JP6976799B2 - Mounting member - Google Patents

Description

The present disclosure relates to a mounting member.

For example, in an exposure apparatus for exposing a light-transmitting substrate such as a glass substrate, a low-reflection member made of colored metal or ceramics is used as a mounting member for the light-transmitting substrate.

For example, Patent Document 1 proposes a film holder provided with a holder base made of aluminum whose surface is anodized. Further, in Patent Document 2, _{a mixed powder obtained by adding titanium oxide powder to alumina powder so as to be 0.1 to 1.0% by mass in terms of TIO 2} and 1.2% by mass or less of a carbon source in terms of C is used. baking becomes, the alumina sintered body has been proposed as a volume resistivity of ^{10 0 ~10 4 Ωcm (10 -2} ~10 2 Ω · m).

Japanese Unexamined Patent Publication No. 2000-206673 Japanese Patent No. 4230175

Since the surface of the mounting member proposed in Patent Document 1 is anodized, the surface is highly insulating and static electricity is easily charged, and the static electricity charged on the mounting member is applied to the mounting object at once. There was a problem that it flowed and caused a problem in the exposed object. In addition, there is a risk that the mounting target may be damaged by the stress when the mounting target is peeled off, such as when the mounting target is attached to the mounting member due to static electricity charged on the surface. ..

On the other hand, since the mounting member proposed in Patent Document 2 has high conductivity, for example, when a static-charged exposed object is mounted on a suction surface, static electricity is generated at once from the exposed object through the mounting member. There is a problem that the electronic parts of the exposure apparatus may be defective due to the flow, or the mounting object may be damaged by sparks due to a large current.

The mounting member of the present disclosure has a suction portion provided with a suction surface for sucking and holding the mounting object, the suction portion is made of aluminum oxide ceramics, and the aluminum oxide ceramics are: It contains oxides of cobalt, iron, nickel and titanium, and the grain boundary phase contains at least one of cobalt spinel, iron spinel and nickel spinel, the adsorption surface having a load length ratio of 25% in the roughness curve. It is characterized in that the cutting level difference (Rδc) between and 75% load length ratio is 0.7 μm or more and 1 μm or less.

According to the present disclosure, it is possible to provide a mounting member having a low reflectance, low charge, and appropriate conductivity.

An example of the mounting member of the present disclosure is shown, (a) is a perspective view, and (b) is a cross-sectional view taken along the line XX'of (a).

Hereinafter, the mounting members of the present disclosure will be described in detail with reference to the drawings.

1A and 1B show an example of a mounting member of the present disclosure, FIG. 1A is a perspective view, and FIG. 1B is a cross-sectional view taken along the line XX'of FIG. 1A.

The mounting member 10 shown in FIG. 1 has a suction portion 2 provided with a suction surface 1 for sucking and holding a mounting object (not shown) such as a light transmissive substrate, and the suction surface 1 has a suction surface 1. It is provided with a large number of through holes 3 to be opened.

An internal space 4 connected to the through hole 3 is provided on the back surface side of the suction portion. The shape of the mounting object is, for example, a square plate.

A support portion 5 for supporting the suction portion 2 is provided below the suction portion 2, and a suction path 6 connected to a suction pipe (not shown) is provided in the thickness direction thereof.

The support portion 5 is made of, for example, aluminum oxide ceramics, and is fixed to the base portion (not shown) by inserting bolts (not shown) into mounting holes 7 arranged at substantially equal intervals on the outer peripheral side.

When the object to be mounted is adsorbed, the pipe is connected to the vacuum pump, air is sucked from the through hole 3 through the suction path 6 and the internal space 4, and the object to be mounted is adsorbed and held.

The mounting member 10 of the present disclosure is made of aluminum oxide ceramics. Here, the aluminum oxide ceramics refers to ceramics whose main component is an aluminum oxide content of 52% by mass or more in a total of 100% by mass of all the components constituting the ceramics.

The aluminum oxide ceramics constituting the mounting member 10 contain oxides of cobalt, iron, nickel and titanium. The aluminum oxide ceramics constituting the mounting member 10, which contains oxides of cobalt, iron, nickel, and titanium, have a relatively low reflectance in the wavelength range of 360 nm to 440 nm because the color tone is dark (black). When the mounting member 10 is used in the exposure apparatus, the extra reflected light caused by the mounting member 10 and the stray light associated therewith are suppressed, and the exposure can be performed with relatively high accuracy.

In addition, cobalt oxide (Co ₃ O ₄ ), iron oxide (Fe ₂ O ₃ ), nickel oxide (NiO) and titanium oxide (TIO ₂ ) are all semi-conductive (volume resistivity). The rate is, for example, 10 ^-4 to 10 ⁷ Ω · m), and the volume resistivity at room temperature is as follows. _{Co 3 O 4: 2~4 × 10} 2 Ω · m, · Fe 2 O 3: 10 3 ~10 8 Ω · m, · NiO: 10 2 Ω · m, · TiO 2: 10 9 Ω · m. Further, when the titanium oxide (TiO ₂ ) is reduced to an oxide whose composition formula is represented by TiO _2-x (0 <x <2), the volume resistivity at room temperature is 10 ³ to 10 ^6. It becomes Ω ・ m.

The aluminum oxide ceramics constituting the mounting member 10 containing these have a volume resistivity of 10 ⁵ to 10 ¹¹ Ωcm (10 ³ to 10 ⁹ Ω ・ m) at room temperature, and the adsorption surface 1 is less charged. Moreover, it has an appropriate conductivity. For this reason, in the exposure apparatus using the mounting member 10, the mounting target is less likely to stick to the suction surface 1, and the electronic components inside the exposure apparatus are damaged due to the flow of static electricity as a large current. Damage to the object to be placed is suppressed.

The content of the cobalt oxide is, for example, 8% by mass or more and 12% by mass or less in terms of the value of _{cobalt (Co) converted into Co 3} O _4. The iron oxide content is, for example, 4% by mass or more and 20% by mass or less in terms of _{iron (Fe) converted into Fe 2} O _3. Further, the content of nickel oxide is, for example, 3% by mass or more and 4% by mass or less in terms of the value of nickel (Ni) converted to NiO. Further, the content of titanium oxide is, for example, 1% by mass or more and 2% by mass or less in terms of the value of _{titanium (Ti) converted to TIO 2.} In this case, the volume resistivity at room temperature of the mounting member, may be 10 ⁴ Ω · m or more 10 ⁸ Ω · m or less. When the volume resistivity is in this range, the probability that the electronic component or the mounting object inside the exposure apparatus is damaged is lower.

The volume resistivity may be obtained according to JIS C 2141: 1992. In addition to the above components, the aluminum oxide ceramics may act as a sintering aid and may contain oxides of silicon, magnesium and calcium as components mainly constituting the grain boundary phase. Hereinafter, the oxides of silicon, magnesium and calcium (SiO ₂ , MgO, CaO) are collectively referred to as an auxiliary agent component. The content of the auxiliary agent component is, for example, 0.6% by mass or more and 2% by mass or less in the total 100% by mass of all the components constituting the aluminum oxide ceramics.

The contents of the above-mentioned main component, coloring component and auxiliary component are determined by crushing a part of aluminum oxide ceramics, dissolving the obtained powder in a solution such as hydrochloric acid, and then ICP (Inductively Coupled Plasma) emission spectroscopy. It is obtained by converting the content of the metal component obtained by using an analyzer (ICP, for example, manufactured by Shimadzu Corporation (ICPS-8100)) into an oxide. For example, the Al content _{is converted to Al 2} O ₃ , and the Co content is converted _{to Co 3} O _4.

In the mounting member 10, the aluminum oxide ceramics may contain at least one of cobalt spinel, iron spinel, and nickel spinel in the grain boundary phase. The reflectance of general aluminum oxide ceramics tends to be higher in the grain boundary phase portion than in the crystal phase portion, and the reflectance of the grain boundary phase portion increases the overall reflectance of the surface of the aluminum oxide ceramics. Often there. When the mounting member 10 contains at least one of cobalt spinel, iron spinel and nickel spinel in the grain boundary phase, the refractive index of these spinels is about 1.74 to 1.80 and the refraction of aluminum oxide. Since the index is close to 1.77, the degree of the relative height of the reflectance of the grain boundary phase portion is suppressed, so that the overall reflectance of the surface of the aluminous aluminum oxide ceramics becomes lower. Cobalt spinel, iron spinel and nickel spinel may have an indefinite composition formula, but are preferably CoAl ₂ O ₄ , FeAl ₂ O ₄ and NiAl ₂ O ₄ having a constant composition formula.

The anorthite whose composition formula is represented as CaAl ₂ Si ₂ O ₅ has a refractive index of 1.58, has a large difference from the refractive index of aluminum oxide, and has a high reflectance. Therefore, the mounting member 10 Preferably have a lower anorthite content.

Further, when the aluminum oxide ceramics contain aluminum titanate in the grain boundary phase, the abnormal grain growth of the crystal particles of aluminum oxide can be suppressed, so that the mechanical strength of the aluminum oxide ceramics should be increased. Can be done. The composition formula of aluminum titanate may be an indefinite ratio, but it is preferably _{Al 2} TiO _{5 having a constant ratio.}

Cobalt spinel, iron spinel, nickel spinel and aluminum titanate can be identified using an X-ray diffractometer (XRD). Further, the existence location may be confirmed by using an X-ray microanalyzer (EPMA) for the grain boundary phase.

In particular, the mounting member 10 of the present embodiment contains 52% by mass or more and 80% by mass or less of aluminum oxide, and the total content of cobalt spinel, iron spinel and nickel spinel is 19% by mass or more and 47% by mass or less. The content of aluminum titanate may be 1% by mass or more and 5% by mass or less. Low reflectance and high mechanical strength can be achieved when the respective contents of aluminum oxide, cobalt spinel, iron spinel, nickel spinel and aluminum titanate meet the above ranges. The contents of cobalt spinel, iron spinel, nickel spinel and aluminum titanate may be determined by Rietveld analysis.

Further, in the mounting member 10 of the present embodiment, the suction surface has a cutting level difference (Rδc) of 0.7 μm between the load length ratio of 25% and the load length ratio of 75% in the roughness curve. It may be 1 μm or less.

Here, the cutting level difference (Rδc) is the height of the cutting levels C (Rrm1) and C (Rrm2) corresponding to the load length ratios Rmr1 and Rmr2 in the roughness curve defined by JIS B0601: 2001, respectively. The difference in direction. When the cutting level difference (Rδc) is large, the unevenness of the surface to be measured becomes large, and when it is small, the unevenness of the surface becomes small. When the cutting level difference (Rδc) on the adsorption surface is 0.7 μm or more, the reflectance can be lowered by increasing the light diffusion on the adsorption surface, and the linking of the object to be placed on the adsorption surface is relaxed. Therefore, the detachment responsiveness can be enhanced. Further, when the cutting level difference (Rδc) of the suction surface is 1 μm or less, the steepness of the convex portion generated on the suction surface is suppressed, so that particles are less likely to be generated from the tip of the convex portion and the suction surface is smooth. The property is improved, leakage during suction is suppressed, and high adsorption force can be obtained.

The cutting level difference (Rδc) between the 25% load length ratio and the 75% load length ratio in the roughness curve of the suction surface 1 is based on JIS B 0601: 2001, and is based on a laser microscope (for example, for example). , Manufactured by KEYENCE Co., Ltd. (VK-9510)). When using the laser microscope VK-9510, for example, the measurement mode is color ultra-depth, the measurement magnification is 400 times, the measurement range per location is 112 μm × 84 μm, the measurement pitch is 0.05 μm, and the λs contour curve filter is 2.5 μm. , The λc contour curve filter may be 0.08 mm, and the measurement points may be 8 points.

Further, in the mounting member 10 of the present disclosure, the adsorption surface 1 has a wavelength range of 360 nm to 440 nm.
The average value of the reflectance in the above may be 7% or less.

A spectrophotometer (for example, CM-2600d manufactured by Konica Minolta Co., Ltd. or its successor model) is used for the reflectance, and the measurement conditions are CIE standard light source D65 for the light source, 10 ° for the viewing angle, and UV 100% for the UV condition. It may be set to, the total reflectance may be measured, and the average value may be obtained.

Further, in the mounting member 10 of the present disclosure, the adsorption surface 1 has a brightness index L ^* of 30 or less in the CIE1976L * a * b * color space, and both the chromaticity indexes a ^* and b ^* are -2. It may be 2 or more and 2 or less.

Within such a range, the adsorption surface 1 has a strong tendency to be achromatic in black, so that the reflectance can be reduced. Further, the tendency of achromatic color becomes stronger, so that color unevenness is suppressed.

The values of the brightness index L ^* and the chromaticity indexes a ^* and b ^* can be obtained in accordance with JIS Z 8722: 2009. For example, a spectrocolor difference meter (NF777 manufactured by Nippon Denshoku Kogyo Co., Ltd. or its successor model) may be used, and the light source may be set to the CIE standard light source D65 and the viewing angle may be set to 2 °.

Next, an example of a method for manufacturing the mounting member of the present disclosure will be described.

First, aluminum oxide (Al ₂ O ₃ ) powder, which is the main component, and cobalt oxide (Co ₃ O ₄ ) powder, iron oxide (Fe ₂ O ₃ ) powder, nickel oxide (NiO) powder, and oxidation as coloring components. Prepare a titanium (TiO ₂ ) powder. Further, as a sintering aid, calcium carbonate (CaCO ₃ ) powder, magnesium hydroxide (Mg (OH) ₂ ) powder and silicon oxide (SiO ₂ ) powder are prepared.

Next, these powders are weighed in a desired amount to obtain a primary raw material powder. For example, in the sintering aid, out of 100% by mass of all the components constituting the ceramic sintered body, the total content of calcium converted to CaO, magnesium converted to MgO, and silicon converted to SiO ₂ is 0.6. Weigh so as to be not less than% by mass and not more than 2% by mass. As for the coloring component, out of 100% by mass of all the components constituting the ceramic sintered body, _{the content of cobalt converted to Co 3} O ₄ is 8% by mass or more and 12% by mass or less, and iron is converted _{to Fe 2} O _3. The content was 4% by mass or more and 6% by mass or less, the content of nickel converted to NiO was 3% by mass or more and 4% by mass or less, _{and the content of titanium converted to TiO 2} was 1% by mass or more and 2% by mass or less. Weigh so that Then, the balance is weighed so as to be _{aluminum oxide (Al 2} O _{3) powder.} ^{By setting the content of the coloring component in such a range, the brightness index L *} in the CIE1976L * a * b * color space of the main surface and the mounting surface is 3
^{It can be a mounting member having a chromaticity index a *} and b ^{* of} 0 or less and both -2 or more and 2 or less.

In order to obtain a mounting member in which the grain boundary phase of aluminum oxide ceramics contains at least one of cobalt spinel, iron spinel and nickel spinel, first, aluminum oxide (Al ₂ O ₃ ) powder is classified and average grains are obtained. Aluminum oxide (Al ₂ O ₃ ) powder having a small diameter is obtained. Then, the cobalt oxide (Co ₃ O ₄ ) powder, the iron oxide (Fe ₂ O ₃ ) powder and the nickel oxide (Ni _{O) powder having the above-mentioned contents are mixed with the aluminum oxide (Al 2} O ₃ ) powder having a small average particle size. The powder may be used after being calcified by calcining at a temperature of 1100 ° C. or higher and 1300 ° C. or lower, and then crushed to a desired average particle size using a crusher such as a ball mill.

In order to obtain a mounting member in which the grain boundary phase of the aluminum oxide ceramic contains aluminum titanate, titanium oxide (TiO ₂ ) powder in the above-mentioned content range is mixed and the temperature is 1100 ° C. or higher and 1300 ° C. or lower. After the calcining synthesis, the powder crushed to a desired average particle size using a crusher such as a ball mill may be used.

Next, with respect to 100 parts by mass of the primary raw material powder, a binder such as PEG (polyethylene glycol) of 0.1 parts by mass or more and 1 part by mass or less and a solvent of 100 parts by mass are weighed and mixed together with the primary raw material powder. -Stir to obtain a slurry.

Then, the slurry is spray-granulated using a spray granulator (spray dryer) to obtain granules, and then a molded body having a desired shape is formed by a powder press molding method or a hydrostatic pressure press molding method (rubber press method). ..

Next, the obtained molded product is subjected to cutting processing as necessary, and is fired in an atmospheric (oxidizing) atmosphere at, for example, at 1400 ° C. or higher and 1500 ° C. or lower for a desired time to obtain a flat plate-shaped sintered body. Can be obtained.

Then, by polishing the main surface of the sintered body, it can be used as the main surface of the substrate constituting the mounting member of the present embodiment. The abrasive grains used in the polishing process may be fine powder for precision polishing, which contains diamond as a main component and has a particle size of # 2000 or more and # 3000 or less specified by the sedimentation test method of JIS R 6001-2: 2017.

In order to obtain a mounting member having a cutting level difference (Rδc) and a cutting level difference (Rδc) of 0.7 μm or more and 1 μm or less, the abrasive grains used in the polishing process are mainly composed of diamond and have the above particle size. The polishing time may be appropriately adjusted by using # 2500 fine powder for precision polishing.

The present invention is not limited to the above-described embodiment, and various changes, improvements, combinations, and the like can be made without departing from the gist of the present invention.

1 Suction surface 2 Suction part 3 Through hole 4 Internal space 5 Support part 6 Suction path 7 Mounting hole 10 Mounting member

Claims (2)

It has a suction part provided with a suction surface for sucking and holding the object to be placed, and the suction part is made of aluminum oxide ceramics, and the aluminum oxide ceramics are oxidized of cobalt, iron, nickel and titanium. The grain boundary phase contains at least one of cobalt spinel, iron spinel and nickel spinel, and the adsorption surface has a load length ratio of 25% and a load length ratio of 75% in the roughness curve. A mounting member having a cutting level difference (Rδc) of 0.7 μm or more and 1 μm or less. The mounting member according to claim 1 , wherein the aluminum oxide ceramics contain aluminum titanate in the grain boundary phase.

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