JP6132055B2 - Method for producing graphene film - Google Patents

Description

  The present technology relates to a method of manufacturing a graphene film using roll-to-roll.

  Film formation process using roll-to-roll (Roll-to-Roll) transports a film formation object (metal foil, etc.) by winding it from an unwinding roll to a take-up roll, while the film formation object A thin film is formed. It is possible to transport a film-forming object having a large area by roll-to-roll, and is suitable for mass production of thin films.

  For example, Patent Document 1 discloses a “graphene roll troll coating apparatus” in which a metal member is conveyed by roll troll (roll to roll) and a graphene (graphene) film is formed on the metal member.

JP 2011-162877 A

  However, in the film forming process using roll-to-roll as described in Patent Document 1, the roll-to-roll is not used because tension is applied to the film formation target by roll-to-roll. The film quality may be deteriorated as compared with the film process.

  In view of the circumstances as described above, an object of the present technology is to provide a method of manufacturing a graphene film that can manufacture a high-quality thin film using roll-to-roll.

A method for producing a graphene film according to an embodiment of the present technology sets a film formation target made of copper in a roll-to-roll mechanism,
The film-forming target is conveyed by the roll-to-roll mechanism,
Supplying a film formation material to the film formation target,
The film-forming object is heated in a state where the tension applied to the film-forming object by the roll-to-roll mechanism is relaxed below the tension at which twin deformation occurs in copper.

  When a tension is applied to copper in a heated state, copper undergoes twin deformation in which the crystal orientation partially changes within the metal crystal. It has been found by the present inventors that twin deformation occurs even at lower tension than plastic deformation, but twin deformation also affects the film quality. Therefore, by reducing the tension applied to the film formation target to be equal to or lower than the tension at which twin deformation occurs in the film formation target, it is possible to prevent deterioration in film quality due to twin deformation.

  The step of heating the film formation target may be performed after the tension applied to the film formation target is relaxed to less than 1 MPa.

  Although heated copper (for example, 950 ° C.) undergoes plastic deformation with a tension of about 8.3 MPa, twin deformation also occurs with a lower tension of about 1 MPa. Therefore, when the film formation target is a metal foil containing copper (including a copper alloy), the tension applied to the film formation target is relaxed to less than 1 MPa (more preferably less than 0.1 MPa). Therefore, it is possible to suppress deterioration of film quality due to twin deformation of copper.

  The film forming material may be a carbon source material containing carbon.

  When a carbon source material (methane or the like) is supplied to a heated film formation target (copper-containing metal foil), the carbon source material is decomposed, and graphene is formed on the film formation target. At the graphene production temperature (for example, 950 ° C.), copper twinning deformation can occur as described above, but it has been found that the film quality (electrical characteristics, etc.) of graphene deteriorates when twinning deformation occurs. In the present technology, as described above, since the occurrence of twin deformation of copper is prevented by relaxing the tension applied to the film formation target, the film quality of graphene due to twin deformation of copper is reduced. Therefore, it is possible to produce high-quality graphene.

  The carbon source material may be methane gas.

  The step of heating the film formation target may be performed by resistance heating.

  The film formation target may be a metal foil, and the thickness of the metal foil may be 1 to 100 μm.

  Hydrogen gas may be supplied together with the film forming material.

  The roll-to-roll mechanism may have a slack detection mechanism.

  It is possible to detect the amount of slack of the film formation object caused by the relaxation of the tension applied to the film formation object by a slack detection mechanism, and the amount of slack of the film formation object is applied to the film formation object. By adjusting the tension, it is possible to keep the tension within an appropriate range.

  You may adjust the tension | tensile_strength applied to the said film-forming target according to the output of the said slack detection mechanism.

  The step of heating the film formation target may be performed after stopping the conveyance of the film formation target by the roll-to-roll mechanism and relaxing the tension.

  According to this manufacturing method, it is possible to relieve the tension applied to the film formation target by the conveyance by stopping the conveyance of the film formation target by the roll-to-roll mechanism.

  As described above, according to the present technology, it is possible to provide a graphene film manufacturing method capable of manufacturing a high-quality thin film using roll-to-roll.

It is a mimetic diagram showing the composition of the film deposition system concerning a 1st embodiment of this art. It is a reverse pole figure which shows the crystal orientation distribution of the copper foil heated in the state in which the low tension | tensile_strength (0.1 MPa) was applied. It is a reverse pole figure which shows the crystal orientation distribution of the copper foil heated in the state in which the high tension | tensile_strength (1 Mpa) was applied. It is an optical microscope image of the graphene formed into a film on the copper foil to which the low tension (0.1 MPa) was applied. It is an optical microscope image of the graphene formed into a film on the copper foil to which high tension | tensile_strength (1 Mpa) was applied. It is a mimetic diagram showing the composition of the film deposition system concerning a 2nd embodiment of this art. It is a schematic diagram which shows the structure of the film-forming apparatus which concerns on the modification 1 of this technique. It is a schematic diagram which shows the structure of the film-forming apparatus which concerns on the modification 2 of this technique.

(First embodiment)
A film forming apparatus according to the first embodiment of the present technology will be described. FIG. 1 is a schematic diagram illustrating a film forming apparatus 100 according to the first embodiment of the present technology. Note that the film formation apparatus 100 according to the present embodiment is a film formation apparatus that forms graphene on a film formation target.

  As shown in the figure, the film forming apparatus 100 includes a chamber 101, an unwinding roll 102, a first guide roll 103, a second guide roll 104, an elastic roll 105, a winding roll 106, a current source 107, and a gas supply system 108. And an evacuation system 109. The unwinding roll 102, the first guide roll 103, the second guide roll 104, the elastic roll 105, and the winding roll 106 constitute a roll-to-roll mechanism. The roll-to-roll mechanism and current source 107 are accommodated in the chamber 101, and the gas supply system 108 and the vacuum exhaust system 109 are connected to the chamber 101. In addition, the film formation target S is set in the roll-to-roll mechanism.

  The chamber 101 houses a roll-to-roll mechanism and a current source 107 and provides a film formation atmosphere. The chamber 101 can be, for example, a vacuum chamber capable of maintaining the inside in a vacuum, but any chamber can be selected according to film forming conditions.

  The unwinding roll 102 is a roll from which the film forming target S is unwound, and adjusts the tension of the film forming target S from the pinch roll 110 (described later) to the unwinding roll 102. The unwinding roll 102 can be driven to rotate by a drive source (such as a motor) not shown. The tension of the film formation target S by the unwinding roll 102 can be adjusted by transmitting power from a driving source by clutch control or the like.

  The first guide roll 103 guides the conveyance of the film formation target S and applies the current supplied from the current source 107 to the film formation target S. The 1st guide roll 103 shall be connected to the drive source which is not shown in figure, and shall be rotationally driven. The first guide roll 103 can be made of a conductive material such as metal.

  The second guide roll 104 guides the conveyance of the film formation target S and applies the current supplied from the current source 107 to the film formation target S. The second guide roll 104 can be connected to a drive source (not shown) and driven to rotate. The second guide roll 104 can be made of a conductive material such as metal.

  The elastic roll 105 is pressed by the second guide roll 104 and sandwiches the film formation target S together with the second guide roll 104. The elastic roll 105 is made of an elastic material having at least a surface (roll surface) having elasticity, and the film formation target S is prevented from sliding with respect to the second guide roll 104 due to the elasticity. The elastic material can be, for example, silicon.

  The second guide roll 104 and the elastic roll 105 constitute a pinch roll 110 that sandwiches the film formation target S conveyed by the roll-to-roll mechanism.

  The winding roll 106 is a roll that winds up the film formation target S, and adjusts the tension of the film formation target S from the pinch roll 110 to the winding roll 106. The winding roll 106 can be rotationally driven by a drive source (not shown) such as a motor. The tension of the film formation target S by the winding roll 106 can be adjusted by transmitting power from a driving source by clutch control.

  The current source 107 is connected to the first guide roll 103 and the second guide roll 104 and applies a current between them. Thereby, an electric current flows into the area | region (henceforth a film-forming area | region) between the 1st guide roll 103 and the 2nd guide roll 104 of the film-forming target S, and the film-forming target S is resistance-heated.

  Note that the film formation target S may be heated by a method different from resistance heating, and in that case, the current source 107 may not be provided. Examples of heating methods different from resistance heating include heating by irradiation with a ceramic heater, halogen lamp, laser, etc., heating by induction current by application of a magnetic field, heating by heat conduction, and the like.

  When the film formation target S is heated by a heating method different from resistance heating, the first guide roll 103 and the second guide roll 104 do not need to be made of a conductive material, and are made of plastic, ceramics, or the like. It is also possible to do.

  The gas supply system 108 supplies a carbon source gas serving as a film forming material into the chamber 101. The gas supply system 108 includes a gas source (gas cylinder or the like) (not shown) and is configured to be able to supply gas into the chamber 101. The gas supply system 108 can supply, for example, methane as a carbon source gas.

  Instead of supplying the carbon source gas from the gas supply system 108, a substance containing a carbon source substance may be supplied into the chamber 101 by another method. For example, a liquid (such as ethanol) containing a carbon source material may be accommodated in the chamber 101, and vapor of such a liquid may be supplied into the chamber 101. Further, it is possible to heat the film-forming object S together with a solid (PMMA (Poly (methyl methacrylate)) or the like containing a carbon source material previously supported on the film-forming object S. When 101 is heated, such a solid can be stored in the chamber 101 and vaporized.

  The evacuation system 109 evacuates the chamber 101. The evacuation system 109 includes a vacuum pump (not shown) and the like, and is configured to evacuate the chamber 101.

  The film forming apparatus 100 has the above configuration.

[About deposition target]
As described above, the film formation target S is set in the roll-to-roll mechanism of the film formation apparatus 100. The film formation target S can be a metal foil, and can be appropriately selected depending on the catalytic activity, film formation conditions, etc., but a material containing copper (including a copper alloy) is suitable. . This is because copper has a catalytic activity for the film formation of graphene and has a property that carbon does not dissolve therein. Further, copper can be removed by an etching solution (iron chloride or the like), which is suitable for transferring the generated graphene to another substance (copper is removed). Furthermore, copper is relatively inexpensive.

  In addition, the film formation target S can be, for example, a foil made of a pure metal such as platinum (Pt), nickel (Ni), or cobalt (Co), or an alloy such as a copper-nickel alloy. For example, an alloy in which platinum having a high catalytic function is added to copper, an alloy in which 0.02 wt% of zirconium (Zr) is added to copper to prevent plastic deformation, and chromium (Cr), tin (Sn), zinc in copper An alloy or the like to which 0.25 wt% of (Zn) is added can be used as the film formation target S. Further, when the film formation target S is heated by resistance heating as described above, the electrical resistance is also taken into consideration.

  Various metals including copper undergo plastic deformation when tension is applied in a heated state. When the film formation target S is deformed, the quality of the thin film formed thereon may be deteriorated. Therefore, it is necessary to prevent the film formation target S from being deformed. In particular, in the roll-to-roll mechanism, tension is applied to the film formation target as it is transported, and this needs to be relaxed.

  Furthermore, when a material containing copper is used as the film formation target S, “twinning deformation” may occur in copper at the graphene generation temperature (for example, 950 ° C.). Twin deformation is deformation caused by a partial change in crystal orientation in a metal crystal, and is generated with a lower tension than plastic deformation. For example, in the case of copper, plastic deformation occurs at an applied tension of about 8.3 Pa (950 ° C.), but twin deformation can occur even at an applied tension of about 1 MPa.

  The present inventors have found that when graphene is formed on a film formation target S made of a material containing copper, the quality (electrical characteristics, etc.) of graphene is deteriorated due to twin deformation of copper. It was. In the present embodiment, the tension applied to the film formation target S is relaxed by the roll-to-roll mechanism, and plastic deformation and twinning deformation of the film formation target S are prevented. It is possible to prevent the resulting deterioration in the quality of the thin film.

  The thickness of the metal foil used as the film-forming target S is not particularly limited, and is preferably 1 to 100 μm, more preferably 10 to 50 μm. The width and length of the metal foil (the length of the film formation region (described later)) are not particularly limited. For example, both width and length can be 10 to 10000 mm, more preferably width 50 to 2000 mm and length 100 to 2000 mm. The transport direction of the film-forming target S (the extending direction of the film-forming region (described later)) is not particularly limited, and can be a vertical direction, a horizontal direction, or an oblique direction.

[Film formation method]
(Film formation method 1)
A film forming method (film forming method 1) using the film forming apparatus 100 will be described. As shown in FIG. 1, the film-forming target S is set in a roll-to-roll mechanism. Specifically, a roll-shaped film formation target S is attached to the unwinding roll 102, and one end of the film formation target S is connected to the first guide roll 103 and the pinch roll 110 (second guide roll 104 and elastic roll 105). To the take-up roll 106. The film formation target S is held between the pinch rolls 110.

  After the film formation target S is set, the inside of the chamber 101 is adjusted to suit the film formation environment. Specifically, the chamber 101 can be evacuated by the evacuation system 109.

  Subsequently, a carbon source gas is introduced into the chamber 101 from the gas supply system 108. The carbon source gas can be, for example, methane gas and hydrogen gas, and the flow rates thereof can be, for example, methane gas 400 sccm and hydrogen gas 50 sccm. The carbon source gas can be adjusted so that the pressure in the chamber 101 is, for example, 0.001 to 120 kPa.

  Subsequently, a current is applied to the film formation target S by the current source 107 via the first guide roll 103 and the second guide roll 104, and the film formation region of the film formation target S is resistance-heated. The heating temperature is not particularly limited as long as it is equal to or higher than the graphene generation temperature (for example, 950 ° C.). By this heating, the carbon source gas supplied to the film formation target S is decomposed, and graphene is formed on the film formation target S at the same time.

  Along with the film formation of the graphene, the film formation target S is transported by a roll-to-roll mechanism. Specifically, the unwinding roll 102 and the winding roll 106 are rotated, and the film-forming target S is unwound from the unwinding roll 102 and wound around the winding roll 106. Further, the first guide roll 103 and the pinch roll 110 are rotated, and the film formation target S is conveyed from the first guide roll 103 to the pinch roll 110.

As the film formation target S is transported, the film formation target S is sequentially supplied to the film formation region, and a thin film of graphene is formed. For example, when an electric current of 8 kA / cm ² is applied by a current source 107 to a film forming region of a copper foil having a width of 230 mm conveyed at a rate of 0.1 m / min by a roll-to-roll mechanism, a film having a length of 400 mm is formed. Of the region, about 200 mm is heated to 1000 ° C. When methane gas contacts the copper surface at this temperature, methane is decomposed by the catalytic action of copper, and graphene is generated. Note that the coverage of the copper foil with graphene is not particularly limited, and the grains (crystal pieces) may not be connected to each other.

By pressing the copper foil with the pinch roll 110 during film formation, it is possible to apply a larger tension to the take-up roll 106 side of the film formation target S than to the pinch roll 110 and wind it up loosely (hardly). is there. On the other hand, it is possible to reduce the tension in the film formation region by reducing the tension on the unwinding roll 102 side of the film formation target S relative to the pinch roll 110.

  The tension applied to the film formation target S is preferably less than 1 MPa, and particularly preferably 0.1 MPa or less, in order to prevent the occurrence of twin deformation. This tension is significantly smaller than the tension at which plastic deformation occurs (8.3 Pa at 950 ° C. for copper).

  The relaxation of the tension applied to the film formation target S is such that the winding tension by the winding roll 106 and the tension in the film formation region are separated by the pinching roll 110 sandwiching the film formation target S. Is possible.

  By relaxing the tension applied to the film formation target S, deformation (plastic deformation and twinning deformation) of the film formation target S is prevented, and the graphene film formed thereon has a high quality. Is possible.

(Film formation method 2)
A film forming method (film forming method 2) using the film forming apparatus 100 will be described. Similar to the film forming method 1, the film forming object S is set in the roll-to-roll mechanism (see FIG. 1). After the film formation target S is set, the inside of the chamber 101 is adjusted to suit the film formation environment as described above, and the carbon source gas is introduced from the gas supply system 108.

  After the film formation target S is conveyed by the roll-to-roll mechanism, the roll-to-roll mechanism is stopped. Thereby, the tension applied to the film formation target S is relaxed. In addition, after the roll-to-roll mechanism is stopped, the pinch roll 110 (the second guide roll 104 and the elastic roll 105) can be slightly rotated backward to relieve the tension applied to the film formation target S. .

  Thereafter, the film formation region of the film formation target S is heated to a predetermined temperature, and the carbon source gas is decomposed by the heat of the film formation target S in the film formation region, and graphene is formed on the film formation target S at the same time. Is done. After a predetermined time elapses, the heating of the film formation target S is stopped, and the generation of graphene is stopped.

  After stopping the generation of graphene, the film-forming target S is transported by the roll-to-roll mechanism so that the new region of the film-forming target S becomes the film-forming region, and the tension is relaxed as described above. The new region is heated to generate graphene, and then the heating is stopped. Thereafter, the transport of the film-forming target S by the roll-to-roll mechanism, the relaxation of the tension, and the generation of graphene are repeated in order.

  Also by such a film formation method, the tension applied to the film formation target S is relaxed, so that deformation (plastic deformation and twin deformation) of the film formation target S is prevented, and film formation is performed thereon. It is possible to make high quality graphene.

[Effects of this embodiment]
As described above, in this embodiment, since the tension applied to the film formation target S is relaxed, twin deformation of the film formation target S is prevented. 2 and 3 are results of measuring the crystal orientation distribution of the copper foil by EBSD (electron backscatter diffraction). FIG. 2 is a measurement result of the copper foil heated in a state where a low tension (0.1 MPa) is applied, and FIG. 3 is a measurement result of the copper foil heated in a state where a high tension (1 MPa) is applied.

  As shown in FIG. 2, when the copper foil is heated in a state where a low tension is applied, the crystal structure of the copper has the same <001> orientation as before heating in each of the X, Y, and Z directions. I understand that On the other hand, as shown in FIG. 3, when the copper foil is heated in a state where a high tension is applied, twin grain boundaries are seen in the crystal structure of copper, and it can be seen that twin deformation occurs. It can be seen that the orientation in the <101> direction is maintained, and the crystal rotates with the <101> direction as the rotation axis. That is, it can be seen from FIGS. 2 and 3 that twin deformation is prevented by relaxing the tension applied to the copper foil. Since twin deformation occurs at a tension sufficiently lower than plastic deformation, plastic deformation does not cause a problem at a low tension at which twin deformation does not occur.

  4 and 5 are optical microscope images of graphene formed on a copper foil. FIG. 4 shows graphene formed on a copper foil to which low tension (0.1 MPa) is applied, and FIG. 5 shows graphene formed on a copper foil to which high tension (1 MPa) is applied. In FIG. 4, the graphene film is uniformly formed, but in FIG. 5, it can be seen that the graphene is cracked. That is, it can be said that high-quality graphene can be produced by relaxing the tension applied to the film formation target S.

(Second Embodiment)
A film forming apparatus according to the second embodiment of the present technology will be described. FIG. 6 is a schematic diagram showing a film forming apparatus 200 according to the second embodiment of the present technology. Note that the film forming apparatus 200 according to the present embodiment is a film forming apparatus that forms graphene on a film formation target.

  As shown in FIG. 6, the film forming apparatus 200 includes a chamber 201, an unwinding roll 202, a first guide roll 203, a first elastic roll 204, a second guide roll 205, a second elastic roll 206, and a third elastic roll 207. A fourth elastic roll 208, a take-up roll 209, a current source 210, a slack detection sensor 211, a gas supply system 212, and a vacuum exhaust system 213.

  A roll-to-roll mechanism including an unwinding roll 202, a first guide roll 203, a first elastic roll 204, a second guide roll 205, a second elastic roll 206, a third elastic roll 207, a fourth elastic roll 208, and a winding roll 209 Is configured. The roll-to-roll mechanism, the current source 210 and the slack detection sensor 211 are accommodated in the chamber 201, and the gas supply system 212 and the vacuum exhaust system 213 are connected to the chamber 201. In addition, the film formation target S is set in the roll-to-roll mechanism.

  The chamber 201 accommodates a roll-to-roll mechanism and a current source 210 and provides a film formation atmosphere. The chamber 201 can be, for example, a vacuum chamber capable of maintaining the inside in a vacuum, but any chamber can be selected according to film forming conditions.

  The unwinding roll 202 is a roll from which the film forming target S is unwound, and adjusts the tension of the film forming target S from the first pinch roll 214 (described later) to the unwinding roll 202. The unwinding roll 202 can be driven to rotate by a drive source (such as a motor) (not shown). The tension of the film formation target S by the unwinding roll 202 can be adjusted by transmitting power from a driving source by clutch control or the like.

  The first guide roll 203 guides the conveyance of the film formation target S and applies the current supplied from the current source 210 to the film formation target S. The first guide roll 203 can be connected to a drive source (not shown) and driven to rotate. The first guide roll 203 can be made of a conductive material such as metal.

  The first elastic roll 204 is pressed by the first guide roll 203 and sandwiches the film formation target S together with the first guide roll 203. The first elastic roll 204 is made of an elastic material having at least a surface (roll surface) having elasticity, and the film formation target S is prevented from sliding with respect to the first guide roll 203 due to the elasticity. The elastic material can be, for example, silicon.

  The first guide roll 203 and the first elastic roll 204 constitute a first pinch roll 214 that sandwiches the film formation target S conveyed by the roll-to-roll mechanism.

  The second guide roll 205 guides the conveyance of the film formation target S and applies the current supplied from the current source 210 to the film formation target S. The second guide roll 205 can be connected to a drive source (not shown) and driven to rotate. The second guide roll 205 can be made of a conductive material such as metal.

  The second elastic roll 206 is pressed by the second guide roll 205 and sandwiches the film formation target S together with the second guide roll 205. The second elastic roll 206 is made of an elastic material having at least a surface (roll surface) having elasticity, and the film formation target S is prevented from sliding with respect to the second guide roll 205 by the elasticity. The elastic material can be, for example, silicon.

  The second guide roll 205 and the second elastic roll 206 constitute a second pinch roll 215 that sandwiches the film formation target S conveyed by the roll-to-roll mechanism.

  The third elastic roll 207 and the fourth elastic roll 208 are disposed between the second pinch roll 215 and the take-up roll 209 and are guided from the second pinch roll 215 to the take-up roll 209. The third elastic roll 20 7 and the fourth elastic roll 208 are made of an elastic material having at least the surface (roll surface) having elasticity, and the elastic material can be, for example, silicon. The third elastic roll 207 and the fourth elastic roll 208 are preferably capable of adjusting the rotational torque by a clutch mechanism or the like.

  The winding roll 209 is a roll that winds up the film formation target S, and adjusts the tension of the film formation target S from the second pinch roll 215 to the winding roll 209. The winding roll 209 can be driven to rotate by a driving source (motor or the like) (not shown). The tension of the film formation target S by the winding roll 209 can be adjusted by transmitting power from a driving source by clutch control.

  The current source 210 is connected to the first guide roll 203 and the second guide roll 205 and applies a current between them. Thereby, an electric current flows into the area | region between the 1st guide roll 203 and the 2nd guide roll 205 of the film-forming target object S, and the film-forming target object S is resistance-heated. Similarly to the first embodiment, the film formation target S can be heated by a heating method different from resistance heating, and in that case, various heating sources instead of the current source 210 are provided. be able to.

  The slack detection sensor 211 detects the slack of the film formation target S conveyed by the roll-to-roll mechanism. The slack detection sensor 211 can include a first optical sensor 216 and a second optical sensor 217. Both the first optical sensor 216 and the second optical sensor 217 are arranged so that the emitted light (detection light) is substantially parallel to the film formation target S, and the first optical sensor 216 includes the second optical sensor 217. It can be provided at a position close to the film object S.

  The first optical sensor 216 includes a light emitting unit 216a and a light receiving unit 216b, and the light receiving unit 216b can receive light (laser or the like) emitted from the light emitting unit 216a. In the present embodiment, when the light emitted from the light emitting unit 216a is received by the light receiving unit 216b, the film forming target S is not slack, that is, the tension of the film forming target S is not relaxed. Judgment can be made. In addition, when the light emitted from the light emitting unit 216a is not received by the light receiving unit 216b, the emitted light is blocked by the film formation target S, that is, the film formation target S is slack. Judgment can be made.

  The second optical sensor 217 includes a light emitting unit 217a and a light receiving unit 217b, and the light receiving unit 217b can receive light (laser or the like) emitted from the light emitting unit 217a. In the present embodiment, when the light emitted from the light emitting unit 217a is not received by the light receiving unit 217b, it can be determined that the slack of the film formation target S is excessive. Further, when the light emitted from the light emitting unit 217a is received by the light receiving unit 217b, it can be determined that the film-forming target S is not excessively slack.

  That is, it is possible to acquire whether the slackness of the film formation target S is within an appropriate range (for example, 10 mm or less) from the output of the slackness detection sensor 211 (the first light sensor 216 and the second light sensor 217). is there. The slack detection sensor 211 is not limited to the one using the optical sensor as shown here, but may be any sensor that can detect the slack of the film formation target S.

  For example, the slack detection sensor 211 is dependent on the resistance value (the area between the first pinch roll 214 and the second pinch roll 215 of the film formation target S) during resistance heating (the length of the film formation area). ) May be used. In addition, when the deposition target S has an excessively loosened state, the electrical contact is arranged at the allowable limit position of the slack of the deposition target S. It may be a sensor that detects contact. Further, the sensor may be a sensor that captures an image of a film formation region by an image sensor and detects slackness of the film formation target S by image recognition.

  The gas supply system 212 supplies a gas as a film forming material into the chamber 201. The gas supply system 108 has a gas source (gas cylinder or the like) (not shown) and is configured to be able to supply a carbon source gas into the chamber 201. As in the first embodiment, instead of the gas supply system 212, a liquid or a solid containing a film forming material can be stored in the chamber 201.

  The evacuation system 213 evacuates the chamber 201. The evacuation system 213 includes a vacuum pump (not shown) and the like, and is configured to evacuate the chamber 201.

  The film forming apparatus 200 has the above configuration. The film formation target S can be a metal foil made of copper or the like, as in the first embodiment.

[Film formation method]
A film forming method using the film forming apparatus 200 will be described. As shown in FIG. 6, the film-forming target S is set in a roll-to-roll mechanism. Specifically, a roll-shaped film formation target S is attached to the unwinding roll 202, and one end of the film formation target S is connected to the first pinch roll 214, the second pinch roll 215, the third elastic roll 207, and the fourth elasticity. The roll 208 is connected to the winding roll 209. The film formation target S is sandwiched between the first pinch roll 214 and the second pinch roll 215.

  After the film formation target S is set, the inside of the chamber 201 is adjusted to suit the film formation environment. Specifically, the chamber 201 can be evacuated by the evacuation system 213.

  Subsequently, a carbon source gas is introduced into the chamber 201 from the gas supply system 212. The carbon source gas can be, for example, methane gas and hydrogen gas, and the flow rates thereof can be, for example, methane gas 400 sccm and hydrogen gas 50 sccm. The carbon source gas can be adjusted so that the pressure in the chamber 201 is, for example, 0.001 to 120 kPa.

  Subsequently, a current is applied to the film formation target S by the current source 210 via the first guide roll 203 and the second guide roll 205, and the film formation target S is resistance-heated. Here, the region where the film formation target S is heated is a region (film formation region) between the first guide roll 203 and the second guide roll 205. The heating temperature is not particularly limited as long as it is equal to or higher than the graphene generation temperature (for example, 950 ° C.).

  When the film formation target S is heated to the graphene generation temperature or higher, the carbon source gas is decomposed by the heat of the film formation target S in the film formation region, and at the same time, graphene is formed on the film formation target S. .

  Along with the film formation of the graphene, the film formation target S is transported by a roll-to-roll mechanism. Specifically, the unwinding roll 202 and the winding roll 209 are rotated, and the film-forming target S is unwound from the unwinding roll 202 and wound around the winding roll 209. Further, the first pinch roll 214 and the pinch roll 215 are rotated, and the film formation target S is conveyed from the first pinch roll 214 to the second pinch roll 215. Further, the third elastic roll 207 and the fourth elastic roll 208 are also rotated, and the film formation target S is guided to the take-up roll 209.

  Here, by adjusting the rotation speed of the first pinch roll 214 or the second pinch roll 215, the tension applied to the film formation target S in the film formation region can be relaxed. Specifically, the rotational speed of the first pinch roll 214 or the second pinch roll 215 can be adjusted based on the output of the slack detection sensor 211 so that the slack of the film formation target S falls within an appropriate range. it can.

  Further, the third elastic roll 207 and the fourth elastic roll 208 can relieve the high tension applied to wind up the film-forming target S by the take-up roll 209. When a large tension gradient is generated at one location of the second pinch roll 215, there is a problem that slip occurs between the film formation target S and the second pinch roll 215. However, such a problem can be solved by gradually relaxing the tension between the take-up roll 209 and the film formation region by the third elastic roll 207 and the fourth elastic roll 208.

  The tension applied to the film formation target S is preferably less than 1 MPa, and particularly preferably 0.1 MPa or less, in order to prevent the occurrence of twin deformation. This tension is significantly smaller than the tension at which plastic deformation occurs (8.3 Pa at 950 ° C. for copper).

  As described above, also in this embodiment, the tension applied to the film formation target S is relaxed, so that deformation (plastic deformation and twin deformation) of the film formation target S is prevented, and the formation is further performed thereon. It is possible to make the graphene film to be high quality.

  The present technology is not limited only to the above-described embodiments, and can be changed without departing from the gist of the present technology.

[Modification]
A modification of the present technology will be described.

(Modification 1)
FIG. 7 is a schematic view showing a film forming apparatus 300 according to the first modification. As shown in the figure, the film forming apparatus 300 includes a chamber 301, an unwinding roll 302, a first guide roll 303, a first elastic roll 304, a second guide roll 305, a third guide roll 306, and a fourth guide roll 307. , A second elastic roll 308, a take-up roll 309 and a conveyor belt 310. Note that the gas supply system, the vacuum exhaust system, and the heating source of the film formation target are the same as those in the first and second embodiments, and the description thereof is omitted.

  A roll-to-roll mechanism including an unwinding roll 302, a first guide roll 303, a first elastic roll 304, a second guide roll 305, a third guide roll 306, a fourth guide roll 307, a second elastic roll 308, and a winding roll 309 The film formation target S is set in the roll-to-roll mechanism. The first guide roll 303 and the first elastic roll 304 constitute a first pinch roll 311, and the fourth guide roll 307 and the second elastic roll 308 constitute a second pinch roll 312.

  In the film forming apparatus 300, the film forming object S unwound from the unwinding roll 302 is wound through the first pinch roll 311, the second guide roll 305, the third guide roll 306, and the second pinch roll 312. It is wound around a take-up roll 309. The film formation target S is sandwiched between the first pinch roll 311 and the second pinch roll 312.

  The conveyance belt 310 is disposed vertically below the film formation target S between the first pinch roll 311 and the second pinch roll 312, and the film formation target S contacts the conveyance belt 310 by gravity. The conveyor belt 310 conveys the film formation target S by the rotation of the belt.

  The film formation on the film formation target S is performed in a film formation region between the first pinch roll 311 and the second pinch roll 312. Since the film formation target S is transported by the transport belt 310, no tension is applied by the roll-to-roll mechanism. Therefore, deformation (plastic deformation and twinning deformation) of the film formation target S due to tension does not occur, and it is possible to prevent film quality deterioration due to deformation of the film formation target S.

(Modification 2)
FIG. 8 is a schematic view showing a film forming apparatus 400 according to the second modification. As shown in the figure, the film forming apparatus 400 includes a chamber 401, an unwinding roll 402, a first guide roll 403, a first elastic roll 404, a second guide roll 405, a third guide roll 406, and a fourth guide roll 407. , A second elastic roll 408, a take-up roll 409, and a transport roll 410. Note that the gas supply system, the vacuum exhaust system, and the heating source of the film formation target are the same as those in the first and second embodiments, and the description thereof is omitted.

  A roll-to-roll mechanism including an unwinding roll 402, a first guide roll 403, a first elastic roll 404, a second guide roll 405, a third guide roll 406, a fourth guide roll 407, a second elastic roll 408, and a winding roll 409 The film formation target S is set in the roll-to-roll mechanism. A first pinch roll 411 is configured by the first guide roll 403 and the first elastic roll 404, and a second pinch roll 412 is configured by the fourth guide roll 407 and the second elastic roll 408.

  In the film forming apparatus 400, the film formation target S unwound from the unwinding roll 402 is wound through the first pinch roll 411, the second guide roll 405, the third guide roll 406, and the second pinch roll 412. It is wound around a take-up roll 409. The film formation target S is sandwiched between the first pinch roll 411 and the second pinch roll 412.

  One or a plurality of transport rolls 410 are arranged vertically below the film formation target S between the first pinch roll 411 and the second pinch roll 412, and the film formation target S contacts the transport roll 410 by gravity. . The conveyance roll 410 conveys the film-forming target S as each roll rotates.

  The film formation on the film formation target S is performed in the film formation region between the first pinch roll 411 and the second pinch roll 412. Since the film formation target S is transported by the transport roll 410, no tension is applied by the roll-to-roll mechanism. Therefore, deformation (plastic deformation and twinning deformation) of the film formation target S due to tension does not occur, and it is possible to prevent film quality deterioration due to deformation of the film formation target S.

  The film formation apparatus according to the present technology is not limited to the one used for film formation of graphene, and can be used for film formation of various thin films. The film forming method is not limited to CVD (Chemical Vapor Deposition), but may be PVD (Physical Vapor Deposition) or any other film forming method that can form a film using a roll-to-roll mechanism.

  In addition, this technique can also take the following structures.

(1)
Set the film-forming object made of copper in the roll-to-roll mechanism,
The film-forming target is conveyed by the roll-to-roll mechanism,
Supplying a film formation material to the film formation target,
A method for producing a graphene film, wherein the film-forming object is heated in a state where the tension applied to the film-forming object by the roll-to-roll mechanism is relaxed below a tension at which twin deformation occurs in copper.

(2)
A method for producing a graphene film according to (1) above,
The step of heating the film formation target is performed after the tension applied to the film formation target is relaxed to less than 1 MPa.

(3)
A method for producing a graphene film according to (1) or (2) above,
A method for producing a graphene film, wherein the film forming material is a carbon source material containing carbon.

(4)
The method for producing a graphene film according to (3) above,
A method for producing a graphene film, wherein the carbon source material is methane gas.

(5)
The method for producing a graphene film according to any one of (1) to (4) above,
The step of heating the film formation target is performed by resistance heating.

(6)
The method for producing a graphene film according to any one of (1) to (5) above,
The film formation target is a metal foil,
The manufacturing method of the graphene film whose thickness of the said metal foil is 1-100 micrometers.

(7)
The method for producing a graphene film according to any one of (1) to (6) above,
A method for manufacturing a graphene film, in which hydrogen gas is supplied together with the film forming material.

(8)
The method for producing a graphene film according to any one of (1) to (7) above,
The method for producing a graphene film, wherein the roll-to-roll mechanism has a slack detection mechanism.

(9)
The method for producing a graphene film according to (8) above,
A method for producing a graphene film, wherein tension applied to the film formation target is adjusted according to an output of the slack detection mechanism.

(10)
The method for producing a graphene film according to any one of (1) to (9) above,
The step of heating the film formation object is performed after stopping the conveyance of the film formation object by the roll-to-roll mechanism and relaxing the tension.

100, 200, 300, 400 ... film forming apparatus 102, 202, 302, 402 ... unwinding roll 103, 104, 203, 205, 303, 307, 403, 407 ... guide roll 105, 204, 206, 303, 304, 308, 404, 408 ... elastic roll 110, 214, 215, 311, 312, 411, 412 ... pinch roll 106, 209, 309, 409 ... take-up roll 107, 210 ... current source 211 ... slack detection sensor

Claims (10)

Set the film-forming object made of copper in the roll-to-roll mechanism,
The film-forming target is conveyed by the roll-to-roll mechanism,
Supplying a film forming material to the film forming object;
A method for producing a graphene film, wherein the film-forming object is heated in a state where the tension applied to the film-forming object by the roll-to-roll mechanism is relaxed below a tension at which twin deformation occurs in copper. It is a manufacturing method of the graphene film according to claim 1,
The step of heating the film formation target is performed after relaxing the tension applied to the film formation target to less than 1 MPa. A method for producing a graphene film according to claim 1 or 2,
The method for producing a graphene film, wherein the film forming material is a carbon source material containing carbon. It is a manufacturing method of the graphene film according to claim 3,
A method for producing a graphene film, wherein the carbon source material is methane gas. A method for producing a graphene film according to any one of claims 1 to 4,
The step of heating the film formation target is performed by resistance heating. A method for producing a graphene film according to any one of claims 1 to 5,
The film formation target is a metal foil,
The manufacturing method of the graphene film whose thickness of the said metal foil is 1-100 micrometers. A method for producing a graphene film according to any one of claims 1 to 6,
A method for manufacturing a graphene film, in which hydrogen gas is supplied together with the film forming material. It is a manufacturing method of the graphene film as described in any one of Claim 1 to 7, Comprising: The said roll to roll mechanism has a slack detection mechanism. The manufacturing method of the graphene film. A method for producing a graphene film according to claim 8,
A method of manufacturing a graphene film, wherein tension applied to the film formation target is adjusted according to an output of the slack detection mechanism. It is a manufacturing method of the graphene film according to claim 1,
The step of heating the film formation object is performed after stopping the conveyance of the film formation object by the roll-to-roll mechanism and relaxing the tension.