KR102180359B1 - Vacuum evaporation apparatus - Google Patents

Abstract

A plurality of crucibles 2, which are respectively evaporated to evaporate the evaporation material (A), and a valve 51 connected to the downstream side of these crucibles 2, and an inlet pipe 11 from these valves 51 A diffusion container 21 that introduces the evaporation material through and diffuses the introduced evaporation material, and a plurality of nozzles 25 for discharging the evaporation material diffused into the interior 22 of the diffusion container toward the substrate K. It is a vacuum evaporation apparatus for depositing on the substrate K in a vacuum state, wherein all of the inlet pipes 11 do not have a branch, the deposition rate is 0.1 to 10 Å/sec, and the diffusion container The internal space thickness (D) is 1m or less and the maximum distance (L) between nozzles is 5m or less, and the relationship between the internal space thickness (D) of the diffusion vessel and the maximum distance (L) between nozzles is given by the formula (1) Any one of to (3) is satisfied.

Description

Vacuum evaporation device{VACUUM EVAPORATION APPARATUS}

The present invention is a vacuum for depositing evaporation materials such as metallic materials and organic materials on the surface of a glass substrate under negative pressure. It relates to an evaporation apparatus (眞空蒸着裝置).

For example, a panel display using an organic EL material is formed by depositing a vapor deposition material such as an organic material on a member to be deposited such as a glass substrate. In general, the evaporation material is heated in an evaporation vessel to evaporate, and the evaporation material, which is the evaporated evaporation material, is guided into a vacuum vessel and the surface of the evaporated member (substrate) disposed in the vacuum vessel It is released to the evaporation.

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

; Japanese Unexamined Patent Application Publication No. 2007-332458

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

Accordingly, it is an object of the present invention to provide a vacuum evaporation apparatus capable of setting a low heating temperature of the evaporation material without taking into account the decrease in conductance in heating the evaporation material.

In order to solve the above problems, the vacuum deposition apparatus according to claim 1 of the present invention comprises a plurality of crucibles each evaporating a deposition material to form an evaporation material, a valve connected to the downstream side of the crucible, and an inlet pipe from these valves. And a diffusion container for introducing the evaporation material and diffusing the introduced evaporation material through the diffusion container, and a plurality of discharge holes for discharging the evaporation material diffused from the inside of the diffusion container toward the substrate. As a vacuum evaporation device for evaporation,

All of the inlet pipes do not have a branch.

In addition, in the vacuum deposition apparatus according to claim 2 of the present invention, in the vacuum deposition apparatus according to claim 1, the relationship between the inner space thickness (D) of the diffusion container and the maximum distance (L) between nozzles is the following equation:

100 × D ≥-1.22 × L ² + 25L-0.51

Is to satisfy.

Further, in the vacuum deposition apparatus according to claim 3 of the present invention, in the vacuum deposition apparatus according to claim 1, the deposition rate is 0.1 Å/sec or more and 10 Å/sec or less,

The inner space thickness (D) of the diffusion container is less than 1m and the maximum distance (L) between nozzles is less than 5m,

In addition, the relationship between the inner space thickness (D)[m] of the diffusion vessel and the maximum distance between nozzles (L)[m] is the following equations (1) to (3)

100 × D ≥-1.22 × L ² + 25L-0.51 ‥‥(1)

100 × D ≤-80 × L + 244 ‥‥(2)

100 × D ≤-0.25 × L + 4.75 ‥‥(3)

It satisfies any one of.

According to the vacuum evaporation apparatus, since conductance hardly decreases in the inlet pipe, it is not necessary to consider the decrease in conductance when heating the evaporation material, and the heating temperature of the evaporation 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 liable to deteriorate by heating.

1 is an overall cross-sectional view of a vacuum evaporation apparatus according to Embodiment 1 of the present invention, wherein (a) is a front cross-sectional view, and (b) is an AA cross-sectional view of (a).
Fig. 2 is a schematic diagram showing a model of an internal space in a diffusion vessel used in the simulation of this vacuum deposition apparatus.
Fig. 3 is a graph showing the results of this simulation, (a) is a graph when the pitch Lt of the discharge hole is small, and (b) is a graph when the pitch Lt of the discharge hole is large.
Fig. 4 is a graph showing a range satisfying equation (1) as a result of this simulation.
Fig. 5 is a graph showing a range satisfying equations (1) to (3) as a result of this simulation.
6 is an overall cross-sectional view of the vacuum deposition apparatus according to Embodiment 2 of the present invention, wherein (a) is a front cross-sectional view and (b) is a side cross-sectional view.
7 is an overall cross-sectional view of a conventional vacuum deposition apparatus.

[Embodiment 1]

Hereinafter, a vacuum deposition apparatus according to Embodiment 1 of the present invention will be described with reference to the drawings.

As shown in Fig. 1(a), this vacuum evaporation apparatus 1 has a plurality of evaporating materials (e.g., Alq3 (aluny quinolium composite)) (A) (two in Fig. 1(a)). ] Of the crucible (2) and a plurality of (two in Fig. 1(a)) flowing in each of the evaporation material, which is the evaporated evaporation material (A), from the crucible 2, respectively. ), and a vacuum vessel (3) that guides the evaporation material introduced by these inlet pipes (11) to the substrate (K) disposed therein and deposits at a predetermined degree of vacuum (negative pressure); , A vacuum pump (not shown in the drawing) is provided to bring the inside of the vacuum container 3 to a predetermined degree of vacuum (negative pressure). Further, in this vacuum container 3, a diffusion container (also referred to as a manifold) 21 for diffusing the evaporation material introduced through the inlet pipe 11, and a substrate K at the lower side. A substrate holder 31 that is supported in a fixed state, and a crystal vibration type film thickness meter (also referred to as QCM (Quarts Crystal Microbalance)) that measures the deposition rate of the substrate K in the vicinity of the substrate holder 31 (41). Has been placed. In addition, on the surface of the diffusion container 21 facing the substrate, as shown in Figs. 1 (a) and (b), a plurality of discharge holes 23 for discharging the diffused evaporation material are formed in front and rear, left and right In addition, a nozzle 25 is attached to each discharge hole 23. In addition, hereinafter, the direction of the crucible 2 viewed from the diffusion container 21 (left and right directions in Fig. 1) is referred to as a left and right direction.

Valves 51 that control the flow rate of the evaporating material are connected to the downstream openings of each of the crucibles 2. In addition, the inlet pipe 11 connects each valve 51 other than the vacuum vessel 3 and the diffusion vessel 21 in the vacuum vessel 3, and is disposed through the side wall 3s of the vacuum vessel 3 Has been. Further, the diffusion container 21 has a rectangular parallelepiped shape in which an inner space 22 for diffusing the evaporation material is formed. In addition, on the substrate K supported by the substrate holder 31, a metal mask M is provided to make the evaporation film to be formed on the substrate K within a desired range.

Next, the inlet pipe 11 and the diffusion vessel 21, which are the gist of the present invention, will be described in detail.

The inlet pipe 11 is a pipe having a constant inner diameter over the entire length. Therefore, the inflow pipe 11 has a structure that makes it difficult to reduce the conductance of the evaporating material flowing therein.

The diffusion container 21 has an inlet 24 formed on the left and right sides thereof through the inlet pipe 11 and the inner space 22, respectively. For this reason, the diffusion container 21 introduces the evaporation material from the inlet 24, diffuses the introduced evaporation material into the inner space 22, and transfers the diffused evaporation material from the nozzle 25 to the substrate (K It is configured to emit toward ). This inner space 22 is also in a rectangular parallelepiped shape, and the two surfaces having the largest area are the substrate-facing surface and the opposite surface.

In the diffusion container 21, if the thickness of the inner space 22 of the diffusion container 21 is D, and the maximum distance between the nozzles of the nozzle 25 is L,

100 × D ≥-1.22 × L ² + 25L-0.51 ‥‥ (1)

Is to satisfy.

In addition, the deposition rate is 0.1 Å/sec or more and 10 Å/sec or less, the thickness (D) of the inner space 22 of the diffusion container 21 is 1 m or less, and the maximum distance L between the nozzles of the nozzle 25 is Less than 5m,

100 × D ≤-80 × L + 244 ‥‥ (2)

100 × D ≤-0.25 × L + 4.75 ‥‥ (3)

Is to satisfy.

By the way, although not shown in the drawing, a heater (for example, a sheath heater) is provided in the crucible 2 for heating and evaporating the evaporation material A. In addition, the valve 51, the inlet pipe 11, the diffusion vessel 21, and the nozzle 25, although not shown in the drawing, a heater (for example, a sheath for preventing the evaporation material passing through the inside from cooling and adhering) Heater) are installed respectively.

Hereinafter, the operation of the vacuum deposition apparatus 1 will be described.

First, a vapor deposition material (A) is put into each crucible 2, and the inside of the vacuum container 3 is set to a predetermined degree of vacuum (negative pressure) with a vacuum pump. And all the valves 51 are closed, and the crucible 2, the valve 51, the inlet pipe 11, the diffusion container 21, and the nozzle 25 are heated with a heater. When the evaporation material (A) in the crucible 2 is heated, the evaporation material (A) evaporates. After that, by opening one valve 51, the evaporation material A (that is, the evaporation material) evaporated from the crucible 2 passes through the valve 51 and the inlet pipe 11 with little decrease in conductance. It flows into the diffusion vessel 21. Then, the evaporation material diffuses into the inner space 22 of the diffusion container 21 and is discharged from the nozzle 25 toward the substrate K. Evaporation is performed by the evaporation material released, and a vapor deposition film is formed on the substrate K. Further, in the vicinity of the substrate K, the deposition rate is measured by the crystal vibration type film thickness measuring device 41, and the flow rate of the evaporation material is appropriately controlled by the valve 51 so that the deposition rate becomes a desired value. When a vapor deposition film having a desired thickness is formed, the valve 51 is closed and another valve 51 is opened, and in the same manner, another vapor deposition film is formed by overlapping the deposition film.

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

As described above, according to the vacuum evaporation apparatus 1 according to the first embodiment, since conductance hardly decreases in the inlet pipe 11, there is no need to consider the decrease in conductance when heating the evaporation material A, and The heating temperature of the material (A) 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 liable to deteriorate by heating.

In addition, the uniformity of the film thickness of the evaporated film can be within ±3%.

[simulation]

Hereinafter, a simulation that leads to equations (1) to (3) in the first embodiment will be described.

In this simulation, as shown in Fig. 2, the inner space 22 (cube shape) according to the first embodiment was approximated, and a cylindrical inner space having a diameter of Dt was obtained. In addition, in this simulation, the discharge hole 23t was made into two in the left-right direction, and the pitch of these discharge holes 23t was taken as Lt.

In the diffusion vessel 21t having the inner space 22t and the discharge hole 23t as described above, the flow rate Q of the evaporating material flowing in, the diameter Dt of the inner space 22t, and the discharge hole ( When the pitch Lt of 23) was varied in various ways, the flow rate ratio (q1/q2) of the evaporation material discharged from the discharge hole 23t was calculated.

Fig. 3(a) shows the result of setting Lt to a small value, and Fig. 3(b) shows the result of setting Lt to a large value. As shown in Fig. 3(a), when Lt is a small value, when Dt is small, the flow rate ratio is stable in a region where the deposition rate (based on the flow rate (Q)) is relatively low, and when Dt is large, the deposition rate ( flow rate In the region where the rate (based on Q) is relatively high, the flow rate ratio is stabilized. In addition, even when Lt is a large value as shown in Fig. 3(b), if Dt is small, the flow rate ratio is stabilized in a region where the deposition rate (based on the flow rate (Q)) is relatively low, and if Dt is large, the deposition rate The flow rate ratio is stabilized in a region where (based on the flow rate Q) is relatively high. Because if Dt is small, the evaporation material becomes a molecular flow when the deposition rate of the evaporation material is less than a predetermined value, while when Dt is large, the evaporation material is viscous when the deposition rate of the evaporation material is higher than another predetermined value. It is because it becomes a flow. On the other hand, when Dt is small and the deposition rate exceeds the predetermined value, or when Dt is large and the deposition rate is less than the other predetermined value, the evaporation material is in a state in which molecules and viscous flows are mixed, so the deposition rate is reduced. If it fluctuates, the flow rate also fluctuates greatly. From the above simulation results, a relational expression between Dt and Lt with a flow rate ratio of 0.94 or more was obtained regardless of the deposition rate. This relational expression becomes the above equation (1). The range of Dt-Lt in which the above formula (1) is satisfied is indicated by hatching in FIG. 4. Further, when the flow rate ratio is 0.94 or more, the film thickness uniformity of the evaporated film is within ±3%.

In addition, from the simulation results, the deposition rate is 0.1Å / sec or more in relation Dt and Lt is the flow rate ratio is more than 0.94 in the range of 10Å / sec or less was obtained. In this relational expression, under the condition that the thickness (D) of the inner space 22 of the diffusion container 21 is 1 m or less and the maximum distance L between the nozzles of the nozzle 25 is 5 m or less, the above equations (2) and (3) ).

Therefore, under the condition that the deposition rate is 0.1 Å/sec or more and 10 Å/sec or less, the thickness D of the inner space 22 is 1 m or less, and the maximum distance L between the nozzles of the nozzle 25 is 5 m or less, the (1 ), (2) or (3), the flow rate ratio is 0.94 or more, that is, the evaporation material is discharged so that the uniformity of the film thickness of the evaporated film is within ±3%. The range of Dt-Lt in which these are satisfied is indicated by hatching in Fig. 5.

In addition, since the value of the simulation is approximately determined by the average free travel of the evaporating molecules and the distance between the walls of the diffusion vessel, the inner space 22t is not limited to the cylindrical diffusion vessel 21t. It can also be applied to diffusion containers of other shapes such as a rectangular parallelepiped shape.

[Example]

Hereinafter, examples in which the first embodiment is more specifically described will be described.

In this embodiment, a vacuum evaporation apparatus 1 having two crucibles 2 and two inlet pipes 11 as shown in FIG. 1 was used. Further, the evaporation material (A(A1)) in one crucible 2 was set to α-NPD, and the deposition material (A(A2)) in the other crucible 2 was set to Alq3. Here, a diffusion container 21 having a maximum distance L of the nozzle 25 between the nozzles is 1.0 m and a thickness D of the inner space 22 is 0.25 m.

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

In addition, in this process, the heating temperature of the evaporation material (A) is 280°C in α-NPD and 340°C in Alq3, so that the vacuum deposition apparatus 1 provided with an inlet tube 11 having a branch portion In comparison, all of them could be reduced by 5°C.

[Embodiment 2]

The vacuum evaporation apparatus 1 according to the second embodiment is capable of co-deposition, unlike the vacuum evaporation apparatus 1 according to the first embodiment.

Hereinafter, a vacuum deposition apparatus 1 according to the second embodiment will be described with reference to FIG. 6, but a diffusion container 21, an inlet pipe 11, and a crystal vibration type film thickness meter 41 different from those of the first embodiment are described. In addition to the description with attention to the arrangement of, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. In the following, the left and right directions in Fig. 6(a) are referred to as left and right directions, and the left and right directions in Fig. 6(b) are referred to as front and rear directions.

As shown in Fig. 6, in this vacuum evaporation apparatus 1, diffusion containers 21 are arranged in a plurality of stages (three stages in Fig. 6) inside the vacuum container 3. A plurality of inlet pipes 11 (two in Fig. 6(b)) are connected to the diffusion container 21H at the upper end in the front-rear direction of the lower left side thereof. A plurality of inlet pipes 11 (two in Fig. 6(b)) are connected to the middle diffusion container 21M in the front-rear direction of the lower right side thereof. To the diffusion container 21L at the lower end, a plurality of inlet pipes 11 (two in Fig. 6B) are connected in the front and rear directions of the middle lower surface. Further, the same number of crucibles 2 and valves 51 as the inlet pipe 11 are disposed below the vacuum container 3. For this reason, all the inflow pipes 11 are disposed substantially vertically through the bottom wall 3b of the vacuum container 3. Further, on the rear surface of each diffusion vessel 21, as shown in Fig. 6(b), a detection nozzle 26 for discharging a part of the evaporation material in each internal space 22 for detection is attached. Further, behind these detection nozzles 26, a crystal vibration type film thickness meter 41 that detects the deposition rate by each diffusion vessel 21H, 21M, 21L based on the evaporation material emitted from the detection nozzle 26 Are arranged respectively.

Hereinafter, the difference from the first embodiment will be described in terms of the action of the vacuum deposition apparatus 1.

In the vicinity of the substrate K, the entire deposition rate by the plurality of diffusion vessels 21H, 21M, 21L is measured by the crystal vibration type film thickness measuring instrument 41, and from the rear of the diffusion vessels 21H, 21M, 21L. Each deposition rate by the diffusion vessels 21H, 21M, and 21L is measured by a crystal vibration type film thickness meter 41, respectively. Then, the flow rate of the evaporation material is appropriately controlled by the valve 51 so that the entire deposition rate and the respective deposition rates of the diffusion vessels 21H, 21M, and 21L become desired values.

As described above, according to the vacuum evaporation apparatus 1 according to the second embodiment, the heating temperature of the evaporation material A can be set low, as in the vacuum evaporation apparatus 1 according to the first embodiment. Thickness uniformity can be made within ±3%. In addition, since a plurality of diffusion vessels 21 are disposed, co-deposition can be performed by introducing different types of evaporation materials for each diffusion vessel 21.

However, in the first and second embodiments, the inlet pipe 11 is shown in the drawings as being substantially horizontal or substantially vertical, but is not limited thereto.

In addition, in the first and second embodiments, 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 attaching the nozzle 25. It can be done.

Further, in the first embodiment, the vacuum evaporation apparatus 1 has been described as having a plurality of crucibles 2, but a single crucible 2 may be provided.

Further, the evaporation material (A) in the plurality of crucibles 2 in the first embodiment may be made of different evaporation materials (A(A1, A2)), or the same. By doing the same, the heating temperature of the evaporation material (A) can be set even lower.

Further, in the first and second embodiments, the height is shown in the drawing as the thickness D of the inner space of the diffusion container 21, but this may be the distance between the substrate facing surface and the opposite surface. In other words, the thickness D of the internal space is an interval when the upper surface of the diffusion container 21 faces the substrate, and the left or right surface of the diffusion container 21 is an interval between the left and right surfaces.

Claims (3)

A plurality of crucibles, each of which evaporates the evaporation material to form an evaporation material,
Valves respectively connected to the downstream openings of these crucibles,
A diffusion vessel that inflows evaporation material from these valves through the inlet pipe and diffuses the evaporation material,
A plurality of discharge holes for discharging the evaporation material diffused from the inside of the diffusion container toward the substrate are formed.
Equipped,
As a vacuum evaporation apparatus for depositing on the substrate in a vacuum state,
Not all of the inlet pipes are provided with a branch ,
The deposition rate is 0.1Å/sec or more and 10Å/sec or less,
The inner space thickness (D) of the diffusion container is less than 1m and the maximum distance (L) between nozzles is less than 5m,
In addition, the relationship between the inner space thickness (D)[m] of the diffusion vessel and the maximum distance between nozzles (L)[m] is shown in the following equations (2) to (3)
100 × D ≤-80 × L + 244 ‥‥(2)
100 × D ≤-0.25 × L + 4.75 ‥‥(3)
Vacuum deposition apparatus, characterized in that satisfying any one of . delete delete

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