JP2801498B2 - Thin film manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for transporting a flexible film substrate by winding it around a heating drum rotating in a vacuum.
The present invention relates to a thin film manufacturing apparatus for continuously depositing a thin film 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 wrapping and transporting the flexible film substrate around a heating drum rotating in a vacuum is known as a thin film manufacturing apparatus. It is already widely used in industry in sputtering equipment and the like. In such a conventional thin film manufacturing apparatus, a touch roll for controlling the running direction of the film in a limited space is provided immediately after the rotating heating drum.

[0003]

In such a thin film manufacturing apparatus, very small scratches often occur on the coating surface, and a thin film, such as an amorphous silicon solar cell, which exhibits an electrical function in a bonding structure of a multilayer film. In a battery or 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 free from scratches.

[0005]

According to the present invention, there is provided a thin film manufacturing apparatus, comprising: a heating drum for heating a flexible film substrate in a reaction chamber for depositing a thin film; Equipped with a touch roll that controls the transport direction, the flexible film substrate is wound around a rotating heating drum and transported in a reaction chamber in which the degree of vacuum is 1.33 kPa or less. In a thin film manufacturing apparatus for continuously depositing a thin film, a sprocket hole is provided in advance in a width direction 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 terminal is provided is smaller than the diameter of the touch roll where the sprocket terminal is provided. It is characterized in that also small.

That is, as a result of intensive studies by the present inventors,
It became clear that fine scratches on the coating surface were generated as follows.

First, even if the flexible film substrate heated by the heating drum and deposited on the thin film loses contact with the heating drum, since the surroundings are in a vacuum, heat is released little and the substrate is not cooled rapidly. In particular, in a vacuum at a pressure of 1.33 kPa or less, which is suitable for plasma CVD, sputtering, and the like, the thermal conductivity due to the residual gas is rapidly reduced as compared with that at normal pressure, so that the influence is large.

On the other hand, the temperature of a conventional touch roll that is not temperature-controlled is close to room temperature. For this reason, the flexible film substrate is rapidly cooled when it separates 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 touch roll surface.

[0009] One of the problems is to prevent a contraction in the width direction by fitting a sprocket hole in the end of the flexible film substrate in advance with a sprocket terminal provided on the touch roll. In addition, the diameter of the touch roll is smaller than that of the outside of the portion where the sprocket terminal of the touch roll is provided, so that the film substrate and the touch roll do not touch each other at the portion, thereby making the flexible film substrate flexible. Can be prevented from contacting the touch roll and being quenched.

[0010] 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 a thin film is formed 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 a thin film manufacturing apparatus according to the present invention is used to form an amorphous silicon thin film exhibiting an electrical function by a bonding structure of a multilayer film by a plasma CVD method, an extremely small scratch generated on the film surface can be obtained. This is more preferable because a short circuit phenomenon due to the above can be prevented.

When a film substrate having a high expansion coefficient is used, the position of a sprocket hole provided in advance on the substrate is determined in consideration of the amount of thermal deformation, or the position and shape of a sprocket terminal provided on the roll edge are determined by heat. 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 as not to cause wrinkles or the like on the film substrate. For example, it is preferable that the sprocket terminal is formed on a cone because the film receives tension in the width direction in accordance with the inclination of the slope and forms a tight state.

[0014]

FIG. 1 shows an apparatus for manufacturing a thin film according to an embodiment of the present invention. That is, this is a schematic configuration of a three-chamber roll-to-roll plasma CVD apparatus for forming an amorphous silicon thin film solar cell 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 the solar cell. Is a p-layer reaction chamber for depositing, and 50 is a film winding chamber. 11 is a film unwinding roll, and 51 is a film unwinding roll. 21, 31 and 41 are heating drums in each reaction chamber. Further, 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
Electrode. Reference numeral 60 denotes a long flexible film substrate. The distance between each heating drum and the touch roll is 5 cm. The room temperature at which this device was installed was 30 ° C.

The flexible film substrate 60 has a thickness of 75 μm.
m of polyethylene naphthalate film (linear expansion coefficient =
A substrate for a flexible solar cell in which an Al / stainless thin film was deposited as a lower electrode on a surface of 0.000013 / ° C. to a thickness of 0.4 μm / 4 nm by a sputtering method was used. And beforehand, a sprocket hole (circular hole with a diameter of about 3mm)
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 diameter of 3 mm. At the center of the touch roll, the distance between the film and the roll surface is 1 mm.

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

In each reaction chamber, a thin film is deposited while the flexible film substrate 60 is conveyed while being in contact with each heating drum. Therefore, the reaction pressure in each reaction chamber and the RF discharge power at the time of depositing a thin film were set to 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 temperatures of the heating drums 21 and 41 are
The surface temperature of the heating drum 31 is controlled at 200 ° C. and the temperature is controlled at 120 ° C. On the other hand, the temperature of each touch roll is approximately 30
It is the same as ° C.

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

Further, as a comparative example, all 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 constructed. As a result, the number of scratches was 12, and the solar cell output was 0.8 μW / cm 2. This is considered to be due to a decrease in the output of the solar cell 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 an apparatus for producing a thin film having no flaws on the surface of the deposited film.

[Brief description of the 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 for depositing solar cell i-layer reaction chamber 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 for 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 take-up chamber 51 Film take-up roll 52 Touch roll without sprocket terminal 60 Flexible film substrate

Continuation of the front page (56) References JP-A-3-72073 (JP, A) JP-A-62-111718 (JP, A) JP-A-2-25567 (JP, A) JP-A-62-112226 (JP, A) , A) Japanese Utility Model Application Sho 59-4761 (JP, U) Japanese Patent Publication No. 57-25895 (JP, B2) Japanese Patent Publication No. Sho 59-34421 (JP, B2) (58) Fields surveyed (Int. Cl. ⁶ , DB Name) C23C 14/56 C23C 14/20 C23C 16/50

Claims (3)

(57) [Claims] A heating chamber for heating a flexible film substrate and a touch roll for controlling the direction of transport of the flexible film substrate drawn from the heating drum are provided in a reaction chamber for depositing a thin film. In a thin film manufacturing apparatus that continuously deposits a thin film on a flexible film substrate while transporting the flexible film substrate around a rotating heating drum in a reaction chamber at a pressure of 1.33 kPa or less. A sprocket hole was previously provided at an end in the width direction of the flexible film substrate, and a touch roller immediately after the heating drum was provided with a sprocket terminal to be fitted into the sprocket hole of the flexible film substrate, and a sprocket terminal was provided. A thin film manufacturing apparatus, wherein the diameter of the touch roll in a portion inside the portion is smaller than the diameter of the touch roll in a portion where the sprocket terminal is provided. 2. A flexible film substrate having a linear expansion coefficient of 0.00
2. The thin film manufacturing apparatus according to claim 1, wherein the temperature is 001 / ° C. or higher. 3. A plasma CV on a flexible film substrate.
3. A thin film manufacturing apparatus according to claim 1, wherein an amorphous silicon thin film is deposited by a method D.