JP2001181837A - Method for depositing thin film by physical vapor deposition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for depositing a thin film by a physical vapor deposition method capable of depositing a thin film with a uniformly flat and precise pattern on a substrate in a short time. SOLUTION: In a vacuum evaporation system used for this producing method, the inside of a vacuum tank 2 is provided with an evaporation source 5, a shutter 3 on the evaporation source side and a shutter 4b on the substrate side. The shutter 4b on the substrate side is a beltlike cover and is provided with an opening part 42b. In this deposition method, while the opening part 42b of the shutter 4b on the substrate side is parallelly moved to the surface of a transparent substrate 1 at a variable speed, the shutter 3 on the evaporation source side is opened, and vapor deposition is started. By using such vacuum evaporation system, the change of film thickness caused by the opening and shuttering of a shutter is reduced, and the film thickness can be made uniform over the whole. Moreover, the film thickness in the moving direction of the opening part 42b can be made flat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming a thin film by a physical vapor deposition method. More specifically, the present invention relates to a method for forming a thin film by a physical vapor deposition method, which can easily form a flat and accurate pattern when forming a deposited film.

[0002]

2. Description of the Related Art In order to form a thin film on a substrate, a physical vapor deposition method such as vacuum vapor deposition is often used. In order to perform such deposition, for example, a vacuum deposition apparatus as shown in FIG. 1 is used. The vacuum evaporation apparatus includes shutters 3 and 4 for controlling evaporation between an evaporation source 5 and a substrate 1 to be evaporated.
a and a mask 62 are provided. Also, shutter 3,
4 a is provided on the evaporation source side and the substrate side, respectively, and has a size to cover the evaporation source 5 and the substrate 1, respectively.

In order to perform vacuum deposition using such a vacuum deposition apparatus, the shutters 3 and 4a are opened and closed. That is, the shutters 3 and 4a are closed to prevent deposition on the substrate 1 until sufficient evaporation is generated from the evaporation source by means such as heating. Then, when performing vapor deposition, the evaporation source side shutter 3 is opened, and then the substrate side shutter 4a is opened. As a result, the evaporant from the evaporation source 5 passes through the open portions of the respective shutters and deposits on the substrate 1.

[0004]

However, when a thin film is formed using the substrate-side shutter 4 shown in FIG. 11A with such a vapor deposition apparatus, the thin film is formed as shown in FIG. A film thickness distribution as shown in b) occurred, and a flat thin film could not be obtained. This thin film has the largest thickness at the central portion coaxial with the evaporation source. In addition, since each shutter opens and closes gradually by rotational movement or parallel movement,
There were a part where the vapor deposition was performed immediately before the completion of the opening and closing, and a part where the vapor deposition was not performed from the start of the opening and closing, and the thickness of the deposited thin film was uneven.

In particular, when a plurality of shutters 4 and 4 are used as shown in FIG. 12A and the opening / closing speed of the shutters is reduced, as shown in FIG. Unevenness occurs around the eyes. This unevenness is negligible when the size of the substrate 1 is small, but cannot be ignored as the size of the substrate 1 increases.
It becomes difficult to deposit a thin film with less unevenness.

Further, since the size of the substrate-side shutter 4a is increased in proportion to the size of the substrate 1, the opening / closing speed is lower than that of the evaporation source-side shutter 3, and the thickness of the thin film formed by evaporation tends to be uneven. Had become. Such thin film unevenness cannot be ignored when it is necessary to form a thin film having a thickness of several よ う な such as an organic EL (electroluminescence) thin film.

To cope with such a problem, Japanese Patent Laid-Open No.
Japanese Patent Application Laid-Open No. 0-317128 discloses a formation method for averaging the thickness of a thin film formed by vapor deposition.
In this forming method, in order to measure the thickness of the thin film at various portions, a plurality of detecting elements using a quartz oscillator or the like are provided, and a shutter is provided so that the film thickness detected by the detecting elements does not become uneven. It is adjusted by each adjusting plate or the like. However, to keep the film thickness constant over a wide range,
Since a large number of detection elements are required and various adjustment plates need to be controlled, the apparatus tends to be complicated.

The present invention has been made to solve the above problems, and a thin film formed by a physical vapor deposition method that can form a thin film having a uniform pattern and a precise pattern on a substrate in a short time. It is an object to provide a forming method.

[0009]

According to a first aspect of the present invention, there is provided a method for forming a thin film by a physical vapor deposition method, wherein an evaporation source and a substrate are provided in a vacuum chamber, and a first shutter can be opened and closed so as to cover the evaporation source. And a method of forming a thin film by a physical vapor deposition method using a physical vapor deposition device in which a second shutter is provided to be able to open and close so as to cover the substrate. Open the second shutter completely, and then
The first shutter is opened to perform vapor deposition, then the first shutter is closed, and then the second shutter is closed.

[0010] The method of forming a thin film by physical vapor deposition according to the second invention uses a physical vapor deposition apparatus in which an evaporation source and a substrate are provided in a vacuum chamber and a shutter is provided to open and close the substrate so as to cover the substrate. Forming a thin film on the substrate by moving the shutter in a short side direction of the opening on the substrate, wherein the shutter has a slit-shaped opening. It is characterized by the following.

Further, as shown in a third aspect of the present invention, the shutter may have a curved opening in which the width at both ends of the long side is wider than the width at the center of the long side.
Further, as shown in the fourth invention, the moving speed of the shutter is lower when the opening is located at the edge of the substrate than when the opening is located at the center of the substrate. It can be gradually changed as follows.

The "physical vapor deposition method" can be exemplified by any vapor deposition method such as a vacuum vapor deposition method, an ion plating method and a sputtering method. Each of the above "shutters"
Any material that can arbitrarily control the evaporation of the evaporation from the evaporation source onto the substrate can be used, and the number, structure, material, shape, and the like can be arbitrarily selected. In addition, the method of opening and closing each shutter can be arbitrarily selected. For example, in the case of the first invention, a mechanism is provided in which one end is disposed on a rotating shaft and the evaporation is controlled by rotating the entire shutter. be able to. Further, a mechanism in which an opening for allowing evaporant to pass therethrough is provided in a belt-like object, a plate-like object, or the like, and the opening is moved in parallel to control vapor deposition can be exemplified.

The shape of the "opening" may be any shape as long as it is a "slit-like" shape that allows only a part of the substrate to be exposed and vapor-deposited. In addition, by appropriately selecting the shape and size of the opening, a vapor deposition film having an arbitrary thickness can be formed at an arbitrary portion of the substrate. The shape may be, for example, a slit shape or a rectangular shape (see, for example, FIG. 4). Further, as shown in the third invention, it is possible to form an opening having a curved shape in which the centers of a pair of opposed long sides are close to each other (for example,
See FIG. 8). Such a shape increases the amount of vapor deposition on both ends and helps to make the film thickness flat.

The opening and closing speed of each shutter can be arbitrarily selected. Further, the opening / closing speed can always be constant, or the speed can be changed according to the degree of opening / closing. When changing the speed, as shown in the fourth invention, the moving speed when the opening is located at the end of the substrate is lower than the moving speed when the opening is located on the substrate. It is preferred that By changing the moving speed in such a manner, the thin film formed on the substrate can be formed flat. The opening and closing movement of each shutter may be made to reciprocate with respect to the substrate, or may be made to move only in one direction.

The method of forming a thin film by the present physical vapor deposition method can be applied to the formation of a thin film of any material and thickness, but is particularly preferable when forming a flat thin film or a thin film having a thickness of several square meters. Examples of this include various thin films (organic EL thin films, electrodes, etc.) constituting an organic EL display element, and any thin film that needs to be formed by a physical vapor deposition method (for example, a display element using a liquid crystal or a semiconductor element, And the like). The organic EL thin film includes at least one of a light emitting layer including an organic fluorescent substance and at least one of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. In the formation, the method for forming the present thin film can be applied.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for forming a thin film by physical vapor deposition according to the present invention will be described with reference to FIGS. [Embodiment 1] This embodiment 1 is a method for forming a thin film using a vacuum evaporation apparatus having a shutter which is opened and closed by rotating a shaft.

FIG. 1 shows a vacuum deposition apparatus used in the present forming method. This vacuum evaporation apparatus includes an evaporation source 5 in a vacuum chamber 2,
The apparatus includes an evaporation source-side shutter 3 as a first shutter and a substrate-side shutter 4a as a second shutter. Further, as shown in FIG. 1, the present vacuum vapor deposition apparatus includes a substrate 1 on which a vapor deposition film is formed.
Place. Further, the substrate 1 is disposed on a turntable 63 that rotates at a constant speed and a constant speed in order to obtain a uniform film thickness.
A mask 62 for covering the deposited thin film into a required pattern shape is provided. Further, a film thickness monitor 7 for measuring the film thickness is provided.

The evaporation source side shutter 3 is a disk-shaped cover provided on the evaporation source 5 side, and has a diameter slightly larger than the crucible of the evaporation source 5. The substrate-side shutter 4 a is a disk-shaped cover provided on the substrate 1 side, and has a diameter slightly larger than that of the substrate 1.

Each of the shutters 3, 4a operates as follows. That is, after the substrate side shutter 4a is opened, the evaporation is started by opening the evaporation source side shutter 3, and the evaporation is stopped by closing (covering) the evaporation source side shutter 3 and then closing the substrate side shutter 4a. . As described above, in the present forming method, the evaporation source side shutter 3 substantially controls the evaporation in order to open the substrate side shutter 4a in advance. On the other hand, in the conventional forming method, after the evaporation source side shutter is opened, the evaporation is started by opening the substrate side shutter,
The evaporation was stopped by closing the evaporation source side shutter after closing the substrate side shutter. The reason why the shutter is provided in two stages is to perform vapor deposition using a plurality of evaporation sources, but it can be said that the substrate side shutter substantially controls the vapor deposition.

The order in which the shutters 3 and 4a are opened and closed in the present forming method is reversed from that in the conventional example because the shutter 4a on the substrate side needs to shield a larger area than the shutter 3 on the evaporation source side. It becomes heavy, and the opening and closing operation becomes slow. Therefore, by using the evaporation source side shutter 3 which can be opened and closed at a higher speed, the evaporation during the opening and closing of the shutter is reduced.

When the evaporation source side shutter 3 is closed and the substrate side shutter 4a is opened, some evaporant remains in the space between the evaporation source side shutter 3 and the substrate side shutter 4a, Although there is a possibility of vapor deposition on the substrate 1, there is no problem in a short time because only a small amount of evaporate remains. However, since there is a small possibility that the evaporant wraps around the gap between the evaporation source side shutter 3 and the evaporation source 5 and adheres to the substrate 1, the evaporation source side shutter 3 is closed and the substrate side shutter 4a is closed. Open time should be minimized. In other words, when starting the vapor deposition, the substrate side shutter 4
It is preferable to open the evaporation source-side shutter 3 immediately after the opening of the shutter a, and it is preferable to close the substrate-side shutter 4a immediately after the evaporation source-side shutter 3 is closed when vapor deposition is stopped.

Further, since the distance between the evaporation source side shutter 3 and the substrate 1 is longer than the distance between the substrate side shutter 4a and the substrate 1, only a part of the evaporation is difficult to be deposited while the evaporation source side shutter 3 is opened and closed. Deposited over. Therefore, unevenness of the thin film deposited on the substrate 1 can be suppressed.

Using such a forming method, the film forming speed is controlled by using the film thickness monitor 7 on the substrate 1 so that the film forming speed is 1 ° / s at the center of the substrate, and the film is formed to have a film thickness of 5 °. Li
A thin film of F or LiO ₂ was produced. As shown in FIG. 2, the distribution of the film thickness manufactured by using such a formation method is a distribution in which the film thickness is not uneven due to the opening and closing of the shutter.

[Embodiment 2] This embodiment 2 is a method for forming a thin film using a vacuum evaporation apparatus provided with a shutter having an opening which moves in parallel. FIG. 3 shows a vacuum deposition apparatus used in the present forming method. This vacuum deposition apparatus is placed in a vacuum chamber 2.
Evaporation source 5 and evaporation source side shutter 3 as a first shutter
And a substrate-side shutter 4b as a second shutter. In addition, as shown in FIG. 3, the present vacuum vapor deposition apparatus arranges a substrate 1 on which a required vapor deposition thin film is formed. Further, unlike the first embodiment, the substrate 1 is a fixed base 63 that does not rotate.
Placed in The substrate 1 is covered with a mask 62 for forming a required pattern shape. Further, a film thickness monitor 7 for measuring the film thickness is provided.

The evaporation source side shutter 3 is a disk-shaped cover provided on the evaporation source 5 side, and has a diameter slightly larger than the crucible of the evaporation source 5. The substrate side shutter 4b is a belt-shaped cover provided on the substrate 1 side as shown in FIGS. 3 and 4, and has a width slightly larger than that of the substrate 1. Further, the substrate side shutter 4
The belt 41b has a rectangular opening 42b as shown in FIG. The opening 42b is provided so that its longitudinal direction coincides with the width direction of the belt 41b, and moves on the substrate 1 in the lateral direction. The length of the opening 42b in the width direction is 10 mm.

In the present forming method, the substrate-side shutter 4
The evaporation source-side shutter 3 is opened and the evaporation is started while the opening 42b of b is moved in parallel on the substrate 1 at the speed shown in FIG. After the opening 42b of the substrate side shutter 4b is moved out of the substrate 1, the evaporation source side shutter 3 is closed to stop the vapor deposition.

As described above, in the present forming method, the portion to be vapor-deposited is formed in a band shape by the opening 42b of the substrate side shutter 4b. Also, as shown in FIG. 5, when the opening 42b is located on the edge of the substrate 1, the moving speed of the substrate-side shutter 4b is about 90% of the speed at the center (Y = 0 cm). Was gradually changed. This makes it possible to compensate for the shortage of the deposit at the end of the substrate 1, and to deposit with a uniform thickness in the moving direction of the opening 42 b.

Using such a forming method, a film thickness monitor 7 is formed on the substrate 1 so that a film forming rate is 11Å / s at the center of the substrate.
The thin film of LiF or LiO ₂ was manufactured so as to have a film thickness of 10 ° by controlling the film forming speed using the method described above. As shown in FIG. 6, the distribution of the film thickness manufactured by using such a formation method is as follows.
The change in the in-plane film thickness distribution due to the opening / closing speed of the shutter was reduced. Further, the difference in unevenness of the film thickness due to the opening and closing of the shutter was reduced to about 11%, and the film thickness could be made uniform over the whole. From the above, it can be understood that this forming method forms a flat thin film by determining the moving speed of the shutter so as to satisfy the required film thickness and film forming speed. Also,
Since the unevenness of the thin film hardly occurs due to the deposition rate, the deposition rate can be increased.

[Embodiment 3] The thin film forming method of Embodiment 3 is different from the forming method of Embodiment 2 in that the shape of the opening of the substrate side shutter is made different and the moving speed of the opening is constant. It is. FIG. 7 shows a vacuum deposition apparatus used in the present forming method. The vacuum evaporation apparatus includes an evaporation source 5, an evaporation source side shutter 3 as a first shutter,
And a substrate-side shutter 4c which is a shutter. Also,
In this vacuum vapor deposition apparatus, as shown in FIG. 7, a substrate 1 on which a required vapor deposition thin film is formed is arranged. Further, the substrate 1 is arranged on a fixed base 63 that does not rotate. The substrate 1 is covered with a mask 62 for forming a required pattern shape. Further, a film thickness monitor 7 for measuring the film thickness is provided.

The evaporation source side shutter 3 is a disk-shaped cover provided on the evaporation source 5 side, and has a diameter slightly larger than the crucible of the evaporation source 5. 7 and 8, the substrate-side shutter 4c is a belt-shaped cover provided on the substrate 1 side, and has a width slightly larger than that of the substrate 1. Further, the substrate side shutter 4
As shown in FIG. 8, the belt 41c of c has an opening 42c whose center in the longitudinal direction is curved inwardly to each other. The longitudinal direction of the opening 42 c is the belt 41.
It is provided so as to coincide with the width direction of c, and moves on the substrate 1 in the short direction. The opening 4
The length in the short direction of 2b is 10 mm at both ends and 8.9 mm at the center.

In the present forming method, after the evaporation source side shutter 3 is opened, the opening 42c of the substrate side shutter 4c is opened.
Is moved in parallel on the substrate 1 at a speed of 10 mm / s to start vapor deposition. Further, the opening 4 of the substrate side shutter 4c is provided.
After closing 2c, the evaporation source side shutter 3 is closed to stop the evaporation.

As described above, in the present forming method, the portion to be vapor-deposited is formed in a band shape by the opening 42c of the substrate side shutter 4c. In addition, since the shape of the opening 42c is a shape having a wide end portion, it is possible to compensate for a deficient deposit that is usually insufficient at the end portion side, and it is possible to perform deposition with a uniform thickness in the longitudinal direction of the opening 42c. .

Using such a forming method, the film forming speed is controlled by using a film thickness monitor on the substrate 1 so that the film forming speed is 11 ° / s at the center of the substrate, and L is formed so that the film thickness becomes 10 °.
A thin film of iF or LiO ₂ was produced. This thin film could make the film thickness in the longitudinal direction of the opening 42c flat. As a result, as shown in FIG. 9, the film thickness distribution due to the opening and closing of the shutter could be reduced to about 11% or less, and the film thickness distribution could be made uniform throughout.

[Embodiment 4] The method of forming a thin film of Embodiment 4 is the same as that of Embodiment 2 except that the moving speed of the opening of the substrate-side shutter is the same as that of Embodiment 2.
In this forming method, as shown in FIG. 7, the same vacuum evaporation apparatus as that in Example 3 was used. Further, as shown in FIG. 5, when the opening 42c is located on the edge of the substrate 1, the moving speed of the substrate-side shutter 4c is about 90% of the speed at the center (Y = 0 cm). Was gradually changed.

Using such a forming method, a film thickness monitor 7 is formed on the substrate 1 so that the film forming rate is 11 ° / s at the center of the substrate.
The thin film of LiF or LiO ₂ was manufactured so as to have a film thickness of 10 ° by controlling the film forming speed using the method described above. The prepared thin film is
As shown in FIG. 10, the change in the film thickness due to the opening and closing of the shutter was as small as about 2%, and the film thickness could be made uniform throughout. That is, by changing the moving speed of the opening 42c, the film thickness in the moving direction of the opening 42c could be made flat. Further, the thickness of the opening 42c in the longitudinal direction could be made flat by the shape of the opening 42c. From the above, it can be understood that the present forming method forms a flat thin film by determining the moving speed of the shutter so as to satisfy the required film thickness and film forming speed. In addition, since the unevenness of the thin film hardly occurs due to the deposition rate, the deposition rate can be increased.

It should be noted that the present invention is not limited to the above embodiment, but may be variously modified within the scope of the present invention according to the purpose and application. That is, each of the shutters 3 and 4a shown in the first embodiment is not limited to one that opens and closes by rotating a disk-shaped cover, and the shape of the cover can be arbitrarily changed. Further, the cover can be divided into a plurality of parts, and the opening and closing method can be made by parallel movement.

Further, the shapes of the openings 42b and 42c shown in the second and third embodiments are not limited to those illustrated, and the distribution of the film thickness to be deposited can be made arbitrary by selecting arbitrarily. it can. Also, the speed of the openings 42b and 42c can be arbitrarily varied.

The shutters of Embodiments 2 and 3 are not limited to the method using the roll-wound belts 41b and 41c shown in each embodiment, and can be arbitrarily selected. For example, it can be an endless track connecting both ends of the belt. Further, a plurality of openings can be provided in the belt. Further, in the vacuum apparatus of each embodiment, the number of sets of the evaporation source-side shutter 3 and the evaporation source 5 is not limited to one, and any number can be provided according to the thin film to be manufactured.

[0039]

According to the method of forming a thin film by the physical vapor deposition method according to the first and second aspects of the present invention, it is possible to suppress unevenness in the thickness of the thin film deposited by opening and closing the shutter. In addition, this third
According to the method of forming a thin film by physical vapor deposition of the present invention, it is possible to suppress unevenness in the thickness of the thin film to be deposited due to the size of the substrate. Further, by the method for forming a thin film by the physical vapor deposition method of the fourth invention, it is possible to suppress unevenness in the thickness of the thin film to be deposited due to the size of the substrate.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a vacuum evaporation apparatus used for a forming method according to a first embodiment.

FIG. 2 is a graph showing a film thickness distribution of a thin film manufactured by the forming method of Example 1.

FIG. 3 is a schematic diagram for explaining a vacuum evaporation apparatus used in the formation method of Example 2.

FIG. 4 is a schematic diagram for explaining a shape of an opening of a substrate-side shutter used in a vacuum evaporation apparatus according to a second embodiment.

FIG. 5 is a graph showing a moving speed of an opening of a substrate-side shutter of Examples 2 and 4.

FIG. 6 is a graph showing a film thickness distribution of a thin film manufactured by the forming method of Example 2.

FIG. 7 is a schematic diagram for explaining a vacuum deposition apparatus used in the formation methods of Examples 3 and 4.

FIG. 8 is a schematic diagram for explaining the shape of an opening of a substrate-side shutter used in the vacuum evaporation apparatuses of Examples 3 and 4.

FIG. 9 is a graph showing a film thickness distribution of a thin film manufactured by the forming method of Example 3.

FIG. 10 is a graph showing a film thickness distribution of a thin film manufactured by the forming method of Example 4.

FIG. 11 is a graph showing (a) a shape of a shutter and (b) a thickness distribution of a manufactured thin film in a conventional forming method.

FIG. 12 is a graph showing (a) a shape of a shutter and (b) a thickness distribution of a manufactured thin film by a conventional forming method.

[Explanation of symbols]

Reference Signs List 1; substrate 2, vacuum chamber 3, evaporation source side shutter (first shutter), 4a, 4b, 4c; substrate side shutter (second shutter), 41b, 41c; belt, 42b, 42c;
Opening 5; evaporation source 61; rotating table 62; mask;
7; film thickness monitor.

Claims (4)

[Claims] An evaporation source and a substrate are provided in a vacuum chamber,
A method of forming a thin film by a physical vapor deposition method using a physical vapor deposition device using a physical vapor deposition device in which a first shutter is provided to be openable and closable so as to cover the evaporation source, and a second shutter is provided to be openable and closable to cover the substrate. When forming the vapor-deposited thin film, the second shutter is completely opened, then the first shutter is opened to perform vapor deposition, then the first shutter is closed, and then the second shutter is closed.
A method for forming a thin film by a physical vapor deposition method, comprising closing a shutter. 2. An evaporation source and a substrate are provided in a vacuum chamber,
A method for forming a thin film by a physical vapor deposition method using a physical vapor deposition device in which a shutter is provided so as to be openable and closable so as to cover the substrate, wherein the shutter has a slit-shaped opening, and a short side of the opening. Forming a thin film on the substrate by moving on the substrate in a direction. 3. The shutter according to claim 1, wherein the width of each of the long sides at both ends is:
3. The method for forming a thin film by physical vapor deposition according to claim 2, comprising a curved opening wider than the width of the center of the long side. 4. The moving speed of the shutter changes gradually so that the moving speed when the opening is located at the edge of the substrate is slower than when the opening is located at the center of the substrate. The method for forming a thin film by a physical vapor deposition method according to claim 2 or 3.