JP2582079Y2 - Film forming equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for forming a thin film by a Langmuir-Blodgett (hereinafter abbreviated as LB) method, and more particularly to a film forming apparatus in which film molecules are oriented in a film plane. The present invention relates to a film forming apparatus.

[0002]

2. Description of the Related Art In recent years, research and development of functional thin films using organic materials have been promoted in the fields of bioelectronics and optoelectronics. One of the thin film forming methods is based on the LB method. In the LB method, the thickness of the thin film (LB film) to be formed can be controlled at the molecular length level.
In order to further enhance the function, a technique for forming an LB film in which film molecules in a film forming surface are oriented in one direction has been studied.

FIG. 3 is a schematic configuration diagram of a conventional film forming apparatus for forming an LB film by orienting film molecules in a plane (Polymer).
Preprints, Japan Vol.39, No.4 1990 , p.1296, I-17
-18).

[0004] A region where the film forming molecules are developed is divided by a movable barrier 31 called a moving wall, and a distance (width, c) between a surface parallel to the film forming surface of the substrate 32 on the film forming molecule developing surface.
) Is the same as the film forming surface of the substrate 32 (stacking region, the film molecules in this region are transferred to the substrate), and the region III
Region I (a film molecule development region) in which the distance (width, indicated by a) of the plane parallel to the film formation surface of the substrate 32 is longer than
And the region III. With the film forming molecules expanded, move the movable barrier 31 to the region I.
When the film is taken up and moved to the upstream side of the substrate while maintaining the width a in the above, the film forming molecules are oriented in the process of moving from the region I to the region III due to the fluidity of the film forming molecules (the film forming molecules are unfolded). It has a length component in at least one direction in the plane, and the directions are aligned). Movable barrier 31
The movable barrier 31 is moved to narrow the development area while controlling the movement of the film molecules while maintaining the film molecules in a solid film state, so that the pressurized film molecules are changed from a gas film state to a solid film state. After the film molecules which seem to be unoriented in the regions II and III at the time of becoming removed and transferred to the dummy substrate and removed, the film which seems to be well oriented in the film forming surface is formed on the substrate 32. Then, an LB film is formed on the substrate.

[0005]

In a conventional film forming apparatus for forming an LB film by in-plane orientation, when the movable barrier 31 is wound and moved to the upstream side of the substrate, the movable barrier 31 is moved at a speed v. In the region I, the film molecules are also moved by the movable barrier.
31 and at a velocity v, but in region III the membrane molecules are a
It flows at a rate of v / c. That is, in the region III, there is a difference between the moving speed of the movable barrier 31 and the moving speed of the membrane molecule. Movable barrier
Because the moving speed of the film molecules is different from that of the movable barrier 31, the film in which the film molecules are oriented in-plane is distorted, especially near the contact of the movable barrier 31, and the film is partially collapsed (solid (Collapse of the film) occurs, and the orientation of the film molecules decreases. For this reason, it has been difficult to form the LB film in a state where the in-plane orientation is favorably performed.

The present invention has been made in view of such a point, and provides a film forming apparatus capable of forming an LB film in a state where film molecules are well oriented in a plane.

[0007]

According to the present invention, there is provided a first barrier having a circular cross section and a taper inside the first barrier having a circular cross section opposite to the first barrier. And a second barrier rotatably provided around the same central axis as the first barrier inside the first barrier, and film-forming molecules are spread on the first barrier or the second barrier. A film-forming apparatus developed in a closed area separated by the first barrier and the second barrier while relatively moving a liquid surface, wherein a surface pressure of film-forming molecules developed in the closed area is reduced. Surface pressure control means for controlling, and a holding means rotatably provided about the same central axis as the first barrier while vertically moving a substrate for transferring film-forming molecules developed in the closed region. And

[0008]

The film-forming molecules developed in the closed area separated by the first barrier and the second barrier flow by the rotation of the second barrier, and are oriented in the surface thereof. The surface pressure control means raises and lowers the liquid surface of the film forming molecules relatively to the first and second barriers to keep the surface pressure constant, and relatively stops by rotating the substrate held by the holding means. The film forming molecules are transferred onto the substrate by the vertical movement of the substrate.

[0009]

FIG. 1 is a schematic structural view of an embodiment of the film forming apparatus of the present invention, and FIG. 2 is a schematic sectional view for explaining an embodiment of the film forming apparatus of the present invention.

Reference numeral 1 denotes a trough serving as a first barrier for containing an aqueous solution for developing film-forming molecules, and has a circular cross section and is formed in a tapered shape in which the diameter of the lower side is reduced. The second trough 1 has a circular cross section and is formed in a tapered shape in which the diameter of the lower portion is larger than that of the trough 1, and is provided inside the trough 1 so as to be rotatable about the same central axis as the center of the trough 1. It is a movable barrier as a barrier. The trough 1 and the movable barrier 2 are formed of stainless steel or an aluminum alloy, and the surfaces thereof are coated with a fluororesin.

Reference numeral 3 denotes a holder as a holding means for holding a substrate 7 on which an LB film is formed by transferring film forming molecules, and is provided so as to move the substrate up and down and to be rotatable about the same central axis as the center of the trough 1. I have. 4 is a trough 1 and a movable barrier 2
Is a sensor for measuring the surface pressure of the film-forming molecules developed in a closed region surrounded by the surface of the film-forming molecules at the same distance from the central axis of the trough 1 to the substrate held by the holder 3. It is installed so as to measure the pressure, and is rotatably provided on the same central axis as the center of the trough 1.

5 is a surface for controlling the surface area of the closed area defined by the trough 1 and the movable barrier 2 by raising and lowering the aqueous solution put into the trough 1 from the bottom of the trough 1. Pump as pressure control means, 6
Is a tank for storing the aqueous solution flowing out and in by the pump 5. The drive of the pump 5 is controlled by a control circuit 5 a in accordance with the surface pressure of the film-forming molecules detected by the sensor 4.

In such a device, the concentration formed by the trough 1 and the movable barrier 2 and the tank 6
Cadmium chloride (CdCl ₂ ) of × 10 ^-3 mol · dm ^-3 and 5 × 1
0 ^-5 potassium bicarbonate mol · dm ^-3 (KHCO ₃₎ is a water temperature 20 ° C., dissolved, an aqueous solution of hydrogen ion concentration pH6.5 is Tamarira. Then, a merocyanine dye having a concentration of 1 × 10 ⁻³ mol · dm ⁻³ (or a cyanine dye or a derivative thereof) and a concentration of 2 × 10 ³ are formed in a closed region (subphase) separated by the trough 1 and the movable barrier 2. A chloroform solution containing ^-3 mol · dm ^-3 arachidic acid (in addition, a chloroform solution containing 1 × 10 ^-3 mol · dm ^-3 phosphatidylethanolamine instead of arachidic acid may be dropped) to form a film. Expand the molecule.

While measuring the surface pressure of the film forming molecules with the sensor 4, the pump 5 is driven by the control of the control circuit 5a to raise and lower the developing surface of the film forming molecules, and the surface pressure is increased to a predetermined value (25 mN ·
m ^-1 ). At this time, the substrate 7 is held above the film forming molecules.

Next, the rotation of the movable barrier 2 is started, and the movable barrier 2 is gradually accelerated from a stationary state to an angular velocity of 1 ° per minute after 15 minutes, and thereafter, the movable barrier 2 is rotated at a constant angular velocity of 1 ° per minute. Let it. As the movable barrier 2 rotates, the film forming molecules in contact with the movable barrier 2 move at the same angular velocity as the movable barrier 2, and the film forming molecules in contact with the trough 1 are almost stopped. The film-forming molecules flow with the applied velocity distribution. When the movable barrier 2 is rotated at this constant angular velocity (1 ° per minute) for approximately one hour, the film-forming molecules developed in the closed region are mostly oriented along the flow direction.

When the film forming molecules are oriented, the substrate 7 held by the holder 3 is moved at a distance equal to the distance from the central axis on which the sensor 5 is installed, and the flow velocity of the film forming molecules at that distance. Rotate around the same central axis at the same speed. That is, the substrate 7 and the film forming molecules immediately below the substrate 7 are not moved relatively.

Then, while maintaining that state, and while controlling the drive of the pump 5 by the control circuit 5a such that the surface pressure measured by the sensor 4 is maintained at the above-mentioned constant value,
The substrate 7 is moved up and down into the film forming molecule to
Transfer (formation of an LB film). The substrate 7 is moved up and down at a speed of, for example, 10 mm / min. Thus, an LB film with good in-plane orientation is formed.

In the LB film thus formed, for example, in an LB film containing a merocyanine dye, a J-aggregate is formed in which merocyanine dye molecules are oriented in an orderly manner. The light intensity of the light absorption peak with respect to the polarized light of 590 nm corresponding to the J-aggregate is measured. It can be seen that the color ratio R is significantly improved, and the film forming molecules are well oriented.

In this embodiment, the trough 1 as the first barrier has a tapered shape in which the lower diameter is reduced, and the movable barrier 2 as the second barrier is in a tapered shape in which the lower diameter is increased. Although it is formed, it may be a taper shape opposite to each other, and, instead of raising and lowering the liquid surface, moving and controlling the two barriers, moving the barrier and the liquid surface relatively Is also good.

[0020]

As is apparent from the above description, the present invention has a tapered trough having a circular cross section and a tapered trough having a circular cross section and having the same central axis as the trough. Equipped with a movable barrier rotatably provided in the
By rotating the movable barrier, the film forming molecules can be oriented. Then, while keeping the surface pressure constant by raising and lowering the liquid surface of the film forming molecules relatively to the trough and the movable barrier, the substrate is rotated and further moved up and down to transfer the film forming molecules in the aligned state to the substrate. LB with good in-plane orientation
A film can be formed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention device.

FIG. 2 is a schematic cross-sectional view for explaining one embodiment of the device of the present invention.

FIG. 3 is a schematic configuration diagram of a conventional film forming apparatus.

[Explanation of symbols]

 Reference Signs List 1 trough (first barrier) 2 movable barrier (second barrier) 3 holder (holding means) 4 sensor 5 pump (surface pressure control means) 5a control circuit 7 substrate

Continuing on the front page (72) Inventor Kaichi Tsujino 2--18 Keihanhondori, Moriguchi City Sanyo Electric Co., Ltd. (72) Inventor Kazuhiko Kuroki 2-18-18 Keihanhondori Moriguchi City Sanyo Electric Co., Ltd. (56) References JP-A-2-184364 (JP, A) JP-A-3-154632 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B05C 3/09 B05D 1/18-1 / 20 H01L 21/208

Claims (1)

(57) [Scope of request for utility model registration] 1. A tapered first bar having a circular cross section.
The rear and the inside of the first barrier have a circular cross section,
The first barrier is formed in a reverse taper shape to the first barrier, and the first barrier is formed.
Rotatably provided on the same center axis as the first barrier
The first barrier or the second barrier.
Relative to the liquid surface on which the film-forming molecules are developed
While, a film forming apparatus that is deployed in the closed region delimited by the second barrier and the first barrier, the closed area
And the surface pressure control means for controlling the surface pressure of the film forming molecules are expanded, rotatable same central axis as said first barrier with vertically moving the substrate to take transferred deposition molecules developed in the closed area A film forming apparatus, comprising: a holding unit provided in the apparatus.