JP2003257866A - Method for manufacturing thin film pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming a thin film pattern not based on a resist. <P>SOLUTION: An oil repellent - lipophilic patterning or a hydrophilic-lipophilic patterning is formed on a substrate surface, and minute liquid drops of a functional solution atomized by ultrasonic waves are introduced onto the surface together with a carrier gas, to adhere to only a lipophilic part or a hydrophilic part. Thus, a functional patterning film is formed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a thin film pattern on a substrate. The thin film is a functional thin film that exhibits a predetermined function in various electronic devices such as display elements and semiconductor elements.

[0002]

2. Description of the Related Art As a method for forming a highly delicate pattern, there is a pattern forming method by photolithography in which a photoresist layer coated on a substrate is subjected to pattern exposure, and after the exposure, the photoresist is developed to form a pattern. Are known. However, in this method, the resist material coating, drying, exposure, development, and cleaning are repeatedly performed and combined, so that the number of steps is large, the manufacturing process is complicated, the yield is low, and it is a resource-intensive process. ,Also,
Since a large amount of the developing solution and the etching solution are used, there is a problem that it is necessary to treat the waste solution.

Further, a pattern-formed body in which regions having different wettability with a liquid are formed on the surface of a substrate has already been used in a wide range of fields of application. In the field of printing, for example, lithographic printing, the plate used consists of a lipophilic site that receives ink and a site that does not, and forms an image of the ink to be printed on the lipophilic site and transfers it to paper or the like. Is printing.

Japanese Patent Laid-Open No. 2001-288578 discloses that
After forming regions with different liquid wettability on the substrate surface,
A method of applying a liquid only to the lyophilic portion by an ink discharge method is shown. However, in the ink ejection method, since the size of the ejected droplets is as large as 10 μm or more, it is not possible to form a fine pattern, and if the solute concentration of the droplets is reduced to form a thin film of 0.1 μm or less. However, there is a problem in that the film thickness becomes uneven during drying.

JP-A-7-257944 and JP-A-7-257944
JP-A-278817 describes the production of ITO and TiO2 thin films by an ultrasonic atomization film forming apparatus.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method capable of producing a finely patterned functional thin film with a uniform thickness by a simple method without using a photoresist. .

[0007]

In the present invention, a fine pattern of a functional solution is generated by an ultrasonic atomizer and deposited on a substrate at a predetermined position. It is characterized by being a manufacturing method for obtaining a functionalized film.

That is, according to the present invention, a functional solution obtained by forming an oil-repellent-lipophilic patterning surface or a water-repellent-hydrophilic patterning surface on a substrate and forming a mist by an ultrasonic atomizer is provided. Is introduced to selectively form a functional film on the lipophilic or hydrophilic portion having good wettability. The particle size of the droplet can be changed by the frequency of ultrasonic waves. Since the size of the liquid droplet is very small compared to that of an ink jet or spray product, it is easy to form a fine pattern and is suitable for obtaining a functional film having a film thickness of 0.1 μm or less. Also, oil repellent-lipophilic patterning or water repellent-
For hydrophilic patterning, it is preferable to use a self-assembled film.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION As the substrate used in the present invention,
Well-known substrates that are usually used as substrates used for various electronic devices such as display element substrates and printed wiring boards can be widely used. For example, soda lime glass substrate, Si substrate, quartz glass substrate, ITO substrate,
Examples include metal substrates and plastic substrates. Oil repellent on the surface-
In order to perform lipophilic patterning or water repellent-hydrophilic patterning, the surface may be modified with an inorganic film such as SiO2 or an organic-inorganic hybrid film.

A patterning technique such as photolithography is used as a method for performing oil-repellent-lipophilic patterning or water-repellent-hydrophilic patterning on the substrate surface. That is, an oil-repellent film or a water-repellent film is first formed on the surface of the substrate, and then UV is passed through a patterned photomask.
And photoetch it to change its lipophilicity or hydrophilicity.

Oil-repellent-lipophilic patterning or water-repellent-hydrophilic patterning obtained by photoetching is more advantageous for forming a functional film as the difference in wettability is larger.
In the case of oil-repellent-lipophilic patterning, the contact angle of the toluene solvent is 50 ° or more in the oil-repellent portion and 10 ° or less in the lipophilic portion. In the case of water-repellent-hydrophilic patterning, the contact angle of water is It is desirable that the water repellent portion be 90 ° or more and the hydrophilic portion be 10 ° or less.

In order to satisfy the above characteristics, it is preferable to use a self-assembled film formed by monolithically orienting single molecules. That is, in the case of a self-assembled film, the oil repellency or water repellency of the film is very good because the oil repellent group or the water repellent group is oriented on the surface, and since it is a monomolecular film, it is photoetched. Is very fast.

The compound forming the self-assembled film is
Formula (I) below

[Chemical 1] (In the formula, X represents a hydrolyzable group, n represents an integer of 1 to 3, and R represents an organic group.), And a silane coupling agent represented by the formula is preferably used. That is, X
Reacts with the hydroxyl groups present on the substrate to form siloxane bonds with the substrate.

To form an oil-repellent or water-repellent self-assembled film, fluoroalkylsilane (FAS) in which R is a fluoroalkyl group is used. Specific examples of FAS include (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane (heptadecafluoro-1,1,2,2-tetrahydrodecyl) trimethoxysilane, 3- (hepta Fluoroisopropoxy) propyltriethoxysilane, (heptadecafluoro-
Examples of compounds include 1,1,2,2-tetrahydrodecyl) dimethylchlorosilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) trichlorosilane, and 3- (heptafluoroisopropoxy) propyltrichlorosilane. You can

To form the water repellent self-assembled film, R may be an alkyl group containing no fluorine. Examples of the compound include normal hexyl trimethoxysilane (n-
_{C 6 H 1 3 Si (OCH} 3) 3), n-decyl trimethoxysilane _{(n-C 10 H 21 Si} (OCH 3) 3), n-hexadecyl trimethoxysilane (n-C ₁₆ H ₃₃ Si
(OCH _{3) 3)} compounds of the like.

After performing the oil repellent / lipophilic patterning or the water repellent / hydrophilic patterning, another self-assembled film may be formed on the lipophilic part or the hydrophilic part. When forming a film containing a metal such as gold, silver, copper, iridium, or gallium as a functional film, a thiol-based self-assembled film is attached to the lipophilic or hydrophilic part to obtain a good bond with the functional film. To do.
Examples of compounds of the thiol-based self-assembled monolayer include compounds such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropylmethyldiethoxysilane. You can

As a method of patterning the self-assembled film, an ultraviolet irradiation method, an electron beam irradiation method, an X-ray irradiation method, Sc
The anning Probe Microscope (SPM) method or the like can be applied. The ultraviolet irradiation method is preferably used in the present invention. The self-assembled film is irradiated with ultraviolet rays having a predetermined wavelength through a photomask opened to form a pattern, and the film at the irradiated portion is decomposed and evaporated to become lipophilic or hydrophilic. When the self-assembled monolayer is FAS, ultraviolet rays having a wavelength of 250 nm or less are used.

After the oil-repellent-lipophilic patterning or the water-repellent-hydrophilic patterning, a functional film is selectively formed on the lipophilic part or the hydrophilic part to atomize the functional solution by ultrasonic waves. A method of introducing the formed droplets onto the patterning film is used. The droplets atomized by ultrasonic waves have a very small size as compared with those formed by inkjet or spraying, and therefore have a property of being hard to adhere to a portion having poor wettability on the substrate. Spherical droplets change to a liquid film in a portion having good wettability.

The ultrasonically atomized droplets are introduced onto a patterned substrate with a carrier gas. The carrier gas is not particularly limited, but in the case of a functional solution that easily reacts with moisture or oxygen, dry nitrogen gas or dry argon gas is used when the film is oxidatively decomposed after being formed into a film on the substrate. Dry air or oxygen-containing dry nitrogen gas is used. Moisture in the carrier gas is not preferable because atomized droplets tend to aggregate during the introduction.

The size of a droplet atomized by ultrasonic waves is
Can be changed by the frequency of ultrasonic waves (Thin
Solid Films, 77 (1981) 81-9.
0). The droplet size is 1 to 3 μm at a frequency of 3 MHz,
It is 4.5 to 6.5 μm at 1 MHz, which is a feature that the size is very small compared to that of an inkjet or spray product, and it has a property of being hard to adhere to a portion having poor wettability. In addition, the droplets can be easily charged and can be landed on the target pattern by electrostatic repulsion. Also, the target landing point can be specified by passing the atomized droplets through a small-diameter tube such as a nozzle.

There is no restriction on the functional solution to be atomized by ultrasonic waves. Any solution can be used as long as it is a solution capable of forming a film exhibiting functionality such as an organic material, an inorganic material, a metal and an organic-inorganic hybrid. Sol solutions and dispersions can also be used. The particle size of the sol or dispersed particles is 0.5 μm or less,
It is preferably 0.1 μm or less.

The membrane to which the functional solution atomized by ultrasonic waves is selectively adhered to the lipophilic part or the hydrophilic part may be dried and fired in order to exert its function. When baking is performed at about 500 ° C., the self-assembled film of the oil-repellent portion or the water-repellent portion is also thermally decomposed and becomes lipophilic or hydrophilic, so that another pattern formation can be repeated.

[0023]

EXAMPLES The formation of a patterned ITO film by the method of the present invention will be described in detail below. However, the present invention is not limited to these.

Example A SiO ₂ coating solution (Atron Si: manufactured by Nippon Soda Co., Ltd.) was used to form a SiO ₂ film having a thickness of 0.1 μm on a soda-lime glass substrate that had been ultrasonically cleaned by a dipping method. The firing conditions were 500 ° C. and 30 minutes.

After the substrate and the quartz substrate were cleaned with ozone, the substrate was placed in a closed container containing pentadecatrifluorodecyltrimethoxysilane (FAS-17), allowed to stand at room temperature for 3 days, and then at 150 ° C. Dry for 1 hour, then F
A self-assembled film of AS-17 was obtained. The contact angle of water of this film was 105 ° and the contact angle of toluene was 62 °, which showed good water repellency and oil repellency. In the elemental analysis of the film by XPS, the F / C ratio was 1.70, and the methoxy group was completely decomposed. There was no difference depending on the substrate.

Then, a photomask was placed above the self-assembled monolayer of FAS-17 and irradiated with ultraviolet rays of 172 nm to decompose FAS-17 to form a pattern of lipophilic or hydrophilic portions. The contact angle of water on the irradiated portion was 5.2 °, and the contact angle of toluene was 2.1 °.

The solution for forming the ITO film is an acetylacetone solution of In acetylacetonate (concentration: 0.25).
It was prepared by adding Sn acetylacetonate (mol / l) to In in an amount of 10 atom%.

The ultrasonic atomizer is shown in FIG. The frequency was 3 MHz, atomization was performed at a rate of 2.5 ml / min, and dry nitrogen gas was introduced onto the substrate as a carrier gas. The liquid film formed on the pattern was dried at 100 ° C. and then baked at 500 ° C. for 30 minutes to obtain a transparent patterned ITO film. The obtained film has a refractive index of 1.9.
5. The ITO crystal film had a thickness of 0.022 μm. The sheet resistance is 550Ω / □, and the uniformity of the sheet resistance is ±
Within 30Ω / □, transmittance is 91% (wavelength 550nm)
Met.

[0029]

INDUSTRIAL APPLICABILITY The present invention is a method of forming a patterned functional thin film that is not based on a resist, and can provide a novel thin film patterning technique that combines an ultrasonic atomization method and a self-assembled film. According to the present invention, it is easy to form a fine pattern of a functional thin film, and 0.1 μ
A uniform thin film can be formed with a film thickness of m or less.

[Brief description of drawings]

FIG. 1 shows a schematic view of an ultrasonic atomization device in an example.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shigeo Yamada             12-8 Goi Minamikaigan, Ichihara, Chiba Japan Soda             Chiba factory F-term (reference) 5F045 AB40 AC07 AF07 AF16 EE02                       EE13 HA01 HA16

Claims (3)

[Claims] 1. A method of forming a functional patterning film, which comprises depositing droplets of a functional solution atomized by ultrasonic waves on a substrate. 2. A droplet of a functional solution atomized by ultrasonic waves is introduced onto the surface on which the oil-repellent-lipophilic pattern or the water-repellent-hydrophilic pattern is formed, and the functional solution is applied only to the lipophilic part or the hydrophilic part. A method for forming a functional patterning film, which comprises depositing. 3. The method for forming a functional patterning film according to claim 2, wherein a self-assembled film is used for oil-repellent-lipophilic patterning or water-repellent-hydrophilic patterning.