JP2023128350A - Electrostatic chuck member and electrostatic chuck device - Google Patents

Abstract

To provide: an electrostatic chuck member capable of reducing problems caused by adhesion of charged foreign particles to its side surface; and an electrostatic chuck device having such an electrostatic chuck member.SOLUTION: An electrostatic chuck member has: a base whose one main surface is a mounting surface on which a plate sample is mounted; and an electrode for electrostatic adsorption disposed opposite the mounting surface or inside the base; where at least a portion of a side peripheral surface of the base that is continuous with the mounting surface has an arithmetic mean roughness Ra of 2 μm or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electrostatic chuck member and an electrostatic chuck device.

Conventionally, in the semiconductor manufacturing process of manufacturing semiconductor devices such as IC, LSI, VLSI, etc., a plate-shaped sample such as a silicon wafer is fixed by electrostatic adsorption to an electrostatic chuck member with an electrostatic chuck function and subjected to a predetermined process. will be applied. In such a process, for example, after a silicon wafer is fixed using an electrostatic chuck device, the silicon wafer is subjected to an etching process or a film forming process using plasma.

When an electrostatic chuck device is used in the manufacturing process as described above, particulate foreign matter (hereinafter referred to as foreign matter particles), typified by wafer residue, may be generated in the electrostatic chuck member. Such foreign particles are charged within the semiconductor manufacturing equipment and adhere to the surface of the electrostatic chuck device. In an electrostatic chuck device to which charged foreign particles (chargeable foreign particles) are attached, plasma stability during the manufacturing process may be impaired and productivity may be reduced. In addition, abnormal discharge occurs during the plasma process due to foreign particles, which impairs the stabilization of the plasma, which may cause a decrease in the yield of devices and dielectric breakdown of the electrostatic chuck device.

To address the above-mentioned problems, in semiconductor manufacturing processes, an electrostatic chuck device contaminated with foreign particles is subjected to plasma cleaning to remove the foreign particles (for example, see Patent Document 1).

Special Publication No. 2013-512564

In recent years, with the aim of improving the yield of semiconductor chips obtained from silicon wafers, proposals have been made to expand the number of electrostatic adsorption electrodes included in electrostatic chuck members. In an electrostatic chuck member with enlarged electrostatic adsorption electrodes, the difference in adsorption force between the center and the periphery of the wafer mounting surface becomes smaller, and the outer periphery of the silicon wafer is processed in the same manner as the center. ) becomes possible. This makes it possible to suitably manufacture semiconductor chips even on the outer periphery of the silicon wafer, improving yield.

On the other hand, when the electrostatic chuck electrode expands, the distance between the side surface of the electrostatic chuck member and the electrostatic chuck electrode becomes closer, and the electric field strength on the side surface of the electrostatic chuck member increases. Therefore, in an electrostatic chuck member in which the electrostatic adsorption electrode is enlarged, charged foreign particles are more likely to be electrostatically adsorbed on the side surface than in a conventional electrostatic chuck.

In the electrostatic chuck member described in Patent Document 1, an inclined portion is provided around the periphery in order to enhance the effect of plasma cleaning. However, although this configuration can effectively perform cleaning before wafer processing, it does not prevent charged foreign particles from adhering to the side surface of the electrostatic chuck member during the manufacturing process. Therefore, there is a problem in that it is not possible to sufficiently suppress problems such as a reduction in device yield (reduction in productivity) and dielectric breakdown of the electrostatic chuck due to abnormal discharge that occurs during the wafer process. Therefore, there has been a need for an electrostatic chuck member that can reduce the influence of charged foreign particles adhering to the side surface of the electrostatic chuck member and suppress the occurrence of abnormal discharge even during wafer processing.

The present invention has been made in view of the above circumstances, and provides an electrostatic chuck that can reduce problems caused by charged foreign particles adhering to the side surfaces, particularly abnormal discharges that occur during wafer processing. The purpose is to provide parts. Another object of the present invention is to provide an electrostatic chuck device having such an electrostatic chuck member.

In order to solve the above problems, one embodiment of the present invention includes the following embodiments.

[1] A substrate having one main surface as a mounting 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 substrate, In the electrostatic chuck member, at least a portion of a side circumferential surface continuous with the mounting surface of the base body has an arithmetic mean roughness Ra of 2 μm or less.

[2] Arithmetic mean roughness Ra is 2 μm or less in a region extending downward from the mounting surface, and the region extends downward from the mounting surface in a cross-sectional view in a direction perpendicular to the normal to the mounting surface. The electrostatic chuck member according to [1], wherein the electrostatic chuck member has a width greater than the thickness of the electrostatic chuck electrode.

[3] The electrostatic chuck member according to [1] or [2], wherein the side circumferential surface has an inclined surface exposed in the field of view from the normal direction of the mounting surface.

[4] The electrostatic chuck member according to [3], wherein the side peripheral surface has a convex curved surface provided in the circumferential direction at the peripheral edge of the placement surface.

[5] The side circumferential surface has a portion that is provided in the circumferential direction and extends outward at the lower end of the side circumferential surface, and the upper surface of the extending portion is a concave curved surface [3] or [4] The electrostatic chuck member described in ].

[6] The side circumferential surface has a main surface parallel to the normal direction and the concave curved surface continuous with the main surface, and the concave surface extends from the main surface in a direction perpendicular to the normal direction. The electrostatic chuck member according to [5], wherein the distance to the outer end of the curved surface is greater than or equal to the thickness of the electrostatic chuck electrode.

[7] Any one of [1] to [6], wherein the distance from the outer peripheral end of the electrostatic adsorption electrode to the side peripheral surface in a direction parallel to the mounting surface is 1000 μm or less. The electrostatic chuck member described in .

[8] An electrostatic device comprising the electrostatic chuck member according to any one of [1] to [7], and a base member that cools the electrostatic chuck member and adjusts the temperature of the electrostatic chuck member. Chuck device.

According to the present invention, it is possible to provide an electrostatic chuck member that can reduce problems caused by charged foreign particles adhering to the side surface. Furthermore, an electrostatic chuck device having such an electrostatic chuck member can be provided.

FIG. 1 is a sectional view showing an electrostatic chuck member 10 according to an embodiment. FIG. 2 is an explanatory diagram of an electrostatic chuck member 20 according to the second embodiment. FIG. 3 is an explanatory diagram of an electrostatic chuck member 20B according to a modification of the second embodiment. FIG. 4 is an explanatory diagram of an electrostatic chuck member 30 according to the third embodiment. FIG. 5 is an explanatory diagram of an electrostatic chuck member 40 according to the fourth embodiment. FIG. 6 is an explanatory diagram of an electrostatic chuck member 50 according to a modification. FIG. 7 is a sectional view showing the electrostatic chuck device. FIG. 8 is an explanatory diagram of a semiconductor manufacturing apparatus having the above-mentioned electrostatic chuck device.

[First embodiment]
Hereinafter, an electrostatic chuck member according to a first embodiment of the present invention will be described with reference to FIG. Note that in all the drawings below, the dimensions and ratios of each component are changed as appropriate to make the drawings easier to read.

《Electrostatic chuck parts》
FIG. 1 is a cross-sectional view showing the electrostatic chuck member 10 of this embodiment, and is a view taken in a cross-sectional view in a direction perpendicular to the normal line of the mounting surface 10x. As shown in FIG. 1, the electrostatic chuck member 10 includes a pair of ceramic plates 11 and 12, an electrostatic chuck 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".

The combination of the pair of ceramic plates 11 and 12 and the insulating layer 15 corresponds to the base in the present invention. One main surface of the base is a mounting surface 10x on which a plate-shaped sample is mounted. An annular protrusion having a square cross section may be provided around the peripheral edge of the mounting surface 10x to prevent cooling gas such as helium (He) from leaking.

Note that in an electrostatic chuck member having microprotrusions on one principal surface of the base, a virtual surface in contact with the top of each microprotrusion is defined as the mounting surface 10x. Moreover, when the virtual surface set in this way is a concave surface or a convex surface, the mean square plane of the virtual surface is set as the mounting surface 10x.

In the electrostatic chuck member 10, the electrode 13 is provided inside the base, but the invention is not limited thereto. In the electrostatic chuck member, the electrode 13 may be provided on the opposite side to the mounting surface 10x.

The cross-sectional view shown in FIG. 1 is a cross-section of the electrostatic chuck member taken by a virtual plane including the center of the smallest circle among the circles circumscribing the electrostatic chuck member 10 in a plan view. . When the electrostatic chuck member 10 is substantially circular in plan view, the center of the circle approximately coincides with the center of the shape of the electrostatic chuck member in plan view.

Note that in this specification, "planar view" refers to a field of view viewed from the Y direction, which is the thickness direction of the electrostatic chuck member.
In addition, "cross-sectional view" means, when the smallest circle is assumed among the circles that are perpendicular to the mounting surface and circumscribe the electrostatic chuck member in plan view, when cut by an imaginary plane that includes the center of this circle. , refers to the field of view in the direction perpendicular to the cross section.

As shown in FIG. 1, the electrostatic chuck member 10 includes a ceramic plate 11, an electrode 13 and an insulating layer 15, and a ceramic plate 12 stacked in this order. That is, the electrostatic chuck member 10 is a bonded body in which a ceramic plate 11 and a ceramic plate 12 are joined together via an electrode 13 and an insulating layer 15. Further, the electrode 13 and the insulating layer 15 are provided in contact with the bonding surface of the ceramic plate 11 facing the ceramic plate 12 and the bonding surface of the ceramic plate 12 facing the ceramic plate 11 .

(ceramic board)
The ceramic plates 11 and 12 have the same outer periphery shape in plan view.

The ceramic plates 11 and 12 have the same composition or the same main component. The ceramic plates 11 and 12 may be made of an insulating material, or may be made of a composite of an insulating material and a conductive material.

The insulating material contained in the ceramic plates 11 and 12 is not particularly limited, but includes, for example, aluminum oxide (Al ₂ O ₃ ), aluminum nitride (AlN), yttrium oxide (Y ₂ O ₃ ), yttrium aluminum garnet ( YAG), etc. Among them, Al ₂ O ₃ and AlN are preferred.

The conductive material contained in the ceramic plates 11 and 12 is not particularly limited, but includes, for example, silicon carbide (SiC), titanium oxide (TiO ₂ ), titanium nitride (TiN), titanium carbide (TiC), carbon material, and rare earth oxide. and rare earth fluorides. Examples of carbon materials include carbon nanotubes (CNT) and carbon nanofibers. Among them, SiC is preferred.

The material of the ceramic plates 11 and 12 has a volume resistivity value of about 10 ¹³ Ω·cm or more and 10 ¹⁷ Ω·cm or less, has mechanical strength, and has durability against corrosive gas and its plasma. There are no particular limitations as long as it is a material. Examples of such materials include Al ₂ O ₃ sintered bodies, AlN sintered bodies, Al ₂ O ₃ -SiC composite sintered bodies, and the like. From the viewpoint of dielectric properties at high temperatures, high corrosion resistance, plasma resistance, and heat resistance, the material of the ceramic plates 11 and 12 is preferably an Al ₂ O ₃ --SiC composite sintered body.

The average primary particle diameter of the insulating material 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 1.0 μm or more and 2.0 μm or less. More preferred.

When the average primary particle size of the insulating material constituting the ceramic plates 11, 12 is 0.5 μm or more and 3.0 μm or less, the ceramic plates 11, 12 are dense, have high voltage resistance, and are highly durable.

The method for measuring the average primary particle diameter of the insulating material constituting the ceramic plates 11 and 12 is as follows. Observe the cut surfaces of the ceramic plates 11 and 12 in the thickness direction using a field emission scanning electron microscope (FE-SEM, JEOL Ltd., JSM-7800F-Prime) at 10,000 times magnification. Then, the average of the particle diameters of 200 insulating materials is determined as the average primary particle diameter using the intercept method.

(Electrostatic adsorption electrode)
The electrode 13 is used to generate charges and fix the plate-shaped sample by electrostatic attraction. The electrode 13 is a thin electrode that extends more in the direction perpendicular to the thickness direction than in the thickness direction. Such an electrode 13 is formed by applying an electrode layer forming paste and sintering it. The thickness of the obtained electrode 13 is adjusted by determining the correspondence between the coating thickness of the electrode layer forming paste and the thickness of the obtained electrode 13 through preliminary experiments. It can be controlled by

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

When the electrode 13 is made of an insulating ceramic and a conductive material, the volume resistivity of the mixed material is preferably about 10 ⁻⁶ Ω·cm or more and 10 ⁻² Ω·cm or less.

When the electrode 13 is composed of a composite of insulating ceramics and a conductive material, the content of the conductive material in the electrode 13 is preferably 15% by mass or more and 100% by mass or less, and 20% by mass or more and 100% by mass. The following are more preferable. If the content of the conductive material is at least the above lower limit, the ceramic plate 12 can exhibit sufficient dielectric properties.

The conductive material contained in the electrode 13 may be conductive ceramics, metal, carbon material, or the like. The conductive materials contained in the electrode 13 include SiC, TiO ₂ , TiN, TiC, tungsten (W), tungsten carbide (WC), molybdenum (Mo), molybdenum carbide (Mo ₂ C), tantalum (Ta), and tantalum carbide. At least one selected from the group consisting of (TaC, Ta ₄ C ₅ ), carbon materials, and conductive composite sintered bodies is preferable.

Examples of the carbon material include carbon black, carbon nanotubes, carbon nanofibers, and the like.

Examples of the conductive composite sintered body include Al ₂ O ₃ --Ta ₄ C ₅ , Al ₂ O ₃ --W, Al ₂ O ₃ --SiC, AlN-W, and AlN-Ta.

When the conductive material contained in the electrode 13 is at least one selected from the group consisting of the above substances, the conductivity of the electrode can be ensured.

The insulating ceramics included in the electrode 13 are not particularly limited, but include, for example, Al ₂ O ₃ , AlN, silicon nitride (Si ₃ N ₄ ), Y ₂ O ₃ , YAG, samarium-aluminum oxide (SmAlO ₃ ), At least one selected from the group consisting of magnesium oxide (MgO) and silicon oxide (SiO ₂ ) is preferable.

Since the electrode 13 is made of a conductive material and an insulating material, the bonding strength between the ceramic plates 11 and 12 and the electrode 13 is improved. Further, since the electrode 13 is made of a conductive material and an insulating material, the mechanical strength of the electrode is increased.

Since the insulating material contained in the electrode 13 is Al ₂ O ₃ , dielectric properties at high temperatures, high corrosion resistance, plasma resistance, and heat resistance are maintained.

The content ratio (mixing ratio) of the conductive material and the insulating material in the electrode 13 is not particularly limited, and is adjusted as appropriate depending on the use of the electrostatic chuck member 10.

(insulating layer)
The insulating layer 15 is provided between the ceramic plates 11 and 12 at a position other than the portion where the electrode 13 is formed, in order to bond the ceramic plates 11 and 12 together. The insulating layer 15 is arranged between the ceramic plate 11 and the ceramic plate 12 (between the pair of ceramic plates) around the electrode 13 in plan view.

The shape of the insulating layer 15 (the shape when the insulating layer 15 is viewed in plan) is not particularly limited, and is appropriately adjusted according to the shape of the electrode 13. The thickness of the insulating layer 15 (width in the Y direction) is equal to the thickness of the electrode 13.

The insulating layer 15 may be made of an insulating material, or may be made of a composite of an insulating material and a conductive material. The volume resistivity value of the insulating layer 15 is 10 ¹³ Ω·cm or more and 10 ¹⁷ Ω·cm or less.

The insulating material constituting the insulating layer 15 is not particularly limited, but is preferably the same as the main component of the ceramic plates 11 and 12. The insulating material constituting the insulating layer 15 is, for example, at least one selected from the group consisting of Al ₂ O ₃ , AlN, Si ₃ N ₄ , Y ₂ O ₃ , YAG, SmAlO ₃ , MgO, and SiO ₂ . It is preferable that there be. The insulating material constituting the insulating layer 15 is preferably Al ₂ O ₃ . Since the insulating material constituting the insulating layer 15 is Al ₂ O ₃ , dielectric properties at high temperatures, high corrosion resistance, plasma resistance, and heat resistance are maintained.

The conductive material constituting the insulating layer 15 is not particularly limited, but is preferably the same as the main component of the ceramic plates 11 and 12. The conductive material constituting the insulating layer 15 is preferably at least one selected from the group consisting of, for example, SiC, TiO ₂ , TiN, TiC, W, WC, Mo, Mo ₂ C, and carbon materials. Examples of the carbon material include carbon nanotubes and carbon nanofibers. The conductive material constituting the insulating layer 15 is preferably SiC.

In the insulating layer 15, the content of the insulating material is preferably 80 mass% or more and 96 mass% or less, more preferably 80 mass% or more and 95 mass% or less, and even more preferably 85 mass% or more and 95 mass% or less. If the content of the insulating material is at least the above lower limit, sufficient voltage resistance can be obtained. If the content of the insulating material is below the above-mentioned upper limit, the static elimination effect of the conductive material contained in the insulating layer 15 can be sufficiently exhibited.

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 even more 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, the static elimination effect of the conductive material can be sufficiently exhibited. If the content of the conductive material is below the above upper limit, sufficient withstand voltage can be obtained.

The average primary particle diameter of the insulating material constituting 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.

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

The average primary particle diameter of the conductive material constituting 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.
If the average primary particle diameter of the conductive material constituting the insulating layer 15 is 0.1 μm or more, sufficient voltage resistance 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.

The method for measuring the average primary particle diameter of the insulating material and the average primary particle diameter of the conductive material constituting the insulating layer 15 is as follows: The method is the same as the method for measuring the primary particle diameter.

The insulating layer 15 may be provided separately from the ceramic plates 11, 12, or may be formed integrally with one of the ceramic plates 11, 12 and then bonded to the other ceramic plate. Good too. In this specification, "integrally formed" means formed as one member (one member). In this sense, a configuration that is "integrally formed with either one of the ceramic plates 11 and 12" means, for example, that the ceramic plate 11 and the insulating layer 15, which were originally two members, are "integrated" into one. ” This is different from the configuration. A member in which a ceramic plate and an insulating layer are integrally formed can be formed by processing a concave part by grinding or polishing on one surface of a ceramic plate (ceramic plate having no concave part).

Furthermore, the insulating layer 15 may be formed integrally with both the ceramic plates 11 and 12.

An electrostatic chuck member in which both the ceramic plates 11 and 12 and the insulating layer are integrally formed can be formed by the following method.

For example, by using a raw material powder of inorganic particles (for example, alumina powder or SiC powder) that is a raw material for ceramic plates, a temporary molded body having the same shape as the ceramic plates 11 and 12 before sintering is formed. After screen printing a conductive paste on one of the obtained temporary moldings, the other temporary molding is stacked to form a laminate. Thereafter, by hot press firing the laminate, an electrostatic chuck member in which both the ceramic plates 11 and 12 and the insulating layer are integrally formed is obtained.

The above temporary formed body may be formed by press molding or by pouring a paste of raw material powder into a mold, or by forming a thin green sheet using raw material powder of inorganic particles, and then laminating the green sheets. It may also be molded.

The thickness of the obtained electrode 13 is adjusted by determining the correspondence between the coating thickness of the electrode layer forming paste and the thickness of the obtained electrode 13 through preliminary experiments. It can be controlled by

(Shape of electrostatic chuck member)
In the following description, the thickness of the ceramic plate 11 will be referred to as "thickness T1," the thickness of the ceramic plate 12 as "thickness T2," and the thickness of the electrode 13 as "thickness T3."

The thickness T1 of the ceramic plate 11 and the thickness T2 of the ceramic plate 12 are appropriately set according to the performance of the electrostatic chuck device or semiconductor manufacturing device in which the electrostatic chuck member 10 is employed. 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. Further, the thickness T2 varies greatly depending on the presence or absence of additional internal electrodes, heaters, etc. formed on the lower ceramic plate, and is selected to be 0.9 mm or more and 4 mm or less, but is not limited thereto.

The thickness T3 of the electrode 13 is appropriately set depending on the performance of the electrostatic chuck device or semiconductor manufacturing device in which the electrostatic chuck member 10 is employed. 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.

The inventors have made extensive studies to suppress problems (reduction in productivity, dielectric breakdown) caused by electrostatic adsorption of charged foreign particles to an electrostatic chuck member. As a result, the inventors focused on the charged foreign particles adhering to the side circumferential surface 10y of the electrostatic chuck member 10 (the side circumferential surface 10y of the base body), and reduced the charged foreign particles adhering to the side circumferential surface 10y. We believe that by doing so, we can effectively suppress the above problems.

It is thought that the amount of charged foreign particles adhering to the side circumferential surface 10y increases by increasing the size of the electrode 13 and shortening the distance in the X direction (width D1) from the outer circumferential end of the electrode 13 to the side circumferential surface 10y. It will be done. Due to the recent increase in the size of the electrode 13, the width D1 is required to be 1 mm or less (1000 μm or less).

Furthermore, in relation to the thickness T1 of the ceramic plate 11, the width D1 is required to be equal to or less than twice the thickness T1 (D1/T1≦2). As the width D1 becomes smaller in this manner, charged foreign particles tend to adhere to the side circumferential surface 10y.

From this point of view, as a result of examining the structure of the electrostatic chuck member, the inventors have solved the problem by adopting (1) a structure that reduces the surface area of the side circumferential surface 10y to which charged foreign particles can adhere. He thought that he could solve the problem and completed his invention. Furthermore, the inventor has completed an electrostatic chuck member that can further solve the problem by adopting (2) a structure in which even if charged foreign particles adhere to the side circumferential surface 10y, they can be easily removed.

Specifically, in the electrostatic chuck member 10 (substrate), the side peripheral surface 10y that is continuous with the mounting surface 10x has an arithmetic mean roughness Ra of at least a portion of 2 μm or less, so that (1) the side peripheral surface is The structure is such that charged foreign particles are difficult to adhere to the surface 10y.

The electrostatic chuck member 10 may have an arithmetic mean roughness Ra of 2 μm or less in a part of the circumferential direction of the side circumferential surface 10y, or may have an arithmetic mean roughness Ra of 2 μm or less in the entire circumferential direction. good. Further, the arithmetic mean roughness Ra of the side circumferential surface 10y may be constant in the circumferential direction or may be varied in the circumferential direction.

The arithmetic mean roughness Ra can be measured using a surface roughness/contour shape measuring device (Surfcom NEX200, manufactured by Tokyo Seimitsu Co., Ltd.). Specifically, the arithmetic mean roughness Ra is measured at four locations in the height direction (y direction) in a region of the side peripheral surface 10y of the electrostatic chuck member 10 where the arithmetic mean roughness Ra is to be controlled. Furthermore, when the electrostatic chuck member 10 is viewed from above, similar measurements are performed at four locations at intervals of 90 degrees in the circumferential direction. The average value of the measured values of the arithmetic mean roughness Ra obtained at four locations in the height direction and four locations in the circumferential direction is calculated and set as the arithmetic mean roughness Ra.

An electrostatic chuck member used in a conventional electrostatic chuck device may be mirror-finished with a mounting surface Ra of about 0.05 μm, preferably about 0.01 to 0.02 μm. In the case of an electrostatic chuck member in which a microprotrusion is provided on the mounting surface, Ra of the tip of the microprotrusion may satisfy the above-mentioned Ra.

On the other hand, in the conventional electrostatic chuck member, the Ra of the side circumferential surface is rougher than that of the mounting surface, and the Ra is finished with a surface accuracy of about 3 to 4 μm. This is because, in manufacturing electrostatic chuck members, attention has been paid to the processing accuracy of the mounting surface in direct contact with the wafer, but no attention has been paid to the side circumferential surface on which the plate-shaped sample is not mounted. Therefore, in the conventional electrostatic chuck member, the side circumferential surface is only polished to the minimum necessary level in consideration of production efficiency. However, the inventors discovered that when the surface accuracy of the side circumferential surface is Ra of about 3 to 4 μm, the surface area to which charged foreign particles can adhere is extremely large, and the internal electrodes close to the side circumferential surface further increase the charging potential. The idea was that it would be easy to adsorb sexual foreign particles, and it would be easy to retain many charged foreign particles.

Therefore, in the electrostatic chuck member 10, the Ra of the side circumferential surface 10y is set to 2 μm or less, which is smoother than the conventional one, and the surface area on which charged foreign particles are adsorbed is reduced. We have devised a simple and effective means that can greatly reduce the amount of charged foreign particles that adhere to and stay on the side circumferential surface by more than half compared to the conventional method.

Normally, it is assumed that charged foreign particles are repeatedly adsorbed and detached from the surface of the electrostatic chuck member during wafer processing. Here, when the amount of charged foreign particles attached per unit surface area increases, it is assumed that the charged foreign particles will adsorb to and detach from the surface of the electrostatic chuck member as an aggregate of a plurality of charged foreign particles. . When such aggregates are adsorbed to and desorbed from the surface of the electrostatic chuck member, it is thought that "abnormal discharge" occurs, which impairs the stability of the plasma and causes a decrease in the yield of manufactured devices.

That is, in semiconductor manufacturing equipment, when charged foreign particles adhere to the side peripheral surface of an electrostatic chuck member during wafer processing, the amount of charged foreign particles attached per unit surface area increases as the above aggregates are formed. Until then, no abnormal discharge occurs at all, and abnormal discharge occurs only when the threshold for forming aggregates is exceeded. In such a case, if the amount of attached charged foreign particles is reduced to, for example, less than a threshold value, the amount of abnormal discharge generated can be significantly suppressed, and a high effect can be expected. The "threshold value" is influenced by various conditions such as the configuration of the semiconductor manufacturing equipment, the type of wafer, and wafer process conditions.

That is, since it is considered that the amount of attached charged foreign particles and the number of occurrences of abnormal discharge are not in a linear relationship but in a correspondence relationship having a threshold value, a simple means of reducing Ra of the side circumferential surface 10y by half compared to the conventional ratio is possible. The inventors came up with the idea that it is expected that the occurrence of abnormal discharge can be significantly suppressed.

The region AR1 having such Ra on the side circumferential surface 10y can be formed by known buffing or brushing.

Ra of the side peripheral surface 10y is preferably 1.5 μm or less, more preferably 0.05 μm or less, and even more preferably 0.01 to 0.02 μm.

The side circumferential surface 10y preferably has an arithmetic mean roughness Ra of 2 μm or less in a region AR1 extending downward from the mounting surface 10x. This region AR1 extends downward from the mounting surface 10x by a thickness greater than the thickness of the electrode 13. That is, when the width of the region AR1 in the Y direction is represented by the symbol T4, it is preferable that T4≧T3.

Many charged foreign particles are generated during plasma etching above the mounting surface 10x, descend and adhere to the side circumferential surface 10y. Therefore, charged foreign particles are relatively more likely to adhere to the upper side of the side peripheral surface 10y than to the lower side. In the electrostatic chuck member 10, by forming the highly precisely polished region AR1 above the side circumferential surface 10y, it is possible to efficiently suppress the adhesion of charged foreign particles to the side circumferential surface 10y. .

Furthermore, by making the region AR1 wider than the thickness of the electrode 13 on the side circumferential surface 10y, it is possible to suppress the charged foreign particles from adhering to the side circumferential surface 10y over a wider area than the thickness of the electrode 13. Therefore, micro discharges caused by charged foreign particles can be suppressed on the side circumferential surface 10y, and dielectric breakdown on the side circumferential surface 10y can be suppressed.

If the area AR1 of the side circumferential surface 10y is expanded, the range in which the adhesion of charged foreign particles can be suppressed is expanded, which is advantageous in solving the problem. On the other hand, forming the region AR1 takes more time and costs more than finishing with conventional surface precision (Ra 3 to 4 μm). Therefore, it is preferable to form the region AR1 with an appropriate size in view of the balance between suppressing the adhesion of charged foreign particles and the labor required for manufacturing (manufacturing time, cost).

From the viewpoint of suppressing the adhesion of charged foreign particles, it is preferable that the region AR1 be wide. For example, the region AR1 may be formed downward from the mounting surface 10x to have a thickness equal to or greater than the thickness T1 of the ceramic plate 11 (T4≧T1), and may be formed to have a width equal to or greater than the combined width of the ceramic plate 11 and the electrode 13. (T4≧T1+T3), and the entire side peripheral surface 10y may be the area AR1 (T4=T1+T3+T2).

According to the electrostatic chuck member 10 configured as described above, it is possible to reduce problems (reduction in productivity, dielectric breakdown) caused by the adhesion of charged foreign particles to the side circumferential surface 10y.

[Second embodiment]
FIG. 2 is an explanatory diagram of an electrostatic chuck member 20 according to the second embodiment. In each of the subsequent embodiments, the same material as the electrostatic chuck member 10 of the first embodiment can be used, but the shapes are different. In each of the subsequent embodiments, detailed explanations of components common to the first embodiment will be omitted.

As shown in FIG. 2, the electrostatic chuck member 20 includes a pair of ceramic plates 21 and 22, an electrostatic chuck electrode 23 and an insulating layer 25 interposed between the pair of ceramic plates 21 and 22. The combination of the pair of ceramic plates 21 and 22 and the insulating layer 25 corresponds to the base of the present invention.

The upper end portion of the side circumferential surface 20y of the electrostatic chuck member 20 is chamfered to form a convex curved surface 20a exposed in the normal direction of the mounting surface 20x. In the visual field of FIG. 2, the convex curved surface 20a is an area from the intersection α with the virtual surface S1 that overlaps with the mounting surface 20x to the intersection β with the virtual surface S2 that is parallel to the Y direction and overlaps with the side circumferential surface 20y. .

In this specification, a "convex curved surface" refers to a curved surface of the side circumferential surface that is convex in the +y direction in a cross-sectional view.
On the other hand, the "slanted surface" described later refers to a surface of the side circumferential surface that has a constant inclination in cross-sectional view.

In the electrostatic chuck member 20, the convex curved surface 20a may be formed in a part of the side peripheral surface 20y in the circumferential direction, or the convex curved surface 20a may be formed in the entire circumferential direction. Further, the curvature of the convex curved surface 20a may be constant in the circumferential direction, or may be varied in the circumferential direction.

When the electrostatic chuck member has corners, the electrostatic field for adsorbing the plate-shaped sample tends to concentrate on the corners, and charged foreign particles attracted by this electrostatic field also tend to adhere firmly. On the other hand, if the corners of the electrostatic chuck member 20 are chamfered to form a convex curved surface 20a, the above-mentioned electrostatic field is dispersed by the convex curved surface 20a and becomes difficult to concentrate at a specific location. As a result, the locations where charged foreign particles are attached are dispersed, and the number of charged foreign particles per unit surface area is reduced, making it easier to suppress abnormal discharge.

Furthermore, when a corner is curved, the area of the convex curved surface 20a that is formed is a surface that traces the virtual surfaces S1 and S2 from the intersection α to the intersection β, that is, the area that exists when the corner is not curved. smaller than the area of the surface. As mentioned above, charged foreign particles tend to adhere to the corners of the electrostatic chuck member, and by making the corners curved, the surface area to which charged foreign particles can adhere can be reduced, thereby preventing abnormal discharge. This is suitable as a configuration for suppressing.

The radius of curvature of the convex curved surface 20a is preferably equal to or greater than the thickness T3 of the electrode 23. By making the curvature of the convex curved surface 20a larger than the thickness T3 of the electrode 23, it is possible to suppress the concentration of electric field on the convex curved surface 20a during plasma processing, and prevent charged foreign particles from reaching specific parts (for example, corners). Concentration of adhesion can be suppressed.

The radius of curvature of the convex curved surface 20a is determined by the following method.
First, regarding the part (convex curved surface) of the electrostatic chuck member that you want to measure, assume the smallest circle that is perpendicular to the mounting surface and circumscribes the electrostatic chuck member in plan view, and that includes the center of this circle. Cut on a virtual plane. The cross section may be ground with a grindstone of No. 1000 or higher.

Next, an enlarged photograph of the obtained cross section is taken. The magnification is set according to the size of the convex curved surface to be measured by observing the convex curved surface using a stereoscope. The magnification is a magnification that allows the radius of curvature to be appropriately measured from the obtained photograph, and is appropriately selected from the range of, for example, 40 times to 200 times.
The radius of curvature of the convex curved surface is measured from the obtained enlarged photograph.

The convex curved surface 20a preferably has an arithmetic mean roughness Ra of 2 μm or less, similar to the region AR1 in the electrostatic chuck member 10 of the first embodiment. By setting the arithmetic mean roughness Ra of the convex curved surface 20a to 2 μm or less, both the effect of the convex curved surface 20a and the effect of increasing the surface precision can be obtained, and charged foreign particles can be effectively removed. adhesion can be suppressed. Like the above-mentioned region AR1, Ra of the convex curved surface 20a is preferably 1.5 μm or less, more preferably 0.05 μm or less, and even more preferably 0.01 to 0.02 μm.

The electrostatic chuck member 20 configured as described above also makes it possible to reduce problems (reduction in productivity, dielectric breakdown) caused by the adhesion of charged foreign particles to the side circumferential surface 20y.

In addition, although the surface formed by chamfering is shown as a convex curved surface 20a that is a continuous curved surface in FIG. 2, it is not limited to this.

FIG. 3 is an explanatory diagram of an electrostatic chuck member 20B according to a modification of this embodiment. As shown in FIG. 3, the electrostatic chuck member 20B includes a pair of ceramic plates 26 and 22, an electrostatic chuck electrode 23 and an insulating layer 25 interposed between the pair of ceramic plates 26 and 22.

The side circumferential surface of the electrostatic chuck member 20B shown in FIG. 3 has an inclined surface 20b in which corners along the imaginary plane S1 and the imaginary plane S2 are chamfered linearly. Furthermore, the two new corners created by chamfering are processed into outwardly convex curved surfaces (convex curved surfaces). "Two corners" are a corner formed at the intersection γ of the virtual surface S1 and the inclined surface 20b that overlaps with the mounting surface 30x, and a virtual surface that is parallel to the Y direction and overlaps with the side circumferential surface 20y. This refers to the corner formed at the intersection δ between S2 and the inclined surface 20b. In this case, it is preferable that the curvature radii r1 and r2 of the convex curved surface formed by the curved surface processing are each greater than or equal to the thickness T3 of the electrode 23.

In the electrostatic chuck member 20B having the above configuration, the corner portion, which had one corner before chamfering, is reduced to two by chamfering, thereby dispersing the concentration of the electrostatic field described above. Furthermore, since the corners formed by chamfering are each processed into curved surfaces, it is possible to reduce problems (reduced productivity, dielectric breakdown) caused by charged foreign particles adhering to the side circumferential surface 20y.

Note that the above-mentioned "two corners" may be further linearly chamfered, and the newly formed corners may be processed into convex curved surfaces.

[Third embodiment]
FIG. 4 is an explanatory diagram of an electrostatic chuck member 30 according to the third embodiment. As shown in FIG. 4, the electrostatic chuck member 30 includes a pair of ceramic plates 31 and 32, an electrostatic chuck electrode 33 and an insulating layer 35 interposed between the pair of ceramic plates 31 and 32. The combination of the pair of ceramic plates 31 and 32 and the insulating layer 35 corresponds to the base of the present invention.

The upper end portion of the side circumferential surface 30y of the electrostatic chuck member 30 is chamfered to form a convex curved surface 30a exposed in the normal direction of the mounting surface 30x. The convex curved surface 30a can have the same configuration as the convex curved surface 20a of the second embodiment.

Further, the side circumferential surface 30y has a portion 30z extending outward at the lower end of the side circumferential surface 30y. The upper surface of this portion 30z is a concave curved surface 30b provided in the circumferential direction of the electrostatic chuck member 30. That is, the side peripheral surface 30y is formed of a convex curved surface 30a on the upper end side, a concave curved surface 30b on the lower end side, and a main surface 30c connecting the convex curved surface 30a and the concave curved surface 30b. The main surface 30c is a surface extending in the Y direction.

In the electrostatic chuck member 30, a convex curved surface 30a may be formed in a part of the side peripheral surface 30y in the circumferential direction, or a convex curved surface 30a may be formed in the entire circumferential direction. Moreover, the curvature of the convex curved surface 30a may be constant in the circumferential direction, or may be varied in the circumferential direction.

Further, in the electrostatic chuck member 30, a concave curved surface 30b may be formed in a part of the side peripheral surface 30y in the circumferential direction, or a concave curved surface 30b may be formed in the entire circumferential direction. Moreover, the curvature of the concave curved surface 30b may be constant in the circumferential direction, or may be varied in the circumferential direction.

Generally, it is known that plasma does not easily reach the lower part of the side peripheral surface of an electrostatic chuck member during plasma cleaning, and even if charged foreign particles are attached, it is difficult to remove them. On the other hand, in the electrostatic chuck member 30, a concave curved surface 30b is formed on the lower end side of the side circumferential surface 30y, and is exposed to the field of view in plan view. This facilitates plasma cleaning of the lower end side of the side circumferential surface 30y. In addition, since the charged foreign particles detached from the side peripheral surface 30y by plasma cleaning fly out in the Y direction, they are less likely to drift near the side peripheral surface 30y, and re-adhesion can be easily suppressed.

The radius of curvature of the concave curved surface 30b is preferably greater than or equal to the thickness T3 of the electrode 33.

The concave curved surface 30b preferably has an arithmetic mean roughness Ra of 2 μm or less, similar to the area AR1 in the electrostatic chuck member 10 of the first embodiment. Since the arithmetic mean roughness Ra of the concave curved surface 30b is 2 μm or less, both the effect of the concave curved surface 30b and the effect of increasing the surface precision can be obtained, and charged foreign particles can be effectively removed. adhesion can be suppressed. Like the above-mentioned region AR1, Ra of the concave curved surface 30b is preferably 1.5 μm or less, more preferably 0.05 μm or less, and even more preferably 0.01 to 0.02 μm.

In the direction orthogonal to the normal direction of the mounting surface 30x, the distance from the main surface 30c to the outer end of the concave curved surface 30b (width D2 of the portion 30z in the X direction) is equal to or greater than the thickness T3 of the electrode 33. and preferable.

The electrostatic chuck member 30 configured as described above can also reduce problems (reduction in productivity, dielectric breakdown) caused by the attachment of charged foreign particles to the side circumferential surface 30y.

In addition, in this embodiment, although the main surface 30c was made into the surface parallel to the Y direction, it is not limited to this. The main surface 30c may also be an inclined surface exposed to the field of view in plan view.

[Fourth embodiment]
FIG. 5 is an explanatory diagram of an electrostatic chuck member 40 according to the fourth embodiment. As shown in FIG. 5, the electrostatic chuck member 40 includes a pair of ceramic plates 41 and 42, an electrostatic adsorption electrode 43 and an insulating layer 45 interposed between the pair of ceramic plates 41 and 42. The combination of the pair of ceramic plates 41 and 42 and the insulating layer 45 corresponds to the base of the present invention.

The side circumferential surface 40y is a continuous linear slope from the upper end to the lower end. The side circumferential surface 40y preferably has an arithmetic mean roughness Ra of 2 μm or less, similar to the region AR1 in the electrostatic chuck member 10 of the first embodiment. Ra of the side peripheral surface 40y is preferably 1.5 μm or less, more preferably 0.05 μm or less, and even more preferably 0.01 to 0.02 μm, similar to the above-mentioned region AR1.

In the electrostatic chuck member 40, a part of the side peripheral surface 40y in the circumferential direction may be an inclined surface, or the entire circumferential direction may be an inclined surface. Further, the inclination angle of the inclined surface may be constant in the circumferential direction or may be varied in the circumferential direction.

Further, the intersection α between the side circumferential surface 40y and the mounting surface 40x in a cross-sectional view may be processed into a curved surface that is convex outward. In this case, the radius of curvature of the curved surface formed by curved surface processing is preferably equal to or greater than the thickness T3 of the electrode 43.

The electrostatic chuck member 40 may be processed into a curved surface in which a part of the intersection α is outwardly convex on a part of the side peripheral surface 40y in the circumferential direction, and all of the above intersections α are outwardly convex. It may be processed into a curved surface. Further, the curvature at the intersection α may be constant in the circumferential direction or may be different in the circumferential direction.

In the electrostatic chuck member 40, the width D2 from the intersection 42a of the upper surface of the ceramic plate 42 and the side peripheral surface 40y to the end 42b of the ceramic plate 42 in the X direction is preferably equal to or larger than the thickness T3 of the electrode 43. . When the width D2 is greater than or equal to the thickness T3, it is possible to suppress the charged foreign particles from adhering to a wider area than the thickness of the electrode 43 on the side circumferential surface 40y, and it is possible to effectively suppress dielectric breakdown.

Further, the width D3 of the side circumferential surface 40y in plan view is preferably equal to or less than the total thickness of the electrostatic chuck member 40 (T1+T2+T3). That is, the inclination angle θ of the side circumferential surface 40y is preferably 45° or more and less than 90°. With such a shape, the mounting surface 40x does not become too small, resulting in an electrostatic chuck member that is both practical and suppresses the adhesion of charged foreign particles. In addition, excessive process burden is less likely to occur in machining the inclined surface.

The electrostatic chuck member 40 configured as described above also makes it possible to reduce problems (reduction in productivity, dielectric breakdown) caused by the adhesion of charged foreign particles to the side circumferential surface 40y.

(Modified example)
In each of the embodiments described above, the entire side circumferential surface is parallel to the Y direction or is an inclined surface exposed in plan view, but the present invention is not limited to this.

FIG. 6 is an explanatory diagram of an electrostatic chuck member 50 according to a modification. As shown in FIG. 6, the electrostatic chuck member 50 includes a pair of ceramic plates 51 and 52, an electrostatic adsorption electrode 43 and an insulating layer 55 interposed between the pair of ceramic plates 51 and 52. The combination of the pair of ceramic plates 51 and 52 and the insulating layer 55 corresponds to the base of the present invention.

In the cross section shown in FIG. 6, the side circumferential surface 50y is a curved surface that is convex outward (in the X direction). The side circumferential surface 50y preferably has an arithmetic mean roughness Ra of 2 μm or less, similar to the region AR1 in the electrostatic chuck member 10 of the first embodiment. Ra of the side circumferential surface 50y is preferably 1.5 μm or less, more preferably 0.05 μm or less, and even more preferably 0.01 to 0.02 μm, similar to the above-mentioned region AR1.

The electrostatic chuck member 50 may have an outwardly convex curved surface in a part of the circumferential direction of the side peripheral surface 50y, or may have an outwardly convex curved surface in the entire circumferential direction. Further, the curvature of the side circumferential surface 50y may be constant in the circumferential direction, or may be varied in the circumferential direction.

In such an electrostatic chuck member 50, there are no corners on the side circumferential surface, and electric field concentration can be effectively dispersed. Therefore, adhesion of charged foreign particles to the side peripheral surface 50y and dielectric breakdown due to discharge can be suppressed during plasma processing.

[Electrostatic chuck device]
Hereinafter, an electrostatic chuck device according to an embodiment of the present invention will be described with reference to FIG. In the following description, an electrostatic chuck device having the above-described electrostatic chuck member 10 will be described, but the other electrostatic chuck members described above can also be employed in the electrostatic chuck device. In the following description, components common to those in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

FIG. 7 is a sectional view showing the electrostatic chuck device of this embodiment. The electrostatic chuck device 100 includes a disc-shaped electrostatic chuck member 10, a disc-shaped base member 103 that cools the electrostatic chuck member 10 and adjusts it to a desired temperature, and the electrostatic chuck member 10 and the base member. 103 and an adhesive layer 104 that joins and integrates them.

In the following description, the electrostatic chuck member 10 side will be referred to as "upper" and the base member 103 side will be referred to as "lower" to indicate the relative positions of each component.

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

[Power supply terminal]
The power supply terminal 116 is a member for applying voltage to the electrode 13.
The number, shape, etc. of the power feeding terminals 116 are determined depending on the form of the electrode 13, that is, whether it is a monopolar type or a bipolar type.

The material of the power supply terminal 116 is not particularly limited as long as it is a conductive material with excellent heat resistance. The material for the power supply terminal 116 is preferably a material whose thermal expansion coefficient is close to that of the electrode 13 and the ceramic plate 12, such as a Kovar alloy, a metal material such as niobium (Nb), or various conductive materials. Preferably, ceramics are used.

[Conductive adhesive layer]
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. Further, the conductive adhesive layer 117 is interposed between the electrode 13 and the power feeding terminal 116 to electrically connect the electrode 13 and the power feeding terminal 116.

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

The resin contained in the conductive adhesive is not particularly limited as long as it does not easily cause cohesive failure due to thermal stress, such as silicone resin, acrylic resin, epoxy resin, phenol resin, polyurethane resin, unsaturated polyester resin, etc. can be mentioned.
Among these, silicone resins are preferred because they have a high degree of expansion and contraction and are difficult to cause cohesive failure due to changes in thermal stress.

[Base member]
The base member 103 is a thick disc-shaped member made of at least one of metal and ceramics. The frame of the base member 103 is configured to also serve as an internal electrode for plasma generation. A flow path 121 is formed inside the frame of the base member 103 to circulate a cooling medium such as water, He gas, _N2 gas, or the like.

The frame of the base member 103 is connected to an external high frequency power source 122. Further, a power supply terminal 116 whose outer periphery is surrounded by an insulating material 123 is fixed in the fixing hole 115 of the base member 103 via the insulating material 123. The power supply terminal 116 is connected to an external DC power supply 124.

The material constituting the base member 103 is not particularly limited as long as it is a metal with 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. are suitably used.

At least the surface of the base member 103 that is exposed to plasma is preferably subjected to an alumite treatment or a resin coating using a polyimide resin. Further, it is more preferable that the entire surface of the base member 103 is subjected to the above-mentioned alumite treatment or resin coating.

By applying alumite treatment or resin coating to the base member 103, the plasma resistance of the base member 103 is improved and abnormal discharge is prevented. Therefore, the plasma resistance stability of the base member 103 is improved, and the occurrence of surface scratches on the base member 103 can also be prevented.

[Adhesive layer]
The adhesive layer 104 is configured to bond and integrate the electrostatic chuck member 10 and the base member 103 together.

The thickness of the adhesive layer 104 is preferably 100 μm or more and 200 μm or less, more preferably 130 μm or more and 170 μm or less.
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 maintained sufficiently. Further, sufficient thermal conductivity between the electrostatic chuck member 10 and the base member 103 can be ensured.

The adhesive layer 104 is formed of, for example, a cured product obtained by heating and curing a silicone resin composition, an acrylic resin, an epoxy resin, or the like.
A silicone-based resin composition is a silicon compound having a siloxane bond (Si-O-Si), and is a resin with excellent heat resistance and elasticity, so it is more preferable.

As such a silicone resin composition, a silicone resin having a thermosetting temperature of 70°C to 140°C is particularly preferable.

Here, if the thermosetting temperature is lower than 70° C., curing will not progress sufficiently during the bonding process when the electrostatic chuck member 10 and the base member 103 are bonded while facing each other, resulting in poor workability, which is preferable. do not have. On the other hand, when the thermosetting temperature exceeds 140°C, the difference in thermal expansion between the electrostatic chuck member 10 and the base member 103 is large, and the stress between the electrostatic chuck member 10 and the base member 103 increases, and the stress between the electrostatic chuck member 10 and the base member 103 increases. This is not preferable because peeling may occur.

That is, when the thermosetting temperature is 70°C or higher, workability is excellent in the bonding process, and when the thermosetting temperature is 140°C or lower, separation between the electrostatic chuck member 10 and the base member 103 is difficult to occur, which is preferable. .

According to the electrostatic chuck device 100 of this embodiment, since it includes the electrostatic chuck member 10 described above, it is possible to suppress the occurrence of dielectric breakdown (discharge) on the side peripheral surface of the electrostatic chuck member.

Note that the electrostatic chuck device 100 may include a focus ring surrounding the electrostatic chuck member. In that case, the shape of the focus ring may be changed to a complementary shape in accordance with the shape of the side peripheral surface of the electrostatic chuck member.

[Semiconductor manufacturing equipment]
FIG. 8 is an explanatory diagram of a semiconductor manufacturing apparatus having the above-mentioned electrostatic chuck device. The semiconductor manufacturing apparatus 1000 includes an electrostatic chuck device 100, a vacuum chamber 200, an upper electrode 300, a magnet 400, a gas supply means 500, a vacuum pump 600, and a plasma stabilization system 700.

The vacuum chamber 200 accommodates the electrostatic chuck device 100 and is used as a reaction field for performing plasma processing inside. The vacuum chamber 200 can employ a known configuration used in semiconductor manufacturing equipment. The vacuum chamber 200 has a gate (not shown) through which a plate-shaped sample is taken in and taken out.

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

The magnet 400 is arranged around the vacuum chamber 200 and generates a vertical magnetic field in the space between the upper electrode 300 and the electrostatic chuck device 100 in the vacuum chamber 200.

Gas supply means 500 supplies plasma gas G into vacuum chamber 200 . The gas supply means 500 supplies plasma gas G into the vacuum chamber 200 from a gas hole provided in the upper electrode 300, for example.

The vacuum pump 600 exhausts the gas in the vacuum chamber 200 and prepares an atmosphere for generating plasma. For example, the vacuum pump 600 is connected below the electrostatic chuck device 100 in the vacuum chamber 200.

The plasma stabilization system 700 stabilizes the plasma state by detecting and compensating for various external factors that change the state of the plasma generated in the semiconductor manufacturing apparatus 1000. The plasma stabilization system 700 includes a detector 710 and a control section 720 that controls the semiconductor manufacturing apparatus 1000 based on the detection result by the detector 710.

Detector 710 directly or indirectly detects the state of plasma within vacuum chamber 200. The number of detectors 710 may be one or more. 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, and the plasma generation internal electrode (not shown) of the upper electrode 300 and the electrostatic chuck device 100. Examples include the capacitance between the upper electrode 300 and the internal electrode for plasma generation, and the like.

The control unit 720 controls the semiconductor manufacturing apparatus 1000 based on the detection value of each item detected by the detector 710 or the amount of change in the detection value per unit time. The control unit 720 stores in advance the correspondence between the detected values of the above items and the state of plasma generated within the vacuum chamber 200. The control unit 720 performs feedback control of the semiconductor manufacturing apparatus 1000 based on the detected value and the above-mentioned correspondence relationship so that the plasma state falls within a predetermined range. Items to be feedback-controlled include, for example, the temperature, degree of vacuum, and bias voltage within the semiconductor manufacturing apparatus.

As a result, the plasma stabilization system 700 can suppress long-term fluctuations in the plasma state in the semiconductor manufacturing apparatus 1000 and stabilize the state.

Such a plasma stabilization system is effective in suppressing fluctuations in the plasma state throughout the manufacturing process using semiconductor manufacturing equipment. On the other hand, the plasma stabilization system was not effective in suppressing state fluctuations for fluctuation factors that occur for an extremely short period of time, such as abnormal discharge during wafer processing.

On the other hand, since the semiconductor manufacturing apparatus 1000 includes the electrostatic chuck device 100 described above, the wafer can suppress abnormal discharge that occurs during the process. Therefore, by including the plasma stabilization system 700, the semiconductor manufacturing apparatus 1000 can stabilize plasma both in the long term and in the short term.

Note that the control unit 720 may be a unique configuration of the plasma stabilization system 700, or a control device that controls the semiconductor manufacturing apparatus 1000 may also have the function.

In such a semiconductor manufacturing apparatus 1000, for example, the ease with which charged foreign particles adhere to the side surface of the electrostatic chuck member 10 is determined by the position of the exhaust port of the vacuum chamber 200 (the connection position of the vacuum pump 600). Trends may vary. When the above-mentioned tendency has been empirically determined for the semiconductor manufacturing apparatus 1000, the electrostatic chuck member 10 has a side circumferential surface at a position where charged foreign particles are likely to adhere, and has a higher arithmetic mean roughness than other side circumferential surfaces. It is preferable to adopt a configuration that suppresses the adhesion of charged foreign particles, such as by keeping Ra small.

According to the semiconductor manufacturing apparatus 1000 of this embodiment, since it includes the electrostatic chuck device 100 described above, the occurrence of dielectric breakdown (discharge) can be suppressed.

Furthermore, the semiconductor manufacturing apparatus 1000 can suppress abnormal discharge (short-term fluctuations in plasma) using the electrostatic chuck device 100, and can suppress long-term fluctuations in plasma using the plasma stabilization system 700. Therefore, stable plasma processing is possible, and a semiconductor manufacturing apparatus with improved yield can be achieved.

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to these examples. The various shapes and combinations of the constituent members shown in the above example are merely examples, and can be variously changed based on design requirements and the like without departing from the gist of the present invention.
In addition, although the above explanation uses silicon wafers, wafers that can be processed with the electrostatic chuck member of the present invention are not only silicon, but also other materials such as indium phosphide or gallium arsenide. It is clear that it is possible.

10, 20, 20B, 30, 40, 50... Electrostatic chuck member, 10x, 20x, 30x, 40x... Placement surface, 10y, 20y, 30y, 40y, 50y... Side peripheral surface, 13, 23, 33, 43 ...electrode for electrostatic attraction (electrode), 20a, 30a...convex curved surface, 30b...concave curved surface, 30c...principal surface, 30z...part, 42b...end part, 100...electrostatic chuck device, 103...base member, AR1... Region, r1, r2...radius of curvature, T1, T2, T3...thickness

Claims (8)

a base whose one main surface is a mounting surface on which a plate-shaped sample is mounted;
an electrostatic adsorption electrode provided on the opposite side of the mounting surface or inside the base;
In the electrostatic chuck member, at least a portion of a side circumferential surface continuous with the mounting surface of the base body has an arithmetic mean roughness Ra of 2 μm or less. The arithmetic mean roughness Ra is 2 μm or less in a region extending downward from the placement surface,
The electrostatic chuck according to claim 1, wherein the region extends downward from the mounting surface by a thickness greater than or equal to the thickness of the electrostatic adsorption electrode when viewed in a cross section in a direction perpendicular to the normal line of the mounting surface. Element. The electrostatic chuck member according to claim 1 or 2, wherein the side circumferential surface has an inclined surface exposed to the field of view from the normal direction of the mounting surface. The electrostatic chuck member according to claim 3, wherein the side circumferential surface has a convex curved surface provided in the circumferential direction at the peripheral edge of the placement surface. The side circumferential surface has a portion provided in the circumferential direction and extending outward at the lower end of the side circumferential surface,
The electrostatic chuck member according to claim 3 or 4, wherein the upper surface of the extending portion is a concave curved surface. The side circumferential surface has a main surface parallel to the normal direction and the concave curved surface continuous with the main surface,
The electrostatic chuck member according to claim 5, wherein a distance from the main surface to an outer end of the concave curved surface in a direction perpendicular to the normal direction is equal to or greater than the thickness of the electrostatic chuck electrode. The electrostatic capacitor according to any one of claims 1 to 6, wherein the distance from the outer peripheral end of the electrostatic adsorption electrode to the side peripheral surface in a direction parallel to the mounting surface is 1000 μm or less. Chuck member. The electrostatic chuck member according to any one of claims 1 to 7,
An electrostatic chuck device comprising: a base member that cools the electrostatic chuck member and adjusts the temperature of the electrostatic chuck member.

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