JP2001308166A - Electrostatic chuck device and vacuum treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the electrostatic attractive force of an electrostatic chuck device which can attract insulating substrates by static electricity. SOLUTION: The electrostatic chuck device 21 has a base 23 and first and second electrodes 271 and 272 which are formed on the surface of the base 23, and the first and second electrodes 271 and 272 have a thickness of 2 μm or less which is smaller than that in a conventional device. When a voltage is applied to between the first and second electrodes 271 and 272, the electric field which is generated between their side faces and does not contribute to the gradient force is reduced since the area of the side faces is reduced, and the electric field which contributes to the gradient force is increased in the contrary. Accordingly, the gradient force is increased and the electrostatic attractive force is further increased as compared to the conventional electrodes having a relatively larger thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic attraction device and a vacuum processing device, and more particularly to an electrostatic attraction device capable of electrostatically attracting an insulating substrate and a vacuum provided with the electrostatic attraction device. It relates to a processing device.

[0002]

2. Description of the Related Art A reference numeral 101 in FIG. 7 shows a conventional sputtering apparatus. This sputtering apparatus 101 has a vacuum chamber 102 connected to a vacuum exhaust system (not shown),
A target 103 made of, for example, a metal is provided above the vacuum chamber 102.

The target 103 is connected to a DC power supply 104 provided outside the vacuum chamber 102, and is configured so that a negative voltage is applied by the DC power supply 104.

On the other hand, below the vacuum chamber 102, an electrostatic attraction device 121 for adsorbing and holding an insulating substrate such as a glass substrate is fixed. FIGS. 8A and 8B show the configuration of the electrostatic suction device 121. FIG. This electrostatic suction device 121
Has a metal plate 124 and a dielectric layer 125 disposed on the metal plate 124. This dielectric layer 125 is made of Al
The first and second electrodes 127 are made of ceramics containing ₂ O ₃ as a main component and made of conductive carbon on the surface thereof.
_1, 127 ₂ is formed by screen printing.

FIG. 1B is a plan view of the first and second electrodes 127 ₁ and 127 ₂ . First and second electrodes 127 ₁ , 12
7 ₂ is formed into a comb-like portions of the teeth are arranged to mesh with each other. (A) of FIG.
-It corresponds to an X-ray sectional view. The first and second electrodes 127 ₁ ,
127 _second width is 4 mm, the distance between the electrodes has a 1 mm, has a thickness of the electrode with 20 [mu] m.

The first and second electrodes 127 ₁ and 127 ₂ are respectively connected to an electrostatic chuck power source 12 provided outside the vacuum chamber 102.
2 when the electrostatic chuck power supply 122 is driven, a DC voltage can be applied between the _first and _second electrodes 127 ₁ and 127 ₂ .
First and second electrodes 127 ₁ and 127 _{2 are provided} on the first and second electrodes 127 ₁ and 127 ₂ , respectively.
A protective film 130 is formed so as to cover the electrodes 127 ₁ and 127 ₂ and the surface of the dielectric layer 125.

In the sputtering apparatus 101 having such a configuration, first, a substrate is carried into the vacuum chamber 102 in a state where the vacuum chamber 102 is evacuated to a vacuum state in advance. Then, the substrate is placed at a predetermined position on the electrostatic suction device 121 by a lifting mechanism (not shown). The substrate mounted on the surface of the electrostatic suction device 121 is indicated by reference numeral 105 in FIG.

Next, the electrostatic chuck power supply 122 is activated,
Positive and negative voltages are applied to the first and second electrodes 127 ₁ and 127 ₂ , respectively. Generally, 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.

F = １ ／ · α · grad (E ² ) In the electrostatic attraction device 121, as described above, the first and second electrodes 127 ₁ and 127 ₂ are both formed in a comb shape, and the teeth thereof are formed. Are arranged so as to mesh with each other, and the distance between the _first and _second electrodes 127 ₁ and 127 ₂ adjacent to each other is extremely small. As a result, when the substrate made of a dielectric is placed on the surface,
(E ² ) has increased.

The substrate 105 receives the above-described gradient force in the surface direction of the electrostatic attraction device 121, and the entire back surface of the substrate 105 is attracted to the surface of the electrostatic attraction device 121. FIG.
Is a diagram schematically showing the state. In FIG. 9, reference symbol E indicates an electric field. Further, the symbol f denotes the substrate 105
Shows the direction of the gradient force acting on.

A heater (not shown) is provided inside the electrostatic attraction device 121, and the electrostatic attraction device 121 is heated to a predetermined temperature in advance.
When the substrate 105 is electrostatically attracted to the surface of the substrate 1, the substrate 105 is heated and its temperature rises.

When the temperature of the substrate 105 is raised to a predetermined temperature,
When a sputtering gas such as, for example, argon gas is introduced into the vacuum chamber 102 and the DC power supply 104 is activated to apply a negative voltage to the target 103, plasma is generated in the vacuum chamber 102 and sputtering is performed on the surface of the substrate 105. Will be

After the thin film having a predetermined thickness is formed on the surface of the substrate 105, the DC power supply 104 is stopped to extinguish the plasma. As described above, a thin film can be formed on the surface of the substrate 105 by the sputtering apparatus 101.

However, in the above-mentioned conventional electrostatic attraction device, there is a demand that the electrostatic attraction force should be further increased so that the substrate can be reliably electrostatically attracted.

[0015]

SUMMARY OF THE INVENTION The present invention has been made to meet the above-mentioned demands of the prior art, and an object of the present invention is to provide an electrostatic attraction device for an insulating substrate which further increases the electrostatic attraction force. It is to provide the technology to do.

[0016]

The inventors of the present invention have studied to further increase the electrostatic attraction force, and as a result, have found that the thicknesses of the first and second electrodes contribute to the electrostatic attraction force. Was found.

FIG. 5A shows a pair of first and second electrodes 12 adjacent to each other in a conventional electrostatic attraction device 121.
7 ₁ and 127 ₂ are shown. First and second electrodes 12
When a voltage is applied between 7 ₁ and 127 ₂ , an electric field E ₁ is generated between the surfaces of the first and second electrodes 127 ₁ and 127 ₂ as shown in FIG. The second electrode 127 ₁ ,
An electric field E ₂ is also generated between the 127 ₂ side surfaces.

Of these, the first and second electrodes 127 ₁ , 1
27 electric field E ₁ between the _second surface, the first, second electrodes 127
_1, 127 ₂ passes through the inside of the substrate placed on, contributes to the electrostatic adsorption by the gradient force, the first opposing electric field E between the second electrode 127 _1, 127 ₂ sides
₂ does not pass through the inside of the substrate and does not contribute to the electrostatic attraction force.

Therefore, the first and second electrodes were formed thinner than before. The thin first and second electrodes are indicated by reference numerals 27 ₁ and 27 ₂ in FIG. A voltage that induces the same amount of charge as the charges induced on the first and second electrodes 127 ₁ and 127 ₂ of the related art is applied to the thin first and second electrodes 127 ₁ and 127 ₂ .
When applied to the second electrodes 27 _1, 27 _2, first opposed to each other, the side area of the second electrode 27 _1, 27 _2, first conventional, the second electrode 127 _1, 127 ₂ , The electric field E ₂ ′ generated between the side surfaces of the _first and _second electrodes 27 ₁ , 272 becomes smaller than the conventional first and second electrodes 12 ₁ , 27 _2.
7 _1, 127 becomes smaller than the electric field E ₂ occurring between _two sides, correspondingly, first and second electrodes 27 _1, 27 ₁ 'of the conventional electric field E generated between the _second surface field E ₁ It becomes larger than. Since the electric field E ₁ ′ generated between the surfaces of the first and second electrodes 27 ₁ and 27 ₂ contributes to the electrostatic attraction force as described above, the electrostatic attraction force is larger than that of the related art.

As described above, it has been confirmed that the electrostatic attraction force can be increased by forming the first and second electrodes thinner as compared with the related art. In particular, the first and second
It has been confirmed that a remarkable effect can be obtained by setting the thickness of the electrode to 2 μm or less, which is thinner than the conventional thickness of about 10 μm to several hundred μm.

[0021] The present invention has been made based on such research, and the invention according to claim 1 has a base and a first and a second electrode which are arranged on the surface of the base in a state of being insulated from each other. An electrostatic chuck having:
The second electrode is characterized in that its thickness is formed to 2 μm or less.

As described above, the first and second electrodes are formed to have a thickness of 2 μm or less and are formed to be thinner than the conventional first and second electrodes. It becomes larger than. The first and second electrodes are formed by patterning by a method such as etching or sandblasting after an electrode material is entirely formed on the surface of the base,
An electrode having a fine pattern and a small film thickness can be easily formed as compared with the related art in which electrodes are formed by screen printing.

Further, in the present invention, as described in claim 2, in the electrostatic attraction device according to claim 1, a protection arranged so as to cover at least the first and second electrode surfaces. It may be configured to have a film. In this case, since the first and second electrodes are not exposed, the first and second electrodes are not exposed.
The second electrode is less likely to corrode.

Further, as set forth in claim 3, there is provided a vacuum chamber capable of evacuating, and an electrostatic chucking device arranged in the vacuum chamber, wherein an object to be treated is placed on the surface of the electrostatic chucking apparatus. A vacuum processing apparatus configured to be capable of performing vacuum processing on the processing target in a state where the processing object is placed, wherein the electrostatic suction device is the electrostatic suction device according to claim 1 or 2. It may be configured as such.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. Reference numeral 1 in FIG. 1 shows a sputtering apparatus according to an embodiment of the present invention. The sputtering apparatus 1 has a vacuum chamber 2 connected to a vacuum evacuation system (not shown), and a target 3 made of, for example, a metal is disposed on the vacuum chamber 2. This target 3
It is connected to a DC power supply 4 provided outside the vacuum chamber 2, and is configured to apply a negative voltage by the DC power supply 4.

On the other hand, an electrostatic suction device 21 for holding an insulating substrate (processing object) such as a glass substrate by suction is fixed below the vacuum chamber 2. Electrostatic suction device 2
2 is shown in FIGS. 2 (a) and 2 (b). This electrostatic suction device 2
1 has a base 23 composed of a metal plate 24 and a dielectric layer 25 disposed on the metal plate 24. Dielectric layer 25
Is made of a ceramic mainly composed of Al ₂ O ₃ , and has first and second electrodes 27 ₁ , 27 ₂ made of Al on its surface.
Are formed.

FIG. 2B is a plan view of the first and second electrodes 27 ₁ and 27 ₂ . The first and second electrodes 27 ₁ and 27 ₂ are formed in a comb shape, and are arranged so that their tooth portions mesh with each other. FIG. 13A corresponds to a cross-sectional view taken along line AA of FIG. The width of the first and second electrodes 27 ₁ and 27 ₂ is 4
mm, the interval between the electrodes is 1 mm, and the thickness of the electrodes is 1.5 μm.

The first and second electrodes 27 ₁ and 27 ₂ are respectively connected to an electrostatic chuck power supply 22 provided outside the vacuum chamber 2. When the electrostatic chuck power supply 22 is driven, the first and second electrodes 27 ₁ and 27 ₂ are driven. It is configured such that a DC voltage can be applied between the _two electrodes 27 ₁ and 27 ₂ .

The first, the second electrode 27 _1, 27 ₂ on the first, so as to cover the second electrode 27 _1, 27 ₂ and the dielectric layer 25 surface protection made of silicon nitride A film 30 is formed.

In order to manufacture the electrostatic attraction device 21 having such a configuration, first, as shown in FIG. 3A, a dielectric layer 25 is formed on a metal plate 24 to form a base 23, and then, as shown in FIG. As shown in FIG. 2B, an Al layer 26 is formed on the surface of the dielectric layer 25 to a thickness of 1.5 μm by a sputtering method.

Next, as shown in FIG. 3C, a resist is applied to the entire surface of the Al layer 26 to form a resist film 41, and then the resist film 41 is exposed using a photomask 42. A latent image corresponding to the pattern formed on the resist film 41 is formed on the resist film 41.

Next, when the resist film 41 is developed, the resist film 41 is patterned according to the pattern formed on the photomask 42. The patterned resist film is indicated by reference numeral 43 in FIG.

The resist film 4 thus patterned
When the Al layer 26 is etched and removed by dry etching using the mask 3 as a mask, as shown in FIG.
Second electrodes 27 ₁ and 27 ₂ are formed. From this state, the resist film 43 patterned as shown in FIG.
Is removed, the first and second electrodes 27 ₁ and 27 ₂ are exposed. Thereafter, as shown in FIG. 4G, when silicon nitride is formed on the entire surface by the plasma CVD method, the protective film 30 covering the surfaces of the first and second electrodes 27 ₁ and 27 ₂ and the dielectric layer 25 is formed. Is formed. Through the above steps, FIG.
(b), the electrostatic attraction device 21 showing the structure is completed.

Conventionally, first and second electrodes made of a conductive electrode material such as carbon or tungsten are formed by screen printing.
It is difficult to form a very fine pattern because the electrodes 127 ₁ and 127 ₂ are formed. However, in the electrostatic chuck 21 of the present embodiment, the first and second electrodes 27 ₁ and 27 2
Due to the patterned 27 ₂ by etching, it can be easily processed in very fine patterns.

In the sputtering apparatus 1 having such a configuration, first, a substrate is carried into the vacuum chamber 2 with the vacuum chamber 2 evacuated to a vacuum state in advance. Then, the substrate is placed at a predetermined position on the electrostatic attraction device 21 by a lifting mechanism (not shown). The substrate mounted on the surface of the electrostatic chuck 21 is indicated by reference numeral 5 in FIG.

Next, the electrostatic chuck power supply 22 is activated, and positive and negative voltages are applied to the first and second electrodes 27 ₁ and 27 ₂ , respectively. The first and second electrodes 27 ₁ and 27 ₂ are formed in a comb shape as described above, and their teeth are arranged so as to mesh with each other.
The distance between the _second electrodes 27 ₁ and 27 ₂ is extremely small. As a result, when the substrate 5 made of a dielectric material is placed on the surface, a large gradient force is applied to the surface of the electrostatic attraction device 21 so that the entire back surface of the substrate 5 is attracted to the surface of the electrostatic attraction device 21. Is done.

In this embodiment, the first and second electrodes 2
7 ₁ , 27 ₂ are connected to conventional first and second electrodes 127 ₁ , 12 ₁
7 ₂ , and as a result, an electric field generated between the surfaces of the adjacent first and second electrodes 27 ₁ and 27 ₂ , which acts on the substrate 5 and has an electrostatic attraction force. Since the component of the electric field contributing to the above increases, the electrostatic attraction force further increases as compared with the related art. Therefore, the insulating substrate can be electrostatically attracted more reliably than before.

A heater (not shown) is provided inside the electrostatic attraction device 21. The electrostatic attraction device 21 is heated to a predetermined temperature in advance, and the substrate 5 is electrostatically attracted to the surface of the electrostatic attraction device 21. Then, the substrate 5 is heated and rises in temperature.

When the temperature of the substrate 5 is raised to a predetermined temperature, a sputtering gas such as argon gas is introduced into the vacuum chamber 2 and a DC power supply 4 is activated to apply a negative voltage to the target 3. Is generated on the substrate 5
Is sputtered on the surface.

After a thin film having a predetermined thickness is formed on the surface of the substrate 5, the DC power supply 4 is stopped to extinguish the plasma. Through the above steps, a thin film can be formed on the surface of the substrate 5. After that, the electrostatic chuck power supply 22 is stopped, the voltage application to the _first and second electrodes 27 ₁ and 27 ₂ is stopped, and the electrostatic adsorption state of the substrate 5 is released. To take out.

In this embodiment, the electrostatic attraction device 21 has the structure shown in FIGS. 2A and 2B, but the electrostatic attraction device of the present invention is not limited to such a structure. Hereinafter, an electrostatic attraction device capable of electrostatically attracting an insulating substrate such as glass will be described. FIG. 6A is a schematic sectional view of a suction device 31 of a first example of such an electrostatic suction device. In this electrostatic suction device 31, the protective film 30 is not provided,
The first and second electrodes 27 ₁ and 27 ₂ are formed on the dielectric layer 25, and the electrode surface is higher than the surface of the dielectric layer 25.

[0042] In the electrostatic chuck 31, first, second electrodes 27 _1, 27 ₂ protective film is not provided on the first and second electrodes 27 _1, 27 ₂ is in close contact with the substrate Therefore, the electrostatic attraction force is further increased as compared with an electrostatic attraction device provided with a protective film.

FIGS. 7B to 7D are cross-sectional views of the second to fourth examples of the electrostatic attraction devices 32 to 34. The electrostatic suction devices 32 to 34 of the second to fourth examples are provided on the surface of each dielectric layer 25,
Recesses are formed so as not to reach the metal plate 24, and the first and second electrodes 27 ₁ , 2
7 ₂ are arranged in a state of being insulated from each other, each of the first, second electrodes 27 _1, 27 ₂ of the bottom portion is disposed on the bottom surface of each recess.

[0044] In the second example of the electrostatic chuck 32 of FIG. (B), first, second electrodes 27 _1, 27 ₂ of the upper end portion is protruded from the upper dielectric layer 25. In the second example of the electrostatic chuck 32, when the substrate is placed thereon, the back surface of the substrate and the dielectric layer 25 with the substrate back surface is in contact with the first, second electrodes 27 _1, 27 ₂ of the upper end A gap is formed between them.

In the electrostatic chuck 33 of the third example shown in FIG. 9C, the upper ends of the _first and _second electrodes 27 ₁ and 27 ₂ are formed at the same height as the surface of the dielectric layer 25. ing. That is, the surface of the dielectric layer 25 and the upper ends of the _first and _second electrodes 27 ₁ and 272 are formed flush with each other. When a substrate is placed on the electrostatic chuck 33, the back surface of the substrate is the first and second electrodes 2
7 _1, in contact with both the 27 _second upper portion and the dielectric layer 25 surface.

The first to third examples of the electrostatic attraction device 31
In to 33, as described above, in both of the state where the substrate is placed, the substrate back surface is first, but in contact with the second electrode 27 _1, 27 ₂ of the tip portion, the substrate is an insulating substrate such as glass Therefore, the first and second electrodes 27 ₁ and 27 ₂ are not short-circuited via the substrate, and an electric field is generated therebetween, so that the substrate can be electrostatically attracted.

In the electrostatic chuck 34 of the fourth example shown in FIG. 4D, the upper ends of the _first and _second electrodes 27 ₁ and 27 ₂ are formed lower than the surface of the dielectric layer 25. . That is, first,
The upper ends of the second electrodes 27 ₁ and 27 ₂ are located in the recessed portions in the recesses, and the surface of the dielectric layer 25 is formed between the _first and _second electrodes 27 ₁ and 27 _2. A projection 29 is formed.

In this electrostatic attraction device 34, when the substrate is placed on the front surface, the back surface of the substrate comes into contact with the upper end of the projection 29, but does not come into contact with the first and second electrodes 27 ₁ and 27 _2. Has become.

Therefore, the substrate does not come into contact with the first and second electrodes 27 ₁ and 27 ₂ having relatively low abrasion resistance. As a result, the life of the _first and _second electrodes 27 ₁ and 27 ₂ is extended.

In this embodiment, the first and second electrodes 2
7 _1, although the 27 _second thickness and 1.5 [mu] m, the present invention is not limited to this as long these thickness 2μm or less, for example, may be the 1 [mu] m, it may be 0.5 [mu] m.

In this embodiment, the Al layer 26 is patterned by dry etching when forming the _first and second electrodes 27 ₁ and 27 _2. However, the present invention is not limited to this. , Wet etching, or sand blasting.

Further, although Al is used as the electrode material of the first and second electrodes 27 ₁ and 27 ₂ , the electrode material of the present invention is not limited to this, but may be made of a metal such as Cu, W or Ti. May be. Furthermore, the electrode material is not limited to metal, and for example, a conductive carbon material may be used.
In this case, after the conductive carbon material is formed on the entire surface of the dielectric layer 25 by a thermal CVD method or the like, the first and second electrodes 27 having a fine pattern and a small thickness are patterned by sandblasting. it is also possible to form a _1, 27 _2.

Although the protective film 30 is made of silicon nitride, the present invention is not limited to this.
N, TaN, WN, GaN, BN, InN, SiAlO
A nitride such as N may be used, or SiO ₂ , Al ₂ O ₃ ,
Oxides such as Cr ₂ O ₃ , TiO ₂ , TiO, and ZnO may be used. Furthermore, diamond, TiC, TaC,
A carbide such as SiC may be used, or an organic polymer such as polyimide, polyurea, or silicone rubber may be used.

As an example of the dielectric layer 25, Al ₂ O ₃
Is the main component, but the present invention is not limited to this,
For example, AlN, TaN, WN, GaN, BN, In
N, a nitride such as SiAlON may be used,
₂ , oxides such as Al ₂ O ₃ , Cr ₂ O ₃ , TiO ₂ , TiO, and ZnO may be used. Furthermore, diamond, Ti
A carbide such as C, TaC, or SiC may be used, or an organic polymer such as polyimide, polyurea, or silicone rubber may be used.

[0055]

According to the present invention, the electrostatic attraction force at the time of electrostatically adsorbing the insulating substrate becomes larger than before.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a vacuum processing apparatus according to an embodiment of the present invention.

FIG. 2A is a cross-sectional view illustrating an example of an electrostatic chuck according to an embodiment of the present invention. FIG. 2B is a plan view illustrating an example of the electrostatic chuck according to an embodiment of the present invention.

3A is a cross-sectional view illustrating a manufacturing process of the electrostatic chuck according to one embodiment of the present invention. FIG. 3B is a cross-sectional view illustrating a subsequent process. FIG. Cross section

FIG. 4D is a cross-sectional view illustrating a subsequent step. FIG. 4E is a cross-sectional view illustrating a subsequent step. FIG. 4F is a cross-sectional view illustrating a subsequent step. Sectional view explaining process

FIG. 5A is a diagram showing an electric field distribution between the first and second electrodes when the thickness of the first and second electrodes is large. FIG. 5B: A diagram between the two electrodes when the thickness of the first and second electrodes is small. Figure showing the electric field distribution of

FIG. 6A is a cross-sectional view illustrating a first example of an electrostatic chuck according to another embodiment of the present invention. FIG. 6B is a cross-sectional view illustrating a second example of the electrostatic chuck according to another embodiment of the present invention. Sectional view for explaining (c): Sectional view for explaining a third example of an electrostatic chucking device according to another embodiment of the present invention. (D): Fourth example of electrostatic chucking device according to another embodiment of the present invention. Sectional view to explain

FIG. 7 is a cross-sectional view illustrating a conventional vacuum processing apparatus.

8A is a cross-sectional view illustrating an example of a conventional electrostatic attraction device. FIG. 8B is a plan view illustrating an example of a conventional electrostatic attraction device.

FIG. 9 is a diagram showing a state where an insulating substrate is electrostatically attracted;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sputtering apparatus (vacuum processing apparatus) 5 ... Substrate (processing object) 23 ... Base 27 ₁ ... 1st electrode 27 ₂ ... 2nd electrode 30 ... Protective film

Continuation of the front page (72) Inventor Toshio Hayashi 2500 Hagizono, Chigasaki-shi, Kanagawa Japan Vacuum Engineering Co., Ltd. (72) Inventor Junpei Yuyama 2500 Hagizono, Chigasaki-shi, Kanagawa Japan Vacuum Engineering Co., Ltd. F-term (reference) 4K029 AA09 CA05 DA02 DC34 JA01 5F031 CA05 HA03 HA08 HA17 HA18 MA29 NA05

Claims (3)

[Claims] A first substrate disposed on the surface of the substrate and insulated from each other;
An electrostatic attraction device having a second electrode, wherein the first and second electrodes have a thickness of 2 μm or less. 2. The electrostatic attraction device according to claim 1, further comprising a protective film disposed so as to cover at least the first and second electrode surfaces. 3. An object to be processed, comprising: a vacuum chamber capable of evacuating; and an electrostatic suction device disposed in the vacuum chamber, wherein the processing object is placed on the surface of the electrostatic suction device. A vacuum processing apparatus configured to be capable of vacuum processing an object, wherein the electrostatic suction apparatus is the electrostatic suction apparatus according to claim 1 or 2. .