JPH05297579A - Fine resist pattern forming material - Google Patents

Abstract

PURPOSE:To obtain a cheap resist pattern forming material which enables fine patterning and gives good working environment by forming a specified plastic film as a protective film on a photosensitive layer formed on a supporting body. CONSTITUTION:A plastic film is formed as a protective film 4 on a photosensitive layer 2 formed on a supporting body 1. This plastic film is subjected to surface treatment so that the interfacial cohesion strength between the protective layer 4 and the photosensitive layer 2 is lower than the interfacial cohesion strength between the supporting body 1 and the photosensitive layer 2 and is lower than the internal aggregation strength of the photosensitive layer 2. As for the protective layer 4, plastic films having high transparency such as polyethylene terephthalate, polyethylene naphthalate, and polyphenylene sulfite can be used. The photosensitive layer is exposed through the transparent protective film for patterning, then the protective film is peeled, and the pattern is transferred to an object for transfer by thermocompression fixing. By transferring the exposed side of the pattern forming material, higher resolution is obtd. than a conventional dry film method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine resist pattern forming material used when various patterns are processed by etching on a substrate or a layer on the substrate.

[0002]

2. Description of the Related Art Conventionally, a screen printing method, an offset printing method, and a dry film method have been widely used for forming a circuit pattern on a printed wiring board, glass or a ceramic board. However, the screen printing method and the offset printing method were suitable for forming a pattern having a relatively large image line width (200 μm or more, and a minimum of 100 μm), but were not suitable for forming an image line width less than that. Moreover, since the ink to be printed has fluidity, there is a drawback that the image area becomes thick due to changes with temperature and aging. For example, in the screen printing method, the line width of the image area to be printed greatly depends on the size of the mesh and the properties of the ink.
The limit is about 00 μm, which is not suitable for a method of forming a fine resist pattern.

Further, in the offset printing method, the ink on the plate is once transferred to the blanket and then retransferred to the printing object, and since the method of transferring twice is adopted, the line width tends to be thick. .. Further, since rubber is generally used for the blanket, the positional accuracy of the image is poor and it is not suitable for forming a fine pattern. In particular, there is a drawback that pinholes and disconnections easily occur in the printed image line due to the characteristics of ink and printing, and it is difficult to form a fine resist pattern. Although the dry film method is actually used for manufacturing a wiring board, the practical minimum line width is about 80 μm. Further, since a polyolefin-based film is generally used as the protective film, the surface of the film is poor in smoothness due to fish eyes in the film, which causes problems such as disconnection of the formed resist pattern and pinholes. However, it is difficult to make the line width fine.

Therefore, in the above method, the resist pattern formation is limited to about 100 μm, and photolithography is generally used for forming a particularly fine pattern. The photolithography method applies a photoresist by spinner coating on the material to be processed, exposes it with an ultraviolet ray through a desired photomask after drying in an oven, and then makes the photoresist a negative type with a predetermined developing solution. If there is a non-exposed portion, and if it is a positive type, the exposed portion is selectively dissolved and removed to form a resist pattern.
However, this photolithography method has many processing steps and is a batch type, so that productivity is poor. In addition, since a large amount of solvent is used in the coating and developing processes, the working environment is bad and there is a problem in safety such as fire. In addition, the restrictions on the apparatus are large, and especially when processing a large substrate or the like, the apparatus becomes expensive, and a large amount of equipment investment is required. That is, there is a drawback that the cost becomes very high in terms of dealing with environmental problems and the size of the processed substrate.

[0005]

DISCLOSURE OF THE INVENTION The present inventor has conducted extensive research in order to solve the above-mentioned problems of the prior art, and as a result, fine patterning can be performed in a relatively simple process, and the screen printing method, offset printing method, Since a solvent such as a photolithography method is not used, an inexpensive resist pattern forming material having a good working environment is provided.

[0006]

That is, according to the present invention, a photosensitive layer provided on a support is subjected to pattern exposure to produce a difference in tackiness between an exposed portion and a non-exposed portion of the photosensitive layer,
Using a pattern forming material, the internal cohesive force of the photosensitive layer transferred to the transfer target such as a substrate is smaller than the interfacial adhesion with the support and the interfacial adhesion with the transfer target. In a resist pattern forming material in which a pattern is transferred to and cured by heat or light, the interfacial adhesive force between the protective layer and the photosensitive layer is provided on the photosensitive layer provided on the support. It is a fine resist pattern forming material using as a protective layer a plastic film having a surface treatment that is lower than the interfacial adhesive strength with and less than the internal cohesive force of the photosensitive layer.

As the support, a plastic film having a rigid and smooth surface such as polyethylene terephthalate, polyethylene naphthalate and polyphenylene sulfide can be used. Generally, polyethylene terephthalate is used, and in particular, biaxially stretched polyethylene terephthalate is suitable in terms of dimensional stability against heat and water and workability. The film thickness of 25 to 250 μm, and more preferably 100 to 200 μm is good for workability and coating stability.

As the protective layer, a highly transparent plastic film such as polyethylene terephthalate, polyethylene naphthalate or polyphenylene sulfide is used. In conventional dry films, polyolefin-based, generally polyethylene film with poor transparency is used as the protective layer film, so the protective film is peeled off during pattern formation and the photosensitive layer side is laminated to the transfer target. After pressure bonding, the pattern exposure was performed from the support side. However, in the method using the fine resist pattern forming material of the present invention, pattern exposure is performed in advance from the highly transparent protective film side, the protective film is peeled off, and then the pattern is transferred to the transfer target by thermocompression bonding. In this method, since the exposed side is transferred, the resolution can be increased as compared with the conventional dry film method. However, when the same type of film is used for the support and the protective layer, particularly when the film having the same surface tension is used, it becomes difficult to peel off the protective film from the photosensitive layer after exposure, so that the protective layer and the photosensitive layer are not exposed. It is necessary to perform treatment for making the interfacial adhesion between the photosensitive layer and the support layer lower than the interfacial adhesion between the support and the photosensitive layer. Examples of the surface treatment agent for the protective film include higher fatty acids such as stearic acid and oleic acid, silicone oil, silicone resin, and fluororesin.

The photosensitive layer eliminates the adhesive force of the cured portion to the transferred material by pattern exposure, enables reproduction of a fine pattern by an appropriate internal cohesive force of the unexposed portion, and peels off the transferred material. Facilitate transfer to.
Having an appropriate internal cohesive force means that the pattern formed by exposure does not transfer at least at all thicknesses, that is, delamination. The internal cohesive force of the photosensitive layer can be variously selected depending on the type or blending ratio of the photopolymerizable compound, dye or pigment used in the photosensitive layer. Furthermore, it also changes depending on the type of the transferred material or the support.

The photosensitive layer is (1) a photopolymerizable compound of a monomer, an oligomer and / or a prepolymer (2) an organic polymer binder which is not photopolymerizable as necessary (3) is activated by actinic rays Photopolymerization initiator (4) Consists of a pigment and / or a dye, and optionally contains a thermal polymerization inhibitor.

Examples of the photopolymerizable compound include (meth)
Acrylic acid, methyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, benzyl (meth) acrylate, carbitol (meth) acrylate, 2-ethylhexyl (meth) acrylate, Lauryl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylamide, N-methylol (meth) acrylamide, styrene, acrylonitrile, N-vinylpyrrolidone, ethylene glycol diacrylate, diethylene glycol di Acrylate, triethylene glycol diacrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butyr Glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,4-butanediol acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol diacrylate, trimethylolpropane triacrylate, dipentaerythritol Hexaacrylate,
Low molecular weight photopolymerizable compounds such as (meth) acrylates of alkylene oxide adducts of phenol, or high molecular weight light such as epoxy acrylates, urethane acrylates, polyester acrylates, alkyd acrylates, acrylate modified products of petroleum resins, and unsaturated polyesters. A polymerizable compound may be used. These compounds are
Used as one kind or as a mixture of two or more kinds.

The organic polymer binder is a thermoplastic,
A polymer having excellent compatibility with a photopolymerizable compound and having no photopolymerizability, for example, polyvinyl chloride, poly (meth) acrylic acid, poly (meth) acrylic acid ester, polyvinyl ether, polyvinyl acetal, urethane resin, epoxy Resin, polyamide, diallyl phthalate resin and the like can be used.

As the photopolymerization initiator, those having a small absorption in the visible light portion are preferable, and for example, benzophenone, 4,4-bis (diethylamino) benzophenone, 4-methoxy-4-dimethylaminobenzophenone, 2-ethylanthraquinone, One or more conventionally known photopolymerization initiators such as phenanthraquinone, benzoin, benzoin methyl ether, and benzoin phenyl ether can be used.

As the pigment and dye, conventionally known pigments can be used. As the dye, a dye identifiable in a yellow room such as malachite green or crystal violet which is generally used in a dry film can be used. As the pigment, an azo-based, phthalocyanine-based, quinacridone-based, anthraquinone-based organic pigment or an inorganic pigment can also be used. The inclusion of dyes and / or pigments in the photosensitive layer provides a contrast between the transferred material and the photosensitive layer when inspecting the transferred pattern after transferring the pattern-exposed photosensitive layer to the transferred material. Is important in the above. In addition, leuco crystal violet is usually used as the photosensitizing dye. Photosensitizing dyes are dyes that change color irreversibly by absorbing light, and after pattern exposure (before transfer)
It is particularly effective when performing the pattern inspection of.

As the thermal polymerization inhibitor, p-methoxyphenol, hydroquinone, t-butylcatechol, pyrogallol, pyridine, arylphosphite, N-nitrosophenylhydroxylamine aluminum salt and the like can be used.

The thickness of the photosensitive layer is preferably about 5 μm. In the research, it was applied on the support using a bar coater, but other coaters can be used as appropriate. next,
Drying after coating can be performed using a hot air oven, a near infrared ray oven, etc., but in the drying step, the photopolymerization initiator does not volatilize so much as to affect the performance, and the photopolymerizable compound does not polymerize so that the oven Care should be taken regarding the temperature range and coating speed. The drying temperature and the coating speed cannot be specified because they are determined by the volatility and reactivity of the photopolymerizable compound. After coating and drying, a protective layer is laminated on the side of the photosensitive layer coated on the support to protect it from air oxidation and polymerization inhibition effect by air during exposure.

In the exposure, the protective layer side is exposed to ultraviolet rays through a desired photomask. At that time, an ultra-high pressure mercury lamp is used as a light source and exposure is performed at about 100 mJ / cm ² . In addition to this, mercury lamps, metal halide lamps,
It is possible to use a xenon lamp. By taking advantage of the difference in adhesiveness between the exposed and non-exposed areas of the photosensitive layer due to pattern exposure, the protective layer is peeled off, and then non-transferred to a transfer object such as a copper plate, ITO film, or polysilicon film by thermal lamination. The photosensitive layer in the exposed area is transferred. In this case, since the internal cohesive force of the non-exposed portion of the photosensitive layer is smaller than the interfacial adhesive force with the support and the interfacial adhesive force with the transfer target,
Cohesive failure occurs inside the photosensitive layer, and the non-exposed portion is pattern-transferred from the fracture surface to the transfer target.

After the transfer to the transfer object, the non-exposed portion transferred by the post-exposure is cured to complete the formation of the resist pattern. After this, a conductive pattern can be formed by etching according to the required requirements. For example, when the transferred body is a copper plate, the wiring pattern can be formed by removing unnecessary copper portions with an etching solution such as ferric chloride solution and peeling off the remaining resist film on the copper wiring.

The cured resist film can be peeled off with a solvent or a physical method, but if the above conditions are inconvenient due to process restrictions, carboxylic acid is added to the resin and monomer of the photosensitive layer. By introducing it, a water-soluble alkali stripping agent can be stripped with an amine-based stripping solution, especially when sodium and potassium ion-free is required. In this case, the introduction of the carboxylic acid into the resin and the monomer is
It is necessary to adjust the acid value to around 100-200.

[0020]

Embodiments of the present invention will be described below. However,
The present invention is not limited to the examples below. [Example 1] Polyester (TOYOBO Byron 300)
19.5 parts was dissolved in 45.5 parts of MEK (methyl ethyl ketone) and shaken for 48 hours to prepare a polymer solution. Next, 2 parts tetraethylene glycol diacrylate (A-4EG manufactured by Shin-Nakamura Chemical), 3 parts trimethylolpropane triacrylate (ATMPT manufactured by Shin-Nakamura Chemical), 2-hydroxy-
2-Methyl-propiophenone (Merck Darocur
1173) 0.7 parts, benzophenone (KAYACURE manufactured by Nippon Kayaku)
0.7 part of BP) and 0.1 part of dye (Malachite Green manufactured by Hodogaya Chemical Co., Ltd.) were added to 65 parts of the polymer solution and stirred by a disper to obtain a photosensitive solution.

The prepared photosensitive solution was applied by a bar coater to a biaxially stretched polyethylene terephthalate film (125 μm thick) which was the support 1, and an infrared lamp (3 kw)
It was irradiated for 30 seconds and dried to form a photosensitive layer 2. The coating amount at this time was 5 μm in dry film thickness. On the dried photosensitive layer 2, a polyethylene terephthalate film (12 μm thick) whose one surface was treated with a silicone release agent (TSM6822 made by Toshiba Silicone) was used as the protective film 4, and the treated surface 3 was placed on the photosensitive layer side. Then, a sandwich structure pattern forming material was prepared. The positive film of the reverse image or the photomask 5 of the reverse image is accurately aligned on the protective film 4 side of the created film by using a register pin or the like, and is used for 30 seconds with a 1.5 kw ultra-high pressure mercury lamp (Camo Denken) ( Pattern exposure was performed by performing pattern exposure of 100 mJ / cm ² ).

Then, the polyethylene terephthalate film of the protective film 4 is peeled off, the photosensitive layer 2 is brought into close contact with the substrate 11 (amorphous silicon), and pressure (50 kg / cm ² ) is applied to transfer it, and then it is supported. By peeling the polyethylene terephthalate film which is the body 1 from the substrate 11, a resolution of 50 μm corresponding to the pattern positive film was obtained. During the transfer, about 3/4 of the photosensitive layer was transferred. Further, the pattern transferred onto the substrate 11 was exposed again using an ultra-high pressure mercury lamp to make the reproduced pattern stronger. Next, using the resist pattern 9 as an etching resist, the substrate is treated with an acid (hydrofluoric acid: nitric acid = 1: 3).
After etching at 0), the resist was peeled off with 1,1,1-trichloroethane, and the intended wiring pattern could be obtained.

[Example 2] 12 parts of diallyl phthalate (DAPL manufactured by Osaka Soto Co., Ltd.) was dissolved in 70 parts of MEK, and trimethylolpropane triacrylate (ATMPT manufactured by Shin Nakamura Chemical Co., Ltd.) 6
Parts and 6 parts of 2-hydroxypropyl acrylate (M-600A manufactured by Kyoeisha Oil and Fat) were mixed. Furthermore, 1.0 part of benzophenone (KAYACUREBP manufactured by Nippon Kayaku Co., Ltd.), 0.2 part of ethyl ketone (manufactured by Hodogaya Chemical Co., Ltd.), and 1.2 parts of pigment (Lionol Blue FG7330 manufactured by Toyo Ink Mfg. Co., Ltd.) were added to the above solution, and the mixture was shaken with a paint conditioner for 2 hours to be exposed. As a sexual solution.

This photosensitive solution was applied in the same manner as in Example 1 to prepare a pattern forming material, which was subjected to pattern exposure, transferred to the substrate 11 (amorphous silicone vapor-deposited glass substrate) and reexposed. By doing so, a resist pattern was formed. The obtained pattern has a resolution of 20 μm, which corresponds to a pattern positive film, and the transfer of the photosensitive layer is about 1
It was / 2. Further, the substrate 11 is treated with acid (hydrofluoric acid: nitric acid = 1: 1: using the obtained resist pattern 9 as an etching resist).
After etching with 30), the resist was removed with an amine-based release agent (MICROPOSIT Remover 1112 manufactured by Shipley Far East).
The target wiring pattern could be obtained by peeling by A).

[0025]

[Table 1]

[0026]

According to the present invention, the conventional screen printing method,
Compared to the offset printing method, finer and more accurate resist pattern formation is possible, and the resolution is comparable to that of the photolithography method. Further, in terms of work environment and safety, it is superior to each of the above-mentioned methods, and in terms of equipment, it is possible to manufacture at a low cost because it does not require expensive and complicated equipment as compared with the photolithography method with excellent resolution. It can be applied to etching resists on various substrates.

[0027]

[Brief description of drawings]

1 is a sectional view of a resist pattern forming material of the present invention, FIG. 2 is a conceptual view of a pattern exposure step, FIG. 3 is a sectional view of a resist pattern forming material after peeling a protective film, FIG. 4 is a conceptual view of a pattern transfer step, FIG. 5 is a conceptual diagram of the post-exposure step after pattern transfer.

[0028]

[Figure 1]

[0029]

[Fig. 2]

[0030]

[Figure 3]

[0031]

[Figure 4]

[0032]

[Figure 5]

[0033]

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Support 2 ... Photosensitive layer 3 ... Release agent treated surface 4 ... Protective film 5 ... Photomask 6 ... Ultraviolet 7 ... Exposed part 8 ... Non-transfer resist layer 9 ... Transfer resist layer 10 ... Amorphous silicon 11 ... Glass plate

Claims (4)

[Claims] 1. A photosensitive layer formed on a support by pattern exposure to produce a difference in tackiness between an exposed portion and a non-exposed portion of the photosensitive layer and transferred to a transfer target such as a substrate. By using a pattern forming material whose internal cohesive force of the layer is smaller than the interfacial adhesion between the support and the transferred material,
In a resist pattern forming material in which a pattern is transferred to an object to be transferred by heat or pressure and is cured by heat or light, an interfacial adhesion between a protective layer and a photosensitive layer is provided on a photosensitive layer provided on a support. A fine film characterized by using as a protective layer a plastic film having a surface treatment that has a force lower than the interfacial adhesion between the support and the photosensitive layer and weaker than the internal cohesive force of the photosensitive layer. Resist pattern forming material. 2. The fine resist pattern forming material according to claim 1, wherein the photosensitive layer contains a dye and / or a pigment. 3. The fine resist pattern forming material according to claim 1, wherein the photosensitive layer contains a dye that develops color by photosensitization. 4. The fine resist pattern forming material according to claim 1, wherein the hardened resist layer in which the photosensitive layer is hardened can be removed by an alkaline aqueous solution.