JP2005205507A - Vacuum-sucking device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum sucking device and its manufacturing method for maintaining the flatness of a sucking surface even in use, by having the sucking surface superior in the flatness. <P>SOLUTION: This vacuum-sucking device 10 is composed of a placing part 11 having a porous structure having an opening air hole and sucking and holding a wafer W by its surface, and a support part 12 for supporting the placing part 11. A recess-projection part 18 is formed at the inside bottom of the support part 12, and a recess-projection part 19 fitted to this recess-projection part 18, is formed on an under surface of the placing part 11, and the placing part 11 and the support part 12 are substantially closely and directly joined. A groove part 13a communicating with the opening air hole possessed by the placing part 11 is arranged on a projecting wall 18a of the recess-projection part 18 as a sucking air hole for generating vacuum suction force in the placing part 11. A first through-hole 13b is arranged in the support part 12 so as to communicate with this groove part 13a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vacuum suction apparatus that holds a semiconductor wafer or the like by vacuum suction and performs a manufacturing method thereof, for example, in order to perform wet processing such as polishing on a semiconductor wafer or glass substrate.

  For example, in a semiconductor device manufacturing process, a vacuum suction device using a vacuum suction force is widely used when a semiconductor wafer is transported, processed, or inspected. As such a vacuum suction device, a device having a plurality of through holes opened in the suction surface is generally used. In this case, since only the through holes exhibit an adsorption action, the suction force in the suction surface is This tends to be non-uniform, which causes problems such as a reduction in the processing accuracy of the semiconductor wafer.

  Therefore, in order to perform more uniform adsorption of the semiconductor wafer, a vacuum adsorption apparatus having a porous mounting portion has been studied. For example, as shown in the vertical cross-sectional view of FIG. 6, the mounting portion 91 is supported so that a porous mounting portion 91 and a space portion 94 are formed below the mounting portion 91. There is known a vacuum suction device 90 that includes a support portion 92 having an intake hole 93 that communicates with 94, and in which the mounting portion 91 and the support portion 92 are joined together with an adhesive such as resin or glass.

  Further, as shown in the vertical sectional view of FIG. 7, a porous mounting portion 81, and a support portion 82 that supports the mounting portion 81 and has an intake hole 83 that communicates with the open air holes of the mounting portion 81. The suction holes 83 of the vacuum suction device 80 shown in FIG. 7 have been changed to a plurality of narrow suction holes 83 ′, such as the vacuum suction device 80 provided with the above and the vacuum suction device 80 ′ shown in the vertical sectional view of FIG. Those having a form are known (see, for example, Patent Documents 1 and 2).

  In these vacuum suction devices 80 and the like, the semiconductor wafer W is sucked and held on the entire surface of the mounting portion 81 and the like by generating a vacuum suction force on the mounting portion 81 and the like through the suction holes 83 and the like provided in the respective vacuum suction devices 80 and the like. It is necessary to increase the flatness of the surface of the mounting portion 81 and the like. Therefore, the surface of the mounting portion 81 and the like is subjected to surface grinding with a diamond grindstone or the like while the mounting portion 81 or the like is held by the support portion 82 or the like.

  However, in the vacuum suction device 90 shown in FIG. 6, since the space portion 94 is formed on the lower side of the placement portion 91, the deformation of the surface of the placement portion 91 during the surface grinding is large, and the flatness is high. It is difficult to get a degree. Even when there is no space such as the space portion 94 below the placement portion 81 as in the vacuum suction devices 80 and 80 'shown in FIGS. 7 and 8, the deformation of the placement portion 81 during surface grinding is deformed. As a result, the intake holes 83 and 83 ′ are transferred to the surface of the mounting portion 81, and a dent is generated, resulting in a problem that the flatness of the surface of the mounting portion 81 is lowered.

  Further, in these vacuum suction devices 80 and 80 ′, the mounting portion 81 and the support portion 82 are joined by an adhesive such as resin or glass, so that the adhesive penetrates into the mounting portion 81. As a result, the thickness of the adhesive tends to be non-uniform, and voids are likely to occur. As a result, the adhesive strength of the mounting portion 81 varies, and the gap of the adhesive portion is transferred to the surface of the mounting portion 81 due to the bending deformation during the surface grinding process, and the flatness of the surface of the mounting portion 81 is deteriorated.

  In this way, when the semiconductor wafer W is vacuum-sucked to the vacuum suction device 80 or the like having the mounting portion 81 or the like whose surface flatness is not good, the semiconductor wafer W is imitated according to the surface form of the mounting portion 81 or the like. Since the warp occurs, the processing accuracy of the semiconductor wafer W decreases.

  Further, in the vacuum suction apparatus 90, since the mounting portion 91 is supported by the support portion 92 only at the periphery thereof, the mounting portion 91 and the mounting portion 91 and the surface of the semiconductor wafer W by the atmospheric pressure applied during the vacuum suction of the semiconductor wafer W There is a problem that the semiconductor wafer W is warped. Further, in the vacuum suction devices 80 and 80 ′, suction holes 83 and 83 ′ are formed on the lower side of the mounting portion 81 and the like, and a gap is formed between the mounting portion 81 and the support portion 82. For the sake of simplicity, the atmospheric pressure causes the suction holes 83 and 83 ′ and the air gap to be transferred to the surface of the mounting portion 81, thereby reducing the flatness of the semiconductor wafer W attracted and held on the surface of the mounting portion 81. There is a problem of doing.

Furthermore, in the structure in which the mounting portion 81 and the like and the support portion 82 and the like are bonded as in the vacuum suction device 80 and the like described above, the outer peripheral side wall of the mounting portion 81 and the inner peripheral side wall of the support portion 82 and the like There is also a problem that a gap is easily generated between the two, thereby causing the semiconductor wafer W to be non-uniformly adsorbed and a problem that the semiconductor wafer W is recessed above the gap and the flatness of the semiconductor wafer W is lowered. is there.
JP-A-53-090871 JP 61-182738 A

  The present invention has been made in view of such circumstances, and provides a vacuum suction device having a suction surface with good flatness and capable of maintaining the flatness of the suction surface even during use, and a method for manufacturing the same. With the goal.

That is, according to the present invention, the mounting portion has a porous structure having open pores, and holds the object to be treated by adsorption on the surface thereof;
A support unit that supports the mounting unit and includes an intake hole that communicates with an open hole of the mounting unit;
Comprising
There is provided a vacuum suction device characterized in that the mounting portion and the support portion are directly joined substantially without a gap.

  In this vacuum suction apparatus, the support portion includes a first uneven portion having a predetermined pattern, and the mounting portion includes a second uneven portion that fits the first uneven portion, and is provided on the support portion. Preferably, the air intake hole includes a groove portion provided in the convex portion so as to open in the concave portion of the first uneven portion and a hole portion communicating with the groove portion. The mounting part preferably has a composite structure made of alumina and glass or a composite structure made of silicon carbide and glass, and the support part is preferably made of any of alumina, zirconia, silicon carbide, and silicon nitride.

Moreover, according to the present invention, a step of producing a vessel-shaped ceramic member;
Preparing a slurry containing a predetermined ceramic powder and glass powder;
Filling the ceramic member with the slurry produced in the slurry preparation step;
Firing the ceramic member filled with the slurry at a temperature equal to or higher than the softening point of the glass powder, and forming a porous portion directly bonded to the ceramic member;
There is provided a method of manufacturing a vacuum suction device characterized by comprising:

  In such a vacuum suction device manufacturing method, as the ceramic member, a concave and convex portion having a predetermined pattern is formed on the inner bottom thereof, and an intake hole is formed in the convex portion so as to open to the concave portion of the concave and convex portion. Before the ceramic member is filled with the slurry, the suction holes are filled with a material that is burned off by heating, and the suction holes and the pores of the porous portion are communicated by a firing step. preferable.

  According to the present invention, since the mounting portion and the support portion are directly joined with substantially no gap, the flatness of the surface of the mounting portion can be remarkably increased, and the object to be processed is held by suction. The bending deformation (warpage) at the time of doing is suppressed. Further, since there is no intake air leakage, the object to be processed can be uniformly adsorbed and held. Furthermore, since the intake holes that communicate directly with the lower surface of the mounting portion are not formed, it is possible to suppress deterioration in flatness due to the surface transfer of the intake holes when the surface of the mounting portion is subjected to surface grinding. In addition, it is possible to prevent the object to be bent from being bent at the time of holding the object to be processed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, a semiconductor wafer will be taken up as an example of an object to be processed, and a vacuum suction apparatus for sucking and holding the semiconductor wafer will be described.

FIG. 1 is a schematic plan view of a vacuum suction device 20 according to the present invention, and FIG. 2 is a vertical sectional view including a line AA in FIG.
The vacuum suction apparatus 20 has a porous structure having pores (open pores; not shown) that communicate with each other, a mounting portion 21 that sucks and holds the semiconductor wafer W, and a support portion that supports the mounting portion 21. 22 is comprised.

  The support portion 22 is made of a ceramic selected from alumina, silicon nitride, silicon carbide, and zirconia. The support portion 22 has a bowl shape, and a plurality of intake holes 23 are formed substantially horizontally at predetermined positions so as to open on the inner side surface thereof. On the other hand, mounting portion 21 is made of alumina and glass, or silicon carbide and glass. The average pore diameter of the open pores of the mounting portion 21 is preferably 10 to 150 μm, and the porosity is preferably 20 to 40%.

  The intake hole 23 communicates with an open hole of the mounting portion 21. In addition, the placement portion 21 is directly joined to the support portion 22 at a side surface and a lower surface thereof with substantially no gap. Here, “directly joined substantially without any gap” means that the porous structure of the placement portion 21 is in contact with the interface of the support portion 22. For this reason, when suction is performed by attaching a suction device such as a vacuum pump to the suction hole 23 of the support part 22, the suction force is applied to the entire surface of the placement part 21 through the open holes of the placement part 21 communicating with the suction hole 23. Will occur. At this time, since the mounting portion 21 and the support portion 22 are joined to each other with substantially no gap, intake air leakage does not occur, and the semiconductor wafer W can be securely held by suction.

  As will be described later, the upper surface of the mounting portion 21 and the upper surface of the outer peripheral portion of the support portion 22 are simultaneously subjected to surface grinding / polishing processing on the surface (that is, the suction surface) of the mounting portion 21 at the final stage of the manufacturing process. It is formed by. In the vacuum suction device 20, since there is substantially no gap between the mounting portion 21 and the support portion 22 and there is no suction hole on the lower side of the mounting portion 21, during surface grinding / polishing processing, It is difficult for the mounting portion 21 to be bent and deformed, and transfer due to an intake hole or the like to the surface of the mounting portion 21 is prevented, so that a suction surface having high flatness can be formed. In addition, since there is substantially no gap between the mounting portion 21 and the support portion 22, even when the semiconductor wafer W is sucked and held, the flatness of the semiconductor wafer W can be maintained high.

  Next, another embodiment of the vacuum suction device according to the present invention will be described. 3 is a plan view showing a schematic structure of the vacuum suction apparatus 10 according to the present invention, FIG. 4 is a vertical sectional view including a line BB shown in FIG. 3, and FIG. 5 is a vertical sectional view including a line CC shown in FIG. It is.

  Similar to the vacuum suction device 20 described above, the vacuum suction device 10 has a porous structure having open pores communicating therewith, and a placement portion 11 that sucks and holds the semiconductor wafer W, and the placement portion 11. And a support portion 12 having an intake hole 13 communicating with an open hole of the mounting portion 11. The material constituting the placement part 11 is the same as each material constituting the placement part 21 of the vacuum suction device 20 described above, and the material constituting the support part 12 is the same as the material constituting the support part 22. It is.

  The support part 12 has a container-like shape, and concavity and convexity parts 18 having a concentric pattern are formed on the inner bottom thereof. The concavo-convex pattern formed on the support portion 12 is not limited to a concentric shape, and may be a lattice shape, a radial shape, a staggered pattern (checkered pattern), or the like. On the convex wall 18a of the concavo-convex portion 18, a ring-shaped groove portion 13a is formed so as to open in a concave portion between adjacent convex walls 18a. A plurality of first through holes 13b are provided at predetermined positions so as to communicate with the groove 13a. Further, a plurality of second through holes 13c are provided at predetermined positions substantially horizontally so as to open on the inner side surface of the support portion 12. The groove 13a, the first through-hole 13b, and the second through-hole 13c constitute the intake hole 13. In addition, you may change the vacuum suction apparatus 10 to the form which does not provide the 2nd through-hole 13c.

  An outer peripheral side surface of the mounting portion 11 is surrounded by the support portion 12, and an uneven portion 19 having a pattern that fits with the uneven portion 18 is formed on the bottom surface of the mounting portion 11, and the mounting portion 11 and the support portion 12 are formed. Is directly joined with substantially no gap. As will be described later with respect to the manufacturing method of the vacuum suction device 10, the concavo-convex portion 19 can be easily formed so that it can be fitted to the concavo-convex portion 18 of the support portion 12 at the stage of forming the mounting portion 11.

  In the vacuum suction device 10, when suction is performed by attaching a vacuum pump to the first through-hole 13 b and the second through-hole 13 c formed in the support portion 12, the open pores of the mounting portion 11 communicating with the groove 13 a and the groove 13 a Through this, a suction force is generated on the entire surface of the mounting portion 11. Note that the number of convex walls 18a (the number of steps) in the concavo-convex portion 18 and the step size of the concavo-convex portion 18 so that a necessary suction force for vacuum-sucking the semiconductor wafer W to the mounting portion 11 can be generated. The number, width, and height of the grooves 13a, the number of first through holes 13b, and the like may be appropriately determined in consideration of the use conditions of the vacuum suction device 10.

  In the vacuum suction device 10 having such a structure, since the mounting portion 11 is held by the support portion 12 over the entire side surface and lower surface, bending deformation during surface grinding is suppressed, and the suction surface has a high flatness. Can be obtained. Further, since the groove portion 13 a is formed in the support portion 12 so as to communicate with the vertical surface of the concavo-convex portion 19 of the mounting portion 11, and the intake hole communicating with the horizontal surface of the concavo-convex portion 19 is not formed, surface grinding is performed. At the time of processing, the transfer of the groove 13a and the first through hole 13b to the surface of the mounting portion 11 does not occur. Furthermore, since the mounting portion 11 and the support portion 12 are directly joined with substantially no gap, there is no intake air leakage, and the semiconductor wafer W can be uniformly held by suction. Furthermore, since the flatness is maintained even when the semiconductor wafer W is held by suction, it is possible to suppress warping or depression of the semiconductor wafer W. Thereby, the semiconductor wafer W can be processed with high accuracy.

  The vacuum suction device according to the present invention is not limited to a circular shape as in the vacuum suction devices 10 and 20 described above, and can be modified according to the shape of the workpiece to be sucked and held. For example, the planar shape of the vacuum suction device according to the present invention may be substantially rectangular.

Next, the manufacturing method will be described by taking the vacuum suction device 10 as an example.
First, a vessel-shaped ceramic member that becomes the support portion 12 is manufactured. For example, a predetermined amount of a binder is added to ceramic powder such as alumina and granulated, and this is uniaxially press-molded and further CIP-molded to produce a disk-shaped press-molded body. Next, this press-molded body is processed into a container shape to form a concave / convex portion of a predetermined pattern on the inner bottom, a groove portion that opens to the concave portion, a first through hole that communicates with the groove portion, and an inner side surface. A second through hole is formed. The obtained processed body is degreased as necessary, and then fired at a predetermined atmosphere, temperature, and time, whereby a ceramic member to be the support portion 12 can be obtained. In addition, the press-molded body may be calcined, the obtained calcined body may be subjected to a process for forming uneven portions and the like, and then a firing treatment may be performed.

  On the other hand, the slurry used for forming the mounting part 11 is prepared. This slurry can be prepared by adding a solvent such as water or alcohol to ceramic powder (alumina powder or silicon carbide powder) and glass powder and mixing them by a known method such as a ball mill or a mixer. The amount of water or alcohol added is not particularly limited, but is preferably adjusted so that desired fluidity can be obtained in consideration of the particle size of the ceramic powder and the amount of glass powder added. .

  Here, in order to finally form the mounting portion 11 having an average pore diameter of 10 to 150 μm and a porosity of 20 to 40%, as ceramic powder (that is, alumina powder or silicon carbide powder) It is preferable to use those having an average particle diameter of 30 μm to 500 μm.

  As the glass which is one of the constituent components of the mounting portion 11, it is preferable to use a glass whose thermal expansion coefficient is smaller than that of the ceramic which is the other constituent component of the mounting portion 11. Thereby, the mounting part 11 which has a structure | tissue substantially continuous with the interface of the support part 12 can be formed in the subsequent baking step. In addition, it is possible to create a state in which compressive stress is applied to the glass having a role as a binder in the mounting portion 11. Since glass is generally weak in tensile strength, the strength of the mounting portion 11 is increased by setting the glass to a state in which a compressive stress is applied, and the occurrence of degranulation or chipping during grinding is suppressed.

  It is preferable that the average particle diameter of the glass powder that is a raw material for forming the mounting portion 11 is smaller than the average particle diameter of the ceramic powder that is the other raw material of the mounting portion 11. This is because if the average particle size of the glass powder is larger than that of the ceramic powder, the filling of the ceramic powder is hindered, causing firing shrinkage when firing above the glass softening point. A gap will be generated at the boundary between the ceramic member and the porous portion formed by firing. The average particle size of the glass powder is preferably 1/3 or less of the average particle size of the ceramic powder, and more preferably 1/5 or less.

  The amount of the glass powder added to the ceramic powder is adjusted in consideration of the particle size (particle size distribution) of the ceramic powder to be used and the viscosity of the glass at the firing temperature. In contrast, if the shrinkage is too small, the bonding strength of the ceramic powder is lowered, and degranulation or chipping occurs. For this reason, the amount of the glass powder is preferably as small as possible within a range where desired bond strength and porosity can be obtained. Specifically, the amount is generally 5 to 30 parts by mass with respect to 100 parts by mass of the ceramic powder. It is preferable.

  Next, a burning material such as resin is filled in the groove, the first through hole, and the second through hole formed in the ceramic member. Next, the prepared slurry is filled in a ceramic member, and a portion that becomes the mounting portion 11 is formed by subsequent firing. At that time, if necessary, it is preferable to apply a vacuum defoaming treatment for removing residual bubbles in the slurry and vibration for increasing the filling rate.

  Thus, after fully drying the ceramic member with which the slurry was filled, it baked at the temperature more than the softening point of the glass for mounting part 11 formation, and forms a porous part. At this time, if the firing temperature is lower than the softening point of the glass, the ceramic member and the porous part cannot be sufficiently integrated, but conversely if the firing temperature is too high, the porous part is deformed and contracted, It is desirable to fire at as low a temperature as possible. Then, the vacuum adsorption apparatus 10 is obtained by grinding the whole surface of the obtained baked body, and also grind | polishing as needed.

  According to such a manufacturing method of the vacuum suction device 10, it is not necessary to separately manufacture the mounting portion 11 and the support portion 12, and the mounting is performed according to the processing shape of the container-like ceramic member constituting the support portion 12. Since the porous portion to be the placement portion 11 can be formed, the process of aligning the boundary between the placement portion 11 and the support portion 12 becomes unnecessary. Thereby, manufacturing cost can be reduced significantly. Further, since no gap is generated at the interface between the placement portion 11 and the support portion 12, no transfer due to such a gap occurs when the placement portion 11 is surface ground. Thereby, an adsorption surface with high flatness can be obtained.

(Example)
As an example, the vacuum suction apparatus 10 shown in FIGS. That is, by a known ceramic member manufacturing method, a dense alumina member (outer diameter: 250 mm, inner diameter: 200 mm, height (thickness): 50 mm, depth: 40 mm, thermal expansion coefficient) having the same structure as the support portion 12. : 8.0 × 10 ⁻⁶ / ° C.), and a resin was filled into the air intake holes provided in the dense alumina member. Also, alumina powder (average particle size: 125 μm), glass powder (borosilicate glass, average particle size: 20 μm, coefficient of thermal expansion: 40 × 10 ⁻⁷ / ° C., softening point: 800 ° C.) and distilled water, 100 : Weighed at a mass ratio of 20:20, and kneaded using a mixer to prepare a slurry.

  The obtained slurry was cast into a dense alumina member, vacuum defoamed, and then subjected to vibration to settle and fill the powder contained in the slurry. This was dried at 100 ° C. and then fired at 1000 ° C. As a result, a porous portion made of alumina and glass was formed in the portion filled with the slurry. Subsequently, the surface of the obtained fired body was subjected to surface grinding with a diamond grindstone to obtain a vacuum suction device 10.

  When the bonding interface between the porous portion (that is, the mounting portion 11) and the dense alumina member (that is, the support portion 12) of this vacuum adsorption device was observed, no cracks or gaps were observed. Further, no defects such as degranulation were observed on the surface of the porous part. Further, the flatness of the surface of the porous portion and the warpage of the semiconductor wafer when a semiconductor wafer having a diameter of 200 mm × thickness of 0.1 mm is sucked and held on the surface of the porous portion is measured by a straightness measuring device. As a result, both were as good as about 0.5 μm.

(Comparative example)
As a comparative example, a vacuum suction device 80 ′ shown in FIG. 8 was produced. That is, the placing part 81 was manufactured by processing the alumina porous body, and the supporting part 82 was manufactured by processing the dense alumina body. After applying a glass paste to the inner surface of the support portion 82, the mounting portion 81 was inserted into the support portion 82 and baked at 800 ° C., and these were glass bonded. The surface of the obtained bonded body was surface ground to obtain a vacuum suction device 10.

  When the boundary (joint part) between the placement part 81 and the support part 82 in the vacuum suction device thus produced was observed, small gaps were observed at a plurality of places. Further, as in the example, the flatness of the surface of the mounting portion 81 was measured, and as a result, it was as large as about 5 μm. Further, when the semiconductor wafer is attracted and held on the mounting portion 81, the warp of the semiconductor wafer is about 15 μm, and deformation larger than the flatness of the surface of the mounting portion 81 occurs.

  The vacuum suction device of the present invention is suitable for, for example, a transfer device such as a semiconductor wafer or a glass substrate, a processing device, an inspection device, and the like.

The top view which shows 1st Embodiment of the vacuum suction apparatus of this invention. FIG. 2 is a vertical sectional view including a line AA shown in FIG. 1. The top view which shows 2nd Embodiment of the vacuum suction apparatus of this invention. FIG. 4 is a vertical sectional view including a line BB shown in FIG. 3. FIG. 4 is a vertical sectional view including a line CC shown in FIG. 3. Sectional drawing which shows an example of the conventional vacuum suction apparatus. Sectional drawing which shows another example of the conventional vacuum suction apparatus. Sectional drawing which shows another example of the conventional vacuum suction apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10; Vacuum suction apparatus 11; Mounting part 12; Support part 13; Intake hole 13a; Groove part 13b; First through-hole 13c; Second through-hole 18: Uneven part 18a; Convex wall 19; 21; Placement part 22; Support part 23; Intake hole 80/80 '/ 90; Vacuum suction device 81/91; Placement part 82/92; Support part 83/83' / 93; Intake hole 94;

Claims (4)

A mounting portion having a porous structure with open pores and adsorbing and holding an object to be processed on its surface;
A support unit that supports the mounting unit and includes an intake hole that communicates with an open hole of the mounting unit;
Comprising
The vacuum suction device, wherein the placement portion and the support portion are directly joined with substantially no gap. The support portion includes a first uneven portion having a predetermined pattern,
The mounting portion includes a second uneven portion that fits with the first uneven portion,
2. The vacuum suction device according to claim 1, wherein the air intake hole includes a groove portion provided in the convex portion so as to open in the concave portion of the first uneven portion and a hole portion communicating with the groove portion. . The placement section has a composite structure made of alumina and glass, or a composite structure made of silicon carbide and glass,
The vacuum suction device according to claim 1, wherein the support portion is made of any one of alumina, zirconia, silicon carbide, and silicon nitride. Producing a bowl-shaped ceramic member;
Preparing a slurry containing a predetermined ceramic powder and glass powder;
Filling the ceramic member with the slurry produced in the slurry preparation step;
Firing the ceramic member filled with the slurry at a temperature equal to or higher than the softening point of the glass powder, and forming a porous portion directly bonded to the ceramic member;
A method for manufacturing a vacuum suction device, comprising:

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