JPS6362542A - Film forming method - Google Patents

Abstract

PURPOSE:To form a pattern without causing destruction and erosion of a film by developing a film forming molecule in a patternlike shape on liquid surface and shifting this patternlike film forming molecule to form the pattern on a support. CONSTITUTION:For example, two kinds of film forming molecules are used and one of which is a molecule (this is defined as a molecule A) showing insulation properties for arachidin or the like and the other a molecule (this is defined as a molecule B) showing electrical conductivity for tetracyanoxymethan docosylpyridinium or the like and these two kinds of molecules are alternately developed in the order of A, B, A, B on liquid 5. After forming unimolecular films (a), (b) consisting of molecules A, B in stripe-shape (a1, b1, a2, b2) respectively on the liquid surface 5, a base plate 7 is vertically moved so as to cross the liquid surface 5 and a stripe-shaped distributing pattern is formed on the base plate 7 by shifting them intact.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a film forming method, and in particular, a novel film forming method capable of forming a monomolecular film or a monomolecular film with a desired pattern on a support. It is related to. The method of the present invention is extremely useful for forming organic semiconductor devices and the like, and will greatly contribute to the development of the electronics field, particularly the molecular electronics field or the bioelectronics field.

(Prior art) In recent years, there has been remarkable progress in the field of electronics using organic materials, such as organic conductor elements, and logic elements using organic materials.
, molecular devices such as memory elements, logic elements made of biologically related substances (eg, biochips), and wires made by punching machines have also been created.

Methods for forming organic thin films when creating the above-mentioned famous devices and wiring using such organic materials include, for example, deposition methods such as evaporation, sputtering, and chemical vapor deposition (CVD). , a film formation method such as the monomolecular film accumulation method called the Langmuir-Prodgett method (hereinafter abbreviated as LB method) (for example, see New Experimental Chemistry Course, Chapter 18, pp. 498-507, published by Maruzen, etc.). generally known. Among these, the LB method can easily form a thin film with a high degree of order and uniformity at room temperature and pressure, unlike the above-mentioned deposition methods that require reduced pressure operations.
has been done. This LB method develops a molecule that has both hydrophilic and hydrophobic sites in an aqueous phase and increases its areal density appropriately.If the balance between hydrophilicity and hydrophobicity is appropriate, the molecule is The film is formed by forming a monomolecular film in the aqueous phase -L with the hydrophilic sites facing downward and the hydrophobic sites facing upward.

In other words, such molecules behave as a two-dimensional particle system, and when the areal density of molecules is low, the two-dimensional ideal gas equation of state is established between the area per molecule (molecular zhanzi mending) and the surface pressure. However, when the surface pressure and the surface density of the molecules are increased, the interaction between the molecules becomes stronger.
It becomes a two-dimensional solid "condensation film (or solid film)." This condensed film has well-aligned molecules and a high degree of order and uniformity. This condensed film can be transferred one layer at a time to a substrate such as glass, and by transferring the monomolecular film in one layer or multiple times on the same substrate, the monomolecular film or monomolecular cumulative film can be transferred from the substrate to the substrate. You can get it easily. The monomolecular film or the molecule-accumulated film thus obtained is a film of extremely high quality with a high degree of order. The methods of transferring to the substrate include vertical immersion method,
Known methods include the water mop deposition method and the rotating drum method.

By using such a production method, various elements such as those listed in h.
At that time, the patterning process for shaping the thin films that make up the functional parts and wiring parts of these elements into the desired pattern is performed using the formation method described in Section F.
It has been common practice to form a film on a substrate by the Q method and then mechanically peel off or remove the # film by etching.

However, this method requires a separate patterning process after film formation, which increases the number of steps.Furthermore, since the film is subjected to physical treatment such as mechanical or etching or chemical treatment after film formation, the film may be damaged by chemical erosion. This may lead to deterioration of the characteristics of the resulting element or wiring.

(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned points, and the purpose of the present invention is to eliminate the drawbacks of the conventional film forming method and prevent film destruction. It is an object of the present invention to provide a novel film forming method that allows pattern formation without causing melt damage and does not cause deterioration of device characteristics.

Another object of the present invention is to provide a novel film forming method that simplifies the number of steps and allows easy patterning even at room temperature and pressure.

(F stage for solving the problems) The above objects of the present invention are achieved by the present invention as described below.

That is, the present invention is a film forming method characterized by forming a pattern on a support by spreading film forming molecules in a pattern on a liquid surface and transferring the patterned film forming molecules.

That is, the method of the present invention specifically applies to the above-mentioned 1 1
In method 1, when deploying a sample molecule on the liquid surface, the film-forming molecule is developed in a shape corresponding to the desired element or wiring pattern, and the film-forming molecule spread on the liquid surface is Film formation is performed by transferring the pattern as it is onto a support. Therefore, in the method of the present invention, patterning is performed at the same time as film formation, and the number of steps in forming elements or wiring can be simplified. Furthermore, since pattern formation does not require special treatments such as conventional mechanical peeling or etching, it does not deteriorate the characteristics of the resulting elements or wiring, and can be easily formed at room temperature and pressure F. It is possible to do this.

In the present invention, the film-forming molecules developed on the liquid surface can be selected and used as desired depending on the required wiring, device characteristics, etc., but the molecules may contain both hydrophobic and hydrophilic sites. Molecules that can easily form a monomolecular film on the liquid surface are preferably used. Specifically, for example, Japanese Patent Application Laid-Open No. 60-246
Examples include charge-transfer type amphipathic organic compounds as disclosed in Japanese Patent No. 357.

Moreover, the support to which the film-forming component p is transferred can be appropriately selected and used according to the required wiring, device characteristics, etc., as well as the film-forming molecules. Specifically, various types of substrates are representative. Of course, the substrate material, shape, etc. are not particularly limited. In addition to such a substrate, the support may be a semiconductor element or the like on which functional layers of various patterns are provided.

Hereinafter, the present invention will be described in detail with reference to the drawings as necessary.

FIG. 1 shows one basic aspect of the present invention. That is, in the present invention, film-forming molecules are spread on the liquid surface in a pattern, as shown in FIG. 1(a), for example.

In this example, two types of film-forming molecules are used, one of which is a molecule that exhibits insulating properties such as araxic acid (this is referred to as molecule A), and the other is a molecule that exhibits conductivity such as tetracyanokidimethanandocylviridinium (this is referred to as molecule A). These two types of molecules are placed on the liquid surface 5 as shown in FIG.
B, A, B...... Expand alternately in the order,
Single molecules 11i each consisting of molecules A and B are on the liquid surface 5.
a, b in striped form (e.g. a8, b3, al,
b2+++...) After forming it,
The substrate 7 was moved vertically up and down across the liquid surface 5 and transferred as it was, and a striped wiring pattern as shown in FIG. 1(b) was formed on the substrate 7.

In the present invention, the above-mentioned spreading of the film-forming molecules onto the liquid surface may be carried out, for example, as follows.

First, the film-forming molecules are dissolved in a required solvent, such as chloroform for the above-mentioned araxic acid, or a mixed solvent of acetonitrile and benzene (1:1) for tetracyanoquidimethanandocylpyridinium. It is developed into an aqueous phase that has a moving barrier etc. that can make the area of the liquid surface variable. At this time, for example, if you want to obtain a striped pattern made of two types of molecules as shown in FIG. The surface pressure of the molecules is raised to obtain a monomolecular film Al. At this time, the moving barrier 4-2 is moved to 4-1 by the hook IO.
It is possible to move back and forth in the same way.

Next, after providing a fixed barrier (not shown) to prevent film diffusion so as to be adjacent to the moving barrier 4-1, the moving barrier 4-1 is moved backward in order to spread the portion 7-B on the liquid surface. move it. In this state, the migration barrier 4-1 and the previous molecule 11Qa
Molecule B is expanded between + and the migration barrier is moved forward in the same manner as above to obtain a monomolecular film. By repeating these operations sequentially, molecules A and B become al, bI,
A stripe-like pattern is obtained on the liquid surface, which is alternately repeated in the order of al, b2-.... On this occasion,
The fixed barrier is preferably moved sequentially each time molecules are spread on the liquid surface, and removed after pattern formation on the liquid surface.

By variously changing the shapes of the moving barrier and the fixed barrier, it is possible to obtain not only the stripe pattern described above but also a pattern of a desired shape on the liquid surface. In addition, it is not necessary that two types of molecules are developed on the liquid surface; for example, it is possible to obtain a pattern by developing molecules A and B as a mixture of molecules each on the liquid surface, or three or more types of molecules can be developed on the liquid surface. Of course, it is also possible to obtain a pattern in which the molecules are independent from each other using the molecules.

Next, FIG. 2 shows an example of an apparatus suitable for implementing the method of the present invention.

The apparatus of this example is suitable for obtaining the above-mentioned stripe pattern, and what is indicated by reference numeral 3 in the figure is a water tank that holds an aqueous phase 13 in which film-forming molecules are developed.

The water tank 3 is provided with moving barriers 4-1 and 4-2. The movement barriers 4-1 and 4-2 are connected to a surface pressure control device 2 connected to a surface pressure sensor 6 via a surface pressure gauge 1, and the surface of the film-forming molecules detected by the surface pressure sensor 6 is The surface pressure of the film-forming molecules can be controlled by controlling the movement of the barriers 4-1 and 4-2 based on the pressure, and independent and arbitrary movement of each is also possible. In addition, what is indicated by the reference numeral 7 in the figure is a substrate as a support, and 8 is a substrate holder that can be moved up and down with respect to the liquid level 5. Transfer of the film-forming molecules to the substrate 7 is as follows.
This is done by moving the substrate 7 held by the substrate holder 8 up and down across the liquid level 5.

Sei II as above! Using two apparatuses, film formation is performed, for example, by the following operations. In addition, the film-forming molecules developed on the liquid surface will be explained as two types, A and H as described in nf.

First, the liquid surface is cleaned, and one side of the solution of film-forming molecules dissolved in the required solvent is poured into the dropper as shown in Fig. 3(a).
2 or the like onto the liquid surface 5 to spread out the molecules on the liquid surface.

As mentioned in 11f1, the film-forming molecules spread out on the liquid surface behave as a two-dimensional particle system, and when the surface density of the molecules is low, there is a two-dimensional ideal relationship between the area per molecule (molecular occupied area) and the surface pressure. It becomes a "gas film" in which the gas equation of state holds true. Next, from this state of the gas film, the moving barrier 4-1 is gradually moved to the left as shown in Figure 3(b), and the area of the liquid surface where the molecules are spread is gradually reduced to increase the areal density. When we increase the intermolecular phase! 1 action becomes stronger, and it becomes a two-dimensional solid "condensation film (or solid film)" through a two-dimensional liquid film.

In this way, a monomolecular film a having M thin film properties with a high degree of order and uniformity in which the molecules are arranged and oriented well is obtained on the liquid surface 5.

At this time, while measuring the surface pressure of the monomolecular film on the liquid surface with the surface pressure sensor 6, the left and right movement of the moving barrier 4-1 is controlled,
Set the surface pressure to be suitable for transfer to the substrate and development of the next molecule. Generally, the suitable surface pressure for transferring to the substrate is 1
It is about 5 to 35 dyn/cm.

After setting such a surface pressure, a fixed barrier 9 for preventing IIQ diffusion is provided adjacent to the moving barrier 4-1,
Thereafter, as shown in FIG. 3(C), the moving barriers 4 to 1 are moved to the right again, and as shown in FIG. 3(d), molecules different from those previously developed are deployed on the liquid surface. . Thereafter, the same operations as above are performed to obtain a monomolecular film made of the molecules as shown in FIG. 3(e).

After repeating this molecule development operation to obtain a striped pattern on the liquid surface similar to that shown in FIG. 1 for each surface (see FIG. 3(f)), the substrate (not shown) was By moving the monomolecular film vertically across the liquid surface 5 and transferring the patterned monomolecular film onto the substrate surface, the pattern of the monomolecular film can be formed on the ζ plate. On this occasion,
By repeatedly moving the substrate up and down, it is possible to obtain a layer of accumulated molecules formed in a pattern on the substrate. Below L of the board is
It is preferable to carry out the process at a speed of about O1-1 c+n/sec.

In addition, the surface pressure sensor is operated during the transfer to the board.
-2 control (in this case, moving barrier 4-1
does not move). For reference, an example of the transfer state of the film-forming molecules 11 onto the substrate 7 is shown in FIG.

Although not specifically shown in 2 above, the film can be transferred to the J and L plates by the vertical immersion method 111 mentioned above, as well as by water immersion method.
Of course, it is also possible to use the drum adhesion method or the rotating drum method.
It's Hi.

〔Example〕

Examples of the present invention are shown below.1-0 Example 1 Using a film forming apparatus as illustrated in FIG. 2, the striped wiring pattern illustrated in FIG. 1 was created in the following manner.

There are two types of composition IIQ component Y-, one of which is araxic acid having insulating properties, and 3 x 10" mol of the molecule.
A chloroform solution of /ff was first adjusted to:A. Separately, using conductive docosylpyridinium ditetracyanoki dimethane as the other film-forming molecule, a solution of 3 x 10゛4 mol/u of this molecule in benzenely acetonitrile (1:1) was prepared. did.

These molecules were added to the aqueous phase (concentration 4 × 10°' mol/fL,
A cadmium chloride aqueous solution (pH 5, 6, water temperature 20° C.) was developed, and wiring in the above stripe pattern was created as follows according to the method illustrated in FIG.

First, an araxic acid solution is spread on the liquid surface 5 of the cadmium chloride aqueous solution, and after the solvent is evaporated and removed, the transfer barrier 4 is moved and the surface pressure is increased to 10 dyn/sing to form a monomolecular film a of araxic acid. Figure 3 (b)
reference).

Next, a fixed barrier 9 was placed adjacent to the moving barrier. After moving the migration barrier 4 to the initial position, docosylpyridinium ditetracyanokidimethane is spread on the liquid surface between the single molecule 11q of alaxic acid and the migration barrier, see FIG. 3(d). ). After removing the solvent by evaporation, the moving 1IiX wall 4 was moved, the surface pressure was increased to 30 dyn/cm, and a single molecule of docosylpyridinium-ditetracyanokidimethane ++i b was formed on the liquid surface to a width of 5 mff1 (see Fig. 3(e)).

After that, repeat the same operation until the liquid level reaches 5. A striped pattern as shown in FIG. 3(f) was obtained.

Finally, the glass substrate (30x IO+nm) was placed at a speed of 10
By transferring the pattern on the surface by making one reciprocation across the liquid surface at a rate of mm/sec, a striped wiring pattern with docosylpyridinium ditetracyanoki dimethane as a conductive layer is formed on the substrate. Obtained. The wiring pattern obtained in this way has no damage to the film and has excellent conductivity.
It was something.

Example 2 A striped wiring pattern was created in the same manner as in Example 1, except that an azulene-based squarylium dye was used instead of araxic acid, and the same results as in Example 1 were obtained.
! ? Ta.

Example 3 A striped wiring pattern was created in the same manner as in Example 1 except that octadecylpyridinium-ditetracyanoquinodimethane was used instead of docosylpyridinium-ditetracyanoquinodimethane. Results similar to 1 were obtained.

〔Effect of the invention〕

As explained above, in the method of the present invention, patterning is performed at the same time as film formation, so that it is possible to simplify the number of elements f or the number of culms during wiring formation. Also,
When forming a pattern, there is no need for conventional treatments such as mechanical stripping or etching, so there is no deterioration in the characteristics of the resulting elements or wiring, and the film can be easily formed at room temperature and pressure. It is highly anticipated that it will make a major contribution to the future development of the electronics field.

4. Brief explanation of the figures Figures 1(a) and 1(b) are schematic diagrams for explaining the basic aspects of the method of the present invention. FIG. 1(b) shows one mode when the molecules are developed on the liquid surface, and FIG. 2(a) shows one mode when the film-formed molecules are transferred to the support -L. 2(b) to 2(b) are examples of a film forming apparatus suitable for embodying the method of the present invention, and FIG. 2(a) is a schematic perspective view of the apparatus, and FIG. 2(b) is a schematic perspective view of the apparatus. A schematic cross-sectional view of the Ji device is shown.
3(a) to 3(f) are diagrams for explaining an example of a film forming operation in the method of the present invention, respectively, and FIG. 4 is a diagram for explaining an example of a state in which film forming molecules are transferred to a substrate. This is a diagram.

Claims (2)

[Claims] (1) A film forming method characterized by forming a pattern on a support by spreading film forming molecules in a pattern on a liquid surface and transferring the patterned film forming molecules. (2) The pattern on the support is a monomolecular film or a monomolecular cumulative film of molecules having at least a hydrophilic site and a hydrophobic site. Film formation method.