JP2011060826A - Electrostatic chuck and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic chuck having improved adhesion between the substrate and the electrode, and to provide a method of manufacturing the same. <P>SOLUTION: In the electrostatic chuck 10 including a ceramic substrate 11 consisting of yttrium oxide, and an electrode 12 provided on the substrate, the substrate has yttrium oxide containing at least one kind of element selected from a group of calcium, magnesium and strontium in the grain boundary phase, and the electrode has platinum and yttrium oxide containing at least one kind of element selected from a group of calcium, magnesium and strontium in the grain boundary phase, wherein the mass ratio of at least one kind of element selected from a group of calcium, magnesium and strontium to the yttrium oxide in the substrate is smaller than the mass ratio of at least one kind of element selected from a group of calcium, magnesium and strontium to the yttrium oxide in the electrode. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electrostatic chuck used for attracting and fixing a semiconductor wafer in a semiconductor manufacturing apparatus such as a plasma etching apparatus, and a manufacturing method thereof.

  In a plasma etching apparatus for etching a semiconductor wafer, an electrostatic chuck is used to attract and fix the semiconductor wafer.

  In this electrostatic chuck, an electrostatic electrode (chuck electrode) is embedded in a substrate made of ceramic such as plate-like alumina, and the semiconductor wafer is fixed to the substrate by an electrostatic force acting between the electrostatic electrode and the semiconductor wafer. It is adsorbed and fixed on the surface (adsorption surface).

Recently, as such an electrostatic chuck, one using yttrium oxide (yttria: Y ₂ O ₃ ) as a base material has been proposed in order to improve corrosion resistance. This electrostatic chuck includes an electrostatic electrode inside an insulator, and the insulator has a laminated structure in which ceramic green sheets mainly composed of yttria are laminated, pressed and fired. Furthermore, the electrostatic electrode is printed on a yttria green sheet with a metallized paste (conductive paste) and fired simultaneously with the insulator. As the metal powder contained in the metallized paste, a raw material powder containing tungsten powder, molybdenum powder or platinum powder as a main component and mixed with yttria powder is used (for example, see Patent Document 1).

  On the other hand, in order to improve the bonding strength between the ceramic substrate and the electrostatic electrode, for example, a flux is included between the ceramic substrate containing alumina and the electrostatic electrode built in the ceramic substrate. An electrostatic chuck having a ceramic material in contact with a substrate has been proposed. (For example, refer to Patent Document 2).

JP 2008-147549 A JP 2009-4649 A

  However, in the electrostatic chuck described in Patent Document 1, there are few restrictions on the shape and thickness of the electrode pattern, but when tungsten powder or molybdenum powder is used as the metal electrode material, the control of the firing conditions is complicated. It must be fired in a reducing atmosphere. For this reason, it is preferable to use platinum (Pt) powder that can be fired in the atmosphere as the electrode material.

  That is, development of a technique for manufacturing an electrostatic chuck using yttrium oxide as a base material and Pt as an electrode material by the simultaneous firing method is required. In this case, there are further problems to be solved. That is, since Pt used as an electrode material has large grain growth during firing, deformation such as warpage and undulation is likely to occur, and voids are easily generated between the substrate and the electrode, resulting in low adhesion. was there.

  Moreover, like the electrostatic chuck described in Patent Document 2, when a ceramic material that includes a flux between the ceramic substrate and the electrostatic electrode and is in contact with the ceramic substrate and the ceramic substrate is provided, the bonding strength is improved, Even though the adhesion can be improved, another material is required and the process is complicated.

  The present invention has been made in response to the above problems of the prior art, and provides an electrostatic chuck with improved adhesion between a substrate and an electrode, and a ceramic green sheet containing yttrium oxide and an oxidation It is an object of the present invention to provide a method for producing an electrostatic chuck using a conductive paste that can be simultaneously fired in an atmosphere and can form a conductor portion having high adhesion to a substrate.

  [Application Example 1] An electrostatic chuck including a ceramic base material made of yttrium oxide and an electrode provided on the base material, wherein the base material is made of calcium, magnesium and strontium in the grain boundary phase. The electrode has yttrium oxide containing at least one element selected, and the electrode has platinum and yttrium oxide containing at least one element selected from the group of calcium, magnesium and strontium in the grain boundary phase, And the mass ratio of at least one element selected from the group of calcium, magnesium and strontium to the yttrium oxide in the substrate is oxidation of at least one element selected from the group of calcium, magnesium and strontium in the electrode It is smaller than the mass ratio with respect to yttrium. To.

  In the present invention, at least one element selected from the group of calcium, magnesium, and strontium that functions as a sintering aid for yttrium oxide is contained in the electrode more than the base material (as an amount relative to yttrium oxide) Sinterability of the common material (yttrium oxide in the electrode) is improved. As a result, the sinterability at the interface between the common material and the substrate is also improved, so that the adhesion between the electrode and the ceramic substrate is improved.

  In addition, sintering aids are added to improve the sinterability of yttrium oxide, a hard-to-sinter material, but increasing the amount of sintering aid powder added to the base material lowers plasma resistance. Leads to. In the present invention, the conductive paste sufficiently contains a sintering aid to improve the sinterability of the co-material and improve the adhesion between the electrode and the ceramic substrate. The amount of the auxiliary agent can be minimized and the plasma resistance of the substrate can be improved.

  [Application Example 2] The electrostatic chuck according to Application Example 1, wherein the platinum and the yttrium oxide in the electrode enter each other's gap.

  In the present invention, since the grain growth of platinum is suppressed by improving the sinterability of the common material, the structure in which platinum and the common material enter each other's voids is obtained, and the adhesion is further improved by the anchor effect. Furthermore, since the platinum shrinkage is reduced by suppressing the grain growth of platinum, deformation such as warpage and undulation is suppressed.

  Application Example 3 In the electrostatic chuck according to Application Example 1 or 2, the electrode has a thickness of 3 to 30 μm.

  The present invention shows a preferred range of electrode thickness. By setting the thickness of the electrode to 3 to 30 μm, it is possible to obtain a stable chucking force, and to suppress deformation of the electrode (warping, waviness, etc.) and a decrease in adhesion between the electrode and the substrate. it can.

Application Example 4 In the electrostatic chuck according to any one of Application Examples 1 to 3, the electrode has a volume resistivity of 1 × 10 ^{−5 to} 5 × 10 ⁻⁴ Ω · cm. To do.

The present invention shows a preferred range of volume resistivity of the electrode. That the volume resistivity of the electrode and less than 1 × ^{10 -5} Ω · cm is difficult for resistivity of platinum is about ^{1 × 10 -5 Ω · cm,} 5 × 10 -4 Ω · cm If it exceeds, stable chucking force may not be expressed.

  [Application Example 5] A conductive paste containing yttrium oxide powder and a powder functioning as a sintering aid for yttrium oxide is obtained by a material containing yttrium oxide powder and powder functioning as a sintering aid for yttrium oxide. A method of manufacturing an electrostatic chuck that is printed on a formed ceramic green sheet and then simultaneously fired, wherein a mass ratio of the sintering aid powder to the yttrium oxide powder in the ceramic green sheet forming material is the conductive property. It is smaller than the mass ratio of the sintering aid powder in the paste to the yttrium oxide powder.

  In the present invention, the powder that functions as a sintering aid for yttrium oxide is contained in the conductive paste more than the material forming the ceramic green sheet, so the sinterability of the co-material (yttrium oxide in the conductive paste) is improved. To do. As a result, since the sinterability at the interface between the common material and the ceramic green sheet is also improved, the adhesion between the conductor portion (conductive paste sintered body) and the base material (ceramic green sheet sintered body) is improved. In addition, since the sinterability of the co-material is improved, grain growth of the metal (for example, platinum) contained in the conductive paste is suppressed, so that the metal and the co-material enter each other's gap, and the anchor Adhesion is further improved by the effect. In addition, since the metal grain growth is suppressed, the firing shrinkage of the metal is reduced, so that deformation such as warping and undulation of the conductor portion is suppressed.

  In addition, sintering aids are added to improve the sinterability of yttrium oxide, a difficult-to-sinter material, but increasing the amount of sintering aid powder added to the base material lowers plasma resistance. Leads to. In the present invention, the conductive paste contains sufficient sintering aids to improve the sinterability of the co-material and improve the adhesion between the conductor part and the base material, The amount of the auxiliary agent can be minimized and the plasma resistance of the substrate can be improved.

  [Application Example 6] In the method of manufacturing an electrostatic chuck according to Application Example 5, the conductive paste includes platinum powder, and the average particle diameter of the platinum powder is the average particle diameter of the yttrium oxide powder included together with the platinum powder. It is characterized by being larger.

  In the present invention, since the average particle diameter of platinum of the conductive paste is larger than the average particle diameter of yttrium oxide as a co-material, the connectivity between the platinum particles is stable during firing, the volume resistivity is stable, and as a result stable. Chuck force is developed. Furthermore, when the average particle diameter of the sintering aid in the conductive paste is smaller than the average particle diameter of yttrium oxide, segregation does not occur, so that the sinterability of yttrium oxide is stabilized.

  Application Example 7 In the method for manufacturing an electrostatic chuck according to Application Example 5 or 6, the conductive paste has a volume ratio of platinum powder to yttrium oxide powder of 30:70 to 80:20. .

  This invention shows the range of the preferable mixing ratio of the platinum powder and the yttrium oxide powder in the conductive paste. By setting the volume ratio of the platinum powder and the yttrium oxide powder to 30:70 to 80:20, it is possible to reduce the difference in thermal expansion coefficient with the base material while maintaining a good volume resistivity. Adhesion between the conductor portion and the substrate can be improved. Moreover, since the amount of the common material which contacts a base material will decrease when the ratio of platinum powder exceeds the said range, adhesiveness falls.

  [Application Example 8] In the method of manufacturing an electrostatic chuck according to any one of Application Examples 5 to 7, the conductive paste is 0.2-2 mass of the sintering aid powder with respect to the yttrium oxide powder. % Content.

  The present invention shows a preferable range of the content of the sintering aid powder in the conductive paste. By setting the content of the sintering aid powder to 0.2 to 2% by mass of the yttrium oxide powder, the sinterability of the common material can be further improved. As a result, since the sinterability at the interface between the common material and the ceramic green sheet is further improved, the adhesion between the conductor portion and the base material can be further improved. In addition, by improving the sinterability of the co-material, it is possible to further suppress the growth of particles such as platinum, and the structure is such that platinum and co-material enter each other's voids, further improving the adhesion by the anchor effect Can be made.

  [Application Example 9] In the method for manufacturing an electrostatic chuck according to any one of Application Examples 5 to 8, the sintering aid powder contains at least one element selected from the group consisting of calcium, magnesium and strontium. It is characterized by being a powder.

  The present invention exemplifies preferred sintering aid powders. By using a powder containing at least one element selected from the group of calcium, magnesium and strontium as the sintering aid powder, the sinterability of the common material can be further improved. As a result, since the sinterability at the interface between the common material and the ceramic green sheet is further improved, the adhesion between the conductor portion and the base material can be further improved. In addition, by improving the sinterability of the co-material, it is possible to further suppress the growth of particles such as platinum, and the structure is such that platinum and co-material enter each other's voids, further improving the adhesion by the anchor effect Can be

  ADVANTAGE OF THE INVENTION According to this invention, the electrostatic chuck which improved the adhesiveness between a base material and an electrode can be provided. In addition, according to the present invention, the manufacture of an electrostatic chuck using a conductive paste that can be simultaneously fired in an oxidizing atmosphere with a ceramic green sheet containing yttrium oxide and can form a conductor portion having high adhesion to the substrate. A method can be provided.

1 is a perspective view showing a partially broken electrostatic chuck device according to an embodiment of the present invention. It is a figure which shows the cross-sectional structure of the electrostatic chuck apparatus shown in FIG. It is a schematic copy figure of the picked-up photograph by the scanning electron microscope (SEM) of the electrostatic electrode formed in one Example of this invention.

  Embodiments according to the present invention will be described below. Although the description will be made based on the drawings, the drawings are provided for illustration only, and the present invention is not limited to the drawings. It should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones.

  FIG. 1 is a partially cutaway perspective view showing an electrostatic chuck device having an electrostatic chuck according to an embodiment of the present invention, and FIG. 2 is a diagram showing a cross-sectional configuration thereof.

  In FIG. 1, reference numeral 10 denotes an electrostatic chuck. The electrostatic chuck 10 includes a base material 11 made of a disk-shaped ceramic having a constant thickness, and an electrostatic electrode 12 embedded therein. Yes. And the electrostatic chuck apparatus 100 is comprised by joining the back surface of the ceramic base material 11 to the surface of the metal base members 20 which consist of aluminum, an aluminum alloy etc., for example. The surface of the ceramic substrate 11 is an adsorption surface 13 for adsorbing and fixing an object to be adsorbed (not shown) such as a semiconductor wafer.

The ceramic substrate 11 is formed in a disk shape having a thickness of 2 mm and a diameter of 300 mm, for example, from a sintered body of a ceramic laminated structure mainly composed of yttrium oxide (Y ₂ O ₃ ).

  The sintered body of this laminated structure is formed as follows. First, an appropriate organic binder or solvent is added to and mixed with a raw material powder containing a powder of yttrium oxide powder and calcium oxide serving as a sintering aid to form a slurry. This is made into a sheet by a doctor blade method to obtain a plurality of ceramic green sheets. These ceramic green sheets are appropriately punched and then laminated to form a ceramic green sheet laminate. This laminate is fired at about 1600 ° C. in an oxidizing atmosphere.

  As a sintering aid for yttrium oxide powder, calcium carbonate, magnesium oxide, and strontium oxide are used in addition to calcium oxide. These sintering aids may be used alone or in a combination of two or more. This sintering aid is preferably contained in a range of 0.01% by mass or more and less than 0.2% by mass with respect to the yttrium oxide powder, and more preferably in a range of 0.05 to 0.15% by mass. . When the content of the sintering aid is less than 0.01% by mass, the sinterability is lowered, and when it is 0.2% by mass or more, the plasma resistance may be lowered. Note that the shape of the ceramic substrate 11 is not particularly limited to a circular shape.

  The electrostatic electrode 12 is for attracting an object to be attracted to the attracting surface 13 by electrostatic force. The electrostatic electrode 12 is formed by printing a conductive paste in a predetermined pattern on a ceramic green sheet in a predetermined pattern, laminating the ceramic green sheet, and simultaneously firing it.

  To the conductive paste, platinum powder, yttrium oxide powder having an average particle size smaller than the platinum powder, and powder functioning as a sintering aid for yttrium oxide are added and mixed with an appropriate organic binder or solvent. The prepared one is used. Examples of the powder that functions as a sintering aid for yttrium oxide include the same powders as those exemplified as the sintering aid for yttrium oxide powder. That is, powders such as calcium oxide, calcium carbonate, magnesium oxide, and strontium oxide are used, and these may be used alone or in combination of two or more. In the conductive paste, the sintering aid is preferably contained in the range of 0.05 to 2% by mass, and more preferably in the range of 0.1 to 1% by mass with respect to the yttrium oxide powder. However, the ratio of the sintering aid to yttrium oxide is such that the conductive paste is larger than the material forming the ceramic green sheet described above. In addition, each average particle diameter of platinum powder and yttrium oxide powder can be measured with a laser diffraction type particle size distribution measuring apparatus.

  By using a conductive paste containing such platinum powder, firing can be performed in an oxidizing atmosphere. By adding yttrium oxide powder having an average particle size smaller than that of platinum powder and adding more powder that functions as a sintering aid for yttrium oxide than the ceramic green sheet (as an amount relative to yttrium oxide powder), Since the sinterability of the material (yttrium oxide in the conductive paste) is improved, and as a result, the sinterability of the interface between the common material and the ceramic green sheet is also improved, the adhesion to the ceramic substrate 11 is improved. Moreover, since the grain growth of platinum is suppressed by improving the sinterability of the common material, the structure in which platinum and the common material enter each other's voids is obtained, and the adhesion is further improved by the anchor effect. Further, since the firing shrinkage of the metal is reduced by suppressing the growth of platinum grains, deformation such as warpage and undulation is suppressed. Therefore, it is possible to form the electrostatic electrode 12 having good adhesion to the ceramic substrate 11 and having no or little deformation such as warpage and swell.

  From the viewpoint of enhancing the adhesion between the electrostatic electrode 12 and the ceramic substrate 11 and suppressing deformation such as warping and undulation of the electrostatic electrode 12, the blending ratio of the platinum powder and the yttrium oxide powder in the conductive paste The volume ratio is preferably 30:70 to 80:20, and more preferably 40:60 to 60:40.

  As a raw material powder, the yttrium oxide powder preferably has an average particle diameter of 0.1 to 5 μm, and the platinum powder has an average particle diameter of 0.5 to 10 μm and larger than the average particle diameter of the yttrium oxide powder. It is preferable. The platinum powder preferably has a particle size smaller than the thickness of the electrode. Further, the sintering aid powder preferably has an average particle size of 0.05 to 5 μm and is smaller than the average particle size of the yttrium oxide powder. The average particle size of the raw material powder can be measured with a laser diffraction particle size distribution measuring device.

  The electrostatic electrode 12 is formed, for example, at a position 300 μm away from the adsorption surface 13 of the ceramic substrate 11, and the thickness is preferably in the range of 3 to 30 μm, and more preferably in the range of 5 to 20 μm. If the thickness of the electrostatic electrode 12 is less than 3 μm, stable chucking force is difficult to develop. Conversely, if the thickness exceeds 30 μm, the difference between the firing shrinkage and the thermal expansion coefficient tends to increase, resulting in a decrease in adhesion and deformation. There is a fear.

The electrostatic electrode 12 preferably has a volume resistivity of 1 × 10 ^{−5 to} 5 × 10 ⁻⁴ Ω · cm, and preferably 1 × 10 ^{−5 to} 3 × 10 ⁻⁴ Ω · cm. More preferred. If the volume resistivity is less than 1 × 10 ⁻⁵ Ω · cm, the specific resistivity of platinum is about 1 × 10 ⁻⁵ Ω · cm, and cannot be lowered any further. 5 × 10 ⁻⁴ Ω · cm If it exceeds, stable chucking force may not be exhibited.

  Although not shown, an electrode terminal for applying an electrode to the electrostatic electrode 12 is provided on the back surface of the ceramic substrate 11, and a pin terminal (not shown) is joined to the electrode terminal. ing. The pin terminal is disposed in a through hole (not shown) provided through the base member 20 in the thickness direction, and a voltage is applied to the electrostatic electrode 12 by joining an external terminal to the pin terminal. The pin terminal may be directly joined to the electrostatic electrode 12 by brazing or the like. In that case, a through hole is provided from the back surface of the ceramic substrate 11 toward the electrostatic electrode 12.

  As described above, the base plate 20 is made of a metal such as aluminum or an aluminum alloy, and has a diameter larger than that of the electrostatic chuck 10 so that the entire electrostatic chuck 10 is placed, for example, a thickness of 40 mm and a diameter of 330 mm. It is a disk shape. In general, a flow path (not shown) for circulating the cooling water is provided inside the base plate 20. The base plate 20 can be cooled by circulating cooling water through the flow path.

  It goes without saying that the present invention is not limited to the contents described in the embodiment described above, and can be implemented in various modes without departing from the gist of the present invention. For example, the electrostatic chuck apparatus 100 shown in FIG. 1 applies a voltage between a plurality of electrostatic electrodes 12 embedded in the electrostatic chuck 10 to thereby provide a surface (suction surface) 13 of the electrostatic chuck 10. It is of a so-called bipolar structure that adsorbs an object to be adsorbed (not shown) such as a semiconductor wafer, but a single electrostatic electrode is embedded inside the electrostatic chuck and arranged outside this electrostatic electrode. A so-called monopolar structure in which an object to be adsorbed is adsorbed by applying a voltage between the electrodes may be used.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but these examples do not limit the scope of the present invention. In addition, the average particle diameter of the raw material powder is measured by a laser diffraction particle size distribution measuring device (LA-750) manufactured by Horiba.

Example 1
Yttrium oxide powder (average particle size 0.8 μm) 99.9% by mass and calcium carbonate powder (CaCO ₃ ) (average particle size 0.1 μm) 0.1% by mass (calculated in terms of calcium oxide (CaO)) as a dispersant The mixture was thoroughly wet-mixed in a mixed solvent of ethanol and toluene (mass ratio 1: 1) to which was added, and then a binder (butyral resin) was added and further mixed to obtain a fluid slurry. Next, a ceramic green sheet having a thickness of 0.2 mm was obtained from this slurry by a doctor blade method.

  Further, the platinum powder (average particle size 2 μm) and the yttrium oxide powder (average particle size 0.8 μm) are weighed so as to have a volume ratio of 1: 1. Calcium carbonate powder (average particle size 0.1 μm) is weighed so as to be 5% by mass, mixed with a dispersant, binder (ethylcellulose) and terpineol, and kneaded with three rolls to prepare a conductive paste. did.

  The ceramic green sheet is cut to a size of 450 mm square, and the four cut ceramic green sheets are laminated under the conditions of 40 ° C. and 0.49 MPa, and then the conductive paste is used on the laminated body. The pattern of the electrostatic electrode was printed by a screen printing method. Further, 10 cut ceramic green sheets were laminated under the same conditions as described above, and a through-hole having a diameter of 5 mm was formed in the laminated body using a drill to serve as a hole for connecting a pin terminal. Thereafter, the laminate (4 layers) on which the pattern of the electrostatic electrode is printed is laminated on the laminate (10 layers) in which the through holes are formed, with the pattern printing surface facing the laminate (10 layers) side. Bonding was performed under the conditions of 5 ° C. and 5.88 MPa.

  The laminated body of ceramic green sheets laminated and pressure-bonded as described above was processed into a disc having a diameter of 400 mm. The processed laminate is degreased at 300 ° C. for 5 hours in the air, then fired at 1600 ° C. in the air, and further corrected for warping at 1500 ° C. in the air. A ceramic sintered body having a thickness of about 2 mm was obtained. The amount of inorganic powder such as yttrium oxide powder in the electrostatic electrode and ceramic sintered body is basically the same as the amount contained in the conductive paste and ceramic green sheet before firing.

  After the ceramic sintered body is subjected to parallel grinding, the ceramic sintered body is bonded to the surface of a metal base plate that has been previously provided with through holes at positions corresponding to the through holes of the ceramic sintered body. Bonding was performed using an agent, and a pin terminal was bonded to the electrostatic electrode with a conductive adhesive to produce an electrostatic chuck device.

Examples 2-9, Comparative Examples 1-4
Except for changing the type and amount of sintering aid powder and yttrium oxide powder used in the conductive paste and base material, and the mixing ratio of platinum powder and yttrium oxide powder in the conductive paste as shown in Table 1 and Table 2. An electrostatic chuck device was manufactured in the same manner as in Example 1.

  The cross section of the ceramic sintered body of the electrostatic chuck device obtained in each of the above examples and comparative examples was imaged with a scanning electron microscope (SEM) (1000 times), and the structure of the electrostatic electrode was dense. While observing the presence or absence of delamination from the ceramic sintered body, the thickness of the electrostatic electrode was measured from the photograph. The volume resistivity of the electrostatic electrode was measured using an insulation resistance meter according to JIS C 2141. These results are shown in the lower column of Tables 1 and 2. FIG. 3 is a schematic copy of a photograph taken by SEM of a cross section of the ceramic sintered body in Example 1. In FIG. 3, reference numerals 101 and 102 denote a platinum particle portion and an yttrium oxide particle portion, respectively. As is apparent from FIG. 3, there is no clear boundary between the co-material and the base material, and it can be seen that the electrode and the base material are in good contact.

  As is clear from Tables 1 and 2, the electrostatic electrodes of the examples in which the ratio of the sintering aid powder to the yttrium oxide powder is larger in the conductive paste than in the base material are both structured. It was dense and no peeling from the ceramic sintered body was observed. On the other hand, the electrostatic electrode of the comparative example in which the ratio of the sintering aid powder to the yttrium oxide powder is the same for the base material and the conductive paste, or the base material is larger than the conductive paste is sufficient. It was not a dense structure and some peeling was observed.

  DESCRIPTION OF SYMBOLS 10 ... Electrostatic chuck, 11 ... Ceramic base material, 12 ... Electrostatic electrode, 13 ... Adsorption surface, 20 ... Base member, 100 ... Electrostatic chuck apparatus, 101 ... Platinum particle part, 102 Yttrium oxide part.

Claims (9)

An electrostatic chuck comprising a ceramic substrate made of yttrium oxide and an electrode provided on the substrate,
The substrate has yttrium oxide containing at least one element selected from the group of calcium, magnesium and strontium in the grain boundary phase;
The electrode has platinum and yttrium oxide containing at least one element selected from the group of calcium, magnesium and strontium in the grain boundary phase, and selected from the group of calcium, magnesium and strontium in the substrate The electrostatic chuck is characterized in that a mass ratio of at least one element to yttrium oxide is smaller than a mass ratio of at least one element selected from the group of calcium, magnesium and strontium to the yttrium oxide in the electrode.   The electrostatic chuck according to claim 1, wherein the platinum and the yttrium oxide in the electrode enter a gap of the other party.   The electrostatic chuck according to claim 1, wherein the electrode has a thickness of 3 to 30 μm. The electrostatic chuck according to claim 1, wherein the electrode has a volume resistivity of 1 × 10 ^{−5 to} 5 × 10 ⁻⁴ Ω · cm. A ceramic green formed of a material including a conductive paste including yttrium oxide powder and powder functioning as a sintering aid for yttrium oxide, and a material including yttrium oxide powder and powder functioning as a sintering aid for yttrium oxide. A method of manufacturing an electrostatic chuck that is fired simultaneously after printing on a sheet,
A static mass characterized in that a mass ratio of the sintering aid powder in the ceramic green sheet forming material to the yttrium oxide powder is smaller than a mass ratio of the sintering aid powder in the conductive paste to the yttrium oxide powder. Manufacturing method of electric chuck.   6. The method of manufacturing an electrostatic chuck according to claim 5, wherein the conductive paste contains platinum powder, and the average particle size of the platinum powder is larger than the average particle size of the yttrium oxide powder contained together with the platinum powder. .   7. The method for manufacturing an electrostatic chuck according to claim 5, wherein the conductive paste has a volume ratio of platinum powder to yttrium oxide powder of 30:70 to 80:20.   8. The electrostatic chuck according to claim 5, wherein the conductive paste contains 0.2 to 2 mass% of the sintering aid powder with respect to the yttrium oxide powder. 9. Method.   9. The electrostatic chuck according to claim 5, wherein the sintering aid powder is a powder containing at least one element selected from the group consisting of calcium, magnesium and strontium. Method.

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