JP2016072350A - Member for adsorption - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relatively strongly adsorb an adsorbed object and to relatively easily remove a foreign substance that is deposited on an adsorption face.SOLUTION: A member for adsorption for adsorbing and holding the adsorbed object includes: a placement body formed from a porous ceramic body including the adsorption face on which the adsorbed object is placed, a bottom face at an opposite side of the adsorption face, and an outer side face continued to the adsorption face and the bottom face; and a support formed from a dense ceramic body including a substrate part including an arrangement face that is opposite to the bottom face, and a protrusive part including an inner side face that surrounds the outer side face. An average pore volume ratio indicating a ratio of a total volume of an average pore group with respect to a total volume of entire pores is 60% or more and 74.5% or less. A large-sized pore volume ratio indicating a ratio of a total volume of a large-sized pore group with respect to the total volume of the entire pores is greater in comparison with a small-sized pore volume ratio indicating a ratio of a total volume of a small-sized pore group with respect to the total volume of the entire pores.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an adsorbing member.

  Conventionally, an adsorbing member has been used as a jig for adsorbing and holding an adsorbent such as a semiconductor wafer or a glass substrate. As such an adsorbing member, for example, in Patent Document 1, the average pore diameter is 10 to 40 μm, and the total pore volume is the pore volume having a pore diameter 0.7 to 1.2 times the average pore diameter. The ratio of the volume of pores having a pore diameter less than 0.7 times the average pore diameter to the volume of all pores is 15% or less, and 1.2 times the average pore diameter. There has been proposed an adsorbing member comprising an adsorbent in which the ratio of the volume of pores having a pore diameter exceeding 10% to the total pore volume is 10% or less.

JP 2004-306254 A

  However, for example, the adsorbing member described in Patent Document 1 has a relatively small average pore diameter of 10 to 40 μm and a small distribution of pore diameters. It was difficult to pull, and the adsorption force per unit area on the adsorption surface was weak. In addition, when this vacuum chuck is used in a polishing apparatus for polishing an object to be adsorbed, the abrasive powder of the object to be adsorbed easily enters and aggregates into pores having a relatively small pore diameter opened on the adsorption surface. When adhering to the adsorption surface, there is also a problem that it cannot be easily removed even if the abrasive powder adhering to the adsorption surface is removed by jetting fluid. The present invention aims to solve such problems.

  An adsorbing member according to an aspect of the present invention is an adsorbing member for adsorbing and holding an object to be adsorbed, and an adsorption surface on which the object to be adsorbed is placed, and a bottom surface opposite to the adsorption surface And a convex body including a mounting body made of a porous ceramic body including the adsorption surface and an outer surface continuous to the bottom surface, a base portion having an arrangement surface facing the bottom surface, and an inner surface surrounding the outer surface. And a support made of a dense ceramic body, and the mounting body includes a plurality of pores, and an average pore diameter of the pores is 41 μm or more and 80 μm or less. A plurality of pores having a pore diameter that is 0.7 times or more and 1.2 times or less of the average pore diameter as an average pore group, and a plurality of pores having a pore diameter exceeding 1.2 times the total average pore diameter Is a large pore group, 0.7 of the average pore size of the whole When a plurality of pores having a pore diameter less than double is a small pore group, the average pore volume ratio indicating the ratio of the total volume of the average pore group to the total volume of the pores is 60% or more and 74.5% or less And the large pore volume ratio indicating the ratio of the total volume of the large pore group to the total volume of the entire pore is the small pore volume indicating the ratio of the total volume of the small pore group to the total volume of the pores. It is characterized by being larger than the ratio.

  The adsorbing member according to one embodiment of the present invention can adsorb the object to be adsorbed relatively strongly, and can remove foreign substances adhering to the adsorbing surface relatively easily.

It is a perspective view which shows an example of the member for adsorption | suction of this embodiment. (A) is a top view which shows an example of the member for adsorption | suction of FIG. 1, (b) is sectional drawing in the AA of (a). The other example of the member for adsorption | suction of this embodiment is shown, (a) is a perspective view, (b) is sectional drawing in the BB line of (a). The other example of the member for adsorption of this embodiment is shown, (a) is a perspective view and (b) is a sectional view in the CC line of (a). It is a schematic diagram which shows the method for measuring the thermal conductivity of the member for adsorption | suction.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view illustrating an example of a suction member according to the present embodiment.

  2A is a plan view showing the adsorbing member of FIG. 1, and FIG. 2B is a cross-sectional view taken along the line AA in FIG.

  A suction member 1a shown in FIGS. 1 and 2 is a suction member for sucking and holding an object to be adsorbed such as a semiconductor wafer or a glass substrate, and an adsorption surface on which an object to be adsorbed (not shown) is placed. 2a, a mounting surface 2 made of a porous ceramic body having a bottom surface 2b opposite to the suction surface 2a, an outer surface 2c connected to the suction surface 2a and the bottom surface 2b, and a placement surface 3a facing the bottom surface 2b. There is provided a support body 3 made of a dense ceramic body having a base portion 3b and a convex portion 3d having an inner side surface 3c surrounding the outer side surface 2c. The mounting body 2 has a plurality of pores, the average pore diameter of the whole pores is 41 μm or more and 80 μm or less, and the pore diameter is 0.7 times or more and 1.2 times or less of the whole average pore diameter. A plurality of pores having an average pore group, and a plurality of pores having a pore diameter exceeding 1.2 times the average pore size as a large pore group, and a pore diameter less than 0.7 times the total average pore size. When the plurality of pores are small pore groups, the average pore volume ratio indicating the ratio of the total volume of the average pore group to the total volume of the whole pores is 60% or more and 74.5% or less, and the total of the pores The large pore volume ratio indicating the ratio of the total volume of the large pore group to the volume is larger than the small pore volume ratio indicating the ratio of the total volume of the small pore group to the total volume of the pores.

  The support 3 is formed with a belt-like portion 3e in the circumferential direction on the bottom surface side, and the belt-like portion 3e is provided with mounting holes 3f at equal intervals along the circumferential direction, via bolts (not shown) or the like. Are connected and fixed to a fixed base (not shown).

  The support body 3 has a plurality of suction holes 3g having openings on the arrangement surface 3a side, and can be placed on the suction surface 2a by sucking air inside the support body 3 through the suction holes 3g. The adsorbed object is adsorbed and held. Further, the top surface 3 h of the convex portion 3 d is flush with the suction surface 2 a of the mounting body 2.

  In the adsorbing member 1a of the present embodiment, the average pore diameter of the entire pores in the mounting body 2 is relatively large, 41 μm or more, and the pressure loss in each pore is reduced, so the ventilation resistance of the mounting body 2 is low. It is suppressed and the object to be adsorbed can be relatively strongly adsorbed and held.

Moreover, the average pore group having a pore diameter of 0.7 times or more and 1.2 times or less of the average pore diameter has a great influence on the pressure loss and heat radiation characteristics of the mounting body 2. Since the average pore volume ratio indicating the ratio of the total volume of the average pore group to the total volume of the pores is 60% or more, the airflow resistance of the mounting body 2 made of a porous ceramic body is relatively low, and the adsorbed body Can be adsorbed relatively strongly. In addition, since the average pore volume ratio is 74.5% or less, the heat dissipation characteristics of the mounting body 2 are relatively high, and even when the temperature of the object to be adsorbed rises, the object to be adsorbed is quickly cooled. be able to.

  Moreover, the mounting body 2 of the adsorbing member 1a of the present embodiment has a large size with respect to the total volume of the pores as compared with a small pore volume ratio indicating a ratio of the total volume of the small pore group to the total volume of the pores. Since the large pore volume ratio indicating the ratio of the total volume of the pore group is large, the ventilation resistance of the mounting body 2 is more sufficiently suppressed. For example, when the object to be adsorbed is polished by using this adsorbing member 1a in a polishing apparatus or the like, the polishing powder enters and aggregates in the pores opened on the adsorption surface 2a, and a part thereof adheres to the adsorption surface 2a. Even if it does, since the ventilation resistance of the member 1a for adsorption | suction is fully suppressed, if a fluid is injected from the base | substrate part 3b side, polishing powder can be removed easily.

  Further, the adsorption member 1a of the present embodiment has a small pore volume ratio of, for example, 15% or less of the mounting body 2 and has a lower ventilation resistance, and is polished by jetting fluid from the base portion 3b side. The powder can be removed relatively easily.

  Further, in the adsorption member 1a of the present embodiment, the porosity of the mounting body 2 is, for example, 28% or more and 38% or less. Since the porosity of the mounting body 2 is 28% or more, the ventilation resistance of the entire porous ceramic body is low, and the object to be adsorbed can be fixed with a relatively low suction force. Moreover, since the porosity is 38% or less, the heat dissipation characteristic of the entire porous ceramic body is relatively high, and it can be applied to an adsorbed body that requires quick heat dissipation.

  Here, the average pore diameter of the entire pores of the mounting body 2, the average pore group, the small pore group, and the pore volume ratio and the respective porosity of the large pore group are all mercury conforming to JIS R 1655-2003. It can be determined according to the press-fitting method.

  3A and 3B show another example of the adsorbing member of the present embodiment, in which FIG. 3A is a perspective view, and FIG. 3B is a cross-sectional view taken along line BB in FIG. The suction member 1b of the embodiment shown in FIG. 3 is different from the embodiment shown in FIGS. 1 and 2 in that the suction surface 2a has a quadrangular shape. The adsorbing member of the embodiment shown in FIG. 3 is suitable for adsorbing a square-plate-shaped adsorbent.

The adsorbing member 1b of the embodiment shown in FIG. 3 includes a porous adsorbing surface 2a, a bottom surface 2b opposite to the adsorbing surface 2a, and an outer surface 2c connected to the adsorbing surface 2a and the bottom surface 2b. A support body 3 including a mounting body 2 made of a body, a base portion 3b having a placement surface 3a facing the bottom surface 2b, and a convex portion 3d having an inner side surface 3c surrounding the outer side surface 2c. Yes. The adsorbing member 1 b further includes a partition wall 3 j made of a dense ceramic body that divides the mounting body 2. In addition, the support 3 is provided with suction grooves 3k ₁ and 3k ₂ that open to the arrangement surface 3a of the base portion 3b, and suction holes 3g ₁ and 3g ₂ that communicate with the suction grooves 3k ₁ and 3k ₂ . . The suction grooves 3k ₁ and 3k ₂ may be appropriately selected after setting the size of the suction surface 2a according to the size of the object to be attracted.

Specifically, when the size of the object to be adsorbed is close to the entire surface of the adsorption surface 2a in plan view, in order to adsorb the object to be adsorbed, all the suction holes 3g ₁ and 3g ₂ are exhausted to the outside. The adsorbents may be adsorbed and held through the suction grooves 3k ₁ and 3k ₂ . Further, if the size and substantially the same size as the portion size of the adsorbent is surrounded by the partition wall 3j in plan view, to adsorb the adsorbent, evacuated only from the suction hole 3 g _1, suction grooves 3k _The adsorbent may be adsorbed and held through ₁ .

  The support 3 is provided with mounting holes 3f at regular intervals along its outer edge, and is connected and fixed to a fixed base (not shown) via bolts (not shown).

  4A and 4B show another example of the adsorbing member of the present embodiment, in which FIG. 4A is a perspective view, and FIG. 4B is a cross-sectional view taken along line CC in FIG.

  The suction member 1c in the example shown in FIG. 4 is different from the embodiment shown in FIG. 3 in that the suction surface 2a is divided into four rectangular regions by a partition wall 3j. The adsorbing member 1c according to the embodiment shown in FIG. 4 is suitable for a case where a plurality of quadrangular objects to be adsorbed are adsorbed simultaneously.

  Next, an example of the manufacturing method of the adsorption member according to the present embodiment will be described.

  First, 15 to 25 parts by mass of silicon powder having an average particle size of 1 to 90 μm is mixed with 100 parts by mass of α-type silicon carbide powder having an average particle size of 90 to 250 μm and used as a molding aid later. Thermosetting resin with a residual carbon ratio after degreasing treatment of 10% or more, for example, phenol resin, epoxy resin, furan resin, phenoxy resin, melamine resin, urea resin, aniline resin, unsaturated polyester resin, urethane At least one of resin and methacrylic resin is added and mixed with a ball mill, a vibration mill, a colloid mill, an attritor, a high-speed mixer or the like. In particular, a resol-type or novolac-type phenol resin is suitable as the molding aid from the viewpoint of low shrinkage after thermosetting.

  Here, the purity of the silicon powder is preferably higher, preferably 95% by mass or more, and particularly preferably 99% by mass or more. In addition, the shape of the silicon powder to be used is not particularly limited, and not only a spherical shape or a shape close thereto, but also an irregular shape can be suitably used. This silicon powder becomes a silicon phase in the subsequent heat treatment, and connects the silicon carbide crystal particles.

  Here, in order to obtain an adsorbing member made of a porous ceramic body having a porosity of 28% or more and 38% or less, 11 parts by mass or more of a molding aid is added to 100 parts by mass of α-type silicon carbide powder. And 18.5 mass parts or less should just be added. The average particle diameter of each powder of silicon carbide and silicon can be measured by a liquid phase precipitation method, a light dropping method, a laser scattering diffraction method, or the like.

  Next, granules are obtained by granulating the mixed raw materials using various granulators such as a rolling granulator, a spray dryer, a compression granulator, an extrusion granulator, and the like. In particular, in order to obtain granules having a large particle size, for example, granules having a particle size of 0.4 mm to 1.6 mm, it is preferable to use a rolling granulator. The granulation time is preferably 30 minutes or longer in consideration of the crushability of the compact.

  In addition, the particle size of the granules obtained by this granulation is preferably 0.4 to 1.6 mm, and even if the particle size is less than 0.4 mm or exceeds 1.6 mm, the crushability of the molded product is deteriorated, Although handling becomes difficult, the collapsibility of a molded object and handling improve by making the particle size of a granule into 0.4-1.6 mm. In particular, the particle size of the granules is preferably 0.5 to 1.5 mm.

  Next, the obtained granules are formed. The pore diameter in the molded body, the volume ratio of the pores, and the like are affected by pressure in molding. In order to obtain a mounting body having an average pore volume ratio of 60% or more and 74.5% or less, the granule is formed by a molding means such as a dry pressure molding method or a cold isostatic pressing method, and the pressure is set at 78. It is molded as 4 to 117.6 MPa, and after degreasing treatment at 400 to 600 ° C. in a non-oxidizing atmosphere such as argon, helium, neon, nitrogen, vacuum, etc., if necessary, in a non-oxidizing atmosphere, 1460 to 1500 What is necessary is just to heat-process at ° C.

  Here, the size of the small pore volume ratio and the large pore volume ratio are both affected by the temperature drop rate, and in order to obtain a mounting body in which the volume ratio of the former pores is larger than the volume ratio of the latter pores, 1400 What is necessary is just to make the temperature-fall rate to 1 degreeC into 1 degreeC / min or more and 2 degrees C / min or less.

  Moreover, what is necessary is just to make the temperature-fall rate to 1400 degreeC into 1.6 degrees C / min or less in order to obtain the mounting body whose small pore volume ratio is 15% or less.

  Next, a support made of a dense ceramic body is prepared. Here, for example, the outer diameter of the convex portion is 143 to 380 mm, and the thickness between the top surface of the convex portion and the bottom surface of the base portion is 14.3 to 60 mm.

_Then, comprises _{SiO 2, Al 2 O 3,} B 2 O 3, CaO, and MgO and TiO _2, that the mass ratio, for example, 30-65%, 10-40%, 10-20%, 4-5 %, 1 to 5%, and 0 to 5% of paste-like glass is applied to the concave portion formed along the inner surface of the convex portion.

  In order to prevent the paste-like glass from entering the suction holes, the resin is filled in the suction holes and cured in advance, and the cured resin may be eliminated by the subsequent heat treatment.

  After the glass application, the mounting body is placed in the concave portion, and then pressurized from the thickness direction by a dedicated pressurizing device. After pressurization, the mounting body 2 and the support body 3 are joined by a bonding layer made of glass by heat treatment at 950 to 980 ° C. And the member for adsorption | suction of this embodiment can be obtained by performing machining, such as grinding and grinding | polishing, on the surface of a convex part and the surface of a mounting body.

  Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.

  First, with respect to 100 parts by mass of α-type silicon carbide powder having an average particle size of 170 μm, silicon powder having an average particle size of 5 μm and 19.3 parts by mass of phenol resin are mixed at the ratio shown in Table 1, Granules were obtained by granulation with a dynamic granulator.

  Next, the obtained granule was molded by a dry pressure molding method at a pressure shown in Table 1, and after degreasing treatment at 500 ° C. in a nitrogen atmosphere, heat treatment was performed at 1480 ° C. in a vacuum atmosphere, It cooled at the temperature-fall rate shown in Table 1, and the mounting body was obtained.

  Next, a support body made of a dense ceramic body having a base portion having an arrangement surface facing the bottom surface of the mounting body and a convex portion having an inner surface surrounding the outer surface was prepared.

_Then, it comprises _{SiO 2, Al 2 O 3,} B 2 O 3, CaO, and MgO and TiO _2, that the mass ratio is 50%, 25%, 15%, 4.5%, 3%, 2.5 % Of paste-like glass was applied to the concave part formed along the inner surface of the convex part.

  The suction holes were previously filled with resin in the suction grooves and cured.

  After the glass application, the mounting body 2 was placed in the concave portion 3a, and then pressurized from the thickness direction with a dedicated pressurizing device. After pressurization, the mounting body 2 and the support body 3 were joined by a bonding layer made of glass by heat treatment at 965 ° C. And after grinding the surface of the mounting body 2 and the surface of the support body 3, it grind | polishes and sample No. which is the member 1a for adsorption | suction shown in FIG. 1-14 were obtained.

Here, the average pore diameter of the entire pores of the mounting body, the average pore group, the pore volume ratio of each of the small pore group and the large pore group are all determined by a mercury intrusion method according to JIS R 1655-2003, The values are shown in Table 1.

  Further, when a semiconductor wafer (not shown) having a diameter of 200 mm is placed on the suction surface of the mounting body, the pressure is sucked at 80 kPa, and the semiconductor wafer is polished 100 μm in the thickness direction using a dry polishing apparatus. The flatness of the surface was measured with a flatness measuring device (Kuroda Seiko Co., Ltd., Nanometro TT). The flatness of the surface was defined as the difference between the highest point and the lowest point on the polished surface.

  In order to measure the ventilation resistance of the adsorption member before and after polishing the semiconductor wafer, a vacuum pump (not shown) is connected to the suction hole 3g via a pipe (not shown), and then sucked at a pressure of 85 kPa. The value of the generated pressure loss was read with a pressure gauge attached to the pipe. A large pressure loss value indicates that the ventilation resistance is high, and a small pressure loss value indicates that the ventilation resistance is low.

  Moreover, the thermal conductivity of each sample was measured as follows. FIG. 5 is a schematic diagram showing a method for measuring the thermal conductivity of the adsorption member. In order to measure the thermal conductivity of the adsorbing member, the soaking plate 4 made of silicon carbide is placed on the hot plate 5 as shown in FIG. Held at 0C. In this state, the adsorbing member is placed on the soaking plate 4 so that the attracting surface comes into contact with the surface of the soaking plate 4, and the temperature at the center of the bottom surface of the support 50 seconds later is set to the thermocouple 6 ( K thermocouple), and the temperature was read by a recorder 7 connected to the thermocouple 6. If this temperature is high, the thermal conductivity of the adsorption member is high, and if this temperature is low, it can be said that the thermal conductivity is low.

  As shown in Table 1, sample no. 2, 4, 5, 7 to 11 and 13 have pores having an average pore diameter of 41 μm or more and 80 μm or less, an average pore volume ratio of 60% or more and 74.5% or less, and a large pore volume ratio of small pores. Since it has a mounting body larger than the volume ratio, it can be seen that the ventilation resistance is low and the heat dissipation characteristics are high, and when the adsorbent is polished using these samples, the adsorbent after polishing is polished. It can be said that the flatness of the surface is small and the increase in the airflow resistance after polishing is suppressed, and it is possible to easily remove the polishing powder by jetting the fluid from the base portion 3b side.

Sample Nos. Having the same average pore diameter and average pore volume ratio were used. Comparing 7-9, sample No. 8.9 is equipped with a mounting body having a small pore volume ratio of 15% or less, so it can be seen that the increase in ventilation resistance after polishing is also suppressed, It can be said that it is possible to further facilitate the removal of the polishing powder by jetting the fluid from the base portion 3b side.

  First, with respect to 100 parts by mass of α-type silicon carbide powder having an average particle diameter of 170 μm, silicon powder having an average particle diameter of 5 μm and a mass ratio of 20.1 parts by mass is shown in Table 1. Granules were obtained by mixing with the phenol resin shown and granulating with a tumbling granulator. Here, the reason why the mass ratio of the phenol resin is changed for each sample is to appropriately set the porosity.

  Next, the obtained granule was molded by a dry pressure molding method at a pressure of 97.9 MPa, degreased at 500 ° C. in a nitrogen atmosphere, then heat-treated at 1480 ° C. in a vacuum atmosphere, and the temperature decreasing rate Was cooled to 1.7 ° C./min to obtain a mounting body. And by the same method as shown in Example 1, sample No. 15-21 were obtained.

  Then, when the average pore diameter of the whole pores of the mounting body, the average pore group, the pore volume ratio of each of the small pore group and the large pore group were determined by a mercury intrusion method according to JIS R 1655-2003, any sample was obtained. The overall average pore diameter was 60 μm, and the pore volume ratios of the average pore group, the small pore group, and the large pore group were 67.3%, 16.8%, and 15.9%, respectively.

  The pressure loss before polishing of the semiconductor wafer and the temperature at the center of the bottom surface of the support 15 were measured by the same method as shown in Example 1, and the values are shown in Table 2.

  As shown in Table 2, sample no. Since 16-20 are equipped with a mounting body having a porosity of 28% or more and 38% or less, the ventilation resistance of the entire mounting body is low, so the object to be adsorbed is fixed with a low suction force. can do. Sample No. Nos. 16 to 20 can be applied to an adsorbed body that requires quick heat dissipation after the adsorbed object is polished since the heat dissipation characteristics of the entire mounting body are high.

  As mentioned above, although the Example of this invention was described, unless it exceeds the summary of this invention, it is not limited to the said Example.

1a, 1b, 1c Adsorption member 2 Mounting body 3 Support body

Claims (3)

An adsorbing member for adsorbing and holding an adsorbent,
A mounting body comprising a porous ceramic body including an adsorption surface on which the object to be adsorbed is mounted; a bottom surface opposite to the adsorption surface; and an outer surface continuous to the adsorption surface and the bottom surface;
A support body made of a dense ceramic body, including a base portion having an arrangement surface facing the bottom surface, and a convex portion having an inner surface surrounding the outer surface;
The above-mentioned mounting body has a plurality of pores, and the average average pore diameter of the pores is 41 μm or more and 80 μm or less, and the average pore diameter is 0.7 times or more and 1.2 times or less of the whole average pore diameter. A plurality of pores having a pore size as an average pore group, and a plurality of pores having a pore size exceeding 1.2 times the overall average pore size as a large pore group, less than 0.7 times the overall average pore size When a plurality of pores having a pore diameter of a small pore group,
The average pore volume ratio indicating the ratio of the total volume of the average pore group to the total volume of the pores is 60% or more and 74.5% or less,
The large pore volume ratio indicating the ratio of the total volume of the large pore group to the total volume of the entire pore is compared with the small pore volume ratio indicating the ratio of the total volume of the small pore group to the total volume of the pore. An adsorption member characterized by being large.   The adsorbing member according to claim 1, wherein the small pore volume ratio is 15% or less.   The adsorbing member according to claim 1 or 2, wherein the porosity of the mounting body is 28% or more and 38% or less.

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