JPS61271052A - Film forming device - Google Patents

Abstract

PURPOSE:To deposit smoothly a monomolecular film on a substrate and to prevent an adverse effect of vibration by providing a device for regulating the quantity of a liq. and for charging and discharging the liq. into and from a water vessel. CONSTITUTION:With respect to a device for forming a film on a substrate in the fields of semiconductor techniques, optical techniques, etc., a device 14 for regulating the quantity of liq. and for charging and discharging liq. into and from a water vessel 1 is provided. When a liq. such as water and chloroform and carbon tetrachloride having higher sp.gr. and insoluble in water are charged and discharged into and from the water vessel 1 through the liq. quantity regulating device 14, the water level 3 in the water vessel 1 is moved upward and downward. Consequently, the transfer of a group of film forming molecules is carried out by moving the water surface 3 not the substrate 7 upward and downward and the substrate 7 can be fixed at a specified position. Accordingly, an adverse effect due to the mechanical vibration caused by the upward and downward movement of the substrate 7 is prevented.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for forming an organic thin film that is a main component of a device, for example in the semiconductor technology field and the optical technology field. The present invention relates to a film forming apparatus that forms a monomolecular layer on a liquid surface and transfers the monomolecular layer onto a substrate to form a monomolecular film or a cumulative film thereof on the substrate.

[Prior 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.

However, recent technological advances in the field of organic chemistry have been remarkable, and logic elements,
Integrated circuit devices such as memory elements and photoelectric conversion elements,
There have been proposals to construct part or all of the functional parts (mainly thin film parts) of optical devices such as microlens arrays and optical waveguides with organic thin films instead of conventional inorganic thin films.

Organic thin films, which are the main components of such devices, are fabricated using single-molecule accumulation methods. The single molecule accumulation method (also known as the Langmuir-Prodgett method, LB method) is a method that utilizes the phyllophilicity and hydrophobicity of molecules with hydrophilic and hydrophobic groups to spread them on water in an orderly manner to form a medium molecule film. A monomolecular film or a monomolecular cumulative film in which monomolecules are laminated on a substrate (these are called LB films) is created by forming a monolayer and then transferring it to the substrate surface.
It is possible to form

Conventionally, this type of device is placed inside a shallow and wide rectangular aquarium 1 with a frame 2 horizontally partitioning a water surface 3, as shown in FIG. The frame 2 functions as a two-dimensional cylinder, and a rectangular float 4 is floated inside the frame 2, and the width of the float 4 is made slightly narrower than the inner dimension of the frame 2, so that it can move smoothly from side to side as a two-dimensional piston. It is possible to move. In order to move the float 4 from side to side, the float 4 is connected to a winding device 6 using a motor or the like via a wire 5.

When forming a monomolecular film, the constituent substances of the film are dissolved in a volatile solvent such as benzene or chloroform, and the solution is dropped onto the water surface 3. After the solvent evaporates, a monomolecular film exhibiting the behavior of a two-dimensional system is left on the water surface 3. When the areal density of 0 molecules is low,
It is called a gas film of secondary gas. By moving the float 4 to the right, the expanse of the water surface 3 on which single molecules expand is reduced and the surface density is increased. As a result, interactions between molecules become stronger, and two-dimensional liquids pass through a liquid film of two-dimensional liquid. Transforms into a solid film. When this solid film is formed, the molecules are arranged and oriented in a neat manner, resulting in a high degree of order and uniform ultra-thin film properties required for materials constituting semiconductors and the like.

As a method of transferring the monomolecular film from the water surface 3 onto the substrate 7 surface, the substrate 7 is attached to the substrate holder 8 while maintaining a constant surface pressure suitable for cumulative operation on the water surface 31:. There is a vertical immersion method in which middle molecules and membranes are transferred by moving the membrane up and down in the vertical direction 9. In this method, Em3 diagram (a
), where the monomolecular film 10 is attached only during immersion,
As shown in FIG. 3(b), the monomolecular membrane 1O is attached both during immersion and during pulling, the Y type, and as shown in FIG. 3(C), the intermediate p[10 is attached only during pulling. There are three types of molds.

In addition, in the part E of FIG. 2, 11 is a hydrophilic part and 12 is a hydrophobic part.

Another method (not shown) is a horizontal adhesion method in which the monomolecular film is transferred by moving the substrate E1 with the medium molecular film adhering surface of the substrate almost parallel to the water surface. be.

[Problem to be solved by the invention] In the conventional method described above, a geared motor is used for the device that moves the board up and down, and vibrations generated by this motor are transmitted to the board, causing overlapping. When the film is attached to the substrate, there is a problem in that the state of attachment is disturbed.

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and provide a film forming method in which a monomolecular film can be smoothly attached to a substrate without the adverse effects of vibration.

[Means for solving the problems] The means taken to solve the above problems will be explained with reference to FIG. 1, which corresponds to an embodiment of the present invention. The purpose is to provide a film forming apparatus having a quantity adjusting section 14.

The liquid supplied to and discharged from the water tank 1 in the present invention is usually water, but it may also be a liquid that is insoluble in water and has a higher specific gravity than water, such as chloroform or carbon tetrachloride.

[Function] According to the present invention, when the liquid is supplied and discharged from the liquid amount adjusting section 14 to the water tank 1, the water level 3 of the water contained in the water tank 1 is raised and lowered thereby. Therefore, the transfer of the film-forming molecules can be carried out by raising and lowering the water surface 3 instead of the substrate 7, and the substrate 7 can remain fixed at a fixed position, and the mechanical It can prevent the negative effects of vibration.

Incidentally, it is expected that some turbulence will occur on the water surface 3 when it is raised and lowered, but even if the water surface 3 is slightly disturbed, the vibrations of this turbulence will not be transmitted to the fixed substrate 7. Therefore, as when the substrate 7 to which mechanical vibration has been applied is immersed below the water surface 3, the substrate 7 vibrates and the water surface 3 is also disturbed by the vibration, and from both the vibration of the substrate 7 and the disturbance of the water surface 3, The orientation of the obtained monomolecular film or its cumulative film is prevented from being impaired.

Note that the film forming principle itself in the present invention is the same as the LB method explained in the conventional example.

[Examples] Hereinafter, the present invention will be described in detail with reference to Examples and the drawings.

FIG. 1 is a longitudinal sectional view showing an example of a film forming apparatus using a horizontal deposition method in which the present invention is implemented. In FIG. 1, the film forming apparatus stores a desired amount of water inside a shallow and wide water tank 1,
The substrate 7 is held by the substrate holder 8 with the surface to which the monomolecular film is to be transferred facing downward, almost upward on the water surface 3, and a liquid flow port 13 is provided in the water, and a liquid volume adjustment device connected to the liquid flow port 13 is provided. A section 14 is attached to the water tank 1 and is generally configured.

The liquid discharged and sucked into the water tank 1 from the liquid flow port 13 is selected to have a specific gravity sufficiently higher than that of water so as not to float to the water surface 3, and a relatively high viscosity so as not to cause wave motion. The liquid flow port 13 is also located near the bottom of the water. Of course, you can also use water itself as the liquid.
In that case, the above consideration is not required.

FIG. 1(a) shows a state in which no liquid is released into the water, the water surface 3 is at a low position, and the substrate 7 is not in contact with the water surface 3. In this state, a monomolecular film constituent material is dropped onto the water surface 3, and a monomolecular film having a desired surface pressure is formed by a surface pressure control means (not shown). Here, when liquid is slowly fed into the water from the liquid flow port 13, the water level 3 rises by an amount corresponding to the amount of liquid, so as shown in FIG. 1(b),
The monomolecular film comes into contact with the lower surface of the substrate 7 and is transferred. In this case, the rise of the water level 3 is very smooth and there is no vibration as in the conventional case, so the transferred film is also precise. Also,
Since there is no need for a mechanism for moving the substrate up and down, the apparatus becomes extremely simple and the substrate 7 can be easily held, making it possible to utilize the advantages of the water mop adhesion method in which a large-sized substrate 7 is formed into an F& film.

In addition, in the above embodiment, the X-type JI that raises the water surface 3
Although the explanation has been made using a Jt film, it is also possible to form a Y-type film in which the substrate 7 is vertically submerged in water in advance to lower the water surface 3.

[Effects of the Invention] As explained below, according to the present invention, the water surface is moved up and down by increasing and decreasing the liquid volume, and the monomolecular film on the water surface is transferred to the substrate, so there is no vibration of the substrate. The monomolecular film adheres smoothly and is precise, and since there is no vertical movement mechanism for the substrate, the equipment is simple and the substrate is easy to hold, so large substrates can be deposited and A film forming apparatus suitable for the deposition method can be provided.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention, FIG. 2 is a perspective view of a conventional example, and FIG. 3 is a structural diagram of molecular orientation in a monomolecular film or a cumulative film.

Claims (1)

[Claims] 1) A film forming apparatus characterized by having a liquid amount adjusting section for supplying and discharging liquid into a water tank.