JP2003286563A - Film-forming apparatus and film-forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film-forming apparatus which precisely and efficiently controls a mixing ratio of materials in multi-elemental codeposition, and to provide a film-forming method. <P>SOLUTION: The film-forming apparatus 1 for forming a vapor deposited film on a substrate W comprises a shield member 5 provided with several openings 5a and 5b each of which can freely adjust the opening area, evaporation sources 7a and 7b arranged at positions of respectively facing to the openings 5a and 5b, in one side with respect to the shield member 5, and a moving means 9 for repetitively moving the substrate W relatively to each of the openings 5a and 5b and each of the evaporation sources 7a and 7b, in the other side with respect to the shield member 5. The openings 5a and 5b are arranged on one circumference, and the moving means 9 relatively revolves the substrate W on the circumference. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film forming apparatus and a film forming method, and more particularly to a film forming apparatus and a film forming method applied when forming thin films having different compositions such as an organic EL element in a laminated manner.

[0002]

2. Description of the Related Art Electroluminescence of organic materials (e
An organic EL element (organic EL element) using luminescence (hereinafter referred to as EL) has an organic layer sandwiched between an anode and a cathode. The organic EL element having such a structure is
The light generated when the holes injected from the anode and the electrons injected from the cathode are recombined in the organic layer is taken out as emission light from the cathode or the anode side, and several hundred to several hundred at a low driving voltage of 10 V or less. It is attracting attention as a light-emitting element capable of high-luminance light emission of several 10,000 cd / m ² . Further, in the organic EL element, it is possible to obtain a light emitting element that emits light of each color by selecting a material for the organic layer, and by forming light emitting elements that emit light of each color in a predetermined state,
It is possible to configure a display device capable of multi-color display or full-color display.

Here, the organic layer provided in each organic EL element is formed by laminating 3 to 5 material layers such as a hole injection layer, a hole transport layer, a light emitting layer and a charge injection layer for each emission color. In general, each layer is made of one or more materials. The formation of each material layer is usually performed by vapor deposition film formation, but the formation of a material layer composed of two or more materials is performed by so-called multi-source co-evaporation.

When performing multi-source co-deposition, the following method is used. First, in the method A, as shown in FIG. 5, the evaporation sources 101a and 101b are arranged in close proximity to each other to form an overlap region of the evaporation materials A and B evaporated from the evaporation sources 101a and 101b. . Then, by disposing the substrate W in this overlap region, a plurality of vapor deposition materials A and B are simultaneously vapor-deposited (co-evaporated) on the surface of the substrate W.

In addition, as shown in FIG. 6, the method section B has vapor deposition materials A and B vaporized from vaporization sources 101a and 101b.
The moving means 103 is arranged so that the substrates W pass therethrough alternately.
The substrate W is revolved around the midpoint between the evaporation sources 101a and 101b, or revolves around itself. This allows
Vapor deposition materials A and B are alternately deposited on the surface of the substrate W. At this time, by setting the revolution speed to a sufficient speed, a material layer having characteristics similar to those of co-deposition can be obtained.

[0006]

In recent years, the laminated structure of organic layers in organic EL devices has been diversified. For this reason,
For example, gradually increase the material composition ratio between the layers stacked above and below,
Alternatively, it has been required to form an organic layer having a layered structure in which the boundary between layers is made unclear by changing it stepwise. Further, it is also required to form a film in which the material composition ratio is controlled in one layer.

However, in any of the above film forming methods (methods A and B), the temperature of the evaporation source is changed in order to change the mixing ratio of the materials (material composition ratio) during film formation. For example, the evaporation rate of the material must be changed. However, the temperature and the evaporation rate do not linearly correspond to each other, and the evaporation rate exhibits unstable behavior by changing the temperature, so that it is difficult to accurately control the mixing ratio. Further, since the responsiveness of the evaporation rate to the temperature change is poor, a long process time is required and the productivity is poor.

[0008] Therefore, an object of the present invention is to provide a film forming apparatus and a film forming method capable of accurately and efficiently controlling the mixing ratio of materials in multi-source co-evaporation.

[0009]

A film forming apparatus of the present invention for solving the above problems is a film forming apparatus for forming a vapor deposition film on a substrate, and a plurality of opening areas can be freely adjusted. A shielding member having an opening, an evaporation source disposed at a position facing each of the openings on one surface side of the shielding member, and further, for each opening and an evaporation source on the other surface side of the shielding member. It is characterized in that it is provided with a moving means for repeatedly moving the substrate relatively.

Further, the present invention is also a film forming method using such a film forming apparatus, in which an evaporation source disposed at a position facing each of the openings on one surface side of the shielding member having the openings. In a state where the vapor deposition material is evaporated, by repeatedly moving the substrate relative to the openings and the evaporation source on the other surface side of the shielding member,
When the vapor deposition material is vapor-deposited on the substrate, the composition ratio of the vapor deposition material is adjusted by adjusting the opening area of each opening.

In the film-forming apparatus having such a structure and the film-forming method using the same, the opening area of each opening provided in the shielding member can be adjusted freely, so that the opening should be located at a position facing these openings. Among the vapor deposition materials evaporated from the evaporation sources respectively arranged, the vapor deposition materials that pass through the openings and are supplied to the other surface side of the shielding member are adjusted depending on the opening area of the openings. It Therefore, on the other surface side of the shielding member, each vapor deposition material is vapor-deposited on the surface of the substrate that moves relative to the opening and the evaporation source, with the composition ratio adjusted immediately by the opening area of the opening. It

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a configuration diagram of a film forming apparatus of the embodiment, and FIG. 2 is a plan view of a shielding member in the film forming apparatus having the configuration shown in FIG. In the following, the configuration of the film forming apparatus will be described with reference to these drawings, and then the film forming method using the film forming apparatus will be described.

<Film Forming Apparatus> Film forming apparatus 1 shown in these figures
Is a film forming apparatus for forming an evaporation film on the surface of the substrate W, and is provided with a shielding member 5, evaporation sources 7a and 7b, and moving means 9 in a vacuum chamber 3 for forming the film. .

The shield member 5 is provided so as to separate the inside of the vacuum chamber 2 into two chambers, an upper chamber and a lower chamber, and has a plurality (two in this case) of openings 5a and 5b. These openings 5a, 5b are arranged on the same circumference with respect to the center point O of the shielding member 3, and are surrounded by two arcs L1, L2 having the common center point O and two radii r1, r2. It has a curved shape. And the distance d between the two arcs L1, L2
Is larger than the maximum width of the surface of the substrate W.

A shutter 11 for freely adjusting the opening area is provided in each of the openings 5a and 5b.
a and 11b are provided. These shutters 11
The a and 11b are arranged on one surface side of the shielding member 5 so as to have a similar shape that is slightly larger than the openings 5a and 5b, for example. The shutters 11a and 11b have driving means (for example, a servo motor) provided outside the vacuum chamber 3.
13a and 13b are connected. These driving means 1
3a and 13b are provided to individually move the shutters 11a and 11b along the same circumference with respect to the center point O. By driving the shutters 11a and 11b by such servomotors 13a and 13b, the openings 5 are formed.
The opening areas of a and 5b are freely adjustable.

In FIG. 1, for convenience of explanation, the opening / closing direction of the openings 5a, 5b by the shutters 11a, 11b is toward the center point O.
The opening / closing direction of the openings 5a and 5b by a and 11b is as shown in FIG.
It is assumed to be in the circumferential direction as shown in.

The evaporation sources 7a and 7b are shield members 5
Each opening 5 is provided on the lower side of the vacuum chamber 3 partitioned by
It is arranged so as to face a and 5b, respectively. In these evaporation sources 7a and 7b, the vapor deposition material A evaporated from the vaporization source 7a uniformly passes through only the entire area of the opening 5a, and the vapor deposition material B evaporated from the evaporation source 7b passes through the entire area of the opening 5b. Shall be installed so that it can pass through evenly.

Further, the moving means 9 holds the film formation surface of the substrate W facing the shielding member 5 side above the vacuum chamber 3 partitioned by the shielding member 5 and opens the held substrate W. It revolves around the circumference on which the parts 5a and 5b are arranged. And in particular the moving means 9
The substrate W is configured to be held and movable so that the entire region of the film formation surface of the substrate W passes through the diffusion range of the vapor deposition substances A and B that have passed through the openings 5a and 5b. The moving speed of the substrate W by the moving means 9 is determined by the shutters 11a, 11
It can be set sufficiently faster than the opening / closing speed of the openings 5a, 5b by b. It should be noted that this moving means 9 is used for a plurality of substrates W within a range in which the substrates W do not overlap each other.
Can be held. The moving means 9 may be configured to revolve the held substrate W while rotating it.

In the film forming apparatus 1 having such a structure,
By evaporating the vapor deposition materials A and B from the evaporation sources 7a and 7b, the vapor deposition materials A and B are shielded by passing through the openings 5a and 5b provided on the evaporation sources 7a and 7b so as to face each other. It is diffused above the member 5. Further, by driving the moving means 9 while the moving means 9 holds the substrate W, the substrate W held by the moving means 9 is moved along the circumference on which the openings 5a and 5b are arranged. It continuously moves in a revolving state and alternately and repeatedly passes over the openings 5a and 5b. Therefore, on the film formation surface of the substrate W, the vapor deposition substances A and B diffused above the shielding member 5 through the openings 5a and 5b.
However, they will be deposited alternately and repeatedly.

At this time, the shutters 11a and 11b are driven by the opening / closing mechanisms 13a and 13b to adjust the opening areas of the openings 5a and 5b, so that the amounts of the vapor deposition substances A and B passing through the shielding member 5 are immediately changed. It becomes possible to adjust it. Therefore, the vapor deposition amounts of the vapor deposition substances A and B deposited on the film formation surface of the substrate W can be immediately adjusted by following the adjustment of the opening areas of the openings 5a and 5b. Therefore, it becomes possible to form a film by multi-source co-evaporation with good controllability of the composition ratio in the film thickness direction.

<Film Forming Method> Next, the film forming apparatus 1 having the above configuration.
An embodiment of a film forming method using is described with reference to FIGS. 1 and 2 and graphs of FIG. Note that FIG. 3 (1) is a graph showing changes with time of the vapor deposition material concentrations (composition ratios) of the vapor deposition materials A and B used for film formation here, and FIG. 3 (2) is
It is a graph which shows the time-dependent change of the aperture ratio of the opening part 5a, and FIG.3 (3) is a graph which shows the time-dependent change of the aperture ratio of the opening part 5b.

First, the moving means 9 holds the substrate W.
Next, the inside of the vacuum chamber 3 is hermetically closed to bring it into a vacuum state, and the openings 5a and 5b of the shielding member 5 are connected to the shutters 11a and 11b.
In the completely closed state, the evaporation material A is evaporated from the evaporation source 7a and the evaporation material B is evaporated from the evaporation source 7b.

After stabilizing the evaporation amount of each of the vapor deposition materials A and B, only the opening 5a is completely opened while the substrate W is revolved (or revolved) by the moving means 9 and the opening 5a is opened. The aperture ratio of is set to 100%. And the opening 5
When a predetermined time has elapsed from the time point (a) at which the opening of a is started (T0) and only the vapor deposition material A that has passed through the opening 5a is deposited on the deposition surface of the substrate W to a predetermined film thickness (T1), the shutter 11 is released.
b starts opening the opening 5b at a predetermined speed. Also,
Simultaneously with opening the opening 5b, the shutter 11a starts closing the opening 5a at a predetermined speed.

In this case, the opening speed of the opening 5b is arbitrarily set by the increasing speed of the opening ratio of the opening 5b, that is, the increasing speed of the deposition amount of the deposition material B on the substrate W. Similarly, the rate of closing the opening 5a is arbitrarily set by the rate of decrease of the opening rate of the opening 5a, that is, the rate of decrease of the deposition amount of the deposition material A on the substrate W.

After that, the opening 5 is opened by the shutter 11a.
From the time point (a) at which a is completely closed (T2), a predetermined time elapses in a state where only the opening 5b is opened.
When only the vapor deposition material B that has passed through the above is deposited on the deposition surface of the substrate W with a predetermined film thickness (T3), the opening portion 5b is closed by the shutter 11b and the film formation is completed.

According to such a film forming method, in the initial stage of film formation, only the opening 5a is opened, and the film is formed with the concentration (composition ratio) of the vapor deposition substance A being 100% ( T0 to T1). After that, by opening the opening 5b at a predetermined speed, the supply amount of the deposition material B gradually increases and the relative supply amount of the deposition material A decreases, and the opening 5a closes at a predetermined speed. During the period from the beginning to the time when the vapor deposition material A is completely closed, film formation is performed until the concentration of the vapor deposition material A gradually decreases and the vapor deposition material B reaches 100% (T
1-T2). Next, in the final stage of film formation, only the opening 5b is opened and film formation is performed with the concentration (composition ratio) of the vapor deposition material B being 100% (T2 to T3).

Therefore, when a lower layer film made of 100% vapor deposition material B was laminated on a lower layer film made of 100% vapor deposition material A, the composition ratio was gradually changed at these interfaces. The film is formed.

When performing such film formation, the amount of vapor deposition substances A and B supplied to the film formation surface of the substrate W should be immediately adjusted with good responsiveness by adjusting the aperture ratio of the openings 5a and 5b. You can For this reason, it becomes possible to perform film formation in which the material composition ratio of the vapor deposition substances A and B is accurately controlled with good productivity.

Then, for example, by applying a film forming method using such a film forming apparatus to the formation of an organic layer of an organic EL element, the material composition ratio between the vertically stacked layers is gradually increased.
Alternatively, an organic layer having a laminated structure in which the boundary between layers is made unclear by changing in stages and an organic layer in which the material composition ratio is controlled in one layer are formed with good controllability of the material composition ratio. It will be possible. However, the film forming apparatus and the film forming method of the present invention shown in the present embodiment are not limited to the formation of an organic layer, and can be widely applied to a film that can be formed by vapor deposition.

In the above embodiment, the shielding member 5 of the film forming apparatus 1 is provided with the two openings 5a and 5b, and the two kinds of vapor deposition materials A and B are provided on the substrate W while controlling their composition ratios. The case of forming a film by vapor deposition (or co-evaporation) on the substrate has been described. However, when the film forming apparatus 1 is provided with three or more openings, by providing evaporation sources for evaporating different vapor deposition materials corresponding to the openings, the maximum number of openings can be increased. It is possible to perform multi-source co-deposition using a matching number of different deposition materials. Therefore, as shown in the graph of the time-dependent change of the concentration of the vapor deposition material in FIG.
It is also possible to perform film formation in which the concentration of C is accurately controlled in the depth direction. In the case of having three or more openings, an evaporation source for evaporating the same vapor deposition material may be arranged for the two openings, and the vapor deposition rate of the vaporization material can be controlled by this.

Further, in this embodiment, as described with reference to FIGS. 1 and 2, the plurality of openings 5a, 5a are formed.
The configuration in which b is arranged along the same circumference and the substrate W is revolved along the circumference has been described. However, the film forming apparatus and the film forming method of the present invention are not limited to the structure of this embodiment as long as the substrate W is repeatedly moved relative to each opening and the evaporation source. Absent.
For example, a configuration is possible in which a plurality of openings are arranged along a straight line and the substrate W is reciprocally moved along the straight line with respect to these openings and the evaporation sources arranged corresponding to these openings. good.

[0032]

As described above, according to the film forming apparatus and the film forming method of the present invention, by controlling the aperture ratio of each of the plurality of apertures, the aperture ratio of the plurality of apertures can be controlled to correspond to the substrate. Since it is possible to immediately control the supply amount of a plurality of vapor deposition substances, it is possible to perform multi-source co-deposition in which the mixing ratio (composition ratio) of a plurality of vapor deposition materials is accurately and efficiently controlled.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of a film forming apparatus according to an embodiment.

2 is a plan view of a shielding member in the film forming apparatus of FIG.

FIG. 3 is a graph for explaining an example of the film forming method of the embodiment.

FIG. 4 is a graph for explaining another example of the film forming method of the embodiment.

FIG. 5 is a conceptual diagram for explaining a conventional film forming method A.

FIG. 6 is a conceptual diagram for explaining a conventional film forming method B.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Film-forming apparatus, 5 ... Shielding member, 5a, 5b ... Opening part, 7
a, 7b ... evaporation source, 9 ... moving means, W ... substrate

Claims (3)

[Claims] 1. A film forming apparatus for forming a vapor deposition film on a substrate, comprising: a shield member having a plurality of openings whose opening area can be adjusted freely; An evaporation source disposed at a position facing each opening, and a moving unit that repeatedly moves the substrate relative to each opening and the evaporation source on the other surface side of the shielding member are provided. A film forming apparatus characterized by the above. 2. The film forming apparatus according to claim 1, wherein the openings are arranged on the same circumference, and the moving unit relatively revolves the substrate along the circumference. Characteristic film forming apparatus. 3. A film forming method for forming a vapor deposition film on a substrate, wherein evaporation is provided at a position facing one of said openings on one surface side of a shielding member having a plurality of openings. while evaporating an evaporation material from the source, the by Rukoto moved relative repeatedly said substrate the respective opening and the evaporation source in the other surface side of the shielding member, each deposited on the substrate When depositing a material, the composition ratio of each said vapor deposition material is adjusted by adjusting the opening area of the said opening part, The film-forming method characterized by the above-mentioned.