U.S. patent application number 13/558809 was filed with the patent office on 2012-11-15 for manufacturing apparatus and manufacturing method of light-emitting device.
This patent application is currently assigned to Semiconductor Energy Laboratory Co., Ltd.. Invention is credited to Yoshiharu Hirakata, Takahiro Ibe, Hisao Ikeda, Shunpei Yamazaki.
Application Number | 20120285379 13/558809 |
Document ID | / |
Family ID | 40088662 |
Filed Date | 2012-11-15 |
United States Patent
Application |
20120285379 |
Kind Code |
A1 |
Hirakata; Yoshiharu ; et
al. |
November 15, 2012 |
Manufacturing Apparatus and Manufacturing Method of Light-Emitting
Device
Abstract
Demands such as higher definition, higher opening aperture, and
higher reliability on a full-color flat panel display have been
increased. Such demands are big objects in advancing higher
definition (increase in the number of pixels) of a light-emitting
device and miniaturization of each display pixel pitch with
reduction in size of the light-emitting device. An organic
compound-containing layer is selectively deposited using a laser
beam which passes through openings of a mask. An irradiated
substrate provided with a light absorption layer and a material
layer containing an organic compound and a deposition substrate
provided with first electrodes are placed so as to face each other.
The light absorption layer is heated by a laser beam which has
passed through the openings of the mask, and the organic compound
at a position overlapping with the heated region is vaporized, and
accordingly the organic compound is selectively deposited over the
deposition substrate.
Inventors: |
Hirakata; Yoshiharu; (Ebina,
JP) ; Ikeda; Hisao; (Isehara, JP) ; Ibe;
Takahiro; (Atsugi, JP) ; Yamazaki; Shunpei;
(Tokyo, JP) |
Assignee: |
Semiconductor Energy Laboratory
Co., Ltd.
|
Family ID: |
40088662 |
Appl. No.: |
13/558809 |
Filed: |
July 26, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12123902 |
May 20, 2008 |
8232038 |
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13558809 |
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Current U.S.
Class: |
118/712 |
Current CPC
Class: |
B23K 26/0732 20130101;
H01L 51/56 20130101; H01L 51/0013 20130101; B23K 26/042 20151001;
C23C 14/048 20130101; H01L 27/3218 20130101; B23K 26/0661
20130101 |
Class at
Publication: |
118/712 |
International
Class: |
B05C 9/14 20060101
B05C009/14 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 1, 2007 |
JP |
2007-147413 |
Claims
1. A manufacturing apparatus comprising: a light source unit
emitting laser light; an optical system forming the laser light
into a rectangular laser beam or a linear laser beam; a light
control unit selectively blocking or reflecting the rectangular
laser beam or the linear laser beam; a scanning unit making a light
absorption layer provided for an irradiated substrate be scanned by
a laser beam that has passed through the light control unit; and an
alignment unit performing alignment of the light control unit, the
irradiated substrate, and a deposition substrate, wherein the laser
beam that has passed through the light control unit heats the light
absorption layer, and the light absorption layer heats a first
material layer provided for the irradiated substrate so that at
least part of the first material layer is gasified, and a second
material layer is formed on the deposition substrate placed facing
the irradiated substrate.
2. The manufacturing apparatus according to claim 1, further
comprising a control apparatus controlling the light source unit,
the light control unit, and the scanning unit.
3. The manufacturing apparatus according to claim 1, wherein a long
side direction of the rectangular laser beam or the linear laser
beam and a scanning direction with the scanning unit are at right
angles to each other.
4. The manufacturing apparatus according to claim 1, wherein the
irradiated substrate is a light-transmitting substrate.
5. The manufacturing apparatus according to claim 1, wherein the
light control unit is selected from the group consisting of a
photomask, a slit, or a metal mask.
6. A manufacturing apparatus comprising: a light source unit
emitting laser light; an optical system forming the laser light
into a rectangular laser beam or a linear laser beam; a light
control unit selectively blocking or reflecting the rectangular
laser beam or the linear laser beam; a scanning unit making a gas
generation layer provided for an irradiated substrate be scanned by
a laser beam that has passed through the light control unit; and an
alignment unit performing alignment of the light control unit, the
irradiated substrate, and a deposition substrate, the irradiated
substrate being stacked with the gas generation layer and a first
material layer, wherein the laser beam that has passed through the
light control unit heats the gas generation layer provided for the
irradiated substrate to gasify the gas generation layer, and
wherein a second material layer is formed on the deposition
substrate placed facing the irradiated substrate.
7. The manufacturing apparatus according to claim 6, further
comprising a control apparatus controlling the light source unit,
the light control unit, and the scanning unit.
8. The manufacturing apparatus according to claim 6, wherein a long
side direction of the rectangular laser beam or the linear laser
beam and a scanning direction with the scanning unit are at right
angles to each other.
9. The manufacturing apparatus according to claim 6, wherein the
irradiated substrate is a light-transmitting substrate.
10. The manufacturing apparatus according to claim 6, wherein the
light control unit is selected from the group consisting of a
photomask, a slit, or a metal mask.
11-16. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a deposition apparatus used
for depositing a material which is capable of being deposited over
a substrate, and a manufacturing apparatus provided with the
deposition apparatus. The present invention also relates to a
deposition method using the deposition apparatus. The present
invention also relates to a light-emitting device including an
organic compound-containing layer, which is formed using the
deposition apparatus, as a light-emitting layer, and a
manufacturing method of the light-emitting device.
[0003] 2. Description of the Related Art
[0004] A light-emitting element using, as a luminous body, an
organic compound which has characteristics such as thinness,
lightness in weight, high-speed response, and DC drive at low
voltage, is expected to be applied to a next-generation flat panel
display. In particular, a display device in which light-emitting
elements are arranged in matrix is considered to have an advantage
in a wide viewing angle and excellent visibility over a
conventional liquid crystal display device.
[0005] A light-emitting element is said to have an emission
mechanism in which by application of voltage to a pair of
electrodes with an organic compound-containing layer interposed
therebetween, electrons injected from a cathode and holes injected
from an anode are recombined in an emission center of the organic
compound-containing layer to form molecular excitons and the
molecular excitons release energy in returning to a ground state;
accordingly light is emitted. As excited states, a singlet excited
state and a triplet excited state are known, and light emission is
considered to be possible through either of these excited
states.
[0006] For a light-emitting device in which such light-emitting
elements are arranged in matrix, a driving method such as passive
matrix driving (simple matrix type) or an active matrix driving
(active matrix type) can be used. However, when the pixel density
is increased, the active matrix type where each pixel (or each dot)
is provided with a switch is considered to be advantageous because
it is capable of lower voltage driving.
[0007] The organic compound-containing layer has a structure
typified by a stacked structure of a hole transporting layer, a
light-emitting layer, and an electron transporting layer. As a
deposition method of these organic compound material, an ink jet
method, an evaporation method, a spin coating method, or the like
are known. EL materials for forming EL layers are broadly
classified into low molecular (monomer) materials and high
molecular (polymer) materials. An evaporation apparatus is used for
depositing low molecular materials.
[0008] In a conventional evaporation apparatus, a substrate is set
on a substrate holder, and a crucible (or an evaporation boat)
which contains an EL material, that is, an evaporation material, a
shutter for preventing the rise of the EL material to be
sublimated, and a heater for heating the EL material in the
crucible are included. The EL material heated by the heater is
sublimated to be deposited on a rotating substrate. At this time,
the substrate and the crucible are kept from each other with a
distance of greater than or equal to one meter for uniform
deposition.
[0009] When manufacture of a full-color flat panel display using
emission colors of red, green, and blue is considered, because the
accuracy of deposition is not so high, pixels are designed so as to
have wide intervals therebetween, or an insulator called a bank is
provided between the pixels.
[0010] Demands such as higher definition, higher opening aperture,
and higher reliability on a full-color flat panel display using
emission colors of red, green, and blue have been increased. Such
demands are big objects in advancing higher definition (increase in
the number of pixels) of a light-emitting device and
miniaturization of each display pixel pitch with reduction in the
size of the light-emitting device. At the same time, demands such
as increase of productivity and reduction in cost have also been
increased.
[0011] The present applicants describe an example of a cross
section of an evaporation mask in Patent Document 1 (Japanese
Published Patent Application No. 2003-313654). In either
cross-sectional structure of the evaporation mask disclosed in
Patent Document 1, the vicinity of an opening of the mask is sharp.
A tapered shape is given as an example of the cross-sectional
structure of the evaporation mask.
SUMMARY OF THE INVENTION
[0012] The present invention provides a manufacturing apparatus
provided with an evaporation apparatus that is one of manufacturing
apparatuses which reduce manufacturing cost by enhancement of EL
material use efficiency and has excellent uniformity or throughput
of deposition of an EL layer, in the case where a full-color flat
panel display using emission colors of red, green, and blue is
manufactured.
[0013] Evaporation accuracy is a big problem when higher definition
(increase in the number of pixels) of a light-emitting device and
miniaturization of each display pixel pitch with reduction in the
size of the light-emitting device is advanced. At the stage before
evaporation, higher definition and miniaturization of each display
pixel pitch can be realized if the following measures are taken:
the layout of the pixels is designed so that an interval between
the pixels is small, the width of an insulator called bank (or
partition wall) provided between the pixels is reduced, or the
like. As for a conventional evaporation apparatus, however, at the
stage of evaporation, the evaporation accuracy is not enough if the
width of a bank or an interval between adjacent pixels is made to
be small, for example, less than or equal to 10 .mu.m.
[0014] In addition, it is an object of the present invention to
provide an evaporation apparatus with high evaporation accuracy
that makes it possible to promote higher definition (increase in
the number of pixels) of a light-emitting device and
miniaturization of each display pixel pitch with and reduction in
the size of the light-emitting device.
[0015] The manufacturing apparatus disclosed in this specification
includes at least a light source of laser light; an optical system
that forms laser light into a rectangular beam; a light control
unit (e.g., a mask or a slit) that selectively blocks or reflects
the rectangular laser beam; a unit for holding a substrate to be
irradiated (hereinafter, the substrate is referred to as an
irradiated substrate) (e.g., a substrate holder); a unit for
holding a substrate over which a film is to be deposited
(hereinafter, the substrate is referred to as a deposition
substrate); and a control apparatus.
[0016] In order to obtain a laser beam with intensity for forming a
thin film, a rectangular beam or a linear beam is preferable which
is condensed more easily than a planar beam with a large area that
makes the whole surface of a substrate irradiated at once.
[0017] As the light control unit, a mask, a slit, or a photomask
from which diffraction of a laser beam is less likely to occur. For
example, it is preferable to use a mask whose openings have an
inner wall that is along the laser beam direction without using a
mask in which the vicinity of an opening is sharply tapered. In
addition, the mask can be made thick in the range of greater than
or equal to 100 .mu.m and less than 1 cm because an evaporation
material does not pass through the opening of the mask unlike an
evaporation mask whose thickness is increased for increase in
deposition accuracy. It can be said that when the mask is thicker,
the mask is less subjected to influence by heat and diffraction of
the laser beam is less likely to occur. As a material for a mask or
a slit, the following is desirably used: a metal material with low
coefficient of thermal expansion that is not easily transformed by
heat (e.g., a refractory metal such as tungsten, tantalum,
chromium, nickel, or molybdenum; an alloy containing these
elements; stainless steel; inconel; or hastelloy). It is desirable
to use a mask using a material with the same coefficient of thermal
expansion as a material used for an irradiated substrate. Although
the mask can be heated at the time of laser beam irradiation,
misalignment is difficult to occur as long as the mask itself has
the same amount of expansion as the irradiated substrate.
[0018] Selective laser beam irradiation can be performed by
combination of a plurality of masks. Both a slit and a mask can
also be used.
[0019] A position of a focal point of a laser beam can be
controlled by an optical system, and thus a region which is smaller
than the opening of the mask can be partially heated. In
particular, the thicker the irradiated substrate is, the longer the
length of a light pass is, and thus, placement of the optical
system, the light control unit, and the irradiated substrate is
performed in consideration of this.
[0020] One aspect of the present invention disclosed in this
specification is a manufacturing apparatus including a light source
unit which emits laser light; an optical system which forms the
laser light into a rectangular laser beam or a linear laser beam; a
light control unit which selectively blocks or reflects the
rectangular laser beam or the linear laser beam; a scanning unit
which makes a light absorption layer provided for an irradiated
substrate be scanned by a laser beam which has passed through the
light control unit; and an alignment unit which performs alignment
of the light control unit, the irradiated substrate, and the
deposition substrate, where the laser beam which has passed through
the light control unit heats the light absorption layer and the
light absorption layer heats a first material layer provided for
the irradiated substrate, so that at least part of the first
material layer is gasified, and accordingly a second material layer
is formed over the deposition substrate placed facing the
irradiated substrate. A low molecular organic material, a high
molecular organic material, or a middle molecular organic material
which has a property between low molecule and high molecule can be
used for the first material layer. Alternatively, a composite
material of an organic material and an inorganic material can be
used for the first material layer.
[0021] In the above-described structure, as the scanning unit which
makes a surface of the light absorption layer be scanned by a laser
beam, a unit for fixing the optical system and moving the substrate
stage, or a unit for fixing the substrate stage and moving an
irradiated region with the laser beam may be used. As for the unit
for moving an irradiated region with a laser beam, a polygon minor,
a galvanometer mirror, or an acousto-optic deflector (AOD) is
desirably used.
[0022] The present invention solves at least one of the
above-described problems.
[0023] When a full-color flat panel display using emission colors
of red, green, and blue is manufactured, at least three irradiated
substrates are prepared in order to form, as appropriate, a red
light-emitting layer, a green light-emitting layer, and a blue
light-emitting layer. Although a different mask may be used for
each light-emitting layer, one mask can be used while the mask is
moved, by position adjustment of the irradiated substrate and the
mask in accordance with a position where the light-emitting layer
is to be formed. The manufacturing apparatus of the present
invention has a structure in which few organic compounds are
attached to the mask. In addition, the mask can be repeatedly used
in such a manner that one irradiated substrate prepared for forming
the light-emitting layer is reused, the positions of the mask and
the irradiated substrate are displaced, that is, the mask is moved.
Accordingly, material use efficiency can be increased. For example,
when a full-color flat panel display using light emission colors of
red, green, and blue is manufactured, after a first deposition of
the red light-emitting layer is terminated, part of a material
layer provided for the first irradiated substrate is removed, and
an area between two adjacent removed areas corresponds to an area
for two pixels. Thus, successive move of the position of the mask
enables one deposition over each of the second deposition substrate
and the third deposition substrate.
[0024] Light-emitting elements which emit light of colors other
than red, green, and blue may be used. Image display may be
performed in combination with a color of white, cyan, magenta,
amber, orange, yellow, or the like. For example, full-color display
may be performed by RGBW four-color driving by use of four kinds of
light-emitting elements.
[0025] In the above-described structure, for the light absorption
layer, a material such as gold, platinum, copper, silver, tungsten,
tantalum, titanium, or molybdenum, or an alloy material of these
materials can be used. In addition, the light absorption layer can
also be referred to as a heat generation layer.
[0026] A layer which generates gas when irradiated with light (also
referred to as a gas generation layer) may be used instead of the
light absorption layer. A gas generation layer and a layer
containing an organic compound are stacked over an irradiated
substrate, laser light is selectively emitted through a mask to
generate gas, and the layer containing an organic compound is
selectively separated, and accordingly the layer containing an
organic compound layer is deposited over a deposition
substrate.
[0027] Another aspect of the present invention is a manufacturing
apparatus including a light source unit which emits laser light; an
optical system which forms the laser light into a rectangular laser
beam or a linear laser beam; a light control unit which selectively
blocks or reflects the rectangular laser beam or the linear laser
beam; a scanning unit which makes a gas generation layer provided
over an irradiated substrate be scanned by a laser beam which has
passed through the light control unit; and an alignment unit which
performs alignment of the light control unit, the irradiated
substrate stacked with the gas generation layer and a first
material layer, and a deposition substrate, where the laser beam
which has passed through the light control unit heats the gas
generation layer provided for the irradiated substrate to gasify
the gas generation layer, and accordingly a second material layer
is formed over the deposition substrate placed facing the
irradiated substrate. A low molecular organic material, a high
molecular organic material, or a middle molecular material which
has a property between low molecule and high molecule can be used
for the first material layer. Alternatively, a composite material
of an organic material and an inorganic material can be used for
the first material layer.
[0028] In the above-described structure, for the layer which
generates gas when irradiated with light, an amorphous silicon film
containing hydrogen; an azide compound or a diazo compound which
generates gas when irradiated with ultraviolet rays and
decomposition is generated; a resin composition in which
microscopic bubbles are included; or the like can be used.
[0029] Another aspect of the present invention is a manufacturing
method of a light-emitting device, including the steps of forming a
layer which generates gas by light irradiation over one of surfaces
of an irradiated substrate; forming a material layer over the gas
generation layer; placing a deposition substrate so that one of
surfaces of the deposition substrate faces the one of the surfaces
of the irradiated substrate; and emitting light which passes
through the other surface of the irradiated substrate to the gas
generation layer to deposit a material layer over the one of the
surfaces of the deposition substrate. Light may be selectively
emitted to the gas generation layer by use of a photomask, a metal
mask, or a slit to selectively deposit the material layer over the
one of the surfaces of the deposition substrate. When a photomask,
a metal mask, a slit, or the like is used, the small size of an
opening thereof makes it easier for the material layer to be
deposited over the one of the surfaces of the deposition
substrate.
[0030] As for the above-described manufacturing method, the light
is not limited to a laser beam. An electric discharge lamp such as
a flash lamp (e.g., a xenon flash lamp or a krypton flash lamp), a
xenon lamp, or a metal halide lamp; a heat generation lamp such as
a halogen lamp or a tungsten lamp can be used.
[0031] As the light source of laser light, one or more of the
following can be used: a gas laser such as an Ar laser, a Kr laser,
or an excimer laser; a laser of which medium is single crystal YAG,
YVO.sub.4, forsterite (Mg.sub.2SiO.sub.4), YAlO.sub.3, or
GdVO.sub.4, or polycrystalline (ceramic) YAG, Y.sub.2O.sub.3,
YVO.sub.4, YAlO.sub.3, or GdVO.sub.4, added with one or more of Nd,
Yb, Cr, Ti, Ho, Er, Tm, and Ta as a dopant; a glass laser; a ruby
laser; an alexandrite laser; a Ti:sapphire laser; a copper vapor
laser; or a gold vapor laser. When a solid-state laser whose laser
medium is solid is used, there are advantages in that a
maintenance-free condition can be maintained for a long time and
output is relatively stable.
[0032] The control apparatus includes a memory portion (e.g., RAM
or ROM) for storing design data of a semiconductor device and a
microprocessor including a CPU or the like and controls a position
of a surface of the irradiated substrate which is to be irradiated
with laser light which has passed through the light control unit.
For example, when a stage to which the deposition substrate is
fixed is moved, emission timing of the laser light source and
moving speed of the stage are synchronized. In order to prevent a
mask to be heated, on and off of the laser light source is
controlled with use of the control apparatus and a laser beam may
be selectively emitted to a band-like region including openings of
the mask while the stage is moved. In the present invention, it is
not particularly necessary that the whole light absorption layer or
the whole gas generation layer be scanned by laser light.
[0033] There is no particular limitation on the shape of the
openings of the mask seen from above. Pixel arrangements such as a
mosaic type in which sequential arrangement in a column direction
or a row direction is performed, a delta type in which unit pixels
are arranged in a zigzag manner in a column direction, and a stripe
type in which light-emitting elements which emit light of the same
color are arranged per pixel column can be realized using the
mask.
[0034] Note that the light-emitting device in this specification
refers to a light-emitting device or a light source (including a
lighting system in its category) without limitation to a
light-emitting device that is capable of full-color display. In
addition, the light-emitting device includes any of the following
modules in its category: a module in which a connector such as an
FPC (flexible printed circuit), a TAB (tape automated bonding)
tape, or a TCP (tape carrier package) is attached to a
light-emitting device; a module having a TAB tape or a TCP provided
with a printed wiring board at the end thereof; and a module having
an IC (integrated circuit) directly mounted over a light-emitting
element by a COG (chip on glass) method.
[0035] Material use efficiency is increased by the manufacturing
apparatus of the present invention, whereby manufacturing cost can
be reduced. In addition, since an area of a region to be vaporized
or the amount of material to be vaporized is limited by the
manufacturing apparatus of the present invention, whereby
attachment of a vaporized material to an inner wall of a deposition
chamber can be suppressed. Thus, frequency of cleaning of the
deposition chamber can be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] In the accompanying drawings:
[0037] FIG. 1 is a perspective view illustrating a manufacturing
apparatus;
[0038] FIGS. 2A to 2C are cross-sectional views illustrating a
manufacturing method of a light-emitting device;
[0039] FIGS. 3A and 3B are views each illustrating a positional
relationship between openings of a mask and a region irradiated
with a laser beam;
[0040] FIGS. 4A and 4B are views each illustrating a positional
relationship between openings of a mask and a region irradiated
with a laser beam;
[0041] FIG. 5 is a view illustrating a positional relationship
between openings of a mask and a region irradiated with a laser
beam;
[0042] FIGS. 6A to 6C are cross-sectional views illustrating a
manufacturing method of a light-emitting device;
[0043] FIG. 7A is a top view of a passive matrix light-emitting
device and FIGS. 7B and 7C are cross-sectional views each
illustrating the same;
[0044] FIG. 8 is a perspective view of a passive matrix
light-emitting device;
[0045] FIG. 9 is a top view of a passive matrix light-emitting
device;
[0046] FIGS. 10A and 10B are views illustrating a structure of a
light-emitting device;
[0047] FIGS. 11A to 11E are diagrams illustrating examples of
electronic devices; and
[0048] FIG. 12 is a diagram illustrating an example of an
electronic device.
DETAILED DESCRIPTION OF THE INVENTION
[0049] Embodiment Modes of the present invention will be
hereinafter described.
Embodiment Mode 1
[0050] FIG. 1 is a perspective view illustrating an example of a
manufacturing apparatus of the present invention. Laser light to be
emitted is output from a laser oscillator 103 (e.g., a YAG laser
apparatus or an excimer laser apparatus); the laser light passes
through a first optical system 104 for forming a laser beam into a
rectangular laser beam, a second optical system 105 for shaping the
laser beam, and a third optical system 106 for collimating the
laser beam; and an optical path is changed into a direction
perpendicular to an irradiated substrate 101 by use of a reflecting
mirror 107. After that, the laser beam passes through a mask 110
having openings which selectively transmits light so that a light
absorption layer 114 is irradiated with the laser beam.
[0051] A material which can be resistant to irradiation with laser
light is used for the mask 110 having the openings. In addition, a
mask whose openings have an inner wall that is along the laser beam
direction is used without using a mask in which the vicinity of an
opening is sharply tapered.
[0052] The shape of a laser spot with which a layer (a light
absorption layer or a gas generation layer) provided for the
irradiated substrate is irradiated is desirably rectangular or
linear. Specifically, a rectangular laser spot, a short side of
which is 1 to 5 mm and a long side of which is 10 to 50 mm may be
used. When a large-area substrate is used, it is desirable that the
long side of the laser spot be 20 to 100 cm in order to shorten the
processing time. In addition, a plurality of laser oscillators and
optical systems shown in FIG. 1 may be provided to process a
large-area substrate in a short time. Specifically, a laser beam
may be emitted from each of the plurality of laser oscillators so
that the area to be processed of one substrate is divided by the
laser beams.
[0053] Note that FIG. 1 shows an example, and there is no
particular limitation on a positional relationship of each optical
system or electrooptical element placed along the path of laser
light. For example, a reflective mirror is not needed to use if the
laser oscillator 103 is placed above the irradiated substrate 101
so that laser light emitted from the laser oscillator 103 is
perpendicular to a principle plane of the irradiated substrate 101.
As each optical system, a collective lens, a beam expander, a
homogenizer, a polarizer, or the like may be used, or these may be
combined. In addition, as each optical system, a slit may be used
in combination.
[0054] Scan by a laser beam is two-dimensionally performed as
appropriate with respect to an irradiated surface, whereby a large
area of the substrate is irradiated with the laser beam. The
irradiated region with the laser beam and the substrate are
substantially moved so that scanning can be performed. In this
embodiment mode, scanning is performed by a moving unit (not shown)
which moves the substrate stage 109 which is holding the substrate
in a horizontal direction.
[0055] The control device 116 is desirably interlocked so that it
can also control the moving unit which moves the substrate stage
109 in the horizontal directions. In addition, the control device
116 is desirably interlocked so that it can also control the laser
oscillator 103. Moreover, the control device 116 is preferably
interlocked with a position alignment system which has an image
pickup device 108 for recognizing position markers.
[0056] The position alignment system aligns the mask 110, the
irradiated substrate 101, and a deposition substrate 100. Although
the mask 110 and the irradiated substrate 101 may be arranged so as
to be in contact with each other, the mask 110 and the irradiated
substrate 101 preferably have an interval therebetween in order to
prevent conduction of heat from the mask 110.
[0057] The light absorption layer 114 and a material layer 115 are
stacked in this order in advance over one of surfaces of the
irradiated substrate 101 which is irradiated with a laser beam. A
heat resistance metal is desirably used for the light absorption
layer 114. For example, tungsten, tantalum, or the like is
used.
[0058] The irradiated substrate 101 and the deposition substrate
100 are placed so that interval d therebetween is at least less
than or equal to 5 mm. In addition, when the deposition substrate
100 is provided with an insulator which serves as a partition wall,
the insulator and the material layer 115 may be placed so as to be
in contact with each other.
[0059] When deposition is performed with use of the manufacturing
apparatus shown in FIG. 1, at least the irradiated substrate 101
and the deposition substrate 100 are placed in a vacuum chamber.
Alternatively, all the components shown in FIG. 1 may be placed in
a vacuum chamber.
[0060] Although the manufacturing apparatus shown in FIG. 1 is an
example of a so-called face-up deposition apparatus in which a
deposition surface of the deposition substrate 100 faces upward, a
face-down deposition apparatus may also be employed. When the
deposition substrate 100 is a large-area substrate, a so-called
vertical placement apparatus may also be employed in which a main
plane of the deposition substrate 100 is perpendicular to a
horizontal plane in order to suppress distortion of the center of
the substrate due to its own weight.
[0061] When a cooling unit for cooling the deposition substrate 100
is provided, a flexible substrate such as a plastic substrate can
be used as the deposition substrate 100.
[0062] When a plurality of manufacturing apparatuses described in
this embodiment mode is provided, a multi-chamber manufacturing
apparatus can be obtained. Needless to say, combination with a
deposition apparatus which employs another deposition method is
possible. In addition, when a plurality of manufacturing
apparatuses described in this embodiment mode is arranged in
series, an in-line manufacturing apparatus can be obtained.
Embodiment Mode 2
[0063] In this embodiment mode, FIGS. 2A to 2C show states before
and after deposition with use of the manufacturing apparatus shown
in FIG. 1.
[0064] A light-transmitting glass substrate is used as an
irradiated substrate 200. A light absorption layer 201 is formed
over the irradiated substrate 200, and an organic
compound-containing layer 202 is formed over the light absorption
layer (FIG. 2A).
[0065] The light absorption layer 201 is formed using a target such
as tantalum, titanium, molybdenum, or tungsten or a target using an
alloy of these metals by a sputtering method or the like. In this
embodiment mode, a tungsten film is formed to a thickness of 100 nm
by a sputtering method. The light absorption layer 201 is formed to
a thickness of greater than or equal to 10 nm, whereby the light
absorption layer 201 can absorb a laser beam and generate heat.
Note that part of a laser beam may be transmitted through the light
absorption layer 201 as long as the light absorption layer 201
generates heat till the sublimation temperature of the organic
compound contained in the organic compound-containing layer 202.
Note that, when part of a laser beam is transmitted through the
light absorption layer 201, an organic compound which is not
decomposed even by laser beam irradiation is desirably used.
[0066] For the organic compound-containing layer 202, liquid in
which an organic compound (or a precursor thereof) is dissolved or
dispersed in a solvent is applied as application liquid by a wet
process such as a spin coating method, a spray coating method, or a
dip coating method. A composite material of an inorganic material
such as molybdenum oxide and an organic material may be used for
the organic compound-containing layer 202. The organic compound is
desirably soluble or dispersive in a solvent. The thickness and
uniformity of an organic compound-containing layer 211 which is to
be formed over a deposition substrate 206 in a later step depend on
the control of this application liquid. Therefore, it is important
to uniformly dissolve or disperse the organic compound in the
application liquid. When a spin coating method is used, the film
thickness can be controlled by the viscosity of the application
liquid, the rotation number of the substrate, or the like.
[0067] As a solvent, a polar solvent or a nonpolar solvent is used.
As a polar solvent, there are THF, acetonitrile, dichloromethane,
dichloroethane, and anisole in addition to water, and lower alcohol
such as methanol, ethanol, n-propanol, i-propanol, n-butanol, and
sec-butanol, and some of these solvents may be mixed to be used. As
a nonpolar solvent, there are hexane, benzene, toluene, chloroform,
ethyl acetate, tetrahydrofuran, methylene chloride, and the like,
and some of these solvents may be mixed to be used.
[0068] The organic compound may be selected as appropriate from
light-emitting substances described below in accordance with a
solvent to be used. For example, in order to obtain reddish light
emission, a substance which exhibits light emission having a peak
of an emission spectrum at 600 to 680 nm may be used as a
light-emitting substance, such as
4-dicyanomethylene-2-isopropyl-6-[2-(1,1,7,7-tetramethyljulolidine-9-y-
l)ethenyl]-4H-pyran (DCJTI);
4-dicyanomethylene-2-methyl-6-[2-(1,1,7,7-tetramethyljulolidine-9-yl)ethe-
nyl]-4H-pyran (DCJT),
4-dicyanomethylene-2-tert-butyl-6-[2-(1,1,7,7-tetramethyljulolidine-9-yl)-
ethenyl]-4H-pyran (DCJTB), periflanthene, or
2,5-dicyano-1,4-bis[2-(10-methoxy-1,1,7,7-tetramethyljulolidine-9-yl)ethe-
nyl]benzene.
[0069] In order to obtain greenish light emission, a substance
which exhibits light emission having a peak of an emission spectrum
at 500 to 550 nm may be used as a light-emitting substance, such as
N,N'-dimethylquinacridon (DMQd), coumarin 6, coumarin 545T, or
tris(8-quinolinolato)aluminum (Alq.sub.3).
[0070] In order to obtain bluish light emission, a substance which
exhibits light emission having a peak of an emission spectrum at
420 to 500 nm may be used as a light-emitting substance, such as
9,10-bis(2-naphthyl)-tert-butylanthracene (t-BuDNA),
9,9'-bianthryl, 9,10-diphenylanthracene (DPA),
9,10-bis(2-naphthyl)anthracene (DNA),
bis(2-methyl-8-quinolinolato)-4-phenylphenolato-gallium (BGaq), or
bis(2-methyl-8-quinolinolato)-4-phenylphenolato-aluminum
(BAIq).
[0071] There is also no particular limitation on the substance
which is used with the light-emitting substance in order to
disperse the light-emitting substance, and the following can be
used, for example: an anthracene derivative such as
9,10-di(2-naphthyl)-2-tert-butylanthracene (t-BuDNA), a carbazole
derivative such as 4,4'-bis(N-carbazolyl)biphenyl (CBP); a metal
complex such as bis[2-(2-hydroxyphenyl)pyridinato]zinc
(Znpp.sub.2), or bis[2-(2-hydroxyphenyl)benzoxazolato]zinc (ZnBOX);
or the like.
[0072] Then, the deposition substrate 206 is placed at a position
facing the surface of the irradiated substrate for which the light
absorption layer 201 and the organic compound-containing layer 202
are provided. In this specification, a first electrode refers to an
electrode which serves as an anode or a cathode of a light-emitting
element. In the light-emitting element, a first electrode, an
organic compound-containing layer over the first electrode, and a
second electrode over the organic compound-containing layer are
included. One of the electrodes, which is formed earlier than the
other in the formation order is referred to as a first electrode.
Edge portions of the first electrode 207 are covered with
insulators 208. It is desirable to use a material having a high
work function as a material used for the first electrode 207. For
example, a stacked structure of a titanium nitride film and a film
containing aluminum as its main component; a three-layer structure
of a titanium nitride film, a film containing aluminum as its main
component, and a titanium nitride film; or the like can be used as
well as a single layer of an indium tin oxide film, an indium tin
oxide film containing silicon, an indium zinc oxide film, a
titanium nitride film, a chromium film, a tungsten film, a zinc
film, a platinum film, or the like.
[0073] In addition, a mask 205 having openings is placed at a
position facing the other surface of the irradiated substrate 200
(FIG. 2B).
[0074] Then, a rectangular laser beam is emitted to the mask 205,
and a surface of the light absorption layer 201 is scanned by a
laser beam which has passed through the openings of the mask 205.
Regions of the light absorption layer 201 which are irradiated with
the laser beam generate heat, and the organic compound is gasified
by use of the heat energy. The gasified organic compound is
attached onto the first electrodes 207. Since interval d between
the deposition substrate 206 and the irradiated substrate 200 is
less than or equal to 5 mm, which is short, then organic
compound-containing layers 211 each of which has an area that is
almost the same as the area of the opening of the mask are
deposited over the deposition substrate 206 (see FIG. 2C). Note
that the deposition is performed in a reduced-pressure atmosphere.
The reduced-pressure atmosphere is obtained in such a manner that a
chamber is evacuated by an evacuation unit to the degree of vacuum
of less than or equal to 5.times.10.sup.-3 Torr (0.665 Pa),
preferably 10.sup.-4 to 10.sup.-6 Pa.
[0075] Although FIG. 2C shows an example in which laser light is
emitted perpendicularly to a main plane of the irradiated
substrate, the present invention is not limited thereto, and the
laser light may be obliquely emitted to the main plane of the
irradiated substrate. For example, a focal length is changed by
control of the thickness of an optical system or the irradiated
substrate, whereby the organic compound-containing layer with an
area that is smaller than the area of the opening of the mask can
also be deposited over the deposition substrate.
[0076] Next, the second electrode is formed by an electron beam
evaporation method. Aluminum or silver, or an alloy thereof is used
for the second electrode. Through the above-described steps, the
light-emitting element can be formed.
[0077] Although FIG. 2C is a view showing that the organic
compound-containing layer 202 at regions which overlap with the
regions irradiated with the laser beam disappears, the present
invention is not limited thereto. When a polymer in which an
organic compound is dispersed is used for the organic
compound-containing layer, the organic compound may be selectively
gasified so that the polymer remains.
[0078] In addition, although FIG. 2C shows an example in which
deposition is performed on each of the adjacent first electrodes
207 in one deposition step, light-emitting layers which emit light
of different colors are formed in different regions in a plurality
of deposition steps when a full-color display device is
manufactured.
[0079] A manufacturing example of a light-emitting device that is
capable of full color display is described below. In this
embodiment mode, an example of a light-emitting device using
light-emitting layers which emit light of three colors is
described.
[0080] Three irradiated substrates each of which is the substrate
shown in FIG. 2A are prepared. A different organic
compound-containing layer is formed over each of the irradiated
substrates. Specifically, the first irradiated substrate provided
with a material layer for a red light-emitting layer, the second
irradiated substrate provided with a material layer for a green
light-emitting layer, and the third irradiated substrate provided
with a material layer for a blue light-emitting layer are
prepared.
[0081] In addition, one deposition substrate provided with first
electrodes is prepared. Note that it is desirable to provide an
insulator which covers edge portions of each of the first electrode
and serves as a partition wall so that the adjacent first
electrodes are not short-circuited. A region which serves as a
light-emitting region corresponds to part of the first electrode,
that is, a region which does not overlap with the insulator and is
exposed.
[0082] Then, the deposition substrate and the first irradiated
substrate are stacked. Furthermore, a mask 14 is put over the first
irradiated substrate, and the positions of the mask 14 and the
irradiated substrate are adjusted. The mask 14 is provided with
openings 16 each of which has a size that is almost the same as
that of one light-emitting region. The mask 14 is desirably
provided with a marker for position adjustment because adjustment
of the positions of the openings 16 and the first electrodes
provided for the deposition substrate is needed. The deposition
substrate is also desirably provided with the marker for position
adjustment. Since the first irradiated substrate is provided with a
light absorption layer, the light absorption layer near the marker
for position adjustment is desirably removed in advance. In
addition, since the first irradiated substrate is provided with the
material layer for the red light-emitting layer, the material layer
for the red light-emitting layer near the marker for position
adjustment is also desirably removed in advance.
[0083] Then, a linear laser beam is emitted so that a long side
direction of the linear laser beam is parallel to the short side of
the rectangular opening 16, and scanning is performed in a long
side direction of the rectangular opening 16. Using the mask
provided with the openings 16 each of which has a size that is
almost the same as that of one pixel makes it possible to prevent
formation of the material layer between adjacent pixels. The mask
having the openings 16 makes it possible to provide a contact
portion between the adjacent pixels. That is, in a light-emitting
element including the first electrodes and second electrodes over
the first electrodes, contact holes for wirings to be electrically
connected to the second electrodes provided over the first
electrodes can be fowled between the adjacent first electrodes. If
openings are arranged in stripes, each of which is longer than the
total length of two pixels arranged in a lengthwise direction, a
material layer can be formed between the two pixels, and thus a
step of removing the material layer is needed.
[0084] In a region which is irradiated with a laser beam which has
passed through the opening 16, the light absorption layer generates
heat and an organic compound contained in the material layer for
the red light-emitting layer, which is in contact with the light
absorption layer, is vaporized, whereby a first deposition is
performed onto the first electrode provided over the deposition
substrate. After the first deposition, the first irradiated
substrate is moved away from the deposition substrate.
[0085] Next, the second irradiated substrate is put over the
deposition substrate. Then, the same mask 14 is put over the second
irradiated substrate and the deposition substrate in such a manner
that the position of the mask 14 is shifted by one pixel from the
position at the time of the first deposition.
[0086] Then, a linear laser beam is emitted so that a long side
direction of the linear laser beam is parallel to the short side of
the rectangular opening 16, and scanning is performed in a long
side direction of the rectangular opening 16.
[0087] In a region which is irradiated with a laser beam which has
passed through the opening 16, the light absorption layer generates
heat and an organic compound contained in the material layer for
the green light-emitting layer, which is in contact with the light
absorption layer, is vaporized, whereby a second deposition is
performed onto the first electrode provided over the deposition
substrate. After the second deposition, the second irradiated
substrate is moved away from the deposition substrate.
[0088] Next, the third irradiated substrate is put over the
deposition substrate. Then, the same mask 14 is put over the third
irradiated substrate and the deposition substrate in such a manner
that the position of the mask 14 is shifted by two pixels from the
position at the time of the first deposition.
[0089] Then, a linear laser beam is emitted so that a long side
direction of the linear laser beam is parallel to the short side of
the rectangular opening 16, and scanning is performed in a long
side direction of the rectangular opening 16, whereby third
deposition is performed. FIG. 3A is a top view illustrating the
state immediately before the third deposition is performed. Exposed
regions of the first electrodes which are not covered with an
insulator 20 is located at the positions which of which overlaps
with the opening 16. The direction indicated by an arrow in FIG. 3A
is a scanning direction 11, and an irradiated region 10 of the
linear laser beam is substantially moved. Note that first films 21
which have been formed in the first deposition step and second
films 22 which have been formed in the second deposition step are
located under regions indicated by the dotted lines in FIG. 3A.
[0090] After third films 23 are formed in the third deposition
step, the mask 14 and the third irradiated substrate are moved away
from the deposition substrate. FIG. 3B is a top view illustrating
the state.
[0091] Accordingly, the first films 21, the second films 22, and
the third films 23 are selectively deposited at regular intervals.
Then, the second electrodes are formed over these films by an
electron beam evaporation method. Thus, the light-emitting elements
are formed.
[0092] Through the above-described steps, a full-color display
device can be manufactured.
[0093] Although the example in which the openings 16 of the mask 14
are rectangular is described in this embodiment mode, the present
invention is not limited thereto, and stripe openings shown in FIG.
1 may be employed. In the case where the stripe openings are
employed, although deposition is also performed between
light-emitting regions which emit color of the same color, the film
is formed over the insulator 20, and thus the portion which
overlaps with the insulator 20 does not serve as a light-emitting
region.
[0094] In addition, there is no particular limitation on the
alignment of the pixels. The shape of one pixel may be polygonal,
for example, hexagonal as shown in FIG. 4B, and a full-color
display may be realized by placement of first films (R) 41, second
films (G) 42, and third films (B) 43. The polygonal pixels shown in
FIG. 4B are formed in such a manner that deposition is performed
while relatively moving the irradiated region 10 in the scanning
direction 11, with the laser beam with use of a mask 34 having
hexagonal openings 36 shown in FIG. 4A.
[0095] In addition, the number of deposition steps for forming the
light-emitting layers which emit light of three colors is not
limited to three, and the larger number of deposition steps may be
employed for forming the light-emitting layers. For example, a mask
54 shown in FIG. 5 is used for the first deposition, and the first
irradiated substrate is scanned by a laser beam with the mask 54
shifted by three pixels while the first irradiated substrate keeps
the position, and thus the second deposition is performed.
Deposition is repeated in this manner, and accordingly formation of
the first films (R) is terminated. Then, the second films (G) and
the third films (B) are formed in the same manner. This deposition
method makes it possible to reduce the number of openings of the
mask and increase the interval between the adjacent openings; thus,
the processing accuracy of the mask can be increased. Although, in
the openings shown in FIG. 3A, a plurality of regions of the light
absorption layer which is heated by the laser beam at the same time
is adjacent to one another, in the case where the alignment of the
openings shown in FIG. 5 is employed, the number of light
absorption layers which are heated by the laser beam at the same
time is decreased and an effect of heat conduction can be
suppressed. In addition, not only can the interval between the
light-emitting regions arranged in row be reduced but also the
interval between the light-emitting regions arranged in column can
be reduced.
[0096] Although the example in which the long side direction of the
linear laser beam and the scanning direction of the scanning unit
are at right angles to each other is described, the present
invention is not particularly limited thereto. Moreover, there is
no particular limitation on the relationship between the openings
of the mask and the scanning direction of the laser beam. Scanning
may be performed in a direction which is perpendicular to the
diagonal of the rectangular opening or in a direction which is
parallel thereto. Also in this case, the number of light absorption
layers which are heated by the laser beam at the same time is
reduced, and an effect of heat conduction can be suppressed. A
light-transmitting glass substrate is a substrate through which
heat is not easily conducted, a mask is heated, and there is little
possibility that the heat is conducted to the light absorption
layer. However, an effect of heat conduction can occur depending on
the scanning speed or the intensity of the laser beam, and
therefore the scanning speed or the intensity of the laser beam is
controlled as appropriate.
[0097] This embodiment mode can be freely combined with Embodiment
Mode 1.
Embodiment Mode 3
[0098] An example in which a gas generation layer which generates
gas when irradiated with light is used instead of a light
absorption layer will be shown in FIGS. 6A to 6C while the example
in which the light absorption layer is used is described in
Embodiment Mode 2.
[0099] An irradiated substrate 300 is prepared. A
light-transmitting quartz substrate is used as the irradiated
substrate 300, a gas generation layer 301 is formed over the
irradiated substrate 300, and an organic compound-containing layer
302 is formed over the gas generation layer 301 (FIG. 6A).
[0100] For the gas generation layer 301, an amorphous silicon film
containing hydrogen at a concentration of greater than or equal to
2 at. % and less than or equal to 20 at. %; an azide compound or a
diazo compound which generates gas by decomposition generated when
irradiated with ultraviolet rays; a resin composition in which
microscopic bubbles are included; or the like is used. In this
embodiment mode, as the gas generation layer 301, an amorphous
silicon film containing hydrogen at a concentrating of 8 at. %
formed by a plasma CVD method is used.
[0101] The same material as the organic compound-containing layer
202 described in Embodiment Mode 2 may be used for the organic
compound-containing layer 302. In addition, an aggregate
(preferably, with the number of molecules of less than or equal to
10) of organic compounds which do not have a sublimation property
or solubility can be used for the organic compound-containing layer
302. Moreover, a low molecular organic material, a high molecular
organic material, or a middle molecular organic material which has
a property between low molecule and high molecule can be used as
the organic compound-containing layer 302. Furthermore, a composite
material of an organic material and an inorganic material can be
used as the organic compound-containing layer 302. A middle
molecular organic material refers to an organic compound, a chained
molecule of which has a length of less than or equal to 5 .mu.m,
preferably less than or equal to 50 nm, or an aggregate
(preferably, with the number of molecules of less than or equal to
10) of organic compounds which do not have a sublimation property
or solubility.
[0102] Then, a deposition substrate 306 is placed at a position
facing a surface of the irradiated substrate for which the gas
generating layer 301 and the organic compound-containing layer 302
are provided. In this embodiment mode, the deposition substrate 306
is placed so that an insulator 308 provided for the deposition
substrate and the organic compound-containing layer 302 provided
for the irradiated substrate 300 are in contact with each
other.
[0103] Next, a mask 305 having openings is placed at a position
facing the other surface of the irradiated substrate 300 (FIG.
6B).
[0104] Then, a rectangular leaser beam is emitted to the mask 305,
and a surface of the gas generation layer 301 is scanned by a laser
beam which has passed through the openings of the mask. Regions of
the gas generating layer 301 which are irradiated with the laser
beam generate gas, and part of the organic compound-containing
layer 302 is separated. Since the organic compound-containing layer
302 is thin, it is separated by ablation of the gas generation
layer 301 and is attached onto first electrodes 307. In addition,
since the gas generation layer 301 is removed, the organic
compound-containing layer 302 is irradiated with the laser beam,
and then it is firmly attached to the surfaces of the first
electrodes 307. Accordingly, an organic compound-containing layers
311 are deposited over the deposition substrate 306 (FIG. 6C). Note
that the deposition is performed using atmospheric pressure under
an inert gas atmosphere from which moisture is removed.
Alternatively, the deposition can be performed under a reduced
pressure atmosphere.
[0105] Since the laser beam is emitted even after the organic
compound-containing layers 302 are attached to the surfaces of the
first electrodes 307, the following may also be used as the organic
compound-containing layer 302: a thin film to which liquid in which
a monomer (an organic compound) which is photo-polymerized is
dissolved or dispersed in a solvent is applied as application
liquid by a wet process such as a spin coating method, a spray
coating method, or a dip coating method. The monomer which is
photo-polymerized may be selected as appropriate from the following
organic substances in accordance with a solvent to be used, for
example: monomers having an unsaturated double bond group such as a
vinyl group (C.dbd.C--) such as N-vinylcarbazole or
9,9'-dimethyl-2-binylfluorene; an acroyl group (C.dbd.C--COO--);
and an allyl group (C.dbd.C--C--). As a photopolymerization
initiator, the following may be used, for example:
2-chlorothiochitosan; benzophenone; a keton-based
photopolymerization initiator such as Michler's ketone; an
acetophenone-based photopolymerization initiator such as
diethoxyacetophenone or 2-hydroxy-2-methyl-1-phenylpropane-1-on;
benzyl; or the like.
[0106] In addition, if necessary, a process for heating the organic
compound-containing layer 311 may be performed. In this embodiment
mode, fine powder of silicon can be attached to the surfaces of the
organic compound-containing layers 311 because the amorphous
silicon film is used. In that case, a process for washing the
surfaces of the organic compound-containing layers 311 may be
performed. When a diazo compound is used instead of the amorphous
silicon film containing hydrogen as the gas generation layer 301,
the gas generation layer 301 is gasified, and thus a washing
process is not needed.
[0107] This embodiment mode can be freely combined with Embodiment
Mode 1 or Embodiment Mode 2.
[0108] The present invention including the above-described
structure is described in more detail in embodiments below.
Embodiment 1
[0109] In this embodiment, an example of manufacturing a passive
matrix light-emitting device over a glass substrate will be
described with reference to FIGS. 7A to 7C, FIG. 8, and FIG. 9.
[0110] In a passive matrix (simple matrix) light-emitting device, a
plurality of anodes arranged in stripes and a plurality of cathodes
arranged in stripes are provided so as to intersect at right
angles, and a light-emitting layer or a fluorescent layer is
interposed at each intersecting point of the anode and the cathode.
Thus, a pixel at an intersection of an anode which is selected (to
which voltage is applied) and a cathode which is selected emits
light.
[0111] FIG. 7A is a top view of a pixel portion before sealing.
FIG. 7B is a cross-sectional view taken along a dashed line A-A' in
FIG. 7A. FIG. 7C is a cross-sectional view taken along a dashed
line B-B' in FIG. 7A.
[0112] An insulating film 1504 is formed as a base insulating film
over a first substrate 1501. Note that the insulating film 1504 is
not necessarily formed if the base insulating film is not needed. A
plurality of first electrodes 1513 is arranged in stripes at
regular intervals over the insulating film 1504. A partition wall
1514 having openings corresponding to pixels is provided over the
first electrodes 1513. The partition wall 1514 having openings is
formed using an insulating material (a photosensitive or
nonphotosensitive organic material (e.g., polyimide, acrylic,
polyamide, polyimide amide, a resist, or benzocyclobutene) or an
SOG film (e.g., a SiO.sub.x film including an alkyl group)). Note
that each opening corresponding to a pixel serves as a
light-emitting region 1521.
[0113] A plurality of inversely-tapered partition walls 1522
parallel to each other is provided over the partition wall 1514
having openings which intersect with the first electrodes 1513. The
inversely-tapered partition walls 1522 are formed by a
photolithography method using a positive-type photosensitive resin,
portion of which unexposed to light remains as a pattern, and by
adjustment of the amount of light exposure or the length of
development time so that a lower portion of a pattern is etched
more.
[0114] FIG. 8 is a perspective view illustrating the state
immediately after formation of the plurality of inversely-tapered
partition walls 1522 parallel to each other. Note that the same
reference numerals are used to denote the same portions as those in
FIGS. 7A to 7C.
[0115] The thickness of the inversely-tapered partition wall 1522
is set to be larger than the total thickness of a conductive film
and a stacked film including a light-emitting layer. When the
conductive film and the stacked film including a light-emitting
layer are stacked over the first substrate having the structure
shown in FIG. 8, the stacked film is separated into a plurality of
regions electrically isolated from one another, which are a stacked
film of a second electrode 1516 and a stacked film 1515R including
a light-emitting layer; a stacked film of the second electrode 1516
and a stacked film 1515G including a light-emitting layer; and a
stacked film of the second electrode 1516 and a stacked film 1515B
including a light-emitting layer, as shown in FIGS. 7A to 7C. The
second electrodes 1516 are electrodes in stripes, which are
parallel to one another and extend along a direction intersecting
with the first electrodes 1513. Note that, although the conductive
films and stacked films each including a light-emitting layer are
also formed over the inversely-tapered partition walls 1522, they
are separated from the stacked film of the second electrode 1516
and the stacked film 1515R including the light-emitting layer; the
stacked film of the second electrode 1516 and the stacked film
1515G including the light-emitting layer; and the stacked film of
the second electrode 1516 and the stacked film 1515B including the
light-emitting layer.
[0116] This embodiment mode describes an example of forming a
light-emitting device which provides three kinds of light emissions
(R, G, and B) and is capable of performing full color display, by
selective formation of the stacked films 1515R, 1515G, and 1515B
each including the light-emitting layer. The stacked films 1515R,
1515G, and 1515B each including the light-emitting layer are formed
into a stripe pattern in which the stacked films are parallel to
one another.
[0117] In this embodiment mode, the stacked films each including
the light-emitting layer are formed using the manufacturing
apparatus shown in FIG. 1. The following substrates are prepared: a
first irradiated substrate over which a light-emitting layer from
which red light emission is obtained is formed, a second irradiated
substrate over which a light-emitting layer from which green light
emission is obtained is formed, and a third irradiated substrate
over which a light-emitting layer from which blue light emission is
obtained is formed. Then, a deposition substrate provided with the
first electrodes 1513 is transferred to the manufacturing apparatus
shown in FIG. 1. Then, the first irradiated substrate is irradiated
with a laser beam having an irradiated area that is the same as one
side of the substrate or longer than that to heat a light
absorption layer, whereby deposition is performed. Next, deposition
is selectively performed on the second irradiated substrate and the
third irradiated substrate as appropriate. The use of the
manufacturing apparatus shown in FIG. 1 enables selective
deposition, and thus the inversely-tapered partition walls 1522 can
be unnecessary.
[0118] Alternatively, stacked films each including a light-emitting
layer which emits light of the same emission color may be formed
over an entire surface to provide a monochromatic light-emitting
elements, whereby a light-emitting device that is capable of
performing monochromatic display or a light-emitting device that is
capable of performing area color display may be provided. Further
alternatively, a light-emitting device that is capable of
performing full color display may be provided by combination of a
light-emitting device which provides white light emission and color
filters.
[0119] In addition, if necessary, sealing is performed using a
sealing material such as a sealing can or a glass substrate for
sealing. In this embodiment mode, a glass substrate is used as a
second substrate, and a first substrate and the second substrate
are attached to each other using an adhesive material such as a
sealant, whereby a space surrounded by the adhesive material such
as a sealant is sealed off. The sealed space is filled with filler
or a dry inert gas. In addition, a desiccant or the like may be put
between the first substrate and the sealing material so that
reliability of the light-emitting device is increased. A small
amount of moisture is removed by the desiccant, whereby sufficient
drying is performed. As the desiccant, a substance which adsorbs
moisture by chemical adsorption, such as an oxide of an alkaline
earth metal such as calcium oxide or barium oxide, can be used.
Alternatively, a substance which adsorbs moisture by physical
adsorption, such as zeolite or silica gel, can be used as another
desiccant.
[0120] Note that a desiccant is not necessarily provided when a
sealing material which is in contact with the light-emitting
element to cover the light-emitting element is provided and the
light-emitting element is sufficiently blocked from outside
air.
[0121] FIG. 9 is a top view of a light-emitting module mounted with
an FPC or the like.
[0122] In a pixel portion for displaying images, scan lines and
data lines intersect with each other so as to cross at right
angles, as shown in FIG. 9.
[0123] The first electrodes 1513 in FIGS. 7A to 7C correspond to
scan lines 1603 in FIG. 9, the second electrodes 1516 correspond to
data lines 1602, and the inversely-tapered partition walls 1522
correspond to partition walls 1604. Light-emitting layers are
interposed between the data lines 1602 and the scan lines 1603, and
an intersection portion indicated by a region 1605 corresponds to
one pixel.
[0124] Note that the scan lines 1603 are electrically connected to
connection wirings 1608 at the ends of the wirings, and the
connection wirings 1608 are connected to an FPC 1609b through an
input terminal 1607. The data lines 1602 are connected to an FPC
1609a through an input terminal 1606.
[0125] If necessary, a polarizing plate, a circularly polarizing
plate (including an elliptically polarizing plate), a retardation
plate (a quarter-wave plate or a half-wave plate), or an optical
film such as a color filter may be provided as appropriate over a
light-emitting surface. In addition, the polarizing plate or the
circularly polarizing plate may be provided with an anti-reflection
film. For example, anti-glare treatment may be carried out by which
reflected light can be diffused by projections and depressions on
the surface so as to reduce the glare.
[0126] Through the above-described steps, the flexible passive
matrix light-emitting device can be manufactured. If the
inversely-tapered partition wall can be unnecessary with the use of
the manufacturing apparatus of the present invention, the element
structure can be drastically simplified and the time needed for the
manufacturing process can be shortened.
[0127] Although the example in which a driver circuit is not
provided over a substrate is shown in FIG. 9, an IC chip including
a driver circuit may be mounted over the substrate.
[0128] When an IC chip is mounted, a data line side IC and a scan
line side IC, in each of which a driver circuit for transmitting a
signal to the pixel portion is formed, are mounted on the periphery
of (outside) the pixel portion by a COG method. The mounting may be
performed using a TCP or a wire bonding method other than the COG
method. TCP is a TAB tape mounted with an IC, and the TAB tape is
connected to a wiring over an element formation substrate to mount
the IC. Each of the data line side IC and the scan line side IC may
be formed using a silicon substrate. Alternatively, it may be one
in which a driver circuit is formed using TFTs over a glass
substrate, a quartz substrate, or a plastic substrate. Although
described here is an example in which a single IC is provided on
one side, a plurality of divided ICs may be provided on one
side.
[0129] This embodiment mode can be combined with any one of
Embodiment Modes 1 to 3.
Embodiment 2
[0130] In this embodiment, an active matrix light-emitting device
formed with use of the manufacturing apparatus shown in FIG. 1 will
be described with reference to FIGS. 10A and 10B. FIG. 10A is a top
view illustrating a light-emitting device, and FIG. 10B is a
cross-sectional view taken along the line A-A' of FIG. 10A. A
reference numeral 1701 indicated by a dotted line denotes a driver
circuit portion (source side driver circuit); 1702 denotes a pixel
portion; 1703 denotes a driver circuit portion (gate side driver
circuit); 1704 denotes a sealing substrate; 1705 denotes a sealant,
and 1707 denotes a space surrounded by the sealant 1705.
[0131] A reference numeral 1708 denotes a wiring for transmitting a
signal input to the source side driver circuit 1701 and the gate
side driver circuit 1703, and the wiring 1708 receives a video
signal, a clock signal, a start signal, a reset signal, and the
like from an flexible printed circuit (FPC) 1709 that is to be an
external input terminal. Although only the FPC is illustrated here,
a printed wiring board (PWB) may be attached to the FPC. The
light-emitting device in the present specification includes, in its
category, not only the light-emitting device itself but also the
light-emitting device provided with the FPC or the PWB.
[0132] Next, a cross-sectional structure will be described with
reference to FIG. 10B. Although a driver circuit portion and a
pixel portion are formed over an element substrate 1710, a pixel
portion 1702 and a source side driver circuit 1701 that is a driver
circuit portion are illustrated here.
[0133] As the source side driver circuit 1701, a CMOS circuit in
which an n-channel TFT 1723 and a p-channel TFT 1724 are combined
is formed. A circuit included in the driver circuit may be a known
CMOS circuit, PMOS circuit, or NMOS circuit. In this embodiment, a
driver-integrated type in which a driver circuit is formed over the
same substrate is described; however, it is not necessary to have
such a structure; and the driver circuit can be formed not over the
substrate but outside the substrate.
[0134] The pixel portion 1702 is formed of a plurality of pixels
each including a switching TFT 1711, a current control TFT 1712,
and an anode 1713 that is electrically connected to a drain of the
current control TFT 1712. An insulator 1714 is formed so as to
cover an end portion of the anode 1713. Here, the insulator 1714 is
formed using a positive type photosensitive acrylic resin film.
[0135] The insulator 1714 is formed so as to have a curved surface
having curvature at an upper and lower end portions thereof in
order to obtain favorable coverage. For example, when a positive
type photosensitive acrylic is used as a material for the insulator
1714, a curved surface having a radius of curvature (0.2 to 3
.mu.m) is desirably formed at the upper end portion of the
insulator 1714. For the insulator 1714, either a negative type that
becomes insoluble in an etchant by photosensitive light or a
positive type that becomes soluble in an etchant by light can be
used, and an inorganic compound such as silicon oxide or silicon
oxynitride can be used as well as an organic compound.
[0136] A light-emitting element 1715 and a cathode 1716 are formed
over the anode 1713. Here, as a material used for the anode 1713, a
material having a high work function is desirably used. For
example, the following structures can be given: a stacked film of a
titanium nitride film and a film containing aluminum as its main
component; a stacked film having a three-layer structure of a
titanium nitride film, a film containing aluminum as its main
component, and a titanium nitride film; and the like as well as a
single-layer film of an indium tin oxide film, an indium tin oxide
film containing silicon, an indium zinc oxide film, a titanium
nitride film, a chromium film, a tungsten film, a zinc film, a
platinum film, or the like. In the case where the anode 1713 is
formed of an indium tin oxide film and a wiring of the current
control TFT 1712 connected to the anode 1713 has a stacked
structure of a titanium nitride film and a film containing aluminum
as its main component or a stacked structure of a titanium nitride
film, a film containing aluminum as its main component, and a
titanium nitride film, resistance of the wiring is low, a favorable
ohmic contact with the indium tin oxide film can be formed, and
further the anode 1713 can be made to serve as an anode. The anode
1713 may be formed using the same material as a first anode in the
light-emitting element 1715. Alternatively, the anode 1713 may be
stacked in contact with the first anode in the light-emitting
element 1715.
[0137] The light-emitting element 1715 has a structure in which the
anode 1713, an organic compound-containing layer 1700, and the
cathode 1716 are stacked; specifically, a hole injecting layer, a
hole transporting layer, a light-emitting layer, an electron
transporting layer, an electron injecting layer, and the like are
stacked as appropriate. The light-emitting element 1715 may be
formed with use of any one of the deposition apparatuses described
in Embodiment Modes 1 to 3.
[0138] A material (Al, Ag, Li, Ca, or an alloy thereof: MgAg, MgIn,
AlLi, calcium fluoride, or calcium nitride) having a low work
function may be used as a material for the cathode 1716; however,
the material for the cathode 1716 is not limited to the above and
can employ a variety of conductive layers by selection of an
appropriate electron injecting material. When light emitted from
the light-emitting element 1715 is made to be transmitted through
the cathode 1716, for the cathode 1716, it is possible to use a
stacked layer of a metal thin film with a reduced film thickness
and a transparent conductive film of an indium oxide-tin oxide
alloy, an indium oxide-zinc oxide alloy, zinc oxide, or the like.
The cathode 1716 may be formed using the same material as a second
cathode in the light-emitting element 1715. Alternatively, the
cathode 1716 may be stacked in contact with the second cathode in
the light-emitting element 1715.
[0139] Furthermore, the sealing substrate 1704 and the element
substrate 1710 are attached to each other with the sealant 1705,
whereby the light-emitting element 1715 is provided in a space 1707
surrounded by the element substrate 1710, the sealing substrate
1704, and the sealant 1705. Note that the space 1707 may be filled
with the sealant 1705 as well as an inert gas (e.g., nitrogen or
argon).
[0140] Note that an epoxy resin is desirably used as the sealant
1705. In addition, such a material is desirably a material which
does not transmit moisture or oxygen as much as possible. As a
material used for the sealing substrate 1704, a plastic substrate
made of FRP (fiberglass-reinforced plastics), PVF (polyvinyl
fluoride), polyester, acrylic, or the like can be used as well as a
glass substrate or a quartz substrate.
[0141] As described above, the light-emitting device including the
light-emitting element can be obtained with use of the
manufacturing apparatus of the present invention. A manufacturing
cost per substrate tends to be high because of TFT manufacturing;
however, the manufacturing apparatus of the present invention shown
in FIG. 1 that is a manufacturing apparatus in which a
film-thickness monitor is not used makes it possible to drastically
reduce deposition process time per substrate and realize drastic
reduction in cost per light-emitting device. In addition, material
use efficiency can be increased, and thus reduction in
manufacturing cost can be realized.
[0142] The light-emitting device described in this embodiment can
be implemented in free combination with the deposition apparatus
described in Embodiment Mode 1 or the manufacturing method
described in Embodiment Mode 2 or Embodiment Mode 3. Furthermore,
if necessary, a chromaticity conversion film such as a color filter
may be used in the light-emitting device described in this
embodiment.
[0143] As an active layer of a TFT which is placed in the pixel
portion 1702, the following can be used as appropriate: an
amorphous semiconductor film, a semiconductor film including a
crystalline structure, a compound semiconductor film including an
amorphous structure, or the like. In addition, as the active layer
of the TFT, a semi-amorphous semiconductor film (also referred to
as a microcrystalline semiconductor film) including a crystalline
region, which is a semiconductor having an intermediate structure
between an amorphous structure and a crystalline structure
(including a single crystal structure and a polycrystalline
structure), and a third condition that is stable in terms of free
energy. A crystal grain of 0.5 to 20 nm is contained in at least
part of the semi-amorphous semiconductor film. The raman spectrum
is shifted to a lower wavenumber side than 520 cm.sup.-1. The
diffraction peaks of (111) and (220) that are thought to be derived
from a Si crystal lattice are observed by X-ray diffraction. In
addition, the semi-amorphous semiconductor film contains hydrogen
or halogen of at least greater than or equal to 1 at. % to
terminate dangling bonds. The semi-amorphous semiconductor film is
formed by glow discharge decomposition (plasma CVD) of a material
gas such as SiH.sub.4 as well as Si.sub.2H.sub.6,
SiH.sub.2Cl.sub.2, SiHCl.sub.3, SiCl.sub.4, SiF.sub.4, or the like.
The above-described material gas may be diluted with H.sub.2, or
H.sub.2 and one or more selected from He, Ar, Kr, or Ne. A dilution
ratio may be in the range of 2 to 1000 times, pressure may be in
the range of 0.1 to 133 Pa, a power supply frequency may be 1 to
120 MHz preferably 13 to 60 MHz, and a substrate heating
temperature may be less than or equal to 300.degree. C., preferably
100 to 250.degree. C. The concentration of an atmospheric
constituent impurity such as oxygen, nitrogen, or carbon, as an
impurity element in the film, is preferably less than or equal to
1.times.1020 cm.sup.-1; in particular, the concentration of oxygen
is less than or equal to 5.times.10.sup.19 cm.sup.3, preferably
less than or equal to 1.times.10.sup.19 cm.sup.3. The electron
field-effect mobility .mu. of a TFT in which the semi-amorphous
semiconductor film is used as the active layer is 1 to 10
cm.sup.3/Vsec.
Embodiment 3
[0144] In this embodiment mode, with reference to FIGS. 11A to 11E,
a variety of electronic devices which are completed by use of a
light-emitting device manufactured by application of the present
invention will be described.
[0145] As electronic devices which are manufactured with use of the
manufacturing apparatus of the present invention, the following are
given: televisions, cameras such as video cameras or digital
cameras, goggle type displays (head mount displays), navigation
systems, audio reproducing devices (e.g., car audio component
stereos and audio component stereos), laptop personal computers,
game machines, portable information terminals (e.g., mobile
computers, cellular phones, portable game machines, and electronic
books), and image reproducing devices provided with recording media
(specifically, the devices that can reproduce a recording medium
such as a digital versatile disc (DVD) and is provided with a
display device capable of displaying the reproduced images),
lighting equipment, and the like. Specific examples of these
electronic devices are shown in FIGS. 11A to 11E.
[0146] FIG. 11A shows a display device, which includes a chassis
8001, a supporting base 8002, a display portion 8003, speaker
portions 8004, video input terminals 8005, and the like. The
display device is manufactured using a light-emitting device
manufactured using the present invention for the display portion
8003. Note that the display device includes all devices for
displaying information in its category, for example, devices for a
personal computer, for receiving TV broadcasting, and for
displaying an advertisement. The manufacturing apparatus of the
present invention makes it possible to drastically reduce
manufacturing cost and provide an inexpensive display device.
[0147] FIG. 11B shows a laptop personal computer, which includes a
main body 8101, a chassis 8102, a display portion 8103, a keyboard
8104, an external connection port 8105, a mouse 8106, and the like.
A light-emitting device which has a light-emitting element formed
with use of the manufacturing apparatus of the present invention is
used for the display portion 8103, and thus the laptop personal
computer is manufactured. The manufacturing apparatus of the
present invention makes it possible to drastically reduce
manufacturing costs and provide an inexpensive laptop personal
computer.
[0148] FIG. 11C shows a video camera, which includes a main body
8201, a display portion 8202, a chassis 8203, an external
connection port 8204, a remote control receiving portion 8205, an
image receiving portion 8206, a battery 8207, an audio input
portion 8208, operation keys 8209, an eyepiece portion 8210, and
the like. A light-emitting device which has a light-emitting
element formed with use of the manufacturing apparatus of the
present invention is used for the display portion 8202, and thus
the video camera is manufactured. The manufacturing apparatus of
the present invention makes it possible to drastically reduce
manufacturing cos and provide an inexpensive video camera.
[0149] FIG. 11D shows desk lighting equipment, which includes a
lighting portion 8301, a shade 8302, an adjustable arm 8303, a
support 8304, a base 8305, and a power supply 8306. A
light-emitting device manufactured with use of the manufacturing
apparatus of the present invention is used for the lighting portion
8301, and thus the desk lighting equipment is manufactured. Note
that the lighting equipment includes a ceiling-fixed lighting
equipment, a wall-hanging lighting equipment, and the like in its
category. The manufacturing apparatus of the present invention
makes it possible to drastically reduce manufacturing cost and
provide inexpensive desk lighting equipment.
[0150] FIG. 11E shows a cellular phone, which includes a main body
8401, a chassis 8402, a display portion 8403, an audio input
portion 8404, an audio output portion 8405, operation keys 8406, an
external connection port 8407, an antenna 8408, and the like. A
light-emitting device which has a light-emitting element with use
of the manufacturing apparatus of the present invention is used for
the display portion 8403, and thus the cellular phone is
manufactured. The manufacturing apparatus of the present invention
makes it possible to drastically reduce manufacturing cost and
provide an inexpensive cellular phone.
[0151] An application of a mobile object in which a light-emitting
device including a light-emitting element formed with use of the
manufacturing apparatus of the present invention is mounted on a
lighting device or a display panel is described with reference to
FIG. 12. In this embodiment, as the mobile object, a train vehicle
body, a car body, an airplane body, and the like, for example, a
two-wheeled motor vehicle, a four-wheeled motor vehicle (including
an automobile, a bus, and the like), a train (including a monorail,
a railway, and the like), ship and vessel, and the like are
given.
[0152] As an example of a display panel which includes, as a
display portion, a light-emitting device which has a light-emitting
element formed with use of the manufacturing apparatus of the
present invention, a mobile object incorporated with a display
device is shown in FIG. 12. FIG. 12 shows an example of a display
panel 9501 mounted on a car body 9502 as the example of the mobile
object incorporated with a display device. The display panel 9501
included as the display portion, which is shown in FIG. 12 is
mounted on the car body, whereby the display panel is capable of
on-demand display of operation of the car body or information input
from inside or outside of the car and has a function of navigating
a destination of the car. In addition, the display panel 9501 can
also be used as a light in the car.
[0153] Note that the light-emitting device which has the
light-emitting element formed with use of the manufacturing
apparatus of the present invention can be applied to not only a
front part of the car body as shown in FIG. 12 but also all sorts
of positions including a ceiling, a glass window, and a door by
being transformed to function as a lighting device or a display
device.
[0154] As described above, the electronic devices or the lighting
equipment using the light-emitting element formed by use of the
manufacturing apparatus of the present invention can be obtained.
The application range of the light-emitting device including the
light-emitting element formed by use of the manufacturing apparatus
of the present invention is so wide that the light-emitting device
can be applied to electronic devices in various fields.
[0155] The light-emitting device described in this embodiment can
be implemented in free combination with the deposition apparatus
described in Embodiment Mode 1 or Embodiment Mode 3, or the
deposition method described in Embodiment Mode 2. In addition, the
light-emitting device can be implemented in free combination with
any one of Embodiments 1 to 3.
[0156] This application is based on Japanese Patent Application
serial no. 2007-147413 filed with Japan Patent Office on Jun. 1,
2007, the entire contents of which are hereby incorporated by
reference.
* * * * *