JP2004207644A - Electrostatic chuck and apparatus for manufacturing bonded substrate using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic chuck capable of flexibly meeting the changes of the arrangement of an alignment mark accompanied by the change of the shape of a substrate and the change of the position of an ultraviolet light irradiating part without changing the electrostatic chuck. <P>SOLUTION: An electrostatic chuck has an internal electrode 9 formed on a base comprising a dielectric substrate and covered by a dielectric film whose upper surface is a chucking surface for mounting an object 2 to be chucked. At least a part of the base and the dielectric film transmit a light having a predetermined wavelength band. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electrostatic chuck used in a manufacturing process of a liquid crystal display device and a bonded substrate manufacturing apparatus using the same, and particularly to a bonded substrate manufacturing apparatus suitable for bonding a plurality of types of substrates by one unit. It is an invention.
[0002]
[Prior art]
2. Description of the Related Art In a bonded substrate manufacturing apparatus used in a manufacturing process of a liquid crystal display device, a method using an electrostatic chuck as a substrate holding device has attracted attention with the recent increase in size of the liquid crystal display device.
As a mechanism for holding the substrate by suction, a method is introduced in which both vacuum suction and electrostatic suction are used and switching is performed according to the surrounding pressure. (See Patent Document 1)
Among the conventional bonded substrate manufacturing processes represented by Patent Document 1, in particular, the process of positioning the substrate and the process of curing the adhesive will be described below.
[0003]
First, a step of performing substrate alignment will be described.
FIG. 2 is a side view showing a schematic configuration of a conventional bonded substrate manufacturing apparatus represented by Patent Document 1. As shown in FIG. In the figure, two electrostatic chucks are arranged in a bonded substrate manufacturing apparatus so as to face each other, and each of the bonded substrates is suction-held one by one. Here, the electrostatic chuck has a structure in which electrodes are provided inside alumina ceramics, and can hold a substrate by electrostatic attraction.
Hereinafter, the upper electrostatic chuck is referred to as a first electrostatic chuck, and the lower electrostatic chuck is referred to as a second electrostatic chuck.
[0004]
A plurality of alignment marks are provided on each of the two substrates, and a mark imaging hole is provided on the second electrostatic chuck at a position corresponding to the alignment mark. Is provided with an image pickup device, which is capable of picking up an alignment mark of both substrates through a mark image pickup hole and confirming a positional shift between the two substrates.
[0005]
Thereafter, the first electrostatic chuck is lowered by the upper moving mechanism, and the two substrates are bonded. At this time, the first electrostatic chuck is lowered while imaging the displacement of the alignment marks on the two substrates by the imaging device so that the displacement between the two substrates does not occur. If a displacement occurs, the lower moving mechanism adjusts the horizontal position of the second electrostatic chuck to eliminate the displacement.
[0006]
Next, the step of curing the adhesive will be described.
In a process before bonding the substrates, an adhesive is applied to an outer peripheral portion of a portion that will eventually become a liquid crystal panel on the substrate. The adhesive used here is generally of the type that is cured by irradiating ultraviolet rays. For this reason, the bonded substrate is transported to a separately provided curing device, and irradiated with ultraviolet rays in the curing device. At this time, the adhesive is often temporarily fixed in the bonded substrate manufacturing apparatus for the purpose of preventing the substrate from being displaced when being transported to the curing device. That is, in the step of applying the adhesive before bonding the substrates, the adhesive for temporary fixing is applied in a spot shape at a plurality of spots further outside the outer peripheral portion. Since the ultraviolet irradiation holes are provided at the positions on the electrostatic chuck corresponding to the application place in the previous period, the substrate is temporarily fixed by irradiating ultraviolet rays to the application place immediately after bonding through the ultraviolet irradiation holes. Can be done.
[0007]
In addition, the present applicant has disclosed in a previous application an invention in which a dense dielectric layer which can be expected to have abrasion resistance is formed on a base material of an electrostatic chuck by an aerosol deposition method. (See Patent Document 2)
[0008]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-229044 [Patent Document 2]
JP 2001-60619 A
[Problems to be solved by the invention]
In an electrostatic chuck used in a conventional bonded substrate manufacturing apparatus, the position of a hole for imaging a positioning mark is arranged in accordance with a positioning mark provided on a substrate. Further, the positions of the holes for ultraviolet irradiation for temporarily fixing the substrate are arranged in accordance with the outer shape of the substrate.
In other words, when the shape of the substrate is changed, it is necessary to change the position of the alignment mark disposed near the outer peripheral portion of the substrate, and accordingly, the position of the mark imaging hole formed in the electrostatic chuck is also changed. Need to change. Similarly, it is necessary to change the position of the ultraviolet irradiation hole.
However, since the electrostatic chuck is generally expensive, there is a problem in terms of cost in replacing the electrostatic chuck having different hole positions according to the substrate shape.
In addition, as a method for coping with a plurality of types of substrate shapes, it is conceivable to previously provide a large number of holes corresponding to various substrate shapes on the electrostatic chuck. Since the pressure at the time of matching does not work evenly on the substrate, it causes a problem such as a display unevenness of the liquid crystal panel.
In other words, the conventional bonded substrate manufacturing apparatus using the electrostatic chuck has a problem that it cannot flexibly cope with a change in the shape of the substrate.
[0010]
The present invention has been made in order to solve the above problems, and an object of the present invention is to provide an electrostatic chuck for changing the position of an alignment mark accompanying a change in the shape of a substrate and changing the position of an ultraviolet irradiation unit. An object of the present invention is to provide an electrostatic chuck that can flexibly respond without replacement, and a bonded substrate manufacturing apparatus using the same.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, a first aspect is to form an internal electrode on a base made of a dielectric, cover the internal electrode with a dielectric film, and set an upper surface of the dielectric film on an adsorption surface on which an object to be adsorbed is placed. In the electrostatic chuck described above, at least a part of the base and the dielectric film transmit light in a predetermined wavelength range.
If at least a part of the base and the dielectric film are made to transmit, for example, visible light having a wavelength range of 0.38 μm to 0.80 μm or ultraviolet light having a wavelength range of 0.25 μm to 0.38 μm, It is possible to image the alignment mark at the time of bonding the substrates from the outside of the electrostatic chuck without providing a hole for marking the mark on the electrostatic chuck. Ultraviolet rays can be applied to the adhesive from the outside of the electric chuck.
[0012]
In order to achieve the above object, a second aspect of the present invention is that the base forming the electrostatic chuck is glass.
With the above configuration, the base is transparent to both visible light for imaging the alignment mark and ultraviolet light for curing the adhesive.
[0013]
In order to achieve the above object, a third aspect is that the dielectric film forming the electrostatic chuck is an alumina film formed by an aerosol deposition method.
With the above configuration, a translucent alumina thin film formed by the aerosol deposition method can be used as a dielectric film of the electrostatic chuck.
[0014]
In order to achieve the above object, in claim 4, the internal electrode is a transparent electrode.
With the above configuration, the entire electrostatic chuck is also transparent with respect to the internal electrodes. Therefore, when designing an electrode pattern, it is not necessary to dispose the alignment mark imaging unit and the ultraviolet irradiation unit, so that the electrostatic chuck is not required. A uniform electrostatic attraction force can be obtained as a whole.
[0015]
In order to achieve the above object, claim 5 has first and second electrostatic chucks, and at least one of the first and second electrostatic chucks is according to any one of claims 1 to 4. The electrostatic chuck according to claim 1, wherein the first and second substrates are electrostatically attracted and held by the first and second electrostatic chucks, respectively, and an alignment mark provided on the first and second substrates is held. In the bonded substrate manufacturing apparatus, the imaging is performed by an imaging device provided on one of the first and second electrostatic chucks, and the first and second substrates are aligned with each other and then bonded. The apparatus is movable with respect to the first and second electrostatic chucks.
With the above structure, the substrates can be bonded after the imaging device has been moved to the position of the alignment mark formed on the first and second glass substrates in advance, so that substrates having various shapes can be bonded. Even when the same electrostatic chuck is used, the positioning at the time of bonding the substrates can be performed by the method described in Patent Document 1.
[0016]
In order to achieve the above object, claim 6 has first and second electrostatic chucks, and at least one of the first and second electrostatic chucks is according to any one of claims 1 to 4. The electrostatic chuck according to claim 1, wherein the first and second substrates are electrostatically attracted and held on the first and second electrostatic chucks, respectively, positioned and attached to each other, and bonded with a light-curable adhesive. In the bonded substrate manufacturing apparatus, a plurality of light irradiation ports for curing the adhesive are provided, and light emitted from the light irradiation ports is transmitted through at least one of the first and second electrostatic chucks. Then, the adhesive is partially irradiated to partially cure the adhesive.
With the above configuration, it is possible to temporarily fix the bonded substrate by irradiating the adhesive with ultraviolet light from the outside of the electrostatic chuck and curing the adhesive without providing a hole in the electrostatic chuck.
[0017]
In order to achieve the above object, in claim 7, the position of the light irradiation port is movable with respect to the first and second electrostatic chucks.
With the above configuration, it is possible to irradiate an ultraviolet ray to an arbitrary position. Therefore, the adhesive is partially cured on substrates of various shapes without changing the electrostatic chuck, and In addition, it is possible to temporarily fix the second glass substrate.
[0018]
In order to achieve the above object, claim 8 has first and second electrostatic chucks, and at least one of the first and second electrostatic chucks is according to any one of claims 1 to 4. The electrostatic chuck according to claim 1, wherein the first and second substrates are electrostatically attracted and held on the first and second electrostatic chucks, respectively, positioned and attached to each other, and bonded with a light-curable adhesive. In the bonded substrate manufacturing apparatus, at least one of the first and second electrostatic chucks is transmitted to irradiate the entire adhesive with light, thereby curing the entire adhesive.
With the above configuration, it is possible to complete the curing of the entire adhesive in the laminating apparatus, so that a curing apparatus in the next step is not required.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a side view showing a schematic configuration of a bonded substrate manufacturing apparatus according to the present invention, and FIG. 2 is a view showing a structure of an electrostatic chuck 1 in FIG. In the figure, the electrostatic chuck 1 forms a transparent internal electrode 9 made of an ITO film on the surface of a base made of quartz glass, and further forms an alumina film by aerosol deposition so as to cover the internal electrode 9. The structure has an adsorption surface on the alumina film.
[0020]
The alumina film formed by the aerosol deposition method is formed so as to have a thickness of about 10 μm. At this thickness, the alumina film becomes a thin white translucent film. Here, the alumina film has a range of 5 to 30 μm, and preferably 5 to 20 μm, in consideration of the degree of transparency and adsorption power. The alumina raw material having an alumina purity of 98% or more, preferably 99% or more, is more preferable in terms of transparency.
[0021]
In this way, since the base made of quartz glass and the ITO film of the internal electrode 9 are transparent, the electrostatic chuck 1 shown in FIG. 1 has an overall structure for visible light having a wavelength of 0.38 μm to 0.80 μm. It is transparent.
Therefore, the conventional mark imaging hole 7 as shown in FIG. 2 is not required. That is, in FIG. 1 according to the present invention, since the alignment mark 3 can be imaged through the transparent second electrostatic chuck 1b, the conventional mark imaging hole 7 is formed in the second electrostatic chuck 1b. There is no need to provide
[0022]
In addition, the quartz glass, the ITO film, and the alumina film formed by the aerosol deposition method in the present embodiment have a wavelength range of ultraviolet light of about 0.25 μm to 0.38 μm, preferably about 0.30 μm to 0.34 μm. By setting the transmittance to 50% or more, the adhesive applied to bond the substrate can be cured by ultraviolet rays.
Therefore, similarly to the mark imaging hole 7, the conventional ultraviolet irradiation hole 6 as shown in FIG. 2 is not required. That is, in FIG. 1 according to the present invention, since the adhesive 10 can be irradiated with ultraviolet rays through the transparent second electrostatic chuck 1b, the second electrostatic chuck 1b can be irradiated with ultraviolet rays in a conventional manner. There is no need to provide the holes 6.
[0023]
It is an object of the present invention to provide an electrostatic chuck 1 that is transparent to light in a predetermined wavelength range, and to propose an apparatus configuration that positively utilizes the fact that the electrostatic chuck is transparent. The various materials constituting the electrostatic chuck 1 and the manufacturing method thereof are not limited to the above examples. For example, the base may be made of quartz or sapphire instead of quartz glass as in the present embodiment.
[0024]
As described above, the electrostatic chuck 1 used in the bonded substrate manufacturing apparatus according to the present invention does not require the conventional mark imaging hole 7 and ultraviolet irradiation hole 6 to be provided. This means that not only the step of forming each hole can be omitted in the manufacturing process of the electrostatic chuck. Hereinafter, advantages obtained by adopting this structure will be described.
[0025]
FIG. 3 is a diagram showing a state where the second electrostatic chuck 1b used in the conventional bonded substrate manufacturing apparatus electrostatically attracts the substrate 2 when viewed from the attracting surface side. As described above, the alignment mark 3 is provided on the substrate 2, and the mark imaging hole 7 is provided on the second electrostatic chuck 1 b at a position corresponding to the alignment mark 3. ing.
[0026]
FIG. 4 shows a second electrostatic chuck 1b of the conventional bonded substrate manufacturing apparatus, which also sucks a substrate 2 having a size different from that of FIG. In this case, since the position of the alignment mark 3 provided on the substrate 2 is different from that of FIG. 3, the second electrostatic chuck 1b shown in FIG. It is necessary to use the second electrostatic chuck 1b whose position has been changed.
3 and 4, for simplicity, the ultraviolet irradiation hole 8 provided in the second electrostatic chuck 1b and the adhesive 10 applied to the substrate 2 are omitted.
[0027]
On the other hand, in the bonded substrate manufacturing apparatus according to the present invention shown in FIG. 1, since the entire electrostatic chuck 1 is transparent, even if the position of the alignment mark 3 is changed according to the shape of the substrate 2, If the imaging device 5 arranged below the second electrostatic chuck 1b is moved to a position corresponding to the alignment mark 3 on the substrate 2, and then moved together with the second electrostatic chuck 1b, It is possible to image the alignment mark 3 and perform the alignment of the substrate 2. That is, it is possible to bond substrates 2 having different shapes by the same electrostatic chuck 1. The arrangement of the ultraviolet irradiation holes 8 is also shown in FIGS. 5 and 6, but it goes without saying that the same effect can be obtained.
[0028]
Further, since the electrostatic chuck 1 in the conventional bonded substrate manufacturing apparatus needs to be provided with the mark imaging hole 7 and the ultraviolet irradiation hole 6, the internal electrode 9 should avoid each hole as shown in FIG. Had to be placed in. Since the chucking force of the electrostatic chuck 1 changes according to the line width of the internal electrodes 9 and the distance between the electrodes, as shown in FIG. If the distance is partially different from that of the other parts, unevenness occurs in the distribution of the electrostatic attraction force. As a result, for example, when the bonded substrate 2 is detached from the electrostatic chuck 1 by pushing up the lift pins, the substrate 2 may not be evenly detached, and the substrate 2 may be damaged.
[0029]
On the other hand, in the bonded substrate manufacturing apparatus according to the present invention shown in FIG. 1, since the entire electrostatic chuck 1 is transparent including the internal electrode 9, the positions of the alignment mark image pickup unit and the ultraviolet irradiation unit are not considered. 8, the internal electrodes 9 can be arranged with a uniform line width and an inter-electrode distance as shown in FIG. 8, and as a result, a uniform electrostatic attraction force can be obtained over the entire attraction surface.
The shape of the internal electrode 9 of the electrostatic chuck 1 according to the present invention is such that the electrode width and the distance between the electrodes are each 1 mm or less, but the internal electrode 9 in FIGS. In this figure, the number of comb teeth of the electrode is reduced.
[0030]
According to the present invention, there has been provided an electrostatic chuck in which the base, the electrode, and the dielectric are all transparent. As an example of the use of the transparent electrostatic chuck, the mounting of the transparent electrostatic chuck in the bonded substrate manufacturing apparatus and the advantages thereof have been introduced in the above-described embodiments. Is introduced below.
[0031]
For example, an electrostatic chuck made of a material transparent to infrared rays having a wavelength of 1 μm to 30 μm may be manufactured and used as a hot plate. In this case, by irradiating the mounted object with infrared rays through the electrostatic chuck, the mounted object can be more uniformly heated as compared with a conventional hot plate.
[0032]
For example, an electrostatic chuck for adsorbing a silicon wafer mounted on a CVD film forming apparatus may be made of a material transparent to visible light and infrared light, that is, light having a wavelength of 0.38 μm to 30 μm. In this case, since the back surface of the silicon wafer can be observed through the electrostatic chuck, it is possible to detect biting of minute particles that hinder uniform heat transfer. In addition, if a mechanism for observing temperature radiation light from the back surface of the electrostatic chuck is provided, it becomes possible to observe the in-plane temperature distribution of the silicon wafer.
[0033]
【The invention's effect】
According to the present invention, there is provided a bonded substrate manufacturing apparatus capable of flexibly coping with a change in the position of an alignment mark and a change in the position of an ultraviolet irradiation unit due to a change in the shape of a substrate without exchanging an electrostatic chuck. It becomes possible.
[Brief description of the drawings]
FIG. 1 is a side view showing a schematic configuration of a bonded substrate manufacturing apparatus according to the present invention.
FIG. 2 is a side view showing a schematic configuration of a conventional bonded substrate manufacturing apparatus.
FIG. 3 is a diagram illustrating a state in which an electrostatic chuck used in a conventional bonded substrate manufacturing apparatus electrostatically suctions a substrate, as viewed from the suction surface side.
FIG. 4 is a diagram illustrating a state in which an electrostatic chuck used in a conventional bonded substrate manufacturing apparatus electrostatically attracts a substrate, as viewed from an attracting surface side.
FIG. 5 is a diagram illustrating a state in which an electrostatic chuck used in a conventional bonded substrate manufacturing apparatus electrostatically attracts a substrate, as viewed from an attracting surface side.
FIG. 6 is a diagram showing a state in which an electrostatic chuck used in a conventional bonded substrate manufacturing apparatus electrostatically attracts a substrate, as viewed from an attracting surface side.
FIG. 7 is a diagram showing an arrangement of internal electrodes of an electrostatic chuck used in a conventional bonded substrate manufacturing apparatus.
FIG. 8 is a diagram showing an arrangement of internal electrodes of an electrostatic chuck used in the bonded substrate manufacturing apparatus according to the present invention.
FIG. 9 is a cross-sectional view showing an electrostatic chuck used in the bonded substrate manufacturing apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Electrostatic chuck 1a ... First electrostatic chuck 1b ... Second electrostatic chuck 2 ... Substrate 3 ... Alignment mark 4 ... Drive device 4a ... Upper drive device 4b ... Lower drive device 5 ... Imaging device 6 ... Ultraviolet irradiation device 7 ... mark imaging hole 8 ... ultraviolet irradiation hole 9 ... internal electrode 10 ... adhesive 11 ... light irradiation port 12 ... alumina film 13 ... base

Claims (8)

In an electrostatic chuck, an internal electrode is formed on a base made of a dielectric, the internal electrode is covered with a dielectric film, and an upper surface of the dielectric film is an adsorption surface on which an object to be adsorbed is placed. And an electrostatic chuck, wherein the dielectric film transmits light in a predetermined wavelength range. The electrostatic chuck according to claim 1, wherein a base forming the electrostatic chuck is glass. 3. The electrostatic chuck according to claim 1, wherein the dielectric film forming the electrostatic chuck is an alumina film formed by an aerosol deposition method. The electrostatic chuck according to any one of claims 1 to 3, wherein the internal electrode is a transparent electrode. It has a 1st and 2nd electrostatic chuck, and at least any one of the said 1st and 2nd electrostatic chuck is an electrostatic chuck as described in any one of Claims 1-4, Comprising: The said 1st and 2nd The first and second substrates are electrostatically attracted and held on the second electrostatic chuck, respectively, and the alignment marks provided on the first and second substrates are aligned with any of the first and second electrostatic chucks. In a bonded substrate manufacturing apparatus in which the first and second substrates are aligned after being imaged by an imaging device provided on one of the substrates, the imaging device includes the first and second electrostatic capacitors. An apparatus for manufacturing a bonded substrate, which is movable with respect to a chuck. It has a 1st and 2nd electrostatic chuck, and at least any one of the said 1st and 2nd electrostatic chuck is an electrostatic chuck as described in any one of Claims 1-4, Comprising: The said 1st and 2nd The adhesive is cured in a bonded substrate manufacturing apparatus in which the first and second substrates are electrostatically adsorbed and held on the second electrostatic chuck, respectively, are aligned with each other, and then bonded and bonded with a photocurable adhesive. A plurality of light irradiation ports for causing the light to pass through at least one of the first and second electrostatic chucks to partially irradiate the adhesive; A laminated substrate manufacturing apparatus, wherein the adhesive is partially cured. The bonded substrate manufacturing apparatus according to claim 6, wherein the position of the light irradiation port is movable with respect to the first and second electrostatic chucks. It has a 1st and 2nd electrostatic chuck, and at least any one of the said 1st and 2nd electrostatic chuck is an electrostatic chuck as described in any one of Claims 1-4, Comprising: The said 1st and 2nd In a bonded substrate manufacturing apparatus, the first and second substrates are electrostatically attracted and held on a second electrostatic chuck, aligned with each other, then bonded, and bonded with a photocurable adhesive. An apparatus for manufacturing a bonded substrate, comprising: irradiating at least one of the second electrostatic chucks with light and irradiating the entire adhesive with light to cure the entire adhesive.

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