JPH06330319A - Thin film production system - Google Patents

Abstract

PURPOSE:To obtain a thin film production system without any damage on the surface of a deposited film. CONSTITUTION:The drums 21, 31 and 41 for heating a flexible-film 60 and the touch rolls 23, 33 and 43 for controlling the traveling direction of the substrate delivered from the drums are provided respectively in reaction chambers 20, 30 and 40 to deposit a thin film. The substrate is wound on the drum in the reaction chamber kept at <=1.33kPa and traveled, and a thin film is continuously deposited on the substrate. In this case, a sprocket hole is previously provided at the end of the substrate 60 in its width direction, further a sprocket terminal to be engaged with the sprocket hole of the substrate is furnished to the touch rolls 23, 33 and 43, and the diameter of the touch roll at the part inside the part provided with the sprocket terminal is made smaller than the diameter of the touch roll at the part furnished with the sprocket terminal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention winds a flexible film substrate around a heating drum rotating in a vacuum and conveys it.
The present invention relates to a thin film manufacturing apparatus for continuously depositing thin films on a flexible film substrate.

[0002]

2. Description of the Related Art A thin film manufacturing apparatus for continuously depositing a thin film on a flexible film substrate while winding and transporting the flexible film substrate around a heating drum rotating in a vacuum, It is already widely used in industry for sputtering equipment. In such a conventional thin film manufacturing apparatus, a touch roll for controlling the traveling direction of the film in a limited space is provided immediately after the rotating heating drum.

[0003]

In such a thin film manufacturing apparatus, a microscopic scratch is often generated on the coating surface, and a thin film that exhibits an electric function in a junction structure of a multilayer film, for example, an amorphous silicon solar cell. In batteries and the like, there is a problem that a short circuit phenomenon occurs and a film having a sufficient function cannot be formed.

An object of the present invention is to solve the above problems and to obtain a thin film manufacturing apparatus in which the surface of a deposited film is not scratched.

[0005]

A thin film manufacturing apparatus according to the present invention comprises a heating drum for heating a flexible film substrate and a flexible film substrate pulled out from the heating drum in a reaction chamber where thin films are deposited. It is equipped with a touch roll that controls the transport direction, and while the flexible film substrate is wound around the rotating heating drum and transported in a reaction chamber in which the degree of vacuum is 1.33 kPa or less, the flexible film substrate is transferred onto the flexible film substrate. In a thin film manufacturing device that deposits thin films continuously, a sprocket hole is provided in advance in the widthwise end of the flexible film substrate, and the touch roll immediately after the heating drum is fitted into the sprocket hole of the flexible film substrate. The diameter of the touch roll inside the part where the sprocket terminals are installed is smaller than the diameter of the touch roll where the sprocket terminals are installed. It is characterized in that also small.

That is, as a result of earnest study by the present inventor,
It was revealed that fine scratches on the coated surface occur as follows.

First, the flexible film substrate heated by the heating drum and deposited with a thin film is not cooled rapidly even if contact with the heating drum is lost because the surroundings are in a vacuum and the heat is not released. Particularly in a vacuum of 1.33 kPa or less suitable for plasma CVD, sputtering, etc., the thermal conductivity due to the residual gas is rapidly reduced as compared with that under normal pressure, and this has a great effect.

On the other hand, the temperature of a conventional touch roll, which is not temperature-controlled, is close to room temperature. Therefore, the flexible film substrate is rapidly cooled when it is separated from the heating drum and comes into contact with the touch roll. At that time, the flexible film substrate contracts in the width direction on the touch roll, and scratches are generated in the width direction of the film by the surface of the touch roll.

Therefore, one is to prevent shrinkage in the width direction by fitting a sprocket hole at the end of the flexible film substrate in advance and a sprocket terminal provided on the touch roll. Furthermore, the diameter of the touch roll is made smaller than that of the outside at the portion inside the sprocket terminal of the touch roll, and the film substrate and the touch roll are prevented from touching at that portion. Can be prevented from coming into contact with the touch roll and being rapidly cooled.

The generation of scratches, which is a problem, is affected by the amount of deformation of the flexible film substrate on the surface of the heating drum or the surface of the touch roll, that is, the amount of thermal expansion. Therefore, when forming a thin film on a flexible film substrate having a linear expansion coefficient of 0.00001 / ° C. or more, it is more preferable to use the thin film manufacturing apparatus according to the present invention.

Alternatively, when the thin film manufacturing apparatus according to the present invention is used when forming a thin film of amorphous silicon which exhibits an electric function in a junction structure of a multi-layer film by the plasma CVD method, very small scratches generated on the film surface are used. This is more preferable because it can prevent a short circuit phenomenon due to.

When a film substrate having a high expansion coefficient is used, the position of the sprocket hole provided in the substrate in advance is set in consideration of the amount of thermal deformation thereof, or the position and shape of the sprocket terminal provided at the roll edge are set to be heat-resistant. It is preferable to design by predicting the amount of deformation.

Further, the shape of the sprocket terminal is determined so that tension in the width direction is applied by the roll so that wrinkles do not occur on the film substrate. For example, when the sprocket terminal is formed in a conical shape, the film is tensioned in the width direction according to the inclination of the inclined surface, and a taut state is formed, which is preferable.

[0014]

EXAMPLES AND COMPARATIVE EXAMPLES FIG. 1 shows a thin film manufacturing apparatus showing an example of the present invention. That is, it is a schematic configuration of a three-chamber separation roll-to-roll plasma CVD apparatus for forming a solar cell of an amorphous silicon thin film on a flexible film substrate.

In the figure, 10 is a film unwinding chamber, 20 is an n-layer reaction chamber for depositing an n-layer of a solar cell, 30 is an i-layer reaction chamber for depositing an i-layer of a solar cell, and 40 is a p-layer of a solar cell. Is a p-layer reaction chamber and 50 is a film winding chamber. Further, 11 is a film winding roll and 51 is a film winding roll. 21 and 31 and 41 are heating drums in each reaction chamber. In addition, 12, 22, 32, 42, and 52 are touch rolls without sprocket terminals. On the other hand 2
3, 33, and 43 are touch rolls with sprocket terminals. 24, 34, and 44 are plasma CVD
It is an electrode for. And 60 is a long flexible film substrate. The distance between each heating drum and the touch roll is 5 cm. The room temperature in which this device is installed is 30 ° C.

The flexible film substrate 60 has a thickness of 75 μ
m polyethylene naphthalate film (coefficient of linear expansion =
A flexible solar cell substrate having an Al / stainless thin film deposited on the surface of 0.000013 / ° C.) as a lower electrode to a thickness of 0.4 μm / 4 nm by a sputtering method was used. And for this, a sprocket hole (circular hole with a diameter of about 3 mm) is provided at the end beforehand.
Were provided at intervals of 15 mm.

On the other hand, the diameter of the touch roll with a sprocket is 100 mm. The sprocket terminal provided on this touch roll has a conical shape and a bottom surface diameter of 3 mm. At the center of the touch roll, the distance between the film and the roll surface is 1 mm.

The flexible film substrate 60 is mounted on the unwinding roll 11 and each reaction chamber 2 for n layer, i layer and p layer is provided.
It is taken up by a take-up roll 51 via 0, 30, 40. Here, the transport speed of the flexible film substrate 60 is 3c.
m / min.

In each reaction chamber, the flexible film substrate 60 is conveyed while being in contact with each heating drum, and a thin film is deposited. Therefore, the reaction pressure in each reaction chamber and the RF discharge power during thin film deposition were 266 Pa and 200 W in the n-layer reaction chamber 20 and the p-layer reaction chamber 40, and 133 Pa and 40 W in the i-layer reaction chamber 30. In this embodiment, the n layer / i layer / p layer are respectively
Deposited to a thickness of 50 nm / 550 nm / 8 nm.

At this time, the surface temperature of the heating drums 21 and 41 is
The temperature of the surface of the heating drum 31 is controlled to 120 ° C, and the surface temperature of the heating drum 31 is controlled to 200 ° C. On the other hand, the temperature of each touch roll is 30
It is the same as ℃.

The amorphous silicon film thus manufactured is
It was observed with a microscope of 0 magnification, and how many scratches were generated in a 2 cm square. Furthermore, an ITO film with a thickness of 60 is formed as a transparent electrode on the amorphous silicon film by another electron beam evaporation apparatus.
nm was deposited to form a solar cell. The output of this solar cell was measured under an illumination of 200 lx fluorescent lamp. As a result, in the present embodiment using the touch roll with the sprocket,
The number of scratches was 0 and the solar cell output was 3.0 μW / square cm.

Further, as a comparative example, all the touch rolls were replaced with those without sprockets, and an amorphous silicon film was deposited in the same manner as described above, and a solar cell was further constructed. As a result, the number of scratches was 12 and the solar cell output was 0.8 μW / square cm. It is considered that this is because the output of the solar cell was reduced due to the influence of the leak current generated by the short circuit due to the scratch.

[0023]

As described above in detail, according to the present invention, it is possible to obtain the thin film manufacturing apparatus in which the surface of the deposited film is not scratched.

[Brief description of drawings]

FIG. 1 is a schematic configuration of a three-chamber separation roll-to-roll plasma CVD apparatus.

[Explanation of symbols]

 10 Film unwinding chamber 11 Film unwinding roll 12 Touch roll without sprocket terminals 20 n-layer reaction chamber for depositing n layers of solar cells 21 Heating drum 22 Touch roll without sprocket terminals 23 Touch roll with sprocket terminals 24 Plasma CVD Electrode 30 for i layer reaction chamber for depositing i layer of solar cell 31 heating drum 32 touch roll without sprocket terminal 33 touch roll with sprocket terminal 34 electrode for plasma CVD 40 p layer for depositing p layer of solar cell Reaction chamber 41 Heating drum 42 Touch roll without sprocket terminal 43 Touch roll with sprocket terminal 44 Electrode for plasma CVD 50 Film winding chamber 51 Film winding roll 52 Touch roll without sprocket terminal 60 Flexible film substrate

Claims (3)

[Claims] 1. A reaction chamber in which thin film deposition is performed is equipped with a heating drum for heating a flexible film substrate and a touch roll for controlling the conveying direction of the flexible film substrate pulled out from the heating drum. In a thin film manufacturing apparatus that continuously deposits thin films on a flexible film substrate while transporting the flexible film substrate wound around a rotating heating drum in a reaction chamber under a pressure of 1.33 kPa or less, A sprocket hole was provided in advance in the widthwise end of the flexible film substrate, and a sprocket terminal fitted to the sprocket hole of the flexible film substrate was provided on the touch roll immediately after the heating drum, and a sprocket terminal was provided. The thin film manufacturing apparatus is characterized in that the diameter of the touch roll inside the portion is smaller than the diameter of the touch roll in the portion where the sprocket terminals are provided. 2. The linear expansion coefficient of the flexible film substrate is 0.00
The thin film manufacturing apparatus according to claim 1, wherein the temperature is 001 / ° C or higher. 3. A plasma CV is formed on a flexible film substrate.
3. A thin film manufacturing apparatus according to claim 1, wherein a thin film of amorphous silicon is deposited by the D method.