High-resistance and high-corrosion-resistance ceramic material and wafer carrying table

Abstract

The invention relates to a high-resistance and high-corrosion-resistance ceramic material and a wafer carrying table. The present invention addresses the problem of having sufficient corrosion resistance at high temperatures and increasing the volume resistivity at high temperatures. The high-resistance and high-corrosion-resistance ceramic material contains magnesium-aluminum nitrogen oxide, and the carbon content is 0.005-0.275% by mass.

Description

[0001] This application is a divisional application of the invention patent application with application number 202211703929.1, application date December 29, 2022, and invention name “High resistance and high corrosion resistant ceramic material and chip carrier”. Technical Field

[0002] The present invention relates to a high-resistance and high-corrosion-resistant ceramic material and a chip placing platform. Background Art

[0003] Semiconductor manufacturing equipment used in dry processes and plasma coating for semiconductor manufacturing uses highly reactive halogen plasmas such as F and Cl for etching and cleaning. Therefore, components incorporated into such semiconductor manufacturing equipment are required to exhibit high corrosion resistance. As a material with high corrosion resistance, a ceramic material having a primary phase of magnesium-aluminum oxynitride is known, as described in Patent Document 1. This ceramic material can withstand the highly reactive halogen plasmas used in semiconductor manufacturing processes for long periods of time.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 5680645 Summary of the Invention

[0007] In recent years, in order to produce high-quality films, process temperatures have been increasing (500° C. or higher). Therefore, not only sufficient corrosion resistance at high temperatures is required, but also the ability to electrostatically adsorb wafers at high temperatures is required.

[0008] The present invention has been made to solve such problems, and its main object is to provide sufficient corrosion resistance at high temperatures and to increase the volume resistivity at high temperatures.

[0009] The high-resistance and high-corrosion-resistant ceramic material of the present invention is a ceramic material containing magnesium-aluminum oxynitride, wherein the carbon content is 0.005 to 0.275% by mass.

[0010] According to this ceramic material, since carbon is contained in an appropriate range, it has sufficient corrosion resistance at high temperatures and can also increase the volume resistivity at high temperatures.

[0011] The wafer placing table of the present invention comprises: a ceramic base body formed of the above-mentioned ceramic material and capable of placing a wafer on its upper surface; and an electrode disposed inside the ceramic base body.

[0012] Alternatively, the chip carrier of the present invention comprises: a ceramic base, which is formed by the above-mentioned ceramic material and can carry chips on the upper surface; a high thermal conductivity base, which is arranged on the lower surface of the ceramic base and has a higher thermal conductivity than the ceramic base; an electrode, which is arranged inside the ceramic base, inside the high thermal conductivity base, or between the ceramic base and the high thermal conductivity base; and a resistive heating element, which is arranged inside the base of the high thermal conductivity base and is lower than the electrode.

[0013] According to such a wafer stage, since the ceramic base is formed of the above-mentioned ceramic material, it has sufficient corrosion resistance at high temperatures and can improve the volume resistivity at high temperatures. Here, the "electrode" can be, for example, an electrostatic electrode, a heater electrode (resistive heating element), or a high-frequency (RF) electrode for plasma generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a longitudinal sectional view of the wafer stage 10 .

[0015] Figure 2 It is a longitudinal sectional view of the wafer stage 20 .

[0016] Figure 3 It is a longitudinal sectional view of the wafer stage 30 .

[0017] Figure 4 It is a longitudinal cross-sectional view of the wafer placement table 40 .

[0018] Figure 5 This is the XRD pattern of Experimental Example 3.

[0019] Figure 6 This is the XRD pattern of Experimental Example 5.

[0020] Figure 7 This is a graph showing the relationship between the C content and the volume resistivity at 500°C.

[0021] Explanation of symbols

[0022] 10 chip loading platform, 12 ceramic substrate, 12a chip loading surface, 14 electrostatic electrode, 16 resistance heating element, 18 axis, 20 chip loading platform, 22 ceramic substrate, 22a chip loading surface, 23 high thermal conductivity substrate, 24 electrostatic electrode, 26 resistance heating element, 28 axis, 30, 40 chip loading platform. DETAILED DESCRIPTION

[0023] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Figures 1 to 4This is a longitudinal cross-sectional view of wafer stages 10-40. It should be noted that in this specification, the terms "up" and "down" do not denote absolute positional relationships, but rather relative positions. Therefore, depending on the orientation of wafer stages 10-40, "up" and "down" may mean "down" and "up," "left" and "right," or "front" and "back." Furthermore, in this specification, the term "to" indicating a numerical range is used to include the numerical values listed before and after it as the lower and upper limits.

[0024] The high-resistance and high-corrosion-resistant ceramic material of this embodiment contains magnesium-aluminum oxynitride and has a carbon content of 0.005 to 0.275% by mass. If the carbon content is within this range, it can have sufficient corrosion resistance at high temperatures and can improve the volume resistivity at high temperatures. For example, when the ceramic material is used for a ceramic substrate having a chip placement surface and a built-in electrostatic electrode, it can electrostatically adsorb the chip at high temperatures, or suppress leakage current flowing between the chip and the electrode when the chip is processed at high temperatures. In addition, when the ceramic material is used for a ceramic substrate having a built-in heater electrode (resistance heating element) or RF electrode, it can suppress leakage current flowing between the chip and the electrode when the chip is processed at high temperatures. When the carbon content is less than 0.005% by mass or exceeds 0.275% by mass, the volume resistivity at 500°C becomes low. The carbon content is preferably 0.005 to 0.21% by mass. The ceramic material of this embodiment preferably contains magnesium-aluminum oxynitride as the main phase. Here, the main phase refers to the phase that contains the most in the overall phase.

[0025] The ceramic material of this embodiment preferably has a volume resistivity of 1×10 9 Ωcm or more. If the volume resistivity at 500℃ is 1×10 9 Ωcm or more, when the ceramic material is used as a ceramic substrate with a wafer placement surface and a built-in electrode, leakage current flowing between the wafer and the electrode when the wafer is processed at high temperature can be fully suppressed. In addition, when the ceramic material is used in an electrostatic chuck, the wafer can be reliably electrostatically attracted by the Johnson-Rabbich force at high temperatures. In addition, the volume resistivity at 500°C is preferably 5×10 11 Thus, when the ceramic material is used in an electrostatic chuck, the adsorption and desorption responsiveness of the wafer can be improved.

[0026] The ceramic material of this embodiment may contain titanium. The inclusion of titanium allows the ceramic material to be black in color. Consequently, color unevenness in the ceramic material can be less noticeable. The titanium content can be set so as not to reduce corrosion resistance and maintain a volume resistivity at 500°C within the above-mentioned range. For example, the titanium content can be set within a range of 0.1 to 1% by mass, calculated as oxide.

[0027] The ceramic material of this embodiment preferably has a magnesium-aluminum oxynitride phase as the main phase, whose XRD peak appears at least at 2θ=47-50° (preferably 47-49°) when using CuKα radiation. Such a ceramic material is preferred because its corrosion resistance to halogenated plasma is equal to or higher than that of spinel. The main phase is preferably consistent with the peak of the magnesium-aluminum oxynitride disclosed in Patent Document 1 (Japanese Patent No. 5680645). It should be noted that the peak of the magnesium-aluminum oxynitride disclosed in Patent Document 1 is inconsistent with the peak of MgAlON (or magnesium aluminum oxynitride) disclosed in Reference 1 (J. Am. Ceram. Soc., 93[2]322-325 (2010)) and Reference 2 (Japanese Patent Application Laid-Open No. 2008-115065). Generally speaking, these MgAlONs are known to be substances in which N components are solid-dissolved in spinel, and are considered to have a crystal structure different from that of the magnesium-aluminum oxynitride disclosed in Patent Document 1.

[0028] Next, an example of manufacturing the ceramic material of the present embodiment is described. The ceramic material of the present embodiment can be manufactured by molding a mixed powder of magnesium oxide, aluminum oxide, aluminum nitride and a carbon source and then firing it. For example, magnesium oxide can be weighed in a manner of 5% by mass to 60% by mass, aluminum oxide can be weighed in a manner of 60% by mass to 90% by mass, and a carbon source can be added thereto for mixing. The resulting powder can be molded and then fired. As a carbon source, an organic binder, an organic dispersant, or carbon powder can be added. The amount of carbon source added is set so that the carbon content in the ceramic material after firing is 0.005 to 0.2% by mass. Alternatively, degreasing can be performed at the stage before firing, and the carbon content in the ceramic material after firing can be adjusted to 0.005 to 0.2% by mass. In this case, the carbon content can be adjusted by the degreasing temperature. The degreasing temperature is preferably set in the range of 300 to 600°C, for example. For molding, for example, the slurry of the mixed powder can be granulated to form granules and then the granules can be powder pressed, or the slurry of the mixed powder can be made into green sheets using a scraper method. The pressure during molding is not particularly limited, and it can be appropriately set to a pressure that can maintain the shape. The firing temperature is preferably above 1750°C, more preferably 1800-1950°C. In addition, the firing is preferably performed by hot pressing, and the pressing pressure during hot pressing is preferably set to 50-300kgf / cm 2 The atmosphere during firing is preferably an atmosphere that does not affect the firing of the oxide raw material, for example, an inert atmosphere such as nitrogen atmosphere, argon atmosphere, helium atmosphere, etc. The pressure during molding is not particularly limited and can be appropriately set to a pressure that can maintain the shape.

[0029] Next, the wafer placement tables 10 to 40 will be described with reference to the drawings.

[0030] like Figure 1 As shown, the wafer placement table 10 is an electrostatic chuck heater, which includes: an electrostatic electrode 14, which is arranged inside the ceramic base 12; and a resistance heating element 16, which is arranged inside the ceramic base 12 and below the electrostatic electrode 14.

[0031] The ceramic base 12 is formed by forming the above-mentioned ceramic material into a disk shape, and has a wafer placement surface 12 a on the upper surface of which a wafer can be placed.

[0032] The electrostatic electrode 14 is a disc-shaped metal plate or metal mesh, which is arranged parallel to the wafer loading surface 12a. In addition to the disc-shaped metal plate and mesh, the electrostatic electrode 14 can also be in the form of foil, punched metal, printed electrode, etc. It should be noted that, for "parallel", except for the case of complete parallelism, even if it is not completely parallel, it is considered to be parallel within the range of the allowed error (such as tolerance). The part of the ceramic substrate 12 that is closer to the upper side than the electrostatic electrode 14 functions as a dielectric layer. When a DC voltage is applied to the electrostatic electrode 14, the wafer placed on the wafer loading surface 12a is adsorbed on the wafer loading surface 12a due to the Johnson-Rabek force (electrostatic force). As the material for the electrostatic electrode 14, for example, W, Mo, W-Mo alloy or their carbides can be cited.

[0033] The resistance heating element 16 is wired from one end to the other end as a whole in a single stroke when observing the ceramic base 12 from above, and generates heat by passing current between one end and the other end. The resistance heating element 16 can be, for example, a component obtained by bending a linear conductor and processing it into a winding body. The wire diameter of the resistance heating element 16 is preferably about 0.3mm to 0.5mm. In the case of a coil shape, the winding diameter is preferably about 2mm to 4mm, and the spacing is preferably about 1mm to 7mm. Here, "winding diameter" refers to the inner diameter of the coil constituting the resistance heating element 16. As the shape of the resistance heating element 16, in addition to the coil shape, various forms such as strip, mesh, spiral spring, sheet, printed electrode, etc. can also be used. As materials for the resistance heating element 16, for example, W, Mo, W-Mo alloy or their carbides can be cited.

[0034] A cylindrical shaft 18 is bonded to the lower surface of the wafer stage 10. Bonding can be performed, for example, by sintering or using a bonding agent (e.g., an inorganic bonding agent). The shaft 18 is preferably made of a member having the same or similar linear thermal expansion coefficient as the ceramic substrate 12. AlN-YAG is preferably used as the material of the shaft 18. YAG is yttrium aluminum garnet (Y3Al5O 12) is an abbreviation of . AIN-YAG may contain titanium, and its content can be, for example, 0.1 to 1% by mass in terms of oxide. When titanium is added, the color of AIN-YAG becomes black, and thus the color unevenness of AIN-YAG can be made less noticeable.

[0035] According to the wafer stage 10 described above, the ceramic base 12 is formed from the aforementioned ceramic material and thus has the same effects as the aforementioned ceramic material, such as having sufficient corrosion resistance at high temperatures and being able to increase the volume resistivity at high temperatures. Furthermore, it is possible to suppress leakage current flowing between the wafer and the electrostatic electrode 14 when electrostatically adsorbing the wafer at high temperatures or processing the wafer at high temperatures. Furthermore, it is possible to suppress leakage current flowing between the wafer and the resistive heating element 16 when processing the wafer at high temperatures.

[0036] Figure 2 The wafer stage 20 shown is an electrostatic chuck heater formed by bonding a high thermal conductivity base 23 with a built-in resistance heating element 26 to the lower surface of a ceramic base 22 with a built-in electrostatic electrode 24. Bonding can be performed, for example, by sintering or using a bonding agent (e.g., an inorganic bonding agent).

[0037] The ceramic base 22 is formed by forming the above-mentioned ceramic material into a disk shape and has a wafer placement surface 22a on the upper surface thereof on which a wafer can be placed. The electrostatic electrode 24 is the same as the above-mentioned electrostatic electrode 14, and therefore its description is omitted.

[0038] The high thermal conductivity substrate 23 is made of a member having a higher thermal conductivity than the ceramic substrate 22 and a linear thermal expansion coefficient that is the same as or similar to that of the ceramic substrate 12. The AlN-YAG may contain titanium, for example, with a content of 0.1 to 1% by mass calculated as oxide. The addition of titanium darkens the color of the AlN-YAG, thereby reducing color unevenness in the AlN-YAG.

[0039] The resistance heating element 26 is the same as the above-mentioned resistance heating element 16, and therefore its description is omitted.

[0040] A cylindrical shaft 28 is joined to the lower surface of the wafer stage 20. The shaft 28 is the same as the shaft 18 described above, and therefore its description is omitted.

[0041] According to the wafer stage 20 described above, the ceramic base 22 is formed of the aforementioned ceramic material, thereby achieving the same effects as the aforementioned ceramic material, such as sufficient corrosion resistance at high temperatures and improved volume resistivity at high temperatures. Furthermore, leakage current flowing between the wafer and the electrostatic electrode 14 can be suppressed during electrostatic attraction of the wafer at high temperatures or during wafer processing at high temperatures.

[0042] Furthermore, in the wafer stage 20 , the highly thermally conductive base 23 is bonded to the lower surface of the ceramic base 22 . Therefore, compared to the wafer stage 10 , it is easier to make the temperature of the wafer placed on the wafer placement surface 22 a uniform.

[0043] Furthermore, the thermal expansion coefficient of the high thermal conductive base 23 is the same as or close to that of the ceramic base 22 , and therefore is unlikely to be separated from the ceramic base 22 even when the temperature is repeatedly increased and decreased.

[0044] In addition to arranging the electrostatic electrode 24 at the interface between the ceramic base 22 and the high thermal conductivity base 23, Figure 3 The wafer stage 30 shown is the same as the wafer stage 20. The wafer stage 30 can also obtain the same effects as the wafer stage 20.

[0045] In addition to the fact that the electrostatic electrode 24 is built into the high thermal conductivity base 23 instead of the ceramic base 22, Figure 4 The wafer stage 40 shown is the same as the wafer stage 20. The resistance heating element 26 is arranged below the electrostatic electrode 24. The wafer stage 40 can also achieve the same effect as the wafer stage 20. However, in the wafer stage 40, the dielectric layer (the portion above the electrostatic electrode 24) is composed of the ceramic base 22 and the highly thermally conductive base 23. Therefore, the wafer stages 10 to 30 whose dielectric layer is composed only of the ceramic base 22 can more easily adjust the suction force of the wafer.

[0046] It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be implemented in various forms as long as it falls within the technical scope of the present invention.

[0047] For example, while the wafer stages 10 to 40 are described as having built-in electrostatic electrodes 14 and 24, they may not be built-in. In this case, leakage current flowing between the wafer and the resistive heating elements 16 and 26 can also be suppressed. Furthermore, RF electrodes may be built-in instead of or in addition to the electrostatic electrodes 14 and 24, or the electrostatic electrodes 14 and 24 may also serve as RF electrodes.

[0048] Alternatively, the outer periphery (upper surface, side surfaces, and lower surface) of the highly thermally conductive substrate 23 may be coated with the aforementioned ceramic material, thereby improving the corrosion resistance of the side surfaces and the lower surface.

[0049] Example

[0050] Hereinafter, examples of the present invention will be described. Experimental Examples 2 to 6, 9 to 11, 13 to 15, and 17 to 19 correspond to examples of the present invention. It should be noted that the following examples do not limit the present invention.

[0051] [Experimental Examples 1 to 7]

[0052] Blending

[0053] In Experimental Example 1, the MgO raw material, Al2O3 raw material, and AlN raw material were weighed to achieve the mass % values shown in Table 1. They were wet-mixed for 4 hours using isopropyl alcohol as a solvent in a nylon pot and 5 mm diameter alumina balls. After mixing, the slurry was removed and dried at 110°C under a nitrogen stream. The mixture was then passed through a 30-mesh sieve to prepare a blended powder.

[0054] In Experimental Example 2, MgO raw materials, Al2O3 raw materials, and AlN raw materials were weighed to achieve the mass percentages shown in Table 1. Isopropyl alcohol was used as a solvent, and 1.0% by mass of an acrylic binder and 0.1% by mass of a polycarboxylic acid dispersant were added. The mixture was wet-mixed for 4 hours using alumina balls in a drum screen. The resulting raw material slurry was spray-dried using a spray dryer to produce granules. The resulting granules were then heated in air at 500°C for 24 hours to produce partially defatted granules.

[0055] In Experimental Example 3, pellets were produced in the same manner as in Experimental Example 2, except that the pellets were heated in the air at 500° C. for 5 hours to perform partial degreasing.

[0056] In Experimental Example 4, pellets were prepared in the same manner as in Experimental Example 2 except that 1.5% by mass of an acrylic binder and 0.5% by mass of a polycarboxylic acid dispersant were added and the pellets were heated in air at 450° C. for 5 hours for partial degreasing.

[0057] In Experimental Example 5, pellets were produced in the same manner as in Experimental Example 4 except that degreasing was not performed.

[0058] In Experimental Example 6, the MgO raw material, Al2O3 raw material, and AlN raw material were weighed to achieve the mass percentages shown in Table 1. Isopropyl alcohol was used as the solvent, and 0.3% by mass of carbon powder was added. The mixture was wet-mixed for 4 hours using a nylon pot and 5 mm diameter alumina balls. After mixing, the slurry was removed and dried at 110°C under a nitrogen stream. The mixture was then passed through a 30-mesh sieve to prepare a blended powder.

[0059] In Experimental Example 7, pellets were produced in the same manner as in Experimental Example 6, except that 0.42% by mass of carbon powder was added.

[0060] ·forming

[0061] At 100kgf / cm 2 The mixed powder or granules were uniaxially pressed under a pressure of 1000 rpm to produce a disk-shaped compact with a diameter of 35 mm and a thickness of about 10 mm, which was then placed in a graphite mold for firing.

[0062] ·Firing

[0063] The ceramic base body is obtained by hot pressing the disk-shaped compact. During the hot pressing, the pressing pressure is set to 200 kgf / cm 2 The sintering was carried out at the sintering temperature (maximum temperature) shown in Table 1. The atmosphere was set to N2 atmosphere until the end of sintering. The holding time at the sintering temperature was set to 4 hours.

[0064] [evaluate]

[0065] (1) Crystallization phase evaluation

[0066] The ceramic substrates obtained in Experimental Examples 1 to 7 were pulverized in a mortar, and the crystalline phase was identified using an X-ray diffractometer. Measurement conditions were CuKα, 40 kV, 40 mA, and 2θ 5-70°, using a sealed tube X-ray diffractometer (Bruker AXS D8 ADVANCE). The results showed that the main phase in all of Experimental Examples 1 to 7 was magnesium-aluminum oxynitride (with a peak at 2θ = 47-49°). This main phase was consistent with the peak of magnesium-aluminum oxynitride identified in Patent Document 1. Figure 5 as well as Figure 6 XRD patterns of representative examples (Experimental Examples 3 and 5) are shown.

[0067] (2) Carbon (C) content

[0068] The C content is determined according to the method for determining the total carbon content described in JIS R1616:2007. Specifically, the sample is burned together with an oxidant by high-frequency heating in an oxygen flow, and the generated carbon dioxide (and carbon monoxide) is fed into an infrared analyzer together with oxygen, and the change in infrared absorption is measured to determine the C content. Table 1 shows the C content of the ceramic substrates obtained in Experimental Examples 1 to 7. The C content is 0.002% by mass and 0.30% by mass in Experimental Examples 1 and 7, respectively, and 0.005 to 0.21% by mass in Experimental Examples 2 to 6. Experimental Example 1 is an implementation product of Patent Document 1, and the C content of Experimental Example 1 is the value when no carbon source is actively added (the C content contained as an impurity).

[0069] (3) Volume resistivity (500°C)

[0070] The volume resistivity was measured at 500°C in the atmosphere by a method based on JIS-C2141. The test piece was 50 mm in diameter × (0.5 to 1 mm), and each electrode was formed with silver in such a manner that the diameter of the main electrode was 20 mm, the inner diameter of the protective electrode was 30 mm and the outer diameter was 40 mm, and the diameter of the external electrode was 40 mm. The applied voltage was 500 V / mm, and the current value was read 3 minutes after the voltage was applied. The room temperature volume resistivity was calculated from the current value. The volume resistivity of the ceramic substrates obtained in Experimental Examples 1 to 7 is shown in Table 2. In the volume resistivity in Table 2, [E8] represents 10 8 , [E10] means 10 10 The volume resistivity at 500°C was 1×10 9 Ωcm or more, but the values are lower than that in Experimental Examples 1 and 7. The relationship between the C content and the volume resistivity at 500°C is shown in the graph. Figure 7 .Depend on Figure 7 The volume resistivity at 500°C is 1×10 9 The C content of Ωcm or more is 0.005 to 0.275 mass %. If it is 0.011 to 0.19 mass %, it reaches 5×10 9 Ωcm or more, better.

[0071] (4) Thermal conductivity (room temperature)

[0072] The thermal conductivity was measured by the laser flash method. Table 2 shows the thermal conductivity of the ceramic substrates obtained in Experimental Examples 2, 3, 5, and 6 at room temperature.

[0073] (5) Average linear thermal expansion coefficient (40-1000°C)

[0074] The average linear thermal expansion coefficient at 1000° C. was measured using a dilatometer (Bruker AXS) in a nitrogen atmosphere at 40 to 1000° C. Table 2 shows the average linear thermal expansion coefficients of the ceramic substrates obtained in Experimental Examples 2, 3, 5, and 6 at room temperature.

[0075] (6) Etching rate

[0076] The etching rates of the ceramic substrates obtained in Experimental Examples 1, 3, 5, and 6 are shown in Table 2. Specifically, the surface of each material was mirror-polished, and a corrosion test under the following conditions was performed using an ICP plasma corrosion test apparatus. The etching rate of each material was then calculated by dividing the step difference between the mask surface and the exposed surface measured by the step profiler by the test time. As a result, Experimental Examples 3, 5, and 6 had the same or higher corrosion resistance as Experimental Example 1 (an implementation product of Patent Document 1 having the same or higher corrosion resistance as spinel).

[0077] ICP: 800W, bias: 300W, inlet gas: NF3 / Ar=75 / 100sccm 13Pa, exposure time: 5 hours, sample temperature: 550°C

[0078] [Table 1]

[0079]

[0080] [Table 2]

[0081]

[0082] ※Mg-Al-ON: magnesium-aluminum oxynitride (XRD: peak at 2θ=47-49°)

[0083] [Experimental Examples 8 to 19]

[0084] In Experiments 8 to 19, the MgO raw material, Al2O3 raw material, and AlN raw material were weighed to achieve the mass % values shown in Table 1. Based on Experiments 1 to 7, blended powders or pellets were prepared, molded, and fired to obtain ceramic substrates. The carbon contents of the resulting ceramic substrates are shown in Table 1. The carbon contents in Experiments 8, 12, and 16 represent values obtained without the active addition of a carbon source (the carbon content present as an impurity).

[0085] [Experimental Example 20]

[0086] Experimental Example 20 is an example of a high thermal conductivity matrix made of AlN-YAG. First, AlN raw material, Y2O3 raw material, Al2O3 raw material and TiO2 raw material were weighed in such a manner as to reach 74.5 mass%, 15 mass%, 10 mass% and 0.5 mass% respectively, and wet-mixed for 4 hours using a nylon pot and alumina balls with a diameter of 5 mm using isopropyl alcohol as a solvent. After mixing, the slurry was taken out and dried at 110°C in a nitrogen flow. It was then sieved through a 30-mesh sieve to prepare a blended powder. Using the blended powder, molding and firing were performed in the same manner as in Experimental Example 1 to obtain a disc-shaped high thermal conductivity matrix. The XRD spectrum of the high thermal conductivity matrix was analyzed, and the result showed that the main phase was AlN-YAG. In addition, the color of the high thermal conductivity matrix was black. The volume resistivity of the obtained high thermal conductivity matrix at 500°C was 5×10 9 Ωcm, the thermal conductivity at room temperature is 81W / m·K, and the thermal expansion coefficient at 40-1000℃ is 6.1×10 -6 / K. That is, the thermal conductivity is about 10 times that of Experimental Examples 2, 3, 5, and 6, and the thermal expansion coefficient is equivalent to that of Experimental Examples 2, 3, 5, and 6. Experimental Example 20 can be used as the shaft 28 of the wafer stages 10 to 40 or the high thermal conductivity base 23 of the wafer stages 20 to 40.

Claims

1. A high-resistance and high-corrosion-resistant ceramic material, comprising magnesium-aluminum oxynitride, wherein: Carbon content is 0.005-0.275% by mass Titanium is contained in an amount of 0.1 to 1 mass%.

2. The ceramic material according to claim 1, wherein The volume resistivity at 500°C is 1×10 9 Ωcm or more.

3. The ceramic material according to claim 1, wherein The main phase is a magnesium-aluminum oxynitride phase whose XRD peak appears at least at 2θ=47 to 50° when using CuKα radiation.

4. A wafer loading platform comprising: A ceramic substrate, the ceramic substrate being formed of the ceramic material according to claim 1 or 2 and capable of placing a wafer on its upper surface; a high thermal conductivity substrate, the high thermal conductivity substrate being disposed on the lower surface of the ceramic substrate and having a thermal conductivity higher than that of the ceramic substrate; an electrode, the electrode being disposed inside the ceramic substrate, inside the high thermal conductivity substrate, or between the ceramic substrate and the high thermal conductivity substrate; and A resistance heating element is arranged inside the substrate of the high thermal conductivity substrate and below the electrode.

5. The wafer stage according to claim 4, wherein: The high thermal conductivity matrix includes AlN and YAG.

6. The wafer stage according to claim 5, wherein: The high thermal conductivity substrate comprises titanium.

7. A wafer loading platform comprising: A ceramic substrate, the ceramic substrate being formed of the ceramic material according to claim 1 or 2 and capable of mounting a wafer on an upper surface thereof; and a shaft, the shaft being coupled to the ceramic base, The shaft is AlN-YAG.

8. The wafer stage according to claim 7, wherein: The shaft contains titanium in an amount of 0.1 to 1 mass %.

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