US20100212832A1

US20100212832A1 - Stage device and plasma treatment apparatus

Info

Publication number: US20100212832A1
Application number: US12/159,387
Authority: US
Inventors: Tamaki Wakasaki; Takashi Satoh; Keiichi Tanaka; Setsuo Nakajima; Satoshi Mayumi; Yoshinori Nakano
Original assignee: Sharp Corp; Sekisui Chemical Co Ltd
Current assignee: Sharp Corp; Sekisui Chemical Co Ltd
Priority date: 2005-12-28
Filing date: 2006-12-22
Publication date: 2010-08-26
Also published as: JPWO2007077765A1; CN101352108B; WO2007077765A1; CN101352108A; JP4919971B2

Abstract

The present invention provides a stage device which does not generate the difference in level between an upper end of a lift pin and a setting surface of a stage in a state where a substrate to be treated is set on the setting surface of the stage, and provides a plasma treatment apparatus which suppresses the occurrence of uneven treatment by using the stage device as an electrode stage. At the center of an electrode stage (2), a spring type lift pin (20) having elasticity in a direction where the pin moves is provided. When the spring type lift pin (20) is at a storage position, a pin upper end (20 a) of the spring type lift pin (20) protrudes above the setting surface (11) of the electrode stage (2). When the substrate (4) to be treated is set and adsorbed on the setting surface (11), the upper end of the lift pin is pressed down to the position that is at the same level as that of the setting surface (11) by a load applied by the substrate (4).

Description

TECHNICAL FIELD

The present invention relates to a plasma treatment apparatus which performs plasma treatment at near atmospheric pressure, and a stage device which can be suitably used in a treatment apparatus, such as the plasma treatment apparatus, and allows a substrate to be treated to be set thereon.

BACKGROUND ART

Conventionally, surface treatment of a substrate made from, for example, glass, plastic, or other material by means of glow discharge plasma at a low pressure ranging from appropriately 0.1 Torr to 10 Torr is widely known and industrially applied. Surface treatment at such a vacuum-level low pressure prevents a shift from discharge to arc discharge, and therefore can be performed even on the substrate made from plastic or other material having a high heat resistance.
However, surface treatment by low-pressure glow discharge plasma requires an expensive vacuum chamber as a treatment container, and an evacuation unit. In addition, upsizing of substrates, typified by the so-called upsizing of a screen for a liquid crystal television or the like, has been developed in some fields. Surface treatment in such fields requires larger vacuum chamber and evacuation unit. This inevitably increases production cost of an apparatus and increases a footprint of the apparatus. Moreover, surface treatment on a substrate having a high water absorption requires a long time to form a vacuum inside the vacuum chamber, which increases treatment cost itself.
In order to overcome the above various kinds of problems, there has been proposed an apparatus which subjects a substrate to surface treatment at an atmospheric pressure while generating glow discharge plasma (for example, see Patent document 1).
Such a plasma treatment apparatus, as illustrated in FIG. 24, includes: an electrode stage 102 that holds a substrate 104 to be treated; and a counter electrode 103 that is disposed to face the electrode stage 102. The counter electrode 103 has a plurality of gas supply holes (not shown) from which a treatment gas is flown. To the counter electrode 103, a power source section 110 for applying a voltage is connected. The electrode stage 102 includes: a lift pin mechanism 120 that holds the substrate 104 by pushing it; and an adsorption groove 106 which allows the substrate 104 to be adsorbed on the surface of the electrode stage 102. The electrode stage 102 is grounded.
The adsorption groove 106 has a gap 108 between the substrate 104 and the electrode stage 102. In the gap 108 plasma easily occurs since a pressure inside the gap 108 is low. Therefore, a voltage drop in the adsorption groove 106 is relatively small.
As illustrated in FIG. 25 showing an equivalent circuit, a circuit configuration in which a resistor 131, a capacitor 132, and a resistor 130 are connected in series can be considered as a circuit configuration between the power source section 110 and a ground 112 in the vicinity of the adsorption groove 106. The resistor 131 shows the occurrence of a voltage drop due to plasma generated in between the counter electrode 103 and the substrate 104. The capacitor 132 is an electrical capacity in the substrate 104. The resistor 130 shows a voltage drop in the adsorption groove 106. A voltage drop in the capacitor 132 is relatively large, but voltage drops in the resistors 132 and 130 are relatively small. Thus, since a voltage drop in the gap 108 of the adsorption groove 106 is small, uneven treatment on the substrate 104 does not actually occur.
Patent document 2 discloses, which does not disclose a plasma treatment apparatus only, the technique of independently controlling the level of lift pins at their upward movement, which pins cause a wafer set on a setting table to be floated above the setting surface of the setting table.
[Patent document 1]
Japanese Unexamined Patent Publication No. 118857/1995 (Tokukaihei 7-118857; published on May 9, 1995)
[Patent document 2]
Japanese Unexamined Patent Publication No. 64132/2002 (Tokukai 2002-64132; published on Feb. 28, 2002)

DISCLOSURE OF INVENTION

Even though an upper end 120 a of the pin (lift pin) at the downward movement of the lift pin mechanism 120 is set so as to be positioned at the same level as the adsorption surface 102 a of the electrode stage 102, the upper end 120 a cannot be positioned according to the setting. This is because mechanical precision of the lift pin mechanism 120 is limited. That is, the upper end 120 a sinks below the adsorption surface 102 a as illustrated in FIG. 24, or protrudes above the adsorption surface 102 a as illustrated in FIG. 26.
When the upper end 120 a of the pin is positioned below the adsorption surface 102 a of the electrode stage 102, a gap 109 occurs due to difference in level between the upper end 120 a of the pin and the substrate 104, as illustrated in FIG. 24.
On the other hand, when the upper end 120 a of the pin is positioned above the adsorption surface 102 a of the electrode stage 102, a gap 111 occurs due to difference in level between the adsorption surface 102 a and the substrate 104, as illustrated in FIG. 26.
As different from the case of the adsorption groove 106, pressures in the gaps 109 and 111 caused by difference in level are atmospheric pressures, and no plasma therefore occurs even when a voltage is applied. As a result, a voltage drop in the gaps 109 and 111 increases.
More specifically, as illustrated in FIG. 27 showing an equivalent circuit, a circuit configuration in which the resistor 131, the capacitor 132, and the resistor 130 are connected in series can be considered as a circuit configuration between the power source section 110 and the ground 112 in the vicinity of the lift pin mechanism 120. The capacitor 133 is an electrical capacity in the gaps 109 and 111 that occur due to difference in level between the pin and the adsorption surface 102 a. Thus, it is inevitable that a voltage drop is relatively large in the gaps 109 and 111 caused by the difference in level since no plasma is generated in the gaps 109 and 111. As a result, uneven treatment and/or the so-called incomplete treatment occur in the substrate 104.
The present invention has been attained in view of the above problems, and an object of the present invention is to provide a stage device which does not cause difference in level between the upper end of a pin in the lift pin mechanism and the setting surface in a state where a substrate is set on the setting surface of a stage, and a plasma treatment apparatus which includes such a stage device and thereby suppresses the occurrence of uneven treatment.
In order to achieve the object, a stage device of the present invention includes: a stage having a setting surface on which a substrate to be treated is set; and a lift pin mechanism having first pins, provided in the stage, each capable of emerging from the setting surface, the first pins being protruded so that the substrate is detached from the setting surface, wherein the lift pin mechanism includes contact adjusting means that brings an upper end of the first pin being withdrawn in the stage into contact with the substrate on the setting surface without lifting the substrate above the setting surface.
A plasma treatment apparatus of the present invention is a plasma treatment apparatus which generates plasma in between an electrode stage and a counter electrode at near atmospheric pressure so as to subject a substrate to be treated being set on the electrode stage to plasma treatment, the plasma treatment apparatus including the above stage device as the electrode stage.
According to the arrangement of the stage device of the present invention, the contact adjusting means included in the lift pin mechanism brings the upper end of the first pin being withdrawn in the stage into contact with the substrate set on the setting surface without lifting the substrate above the setting surface (corresponding to adsorption surface). This makes it possible to make the upper end of the first pin positioned at the same level as the setting surface through the use of the substrate.
That is, through the use of the substrate, the stage device is realized in which there is no difference in level between the upper end of the first pin and the setting surface in a state where the substrate is set on the setting surface.
In the plasma treatment apparatus of the present invention, such a stage device of the present invention is used as the electrode stage. This allows the substrate to come into contact with both the setting surface and the first pin even in the vicinity of the first pin.
This arrangement is free from a gap caused by difference in level between the above-described lift pin (first pin) and the setting surface, i.e. a gap between the substrate and lift pin (first pin) or a gap between the substrate and the setting surface, where no plasma is generated and a great voltage drop occurs. This makes it possible to reduce the occurrence of uneven treatment and incomplete treatment on the substrate.
Therefore, it is possible to provide a stage device and a plasma treatment apparatus both of which are arranged such that no difference in level occurs between the upper end of the first pin and the setting surface in a state where the substrate is set on the setting surface.
A display panel substrate of the present invention is a display panel substrate for use in manufacturing a display panel, and the display panel substrate is subjected to surface treatment by means of the above plasma treatment apparatus of the present invention capable of effectively reducing the occurrence of uneven treatment. By manufacturing a display panel including such a display panel substrate, it is possible to provide a display device having an excellent display quality without display irregularity.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view illustrating an embodiment of the present invention and a cross-sectional view schematically illustrating the structure of a plasma treatment apparatus of First Embodiment.

FIG. 2 is a plan view illustrating an appearance of an electrode stage installed in the plasma treatment apparatus illustrated in FIG. 1.

FIG. 3 is a cross-sectional view taken along a line B-B′ of FIG. 2.

FIG. 4 is a cross-sectional view taken along a line A-A′ of FIG. 2, illustrating the state where a lift pin is at a storage position and a substrate is not set on the electrode stage.

FIG. 5 is a cross-sectional view taken along a line A-A′ of FIG. 2, illustrating the state where the lift pin is at the storage position and the substrate is set on the electrode stage.

FIG. 6 is a cross-sectional view taken along a line A-A′ of FIG. 2, illustrating the state where the lift pin is at the storage position and the substrate set on the electrode stage is adsorbed.

FIG. 7 is a cross-sectional view taken along a line A-A′ of FIG. 2, illustrating the state where the lift pin is at a protrusion position and the substrate is detached from the electrode stage.

FIG. 8( a) is a cross-sectional view schematically illustrating an essential part in the vicinity of the lift pin in the plasma treatment apparatus illustrated in FIG. 1, and FIG. 8( b) is an equivalent circuit diagram of FIG. 8( a).

FIG. 9 is an explanatory view of the problem that can occur in a case where a spring type pin is disposed in the outer region of the electrode stage.

FIG. 10 is an explanatory view illustrating that abnormal electrical discharge occurs when an electrode surface in the outer region of the electrode stage is exposed, wherein FIG. 10( a) is a cross-sectional view schematically illustrating an essential part of a plasma treatment apparatus having an exposed electrode surface, and FIG. 10( b) is an equivalent circuit diagram of FIG. 10( a).

FIG. 11 is an explanatory view illustrating that abnormal electrical discharge does not occur when an insulating section is provided in the outer region of the electrode stage, wherein FIG. 11( a) is a cross-sectional view schematically illustrating an essential part of the plasma treatment apparatus illustrated in FIG. 1, and FIG. 11( b) is an equivalent circuit diagram of FIG. 11( a).

FIG. 12 is a plan view illustrating an appearance of another electrode stage that can be installed in the plasma treatment apparatus illustrated in FIG. 1.

FIGS. 13( a) through 13(e) are cross-sectional views illustrating the structure of an electrode stage installed in a plasma treatment apparatus of another embodiment of the present invention, wherein an insulating section provided in the outer region of the electrode stage is movable.

FIG. 14 is a cross-sectional view schematically illustrating an essential part in the vicinity of the lift pin in a modified example of the plasma treatment apparatus illustrated in FIG. 1.

FIG. 15 is a cross-sectional view schematically illustrating an essential part in the vicinity of the lift pin in a modified example of the plasma treatment apparatus illustrated in FIG. 1.

FIG. 16 is a cross-sectional view illustrating the structure of an electrode stage installed in a plasma treatment apparatus of another embodiment of the present invention, wherein the spring type lift pin moves up and down in different manner.

FIG. 17 is a view illustrating another embodiment of the present invention and a plan view illustrating an appearance of an electrode stage installed in a plasma treatment apparatus of Second Embodiment.

FIG. 18 is a cross-sectional view taken along a line C-C′ of FIG. 17, illustrating the state where the lift pin is at the storage position and a substrate set on the electrode stage is adsorbed.

FIG. 19 is a plan view illustrating an appearance of an electrode stage installed in the plasma treatment apparatus illustrated in FIG. 1.

FIG. 20 is a cross-sectional view taken along a line D-D′ of FIG. 19, illustrating the state where the lift pin is at the storage position and a substrate set on the electrode stage is adsorbed.

FIGS. 21( a) through (d) are cross-sectional views illustrating the procedural steps for manufacturing a liquid crystal panel in which a color filter is formed on the substrate with the use of the plasma treatment apparatus illustrated in FIG. 1 or 17.

FIGS. 22( a) and 22(b) are plan views illustrating examples of a pattern of black matrices for use in formation of a color filter.

FIG. 23 is a plan view illustrating the state after the ink delivery illustrated in FIG. 21( b).

FIG. 24 is a cross-sectional and enlarged view of a conventional plasma treatment apparatus.

FIG. 25 is a circuit diagram illustrating an equivalent circuit of an adsorption groove in the conventional plasma treatment apparatus.

FIG. 26 is a cross-sectional and enlarged view of another conventional plasma treatment apparatus.

FIG. 27 is a circuit diagram illustrating an equivalent circuit of a part in the vicinity of a lift pin in the conventional plasma treatment apparatus.

EXPLANATIONS OF REFERENCE NUMERALS

- S plasma treatment apparatus
- 2 electrode stage
- 3 counter electrode
- 4 substrate to be treated
- 6 adsorption mechanism
- 6 a adsorption holes
- 7 lift pin mechanism
- 11 adsorption surface
- 18 a treatment region
- 18 b non-treatment region
- 20 spring type lift pin (first pin)
- 28 fixed type lift pin (second pin)

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment of the Present Invention

FIGS. 1 through 11 illustrate First Embodiment of the present invention. As illustrated in a cross-sectional view of FIG. 1, a plasma treatment apparatus S of the present embodiment is arranged such that an electrode stage device (stage device) 35 and a counter electrode 3 are provided in a chamber 1. A substrate 4 to be treated (hereinafter simply referred to as “substrate 4”), such as a glass substrate, held on an electrode stage 2 of the electrode stage device 35 is subjected to plasma treatment at near atmospheric pressure.
The counter electrode 3 is realized by an electrically conductive member and is disposed so as to face the electrode stage 2. To the counter electrode 3, a power source section 10 is connected, and electrical discharge can occur between the counter electrode 3 and the electrode stage 2. The counter electrode 3 is located inside the chamber 1 at an upper position thereof, and the counter electrode 3 is connected to the gas injection pipe 9, through which a treatment gas is injected into the counter electrode 3. One end of the gas injection pipe 9 is connected to the surface of the counter electrode 3 opposite to the surface thereof facing the electrode stage 2. Further, the counter electrode 3 has a plurality of gas injection holes 8, through which the treatment gas supplied from the gas injection pipe 9 to the counter electrode 3 is supplied toward the substrate 4.
The structure of the counter electrode 3 is not limited to the above structure. The counter electrode 3 may be of any structure as long as gas is evenly injected in between the counter electrode 3 and the electrode stage 2.
The other end of the gas injection pipe 9 extends to the outside of the chamber 1 and is connected to a gas supply source. The bottom of the chamber 1 is connected to a discharge pipe 5, through which an exhaust gas in the chamber 1 is discharged.
The electrode stage device 35 has the electrode stage 2, and an adsorption mechanism 6 and a lift pin mechanism 7, both of which are provided in the electrode stage 2.
The electrode stage 2 is the one on which the substrate 4 is set. The electrode stage 2 has an electrode section 2 a and an insulating section 2 b. The electrode section 2 a is realized by a electrically conductive member in the form of plate. The insulating section 2 b is realized by insulators arranged around the electrode section 2 a. The top surfaces of the electrode section 2 a and the insulating section 2 b are a setting surface 11, on which the substrate 4 is set. The electrode section 2 a is grounded.
As illustrated in FIG. 2, the area on the setting surface 11 is divided into: a treatment region 18 a in which plasma treatment is performed, and a non-treatment region 18 b in which plasma treatment is not performed (or in which a predetermined quality of treatment is not exhibited). In FIG. 2, the area surrounded by a dashed-dotted line is the treatment region 18 a, and the area including the insulating section 2 b outside the dashed-dotted line is the non-treatment region 18 b. The non-treatment region 18 b is set so that a non-pixel region of the substrate 4 set on the setting surface 11 is positioned on the non-treatment region 18 b. In consideration of measurement of the non-pixel region of the substrate 4, a width of the insulating section 2 b is preferably 5 mm or greater, more preferably 5 mm to 10 mm.
The insulating section 2 b has the function of preventing the occurrence of abnormal electrical discharge. More specifically, if the electrode section 2 a was exposed toward the side surface of the electrode stage 2 on the assumption that the substrate 4 is of the same size as the electrode stage 2, electrical discharge between the electrode stage 2 and the counter electrode 3 due to their electrodes exposed, i.e. abnormal electrical discharge would occur at the point A illustrated in FIG. 10( a) without the intervention of a capacitor of the substrate 4. FIG. 10( b) is an equivalent circuit diagram of FIG. 10( a). The resistor 33 shows the occurrence of a voltage drop due to direct electrical discharge between the counter electrode 3 and the electrode stage 2.
On the contrary, the electrode stage 2 is surrounded by the insulating section 2 b in the present embodiment. With this arrangement, no abnormal electrical discharge occurs as illustrated in FIG. 11( a) and FIG. 11( b), which is an equivalent circuit diagram of FIG. 11( a), and electrical discharge (normal electrical discharge) occurs by way of a capacitor 32 of the substrate 4. Note that the resistor 31 shows the occurrence of a voltage drop between the counter electrode 3 and the substrate 4.
As illustrated in FIG. 1, an adsorption mechanism 6 causes the substrate 4 to be adsorbed onto the setting surface 11 of the electrode stage 2. In the present embodiment, the adsorption mechanism 6 is made up of a plurality of adsorption holes 6 a, each of which is a vertically long hole being circular in cross section and formed in the setting surface 11.
As illustrated in FIG. 3, a plurality of exhaust passages 19 on the rear surface side of the electrode stage 2. Each of the adsorption holes 6 a is connected to a vacuum pump 50 via the exhaust passage 19. The exhaust passages 19 are depressurized by the vacuum pump 50 when driven, thereby generating vacuum force (negative pressure) in the adsorption holes 6 a. That is, when the vacuum pump 50 is driven with the substrate 4 set on the setting surface 11, vacuum force occurs in the adsorption holes 6 a. This makes it possible to adsorptively hold the substrate 4 on the setting surface 11.
As illustrated in FIG. 2, the adsorption holes 6 a are evenly arranged in a matrix manner in the setting surface 11 of the electrode stage 2. The adsorption holes 6 a are formed so as to be dispersed across the setting surface 11, whereby the substrate 4 can be adsorptively held evenly over the entire setting surface 11.
As illustrated in FIG. 3, the adsorption holes 6 a are connected in groups of at least two to each of the exhaust passages 19. This arrangement realizes a simpler structure than the arrangement in which the adsorption holes 6 a are connected to the respectively corresponding exhaust passages 19.
Although there is a gap between the substrate 4 and the electrode stage 2, the problem of uneven treatment occurs less frequently. This is because internal pressures of the adsorption holes 6 a are depressurized by vacuuming, which facilitates plasma generation and causes a relatively small voltage drop. However, if the diameter of the adsorption holes 6 a is large, uneven treatment may occur even when the gap is at a negative pressure. Therefore, it is desirable that the diameter of the adsorption holes 6 a is not greater than 0.5 mm.
If the pitch between the adsorption holes 6 a is not greater than 100 mm, it complicates working on the electrode stage 2 and the insulating section 2 b. This results in high production cost. On the other hand, if the pitch is too large, it affects the capability of the adsorption holes 6 a in adsorbing the substrate 4 onto the setting surface 11. This requires negative pressure to be increased. In view of this, the pitch between the adsorption holes 6 a is preferably in the range from 100 mm to 200 mm.
Apart from the above arrangement, the adsorption mechanism 6 may be made up of a plurality of adsorption grooves which are formed in the electrode stage 2 and concentrically aligned in a rectangular ring manner (square-shaped-frame manner) in planar view. In this case, the adsorption grooves may be connected to a vacuum pump or the like via exhaust passages formed at the bottoms of the respective adsorption grooves. Also in this case, it is desirable that a width of the adsorption groove is not greater than 0.5 mm.
The lift pin mechanism 7 sets the substrate 4 on the electrode stage 2 and detaches the substrate 4 from the electrode stage 2, by means of lift pins which are arranged capable of emerging from the setting surface 11 of the electrode stage 2. In the present embodiment, contact adjusting means is provided that brings the upper end of the lift pin being withdrawn in the electrode stage 2 into contact with the substrate 4 on the setting surface 11 without lifting the substrate 4 above the setting surface 11, although details thereof will be described later. With this arrangement, it is possible to reduce the occurrence of the previously described uneven treatment during the plasma treatment.
In the plasma treatment apparatus S having such an arrangement, plasma is generated in between the counter electrode 3 and the electrode stage 2 when the power source section 10 a applies a voltage ranging, for example, from 1 kV through several tens of kV in between the counter electrode 3 and the electrode stage 2 while a treatment gas is supplied in between the counter electrode and the electrode stage 2. With this plasma, the substrate 4 is subjected to plasma treatment.
For example, in order to perform etching with respect to a thin film formed on the substrate 4 (thin film having chemical, mechanical, optical, or electrical properties), the treatment gas is preferably a mixed gas of CF4, and He or Ar. In order to perform treatment for making the substrate 4 water repellent (liquid repellent), the treatment gas can be a fluorine-containing gas such as CF4, C2F6, or SF6. In order to form a thin film of a metal oxide film made from SiO2, TiO2, SnO2, or the like on the surface of the substrate 4, thereby making the substrate 4 hydrophilic, the treatment gas can be a metal hydride gas (hydrogenated metal gas), a halogenated metal gas, a gas of an organic metal compound such as metallic alcoholate, or water vapor.
Next, the lift pin mechanism 7 installed in the electrode stage device 35 of the plasma treatment apparatus S will be described in detail with reference to FIGS. 4 through 7. FIGS. 4 through 7 are cross-sectional views taken along a line A-A′ of FIG. 2.
As described previously, the lift pin mechanism 7 is provided with lift pins that are arranged capable of emerging from the setting surface 11 of the electrode stage 2. In this case, the lift pin mechanism 7 is provided with two types lift pins, spring type lift pins (first pins) 20 and fixed type lift pins (second pins) 28. Each of the spring type lift pins 20 is provided with a coil spring (elastic body) 23 having elasticity in a direction where the pin moves. Each of the fixed type lift pins 28 is not provided with the spring 23. As illustrated in FIG. 2, the spring type lift pins 20 are disposed in the electrode section 2 a, which is located in the center of the electrode stage 2. The fixed type lift pins 28 are disposed in the insulating section 2 b, which is located in the periphery of the electrode stage 2.
As illustrated in FIG. 4, the spring type lift pins 20 and the fixed type lift pins 28 are each provided in a cylinder 26, which is formed in the electrode stage 2. The cylinder 26 is realized by a cylindrical hole opened in the setting surface 11. The spring type lift pins 20 and the fixed type lift pins 28 are each arranged to be movable in a direction along the length of the cylinder 26 (i.e. up and down), and they move from a storage position shown in FIG. 4 to a protrusion position shown in FIG. 7, and vice versa.
The storage position is such a position that upper ends 20 a of the spring type lift pins 20 and upper ends 28 a of the fixed type lift pins 28 are positioned near the setting surface 11. The protrusion position is such a position that the upper ends 20 a of the spring type lift pins 20 and the upper ends 28 a of the fixed type lift pins 28 are protruded above the setting surface 11, so that the substrate 4 set on the setting surface 11 can be detached from the setting surface 11. These spring type lift pins 20 and fixed type lift pins 28 are electrically grounded as in the electrode stage 2.
Each of the spring type lift pins 20 is arranged such that a piston section 21 formed in the form of a column along the inner walls of the cylinder 26 is coupled via the coil spring (elastic body) 23 to a pin upper section 22 formed in the form of a bolt so as to be flat on top. The coil spring 23 is the contact adjusting means that brings the upper end 20 a into contact with the substrate 4 on the setting surface 11 without lifting the substrate 4 above the setting surface 11, and the coil spring 23 is also elasticity function imparting means that imparts to the spring type lift pin 20 the function having elasticity in the direction where the pin 20 moves. The spring type lift pin 20 is imparted the function having elasticity by the coil spring 23, thereby having elasticity in the length direction, i.e. in the direction where the pin moves.
That is, with the arrangement in which the spring type lift pin 20 has elasticity in the direction where the pin moves, the upper end 20 a of the spring type lift pin being withdrawn in the electrode stage 2 can be brought into contact with the substrate 4 on the setting surface 11 by means of elasticity of the spring type lift pin 20, without lifting the substrate 4 above the setting surface 11, even if the upper end 20 a of the spring type lift pin 20 cannot be stopped accurately at the position that is at the same level as the setting surface 11 a.
In the present embodiment, as illustrated in FIG. 4, in a state where the spring type lift pin 20 is at the storage position, and the substrate 4 is not set on the setting surface 11 so that no load is applied onto the pin upper section 22, the upper end 20 a of the spring type lift pin 20 is protruded slightly above the setting surface 11. The amount of protrusion by which the upper end 20 a of the spring type lift pin 20 is protruded above the setting surface 11 under no load, is the amount by which the upper end 20 a can be pressed down to the same level as the setting surface 11 by the self weight of the substrate 4 that exceeds spring force of the spring type lift pin 20. The amount of protrusion, which can be set appropriately, is, for example, in the range from 0.3 mm to 0.8 mm.
As illustrated in FIG. 6, the spring type lift pin 20 is completely pressed down into the cylinder 26 when the substrate 4 is set on the setting surface 11 and the substrate 4 is adsorbed by the action of the adsorption mechanism 6. Since the pin upper end 20 a of the spring type lift pin 20 being pressed down into the cylinder 26 is pushed to the substrate 4 by the force with which the coil spring 23 returns to its original state, the substrate 4 comes into contact with both the setting surface 11 and the lift pins even in the vicinity of the lift pins.
With this arrangement, the plasma treatment apparatus S of the present embodiment is free from the previously-described gap that occurs during the plasma treatment due to the difference in level between the upper end 20 a of the spring type lift pin 20 and the setting surface 11. This makes it possible to reduce the occurrence of uneven treatment.
Incidentally, in order to completely press down the spring type lift pin 20 into the cylinder 26 by the force (load) with which the substrate 4 adsorbed by the adsorption mechanism 6 applies to the pin upper section 22, the upper end 20 a needs to be positioned below the setting surface 11 in a state where the force (load) with which the substrate 4 applies to the pin upper end 22 is proportional to the force with which the coil spring 23 returns to its original state. Such a design is easily made since a load applied by the substrate to be treated can be increased by means of the adsorption action of the adsorption mechanism 6.
However, as a matter of course, the present embodiment permits a design that can be made considering only a load applied by the self weight of the substrate 4, without considering the adsorption action of the adsorption mechanism 6. In this case, a load applied to one spring type lift pin 20 varies depending upon the weight of the substrate 4, the number of the spring type lift pins 20 disposed, warpage of the substrate, and other factors. Therefore, assuming that spring forces of the coil springs 23 are identical with each other, the position of the upper end 20 a in a state where the load applied by the substrate 4 is proportional to the force with which the coil spring 23 returns to its original state is varied by the load applied by the substrate 4. This may cause the upper end 20 a to be positioned above the setting surface 11 in the periphery of the setting surface 11 to which a light load is applied. If the upper end 20 a in such a proportional state comes above the setting surface 11, the spring type lift pin 20 holds itself with the upper end 20 a protruding above the setting surface 11 even when the substrate 4 is set on the setting surface 11.
On the contrary, the substrate 4 is adsorptively held on the setting surface 11 in the present embodiment. This ensures the substrate 4 to be brought into contact with the setting surface 11 even if the substrate 4 is lightweight. In addition, the spring force of the coil spring 23 can be set in accordance with a load applied to the pin upper section 22 in the state where the substrate 4 is adsorbed. This makes it possible to make the spring force stronger than a spring force set in accordance with only a load applied by the self weight of the substrate 4, thus allowing the coil spring 23 to be easily designed, and allowing the coil spring 23 to have a longer life span.
Further, the spring type lift pin 20 is arranged such that a cylindrical member 24 is provided between the piston section 21 and the pin upper section 22 so as to surround the coil spring 23. The lower end of the cylindrical member 24 is fixed to the piston section 21, and the upper end thereof is free. At the shaft of the pin upper section 22, a sword-guard-like stopper 25 is provided so as to come into contact with the cylindrical member 24.
The cylindrical member 24 and the stopper 25 are the ones that restrict the constriction of the coil spring 23. That is, the coil spring 23 constricts when the pin upper section 22 moves downward by being pressed, but the constriction is stopped when the stopper 25 comes into contact with the cylindrical member 24.
In such a manner, the constriction of the coil spring is restricted. This defines a minimum length measurement of the spring type lift pin 20, thus suppressing the deterioration of the coil spring 23 without a pressure more than necessary applied to the coil spring 23. At the step of detaching the substrate 4 from the electrode stage 2, the coil spring 23 is made function as a columnar member by the cylindrical member 24 and the stopper 25. This allows the coil spring 23 to function in the same manner as the fixed type lift pin 28, thus ensuring the substrate 4 to be stably detached.
In this case, the coil spring 23 needs to be constricted until the upper end 20 a of the spring type lift pin 20 comes down to the position that is at the same level as the setting surface 11. In view of this, a distance between the cylindrical member 24 and the stopper 25, i.e. a distance traveled by the stopper 25 until the stopper 25 comes into contact with the cylindrical member 24 needs to be set longer than the amount by which the upper end 20 a is protruded above the setting surface 11 at the storage position.
Meanwhile, the fixed type lift pin 28 is formed in the form of a column along the inner walls of the cylinder 26, and the diameter of the fixed type lift pin 28 on the rear surface side of the electrode stage 2 (underside in FIG. 4) is greater than the diameter on the setting surface 11 side (topside in FIG. 4). The fixed type lift pin 28 is designed in such a manner that, as illustrated in FIGS. 4 through 6, the upper end of the fixed type lift pin 28 is positioned below the setting surface 11 in a state where the fixed type lift pin 28 is moved downward to the storage position, and that, as illustrated in FIG. 7, the upper end 28 a is positioned at the same level of the upper end 20 a of the spring type lift pin 20 that lifts up the substrate 4 in a state where the fixed type lift pin 28 is at the protrusion position.
When the upper end of the fixed type lift pin 28 is positioned below the setting surface 11, a gap 49 occurs between the upper end 28 a of the fixed type lift pin 28 and the substrate 104. This causes a voltage drop. However, the voltage drop does not affect the quality of treatment on the substrate 4 since the fixed type lift pins 28 are disposed in the non-treatment region 18 b.
Next, the following will describe how to subject the substrate 4 to plasma treatment by means of the above plasma treatment apparatus S.
First of all, in a substrate adsorbing step, the substrate 4 is set on the electrode stage 2 in a state where the spring type lift pin 20 and the fixed type lift pin 28 in the lift pin mechanism 7 are moved to the respective storage positions, as illustrated in FIG. 4. In the state where the substrate 4 is set on the electrode stage 2, the upper end 20 a of the spring type lift pin 20 is protruded above the setting surface 11, as illustrated in FIG. 5. With this, the substrate 4 slightly floats away from the electrode stage 2 in an area corresponding to the center of the electrode stage 2.
Then, the vacuum pump 50 is driven so that the adsorption holes 6 a are depressurized, which makes the substrate 4 adsorptively held on the setting surface 11, as illustrated in FIG. 6. At this moment, the upper end 20 a of the spring type lift pin 20 is completely pressed down into the cylinder 26, which brings the substrate 4 into contact with the electrode stage 2. Further, the upper end 20 a is brought into contact with the substrate 4 by the spring force of the spring type lift pin 20.
Then, in a plasma generating step, the treatment gas is injected into the counter electrode 3 and evenly supplied from the gas injection holes 8 to the area between the counter electrode 3 and the electrode stage 2. In this state, a predetermined magnitude of voltage is applied from the power source section 10 to the counter electrode 3, so that plasma is generated in the area between the counter electrode 3 and the substrate 4 on the electrode stage 2 at near atmospheric pressure. With the generated plasma, the substrate 4 is subjected to plasma treatment such as etching. The exhaust gas in the chamber 1 is discharged via the discharge pipe 5.
Next, in the substrate detaching step, after the plasma treatment performed, application of a voltage by the power source section 10 and gas supply from the gas injection pipe 9 are stopped. Thereafter, the operation of the vacuum pump 50 is stopped, which moves the spring type lift pin 20 and the fixed type lift pin 28 in the lift pin mechanism 7 from the respective storage positions to the protrusion position. This causes the substrate 4 to be detached from the setting surface 11 for carrying.
Through the above steps, the substrate 4 is subjected to plasma treatment in the plasma treatment apparatus S.
Thus, according to the present embodiment, the setting surface 11 of the electrode stage 2 can be made at the same level as the upper end 20 a of the spring type lift pin 20 in the lift pin mechanism 7 during the plasma treatment, and the substrate 4 can be brought into contact with both the electrode stage 2 and the spring type lift pin 20. Therefore, plasma is generated without a gap between the substrate 4 and the electrode stage 2 or between the substrate 4 and the upper end 20 a of the spring type lift pin 20, in the vicinity of the spring type lift pin 20. As a result of this, it is possible to subject the whole area of the substrate 4 to even plasma treatment while suppressing a voltage drop caused by the gap. This makes it possible to reduce the occurrence of uneven plasma treatment and incomplete plasma treatment at near atmospheric pressure.
FIG. 8( a) is a cross-sectional view schematically illustrating an essential part of the plasma treatment apparatus S, and FIG. 8( b) illustrates an equivalent circuit diagram of FIG. 8( a). In FIG. 8( b), a circuit configuration in which the resistor 31 and the capacitor 32 are connected in series can be considered as a circuit configuration between the power source section 10 and a ground 12 in the vicinity of the spring type lift pin 20. The resistor 31 shows the occurrence of a voltage drop due to plasma 14 generated in between the counter electrode 3 and the substrate 4. The capacitor 32 is an electrical capacity in the substrate 4.
As is apparent from comparison between the equivalent circuit in FIG. 8( b) and the equivalent circuit of the conventional plasma treatment apparatus described previously in BACKGROUND ART and illustrated in FIG. 25, an electrical capacity of a gap caused by difference in level between the lift pin of the lift pin mechanism and the setting surface 11 does not exist in the arrangement in First Embodiment, which suppresses a voltage drop.
In the present embodiment, the fixed type lift pins 28 are disposed in the outer region of the electrode stage 2, and the upper end 28 a of the fixed type lift pin 28 at the storage position is positioned below the setting surface 11. However, as a matter of course, all of the lift pins, including the lift pins disposed in the outer region of the electrode stage 2, can be changed to the spring type lift pins 20.
However, this case may give rise to the problem illustrated in FIG. 9. That is, the spring type lift pin 20 disposed in the outer region of the setting surface 11 interferes with the contact between the substrate 4 and the electrode stage 2 because a load applied by the self weight of the substrate 4 is low, while the spring type lift pin 20 disposed in the center of the setting surface 11 comes down to a desired position because a load applied by the self weight of the substrate 4 is high. This problem may be improved to some extent by means of sucking force of the adsorption mechanism 6. However, if the spring force of the spring type lift pin 20 is strong, there is the possibility that the substrate 4 cannot contact with the electrode stage 2 even by means of sucking force. Therefore, as adopted in the present embodiment, the fixed type lift pins 28 are preferably used as the lift pins disposed in the outer region of the electrode stage 2. The outer region of the electrode stage 2 is normally non-treatment region 18 b, on which the region other than display region of the substrate 4, i.e. a non-pixel region of the substrate 4 is set. Therefore, the occurrence of uneven treatment in the vicinity of the lift pins is not serious problem.
In the present embodiment, as illustrated in FIG. 2, the fixed type lift pins 28 are provided in the insulating section 2 b of the non-treatment region 18 b. However, the fixed type lift pins 28 may be provided in the electrode section 2 a of the non-treatment region 18 b, as illustrated in FIG. 12. In short, the present embodiment only needs to has an arrangement in which the fixed type lift pins 16 are disposed in the non-treatment region 18 b, and all of the lift pins in the treatment region 18 a are the spring type lift pins 20.
Further, in the present embodiment, the fixed type lift pins 28 are disposed in the insulating section 2 b of the electrode stage 2, and the cylinders 26 are formed in the insulating section 2 b. However, in a case where it is difficult to form holes or the like as the cylinders 26 in the insulating section 2 b, a mechanism for detaching an insulating section 39, which is employed instead of the insulating section 2 b, from the electrode stage 2 may be provided separately as illustrated in FIGS. 13( a) through 13(e). In this case, the fixed type lift pins 28 are provided below the insulating section 39, and at the rise of the fixed type lift pin 28, the insulating section 39 above the fixed type lift pins 28 retracts, so that the substrate 4 is set on the fixed type lift pins 28. In this case, a cylinder 30 in which the fixed type lift pin 28 moves is formed separately.
Still further, as illustrated in FIG. 8( a), which is a cross-sectional view schematically illustrating the essential part, the present embodiment makes it possible to eliminate a gap between the substrate 4 and the electrode stage 2 and a gap between the substrate 4 and the spring type lift pin 20, which gaps occur due to difference in level between the upper end 20 a of the spring type lift pin 20 and the setting surface 11, in the vicinity of the spring type lift pin 20 disposed in the treatment region 18 a. However, a small gap 15 remains between the cylinder 26 formed in the electrode stage 2 and the spring type lift pin 20.
In a case where unevenness caused by such a small gap 15 is detected after the plasma treatment, it is more preferable that films 34 of different dielectric constants are formed respectively on the upper end 20 a of the spring type lift pin 20, as illustrated in FIG. 14, and on the surface of the electrode stage 2 in the vicinity of the spring type lift pin 20, as illustrated in FIG. 15. With this arrangement, it is possible to make invisible and less noticeable unevenness that would occur corresponding to the position where the spring type lift pin 20 is located. In FIGS. 14 and 15, Reference numeral 14 indicates plasma that is generated in between the counter electrode 3 and the substrate 4.
Yet further, in the present embodiment, the spring type lift pin 20 holds its position in the storage position, which is a state in which the spring type lift pin 20 is withdrawn underneath the setting surface 11, in such a manner that the upper end 20 a is protruded above the setting surface 11 in a state where the substrate 4 is not set on the setting surface 11.
However, the spring type lift pin 20 does not necessarily holds its position in the storage position in such a manner that the upper end 20 a is protruded above the setting surface 11. Alternatively, as illustrated in FIG. 16( a), the spring type lift pin 20 may hold its position in such a manner that the upper end 20 a is located below the setting surface 11. In this case, after the substrate 4 is set on the setting surface 11, the spring type lift pin 20 moves upwards to such a position that the substrate 4 does not float away from the setting surface, as illustrated in FIG. 16( b).
Also in such an arrangement, variations of stop positions of the lift pins are compensated for by means of the elasticity given to the spring type lift pins 20 in the direction where the pins move, so that the whole area of the substrate 4 can be subjected to even plasma treatment. This makes it possible to reduce the occurrence of uneven plasma treatment and the so-called incomplete treatment at near atmospheric pressure.
Note that in the arrangement illustrated in FIG. 2, eight spring type lift pins 20 are disposed in the center of the setting surface 11. However, the number of spring type lift pins 20 disposed and the spacing between the spring type lift pins 20 may be set in a manner which does not interfere with the detachment of the substrate 4. Ditto with the fixed type lift pins 28 disposed in the outer region of the electrode stage 2.
Further, in the present embodiment, the coil spring 23, which makes up part of the spring type lift pin 20, is taken as an example of the elasticity function imparting means. In short, the elasticity function imparting means only needs to impart to the lift pin the function having elasticity in a direction where the pin moves. For example, a lift pin having no elasticity in its movement direction, like the fixed type lift pin 28, may be supported by a coil spring, a blade spring, or a rubber material, which is provided separately from the lift pin, so that the lift pin is imparted the function having elasticity in the movement direction.

Second Embodiment

FIGS. 17 through 20 illustrate Second Embodiment of the present invention. In the following descriptions of embodiments, for convenience of explanation, members having the same functions as those described in First Embodiment are given the same reference numerals and explanations thereof are omitted here.
The apparatus in Second Embodiment is different from that in First Embodiment illustrated in FIG. 2 in that a plurality of adsorption holes 6 a, which makes up an adsorption mechanism 6 formed in the setting surface 11 of the electrode stage 2 in the plasma treatment apparatus S, are arranged as illustrated in FIG. 17.
That is, the arrangement in which the adsorption holes 6 a are arranged evenly beneath the setting surface 11 of the electrode stage 2, as illustrated in FIG. 19, may cause the problem as illustrated in FIG. 20, depending upon the magnitude of spring force exerted by the coil spring 23 of the spring type lift pin 20. That is, the substrate 4 cannot be attracted and adsorbed to the electrode stage 2 by means of sucking force exerted by the adsorption mechanism 6. FIG. 20 is a cross-sectional view taken along a line D-D′ of FIG. 19. Even in a case where the adsorption holes 6 a are arranged evenly, adsorption force can be increased by decreasing a pitch between the adsorption holes 6 a. This avoids the adsorption force from becoming weaker than the spring force of the coil spring 23 in the spring type lift pin 20, but inevitably causes a high production cost.
In order to solve the above problem, the apparatus in Second Embodiment is arranged as illustrated in FIG. 17. That is, in the center of the setting surface 11, the adsorption holes 6 a are more densely disposed in the area where the spring type lift pins 20 of the lift pin mechanism 7 are disposed than in the other area. A pitch between the adsorption holes 6 a is preferably in the range from 20 mm to 100 mm in the area where the spring type lift pins 20 are disposed. In an area other than the area where the spring type lift pins 20 are disposed, a pitch between the adsorption holes 6 a may be set in a manner which does not interfere with the adsorption force. In this case, a pitch between the adsorption holes 6 a is designed to be 100 mm in the high-density area and 200 mm in the other area.
With the electrode stage 2 arranged in this manner, it is possible to obtain the same effect as obtained in First Embodiment, and it is possible to reliably attract and adsorb the substrate 4 to the electrode stage 2, as illustrated in FIG. 18, even if spring force of the coil spring 23 in the spring type lift pin 20 is strong. That is, a pitch between the adsorption holes 6 a is changed according to the type of lift pins in the lift pin mechanism 7 beneath the setting surface 11. This brings a plasma treatment apparatus that can improve the occurrence of uneven treatment while suppressing an increase in production cost. FIG. 18 is a cross-sectional view taken along a line C-C′ of FIG. 17.
In First and Second Embodiments, the spring type lift pins 20 having elasticity in a direction of their movement are disposed so that no gap occurs between the substrate 4 and the electrode stage 2 and between the substrate 4 and the upper end of the lift pin in the vicinity of the lift pin. However, First and Second Embodiments are not limited to this. Alternatively, other arrangement may be adopted as long as it enables the substrate 4 in the vicinity of the lift pin to contact with both the electrode stage 2 and the lift pin.
Next, with reference to FIGS. 21 through 23, the following will describe the procedural steps for manufacturing a liquid crystal panel in which the surface of a substrate is subjected to plasma treatment so that a color filter is formed on the substrate, with the use of the plasma treatment apparatus described in First and Second Embodiments.
First of all, as illustrated in FIG. 21( a), black matrices 41 are formed on a substrate 40 so that concavities 42 are formed.
As the substrate 40, a glass substrate or a plastic substrate is preferably used. However, type of the substrate 40 is not particularly limited as long as it has essential properties of a color filter, such as transparency and mechanical strength. Generally, examples of a pattern of the black matrices 41 include, but are not particularly limited to, a matrix pattern illustrated in FIG. 22( a) and a stripe pattern illustrated in FIG. 22( b). In the following description, the matrix pattern illustrated in FIG. 22( a) is taken as an example.
The black matrices 41 form the concavity 42 for receiving ink, and function as a barrier (wall) for preventing inks of different colors in the adjacent concavities 42 from being mixed. A method for forming the black matrices 41 is not particularly limited, and the black matrices 41 may be formed by a known method. For example, it is possible to form the black matrices 41 by performing patterning with a black resin by photolithography or the like method. The thickness of the black matrix is preferably in the range from 0.5 μm to 3.0 μm, particularly preferably 1.0 μm to 2.0 μm.
Then, the substrate 40 on which the black matrices 41 are formed is set on the electrode stage 2 of the plasma treatment apparatus S of First and Second Embodiments so that the black matrices 41 are subjected to water repellent treatment (water repellency step).
The treatment gas is preferably a fluorine-containing gas such as CF4, C2F6, or SF6. However, the treatment gas is not limited to a fluorine-containing gas and may be a gas that gives the black matrices 41 water repellency that can prevent mixture of inks.
In a case where it is necessary to improve water repellency of the concavities 42, UV treatment or plasma treatment using Ar, He, or O2 as a treatment gas may be performed before the above water repellency step (hydrophilicity step).
Next, as illustrated in FIG. 21( b), ink 44 is delivered from a nozzle 43 of an inkjet device (ink delivery step).
The ink 44 is selectively delivered to only the concavities 42 provided between the black matrices 41 while the nozzle 43 goes over the black matrices 41. The delivered ink 44 is preferably thermosetting ink having pigment dispersed therein. The ink 44 can be delivered by a known method.
FIG. 23 is a plan view of a color filter in a state where the ink 44 is delivered, when viewed from above the substrate 40. In FIG. 23, the inks 44, 45, 46 are inks in which red, blue, green pigments are dispersed, respectively. Since FIG. 21 is a cross-sectional view, only the ink 44, i.e. ink of red color is shown in FIG. 21.
Thereafter, the ink 44 is dried so as to form a color layer 48. For example, the color layer 48 can be formed by evaporating a solvent in the ink 44 and then burning the ink 44 for thermal polymerization of the ink 44. A method for evaporating a solvent of ink and a burning method may be selected appropriately from known methods according to the states of the ink 44 and the substrate 40.
Through the improvement of the problem of unevenness occurring in the vicinity of a lift pin in the plasma treatment apparatus, a color filter manufactured by the above manufacturing method has an excellent display quality without unevenness. A liquid crystal display device having the thus manufactured color filter provides high-performance, high-quality display and offers a comfortable viewing environment to the user.
Now, taking an example, the following will more specifically describe the procedural steps for manufacturing a liquid crystal panel in which the surface of a substrate is subjected to plasma treatment so that a color filter is formed on the substrate, with the use of the plasma treatment apparatus described in First and Second Embodiments. The present example will be also described with reference to FIG. 21.
First of all, as illustrated in FIG. 21( a), the black matrices 41 were formed on the substrate 40 so that the concavities 42 were formed. In the present example, the substrate 40 was a 0.7 mm-thick glass substrate. The black matrices 41 were formed with a resin black and formed 1.5 μm thick by spin coating and photo process.
Next, the substrate 40 on which the black matrices were formed was subjected to UV treatment for hydrophilic treatment of the concavities. Then, in the present example, plasma treatment was performed with a fluorine-containing gas by means of the plasma treatment apparatus S of First and Second Embodiments, so that water-repellent treatment was performed on the black matrices 41. In the present example, a contact angle of the hydrophilic concavity 42 with respect to pure water was approximately 10°, and a contact angle of the black matrix 41 with respect to pure water was approximately 90° to 100°.
Next, the ink 44 was delivered from the nozzle 43 as illustrated in FIG. 21( b). As illustrated in FIG. 23, the ink is selectively delivered to only the concavities 42 provided between the black matrices 41 while the nozzle goes over the black matrices 41. In the present example, ink delivery was performed at 25° C. by means of an inkjet device, and inks of three colors R, G, B were delivered at the same time by 5 pl per drop. The ink 44 (ditto for ink 45 and ink 46) after delivered was convex in the concavity 42, as illustrated in FIG. 21( c).
Next, a solvent was evaporated at 100° C. for 10 minutes by means of a hot plate. Then, the ink 44 was burned in an oven at 220° C. for 30 minutes for thermal polymerization of the ink 44. As a result, the colored layer 48 was formed as illustrated in FIG. 21( d).
As described above, a stage device of the present invention includes: a stage having a setting surface on which a substrate to be treated is set; and a lift pin mechanism having first pins, provided in the stage, each capable of emerging from the setting surface, the first pins being protruded so that the substrate is detached from the setting surface, wherein the lift pin mechanism includes contact adjusting means that brings an upper end of the first pin being withdrawn in the stage into contact with the substrate on the setting surface without lifting the substrate above the setting surface.
A plasma treatment apparatus of the present invention is a plasma treatment apparatus which generates plasma in between an electrode stage and a counter electrode at near atmospheric pressure so as to subject a substrate to be treated being set on the electrode stage to plasma treatment, the plasma treatment apparatus including the above stage device as the electrode stage.
According to the arrangement of the stage device of the present invention, the contact adjusting means included in the lift pin mechanism brings the upper end of the first pin being withdrawn in the stage into contact with the substrate set on the setting surface without lifting the substrate above the setting surface (corresponding to adsorption surface). This makes it possible to make the upper end of the first pin positioned at the same level as the setting surface through the use of the substrate.
That is, through the use of the substrate, the stage device is realized in which there is no difference in level between the upper end of the first pin and the setting surface in a state where the substrate is set on the setting surface.
In the plasma treatment apparatus of the present invention, such a stage device of the present invention is used as the electrode stage. This allows the substrate to come into contact with both the setting surface and the first pin even in the vicinity of the first pin.
This arrangement is free from a gap caused by difference in level between the above-described lift pin (first pin) and the setting surface, i.e. a gap between the substrate and lift pin (first pin) or a gap between the substrate and the setting surface, where no plasma is generated and a great voltage drop occurs. This makes it possible to reduce the occurrence of uneven treatment and incomplete treatment on the substrate.
In the stage device of the present invention and the plasma treatment apparatus of the present invention, the contact adjusting means includes elasticity function imparting means that imparts to the first pin a function having elasticity in a direction where the first pin moves, and the upper end of the first pin is brought into contact with the substrate by the elasticity imparted by the elasticity function imparting means.
With this arrangement, the contact adjusting means is realized by elasticity function imparting means that imparts to the first pin the function having elasticity in a direction where the first pin moves, and the upper end of the first pin is brought into contact with the substrate by the elasticity imparted by the elasticity function imparting means. That is, even in the event when the first pin cannot be stopped at such a position that the upper end of the first pin is at the same level as the setting surface due to the limitation of the lift pin mechanism in terms of mechanical precision, the event can be compensated for by a simple arrangement using elasticity. This makes it possible to make the upper end of the first pin bring into contact with the substrate without floating the substrate above the setting surface.
The elasticity function imparting means is realized by, for example, an elastic body being provided to the first pin and having elasticity in the direction where the first pin moves.
The stage device and the plasma treatment apparatus of the present invention can be arranged such that when each of the first pins is at a storage position where the first pin is withdrawn in the stage, the upper end of the first pin is protruded above the setting surface in a state where the substrate is not set on the setting surface, and the upper end of the first pin is positioned at the same level as the setting surface by a load applied by the substrate in a state where the substrate is set on the setting surface.
The stage device and the plasma treatment apparatus of the present invention can be also arranged such that when each of the first pins is at a storage position where the first pin is withdrawn in the stage, the upper end of the first pin is positioned below the setting surface in a state where the substrate is not set on the setting surface, and after the substrate is set on the setting surface, the first pin moves upward so that the upper end thereof comes into contact with the substrate.
Further, the stage device and the plasma treatment apparatus of the present invention is preferably arranged such that the stage is provided with an adsorption mechanism that adsorptively holds the substrate on the setting surface.
Provision of the adsorption mechanism allows the substrate to be adsorptively held on the setting surface. This makes it possible to securely fix the substrate as compared with the arrangement in which the substrate is just set on the setting surface. In addition, a load exerted on the first pin becomes stronger than a load caused only by the self weight of the substrate. This makes it easy to impart elasticity in the direction where the first pin moves and make the upper end of the first pin brought into contact with the substrate without lifting the substrate above the setting surface.
That is, in order to make the upper end of the first pin brought into contact with the substrate without floating the substrate above the setting surface by means of the elasticity of the first pin, the upper end of the first pin needs to be positioned below the setting surface in a state where a load received from the substrate being set is proportional to a force with which the first pin deformed by the load is returned to its original state.
With this arrangement, it is possible to easily make such a design that the upper end of the first pin is positioned below the setting surface in a state where a load received from the substrate is proportional to the force with which the first pin is returned to its original state.
In this case, it is preferable that the adsorption mechanism has a stronger adsorption force in the vicinity of the first pin to which the function having elasticity is imparted than an adsorption force in other area. This makes it possible to more effectively obtain the above action caused by using adsorption force.
Further, the stage device and the plasma treatment apparatus of the present invention can be arranged such that the lift pin mechanism has second pins, provided in the outer region of the stage, each capable of emerging from the setting surface and having no elasticity in a direction where the second pin moves, and an upper end of the second pin is positioned below the setting surface in a state where the second pin is withdrawn in the stage.
As described previously, in order to make the upper end of the first pin brought into contact with the substrate without floating the substrate above the setting surface by means of the elasticity of the first pin, the upper end of the first pin needs to be positioned below the setting surface in a state where a load received from the substrate is proportional to a restoring force. However, since a load received from the substrate is low in the outer region of the stage, the upper end of the first pin may be positioned above the setting surface in a state where both of the forces are proportional to each other. As a result, the substrate may float in an area corresponding to the outer region of the stage.
On the contrary, in the above arrangement, the second pins each of which is capable of emerging from the setting surface and has no elasticity in the direction where the second pin moves are disposed in the outer region of the stage, and the upper end of the second pin is positioned below the setting surface in a state where the second pin is withdrawn in the stage. This prevents the substrate from being floated in an area corresponding to the outer region of the stage.
A display panel substrate of the present invention is a display panel substrate for use in manufacturing a display panel, and the display panel substrate is subjected to surface treatment by means of the above plasma treatment apparatus of the present invention capable of effectively reducing the occurrence of uneven treatment. By manufacturing a display panel including such a display panel substrate, it is possible to provide a display device having an excellent display quality without display irregularity.

INDUSTRIAL APPLICABILITY

The present invention can be applied to the manufacture of a display panel substrate and the like, for example.

Claims

1. A stage device comprising:

a stage having a setting surface on which a substrate to be treated is set; and

a lift pin mechanism having first pins, provided in the stage, each capable of emerging from the setting surface, the first pins being protruded so that the substrate is detached from the setting surface,

wherein the lift pin mechanism includes contact adjusting means that brings an upper end of the first pin being withdrawn in the stage into contact with the substrate on the setting surface without lifting the substrate above the setting surface.

2. The stage device according to claim 1, wherein

the contact adjusting means comprises elasticity function imparting means that imparts to the first pin a function having elasticity in a direction where the first pin moves, and the upper end of the first pin is brought into contact with the substrate by the elasticity imparted by the elasticity function imparting means.

3. The stage device according to claim 2, wherein

the elasticity function imparting means is an elastic body being provided to the first pin and having elasticity in the direction where the first pin moves.

4. The stage device according to claim 2, wherein

when each of the first pins is at a storage position where the first pin is withdrawn in the stage, the upper end of the first pin is protruded above the setting surface in a state where the substrate is not set on the setting surface, and the upper end of the first pin is positioned at the same level as the setting surface by a load applied by the substrate in a state where the substrate is set on the setting surface.

5. The stage device according to claim 2, wherein

when each of the first pins is at a storage position where the first pin is withdrawn in the stage, the upper end of the first pin is positioned below the setting surface in a state where the substrate is not set on the setting surface, and after the substrate is set on the setting surface, the first pin moves upward so that the upper end thereof comes into contact with the substrate.

6. The stage device according to claim 1, wherein

the stage is provided with an adsorption mechanism that adsorptively holds the substrate on the setting surface.

7. The stage device according to claim 6, wherein

the adsorption mechanism has a stronger adsorption force in the vicinity of the first pin to which the function having elasticity is imparted than an adsorption force in other area.

8. The stage device according to claim 2, wherein

the lift pin mechanism has second pins, provided in an outer region of the stage, each capable of emerging from the setting surface and having no elasticity in a direction where the second pin moves, and an upper end of the second pin is positioned below the setting surface in a state where the second pin is withdrawn in the stage.

9. A plasma treatment apparatus which generates plasma in between an electrode stage and a counter electrode at near atmospheric pressure so as to subject a substrate to be treated set on the electrode stage to plasma treatment, the plasma treatment apparatus including a stage device according to claim 1 as the electrode stage.

10. A display panel substrate for use in manufacturing a display panel,

the display panel substrate being subjected to surface treatment by means of a plasma treatment apparatus according to claim 9.