JP4038816B2 - Surface treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface treatment apparatus and a surface treatment method for treating the surface of an object to be treated (also referred to as a workpiece) by performing plasma discharge under atmospheric pressure or a pressure near atmospheric pressure.
[0002]
[Prior art]
There has been proposed an apparatus for performing a surface treatment on an object to be processed using plasma discharge under atmospheric pressure or a pressure near atmospheric pressure. The advantage of surface treatment by plasma discharge under atmospheric pressure or near atmospheric pressure is that it does not require equipment for formation and control in a low-pressure atmosphere compared to plasma discharge under vacuum, and can be used for large-area treatment. It is easy to realize and reduce manufacturing costs.
Such a surface treatment apparatus using plasma generates a plasma discharge generation part (also referred to as a discharge region) generated under a pressure near atmospheric pressure between a pair of electrodes. A gas is introduced from one electrode through the vent hole. This gas enters the plasma discharge generating part through the porous body after passing through the vent hole. By doing in this way, a uniform surface treatment can be given to a processed object (for example, refer to patent documents 1).
[0003]
[Patent Document 1]
JP-A-6-2149 (first page, FIG. 1)
[0004]
[Problems to be solved by the invention]
However, such a conventional plasma surface treatment apparatus has the following problems.
A conventional plasma surface treatment apparatus used under atmospheric pressure forms one discharge generating portion between a pair of electrodes. And this one discharge generation part activates the reactive gas (also called process gas) required for one kind of process, and performs a desired surface treatment with respect to a to-be-processed object.
With such a structure, when it is necessary to perform processing using another type of reaction gas, it is necessary to switch the gas type from one type of reaction gas already used to another type of reaction gas.
[0005]
When a plurality of types of surface treatments are continuously performed on the object to be processed by switching the gas types in this way, it takes time to switch the gas types as described above, and the surface treatment work time is considerable. It takes a long time.
Moreover, since the conventional plasma processing apparatus has only one discharge generation part, it cannot expose to the discharge generation part in multiple times with respect to the surface of one to-be-processed object.
[0006]
Therefore, the present invention solves the above-described problems, and can form a plurality of discharge generation portions between a pair of application-side electrode portions and ground-side electrode portions, thereby allowing multiple surface treatments to be performed on one object. It is another object of the present invention to provide a surface treatment apparatus and a surface treatment method capable of performing a plurality of types of surface treatment on a single object by using a plurality of types of gas.
[0007]
[Means for Solving the Problems]
The surface treatment apparatus of the present invention treats the surface of an object to be processed by performing plasma discharge under an atmospheric pressure or a pressure in the vicinity of atmospheric pressure between an application-side electrode portion and a ground-side electrode portion that are arranged to face each other. The application-side electrode portion has an electrode having a plurality of protrusions protruding toward the ground-side electrode portion side, and is provided on the electrode so as to face the ground-side electrode portion, Supply a plurality of kinds of gases between the dielectric having a boundary part protruding partly in the direction of the earth side electrode part and the dielectric of the application side electrode part and the earth side electrode part. A plurality of gas supply units, wherein the ground side electrode unit is movable in parallel to the application side electrode unit with the object to be processed placed thereon, and the ground side electrode unit and the dielectric Position corresponding to each protrusion of the electrode between the body And each form a discharge generating portion of the plasma discharge in the boundary portion of the dielectric is disposed between each of said discharge generating portion, the plurality of the gas supply unit disposed across the boundary It is characterized by being.
[0008]
According to such a configuration, the discharge generation part of the plasma discharge can be formed at a position corresponding to each protrusion of the electrode between the ground side electrode part and the dielectric. Therefore, by moving the object to be processed together with the ground side electrode part with respect to the object to be processed placed on the earth side electrode part, the surface of one object to be processed can be exposed to the discharge generating part a plurality of times. From this, the surface of the object to be treated is more activated and the amount of gas activated is increased, so that the reaction is promoted and the treatment rate is increased.
[0010]
In the above configuration, it is desirable that the application-side electrode unit includes a plurality of the gas supply units.
According to such a configuration, since the application-side electrode unit has a plurality of gas supply units, it is possible to supply different types of gas from each gas supply unit. Therefore, a plurality of types of surface treatment can be performed on the surface of one object to be processed continuously or simultaneously using a plurality of types of gases.
[0011]
In the above configuration, it is desirable that the gas supply unit supplies a plurality of types of gases.
According to such a configuration, the gas supply unit can supply a plurality of types of gases.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.
First Embodiment Fig. 1 shows a first preferred embodiment of the surface treatment apparatus of the present invention.
The surface treatment apparatus 10 is also called an atmospheric pressure plasma surface treatment apparatus.
The surface treatment apparatus 10 is an apparatus that can perform surface treatment on a surface of an object to be processed continuously or simultaneously using a plurality of discharge generators by plasma discharge under atmospheric pressure or a pressure near atmospheric pressure. The surface treatment apparatus 10 is an apparatus that continuously performs surface treatment of an object to be processed with one kind of gas.
[0018]
The surface treatment used in the embodiment of the present invention includes surface modification such as ashing, etching, hydrophilic treatment and water repellent treatment, cleaning, film formation and the like. The ashing process is a process for removing organic substances on the surface of an object to be processed such as a glass substrate. The etching process is a process for removing a film formed on the surface of an object to be processed such as a glass substrate. A hydrophilic process is a process which forms a hydrophilic film | membrane on the surface of to-be-processed objects, such as a glass substrate, for example. The water repellent treatment is a treatment for forming a water repellent film on the surface of a target object such as a glass substrate.
The kind of plasma generated in the surface treatment apparatus 10 is glow discharge plasma generated under atmospheric pressure or a pressure near atmospheric pressure. This glow discharge plasma is generated with the occurrence of glow discharge in the plasma generating gas.
[0019]
The surface treatment apparatus 10 illustrated in FIG. 1 includes an application side electrode unit 20, a ground side electrode unit 30, a gas storage unit 21, an AC power source (also referred to as RF power source) 23, and a movement operation unit 25.
The application-side electrode unit 20 and the ground-side electrode unit 30 form a so-called parallel plate type plasma discharge device. The application side electrode unit 20 can also be referred to as a first electrode unit, and the ground side electrode unit 30 can also be referred to as a second electrode unit. The application side electrode unit 20 and the ground side electrode unit 30 are arranged in parallel with a gap therebetween.
As described above, the surface treatment apparatus 10 has a pair of the application-side electrode unit 20 and the ground-side electrode unit 30 and constitutes a so-called one direct discharge type discharge means.
[0020]
First, the structure of the application side electrode unit 20 shown in FIG. 1 will be described.
The application-side electrode unit 20 shown in FIG. 1 has a flat electrode 40 and a flat dielectric 41.
The electrode 40 is electrically connected to the AC power source 23. The AC power supply 23 is grounded. The electrode 40 is supplied with high frequency power from the AC power source 23. The electrode 40 is made of a highly conductive material that can be an electrode, such as aluminum, copper, stainless steel (SUS), titanium, tungsten, or the like.
[0021]
The following points are particularly characteristic in the shape of the electrode 40 of the application-side electrode portion 20.
One surface 43 of the electrode 40 is electrically connected to the AC power source 23. This one surface 43 is a flat surface. On the other hand, a plurality of protrusions 45 (three in the illustrated example) are formed on the other surface 44 side at regular intervals. As shown in the cross section in FIG. 1, each of the rectangular protrusions 45 is formed so as to protrude toward the ground-side electrode portion 30 side. The tip surface 45A of the protrusion 45 is flat in the first embodiment of FIG. The front end face 45 </ b> A faces the ground side electrode part 30 and is parallel to the ground side electrode part 30.
Each of these protrusions 45 is a portion for forming discharge generation portions 50, 51, 52 of plasma discharge between the ground-side electrode portion 30 and the dielectric 41. The discharge generators 50, 51, 52 are also called discharge areas or discharge generation areas.
[0022]
The dielectric 41 is fixed to the other surface 44 side of the electrode 40. Each protrusion 45 is fitted and fixed in the recess 41 </ b> A of the dielectric 41.
The dielectric 41 is made of, for example, ceramics such as alumina or silicon nitride, quartz, or the like. The dielectric 41 determines the generation area of the discharge generating portion so that unnecessary discharge does not occur in other portions.
The inner surface 41 </ b> B of the dielectric body 41 faces in parallel with the ground-side electrode unit 30. The inner surface 41 </ b> B is a surface parallel to the ground side electrode portion 30. Discharge generators 50, 51, 52 can be generated at positions corresponding to the protrusions 45 between the ground-side electrode part 30 and the inner surface 41 B of the dielectric 41.
[0023]
The application-side electrode unit 20 has a plurality of, for example, two gas supply units 60 and 61. The gas supply units 60 and 61 are holes that communicate with the electrode 40 and the dielectric 41. The gas supply units 60 and 61 are connected to the gas storage unit 21.
As a result, the mixed gas of the carrier gas and the reaction gas stored in the gas storage unit 21 passes through the gas supply units 60 and 61 and between the discharge generation units 50 and 51 and the discharge generation units 51 and 52. Can be supplied to each region. That is, the mixed gas can be supplied between the inner surface 41 </ b> B of the dielectric body 41 and the surface 71 of the object 70 mounted on the ground-side electrode unit 30 through the gas supply units 60 and 61. As a kind of the mixed gas, for example, when a hydrophilic treatment is performed on the surface 71 of the workpiece 70, He is used as a carrier gas and O ₂ is used as a reactive gas. The mixed gas of He and O ₂ can be supplied between the inner surface 41B of the dielectric 41 and the object 70 through the gas supply units 60 and 61.
[0024]
Next, the earth side electrode part 30 will be described.
As described above, the ground-side electrode unit 30 is an electrode unit that is arranged in parallel to face the application-side electrode unit 20. The earth side electrode unit 30 is grounded. The earth side electrode part 30 is a flat plate-like member and is also called an earth table.
The ground side electrode part 30 is movable in the transport direction T along the guide rail 80. In order to move the ground side electrode part 30, the moving operation part 25 is connected to the ground side electrode part 30. The movement operation unit 25 can use various actuators such as a fluid pressure cylinder and an electric motor.
The ground side electrode part 30 can be made of the same material as that of the electrode 40, for example.
A workpiece 70 is mounted on the mounting surface 30 </ b> E of the earth-side electrode unit 30. The object 70 is, for example, a silicon substrate or a glass substrate used for a liquid crystal display (LCD).
[0025]
Next, an example of a surface treatment method for performing a surface treatment on the surface 71 of the workpiece 70 using the surface treatment apparatus 10 shown in FIG. 1 will be described with reference to FIG.
2, in order to face the plurality of protrusions 45 of the electrode 40 of the application side electrode unit 20 shown in FIG. 1 via the dielectric 41, the target object 70 is connected to the ground side electrode unit 30. Is mounted on the mounting surface 30E.
The workpiece 70 is mounted on the ground-side electrode unit 30 so that the ground-side electrode unit 30 can be moved, for example, in the transport direction T by the operation of the moving operation unit 25. Thereby, the electrode 40, the dielectric 41, and the to-be-processed object 70 face.
In this state, the inter-electrode distance L refers to the distance between the front end surface 45A of each protrusion 45 and the mounting surface 30E of the ground-side electrode portion 30. In the first embodiment, for example, the protrusion height of each protrusion 45 is the same. However, the protrusion height of each protrusion 45 may be different. The case where the protruding heights are different is, for example, when different gases are used.
[0026]
Next, the process proceeds to the discharge generation step ST2 shown in FIG. In step ST2, when the AC power supply 23 supplies high-frequency AC power to the electrode 40, plasma discharge discharge generators 50, 51, and so on at positions corresponding to the protrusions 45 between the ground-side electrode unit 30 and the dielectric 41. 52 are formed respectively.
In this state, the gas in the gas storage unit 21 is supplied to the discharge generation units 50, 51, 52 through the gas supply units 60, 61. As a result, atmospheric pressure plasma is generated in the discharge generator 50 to generate excited active species of the reaction gas. The excited active species can perform, for example, a hydrophilic treatment on the surface of the object to be processed 70.
[0027]
In this case, the workpiece 70 can be reciprocated along the conveyance direction T along the guide rail 80 together with the ground-side electrode unit 30 by operating the movement operation unit 25. For this reason, the surface 71 of the workpiece 70 is exposed multiple times by the plurality of discharge generators 50, 51, 52.
As a result, activation of the surface of the object to be processed 70 is promoted and the amount of gas activated is increased, and as a result, the reaction is promoted. Thus, the processing rate in the surface treatment can be increased.
In addition, since the plurality of discharge generating units 50, 51, 52 are generated, the exposure process is repeatedly performed on the surface 71 of the object to be processed 70. Is stable and the treatment distribution becomes uniform. Thus, the quality of the treated surface of the surface 71 of the workpiece 70 can be improved.
[0028]
Furthermore, since the discharge generating parts 50, 51, 52 are generated as described above, the amount of molecules to be activated is increased because the reaction gas is exposed to the discharge many times. Reaction with the surface proceeds. Therefore, since the supply amount of the reaction gas can be reduced, the efficiency when using the gas can be improved.
As described above, since the discharge generators 50, 51, and 52, which are a plurality of discharge generation sites, can be generated between the pair of application-side electrode units 20 and the ground-side electrode unit 30, the above-described merit occurs. .
[0029]
The gas supply unit 21 in FIG. 1 not only sends the mixed gas to the gas supply units 60 and 61 but can also send only the carrier gas (for example, He) if necessary for processing.
In step ST3 for removing the object to be processed in FIG. 2, after the object 70 to be processed has been removed from the mounting surface 30E, a new object 70 is mounted on the mounting surface 30E.
[0030]
Second embodiment Fig. 3 shows a second embodiment of the surface treatment apparatus of the present invention.
The surface treatment apparatus 100 shown in FIG. 3 has the same structure in most parts as compared with the surface treatment apparatus 10 shown in FIG. Therefore, in the case where the part of the surface treatment apparatus 100 shown in FIG. 3 is the same as the corresponding part of the surface treatment apparatus 10 shown in FIG.
[0031]
The surface treatment apparatus 100 shown in FIG. 3 is different from the surface treatment apparatus 10 shown in FIG. 1 in that one gas supply unit 160 is provided. The gas supply unit 160 is connected to the gas storage unit 21. The gas supply unit 160 is a hole formed through the electrode 40 and the dielectric 41. The gas supplied from the gas supply unit 160 is, for example, a mixed gas of O ₂ as a reaction gas and He as a carrier gas. This mixed gas is supplied between the dielectric 41 and the surface 71 of the object 70.
Of course, one gas supply unit 160 may be provided in the application-side electrode unit 20 instead of a plurality of gas supply units.
[0032]
Third embodiment Fig. 4 shows a third embodiment of the surface treatment apparatus of the present invention.
The parts of the surface treatment apparatus 200 shown in FIG. 4 are the same as the parts of the surface treatment apparatus 10 of FIG.
As the ground side electrode section 30, the moving operation section 25, the AC power source 23, and the object to be processed 70 in FIG. 4, the same one as shown in FIG. 1 can be adopted.
[0033]
The surface treatment apparatus 200 shown in FIG. 4 has an application side electrode part 220 and a ground side electrode part 30. The application side electrode unit 220 is also called a first electrode, and the ground side electrode unit 30 is also called a second electrode. The application side electrode unit 220 and the ground side electrode unit 30 face each other and have a pair of parallel plate type electrode structures for plasma discharge.
The surface treatment apparatus 200 is an apparatus that performs surface treatment of an object to be processed continuously or simultaneously using a plurality of types of gases.
[0034]
The application side electrode unit 220 illustrated in FIG. 4 includes an electrode 240 and a dielectric 241. The electrode 240 can be made of the same material as the electrode 40 shown in FIG. The electrode 240 has a plurality of, for example, two protrusions 245. The tip end surface 245A of the protrusion 245 faces in parallel to the ground electrode portion 30 side.
The electrode 240 is integrated by combining with the dielectric 241. The dielectric 241 is made of ceramics, quartz, or the like, similar to the dielectric 41 of the embodiment of FIG.
[0035]
The dielectric 241 has a recess 241A. The protrusions 245 of the electrode 240 are fitted in these recesses 241A. Characteristically, the inner surfaces 241B and 241C of the dielectric 241 are separated by a central boundary portion 255. The inner surfaces 241B and 241C thus divided by the boundary portion 255 are surfaces corresponding to the protrusions 245 and 245 of the electrode 240, respectively.
The front end surface 255 </ b> A of the boundary portion 255 protrudes toward the ground-side electrode unit 30 and faces the object 70 with a slight gap left.
[0036]
The application-side electrode unit 220 has two gas supply units 260 and 261. The gas supply unit 260 is connected to the first gas storage unit 300. The gas supply unit 261 is connected to the second gas storage unit 301.
The first gas storage unit 300 stores, for example, a mixed gas of He as a carrier gas and CF ₄ (carbon tetrafluoride) as a reaction gas. The second gas storage unit 301 stores, for example, a mixed gas of He as a carrier gas and O ₂ as a reaction gas.
The gas supply unit 260 supplies the gas in the first gas storage unit 300 to the discharge generation unit 250 side. The gas supply unit 261 supplies the mixed gas stored in the second gas storage unit 301 to the other discharge generation unit 251 side.
[0037]
Next, an example of a method in which the surface treatment apparatus 200 illustrated in FIG. 4 performs a surface treatment on the surface 71 of the workpiece 70 will be described.
A workpiece 70 is mounted on the ground electrode 30. When the movement operation unit 25 is operated, the ground-side electrode unit 30 and the object 70 are moved in the transport direction T along the guide rail 80. Thereby, the application side electrode part 220 and the to-be-processed object 70 face.
Discharge generators 250 and 251 are generated between the application-side electrode unit 220 and the ground-side electrode unit 30. Then, the mixed gas on the first gas storage unit 300 side is supplied from the gas supply unit 260 to the discharge generation unit 250. Similarly, the gas supply unit 261 supplies the mixed gas from the second gas storage unit 301 to the discharge generation unit 251.
[0038]
As a result, different types of process gases can be flowed to the surface 71 of the object 70 to be processed in the plurality of discharge generating portions 250 and 251. Thereby, for example, hydrophilic treatment and water repellency treatment can be performed on the surface 71 of the object 70. In this case, since the dielectric 241 has the boundary portion 255, the boundary portion 255 can prevent the gas on the discharge generation unit 250 side from being mixed with the gas on the discharge generation unit 251 side. .
The object 70 can continuously perform different types of treatment by reacting with the activated reaction gas in each of the discharge generation units 250 and 251 by the reciprocation of the ground side electrode unit 30 in the transport direction T. it can.
[0039]
Thus, there are the following merits by adopting the structure of the surface treatment apparatus 200 shown in FIG.
When a process is performed using a plurality of different process gases, the pair of application-side electrode unit 220 and ground-side electrode unit 30 can perform the process. Therefore, unlike the conventional case, the number of surface treatment devices is only one, and a plurality of treatments can be performed by using one surface treatment device, so that the number of devices can be reduced.
[0040]
Moreover, since the number of devices can be reduced, the ground area occupied by the devices can be reduced, and the device cost can be reduced.
Moreover, the conveyance part for conveying a to-be-processed object between several different apparatuses conventionally required becomes unnecessary.
Since the surface treatment apparatus 200 of FIG. 4 can perform a plurality of process treatments simultaneously or continuously on the surface 71 of the workpiece 70, the treatment rate can be improved and the influence of the change over time of the treatment can be reduced. Can do.
[0041]
The surface treatment apparatus of the present invention is a parallel plate type plasma treatment apparatus as described above. The surface treatment apparatus of the present invention uses plasma discharge under atmospheric pressure or a pressure near atmospheric pressure, and can perform a plurality of surface treatments such as surface modification and etching continuously or simultaneously. The surface treatment includes ashing, etching, surface modification such as hydrophilic treatment and water repellent treatment, cleaning, and film formation.
[0042]
As the gas, for example, He, He + O ₂ , and He + CF ₄ are used, and a plurality of discharge generating portions can be generated by a pair of application side electrode portions and ground side electrode portions. A plurality of types of surface treatments can be performed simultaneously or continuously by activating a process reaction gas (also referred to as a reactive gas) by such a plurality of discharge generating portions.
[0043]
In the embodiment of the present invention, for example, He is used as the carrier gas. For example, a mixed gas of He + CF ₄ can be used for the water repellent treatment, and a mixed gas of He + O ₂ can be used for the hydrophilic treatment.
In the embodiment of the present invention, various types of objects to be processed can be adopted depending on the processing purpose. The object to be processed is, for example, an electronic component such as a packaged IC, a silicon substrate, a glass substrate used for a liquid crystal display (LCD), or a plastic plate.
The present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the claims.
A part of each configuration of the above embodiment can be omitted, or can be arbitrarily combined so as to be different from the above.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment of a surface treatment apparatus of the present invention.
FIG. 2 is a diagram showing an example of a surface treatment method of the present invention.
FIG. 3 is a diagram showing a second embodiment of the surface treatment apparatus of the present invention.
FIG. 4 is a view showing a third embodiment of the surface treatment apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Surface treatment apparatus, 20 ... Application side electrode part, 21 ... Reaction gas storage part, 23 ... AC power supply, 30 ... Ground side electrode part, 40 ... Application side electrode part , 41... Application side electrode part dielectric, 45... Electrode projection, 50, 51, 52... Discharge generation part (also called discharge region), 60, 61. 70 ... object to be processed, 71 ... surface of object to be processed

Claims (1)

A surface treatment apparatus for treating the surface of an object to be processed by plasma discharge under atmospheric pressure or a pressure in the vicinity of atmospheric pressure between an application-side electrode portion and a ground-side electrode portion arranged to face each other,
The application side electrode part is
An electrode having a plurality of protrusions protruding toward the ground side electrode portion side;
A dielectric provided on the electrode and facing the ground side electrode portion, and a part of the facing side has a boundary portion protruding in the direction of the ground side electrode portion;
A plurality of gas supply units for supplying a plurality of types of gas between the dielectric of the application side electrode unit and the ground side electrode unit;
The ground-side electrode part is movable in parallel to the application-side electrode part in a state where the object to be processed is placed, and each protrusion of the electrode between the ground-side electrode part and the dielectric The discharge generation part of the plasma discharge is respectively formed at a position corresponding to
The surface treatment apparatus according to claim 1, wherein the boundary portion of the dielectric is disposed between the discharge generation units, and the plurality of gas supply units are disposed with the boundary portion interposed therebetween.

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