sintered bodies, etc. can be cited. From the viewpoints of dielectric properties at high temperatures, high corrosion resistance, plasma resistance, and heat resistance, the materials of the ceramic plates 11 and 12 are preferably Al2O3-SiC composite sintered bodies.

[0060] The average primary particle size of the insulating materials constituting the ceramic plates 11 and 12 is preferably 0.5 μm or more and 3.0 μm or less, more preferably 0.7 μm or more and 2.0 μm or less, and further preferably 1.0 μm or more and 2.0 μm or less.

[0061] If the average primary particle size of the insulating materials constituting the ceramic plates 11 and 12 is 0.5 μm or more and 3.0 μm or less, dense ceramic plates 11 and 12 with high withstand voltage and high durability can be obtained.

[0062] The measuring method of the average primary particle size of the insulating materials constituting the ceramic plates 11 and 12 is as follows. The cut surface in the thickness direction of the ceramic plates 11 and 12 is observed by magnifying 10,000 times with a field emission scanning electron microscope (FE-SEM, manufactured by JEOL Ltd., JSM-7800F-Prime), and the average of the particle sizes of 200 insulating materials is set as the average primary particle size by the intercept method.

[0063] (Electrostatic adsorption electrode)

[0064] The electrode 13 is used to generate charges and fix the plate-shaped specimen by means of electrostatic adsorption force. The electrode 13 is a thin electrode that has a greater breadth in a direction orthogonal to the thickness direction compared to the thickness direction. Such an electrode 13 is formed by coating a slurry for forming an electrode layer and sintering it. The thickness of the obtained electrode 13 can be controlled as follows: By conducting preliminary experiments, the correspondence between the coating thickness of the slurry for forming an electrode layer and the thickness of the obtained electrode 13 is obtained in advance, and thus the coating thickness of the slurry for forming an electrode layer is adjusted.

[0065] The electrode 13 is composed of a sintered body of particles of a conductive material or a composite body (sintered body) of particles of an insulating ceramic and particles of a conductive material.

[0066] When the electrode 13 is composed of an insulating ceramic and a conductive material, the volume resistivity of these mixed materials is preferably 10 -6 Ω·cm or more and 10 -2 Ω·cm or less approximately.

[0067] When the electrode 13 is composed of a composite body of an insulating ceramic and a conductive material, in the electrode 13, the content of the conductive material is preferably 15% by mass or more and 100% by mass or less, more preferably 20% by mass or more and 100% by mass or less. If the content of the conductive material is above the above lower limit value, sufficient dielectric properties can be exhibited to the ceramic plate 12.

[0068] The conductive material contained in the electrode 13 can be a conductive ceramic, or a conductive material such as a metal or a carbon material. The conductive material contained in the electrode 13 is preferably at least one selected from the group consisting of SiC, TiO2, TiN, TiC, tungsten (W), tungsten carbide (WC), molybdenum (Mo), molybdenum carbide (Mo2C), tantalum (Ta), tantalum carbide (TaC, Ta4C5), carbon materials, and conductive composite sintered bodies.

[0069] Examples of the carbon material include carbon black, carbon nanotubes, carbon nanofibers, etc.

[0070] Examples of the conductive composite sintered body include Al2O3-Ta4C5, Al2O3-W, Al2O3-SiC, AlN-W, AlN-Ta, etc.

[0071] By the conductive material contained in the electrode 13 being at least one selected from the group consisting of the above substances, the conductivity of the electrode can be ensured.

[0072] The insulating ceramic contained in the electrode 13 is not particularly limited. For example, it is preferably at least one selected from the group consisting of Al2O3, AlN, silicon nitride (Si3N4), Y2O3, YAG, samarium-aluminum oxide (SmAlO3), magnesium oxide (MgO), and silicon dioxide (SiO2).

[0073] Since the electrode 13 is formed of a conductive material and an insulating material, the bonding strength between the ceramic plates 11 and 12 and the electrode 13 is improved. Also, since the electrode 13 is formed of a conductive material and an insulating material, the mechanical strength as an electrode becomes stronger.

[0074] When the insulating material contained in the electrode 13 is Al2O3, the dielectric properties, high corrosion resistance, plasma resistance, and heat resistance at high temperatures can be maintained.

[0075] The ratio (mixing ratio) of the content of the conductive material and the insulating material in the electrode 13 is not particularly limited and can be appropriately adjusted according to the use of the electrostatic chuck member 10.

[0076] The outer edge 13x of the electrode 13 overlaps with the annular protrusion 112 in a plan view. As Figure 2 shown, in the electrostatic chuck member 10, the outer edge 13x is located at a position outside the center (indicated by the reference numeral M) in the width direction (X direction) of the annular protrusion 112.

[0077] (Insulating layer)

[0078] The insulating layer 15 is a structure provided to bond the ceramic plates 11 and 12 to each other between the ceramic plates 11 and 12 and at positions other than the portion where the electrode 13 is formed. The insulating layer 15 is disposed around the electrode 13 between the ceramic plates 11 and 12 (between a pair of ceramic plates) in a plan view.

[0079] The shape of the insulating layer 15 (the shape when the insulating layer 15 is viewed from above) is not particularly limited and can be appropriately adjusted according to the shape of the electrode 13. The thickness (width in the Y direction) of the insulating layer 15 is equal to the thickness of the electrode 13.

[0080] The insulating layer 15 may be composed of an insulating material or a composite of an insulating material and a conductive material. The volume resistivity of the insulating layer 15 is 10 13 Ω·cm or more and 10 17 Ω·cm or less.

[0081] The insulating material forming the insulating layer 15 is not particularly limited, but is preferably the same as the main components of the ceramic plates 11 and 12. The insulating material forming the insulating layer 15 is preferably, for example, at least one selected from the group consisting of Al2O3, AlN, Si3N4, Y2O3, YAG, SmAlO3, MgO, and SiO2. The insulating material forming the insulating layer 15 is preferably Al2O3. By using Al2O3 as the insulating material forming the insulating layer 15, the dielectric properties, high corrosion resistance, plasma resistance, and heat resistance at high temperatures can be maintained.

[0082] The conductive material forming the insulating layer 15 is not particularly limited, but is preferably the same as the main components of the ceramic plates 11 and 12. The conductive material forming the insulating layer 15 is preferably, for example, at least one selected from the group consisting of SiC, TiO2, TiN, TiC, W, WC, Mo, Mo2C, and carbon materials. As the carbon materials, for example, carbon nanotubes, carbon nanofibers, etc. can be cited. The conductive material forming the insulating layer 15 is preferably SiC.

[0083] In the insulating layer 15, the content of the insulating material is preferably 80% by mass or more and 96% by mass or less, more preferably 80% by mass or more and 95% by mass or less, and further preferably 85% by mass or more and 95% by mass or less. If the content of the insulating material is at least the above lower limit value, sufficient withstand voltage can be obtained. If the content of the insulating material is at most the above upper limit value, the charge removal effect of the conductive material contained in the insulating layer 15 can be sufficiently exhibited.

[0084] In the insulating layer 15, the content of the conductive material is preferably 4% by mass or more and 20% by mass or less, more preferably 5% by mass or more and 20% by mass or less, and further preferably 5% by mass or more and 15% by mass or less. If the content of the conductive material is at least the above lower limit value, the charge removal effect of the conductive material can be sufficiently exhibited. If the content of the conductive material is at most the above upper limit value, sufficient withstand voltage can be obtained.

[0085] The average primary particle diameter of the insulating material forming the insulating layer 15 is preferably 0.5 μm or more and 3.0 μm or less, more preferably 0.7 μm or more and 2.0 μm or less.

[0086] If the average primary particle diameter of the insulating material forming the insulating layer 15 is 0.5 μm or more, sufficient withstand voltage can be obtained. On the other hand, if the average primary particle diameter of the insulating material forming the insulating layer 15 is 3.0 μm or less, processing such as grinding is easy.

[0087] The average primary particle diameter of the conductive material forming the insulating layer 15 is preferably 0.1 μm or more and 1.0 μm or less, more preferably 0.1 μm or more and 0.8 μm or less.

[0088] If the average primary particle diameter of the conductive material constituting the insulating layer 15 is 0.1 μm or more, sufficient withstand voltage can be obtained. On the other hand, if the average primary particle diameter of the conductive material constituting the insulating layer 15 is 1.0 μm or less, processing such as grinding is easy.

[0089] The method for measuring the average primary particle diameter of the insulating material and the conductive material constituting the insulating layer 15 is the same as the method for measuring the average primary particle diameter of the insulating material and the conductive material constituting the ceramic plates 11 and 12.

[0090] The insulating layer 15 can be provided separately from the ceramic plates 11 and 12, or can have a structure in which it is formed integrally with either one of the ceramic plates 11 and 12 and then joined to the other ceramic plate.

[0091] In this specification, the so-called "formed integrally" means formed as one part (being one part). In this sense, the structure of "formed integrally with either one of the ceramic plates 11 and 12" is different from, for example, a structure in which the ceramic plate 11 and the insulating layer 15, which were originally two parts, are "integrated" into one. The part in which the ceramic plate and the insulating layer are formed integrally can be formed by, for example, performing recess processing on one surface of the ceramic plate (the ceramic plate without recesses) used as the material by grinding or polishing.

[0092] Moreover, the insulating layer 15 can also have a structure in which it is formed integrally with both of the ceramic plates 11 and 12.

[0093] The electrostatic chuck member in which both of the ceramic plates 11 and 12 are formed integrally with the insulating layer can be formed by the following method.

[0094] For example, using raw material powders of inorganic particles (for example, alumina powder or SiC powder) that are raw materials of the ceramic plates, a green compact before sintering having the same shape as the ceramic plates 11 and 12 is formed. After screen-printing a conductive paste on one surface of the obtained green compact, another green compact is overlapped to form a laminate. Then, by subjecting the laminate to hot press sintering, an electrostatic chuck member in which both of the ceramic plates 11 and 12 are formed integrally with the insulating layer can be obtained.

[0095] The above-mentioned green compact can be formed by press molding or by flowing a slurry of the raw material powder into a molding die, or can be formed by laminating green sheets after forming a thin green sheet using the raw material powder of the inorganic particles.

[0096] The thickness of the obtained electrode 13 can be controlled as follows: By previously obtaining the correspondence between the coating thickness of the slurry for forming the electrode layer and the thickness of the obtained electrode 13 through preliminary experiments, the coating thickness of the slurry for forming the electrode layer is adjusted.

[0097] (Shape of the electrostatic chuck component)

[0098] Next, use Figure 2 and Figure 3 to describe the shape of the electrostatic chuck component 10. In the following description, the thickness of the ceramic plate 11 is set as "thickness T1", the thickness of the ceramic plate 12 is set as "thickness T2", and the thickness of the electrode 13 is set as "thickness T3". Moreover, the distance in the X direction from the outer edge 13x of the electrode 13 to the side peripheral surface 10y is set as "width L1", and the distance in the X direction of the annular protrusion 112 is set as "width L2".

[0099] The thickness T1 of the ceramic plate 11 and the thickness T2 of the ceramic plate 12 can be appropriately set according to the performance of the electrostatic chuck device or semiconductor manufacturing device using the electrostatic chuck component 10. As an example, the thickness T1 is preferably 100 μm or more and 900 μm or less, more preferably 400 μm or more and 600 μm or less. And the thickness T2 varies greatly depending on the presence or absence of additional internal electrodes or heaters formed on the lower ceramic plate, and 0.9 mm or more and 4 mm or less are selected, but are not limited to these.

[0100] The thickness T3 of the electrode 13 can be appropriately set according to the performance of the electrostatic chuck device or semiconductor manufacturing device using the electrostatic chuck component 10. As an example, the thickness T3 is preferably 5 μm or more and 40 μm or less, more preferably 10 μm or more and 20 μm or less.

[0101] The width L1 is preferably 500 μm or more and 2000 μm or less. And the width L2 of the annular protrusion 112 is preferably 500 μm or more and 3500 μm or less.

[0102] In order to effectively obtain the adsorption force of the wafer adsorbed on the annular protrusion 112, the width L1 can satisfy L1 < L2. For example, when the width L2 is 3500 μm, the width L1 can be set to 1800 μm, and when the width L2 is 2000 μm, the width L1 can be set to 700 μm.

[0103] On the side peripheral surface 10y of the base body of the electrostatic chuck component 10 that is continuous with the placement surface 10x, there are at least a first curved surface CS1 provided circumferentially along the peripheral edge of the placement surface 10x and a second curved surface CS2 provided circumferentially at a height position different from the first curved surface CS1. Both the first curved surface CS1 and the second curved surface CS2 of the electrostatic chuck component 10 are convex curved surfaces.

[0104] And at least a part of the first curved surface CS1 is provided on the annular protrusion 112. In other words, at least a part of the first curved surface CS1 is provided on the outer peripheral side of the annular protrusion 112.

[0105] Further, on the side circumferential surface 10y of the electrostatic chuck member 10, between the first curved surface CS1 and the second curved surface CS2 is an inclined surface 10a that is exposed to the field of view in the direction of the mounting surface 10x. That is, the side circumferential surface 10y includes the first curved surface CS1, the inclined surface 10a, and the second curved surface CS2 in order from the mounting surface 10x side.

[0106] In this specification, the so-called "convex curved surface" refers to a curved surface in the side circumferential surface that protrudes in the +y direction in a cross-sectional view.

[0107] On the other hand, the so-called "inclined surface" refers to a surface in the side circumferential surface that has a constant inclination in a cross-sectional view.

[0108] The inclined surface 10a is a surface obtained by linearly chamfering the corner along the virtual surface S1 and the virtual surface S2. Moreover, at both ends of the inclined surface 10a in the field of view, the two new corners generated by the chamfering are processed into the first curved surface CS1 and the second curved surface CS2, which are convex curved surfaces (convex surfaces) protruding outward. Figure 2 At both ends of the inclined surface 10a in the field of view, the two new corners generated by the chamfering are processed into the first curved surface CS1 and the second curved surface CS2, which are convex curved surfaces (convex surfaces) protruding outward.

[0109] The radius of curvature r1 of the first curved surface CS1 and the radius of curvature r2 of the second curved surface CS2 are preferably each equal to or greater than the thickness T3 of the electrode 13. By making the radii of curvature of the first curved surface CS1 and the second curved surface CS2 greater than the thickness T3 of the electrode 13, it is possible to suppress the concentration of the electric field on the first curved surface CS1 and the second curved surface CS2 during plasma processing, and it is possible to suppress the concentrated adhesion of charged foreign particles at specific portions (for example, corners).

[0110] In addition, the radii of curvature of the first curved surface CS1 and the second curved surface CS2 are related to the shape formed as a result of polishing and grinding the base of the electrostatic chuck member 10. Among the conductive material and the insulating material constituting the base, even if there are particles having a particle diameter larger than the radii of curvature of the first curved surface CS1 and the second curved surface CS2, and the particles are disposed on the first curved surface CS1 or the second curved surface CS2, the shape or particle diameter of these particles will change due to polishing and grinding. Therefore, the radii of curvature of the first curved surface CS1 and the second curved surface CS2 do not depend on the particle diameter of the base material.

[0111] The radius of curvature r1 of the first curved surface CS1 and the radius of curvature r2 of the second curved surface CS2 are obtained by the following method.

[0112] First, for the part (convex curved surface) of the electrostatic chuck member to be measured, when assuming the smallest circle among the circles circumscribing the electrostatic chuck member in a top view, it is cut using a virtual plane perpendicular to the mounting surface and including the center of the circle. The cross-section can be ground using a grindstone of 1000 or more.

[0113] Next, a magnified photograph of the obtained cross-section is taken. The magnification factor is set according to the size of the convex curved surface to be measured by observing it with a stereoscope. The magnification factor is a multiple that enables the appropriate measurement of the radius of curvature from the obtained photograph and is appropriately selected from the range of 40 to 200 times, for example.

[0114] Measure the radii of curvature r1 and r2 of the convex curved surface based on the obtained magnified photograph.

[0115] The above measurement method is also used in the same way when measuring the radius of curvature of the concave curved surface described later.

[0116] The electrostatic chuck member 10 can form the first curved surface CS1 and the second curved surface CS2 in a part of the circumferential direction of the side circumferential surface 10y, or can form the first curved surface CS1 and the second curved surface CS2 in the entire circumferential direction. Moreover, the curvatures of the first curved surface CS1 and the second curved surface CS2 can be constant in the circumferential direction or different in the circumferential direction.

[0117] It is considered that the amount of charged foreign particles attached to the side circumferential surface 10y increases as the electrode 13 is enlarged and the distance (width L1) in the X direction from the outer edge 13x of the electrode 13 to the side circumferential surface 10y becomes shorter. Due to the enlargement of the electrode 13 in recent years, it is required to set the width L1 to 1 mm or less (1000 μm or less).

[0118] Moreover, the distance (width L1) from the outer edge 13x to the side circumferential surface 10y is preferably equal to or greater than the distance from the upper surface of the electrode 13 to the mounting surface 10x (thickness T1 of the ceramic plate 11) (T1 ≤ L1). Thereby, dielectric breakdown on the side of the side circumferential surface 10y can be suppressed.

[0119] At this time, in relation to the thickness T1 of the ceramic plate 11, it is required to set the width L1 to 2 times or less of the thickness T1 (L1 / T1 ≤ 2). Thus, by making the width L1 smaller, charged foreign particles are likely to adhere to the side circumferential surface 10y.

[0120] From this point of view, the inventors et al. have studied the structure of the electrostatic chuck member, and as a result, it is considered that by adopting a structure that suppresses the concentration of the electrostatic field that is the cause of the attachment of charged foreign particles, the attachment of charged foreign particles to the side circumferential surface 10y can be suppressed.

[0121] Conventional electrostatic chuck components have corners formed at the upper part of their side circumferential surfaces. Moreover, as in the electrostatic chuck component described in Patent Document 1, when chamfering the upper part of the side circumferential surface, two corners are formed on the side circumferential surface. Such corners have points (vertices) where two straight lines (surfaces of the faces) come into contact when observed in cross-section. On the other hand, the electrostatic field for adsorbing a plate-like specimen tends to concentrate at the corners of the above-mentioned side circumferential surface, and charged foreign particles attracted by this electrostatic field also tend to adhere in large quantities and firmly within a narrow range around the corners of the side circumferential surface.

[0122] In contrast, if the corners are curved to become the first curved surface CS1 and the second curved surface CS2 as in the electrostatic chuck component 10, the above-mentioned electrostatic field is dispersed on the first curved surface CS1 and the second curved surface CS2 and is less likely to concentrate at a specific part. As a result, the attachment sites of the charged foreign particles are dispersed, and the number of charged foreign particles per unit surface area decreases, and as a result, abnormal discharge is easily suppressed.

[0123] Moreover, if the corners are curved, the areas of the formed first curved surface CS1 and second curved surface CS2 are smaller than the area of the surface formed by extending from the end of the mounting surface 10x along the virtual surface S1 and the virtual surface S2 to the lower end of the second curved surface CS2 (that is, the surface that existed when the corners were not curved). As described above, charged foreign particles tend to adhere to the corners of the electrostatic chuck component. As a result, if the corners are curved, the surface area of the part where the charged foreign particles can adhere can be reduced, and thus it is suitable as a structure for suppressing abnormal discharge.

[0124] Furthermore, a third curved surface CS3 is provided on the inner circumferential side of the annular protrusion 112, and the third curved surface CS3 is a convex curved surface provided along the circumferential direction of the annular protrusion 112.

[0125] In the electrostatic chuck component 10, the outer edge 13x of the electrode 13 overlaps the annular protrusion 112 in a plane. And when a voltage is applied to the electrode 13 during plasma processing, the electric field tends to concentrate at the outer edge 13x of the electrode 13. Therefore, if the annular protrusion 112 has a corner, the electric field concentrated at the outer edge 13x during plasma processing is first likely to concentrate at the corner of the annular protrusion 112, and thus charged foreign particles are likely to adhere to the corner.

[0126] In contrast, the annular protrusion 112 not only has the first curved surface CS1 provided on the outer circumferential side, but also has the third curved surface CS3 as a convex curved surface provided on the inner circumferential side, thus removing the corners where the electric field is likely to concentrate. Therefore, during plasma processing, it is possible to suppress the concentration and fixation of charged foreign particles on the annular protrusion 112.

[0127] Moreover, as Figure 2As shown, when the outer edge 13x is located at a position outside the center in the width direction of the annular protrusion 112, the radius of curvature r1 of the first curved surface CS1 can be greater than the radius of curvature r3 of the third curved surface CS3.

[0128] If the outer edge 13x is located outside, the distance W1 from the outer edge 13x to the first curved surface CS1 is shorter than the distance W3 from the outer edge 13x to the third curved surface CS3. At this time, if the first curved surface CS1 and the third curved surface CS3 are compared, a stronger electric field is concentrated on the first curved surface CS1 than on the third curved surface CS3. Therefore, by making the radius of curvature r1 greater than the radius of curvature r3, the electric field can be easily dispersed in the first curved surface CS1, and thus the concentrated adhesion of charged foreign particles can be effectively suppressed.

[0129] Moreover, the first curved surface CS1 can be provided so as to straddle the ceramic plate 11 located below the annular protrusion 112 from the annular protrusion 112. At this time, the radius of curvature r1 is greater than the height H of the annular protrusion 112. At this time, it is preferably easy to configure the radius of curvature r1 to be greater than the radius of curvature r3.

[0130] The radius of curvature r1 of the first curved surface CS1 and the radius of curvature r3 of the third curved surface CS3 are preferably each equal to or greater than the thickness T3 of the electrode 13 (satisfying the following formulas (A1) and (A2)).

[0131] [Thickness T3 of the electrostatic adsorption electrode] ≤ [Radius of curvature r1 of the first curved surface CS1]…(A1)

[0132] [Thickness T3 of the electrostatic adsorption electrode] ≤ [Radius of curvature r3 of the third curved surface CS3]…(A2)

[0133] The radius of curvature r3 of the third curved surface CS3 is preferably equal to or greater than the thickness T3 of the electrode 13. By making the radius of curvature r3 greater than the thickness T3, the concentration of the electric field on the third curved surface CS3 can be suppressed during plasma processing, and the concentrated adhesion of charged foreign particles can be suppressed.

[0134] In addition, the radius of curvature of the third curved surface CS3, similar to the radii of curvature of the first curved surface CS1 and the second curved surface CS2, does not depend on the particle size of the base material.

[0135] The radius of curvature r3 of the third curved surface CS3 is obtained by the same method as the radii of curvature of the first curved surface CS1 and the second curved surface CS2.

[0136] In the electrostatic chuck member 10, the third curved surface CS3 can be formed in a part in the circumferential direction on the inner circumferential side of the annular protrusion 112, or can be formed in the entire circumferential direction. Moreover, the radius of curvature of the third curved surface CS3 can be constant in the circumferential direction or different in the circumferential direction.

[0137] In addition, when the outer edge 13x is located at the center in the width direction of the annular protrusion 112, the radius of curvature r1 of the first curved surface CS1 can be made to coincide with the radius of curvature r3 of the third curved surface CS3.

[0138] (Surface roughness)

[0139] Preferably, the arithmetic mean roughness Ra of the first curved surface CS1, the second curved surface CS2, and the third curved surface CS3 is 2 μm or less. By setting the arithmetic mean roughness Ra of the first curved surface CS1, the second curved surface CS2, and the third curved surface CS3 to 2 μm or less, it is possible to reduce the charged foreign particles adhering to the first curved surface CS1, the second curved surface CS2, and the third curved surface CS3, and thus it is possible to effectively suppress the above-mentioned adverse conditions.

[0140] The arithmetic mean roughness Ra can be measured using a surface roughness and profile shape measuring machine (SURFCOM NEX200, manufactured by TOKYO SEIMITSU CO., LTD.). Specifically, for the first curved surface CS1 and the second curved surface CS2, when looking down at the electrostatic chuck member 10, the same measurement is performed at four locations every 90° in the circumferential direction. For the measured values of the arithmetic mean roughness Ra respectively obtained at the four locations in the circumferential direction, the average value is calculated and used as the arithmetic mean roughness Ra.

[0141] In the electrostatic chuck members used in conventional electrostatic chuck devices, the Ra of the mounting surface is sometimes mirror-polished to about 0.05 μm, preferably about 0.01 to 0.02 μm. When there are minute protrusions provided on the mounting surface of the electrostatic chuck member, the Ra at the tip of the minute protrusions sometimes satisfies the above-mentioned Ra.

[0142] On the other hand, in conventional electrostatic chuck members, the Ra of the side peripheral surface is finished to be rougher than the mounting surface and is finished with a surface accuracy of about 3 to 4 μm in Ra. The reason for this is that when manufacturing the electrostatic chuck member, attention is paid to the processing accuracy of the mounting surface in direct contact with the wafer, and the side peripheral surface on which the plate-like specimen is not mounted is not paid attention to. Therefore, in conventional electrostatic chuck members, based on considerations of production efficiency, only the necessary minimum amount of polishing is performed on the side peripheral surface. However, the inventors obtained the following idea: when the surface accuracy of the side peripheral surface is about 3 to 4 μm in Ra, the surface area on which charged foreign particles can adhere is very wide, and it is easy to further adsorb charged foreign particles through the internal electrode close to the side peripheral surface, and it is easy for a large amount of charged foreign particles to stay.

[0143] Therefore, a simple and effective method is devised as follows: in the electrostatic chuck member 10, the Ra of the first curved surface CS1 and the second curved surface CS2 of the side peripheral surface 10y is set to 2 μm or less, which is smoother than before, to form a structure that reduces the surface area for adsorbing charged foreign particles, and the Ra of the side peripheral surface 10y is halved compared to before. Thus, the charged foreign particles attached and retained on the side peripheral surface can be significantly reduced to less than half compared to before.

[0144] Generally, it is assumed that charged foreign particles repeatedly adsorb to and desorb from the surface of the electrostatic chuck member in the wafer process. Here, it is assumed that if the amount of attachment per unit surface area of the charged foreign particles increases, the charged foreign particles adsorb to the surface of the electrostatic chuck member in the form of aggregates formed by multiple particles and desorb from the surface. It is considered that in the case where such aggregates adsorb to and desorb from the surface of the electrostatic chuck member, "abnormal discharge" that first damages the plasma stability and causes a reduction in the yield of the manufactured components occurs.

[0145] That is, in a semiconductor manufacturing apparatus, when charged foreign particles attach to the side peripheral surface of the electrostatic chuck member in the wafer process, abnormal discharge does not occur at all until the amount of attachment per unit surface area of the charged foreign particles increases to the extent of forming the above-mentioned aggregates, and abnormal discharge occurs only when it exceeds the threshold for forming the above-mentioned aggregates. In this case, if the amount of attachment of the charged foreign particles is reduced, for example, reduced below the threshold, the amount of abnormal discharge can be significantly suppressed, and high effects can be expected. The "threshold" is affected by various conditions such as the structure of the semiconductor manufacturing apparatus, the type of wafer, and the wafer process conditions.

[0146] That is, it is considered that the relationship between the amount of attachment of charged foreign particles and the number of abnormal discharges is not a linear relationship but a corresponding relationship with a threshold. Therefore, the concept of the inventors et al. is attributed to the following: by a simple method of halving the Ra of the side peripheral surface 10y compared to before, it is expected to significantly suppress the occurrence of abnormal discharge.

[0147] The Ra of the first curved surface CS1 and the second curved surface CS2 is preferably 1.5 μm or less, more preferably 1.0 μm or less, further preferably 0.05 μm or less, and particularly preferably 0.01 - 0.02 μm.

[0148] By making the radii of curvature of the first curved surface CS1 and the second curved surface CS2 of the side peripheral surface 10y larger than the thickness of the electrode 13, it is possible to suppress the attachment of charged foreign particles wider than the thickness of the electrode 13 on the side peripheral surface 10y. Therefore, microdischarge caused by charged foreign particles can be suppressed on the side peripheral surface 10y, and thus dielectric breakdown on the side peripheral surface 10y can be suppressed.

[0149] Method for Manufacturing an Electrostatic Chuck Member

[0150] Figure 4 This is an explanatory diagram showing an example of a method for manufacturing the above-described electrostatic chuck member. The electrostatic chuck member 10 can be manufactured through the following processes: First, a disk-shaped sintered body having ceramic plates 11, 12, electrodes 13, an insulating layer 15 and unprocessed first curved surface CS1 and second curved surface CS2 is obtained (process of obtaining the sintered body), and the side peripheral surface of the obtained sintered body is ground using a rotary grinding stone (grinding process).

[0151] At this time, the cross-section of the rotary grinding stone G including the rotation axis L of the rotary grinding stone G has a shape complementary to the shapes of the first curved surface CS1, the second curved surface CS2, and the inclined surface 10a of the cross-section of the field of view of Figure 2 , Figure 3 . In the rotary grinding stone G, the radius of curvature of the portion corresponding to the first curved surface CS1 is the same as the radius of curvature of the first curved surface CS1, which is r1. Also, the radius of curvature of the portion corresponding to the second curved surface CS2 is the same as the radius of curvature of the second curved surface CS2, which is r2. By grinding the peripheral portion of the mounting surface 10x using such a rotary grinding stone, it is possible to easily form the electrostatic chuck member 10 having the first curved surface CS1 and the second curved surface CS2.

[0152] By adopting such a manufacturing method, it is not necessary to change the fixing angle of the grinding stone according to the curved surface in order to form the first curved surface CS1 and the second curved surface CS2, and it is possible to easily manufacture the electrostatic chuck member having the first curved surface CS1 and the second curved surface CS2. Also, by precisely manufacturing the rotary grinding stone G, it is possible to manufacture the electrostatic chuck member 10 with high reproducibility.

[0153] In addition, in the above description, the rotary grinding stone G has a shape complementary to the first curved surface CS1 and the second curved surface CS2, but it is also possible to perform processing using a rotary grinding stone having a shape complementary to at least a part of either the first curved surface CS1 or the second curved surface CS2. And by performing processing using such a rotary grinding stone, it is possible to significantly reduce the replacement or angle adjustment of the grinding stone, thereby improving the production efficiency. Also, it is possible to suppress manufacturing deviations caused by the replacement or angle adjustment of the grinding stone.

[0154] Also, for the third curved surface CS3, it is also possible to form it by grinding using a rotary grinding stone in the same manner as the first curved surface CS1 and the second curved surface CS2. If necessary, it is also possible to further perform finish polishing using a brush or a polishing wheel.

[0155] According to the electrostatic chuck member 10 having the structure as described above, it is possible to reduce the problems (decrease in productivity, insulation breakdown) caused by the attachment of charged foreign particles to the side peripheral surface 10y.

[0156] In addition, in the present embodiment, the side peripheral surface 10y has two convex curved surfaces (first curved surface CS1, second curved surface CS2), but is not limited thereto. The side peripheral surface 10y may also have the following structure: in addition to having the convex curved surface (i.e., the first curved surface CS1) provided along the circumferential direction at the peripheral portion of the mounting surface 10x and the second curved surface CS2 provided along the circumferential direction at a height position different from that of the first curved surface CS1, it may also have convex curved surfaces (i.e., the third curved surface, the fourth curved surface,...) provided along the circumferential direction at height positions different from that of the first curved surface CS1.

[0157] [Second Embodiment]

[0158] Figure 5 FIG. 7 is an explanatory view of the electrostatic chuck member 20 according to the second embodiment. In the following embodiments, the same materials as those of the electrostatic chuck member 10 of the first embodiment can be used, and the shapes of the electrostatic chuck members are different. In the following embodiments, detailed descriptions of the same constituent elements as those of the first embodiment are omitted.

[0159] As Figure 5 shown, the electrostatic chuck member 20 includes a pair of ceramic plates 11 and 22, and an electrostatic adsorption electrode 23 and an insulating layer 25 interposed between the pair of ceramic plates 11 and 22. The structure formed by combining the pair of ceramic plates 11 and 22 and the insulating layer 25 corresponds to the substrate of the present invention.

[0160] The ceramic plate 11 is the same as the ceramic plate of the above-described electrostatic chuck member 10. At the upper end portion of the side peripheral surface 20y of the electrostatic chuck member 20, the first curved surface CS1, the inclined surface 20a, and the second curved surface CS2 are formed in the same manner as in the above-described electrostatic chuck member 10.

[0161] Moreover, the side peripheral surface 20y has a portion 20z extending outward at the lower end portion of the side peripheral surface 20y. The upper surface of this portion 20z is a concave curved surface CS0 provided along the circumferential direction of the electrostatic chuck member 20. That is, the side peripheral surface 20y is formed by the first curved surface CS1, the inclined surface 20a, the second curved surface CS2 at the upper end side, the concave curved surface CS0 at the lower end side, and the main surface 20b connecting the second curved surface CS2 and the concave curved surface CS0. The main surface 20b is a surface extending in the Y direction.

[0162] The electrostatic chuck member 20 may form the first curved surface CS1 and the second curved surface CS2 at a part in the circumferential direction of the side peripheral surface 20y, or may form the first curved surface CS1 and the second curved surface CS2 over the entire circumference. Moreover, the curvatures of the first curved surface CS1 and the second curved surface CS2 may be constant in the circumferential direction, or may be different in the circumferential direction.

[0163] Further, the electrostatic chuck member 30 may form a concave curved surface CS0 in a part in the circumferential direction of the side circumferential surface 30y, or may form a concave curved surface CS0 in the entire circumferential direction. Further, the radius of curvature of the concave curved surface CS0 may be constant in the circumferential direction or may be different in the circumferential direction.

[0164] Generally, it is known that the lower part of the side circumferential surface of the electrostatic chuck member is difficult for plasma to reach during plasma cleaning, and even if charged foreign particles are attached, they are difficult to remove. In contrast, in the electrostatic chuck member 20, a concave curved surface CS0 is formed on the lower end side of the side circumferential surface 20y and is exposed to the field of view in a plan view. Thereby, the plasma cleaning of the lower end side of the side circumferential surface 20y becomes easy. And, the charged foreign particles detached from the side circumferential surface 20y by plasma cleaning will fly out in the Y direction, so they are not likely to float near the side circumferential surface 20y, thus easily suppressing reattachment.

[0165] The radius of curvature r0 of the concave curved surface CS0 is preferably equal to or greater than the thickness T3 of the electrode 23.

[0166] The radius of curvature r1 of the first curved surface CS1 and the radius of curvature r0 of the concave curved surface CS0 preferably have the relationship of the following formula (1).

[0167] [Radius of curvature r1 of the first curved surface CS1] < [Radius of curvature r0 of the concave curved surface CS0] … (1)

[0168] Further, the radius of curvature r2 of the second curved surface CS2 and the radius of curvature r0 of the concave curved surface CS0 preferably have the relationship of the following formula (2).

[0169] [Radius of curvature r2 of the second curved surface CS2] < [Radius of curvature r0 of the concave curved surface CS0] … (2)

[0170] In the side circumferential surface of a general electrostatic chuck member, abnormal discharge is likely to occur at the upper corner part where the attracting electric field is concentrated and charged foreign particles are concentrated in a narrow range, and at the lower corner part where the shielding property is high and charged foreign particles are likely to accumulate in large quantities. In the electrostatic chuck member 20, by setting the upper corner part as the first curved surface CS1 and the second curved surface CS2 and setting the lower corner part as the concave curved surface CS0, the accumulation of charged foreign particles is suppressed.

[0171] Here, if the first curved surface CS1 and the second curved surface CS2 are formed to be large, the placement surface 20x becomes relatively narrow, and the area of the plate-like specimen that can be placed becomes smaller.

[0172] On the other hand, for an electrostatic chuck member that satisfies the above (1) and (2), it is easy to balance ensuring the area of the placement surface 20x and suppressing abnormal discharge, so it is preferred.

[0173] Preferably, the arithmetic mean roughness Ra of the concave surface CS0 is 2 μm or less. By setting the arithmetic mean roughness Ra of the concave surface CS0 to 2 μm or less, two effects, namely the effect based on the concave surface CS0 and the effect based on improved surface accuracy, can be obtained, and the attachment of charged foreign particles can be effectively suppressed. Similarly to the above-described surface, the Ra of the concave surface CS0 is preferably 1.5 μm or less, more preferably 1.0 μm or less, further preferably 0.05 μm or less, and particularly preferably 0.01 to 0.02 μm.

[0174] In the direction orthogonal to the normal direction of the mounting surface 20x, the distance from the main surface 20b to the outer end of the concave surface CS0 (the width L3 of the portion 20z in the X direction) is preferably equal to or greater than the thickness T3 of the electrode 23.

[0175] According to the electrostatic chuck member 20 having the above-described structure, it is also possible to suppress the concentration of the electrostatic field by the functions of the first surface, the second surface, and the third surface, thereby suppressing the attachment of charged foreign particles, and reducing the problems (decrease in productivity, insulation breakdown) caused by the attachment of charged foreign particles to the side peripheral surface 20y.

[0176] In addition, in the present embodiment, the main surface 20b is set to a surface parallel to the Y direction, but it is not limited thereto. The main surface 20b may also be set to an inclined surface exposed in the top view.

[0177] [Third Embodiment]

[0178] Figure 6 It is an explanatory view of an electrostatic chuck member 30 according to the third embodiment. As Figure 6 shown, the electrostatic chuck member 30 includes a pair of ceramic plates 31, 32, and an electrostatic adsorption electrode 33 and an insulating layer 35 interposed between the pair of ceramic plates 31, 32. The structure formed by combining the pair of ceramic plates 31, 32 and the insulating layer 35 corresponds to the base body of the present invention.

[0179] The upper end portion of the side peripheral surface 30y of the electrostatic chuck member 30 is chamfered to form a first curved surface CS1 exposed in the view from the normal direction of the mounting surface 30x. The first curved surface CS1 is a convex surface.

[0180] The electrostatic chuck member 30 may form the first curved surface CS1 in a part in the circumferential direction of the side peripheral surface 30y, or may form the first curved surface CS1 in the entire circumferential direction. Further, the radius of curvature of the first curved surface CS1 may be constant in the circumferential direction or may be different in the circumferential direction.

[0181] Further, at the lower end of the side circumferential surface 30y, the side circumferential surface 30y has a portion 30z extending outward, similarly to the electrostatic chuck member 20 of the second embodiment. The upper surface of the portion 30z is a concave curved surface CS0 provided along the circumferential direction of the electrostatic chuck member 30. The concave curved surface CS0 corresponds to the "second curved surface" in the present invention.

[0182] The radius of curvature r1 of the first curved surface CS1, the radius of curvature r0 of the concave curved surface CS0, the thickness T3 of the electrode 33, and the thickness T2 of the ceramic plate 32 (the thickness of the substrate from the lower surface of the electrostatic adsorption electrode to the lower surface of the substrate) preferably have the relationship of the following formula (3).

[0183] [The thickness T3 of the electrode 33] < [The radius of curvature r1 of the first curved surface CS1] < [The radius of curvature r0 of the concave curved surface CS0] < [The thickness T2 of the ceramic plate 32]... (3)

[0184] First, as described above, if [The radius of curvature r1 of the first curved surface CS1] < [The radius of curvature r0 of the concave curved surface CS0] is satisfied, it is easy to balance ensuring the area of the placement surface 30x and suppressing abnormal discharge, so it is preferred.

[0185] Next, in the electrostatic chuck member where [The thickness T3 of the electrode 33] < [The radius of curvature r1 of the first curved surface CS1], the electric field concentrated at the corner of the upper part of the side circumferential surface in the conventional electrostatic chuck member (the electrostatic chuck member without the first curved surface CS1) can be dispersed more widely than the thickness of the electrode 33, thereby suppressing the accumulation of charged foreign particles.

[0186] Moreover, in the electrostatic chuck member where [The radius of curvature r0 of the concave curved surface CS0] < [The thickness T2 of the ceramic plate 32], the plan view area of the electrostatic chuck member does not become too large, and it is not easy to cause defects or cracks on the ceramic plate 32, so it is preferred.

[0187] It is preferred that the arithmetic mean roughness Ra of the first curved surface CS1 and the concave curved surface CS0 is 2 μm or less. The Ra of the first curved surface CS1 and the concave curved surface CS0 is preferably 1.5 μm or less, more preferably 0.05 μm or less, and further preferably 0.01 - 0.02 μm.

[0188] According to the electrostatic chuck member 30 having the structure as described above, it is also possible to reduce the problems (decrease in productivity, dielectric breakdown) caused by the attachment of charged foreign particles to the side circumferential surface 30y through the functions of the first curved surface, the second curved surface, and the third curved surface.

[0189] In addition, in the present embodiment, the main surface 30b is set as a surface parallel to the Y direction, but it is not limited thereto. The main surface can also be set as an inclined surface exposed in the plan view.

[0190] Figure 7 It is an explanatory diagram of an electrostatic chuck member 40 according to a modified example of the third embodiment. As Figure 7 shown, the electrostatic chuck member 40 includes a pair of ceramic plates 41 and 42, and an electrostatic adsorption electrode 43 and an insulating layer 45 interposed between the pair of ceramic plates 41 and 42. The structure formed by combining the pair of ceramic plates 41 and 42 and the insulating layer 45 corresponds to the substrate of the present invention.

[0191] The side circumferential surface 40y has a first curved surface CS1 provided at the upper end and a concave curved surface CS0 provided at the lower end. The concave curved surface CS0 is provided in a portion 40z extending outward. The surface (main surface) 40b between the first curved surface CS1 and the concave curved surface CS0 is a continuous linear inclined surface.

[0192] The electrostatic chuck member 40 may have a part of the circumferential direction of the main surface 40b as an inclined surface, or the entire circumferential direction of the main surface 40b may be an inclined surface. Moreover, the inclination angle θ of the main surface 40b may be constant in the circumferential direction or may be different in the circumferential direction.

[0193] According to the electrostatic chuck member 40 having the above-described structure, it is also possible to suppress the concentration of the electrostatic field by the functions of the first curved surface, the second curved surface, and the third curved surface, thereby suppressing the adhesion of charged foreign particles, and reducing the problems (decrease in productivity, insulation breakdown) caused by the adhesion of charged foreign particles to the side circumferential surface 40y.

[0194] [Electrostatic chuck device]

[0195] Hereinafter, with reference to Figure 8 an example of an electrostatic chuck device according to an embodiment of the present invention will be described. In the following description, an electrostatic chuck device having the above-described electrostatic chuck member 10 will be described, but the electrostatic chuck device can also employ the above-described other electrostatic chuck members, respectively. In the following description, the same reference numerals are assigned to the same constituent elements as those in the first embodiment, and detailed descriptions thereof are omitted.

[0196] Figure 8 It is a cross-sectional view showing the electrostatic chuck device of the present embodiment. The electrostatic chuck device 100 has a disk-shaped electrostatic chuck member 10, a disk-shaped base member 103 that cools the electrostatic chuck member 10 and adjusts it to a desired temperature, and an adhesive layer 104 that joins and integrates these electrostatic chuck member 10 and base member 103.

[0197] In the following description, the side of the electrostatic chuck member 10 may be referred to as "upper", and the side of the base member 103 may be referred to as "lower" to indicate the relative positions of the respective structures.

[0198] [Electrostatic chuck member]

[0199] The electrostatic chuck member 10 includes, in addition to the ceramic plates 11 and 12 , the electrode 13 and the insulating layer 15 , a power supply terminal 116 provided in a fixing hole 115 of the base member 103 so as to be in contact with the electrode 13 .

[0200] [Power supply terminal]

[0201] The power supply terminal 116 is a member for applying a voltage to the electrode 13 .

[0202] The number, shape, etc. of the power supply terminals 116 are determined according to the form of the electrode 13 , that is, whether it is a monopolar type or a bipolar type.

[0203] The material of the power supply terminal 116 is not particularly limited as long as it is a conductive material with excellent heat resistance. As the material of the power supply terminal 116, it is preferably a material having a thermal expansion coefficient close to that of the electrode 13 and the ceramic plate 12. For example, metal materials such as Kovar and niobium (Nb) and various conductive ceramics can be appropriately used.

[0204] [Conductive adhesive layer]

[0205] The conductive adhesive layer 117 is provided in the fixing hole 115 of the base member 103 and in the through hole 118 of the ceramic plate 12. The conductive adhesive layer 117 is interposed between the electrode 13 and the power supply terminal 116 to electrically connect the electrode 13 and the power supply terminal 116.

[0206] The conductive adhesive constituting the conductive adhesive layer 117 includes a conductive substance such as carbon fiber or metal powder, and a resin.

[0207] The resin contained in the conductive adhesive is not particularly limited as long as it is a resin that is unlikely to cause cohesive failure due to changes in thermal stress, and examples thereof include silicone resins, acrylic resins, epoxy resins, phenol resins, polyurethane resins, and unsaturated polyester resins.

[0208] Among these, silicone resins are preferred because they have high elasticity and are less likely to cause cohesive failure due to changes in thermal stress.

[0209] [Base parts]

[0210] The base member 103 is a thick disk-shaped member formed of at least one of metal and ceramic. The main body of the base member 103 is configured to serve as an internal electrode for plasma generation. A flow path 121 is formed inside the main body of the base member 103 to circulate a cooling medium such as water, He gas, or N2 gas.

[0211] The main body of the base member 103 is connected to an external high-frequency power supply 122. Further, within the fixing hole 115 of the base member 103, a power supply terminal 116 whose outer periphery is surrounded by an insulating material 123 is fixed via the insulating material 123. The power supply terminal 116 is connected to an external DC power supply 124.

[0212] The material constituting the base member 103 is not particularly limited as long as it is a metal having excellent thermal conductivity, electrical conductivity, and workability or a composite material containing these metals. As the material constituting the base member 103, for example, aluminum (Al), copper (Cu), stainless steel (SUS), titanium (Ti), etc. can be suitably used.

[0213] It is preferable to perform anodization or resin coating using a polyimide-based resin on at least the surface of the base member 103 that is exposed to the plasma. Further, it is more preferable to perform the anodization or resin coating on the entire surface of the base member 103.

[0214] By performing anodization or resin coating on the base member 103, the plasma resistance of the base member 103 is improved, and abnormal discharge can be prevented. Therefore, the plasma stability of the base member 103 is improved, and the occurrence of surface damage to the base member 103 can be prevented.

[0215] [Adhesive layer]

[0216] The adhesive layer 104 is structured to integrally bond the electrostatic chuck member 10 and the base member 103.

[0217] The thickness of the adhesive layer 104 is preferably 100 μm or more and 200 μm or less, and more preferably 130 μm or more and 170 μm or less.

[0218] If the thickness of the adhesive layer 104 is within the above range, the adhesive strength between the electrostatic chuck member 10 and the base member 103 can be sufficiently maintained. And the thermal conductivity between the electrostatic chuck member 10 and the base member 103 can be sufficiently ensured.

[0219] The adhesive layer 104 is formed, for example, of a cured product obtained by heating and curing a silicone-based resin composition, an acrylic resin, an epoxy resin, or the like.

[0220] The silicone-based resin composition is a silicon compound having a siloxane bond (Si-O-Si) and is a resin having excellent heat resistance and elasticity, and thus is more preferable.

[0221] As such a silicone-based resin composition, a silicone resin having a thermal curing temperature of 70°C to 140°C is particularly preferable.

[0222] Here, if the thermal curing temperature is lower than 70°C, when the electrostatic chuck member 10 and the base member 103 are joined in a facing state, since curing does not proceed sufficiently during the joining process and the workability is poor, it is not preferable. On the other hand, if the thermal curing temperature exceeds 140°C, the thermal expansion difference between the electrostatic chuck member 10 and the base member 103 is large, the stress between the electrostatic chuck member 10 and the base member 103 increases, and sometimes peeling occurs between them, so it is not preferable.

[0223] That is, if the thermal curing temperature is 70°C or higher, the workability is excellent during the joining process, and if the thermal curing temperature is 140°C or lower, it is difficult to peel between the electrostatic chuck member 10 and the base member 103, so it is preferable.

[0224] According to the electrostatic chuck device 100 of the present embodiment, since it has the above-described electrostatic chuck member 10, it is possible to suppress dielectric breakdown (discharge) on the side peripheral surface of the electrostatic chuck member.

[0225] In addition, the electrostatic chuck device 100 may have a focusing ring surrounding the electrostatic chuck member. In this case, the shape of the focusing ring may also be changed to a complementary shape according to the shape of the side peripheral surface of the electrostatic chuck member.

[0226] [Semiconductor manufacturing device]

[0227] Figure 9 It is an explanatory diagram showing an example of a semiconductor manufacturing device having the above-described electrostatic chuck device. The semiconductor manufacturing device 1000 includes an electrostatic chuck device 100, a vacuum chamber 200, an upper electrode 300, a magnet 400, a gas supply mechanism 500, a vacuum pump 600, and a plasma stabilization system 700.

[0228] The vacuum chamber 200 is used as a reaction field for accommodating the electrostatic chuck device 100 and performing plasma processing inside. The vacuum chamber 200 can adopt a known structure used in semiconductor manufacturing devices. The vacuum chamber 200 has a gate (not shown) for loading and unloading plate-shaped specimens.

[0229] The upper electrode 300 is a counter electrode that is accommodated in the vacuum chamber 200 and is used in cooperation with the electrostatic chuck device 100 when generating plasma in the vacuum chamber 200. The upper electrode 300 is connected to a power supply (not shown).

[0230] The magnet 400 is disposed around the vacuum chamber 200 and generates a longitudinal magnetic field in the space between the upper electrode 300 and the electrostatic chuck device 100 in the vacuum chamber 200.

[0231] The gas supply mechanism 500 supplies the plasma gas Gas into the vacuum chamber 200. The gas supply mechanism 500 supplies the plasma gas Gas into the vacuum chamber 200, for example, through the gas holes provided in the upper electrode 300.

[0232] The vacuum pump 600 discharges the gas in the vacuum chamber 200 to adjust the atmosphere for generating plasma. The vacuum pump 600 is connected, for example, to a position in the vacuum chamber 200 that is lower than the electrostatic chuck device 100.

[0233] The plasma stabilization system 700 detects and compensates for various external factors that change the state of the plasma generated in the semiconductor manufacturing apparatus 1000, thereby stabilizing the state of the plasma. The plasma stabilization system 700 includes a detector 710 and a control unit 720 that controls the semiconductor manufacturing apparatus 1000 based on the detection results detected by the detector 710.

[0234] The detector 710 directly or indirectly detects the state of the plasma in the vacuum chamber 200. The detector 710 can be one or more. Examples of the items detected by the detector 710 include, for example, the degree of vacuum in the vacuum chamber 200, the color of the plasma, the temperature of the plasma, the capacitance between the upper electrode 300 and the internal electrode (not shown) for plasma generation provided in the electrostatic chuck device 100, and the inductance between the upper electrode 300 and the internal electrode for plasma generation.

[0235] The control unit 720 controls the semiconductor manufacturing apparatus 1000 based on the detection values of the respective items detected by the detector 710 or the change amount per unit time of the detection values. The control unit 720 prestores the correspondence relationship between the detection values of the above items and the state of the plasma generated in the vacuum chamber 200. The control unit 720 performs feedback control on the semiconductor manufacturing apparatus 1000 based on the detection values and the above correspondence relationship so that the state of the plasma falls within a preset range. Examples of the items for feedback control include, for example, the temperature, the degree of vacuum, and the bias voltage inside the semiconductor manufacturing apparatus.

[0236] Thus, the plasma stabilization system 700 can suppress the long-term variation of the plasma state in the semiconductor manufacturing apparatus 1000, thereby stabilizing the state.

[0237] Such a plasma stabilization system is effective in suppressing the long-term variation of the plasma state of the entire manufacturing process using the semiconductor manufacturing apparatus. On the other hand, the plasma stabilization system has no effect of suppressing the state variation for the variation factors that occur in an extremely short time, such as abnormal discharge in the wafer process.

[0238] On the other hand, since the semiconductor manufacturing apparatus 1000 has the above-described electrostatic chuck device 100, abnormal discharge occurring in the wafer process can be suppressed. Therefore, the semiconductor manufacturing apparatus 1000 can stabilize the plasma both in the long term and in the short term by having the plasma stabilization system 700.

[0239] In addition, the control unit 720 may be an inherent structure of the plasma stabilization system 700, and a control device that controls the semiconductor manufacturing apparatus 1000 may also have this function.

[0240] In such a semiconductor manufacturing apparatus 1000, for example, depending on the position of the exhaust port of the vacuum chamber 200 (the connection position of the vacuum pump 600), the tendency of the attachment of charged foreign particles on the side peripheral surface of the electrostatic chuck member 10 may sometimes be different. In the case where the above tendency has been empirically determined for the semiconductor manufacturing apparatus 1000, the electrostatic chuck member 10 may adopt the following structure: by making the arithmetic mean roughness Ra of the side peripheral surface at the position where charged foreign particles are likely to attach smaller than that of other side peripheral surfaces, etc., the attachment of charged foreign particles is suppressed.

[0241] According to the semiconductor manufacturing apparatus 1000 of the present embodiment, since it has the above-described electrostatic chuck device 100, dielectric breakdown (discharge) can be suppressed.

[0242] Moreover, the semiconductor manufacturing apparatus 1000 can suppress abnormal discharge (short-term variation of plasma) through the electrostatic chuck device 100, and can suppress the long-term variation of plasma through the plasma stabilization system 700. Therefore, not only can stable plasma processing be performed, but also a semiconductor manufacturing apparatus with improved yield can be provided.

[0243] As described above, the preferred embodiments of the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to this example. The shapes or combinations of the respective components shown in the above example are merely examples, and various changes can be made within the scope of the gist of the present invention based on design requirements and the like. For example, materials, positions, ratios, amounts, types, numbers, sizes, values, etc. can be omitted, added, changed, replaced, exchanged, and other changes can be made. Between the embodiments, the preferred conditions or examples can be exchanged or shared with each other.

[0244] Moreover, in the above description, a silicon wafer has been described, but obviously, the wafers that can be processed by the electrostatic chuck member of the present invention can be not only silicon, but also indium phosphide-based, gallium arsenide-based, or other materials.

[0245] Industrial Applicability

[0246] The present invention provides an electrostatic chuck component, which can solve the problems caused by the attachment of charged foreign particles to the side surface, and in particular can reduce abnormal discharges occurring in the wafer process. Further provided is an electrostatic chuck device having such an electrostatic chuck component.

[0247] Description of Reference Numerals

[0248] 10, 20, 30, 40, 50 - Electrostatic chuck components

[0249] 10a, 20a - Inclined surfaces

[0250] 10x, 20x, 30x - Mounting surfaces

[0251] 10y, 20y, 30y, 40y - Side circumferential surfaces

[0252] 11, 12, 22, 31, 32, 41, 42 - Ceramic plates

[0253] 11x - Space

[0254] 11y - Bottom

[0255] 13, 23, 33, 43 - Electrodes (electrostatic adsorption electrodes)

[0256] 13x - Outer edge

[0257] 15, 25, 35, 45 - Insulating layers

[0258] 20b, 30b, 40b - Main surfaces

[0259] 20z, 30z, 40z - Parts

[0260] 100 - Electrostatic chuck device

[0261] 103 - Substrate component

[0262] 103a - Upper surface

[0263] 104 - Adhesive layer

[0264] 111 - Micro protrusions

[0265] 112 - Annular protrusion part

[0266] 115 - Fixing holes

[0267] 116 - Power supply terminals

[0268] 117 - Conductive adhesive layer

[0269] 118 - Through holes

[0270] 121 - Flow path

[0271] 122 - High - frequency power supply

[0272] 123 - Insulating material

[0273] 123 - DC power supply

[0274] 200 - Vacuum chamber

[0275] 300 - Upper electrode

[0276] 400 - Magnet

[0277] 500 - Gas supply mechanism

[0278] 600 - Vacuum pump

[0279] 700 - Plasma stabilization system

[0280] 710 - Detector

[0281] 720 - Control unit

[0282] 1000 - Semiconductor manufacturing apparatus

[0283] C - Center

[0284] CS1 - First curved surface

[0285] CS0 - Concave curved surface

[0286] CS2 - Second curved surface

[0287] CS3 - Third curved surface

[0288] G - Rotating magnet

[0289] L - Rotation axis

[0290] L1, L2, L3 - Width

[0291] H - Height

[0292] M - Center in the width direction

[0293] N - Normal

[0294] r1, r2, r3, r0 - Radius of curvature

[0295] S, S1, S2 - Virtual surface

[0296] T1, T2, T3 - Thickness

[0297] W1, W2, W3 - Distance

[0298] θ - Tilt angle.

Claims

1. An electrostatic chuck component, comprising: A base body having a mounting surface on one main surface for mounting a plate-like specimen; and An electrostatic adsorption electrode provided on the side opposite to the mounting surface or inside the base body, On the side peripheral surface of the base body continuous with the mounting surface, at least having: A first curved surface which is a convex curved surface provided along the circumferential direction at the peripheral edge of the mounting surface; and A second curved surface which is provided along the circumferential direction at a height position different from that of the first curved surface, The base body has an annular protrusion provided along the peripheral edge of the mounting surface, The outer edge of the electrostatic adsorption electrode overlaps with the annular protrusion in a top view, At least a part of the first curved surface is provided on the outer peripheral side of the annular protrusion, A third curved surface is provided on the inner peripheral side of the annular protrusion, and the third curved surface is a convex curved surface provided along the circumferential direction of the inner periphery.

2. The electrostatic chuck component according to claim 1, wherein In a top view, the outer edge is located at a position more on the outer peripheral side than the center in the width direction of the annular protrusion, The radius of curvature of the first curved surface is greater than the radius of curvature of the third curved surface.

3. The electrostatic chuck component according to claim 2, wherein The first curved surface is provided across the lower part of the annular protrusion in the base body from the annular protrusion.

4. The electrostatic chuck component according to claim 1, which satisfies the following formulas (A1) and (A2), [Thickness of the electrostatic adsorption electrode] ≤ [Radius of curvature of the first curved surface] … (A1) [Thickness of the electrostatic adsorption electrode] ≤ [Radius of curvature of the third curved surface] … (A2).

5. The electrostatic chuck component according to claim 1, wherein The distance from the outer edge to the side peripheral surface is equal to or greater than the distance from the upper surface of the electrostatic adsorption electrode to the mounting surface.

6. The electrostatic chuck component according to claim 1, wherein The distance from the outer edge to the side peripheral surface is equal to or greater than the distance from the upper surface of the electrostatic adsorption electrode to the mounting surface.

7. An electrostatic chuck device, comprising: The electrostatic chuck component according to any one of claims 1 to 6; and A base component for cooling the electrostatic chuck component and adjusting the temperature of the electrostatic chuck component.

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