JP2677587B2 - Organic thin film manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to an apparatus for producing an organic thin film, and more particularly to an apparatus for producing an organic thin film by the Langmuir-Projet method.

(Prior Art) Recently, Langmuir. Research and development of electrical devices using organic thin films made by the projet method (LB method) is becoming active. In order to apply the organic thin film prepared by the LB method to the device, it is necessary to manufacture a cumulative film having a uniform structure and no defects.

In the LB method, first, the molecules spread on the water surface are compressed by compression until they become a condensed film. The surface molecular density of the monomolecular film is monitored as a surface pressure π by a surface pressure gauge and compressed to a predetermined value. Next, the substrate usually rises and falls vertically to the water surface, and the monolayer on the water surface is accumulated on the substrate.

(Problems to be solved by the invention) In the LB method, by performing cumulative operation of the substrate, the monolayer on the water surface near the substrate decreases and the surface pressure decreases, but this decrease immediately spreads over the entire monolayer and is averaged. As detected by the surface pressure gauge, the device moves the bar in the direction of compression until the surface pressure returns to a predetermined value. In this way, it is possible to always carry out the accumulating operation at a predetermined surface pressure, and a cumulative film having a constant surface molecular density can be obtained on the substrate. However, the molecule exhibiting the above properties is an aliphatic molecule or the like. Limited to a very small number. On the other hand, dye-containing molecules and molecules such as macromolecules have large viscoelastic properties of a monomolecular film, and a decrease in surface pressure near the substrate does not reach the surface pressure gauge. The viscoelastic property of a monolayer on the surface of water is the propagation and relaxation characteristics of stress (surface pressure) generated when an area strain is applied to the monolayer. The viscosity of the monolayer causes a delay in the time it takes for changes in surface pressure to propagate to the surface pressure gauge. Since the accumulating operation is continued as it is, the surface density of the condensed film in the vicinity of the substrate is unilaterally decreased, and it is not possible to obtain a defect-free accumulative film having a highly viscoelastic molecule.
There is a moving wall system as an apparatus for manufacturing an organic thin film that has been improved so as to be compatible with molecules having high viscoelasticity. In this moving wall system, the entire side wall of the organic thin film developed on the water surface is uniformly moved at the same speed as the compression bar. However, the inventors of the present invention have conducted intensive studies and found that for molecules with high viscoelasticity, the monolayer on the surface of the water near the bar moves at almost the same speed as the bar, but the monolayer on the surface of the water located far from the bar. Since the molecular film hardly moves, if the monolayer is compressed by the moving wall method, the monolayer will be pulled in the direction of movement of the side wall at a location separated from the bar, and excessive compression will be performed on the side wall. I will end up. For this reason, the compression of the monomolecular film on the water surface becomes non-uniform, and if it is compressed to a predetermined pressure, the monomolecular layer may also collapse, and it is not possible to form a clean LB film without defects.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an apparatus for manufacturing an organic thin film capable of forming an LB film having a uniform structure and no defects.

[Configuration of the invention]

(Means for Solving the Problem) The present invention relates to a container A containing a liquid for developing a film-forming molecule, and the inside of the container A for compressing the area of the molecule developed in the container A. In an apparatus for producing an organic thin film having a compressing means for sliding, an expandable and contractable operating wall provided on the sliding surface of the container A and having an end fixed to the sliding surface of the container A and the compressing means is provided. This is a device for manufacturing an organic thin film.

(Operation) In the apparatus for producing an organic thin film according to the present invention, the operation wall contracts as the compression means compresses the monolayer on the water surface.
That is, since the operation wall near the compression means moves in the compression direction along with the movement of the compression means, even the molecules having high viscoelasticity move in the compression direction in the molecules near the side wall. At a position far from the compression means, the monomolecular film on the water surface hardly moves, but the moving wall hardly moves. In this way, the moving wall, which is a side wall, moves about the same distance as the moving distance of the monomolecular film on the water surface, so that the film is uniformly compressed in the entire container A.
Therefore, it becomes easy to control the surface pressure of the monolayer on the water surface,
It becomes possible to accumulate clean LB films without defects.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of an organic thin film manufacturing apparatus according to the present invention. In FIG. 1, the trough (1) is filled with water, and a monomolecular film is developed on this water surface. The monolayer is compressed into the movable compression barrier (2). The moving movable barrier (2) is driven by the driving means 3, and this movement causes the working wall (4) to contract. The operation wall (4) is fixed at 5 and 6 to the movable compression barrier (2) and the trough (1) so as not to affect the movement of the operation wall. The surface pressure is measured by the pressure sensor (7).

The trough (1) and the movable compression barrier (2) are Teflon processed. The operating wall (4) was made of silicone rubber, and the one with the length of the inner wall of the trough was about 1/2 so that it could be expanded and contracted to the vicinity of the center of the trough. Other than these, fluororubber, nitrile rubber, polyethylene-polypropylene, terpolymer, etc. may be used.

In this embodiment, the operation wall (4) is arranged so as to be the inner wall of the trough (1), but the operation wall may be provided at a position separated from the inner wall of the trough by a predetermined distance. Further, the operation wall (4) may be fixed to the trough (1) at any position as long as it is the inner wall of the trough, and it is appropriately set according to the compression area, that is, the moving distance of the compression movable barrier. is there. In this embodiment, the operation wall is made of a stretchable and hydrophobic material, but any other material having a stretchable function may be used. It is sufficient that only contraction is possible, and there is no limitation that it may be restored or expanded, but it is preferable that the structure is elastic.

FIG. 2 shows that aluminum stearate, which has a large viscoelasticity, was treated with an organic thin film forming apparatus of this embodiment at a water temperature of 19 ° C., a pH of 4.70,
This is an observation of compression characteristics when expanded and compressed on a water surface with an aluminum concentration of 1 × 10 ^-5 M. Sulfur fine particles were sprayed on the monomolecular film in evenly spaced stripes, and the stripes were obtained after compressing the surface area. It is a pattern. On the other hand, FIG. 3 and FIG. 4 show the same observations with a conventional device (having no operation wall) and a moving wall type device, respectively.

As is apparent from FIG. 2, in the organic thin film forming apparatus of this example, the flow pattern is almost uniformly compressed and there is no distortion in the flow pattern, whereas in the conventional apparatus and the moving wall type apparatus, the flow pattern is distorted. As can be seen, the compression is not uniform across the trough.

 Next, the following cumulative experiment was conducted.

A 25 mm × 40 mm × 0.5 mm silicon substrate was left in a gas phase of hexamethyldisilazane for 24 hours to prepare a completely hydrophobic substrate. The contact angle of this substrate with pure water was measured to be about 90 °. Next, add water (pH 6.0 ±) to the trough (1).
0.1, temperature 19 ± 0.1 ° C).

A solution of 50.8 mg of N, N-dioctadecyl P-phenylenediamine (hereinafter abbreviated as PD-2C ₁₈ ) dissolved in 100 ml of toluene (140 μ) was dropped on the water surface of this example to develop a monomolecular film.

Next, the monolayer on the water surface was compressed until the surface pressure became 25 dyn / cm. The silicon substrate of No. 1 was brought close to the water surface while keeping it horizontal, and the monomolecular film on the water surface was transferred to the glass substrate by contact with the water surface, and the glass substrate was submerged in the water (horizontal deposition method).

A monomolecular film was formed on the water surface in the same manner as above, and the glass substrate inverted in water was pulled up horizontally to accumulate the second layer.

 The operations of to were repeated to form six monomolecular layers.

The organic thin film obtained as described above was observed by a differential interference microscope for dripping of the film structure in air at room temperature, and it was found that no special structure was observed and the film had a uniform and clean film structure.

Comparative Example Similar to the example, 10 layers of PD-2C ₁₈ thin film were accumulated on a silicon substrate using a conventional apparatus.

About the obtained organic thin film, by a differential interference microscope,
When the film was observed at room temperature in air, particles having a diameter of several tens of μm, which are considered to be PD-2C ₁₈ particles, were observed on the entire surface of the film, and it was found that the film structure was not uniform.

〔The invention's effect〕

As described in detail above, according to the present invention, it is possible to provide an organic thin film that can obtain a uniform and clean film structure.

[Brief description of the drawings]

FIG. 1 is a schematic view of an embodiment of the present invention, and FIGS. 2 to 4 are views for explaining the characteristics of the present invention. 1 ... Trough (container A) 2 ... Movable barrier for compression (compression means) 4 ... Wall 5,6 ... Fixed part

Claims (2)

(57) [Claims] 1. An organic apparatus comprising: a container for containing a liquid for developing a film-forming molecule; and a compression means for sliding in the container to compress the area of the molecule developed in the container. An apparatus for producing an organic thin film, comprising: a thin film producing apparatus, which is provided on a sliding surface of a container, and is provided with an extendable and retractable operation wall whose ends are fixed to the sliding surface of the container and the compression means. . 2. The operating wall is arranged perpendicular to the compression means,
2. The apparatus for manufacturing an organic thin film according to claim 1, wherein the apparatus operates so as to correspond to the movement of the compression means.