JP2970925B2 - Method of forming monolayer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for forming a monomolecular film on a liquid surface, and more particularly, to a monomolecular film having a uniform film thickness by changing the temperature of a liquid surface of a trough. The present invention relates to a technology capable of forming

[Prior Art] A conventional monomolecular film forming apparatus (generally a Langmuir-Blodgett film manufacturing apparatus) uses a double-bottomed water tank. The upper water tank is a trough where a monomolecular film is formed on the liquid surface. On the other hand, the lower water tank is provided with a water circulation means for circulating water, a heating means and a cooling means for changing the temperature of the water in the water tank, and by controlling the temperature of the water circulating in the water tank, the liquid in the upper water tank is controlled. The surface temperature is maintained at a predetermined temperature or the temperature is changed.

[Problems to be Solved by the Invention] In the conventional method of forming a monomolecular film, when changing the temperature of the upper water tank, first, it is necessary to change the temperature of the water of the lower water tank. Since the amount of water used in the lower water tank is relatively large, the heat capacity of the circulating water increases.

As a result, when changing the temperature of the liquid level of the trough, first, it is necessary to change the temperature of the circulating water in the lower water tank having a large heat capacity, which causes a problem that the changing speed of the temperature of the liquid level of the trough becomes slow. Had.

An example of a problem that occurs when the temperature change of the liquid level of the trough is slow is shown.

When heat treatment is performed on a monomolecular film on the liquid surface, if the temperature of the liquid surface of the trough is slow, some of the monomolecules will dissolve in the liquid before the liquid surface temperature changes to the target temperature. Would.
As a result, the conventional monomolecular film accumulating device has a problem that the quality of the heat-treated monomolecular film is deteriorated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for forming a monomolecular film in which the temperature of a liquid surface of a trough changes rapidly.

[Means for Solving the Problems] In order to achieve the above object, a temperature control attached to the bottom surface of the trough based on a detection signal from a liquid temperature detecting member for detecting a temperature of a liquid stored in the trough. A step of controlling the driving of the member to maintain the liquid temperature at a predetermined temperature; and a step of fixing the liquid temperature to a monomolecular film forming water surface of a trough liquid surface divided into a monomolecular film forming water surface and a monomolecular film non-forming water surface by a fixed partition plate. Forming a monomolecular film by spreading the molecular film solution, a first surface pressure detecting member for detecting a liquid surface pressure of a monomolecular film-formed water surface, and a second surface pressure detecting member for detecting a liquid surface pressure of a non-monomolecular film-formed water surface Based on each detection signal from the surface pressure detecting member, the movable partition plate provided so as to intersect with the liquid surface of the monomolecular film forming water surface is controlled to move and compress the monomolecular film to a preset surface pressure. The temperature adjustment member and the temperature detection member. A step of heating or cooling at least the liquid on the surface of the monomolecular film forming water to heat-treat the developed monomolecular film.

Example Next, the method of the present invention will be described with reference to the drawings showing an example of an apparatus embodying the method for forming a monomolecular film of the present invention.

(Structure of Example) FIG. 1 is a schematic view of an apparatus for forming a monomolecular film.

B) Schematic description of the monomolecular film forming apparatus 1.

The apparatus 1 for forming a monomolecular film is roughly divided into a trough 2 for storing a liquid, a film compressing means 3 for compressing a monomolecule developed on the liquid surface of the trough 2 to form a monomolecular film on the liquid surface, 2
Thermo-modules (temperature changing means of the present invention) which are attached to the lower surface of the device and change the temperature of the liquid surface of the trough 2
4 and a control device 5 for controlling the membrane compression means 3 and the plurality of thermo modules 4.

B) Description of the trough 2 The trough 2 is a shallow, approximately rectangular container of, for example, about 4 mm, and stores therein a liquid such as pure water having a water depth of about 1 mm to 3 mm. In the trough 2, at least the bottom plate 2a is formed of a material having excellent thermal conductivity (eg, aluminum, copper, or the like).

At the approximate center of the trough 2 in this embodiment, a fixed partition plate 6 is provided. The fixed partition plate 6 separates a first water surface 7 on which a monomolecular film is formed from a second water surface 8 on which no monomolecular film is formed.

C) Description of the membrane compression means 3.

The membrane compression means 3 of the present embodiment includes a movable partition plate 9 provided on the first water surface 7 and an actuator (not shown) for driving the movable partition plate 9. The movable partition plate 9 is moved to form a monomolecular film forming water surface 10 surrounded by the movable partition plate 9, the fixed partition plate 6, and the horizontal plate of the trough 2.
Area changes. For this reason, the monomolecules developed on the liquid surface are compressed by the movable partition plate 9 by deploying the monomolecules on the monomolecular film forming water surface 10 and moving the movable partition plate 9 toward the fixed partition plate 6, A monolayer is formed. Also,
The movable partition plate 9 also keeps the formed monomolecular film.

The actuator for driving the movable partition plate 9 is
It is controlled by the control device 5.

D) Description of the thermo module 4.

The thermo module 4 is a well-known module in which a plurality of thermoelectric elements having a Peltier effect are combined. The plurality of thermo modules 4 are directly attached to almost the entire lower surface of the bottom plate 2 a of the trough 2. Thus, the plurality of thermo modules 4 are in thermal contact with the solution in the trough 2 via the bottom plate 2a of the trough 2. The energization directions and current values of the plurality of thermomodules 4 are controlled by the control device 5. Reference numeral 4a shown in the figure denotes a heat absorber / radiator that enhances the heat absorption / radiation effect of the thermo module 4.

E) Description of the control device 5.

The control device 5 of the present embodiment uses a microcomputer 11, and the microcomputer 11 includes a film pressure control unit 12 for controlling an actuator, and a thermo module 4
And temperature control means 13 for controlling the temperature.

On the other hand, the control device 5 includes a first surface pressure sensor 14 for detecting the surface pressure of the water surface 10 on which a monomolecular film is formed (water surface on which a monomolecular film is formed), and a second water surface 8 (water surface on which no monomolecular film is formed).
A second surface pressure sensor 15 for detecting the surface pressure of the water, and a temperature detection sensor 16 for detecting the temperature of the water surface 10 (the liquid surface in which the trough 2 is stored) of the monomolecular film forming water.

Further, the control device 5 includes a control panel 17 for giving an instruction signal to the computer 11. The control panel 17 includes an operation switch (not shown), a membrane pressure setting device (not shown) for setting the pressure of the monomolecular film, and a temperature setting device (not shown) for setting the temperature of the water surface 10 on which the monomolecular film is formed.
And a plurality of switches and setting devices.

The film pressure control means 12 of the microcomputer 11 controls the actuator drive circuit 18 for driving the actuator by a program for controlling the pressure of the monomolecular film. Specifically, the membrane pressure control means 12 subtracts the pressure of the water surface, which is detected by the second surface pressure sensor 15 and has no monolayer, from the pressure of the monolayer detected by the first surface pressure sensor 14. Then, the actuator drive circuit 18 is controlled so that the subtracted value always becomes the pressure set by the membrane pressure setting device of the control panel 17, and the actuator is operated.
The position of the movable partition plate 9 is controlled.

The temperature control means 13 of the microcomputer 11
A DC power supply circuit that applies a current to a plurality of thermo modules 4 with a program that controls the temperature of the water surface 10 on which a monomolecular film is formed.
Control 19 Specifically, the temperature control means 13 controls the DC power supply circuit 19 so that the temperature detected by the temperature detection sensor 16 becomes the temperature set by the temperature setting device of the control panel 17, and It controls the temperature of the film-forming water surface 10.

The monomolecular film forming apparatus 1 described above is applied to, for example, an LB film manufacturing apparatus that manufactures a Langmuir-Blodgett film (LB film) in which monomolecular films are accumulated. The LB film manufacturing apparatus stacks the monomolecular film formed by the monomolecular film forming apparatus 1 on the surface of a substrate (not shown).

(Operation of Example) An operation of performing heat treatment on a monomolecular film using the monomolecular film forming apparatus 1 will be briefly described.

First, the temperature of the monomolecular film forming water surface 10 is made to match the temperature set by the temperature setting device of the control panel 17.

If they do not match, the operation of the temperature control means 13 of the microcomputer 11 controls the energization of the plurality of thermomodules 4, and the plurality of thermomodules 4 communicate with the temperature of the liquid in the trough 2 via the bottom plate 2 a of the trough 2. Thus, the temperature of the liquid surface is directly changed. Since the water depth of the liquid stored in the trough 2 is very shallow, the heat capacity of the liquid is small. Therefore, the temperature of the water surface 10 on which the monomolecular film is formed can be quickly matched with the temperature set by the temperature setting device.

Next, a monomolecular film is developed on the monomolecular film forming water surface 10.

Subsequently, the movable partition plate 9 is operated to form a monomolecular film. Specifically, the surface pressure obtained by subtracting the surface pressure of the second water surface 8 from the surface pressure of the monomolecular film forming water surface 10 is set by the film pressure setting device of the control panel 17 by the operation of the film pressure control means 12. The movable partition plate 9 is operated so as to coincide with the surface pressure. Then, a surface pressure obtained by subtracting the surface pressure of the second water surface 8 from the surface pressure of the water surface 10 for forming a monomolecular film coincides with the surface pressure set by the film pressure setting device, whereby a monomolecular film is formed.

Here, the set temperature of the temperature setting device is changed to perform the heat treatment on the monomolecular film.

Then, the operation of the plurality of thermo modules 4 is controlled by the operation of the temperature control means 13 such that the temperature of the monomolecular film forming water surface 10 matches the temperature set by the temperature setting device. As described above, the plurality of thermo modules 4 directly change the temperature of the liquid in the trough 2 and thus the temperature of the liquid level via the bottom plate 2a of the trough 2. The water depth of the liquid stored in the trough 2 is very shallow, and the heat capacity of the liquid is small. Therefore, the temperature of the water surface 10 on which the monomolecular film is formed can be quickly matched with the temperature set by the temperature setting device.
That is, heat treatment can be quickly performed on the monomolecular film.

During this heat treatment, the surface pressure of the monomolecular film-forming water surface 10 changes due to a change in the temperature of the liquid, but the pressure of the monomolecular film is always set to the pressure set by the film pressure setter by the action of the film pressure control means 12. Is maintained.

(Effects of the embodiment) In the embodiment, the plurality of thermo modules 4 change the temperature of the liquid in the trough 2 via the bottom plate 2a of the trough 2. As a result, the monomolecular film forming apparatus 1 of the present embodiment
As compared with a conventional monomolecular film forming apparatus, the temperature change of the monomolecular film forming water surface 10 can be made faster.

When the heat treatment is performed on the monomolecular film, the heat treatment can be performed quickly, so that the single molecule does not dissolve in the solution during the heat treatment or the amount of the dissolution can be reduced. Therefore, a high-quality monomolecular film subjected to the heat treatment can be formed in the trough 2. Further, by laminating the heat-treated monomolecular film on the substrate surface, a high-quality LB film can be formed.

Since the thermal load on the plurality of thermo modules 4 is small (mainly the heat capacity of the trough 2 and the liquid in the trough 2),
It also has the effect of suppressing overshoot when the temperature is changed.

In addition, since the pressure of the monomolecular film was measured using the two surface pressure sensors 14 and 15, even if the temperature of the liquid surface changes greatly, such as when performing heat treatment of the monomolecular film, the pressure of the monomolecular film can be accurately measured. You can know. Therefore, even if the temperature of the liquid surface changes, the pressure of the monomolecular film can always be kept at an accurate value.

(Modification) In the present embodiment, an example is shown in which a thermo module 4 capable of both heating and cooling of the liquid in the trough 2 is used as the temperature changing means, but the present invention is not limited to this. , For example, heating means only for heating (for example, electric heater)
Or cooling means only for cooling (refrigerant cycle refrigerant evaporator)
Or a combination thereof. Further, a heat exchanger of a heat pump refrigeration cycle that performs heat radiation and heat absorption may be used as the temperature changing unit.

Further, although the example in which the temperature changing means is attached to the lower surface of the bottom plate 2a is shown, the bottom plate 2a itself may be constituted by the temperature changing means, provided in the bottom plate 2a, or attached to the upper surface of the bottom plate 2a.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for forming a monomolecular film. In the figure, 1... Monomolecular film forming apparatus, 2... Trough, 4.
... thermo module, (temperature changing means), 5 ... control device, 8 ... second water surface (water surface on which no monomolecular film is formed),
9: movable partition plate, 10: water surface on which a monomolecular film is formed (water surface on which a monomolecular film is formed), 12: film pressure control means, 13: temperature control means, 14: first surface pressure sensor, 15 ... second surface pressure sensor, 16 ... temperature detection sensor

Claims (1)

(57) [Claims] A temperature control member mounted on a bottom surface of the trough is driven and controlled based on a detection signal from a liquid temperature detection member for detecting a temperature of a liquid stored in the trough, so that the liquid temperature is maintained at a predetermined temperature. Maintaining step and forming a monomolecular film by spreading the monomolecular solution on the monomolecular film forming water surface of the trough liquid surface divided into a monomolecular film forming water surface and a monomolecular film non-forming water surface by a fixed partition plate And a step of detecting the surface pressure of the monomolecular film-forming water surface and detecting the liquid surface pressure of the non-monomolecular film-forming water surface using the detection signals from the second surface pressure detection member. A step of controlling the movement of a movable partition plate provided so as to intersect with the liquid surface of the molecular film forming water surface, compressing the monomolecular film to a predetermined surface pressure, and at least a temperature adjusting member and a temperature detecting member. Heat the liquid on the surface of the monomolecular film Retirement forming method of monomolecular film comprising the step of heat treating the monolayer was deployed.