JPS60193536A - Film forming device - Google Patents

Abstract

PURPOSE:To enable not only the easy continuous accumulation of monomolecular films and an improvement in the attaining rate of the accumulation by controlling the surface pressure of the monomolecular films so as to obtain desired surface density and interposing additionally a temp. control means into a liquid circulating system. CONSTITUTION:A circulating path 12 and a heat exchanger 31 are provided in a liquid tank 3 contg. a liquid for spreading of molecules for film forming. The temp. of the circulating water is controlled by, for example, passing the liquid having a desired temp. into the heat exchanger 31 while controlling the temp. with a temp. controller 32 via a temp. sensor 33 provided in the tank 3. As a result, the temp. of the water in the tank 3 is controlled with + or -0.5 deg.C accuracy in a 5-80 deg.C range. The easy control of the temp. conditions in the stage of accumulating the monomolecular films is thus made possible. As a result, not only the easy continuous accumulation of the monomolecular films but also the improvement in the temp. conditions, i.e., the improvement in the attaining rate of the accumulation in the stage of accumulation are thus 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 LB film manufacturing apparatus using the Langmuir-Prodgett 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 technological progress in the field of organic chemistry has lagged significantly behind 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. Based on this technical background, 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. The proposal to replace part or all of the conventional inorganic thin film with an organic thin film led to the creation of molecular electronic devices and bio-related devices in which a single organic molecule has functions such as logic elements and memory elements. Several research institutes have recently announced proposals to create logic elements made of materials (eg, bio-φ chips).

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-Prodgett method (LB method).

The LB method refers to the parent tree group 1a and the hydrophobic group t in FIG.
A single molecule L composed of b, that is, a membrane constituent substance, is dissolved in a volatile solvent such as benzene or chloroform, and dropped onto the water surface surrounded by a frame 4 arranged in a water tank 3, and after the solvent evaporates. The monomolecular film 2 left on the water surface (at this point, it is a gas film) 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, which is then vertically immersed. This is a method of transferring to a substrate (not shown) by a method or a water immersion 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 film) on the water surface is required to have uniformity and properties, when the monomolecular film is continuously transferred to the substrate-L while keeping its surface density constant. Since the area surrounded by the frame gradually decreases and approaches O, there is naturally a limit to the number of times it can be transferred.

<Disclosure of the Invention> The purpose of the present invention is to solve the above-mentioned problems, and for this purpose, the surface pressure of the monomolecular film is controlled so as to obtain the desired areal density, and furthermore, the temperature is controlled in the liquid circulation system. By interposing a control means, it is possible not only to easily and continuously accumulate a monomolecular film, but also to improve the temperature conditions during the accumulation.

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

When the monomolecular film 2 is spread on a water surface with a certain flow velocity, the monomolecular film 2 moves in the direction of the water flow (in the direction of the arrow) due to the attractive force between the molecules constituting the f-film 2 and the water. ) is pulled with a constant force. At this time, if there is a barrier 8 at f where the monomolecular film 2 is flowing, which can block only the movement of the monomolecular film 2 without affecting the flow of water, then the monomolecular n! ! 2 is pressed against this barrier 8 with a certain force. That is,
This shows that the force with which the middle molecular film 2 presses against the barrier 8, in other words, the surface pressure of the monomolecular film 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. In addition, in each drawing, the same reference numerals indicate rotating components and assume that they have the same functions.

First, a first embodiment will be described with reference to FIG. Stearic acid in the solvent chloroform at 1 x 10-'M/! A solution of 0.1 ma+ dissolved at a rate of 20 am/se
When a drop is dropped in a region 9 of the flow seen from the barrier 8 (hereinafter referred to as the dripping region 9) on the water surface flowing in the direction of the arrow at a speed of A monomolecular film 2 of approximately 120 cm" was formed. When the surface pressure of the monomolecular 11!! 2 was measured using a surface pressure measuring device (not shown), it showed a value of 24 dyne/cm, and the monomolecular film 2 was as desired. It was confirmed that a solid state was formed.

Furthermore, when the velocity was varied in the range of 15 to 25 cIIl/sec, it was confirmed that the surface pressure changed almost in proportion to this, and it became clear that the surface pressure could be controlled by the flow velocity. Also, at this time, the dropping amount is also 0.05 to 0.3
It was confirmed that when the surface pressure was changed within a range of ml, 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,
In a region 10 near the barrier 8 (hereinafter referred to as the accumulation region IO), a monomolecular film was accumulated on the substrate by the vertical dipping method, and a good film with an accumulation rate of 80 to almost 100% was obtained. I was able to get it.

Then, while controlling the flow rate so that the surface pressure remains constant,
And middle molecule jl! As a result of repeating the accumulation operation while compensating for the decrease in the amount of film 2 transferred to the substrate in the accumulation region 10 by dropping the film constituent material in the dropping region 9, it is possible to easily achieve continuous accumulation, which was difficult with conventional devices. was completed.

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

This embodiment is characterized in that, in the first embodiment, 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 third embodiment will be described with reference to FIG.

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

Specifically, a heat exchanger 31 is installed, which is a Pyrex glass tube with a diameter of 378 inches and a wall thickness of 0.5 mm, wrapped around a hollow copper pipe through which circulating water passes, and a temperature sensor installed in the water tank 3 is installed. The temperature of the circulating water was controlled by flowing a liquid at a desired temperature into the copper pipe through the copper pipe 33 under control of the temperature control device 32. As a result, the water in the aquarium,
It was possible to control with an accuracy of ±0.5°C in the range of 5 to 80°C. 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.

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

This embodiment is characterized in that a dust removal filter 18 is inserted in the middle of the circulation path 12, as shown in the figure. 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 several times. 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 fifth embodiment will be explained according to FIG. 7.

As shown in the figure, this embodiment is characterized in that a PH control device 30 is provided in a part of the circulation path 12. 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. Because of the flow, it became possible to obtain the required p)l within a very short time (5 to 30 minutes). Furthermore, it is clear that according to this device, it is also possible to control the pH while the monomolecular film is formed on the water surface.

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

This embodiment is a slight improvement of the first embodiment. That is, in the first embodiment, in the accumulation region 10, the flow of water is disturbed by the substrate (not shown) submerged in water in the case of accumulation by the vertical immersion method, as well as by the barrier 8, and the monomolecular film 2 is bent. This is not desirable because the surface pressure that should be on the feet may change 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 area IO. Specifically, a region 11 (including the dropping region 9) that forms the surface pressure of the middle molecule II@2 (
Hereinafter, it will be referred to as a surface pressure forming region 11. ) was made shallow to 1 cm, and the depth of the water tank in cumulative area 10 was made deep to 10c+o. As a result, even if the flow velocity in the surface pressure forming region 11 was 20 cm/sθC, the flow velocity in the accumulation region 1O was about 1/10 that of the one found in the first embodiment. The yield has increased from 20 to 60% to 50 to 100%.

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

This embodiment is a modification of the sixth 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 width of the water tank in the surface pressure forming area 11 including the droplet area 9 was narrowed to 2c+++, and the width of the water tank in the accumulation area 10 was widened to 20 cm. As a result, even if the flow velocity in the surface pressure forming region 11 was 20 cm/sec, the flow velocity in the accumulation region IO was about 1/10, and when the monomolecular film was accumulated on the substrate, the yield was lower in the first embodiment. improved from 20 to 60% to 50 to 100%.

Next, the eighth embodiment will be described with reference to FIGS. 1θ (a) and (, b).

In this embodiment, a single aquarium is partitioned off only near the water surface by a plurality of (five in this embodiment) fan-shaped barriers 8.
Hereinafter, the partitioned areas will be referred to as blocks. ), water flows into each block from near the center toward the outer periphery. The apparatus according to this embodiment has the following features regarding the ability to accumulate the monomolecular film 2 on the substrate and the ease of continuous accumulation.
This is similar to 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 process, it was possible to easily form a hetero-accumulated film (the constituent molecules of the monolayer differ in the direction of accumulation). 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 membrane that forms a Y-type membrane has hydrophobicity between the parent wood yarns as well. They were also able to freely set their own standards among the base comrades.

Finally, the ninth embodiment is shown in FIGS. 11(a) and (b).
Explain according to the following.

This embodiment differs from the previous embodiment in that the barrier 8 is configured to be movable in one direction (1-1).

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. I was able to do that.

As explained above, by interposing a temperature control mechanism in the liquid circulation system, the present invention not only allows easy continuous accumulation of a monomolecular film, but also achieves bidirectional temperature conditions during accumulation, that is, accumulation is achieved. This has the effect of improving the ratio.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of a conventional LB film production apparatus, and Figure 2 is a
A diagram explaining the principle of the method of controlling the surface pressure of a monomolecular film by a water flow. Figure 3 is the first embodiment of the present invention. Figure 4 is a schematic diagram of the second embodiment. Figure 5 is the third embodiment. FIG. 6 is a schematic diagram of the fourth embodiment, FIG. 7 is a schematic diagram of the fifth embodiment, FIG. 8 is a schematic cross-sectional diagram of the sixth embodiment,
FIG. 9 is a schematic perspective view of the seventh embodiment, 1θ diagram (a),
11(b) is a schematic perspective view and a cross-sectional view of the eighth embodiment, and FIGS. 11(a) and (b) are schematic cross-sectional views of the ninth embodiment before and after removing the barrier 8, respectively. It is a diagram. 1-m-monomolecule 1a-m-parent wood group lb--1 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-m-Surface pressure forming region 12-m-Circulation path 13-m-Water tank 14-m-Pump 15--Gate valve 16--Filter 21--pH Sensor 30---pH control device 31-m-heat exchanger 32-m-temperature control device 33-m-temperature sensor Patent applicant: Canon Corporation Figure 4F Figure 6 Figure 11

Claims (1)

[Claims] A film forming apparatus comprising a liquid tank containing a liquid for developing molecules for film forming, and further comprising means for controlling the temperature of the liquid.