JP6222929B2 - Vacuum deposition equipment - Google Patents

Description

  The present invention relates to a vacuum deposition apparatus for depositing a deposition material such as a metal material or an organic material under a negative pressure on the surface of a glass substrate, for example.

  For example, a panel display using an organic EL material is formed by evaporating an evaporation material such as an organic material on an evaporation target member such as a glass substrate. Normally, the evaporation material is heated and evaporated in an evaporation container, and the evaporation material, which is the evaporated evaporation material, is introduced into the vacuum container and released to the surface of a member to be evaporated (substrate) disposed in the vacuum container. The vapor deposition is performed.

  As such a vapor deposition apparatus, one end side is connected to a raw material supply source, and a supply pipe branched into a plurality at the other end side is connected to a supply end in which a large number of openings for discharging the evaporation material are formed, and the supply pipe A configuration in which a flow rate control means is provided at the branched portion is disclosed (for example, see Patent Document 1). This configuration is intended to obtain a deposited film having a uniform thickness.

JP 2007-332458 A

  However, the vapor deposition apparatus disclosed in Patent Document 1 has a branch portion in a supply pipe or an introduction pipe, and this causes a decrease in conductance. For this reason, in the conventional vapor deposition apparatus, it is necessary to consider a decrease in conductance in heating the vapor deposition material, and the heating temperature of the vapor deposition material has to be set high. Therefore, the conventional vapor deposition apparatus has a problem that it is not particularly suitable for vacuum vapor deposition of a vapor deposition material having a relatively low decomposition temperature, that is, a vapor deposition material that is easily deteriorated by heating.

  Accordingly, an object of the present invention is to provide a vacuum vapor deposition apparatus that can set the heating temperature of the vapor deposition material to be low without considering the decrease in conductance in the heating of the vapor deposition material.

  In order to solve the above problems, a vacuum vapor deposition apparatus according to claim 1 of the present invention includes a plurality of crucibles each of which vaporizes a vapor deposition material to obtain an evaporation material, and downstream of these crucibles.OpeningInEachA connected valve, a diffusion container for introducing the evaporation material from the valves through the introduction pipe and diffusing the introduced evaporation material, and a plurality of the discharge materials for releasing the evaporation material diffused in the diffusion container toward the substrate A vacuum deposition apparatus comprising a discharge hole and performing deposition on the substrate under vacuum,
  All of the above introduction pipes do not have a branch,
  The deposition rate is 0.1 Å / sec or more and 10 Å / sec or less,
  The internal space thickness (D) of the diffusion container is 1 m or less and the maximum distance between nozzles (L) is 5 m or less,
  In addition, the relationship between the internal space thickness (D) of the diffusion container and the maximum distance (L) between the nozzles is expressed by the following equation:(2)~ (3)
100 × D ≦ 80 × L + 244 (2)
  100 × D ≦ −0.25 × L + 4.75 (3)
One of the above is satisfied.

  According to the vacuum vapor deposition apparatus, since the conductance hardly decreases in the introduction pipe, it is not necessary to consider the decrease in conductance in heating the vapor deposition material, and the heating temperature of the vapor deposition material can be set low. For this reason, it is particularly effective for vacuum deposition of a vapor deposition material having a relatively low decomposition temperature, that is, a vapor deposition material that is easily deteriorated by heating.

It is whole sectional drawing of the vacuum evaporation system which concerns on Embodiment 1 of this invention, (a) is front sectional drawing, (b) is AA sectional drawing of (a). It is a schematic diagram which shows the model of the internal space in the diffusion container used by simulation of the same vacuum evaporation system. It is a graph which shows the result of the simulation, (a) is a graph when the pitch Lt of discharge holes is small, (b) is a graph when the pitch Lt of discharge holes is large. It is a graph which shows the range which satisfy | fills Formula (1) as a result of the simulation. It is a graph which shows the range which satisfy | fills Formula (1)-(3) as a result of the simulation. It is whole sectional drawing of the vacuum evaporation system which concerns on Embodiment 2 of this invention, (a) is front sectional drawing, (b) is side sectional drawing. It is whole sectional drawing of the conventional vacuum evaporation system.

[Embodiment 1]
Hereinafter, the vacuum evaporation system concerning Embodiment 1 of the present invention is explained based on a drawing.
As shown in FIG. 1A, this vacuum vapor deposition apparatus 1 includes a plurality of [two in FIG. 1A] crucibles 2 for evaporating a vapor deposition material (for example, Alq3) A, and an evaporated vapor deposition material A. A plurality of [two in FIG. 1 (a)] introducing pipes 11 for introducing the evaporating material from the crucible 2, and the evaporating material introduced through these introducing pipes 11 are guided to a substrate K disposed inside, and are given a predetermined amount. A vacuum vessel 3 for vapor deposition at a vacuum level (negative pressure), and a vacuum pump (not shown) for setting the inside of the vacuum vessel 3 to a predetermined vacuum level (negative pressure) are provided. The vacuum vessel 3 includes a diffusion container (also referred to as a manifold) 21 for diffusing the evaporation material introduced through the introduction pipe 11, a substrate holder 31 for holding the substrate K in a fixed state, and the substrate. A quartz vibration type film thickness meter (also referred to as QCM) 41 for measuring a deposition rate with respect to the substrate K is disposed in the vicinity of the holder 31. Further, as shown in FIGS. 1 (a) and 1 (b), a large number of discharge holes 23 for discharging the diffused evaporation container are formed in the front, rear, left and right on the surface of the diffusion container 21 facing the substrate. A nozzle 25 is attached to the hole 23. Hereinafter, the direction of the crucible 2 as viewed from the diffusion container 21 (the left-right direction in FIG. 1) is referred to as the left-right direction.

  Valves 51 for controlling the flow rate of the evaporating material are respectively connected to the downstream openings of the crucibles 2. The introduction pipe 11 connects each valve 51 outside the vacuum vessel 3 to the diffusion vessel 21 in the vacuum vessel 3 and is disposed through the side wall 3 s of the vacuum vessel 3. Further, the diffusion container 21 has a rectangular parallelepiped shape in which an internal space 22 for diffusing the evaporation material is formed. Further, the substrate K held by the substrate holder 31 is provided with a metal mask M that makes the vapor deposition film generated on the substrate K a desired range.

Next, details of the introduction tube 11 and the diffusion container 21 which are the gist of the present invention will be described.
The introduction tube 11 is a tube having a constant inner diameter over the entire length. Therefore, the introduction pipe 11 has a structure that hardly reduces the conductance of the evaporation material to be introduced.

  The diffusion container 21 is formed with introduction ports 24 on the left and right side surfaces thereof for communicating the inside of the introduction pipe 11 and the internal space 22. Therefore, the diffusion container 21 introduces the evaporation material from the introduction port 24, diffuses the introduced evaporation material in the internal space 22, and discharges the diffused evaporation material from the nozzle 25 toward the substrate K. It is configured as follows. The internal space 22 has a rectangular parallelepiped shape, and the two surfaces having the largest area are the substrate facing surface and the opposite surface.

The diffusion container 21 is configured such that the thickness of the inner space 22 of the diffusion container 21 is D, and the maximum distance between nozzles of the nozzle 25 is L.
100 × D ≧ −1.22 × L ² + 25L−0.51 (1)
It satisfies.

In addition, the deposition rate is 0.1 Å / sec or more and 10 Å / sec or less, the thickness (D) of the internal space 22 of the diffusion container 21 is 1 m or less, and the maximum distance (L) between nozzles of the nozzle 25 is 5 m. Below,
100 × D ≦ 80 × L + 244 (2)
100 × D ≦ −0.25 × L + 4.75 (3)
It satisfies.

  Although not shown, the crucible 2 is provided with a heater (for example, a sheath heater) for heating and evaporating the vapor deposition material A. The valve 51, the introduction pipe 11, the diffusion container 21, and the nozzle 25 are each provided with a heater (for example, a sheath heater) for preventing the evaporation material passing through the inside from being cooled and attached. ing.

Hereinafter, the operation of the vacuum deposition apparatus 1 will be described.
First, the vapor deposition material A is put into each crucible 2, and the inside of the vacuum vessel 3 is set to a predetermined degree of vacuum (negative pressure) with a vacuum pump. Then, all the valves 51 are closed, and the crucible 2, the valve 51, the introduction pipe 11, the diffusion container 21, and the nozzle 25 are heated with a heater. When the vapor deposition material A in the crucible 2 is heated, the vapor deposition material A evaporates. Thereafter, by opening one valve 51, the evaporated deposition material A (that is, the evaporation material) from the crucible 2 passes through the valve 51 and the introduction pipe 11 with almost no decrease in conductance, and is introduced into the diffusion container 21. Is done. Then, the evaporation material diffuses in the internal space 22 of the diffusion container 21 and is discharged from the nozzle 25 toward the substrate K. Vapor deposition is performed by the released evaporation material, and a vapor deposition film is generated on the substrate K. Further, the vapor deposition rate is measured in the vicinity of the substrate K by the quartz vibration type film thickness meter 41, and the flow rate of the evaporation material is appropriately controlled by the valve 51 so that the vapor deposition rate becomes a desired value. When the vapor deposition film having a desired thickness is generated, the valve 51 is closed and the other one valve 51 is opened. Similarly, another vapor deposition film is formed on the vapor deposition film.

  Here, since the vapor deposition rate, the thickness (D) of the internal space 22 and the maximum distance (L) between the nozzles of the nozzle 25 are as described above, the evaporation material of the internal space 22 has a uniform film thickness of the vapor deposition film. It is discharged from the nozzle 25 so as to be within ± 3%.

  As described above, according to the vacuum vapor deposition apparatus 1 according to the first embodiment, the conductance hardly decreases in the introduction pipe 11, so it is not necessary to consider the decrease in conductance in the heating of the vapor deposition material A. The heating temperature can be set low. For this reason, it is particularly effective for vacuum deposition of a vapor deposition material having a relatively low decomposition temperature, that is, a vapor deposition material that is easily deteriorated by heating.

Further, the film thickness uniformity of the deposited film can be within ± 3%.
[simulation]
Hereinafter, the simulation that led to deriving the equations (1) to (3) in the first embodiment will be described.

  In this simulation, as shown in FIG. 2, a cylindrical internal space having a diameter of Dt is used as an approximation of the internal space 22 (cuboid shape) according to the first embodiment. In this simulation, two discharge holes 23t are provided in the left-right direction, and the pitch of these discharge holes 23t is Lt.

  When the flow rate Q of the evaporation material to be introduced, the diameter Dt of the internal space 22t, and the pitch Lt of the discharge holes 23 are varied in the diffusion container 21t in which the internal space 22t and the discharge holes 23t are formed as described above. The flow rate ratio q1 / q2 of the evaporation material discharged from the discharge hole 23t was calculated.

FIG. 3A shows the result of setting Lt to a small value, and FIG. 3B shows the result of setting Lt to a large value. As shown in FIG. 3 (a), when Lt is a small value, Dt (based on the flow rate rate Q) is less if the deposition rate is the flow rate ratio is stabilized at a relatively low region, the larger the Dt evaporation rate (flow rate The flow ratio is stable in a region where the rate Q is relatively high. Similarly, as shown in FIG. 3B, when Lt is large, similarly, if Dt is small, the flow rate ratio is stabilized and Dt is large in a region where the deposition rate ( based on the flow rate Q) is relatively low. If the deposition rate ( based on the flow rate Q) is relatively high, the flow rate ratio is stabilized. This is because, the smaller the Dt, the evaporation rate of the evaporation material is equal to or less than a predetermined value, while the evaporation material comprising a molecular flow, the greater the Dt, at a deposition rate of the evaporation material is other than the predetermined value, the evaporation material This is because it becomes a viscous flow. On the other hand, when Dt is small and the vapor deposition rate exceeds the predetermined value, or when Dt is large and the vapor deposition rate is less than the other predetermined value, the evaporation material is in a state in which molecular flow and viscous flow are mixed. Therefore, when the deposition rate is changed, the flow rate ratio is also greatly changed. From the above simulation results, a relational expression between Dt and Lt was obtained in which the flow rate ratio was 0.94 or more regardless of the deposition rate. This relational expression is the above expression (1). The range of Dt−Lt that satisfies the above equation (1) is shown by hatching in FIG. If the flow rate ratio is 0.94 or more, the film thickness uniformity of the deposited film is within ± 3%.

Furthermore, from the above simulation results, a relational expression between Dt and Lt was obtained in which the flow rate ratio was 0.94 or more within the range of the deposition rate of 0.1 Å / sec to 10 Å / sec. This relational expression becomes the above expressions (2) and (3) under the condition that the thickness (D) of the internal space 22 of the diffusion container 21 is 1 m or less and the maximum distance (L) between the nozzles 25 is 5 m or less. .

  Therefore, the above conditions are satisfied under the conditions that the vapor deposition rate is 0.1 Å / sec or more and 10 Å / sec or less, the thickness (D) of the internal space 22 is 1 m or less, and the maximum distance (L) between the nozzles 25 is 5 m or less. If any one of (1), (2) and (3) is satisfied, the material is discharged from the evaporation material so that the flow rate ratio is 0.94 or more, that is, the film thickness uniformity of the deposited film is within ± 3%. The range of Dt−Lt in which these are satisfied is shown by hatching in FIG.

  Note that the value of the above simulation is substantially determined by the mean free path of the evaporated molecules and the distance between the wall surfaces of the dispersion container. Therefore, the internal space 22t is not limited to the cylindrical diffusion container 21t, and the like such as a rectangular parallelepiped shape. It can be applied to a diffusion container having a shape of

Hereinafter, examples that more specifically illustrate the first embodiment will be described.
In this embodiment, as shown in FIG. 1, a vacuum vapor deposition apparatus 1 having two crucibles 2 and two introduction pipes 11 was used. The vapor deposition material A (A1) in one crucible 2 was α-NPD, and the vapor deposition material A (A2) in the other crucible 2 was Alq3. Here, the diffusion container 21 in which the maximum distance (L) between the nozzles of the nozzle 25 is 1.0 m and the thickness (D) of the internal space 22 is 0.25 m is used.

  Using the vacuum deposition apparatus 1, an α-NPD deposition film was formed on the substrate K at a deposition rate of 1.0 Å / sec, and an Alq3 deposition film was formed on the deposition film. The film thickness uniformity of these vapor-deposited films was all within ± 3%.

  Further, in this process, the heating temperature of the vapor deposition material A is 280 ° C. for α-NPD and 340 ° C. for Alq 3, both of which are compared with the vacuum vapor deposition apparatus 1 provided with the introduction pipe 11 having a conventional branch portion. The temperature could be lowered by 5 ° C.

[Embodiment 2]
Unlike the vacuum deposition apparatus 1 according to the first embodiment, the vacuum deposition apparatus 1 according to the second embodiment can perform co-deposition.

  Hereinafter, the vacuum vapor deposition apparatus 1 according to the second embodiment will be described with reference to FIG. 6, but paying attention to the arrangement of the diffusion container 21, the introduction tube 11, and the quartz vibration type film thickness meter 41, which is different from the first embodiment. While describing, about the same structure as the said Embodiment 1, the same number is attached | subjected and the description is abbreviate | omitted. In the following, the left-right direction on FIG. 6A is referred to as the left-right direction, and the left-right direction on FIG. 6B is referred to as the front-rear direction.

  As shown in FIG. 6, in this vacuum vapor deposition device 1, a diffusion container 21 is arranged in a plurality of stages (three stages in FIG. 6) inside the vacuum container 3. A plurality of [two in FIG. 6B] introduction pipes 11 are connected to the upper diffusion container 21H in the front-rear direction of the lower surface on the left side. A plurality of [two in FIG. 6B] introduction pipes 11 are connected to the middle diffusion container 21M in the front-rear direction of the lower surface on the right side. A plurality of [two in FIG. 6B] introduction pipes 11 are connected to the lower diffusion container 21L in the front-rear direction of the inner lower surface. Further, the same number of crucibles 2 and valves 51 as the introduction pipe 11 are arranged below the vacuum vessel 3. For this reason, all the introduction pipes 11 are disposed substantially vertically through the bottom wall 3 b of the vacuum vessel 3. Furthermore, as shown in FIG. 6B, a detection nozzle 26 that discharges a part of the evaporation material in each internal space 22 for detection is attached to the rear surface of each diffusion container 21. Further, behind these detection nozzles 26, crystal vibration type film thickness meters 41 for detecting vapor deposition rates by the diffusion containers 21H, 21M, and 21L based on the evaporation material discharged from the detection nozzles 26 are respectively arranged. Yes.

Hereinafter, the difference of the operation of the vacuum vapor deposition apparatus 1 from the first embodiment will be described.
In the vicinity of the substrate K, the entire deposition rate by the plurality of diffusion containers 21H, 21M, and 21L is measured by the quartz vibrating film thickness meter 41, and behind the diffusion containers 21H, 21M, and 21L, by the diffusion containers 21H, 21M, and 21L. Each deposition rate is measured by the quartz vibration type film thickness meter 41. Then, the flow rate of the evaporation material is appropriately controlled by the valve 51 so that the entire vapor deposition rate and the vapor deposition rates of the diffusion containers 21H, 21M, and 21L have desired values.

  Thus, according to the vacuum evaporation apparatus 1 which concerns on the said Embodiment 2, while the heating temperature of the vapor deposition material A can be set low similarly to the vacuum evaporation apparatus 1 which concerns on Embodiment 1, the film thickness of a vapor deposition film is uniform The sex can be within ± 3%. Moreover, since the several diffusion container 21 is arrange | positioned, co-evaporation can be performed by introduce | transducing a vaporization material from which a kind differs for every diffusion container 21. FIG.

In the first and second embodiments, the introduction pipe 11 is illustrated as being substantially horizontal or substantially vertical. However, the present invention is not limited to this.
Further, in the first and second embodiments described above, the diffusion container 21 has been described as having the nozzle 25 attached to the substrate-facing surface, but the evaporation material is directly discharged from the discharge hole 23 without the nozzle 25 being attached. It may be.

In the first embodiment, the vacuum vapor deposition apparatus 1 has been described as including a plurality of crucibles 2, but may include a single crucible 2.
Further, the vapor deposition materials A in the plurality of crucibles 2 in the first embodiment may be different ones (A1, A2) or the same. By making it the same, the heating temperature of the vapor deposition material A can be set still lower.

  In the first and second embodiments, the height is illustrated as the thickness (D) of the internal space of the diffusion container 21, but this may be any distance between the substrate facing surface and the opposite surface. That is, the thickness (D) of the internal space is a vertical space when the upper surface of the diffusion container 21 is a substrate-facing surface, and a horizontal space when the left or right surface of the diffusion container 21 is a substrate-facing surface.

K substrate A vapor deposition material 2 crucible 11 introduction pipe 21 diffusion container 22 internal space 23 discharge port 24 introduction port

Claims (1)

A plurality of crucibles each for evaporating vapor deposition material to evaporate material, valves connected to respective downstream openings of these crucibles, diffusion that introduces the evaporative material from these valves through the introduction pipe and diffuses the introduced evaporative material A vacuum deposition apparatus comprising a container and a plurality of discharge holes for discharging the evaporated material diffused inside the diffusion container toward the substrate, and performing deposition on the substrate under vacuum,
All of the above introduction pipes do not have a branch part ,
The deposition rate is 0.1 Å / sec or more and 10 Å / sec or less,
The internal space thickness (D) of the diffusion container is 1 m or less and the maximum distance between nozzles (L) is 5 m or less,
And the relationship between the internal space thickness (D) of the diffusion container and the maximum distance (L) between the nozzles is expressed by the following equations (2) to (3).
100 × D ≦ 80 × L + 244 (2)
100 × D ≦ −0.25 × L + 4.75 (3)
Any one of the above is satisfied.

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