JP2582089B2 - Photosensitive microgel ultrafine particles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to photosensitive microgel ultrafine particles. More specifically, the present invention relates to resist materials for manufacturing ICs, printed circuit boards, displays, etc.
Or high resolution and high sensitivity, useful as paints, inks, etc., with a particle size of less than 100 nm (nanometers), and even 50 nm
The present invention relates to the following ultra-fine particles of a cinnamic acid-based photosensitive microgel.

(Background Art) Conventionally, photosensitive materials used for resist materials include:
Known are those in which a functional group that reacts to light is introduced into a linear polymer chain, and those in which an additive that reacts to light is added to a linear polymer.

Usually, the performance required for such a resist material includes high resolution, high sensitivity, high dry etching resistance, substrate adhesion, heat resistance, chemical resistance, and ease of removal after use. There are things that conflict with each other.
This is a very important issue when considering photosensitive materials.

For example, high sensitivity is achieved not only by increasing the molecular weight of the material and improving the reactivity of the reactive functional group itself, but also by increasing the concentration of the reactive group and improving the mobility of the polymer chain. . However, the improvement of the reactivity and the concentration of the reactive group and the improvement of the mobility of the polymer chain require the low molecular weight of the raw material itself, dry etching resistance, substrate adhesion, and chemical resistance. Such as performance degradation,
It causes deterioration of material performance.

For these reasons, it is difficult to respond to many different required performances with one resist material. At present, a multi-layered resist in which a plurality of materials are multi-layered is used. These multi-layer resists cause a complicated manufacturing process and an increase in cost. Therefore, it is necessary to realize a high-performance single resist material capable of meeting conflicting performance requirements.

Further, with respect to the printing of a pattern on a resist material and the development thereof, the conventional material mainly utilizes a change in solubility of a polymer caused by light irradiation. In this case, the dissolution of the polymer involves a swelling phenomenon due to the entanglement of the molecular chains, and the swelling of the resist material causes deformation of the formed pattern. Therefore, realization of a non-swelling resist material for obtaining high resolution has been desired.

As described above, conventional resist materials, and even paints,
In the case of inks, etc., materials consisting of linear polymers and photosensitive groups introduced into them have many drawbacks, and it is necessary to realize new structures and photosensitive materials with excellent properties that overcome these drawbacks. I was

More specifically, linear polymers having a cinnamic acid group, which is a photoreactive functional group, are known as distinctive photosensitive substances, and cinnamic acid and its esters are cross-linked by light. This cinnamic acid-based photosensitive polymer has been used for image formation because it causes a reaction to form a cyclobutane ring and insolubilizes, but the reactivity of the photoreactive group and the polymer chain In fact, there is no mutual contradiction between the mobility and various properties such as high sensitivity of the molecular weight and the like, and the problem of expansion has not been solved.

(Purpose of the Invention) The present invention has been made in view of the above circumstances, improves the disadvantages of conventional resist materials and the like, can meet conflicting performance requirements, and has high sensitivity. ,
It is an object of the present invention to provide a new photosensitive material which is not limited in resolution due to swelling of the material. For more information,
Specifically, an object of the present invention is to provide a novel photosensitive material as a cinnamic acid-based polymer.

(Disclosure of the Invention) The present invention provides a photosensitive microgel obtained by reacting acrylate or methacrylate microgel ultrafine particles with cinnamic acid or a derivative thereof to bond cinnamic acid groups in order to achieve the above object. Provide microparticles.

These photosensitive microgel ultrafine particles have a structure in which ultrafine particles made of an acrylate or methacrylate polymer are reacted with cinnamic acid or a derivative thereof, and a cinnamate bond or the like is formed on the surface of the ultrafine particles. is there.

Microgel ultrafine particles composed of an acrylate or methacrylate polymer include (meth) acrylate monomers such as methyl acrylate or methyl methacrylate, ethyl acrylate or ethyl methacrylate, butyl acrylate or butyl methacrylate,
Hydroxyethyl methacrylate having a reactive group with cinnamic acid or a derivative thereof, and ethylene glycol di (meth) acrylate which is a polyfunctional monomer;
Alternatively, it can be produced by adding another olefinic monomer such as divinylbenzene and styrene as necessary and subjecting it to emulsion polymerization. Furthermore, hydroxyethyl cinnamate or the like may be reacted with the gel fine particles having a carboxylic acid group as a reactive group by hydrolysis. In this case, although a surfactant is used, the particle size of the microgel particles differs depending on the amount of the surfactant used. Usually, the smaller the amount used, the larger the particle size, and it has a non-spherical structure in which small particles are aggregated. As exemplified in the examples described below, in the present invention, the microgel ultrafine particles,
It consists of a single particle or an aggregate thereof, and in each case its particle size is generally less than 100 nm (nanometers) and even less than 50 nm.

Such microgel superparticles are dissolved in a suitable solvent, for example, pyridine, DMF, DMSO, other polar solvents, and reacted with cinnamate chloride, cinnamate, etc., and the microgel superparticle surface is treated with a cinnamic acid derivative. Create a bond.

The microgel superparticles having cinnamate groups introduced therein have (a) a much larger molecular weight than conventional linear polymers, and (b) a reactive group bonded to the surface of the ultrafine particles. Is filled with a high concentration of a reactive group, and the sensitivity is extremely high, and the inside of the fine particles can maintain the performance required for a resist material or the like.

(C) In addition, since there is no entanglement of molecular chains as in the case of linear polymers, there is no swelling of the resist during pattern development, and high resolution can be obtained.

Next, examples are shown, and the present invention will be described in more detail with respect to photosensitive microgel superparticles.

Example 1 A monomer mixture consisting of 20 mol% of n-butyl methacrylate, 5 mol% of ethylene glycol dimethacrylate, and 75 mol% of 2-hydroxyethyl methacrylate was
The mixture was added to an aqueous solution containing 10 mol% of sodium dodecyl sulfate based on the total amount of the monomers, and emulsified. A water-soluble polymerization initiator consisting of sodium persulfate was added to this emulsion,
The polymerization reaction was carried out at a temperature of ° C.

After completion of the reaction, sodium chloride was added to separate ultrafine gel particles having a particle size of about 40 nm of a methacrylate polymer as a product.

The resulting gel ultrafine particles were dissolved in pyridine, and the hydroxyl groups in the microgel were reacted with cinnamate chloride to produce photosensitive gel ultrafine particles having cinnamate groups on the surface.

The ultrafine particles were dissolved in chloroform, the solution was applied to a glass plate, and dried to form a film. When the photosensitivity of this film was compared with that of a conventional type of polyvinyl cinnamate, the photomicrogel ultrafine particles of the present invention had a photoinsolubilizing rate that was about 50 times higher and the developing characteristics were good.

Example 2 Ultrafine photosensitive microgel particles were produced in the same manner as in Example 1. However, the ratio of the surfactant (sodium dodecyl sulfate) added as an emulsifier in the production of microgel superparticles was changed as shown in Table 1.

Table 1 shows the particle size of the microgel superparticles and the photosensitivity in comparison with polyvinyl cinnamate in this case.
In each case, it can be seen that excellent sensitivity is exhibited. In addition, the particle size of the microgel superparticle can be controlled by the amount of the surfactant used.

Example 3 Using 50 mol% of n-butyl methacrylate, 2.5 mol% of ethylene glycol dimethacrylate and 47.5 mol% of 2-hydroxyethyl methacrylate, microgel superparticles were produced in the same manner as in Example 1, and then cinnamic acid The cinnamic acid chloride was reacted so that the group became 50 mol%.

The particle size of the obtained microgel superparticle was about 30 nm, and the sensitivity of photosensitivity was about 8 times that of polyvinylcinnamic acid.

Example 4 Methyl methacrylate and a small amount of divinylbenzene were mixed and microgel ultrafine particles were produced in the same manner as in Example 1.

It was dissolved in sulfuric acid and then hydrolyzed to obtain ultrafine DMF-soluble gel particles having a carboxylic acid group as a reactive group on the surface. This was further reacted with 2-hydroxyethyl cinnamate to obtain water-soluble photosensitive ultrafine particles.

(Effects of the Invention) As described in detail above, the present invention provides photosensitive microgel ultrafine particles useful as a resist material or the like, which is a highly sensitive photosensitive material having excellent material properties and a high resolution.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-47-34794 (JP, A) JP-A-49-40391 (JP, A) JP-A-54-126019 (JP, A) JP-A 55-34 156941 (JP, A) JP-A-53-65104 (JP, A) JP-A-55-75403 (JP, A) JP-A-59-117553 (JP, A) JP-A-59-197413 (JP, A) JP-A-62-173455 (JP, A) JP-A-62-177007 (JP, A)

Claims (1)

(57) [Claims] 1. Photosensitive microgel ultrafine particles characterized in that acrylate or methacrylate microgel ultrafine particles are reacted with cinnamic acid or a derivative thereof to bond cinnamate groups.