JPH1150236A - Evaporation source for metallic material and vacuum treating device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaporation source for a metallic material capable of subjecting the material having high reactivity and a low work function to vapor deposition at an adequate evaporation rate. SOLUTION: The evaporation source 3 for the metallic material has a vessel 32 for evaporation comprised a blind cylindrical main body part 30 which is capable of housing the evaporation material and a disk-shaped cap part 31 which is attachable and detachable to and from the main body part 30. A disk- shaped partition part 30c is formed on the concentric axis with a peripheral wall part 30a within the main body part 30. An annular housing part 30d is formed within the main body part 30 by the peripheral wall part 30a and partition part 30c of the main body part 30. A leading-out part 31a of a circular truncated cone shape is projected and formed in the central part of a rear surface 31e facing the main body part 30 of the cap part 31. A spacing is formed between the partition part 30c of the main body part 30 and the leading-out part 31a of the cap part 31 in the meshed state of the main body part 30 and the cap part 31 so that the vapor 9a of lithium is discharge in bypass from the evaporation port 31b of the leading-out part 31a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporation source for a metal material used for vacuum evaporation, and more particularly to an organic electroluminescence (EL) device.
minescence) Lithium (L) used for the cathode material of the element
The present invention relates to a metal material evaporation source for evaporating i) and the like.

[0002]

2. Description of the Related Art In recent years, organic EL elements have been receiving attention as elements for full-color flat panel displays. An organic EL element is a self-luminous element that electrically excites a fluorescent organic compound to emit light, and is capable of emitting high-brightness, a wide viewing angle, surface light, thin and multicolor light, and has a low voltage of several volts. All the solid-state devices emit light when a direct current is applied thereto, and have the characteristic that their characteristics change little even at low temperatures.

FIG. 4 shows a structure of a general organic EL element. As shown in FIG.
00 is, for example, ITO formed on the glass substrate 101.
A hole injecting / transporting layer 103 and a light emitting layer 104 each made of an organic material are formed on an anode electrode 102 made of, and a cathode electrode 105 is formed thereon. Then, the anode electrode 102 and the cathode electrode 105
And a low voltage of about 8V is applied between them. In this case, as the material of the cathode electrode 105, an alloy of magnesium and silver (Mg / Ag) is often used. In recent years, an alloy of lithium and aluminum (Li / Al), which are metals having a small work function, has been used. Some have been proposed.

[0004]

The low work function metal used for the cathode electrode 105, particularly lithium, is very active and easily oxidizes when exposed to air. For this reason, lithium is usually stored in oil. In addition, when lithium is heated, it evaporates at a stretch. Therefore, when depositing lithium, lithium is gradually evaporated by melting it with a high melting point metal. However, such a conventional method has a problem that vapor deposition cannot be performed efficiently.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and is intended for a metal material capable of vapor deposition at a proper evaporation rate on a highly reactive metal material having a low work function. It is an object of the present invention to provide an evaporation source and a vacuum processing apparatus using the same.

[0006]

According to a first aspect of the present invention, there is provided an evaporating container for storing an evaporating material, wherein the evaporating material stored in the evaporating container is evaporated. A metal material evaporation source for forming a vapor deposition film on a substrate in a vacuum chamber, wherein the evaporation container is provided with a lead-out path for guiding the vapor of the evaporation material to the outside of the container by bypassing the vapor. An evaporation source for a metal material, characterized in that:

In the case of the first aspect of the present invention having the above-described structure, during vapor deposition, the vapor of the evaporating material is guided to the outside of the evaporating container by passing through the lead-out path in the evaporating container. Even when a metal material having a high work function and a low work function is used, evaporation can be performed at an appropriate evaporation rate without evaporation at a stretch.

In this case, as in the invention described in claim 2,
2. The evaporation source for a metal material according to claim 1, wherein the evaporation container has a main body having a bottomed upper end opening capable of storing the evaporation material, and an evaporation port for discharging the vapor of the evaporation material. And a cover part which can be inserted into and removed from the main body part through the opening. It is also effective that a guide portion is formed in the portion to cover the opening of the storage portion and to guide the vapor of the evaporation material stored in the storage portion to the evaporation port by bypassing the vapor.

According to the second aspect of the present invention, by removing the lid from the main body, the evaporating material can be easily carried into the housing through the opening.

On the other hand, when the lid is attached to the main body,
A guide path formed in the lid forms a lead-out path for bypassing and discharging the vapor of the vaporized material, thereby enabling vapor deposition to be performed at an appropriate vaporization rate.

In this case, as in the invention according to claim 3,
The metal material evaporation source according to claim 2, wherein the housing portion is provided in a peripheral portion inside the main body portion,
It is also effective that the guide portion is formed so as to protrude at a central portion of the lid portion facing the main body portion, and the evaporating port is provided at the top of the guide portion.

According to the third aspect of the present invention, the lead-out path for bypassing and discharging the vapor of the evaporation material can be formed with a compact configuration. That is, according to the present invention, the guide portion projecting from the central portion of the lid portion is formed to enter the space of the housing portion provided at the peripheral portion inside the main body portion. Then, a lead-out path is formed such that the vapor of the evaporating material flowing out of the opening of the storage portion is deflected by the guide portion protrudingly formed on the lid portion and discharged from the evaporation port provided at the top of the guide portion. You.

According to a fourth aspect of the invention, in the metal material evaporation source according to the third aspect, the main body has a cylindrical shape with a bottom, and the lid has a disk shape. It is also effective that the guide has a truncated cone shape.

According to the fourth aspect of the present invention, it is possible to form a path for leading out the vapor of the evaporation material into a point-symmetrical shape,
It is possible to uniformly discharge the vapor of the evaporation material.

According to a fifth aspect of the present invention, in the metal material evaporation source according to any one of the third and fourth aspects, a portion of the lid portion facing the substrate is provided.
It is also effective that a recess is provided such that the opening area increases from the bottom toward the opening end, and the evaporation port is provided at the bottom of the recess.

According to the fifth aspect of the present invention, since the vapor of the evaporation material discharged from the evaporation port is sufficiently diffused along the concave portion of the lid, a uniform vapor deposition film is formed on the substrate. Becomes possible.

On the other hand, according to the invention of claim 6, the invention is characterized in that a vacuum processing tank for forming a vapor-deposited film on a substrate is provided in a vacuum processing tank.
A vacuum processing apparatus, comprising the metal material evaporation source according to any one of the above.

According to the sixth aspect of the present invention, it is possible to obtain a vacuum processing apparatus capable of forming a uniform vapor-deposited film at an appropriate evaporation rate on a highly reactive metal material such as lithium.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the metal material evaporation source according to the present invention will be described below in detail with reference to the drawings. FIG. 1A shows a schematic configuration of a vacuum deposition apparatus which is an embodiment of a vacuum processing apparatus according to the present invention, and FIG. 1B shows an evaporation source for a metal material according to the present invention. It is sectional drawing which shows a structure.

FIG. 2A is a configuration diagram showing a state in which a lid and a main body of the metal material evaporation source of FIG. 1B are separated, and FIG. FIG. 2 (c) is a plan view showing a lid portion of the evaporation source, and FIG. 2 (c) is a plan view of the main body of the metal material evaporation source as viewed from above.

As shown in FIG. 1A, a vacuum deposition apparatus 1 of the present embodiment has a vacuum processing tank 2 connected to a vacuum exhaust system (not shown). The metal material evaporation source 3 accommodated in the heating container C is provided. Here, the container C is configured such that a heater H made of, for example, tantalum is embedded in a wall portion formed so as to surround the metal material evaporation source 3.

A shutter 4 is provided in the vicinity of the metal material evaporation source 3 to confine the vapor of the metal material as the evaporation material. In the vicinity of the shutter 4, a film forming speed is measured. A film thickness monitor 5 is provided.

On the other hand, a substrate holder 6 is provided above the vacuum processing tank 2, and a substrate (substrate) 7 on which a deposition film is to be formed is fixed to the substrate holder. Further, below the substrate 7, a main shutter 8 for blocking the vapor of the metal material is provided.

As shown in FIG. 1B, the metal material evaporation source 3 according to the present embodiment has an evaporation container 32 composed of a main body 30 and a lid 31. Here, both the main body 30 and the lid 31 are formed using graphite.

On the other hand, the main body 30 is formed of a cylindrical member having a bottom, and an opening is formed in an upper portion thereof. A screw portion 30b is provided above the peripheral wall portion 30a of the main body 30.
Are formed.

The inside of the main body 30 includes a peripheral wall 30.
A cylindrical partition part 30c is formed on the same axis as a. Here, the height of the partition part 30c is formed slightly lower than the height of the peripheral wall part 30a.

As shown in FIG. 2C, the peripheral wall 30a of the main body 30 and the partition 30c form the main body 30.
An annular housing portion 30d is formed in the inside. An active metal material such as lithium (Li), sodium (Na), calcium (Ca), and potassium chloride (KCl) is stored in the storage section 30d through the opening.

On the other hand, as shown in FIG.
Is a disc-shaped member, and the lid 31 is
Has a diameter slightly larger than the diameter of Further, a flange portion 31c is formed at a peripheral portion of the lid portion 31, and the above-described main body portion 30 is formed inside the flange portion 31c.
A threaded portion 31d that meshes with the threaded portion 30b is formed.

At the center of the lower surface 31e of the lid 31 facing the main body 30, a frustoconical lead-out portion 31a is formed so as to protrude. In this case, as shown in FIG. 1B, in a state where the main body 30 and the lid 31 are engaged with each other, the partition 30 c of the main body 30 and the lead-out part 31 a of the lid 31.
And a gap is formed between them. Further, an evaporating port 31b is provided at the top of the lead-out section 31a located at the center of the lid section 31. With such a configuration, the opening of the housing portion 30d of the main body 30 is covered by the lower surface 31e of the lid portion 31 and the lead-out portion 31a, and the vapor of the evaporation material flowing out of the housing portion 30d is covered by the lid portion. Lower surface 31e of 31 and lead-out part 31a (guide part)
A discharge path is formed that is deflected by the discharge port and discharged from the evaporation port 31b of the discharge section 31a.

When, for example, lithium is deposited by using the metal material evaporation source 3 having the above-described structure, FIG.
As shown in (b), the solid lithium 9 is stored in the accommodating portion 30d of the main body 30 in a state where the main body 30 and the lid 31 are separated.
And then the screw portion 31d of the lid portion 31 and the main body portion 3
No. 30 screw part 30d and the lid part 31
Fix to 0. In this state, the surface of the solid lithium 9 is oxidized to form a film.

Then, the metal material evaporation source 3 is set at a predetermined position in the vacuum processing tank 2, and the above-described heater H is energized to heat the lithium 9. As a result, when the lithium 9 is melted and liquefied and heating is continued, the oxide film is broken at a temperature of about 700 ° C., and the lithium 9A is in a stable vaporized state.

In the present embodiment, as shown in FIG. 1B, the lithium vapor 9a is supplied to the lid 31 of the evaporation container.
The flow direction is directed downward by the lower surface 31e and the lead-out portion 31a, and is discharged from the evaporation port 31b. In this case, the component of the oxide film formed on the surface of the solid lithium 9 is also contained in the lithium vapor 9a,
The components of the oxide film are also discharged from the evaporation port 31b.

Here, as shown in FIG. 1A, when the shutter 4 is kept closed, the evaporating port 3 of the lid 31 is closed.
Lithium vapor 9a flowing out of 1b adheres to shutter 4. Therefore, after all the components of the oxide film in the evaporation container 32 have flowed out, the heating temperature is maintained at about 600 ° C., and the shutter 4 and the main shutter are opened, so that the oxide-free lithium is applied to the substrate 7. Can be deposited.

As described above, according to the present embodiment,
At the time of vapor deposition, since the vapor 9a of lithium is bypassed in the evaporation container 32 and guided to the outside, vaporization can be performed at an appropriate vaporization rate without being vaporized at once.

In the present embodiment, the lid 31
Is detachable from the main body 30,
By removing the lid 31 from the main body 30, the solid lithium 9 can be easily carried into the housing 30d through the opening.

Further, according to the present embodiment, the lithium vapor 9a can be uniformly discharged using the compact evaporation container 32, and the evaporation port 3 of the lid 31 can be uniformly discharged.
Since the lithium vapor 9a discharged from 1b is sufficiently diffused along the upper surface of the lead-out portion 31a of the lid 31, a uniform vapor deposition film can be formed on the substrate 7.

The present invention is not limited to the above-described embodiment, but can be variously modified. For example,
In the above-described embodiment, the evaporation container is constituted by the main body and the detachable lid. However, the present invention is not limited to this, and the evaporation container may be formed integrally. is there. However, if the main body and the lid are formed separately as in the above-described embodiment, there is a merit that the insertion of the evaporation material becomes easy.

Also, various modifications can be made to the shapes of the housing portion of the main body portion and the lead-out portion of the lid portion without departing from the present invention.

Further, the material of the evaporation container is not limited to graphite, but various materials can be used. However, in order to heat the evaporation material uniformly, it is preferable to use graphite.

Further, the present invention is not limited to an apparatus for forming a cathode electrode of an organic EL element, but can be applied to various vapor deposition apparatuses. However, the present invention is particularly effective when forming a cathode electrode of an organic EL element using lithium or the like.

FIG. 3 shows another embodiment of the metal material evaporation source according to the present invention, and shows another example of the evaporation container.

As shown in FIG. 3, this evaporation container 20
In the same manner as in the above-described embodiment, the main body 21 is made up of a main body 21 made of, for example, graphite and a lid 22, and accommodates the liquid lithium 9A.

In this embodiment, the lid 22 is not provided with an evaporation port, and a U-shaped outlet pipe 23 is attached to the peripheral wall 21a of the main body 21. In this case, the end of the outlet pipe 23 inside the evaporation container 20 is
It is arranged toward. Also, outside the evaporation container 20, the end of the outlet pipe 23 is directed upward.

In the present embodiment having such a configuration, the lithium vapor 9a hits the lower surface of the lid 22 and rebounds inside the evaporating container 20, and then is discharged to the outside through the inside 23a of the outlet pipe 23. Is done. As described above, also in the present embodiment, since the lithium vapor 9a is bypassed and led to the outside, vapor deposition can be performed at an appropriate evaporation rate without being vaporized at once.
Other configurations and operations are the same as those of the above-described embodiment, and thus detailed description thereof will be omitted.

[0045]

As described above, according to the present invention, it is possible to perform uniform evaporation at a proper evaporation rate on a highly reactive metal material having a low work function. As described above, according to the present invention, it is possible to efficiently form the cathode electrode of the organic EL element particularly by using lithium.

[Brief description of the drawings]

FIG. 1A is a schematic configuration diagram of a vacuum evaporation apparatus which is an embodiment of a vacuum processing apparatus according to the present invention. FIG. 1B is a view showing a configuration of an embodiment of a metal material evaporation source according to the present invention. Cross section shown

2A is a configuration diagram showing a state in which a lid portion and a main body portion of the metal material evaporation source in FIG. 1B are separated from each other. FIG. 2B is a plan view showing a lid portion of the metal material evaporation source. Figure (c): Top view of the main body of the metal material evaporation source viewed from above

FIG. 3 is a cross-sectional view showing the configuration of another example of the evaporation container of the metal material evaporation source according to the invention

FIG. 4 is a cross-sectional view illustrating a configuration of a general organic EL element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vacuum evaporation apparatus 2 ... Vacuum processing tank 3 ... Evaporation source for metal materials 4 ... Shutter 7 ... Substrate (base)
8 Main shutter 9 Solid state lithium
9A: Lithium in liquid state 9a: Lithium vapor
Reference Signs List 30 main body part 30a peripheral wall part 30b screw part 30c partition part 30d accommodation part 31 lid 31a lead-out part (guide part) 31b
Evaporation port 31c: Flange part 31d: Screw part
31e: Lower surface (guide portion) C: Container for heating H: Heater

Claims (6)

[Claims] 1. An evaporation source for a metal material for evaporating an evaporation material contained in the evaporation container and forming an evaporation film on a substrate in a vacuum chamber. An evaporation source for a metal material, wherein the evaporation container is provided with a lead-out path for bypassing the vapor of the evaporation material and leading the vapor to the outside of the container. 2. The metal material evaporation source according to claim 1, wherein the evaporation container has a bottomed upper end opening-shaped main body capable of storing the evaporation material, and an evaporation port for discharging the vapor of the evaporation material. And a cover part that is capable of being inserted into and removed from the main body part. The housing part is provided inside the main body part and through which an evaporating material can be inserted through an opening. A guide portion is formed at a portion facing the inside of the portion to cover the opening of the storage portion and to guide the vapor of the evaporation material stored in the storage portion to the evaporation port by bypassing the vapor. Evaporation source for metal materials. 3. The evaporation source for a metal material according to claim 2, wherein the housing portion is provided at a peripheral portion inside the main body portion, and the storage portion is provided at a central portion of the lid portion facing the main body portion. An evaporating source for a metal material, wherein a guide portion is formed so as to protrude, and the evaporating port is provided at a top portion of the guide portion. 4. The metal material evaporation source according to claim 3, wherein the main body has a cylindrical shape with a bottom, the lid has a disk shape, and the guide has a truncated cone shape. An evaporation source for a metal material, characterized in that: 5. The evaporation source for a metal material according to claim 3, wherein an opening area of a portion of the lid facing the base increases from a bottom to an opening end. An evaporating source for a metal material, wherein the evaporating port is provided at a bottom portion of the concave portion. 6. The vacuum source according to claim 1, wherein the evaporation source for a metal material is provided in a vacuum processing tank for forming an evaporation film on a substrate. Processing equipment.