KR20120039589A - Fluorescence pattern of the fluorescent dye incorporated photo-crosslinkable photoresiet - Google Patents

Abstract

PURPOSE: The fluorescence pattern of photo-crosslinkable photoresist mixed with fluorescent dye is provided to improve visibility and stability by blocking the influence of external environment. CONSTITUTION: Chemically amplified photoresist composition based on crosslinkable polymer, photo acid generator, fluorescent substance, and organic solvent is coated on a substrate. A patterned photo-mask is arranged on the coated substrate to be exposed. Fluorescent patterns(3) are formed based on a post baking operation. The post baking operation is implemented at a temperature between 90 and 120 degrees Celsius for 2 to 8 minutes. The photo acid generator is selected from triphenylsulfonium hexafluoroantimonite and triphenylsulfonium triflate.

Description

Fluorescence pattern of the fluorescent dye incorporated photo-crosslinkable photoresiet}

The present invention relates to a method of forming a fluorescent pattern using a photocrosslinkable photoresist containing fluorescence.

Fluorescent materials have been used for the brightening of paper and textiles. As a method of forming the fluorescence pattern, published in the journal Polym. Adv. Technol., 17, 841 (2006) 'Fabrication of micropatterns with dyes in polymer films by selective doping of dye vapor in a vacuum'. According to the journal, as a method of forming a fluorescent pattern, the author uses a hydrophilic property of a carboxyl group formed by a photochemical structural change of a photosensitive diazonaphthoquinone (DNQ) material mixed with a novolak-based resin. In this state, a fluorescent dye vapor adsorption method is used and a method of forming a fluorescent pattern by physical adsorption is proposed. However, when the fluorescent pattern is simply formed by physical adsorption, physical loss and long-term stability are disadvantageous. In US Patent 5298363, a fluorescent dye and an acrylic polymer are dissolved in an organic solvent, coated on a glass or silicon wafer surface, and then a pattern is formed by photolysis / removing the irradiated area using a high energy beam or UV through a photomask. The content of forming a pattern by causing a photocrosslinking reaction by adding a photoinitiator and a polyacryl oligomer is described. However, the UV irradiation range is narrow and the photoresist is mainly acrylic type, so there is a limit to use. In addition, since the substrate is made of glass or silicon wafer, its use is also limited.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of forming a fluorescent pattern which maintains a fluorescent color for a long time while blocking the influence of an external environment using a photocrosslinkable photoresist composition including a fluorescent substance having a fluorescent color in a specific light source.

In addition, an object of the present invention is to form fluorescent nano or micro patterns on various substrates using photocrosslinkable photoresist compositions including phosphors.

In the method of forming a fluorescent pattern,

a) coating a chemically amplified photoresist composition comprising a crosslinking polymer, a photoacid generator, a phosphor, and an organic solvent on a substrate, raising a patterned photomask, and then exposing the substrate;

b) forming a fluorescent pattern by postbaking after the exposure;

It relates to a fluorescent pattern forming method comprising a.

The present invention is a chemically amplified photoresist, the crosslinking reaction between the crosslinking polymer chains due to the thermochemical reaction of the photoacid catalyst produced by photolysis of the photoacid generator due to the light irradiation during the exposure in step a) Neka The fluorescent type of the TV type is formed. The fluorescent pattern formed by the fluorescent pattern forming method according to the present invention has the advantage of maintaining the pattern structure firmly and blocking the influence of the external environment due to crosslinking between the polymer chains, thereby maintaining the fluorescent color for a long time.

More specifically, the present invention may be exposed to a light source having a specific wavelength according to the type of photoacid generator in step a) and then crosslinked by a thermochemical reaction to form a fluorescent pattern. In addition, as a substrate, a pattern may be formed on various substrates such as a silicon wafer, a glass surface, a polymer film, or a paper surface. The photoacid generator in step a) may include 0.1 to 5% by weight based on the total photoresist composition.

Hereinafter, the present invention will be described in more detail.

The present invention is a crosslinking polymer in step a) is a vinyl group; Oxetane group; Epoxy groups; Tetrahydrofuran group; Alkoxysilane groups; Carboxyl group and hydroxyl group; Aldehyde and hydroxy groups; A crosslinking polymer containing at least one functional group selected from the group consisting of may be used, and specific examples thereof may include commercially available SU-8 or polyglycidyl methacrylate.

When the chemically amplified photoresist composition is exposed to a light source in step a), as the photoacid generator forms some acid by light irradiation, the acid acts as a catalyst to cause a crosslinking reaction, and post-baking in step b). Crosslinking reaction occurs due to the chain reaction. Due to the crosslinking reaction, phosphors are confined to the crosslinked structure, so that the phosphors can maintain high fluorescence stability as compared with the simple physisorbed phosphors.

In the post-heating reaction in step b), the temperature is more preferably 90 to 120 ° C. under 1 μm of coating thickness, and 2 to 8 minutes of treatment is good. The present invention can use a wide range of cross-linking polymers can be used in a wide range of light sources, more specifically, can be selectively used from 13.4nm (EUV) to 450nm (g-line UV), ArF / KrF / F 2 laser Light such as beams, electron beams, and x-rays is also possible. The pattern formation method is characterized by crosslinking reaction through thermochemical reaction using photoacid generator. The type of substrate is advantageous in that it can be used including not only silicon wafer and glass, but also various kinds of polymer films and paper surfaces.

After coating the chemically amplified photoresist composition in step a) and before the exposure step of exposing the substrate on which the thin film is formed to a light source, a soft-baking process is performed through various heat sources including a hot plate to remove the organic solvent. The adhesion of the thin film surface can be reduced. The soft baking may be processed at 80 to 100 ° C. for 80 to 120 seconds. After performing the soft baking process, the patterned photomask is placed on the coated substrate for pattern formation.

At this time, more preferably, the patterned photomask is raised on the coated substrate in the present invention has the advantage of good UV shielding power and easy manufacturing process.

After the photomask is raised, an exposure step is performed to cure the photoresist composition containing the phosphor, wherein the wavelength of the light source may vary depending on the type of the crosslinked photoresist. More specifically, when SU-8 is used, I-Line UV can be irradiated with a light source. After the post-heating reaction in step b), a fluorescent pattern may be formed by removing the coated photoresist composition in the non-exposed area using a developer.

The present invention provides a fluorescent pattern forming method comprising a photoacid generator in the step a) comprises 0.1 to 5% by weight based on the total photoresist composition. In the present invention, the photoacid generator is diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroarsenate, diphenyliodonium hexafluoroantimonate, and diphenylparadonate. At least one selected from toluenylsulfonium triflate, triphenylsulfonium hexafluoro antimonite, and triphenylsulfonium triflate is recommended. More preferably, triphenylsulfonium hexafluoro antimonite and triphenylsulfonium triflate may be used.

The organic solvent in step a) is not particularly limited, but is preferably propylene glycol monomethyl ether PGME (Propylene Glycol MonomethylEther), gamma butyrolactone (GBR), ethyl lactate EL (ethyl lactate), cyclopenta Non-CP (cyclopentanone), methyl ethyl ketone MEK (methyl ethyl ketone), propylene glycol monoethyl ether acetate PGMEA (cyclohexanone) can be selected from cyclohexanone, more specifically, propylene glycol monoethyl ether acetate PGMEA (Propylene Glycol Monomethyl Ether Acetate).

In the step a), the phosphor may be used without limiting the fluorescent material, and more preferably as a fluorescent dye, Fluorescein isothiocyanate (FITC), Rhodeminbi-isothiocyanate (RITC ( Rhodamine B-isothiocyanate)) can be used to select one or more.

The present invention is characterized by using two or more fluorescent dyes having different excitation wavelengths in order to vary the fluorescent pattern. In the fluorescent pattern forming method according to the present invention, by mixing one or more phosphors in one photoresist solution, only the corresponding fluorescent color can be detected by a fluorescence microscope, and various patterns can be formed.

The fluorescence pattern formed by the present invention is not easily observed in the bright field of the microscope, but when the light and the filter of a specific excitation wavelength are used, the fluorescence pattern can be observed by the color of the fluorescent dye. Therefore, in the case of using a fluorescence microscope, the fluorescent image can be selectively obtained according to the mixed fluorescent dyes by changing the combination of the excitation wavelength and the filter, and a mixed fluorescent image can also be obtained. In addition, since the micropattern can be implemented, it is not easily exposed to the optical or the naked eye, but the fluorescent color can be clearly identified through a fluorescence microscope, so that the fluorescence pattern formed by the present invention can be used for copy protection. More specifically, it can be used as a reference pattern of the copy protection label.

The present invention also provides a method of forming a fluorescent pattern,

It provides a method of forming a fluorescent pattern comprising the step of coating a non-chemically amplified photoresist composition consisting of a photosensitive cross-linked polymer, a phosphor, and an organic solvent on the substrate and raising the patterned photomask. Hereinafter, the fluorescent pattern forming method will be described in more detail.

The fluorescent pattern forming method uses a non-chemically amplified photoresist and relates to a method of forming a negative type fluorescent pattern by photocrosslinking of a photosensitive crosslinked polymer by light irradiation. The fluorescent pattern forming method according to the above method has the advantage of maintaining the fluorescent pattern structure firmly due to the crosslinking between the polymer chains and blocking the influence of the external environment, thereby maintaining the fluorescent color for a long time. In addition, there is an advantage that the fluorescent pattern can be formed on a variety of substrates, including silicon wafer, glass surface, polymer film, paper surface.

The photosensitive cross-linked polymer may use a photoresist including a photosensitive functional group and a functional group, and more preferably, a functional group selected from azoketo group, azide group, and nitrobenzyl group as the light sensitive functional group. The functional group may include at least one functional group selected from a hydroxy group, an amine group, a primary or secondary amine derivative group, an acyl halide group, a benzene group, and a benzene derivative group. Specific examples of the photosensitive crosslinkable polymer include poly (diazo-3-oxo-butyryloxy) ethyl methacrylate-co (poly (2- (2-diazo-3-oxo-butyryloxy) ethyl methacrylate-co). -hydroxyethyl methacrylate) When a non-chemically amplified photoresist composition including the photosensitive crosslinkable polymer is exposed to a light source, the photosensitive functional group is crosslinked between polymer chains during photolysis and recombination reactions. This results in confining the phosphor contained in the crosslinked structure, since the phosphor is confined in the crosslinked structure, and thus the phosphor has a higher fluorescence stability than the physically adsorbed phosphor, and thus the phosphor can maintain the phosphor for a long time. Since the organic solvent is as described above, a description thereof will be omitted.

The wavelength of the light source can be varied depending on the type of photosensitive crosslinking photoresist, so that the application range of the light source is wide. The present invention can reduce the adhesion of the thin film surface by removing the organic solvent by a soft-baking process through various heat sources including a hot plate before coating the photoresist composition and raising the patterned photomask. The pattern is more preferably a pattern. The soft baking is treated at 80-100 ° C. for 80-120 seconds. After performing the soft baking process, the patterned photomask is placed on the coated substrate for pattern formation. After the photomask is raised, an exposure step is performed to cure the photoresist composition containing the phosphor.

The wavelength of the light source during the exposure may vary depending on the conditions of the applied photoresist. After the crosslinking reaction occurs in the photolytic recombination reaction by the exposure, the coated photoresist composition in the non-exposed region is removed to form a fluorescent pattern. The phosphor may be used without being limited to the fluorescent material, and more preferable examples thereof are as described above, and thus will be omitted.

The present invention is characterized by using two or more fluorescent dyes having different excitation wavelengths in order to vary the fluorescent pattern. In the fluorescent pattern forming method according to the present invention, by mixing one or more phosphors in one photoresist solution, only the corresponding fluorescent color can be detected by a fluorescence microscope, and various patterns can be formed.

The fluorescence pattern formed by the present invention is not easily observed in the bright field of the microscope, but when the light and the filter of a specific excitation wavelength are used, the fluorescence pattern can be observed by the color of the fluorescent dye. Therefore, in the case of using a fluorescence microscope, the fluorescent image can be selectively obtained according to the mixed fluorescent dyes by changing the combination of the excitation wavelength and the filter, and a mixed fluorescent image can also be obtained. In addition, since the micropattern can be implemented, it is not easily exposed to the optical or the naked eye, but the fluorescent color can be clearly identified through a fluorescence microscope, so that the fluorescence pattern formed by the present invention can be used for copy protection. More specifically, it can be used as a reference pattern of the copy protection label.

The fluorescent pattern formed by the fluorescent pattern forming method according to the present invention is firmly maintained and blocks the influence of the external environment, thereby maintaining the fluorescent color for a long time. The light source to be irradiated also has a wide range of applications, and shows improved fluorescence characteristics, thereby providing high stability and visibility.

More specifically, after the exposure using a light source of various wavelengths selectively according to the type of photoresist, the fluorescent pattern may be formed by postbaking or photolysis / recombination according to the type. Since the phosphor is confined in the crosslinked net by the reaction, the fluorescence can be maintained for a long time.

The applied substrate of the present invention is not only a silicon wafer, glass, but also a variety of polymer films and papers, etc., there is an advantage that can use a variety of substrates.

In the fluorescent pattern forming method according to the present invention, by mixing one or more phosphors in one photoresist solution, only the fluorescent color can be detected by a fluorescent microscope, and various patterns can be formed. In addition, since the micropattern can be implemented, it is not easily exposed to the optical or the naked eye, but the fluorescent color can be clearly identified through a fluorescence microscope, and thus it can be applied to the copy protection technology.

1 is a result of observing the fluorescence pattern formed in Example 1 according to the present invention through a general microscope and a fluorescence microscope.
Figure 2 is the result of observing the fluorescence pattern formed in Example 2 according to the present invention through a normal microscope and a fluorescence microscope.
3 is a result of observing the fluorescent pattern formed in Example 3 according to the present invention through a general microscope and a fluorescence microscope.

Hereinafter, the present invention will be described by way of example for the detailed description of the present invention, but the present invention is not limited to the following examples.

 Example 1 Glass Substrate

The substrate was cut using a glass cutter blade at 2 cm x 2 cm using a transparent glass slide. In order to improve the adhesion with the photoresist composition, the glass surface was washed after a general washing process and dried. Rhodamine B fluorescent dye was dissolved in propylene glycol monoethyl ether acetate PGMEA (Propylene Glycol Monomethyl Ether Acetate) at a concentration of 0.5 mg / ml, and then a photoresist (SU-8 2000.5 (MicroChem Corp) containing 5 wt% of a photoacid generator for I-line. .) 1: 1 ratio with the solution was mixed to make a fluorescent dye 0.25 mg / ml concentration to prepare a photoresist composition for the fluorescent pattern.

The photoresist composition was dropped on the washed glass surface by about 0.1 ml and spin-coated to prepare a thin film uniformly to a thickness of 1 μm or less. Initial spin coating started at 500 rpm (10 seconds) and reached the final 2000 rpm (50 seconds) and surface coated for a total of 1 minute. The thin film-formed glass pieces are placed on a hot plate and soft-baked at 95 ° C. for 90 seconds to remove organic solvents to reduce the adhesion of the thin film surface. The patterned photomask was placed on it. This was exposed to I-Line UV for 40 seconds to cure the photoresist containing the fluorescent dye, and then heated for 5 minutes on a hot plate to crosslink. (Post Exposure Bake). Using a developer, the fluorescent photoresist in the non-exposed area was removed to form a fluorescent pattern.

1 is a result of observing the fluorescence pattern formed in Example 1 through a normal microscope and a fluorescence microscope. 1 is an image observed with a normal microscope, 2 is a fluorescence image observed through a fluorescence microscope, 3 is a fluorescence formed Represents a pattern.

Example 2 PET Film Substrate

In the same manner as in Example 1, but instead of the glass slide substrate cut and washed with PET (polyethylene terephthalate) 3 cm X 3 cm, used as a phosphor instead of Rhodamine B fluorescent dye fluorescein isothiocyanate (FITC (Fluorescein isothiocyanate)) and the exposure time was 45 seconds difference, and the rest was carried out in the same manner as in Example 1. 2 is a result of observing the fluorescence pattern formed in Example 2 through a general microscope and a fluorescence microscope. 1 is an image observed with a normal microscope, 2 is a fluorescent image observed through a fluorescence microscope, and 3 is a fluorescent pattern formed.

Example 3 Paper Substrate

In the same manner as in Example 1, instead of using a glass slide substrate cut and washed 2 cm X 2 cm of paper, Rhodamine non-isothiocyanite (RITC (Rhodamine B) instead of Rhodamine B fluorescent dye as a phosphor -isothiocyanate)) and the exposure time of 50 seconds was different, the rest was carried out in the same manner as in Example 1. 3 is a result of observing the fluorescence pattern formed in Example 3 through a general microscope and a fluorescence microscope. 1 is an image observed with a normal microscope, 2 is a fluorescent image observed through a fluorescence microscope, and 3 is a fluorescent pattern formed.

1. Images observed under normal microscope
2 Fluorescence Image Observed by Fluorescence Microscope
3 formed fluorescent pattern

Claims (9)

In the fluorescent pattern forming method,
a) coating a chemically amplified photoresist composition comprising a crosslinking polymer, a photoacid generator, a phosphor, and an organic solvent on a substrate, raising a patterned photomask, and then exposing the substrate;
b) forming a fluorescent pattern by postbaking after the exposure;
Fluorescent pattern forming method comprising a. The method of claim 1,
The post-heating reaction in step b) is a fluorescent pattern forming method of 2 to 8 minutes treatment at 90 ~ 120 ℃. The method of claim 1,
The photoacid generator in step a) comprises a phosphor pattern of 0.1 to 5% by weight based on the total photoresist composition. The method of claim 1,
The photoacid generator in step a) is selected from triphenylsulfonium hexafluoro antimonite (triphenylsulfonium hexafluoro antimonite), triphenylsulfonium triflate (fluorescence pattern forming method). The method of claim 1,
The crosslinking polymer in step a) is a vinyl group; Oxetane group; Epoxy groups; Tetrahydrofuran group; Alkoxysilane groups; Carboxyl group and hydroxyl group; An aldehyde group and a hydroxyl group; fluorescent pattern forming method comprising at least one functional group selected from the group consisting of. The method of claim 1,
And a soft-baking process after the coating and before exposure. The method of claim 1,
The phosphor is a fluorescent pattern forming method of two or more fluorescent dyes having different wavelengths. The method of claim 1,
The phosphor is at least one selected from Fluorescein isothiocyanate (FITC), Rhodamine B-isothiocyanate (RITC (Rhodamine B-isothiocyanate)). The fluorescent pattern formed by any one of claims 1 to 5 is a method for forming a fluorescent pattern for copy protection.

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