JPS63162058A - Organic thin film forming device - Google Patents

Abstract

PURPOSE:To cumulatively form a hetero-structured film of good quality, by providing plural each other independent water tanks developing each monomolecular film of each amphiphilic organic molecule, and constructing so as to transfer a sample base plate from outside of said water tanks. CONSTITUTION:Each monomolecular film of each amphiphilic organic molecule is developed in the plural each other independent water tanks 1-3. In order to stick a monomolecular film to a base plate, a base plate driving means 18 horizontally keeps the base plate and drives it up and down. And a base plate transfer means consisting of guide rails 37, a screw 38, a motor 39 and gears 40 transfers said base plate between the water tanks 1-3. As a result, a hetero-structured film of good quality is cumulatively formed.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an organic thin film forming apparatus, and more particularly to an organic thin film forming apparatus for obtaining a beta structure film in which a plurality of types of organic thin films are accumulated. Regarding.

(Prior Art) In recent years, there has been remarkable progress in material technology using organic molecules, and as a result, there is a growing momentum to realize new functional elements using organic molecules. In particular, the development of devices using ultra-thin films made of organic molecules is being actively studied.

Conventional methods for forming organic thin films include the spin code method, vacuum evaporation method, and Langmuir-Prodgett method.
The ir-Brodgett method and the like are known. Among these, the Langmuir-Prodgett method in particular has attracted a great deal of attention in recent years as the only thin film forming method that can align and stack organic molecules in units of λ. In the following description, the Langmuir-Prodgett method will be abbreviated as the LB method, and the film formed by this LB method will be referred to as the LB method.
Devices to which the LB method is being considered include MiS-type light emitting devices (IS) transistors using the LB method as an insulating film, photoelectric conversion devices using dye molecules, optical recording media, various sensors, and devices using polar film structures. There are piezoelectric elements, etc. Also L
The use of BIEQ as a resist for ultrafine processing is also being considered.

By the way, in the usual LB method, a single amphiphilic molecule is spread on the water surface, compressed to a predetermined surface pressure to form a condensed film, and then the sample substrate is coated with this monomolecular film. A method is adopted in which a thin film of organic molecules is accumulated on the substrate by moving it up and down across the substrate. This method is called the vertical immersion method.

On the other hand, a method of depositing an organic molecule thin film onto a substrate by bringing the sample substrate into contact with the developed monomolecular film in parallel is called a horizontal deposition method. The structure of the cumulative monolayer obtained by these methods is Y-type, in which hydrophilic groups and hydrophobic groups are accumulated adjacent to each other, and X-type, in which hydrophobic groups are accumulated adjacent to the parent group. and Y type. Due to the parent-like or hydrophobic nature of the substrate surface, the hydrophilic group side of the first monolayer attached becomes the substrate side, and the parent group of the next monolayer is attached to the hydrophobic group of the monolayer, and the monolayers are sequentially attached. X is the accumulation of molecular membranes
Y-type is the type that accumulates in the opposite way.

In any of the above-mentioned methods, the range of application is limited if the cumulative monolayer is made of a single component.

Therefore, research on methods for forming alternately cumulative films (heterostructure films) of different types of molecules is increasing. In order to accumulate multiple types of organic molecular films, it is necessary to spread different organic molecular films in different areas in the water tank, and then sequentially immerse the sample substrate into the areas where the specific monomolecular films have been spread. . All of the conventionally proposed apparatuses for forming such alternating cumulative films are those in which a single water tank is divided by a fixed barrier so that a plurality of types of monomolecular films can be developed. The lower portions of the organic molecular membrane development regions separated by fixed barriers are in communication, and water is common to all development regions. However, such a conventional alternating cumulative film forming apparatus has the following problems.

First, in order to develop a monomolecular film, it is desirable to optimally set aqueous phase conditions (for example, pH 9 temperature, ion concentration) depending on the organic molecule. However, in a common water tank, it is not possible to set different pH values, temperatures, etc. for different monomolecular film development areas. Therefore, the selection range of developing molecules is limited. In addition, in order to transport the sample substrate between different monomolecular film development areas, (a) a fixed barrier is formed of a flexible material and a gate section is provided thereon through which the sample substrate support rod can pass; , (b) It has been proposed to use a fixed barrier as a rotation axis to hold a sample substrate on the fixed barrier so that it can be rotated. However, when the sample substrate is transported through the gate section in the structure (a), mutual mixing of developed molecules and fluctuations in surface pressure occur. This makes it difficult to form a good quality heterostructure film. In addition, in these configurations, the type of alternate cumulative film is 2f! J, it is not possible to accumulate three or more types of monomolecular films.Furthermore, in these conventional devices, the sample substrate must be transported inside a water tank, which causes peeling of the organic thin film already attached to the substrate. There are cases.

Furthermore, since all of the above methods are film forming methods based on the vertical dipping method, the Y-type hetero-cumulative film (
A structure in which 114 water groups or hydrophobic groups are adjacent to each other can only be obtained. For this reason, there arises the disadvantage that it is not possible to adequately cope with the formation of various film structures including other types, which are required in the development of functional elements that actively utilize interactions between different types of molecules. In this way, conventionally proposed methods produce high-quality heterogeneous molecules composed of multiple different molecules. Itllll! In practice, formation of J is expected to be extremely difficult, and
Its scope of application will also be significantly limited.

(Problems to be Solved by the Invention) As described above, in the conventional organic thin film forming apparatus, since the water tank is common, the selection range of cumulative film constituent molecules is narrow, and the sample substrate is transported inside the water tank. Therefore, it has been difficult to obtain a high-quality heterostructure film composed of various constituent molecular films.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an organic thin film forming apparatus that can obtain a high quality heterostructure film.

[Structure of the invention]

(Means for Solving the Problems) The heterostructure film forming apparatus of the present invention has a plurality of mutually independent water tanks in which a monomolecular film of amphiphilic organic molecules is developed, and A substrate driving means for driving the substrate up and down in order to deposit a monomolecular film on the horizontally held substrate, and a substrate transport means for transporting the substrate between the water tanks outside of each water tank are provided. A compressed WA drive system surface pressure detector for the monomolecular film to be developed is provided for each water tank.

The present invention is further characterized in that, in addition to the basic structure described above, a cassette is provided for partitioning the immersion area of the substrate in the water tank, and a cassette driving means for driving the cassette up and down independently of the substrate. .

(Function) With this configuration, there are multiple independent aquariums, so
The desired aqueous phase composition can be set in each water tank, and each developed molecular film can be made into a desired condensed film6.Furthermore, since the substrate is transported outside the water tank, there is no possibility of contamination with different kinds of developed molecules. This also prevents the peeling phenomenon of the monomolecular film attached to the substrate. Therefore, a high-quality heterostructure film can be obtained, and the substrate can be held horizontally, and a film can be formed on one side of the substrate at the same time, making it suitable for mass production.

In addition, in the present invention in which a partitioning cassette is combined, it is possible to partition the molecular region adhering to the substrate, thereby preventing the adhesion of excess molecules, making it possible to form a uniform heterostructure film. The surface pressure of the unfolded molecules can be lowered before increasing the molecular weight, and destruction of the molecules can be prevented.

(Example) The present invention will be explained in detail below.

FIG. 1 shows an embodiment of a heterostructure film forming apparatus using three completely independent water tanks 1, 2.3 in which three types of amphipathic organic molecules are developed. Each water tank 1°2.3 has a vibration-proof stand 5
is fixed by legs 4.

These water tanks 1, 2.3 each independently have a surface pressure detector and a compression drive system for condensing molecules developed on the water surface into a film at a desired surface pressure. In the figure, the surface pressure detector 7 is shown on the water tank 1, but in reality there are similar surface pressure detectors on the water tanks 2 and 3. This is a so-called Wilhelmy type method that uses an electronic balance to measure the surface tension of a suspended and developed molecular film. Regarding the water 'Wj3, the basic component of the compression drive system is a movable barrier 8 made of Teflon for spreading and compressing organic molecules on the water surface. This movable barrier 8 is held by a parallel spring 9 on a support stand 10, and this support stand 10 is slidably held by a guide 11 fixed to the stand and connected to a screw 12. This screw 12 has both ends attached to the support base 14.
．． 15, and the power from the motor 13 is transferred to the gear 1.
6.17. That is, by driving the motor 13, the movable barrier 8 is moved by the screw 1.
2, thereby forming a condensed film with a predetermined surface pressure. The configuration of the compression drive system is the same for the other water tanks 1 and 2 as well. In the figure, the drive unit including the motor is installed on the left side for water tanks 1 and 2, and on the right side for water tank M93, but this is due to consideration of storage space.The substrate for forming 6 films is placed horizontally. A substrate driving device 18 is provided to perform vertical movement such as holding the substrate and lowering it to the surface of the aquarium and lifting it up.

The electric transmission mechanism between each water tank of the board driving device 18 is constructed on pillars 36a and 36b fixed on the vibration-proof pedestal 5. The configuration of this transport mechanism is as follows. The power of the motor 39 as a drive source is transmitted to the screw 3 through a gear 40.
8, and the substrate driving device 18 can freely move in the air between the water tanks by being guided by the guide rails 37.

Figure 2 is the board drive system! ! 18 details. A motor 29 is fixed on the support substrate 30 as a power source for vertically moving the substrate 20 as a sample.

This power is transmitted to the screw 27 via the gear 28 and applied to the support base 50 on the guide 26. This support stand 50
A guide 51 holding the substrate 20 is attached above. By driving the motor 29, the sample substrate 20 can be moved up and down the water surface of the water tank any number of times.

Further, the partition cassette 31 is held on an arm 32 fixed on a guide 33 via a screw 34 so that the partition cassette 31 can be moved independently of the vertical movement of the sample substrate 20.

Here, the partition cassette 31 is in the form of a thin film, for example, about one inch thick, and is suitably made of a material such as Teflon (PTFE composite material). Note that the partitioning cassette 31 may be a thin wire-like one or the like.The process of forming a heterostructure film using an apparatus configured in this way will be specifically described below.

FIG. 3 shows how the monomolecular film accumulates in each tank when a heterostructure film is formed by moving the substrates in the order of tanks 1, 2, and 3 in a structure in which the partition cassette 31 is not used or is not used. ing. Monomolecular films of different molecules 41, 42, and 43 are formed at a predetermined surface pressure in the water tanks 1, 2, and 3, respectively. First, in step (2) in which the substrate 20 is lowered to the molecules 41 in the water tank 1 and then raised, a monomolecular film is formed with the hydrophobic group side of the molecules 41 in contact with the substrate 20.

Next, this substrate 20 is transported onto the water tank 2, and the molecules 42 in the water tank 2 are
In the step (3) of lowering and then raising the substrate 20 to 0, a monomolecular film of the molecules 42 is accumulated with the hydrophobic groups of the molecules 42 attached to the hydrophilic groups of the molecules 41 that have already been formed. In the step (2) of transporting the substrate 20 onto the aquarium 3, lowering it to the molecule 43 in the aquarium 3, and then raising it, the hydrophobic group of the molecule 43 attaches to the parent group of the molecule 42 that has already been formed. Molecular membranes are accumulated. In this manner, according to this embodiment, since a plurality of independent water tanks are provided, contamination by mixing of developed molecules with each other is prevented. Furthermore, since the aqueous phase composition can be set to arbitrary pH, temperature, and ion concentration in each water tank, the selection range of molecules to be developed is expanded.

Furthermore, since the substrate is taken out of the water tank and transported through the air, it is possible to prevent the attached monomolecular film from peeling off during transport inside the water tank. Furthermore, in the vertical immersion method, the substrate must be moved in and out of the water phase at a very low speed of about 0.3 m/min, which takes time to form a film, but it is not possible to raise and lower the substrate horizontally in this way. This allows film formation to be performed in a short time, making it suitable for mass production.

FIG. 4 shows the process of forming a heterostructure membrane using the partition cassette 31, taking the water tank 1 as an example.

The state shown in FIG. 4(a) shows the state before the molecules 41 developed on the water surface of the water tank 1 form a desired condensation film with the water phase composition 55. In FIG. 4(b), the movable barrier 8 After driving the expanded molecules 41 to form a desired condensed film, the partitioning cassette 31 is lowered to separate the monomolecular film formed at a predetermined surface pressure from the water surface by the area of the substrate 20. Single molecules 41 are accumulated by falling in parallel.

In FIG. 4(c), after bowing the board 20,
After moving the movable barrier 8 to make the surface pressure of the developed molecular film on the water surface smaller than a predetermined value, the partition cassette 31 is pulled up.

Here, the reason why the partition cassette 31 is pulled up after reducing the surface pressure of the developed molecular membrane below a predetermined value is 1. For example, if the partition cassette 31 is pulled up without lowering the surface pressure,
This is because, due to the high surface pressure, surrounding molecules may rapidly flow into the portions of the partition cassette 31 where there is no molecular membrane, leading to the possibility that the molecules may be destroyed.

In FIG. 4(d), the monomolecular film on the water surface is again compressed to a predetermined surface pressure. Here, the same kind of monomolecular film is placed on the substrate 20.
If it accumulates on the same water film, from Figure 4 (a) to (d)
) To accumulate different monomolecular films on the substrate 20 by repeating the process, the substrate transport system is driven and the substrate 20 is transferred to the water tank 2. Alternatively, by moving to the water tank 3 and repeating the same process (Fig. 4 (a) to (d)), many kinds of monomolecular films are formed in the stacking direction, for example, as shown in Fig. 6, hydrophilic groups and hydrophobic groups are separated. Accumulated in adjacent structures.

By using the partition cassette 31, only molecules corresponding to the area of the substrate 20 adhere to the substrate 20. Therefore, unnecessary molecules around the substrate 20 can be prevented from adhering when the substrate 20 is pulled up (for example, the film around the substrate 20 becomes two layers), and a uniform heterostructure film can be formed. Furthermore, by using the partition cassette 31, the surface pressure of the developed molecular film can be lowered after molecules are attached to the substrate 20 as described above, and breakage of the molecules does not occur.

The present invention is not limited to the above embodiments.

For example, in the embodiment, a case was explained in which three water tanks were used, but the present invention is effective as long as there are at least two water tanks.
It is also possible to form a complex heterostructured film by preparing four or more water tanks and deploying various molecules. Further, the specific configurations of the substrate driving means and the substrate transporting means for vertically moving the substrate can be modified in various ways without departing from the spirit thereof.

〔Effect of the invention〕

As described above, according to the present invention, by providing a plurality of independent water tanks and configuring the sample substrate to be transported outside of these tanks, it is possible to cumulatively form a high-quality heterostructure film. A thin film forming device is obtained. In addition, a partition cassette is provided to separate a part of the monomolecular film spread on the water surface of the water tank into which the sample substrate is immersed, and this can be driven vertically independently of the vertical movement of the substrate. By this, a uniform heterostructure film can be formed without causing destruction of the monomolecular film.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a heterostructure film forming apparatus according to an embodiment of the present invention, FIG. 2 is a perspective view showing the substrate drive unit in detail, and FIG. 3 is a perspective view showing a case where a partition cassette is not used. Figures 4 and 5 are diagrams for explaining the state of heterostructure film accumulation.
The figure is a diagram for explaining the state of heterostructure film accumulation when a partition cassette is used.
FIG. 2 is an enlarged view schematically showing a heterostructure film obtained by the method shown in the figure. 1.2.3... Water tank, 4... Legs, 5... Frame, 7... Surface pressure detector. 8... Movable barrier for compression, 9... Parallel spring, 10
...Support stand, 11...Guide, 12
...Screw, 13...Motor, 14
, 15... Support stand, 16.17... Gear,
18... Substrate driving device, 20... Substrate, 26
...Guide, 27...Screw, 28...
・Gear, 29...Motor, 30...
Support substrate. 31... Partition cassette (partition means), 32...
Arm, 33... Support stand 34... Screw, 39... Motor, 36... Pillar, 37... Guide rail, 38... Screw, 39... Motor. 40...gear, 41.42.43...
- Molecules, 50...Support, 55...Aqueous phase composition. Agent Patent Attorney Noriyuki Chika Yudo Kikuo Takehana Figure 2 Figure 3

Claims (4)

[Claims] (1) A plurality of independent water tanks in which a monomolecular film of amphiphilic organic molecules is developed, and a substrate is held horizontally and driven up and down in order to attach the monomolecular film developed in these tanks to the substrate. An apparatus for forming an organic thin film, comprising: a substrate driving means for transporting the substrate; and a substrate transporting means for transporting the substrate between the plurality of water tanks. (2) A plurality of independent water tanks in which monomolecular films of amphiphilic organic molecules are developed, and the substrate is held horizontally and driven up and down in order to attach the monomolecular films developed in these tanks to the substrate. a substrate driving means for partitioning the immersion area of the substrate in the water tank; a driving means for driving the partitioning means up and down independently of the substrate; and transporting the substrate between the plurality of water tanks. 1. An apparatus for forming an organic thin film, comprising: a substrate conveying means. (3) The organic thin film according to claim 1 or 2, wherein each of the plurality of water tanks is provided with a compression system for the monomolecular film to be developed and a surface pressure measuring device. Forming device. (4) The substrate transport means includes a guide rail that is disposed above the plurality of water tanks and slidably suspends the substrate drive means, and a means for driving the substrate drive means along the guide rail. An apparatus for forming an organic thin film according to claim 1 or 2, characterized in that the apparatus comprises: