JP2008291297A - Vacuum deposition system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum deposition system requiring no maintenance and capable of depositing an excellent film of an evaporation material on a vapor-deposited material. <P>SOLUTION: The vacuum deposition system comprises a vacuum chamber, an evaporation source arranged in the vacuum chamber to heat and evaporate an evaporation material, a holding mechanism arranged opposite to the evaporation source to hold a vapor-deposited material, a shutter part which is arranged between the evaporation source and the holding mechanism to prevent the evaporation material on the vapor-deposited material in a non-film deposition mode, and a heating mechanism for heating the shutter part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vacuum vapor deposition apparatus, and more particularly to a vacuum vapor deposition apparatus that heats and evaporates an evaporation material to form a film of the evaporation material on the amount of the evaporation target material.

  When irradiated with radiation (X-rays, α-rays, β-rays, γ-rays, electron beams, or ultraviolet rays), a part of this radiation energy is accumulated, and then irradiated with excitation light such as visible light, A phosphor exhibiting stimulated emission corresponding to the above-mentioned accumulated radiation energy is known. This phosphor is called a storage phosphor (stimulable phosphor) and is used for various applications such as medical applications.

  As an example, a radiation image information recording / reproducing system using a sheet (phosphor sheet) having a layer containing this stimulable phosphor (hereinafter referred to as a phosphor film) is known. This phosphor sheet is also called a radiation image conversion panel (IP), but in the following description, it is called a phosphor sheet. An example of such a system that has already been put into practical use is FCR (Fuji Computed Radiography: trade name of Fuji Film Medical Co., Ltd.).

  In this system, first, radiographic image information of a subject such as a human body is recorded on a phosphor sheet (phosphor film thereof). After recording, the phosphor sheet is two-dimensionally scanned with excitation light such as laser light to emit stimulated emission light. The stimulated emission light is photoelectrically read to obtain an image signal, and an image reproduced based on the image signal is output as a visible image to a recording material such as a photographic photosensitive material or a display device such as a CRT. The phosphor sheet that has been read is used repeatedly after the remaining image is erased.

The above phosphor sheet is usually prepared by applying a coating solution prepared by dispersing a powder of a stimulable phosphor in a solvent containing a binder and the like, and applying it to a sheet-like support made of glass or resin. It is manufactured by drying and forming a phosphor film.
On the other hand, a phosphor sheet obtained by forming a phosphor film on a support by physical vapor deposition (vapor deposition) such as vacuum deposition or sputtering is also known.

  Impurities can be reduced by depositing the phosphor on the support in a vacuum, and there are almost no components other than the storage phosphor such as a binder. Can do.

  As such an apparatus for forming a phosphor film on a support in vacuum, for example, the holding unit described in the cited document 1 corresponds to vacuum deposition at a pressure of 0.05 to 10 Pa. There is a vacuum vapor deposition apparatus having a prevention means for preventing evaporation particles from adhering to the substrate to be processed held by the substrate.

Japanese Patent Application Laid-Open No. 2005-126821

  As described in Patent Document 1, by providing a shutter as a prevention means, it is possible to prevent evaporation particles from adhering to the substrate to be processed during pretreatment, and to form a uniform film on the substrate to be processed. .

However, in the apparatus described in Patent Document 1, since the heating evaporation source is shielded by the shutter during preprocessing, the vapor of the evaporation material touches the shutter. For this reason, there is a problem in that the evaporation material adheres to the shutter, and the shutter cannot be moved when it is thickly laminated. In particular, when the distance between the shutter and the heating evaporation source is short, the amount of evaporation material adhering to the shutter increases. Further, since the evaporation material is likely to accumulate between the shutter and the heating evaporation source, the shutter cannot be moved easily.
Thus, if the shutter cannot be moved, it cannot be used as a device, and the shutter needs to be replaced or maintained.

  Further, when the evaporating material adheres to the shutter, the evaporating material is lost, so that there is a problem that the efficiency of using the evaporating material is lowered.

An object of the present invention is to provide a vacuum vapor deposition apparatus that eliminates the problems based on the above-described prior art, requires less maintenance, and can form a good film of an evaporation material on a vapor deposition material.
Another object of the present invention is to provide a vacuum vapor deposition apparatus capable of efficiently using an evaporation material in addition to the above-described problems.

In order to solve the above problems, the present invention comprises a vacuum chamber,
An evaporation source disposed in the vacuum chamber for heating and evaporating the evaporation material;
A holding mechanism that is disposed opposite to the evaporation source and holds the vapor deposition material;
A shutter unit that is disposed between the evaporation source and the holding mechanism and prevents the evaporation material from adhering to the evaporation target material during non-film formation;
Provided is a vacuum deposition apparatus having a heating mechanism for heating the shutter portion.

Here, it is preferable that the heating mechanism heats the shutter unit to a temperature at which the evaporating material becomes droplets.
The evaporation material is preferably an alkali halide material.
Moreover, it is preferable that the said heating mechanism heats the said shutter part to the temperature of 300 to 400 degreeC lower than melting | fusing point of the said evaporation material.
The distance between the shutter and the opening of the evaporation source is preferably 1 mm or more and 3 mm or less.

  The shutter unit includes a shutter plate that can shield the heating source, and a moving mechanism that moves the shutter plate, and the moving mechanism is a position that faces the evaporation source when the shutter plate is not formed. It is preferable that the shutter plate is disposed at a position not facing the evaporation source during film formation.

According to the present invention, by heating the shutter with the heating mechanism, it is possible to prevent the evaporation material from being thickly attached and deposited on the shutter, and to prevent the shutter from becoming unable to move.
Furthermore, by providing the shutter, it is possible to prevent the evaporation material from adhering to the vapor deposition material during non-vapor deposition, and it is possible to form a more uniform vapor deposition film on the vapor deposition material.

A vacuum deposition apparatus according to the present invention will be described in detail based on an embodiment shown in the accompanying drawings.
FIG. 1 is a front view showing a schematic configuration of an example of a vacuum vapor deposition apparatus of the present invention, and FIGS. 2A and 2B are top views showing schematic configurations of a heating evaporation source and a shutter part of the vacuum vapor deposition apparatus, respectively. FIG. Here, FIG. 2A shows a state where the opening of the crucible is closed by the shutter plate of the shutter portion, and FIG. 2B shows a state where the opening of the crucible is opened.

The vacuum deposition apparatus 10 includes a vacuum chamber 12, a substrate holding unit 14, a heating evaporation source 16, a shutter unit 18, a heating mechanism 20, a vacuum pump 22, a valve 24, an exhaust path 26, and a gas introduction unit. 28, and a film of the deposition material M is formed on the surface of the substrate S by vacuum deposition.
More specifically, the vapor deposition apparatus 10 depressurizes the inside of the vacuum chamber 12 and heats and evaporates the evaporation material accommodated in the evaporation source 16, thereby evaporating the surface of the substrate S held by the substrate holding unit 14. Then, the evaporation material M is deposited.
The vapor deposition apparatus 10 of the present invention prevents evaporation material from adhering to other than the substrate S in addition to the illustrated members, and a deposition cover that guides the evaporation material M evaporated from the heating evaporation source 16 to the substrate S. Of course, various members of the vacuum deposition apparatus may be included.

  In the present invention, the substrate S to be used is not particularly limited, and a glass plate, a plastic (resin) film or plate, a metal plate, or the like corresponding to the product to be manufactured may be used.

On the other hand, in the present invention, the evaporation material to be formed (film formation) on such a substrate S is not particularly limited. However, when a radiation image conversion panel is manufactured as a preferable evaporation material, an alkali halide phosphor ( Examples thereof include alkali metal halide phosphors.
Various alkali halide phosphors can be used. Among them, a preferable example is that, in particular, the effects of the present invention are easily exhibited and good photostimulated luminescence characteristics can be obtained. An alkali halide-based stimulable phosphor represented by the general formula “M ^I X · aM ^II X ′ ₂ · bM ^III X ″ ₃ : cA” disclosed in JP-A-61-72087 is preferred. Illustrated.
(In the above formula, M ^I is at least one selected from the group consisting of Li, Na, K, Rb and Cs, and M ^II is Be, Mg, Ca, Sr, Ba, Zn, Cd, Cu and at least one trivalent metal selected from the group consisting of Ni, M ^III is, Sc, Y, La, Ce , Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, At least one trivalent metal selected from the group consisting of Tm, Yb, Lu, Al, Ga and In, and X, X ′ and X ″ are selected from the group consisting of F, Cl, Br and I A is from Eu, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Gd, Lu, Sm, Y, Tl, Na, Ag, Cu, Bi, and Mg. At least one selected from the group consisting of . Also, a 0 ≦ a <0.5, a 0 ≦ b <0.5, it is 0 <c ≦ 0.2.)
Among them, M ^I contains at least Cs, X contains at least Br, and has excellent photostimulated luminescence properties and the effects of the present invention can be obtained particularly well. However, an alkali halide photostimulable phosphor that is Eu or Bi is preferred, and among these, photostimulable phosphors represented by the general formula “CsBr: Eu” are particularly preferred.

  In addition, U.S. Pat. No. 3,859,527, JP-A-55-12142, 55-12144, 55-12145, 56-116777, 58-69281. 58-206678, 59-38278, 59-75200, and the like, various photostimulable phosphors disclosed in each publication can be suitably used.

  The present invention has a (stimulable) phosphor layer composed of such a stimulable phosphor, and once accumulates and records a radiographic image of a subject and responds to the radiographic image recorded by the incidence of excitation light. It is not limited to the formation of a phosphor layer (that is, a vapor deposition film) in a stimulable (accumulative) phosphor panel (so-called IP (Imaging Plate)) that emits a stimulated emission light, but an alkali halide phosphor. If so, an apparatus may be used that forms a phosphor layer made of a phosphor that emits (fluoresces) upon incidence of radiation, which is used in a scintillator panel or the like.

Various phosphors can be used as long as the phosphor is an alkali halide phosphor. Similarly, the effect of the present invention is easily exhibited and good fluorescence characteristics can be obtained. In terms of the general formula:
M ^I X · aM ^II X ′ ₂ · bM ^III X ″ ₃ : zA
An alkali halide phosphor represented by the formula is preferably exemplified.
(In the above formula, M ^I represents at least one alkali metal selected from the group consisting of Li, Na, K, Rb and Cs, and M ^II represents Be, Mg, Ca, Sr, Ba, Ni, Cu, Zn. And at least one alkaline earth metal or divalent metal selected from the group consisting of Cd, and M ^III is Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, It represents at least one rare earth element or trivalent metal selected from the group consisting of Ho, Er, Tm, Yb, Lu, Al, Ga and In. X, X ′ and X ″ are F, Cl, Represents at least one halogen selected from the group consisting of Br and I, and A represents Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Na, Mg, Cu, Ag Represents at least one rare earth element or metal selected from the group consisting of Tl, Bi, and a, b and z are 0 ≦ a <0.5, 0 ≦ b <0.5 and 0 <z, respectively. <Represents a numerical value within the range of 1.0.)
In particular, it is preferred that Cs is contained as M ^{I in the} general formula, ^I is preferably contained as X, T1 or Na is preferably contained as A, and z is 1 × 10 ^-4 ≦ z ≦ 0.1 is preferable. Among these, alkali metal halide phosphors represented by the formula “CsI: Tl” are preferably used.

  The vacuum chamber 12 is a highly airtight container formed of iron, stainless steel, aluminum or the like. As the vacuum chamber 12, various vacuum chambers (bell jars, vacuum tanks) used in a vacuum deposition apparatus can be used. Further, an exhaust path 26 is connected to the vacuum chamber 12. Further, a three-way valve 24 is connected to the exhaust path 26.

The vacuum pump 22 is connected to the exhaust path 26 via the three-way valve 24 and exhausts the air inside the vacuum chamber 12 to reduce the pressure inside the vacuum chamber 12 to a predetermined degree of vacuum.
There is no restriction | limiting in particular in the vacuum pump 22, As long as it can achieve a required ultimate vacuum degree, the various thing utilized with a vacuum evaporation system can be utilized. As an example, an oil diffusion pump, a cryopump, a turbomolecular pump or the like may be used, and a cryocoil or the like may be used in combination as an auxiliary.

The gas introduction unit 28 is connected to the exhaust path 26 via the three-way valve 24 and introduces argon into the vacuum chamber 12. As the gas introduction unit 28, for example, a mechanism having various configurations such as a mechanism having a cylinder and an adjusting unit that adjusts the gas flow rate can be used.
Here, in this embodiment, argon is introduced into the vacuum chamber 12, but the present invention is not limited to this, and an inert gas such as neon gas or nitrogen gas may be introduced. Moreover, you may introduce gas other than an inert gas as needed.

The three-way valve 24 includes a state in which the exhaust passage 26 is airtightly closed, a state in which the vacuum pump 20 and the exhaust passage 26 are in communication, and a state in which the gas introduction unit 28 and the vacuum pump 20 are in communication. This is a known three-way valve for switching.
In this embodiment, the three-way valve is used to connect the vacuum pump 22, the exhaust path 26, and the gas introduction unit 28. However, the present invention is not limited to this, and, for example, two exhaust paths are provided. And a vacuum pump and a gas introduction unit may be separately connected to each exhaust path.

The substrate holding unit 14 is disposed on the upper surface of the vacuum chamber 12, that is, the upper surface in the vertical direction, and holds the substrate S.
The substrate holder 14 includes a substrate holder 30 that holds the substrate S and a holder mounting portion 32 that supports the substrate holder 30.

The substrate holder 30 is a member that accommodates / holds the substrate S in a state where the film formation region of the substrate S is opened toward the heating evaporation source 16.
The method of holding the substrate S by the substrate holder 30 is not particularly limited, and various methods for holding the plate-like member from the upper side in the vertical direction, such as a method of holding the substrate with a jig or the like, a method of using static electricity, a method of using adsorption, etc. The method can be used. Further, if possible depending on the deposition region of the substrate S, etc., a holding means for pressing the four corners of the substrate S from below and a holding means for pressing the four sides of the substrate S from below may be used using a jig or the like. . Further, the substrate holder 30 may also serve as a mask that regulates a film formation region on the film formation surface of the substrate S, or a mask may be provided separately.

The holder mounting portion 32 is fixed to the upper surface inside the vacuum chamber 12, and various methods such as a method of using a fitting or engaging member on the lower surface (that is, the surface on the heating evaporation source 16 side described later) are used. A means for supporting the substrate holder 30 is provided. The holder mounting part 32 fixes the substrate holder 30 to a predetermined position in a detachable state by the support part.
The substrate S is accommodated in the substrate holder 30, and further, the substrate holder 30 is mounted on the holder mounting portion 32, so that the film formation region is opened to the heating evaporation source 16 and is placed in a predetermined position in the vacuum chamber 12. Fixed.
Here, the substrate holding unit 14 conducts heat conduction for uniformly and uniformly transmitting the heat generated by the heating unit for heating the substrate S accommodated in the substrate holder 30 and the lower surface of the holder mounting unit 32 to the substrate S. An adhesive sheet or the like may be provided.
Furthermore, a heat conductive sheet may be provided on the inner surface of the substrate holder 30 in close contact with the back surface of the substrate S (the opposite surface to the surface on which the evaporation material is deposited). By providing a heat conductive sheet also on the inner surface of the substrate holder 30, the heat generated by the heating means can be uniformly transmitted to the substrate S without unevenness.

The heating evaporation source 16 faces the substrate holding part 14 in the vacuum chamber 12 and is disposed below the substrate holding part 14 in the vertical direction, and heats and melts the evaporation material M to the substrate S. Evaporate towards.
The heating evaporation source 16 includes a crucible 36 that houses (or stores) the evaporation material M, and a heating source 38 that heats the crucible 36 and heats the evaporation material M.

The crucible 36 is a resistance heating container having an opening formed on the substrate holding part 14 side, and is an evaporation source that stores the evaporation material M therein.
The heating source 38 is a power source that applies a predetermined current to the crucible 36. By applying a current to the crucible 38 by the heating source 38, the crucible 38 is resistance-heated.
Thus, the heating evaporation source 16 heats and evaporates the evaporation material M by resistance heating the crucible 36 by the heating source 38.
Further, the crucible 18 may be provided with a temperature measuring means for measuring the temperature of the evaporation material M (or the crucible 18). Here, a thermocouple etc. are illustrated as a temperature measurement means.
By measuring the temperature with the temperature measuring means and adjusting the amount of heating of the crucible 36 by the heating source 38 according to the measurement result, the crucible 36 can be kept at a constant temperature, and the temperature of the evaporation material M is kept constant. can do. Thereby, the evaporation material M can be evaporated stably.

In the present invention, the crucible as the evaporation source is not limited to the one having the above-described configuration, and all kinds of crucibles such as a so-called boat-type crucible and a cup-type crucible having an open upper end surface are all included. Is available.
The heating mechanism is not limited to a heating mechanism that applies a current to the resistance heating crucible 36 and heats it, but depends on film forming conditions such as the degree of vacuum during vapor deposition, such as induction heating or electron beam (EB) heating. If available, all the various heating mechanisms used in vacuum deposition can be used.

The shutter unit 18 is disposed between the heating vapor deposition source 16 and the substrate holding unit 14, and includes a movable shutter plate 40 and a moving mechanism 42 that moves the shutter plate 40.
The shutter plate 40 is a plate member made of tungsten having a larger area than the opening of the crucible 36 and capable of moving to a position facing the opening of the crucible 36. Further, a heating mechanism 20 to be described later is disposed on the surface of the shutter plate 40 on the substrate holding unit 14 side.

The moving mechanism 42 includes a rotation shaft 44 and a support portion 46 that is connected to the rotation shaft 44 and supports the shutter plate 40, and the rotation shaft 44 that is disposed at a predetermined distance from the shutter plate 40 is used as an axis. This is a moving mechanism that rotates the shutter plate 40 in a direction parallel to the surface of the shutter plate 40.
The rotation shaft 44 is a shaft that rotates around a direction perpendicular to the surface of the shutter plate 40 (that is, the vertical direction in FIG. 1), and is rotated by a motor or the like.
The support portion 46 includes a support portion 46 a and a support portion 46 b, the support portion 46 a connects one end portion of the shutter plate 40 and the rotating shaft 44, and the support portion 46 b is the other end of the shutter plate 40. The part and the rotating shaft 44 are connected. In this way, the support portions 46 a and 46 b are connected to the opposing ends of the shutter plate 40, and the shutter plate 40 is fixed to the rotating shaft 44. Thereby, by rotating the rotating shaft 44, the shutter plate 40 also rotates about the rotating shaft (that is, the axis).

  The moving mechanism 42 rotates the rotating shaft 44 to move the shutter plate 40 in a direction parallel to the surface of the shutter plate 40 around the direction perpendicular to the surface of the shutter plate 40, thereby opening and closing the shutter plate 40. Let Specifically, as shown in FIGS. 2A and 2B, the moving mechanism 42 moves the shutter plate 40 about the rotation shaft 44 to a position facing the opening of the crucible 36 (FIG. 2A). 2) (the position shown in FIG. 2B) that does not overlap with the opening of the crucible 36 from the position shown in FIG. 2B, and conversely, the opening of the crucible 36 Are moved from a position where they do not overlap to a position facing the opening of the crucible 36.

The shutter unit 18 arranges (or moves) the shutter plate 40 at a position facing the opening of the crucible 36 at the start of heating of the evaporation material M by the heating evaporation source 16, that is, before the start of vapor deposition, and is accommodated in the crucible 36. When the evaporated material M is heated, the vapor of the evaporated material M becomes stable, and when the evaporation material M starts to be deposited on the substrate S, the shutter plate 40 is moved to a position that does not overlap the opening of the crucible 36. .
As described above, by arranging the shutter plate 40 of the shutter unit 18 at a position facing the opening of the crucible 36 at the start of heating, the vapor of the evaporation material M evaporated by the crucible 36 can be shielded, and unstable evaporation is performed. It is possible to prevent the vapor of the material M from adhering to the deposition material. Further, even when the evaporation material M bumps at the time of heating, it is possible to prevent the evaporation material M from being scattered around.

  The shutter plate 40 is provided with temperature measuring means (not shown) for measuring the temperature of the shutter plate 40. Here, a thermocouple is illustrated as a temperature measurement means.

  The heating mechanism 20 is a power source for resistance heating, and the wiring 20a connected to the power source is connected to both ends of the surface of the shutter plate 40 on the substrate holding unit 14 side. The heating mechanism 20 applies a predetermined current to the shutter plate 40 via the wiring 20a and heats the shutter plate 40 to a predetermined temperature by resistance heating. Here, by adjusting the amount of heating by the heating mechanism 20 while detecting the temperature of the shutter plate 40 by the temperature measuring means described above, the shutter plate 40 can be heated to any temperature (heating adjustment).

By heating the shutter plate 40 to a predetermined temperature by the heating mechanism 20, it is possible to prevent the evaporation material M from being attached and deposited thickly on the shutter plate 40 and preventing the shutter plate 40 from being opened and closed.
Thereby, even when the vacuum evaporation apparatus is used for a long time, the shutter plate can be prevented from being opened and closed due to the deposition of the evaporation member M, and the frequency of maintenance such as removal of the evaporation material M deposited on the shutter can be reduced. .

Further, when the shutter plate 40 is brought close by heating the shutter plate 40 by the heating mechanism 20, specifically, the distance between the shutter plate 40 and the opening of the crucible 36 is 3 mm or less, particularly 1 mm or more and 3 mm or less. Even in this case, it is possible to prevent the vapor deposition member from being deposited thickly between the shutter plate 40 and the crucible 36, and to prevent the shutter plate 40 from becoming unable to move.
Further, by setting the distance between the shutter plate 40 and the crucible 36 to 1 mm or more and 3 mm or less, the vapor of the evaporation material M can be efficiently shielded, and even when the evaporation material M in the crucible 36 bumps, It is possible to more reliably prevent the evaporation material M from being scattered around.

Here, it is preferable that the heating mechanism 20 heats the shutter plate 40 to a temperature at which the evaporation material M becomes droplets.
By heating the shutter plate 40 to a temperature at which the evaporation material M becomes droplets, it is possible to more reliably prevent the evaporation material from being deposited thickly on the shutter plate 40. In the present embodiment, the evaporation material having a slight thickness may actually be deposited on the shutter plate 40, but by heating to a temperature at which the crucible side surface of the deposited evaporation material becomes droplets. It is possible to prevent the evaporation material from being deposited thickly.
Further, by evaporating the evaporating material M that contacts the shutter plate 40, the evaporating material M that has been formed into droplets can be dropped into the crucible 36 directly below. As a result, the evaporation material adhering to the shutter plate 40 can be collected, the utilization efficiency of the evaporation material M can be increased, and the amount of evaporation material (that is, the amount charged) accommodated in the crucible 36 can be reduced. The dissolution time of the evaporation material can be shortened. As described above, since the processing can be performed in a short time, the amount of the evaporation material M attached to and deposited on the portion other than the substrate S of the vacuum chamber 12 can be further reduced.

Furthermore, it is preferable that the heating mechanism 20 heats the shutter plate 40 to a temperature lower than the melting point of the evaporation material M by 300 ° C. or more and 400 ° C. or less.
By heating the shutter plate 40 to the above temperature range, the evaporation material is more reliably formed into droplets together with the radiant heat from the crucible, so that the evaporation material does not deposit thickly on the shutter plate 40, and the shutter The plate 40 can be prevented from being opened and closed, and the evaporation material can be collected in the crucible by more reliable droplet formation, and the utilization efficiency of the evaporation material M can be increased.
When an alkali halide material is used as the evaporating material, the use efficiency of the evaporating material can be more reliably increased by setting the above temperature range, and in particular, when cesium bromide (CsBr) is used. Can more reliably increase the utilization efficiency of the evaporation material.

  Here, in the present embodiment, tungsten is used as the shutter plate 40, but the present invention is not limited to this, and materials that generate heat by various energizations such as tantalum, molybdenum, and carbon can be used. Furthermore, the shutter plate 40 is not limited to a material that generates heat when energized, and can be made of various materials such as metals and resins having a certain heat resistance.

  The heating mechanism is not limited to a heating mechanism that applies current to the shutter and heats directly by resistance heating. Heating means such as a sheath heater, a lamp heater, a heat medium, or a Peltier element is installed in the shutter, and the shutter is heated by the heating means. Various heating mechanisms such as a heating mechanism that heats the substrate can be used. Further, the arrangement position and the number of arrangement of the heating mechanism are not particularly limited as long as the shutter unit (specifically, the shutter plate) can be heated.

Also, the moving mechanism is not particularly limited, and various moving mechanisms can be used. For example, a linear mechanism, a mechanism that moves by a biasing force of a spring, a mechanism that moves by a wire, and the like can be used.
In the present embodiment, the shutter plate 40 is rotated about the axis perpendicular to the surface of the shutter plate, and the opening of the crucible 36 (more precisely, the vapor of the evaporation material M evaporated in the crucible 36). Etc.) is switched (that is, the shutter plate 40 is opened / closed), but the present invention is not limited to this, and various opening / closing mechanisms that switch whether to block the opening of the crucible 36 may be used. it can. For example, the shutter plate is configured to move in parallel, and at the start of heating, the shutter plate is disposed at a position opposite to the crucible opening, thereby shielding the crucible opening and depositing on the substrate S (that is, onto the substrate S). In the film formation, the opening of the crucible may be opened by moving the shutter plate from a position facing the opening of the crucible. A door-like moving mechanism that opens and closes with one side of the shutter as an axis can also be used.

Here, an example of a shutter unit that translates the shutter plate will be described in more detail.
3A and 3B are schematic top views showing a schematic configuration of another example of a shutter portion that can be used in the vacuum evaporation apparatus of the present invention. Here, FIG. 3A shows a state where the opening of the crucible is closed by the shutter plate of the shutter portion, and FIG. 3B shows a state where the opening of the crucible is opened.

The shutter unit 51 is disposed between the heating vapor deposition source 16 and the substrate holding unit 14 and includes a movable shutter plate 52 and a moving mechanism 54 that moves the shutter plate 52.
The shutter plate 52 is a plate member made of tungsten having a larger area than the opening of the crucible 36 and capable of moving to a position facing the opening of the crucible 36. Further, a heating mechanism 50 is disposed on the surface of the shutter plate 52 on the substrate holding unit 14 side.
The moving mechanism 54 is a moving mechanism that moves the shutter plate 52 in a direction parallel to the surface of the shutter plate 52. The moving mechanism 54 is rotatably fixed to an end portion of the screw shaft 54a and a driving portion 54b that rotates the screw shaft 54a and rotates the screw shaft 54a in the axial direction, and is fixed to the shutter plate 52. And a support portion 54d that supports the shutter plate 52 and the drive portion 54b.

  The moving mechanism 54 rotates the screw shaft 54a by the drive unit 54b, thereby moving the shutter plate 52 in the axial direction of the screw shaft 54a to open and close the shutter plate 52. Specifically, as shown in FIGS. 3A and 3B, the moving mechanism 54 moves the shutter plate 52 from the position facing the opening of the crucible 36 (position shown in FIG. 3A). From the position that does not overlap with the opening of the crucible (that is, the position at which the vapor of the evaporation material M evaporated by the crucible 36 is not shielded, the position shown in FIG. 3B). It moves to the position which opposes 36 opening.

The heating mechanism 50 of the present embodiment is a heating means such as a sheath heater, and is disposed at both ends of the surface of the shutter plate 40 on the substrate holding unit 14 side.
The shutter portion having the above configuration can also be used.

  In this embodiment, the deposited film is formed by vacuum deposition while the substrate S is fixed. However, the present invention is not limited to this, and the deposited film may be formed while the substrate S is rotated. The vapor deposition film may be formed while reciprocating the film.

Moreover, although the heating evaporation source 16 of the present embodiment is configured with only one crucible 18, the present invention is not limited to this, and the heating evaporation source may be configured with a plurality of evaporation sources (crucibles). Good.
In the case where a plurality of evaporation sources are used, a single vacuum deposition in which all the evaporation sources are filled with the same film forming material or a multi-source vacuum evaporation in which a plurality of film forming materials are charged into different evaporation sources may be used.

In addition, the vacuum deposition apparatus evaporates the phosphor (matrix) film-forming material and the activator film-forming material separately on the surface of the substrate S by binary vacuum deposition ( It is preferable to produce a conversion panel by forming a phosphor layer.
For example, in the case of CsBr: Eu exemplified as a preferable stimulable phosphor, cesium bromide (CsBr) is used as a film forming material for the phosphor, and europium bromide (EuBr _x ) is used as a film forming material for the activator component. (X is usually 2 to 3 but 2 is preferred)), and phosphors represented by CsBr: Eu are obtained by binary vacuum deposition in which both are put into different evaporation sources and heated and evaporated independently. A layer (that is, a deposited film) is formed.

Here, in the case of performing binary vacuum evaporation in which the evaporation material of the phosphor and the evaporation material of the activator are independently heated and evaporated, a common shutter may be provided for a plurality of evaporation sources. A shutter may be arranged for each evaporation source.
Here, in the case where a common shutter is disposed with respect to the evaporation source of a plurality of evaporation materials (when a plurality of vacuum depositions and a plurality of film formation materials are mixed to adjust the film formation material) A common temperature region is detected in all (or a plurality of types occupying a large quantity ratio) in the temperature range of the film forming material from the melting point to 300 ° C. or higher and the melting point to 400 ° C. or lower. It is preferred to heat the shutter in the area.
Or you may set the temperature of a heat generating body corresponding to melting | fusing point of the film-forming material with the largest quantity in a fluorescent substance layer (film-forming material with the largest vapor deposition amount in a fluorescent substance layer). For example, as described above, in the stimulable phosphor, since most of the phosphor layer is a phosphor as described above, if the shutter is heated according to the melting point of the film forming material of the phosphor component, Good. That is, in the case of forming a phosphor layer composed of CsBr: Eu using the cesium bromide and europium bromide, the shutter is selected according to the melting point (636 ° C.) of cesium bromide that is a film forming material of the phosphor component. May be heated to bring the shutter to a predetermined temperature.

  Hereinafter, the vacuum vapor deposition method of the present invention will be described in more detail by explaining the operation of the vapor deposition apparatus 10 shown in FIG.

First, the substrate holder 30 that accommodates the substrate S is mounted at a predetermined position of the substrate plate, and the crucible 18 is filled with a predetermined amount of the evaporation material M.
Next, the vacuum chamber 12 is closed and evacuated by the vacuum pump 22 to evacuate to a predetermined degree of vacuum.
After exhausting with the vacuum pump 22 and making the inside of the system (that is, inside the vacuum chamber 12) a high degree of vacuum, the three-way valve 24 is switched, and argon gas is introduced into the system from the gas introduction unit 28, and 0.01 to The degree of vacuum is about 3 Pa (hereinafter referred to as medium vacuum for convenience).

  When the degree of vacuum in the vacuum chamber 12 reaches a predetermined degree, the crucible 36 is energized by the heating source 38 and heating of the evaporation material M is started.

Here, when heating of the evaporation material M in the crucible 36 is started, the shutter plate 40 is in a closed state. That is, the shutter plate 40 is disposed (or moved) at a position facing the opening of the crucible 36. The shutter plate 40 is heated to a predetermined temperature by the heating mechanism 20.
Thus, by heating the shutter plate 40 at a position facing the crucible 36, it is possible to prevent the evaporation material M from adhering to the substrate S before the start of vapor deposition, and the evaporation material M is shuttered on the shutter plate 40. It is also possible to prevent the plate from being deposited so thick that it cannot move.

  Thereafter, when the temperature of the evaporation material M (and / or the crucible 36) reaches a predetermined temperature, the shutter plate 40 is opened (that is, the shutter plate 40 is moved to a position where the opening of the crucible 36 is not shielded). And the formation of the deposited film on the substrate S is started. After opening the shutter plate 40, heating by the heating mechanism 20 is stopped.

When the deposited film having a predetermined layer thickness is formed, the heating of the crucible 36 by the heating source 38 is stopped, the inside of the vacuum chamber 12 is returned to atmospheric pressure, the vacuum chamber 12 is opened, and the substrate S on which the deposited film is formed. Take out.
In addition, the layer thickness (film thickness) of the vapor deposition film may be controlled by a film formation rate according to a previously known heating condition, or may be controlled by directly measuring the layer thickness using a displacement meter or the like, You may control by the evaporation meter etc. which use a crystal oscillator etc.
In this way, the vacuum evaporation apparatus 10 forms the evaporation film of the evaporation material M on the substrate S.

Here, an alkali halide material (specifically, a phosphor), in particular, an alkali halide photostimulable phosphor, in particular, a phosphor layer made of a stimulable phosphor represented by CsBr: Eu is used. When forming, vacuum deposition is performed by heating the film-forming material by resistance heating or the like under medium vacuum so that a uniform and highly accurate phosphor layer (that is, a vapor-deposited film) can be formed. It is preferred to do so.
A phosphor layer made of a photostimulable phosphor formed by vacuum deposition has a columnar crystal structure in many cases. The phosphor layer obtained by forming under such a medium vacuum, particularly the CsBr: Eu The alkali halide phosphor layer such as has a particularly good columnar crystal structure, and is preferable in terms of photostimulable light emission characteristics and image sharpness.

Hereinafter, the vacuum vapor deposition apparatus of the present invention will be described in more detail with specific examples.
In this example, the vapor deposition apparatus 10 shown in FIG. 1 was used.
First, the crucible 36 was made of tantalum for resistance heating, and an R-type (platinum-rhodium) thermocouple was inserted into the crucible 36 and fixed.
Next, the shutter plate 40 was a plate-shaped member made of tungsten having a thickness of 1.0 mm, and was disposed above the opening of the crucible 36. Here, the distance between the opening of the crucible 36 and the shutter plate 40 (specifically, the shortest distance between the opening of the crucible 36 and the shutter plate 40) was set to 2 mm.
Further, a heating mechanism 20 for applying a current to the shutter plate 40 and performing resistance heating is connected to both end portions (both end portions in the diameter direction) of the shutter plate 40, and the surface on the substrate holding portion 14 side (that is, the back surface of the shutter). An R-type thermocouple was brought into contact with the side and pressed / fixed with a spring.

First, 600 g of cesium bromide (CsBr melting point 636 ° C.) powder was charged in the crucible 36.
Next, the vacuum chamber 12 was closed, the three-way valve 24 was opened, the vacuum pump 22 and the exhaust path 26 were passed, and the inside of the vacuum chamber 12 was exhausted. As the vacuum pump 22 (vacuum exhaust device), a combination of a rotary pump, a mechanical booster pump, and a diffusion pump was used, and a cryopump for moisture exhaust was also used.
Thereafter, when the degree of vacuum in the vacuum chamber 12 becomes 2 × 10 ⁻³ Pa, the three-way valve 24 is switched to pass through the gas introduction part 28 and the exhaust path 26, and the gas introduction part 28 is used to create a vacuum. Argon gas was introduced into the chamber 12 to set the degree of vacuum in the vacuum chamber to 1 Pa.

Next, a current of 140 A was supplied from the heating mechanism 40 to the shutter plate 40.
Further, by energizing the crucible 36 and using the temperature measurement result of the R-type thermocouple inserted therein, the shutter plate 40 is closed while performing feedback control so that the temperature in the crucible 36 becomes a constant temperature of 670 ° C. In this state, current was applied from the heating source 38 to heat the crucible 36 for 120 minutes to melt the evaporation material M.

When the shutter plate 40 was heated by the heating mechanism 20 as in the present embodiment, the shutter 40 was openable and closable even after 120 minutes of heating.
Here, the temperature of the shutter plate 40 after the evaporation material M was heated for 120 minutes was measured. Here, the temperature of the shutter plate 40 is the temperature of the rear surface of the shutter (that is, the surface on the substrate holding portion side) calculated from the temperature measurement result of the abutting R-type thermocouple.
As a result of the measurement, the temperature on the back side of the shutter plate 40 was 248 ° C.
Further, after the introduction of the argon gas is stopped, the inside of the vacuum chamber 12 is returned to the atmospheric pressure, the crucible 36 is taken out, the amount (weight) of cesium bromide remaining in the crucible 18 is measured, The evaporation amount of the evaporation material M (that is, the remaining amount in the 600-crucible) was calculated.
As a result of calculation, the evaporation amount of the evaporation material M was 48.5 g.

Further, the evaporation amount of the evaporation material was calculated for a plurality of examples in which only the current applied to the shutter plate 40 was changed and the temperature of the shutter plate was changed under the same conditions as in the above-described example.
As a result of the measurement, when the temperature on the rear surface of the shutter plate was 306 ° C., the evaporation amount of the evaporation material M was 54.8 g. Further, when the temperature on the rear surface of the shutter plate was 402 ° C., the evaporation amount of the evaporation material M was 152.0 g. When the temperature on the rear surface of the shutter plate was 511 ° C., the evaporation amount of the evaporation material M was 212.0 g.
In both cases, the shutter plate 40 was openable and closable even after the evaporation material M was heated for 120 minutes.

Next, for the sake of comparison, the measurement was also performed when the evaporation material M was heated for 120 minutes without heating the shutter plate 40 by the heating mechanism 38.
After the evaporation material M is heated for 120 minutes without heating the shutter plate 40 by the heating mechanism 38, the evaporation material M is deposited thickly between the shutter plate 40 and the crucible 36, and the shutter plate 40 cannot be moved. there were.
Further, as a result of measuring the temperature of the shutter plate and the evaporation amount of the evaporation material, the temperature of the back surface of the shutter plate was 215 ° C., and the evaporation amount of the evaporation material M was 79.5 g.
The measurement results are shown in Table 1 below and FIG. Here, in FIG. 4, the vertical axis is the evaporation amount [g], and the horizontal axis is the shutter back surface temperature [° C.].

Thus, it can be seen that heating the shutter plate with the heating mechanism prevents the shutter plate or the evaporation material from being deposited thickly between the shutter plate and the crucible and preventing the shutter plate from being opened and closed.
Further, as shown in Table 1 and FIG. 4, the temperature of the shutter plate is a temperature that is 300 ° C. or more and 400 ° C. or less lower than the melting point (636 ° C.) of cesium bromide (CsBr) that is an evaporation material, that is, 236 ° C. or more. By setting it as 336 degrees C or less, the evaporation amount of the evaporation material at the time of pre-processing can be decreased rather than the case where a shutter board is not heated with a heating mechanism. That is, the utilization efficiency of the evaporation material can be increased.
From the above, the effects of the present invention are clear.

  As mentioned above, although the vacuum evaporation system concerning the present invention was explained in detail, the present invention is not limited to the above embodiment, and various improvements and changes are made without departing from the gist of the present invention. Also good.

  For example, since the present invention can produce a phosphor sheet with uniform X-ray characteristics, the evaporation material is an alkali halide material as described above, and a vapor deposition film of the alkali halide material is formed on the substrate. However, it is preferably used as a vacuum vapor deposition apparatus for producing a radiation image detector, but is not limited thereto, and can be used as various vacuum vapor deposition apparatuses using various evaporation materials.

It is a front view which shows schematic structure of an example of the vacuum evaporation system of this invention. (A) And (B) is a top view which shows schematic structure of the heating evaporation source and shutter part of the vacuum evaporation system shown in FIG. 1, respectively. (A) And (B) is a perspective view which shows schematic structure of the other example of the shutter part which can be used for the vacuum evaporation system of this invention. It is a graph which shows the relationship between the temperature of a shutter board | plate, and the evaporation amount of the evaporation material in a crucible.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vacuum evaporation apparatus 12 Vacuum chamber 14 Substrate holding part 16 Heating evaporation source 18 Shutter part 20 Heating mechanism 22 Vacuum pump 24 Valve 26 Exhaust path 28 Gas introducing part 30 Substrate holder 32 Holder mounting part 36 Crucible 38 Heating source 40 Shutter plate 42 Shutter Drive mechanism 44 Rotating shaft 46 Support part S Substrate M Evaporating material

Claims (6)

A vacuum chamber;
An evaporation source disposed in the vacuum chamber for heating and evaporating the evaporation material;
A holding mechanism that is disposed opposite to the evaporation source and holds the vapor deposition material;
A shutter unit that is disposed between the evaporation source and the holding mechanism and prevents the evaporation material from adhering to the evaporation target material during non-film formation;
A vacuum evaporation apparatus having a heating mechanism for heating the shutter portion.   The vacuum evaporation apparatus according to claim 1, wherein the heating mechanism heats the shutter unit to a temperature at which the evaporation material is formed into droplets.   The vacuum evaporation apparatus according to claim 1, wherein the evaporation material is an alkali halide material.   The vacuum evaporation apparatus according to any one of claims 1 to 3, wherein the heating mechanism heats the shutter unit to a temperature lower by 300 ° C or more and 400 ° C or less than a melting point of the evaporation material.   The vacuum evaporation apparatus according to any one of claims 1 to 4, wherein a distance between the shutter and the opening of the evaporation source is 1 mm or more and 3 mm or less. The shutter unit is
A shutter plate capable of shielding the heating source;
A moving mechanism for moving the shutter plate,
6. The moving mechanism according to claim 1, wherein the shutter plate is disposed at a position facing the evaporation source during non-film formation, and the shutter plate is disposed at a position not opposed to the evaporation source during film formation. The vacuum evaporation apparatus as described.

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