JP2004146585A - Attraction device and vacuum processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a attraction device for holding an object to be attracted wherein conductors and insulators are intermingled. <P>SOLUTION: A main body 14 of the attraction device 10 comprises a support body 11 and first and second electrodes 15a and 15b. In a surface of the main body 14 where the first and second electrodes 15a and 15b are formed, recessed potions 12 are so formed as to correspond to device regions 25. When the object to be attracted 20 is placed on the first and the second electrodes 15a and 15b, a distance between the installation surface 29 and the surface of the first and the second electrodes 15a and 15b is large at places where the device regions are located, while it is small at places where the insulator regions 26 are located, resulting in making the attraction force which attracts the device regions 25 and the attraction force which attracts the insulator regions 26 nearly equal. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electrostatic attraction device, and more particularly to an attraction device that adsorbs an attraction object having a device pattern formed on an insulating substrate.
[0002]
[Prior art]
Reference numeral 121 in FIG. 9 indicates a conventional suction device used for suctioning an insulating substrate such as a glass substrate. The adsorption device 121 includes a support 125, first and second electrodes 126 and 127 disposed on the surface of the support 125, and a protective layer 130 covering the surfaces of the first and second electrodes 126 and 127. are doing.
[0003]
When an insulating substrate is placed on the surface of the suction device 121 on which the protective layer 130 is formed and positive and negative voltages are applied to the first and second electrodes 126 and 127, respectively, the first and second electrodes 126, An electric field is formed between the two.
In general, when a dielectric having a polarizability α is placed in an inhomogeneous electric field E, a gradient force expressed by the following formula acts on the dielectric per unit area.
[0004]
f = 1/2 · α · grad (E ² )
The first and second electrodes 126 and 127 are formed in a comb shape by patterning, and their teeth are arranged so as to mesh with each other. The distance between the first and second electrodes 126 and 127 adjacent to each other is set. Is very small. As a result, when the insulating substrate is placed on the surface, grad (E ² ) in the above equation is large.
[0005]
The insulating substrate receives the above-described gradient force, and the entire back surface of the substrate is adsorbed to the surface of the suction device 121, and as a result, is held by the suction device 121.
By the way, in the actual manufacturing process, conductors such as wiring and transistors are often formed on an insulating substrate, and when such a conductor and an insulator such as a glass substrate are adsorbed, There is a problem that the in-plane distribution of the attraction force becomes non-uniform and the stability of the attraction is low.
[0006]
[Problems to be solved by the invention]
The present invention has been created in order to meet the demands of the above-mentioned prior art, and its purpose is to make the in-plane distribution of the adsorbing force uniform when adsorbing an adsorbing object in which a conductor and an insulator are mixed. It is to provide a suction device.
[0007]
[Means for Solving the Problems]
The present inventors prepared two types of adsorption target objects, which are a rectangular glass substrate with a side of 50 cm and have no wiring formed thereon, and an adsorption target object having wiring formed on one surface of the glass substrate. did.
[0008]
The objects to be adsorbed are arranged on the electrodes 126 and 127 with the surface on which the wiring is not formed (placement surface) facing downward, and the placement surface is placed on the first and second electrodes 126 and 127. Suction was performed in a state of being separated from the surface by 0 to 1.2 mm, and the suction force was measured. The width of the comb teeth of the first and second electrodes 126 and 127 of the suction device 121 was 3 mm, and the interval between them was 1 mm.
[0009]
Figure 10 is a distance to the mounting surface of electrode 126 and 127 surface (separation distance) is a graph showing the relationship between the suction force, the suction force of the code L ₁ in the figure adsorption object which wiring is formed shows the change, reference numeral L ₂ represents the change in the suction force of the suction objects when not formed wiring.
[0010]
As is clear from FIG. 10, the suction target having the wiring has a larger suction force than the suction target having no wiring, and the suction target has no wiring and has no wiring. Also, as the separation distance increases, the attraction force decreases. For example, focusing on the separation distance at which the suction force becomes 1 kPa, the separation distance is about 0.2 mm for the suction target having no wiring, whereas the separation distance is about 0.6 mm for the suction target having wiring. And has become larger.
[0011]
From these facts, if the separation distance of a portion having a conductor such as a wiring is made larger than that of a portion having no conductor, the difference in the attraction force between the portion having the conductor and the portion having no conductor is eliminated, and the attraction force is reduced. Is considered to be uniform in the plane.
[0012]
The invention according to claim 1 based on the above knowledge has an apparatus main body, the apparatus main body includes a support, and first and second electrodes disposed on the support, First, when a voltage is applied to the second electrode, the suction device is configured to suction the insulating substrate, and the device main body has a concave portion at a position corresponding to a position of a device region in the insulating substrate. Formed, a convex portion is arranged around the concave portion, and when the insulating substrate and the suction device are relatively positioned, the distance from the first plane where the tip of the convex portion is located to the mounting surface is And a suction device in which the distance from the second plane where the bottom surface of the concave portion is located to the mounting surface is smaller.
The invention according to claim 2 is the suction device according to claim 1, wherein both the first and second electrodes are disposed at a tip of the projection.
The invention according to claim 3 is the suction device according to any one of claims 1 and 2, wherein both the first and second electrodes are arranged on a bottom surface of the concave portion. It is.
The invention according to a fourth aspect is the suction device according to any one of the first to third aspects, wherein the apparatus main body has a plurality of the concave portions, and the bottom surfaces of the concave portions are the same as each other. And a distance from the second plane to the placement surface is constant when the insulating substrate is placed on the suction device.
The invention according to claim 5 is the suction device according to any one of claims 1 to 4, wherein a bottomed hole is formed on one surface of the support at a portion where the recess is located, This is an adsorption apparatus in which the thickness of the conductive film constituting the first and second electrodes is constant.
The invention according to claim 6 is the adsorption device according to any one of claims 1 to 4, wherein the first and second electrodes are arranged on a flat surface of the support, In the conductive film forming the first and second electrodes, a film thickness of a portion where the concave portion is located is smaller than a film thickness of a portion where the concave portion is not located.
The invention according to claim 7 is the suction device according to any one of claims 1 to 6, further comprising a protective layer, wherein the concave portion and the convex portion are covered with the protective layer. It is.
The invention according to claim 8 is the suction device according to claim 7, wherein a portion where the concave portion is located on the surface of the protective layer is lower than a portion where the convex portion is located. .
The invention according to claim 9 is the suction device according to claim 7, wherein the surface of the protective layer is flattened.
According to a tenth aspect of the present invention, there is provided a vacuum tank, and the suction device according to any one of the first to ninth aspects, wherein the suction device is disposed in the vacuum tank, and It is a vacuum processing device that is closely attached to the suction device in the vacuum chamber.
[0013]
The present invention is configured as described above, and the concave portion of the device main body has a planar distance from the reference position of the device main body, and a planar distance from the reference position of the insulating substrate to the device region. Are formed at equal positions, the suction device and the insulating substrate are aligned so that the reference positions face each other, and when the insulating substrate is placed on the suction device, the device region is placed on the concave portion. Is to be placed.
[0014]
In the portion where the device region is located, the distance from the mounting surface to the conductive film surface is separated by the depth of the concave portion, so that the attraction force generated when a voltage is applied to the first and second electrodes is reduced.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Reference numerals 1 and 10 in FIG. 1 respectively denote a sputtering apparatus and a suction apparatus which are vacuum processing apparatuses according to an embodiment of the present invention.
[0016]
Reference numeral 20 in FIGS. 2 and 3 indicates an object to be suctioned by the suction device 10. The adsorption target 20 has an insulating substrate 21 made of high-purity quartz glass, and a conductive film such as a patterned ITO (indium tin oxide) thin film is arranged on one surface thereof.
[0017]
The conductive film is densely formed in a predetermined region on the surface of the insulating substrate 21. Reference numeral 25 in FIGS. 2 and 3 denotes a device region that is a region where conductive films are densely arranged, and reference numeral 26 in the same drawing denotes a region located between the device regions and an insulator other than the device region. 2 shows a plurality of device regions 25 which are located apart from each other.
[0018]
Here, two to a plurality of device regions 25 are arranged in a horizontal line at equal intervals, and a group of device regions 25 arranged in a horizontal line are arranged in parallel and at equal intervals. That is, the device regions 25 on the insulating substrate 21 are arranged in a matrix. A grid-like portion between the device regions 25 is an insulator region 26, and no conductive film is arranged in the insulator region 26, or even if the conductive film is arranged, the density is extremely small. .
[0019]
FIG. 4 is a plan view of the suction device 10 for sucking such 20. FIG. 5 is a sectional view taken along line AA of FIG. 4, and FIG. 6 is a sectional view taken along line BB of FIG. ing.
4 to 6, the suction device 10 has a device main body 14 and a protective layer 13. In FIG. 4, the protective layer 13 is omitted. The apparatus main body 14 has a support 11, first and second electrodes 15 a and 15 b, and a recess 12.
[0020]
The support 11 is made of a plate made of an insulating material such as ceramic. The first and second electrodes 15a and 15b are formed of a thin film (conductive film) of a conductive material such as tungsten (W), and the conductive film is disposed in close contact with one surface of the support 11.
[0021]
The recess 12 includes a hole formed on the surface of the support 11 on which the conductive film is disposed, and, as described later, first and second electrodes 15a and 15b disposed on the bottom surface of the hole. ing.
[0022]
The planar position of the concave portion 12 on the support 11 is arranged at a position corresponding to the planar position of the device region 25 on the insulating substrate 21. As described above, the device region 25 is arranged in a matrix. , The concave portions 12 are also arranged in a matrix.
[0023]
Assuming that the periphery of the concave portion 12 or a portion between the concave portions 12 is a convex portion 16, the convex portion 16 has a lattice shape corresponding to the insulator region 26, and has a bottom surface of the concave portion 12 and a tip of the convex portion 16. Conductive films constituting the first and second electrodes 15a and 15b are arranged.
[0024]
The first and second electrodes 15a and 15b are each formed in a comb-like pattern by the above-described patterning of the conductive film. A plurality of comb teeth are provided for the first and second electrodes 15a and 15b, respectively, and the teeth of each comb are straight. The comb-like pattern of the first electrode 15a and the comb-like pattern of the second electrode 15b are separated from each other, and the first and second electrodes 15a and 15b are insulated from each other.
[0025]
The teeth of the combs of the first and second electrodes 15a and 15b extend in parallel to one of the horizontal and vertical directions in which the concave portions 12 are arranged. The comb teeth of the first electrode 15a and the comb teeth of the second electrode 15b extend only on the convex portion 16 and extend over both the convex portion 16 and the concave portion 12. Each includes both.
[0026]
The comb teeth of the first electrode 15a and the comb teeth of the second electrode 15b are arranged so as to mesh with each other, so that the teeth of the first electrode 15a and the teeth of the second electrode 15b are They are arranged alternately.
[0027]
The comb teeth of the first electrode 15a and the comb teeth of the second electrode 15b are arranged adjacent to each other on any position on the convex portion 16, and the width and interval of the teeth of the comb are constant. It has become. That is, since the adjacent portions of the first and second electrodes 15a and 15b are uniformly distributed on the convex portion 16, positive and negative voltages are applied to the first and second electrodes 15a and 15b. Thus, a uniform electric field is formed at positions near the surfaces of the first and second electrodes 15a and 15b on the support 11 constituting the convex portion 16.
[0028]
Further, here, the first and second electrodes 15a and 15b are also arranged in each concave portion 12 at the same interval as the first and second electrodes 15a and 15b in the convex portion 16. A uniform electric field is formed in the vicinity of the surface between the first and second electrodes 15a and 15b on the supporting member 11 to be formed, but the electric field of the concave portion 12 is higher than that of the convex portion 16 at the same height. It becomes smaller than the electric field.
[0029]
The protective layer 13 is formed of a thin film of an insulating material such as silicon dioxide (SiO ₂ ). The surfaces of the first and second electrodes 15a and 15b are covered with the protective layer 13, and the above-mentioned adsorption target 20 contacts the protective layer 13, so that the first and second electrodes 15a and 15b are protected. It is supposed to be.
[0030]
The sputtering apparatus 1 shown in FIG. 1 has a vacuum chamber 2, and the above-described adsorption apparatus 10 is arranged on the bottom wall side in the vacuum chamber 2 with the surface on which the protective layer 13 is formed facing the ceiling. Have been.
[0031]
In order to process the adsorption target 20 using the above-described sputtering apparatus 1, first, the vacuum exhaust system 8 connected to the vacuum chamber 2 is activated, and after forming a vacuum atmosphere of a predetermined pressure in the vacuum chamber 2, The suction object 20 is carried into the vacuum chamber 2 while maintaining the vacuum atmosphere.
[0032]
With the surface on which the device region 25 of the suction target 20 is formed facing upward, the suction target 20 and the suction device 10 are relatively positioned, and the side of the insulating substrate 21 on which the device region 25 is formed. When the mounting surface 29 on the opposite side to the surface is brought into contact with the surface of the protective layer 13 on the convex portion 16 and the suction target 20 is mounted on the suction device 10, as shown in FIG. The concave portion 12 is disposed immediately below 25, and the convex portion 16 is disposed immediately below the insulator region 26.
[0033]
Since the protrusions 16 are composed of the flat surface of the support 11 and a conductive film having a constant thickness, the conductive film surface at the tip of each protrusion 16 is located on the same first plane 18. In addition, the holes constituting the recesses 12 are uniform in depth, and the recesses 12 are formed of the holes and a conductive film having a constant thickness. It is located on the second plane 19.
[0034]
The thickness of the protective layer 13 is constant, and the mounting surface 29 is in contact with the surface of the protective layer 13 on the protrusion 16. The distance W ₁ from the contact surface 29 to the first plane 19 is smaller than the distance W ₂ from the contact surface 29 to the second plane 19 by the depth of the recess 12. I have.
[0035]
As described above, the attraction force when the conductor density is high as in the device region 25 is larger than the attraction force when the conductor density is low as in the insulator region 26, but when the conductor density is high. Also, as the separation distance increases, the attraction force decreases.
[0036]
The film thickness and material of the insulating substrate 21 are known in advance, and the distance W ₂ from the mounting surface 29 to the second plane 19 depends on the attraction force applied to the device region 25 and the attraction force applied to the insulator region 26. The depth of the concave portion 12 is increased so as to be substantially equal.
[0037]
Therefore, when the electrostatic chuck power supply 7 is activated and positive and negative voltages are applied to the first and second electrodes 15a and 15b, the device region 25 and the insulator region 26 are attracted with the same magnitude of the attracting force, and The object 20 is stably held by the adsorption device 10.
[0038]
The suction device 10 is provided with a heating unit (not shown). When the suction device 10 is heated in a state where the suction target 20 is in close contact with the suction device 10, the suction target 20 is heated to a predetermined temperature.
[0039]
Next, while introducing a sputtering gas such as an argon (Ar) gas into the vacuum chamber 2, a vacuum atmosphere of a predetermined pressure is maintained in the vacuum chamber 2, a sputter power supply 6 is activated, and a voltage is applied to the target 5. Then, the target 5 is sputtered, and a thin film grows on the adsorption target 20.
[0040]
When the thin film has grown to a predetermined thickness, the sputtering is stopped, and then the application of the voltage to the first and second electrodes 15a and 15b is stopped. It can be lifted from the suction device 10.
[0041]
In the above, the case where the concave portion 12 is constituted by the hole of the support 11 and the conductive film having a constant thickness has been described, but the present invention is not limited to this.
Reference numeral 50 in FIG. 8 indicates a suction device according to another example of the present invention. The suction device 50 has a device main body 54 and a protective layer 53.
[0042]
The device main body 54 includes a support body 51 whose front and back surfaces are flat, and first and second electrodes 55a and 55b formed on the flat surface of the support body 51. The thickness of the conductive film forming the electrodes 55a and 55b is not constant.
[0043]
In the adsorption device 10 described above, the concave portion 12 is formed by the hole of the support 11 and the conductive film having a constant thickness. A thick portion 56 is disposed at a position corresponding to the device region 25 of the adsorption target 20 as described above, and the thick portion 56 corresponds to the insulator region 26. After the suction target 20 and the suction device 50 are relatively positioned, they are placed on the surface of the protective layer 53 formed on the surfaces of the first and second electrodes 55a and 55b. When the placement surface 29 is brought into contact with the object to be sucked 20, the device region 25 is arranged on the thin portion 52, and the insulator region 26 is arranged on the thick portion 56.
[0044]
The protective layer 53 is formed so as to cover the thin portion 52 and the thick portion 56. The surface of the protective layer 53 is flat, and the distance from the flat surface of the support 51 to the flat surface of the protective layer 53 is uniform. Therefore, when the mounting surface 29 is brought into close contact with the flat surface of the protective layer 53, the distance from the mounting surface 29 to the thick portion 56 is the distance from the mounting surface 29 to the thin portion 52. Smaller than.
[0045]
That is, the thin portion 52 and the thick portion 56 of the suction device 50 correspond to the concave portion 12 and the convex portion 16 of the suction device 10 shown in FIGS. Also in this suction device 50, the distance from the first plane 58 where the tip of the thick part 56 is located to the mounting surface 29 is the distance from the second plane 59 where the bottom of the thin part 52 is located. As shown in FIG. 10, if the distance to the mounting surface 29 can be formed at a constant voltage and a separation distance at which the attraction force becomes equal, the in-plane distribution of the attraction force applied to the attraction object 20 becomes uniform.
[0046]
Sign L ₁ in FIG. 8 from the flat surface of the protective layer 53, the electrode 55a of the large thickness portion 56, indicates the distance to the 55b surface, reference numeral L ₂ is a thin film thickness from the flat surface of the protective layer 53 The distance of the portion 52 to the surface of the electrodes 55a and 55b is shown. For example, in order to make uniform 1kPa the suction force of the entire surface in FIG. 10, the distance _{L 1} 0.7 mm, the distance _{L 2} may be set to 0.3 mm.
[0047]
The case where the insulating substrate 21 of the adsorption target 20 is made of high-purity quartz glass has been described above. For example, heat-resistant glass (here, Pyrex glass (registered trademark), room temperature resistivity 10 ¹⁴ Ω · cm) is used. Alternatively, another kind of glass such as non-alkali glass or a resin made of polyimide resin or polycarbonate resin can be used.
[0048]
When the holes are formed in the support 11, the forming method is not particularly limited, and various methods such as blasting and wet etching can be used.
The conductive films forming the first and second electrodes 15a and 15b are not limited to those made of tungsten, but may be made of various conductive materials such as copper, aluminum, and pyrolytic graphite (PG). Various methods for forming a conductive film, such as a CVD method and a PVD method, can be used.
[0049]
The insulating material forming the protective layer 13 is not limited to silicon dioxide, but may be any of various insulating materials such as aluminum oxide (Al ₂ O ₃ ), aluminum nitride (AlN), and pyrolytic boron nitride (P-BN). The protective layer 13 can be configured. Alternatively, without forming the protective layers 13 and 53, the first and second electrode surfaces may be exposed, and the mounting surface 29 may be brought into direct contact with the surfaces of the first and second electrodes.
[0050]
Although the sputtering apparatus 1 has been described above as an example of the vacuum processing apparatus of the present invention, the present invention is not limited to this. And various vacuum processing apparatuses such as an etching apparatus and an ion implantation apparatus. Further, if a transfer mechanism is provided in the suction device 10 of the present invention, the suction device 10 can be used as a so-called transfer device that transfers between vacuum processing devices while sucking the suction target object 20.
[0051]
【The invention's effect】
When a suction target is placed on the suction device of the present invention, a device region where conductors such as wiring are densely arranged is arranged on a concave portion, and an insulating region where wiring is not densely arranged is arranged on a convex portion. Therefore, in the device region, the distance from the mounting surface to the electrode surface is larger than that in the insulator region, and the distance is such that the attraction force of the device region is substantially equal to that of the insulator region. The inner distribution becomes uniform, and the adsorption target is stably held.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an example of a film forming apparatus used in the present invention. FIG. 2 is a plan view illustrating an example of an object to be adsorbed. FIG. FIG. 5 is a plan view for explaining first and second electrodes of the suction device according to an example of the invention; FIG. 5 is a view corresponding to a cross-sectional view taken along the line AA of FIG. 4; FIG. FIG. 7 is a cross-sectional view showing a state where an object to be adsorbed is placed on an adsorption device. FIG. 8 is a cross-sectional view for explaining another example of the adsorption device of the present invention. FIG. 10 is a cross-sectional view for explaining a conventional suction device. FIG. 10 is a graph showing a relationship between a separation distance and a suction force.
20 ... adsorption object 10, 50 ... adsorption device 11, 51 ... support body 12, 52 ... concave portion 14, 54 ... device main body 15a, 15b, 55a, 55b ... first and second electrodes 18 , 58 ... first plane 19, 59 ... second plane 29 ... mounting surface

Claims (10)

Having an apparatus body,
The device body has a support and first and second electrodes disposed on the support,
When a voltage is applied to the first and second electrodes, an adsorption device configured to adsorb the insulating substrate,
In the device main body, a concave portion is formed at a position corresponding to a position of a device region in the insulating substrate, and a convex portion is arranged around the concave portion,
When the insulating substrate and the suction device are relatively aligned with each other, the distance from the first plane where the tip of the convex portion is located to the mounting surface is equal to the distance from the second plane where the bottom surface of the concave portion is located. An adsorption device that is smaller than the distance to the mounting surface. The suction device according to claim 1, wherein both the first and second electrodes are disposed at a tip of the protrusion. The suction device according to claim 1, wherein both the first and second electrodes are arranged on a bottom surface of the concave portion. The device body has a plurality of the concave portions, the bottom surfaces of the concave portions are respectively located on the same second plane,
When the insulating substrate is placed on the suction device,
The suction device according to any one of claims 1 to 3, wherein a distance from the second plane to the placement surface is constant. 5. A bottomed hole is formed at a portion where the concave portion is located on one surface of the support, and a film thickness of a conductive film forming the first and second electrodes is made constant. 6. The adsorption device according to any one of the above. The first and second electrodes are arranged on a flat surface of the support, and the thickness of the portion where the recess is located in the conductive film forming the first and second electrodes is The suction device according to any one of claims 1 to 4, wherein the film thickness is smaller than a film thickness of a portion where the concave portion is not located. The suction device according to any one of claims 1 to 6, further comprising a protective layer, wherein the concave portion and the convex portion are covered with the protective layer. The suction device according to claim 7, wherein a portion of the surface of the protective layer where the concave portion is located is lower than a portion where the convex portion is located. The suction device according to claim 7, wherein the surface of the protective layer is flattened. It has a vacuum tank and the adsorption device according to any one of claims 1 to 9, wherein the adsorption device is arranged in the vacuum tank, and the object to be adsorbed is the adsorption device in the vacuum tank. Vacuum processing equipment to be in close contact with.

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