U.S. patent application number 12/816470 was filed with the patent office on 2011-01-13 for vacuum vapor deposition apparatus.
Invention is credited to Yuji YANAGI.
Application Number | 20110005462 12/816470 |
Document ID | / |
Family ID | 42753429 |
Filed Date | 2011-01-13 |
United States Patent
Application |
20110005462 |
Kind Code |
A1 |
YANAGI; Yuji |
January 13, 2011 |
VACUUM VAPOR DEPOSITION APPARATUS
Abstract
In a vacuum vapor deposition apparatus including a plurality of
linear-shaped vaporization sources, equal-thickness surfaces are
calculated for vaporization containers, respectively. Each of the
equal-thickness surfaces indicates where a deposition amount of
vapor of a vaporization material released from release holes in the
corresponding vaporization container is the same per unit time.
Then, the vaporization containers are placed in such a manner that
contact points of the respective equal-thickness surfaces all
coincide with each other on a deposition surface of a substrate,
each of the contact points being where the corresponding
equal-thickness surfaces come in contact with the surface of the
substrate.
Inventors: |
YANAGI; Yuji; (Tokyo,
JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
Suite 800, 2033 K Street, N.W.
Washington
DC
20006
US
|
Family ID: |
42753429 |
Appl. No.: |
12/816470 |
Filed: |
June 16, 2010 |
Current U.S.
Class: |
118/726 |
Current CPC
Class: |
C23C 14/12 20130101;
C23C 14/243 20130101; C23C 14/24 20130101; C23C 14/543
20130101 |
Class at
Publication: |
118/726 |
International
Class: |
C23C 14/56 20060101
C23C014/56; C23C 14/54 20060101 C23C014/54; C23C 14/24 20060101
C23C014/24 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 10, 2009 |
JP |
2009-163239 |
Claims
1. A vacuum vapor deposition apparatus in which a plurality of
vaporization containers each containing a vaporization material and
having a plurality of release holes arranged linearly are placed in
parallel with arrangement directions of the plurality of release
holes, and the vaporization containers are heated to evaporate or
sublimate the respective vaporization materials, and vapors of the
respective materials are released through the plurality of release
holes, as well as the vaporization materials are mixed together and
deposited on an entire surface of a substrate by relatively moving
the substrate and the vaporization containers in a direction
perpendicular to the arrangement directions of the plurality of
release holes, wherein: equal-thickness surfaces are calculated for
the vaporization containers, respectively, each of the
equal-thickness surfaces indicating where a deposition amount of
the vapor of the vaporization material released from the release
holes in the corresponding vaporization container is the same per
unit time; and the vaporization containers are placed in such a
manner that contact points of the respective equal-thickness
surfaces all coincide with each other on the surface of the
substrate, each of the contact points indicating where the
corresponding equal-thickness surfaces come in contact with the
surface of the substrate.
2. The vacuum vapor deposition apparatus according to claim 1,
wherein in a case where the vaporization containers include nozzles
projecting from the vaporization containers and where the release
holes are provided to penetrate through the nozzles, the
vaporization containers are placed to stand vertically and the
nozzles are tilted in such a manner that the contact points of the
respective equal-thickness surfaces all coincide with each other on
the surface of the substrate.
3. The vacuum vapor deposition apparatus according to claim 1,
wherein the vaporization containers each include therein a current
plate having a plurality of passage holes through which the
corresponding vapor passes; and as conductance per unit length in
the arrangement directions of the plurality of release holes,
conductance by the passage holes is made proportional to
conductance by the release holes.
Description
TECHNICAL FIELD
[0001] The present invention relates to a vacuum vapor deposition
apparatus which forms a thin film by depositing multiple
vaporization materials simultaneously on a deposition target such
as a substrate.
BACKGROUND ART
[0002] A vacuum vapor deposition apparatus is an apparatus for
forming a thin film as follows. First, a deposition target and a
vaporization container containing a vaporization material are
placed inside a vacuum chamber in the apparatus. Then, while the
inside of the vacuum chamber is depressurized, the vaporization
container is heated to melt and vaporize the vaporization material
through evaporation or sublimation. The vaporized material is then
deposited on a surface of the deposition target to thereby form a
thin film. As a method of heating the vaporization container, the
vacuum vapor deposition apparatus employs methods such as an
external heating method using an external heater to heat the
vaporization container containing the vaporization material. In
recent years, vacuum vapor deposition apparatuses have been used
not only to form metal thin films and oxide thin films using metal
materials, but also to form organic thin films by depositing
organic materials, as well as to form small molecular organic thin
films by simultaneously depositing multiple organic materials. For
example, vacuum vapor deposition apparatuses are used to form
organic electroluminescent elements (hereinafter, referred to as
organic EL elements) for flat panel displays.
[0003] The vacuum vapor deposition apparatus is also capable of
forming a thin film by simultaneously depositing multiple
vaporization materials on a substrate or the like (simultaneous
deposition). For example, when a luminescent layer is to be formed
through a deposition process for an organic EL element, a host
material and a luminescent material are used as the vaporization
materials. These materials are simultaneously deposited to form the
luminescent layer. Thus, in formation of a luminescent layer, the
mixing ratio of a host material and a luminescent material is an
important factor that influences the properties of the luminescent
layer.
[0004] {Citation List}
[0005] {Patent Literatures}
[0006] {Patent Literature 1} Japanese Patent Application
Publication No. 2004-095275
[0007] {Patent Literature 2} Japanese Patent Application
Publication No. 2002-348658
[0008] {Patent Literature 3} Japanese Patent Application
Publication No. 2006-57173
[0009] {Patent Literature 4} Japanese Patent Application
Publication No. 2006-249572
[0010] {Patent Literature 5} Japanese Patent Application
Publication No. 2009-127066
SUMMARY OF INVENTION
Technical Problem
[0011] As the screen sizes of flat panel displays such as liquid
crystal displays increase, the substrates used therefore also
increase in size. Similarly, larger substrates are desired for
organic EL elements, which are also applicable to displays and
illuminations. In an organic EL display, thin films need to be
deposited uniformly and homogeneously on a substrate. However, the
larger the substrates become, the more difficult it becomes to form
uniform and homogeneous thin films. There have been increasing
demands for higher panel qualities particularly in recent years,
requiring further increase in the uniformity and
homogeneousness.
[0012] A conventional vacuum vapor deposition apparatus <Patent
Literature 1> includes a vaporization source which allows a
vaporization material to be vaporized through linearly-arranged
multiple openings. The vaporized material is then deposited on a
large substrate by moving the vaporization source and the substrate
relative to each other, whereby a thin film having a relatively
uniform film thickness is formed. In recent years, there have been
demands to reduce manufacturing cost by improving the utilization
of expensive organic materials, and also to improve productivity
through high-rate film formation. These demands have been satisfied
by reducing the distance between a vaporization source and a
substrate. However, in a case of performing simultaneous deposition
by arranging two linear-shaped vaporization sources side by side,
it is not easy to form a homogeneous thin film with this type of
apparatus. This is because a mixing ratio of deposited vaporization
materials changes in the film thickness direction (details will be
explained later by use of FIG. 5.)
[0013] The present invention has been made in view of the above
circumstances, and has an object to provide a vacuum vapor
deposition apparatus capable of forming a homogeneous thin film
having a constant mixing ratio of multiple vaporization materials
in the film thickness direction, when mixing and depositing the
vaporization materials using multiple linear-shaped vaporization
sources.
Solution to Problem
[0014] In a vacuum vapor deposition apparatus for solving the above
problem according to a first invention, a plurality of vaporization
containers each containing a vaporization material and having a
plurality of release holes arranged linearly are placed in parallel
with arrangement directions of the plurality of release holes. The
vaporization containers are heated to evaporate or sublimate the
respective vaporization materials, and vapors of the respective
materials are released through the plurality of release holes.
Moreover, the vaporization materials are mixed together and
deposited on an entire surface of a substrate by relatively moving
the substrate and the vaporization containers in a direction
perpendicular to the arrangement directions of the plurality of
release holes. The apparatus is characterized in that
equal-thickness surfaces (or equal film thickness surfaces) are
calculated for the vaporization containers, respectively, each of
the equal-thickness surfaces indicating where a deposition amount
of the vapor (or film thickness) of the vaporization material
released from the release holes in the corresponding vaporization
container is the same per unit time. In addition, the vaporization
containers are placed in such a manner that contact points of the
respective equal-thickness surfaces all coincide with each other on
the surface of the substrate, each of the contact points indicating
where the corresponding equal-thickness surfaces come in contact
with the surface of the substrate.
[0015] A vacuum vapor deposition apparatus for solving the above
problem according to a second invention provides the vacuum vapor
deposition apparatus described in the first invention having the
following features. In a case where the vaporization containers
include nozzles projecting from the vaporization containers and
where the release holes are provided to penetrate through the
nozzles, the vaporization containers are placed to stand vertically
and the nozzles are tilted in such a manner that the contact points
of the respective equal-thickness surfaces all coincide with each
other on the surface of the substrate. Here, each of the contact
points indicates where the corresponding equal-thickness surfaces
come in contact with the surface of the substrate.
[0016] A vacuum vapor deposition apparatus for solving the above
problem according to a third invention provides the vacuum vapor
deposition apparatus described in the first invention having the
following features. The vaporization containers each include
therein a current plate having a plurality of passage holes through
which the corresponding vapor passes. In addition, as conductance
per unit length in the arrangement directions of the plurality of
release holes, conductance by the passage holes is made
proportional to conductance by the release holes.
ADVANTAGEOUS EFFECTS OF INVENTION
[0017] According to the first and second features, the vaporization
containers are placed in such a manner that contact points of the
equal-thickness surfaces, at which they come in contact with the
surface of the substrate, would coincide with each other on the
surface of the substrate. Here, each equal-thickness surface
indicates where the deposition amount of the vapor of the
corresponding vaporization material is the same per unit time. This
allows formation of a homogeneous thin film having a substantially
constant mixing ratio of the vaporization materials. As a result,
an organic EL element with a higher quality is manufactured.
[0018] According to the third feature, the vaporization containers
each include therein the current plate having the multiple passage
holes, and as conductance per unit length in the longitudinal
directions of the vaporization containers, conductance by the
passage holes is made proportional to conductance by the release
holes. This allows control on the distribution of the vapor of each
vaporization material in the longitudinal direction even when the
vaporization state of the vaporization material is changed in the
linear vaporization container in the longitudinal direction (the
arrangement direction of the multiple release holes). Hence, a thin
film having a more uniform film thickness distribution in the
longitudinal direction can be achieved also for a large substrate.
As a result, an element which is homogeneous and having uniform
properties is formed.
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1 is a schematic configuration diagram showing an
exemplary embodiment of a vacuum vapor deposition apparatus
according to the present invention.
[0020] FIG. 2 is a cross-sectional view showing an example of a
linear-shaped vaporization source of the vacuum vapor deposition
apparatus according to the present invention.
[0021] FIG. 3A is a diagram for explaining a configuration of a
heating mechanism and a control mechanism in a vaporization
container of the vacuum vapor deposition apparatus according to the
present invention. FIG. 3B is a modification of the
configuration.
[0022] FIGS. 4A to 4C are diagrams showing an example of the
structure of the vaporization container of the vacuum vapor
deposition apparatus according to the present invention. FIG. 4A is
a cross-sectional view of the vaporization container in its
longitudinal direction. FIG. 4B is a top view of the vaporization
container. FIG. 4C is a top view of a current plate inside the
vaporization container.
[0023] FIG. 5A is a diagram for explaining how two vaporization
sources are placed in general. FIG. 5B is a graph showing the
profiles of deposition amounts at certain positions in a transport
direction regarding the placement.
[0024] FIG. 6A is a diagram for explaining how two vaporization
sources are placed in the vacuum vapor deposition apparatus
according to the present invention. FIG. 6B is a graph showing the
profiles of deposition amounts at certain positions in the
transport direction regarding the placement.
[0025] FIG. 7 is a diagram for explaining how three vaporization
sources are placed in the vacuum vapor deposition apparatus
according to the present invention.
[0026] FIG. 8 is a cross-sectional view showing another example
(second example) of the linearly-shaped vaporization sources of the
vacuum vapor deposition apparatus according to the present
invention.
[0027] FIG. 9 is a diagram for explaining how two vaporization
sources with nozzles are placed in the vacuum vapor deposition
apparatus according to the present invention.
[0028] FIG. 10 is a diagram for explaining how three vaporization
sources with nozzles are placed in the vacuum vapor deposition
apparatus according to the present invention.
DESCRIPTION OF EMBODIMENTS
[0029] Embodiments of a vacuum vapor deposition apparatus according
to the present invention will be described in detail with reference
to FIGS. 1 to 10.
First Example
[0030] FIG. 1 is a schematic configuration diagram showing the
configuration of a vacuum vapor deposition apparatus of a first
example. FIG. 1 shows a cross section taken along a plane
perpendicular to the transport direction of a substrate in the
vacuum vapor deposition apparatus. The vacuum vapor deposition
apparatus of the first example is installed as a part (vacuum vapor
deposition apparatus section) of an inline system for forming
organic EL elements. Thus, the vacuum vapor deposition apparatus of
the first example will be described below by taking formation of an
organic EL element as an example; however, the vacuum vapor
deposition apparatus of the first example is not limited to this,
and is applicable to formation of a metal thin film of a metal
material, an insulating thin film of an insulating material, and
the like. The vacuum vapor deposition apparatus of the first
example is also applicable to deposition using only one
vaporization material as well as to deposition using multiple
vaporization materials (multi-source simultaneous deposition; also
called co-deposition in a case of two vaporization materials).
[0031] The inline system includes multiple processing apparatuses
(e.g., a vacuum vapor deposition apparatus, and the like). The
whole system is configured by a vacuum chamber through which
multiple substrates are transported continuously, each substrate
being subjected to successive processes for formation of organic EL
elements (e.g., formation of luminescent layers as organic thin
films, formation of electrodes as metal thin films, and the like).
These processes require structures for carrying in the substrates
from the atmosphere side to the vacuum chamber and for carrying out
the substrates from the vacuum chamber, such as a charging chamber
and a discharging chamber. These structures may be obtained by
known techniques, and thus illustration thereof is omitted
here.
[0032] In the vacuum vapor deposition apparatus for forming an
organic thin film for an organic EL element, for example, a vacuum
chamber 1 is connected to a vacuum pump 3 via a valve 2 as shown in
FIG. 1, allowing the inside of the vacuum chamber 1 to be evacuated
to a high vacuum state. A substrate 4 on which to deposit an
organic thin film is positioned on the center of an unillustrated
tray. With rotation of transport rollers 6 driven by a drive source
5, the substrate 4 is transported together with the tray from the
front side toward the further side of FIG. 1. Note that in the
first example, vaporization sources 20 to be described later are
fixed at certain positions and the substrate 4 is caused to move;
in contrast, the substrate 4 may be fixed at a certain position and
the vaporization sources 20 may be caused to move.
[0033] Below a path of the substrate 4, arranged are the
vaporization sources 20 each including a vaporization container 8
in which a vaporization material is contained, a heater for heating
9 placed around each vaporization container 8, and the like. Each
vaporization source 20 is formed as a linear-shaped vaporization
source elongated in the horizontal direction (hereinafter, referred
to as a broad width direction of the substrate 4) perpendicular to
the transport direction of the substrate 4, and has a length equal
to or slightly greater than the length of the substrate 4 in the
board width direction. In a case of multi-source simultaneous
deposition, multiple vaporization sources 20 are arranged in
parallel with the board width direction of the substrate 4 as shown
in FIGS. 5 and 6 to be described later.
[0034] Above each vaporization container 8, provided is a
vaporization rate detector 10 (e.g., crystal monitor head or the
like) to detect the vaporization rate of the corresponding
vaporization material 7 vaporized from the vaporization container
8. This vaporization rate detector 10 is connected to a
vaporization rate controller 11. The vaporization rate controller
11 controls the control output to a heating power source 12 on the
basis of the vaporization rate detected by the vaporization rate
detector 10 so that the vaporization rate would remain at a
predetermined value. The heating power source 12 feeds the heater 9
with the power controlled on the basis of the control output so
that the vaporization rate would remain constant. Here, the control
described above refers to control of temperature at the time of
deposition. Meanwhile, in a case of controlling the temperature
until the temperature of the vaporization container 8 reaches a
vaporization temperature, i.e., control of temperature rising, the
temperature is controlled by switching the control means for
controlling the heating power source 12 to a thermocouple and a
temperature controller (both unillustrated) provided to a bottom
portion of the vaporization container. In a case of multi-source
simultaneous deposition, each individual vaporization source 20 is
provided with the above-mentioned heating mechanism and the control
mechanisms.
[0035] When each vaporization container 8 is heated using the
vaporization rate detector 10, the vaporization rate controller 11,
the heating power source 12, and the heater 9 as described above,
the vaporization material 7 contained in the vaporization container
8 is evaporated or sublimated. The vapor of the vaporization
material 7 is then released in accordance with a constant
vaporization rate through multiple release holes 13 to be described
later. The board width direction of the substrate 4 is the same as
the direction in which the multiple release holes 13 are arranged.
The substrate 4 and each vaporization source 20 are caused to
relatively move in the direction perpendicular to the board width
direction and the direction in which the release holes 13 are
arranged. Hence, the vaporization materials 7 vaporized from the
respective vaporization sources 20 are mixed together and deposited
on the entire surface of the substrate 4.
[0036] Next, a structure of the vaporization source 20 will be
described in detail using FIGS. 2 to 4C.
[0037] FIG. 2 is a cross-sectional view of the vaporization source
of the first example, taken along a plane perpendicular to the
longitudinal direction of the linear vaporization source. In a case
of multi-source simultaneous deposition, each vaporization source
has the same structure.
[0038] The vaporization container 8 placed inside the vaporization
source 20 is formed to be elongated in the board width direction of
the substrate 4, and has a length equal to or slightly greater than
the length of the substrate 4 in the board width direction. The
multiple release holes 13 are provided in an upper surface (surface
on the substrate 4 side) of the vaporization container 8. A current
plate 14 having multiple passage holes 18 is placed between the
release holes 13 and the vaporization material 7 inside the
vaporization container 8. As will be explained using
later-described FIGS. 4A to 4C, the positions of the release holes
13 and the passage holes 18 in the longitudinal direction are
arranged in such a manner that the film thickness distribution of a
thin film formed by deposition of the vaporization material 7 would
be uniform in the board width direction of the substrate 4.
[0039] For installation and removal of the vaporization container 8
as well as for the arrangement of the release holes 13, the heater
9 is not placed above the vaporization container 8. Accordingly, in
order to compensate temperature decrease in the release holes 13,
the heater 9 is disposed densely on the release holes 13 side and
the lower heater 9 is disposed sparsely on a lower side (on the
vaporization material 7 side). Such disposition prevents
temperature decrease in the release holes 13 and thus avoids
clogging of the release holes 13 by the vaporization material 7.
The heater 9 and the heating power source 12 will be further
described later using FIGS. 3A and 3B.
[0040] In addition, a radiation preventive plate 15 is placed
around the entire surface of the outer periphery of the heater 9
except a part immediately above the release holes 13. This
radiation preventive plate 15 functions to preserve and equalize
the heat of the vaporization container 8. Moreover, an outer
periphery of the radiation preventive plate 15 is covered by a
water-cooling jacket 16 and a heat insulating plate 17. The
water-cooling jacket 16 has therein a passage (unillustrated)
through which cooling water flows and is cooled by the cooling
water. The heat insulating plate 17 has opening portions 17a at
positions corresponding to the arrangement positions of the release
holes 13 and is in contact with an upper opening portion of the
water-cooling jacket 16. The water-cooling jacket 16 and the heat
insulating plate 17 functions to prevent heat radiation to the
vacuum chamber 1 and the substrate 4. A material having high heat
conductivity, such as aluminum, is suitable for the heat insulating
plate 17. Note that the opening portions 17a in the heat insulating
plate 17 are each formed into a tapered shape becoming wider toward
the substrate 4 in order to avoid the vapor of the vaporization
material 7 adhering thereto.
[0041] Next, a configuration of the heating mechanism and the
control mechanism in the vaporization container 8 will be described
with reference to FIG. 3A. FIG. 3A is a diagram for explaining the
configuration of the heating mechanism and the control mechanism of
the first example.
[0042] The release holes 13 in the vaporization container 8 are
exposed to the substrate 4 to be subjected to deposition. Thus, if
no countermeasure is taken, the temperature near the release holes
13 become lower than that inside the vaporization container 8.
Moreover, when the vaporization container 8 is elongated, a
temperature variation is likely to occur in the longitudinal
direction. As a countermeasure, described in Patent Literature 1 is
a method by which multiple temperature control means are provided
separately in the longitudinal direction and vaporization rate
control is performed for each separate region. However, in reality,
it is extremely difficult to control the temperature on heaters by
detecting the vaporization rate for each separate region, and the
method requires a complicated structure.
[0043] To solve this, in the first example, the heating mechanism
to heat the vaporization container 8 is formed by one heating power
source 12 and one heater 9, and the control mechanism therefore is
formed by one vaporization rate detector 10 and one vaporization
rate controller 11 as shown in FIG. 3A. In this way, the heating
mechanism and the control mechanism serves as a single system. The
heater 9 is formed of one hot wire wound in spirals around an outer
surface of the vaporization container 8. The heater 9 is disposed
in such a manner that its pitches would be denser on the release
holes 13 side than on the vaporization container 7 side, by winding
the heater 9 densely around an upper portion (the release holes 13
side) of the vaporization container 8 and sparsely around a lower
portion (the vaporization material 7 side) thereof. Such structure
allows single system heat control. Accordingly, it is possible to
control the vaporization rate easily and stably over a long period
of time, allowing formation of a thin film having a uniform film
thickness and thus formation of an element having stable
properties.
[0044] Meanwhile, since the heater 9 is wound around the outer
surface of the vaporization container 8 multiple times, one heater
may not provide a sufficient output if a required overall length
exceeds a usable heater length. In such case, multiple heaters may
be used. When multiple heaters are to be used, the heaters are
similarly wound around the outer surface of the vaporization
container 8. For example, as shown in FIG. 3B, two heaters may be
used which are a heater 9a wound densely on an upper portion side
and a heater 9b wound sparsely on a lower portion side. In this
case, the heaters 9a and 9b are connected to each other in parallel
or series so that power is fed thereto using one heating power
source 12. This structure also allows single system heat control.
Accordingly, it is possible to control the vaporization rate easily
and stably over a long period of time, allowing formation of a thin
film having a uniform film thickness and thus formation of an
element having stable properties.
[0045] In general, individual heaters differ from each other in
resistance even when they have the same length. Thus, using
multiple heaters requires different powers. However, by winding the
heaters 9a and 9b around the outer surface of the vaporization
container 8 for example as shown in FIG. 3b, both heaters 9a and 9b
can be disposed in the longitudinal direction of the vaporization
container 8. Accordingly, even in the case of using multiple
heaters, an influence in heating by the difference between the
heaters 9a and 9b does not appear in the longitudinal direction of
the vaporization container 8. Hence, the temperature distribution
of the vaporization container 8 in its longitudinal direction can
be made uniform.
[0046] Next, the arrangement of the release holes 13 and the
passage holes 18 in the current plate 14 in the first example will
be described with reference to FIGS. 4A to 4C. FIG. 4A is a
cross-sectional view of the vaporization container 8 in its
longitudinal direction. FIG. 4B is a top view of the vaporization
container 8. FIG. 4C is a top view of the current plate 14. In the
following description, the amount of vapor vaporized from the
vaporization material 7 itself will be called a "vaporization
amount", whereas the amount of vapor other than that such as the
amount of vapor in the release holes 13 and in the passage holes 18
will be called a "vapor amount" to make a clear distinction
therebetween.
[0047] The multiple release holes 13 are formed in an upper surface
(surface on the substrate 4 side) of the vaporization container 8
linearly in the longitudinal direction of the vaporization
container 8. All the release holes 13 have a circular shape with
the same diameter (with the same area). The release holes 13 are
arranged such that the intervals therebetween would be denser
toward both end portions from the center of the vaporization
container 8 in its longitudinal direction. In this way, conductance
by the release hole 13 becomes larger toward both end portions of
the vaporization container 8. Assuming that the intervals between
the release holes 13 from each end side to the center are W.sub.11,
W.sub.12, W.sub.13, and W.sub.14 in FIG. 4B for example, the
intervals W.sub.13 and W.sub.14 near the center are equivalent, and
the intervals W.sub.11, W.sub.12, W.sub.13, and W.sub.14 have a
relationship of W.sub.14.apprxeq.W.sub.13>W.sub.12>W.sub.11
from the center to each end side.
[0048] The vaporization source 20 is a linear-shaped vaporization
source. Thus, as for the film thickness distribution on the
substrate 4, the film thickness distribution in the board width
direction should be taken into consideration. The linear
vaporization source 20 may be assumed as what is obtained by
arranging many point vaporization sources. For this reason, the
thickness distribution, in the board width direction of the
substrate 4, of a film formed by the linear vaporization source 20
can be calculated based on geometric superposition of amounts of
vapor released from the many point vaporization sources. Using this
fact, a vapor amount necessary for each assumptive point
vaporization source on the vaporization source 20 is calculated so
that the film thickness distribution in the board width direction
of the substrate 4 would be uniform. Based on the calculated vapor
amounts, conductance on the upper surface of the vaporization
container 8 is calculated per unit length. Once conductance is
calculated per unit length, conductance of each of the release
holes 13 can be calculated based on the diameter and length of the
release hole 13 and the average speed of vaporized molecules (see
Gorou Tominaga, Hiroo Kumagai, "Shinkuu no Butsuri to Ouyou,"
Shokabo Publishing Co., Ltd, 1970, or the like for example).
Accordingly, the arrangement intervals between the release holes 13
in the longitudinal direction of the vaporization container 8 are
calculated.
[0049] Calculation of the arrangement intervals of the release
holes 13 in the longitudinal direction of the vaporization
container 8 indicates as follows. The arrangement intervals between
the release holes 13 on both end sides need to be denser than the
arrangement intervals between the release holes 13 on the center
side (i.e., conductance per unit length needs to be larger on both
end sides than on the center side), in order to make the film
thickness distribution uniform in the board width direction of the
substrate 4. For this reason, in the first example, the intervals
have the relationship of
W.sub.14.apprxeq.W.sub.13>W.sub.12>W.sub.11 as mentioned
above. It should be noted that such arrangement intervals of the
release holes 13 are set under the assumption that the vapor amount
of the vaporization material 7 immediately below the release holes
13 is uniform. However, in reality, even when each vaporization
amount per unit length of the vaporization material 7 itself is
uniform, diffusion of the vapor reduces the vapor amounts of the
vaporization material 7 on both end sides of the vaporization
container 8 immediately below the release holes 13. Thus, even with
denser arrangement intervals of the release holes 13 on both end
sides (or with larger conductance on both end sides), the vapor
amounts on both end sides of the vaporization container 8 are
smaller than the estimated amounts. This hinders improvement of the
film thickness distribution in the board width direction of the
substrate 4.
[0050] Moreover, in a case of an elongated vaporization container
8, a variation in temperature of the vaporization container 8
and/or a change in state of the vaporization material 7 itself may
largely vary a vaporization state, which may possibly make the
vaporization amount ununiform in the longitudinal direction of the
vaporization container 8. Particularly, when the vaporization
material 7 is an organic material, state of the material may be
changed significantly by a temperature variation. In such case, the
vaporization amount becomes ununiform in the longitudinal
direction, and, additionally, the vaporization material 7 may be
left unevenly along with consumption of the vaporization material
7. This, as a result, makes the vaporization amount even more
ununiform in the longitudinal direction.
[0051] To solve this, in the first example, the current plate 14
having the passage holes 18 through which the vapor of the
vaporization material 7 passes is provided inside the vaporization
container 8 so that the vapor amounts of the vaporization material
7 immediately below the release holes 13 are made uniform. With
this configuration, it is possible to handle ununiform vaporization
amounts of the vaporization material 7 in the longitudinal
direction. Hereinafter, the structure of the current plate 14 will
be described with reference to FIG. 4C.
[0052] The current plate 14 is placed between the release holes 13
and the vaporization material 7 inside the vaporization container 8
so as to separate the release holes 13 side and the vaporization
material 7 side. The multiple passage holes 18 are provided to
penetrate through the current plate 14 and formed to be aligned in
two straight lines extending in the longitudinal direction of the
current plate 14. All the passage holes 18 have a circular shape
with the same diameter (with the same area). The passage holes 18
are arranged such that the intervals therebetween would be denser
toward both end portions from the center of the current plate 14 in
its longitudinal direction. In this way, conductance by the passage
holes 18 is made proportional to conductance by the release holes
13. Assuming that the intervals between the passage holes 18 from
each end side to the center are W.sub.21, W.sub.22, W.sub.23,
W.sub.24, and W.sub.25 in FIG. 4C for example, the intervals
W.sub.23, W.sub.24, and W.sub.25 near the center are mutually
equivalent, and the intervals W.sub.21, W.sub.22, W.sub.23,
W.sub.24, and W.sub.25 have a relationship of
W.sub.25.apprxeq.W.sub.24.apprxeq.W.sub.23>W.sub.22>W.sub.21
from the center to each end side.
[0053] The passage holes 18 are arranged such that the release
holes 13 and the passage holes 18 are not aligned colinearly when
viewed from the surface of the vaporization material 7, for the
following reason. The vaporization material 7 may be a material
that is easy to bump (splash), such as an organic material. When
such material bumps, the above arrangement prevents the vapor
generated by the bumping from directly passing the passage holes 18
and the release holes 13 to directly adhere to the substrate 4.
Since the arrangement prevents vapor generated by bumping from
directly adhering to the substrate 4, it is possible to
significantly improve a product quality.
[0054] It seems that the vapor amounts of the vaporization material
7 immediately below the release holes 13 should become uniform if
the passage holes 18 are arranged to have equal intervals
therebetween. However, this is also under the assumption that the
vapor amounts of the vaporization material 7 below the current
plate 14 are uniform. In reality, immediately below the current
plate 14, the vapor amounts of the vaporization material 7 on both
end sides of the vaporization container 8 decrease as well. Thus,
the amounts of vapor passing through the passage holes 18 on both
end sides of the current plate 14 are smaller than the estimated
amounts. As a result, even with denser arrangement intervals of the
release holes 13 on both end sides (or with larger conductance on
both end sides), the amounts of vapor passing through the release
holes 13 on both end sides of the vaporization container 8 are
smaller than the estimated amounts. This hinders improvement of the
film thickness distribution in the board width direction of the
substrate 4. Moreover, when there is a variation in temperature of
the vaporization container 8, a change in state of the vaporization
material 7, and/or an unevenness in the vaporization material 7,
the vaporization amounts of the vaporization material 7 become
ununiform in the longitudinal direction. As a result, the film
thickness distribution in the board width direction of the
substrate 4 is deteriorated.
[0055] Thus, the arrangement intervals between the passage holes 18
are calculated in basically the same way as the arrangement
intervals between the release holes 13. For example, a vapor amount
necessary for each assumptive point vaporization source on the
current plate 14 is calculated so that the vapor amounts
immediately below the release holes 13 would be uniform. Based on
the calculated vapor amounts, conductance on the upper surface of
the current plate 14 is calculated per unit length. Then, based on
the calculated conductance per unit length and conductance of each
of the release holes 18, the arrangement intervals between the
passage holes 18 in the longitudinal direction of the current plate
14 are calculated. Calculation of the arrangement intervals between
the passage holes 18 in the longitudinal direction of the current
plate 14 indicates as follows. The arrangement intervals between
the passage holes 18 on both end sides need to be denser than the
arrangement intervals between the passage holes 18 on the center
side (i.e., conductance per unit length needs to be larger on both
end sides than on the center side), in order to make uniform the
vapor amounts immediately below the release holes 13. For this
reason, in the first example, the intervals have the relationship
of
W.sub.25.apprxeq.W.sub.24.apprxeq.W.sub.23>W.sub.22>W.sub.21
as mentioned above. Accordingly, the arrangement intervals between
the release holes 13 and the arrangement intervals between the
passage holes 18 come to have the same arrangement tendency.
Thereby, as conductance per unit length in the longitudinal
direction, conductance by the passage holes 18 is made proportional
to conductance by the release holes 13.
[0056] In FIG. 4B described above, the arrangement intervals of the
release holes 13 having the same diameter are changed to alter
conductance per unit length in the vaporization container 8.
However, the arrangement intervals between the release holes 13 may
be set at a fixed length, and, instead, the sizes of the release
holes 13 may be changed to alter conductance per unit length.
[0057] In FIG. 4C described above, the arrangement intervals of the
passage holes 18 having the same diameter are changed to alter
conductance per unit length for the current plate 14. However, the
arrangement intervals between the passage holes 18 may be set at a
fixed length, and, instead, the sizes of the passage holes 18 may
be changed to alter conductance per unit length.
[0058] Further, the release holes 13 and the passage holes 18 each
have a circular shape in FIGS. 4B and 4C described above, but may
have a square shape, an elliptic shape, a rectangular shape, or the
like. Furthermore, one release hole 13 is associated with two
passage holes 18 but may be associated with one or otherwise many
(3 or more) passage holes 18.
[0059] According to the above structure, the current plate 14 is
provided inside the vaporization container 8, and the release holes
13 in the vaporization container 8 and the passage holes 18 in the
current plate 14 are arranged to have the positional relationship
mentioned above. Accordingly, the vapor amounts immediately below
the release holes 13 can be made uniform, which in turn increases
the amount of vapor flow on each end side compared to that on the
center side. This suppresses a decrease in film thickness at both
end portions of the substrate 4 and thus makes uniform the film
thickness distribution in the board width direction of the
substrate 4. Consequently, a thin film having a desired uniform
film thickness distribution can be obtained.
[0060] In addition, in the vacuum vapor deposition apparatus of the
first example, the vaporization sources are placed as shown in FIG.
6A or 7 to be described later so that the mixing ratio in a
deposited thin film obtained by multi-source simultaneous
deposition would remain constant in the film thickness direction.
FIG. 5A is a diagram for explaining how two vaporization sources
are placed in general, and FIG. 5B is a graph showing the profile
of the deposition amounts at certain positions in the transport
direction regarding the placement. FIG. 6A is a diagram for
explaining how two vaporizations sources are placed in the first
example, and FIG. 6B is a graph showing the profile of the
deposition amounts at certain positions in the transport direction
regarding the placement. FIG. 7 is a diagram for explaining how
three vaporization sources are placed in the first example. Note
that description will be given while showing only the substrate and
the vaporization containers inside the vaporization sources in
FIGS. 5A to 7 for simple illustration.
[0061] In general, in a case of two vaporization sources
(vaporization containers) vaporization containers 8a and 8b are
placed to tilt in such a manner that normal lines La and Lb from
the centers of release holes 13a and 13b of the vaporization
containers 8a and 8b, respectively, coincides with one another on a
deposition surface of the substrate 4, as shown in FIG. 5A. In a
case of such placement, calculation of equal-thickness surfaces 19a
and 19b for the vaporization containers 8a and 8b indicates as
follows, each of the equal-thickness surfaces 19a and 19b being
where the deposition amount of the vapor of vaporization material
released from corresponding one of release holes 13a and 13b is the
same per unit time. Specifically, the equal-thickness surfaces 19a
and 19b intersect with each other at a position where the
deposition surface of the substrate 4 intersects with the normal
lines La and Lb (also intersecting with a center line C showing the
apparatus center in FIG. 5A).
[0062] According to the cosine law, the equal-thickness surfaces
19a and 19b are desirably spherical or ellipsoidal (see Tatsuo
Asamaki, Hakumaku Sakusei no Kiso, The Nikkan Kogyo Shimbun, Ltd.,
2005, or the like for example). In the case of FIG. 5A, the
equal-thickness surfaces 19a and 19b are depicted as ellipsoidal.
In addition, the equal-thickness surfaces 19a and 19b are similar
to how soap bubbles inflate while becoming thinner. The
equal-thickness surfaces 19a and 19b indicate positions where
adhesion of equal film thickness takes place. Even when the
vaporization containers 8a and 8b have an uneven mixing ratio (an
uneven ratio of deposition amounts or film thicknesses), the
equal-thickness surfaces are depicted as having the same shape and
size. This means for example that the equal-thickness surface 19a
represents a film thickness of 100 nm, the equal-thickness surface
19b represents a film thickness of 1 nm, and thus a film having a
mixing ratio of 100:1 is formed.
[0063] From FIG. 5A, it can be seen that the equal-thickness
surfaces 19a and 19b expand from the vaporization containers 8a and
8b, respectively, and come in contact with the substrate 4 before
intersecting with each other on the substrate 4. The positions
where the equal-thickness surfaces 19a and 19b first come in
contact with the substrate 4 are positions where the thicknesses of
the films deposited from the vaporization containers 8a and 8b
become the largest.
[0064] Measurement of the deposition amounts in the height
direction of the substrate 4 at each position in a transport
direction T shows the following. As shown in FIG. 5B, the
deposition amounts with the vapors of the respective vaporization
materials take their largest values at different positions. With
these positions as the peaks, the deposition amounts each decrease
approximately symmetrically. Note that FIG. 5B is a graph showing
deposition amounts (corresponding to film thicknesses) within such
a range that the distance between the substrate 4 and the
vaporization containers 8a and 8b is 1, and the distance in the
transport direction is 4. The deposition amounts from the
vaporization containers 8a and 8b are different from each other,
but their largest deposition amounts are illustrated as being equal
for the sake of comparison. As is apparent from FIG. 5B, although
the mixing ratio in the formed film is the same as a whole, the
mixing ratio deviates at any position in the transport direction,
and the amounts of the deviation are large.
[0065] The substrate 4 is subjected to simultaneous deposition
while moving in the transport direction T. Thus, the profile shown
in FIG. 5B corresponds to the mixing ratio in the film thickness
direction of the thin film formed by the simultaneous deposition,
and the deviated mixing ratio indicates that the mixing ratio of
the deposited vaporization materials vary in the film thickness
direction of the deposited thin film. For this reason, the film is
hardly a homogeneous thin film. In recent years, there have been
demands to reduce manufacturing cost by improving the utilization
of expensive organic materials, and also to improve productivity
through high-rate film formation. These demands have been satisfied
by reducing the distances between vaporization sources and a
substrate. This in turn increases the amount of deviation in the
mixing ratio. Because the equal-thickness surfaces are actually
almost spherical, the amount of deviation in the mixing ratio
appears to be even more remarkable.
[0066] On the other hand, in the first example, in a case of two
vaporization sources (vaporization containers) (in a case of
double-source simultaneous deposition), the vaporization containers
8a and 8b are placed to tilt in such a manner that contact points
of the equal-thickness surfaces 19a and 19b, at which they come in
contact with the deposition surface of the substrate 4, would
coincide with each other on the deposition surface of the substrate
4, as shown in FIG. 6A. For example, to form a luminescent layer of
an organic EL element, a host material and a luminescent material
as vaporization materials need to be mixed and deposited. In this
case, the equal-thickness surface 19a and the equal-thickness
surface 19b are calculated in accordance with the mixing ratio of
the host material and the luminescent material. Here, the
equal-thickness surface 19a indicates where the deposition amount
of the vapor of the host material released from the release holes
13a is the same per unit time, and the equal-thickness surface 19b
indicates where the deposition amount of the vapor of the
luminescent material released from the release holes 13b is the
same per unit time. Then, the vaporization containers 8a and 8b are
placed to tilt in such a manner that contact points of the obtained
equal-thickness surfaces 19a and 19b, at which they come in contact
with the deposition surface of the substrate 4, would coincide with
each other on the deposition surface of the substrate 4.
[0067] The equal-thickness surfaces 19a and 19b described above can
be calculated through simulations of vapor flux distributions using
parameters such as the temperatures, positions, and inclinations of
the vaporization containers 8a and 8b in accordance with the types
of vaporization materials. For example, an equal-thickness surface
from one release hole 13 is a spherical or ellipsoidal matter
(whose cross section is circular or elliptic) having the release
hole 13 as its origin. Then, since the multiple release holes 13a
and 13b are arranged linearly in the respective vaporization
containers 8a and 8b, the equal-thickness surfaces 19a and 19b may
be regarded as continuously-connected spherical or ellipsoidal
matters obtained by partially superposing the spherical or
ellipsoidal matters on one another in the arrangement directions of
the respective multiple release holes 13a and 13b. That is, the
equal-thickness surfaces 19a and 19b may be regarded as elongated
matters having circular or elliptic cross sections. Therefore, when
the contact points of the equal-thickness surfaces 19a and 19b, at
which they come in contact with the deposition surface of the
substrate 4, coincides with each other on the deposition surface of
the substrate 4 at any position in the arrangement directions of
the multiple release holes 13a and 13b, the contact points of the
equal-thickness surfaces 19a and 19b, at which they come in contact
with the deposition surface of the substrate 4, is regarded as
substantially coinciding with each other on the deposition surface
of the substrate 4 at all the positions in the arrangement
directions of the multiple release holes 13a and 13b.
[0068] Meanwhile, under the same conditions, the sizes of the
equal-thickness surfaces 19a and 19b remain the same regardless of
the types of vaporization materials or film thicknesses but differ
from each other depending on the distances between the vaporization
sources and the substrate. Thus, by using the vaporization rate
detectors 10 and the vaporization rate controllers 11 to detect and
control the deposition amounts (vaporization rates) from the
vaporization containers 8a and 8b, respectively, films can be
formed with a desired mixing ratio. Nonetheless, it is desirable
that the sizes of the equal-thickness surfaces 19a and 19b of the
vaporization materials be approximately equal to each other. In
this way, it is possible to place the vaporization containers 8a
and 8b symmetrically with respect to the center line C, and also to
obtain deposition amount profiles of extremely similar shapes as
shown in FIG. 6B to be described below.
[0069] Measurement of the deposition amounts in the height
direction of the substrate 4 at each position in the transport
direction T shows the following. As shown in FIG. 6B, the
deposition amounts with the vapors of the respective vaporization
materials both take their largest values at a position where the
deposition surface of the substrate 4 intersect with the center
line C. With these positions as the peaks, the deposition amounts
each decrease symmetrically. The mixing ratio at the center line C
position is a desired mixing ratio. The mixing ratios at the other
positions deviate by a quite small margin. Nonetheless, the
deviated amounts are significantly smaller than those in FIG. 5B.
The substrate 4 is subjected to simultaneous deposition while
moving in the transport direction T. Thus, the profile shown in
FIG. 6B corresponds to the mixing ratio in the film thickness
direction of the thin film formed by the simultaneous deposition.
This profile indicates that a variation in mixing ratio of the
deposited vaporization materials can be significantly suppressed in
the film thickness direction of the deposited thin film. In sum,
the first example makes it possible to keep the mixing ratio in the
film thickness direction substantially constant and thus to form a
homogeneous thin film, thereby enabling manufacturing of an organic
EL element or the like with a higher quality.
[0070] Here, to cause the contact points of the equal-thickness
surfaces 19a and 19b, at which they come in contact with the
deposition surface of the substrate 4, to coincide with each other
on the deposition surface of the substrate 4 may be expressed as
follows. Specifically, with reference to FIG. 6B for explanation, a
position in the transport direction where the deposition amount of
the vaporization material vaporized from the vaporization container
8a reaches largest in the height direction of the substrate 4
coincides, on the deposition surface of the substrate 4, with a
position in the transport direction where the deposition amount of
the vaporization material vaporized from the vaporization container
8b reaches largest in the height direction of the substrate 4.
[0071] Further, in a case of three vaporization sources
(vaporization containers) (in a case of triple-source simultaneous
deposition) as shown in FIG. 7, the normal lines La, Lb, and Lc
from the centers of the release holes 13a, 13b, and 13c of the
vaporization containers 8a, 8b, and 8c, respectively, should not
coincide with one another on the deposition surface of the
substrate 4. Instead, equal-thickness surfaces 19a, 19b, and 19c
are calculated for the vaporization containers 8a, 8b, and 8c,
respectively. Here, each of the equal-thickness surfaces 19a, 19b,
and 19c indicates where the deposition amount of the vapor of the
vaporization material released from corresponding one of the
release holes 13a, 13b, and 13c is the same per unit time. Then,
the vaporization containers 8a, 8b, and 8c are placed to tilt in
such a manner that contact points of the equal-thickness surfaces
19a, 19b, and 19c, at which they come in contact with the
deposition surface of the substrate 4, would all coincide with one
another on the deposition surface of the substrate 4.
[0072] According to this structure, as in the case of the
double-source simultaneous deposition, the mixing ratio in the film
thickness direction is kept substantially constant and thus a
homogeneous thin film is formed. Thereby, an organic EL element
with a higher quality can be manufactured. Meanwhile, to form a
luminescent layer of an organic EL element by triple-source
simultaneous deposition, the materials in the vaporization
containers 8a and 8b on both sides should be host materials whereas
the material in the vaporization container 8c in the middle should
be a luminescent material as dopant.
Second Example
[0073] In addition to the vaporization source shown in FIG. 2, a
vaporization source shown in FIG. 8 is also applicable to the
present invention. In that case, the other configurations may be
the same as those described in the first example, and thus only the
vaporization source is illustrated here. FIG. 8 is a
cross-sectional view taken along a plane perpendicular to the
longitudinal direction of the linear-shaped vaporization
source.
[0074] As shown in FIG. 8, a vaporization source 20' of a second
example has approximately the same structure as that of the
vaporization source 20 shown in FIG. 2. However, in this structure,
nozzles 21 projecting up to an upper surface of the heat insulating
plate 17 are provided to an upper surface (surface on the substrate
4 side) of a vaporization container 8', and the release holes 13
are provided to penetrate through the nozzles 21. With the nozzles
21, the position of the upper plane of each release hole 13 in its
height direction is made as high as the position of the upper
surface of the heat insulating plate 17 in its height direction.
This eliminates a possibility of the vapor of the vaporization
material 7 adhering to the heat insulating plate 17. Accordingly,
opening portions 17b in the heat insulating plate 17 do not need to
be tapered and, instead, are formed to penetrate vertically through
the heat insulating plate 17. The other configurations are the same
as those of the vaporization source 20 shown in FIG. 2, and thus
the same components in FIG. 8 are denoted by the same reference
signs and description thereof will be omitted.
[0075] In addition, in the second example, the vaporization sources
are placed as shown in FIG. 9 or 10 so that the mixing ratio in a
deposited thin film obtained by multi-source simultaneous
deposition would remain constant in the film thickness direction.
FIG. 9 is a diagram for explaining how two vaporization sources are
placed in the second example. FIG. 10 is a diagram for explaining
how three vaporization sources are placed in the second example.
Note that description will be given also in FIGS. 9 and 10 while
showing only the substrate and the vaporization containers inside
the vaporization sources for simple illustration.
[0076] In the second example, in a case of two vaporization sources
(vaporization containers) (in a case of double-source simultaneous
deposition), equal-thickness surfaces 24a and 24b are calculated
for the vaporization containers 8a' and 8b', respectively. Here,
each of the equal-thickness surfaces 24a and 24b indicates where
the deposition amount of the vapor of the vaporization material
released from corresponding one of nozzles 21a and 21b is the same
per unit time. Then, as shown in FIG. 9, vaporization containers
8a' and 8b' are placed to stand vertically and also nozzles 21a and
21b thereof are tilted in such a manner that contact points of
equal-thickness surfaces 24a and 24b, at which they come in contact
with the deposition surface of the substrate 4, would coincide with
each other on the deposition surface of the substrate 4.
[0077] The equal-thickness surfaces 24a and 24b are calculated for
the vaporization containers 8a' and 8b', respectively. Under the
same conditions, the sizes of the equal-thickness surfaces 24a and
24b remain the same regardless of the types of vaporization
materials or film thicknesses but differ from each other depending
on the distances between the vaporization sources and the
substrate. Thus, by using the vaporization rate detectors 10 and
the vaporization rate controllers 11 to detect and control the
deposition amounts (vaporization rates) from the vaporization
containers 8a' and 8b', respectively, films can be formed with a
desired mixing. Nonetheless, it is desirable that the sizes of the
equal-thickness surfaces 24a and 24b of the vaporization materials
be approximately equal to each other. In this way, it is possible
to place the vaporization containers 8a' and 8b' symmetrically with
respect to the center line C, and also to obtain deposition amount
profile as shown in FIG. 6B described above.
[0078] In the second example too, to cause the contact points of
the equal-thickness surfaces 24a and 24b, at which they come in
contact with the deposition surface of the substrate 4, to coincide
with each other on the deposition surface of the substrate 4 means
the same as what is explained above with reference to FIG. 6B.
Specifically, a position in the transport direction where the
deposition amount of the vaporization material vaporized from the
vaporization container 8a' reaches largest in the height direction
of the substrate 4 coincides, on the deposition surface of the
substrate 4, with a position in the transport direction where the
deposition amount of the vaporization material vaporized from the
vaporization container 8b' reaches largest in the height direction
of the substrate 4. According to this structure, the mixing ratio
in the film thickness direction is kept substantially constant and
thus a homogeneous thin film is formed. Thereby, an organic EL
element with a higher quality can be manufactured.
[0079] Further, in a case of three vaporization sources
(vaporization containers) (in a case of triple-source simultaneous
deposition), the normal lines La, Lb, and Lc from the centers of
the nozzles 21a, 21b, and 21c of the vaporization containers 8a',
8b', and 8c', respectively, should not coincide with one another on
the deposition surface of the substrate 4. Instead, the
equal-thickness surfaces 24a, 24b, and 24c are calculated for the
vaporization containers 8a', 8b', and 8c', respectively. Here, each
of the equal-thickness surfaces 24a, 24b, and 24c indicates where
the deposition amount of the vapor of the vaporization material
released from corresponding one of the nozzles 21a, 21b, and 21c is
the same per unit time. Then, as shown in FIG. 10, the vaporization
containers 8a', 8b', and 8c' are placed to stand vertically and
also the nozzles 21a, 21b, and 21c thereof are tilted in such a
manner that contact points of the equal-thickness surface 24a, 24b,
and 24c, at which they come in contact with the deposition surface
of the substrate 4, would all coincide with one another on the
deposition surface of the substrate 4.
[0080] According to this structure, as in the case of the
double-source simultaneous deposition, the mixing ratio in the film
thickness direction is kept substantially constant and thus a
homogeneous thin film is formed. Thereby, an organic EL element
with a higher quality can be manufactured. Meanwhile, to form a
luminescent layer of an organic EL element by triple-source
simultaneous deposition, the materials in the vaporization
containers 8a' and 8b' on both sides should be host materials
whereas the material in the vaporization container 8c in the middle
should be a luminescent material as dopant. In the second example,
the vaporization containers 8a', 8b', and 8c' do not need to be
placed in a tilted manner, and thus can be installed easily.
INDUSTRIAL APPLICABILITY
[0081] A vacuum vapor deposition apparatus according to the present
invention is suitable particularly for a case where the deposition
target is a large substrate, and also suitable for a case where the
vaporization materials are organic materials.
REFERENCE SIGNS LIST
[0082] 1 VACUUM CHAMBER [0083] 2 VALVE [0084] 3 VACUUM PUMP [0085]
4 SUBSTRATE [0086] 5 DRIVE SOURCE [0087] 6 TRANSPORT ROLLER [0088]
7 VAPORIZATION MATERIAL [0089] 8, 8a, 8b, 8a', 8b' VAPORIZATION
CONTAINER [0090] 9 HEATER [0091] 10 VAPORIZATION RATE DETECTOR
[0092] 11 VAPORIZATION RATE CONTROLLER [0093] 12 HEATING POWER
SOURCE [0094] 13, 13a, 13b, 13c RELEASE HOLE [0095] 14 CURRENT
PLATE [0096] 15 RADIATION PREVENTIVE PLATE [0097] 16 WATER-COOLING
JACKET [0098] 17 HEAT INSULATING PLATE [0099] 18 PASSAGE HOLE
[0100] 20, 20' VAPORIZATION SOURCE [0101] 19a, 19b, 19c
EQUAL-THICKNESS SURFACE [0102] 21, 21a, 21b, 21c NOZZLE [0103] 24a,
24b, 24c EQUAL-THICKNESS SURFACE
* * * * *