阅读说明：本技术 氮化铝质烧结体以及半导体保持装置 (Aluminum nitride sintered body and semiconductor holding device ) 是由 王雨丛 佐藤政宏 口町和一 于 2018-05-29 设计创作，主要内容包括：本发明的氮化铝质烧结体(1)包含含有Mg的氮化铝的晶体颗粒(2)；具有石榴石型的晶体结构且含有稀土类元素和Al的复合氧化物；以及含有Mg和Al的复合氮氧化物。在氮化铝的晶体颗粒(2)间散布有复合氧化物的颗粒(3)和复合氮氧化物的颗粒(4)。复合氧化物可以含有Y。将氮化铝的晶体颗粒(2)所包含的全部金属元素设为100mol％时,氮化铝的晶体颗粒(2)的Mg的含量可以为0.1mol％以上且1.0mol％以下。本发明的半导体保持装置具备该氮化铝质烧结体(1)和静电吸附用电极(13)。(The aluminum nitride sintered body (1) of the present invention comprises crystal particles (2) of aluminum nitride containing Mg; a composite oxide having a garnet-type crystal structure and containing a rare earth element and Al; and composite nitrogen oxides containing Mg and Al. Particles (3) of a composite oxide and particles (4) of a composite oxynitride are dispersed among crystal particles (2) of aluminum nitride. The composite oxide may contain Y. The content of Mg in the aluminum nitride crystal particles (2) may be 0.1 mol% or more and 1.0 mol% or less, assuming that all the metal elements contained in the aluminum nitride crystal particles (2) are 100 mol%. The semiconductor holding device of the present invention comprises the aluminum nitride sintered body (1) and an electrostatic adsorption electrode (13).)

1. An aluminum nitride sintered body, comprising:

crystal particles of aluminum nitride containing Mg;

a composite oxide having a garnet-type crystal structure and containing a rare earth element and Al; and

contains a composite nitrogen oxide of Mg and Al,

the granular composite oxide and the granular composite oxynitride are dispersed among the crystal grains of the aluminum nitride.

2. The aluminum nitride sintered body according to claim 1, wherein,

the composite oxide contains Y.

3. The aluminum nitride sintered body according to claim 1 or 2, wherein,

the amount of Mg contained in the aluminum nitride crystal particles is 0.1 mol% or more and 1.0 mol% or less, assuming that all the metal elements contained in the aluminum nitride crystal particles are 100 mol%.

4. A semiconductor holding device comprising an aluminum nitride sintered body and an electrostatic adsorption electrode,

the aluminum nitride sintered body according to any one of claims 1 to 3.

Technical Field

The present invention relates to an aluminum nitride sintered body and a semiconductor holding device.

Background

In a semiconductor manufacturing apparatus used in a dry process (film formation, cleaning, dry etching, etc.) for semiconductor manufacturing, a halogen-based plasma such as F, Cl, which has high reactivity, is used as a substance for film formation, etching, or cleaning. As a material for holding a semiconductor wafer used in such a semiconductor manufacturing apparatus, for example, a heater, an electrostatic chuck, or the like, an aluminum nitride sintered body is used. The aluminum nitride sintered body has high mechanical strength, high thermal shock resistance, high volume resistivity, high thermal conductivity, and high corrosion resistance to halogen-based gases. When the corrosion resistance to halogen-based gas is high, the corrosion resistance to halogen-based plasma is also high. Hereinafter, the corrosion resistance to plasma is sometimes referred to as plasma resistance.

Semiconductor integrated circuits require further refinement and densification. As one of the methods for further miniaturizing and densifying a semiconductor integrated circuit, an attempt has been made to process a semiconductor wafer or the like at a high temperature of, for example, 600 ℃. However, at such high temperatures, the resistivity of the usual aluminum nitride sintered body is lowered to 10⁶Not more than Ω m, it is difficult to maintain the insulation property.

As an aluminum nitride sintered body having excellent insulation properties in a high temperature region, an aluminum nitride sintered body to which magnesium or a compound containing magnesium is added is known. For example, patent document 1 discloses a ceramic sintered body having aluminum nitride which contains a crystal boundary phase of magnesium and has high insulation resistance at 700 ℃. Patent document 2 discloses an aluminum nitride sintered body having a high volume resistivity at 800 ℃, which includes aluminum nitride, a rare earth compound, and MgAl₂O₄The aluminum nitride sintered body of (1).

Disclosure of Invention

The aluminum nitride sintered body of the present invention comprises crystal particles of aluminum nitride containing Mg, a composite oxide having a garnet-type crystal structure and containing a rare earth element and Al, and a composite oxynitride containing Mg and Al, wherein the composite oxide and the composite oxynitride in the form of particles are dispersed among the crystal particles of aluminum nitride.

The semiconductor holding device of the present invention has an aluminum nitride sintered body and an electrostatic adsorption electrode, and the aluminum nitride sintered body is the above aluminum nitride sintered body.

Drawings

Fig. 1 is a sectional view schematically showing a structure in one embodiment of an aluminum nitride sintered body.

Fig. 2 is a perspective view showing an example of the electrostatic chuck.

FIG. 3 is a cross-sectional view taken along line iii-iii of FIG. 2.

Fig. 4 is a perspective view showing another example of the electrostatic chuck.

Fig. 5 is a sectional view taken along line v-v of fig. 4.

Detailed Description

As shown in fig. 1, an aluminum nitride sintered body 1 of the present embodiment includes crystal grains 2 of aluminum nitride containing Mg, a composite oxide containing a rare earth element and Al, and a composite oxynitride containing Mg and Al. The crystal particles 2 of aluminum nitride are interspersed with the granular composite oxide and the composite oxynitride, that is, the composite oxide interspersed particles 3 and the composite oxynitride particles 4. Here, the granular state means, for example, a case where the aspect ratio of the maximum length to the minimum length or thickness of the cross section is 5 or less.

The aluminum nitride crystal has Al and N present in a ratio of 1: 1 and forms a crystal lattice. When oxygen (O) is dissolved in the aluminum nitride crystal, Al vacancies are generated. This is because Al and O become stable at a ratio of 2: 3. Since Al vacancies serve as a conductive carrier at high temperatures, the insulation resistance of the aluminum nitride sintered body having aluminum nitride crystals with oxygen dissolved therein is lowered at high temperatures. Hereinafter, the volume resistivity may be used instead of the insulation resistance.

Since the aluminum nitride sintered body 1 of the present embodiment contains a rare earth element, a part of oxygen dissolved in the crystal grains 2 of aluminum nitride reacts with the rare earth element. As a result, the amount of oxygen dissolved in the crystal grains 2 of aluminum nitride is reduced. The more the amount of the rare earth element contained in the aluminum nitride sintered body 1, the less the amount of oxygen solid-dissolved in the crystal grains 2 of aluminum nitride.

Further, the crystal grains 2 of aluminum nitride contain Mg, that is, Mg is solid-dissolved in the crystal grains 2 of aluminum nitride, whereby oxygen solid-dissolved in the crystal grains 2 of aluminum nitride is bonded to Mg. As a result, the generation of Al vacancies in the aluminum nitride crystal grains 2 is suppressed, and high insulation resistance can be maintained even at high temperatures. Hereinafter, aluminum nitride may be abbreviated as AlN. For example, the aluminum nitride sintered body 1 may be simply referred to as an AlN sintered body 1, and the crystal grains 2 of aluminum nitride may be simply referred to as AlN grains 2.

Further, in the present embodiment, the particles 3 containing a composite oxide of a rare earth element and Al have a garnet-type crystal structure. The composite oxide of the rare earth element and Al forms a garnet-type (R) depending on the ratio of the rare earth element (R) to Al₃Al₅O₁₂) Perovskite type (RAlO)₃) Melilite type (R)₄Al₂O₉) And the like. Among them, a composite oxide having a garnet-type crystal structure has high insulation resistance particularly at high temperatures. Therefore, the particles 3 contained in the aluminum nitride sintered body 1, that is, the composite oxide of the rare earth element and aluminum have a garnet-type crystal structure, so that the volume resistivity of the aluminum nitride sintered body 1 of the present embodiment is increased at high temperature. Hereinafter, the composite oxide of the rare earth element and Al may be simply referred to as a composite oxide, and the particles 3 containing the composite oxide of the rare earth element and Al may be simply referred to as composite oxide particles 3.

A composite oxide having a crystal structure other than the garnet type may be substantially absent in the aluminum nitride sintered body 1. In other words, the aluminum nitride sintered body 1 of the present embodiment can also be measured by X-ray diffraction (XRD) without detecting the crystal phase of the composite oxide other than the garnet structure.

The AlN sintered body 1 of the present embodiment further includes particles 4 containing a composite oxynitride of Mg and Al. Plasma resistance of composite nitrogen oxide (MgAlON) of Mg and Al is higher than that of MgAl₂O₄And Mg-containing oxides such as MgO have high plasma resistance. Such a composite nitrogen oxide exists between the crystal grains 2 of aluminum nitride, and the AlN sintered body 1 has high plasma resistance.

In addition, with MgAl₂O₄The difference between the thermal expansion coefficient of a composite oxynitride (MgAlON) of Mg and Al and the thermal expansion coefficient of AlN is smaller than that of Mg-containing oxides such as MgO. Therefore, MgAl exists between the crystal grains 2 of AlN₂O₄In the case of MgO, as in the present embodiment, when a composite oxynitride (MgAlON) of Mg and Al exists between the AlN crystal grains 2, the residual stress received in the vicinity of the grain boundaries of the AlN crystal grains 2 can be reduced, and the plasma resistance of the AlN sintered body 1 can be improved. As described above, in the present embodiment, the particles 4 containing a composite oxynitride of Mg and Al exist between the crystal particles 2 of aluminum nitride, whereby the plasma resistance of the aluminum nitride sintered body 1 can be maintained high. Hereinafter, the particles 4 containing a composite oxynitride of Mg and Al may be simply referred to as composite oxynitride particles 4.

In the present embodiment, the composite oxide particles 3 and the composite oxynitride particles 4 are dispersed among the AlN particles 2. That is, in the cross section of the AlN sintered body 1, the composite oxide particles 3 and the composite oxynitride particles 4 are present as particles on the grain boundary triple points or the grain boundary between the AlN particles 2, rather than covering the surfaces of the AlN particles 2 as continuous grain boundary layers. In other words, the AlN particles 2 and the adjacent other AlN particles 2 have a predetermined proportion, for example, 30% or more of a portion that is in direct contact without another phase (grain boundary layer such as a composite oxide crystal or a composite oxynitride). The ratio of the portions where the AlN particles 2 directly contact each other may be, for example, an average value of the ratios where the outlines of the AlN particles 2 directly contact the outlines of the other AlN particles 2 on the cross section of the AlN sintered body 1.

AlN has high thermal conductivity, and the thermal conductivity of the AlN sintered body 1 is affected by the crystal structure of the AlN particles 2 and the structure of the sintered body. For example, if other elements such as oxygen are dissolved in the AlN particles 2 in a solid solution to disturb the crystal structure, or if a grain boundary layer having low thermal conductivity is sandwiched between the AlN particles 2, the thermal conductivity of the AlN sintered body 1 decreases.

In order to improve characteristics other than thermal conductivity, for example, insulation properties of the AlN particles 2 at high temperatures, when Mg is dissolved in the AlN particles 2 during firing of the AlN sintered body 1, or when a solid solution amount of oxygen dissolved in the AlN particles 2 is to be reduced by adding a rare earth element, the remaining additive components may form a grain boundary phase to cover the surfaces of the AlN particles 2, and heat conduction between adjacent AlN particles 2 may be reduced. In the present embodiment, the composite oxide and the composite oxynitride that are not dissolved in the AlN particles 2 are not coated on the surfaces of the AlN particles 2 as grain boundary layers, but are dispersed as the composite oxide particles 3 and the composite oxynitride particles 4 on the grain boundary triple points or the interplanar grain boundaries between the AlN particles 2, respectively. In this case, the adjacent AlN particles 2 have portions in direct contact with each other, and therefore the thermal conductivity of the AlN sintered body 1 can be maintained high.

In addition, for example, even if the composite oxide or the composite oxynitride has a low volume resistivity, the volume resistivity of the AlN sintered body 1 can be maintained high by dispersing the composite oxide particles 3 and the composite oxynitride particles 4 in such a manner that the composite oxide particles and the composite oxynitride particles are not present continuously at the grain boundaries of the AlN particles 2, but the granular composite oxide and the composite oxynitride particles are present separately and independently at the grain boundaries of the AlN particles 2.

The AlN particles 2 may have an average particle diameter of, for example, 10 μm or less. Further, the thickness may be 1 μm or more and 10 μm or less, and further 3 μm or more and 8 μm or less. By reducing the average particle size of the AlN particles 2 to 10 μm or less, the number of grain boundaries in the AlN sintered body 1 increases. When the number of grain boundaries increases, the composite oxide and the composite nitrogen oxide become granular and are dispersed in a plurality of grain boundaries. As a result, the composite oxide particles 3 and the composite oxynitride particles 4 can be dispersed in the grain boundaries between the AlN particles 2. The average particle diameters of the composite oxide particles 3 and the composite oxynitride particles 4 may be 3 μm or less, respectively. By setting the average particle diameters of the AlN particles 2, the composite oxide particles 3, and the composite nitrogen oxide particles 4 within this range, the thermal conductivity and the volume resistivity of the AlN sintered body 1 can be maintained high.

The point that the composite oxide particles 3 and the composite oxynitride particles 4 are dispersed among the AlN particles 2 can be confirmed, for example, as follows. The fracture surface of the AlN sintered body 1 or the mirror-polished cross section may be observed structurally using a Scanning Electron Microscope (SEM), a Scanning Transmission Electron Microscope (STEM), a Transmission Electron Microscope (TEM), or the like with an element analyzer, and the presence of particles or a grain boundary layer may be confirmed. The observed grains and grain boundary layer may be subjected to elemental analysis to confirm the composition of the grains and grain boundary layer.

When the total metal elements contained in the AlN particles 2 is set to 100 mol%, the content of Mg contained in the AlN particles 2, that is, the solid solution amount of Mg that is solid-dissolved in the AlN particles 2, may be, for example, 0.1 to 1.0 mol%, and particularly, may be 0.3 to 0.6 mol%. By setting the Mg content contained in the AlN particle 2 to 0.1 mol% or more, the resistivity of the AlN particle 2 can be increased. By setting the Mg content contained in the AlN particles 2 to 1.0 mol% or less, the thermal conductivity of the AlN particles 2 can be maintained high. The content of Mg contained in the AlN particles 2 can be obtained by performing local elemental analysis such as wavelength dispersive X-ray spectroscopy (WDS), energy dispersive X-ray spectroscopy (EDS), Secondary Ion Mass Spectroscopy (SIMS) and the like of the AlN particles 2 using the fracture surface or the mirror-polished cross section of the AlN sintered body 1.

The kind of rare earth element forming the composite oxide particles 3 is not particularly limited. Examples of the rare earth elements include Y, La, Ce, Ho, Gd, Nd, Sm, Dy, Yb, Er, Lu, and the like. Among them, Y (yttrium) can be used. Y is likely to form a garnet-type crystal structure with Al, and is highly efficient in reducing the amount of oxygen dissolved in AlN crystal. Garnet-type composite oxide phase formed with other rare earth elements and AlIn contrast, a composite oxide of Y and Al (Y) having a garnet-type crystal structure₃Al₅O₁₂Also known as YAG) has a higher volume resistivity. The presence of the garnet-type complex oxide 3 in the AlN sintered body 1 can be confirmed by X-ray diffraction (XRD) measurement of the AlN sintered body 1.

The thermal conductivity and plasma resistance of the AlN sintered body 1 are also greatly affected by the density of the AlN sintered body 1. In order to achieve high thermal conductivity and plasma resistance, the open porosity of the AlN sintered body 1 may be 0.2% or less.

The aluminum nitride sintered body 1 of the present embodiment can also be produced as follows. For example, an aluminum nitride powder having a purity of 99% or more, an average particle diameter of 0.5 to 1.0 μm and an oxygen content of 1.2 mass% or less, an average particle diameter of 0.5 to 1.2 μm and a specific surface area BET of 3m is prepared as a raw material²/g～10m²A rare earth compound powder per g, and a powder of a magnesium (Mg) -containing compound having a purity of 99% or more and an average particle diameter of 0.5 to 1.2 μm, for example, magnesium hydroxide (Mg (OH)₂) Powder, magnesium carbonate (MgCO)₃) Powder or magnesium oxide (MgO) powder. Hereinafter, the aluminum nitride powder may be referred to as AlN powder, and a compound containing magnesium (Mg) may be referred to as a Mg-containing compound.

Added in terms of oxide (R) to 100 mol% of the AlN powder₂O₃Expressed as R, rare earth element) of 0.08 mol% to 1.2 mol% and a powder of a Mg-containing compound of 0.3 mol% to 4.0 mol% in terms of oxide (MgO-expressed) are mixed to prepare a mixed powder. Hereinafter, unless otherwise specified, the additive amount is expressed in terms of oxide. An organic binder is appropriately added to the obtained mixed powder, and the mixture is molded into a predetermined shape to obtain a molded body.

The obtained compact is fired in a nitrogen atmosphere at a predetermined maximum temperature and firing curve, thereby obtaining an AlN sintered body according to the present embodiment.

The amount of the rare earth oxide powder added was set to 100 mol% based on the AlN powderWhen the content is 0.08 mol% or more in terms of oxide, oxygen contained in the AlN particle 2 can be reduced, and the resistivity of the AlN particle 2 can be increased. By setting the addition amount of the rare earth oxide powder to 1.2 mol% or less, the garnet-type crystal structure of the rare earth element and Al is easily formed, and it is difficult to form other perovskite-type (RAlO) crystals₃) Melilite type (R)₄Al₂O₉) Other crystal structures with low resistivity and low thermal conductivity at high temperatures. This can improve the volume resistivity and thermal conductivity of the AlN sintered body 1. The amount of the rare earth oxide powder added may be set to 0.15 mol% to 0.45 mol%, in particular. The rare earth compound added to the AlN powder may be an organic salt, an inorganic salt, or a solution thereof, in addition to the oxide powder.

By setting the amount of addition of the Mg-containing compound powder to 0.3 mol% or more in terms of oxide with respect to 100 mol% of the AlN powder, Al vacancies existing in the AlN particles 2 can be reduced. By setting the addition amount of the Mg-containing compound powder to 4.0 mol% or less, excessive solid solution of Mg can be suppressed, and the thermal conductivity of the AlN particles 2 can be maintained. The amount of the powder of the Mg-containing compound to be added may be set to 0.5 mol% to 1.7 mol%, in particular. The Mg-containing compound added to the AlN powder may be an organic salt, an inorganic salt, or a solution thereof, in addition to magnesium oxide, magnesium hydroxide, and magnesium carbonate. Among these, magnesium hydroxide is decomposed by heating, and the surface activity of the decomposed powder is high, so when used as a Mg-containing compound, Mg is easily dissolved in the AlN particles 2.

The term "1.0 mol% in terms of oxide" added to 100 mol% of the AlN powder means that 1.0mol of R is added to 100mol of AlN₂O₃The rare earth compound of (1). The Mg-containing compound added in an amount of 1.0 mol% in terms of oxide to 100 mol% of the AlN powder means that 1.0mol of MgO is added to 100mol of AlN.

Further, by setting the amount of oxygen contained in the AlN powder to 1.2 mass% or less, the AlN sintered body 1 having high volume resistivity and thermal conductivity can be efficiently obtained.

The raw materials may be mixed by a known method, for example, by a method such as rotary ball milling, vibration ball milling, bead milling, or high-speed stirring. The forming method may use well-known forming. Specific examples of the molding method include sheet molding such as die pressing, cold isostatic pressing, doctor blade method and rolling method, extrusion molding, and the like.

The firing may be performed under predetermined conditions as shown below. The specified conditions refer to conditions concerning the temperature rise in the temperature rise process from 1500 ℃ to the maximum temperature, the maximum temperature and the holding time, and the cooling rate in the cooling process from the maximum temperature to 1400 ℃.

In the temperature rise process from 1500 ℃ to the highest temperature, the temperature rise speed is set to be 0.5 ℃/min to 5.0 ℃/min. If the temperature increase rate is set to 5.0 ℃/min or less, it is possible to ensure a time for the rare earth element to react with oxygen present in AlN and a time for Mg to diffuse into AlN particles 2 during the temperature increase process. In addition, in the temperature raising process, AlN and MgO react to form a solid solution in the vicinity of the surface of the AlN particle 2. The solid solution forms MgAlON during subsequent holding at the highest temperature. By setting the temperature rise rate to 0.5 ℃/min or more, the grain growth of the AlN particles 2 can be suppressed, and a dense AlN sintered body 1 can be obtained. In this temperature raising process, the phases of compounds other than AlN formed on the surfaces of the AlN particles 2 are collectively referred to as grain boundary phases.

The maximum temperature of firing is 1700 to 1900 ℃. By setting the maximum temperature to 1700 ℃ or higher, the above-described respective reactions sufficiently proceed, and densification also proceeds. By setting the maximum temperature to 1900 ℃ or lower, the grain growth of the AlN grains 2 can be suppressed. The maximum temperature of the firing may be in the range of 1750 to 1850 ℃ from the viewpoint of the progress of densification and the suppression of grain growth. The holding time at the highest temperature may be arbitrarily changed depending on the average particle diameter of the raw material, the specific surface area, the filling ratio of the compact, and the size of the compact.

In the cooling process from the highest temperature to 1400 ℃, the cooling temperature may be set to 0.3 ℃/min to 5.0 ℃/min. In the cooling process, the surface tension between the AlN particles 2 and the grain boundary phase changes with a decrease in temperature. By setting the cooling rate to 0.3 ℃/min or more, the grain growth of the AlN particles 2 can be suppressed, and a dense AlN sintered body 1 can be obtained. By setting the cooling rate to 5.0 ℃/min or less, the time for the grain boundary phase to move can be secured according to the change in the surface tension between the AlN particles 2 and the grain boundary phase. As a result, the grain boundary phase is concentrated from the grain boundary between both surfaces toward the triple point of the grain boundary, or the grain boundary phase is locally aggregated at the grain boundary between both surfaces to form a granular shape, and the AlN sintered body 1 having a structure in which the composite oxide particles 3 and the composite oxynitride particles 4 are dispersed among the AlN particles 2 is obtained. In such an AlN sintered body 1, the AlN particles 2 have portions in direct contact with each other at grain boundaries. As a result, the AlN sintered body 1 has high thermal conductivity and high volume resistivity.

In the cooling process, if the cooling rate exceeds 5.0 ℃/min, it is difficult to ensure the time for the grain boundary phase to move. Therefore, the crystal boundary phase covers the surface of the AlN particle 2, and the thermal conduction between adjacent AlN particles 2 may decrease.

Instead of the control of the temperature increase rate in the temperature increase process and the control of the cooling rate in the cooling process as described above, a process of holding at a specific temperature in the temperature increase process and a specific temperature in the cooling process for a predetermined time may be added to the firing process.

In the AlN sintered body 1 of the present embodiment, the metal elements may include Si, Ca, Ti, Mn, Ni, Mo, W, and the like in an amount of 0.5 mass% or less in addition to the Al, Mg, and rare earth element (R) described above. By adding these metal elements, sinterability and bondability to the electrode can be improved without lowering the required function.

Fig. 2 is a perspective view showing an example of an electrostatic chuck as a semiconductor holding device, and fig. 3 is a sectional view of line iii-iii of fig. 2. As shown in fig. 3, the electrostatic chuck 11 includes an electrostatic attraction electrode 13 on a surface of an insulating ceramic substrate 12. A dielectric layer 14 is provided on the surface of the ceramic substrate 12 so as to cover the electrostatic attraction electrode 13. The upper surface of the dielectric layer 14 is an adsorption surface 16 to which a fixed object 15 such as an Si wafer is adsorbed. A power supply terminal 17 electrically connected to the electrostatic chuck electrode 13 is provided on the surface of the electrostatic chuck 11 opposite to the attraction surface 16.

The dielectric layer 14 is formed of the aluminum nitride sintered body 1 of the present embodiment, which has excellent mechanical strength and thermal shock resistance, high volume resistivity, high thermal conductivity, and high corrosion resistance against halogen-based gas.

The ceramic substrate 12 may be made of an insulating ceramic such as alumina, silicon nitride, or aluminum nitride. In particular, by forming the ceramic body 12 from the aluminum nitride sintered body 1, simultaneous firing with the aluminum nitride sintered body 1 constituting the dielectric layer 14 can be achieved. Further, by forming the ceramic base 12 from the aluminum nitride sintered body 1 similarly to the dielectric layer 14, the difference in thermal expansion coefficient between the ceramic base 12 and the dielectric layer 14 is reduced. As a result, the electrostatic chuck 11 is less likely to be deformed such as warped or distorted during firing, and is highly reliable.

The electrostatic adsorption electrode 13 and the power supply terminal 17 may be formed of a heat-resistant metal such as tungsten, molybdenum, or platinum. These heat-resistant metals have a similar thermal expansion coefficient to the aluminum nitride sintered body 1 constituting the ceramic base 12. Therefore, when the heat-resistant metal is used for the electrostatic attraction electrode 13 and the power supply terminal 17, the adhesion between the electrostatic attraction electrode 13 and the power supply terminal 17 and the ceramic base 12 is increased during the firing and heating. In addition, in the case where the power supply terminal 17 is exposed to a corrosive gas, the power supply terminal 17 may be formed using an iron-cobalt-chromium alloy.

Fig. 2 and 3 show the electrostatic chuck 11 including only the electrostatic attraction electrode 13 in the ceramic substrate 12, and for example, the electrostatic chuck 11 may have a heating electrode embedded therein in addition to the electrostatic attraction electrode 13. By embedding the heating electrode, the electrostatic chuck 11 can be directly heated, and heat loss can be significantly suppressed as compared with the case of the indirect heating method.

Fig. 4 is a perspective view showing another example of the electrostatic chuck as the semiconductor holding device, and fig. 5 is a sectional view taken along line v-v of fig. 4. The electrostatic chuck 11 includes an insulating base 12 having insulating properties and a disk-shaped dielectric plate 14 made of the aluminum nitride sintered body 1 of the present embodiment. An electrostatic attraction electrode 13 is formed on the lower surface of dielectric plate 14. The insulating base 12 and the dielectric plate 14 are bonded together via an adhesive 18 such as glass, solder, or an adhesive. The electrostatic attraction electrode 13 is interposed between the insulating base 12 and the dielectric plate 14. The upper surface of the dielectric plate 12 is an adsorption surface 16 to which a fixed object 15 such as an Si wafer is adsorbed. A power supply terminal 17 electrically connected to the electrostatic attraction electrode 13 is provided on the surface of the electrostatic chuck 11 opposite to the attraction surface 16.

The insulating substrate 12 may be made of an insulating material such as various ceramics including sapphire, alumina, silicon nitride, and aluminum nitride. The material of the electrostatic adsorption electrode 13 may be copper, titanium, or other metal, or TiN, TaN, WC, or the like. The electrostatic attraction electrode 13 may be formed on the lower surface of the dielectric plate 14 by vapor deposition, metallization, plating, PVD, CD, or the like.

The dielectric plate 14 and the insulating base 12 are prepared separately in advance and bonded by the adhesive 18, whereby the electrostatic chuck 11 can be easily manufactured.

Although the above examples show the single-electrode electrostatic chuck 11, the two-electrode electrostatic chuck may be used.

The base body 12 of the semiconductor holding device shown in fig. 2, 3, 4, and 5 may have a flow path through which a heat medium flows. By flowing the heat medium through the flow path provided inside the base 12, the temperature of the object 15 fixed to the suction surface 16 can be controlled more easily.