JP2010024484A - Surface treatment apparatus and surface treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface treatment apparatus which prevents treatment nonuniformity and can stably form an adequate film, and to provide a surface treatment method. <P>SOLUTION: The surface treatment apparatus 1 comprises: a film-forming chamber 3 for arranging a substrate to be treated W therein; a pump 5 for decompressing the inside of the film-forming chamber 3; a treatment agent vaporization device 21 for vaporizing a silane coupling agent Y1 therein; a gas supply device 22 for supplying a carrier gas to the treatment agent vaporization device 21; and a first circulating system 40 for circulating the gas in the film-forming chamber 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a surface treatment apparatus and a surface treatment method.

  2. Description of the Related Art A liquid crystal device used as a light modulation unit of a projection display device such as a liquid crystal projector has a configuration in which a sealing material is disposed at a peripheral portion between a pair of substrates and a liquid crystal layer is sealed at the center. Electrodes for applying a voltage to the liquid crystal layer are formed on the inner surfaces of the pair of substrates, and an alignment film for controlling the alignment of the liquid crystal molecules when a non-selective voltage is applied is formed on the inner surfaces of these electrodes. With such a configuration, the liquid crystal device modulates light source light based on a change in the orientation of liquid crystal molecules when a non-selection voltage is applied and when a selection voltage is applied, thereby forming a display image.

  By the way, as the alignment film described above, a film obtained by rubbing the surface of a polymer film made of polyimide or the like to which a side chain alkyl group is added is generally used. However, although such a rubbing method is simple, various disadvantages have been pointed out in order to impart alignment characteristics to the polyimide film by physically rubbing the polyimide film. Specifically, (1) it is difficult to ensure uniformity of orientation, (2) traces are likely to remain during rubbing, (3) control of orientation direction and selective pretilt angle. Control is not possible, and it is not suitable for a liquid crystal panel using a multi-domain used to obtain a wide viewing angle. (4) The breakdown of the thin film transistor element or the alignment film due to static electricity from the glass substrate. Resulting in a decrease in yield, and (5) display defects due to the generation of dust from the rubbing cloth.

  In addition, when such an alignment film made of an organic material is used in a device equipped with a high output light source such as a liquid crystal projector, the organic material is damaged by light energy, resulting in alignment failure. In particular, when the projector is downsized and the brightness is increased, the energy per unit area incident on the liquid crystal panel is increased, the polyimide itself is decomposed by the absorption of incident light, and the light is absorbed. The decomposition is further accelerated by heat generation. As a result, a great deal of damage is added to the alignment film, and the display characteristics of the device deteriorate.

Therefore, in order to eliminate such inconvenience, application of an alignment film made of an inorganic material has been promoted. Inorganic alignment film formation includes vapor deposition and sputtering, but it is difficult to form a low defect density film on a large substrate by vapor deposition, and there is a strong demand for the formation of inorganic alignment films by sputtering. It has been.
A method of surface-treating an inorganic alignment film (SiO2) obtained by this sputtering method with an aliphatic alcohol or a silane coupling agent is disclosed (for example, Patent Documents 1 and 2).
JP 2004-47211 A JP 2007-127757 A

  By the way, as the surface treatment using a silane coupling agent, in addition to the above-described liquid phase treatment, a gas phase treatment for supplying a gas phase silane coupling agent to a substrate is known. In this case, if the treatment is performed under atmospheric pressure, the diffusibility of the material is not so good and the treatment takes time.

  In addition, there is a problem that uneven processing occurs due to the influence of water adhering to the inorganic alignment film, contaminants, etc., and uniform surface treatment cannot be performed.

  The present invention has been made in view of the above-mentioned problems of the prior art, and aims to provide a surface treatment apparatus and a surface treatment method capable of preventing uneven processing and efficiently obtaining a good coating film. Yes.

  In order to solve the above problems, a surface treatment apparatus of the present invention includes a film formation chamber in which a substrate to be processed is disposed, a decompression device that depressurizes the film formation chamber, a treatment agent vaporizer that vaporizes a treatment agent, A gas supply device that supplies a carrier gas to the processing agent vaporizer and a circulation system that circulates the gas in the film formation chamber are provided.

  According to the present invention, a film forming chamber in which a substrate to be processed is disposed, a pressure reducing device that depressurizes the film forming chamber, a processing agent vaporizing device that vaporizes a processing agent, and a carrier gas is supplied to the processing agent vaporizing device. Since the gas supply device and the circulation system for circulating the gas in the film formation chamber are provided, the atmosphere in the film formation chamber can be kept uniform during the surface treatment. This makes it possible to eliminate processing unevenness on the substrate and perform more uniform surface treatment. Therefore, a good film can be efficiently obtained on the substrate.

Moreover, it is preferable to further include a second circulation system that circulates the gas via the treatment agent vaporizer.
According to the present invention, since the second circulation system that circulates the gas via the treatment agent vaporizer is further provided, the amount (concentration) of the treatment agent in the film forming chamber is kept constant during the surface treatment. be able to. For example, by maintaining the treatment agent in the film formation chamber in a saturated state, the film formation rate can be improved and surface treatment can be performed in a short time.

Moreover, it is preferable that a fan is provided in the circulation system.
According to the present invention, since the fan is provided in the circulation system, the gas circulation efficiency is improved, the atmosphere in the film forming chamber can be made uniform efficiently, and the reaction of the treatment agent can be promoted.

In addition, it is preferable to have a moisture supply device that supplies moisture to the film formation chamber.
According to the present invention, since the moisture supply device that supplies moisture to the film formation chamber is provided, the moisture on the substrate can be saturated (or a state close thereto). Thereby, it becomes easy to adjust the moisture content on the substrate to a suitable moisture content in the surface treatment.

In addition, it is preferable to include a substrate holding unit that holds the substrate to be processed, and a transfer device that moves the substrate holding unit forward and backward with respect to the film formation chamber.
According to the present invention, since the substrate holding unit that holds the substrate to be processed and the transfer device that moves the substrate holding unit forward and backward with respect to the film forming chamber, the substrate is carried into and out of the film forming chamber. Work becomes easy and these operations can be performed quickly.

Moreover, it is preferable that the substrate holding unit is configured to hold a plurality of the substrates to be processed.
According to the present invention, since the substrate holding unit is configured to be able to hold a plurality of substrates to be processed, surface treatment can be performed on many substrates at a time, and the throughput is improved.

The treatment agent vaporizer includes a treatment agent holding unit for holding the treatment agent, a treatment agent supply unit for quantitatively supplying a liquid treatment agent to the treatment agent holding unit, and heating the liquid treatment agent. It is preferable to have a heating part.
According to the present invention, the processing agent vaporizer includes a processing agent holding unit that holds the processing agent, a supply unit that quantitatively supplies the liquid processing agent to the processing agent holding unit, and heating that heats the liquid processing agent. A necessary amount of the processing agent can be continuously supplied.

  In the surface treatment method of the present invention, the treatment agent is vaporized under a pressure lower than atmospheric pressure, and the treatment substrate is exposed to an atmosphere of the treatment agent to form a film of the treatment agent on the treatment substrate. A treatment step, wherein in the surface treatment step, a gas in a film formation chamber in which the substrate to be treated is arranged is circulated.

  According to the present invention, there is provided a surface treatment step of forming a coating film of the treatment agent on the substrate to be treated by vaporizing the treatment agent under a pressure lower than atmospheric pressure and exposing the substrate to be treated to the atmosphere of the treatment agent. In the surface treatment step, since the gas in the film formation chamber in which the substrate to be processed is disposed is circulated, the atmosphere in the film formation chamber can be made uniform during the surface treatment. Thereby, the surface treatment is uniformly applied to the substrate, and uneven processing can be prevented.

In the surface treatment step, the vaporized treatment agent is preferably supplied while exhausting.
According to the present invention, in the surface treatment process, since the vaporized treatment agent is supplied while exhausting, the amount (concentration) of the treatment agent in the film forming chamber can be kept constant. For example, by saturating the treatment agent in the film formation chamber, the reaction of the treatment agent is promoted, the film formation efficiency is improved, and the treatment time can be shortened.

In addition, it is preferable to sequentially perform a moisture removal step of removing moisture on the surface of the substrate to be processed and a moisture supply step of supplying moisture to the surface of the substrate to be processed before the surface treatment step.
According to the present invention, prior to the surface treatment step, the moisture removal step of removing moisture on the surface of the substrate to be treated and the moisture supply step of supplying moisture to the surface of the substrate to be treated are sequentially performed. The moisture content on the substrate can be adjusted to a moisture content suitable for the surface treatment.

In the moisture supply step, it is preferable that the surface of the substrate to be processed is in a moisture saturated state.
According to the present invention, in the moisture supply process, the surface of the substrate to be processed is brought into a water saturation state, so that it is easy to adjust the moisture content on the substrate to the moisture content required in the surface treatment process.

Moreover, it is preferable to have the water | moisture-content adjustment process which removes the water | moisture content of the surface of the said to-be-processed substrate partially after the said water | moisture-content supply process.
According to the present invention, after the moisture supply step, the moisture adjustment step of partially removing the moisture on the surface of the substrate to be processed is provided, so that the saturated moisture can be adjusted to a moisture amount suitable for the surface treatment.

  Moreover, it is preferable that the said processing agent is a silane coupling agent represented by following General formula (1).

  According to the present invention, since the silane coupling agent represented by the formula (1) is used, an extremely thin film can be formed substantially uniformly on the substrate to be processed, and the physical properties of the surface of the substrate to be processed And chemical properties can be modified. Further, by forming a silane coupling agent into a film, the surface of the substrate to be processed becomes a water-repellent surface, and the water resistance of the substrate to be processed can be improved.

Moreover, it is preferable to form an alignment film on the to-be-processed substrate by having an inorganic film on the to-be-processed substrate and forming the coating film on the surface of the inorganic film.
According to the present invention, an inorganic film is formed on a substrate to be processed, and an alignment film is formed on the substrate to be processed by forming a film of a silane coupling agent on the surface of the inorganic film. An excellent substrate to be processed is obtained, which is suitable for application to a liquid crystal display device.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

[Surface treatment equipment]
FIG. 1 is a schematic diagram showing a schematic configuration of the surface treatment apparatus of the present embodiment, and FIG. 2 is a block diagram showing a schematic configuration of the surface treatment apparatus.
As shown in FIG. 1, the surface treatment apparatus 1 introduces vapor of a silane coupling agent Y1 into a substrate W (substrate to be treated) having an inorganic film 10 and performs surface treatment on the substrate W. An apparatus for forming an inorganic alignment film, which is a treatment agent supply device 2, a film formation chamber 3, a pump 5 (decompression device), a valve 8, a moisture supply device 9, a transfer device 11, and a substrate holder. 12, a first circulation system 40, and a second circulation system 50.

  The substrate W is made of quartz, glass, sapphire, etc., and has a transparent electrode, wiring, interlayer insulating film, etc. (all not shown) on the surface, and an inorganic film formed on the outermost layer by sputtering or vapor deposition. 10 is provided. The inorganic film 10 is composed of an oxide film such as SiO2.

  The processing agent supply device 2 is for vaporizing the silane coupling agent Y1 as the processing agent and supplying the vaporized silane coupling agent Y2 to the film forming chamber 3. The processing agent supply device 2 includes a processing agent vaporization device 21 and a gas supply device 22.

  The processing agent vaporizer 21 includes a processing agent holding unit 211 that holds the silane coupling agent Y1 in the vaporizing chamber 210, and a processing agent supply unit 212 that quantitatively supplies the silane coupling agent Y1 to the processing agent holding unit 211. And a heating unit 213 for heating the silane coupling agent Y1 supplied to the processing agent holding unit 211. Then, the processing agent holding unit 211 and the heating unit 213 are controlled by the control device 7 shown in FIG. 2, whereby the internal atmosphere of the vaporization chamber 210 is controlled.

  As the silane coupling agent Y1 to be used, a silane coupling agent represented by the following general formula (1) can be used.

OR is an alkoxy group, R represents a methyl group _(CH 3), an alkyl group such as ethyl group _(C 2 _{H 5).} This R is desorbed after the reaction, and only the bond of A-Si bond and Si-O-Si remains.
This R has a very wide range of choices. Examples of silane coupling agents include octadecyltriethoxysilane, tridecafluorooctyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, and N-phenyl-3-aminopropyl. Trimethoxysilane, p-styryltrimethoxysilane, p-trifluoromethylphenyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and 3-glycidoxypropyltrimethoxysilane are preferably used. Can do. Further, octyltrimethoxysilane, glycidoxypropyltrimethoxysilane, tridecafluorotetrahydrooctyltriethoxysilane, and the like can also be used.

  The gas supply device 22 is for supplying a carrier gas into the vaporizing chamber 210, and is connected to the processing agent vaporizing device 21 (vaporizing chamber 210) via a pipe 6A. The carrier gas is selected according to the type of silane coupling agent Y1 used, and for example, nitrogen gas (N2) or argon gas (Ar) can be used. The gas supply device 22 can control the supply amount of the carrier gas.

  The film forming chamber 3 is a container that can accommodate the substrate W having the inorganic film 10 therein, and is made of a metal such as stainless steel. The film forming chamber 3 is configured to be hermetically sealed, and the inside can be depressurized by a pump 5 connected through pipes 6C and 6E.

  Specifically, the film forming chamber 3 of the present embodiment has a main body 31 and a lid 32 that can be attached to and detached from the main body 31, and the lid 32 constitutes the bottom of the film forming chamber 3. It is supposed to be. A sealed space is formed by attaching the lid 32 to the main body 31. A flange portion 31 </ b> A projecting outward is provided at the lower peripheral edge of the main body portion 31, and an annular sealing material 33 such as an O-ring is disposed between the flange portion 31 </ b> A and the lid portion 32. The sealing material 33 may be provided on either side of the main body portion 31 and the lid portion 32.

  As described above, when the lid portion 32 is attached to the main body portion 31, the sealing material 33 is interposed therebetween, so that a sealed state inside the film forming chamber 3 can be secured. . Then, the vaporized silane coupling agent Y2 is introduced from the processing agent supply device 2 through the pipe 6B into the film forming chamber 3 which is a sealed space.

  In the present embodiment, a resistance heater (not shown) is provided in the film forming chamber 3, and the temperature inside the film forming chamber 3 (the temperature of the substrate W) can be maintained at a predetermined temperature. It has become.

  The substrate holding unit 12 is disposed in the film forming chamber 3 and is configured to hold a plurality of substrates W in a state of being separated from each other. The substrate holding portion 12 is preferably configured so as not to block the flow of the vaporized silane coupling agent Y2, and may be, for example, a mesh-like one having good air permeability.

  The transport device 11 includes a support member 113 that can be expanded and contracted, and includes a substrate holding unit 12 at an end thereof. Then, by moving the support member 113 forward and backward with respect to the film forming chamber 3, the substrate holding unit 12 is carried into and out of the film forming chamber 3. Further, the substrate holding part 12 carried out from the film forming chamber 3 is accommodated in the accommodating part 13 disposed below the film forming chamber 3. The support member 113 is also connected to the lid portion 32 of the film forming chamber 3 described above, and is accommodated in the accommodating portion 13 together with the substrate holding portion 12.

The support member 113 is provided with a cylinder portion 112 on the inner side in the axial direction than the substrate holding portion 12 and the lid portion 32. By providing this cylinder part 112, the substrate holding part 12 in the film forming chamber 3 can be moved up and down with the lid part 32 attached to the main body part 31.
Further, by attaching the lid portion 32 to the main body portion 31, a sealed state in the film forming chamber 3 is ensured.

The first circulation system 40 includes a circulation path 41 and a fan 42. The circulation path 41 is a path that returns from the film formation chamber 3 to the film formation chamber 3 via a plurality of branch paths 41A, ..., main path 41B. The plurality of branch paths 41A are arranged in a line along the wall 3b of the film formation chamber 3, and are arranged so as to follow the arrangement direction of the plurality of substrates W described above. The main channel 41B is connected to the upper surface 3a side of the film forming chamber 3 at the end opposite to the branch channel 41A.
The fan 42 is disposed in the film forming chamber 3 and circulates the gas in the film forming chamber 3 through the circulation path 41.
By such a second circulation system 50, the gas (silane coupling agent Y <b> 2) in the film forming chamber 3 is agitated to make a uniform atmosphere.

The second circulation system 50 includes a circulation path 51 and a fan 52. The circulation path 51 is a path that returns from the film formation chamber 3 to the film formation chamber 3 via the pipe 6C, the valve 8, the pipe 6F, the vaporization chamber 210, and the pipe 6B. The fan 52 is disposed in the vaporization chamber 210 on the circulation path 51 and circulates the gas in the film forming chamber 3 through the circulation path 51.
By such a second circulation system 50, the vaporized silane coupling agent Y2 is circulated between the vaporization chamber 210 and the film formation chamber 3.

  The pump 5 is disposed on the pipe 6E and is connected to the film forming chamber 3 through the valve 8 and the pipe 6C. The pump 5 is driven under the control of the control device 7 and discharges air in the film forming chamber 3 according to the open / closed state of the valve 8 to form a reduced pressure atmosphere in the film forming chamber 3. Is possible.

  The valve 8 is a three-way valve capable of switching three paths under the control of the control device 7 shown in FIG. 2, and is connected to the pipes 6C, 6E, and 6F. That is, by controlling the opening and closing of the valve 8, there are a path connecting the film forming chamber 3 and the pump 5, a path connecting the film forming chamber 3 and the vaporizing chamber 210, and a path connecting the pump 5 and the vaporizing chamber 210. It can be switched. Thereby, a reduced pressure atmosphere can be formed not only in the film formation chamber 3 but also in the vaporization chamber 210.

The moisture supply device 9 includes an evaporator 19 and a gas supply device 23, and is connected to the film forming chamber 3 through a pipe 6D. The moisture supply device 9 generates water vapor by heating the water supplied into the evaporator 19 and supplies the water vapor into the film forming chamber 3 together with the carrier gas sent from the gas supply device 23. . Note that the gas supply device 22 may be connected to both the processing agent vaporization device 21 and the evaporator 19 without providing the gas supply device 23.
These functions may also be used.

  As shown in FIG. 2, the control device 7 includes a processing agent vaporizer 21 (a processing agent supply unit 212, a heating unit 213), a gas supply device 22, a first circulation system 40, a second circulation system 50, a transport device 11, The pump 5, the valve 8, the fans 42 and 52, and the moisture supply device 9 (evaporator 19, gas supply device 23) are electrically connected to each other, and control the operation of the surface treatment apparatus 1 in an integrated manner.

  Specifically, the control device 7 controls the treatment atmosphere in the vaporization chamber 210 by controlling the treatment agent vaporization device 21 and the gas supply device 22, and sets the optimum conditions for vaporization of the silane coupling agent Y1. Is possible. The optimum conditions for vaporization of the silane coupling agent Y1 are conditions under which the silane coupling agent Y1 vaporizes in the shortest time in a controllable processing atmosphere. That is, in the present embodiment, the temperature and pressure inside the vaporizing chamber 210 are controlled by the control device 7 so that the silane coupling agent Y1 vaporizes in the shortest time.

  Further, the control device 7 controls the processing atmosphere in the film forming chamber 3 by controlling the pump 5 and the valve 8 so that the conditions are optimal for the surface treatment of the substrate W by the vaporized silane coupling agent Y2. Is possible. The optimum condition for the surface treatment of the substrate W with the vaporized silane coupling agent Y2 is a condition in which the surface treatment is completed in the shortest time in a controllable treatment atmosphere. The surface treatment is completed when a silane coupling agent having a predetermined film thickness is formed on the surface of the substrate W. In other words, in the present embodiment, the control device 7 causes the temperature and pressure inside the film forming chamber 3 to form a silane coupling agent having a predetermined thickness on the surface of the substrate W in the shortest time. Controlled.

  Further, the control device 7 controls the first circulation system 40 and the second circulation system 50, respectively. By controlling the first circulation system 40, the atmosphere in the film forming chamber 3 is kept constant, and by controlling the second circulation system 50, the concentration of the silane coupling agent Y2 in the film forming chamber 3 is kept constant.

[Surface treatment method]
Next, an example of a surface treatment method using the surface treatment apparatus according to the present invention will be described.
FIG. 3 is an explanatory diagram of the surface treatment for the substrate. In addition, in FIG. 3, it is a figure which shows typically the reaction state of a silane coupling agent.
Processing conditions
Silane coupling agent: (C10H21Si (OCH3) 3)
Surface treatment temperature: 130-200 ° C
Surface treatment time: 90-240 minutes
Carrier gas flow rate: 500cc / min or less (atmospheric pressure conversion)
Pressure in the deposition chamber: about 500 Pa

First, a substrate W having an inorganic film 10 is prepared, and moisture removal processing is performed on the substrate W by pressurizing and reducing the inside of the film formation chamber 3 in which the substrate W is disposed (moisture removal step).
As shown in FIG. 3A, a large number of polarized hydroxyl groups are present on the surface of the inorganic film 10 to form silanol groups (Si—OH). In particular, due to the presence of the hydrophilic silanol group, water (humidity) is likely to exist in the region R indicated by the broken line in the figure. When surface treatment is performed in this state, the silane coupling agent Y2 is excessively reacted in a lump due to the influence of moisture on the substrate W (adherent water and volatile contaminants), or conversely, an unreacted region. Will occur. Here, in order to avoid such an inconvenience of the surface treatment, moisture on the inorganic film 10 is removed as much as possible.

  Specifically, the processing atmosphere in the film forming chamber 3 is set to a condition suitable for the moisture removal process by the control device 7. The control device 7 closes the valve 8 and the valve 18 to seal the film forming chamber 3, and then drives the pump 5 so that the pressure in the film forming chamber 3 is lower than atmospheric pressure (predetermined depressurized atmosphere). To. At this time, it is effective to repeatedly introduce and discharge the carrier gas from the gas supply device 22 into the film forming chamber 3 to replace water molecules and the like adhering to the surface of the substrate W with carrier gas molecules.

  At the same time, the inside of the film forming chamber 3 (substrate W) is heated by a resistance heater (not shown). The heating temperature is preferably about the surface treatment temperature. Under such high temperature and reduced pressure atmosphere, the adhering water and volatile contaminants on the substrate W are removed. In the present embodiment, not only adhering water and contaminants, but also OH groups on the surface of the substrate W are excessively removed as shown in FIG.

  Hereinafter, the temperature in the film forming chamber 3 (substrate W) is maintained until the surface treatment is completed. The temperature in the film forming chamber 3 can be adjusted by controlling a resistance heater (not shown) provided in the film forming chamber 3 by the control device 7.

Next, the water vapor generated by the evaporator 19 is introduced into the film forming chamber 3 together with the carrier gas, and as shown in FIG. 3C, the surface of the substrate W in which the OH group is deficient is saturated with the OH group ( Moisture supply process). At this time, maintaining the surface of the substrate W in a water saturated state for a predetermined time is effective in making the amount of OH groups on the surface of the substrate W uniform.
In the moisture supply process, the surface of the substrate W does not necessarily need to be in a water saturated state, but by maintaining the water saturated state or a state close thereto, the amount of water on the substrate W is subjected to surface treatment in the next step. It becomes easy to adjust to the optimal amount.

  Next, the amount of moisture on the substrate W is adjusted (moisture adjusting step). Specifically, the carrier gas or a carrier gas containing a small amount of moisture is introduced into the film forming chamber 3 by the moisture supply device 9 and the introduced carrier gas is exhausted by the pump 5 in parallel. The inside of the chamber 3 is kept in a constant reduced pressure state. As a result, the OH group on the substrate W is partially removed. In this way, the amount of OH groups on the surface of the substrate W is controlled to an amount required in the surface treatment process.

Next, the silane coupling agent Y1 stored in the vaporization chamber 210 of the treatment agent vaporizer 21 is vaporized.
First, by opening the valve 8 and driving the pump 5, the inside of the vaporizing chamber 210 is depressurized to a pressure lower than the atmospheric pressure. Thereafter, the vaporizing chamber 210 is hermetically sealed, the silane coupling agent Y1 is quantitatively supplied from the processing agent supply unit 212 to the processing agent holding unit 211, and the silane coupling agent Y1 is heated by the heating unit 213 to be vaporized. Let By heating the silane coupling agent Y1 in such a reduced pressure atmosphere, the vaporization rate can be increased.

  Thereafter, a predetermined amount of carrier gas is introduced into the vaporization chamber 210 from the gas supply device 22. The flow rate of the carrier gas is 500 cc / min or less (in terms of atmospheric pressure). The vaporized silane coupling agent Y2 is supplied into the film forming chamber 3 together with the carrier gas (N2) introduced into the vaporizing chamber 210.

Next, the surface treatment of the substrate W is performed by the silane coupling agent Y2 introduced into the film forming chamber 3 (surface treatment step).
The inside of the film forming chamber 3 becomes about 500 Pa by introduction of the silane coupling agent Y2 and the carrier gas. Specifically, the carrier gas is introduced into and discharged from the film forming chamber 3 so that the reduced pressure atmosphere in the film forming chamber 3 is constant. Thereafter, a predetermined amount of the silane coupling agent Y 2 is introduced from the silane coupling agent supply unit 212, heated by the heating unit 213 to generate silane coupling agent vapor, and heated in the film forming chamber 3. Supply steam. In addition, since the pressure in the film forming chamber 3 slightly increases with the generation of the silane coupling agent vapor, the pressure is adjusted by exhausting with the pump 5 as necessary. However, as a feature of the present invention, since the chemical reaction proceeds in the sealed container, it is not always necessary to keep the pressure constant.

  The pressure in the film formation chamber 3 during the surface treatment is set lower than the atmospheric pressure. Specifically, it is more preferably set to 1000 Pa or less in consideration of diffusibility and reliquefaction of the vaporized silane coupling agent Y2 which is set within a range of 50 to 5000 Pa. Moreover, by setting it as a pressure-reduced atmosphere, the vapor deposition silane coupling agent Y2 is filled in the film-forming chamber 3, and it becomes possible to expose the whole board | substrate W to the atmosphere of the silane coupling agent Y2.

  Since the substrate W is disposed in the film forming chamber 3, the substrate W is exposed to the atmosphere of the vaporized silane coupling agent Y2, and as shown in FIG. 3D, the silane coupling agent. The hydrolyzable group of Y2 reacts with the OH group. The silane coupling agent Y2 introduced from the vaporization chamber 210 into the film formation chamber 3 is unreacted by holding the vaporization chamber 210 and the film formation chamber 3 in which the substrate W is disposed in a sealed state for a predetermined time. It is not exhausted in the middle of the reaction, so that the use efficiency is improved and at the same time the time until the reaction is completed can be shortened.

  In the present embodiment, the gas (carrier gas and silane coupling agent Y2) in the sealed film formation chamber 3 is circulated during the surface treatment. Specifically, by driving the fan 42 by the control device 7, the unreacted silane coupling agent Y 2 together with the carrier gas is discharged from the film forming chamber 3 in the gas phase state, and is again formed through the circulation path 41. It is circulated by introducing it into the membrane chamber 3. In this way, the atmosphere in the film forming chamber 3 is maintained uniformly by circulating the gas in the film forming chamber 3 through the circulation path 41.

  At the same time, the gas in the film forming chamber 3 is circulated through the circulation path 51 in order to continuously supply the silane coupling agent Y 2 into the film forming chamber 3. That is, the gas in the film forming chamber 3 is circulated between the vaporizing chamber 210. Here, by driving the fan 52 by the control device 7, the gas in the film formation chamber 3 is caused to flow into the circulation path 51 and the gas is caused to flow into the vaporization chamber 210. The gas introduced into the vaporizing chamber 210 is mixed with the newly vaporized silane coupling agent Y2 and introduced into the film forming chamber 3 together with the carrier gas. According to the conventional method, since a fresh carrier gas is introduced and exhausted in parallel, a considerable amount of unreacted silane coupling agent is inevitably exhausted. The silane coupling agent Y2 is held in the film forming chamber 3. Therefore, even if the reaction takes time, the silane coupling agent Y2 can be held in the film formation chamber 3 until the reaction is completed, and the processing time can be shortened after all.

  In this way, surface treatment is performed on the substrate W, and as a result, a film of a silane coupling agent is formed on the inorganic film 10. In the present embodiment, since the amount of OH groups on the surface of the inorganic film 10 is adjusted before the surface treatment step, it is possible to perform the surface treatment in a state where inconvenience due to the OH groups is avoided.

  Such surface treatment is continued until a film having a predetermined thickness is formed on the substrate W. When all of the silane coupling agent Y1 in the processing agent holding unit 211 has evaporated, the processing agent supply unit 212 replenishes it as needed.

  The surface treatment time is about 90 to 240 minutes, and is appropriately set according to the pressure and temperature in the film forming chamber 3. In this embodiment, since the internal pressure of the film forming chamber 3 is about 500 Pa and the processing temperature is 130 to 200 ° C., the processing time is appropriately set in order to obtain a desired film thickness according to these processing pressure and processing temperature. Is done. Here, a uniform surface treatment is possible if the treatment pressure is low, and the surface treatment is completed in a short time if the treatment temperature is high. This also varies depending on the type of silane coupling agent used. In this way, the surface treatment for the substrate W is completed.

  In the treatment of the surface of the inorganic film (SiO2 film) using the silane coupling agent, the Si-OH group on the SiO2 surface is consumed and the reactive group of the silane coupling agent is bonded. Therefore, it is very important to control the amount of Si—OH groups on the SiO 2 surface. In addition, since the silane coupling agent only coats the SiO2 surface one layer, the required amount is small, but since it reacts via the intermediate state after adhering to the SiO2 surface, the reaction rate is slow and the high temperature is not maintained for nearly 1 hour. And the reaction is not completed. The surface treatment apparatus 1 and the surface treatment method in the present embodiment reflect such reaction characteristics.

  In the surface treatment apparatus 1 and the surface treatment method of the present embodiment described above, the amount of moisture on the substrate W is adjusted before the surface treatment. Conventionally, since the water trapped in the inorganic film (SiO 2) or in the pinhole is released and the Si—OH group is formed, it takes a long time to complete the reaction. It was. In contrast, in the present embodiment, by controlling the amount of Si—OH groups on the SiO 2 surface that contributes to the reaction, it is possible to efficiently react the required amount of the silane coupling agent Y 2. As well as the amount of silane coupling agent used.

  In addition, the volatile contaminants are reliably removed together with the adhering water adhering to the substrate W in the moisture removing step, while the insufficient Si—OH groups are replenished in the moisture supplying step. The reaction can proceed rapidly. Furthermore, since the adhering water, contaminants, and the like are removed, a portion where the silane coupling agent Y2 is not reacted can be eliminated, so that uniform treatment is possible.

  In the present embodiment, the surface treatment is performed in a high temperature and reduced pressure atmosphere. As a result, the silane coupling agent Y2 enters better into the gap in the surface layer portion of the inorganic film 10 and easily reacts with the Si—OH group in the gap. For this reason, the bonding reaction of the silane coupling agent Y2 to the inorganic film 10 is further accelerated, and the processing time can be shortened.

  Furthermore, according to the present embodiment, the inside of the film forming chamber 3 is stirred by the first circulation system 40, and the concentration of the silane coupling agent Y2 in the film forming chamber 3 is always made constant by the second circulation system 50. Thus, the atmosphere in the film forming chamber 3 can be kept uniform. Thereby, the processing unevenness on the substrate W can be eliminated and the film formation efficiency can be improved, so that a uniform surface treatment can be performed in a short time.

  Thus, by performing the surface treatment with the silane coupling agent on the substrate W having the inorganic film 10, a substrate having an inorganic alignment film suitable for application to a liquid crystal device can be obtained.

[Comparison of pure water contact angle]
Next, with respect to the sample substrate after the surface treatment and the sample substrate before the surface treatment, several pure water contact angles on each surface were obtained and compared as data.
As a result, the average value of the pure water contact angle of the sample substrate before the surface treatment was 5 degrees or less, whereas the average value of the pure water contact angle of the sample substrate after the surface treatment was 40 to 100 degrees. Rose to. Moreover, when the surface treatment was continuously performed on a plurality of sample substrates, the pure water contact angles for each substrate were compared. Here, the surface treatment process was repeated 5 times or more, and the variation in the pure water contact angle between the substrates W obtained by each treatment was within ± 5 degrees.

  As can be seen from the above results, according to the surface treatment apparatus 1 and the surface treatment method of the present embodiment, the silane coupling agent Y2 is introduced into the film formation chamber 3 in a predetermined atmosphere during the surface treatment and discharged. It was found that the amount of deposits and residues derived from the silane coupling agent in the film forming chamber 3 can be greatly reduced by performing the above. Thereby, even if the surface treatment is continuously performed on a plurality of substrates, a stable surface treatment can be performed, and thus a good coating can be obtained on the substrate. Therefore, it was confirmed that uneven processing was prevented and uniform surface treatment was possible.

  In addition, according to the surface treatment apparatus 1 and the surface treatment method of the present embodiment, the physical property and the chemical property of the surface of the inorganic film 10 are improved by forming the coating film of the silane coupling agent on the substrate W. The surface of the inorganic film 10 becomes a water repellent surface and the water resistance of the substrate W is improved. When the substrate W is used as a substrate of a liquid crystal device, the pretilt angle of liquid crystal molecules can be controlled by adjusting the pure water contact angle on the surface of the inorganic alignment film. Since the pure water contact angle can be adjusted according to the number of surface treatments, the pure water contact angle may be appropriately detected during the surface treatment in order to obtain a desired pretilt angle.

The pure water contact angle can also be controlled by the concentration of the silane coupling agent Y2 in the film forming chamber 3, the processing temperature, the processing time, and the processing pressure.
When the processing pressure is low, the diffusibility of the silane coupling agent Y2 is increased, so that the uniformity in the film forming chamber 3 can be obtained, and a good film without processing unevenness can be formed. Furthermore, the desired pure water contact angle can be obtained in a shorter time when the treatment temperature is higher.

  The preferred embodiments according to the present invention have been described above with reference to the accompanying drawings. However, it goes without saying that the present invention is not limited to such examples, and the above embodiments may be combined. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  For example, in the previous embodiment, the processing agent supply device 2 and the moisture supply device 9 are provided, respectively, but the evaporator 19 and the valve 18 are connected to the pipe 6A in order from the film formation chamber 3 side. May be.

  A plurality of fans may be provided in the film formation chamber 3. Thereby, since the inside of the film formation chamber 3 can be efficiently stirred, it is effective in promoting the reaction of the silane coupling agent Y2.

The schematic diagram which shows schematic structure of the surface treatment apparatus of this embodiment. The block diagram which shows schematic structure of the surface treatment apparatus of this embodiment. Explanatory drawing of the surface treatment with respect to a board | substrate.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Surface treatment apparatus, 2 ... Treatment agent supply apparatus, 3 ... Film-forming chamber, 5 ... Pump (decompression apparatus), 9 ... Water supply apparatus, 12 ... Substrate holding part, 10 ... Inorganic film, 11 ... Conveyance apparatus, 21 ... treatment agent vaporizer, 22 ... gas supply device, 40 ... first circulation system, 42, 52 ... fan, 50 ... second circulation system, 211 ... treatment agent holding part, 212 ... treatment agent supply part (supply part), 213 ... heating unit, W ... substrate (substrate to be processed), Y1 ... silane coupling agent (liquid phase state), Y2 ... silane coupling agent (gas phase state)

Claims (14)

A film formation chamber in which a substrate to be processed is disposed;
A decompression device for decompressing the film forming chamber;
A treatment agent vaporizer for vaporizing the treatment agent;
A gas supply device for supplying a carrier gas to the treatment agent vaporizer;
And a circulation system for circulating a gas in the film formation chamber. The surface treatment apparatus according to claim 1, further comprising a second circulation system that circulates the gas via the treatment agent vaporizer. The surface treatment apparatus according to claim 1, wherein a fan is provided in the circulation system. The surface treatment apparatus according to claim 1, further comprising a moisture supply device that supplies moisture to the film formation chamber. A substrate holder for holding the substrate to be processed;
The surface treatment apparatus according to claim 1, further comprising: a transfer device that moves the substrate holding unit forward and backward with respect to the film formation chamber. The surface treatment apparatus according to claim 5, wherein the substrate holding unit is configured to hold a plurality of the substrates to be processed. The treatment agent vaporizer is
A treatment agent holding part for holding the treatment agent;
A treatment agent supply unit that quantitatively supplies a liquid treatment agent to the treatment agent holding unit;
A heating unit for heating the liquid treatment agent;
The surface treatment apparatus according to claim 1, comprising: Vaporizing the treatment agent under a pressure lower than atmospheric pressure, and having a surface treatment step of forming a film of the treatment agent on the substrate to be treated by exposing the substrate to be treated to the atmosphere of the treatment agent;
In the surface treatment step, a gas is circulated in a film formation chamber in which the substrate to be treated is arranged. The surface treatment method according to claim 8, wherein in the surface treatment step, the vaporized treatment agent is supplied while exhausting. Before the surface treatment step,
A moisture removal step of removing moisture on the surface of the substrate to be processed;
The surface treatment method according to claim 8, wherein a moisture supply step of supplying moisture to the surface of the substrate to be processed is sequentially performed. In the moisture supply step,
The surface treatment method according to claim 10, wherein a surface of the substrate to be treated is saturated with water. After the water supply step,
The surface treatment method according to claim 10, further comprising a moisture adjustment step of partially removing moisture on the surface of the substrate to be processed. The surface treatment method according to claim 8, wherein the treatment agent is a silane coupling agent represented by the following general formula (1).

The alignment film is formed on the substrate to be processed by forming an inorganic film on the substrate to be processed, and forming the coating on the surface of the inorganic film. The surface treatment method according to item.

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