JP4101017B2 - Adsorption device and adsorption method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrostatic adsorption device, and more particularly, to an adsorption device that adsorbs an adsorption object having a device pattern formed on an insulating substrate.
[0002]
[Prior art]
Reference numeral 121 in FIG. 9 denotes a conventional suction device used for suction of 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. is doing.
[0003]
When an insulating substrate is placed on the surface of the adsorption device 121 where 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 127.
In general, when a dielectric having a polarizability α is placed in a non-uniform electric field E, a gradient force expressed by the following equation per unit area acts on the dielectric.
[0004]
f = 1/2 · α · grad (E ² )
The first and second electrodes 126 and 127 are both comb-shaped by patterning and arranged such that their tooth portions mesh with each other, and the distance between the first and second electrodes 126 and 127 adjacent to each other. Is very small. As a result, when the insulating substrate is placed on the surface, grad (E ² ) in the above equation becomes large.
[0005]
The insulating substrate receives the above-described gradient force, and the entire back surface of the substrate is adsorbed on the surface of the adsorption device 121 and is held by the adsorption device 121 as a result.
By the way, in the actual manufacturing process, conductors such as wiring and transistors are often formed on an insulating substrate, and when adsorbing a mixture of such a conductor and an insulator such as a glass substrate, There is a problem that the in-plane distribution of the adsorption force becomes non-uniform and the stability of adsorption is low.
[0006]
[Problems to be solved by the invention]
The present invention was created to meet the demands of the above prior art, and its purpose is to make the in-plane distribution of the suction force uniform when suctioning a suction object in which a conductor and an insulator are mixed. It is to provide an adsorption device.
[0007]
[Means for Solving the Problems]
The present inventors prepared two types of adsorption objects: an adsorption object composed of a rectangular glass substrate with a side of 50 cm and no wiring formed thereon, and an adsorption object formed with wiring formed on one surface of the glass substrate. did.
[0008]
Those objects to be attracted are arranged on the electrodes 126 and 127 with the surface (mounting surface) on which the wiring is not formed facing downward, and the mounting surfaces are the first and second electrodes 126 and 127. It was made to adsorb | suck in the state 0-1.2 mm away from the surface, and the adsorption power was measured. In addition, the width | variety of the comb tooth of the 1st, 2nd electrodes 126 and 127 of the adsorption | suction apparatus 121 was 3 mm, and the space | interval was 1 mm.
[0009]
FIG. 10 is a graph showing the relationship between the distances (separation distances) from the surfaces of the electrodes 126 and 127 to the placement surface and the suction force, and the symbol L ₁ in FIG. ₁₀ indicates the suction force of the suction object on which the wiring is formed. The symbol L ₂ indicates the change in the adsorption force of the object to be adsorbed when no wiring is formed.
[0010]
As is clear from FIG. 10, the suction object having wiring has a larger suction force than the suction object having no wiring, and the case where the wiring object is provided and the case where the wiring object is not provided. However, the greater the separation distance, the smaller the attractive force. For example, when focusing attention on the separation distance at which the suction force is 1 kPa, the separation distance is about 0.2 mm for the adsorption object having no wiring, whereas the separation distance is about 0.6 mm for the adsorption object having the wiring. It is getting bigger.
[0011]
From these facts, if the separation distance of the part having a conductor such as wiring is made larger than the part having no conductor, there is no difference in the adsorption force between the part having the conductor and the part having no conductor, and the adsorption force The in-plane distribution is considered to be uniform.
[0012]
The invention according to claim 1 made on the basis of the above knowledge has an apparatus main body, and the apparatus main body is adjacent to the support, the first electrode disposed on the support, and the first electrode. And arranging a second substrate, an insulating substrate on the mounting surface of the apparatus body, and applying a positive voltage and a negative voltage to the first electrode and the second electrode, An adsorption apparatus configured to adsorb the insulating substrate, wherein the apparatus main body includes a convex portion in which upper ends of the first and second electrodes are positioned on a first plane, and the first and first electrodes. The upper end of the second electrode has a recess located in the second plane, and the distance between the first plane and the mounting surface is smaller than the distance between the second plane and the mounting surface. The convex portions are arranged in a lattice pattern, and the concave portions are suction devices arranged in a matrix between the convex portions .
The invention according to claim 2 includes an apparatus main body, and the apparatus main body is a support, a first electrode disposed on the support, and a second disposed adjacent to the first electrode. When an insulating substrate is disposed on the mounting surface of the apparatus body and a positive voltage and a negative voltage are applied to the first electrode and the second electrode, the insulating substrate is adsorbed. The apparatus main body includes a convex portion in which upper ends of the first and second electrodes are positioned on a first plane, and upper ends of the first and second electrodes are first. A recess located on the second plane, and the distance between the first plane and the placement surface is insulated by a suction device that is smaller than the distance between the second plane and the placement surface. An adsorption method for adsorbing the insulating substrate having a physical region and a device region in which conductors are more densely arranged than the insulating region. I, the recess directly under the device region having said insulating substrate to be adsorbed, the convex portion is a suction way to keep directly under the insulator region having said insulating substrate to be adsorbed.
[0013]
The present invention is configured as described above, and the recess of the apparatus main body has a planar distance from a position serving as a reference of the apparatus main body to a planar distance from a position serving as a reference of the insulating substrate to the device region. Since the suction device and the insulating substrate are aligned so that the reference positions face each other, and the insulating substrate is placed on the suction device, the device region is placed on the recess. It is supposed to be placed.
[0014]
In the portion where the device region is located, the distance from the mounting surface to the surface of the conductive film is separated by the depth of the recess, so that the attractive force generated when a voltage is applied to the first and second electrodes is reduced.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
Reference numerals 1 and 10 in FIG. 1 denote a sputtering apparatus and an adsorption 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 adsorbed by the adsorption device 10. The adsorption object 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 disposed 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 indicates a device region, which is a region where conductive films are densely packed. Reference numeral 26 in FIG. 3 indicates an insulator located between the device regions and other than the device region. A plurality of device regions 25 are spaced apart from each other.
[0018]
Here, two or more device regions 25 are arranged in a horizontal row at equal intervals, and a group of device regions 25 arranged in a horizontal row are arranged in parallel with each other at equal intervals. That is, the device regions 25 on the insulating substrate 21 are arranged in a matrix. A lattice-like portion between the device regions 25 is an insulator region 26, and no conductive film is disposed in the insulator region 26, or even if it is disposed, the density thereof is extremely small. .
[0019]
4 shows a plan view of the adsorption device 10 for adsorbing 20 as described above, FIG. 5 shows a sectional view taken along the line AA in FIG. 4, and FIG. ing.
4 to 6, the adsorption device 10 includes a device main body 14 and a protective layer 13. In FIG. 4, the protective layer 13 is omitted. The apparatus main body 14 includes a support 11, first and second electrodes 15 a and 15 b, and a recess 12.
[0020]
The support 11 is composed of a plate made of an insulating material such as ceramic. The first and second electrodes 15 a and 15 b are made 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 in the surface of the support 11 on which the conductive film is disposed, and first and second electrodes 15a and 15b disposed on the bottom surface of the hole as will be described later. ing.
[0022]
The planar position of the recess 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. As described above, the device region 25 is arranged in a matrix. The recesses 12 are also arranged in a matrix.
[0023]
If the portion around the recess 12 or between the recesses 12 is a protrusion 16, the protrusion 16 has a lattice shape corresponding to the insulator region 26, and the bottom of the recess 12 and the tip of the protrusion 16 Conductive films constituting the first and second electrodes 15a and 15b are disposed.
[0024]
The first and second electrodes 15a and 15b are each formed in a comb-like pattern by patterning the conductive film described above. A plurality of comb teeth are provided for the first and second electrodes 15a and 15b, and the comb teeth are linear. The comb pattern of the first electrode 15a and the comb 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 comb teeth of the first and second electrodes 15a and 15b extend in parallel with either the horizontal direction in which the concave portions 12 are arranged or the vertical direction. 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 across both the convex portion 16 and the concave portion 12. Each includes both.
[0026]
The comb tooth portion of the first electrode 15a and the comb tooth portion of the second electrode 15b are arranged to mesh with each other. Therefore, the teeth of the first electrode 15a and the teeth of the second electrode 15b are arranged. They are lined up 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 the convex portion 16, and the width and interval of the comb teeth 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. A uniform electric field is formed in the vicinity of the surface of the first and second electrodes 15a and 15b on the support 11 constituting the convex portion 16.
[0028]
Also, here, the first and second electrodes 15a and 15b are also arranged in the respective recesses 12 at the same interval as the first and second electrodes 15a and 15b in the projections 16. A uniform electric field is formed in the vicinity of the surface between the first and second electrodes 15 a and 15 b on the supporting member 11, but the electric field of the concave portion 12 is the same as that of the convex portion 16. It becomes smaller than the electric field.
[0029]
The protective layer 13 is composed of a thin film of an insulating material such as silicon dioxide (SiO ₂ ). Since the surfaces of the first and second electrodes 15a and 15b are covered with the protective layer 13, and the adsorption target 20 described above is in contact with the protective layer 13, the first and second electrodes 15a and 15b are protected. It has come to be.
[0030]
The sputtering apparatus 1 shown in FIG. 1 has a vacuum chamber 2, and the adsorption device 10 described above 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 side. Has been.
[0031]
In order to process the adsorption object 20 using the sputtering apparatus 1 described above, first, the vacuum exhaust system 8 connected to the vacuum chamber 2 is activated, and after a vacuum atmosphere of a predetermined pressure is formed in the vacuum chamber 2, The adsorption object 20 is carried into the vacuum chamber 2 while maintaining the vacuum atmosphere.
[0032]
With the surface on which the device area 25 of the adsorption object 20 is formed facing upward, the adsorption object 20 and the adsorption apparatus 10 are relatively aligned, and the side on which the device area 25 of the insulating substrate 21 is formed 7 is brought into contact with the surface of the protective layer 13 on the convex portion 16 and the adsorption object 20 is placed on the adsorption device 10, as shown in FIG. Concave portion 12 is disposed immediately below 25, and convex portion 16 is disposed directly below insulator region 26.
[0033]
Since the convex portion 16 is composed of a flat surface of the support 11 and a conductive film having a constant film thickness, the conductive film surface at the tip of each convex portion 16 is located on the same first plane 18. In addition, since the holes constituting the recesses 12 are uniform in depth, and the recesses 12 are formed by the holes and the conductive film having a constant film thickness, the conductive film surface on the bottom surface of each recess 12 is the same. Located in the second plane 19.
[0034]
The film 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 convex portion 16, so that the mounting surface 29 is against the first and second planes 18 and 19. The separation distance W ₁ from the contact surface 29 to the first plane 19 is smaller than the separation distance W ₂ from the contact surface 29 to the second plane 19 by the depth of the recess 12. Yes.
[0035]
As described above, the attracting force when the conductor density is large as in the device region 25 is larger than the attracting force when the conductor density is small as in the insulator region 26. However, as the separation distance increases, the attractive force decreases.
[0036]
The film thickness and material of the insulating substrate 21 are known in advance, and the separation distance W ₂ from the mounting surface 29 to the second plane 19 has an adsorption force applied to the device region 25 and an adsorption force applied to the insulator region 26. The depth of the recess 12 is increased so as to be substantially equal.
[0037]
Accordingly, when the electrostatic chuck power source 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 amount of attracting force, and are attracted. The object 20 is stably held by the adsorption device 10.
[0038]
The adsorption device 10 is provided with a heating means (not shown). When the adsorption device 10 is heated with the adsorption object 20 in close contact with the adsorption device 10, the adsorption object 20 is heated to a predetermined temperature.
[0039]
Next, when a sputtering atmosphere such as argon (Ar) gas is introduced into the vacuum chamber 2, a vacuum atmosphere at a predetermined pressure is maintained in the vacuum chamber 2, the sputtering power source 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 object 20.
[0040]
When the thin film has grown to a predetermined thickness, the sputtering is stopped, and then, when the voltage application to the first and second electrodes 15a and 15b is stopped, the adsorption force is released, and the adsorption object 20 after the film formation process is removed. It can be lifted from the adsorption device 10.
[0041]
The above describes the case where the recess 12 is formed by the hole of the support 11 and the conductive film having a constant film thickness, but the present invention is not limited to this.
Reference numeral 50 in FIG. 8 shows a suction device according to another example of the present invention. The adsorption device 50 includes a device main body 54 and a protective layer 53.
[0042]
The apparatus 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 film thickness of the conductive film constituting the electrodes 55a and 55b is not constant.
[0043]
In the adsorption device 10 described above, the recess 12 is formed by the hole of the support 11 and the conductive film having a constant film thickness. However, in this adsorption device 50, the portion 52 having a thin film thickness and the conductive film are formed. The 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. Since the suction object 20 and the suction device 50 are relatively aligned with each other, 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 and the adsorption object 20 is placed, the device region 25 is disposed on the thin portion 52 and the insulator region 26 is disposed 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. Accordingly, when the placement surface 29 is brought into close contact with the flat surface of the protective layer 53, the distance from the placement surface 29 to the thick portion 56 is the distance from the placement surface 29 to the thin portion 52. Smaller than.
[0045]
That is, the thin portion 52 and the thick portion 56 of the adsorption device 50 correspond to the concave portion 12 and the convex portion 16 of the adsorption device 10 shown in FIGS. Also in this adsorption device 50, the distance from the first plane 58 where the tip of the thick part 56 is located to the placement surface 29 is from the second plane 59 where the bottom face of the thin part 52 is located. If the distance to the placement surface 29 can be formed with a separation distance at which the suction force becomes equal at a constant voltage as shown in FIG. 10, the in-plane distribution of the suction force applied to the suction target 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 to the electrode 55a, 55b surface of the part 52 is shown. For example, in FIG. 10, in order to make the adsorption force of the entire surface uniform at 1 kPa, the distance L ₁ may be 0.7 mm and the distance L ₂ may be 0.3 mm.
[0047]
The above has described the case where the insulating substrate 21 of the adsorption object 20 is made of high-purity quartz glass. For example, heat-resistant glass (here, Pyrex glass (registered trademark), room temperature resistivity 10 ¹⁴ Ω · cm) Alternatively, other types of glass such as non-alkali glass, or those made of resin such as polyimide resin or polycarbonate resin can be used.
[0048]
When forming a hole in the support body 11, the formation method is not specifically limited, Various methods, such as a blast process and wet etching, can be used.
The conductive films constituting the first and second electrodes 15a and 15b are not limited to those made of tungsten, and those made of various conductive materials such as copper, aluminum, pyrolytic graphite (PG), etc. may be used. In addition, as a method for forming the conductive film, various film formation methods such as a CVD method and a PVD method can be used.
[0049]
The insulating material constituting the protective layer 13 is not limited to silicon dioxide, and various insulating materials such as aluminum oxide (Al ₂ O ₃ ), aluminum nitride (AlN), and pyrolytic boron nitride (P-BN) can be used. The protective layer 13 can be configured. In addition, the first and second electrode surfaces may be exposed without forming the protective layers 13 and 53, and the placement surface 29 may be in direct contact with the surfaces of the first and second electrodes.
[0050]
Moreover, although the sputtering apparatus 1 was demonstrated as an example of the vacuum processing apparatus of this invention above, this invention is not limited to this, If it has the adsorption | suction apparatus 10 of this invention, a vacuum evaporation system There are various film forming apparatuses such as a vacuum processing apparatus such as an etching apparatus and an ion implantation apparatus. Moreover, if the adsorption | suction apparatus 10 of this invention is provided with a conveyance mechanism, it can be used as what is called a conveyance apparatus which conveys between the vacuum processing apparatuses, adsorb | sucking the adsorption | suction target object 20. FIG.
[0051]
【The invention's effect】
When an object to be sucked is placed on the suction device of the present invention, a device region where conductors such as wiring are densely arranged is arranged on the concave portion, and an insulating region where wiring is not densely arranged is arranged on the convex portion. Therefore, in the device area, the distance from the mounting surface to the electrode surface is larger than the insulator area, and the distance is such that the adsorption force of the device area is substantially equal to that of the insulator area. The internal distribution becomes uniform, and the adsorption object is stably held.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining an example of a film forming apparatus used in the present invention. FIG. 2 is a plan view showing an example of an object to be adsorbed. FIG. 3 is a sectional view taken along the line ZZ in FIG. The top view for demonstrating the 1st, 2nd electrode of the adsorption | suction apparatus of an example of invention. FIG. 5 The figure corresponded in AA cut-line sectional drawing of FIG. FIG. 7 is a cross-sectional view showing a state where an object to be sucked is placed on the suction device. FIG. 8 is a cross-sectional view for explaining a suction device according to another example of the present invention. Sectional drawing for demonstrating the adsorption apparatus of a prior art [FIG. 10] The graph which shows the relationship between a separation distance and adsorption | suction power
20 …… Adsorption object 10, 50 …… Adsorption device 11, 51 …… Support 12, 52 …… Recess 14, 54 …… Device main body 15a, 15b, 55a, 55b …… First and second electrodes 18 58 …… First plane 19, 59 …… Second plane 29 …… Placement surface

Claims (2)

Having a device body,
The apparatus main body includes a support, a first electrode disposed on the support, and a second electrode disposed adjacent to the first electrode,
An adsorption apparatus configured to adsorb the insulating substrate when an insulating substrate is disposed on the mounting surface of the apparatus body and a positive voltage and a negative voltage are applied to the first electrode and the second electrode. Because
The apparatus main body includes a convex portion in which upper ends of the first and second electrodes are located on a first plane, and a concave portion in which upper ends of the first and second electrodes are located on a second plane. ,
The distance between the first plane and the placement surface is smaller than the distance between the second plane and the placement surface ,
The adsorption device in which the convex portions are arranged in a lattice pattern and the concave portions are arranged in a matrix between the convex portions . Having a device body,
The apparatus main body includes a support, a first electrode disposed on the support, and a second electrode disposed adjacent to the first electrode,
An adsorption apparatus configured to adsorb the insulating substrate when an insulating substrate is disposed on the mounting surface of the apparatus body and a positive voltage and a negative voltage are applied to the first electrode and the second electrode. Because
The apparatus main body includes a convex portion in which upper ends of the first and second electrodes are located on a first plane, and a concave portion in which upper ends of the first and second electrodes are located on a second plane. ,
The distance between the first plane and the placement surface is such that the conductor is more than the insulator region and the insulator region by a suction device that is smaller than the distance between the second plane and the placement surface. A method of adsorbing the insulating substrate having densely arranged device regions,
The concave portion is disposed immediately below a device region of the insulating substrate to be attracted,
The said convex part is the adsorption | suction method arrange | positioned directly under the insulator area | region which the said insulated substrate of adsorption | suction object has.

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