JP2912562B2 - Submicron lithography method for fine particle film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a submicron lithography method. More specifically, the present invention relates to a submicron lithography method for a single-particle film or a multi-particle film of fine particles spread on a solid substrate useful for optical elements, high-resolution printing, molecular photosensitive paper, holograms, information storage elements, and the like. Things.

[0002]

BACKGROUND OF and THE INVENTION Conventionally, as a method for patterning of the single-particle film or the multi-particle film of fine particles developed on the solid foundation, and lithography method, advection aggregate method, a method of radiation polymerization or the like that It is known as a typical one. The lithography method is a monomer / polymer solvent (photoresist) having a photocrosslinking material or photoreactive group.
Is thinly coated on a substrate surface (for example, a wafer), masked, and then irradiated with light (a light having a wavelength at which a photocrosslinking material or a photoreactive group can react) to partially change the solubility of the photoresist (crosslinking reaction). And solubilization by bond breaking) and baking and transferring predetermined patterning. The resist pattern transferred by this method is subjected to processes such as etching, ion implantation, ion beam processing, and plasma processing. In addition, when forming a high-density pattern to avoid blurring of the pattern due to the diffraction effect, short-wavelength ultraviolet rays, electron beams,
X-rays, ion beams and the like are used.

A single-particle film or a multi-particle film by the advection accumulation method is
A method established by the inventors of the present invention,
A single-particle film or a multi-particle film is formed on a substrate by immersing a substrate with a flat surface that is easily compatible with a solvent such as glass in a suspension solvent (for example, an aqueous solution) in which particles are dispersed, and controlling the concentration of particles and the pulling speed. It is a method of forming. Radiation polymerization is a method of irradiating a specific material with radiation or the like to induce a cross-linking reaction or bond breaking within the material, thereby changing the material properties. Generally, it is known that a polymer such as polystyrene causes a cross-linking reaction in a molecule by irradiation with radiation.

However, these conventional methods of forming a pattern using a fine particle film still have problems to be solved. For example, in the case of a lithography method , a photoresist is required to be applied. The resist is not configured for the purpose of surface patterning itself, but is merely removed as a secondary matter. For this reason, a pattern is not formed directly on the surface on which a pattern is to be formed, but is merely an indirect means. In addition, a single-particle layer or a multi-particle film formed by advection accumulation has a limitation that, although a uniform film can be provided over a large area on the substrate surface, a fine pattern is not provided. Further, radiation polymerization is performed for property modification of the entire material, and is not suitable for local modification such as pattern formation. As described above, conventionally, there has been no known means for directly finely and locally patterning a fine particle film constituting a target surface.

The present invention has been made in view of the above circumstances, and solves the problems of the prior art.
A new submicron lithography method that can directly create fine and local positive patterns with fine particles that constitute a single-particle film or a multi-particle film of uniform fine particles
It is intended to provide law .

[0006]

According to the present invention, there is provided an electron beam having a submicron particle size.
Or an electron beam or of the crosslinking reaction by irradiation with ultraviolet rays polymer particles ultraviolet due to crosslinking reaction to produce the single layer or multi-particle film on a solid substrate formed in an integrated
And then heat to melt the unreacted fine particles.
Provided is a submicron lithography method characterized by writing a pattern more directly.

[0007]

According to the present invention, an electron beam or light is directly applied to a single-particle film or a multi-particle film composed of submicron fine particles by the above-described method to locally follow a predetermined pattern. Cross-linking reaction between the fine particles and various chemical reactions change the solubility and melting degree of the fine particles themselves and the aggregate of the pattern arrangement of the fine particles, so that only the targeted patterned single-particle film or multi-particle film Is obtained as a so-called positive pattern. In this case, the fine particles have a particle size on the order of microns, and may be appropriate particles such as polymer fine particles or reactive inorganic substances. Among them, in the present invention, polymer fine particles such as polystyrene, polyacrylate, polyamide, polyurethane, and polyolefin are preferable, and natural or synthetic proteins may be used.

A single particle layer or a multi-particle layer of these fine particles is
It may be one formed on a solid substrate by the advection accumulation method as described above, or one obtained by developing a suspension on a substrate plane and evaporating the solvent. The energy beam may be an appropriate one such as an electron beam, an ultraviolet ray, a laser beam, or an ion. Among them, in the case of a polymer fine particle, an electron beam or an ultraviolet ray can be suitably used.

The type of the substrate is not particularly limited. Glass, ceramics, silicon, other semiconductors and insulators, and also polymers and metals may be used. Less than,
The present invention will be described in more detail with reference to Examples.

[0010]

EXAMPLES As fine particles, monodisperse polystyrene latex fine particles having a particle diameter of 144 nm (Nippon Synthetic Rubber: ST)
ADEX) was used. Glass and silicon wafers were used for the substrates. First, a dense particle film (particles) having a two-dimensional spread from a dispersion of polystyrene fine particles having a concentration of 1 to 0.1 wt% to a solid surface of submicron particles by the advection accumulation method described above, which was devised by the present inventors. Crystal film
The preparation method of the can) be referred to as to form a single particle layer and multi-particle film. These single particle film and multi particle film
Observation with a low-power field emission scanning electron microscope confirmed that the film was actually a single-particle film or a multi-particle film. Particle size 14
In the case of a single-particle film or a multi-particle film of polystyrene having a thickness of 4 nm, light is emitted when light is applied, and thus, a fiber microscope (Scholly: Fiber Optim) is used.
This color development was observed in c).

Next, for example, the single-particle film formed as described above was irradiated with an electron beam of an electron microscope to perform a cross-linking reaction in the fine particles. The electron dose used was 10 ⁵ to 10
The range was ⁸ C m ^-2 . This range is based on the following experiment
Based on strategic considerations. That is, as shown in FIG. 1, in the case of polystyrene latex fine particles, 10 ⁵ Cm
It is confirmed that the cross-linking within the particles starts from around ^-2 , the heat resistance is improved, the melting temperature is raised , and in the case of polystyrene fine particles not irradiated with an electron beam, the melting point is 140 to 150 ° C. I have. Therefore, in this embodiment,
Was irradiated with an electron beam at an electron dose as described above.
Next, the single-particle film after the electron beam irradiation was heated to 160 ° C. or higher to dissolve the unirradiated portion of the polystyrene particles. As a result, the particle thin film remained in the irradiated portion, and the shape of the particles was not observed in the unirradiated portion. From the observation with a fiber microscope, the coloring phenomenon of the polystyrene single particle film of 144 nm was confirmed in the irradiated portion, and no coloring was observed in the unirradiated portion.

The width of the portion irradiated with the electron beam could be reduced to three polystyrene fine particles. In the case of a multi-particle film, since the penetration of the electron beam through the film is not so large, a crosslinking reaction does not occur up to the lowermost particles. Has been confirmed to be preferable as a lithography method .

In the above embodiments, monodisperse polystyrene particles were used as the material of the nanometer particles. In addition, various polymer fine particles (polyacrylic particles) or the like which undergo a cross-linking reaction in the particles may be used. . As the solid substrate for carrying the pattern, any substrate may be used as long as it is used in a method for forming a two-dimensional crystal on the solid surface of nanometer particles. However, a material that is flat compared to the particle diameter is preferred. When applying to electrical and optical characteristics,
A material having conductivity, a material having good transmittance and reflection characteristics, and the like can be considered. For example, metal (gold, silver, platinum, aluminum, etc.)
In addition to high-orientation graphite, ceramics such as silicon, conductive glass (ITO glass), polymers, biological films, and the like may be used.

The particles are used by suspending them in a solvent. However, in addition to the water used here, various organic solvents in which the particles can be dispersed, such as methanol / ether / benzene / emulsion, may be used. As the electron beam source, a source other than the electron gun of the electron microscope used in this embodiment may be used, or a source other than the electron beam, for example, X-ray / ultraviolet light, laser light, or the like may be used. In addition to irradiating a focused beam, a pattern may be formed by masking.

The device used in the present invention may be attached to various devices. Furthermore, the pattern may be developed by melting the unirradiated portion by heating as in the above-described embodiment, or by dissolving with various chemicals.

[0016]

As described above in detail, in the present invention, it is possible to directly form an irradiation pattern in which an irradiation portion is left in a positive type. Further, the single-particle film or the multi-particle film remaining as a pattern develops a unique color. Applications to optical elements, high resolution printing, holograms, applications to information storage elements, etc. are expected.

[Brief description of the drawings]

FIG. 1 is a relationship diagram showing a relationship between an irradiation electron amount to a polystyrene single particle film and melting by heating in an example of the present invention.

Continuation of the front page (51) Int.Cl. ⁶ identification code FI G03F 7/26 521 G03F 7/26 521 7/38 511 7/38 511 (58) Investigated field (Int.Cl. ⁶ , DB name) G03F 7 / 26,7 / 36,7 / 38

Claims (2)

(57) [Claims] 1. An electron beam or a violet having a submicron particle size.
Cross-linking reaction is performed by irradiating an electron beam or ultraviolet ray to a single-layer or multilayer fine-particle film on a solid substrate formed by accumulating polymer fine particles generated by a cross-linking reaction by an external line , and then
A submicron lithography method wherein a pattern is directly written by heating to melt unreacted fine particles . 2. The method according to claim 1, wherein the polymer fine particle film has an electric charge of at least 10 ⁵ Cm ⁻²
After irradiating the particles with a cross-linking reaction to generate a cross-linking reaction,
2. The submicron lithography method according to claim 1, wherein the heat treatment is performed at a temperature of 0 ° C. or more .