JP2012039011A - Electrostatic chuck and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a feeding terminal of an electrostatic chuck which has no crack generation in an electrode and a dielectric layer near the feeding terminal.SOLUTION: An electrostatic chuck has an electrode made of a metal layer embedded in a plate-like insulation material one surface of which is an absorption face and the reverse surface of which has a terminal hole for inserting a terminal reaching the electrode. A feeding terminal A contacting the electrode and a feeding terminal B positioned a space away from the feeding terminal A are positioned in the terminal hole. The outer peripheral surfaces of the feeding terminals A and B are surrounded by conductive paste uniformly to fill the gap between the terminals and the terminal hole, and the surface area of the feeding terminal B on the side which does not face the feeding terminal A is larger than the area of the feeding terminal A on the side which faces the feeding terminal B.

Description

The present invention relates to an electrostatic chuck used for, for example, an electrostatic chucking of various electrically insulating substrates in a semiconductor manufacturing apparatus and a manufacturing method thereof.

In a process of processing an insulating material such as a patterning mask for a semiconductor manufacturing apparatus or an LED, as a method for fixing these insulating materials, for example, an uneven electric field is formed on the adsorption surface of the electrostatic chuck. There is a method of using a gradient force generated by the above.

The basic structure of the electrostatic chuck is composed of a base material portion serving as a base, an electrode for generating an adsorption force thereon, and a dielectric layer for holding an adsorbate thereon. Among these, there are several methods as the structure of the power supply terminal portion that is applied to the electrode by opening a hole in the base material portion and inserting a terminal such as a power supply metal in order to apply a current to the electrode.

For example, Patent Document 1 discloses a power supply terminal for a ceramic component in which an internal electrode is embedded and the power supply terminal does not drop out or fail to be electrically connected to the internal electrode even in an environment exposed to a thermal cycle. As a joining structure, a technique is disclosed in which a power feeding terminal is made of molybdenum or tungsten having a nickel coating film on the surface, and the power feeding terminal is joined to an internal electrode by brazing.

In Patent Document 2, as a power feeding structure for an electrostatic chuck that is unlikely to crack in a lower insulating layer, an electrode layer, and a surface insulating dielectric layer, a through hole that penetrates between the upper and lower surfaces of a metal substrate, and a wiring disposed in the through hole are disclosed. A power supply terminal for supplying a voltage supplied from the lower surface side of the metal substrate to the electrode layer laminated on the upper surface side, and insulating between the inner wall of the through hole and the power supply terminal formed of an electrically insulating material And an insulating holding member for holding the power supply terminal, the power supply terminal having a power supply side end protruding to the upper surface side of the metal substrate, and the tip of the power supply side end is located below the electrode layer and the lower part A technique is disclosed in which the electrode layer is located below the interface between the electrode layer and the surface insulating dielectric layer on the electrode layer side from the interface with the insulating layer.

  In Patent Document 3, a metal layer is embedded in a plate-like glass having front and back surfaces, the metal layer is an electrode, the short distance from the metal layer to the glass surface is the dielectric layer, and the distance from the metal layer to the glass surface In the glass electrostatic chuck in which the long side is the base material layer and the thickness of the dielectric layer is 40 μm or more and 300 μm or less, the conductive paste is placed in the hole for the feeding terminal processed into the base material having at least the dielectric layer made of silica glass. A power feeding method is disclosed in which a conductive wire is fixed to a metal layer.

Japanese Patent Laid-Open No. 2005-19480 WO2008 / 035395 JP 2009-32718 A

  The technique of Patent Document 1 uses brazing for joining electrodes and terminals. In this method, heating is performed from 800 ° C. to 1000 ° C. at the time of brazing, and then cooling is performed. Thus, there is a problem that stress remains in the base material and cracks are generated near the joint between the electrode and the terminal.

In the technique of Patent Document 2, the power supply side end portion of the power supply terminal has a top surface having a predetermined area at the tip, and is formed in a protrusion shape that gradually decreases in diameter toward the tip. Dispersion of stress becomes possible. Therefore, cracks in the surface insulating dielectric layer, the electrode layer, and the lower insulating layer due to the thermal load due to the thermal gradient of the power feeding structure and the thermal load due to the thermal cycle can be suppressed. Therefore, it can be said that it is a feature that problems such as local deterioration of temperature characteristics of the electrostatic chuck and generation of particles can be avoided as much as possible. However, in Patent Document 2, since a method called thermal spraying is used, there is a problem that manufacturing difficulty is high and manufacturing cost increases.

The technique of patent document 3 fixes a conducting wire to a metal layer using an electrically conductive paste as a joining method of the electrode and electric power feeding terminal in an electrostatic chuck made from quartz. However, in this method, the electrode faces the hole in the step of grinding the dielectric layer to a predetermined thickness of 40 μm after forming the electrode and the dielectric layer on the base material layer having the holes for the feeding terminals. There was a problem that stress was locally concentrated at the location and cracks were generated. This is a problem caused by a thin dielectric layer.

Along with the demand for improving the attractive force, it is required to further reduce the thickness of the dielectric layer of the electrostatic chuck. However, it has been difficult in the past to manufacture an electrostatic chuck with a thin dielectric layer, particularly in an electrostatic chuck made of a very brittle material such as silica glass.

The present invention has been made in view of such problems. Particularly in an electrostatic chuck having a thin dielectric layer, stress and load are reduced in an electrode and a dielectric layer in the vicinity of the power supply terminal of the electrostatic chuck, and cracks are generated. The present invention provides a high-quality electrostatic chuck with reduced generation and a method for manufacturing the same.

An electrostatic chuck according to the present invention is an electrostatic chuck in which an electrode made of a metal layer is embedded in a plate-shaped insulating material, one surface being an attracting surface, and a terminal reaching the electrode on the back surface The terminal hole is formed with a power supply terminal A that contacts the electrode, and a power supply terminal B that is positioned to provide a space with the power supply terminal A. The outer peripheral surfaces of A and the power supply terminal B are surrounded by an integral conductive paste so as to fill the space between the terminal holes, and the area of the surface of the power supply terminal B that does not face the power supply terminal A is the power supply of the power supply terminal A. It is characterized by being larger than the area on the side facing the terminal B. By adopting such a configuration, in an electrostatic chuck having a thin dielectric layer, it is possible to reduce stress and load applied to the power supply terminal and the nearby dielectric layer.

In the electrostatic chuck according to the present invention, it is preferable that an interval between the space portions in a vertical direction with respect to the attracting surface is 10 μm or more and 1000 μm or less. By adopting such a configuration, it is possible to more effectively increase the strength against stress and load applied to the power supply terminal and the dielectric layer in the vicinity thereof in an electrostatic chuck having a thin dielectric layer.

In the electrostatic chuck according to the present invention, it is preferable that both the dielectric layer and the base material layer are made of silica glass. By adopting such a configuration, even when silica glass that can be suitably used for a semiconductor manufacturing apparatus is applied, the dielectric in the vicinity of the power supply terminal can be used when manufacturing an electrostatic chuck with a thin dielectric layer. It becomes possible to reduce the stress and load applied to the layer.

And the manufacturing method of the electrostatic chuck according to the present invention includes an electrode made of a metal material on either one surface of a plate-like insulating material forming a dielectric layer or one surface of another plate-like insulating material forming a base portion. Forming a pattern to form a dielectric layer; forming a terminal hole in the other plate-shaped insulating material to produce the base portion; and bonding the dielectric layer and the base portion. In addition, the method includes a step of manufacturing an electrostatic chuck main body and a step of inserting a conductive paste and a power supply terminal into the terminal hole of the electrostatic chuck main body to fix the power supply terminal. By adopting such a configuration, it is possible to efficiently manufacture an electrostatic chuck made of silica glass that can be suitably used particularly for a semiconductor manufacturing apparatus.

According to the present invention, in an electrostatic chuck with a thin dielectric layer, preferably an electrostatic chuck with a dielectric layer made of silica glass having a thickness of 10 μm to 200 μm, the stress applied to the feeding terminal and the nearby dielectric layer It is possible to provide an electrostatic chuck and a method for manufacturing the same that can reduce the load.

The detailed contents of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram showing a shape of a power feeding terminal portion of an electrostatic chuck and its periphery from a cross-sectional direction according to an embodiment of the present invention. Note that FIG. 1 is a conceptual diagram for explaining each constituent element of the present invention, and is different from the dimensional ratio in an actual electrostatic chuck.

The conceptual diagram which looked at the electric power feeding terminal part of the electrostatic chuck based on one Embodiment of this invention, and the shape of the periphery from the cross section. The conceptual diagram which showed typically the state which the stress concerning the electric power feeding terminal part of an electrostatic chuck propagates to a base material part based on one Embodiment of this invention. The conceptual diagram which looked at the electric power feeding terminal part of the electrostatic chuck based on other embodiment of this invention, and the shape of the periphery from the cross section. The conceptual diagram which looked at the electrode pattern of the electrostatic chuck based on one Embodiment of this invention from the upper surface.

The electrostatic chuck according to the present invention is an electrostatic chuck in which an electrode 3 made of a metal layer is embedded in a plate-shaped insulating material, and one surface is an adsorption surface 21, and the back surface 22 has the electrode on the back surface 22. A terminal hole 4 for inserting a terminal reaching 3 is formed, and the terminal hole 4 is provided with a power supply terminal A (51 in FIG. 1) in contact with the electrode 3, a power supply terminal A, and a space portion 7. The power supply terminal B (52 in FIG. 1) is disposed, and the outer peripheral surfaces of the power supply terminal A and the power supply terminal B are surrounded by the integral conductive paste 6 so as to fill the space between the terminal hole 4 and the power supply terminal B. The area of the surface not facing the power supply terminal A is larger than the area of the power supply terminal A facing the power supply terminal B.

When the electrostatic chuck according to the present invention is viewed from a cross section as shown in FIG. 1, the electrostatic chuck body 1 is provided with a dielectric layer 11 made of an insulating material and an insulating material provided to support the dielectric layer. It is comprised from the base material layer 12. FIG. Here, the main surface on the dielectric layer side is the adsorption surface 21, and the main surface on the base material layer side is the back surface 22. And the electrode 3 of the metal layer which is formed between the dielectric layer 11 and the base material layer 12, and generate | occur | produces attraction | suction force by applying electricity is embed | buried. In addition, a power supply terminal 5 for supplying electricity to the electrode 3 and a terminal hole 4 provided in the base member 12 for inserting the power supply terminal 5 are formed.

The dielectric layer 11 is made of an insulating material, and various known materials that can be used for an electrostatic chuck can be applied. Examples thereof include aluminum nitride, alumina, silicon nitride, boron nitride, and silica glass. When it is required to be a high-purity member due to factors such as usage environment, high-purity silica glass is preferably used.

The base material layer 12 is also made of an insulating material, and various known materials that can be used for an electrostatic chuck can be applied. Examples thereof include aluminum nitride, alumina, silicon nitride, and boron nitride, and high-purity silica glass is preferably used. Usually, the same material is applied to the base material layer 12 and the dielectric layer 11, but different materials may be used. In particular, when silica glass is applied, appropriate amounts of various additives may be added to change the physical properties thereof, so that materials corresponding to the physical properties required at the respective portions of the dielectric layer 11 and the base material layer 12 may be used.

The electrode 3 is formed to generate a Coulomb force, a Johnson-Rahbek force, or a gradient force as an attracting force with respect to the electrostatic chuck. The electrode 3 is made of a band-like or foil-like metal material having a predetermined width with respect to the suction surface 21 and a predetermined thickness with respect to the depth direction of the suction surface 21. The electrodes 3 have various pattern shapes arranged at regular intervals with respect to the plane direction, and the adsorbate can be strongly adsorbed and held in a wide area. The width, thickness, and interval of the electrodes 3 can be designed in a timely manner according to the required electrostatic chuck specifications. Note that the thickness of the dielectric layer 11 is an imaginary plane including the entire pattern of the electrode 3 and indicates an average distance from the surface on the suction surface side to the suction surface 21 of this plane. Although an average space | interval is not specifically limited, As an example, it can show by the average value of 5 points in a plane which consists of a center part and 4 points inside 10 mm of outer periphery.

A known material that can be applied to an electrostatic chuck is used as the material of the electrode 3. As an example, there is a single layer made of any one of Ni, Mo, W, Pt and Ti, or a single layer made of two or more of these alloys. A multilayer structure made of metal may be used.

In the base material layer 12, a terminal hole 4 for inserting the power supply terminal 5 reaching the electrode 3 is formed. The terminal hole 4 is in a state of being opened from the back surface 22 to one surface of the electrode 3. Here, opening means that a hole is formed on the back surface side of the base material layer 12, and the thickness of the base material layer 12. It is shown that the opening is formed substantially perpendicular to the direction. The shape of the terminal hole 4 has an inner surface shape substantially conforming to the outer shape of the power supply terminal 5 described later. Also, the conductive paste 6 described later is filled in the inner surface of the terminal hole 4 and the outer surface of the power supply terminal 5 so that the terminal hole 4 and the power supply terminal 5 are bonded and fixed.

And the terminal hole 4 consists of the terminal hole 41 and the terminal hole 42 which were designed so that the cross-sectional area with respect to the adsorption surface 21 direction might differ by the side which contact | connects the electrode 3, and the back surface 22 side. At this time, it is preferable that the terminal hole 41 is completely covered with one surface of the electrode 3 with respect to the plane direction, that is, the opening area of the terminal hole 41 is smaller than the contact area with the electrode 3. If the opening area of the terminal hole 41 is larger than the contact area of the electrode 3, a part of the electrode 3 is peeled off when the terminal hole 41 and the electrode 3 vacated in advance are bonded, and the electrode 3 and the feeding terminal A are Since there is a possibility that electrical continuity cannot be obtained, it is not preferable.

Here, the shape of the terminal hole 4 viewed from the plane direction of the suction surface 21 is preferably a circular shape because of ease of processing. However, it is not necessarily a so-called perfect circle, and may be, for example, an elliptical shape or a polygon with a corner.

The terminal hole 4 is provided with a power supply terminal 5 for supplying electricity to the electrode 3, and the power supply terminal 5 is provided with a power supply terminal A (51 in FIG. 1) and a space portion 7 to be located. (52 in FIG. 1). The outer surface of the power supply terminal 5 is surrounded by an integral conductive paste 6 so as to fill the space between the terminal holes 4. By adopting such a structure, one surface of the electrode 3 and one end face of the power supply terminal A are in contact with each other, and a current is applied to the electrode 3 from the power supply lead 8 via the conductive paste 6 and the power supply terminal B.

As the material of the power supply terminal 5, a known material that can be applied to the electrostatic chuck is used, and any one of Ni, Mo, W, Pt, and Ti, or two or more of these are used. An alloy or a composite structure composed of two or more metals may be used. The power supply terminal A and the power supply terminal B do not need to be made of the same material, and may be made of different materials.

Further, a space portion 7 is formed between the power supply terminal A and the power supply terminal B. That is, a space 7 having substantially the same shape and area as the opposing end surfaces of the power supply terminal A and the power supply terminal B and having a substantially constant interval in the vertical direction with respect to the suction surface 21 is formed. It can be said that this is close to the image that a so-called gap or gap is formed slightly away from the state where the feeding terminal A and the feeding terminal B are once in contact with each other.

The space 7 in the present invention has an effect of preventing the load applied in the vertical direction from the power supply terminal B to the suction surface 21 from propagating to the power supply terminal A. FIG. 2 is a conceptual diagram schematically showing how the stress propagates. As shown in FIG. 2, the load 101 applied in the vertical direction from the power supply terminal B to the suction surface 21 does not propagate to the power supply terminal A because the power supply terminal A and the power supply terminal B are separated. The stress 102 generated in the power supply terminal B by the load 101 propagates only to the base material portion 12. Even if the power supply terminal B is pushed up and moves slightly upward, the power supply terminal B and the power supply terminal A do not come into contact with each other due to the presence of the space 7, and the stress 102 does not propagate to the power supply terminal A.

A conductive paste 6 is filled in the gap between the terminal hole 4 and the power supply terminal 5. The conductive paste 6 has a function of securing energization between the power supply terminal 5 and the electrode 3 and fixing the power supply terminal 5 and the base material portion 12. In addition, since electricity supply between the power supply terminal A and the power supply terminal B is ensured by the conductive paste 6, there is no particular problem in this respect even if the power supply terminal A and the power supply terminal B are not in direct contact.

Examples of the conductive paste 6 include a mixture of a resin and a conductive material such as a metal. However, the conductive paste 6 is not particularly limited, and widely known materials can be applied.

The area of the surface of the power supply terminal A and the power supply terminal B that does not face the power supply terminal A of the power supply terminal B is larger than the area of the surface of the power supply terminal A that faces the power supply terminal B. Thereby, the stress due to the load applied to the power supply terminal B can be propagated not to the power supply terminal A but to the base material layer 12.

In FIG. 2, when a force 101 in the vertical direction with respect to the suction surface 21 is applied to the power supply terminal B, the stress 102 propagates in the power supply terminal B, and in the plane direction of the suction surfaces of the terminal holes 41 and 42. At the boundary surface 103, the power supply terminal B is pushed up and comes into contact with a portion wider than the terminal hole 41 of the base material layer 12, so that the stress 102 is propagated only to the base material layer 12. That is, the configuration in which the area of the surface of the power supply terminal B that does not face the power supply terminal A is larger than the area of the surface of the power supply terminal A that faces the power supply terminal B is defined by defining the size relationship. Thus, a state in which stress propagates is created.

As a result, the electrode 3 is prevented from being damaged due to the load applied to the power supply terminal A, and further, the occurrence of cracks in the dielectric layer 11 due to the stress propagated from the electrode 3 is avoided. In particular, when the dielectric layer 11 is very thin, the influence of the stress generated at the interface between the electrode 3 and the dielectric layer 11 is very large. Therefore, according to the present invention, the generation of this stress can be suppressed extremely effectively.

In addition, when the ratio of the area of the end surfaces of the power supply terminal A and the power supply terminal B is 51a: 52a shown in FIG. 1, the range of 1: 5 to 1: 225 is preferable, and 1: 5 to 1: 150 is more preferable. . If this ratio is too small, the contact area between the power supply terminal B and the base material layer 12 is reduced, the stress per unit area at this part is increased, and the base material portion 12 is damaged when an excessive load is applied. There are concerns that arise. However, if this ratio is too large, it will hardly contribute to the effect of the present invention, but there is a concern that the cost and the design freedom of the electrostatic chuck will be severely limited or the design difficulty will increase. Is also not preferred.

Although the terminal hole 4 and the power supply terminal 5 according to the present invention have exemplified the shape of the cross-sectional shape having one step as shown in FIG. 1 as one aspect thereof, the shape is not particularly limited. For example, a multi-stage shape as shown in FIG. 3 (1), a shape formed with a continuous curved surface as shown in FIG. 3 (2), or a linear shape as shown in FIG. 3 (3) may be used. Further, the cross-sectional shape of the power supply terminal A is not particularly limited, and for example, the areas of the upper and lower end surfaces of the power supply terminal A may be different as shown in FIG. Of course, the cross-sectional shape of the power supply terminal A may be a curved shape as clearly shown in another example of the power supply terminal B.

In addition, the feed terminal B can be provided with a through hole 9 so that the space 7 and the back surface 22 side are open. The through-hole 9 has a role of letting gas accumulated in a gap remaining near the electrode 3 to the outside of the electrostatic chuck 1. When the gas accumulates, particularly when an electrostatic chuck is used under vacuum, a pressure difference from the outside of the electrostatic chuck 1 is generated, and the staying gas expands to cause cracks in the base material layer 12 and the electrode 3. This is not preferable because it causes peeling.

In the electrostatic chuck according to the present invention, it is preferable that an interval between the space portions 7 in the vertical direction with respect to the attracting surface 21 is 10 μm or more and 1000 μm or less. If it is less than 10 μm, the interval is so narrow that there is a concern that the stress is propagated through the conductive paste 6, which is not necessarily preferable. However, if it exceeds 1000 μm, the effect of the present invention is not affected, but the electrical continuity between the power supply terminal A and the power supply terminal B may be impaired through the conductive paste 6 applied to the side wall of the space portion 7. Yes, this is also not preferable.

In the electrostatic chuck according to the present invention, it is preferable that both the dielectric layer 11 and the base material layer 12 are made of silica glass. Since silica glass can be produced with high purity and is excellent in workability, it is particularly suitable for application to a semiconductor manufacturing apparatus. Or you may use what added various metal elements to silica glass timely according to the intended purpose.

One form of the manufacturing method of the electrostatic chuck which concerns on this invention is based on the metal material in either one surface of the plate-shaped insulating material which forms a dielectric layer, or one surface of the other plate-shaped insulating material which forms a base-material part. Forming a dielectric layer by forming an electrode pattern, forming a terminal hole by forming a terminal hole in the other plate-shaped insulating material, and forming the dielectric layer and the base material portion. The electrostatic chuck main body is manufactured by pasting together, and the step of fixing the power supply terminal by inserting a conductive paste and a power supply terminal into the terminal hole of the electrostatic chuck main body. Each of these steps does not require a special method, and widely known methods can be applied depending on the material to be used and the purpose of use.

As described above, the electrostatic chuck according to the present invention can suppress the load transmitted from the dielectric layer to the base material layer by reducing the stress and load applied to the power supply terminal and the dielectric layer in the vicinity thereof. Thereby, the crack generation of a base material layer is also reduced. Further, particularly when the dielectric layer is thin, it is possible to provide an electrostatic chuck in which generation of cracks and cracks is suppressed.

Hereinafter, a preferred embodiment of the present invention will be described with reference to FIG. 1, but the present invention is not limited to this example.
(Experiment 1)

A silica glass plate having a diameter of 150 mm and an average thickness of 5 mm is prepared as the dielectric layer 11, and a bipolar metal electrode 3 having a circular comb pattern is formed using a Mo metal film with respect to a range of 148 mm in diameter on the upper surface. It formed by the vacuum evaporation method. A view of the pattern of the electrode 3 as viewed from above is shown in FIG. The film thickness of the electrode 3 is 0.3 μm on average, the width of the electrode 3 is 2 mm on average, and the distance between the electrodes 3 is 0.5 mm on average. Next, a silica glass plate having a diameter of 150 mm and an average thickness of 5 mm was prepared as the base material layer 12. Round terminal holes 4 were formed at two locations corresponding to the outermost electrode portions of the electrode pattern. Then, a sample (Example 1) of a terminal hole 4 comprising a terminal hole 42 having a diameter of 5.1 mm on the back surface 22 and a terminal hole 41 having a diameter of 1.1 mm at a position 4 mm from the back surface 22 in the vertical direction, and the back surface 22 side. Samples (Comparative Example 1) each consisting only of a terminal hole 4 having a diameter of 5.1 mm were produced in the entire vertical direction.

Next, the dielectric layer 11 on which the electrode pattern is formed and the base material layer 12 are overlapped, and pressure fusion at 1300 ° C. and 20 MPa is performed under a reduced pressure of 10 Pa. An electric chuck base was obtained. Then, grinding and polishing were performed so that the average thickness of the dielectric layer 11 of the base of the electrostatic chuck was 150 μm. Then, a cylindrical power supply terminal A made of Mo having a diameter of 1 mm and a length of 0.95 mm processed according to the shape of the terminal hole 4 and a diameter of 5 mm and a length of 5 mm with a through hole having a diameter of 1 mm at the center. After preparing the power feeding terminals B made of Mo and applying the conductive paste of Dortite D-753 (Fujikura Kasei) to the inner wall surface of the terminal hole 4 and one surface of the electrode 3 exposed to the terminal hole 4, the space The feeding terminal A and the feeding terminal B were continuously inserted and fixed so that the interval between the portions 7 was 10 μm. Thus, the electrostatic chuck of Example 1 was obtained. In addition, a cylindrical power supply terminal made of Mo having a diameter of 5 mm and a length of 6 mm was prepared in accordance with the shape of the terminal hole having a through hole having a diameter of 1 mm at the center. The electrostatic chuck of Comparative Example 1 was obtained in the same manner as in Example 1.

In the evaluation method, a load of 0.53 kg / mm ² was applied in the vertical direction of the back surface 22 to the power supply terminal B of each sample protruding from the back surface 22. Specifically, a weight of 10 kg was placed on the power supply terminal B through a plate. Thereafter, the power supply terminal 5 of each sample and the vicinity thereof (about 5 mm diameter range) are visually observed from the upper and lower surfaces under a dark field spot lamp, and cracks are generated in the dielectric layer 11 or the base material layer 12. The presence or absence of cracks and the presence or absence of cracks in the electrode 3 were confirmed.

As a result of the evaluation, in Example 1, neither crack generation nor crack generation in the dielectric layer and the base material layer was observed, but in Comparative Example 1, both crack generation and crack generation were confirmed.
(Experiment 2)

A dielectric layer 11 was produced in the same manner as in Example 1. Next, as the base material layer 12, the same material as in Example 1 was prepared, and the terminal hole 4 consisting of the terminal hole 41 having a diameter of 1.1 mm and the power supply terminal A having a diameter of 1 mm at the position 4 mm in the vertical direction from the back surface 22. These conditions were fixed, and a sample in which several types of diameters of the terminal hole 42 located on the back surface 22 and the power supply terminal B were shaken was produced. The contents are shown in Table 1. The manufacturing conditions other than the conditions shown in Table 1 and the evaluation method were all in accordance with Example 1.

From the results shown in Table 1, in the scope of the present invention, except for a part, no cracks were generated in the dielectric layer and the base material layer, and no cracks were generated in the electrodes. was gotten. However, when the area ratio of the end face of the power supply terminal is out of 1: 5, that is, 1: 2, the occurrence of cracks in the dielectric layer was confirmed although it was slight compared with Example 1. Further, when the area ratio was outside 1: 225, that is, 1: 300 and 1: 500, neither the dielectric layer or the base layer was cracked nor the electrode was cracked. There was concern about the difficulty of designing. Therefore, these were somewhat inferior to those of the more preferred embodiment of the present invention.
(Experiment 3)

Using the sample preparation conditions of Example 1, by changing the length of the power supply terminal A, a sample in which the spacing of the space portion 7 was changed according to the contents of Table 2 was prepared. An electric chuck was manufactured and evaluated.

From the results shown in Table 2, the same results as in Example 1 were obtained within the preferred range of the present invention. However, in the case where the space 7 has an interval of less than 10 μm, that is, 5 μm, a slight crack was observed in the electrode 3. Further, when the space 7 has an interval of more than 1000 μm, that is, 2000 μm, there is a possibility that the electrical continuity between the power supply terminal A and the power supply terminal B is impaired through the conductive paste applied to the side wall of the space. These were somewhat inferior when compared with the more preferable implementation range of the present invention.

As described above, in the electrostatic chuck according to the present invention, particularly in an electrostatic chuck having a thin dielectric layer, the stress and load applied to the power supply terminal and the dielectric layer in the vicinity thereof can be efficiently dispersed. It is possible to provide an electrostatic chuck and a method of manufacturing the same that can be stably obtained.

The electrostatic chuck according to the present invention is suitably used for, for example, a semiconductor manufacturing apparatus for electrostatic adsorption of various electrically insulating substrates. Further, the structure of the power supply terminal portion of the electrostatic chuck according to the present invention can be suitably used for a structure in which a power supply portion for supplying electricity to the inside of the insulator is provided, for example, a heater or a sensor. .

DESCRIPTION OF SYMBOLS 1 ... Electrostatic chuck body, 11 ... Dielectric layer, 12 ... Base material layer, 21 ... Adsorption surface, 22 ... Back surface, 3 ... Electrode, 4 ... Terminal hole, 41 ... Terminal hole 1, 42 ... Terminal hole 2, 5 ... Power feeding terminal, 51 ... Power feeding terminal A, 52 ... Power feeding terminal B, 51a ... End surface portion of the power feeding terminal A facing the power feeding terminal B, 52a ... End surface portion of the power feeding terminal B on the side not facing the power feeding terminal A, 6 ... conductive paste, 7 ... space, 8 ... power supply lead, 9 ... through hole.

Claims (4)

An electrostatic chuck in which an electrode made of a metal layer is embedded in a plate-shaped insulating material, one surface is an adsorption surface, and a terminal hole for inserting a terminal reaching the electrode is formed on the back surface The terminal hole is provided with a power supply terminal A in contact with the electrode, and a power supply terminal B positioned with the power supply terminal A and a space, and the outer peripheral surfaces of the power supply terminal A and the power supply terminal B are arranged. The area of the surface of the power supply terminal B facing the power supply terminal B is larger than the area of the power supply terminal B facing the power supply terminal B. Electrostatic chuck characterized by being large. The electrostatic chuck according to claim 1, wherein an interval between the space portions in a vertical direction with respect to the attracting surface is 10 μm or more and 1000 μm or less. The electrostatic chuck according to claim 1, wherein each of the dielectric layer and the base material layer is made of silica glass. Forming a dielectric layer by forming an electrode pattern of a metal material on either one surface of a plate-like insulating material forming a dielectric layer or one surface of another plate-like insulating material forming a base portion; and Forming a base hole by forming a terminal hole in another plate-like insulating material; bonding the dielectric layer and the base plate to make an electrostatic chuck body; and The electrostatic chuck according to claim 1, further comprising a step of inserting a conductive paste and a power supply terminal into the terminal hole of the electric chuck main body and fixing the power supply terminal. Production method.