JP2002282807A - Method and device for cleaning substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply a method and device for cleaning a substrate which, in a cleaning device that uses cleaning liquid, solves the shortage of adhering power in the next process caused by the residue of cleaning liquid or rinse liquid after cleaning, without sacrificing its productivity and profitability. SOLUTION: At a cleaning device which cleans a substrate, this substrate cleaning method characteristically has a first cleaning process where cleaning is done by using a cleaning liquid, and a second cleaning process where the substrate is exposed to plasma which discharges electricity under atmospheric pressure while cleaning is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for cleaning a substrate. In particular, the present invention relates to a method and an apparatus for cleaning a color filter manufacturing process used for a color liquid crystal display device, and more particularly to a method and an apparatus for cleaning before forming a transparent conductive film on an organic coloring layer and an overcoat layer.

[0002]

2. Description of the Related Art In a color filter manufacturing process, a chromium film is formed on a transparent substrate such as glass using a vacuum film forming method, a photoresist is applied, a photomask is arranged, and exposure, development, and the like are performed. Chromium etching and photoresist stripping are performed to form a patterned black light-shielding layer. Particularly in recent years, in consideration of the influence on the global environment, a resin black matrix (BM) using a light-shielding resin as a black light-shielding layer without using harmful chromium has been developed and manufactured. Next, after applying the first color photosensitive material from above the black light-shielding layer, a photomask is arranged and exposed, and then development is performed to form a first color pattern. Is formed. Finally, a color filter is completed through a step of forming a transparent conductive film layer used as an electrode for driving a liquid crystal on the color pattern. At this time, an overcoat layer may be formed between the color pattern and the transparent conductive film for the purpose of protecting pixels and flattening the color pattern.

Incidentally, the transparent conductive layer is required to have a high light transmittance and a low resistance value. In view of these points, as a preferable material, indium oxide (ITO) to which tin oxide is added is used. Is widely used. As a method of forming the ITO film, methods such as sputtering, ion plating, and vacuum deposition are known, but all require heating the substrate under a reduced pressure atmosphere. In many cases, a sputtering method is used which can obtain a high light transmittance and a low resistance value at a relatively low temperature. The thickness of the transparent conductive film is preferably thicker from the viewpoint of the resistance value. However, as the thickness increases, the transparency deteriorates, and there is a disadvantage that the transmittance of the color filter decreases. Therefore, the thickness of the transparent conductive film is 500 to 3
Thicknesses on the order of 000 angstroms are commonly employed.

On the other hand, in the process of manufacturing these color filters, a step of cleaning the substrate is essential. This cleaning process, which is usually called pre-cleaning, is provided before and after each color filter manufacturing process. Before cleaning, the surface of the substrate has particles and oils and fats, as well as residues from the previous process, attached to the surface. These deposits cause pinholes,
In addition to lowering the productivity and yield of the manufacturing process,
Since the adhesion of the film in the next step is significantly reduced, the quality and reliability of the color filter are reduced.

[0005] Above all, when the above-mentioned transparent conductive film is formed, cleaning before the formation is very important because it affects the adhesion between the undercoat and the transparent conductive film. This transparent conductive film is used as an electrode for driving a liquid crystal,
Since it is formed only in the pixel display area where the color pixel layer of the color filter is formed, it is usually necessary to perform patterning.

Generally, color LCDs have the STN system and the T
There are two types of the FT system, and the method of patterning the transparent conductive film differs depending on each type. In the case of the STN method, the width is 5 to 20 μm, and the width of the transparent conductive film is 100 to 3
An electrode pattern of 00 μm is formed on the pixel by etching. Therefore, in the etching process, if the adhesion between the color filter and the transparent conductive film is poor, the transparent conductive film is over-etched or peeled off, and the electrode becomes thinner. Things happen. Therefore, for example, Japanese Patent Application Laid-Open No. 62-153
826 As shown in Japanese and Sho 63-44627 discloses to form an inorganic insulating film such as SiO ₂ for improving the patterning performance of the transparent conductive film between the transparent conductive film and the overcoat layer Method and, for example, JP-A-3-65
As disclosed in Japanese Patent Publication No. 902, a method of improving the patterning performance by forming a transparent conductive film having good adhesion to the overcoat layer as the first layer by using two transparent conductive films, and the like is adopted. However, it is preferable to omit the former from the viewpoint of increasing the cost and lowering the yield due to the formation of the intermediate layer, and it is necessary to form two different types of transparent conductive films for the latter. -There was a problem that economic efficiency deteriorated remarkably.

On the other hand, in the TFT method, patterning in a pixel is not performed, and a transparent conductive film is formed on the entire surface of a pixel display area in which a colored pixel layer of the color filter is formed. As shown in the publication, a transparent conductive film is formed by a mask film forming method in which a film is patterned using a patterned metal mask. Normally, in the case of the TFT method, an intermediate layer is not formed to avoid an increase in cost, and a transparent conductive film is formed directly on the overcoat. Therefore, if the adhesion between the overcoat and the transparent conductive film is poor, the quality and reliability of the color filter such as the occurrence of unevenness on the surface of the overcoat and the unevenness of the transparent conductive film are significantly reduced. Further, these drawbacks do not occur immediately after the formation of the transparent conductive film, and for example, there is a problem that when forming an alignment film on the transparent conductive film, it becomes evident by processing in the next step such as heating or moist heat of the substrate.

By the way, the method of cleaning the substrate can be roughly classified as follows.
Dry cleaning and wet cleaning using a cleaning liquid can be divided. Examples of the dry cleaning include, for example, JP-A-58-147.
No. 143 and Japanese Patent Application Laid-Open No. 4-116837, plasma cleaning in which the surface to be cleaned is ashed by plasma discharge in a vacuum to remove dirt, and chemicals of organic substances are utilized by using the energy of ultraviolet rays. There is UV ozone cleaning that breaks bonds and excites oxygen in the air to decompose dirt by the excited oxygen. Above all, UV ozone cleaning using an excimer lamp with a center wavelength of 172 nm uses a conventional low-pressure mercury lamp. Since excited oxygen can be generated at a higher density than in the case where it is used, it is used for high-speed cleaning. However, in such dry cleaning, if a long-term treatment is performed, the quality of the substrate to be treated is adversely affected, so that the treatment cannot be performed for a long time, and therefore, there is a problem that the ability to remove organic substances having a large molecular weight is particularly poor. I do.

On the other hand, wet cleaning involves chemical aqueous solution, organic solvent,
This cleaning is performed using a liquid cleaning liquid such as a surfactant, a cleaning agent solution, ionized water, ozone water, and water.
At this time, these cleaning liquids are appropriately selected depending on the surface of the target substrate to be cleaned, contaminants, and the like, and are used in combination with a physical cleaning method. Physical cleaning methods include brush cleaning in which the cleaning solution is applied to the surface to be cleaned while applying the cleaning solution to the rotating brush, and jet spray in which the cleaning solution is sprayed from a nozzle to remove the surface dirt from the surface to be cleaned and rinse away. Ultrasonic cleaning, in which ultrasonic waves are applied to the object to be cleaned immersed in the cleaning and cleaning liquid to promote peeling of adherents and dissolution and dispersion of dirt in the cleaning liquid by cavitation for cleaning, vibration acceleration by ultrasonic waves in a frequency band of about 1 MHz. Is generally used to wash the surface to be cleaned by giving the liquid to the molecules of the cleaning liquid.

Incidentally, in the wet cleaning, a step of rinsing the cleaning agent after the cleaning and a step of drying the substrate are required. In the color filter manufacturing process, pure water is usually used as a rinsing liquid, and the cleaning liquid attached to the substrate surface is rinsed off with the pure water. After the rinsing, the substrate is dried by a drying process. Air knife drying, which drains water by passing between two narrow slits blown by high-pressure air, spin drying, which rotates the substrate at high speed and drains the surface by centrifugal force, pure water Pull up the substrate in a vertical direction at a constant slow speed from inside to remove the water on the surface Pull up drying, install the substrate in a drying chamber under reduced pressure, increase the evaporation rate of water to remove water by vacuum drying, heat-treat the substrate Heat drying for dehydrating water by heating, hot air drying for blowing heated clean air onto the substrate to evaporate water, etc. are used. It takes a long and powerful processing time to completely remove the cleaning liquid and pure water. However, long-time rinsing / drying requires large-sized, complicated, and high-performance processing equipment, and long-time processing also reduces the tact time. -There is a problem that economic efficiency is significantly deteriorated. For this reason, the rinsing and drying processes after the wet cleaning are performed with minimum facilities and equipment within a range that does not impair productivity.

[0011]

However, in order to clarify the cause of the adhesion failure of the color filter, the present inventors conducted a detailed analysis of the substrate after passing through the cleaning process. Disconnection during etching of the transparent conductive film in the filter, (2) the need for an intermediate layer in the STN color filter, and (3) unevenness in the TFT color filter are all caused by insufficient adhesion of the transparent conductive film. It was found that the cause was insufficient cleaning in the cleaning process, particularly because the cleaning liquid or the rinsing liquid used in the wet cleaning was not sufficiently peeled off and adhered and deposited on the substrate as residue.

The present invention solves the above-mentioned problems. In the wet cleaning, the residue remaining on the substrate after cleaning, particularly, the cleaning liquid or the rinsing liquid used for cleaning is not sufficiently removed, and the flow to the next step is not completed. And the adhesion of the film formed in the next step is reduced, and furthermore, the etching and
It is an object of the present invention to provide a substrate cleaning method and a cleaning apparatus for solving the problem that the quality is remarkably deteriorated by heating and wet heat, without impairing productivity and economy.

[0013]

In order to solve the above-mentioned problems, a transparent conductive film forming apparatus of the present invention has the following configuration.
That is, (1) a method for cleaning a substrate includes a first cleaning step of performing cleaning using a cleaning liquid and a second cleaning step of performing cleaning by exposing the substrate to plasma discharged at atmospheric pressure. A method for cleaning a substrate, comprising:

(2) The method for cleaning a substrate according to (1), wherein the substrate is a transparent substrate or a color filter substrate having an organic film formed on the transparent substrate.

(3) The method for cleaning a substrate according to (2), wherein the organic film formed on the transparent substrate comprises a patterned organic coloring layer and an overcoat layer.

(4) The overcoat layer is made of an acrylic resin, an epoxy resin, a urethane resin, a urea resin, a polyvinyl alcohol resin, a melamine resin, a silicone resin, an imide modified silicone resin, a polyamide resin, a polyamide imide resin, and a polyimide resin. The method for cleaning a substrate according to (3), wherein the substrate is formed from any one selected from the group consisting of:

(5) After the first cleaning step, the substrate is dried at a temperature of 100 ° C. or more and 250 ° C. or less, and then the second cleaning step is performed.
The method for cleaning a substrate according to any one of (4) and (4).

(6) The method for cleaning a substrate according to any one of (1) to (5), wherein a treatment by ultraviolet irradiation is performed before and / or after the first cleaning step.

(7) The cleaning liquid used in the above-mentioned cleaning is pure water or alkali.
(6) The method for cleaning a substrate according to any of (6).

(8) After completion of the second cleaning step, a transparent conductive film is formed on the organic film.
The method for cleaning a substrate according to any one of (1) to (7).

(9) The method for cleaning a substrate according to any one of (1) to (8), wherein the transparent conductive film is patterned.

(10) In a cleaning apparatus for cleaning a substrate, first cleaning means for performing cleaning using a cleaning liquid;
And a second cleaning means for exposing the substrate to plasma discharged at atmospheric pressure to perform cleaning.

(11) A color filter manufactured by using the method for cleaning a substrate according to any one of claims 1 to 9 or the apparatus for cleaning a substrate according to the above (10).

(12) A method for cleaning a substrate according to any one of the above (1) to (9), or a color filter manufactured by using the apparatus for cleaning a substrate according to the above (10). Production method. It is.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a cleaning method for cleaning a substrate, comprising a first cleaning step of cleaning using a cleaning liquid, and a discharge at atmospheric pressure performed subsequent to the first cleaning step. A second cleaning step of exposing the substrate to the generated plasma to perform cleaning.

The substrate used in the present invention is not particularly limited, but a glass having high light transmittance, excellent mechanical strength and dimensional stability is optimal, and soda glass, alkali-free glass, borosilicate glass, quartz glass And the like are preferred.
In addition, a plastic plate such as a polyimide resin, an acrylic resin, a polyester resin, and a polycarbonate resin, a film wound into a roll, and further, metal, wood, and paper can be used. When used for color filters with one or more color patterns, various plastic and inorganic thin films that satisfy the required characteristics of color filters are patterned and laminated on glass, plastic, or film. A composite is used.

The black matrix layer of the color filter substrate used in the present invention is not particularly limited, but may be an inorganic resin such as a multilayer film of chromium, chromium and chromium oxide, chromium nitride, a nickel alloy, a titanium alloy, an acrylic resin, or a polyimide. An organic material in which a black pigment is dispersed in a resin or the like is used. Both inorganic and organic types are preferably used in the present invention, but it is advantageous to use an organic type which is more advantageous in terms of manufacturing cost than an inorganic type which requires a complicated vacuum system for film formation and has less influence on the global environment. desirable. The thickness of the black matrix layer is often 0.1 to 0.3 μm for an inorganic type and 0.5 to 2 μm for an organic type. The black matrix layer usually forms a predetermined pattern by a photolithography method, an inkjet method, or a printing method.

The coloring layer is not particularly limited, but a layer in which a pigment is dispersed in a resin or the like is used. As the resin, a material that does not soften, decompose, or discolor even in an annealing treatment at 180 ° C. or higher can be used. Epoxy resin, urethane resin, urea resin, acrylic resin, polyvinyl alcohol resin, melamine resin, polyamide resin, polyamide imide Resins, polyimide resins and mixtures thereof are preferably used. Among these, a polyimide resin, an acrylic resin, or an epoxy resin, which is excellent in heat resistance and adhesion, is more preferable.

The color filter of the present invention forms an overcoat layer if necessary. The overcoat layer is not particularly limited, but includes a polyimide resin, a silicone resin obtained by condensation polymerization of an organosilane, an imide modified silicone resin obtained by condensation polymerization of an organosilane and a compound having an imide group, an epoxy resin, and an acrylic resin. Resin, urethane resin, urea resin, polyvinyl alcohol resin,
Melamine resin, polyamide resin, polyamideimide resin, and the like are used.

The transparent conductive film used in the present invention includes:
There are tin oxide, indium oxide, zirconium oxide, zinc oxide, cadmium oxide, indium oxide (ITO) to which tin oxide is added, and among others, ITO is preferable in terms of high transparency and low resistance. The addition amount of tin oxide in ITO is preferably in the range of 5 to 15% by weight to reduce the resistance value, and more preferably 8 to 12%.

The thickness of the transparent conductive film varies depending on the required surface resistance value, but is preferably in the range of 0.01 to 0.5 μm, more preferably 0.05 to 0.3 μm. If the film thickness is too thin, the film will not be uniform and the resistance value will be unstable. On the other hand, if the film thickness is too large, the transparency of the film deteriorates.

The transparent conductive film is formed by a sputtering method, since a film having a low resistance value and a high transparency can be obtained even if the film is formed at a temperature of 250 ° C. or less so as not to damage the color filter. Is preferred. Among them, the DC magnetron sputtering method which can obtain a high film forming rate is more preferable, but the present invention is not limited to these. As a type of the film forming apparatus, a batch type, an in-line type, a single-wafer type, and the like can be used, but an in-line type is preferable in terms of excellent productivity. In the case of the in-line type, by providing a heat treatment chamber after the deposition zone, annealing can be performed without impairing productivity. As the sputtering target, an ITO sintered body target or an indium-tin alloy target can be used.

The film forming temperature of the ITO film is desirably in the range of 20 to 180.degree. C. since it becomes an amorphous state and the residual stress can be reduced, and more preferably 80 to 160.degree.
If the film is formed at a temperature exceeding 180 ° C., the ITO crystallizes at the time of film formation, resulting in a film having large residual stress, which is not preferable. If the residual stress is too large, there is a problem that the adhesion of the ITO film is deteriorated. When the ITO film is formed at a low temperature of 200 ° C. or less, it is preferable to perform an annealing process after the ITO film is formed in order to improve the resistance value and the transmittance of the ITO film. The annealing temperature is desirably in the range of 180 to 280C, more preferably 200 to 260C. 180
If the temperature is lower than 0 ° C., the film is not crystallized, and even if the film is annealed, the resistance is not lowered to a practical level, which is not preferable. Also, 280
If the temperature exceeds ℃, it exceeds the heat resistance temperature of the resin or pigment used in the colored layer, and therefore, it is not preferable because unevenness occurs in the color filter and the color is faded.

In the cleaning apparatus according to the present invention, the transfer of the processing substrate may be performed as a batch process or as a single-wafer process. As a method of transporting the substrate when performing the single-wafer processing, there are a transport roller, a transfer machine, a transport arm, a suction table, and the like, and transport by the transport roller is preferably used, but is not particularly limited.

In the cleaning method according to the present invention, first, a first cleaning step of performing cleaning using a cleaning liquid is performed. The washing liquid used here is not particularly limited, and for example, a nonionic or ionic surfactant, pure water, an acid or alkali aqueous solution, functional water such as ozone water or ion water, or the like is preferably used. Among them, NaOH, which is particularly effective in decomposing and removing organic pollutants such as oils and fats,
An aqueous solution of an inorganic alkali such as KOH or an aqueous solution of an organic alkali such as tetramethylammonium hydroxide, ammonia or choline is preferably used.

The concentration and temperature of the alkaline solution are appropriately selected depending on the kind of the alkali used, the kind of the organic film of the color filter to be treated, and the like. For example, when the color filter after the formation of the acrylic overcoat is washed using tetraammonium hydroxide, the concentration is preferably in the range of 0.1 to 5 wt%, and particularly preferably 0.5 to 2 wt%. %. Further, the temperature is preferably used in a range of 15 to 60 ° C, and particularly preferably used in a range of 20 to 40 ° C.

As a processing method, various methods such as a spin method, a shower method, and a dip method are selected, and are appropriately selected depending on the shape of the substrate and the transfer method. At this time, the cleaning can be performed more effectively by appropriately combining physical cleaning such as brush cleaning, jet spray cleaning, ultrasonic cleaning, and megasonic cleaning.

After the wet cleaning using the cleaning liquid, a rinsing step and a drying step for removing the cleaning liquid and drying the substrate are preferably performed. Usually, pure water is often used as the rinsing liquid, and treatment methods such as spin method, shower method, dipping method, brush cleaning, jet spray cleaning, ultrasonic cleaning,
It is preferable to use a combination of physical cleaning such as megasonic cleaning as appropriate from the viewpoint of improving the cleaning power.

The rinsed pure water is dried by a drying device. The drying device is not particularly limited, and various drying devices such as air knife drying, spin dry, pull-up drying, vacuum drying, heat drying, and hot air drying can be appropriately used in combination. Among them, it is preferable to use heat drying in that moisture on the substrate surface can be efficiently evaporated and removed. As a heating method, a hot plate method in which a substrate is heated by bringing a substrate into close contact with or close to a flat metal plate, an IR oven method using an infrared heater or an infrared lamp as a heating source, or hot air in a closed box is used. A hot-air oven system for circulating and heating the substrate is generally used. The substrate temperature during drying is preferably as high as possible to promote the evaporation of water, but care must be taken because if the temperature is too high, the underlying substrate is damaged. Therefore, the drying temperature is preferably from 100 ° C to 250 ° C, and most preferably from 150 ° C to 200 ° C.

Further, in the present invention, after the wet cleaning is performed, the substrate is exposed to plasma discharged at atmospheric pressure as a second cleaning step to clean the substrate. The substrate surface is treated by the excited active species generated by plasma discharge at atmospheric pressure.However, unlike conventional plasma cleaning equipment, discharge is performed under atmospheric pressure, and no vacuum equipment is required. Since it can be used in a system, the apparatus can be simplified and downsized, and furthermore, continuous processing by in-line equipment is possible. Further, since the excited active species are directly supplied to the substrate, the residual can be removed at a much higher speed as compared with the conventional UV-ozone cleaning. By utilizing the plasma discharge under the atmospheric pressure, both productivity and economic efficiency can be improved.

Further, the plasma generated under the atmospheric pressure has a short mean free path and a small diffusion, so that only the substrate surface can be treated. Therefore, it is possible to remove only the residue of the surface cleaning solution by ashing. Hardly cause physical and electrical damage to the substrate itself. That is, compared to plasma generated under reduced pressure, damage to a substrate to be processed is small, and only a portion to be processed can be partially and selectively processed. For removal, a plasma treatment under atmospheric pressure can be suitably used.

The processing method using the atmospheric pressure plasma is not particularly limited. However, a high voltage or high frequency DC voltage is applied to the supplied gas to generate plasma, and the gas excited by the plasma is used to process the gas itself. Alternatively, a method of exposing the substrate surface to clean the substrate surface can be suitably used. The gas supplied at this time is preferably an inert gas or a mixed gas of an inert gas and a reactive gas in order to stabilize the discharge. Helium, as an inert gas,
Argon, neon, krypton, or the like can be used, but helium or argon is preferably used in consideration of discharge stability and economy. The reaction gas can be arbitrarily selected depending on the substrate to be processed and the type of cleaning liquid adhering to the substrate surface as residue. For example, in the case of tetraammonium hydroxide, it is preferable to use an oxidizing gas such as oxygen, air, CO ₂ , and N ₂ O.

The method of exposing the substrate to the atmospheric pressure plasma includes a direct method in which the substrate is directly transported into the plasma to perform the plasma processing, and a method in which the active species generated in the plasma generating unit are not exposed to the plasma. Any of the indirect methods of conducting a treatment with a gas or the like to the substrate disposed in the substrate can be suitably adopted. However, in the former direct method, when there are protrusions and irregularities on the substrate surface,
For example, when metal is present inside the substrate or on the surface layer, such as when the black matrix layer is made of chromium, a strong plasma is generated partially, resulting in variations in the processing range and discharge marks on the substrate surface. Electrical damage may occur. Therefore, when employing the direct method, it is preferable to optimize plasma generation conditions such as applied power, introduced gas, electrode structure, and electrode-substrate distance, depending on the discharge state and the processing substrate, and furthermore, the surface of the substrate to be processed In order to eliminate irregularities, protrusions, and the like as much as possible, it is preferable to polish or remove the protrusion. Of course, it is also preferable to improve the flatness of the treated surface as much as possible by overcoating in order to prevent local plasma damage.

On the other hand, when performing the plasma processing by the latter indirect method, the distance between the substrate and the plasma becomes important. Since the active species generated by the plasma have a lifetime, if the distance between the substrate and the plasma is too large, the processing capacity is significantly reduced. Therefore, there is a certain restriction on the distance relationship between the substrate and the plasma, and the distance between the plasma and the substrate is preferably within 30 mm, more preferably within 10 mm. However, it is hardly damaged by the plasma, and it is possible to perform a partial and selective treatment by using a substrate transfer facility such as an XY stage. The second cleaning step of exposing and cleaning the substrate can be more suitably used.

In the present invention, subsequent to the drying step in the first cleaning step using the cleaning liquid, a second cleaning step using plasma discharged at atmospheric pressure is performed. As a method of transporting the substrate between the first cleaning step and the second cleaning step, the substrate is continuously transferred and processed by a transfer conveyor, a transfer arm, a transfer robot, or the like using a roller or a spherical roller. Although it is more preferable to prevent the particles from re-adhering, for example, AGV (Automated G
uided vehicle) or RGV (Rail G)
uided Vehicle), MGV (Manual
Even if the substrate is transported to the second cleaning step after completion of the first cleaning step via a transfer device such as Guided Vehicle), the same effect can be obtained. Further, before, after, or before or after the first cleaning step, dry cleaning such as surface treatment by ultraviolet irradiation is performed, and then a plasma processing under atmospheric pressure, which is the second cleaning step, is performed. This is also preferable in the present invention because the cleaning effect by dry cleaning is taken into consideration and the residue can be removed by plasma.

[0046]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited thereto.

(Example 1) A length of 400 mm and a width of 50 made of non-alkali glass (OA-10, manufactured by Nippon Electric Glass)
A black color paste was spin-coated on a transparent substrate having a thickness of 0 mm and a thickness of 0.7 mm, and then dried by heating at 110 ° C. for 15 minutes to obtain a polyimide precursor film having a thickness of 1.5 μm. A positive photoresist is spin-coated on this film,
For 20 minutes to obtain a resist film having a thickness of 1.0 μm. Then, after UV exposure through a photomask,
Tetramethylammonium hydroxide 2.4%
After removing unnecessary portions of the photoresist and the polyimide precursor film by etching using a developing solution composed of an aqueous solution of the above, the remaining photoresist was removed by methyl cellosolve acetate. This was heated at 300 ° C. for 30 minutes to form a light-shielding layer having a predetermined shape. Next, red, green, and blue pixels having a predetermined shape were formed on the substrate by using a red paste, a green paste, and a blue paste. On this, a transparent imide-modified silicone resin is dried to a thickness of 1
After coating to a thickness of μm, this was dried to produce a color filter with an overcoat.

After the color filter substrate with the overcoat was cleaned by a cleaning apparatus, an ITO film used as a transparent conductive film was formed by a sputtering method.

FIG. 1 is a schematic view of a cleaning apparatus showing an example of the cleaning method according to the present invention. The cleaning apparatus is a single-wafer processing, performs a first processing tank 1 for cleaning using an alkaline solution, a second processing tank 2 for rinsing with pure water, a third processing tank 3 for draining, and Fourth processing tank 4 for drying and fifth processing tank 5 for performing plasma processing under atmospheric pressure
It is composed of The first processing tank 1 had a length of 300 cm, the third processing tank 3 had a length of 100 cm, and the other processing tanks had a length of 200 cm. The substrate 6 was transported in the cleaning device at a speed of 130 cm / min by the substrate transport roll 7.

As the alkaline liquid, 0.8% tetramethylammonium hydroxide (T
MAH) was supplied to the front and back surfaces of the substrate by the detergent shower 8, and the cleaning was performed by the rotating brush 9. The detergent shower 8 and the pure water shower 10 described later used nozzles that spread in a fan shape, and were arranged such that the liquid spread over the entire surface of the substrate when the substrate was transported. As the material of the rotating brush 9, nylon 6-10 roll brushes were installed facing each other on both sides of the substrate. The diameter is 70 mm and the total length is 400 mm. The number of rotations is 400 rpm, the distance between the brushes is 300 mm for both upper and lower sides, and the amount of the brush 9 pressed into the substrate 6 is adjusted so that the brush is pressed into the 0.5 mm substrate. did.

In the second processing tank 2, pure water is supplied to the entire surface of the substrate 5 by a pure water shower 10 in order to remove the TMAH solution adhering to the substrate surface, and 5 kg / cm
Rinsing ability was enhanced by using high-pressure pure water of No. ² .

Next, in the third processing tank 3, the pure water on the surface of the substrate 6 is blown off by the air knives 11 arranged above and below to dry the substrate surface. , The substrate was dried by heating to a temperature of 180 ° C.

Thereafter, plasma was generated in the fifth processing tank 5 using the atmospheric pressure plasma generator 13, and the active species generated in the plasma were led to the surface of the substrate 5 by gas to perform the processing. . The atmospheric pressure plasma generator 13 used was an atmospheric pressure plasma cleaning device Aiplasma manufactured by Matsushita Electric Works Machine & Vision Co., Ltd. At this time, since the processing width of the plasma generator is 50 mm, the substrate 5 is transported to the fifth processing tank 5 by the transport roll 6 and then placed on the XY stage 14 and transported to the left and right at a speed of 100 mm / s. The whole surface was processed. At this time, the processing time with the atmospheric pressure plasma per substrate was 30 seconds. The plasma generator 13 uses a 13.56 MHz high frequency power supply, an applied voltage of 700 kW, and argon 1 as an introduced gas.
0 l / min, helium 2 l / min and oxygen 400
Plasma was generated using a mixed gas of ml / min. The distance between the plasma generator 13 and the substrate 7 was 5 mm.

After the above cleaning, the entire surface of the overcoat layer is coated with a film having a thickness of 3 by magnetron sputtering.
When an ITO film having a thickness of 000 Å was formed, and then the ITO film was patterned by a photolithography method, no etching failure such as ITO peeling or disconnection occurred, and a good pattern could be formed. .

Further, in order to conduct a reliability test of the obtained color filter, the color filter after the ITO film formation was placed in a thermo-hygrostat at a temperature of 60 ° C. and a humidity of 90% for 48 hours, and then placed in an oven for 250 hours. Heat treatment was performed at 1 ° C. × 1 hour, but no defects such as unevenness occurred on the color filter surface.

(Example 2) When a color filter with an overcoat prepared under the same conditions as in Example 1 is cleaned using the same cleaning apparatus as in Example 1, the fourth processing tank 4 for drying the substrate is used. Thereafter, UV-ozone treatment was performed using an excimer UV lamp (Ushio Inc. UER20-172). The excimer UV lamp has an output of 150 W, and three excimer UV lamps are installed in a direction perpendicular to the substrate transport direction, and the total length is 400 m so that the entire width of the substrate can be irradiated.
m. At this time, the processing time by UV per substrate was 30 seconds. Thereafter, plasma processing was performed using the same atmospheric pressure plasma apparatus as in Example 1. Further, after that, an ITO film was formed under the same conditions as in Example 1, and etching was performed in the same manner as in Example 1. As a result, no defect such as peeling or disconnection occurred, and the reliability was the same as in Example 1. Even when the test was performed, no unevenness or the like was generated at all, and extremely good results were obtained.

(Comparative Example 1) A color filter with an overcoat prepared under the same conditions as in Example 1 was used under the same cleaning apparatus as in Example 1 in a state in which no atmospheric pressure plasma was generated, that is, under conditions where plasma processing was not performed. After the cleaning, the ITO film was formed and etched under the same conditions as in Example 1. When the etching was performed, disconnections frequently occurred due to insufficient adhesion between the ITO film and the overcoat film. It became.

(Comparative Example 2) A color filter with an overcoat produced under the same conditions as in Example 1 was used in the same cleaning apparatus as in Example 1, and the same UV cleaning apparatus as in Example 2 was used instead of the atmospheric pressure plasma apparatus. The residue of the cleaning solution was removed by ultraviolet rays using the method. The UV lamp is 1 as in the second embodiment.
It had an output of 50 W, was installed three in the direction orthogonal to the substrate transport direction, and had a total length of 400 mm so that the entire width of the substrate could be irradiated. At this time, the processing time by UV per substrate was 30 seconds. After the UV treatment, the ITO film was formed and etched under the same conditions as in Example 1. When the ITO film was formed and etched, a partial disconnection occurred, a product defect occurred, and the adhesion was practically insufficient. When a reliability test was performed on the substrate after the ITO film formation under the same conditions as in Example 1, uneven reflection and overcoat were partially generated, and the reliability was insufficient.

In the above Examples and Comparative Examples, the cleaning apparatus according to the present invention was used as pre-cleaning before forming the ITO film.
Even when used for cleaning before and after the formation of the black matrix layer and before and after the formation of the alignment film for aligning the liquid crystal molecules in a predetermined direction, the same effect is obviously exerted for improving the adhesion.

[0060]

By using the cleaning device of the present invention,
Insufficient adhesion in the next step due to residue of the cleaning liquid or the rinsing liquid when performing cleaning using the cleaning liquid can be eliminated without impairing productivity and economy.

[Brief description of the drawings]

FIG. 1 is an overall schematic view showing an example of a cleaning device according to the present invention.

[Explanation of symbols]

 1: First processing tank 2: Second processing tank 3: Third processing tank 4: Fourth processing tank 5: Fifth processing tank 6: Substrate to be processed 7: Transport roll 8: Detergent shower 9: Brush 10: Pure water Shower 11: Air knife 12: IR heater 13: Atmospheric pressure plasma device 14: XY stage

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) G09F 9/00 338 G09F 9/00 338 5G435 H01L 21/304 641 H01L 21/304 641 645 645C 645D 651 651G (72) Invention Person Hiroshi Kobayashi 1-1-1, Sonoyama, Otsu City, Shiga Prefecture F-term in the Shiga Plant of Toray Industries (reference) 2H048 BA00 BA02 BA11 BB02 BB37 BB42 2H088 FA21 FA25 FA30 HA01 HA02 HA04 HA12 MA20 2H091 FA02Y FB02 GA02 GA16 LA30 3B AA02 AA46 AB14 BB21 BB82 BC01 CC01 3B201 AA02 AA46 AB14 BB21 BB82 BB83 BB92 BB93 BB96 BC01 CC01 5G435 AA04 AA17 CC12 GG12 KK05 KK07

Claims (12)

[Claims] 1. A method of cleaning a substrate, comprising: a first cleaning step of performing cleaning using a cleaning liquid; and a second cleaning step of performing cleaning by exposing the substrate to plasma discharged at atmospheric pressure. A method for cleaning a substrate, comprising: 2. The method according to claim 1, wherein the substrate is a transparent substrate or a color filter substrate having an organic film formed on the transparent substrate. 3. The method according to claim 2, wherein the organic film formed on the transparent substrate comprises a patterned organic coloring layer and an overcoat layer. 4. The method according to claim 1, wherein the overcoat layer comprises an acrylic resin,
It is formed from any one selected from an epoxy resin, a urethane resin, a urea resin, a polyvinyl alcohol resin, a melamine resin, a silicone resin, an imide-modified silicone resin, a polyamide resin, a polyamideimide resin, and a polyimide resin, or a mixture thereof. 4. The method for cleaning a substrate according to claim 3, wherein: 5. After the first cleaning step, the substrate is removed
The method for cleaning a substrate according to any one of claims 1 to 4, wherein the second cleaning step is performed after drying at a temperature of not less than 250C and not more than 250C. 6. The method for cleaning a substrate according to claim 1, wherein a treatment by ultraviolet irradiation is performed before and / or after the first cleaning step. 7. The method for cleaning a substrate according to claim 1, wherein the cleaning liquid used for the cleaning is pure water or alkali. 8. The method according to claim 1, wherein a transparent conductive film is formed on the organic film after the completion of the second cleaning step. 9. The method for cleaning a substrate according to claim 1, wherein said transparent conductive film is patterned. 10. A cleaning apparatus for cleaning a substrate, comprising: first cleaning means for performing cleaning using a cleaning liquid; and second cleaning means for performing cleaning by exposing the substrate to plasma discharged at atmospheric pressure. An apparatus for cleaning a substrate, comprising: 11. A color filter manufactured by using the substrate cleaning method according to claim 1 or the substrate cleaning apparatus according to claim 10. 12. A method for manufacturing a color filter, comprising manufacturing using the method for cleaning a substrate according to claim 1 or using the apparatus for cleaning a substrate according to claim 10.