JPS60193531A - Film forming device - Google Patents

Abstract

PURPOSE:To enable easy continuous accumulation of monomolecular films by providing a means for decelerating the flow of a liquid for spreading molecules for film forming to a liquid tank contg. said liquid. CONSTITUTION:A means 7 for decelerating the flow of a liquid for spreading molecules for film forming is provided in a liquid tank 3 contg. said liquid. A good film having 90- about 100% rate of accumulation is obtd. when the accumulation of the monomolecular films on a substrate is executed by a vertical dipping method. The accumulating operation is thereafter repeated under the control of the flow rate so as to maintain the specified surface pressure while the decrease in monomolecular films 2 as a result of transfer to the substrate in an accumulating region 10 is compensated by dropping a film constituting material in a dropping region 9. As a result, the continuous accumulation which is difficult with the conventional device is easily made possible.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an apparatus for producing a thin film, which is a functional part of a semiconductor or an optical device, and particularly relates to a production apparatus for a thin film that is a functional part of a semiconductor or an optical device, and in particular, a single molecule accumulation method,
That is, the present invention relates to an LBH manufacturing apparatus using the Langmuir-Blodgett method (LB method).

(Background Art) Conventionally, the use of materials in the semiconductor technology field and the optical technology field has mainly focused on inorganic materials that are relatively easy to handle. One reason for this is that the technological progress in the field of organic chemistry has been much faster than that in the field of inorganic materials.

However, recent technological advances in the field of organic chemistry have been remarkable, and it is said that the development of materials for inorganic substances has almost reached its limit. Therefore, there is a demand for the development of functional organic materials as new functional materials that surpass inorganic materials. The advantages of organic materials are that they are inexpensive, easy to manufacture, and highly functional. On the other hand, organic materials that have overcome heat resistance and mechanical strength, which have been thought to be inferior, have recently been created one after another. Against this technical background, some of the functional parts (mainly thin film parts) of IC devices such as logic elements, memory elements, and photoelectric conversion elements, and optical devices such as microlens arrays and optical waveguides. Or, the proposal to replace the entire structure with organic thin films instead of conventional inorganic thin films led to the development of molecular electronic devices and bio-related materials in which organic molecules of l(!i have functions such as logic elements and memory elements). Several research institutions have recently announced proposals to create logic devices (e.g., biochips) consisting of

Thin films used to create the various devices described above using such organic materials can be formed by a known single molecule accumulation method, that is, the Langmuir-Blodgett method (LB method).

The LB method refers to the parent tree group 1a and the hydrophobic group t in FIG.
A single molecule l, that is, several molecules composed of b, is dissolved in a volatile solvent such as benzene or chloroform, and dropped onto a water surface surrounded by a frame 4 arranged in a water tank 3. The monomolecular film (gas s at this point) 2 left on the water surface after volatilization is transformed into a solid film by reducing the area surrounded by the frame 4 and increasing the areal density of the monomolecular film 2. This is a method of transferring to a substrate (not shown) by a vertical dipping method or a horizontal adhesion method.

However, according to this method, the area of the monolayer on the water surface decreases by the amount of the monolayer transferred onto the substrate. In other words, since the monomolecular film (solid III) on the water surface is required to be uniform, while keeping its areal density constant,
Moreover, when the monomolecular film is continuously transferred onto the substrate, the area surrounded by the frame gradually decreases and approaches 0, so there is naturally a limit to the number of times the monomolecular film can be transferred.

DISCLOSURE OF THE INVENTION The purpose of the present invention is to solve the above-mentioned problems, and for this purpose, by controlling the surface pressure of the monomolecular film so as to obtain a desired areal density, it is possible to easily form a medium-molecular film. This makes it possible to perform continuous accumulation of .

The principle of the present invention will be explained below with reference to FIG.

Flow control device (not shown) consisting of a pump, pulp, etc.
When a monomolecule M2 is spread out on a water surface with a certain flow velocity controlled by ) is pulled with a constant force. At this time, if there is an obstacle v8 in the flow of the single molecule M2 that can block only the movement of the single molecule I8!2 without affecting the flow of water,
The monomolecular film 2 is pressed against this barrier 8 with a certain force. That is, the force with which the monomolecular film 2 presses against the barrier 8,
In other words, it shows that the surface pressure of the single molecule [2 can be easily controlled by changing the water flow rate.

The present invention is characterized by applying this principle.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that in each drawing, the same reference numerals represent the same structural members and have the same functions.

First, a first embodiment will be described with reference to FIG. A solution of stearin in the solvent chloroform at a ratio of 1 x 10'M #0. l■l flows in the direction of the arrow at a speed of 20 cm/sec under the control of the flow rate control device 7, on the water surface, in the upstream region 9 as seen from the barrier 8 (hereinafter referred to as the dripping region 9).
It is called. ) and expanded, #
A single molecule $2 of approximately 120 cm'' was formed on the water surface surrounded by walls 8.

When the surface pressure of the monomolecule [2] was measured using a surface pressure measuring device (not shown), it showed a value of 24 dyne/c, indicating that a monomolecular film was formed. Furthermore, when the velocity was varied in the range of 15 to 25 c/sec, it was confirmed that the surface pressure changed approximately in proportion to this, and it became clear that the surface pressure could be controlled by the flow velocity. Also, at this time, the amount of one drop is 0.05 to 0.3 ■l.
It was confirmed that when the surface pressure was varied within the range of , the surface pressure also changed in proportion to this.

In other words, it has become clear that the surface pressure can also be controlled by the amount of dripping.

On the other hand, the area near barrier 8! 0 (hereinafter referred to as accumulation area!0), when the monomolecular film was accumulated on the substrate by the vertical dipping method, the accumulation rate was 80 to almost 100.
% of good films could be obtained.

Then, while controlling the flow rate so that the surface pressure remains constant,
In addition, as a result of repeating the cumulative M operation while compensating for the decrease in single-molecule fi2 transferred to the substrate in the accumulation region 10 by dropping the film constituent material in the dropping region 9, continuous accumulation, which was difficult with conventional equipment, was made easier. was able to achieve this.

Next, a second embodiment will be explained according to FIG.

This embodiment is a slight improvement of the first embodiment. That is, in the first embodiment, in the accumulation region lO, the flow of water is disturbed by the submerged substrate (not shown) and the barrier 8 when accumulating with vertical immersion fN, and the single molecules B2 are bent. This is undesirable because the surface pressure, which should be constant, may fluctuate temporarily. Therefore, in this embodiment, the first embodiment is improved by varying the depth of the water tank and slowing down the flow (flow velocity) of water in the accumulation region 10. Specifically, a region 11 (hereinafter referred to as
This is called a surface pressure forming region 11. ) was made shallow to 1 cm+, and the depth of the water tank in the cumulative area IO was made deep to 10 cm. As a result, even if the flow rate in the surface pressure forming region 11 was 20 c layers/sec, the flow rate in the accumulation region IO was about 1/10, and when the monomolecular film was accumulated on the substrate, it was found that Yield is 20
It improved from ~60% to 50-100%.

In other words, by varying the depth of the water tank as in this embodiment, in addition to realizing the easy continuous accumulation achieved in the first embodiment, it is also possible to improve the accumulation achievement rate. It became possible.

Next, a third embodiment will be described with reference to FIG.

This embodiment is a modification of the second embodiment, and is an improvement over the first embodiment by varying the width of the water tank and slowing down the flow velocity in the accumulation region 10. Specifically, the surface pressure forming area including the dropping area 9! The width of the water tank in (1) was narrowed to 2 cm, and the width of the water tank in the cumulative area IO was widened to 20 cm. As a result, the surface pressure forming area 11
Even if the flow velocity at is 20c/sec, the cumulative area is 10
The flow rate was reduced to about 1/10, and when the monomolecular film was accumulated on the substrate, the yield was 2 in the first example.
It improved from 0 to 60% to 50 to 100%.

That is, by varying the width of the water tank, the same effect as in the second embodiment was obtained.

Next, a fourth embodiment will be described with reference to FIGS. 6(a) and 6(b).

In this embodiment, one aquarium is partitioned off only near the water surface by a plurality of fan-shaped barriers 8 (5 (II) in the unembodied example (hereinafter, the partitioned area will be referred to as a block)), and the center The structure is such that water flows into each block from the vicinity toward the outer periphery.
The ability to accumulate on the substrate and the ease of continuous accumulation are the same as in the first embodiment.

Furthermore, a unique feature of this embodiment is that it is possible to easily accumulate different types of single molecules (heterostructure). That is, a monomolecular film of a different material is spread on the water surface for each block in advance, and after the monomolecular film is accumulated on the substrate using the vertical dipping method in one block, the same operation is performed in another block. By repeating this, a heterogeneous 1!1 (the constituent molecules of the monolayer differ in the cumulative direction) J8! It was easy to form. At this time, it is possible to move between blocks in the gas phase or in the aqueous phase, so for example, a heterojunction in a film forming a Y-type film has hydrophobicity between the parent wood groups as well. They were also able to freely set their own standards among the base comrades.

Next, a fifth embodiment will be explained according to FIG. 7.

This embodiment is characterized in that, in the previous embodiments, the outflowing water is recycled and returned to the aquarium, thereby reusing the water. In FIG. 7, Pyrex glass tubes are used for most of the circulation path 12, and the water accumulated in the water tank 13 is pumped out by a pump 14, and the flow rate is controlled by a gate valve 15. .

In this way, by circulating the outflowing water, there is no need for a system to replenish lost water, and the entire device becomes simpler.

Next, a sixth embodiment will be described with reference to FIG.

As shown in FIG. 1, this embodiment is characterized in that a filter 16 for removing dust is inserted in the middle of the circulation path 12. Specifically, when we inserted the filter 16 that removes dust of 0.5 μs or longer, we found that it removed visible particles in the aquarium by using the device only 2 to 5 times (5 to 10 hours). Garbage was confirmed in 100
No visible dust was found even after using the device more than once. That is, water could be easily purified with a simple configuration of inserting a filter into the circulation system of the water channel.

Next, a seventh embodiment will be explained according to FIG. 9.

As shown in the figure, this embodiment is characterized in that a PH control device 3o is provided in a part of the circulation path I2. Specifically, when predetermined amounts of sodium hydroxide solution and hydrochloric acid were respectively mixed into the device using a micro cylinder, diffusion of sodium hydroxide and hydrochloric acid, which was difficult in the past, was achieved in this example. Since the water was flowing, it became possible to obtain a predetermined pH within a very short time (5 to 30 minutes). Furthermore, it is clear that this device is capable of controlling pH even when a monomolecular film is formed on the water surface.

Next, an eighth embodiment will be explained according to FIG. 10.

In this embodiment, as shown in Figure 1, the circulation path 12
It is characterized in that a heat exchanger 31 is provided in a part of the unit.

Specifically, it has a diameter of 378 inches and a wall thickness of 0 through which the circulating water passes.
．． A heat exchanger 31 is provided in which a 5 am Pyrex glass tube is wrapped around a hollow copper pipe. The temperature of the circulating water was controlled by flowing a liquid at that temperature. As a result, the water in the aquarium was reduced to 5
It was possible to control the temperature by pre-soaking at ±0.5°C in the range of ~80'O. Therefore, it has become possible to easily control the temperature conditions during monomolecular film accumulation. Also,
It is clear that according to this apparatus, it is also possible to control the temperature while the monomolecular film is formed on the water surface.

Finally, let us explain the ninth embodiment to the first! This will be explained according to figures (a) and (b).

This embodiment is characterized in that the barrier 8 in the previous embodiment is configured to be movable in the vertical direction. Specifically, the barrier 8 is operated by a motor (not shown) (however,
It is also possible to do it manually. ), it becomes possible to wash away the unnecessary monomolecular film 2 on the water surface and clean the water surface, greatly reducing the effort and time required for preparation for monomolecular film accumulation. was completed.

As explained above, the present invention facilitates continuous formation of a monomolecular film by varying the depth or width of the liquid bath so as to reduce the movement speed of film-forming molecules from the dropping region to the accumulation region. In addition to the accumulation, there is an effect of improving the cumulative achievement rate of the monolayer.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of a conventional LB film production apparatus, and Figure 2 is a
A diagram explaining the principle of a method for controlling the surface pressure of a monomolecular film by a water flow, FIG. 3 is a schematic sectional view of the first embodiment of the present invention, and FIG. 4 is a schematic sectional diagram of the second embodiment. 5 is a schematic perspective view of the third embodiment, FIGS. 6(a) and 6(b) are a schematic perspective view and a sectional view of the fourth embodiment, respectively, and FIG. 7 is a schematic perspective view of the fifth embodiment. 8 is a schematic configuration diagram of the sixth embodiment, FIG. 9 is a schematic configuration diagram of the seventh embodiment, and FIG. 10 is a schematic configuration diagram of the seventh embodiment.
The figure is a schematic configuration diagram of the eighth embodiment, FIG. 11(a), (
b) are schematic cross-sectional views before and after removing the barrier 8 in the ninth embodiment, respectively. 1--1 Monomolecule 1a-m-parent wood group 1b-m-hydrophobic group 2-m-monolayer 3-m-water tank 4-frame 7-m-water flow generator 8-m-barrier 9-m- Dripping region 10--1 Accumulation region 11--1 Surface pressure forming region 12-m-Circulation path 13-m-Water tank 14-m-Pump 15-m-Gate valve 18-m-Filter 21--pH Sensor 3O---pH control device 31-m-Heat exchanger 32-m-Temperature control device 33-m-Temperature sensor Patent applicant Canon Corporation Fig. 1 Fig. 2 Fig. 7 Fig. 2 Fig. 8 Fig. 9

Claims (1)

[Claims] A film forming apparatus comprising: a liquid tank containing a liquid for developing film forming molecules; and means for slowing down the flow of the liquid.