JP4669526B2 - Electron beam gun and vacuum deposition system - Google Patents

Description

  The present invention relates to an electron beam gun that is provided in, for example, a plasma-assisted deposition type vacuum film forming apparatus and used to heat and deposit a film forming material, and particularly projects into a vacuum container of the vacuum film forming apparatus. The present invention relates to an electron beam gun provided with a pole piece to be used, and a vacuum film forming apparatus as described above provided with the electron beam gun.

  As an electron beam gun provided with such a pole piece, for example, Patent Document 1 discloses a magnet for rotating an electron beam emitted from an electron source by a magnetic field by about 270 degrees and irradiating an irradiated material from a substantially vertical direction. A pole piece disposed above the electron source to lift the magnetic field distribution from the magnet upward and lift the center of rotation of the electron beam upward; A deflection coil that generates a scanning magnetic field that scans the position where the electron beam spot rotated by the pole piece irradiates the irradiated material, and at least the side of the pole piece facing the irradiated material, Has been proposed that has a thermally conductive cover that prevents the deterioration of magnetic properties associated with the temperature rise of the pole piece by extracting the radiant heat of the pole piece to the outside. .

In addition, in the patent document 2, the inventor of the present invention also discloses a change in magnetic properties of a pole piece even when exposed to plasma electrons in an electron beam gun having a pole piece protruding into a vacuum film forming apparatus of a plasma assist deposition method. In order to keep the electron beam trajectory stable by suppressing the surface of the pole piece, the surface of the part protruding into the device of the pole piece was covered with an insulator by wrapping a tape made of an insulator or spraying the insulator. Propose something.
JP-A-2005-48219 JP 2005-344137 A

  By the way, even when the pole piece is covered with an insulator in this way, or when the irradiated material side of the pole piece is covered with a thermally conductive cover, the surface of the covered insulator or cover is heated. It is inevitable that the vapor of the irradiated material that has evaporated adheres and deposits of evaporate occur. During a long-term film formation operation, this evaporant continuously accumulates on the irradiated material side of the pole piece covered with the cover or the insulator and grows. Since an object is peeled off and falls onto a crucible holding an irradiated material, there is a possibility of adversely affecting a reliable and stable film formation. On the other hand, if the deposited film is interrupted one by one before the deposited material becomes a certain size and the deposited material is removed, efficient film deposition is not desired.

  The present invention has been made under such a background, and in the electron beam gun provided with the pole piece as described above, the deposition is largely prevented and the film formation is greatly adversely affected. It is an object of the present invention to provide an electron beam gun capable of preventing the above and a vacuum film forming apparatus capable of reliably performing stable and efficient film formation with the electron beam gun.

  In order to solve the above problems and achieve such an object, an electron beam gun according to the present invention includes a pole piece that protrudes from an electron beam gun main body, and a cover around which the pole piece is rotated about an axis. It is covered with. In addition, the vacuum film forming apparatus of the present invention is characterized in that such an electron beam gun is disposed in a vacuum container that accommodates the vapor deposition material and the film formation target.

  Therefore, in such an electron beam gun of the present invention, the vapor of the vapor deposition material heated and evaporated by the electron beam gun adheres to the surface of the cover, and the evaporated material is deposited. Since it is rotated, the vapor deposited material is deposited with a uniform thickness evenly in the rotation direction of the cover, and it is possible to prevent the evaporated material from being continuously deposited and growing greatly at one place. For this reason, even in a relatively long-term film formation operation, it is possible to prevent the deposit that has grown greatly from peeling off, and it is possible to perform efficient film formation reliably and stably.

  Further, the deposit of the vapor deposited on the surface of the cover in this way may be removed when the film forming operation of a predetermined process is completed, but is irradiated from the electron beam gun main body outside the cover. By providing the scraper at a position away from the electron beam irradiation position around the axis, the deposited material deposited on the cover surface can be scraped off or removed by the scraper as the cover rotates. Even when a continuous film forming operation is performed over a long period of time, it is possible to prevent evaporation from being deposited and growing into a large deposit. In particular, when the scraper is disposed outside the cover in this way, the deposit scraped by the scraper can be collected without being scattered around by disposing the tray below the scraper. It is possible to simplify the processing after the film forming operation is completed.

  As described above, according to the present invention, it is possible to prevent evaporation material obtained by heating and evaporating the evaporation material from being accumulated in one place and growing greatly, and even when a long-term film forming operation is performed. Efficient and stable because it is possible to prevent the need to remove the deposits by interrupting the work, or the situation where the grown deposits peel off and interfere with the film formation. It is possible to reliably perform the film forming operation.

  FIG. 1 shows an embodiment of the vacuum film forming apparatus of the present invention, and FIGS. 2 and 3 show an embodiment of the electron beam gun of the present invention used in this vacuum film forming apparatus. In the vacuum film forming apparatus of the present embodiment, the resin film F wound around the film forming roller is placed on the upper surface in the vacuum vessel 1 which is evacuated by a vacuum exhaust means (not shown) with the film forming surface S facing downward. At the bottom of the vacuum vessel 1, the evaporation source 3 for evaporating the evaporation material by the electron beam gun 2 of the present embodiment and the evaporation material evaporated in the evaporation source 3 are directed to the bottom. A plasma emission source 4 for irradiating the plasma B is disposed so as to face the film formation surface S, and a thin film of a vapor deposition material on the film formation surface S is formed using the resin film F as a film formation object. It is a vacuum film forming apparatus of a plasma assist vapor deposition method.

  The vacuum vessel 1 has a rectangular parallelepiped box shape, and a pair of holding rollers 5 for holding a resin film F for forming a thin film, a plurality of intermediate rollers 6, and one film forming roller 7 are included therein. These are supported by a driving means (not shown) so as to be rotatable around their central axes. Further, in the vacuum container 1, an upper deposition plate 8 having an opening formed so as to expose the lower part of the film forming roller 7 is disposed horizontally below the central part in the vertical direction. At the bottom of the vacuum vessel 1, the bottom where the position of the electron beam gun 2 of the evaporation source 3, the irradiation position Q of the electron beam by the electron beam gun 2, and the position of the plasma emission source 4 are opened. A deposition plate 9 is also disposed horizontally, and on the inner wall surface side of the vacuum vessel 1 between the upper deposition plate 8 and the bottom deposition plate 9, a film forming roller together with the deposition plates 8 and 9. 2 is disposed between the evaporation source 3 and the plasma emission source 4 so as to define a box-shaped space.

  In the vacuum film forming apparatus configured as described above, the resin film F on which a thin film is formed is wound around one of the pair of holding rollers 5 and held from one holding roller 5 to the intermediate roller 6. Then, the film is wound around the lower portion of the film forming roller 7 and further wound around the other holding roller 5 via the intermediate roller 6. In the resin film F, the downward surface of the film roll 7 is wound around the lower part of the film forming roller 7 to be the film formation surface S. By generating the vapor A and irradiating the plasma B from the plasma emission source 4 toward the material vapor A to cause ionization, the deposition surface S mainly passes through the opening of the upper deposition preventing plate 8. At this time, a thin film made of this vapor deposition material is formed on the deposition surface S.

  On the other hand, the evaporation source 3 disposed at the bottom of the vacuum vessel 1 holds the evaporation material and adjoins the crucible 11 disposed at the irradiation position Q as shown in FIG. The beam gun 2 is arranged. A plurality of crucibles 11 may be arranged in a ring shape on a hearth (not shown), and a multipoint hearth that is evaporated by sequentially rotating and positioning to the irradiation position Q may be used. The deposition material positioned at the irradiation position Q may be evaporated by continuously rotating a hearth formed with a ring-shaped groove for holding the deposition material sequentially supplied from the mechanism.

  In this embodiment, the electron beam gun 2 that heats and evaporates the vapor deposition material is provided with a copper electron beam gun main body 13 with a scan coil (not shown) built in on the base 12. A cooling water passage is formed in the beam gun main body 13 so that the water can be cooled by the cooling water. A thermoelectron emission source (filament) (not shown) is disposed below the portion of the electron beam gun main body 13 opposite to the irradiation position Q.

  Further, a pair of pole pieces 14 are provided on both sides of the electron beam gun main body 13 across a straight line connecting the thermoelectron emission source and the irradiation position Q in plan view so as to protrude upward in the vertical direction. . These pole pieces 14 are formed in a rectangular column shape with a square cross section by a ferromagnetic metal such as iron, iron alloy, nickel, cobalt, etc., and a magnetic field is induced outside the electron beam gun main body 13 by inducing magnetic flux from the scan coil. The electron beam emitted from the thermionic emission source is deflected 270 ° by the magnetic field formed by the pole piece 14 from the opening 15 opened in the electron beam gun main body 13, and the inside of the crucible 11 The vapor deposition material is irradiated vertically from above to heat and evaporate the vapor deposition material. The upper end portions of these pole pieces 14 are formed so as to be bent perpendicularly to the vertical direction in which the pole pieces 14 protrude and to face each other.

  A cover 16 is provided for each of the pole pieces 14 so as to cover the periphery of each pole piece 14, and each of the covers 16 is rotatable around a predetermined axis O. In this embodiment, the cover 16 is formed in a bottomed cylindrical shape from a heat-resistant nonmagnetic material such as SUS316 or copper, and the pole piece 14 protrudes with the center line of the cylinder as the axis O. As shown in FIG. 3 in plan view, the pole piece 14 is positioned on the opposite side to the side where the opening 15 is provided, and the disc-shaped bottom plate portion is directed upward. Thus, the pole piece 14 is disposed so as to be covered from above, and so as not to overlap the opening 15 of the electron beam gun main body 13 in plan view.

  In the vacuum vessel 1, a rotary shaft 17 is supported and erected along the axis O so as to be rotatable around the axis O, and the cover 16 is provided on the upper end portion of the rotary shaft 17 with the bottom plate portion. Is attached via an insulator such as an insulator so that it is supported so as to be spaced from the pole piece 14 covered inside. Furthermore, a power transmission member 18 such as a belt such as a steel belt or a gear is attached to the lower end portion of the rotary shaft 17, and a drive shaft of a drive source 19 such as a motor provided in the vacuum vessel 1 is attached to the rotary shaft 17. By being connected to the rotary shaft 17 via the power transmission member 18, the cover 16 is continuously rotated at a relatively slow constant speed in a constant rotation direction indicated by T in FIGS.

  Note that the drive source 19 may be disposed outside the vacuum vessel 1 and the rotary shaft 17 may be rotated via the power transmission member 18 so that the drive shaft penetrates the vacuum vessel 1 in an airtight manner. . Further, for example, when the evaporation material is heated and evaporated by continuously rotating the hearth as described above, the rotation driving means for rotating the hearth and the rotary shaft 17 are provided with a speed reduction mechanism as necessary. It is also possible to connect them via, for example.

  Furthermore, in the present embodiment, a very small interval is provided on the outer peripheral surface of the cover 16 at a position away from the irradiation position Q around the axis O on the outside of the cover 16 thus rotated around the axis O in the vacuum vessel 1. A scraper 20 is provided as a scraping or stripping member so as to be close to or in contact with the outer peripheral surface of the cover 16. The scraper 20 is formed in a plate shape by the same steel material as the cover 16 such as SUS316, for example, so that the side ridge portion extending in a straight line shape becomes an edge and approaches or comes into contact with the outer peripheral surface of the cover 16. The vacuum cover 1 is fixedly attached to the rotating cover 16.

  Furthermore, a tray 21 is disposed below the scraper 20 in the vacuum container 1. More specifically, the tray 21 is disposed so that the edge of the scraper 20 opens upward just below a portion that is close to or in contact with the outer peripheral surface of the cover 16. Further, the scraper 20 is located on the opposite side of the electron beam gun main body 13 from the opening 15 across the axis O, and the portion where the edge is close to or in contact with the outer peripheral surface of the cover 16 as shown in FIG. When viewed from the irradiation position Q, the cover 16 is disposed so as to be substantially hidden. 2, the rotating shaft 17, the power transmission member 18, and the drive source 19 of the right cover 16 are not shown. In FIGS. 2 and 3, the scraper 20 and the tray 21 of the left cover 16 are not shown. Has been.

  The evaporation material is heated and evaporated as described above while the cover 16 is rotated around the axis O by the electron beam gun 2 having such a configuration and the vacuum film forming apparatus including the electron beam gun 2, and the film formation target (resin film) When the film is formed in F), the vapor A of the vapor deposition material adheres to the surface of the cover 16 covering the periphery of the pole piece 14 and is uniformly deposited so that the thickness becomes uniform in the rotation direction T. That is, the deposit does not grow greatly at a specific location, particularly the electron beam irradiation position Q side on the crucible 11 side where the material vapor A is generated, and the thickness of the deposit is reduced as compared with the case where the deposit grows large. Therefore, there is no adverse effect on the film formation such as the deposits grown in this way are peeled off and dropped on the crucible 11, and the film forming operation is interrupted to prevent such a situation. Without removing the deposit, reliable and stable film formation can be performed efficiently.

  In particular, as in the present embodiment, the film formation object is a resin film F or the like, and the film formation is performed while the resin film F wound around the holding roller 5 is wound around the film formation roller 7 and travels. In the case of forming a thin film on the surface S, the film forming operation must be continuously performed for several hours or more, and the adhesion of deposits tends to increase. According to the electron beam gun 2 and the vacuum film forming apparatus, smooth film forming work can be promoted without interrupting the work on the way.

  In addition, in the present embodiment, the scraper 20 is disposed outside the cover 16, and the edge thereof is close to or in contact with the outer peripheral surface of the cover 16, so that the cover 16 is shown in FIGS. The deposit C adhering to the surface can be scraped off or removed by the scraper 20 by the rotation of the cover 16 itself. For this reason, since the deposit C adhering with a uniform thickness as described above can be removed before the thickness increases or immediately after adhering, the adverse effect on the film forming operation can be prevented more reliably. At the same time, continuous film formation can be performed over a long period of time.

  Further, in this embodiment, the scraper 20 is located away from the electron beam irradiation position Q around the axis O, that is, away from the position where the vapor A is generated from the vapor deposition material held in the crucible 11. Therefore, the vapor hardly adheres to and accumulates on the scraper 20, and a smoother film forming operation can be achieved. In addition, since the scraper 20 is on the opposite side of the opening 15 of the electron beam gun body 13 through which the electron beam passes with respect to the axis O, it does not affect the heating and evaporation of the vapor deposition material.

  Furthermore, in the present embodiment, the tray 21 is disposed below the scraper 20, and the scraped-off deposit C can be collected in the tray 21 without being scattered around. Accordingly, the deposit C collected in the tray 21 may be processed after the long-time film forming operation is completed, so that the processing operation can be simplified by omitting the cleaning work after the film forming operation is completed. Is more efficient.

It is a front view which shows one Embodiment of the vacuum film-forming apparatus of this invention. It is a front view which shows one Embodiment of the electron beam gun of this invention used for the vacuum film-forming apparatus shown in FIG. FIG. 3 is a plan view of the embodiment shown in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Electron beam gun 3 Evaporation source 11 Crucible 13 Electron beam gun main body 14 Pole piece 16 Cover 17 Rotating shaft 19 Drive source 20 Scraper 21 Receptacle O Axis of cover 16 T Rotation direction of cover 16 Q Electron beam irradiation position F Resin film (Film formation)
A Material vapor

Claims (4)

  An electron beam gun comprising: a pole piece extending from an electron beam gun main body; and the periphery of the pole piece is covered with a cover that is rotated about an axis.   2. The electron beam gun according to claim 1, wherein a scraper is provided outside the cover at a position separated from the irradiation position of the electron beam irradiated from the electron beam gun main body around the axis. 3.   The electron beam gun according to claim 1, wherein a tray is disposed below the scraper.   A vacuum film forming apparatus, wherein the electron beam gun according to any one of claims 1 to 3 is disposed in a vacuum container that accommodates a vapor deposition material and an object to be deposited.

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