JPH01263267A - Method and device for vacuum deposition - Google Patents

Abstract

PURPOSE:To accurately control the composition of a film consisting of both a vapor deposition material high in vapor pressure and the vapor deposition material low therein by stopping vapor deposition of an evaporation layer incorporating the high-vapor pressure vapor deposition material and simultaneously cooling an evaporation vessel to rapidly control vapor deposition of the high-vapor pressure vapor deposition material. CONSTITUTION:In the inside of a vacuum deposition chamber 11, the high-vapor pressure vapor deposition material (e.g. S) is contained in a vessel 20 provided with a heating zone and a cooling zone. Further a low-vapor pressure vapor deposition material (e.g. Zn) is contained in a vessel 15 provided with only the heating zone. Then a compd. (e.g. ZnS) having the above-mentioned composition is vapor-deposited on a body 12 to be vapor-deposited by actuating the heating zones of both vessels 15, 20. After completely finishing vapor deposition, the cooling zone is immediately actuated to cool the high-vapor pressure vapor deposition material.

Description

[Detailed Description of the Invention] [Summary] Regarding a vapor deposition method and vapor deposition apparatus for vapor depositing a vapor deposition material containing a material with high vapor pressure, the purpose of the vacuum vapor deposition method is to facilitate composition control of a Fuji deposited film. A high vapor pressure evaporation material is stored in a container provided with a heating zone and a cooling zone, a low vapor pressure evaporation material is stored in a container provided with only a heating zone, and the heating zones of both containers are operated to generate the high vapor pressure. The present invention is characterized in that a compound having a composition consisting of a pressure vapor deposition material and a low vapor pressure vapor deposition material is vapor deposited, and then, immediately after the vapor deposition is completed, the cooling zone is operated to cool the high vapor pressure vapor deposition material.

The vacuum evaporation apparatus is characterized in that it includes a evaporation material storage container around which a heater and a cooling pipe are wound.

[Industrial application field]

The present invention relates to a vacuum evaporation method and a vacuum evaporation apparatus, and more particularly to a evaporation method and an evaporation apparatus for depositing a evaporation material containing a material with a high vapor pressure.

For example, as OA equipment becomes more and more complex, there is a demand for the development of thin and lightweight display devices, that is, flat displays, and research is underway on BL display devices that meet these demands.

The light-emitting layer of such an EL display panel contains sulfur (S) having a high vapor pressure, and it is difficult to control the amount of sulfur. Therefore, it is desired to form a stable light-emitting layer.

[Conventional technology]

In an EL display device, the light-emitting layer is a thin film based on sulfide, such as zinc sulfide (zinc sulfide) doped with manganese.
ZnS (Mn) or the like is used, and such a thin film (thickness of several thousand layers) is deposited by a vacuum evaporation method.

Figure 3 shows a cross-sectional view of the structure of a thin film iEL display, where 1 is the glass base and 2 is the seal glass.

3 is a transparent electrode, 4 and 6 are first . The second insulating film, 5 is a light emitting layer, and 7 is a back electrode. As shown in the figure, the structure is a three-layer structure in which a light-emitting layer is sandwiched between insulating films on both sides, and the total thickness of the three layers including the light-emitting layer, excluding the glass substrate 1 and sealing glass 2, is less than 2 μm. It is extremely thin, and by applying an AC voltage (driving pulse) of about 200 V to such a thin film part, a high electric field of I XIO' V/cm or more is generated in the light emitting layer, and electroluminescence is obtained. . Therefore, its modification is extremely important, and in particular, the film quality of the light emitting layer is important because it affects the brightness.

In addition, since the driving voltage is high as mentioned above, there is a problem in that the manufacturing cost of the driving circuit is high, and there is a demand for lowering the driving voltage, but in order to lower the voltage, it is also necessary to It is necessary to improve the film quality (crystallinity) of the layer to improve luminous efficiency.

Now, recently, as a formation method to improve the film quality and crystallinity of the light emitting layer, for example, for a light emitting layer made of ZnS:Mn,
Zn and S are deposited from separate containers (houses), so-called MSD (Multi 5source Depo).
) method is being considered. This is because when Zn5 (compound) with a small amount of Mn (luminescent center) added is housed in a single house and heated and evaporated using a normal vapor deposition method, a large amount of S with high vapor pressure evaporates. , Z of ZnS
This is because the composition of n and S changes, making it difficult to achieve a ZnS compound composition ratio.

FIG. 4 shows a cross-sectional view of a conventional vacuum evaporation apparatus to which the MSD method is applied, and 11 is a vacuum evaporation chamber.

12 is a substrate to be evaporated, 13 is a heater for heating the substrate, 14 is a vacuum exhaust port, 15 is a Zn house, and 16 is an S house. Mn, which is the center of luminescence, is added to one or both of them. Using such a vacuum evaporation apparatus, the Zn house 15 and the S house 16 are heated separately to adjust the temperature of the houses and control the amount of evaporation of each, thereby producing ZnS that matches the compound composition ratio.
It becomes easier to form compounds.

Figures 5(a) and (bl) are perspective views of conventional containers (houses) containing these Zn-￥)S, and in the same figure (fa), the house is an alumina crucible 17, surrounded by tungsten. It has a structure in which a heater wire 71 made of a wire or a tantalum wire is wound around it.The figure (b) shows a boat 18 made of tantalum (Ta) with a box-shaped house, which is heated by directly passing an electric current through the boat. It is something.

Note that this MSD method is known as a deposition method suitable for atomic layer epitaxial growth (ALE), in which high-quality crystals are obtained by growing one atomic layer at a time.

(Problem to be Solved by the Invention) However, in the above embodiment, the heating temperature of the Zn house 15 is as high as 300 to 400°C, and the temperature control of raising and lowering the temperature is relatively easy. In S House 16, the heating temperature is low at around 90℃, making it difficult to control the temperature.
There is a problem that the heating temperature is not easily lowered and it is difficult to stop evaporation immediately, and therefore, there is a drawback that the ZnS compound composition ratio cannot be accurately controlled.

The present invention eliminates these drawbacks and provides a vacuum evaporation method and an apparatus therefor that facilitate control of the composition of a deposited film.

[Failure to solve the problem]

The purpose is to store a high vapor pressure evaporation material in a container equipped with a heating zone and a cooling zone, and to store a low vapor pressure evaporation material in a container equipped with only a heating zone, and to operate the heating zones of both containers. A vacuum evaporation method in which a compound having a composition consisting of the high vapor pressure evaporation material and the low vapor pressure evaporation material is vapor-deposited, and then, immediately after the completion of vapor deposition, only the cooling zone is operated to cool the high vapor pressure evaporation material. achieved by.

Further, the vacuum evaporation apparatus is characterized in that it is equipped with a evaporation material storage container around which a heater and a cooling vibrator are wound.

[For production]

That is, the present invention provides a method for quickly suppressing evaporation of the high vapor pressure evaporation material by depositing a vapor deposition layer containing a high vapor pressure evaporation material such as S to a desired thickness, and then simultaneously cooling the evaporation layer and stopping the evaporation. and an apparatus, which makes it easier to accurately control the U formation of the deposited film.

〔Example〕

Hereinafter, embodiments will be described in detail with reference to the drawings.

FIG. 1 shows a cross-sectional view of a vacuum evaporation apparatus to which the MSD method according to the present invention is applied, and 15 is a Zn house.

20 is the S house, and the symbols of other members are the same parts as in FIG. 4 and are given the same symbols.

FIG. 2 is an enlarged perspective view of the S house (container) 20 shown in FIG. 1. The house is an alumina crucible 21, around which heating wires 22 and cooling vibrators 23 are alternately wound. .

Using this vacuum evaporation apparatus, the inside of the vacuum evaporation chamber 11 is
After exhausting the air to below 0 Torr, remove the weed-covered substrate to approximately 30 Torr.
The temperature of each house is adjusted by heating the Zn house 15 and the S house 20 separately, and the amount of evaporation of each is controlled to deposit a ZnS compound that matches the composition ratio to form the required film. Deposit to a thickness (eg, 5,000 to 7,000). At this time, the S house 20 is heated by the heater wire 22 (heating zone) and maintained at about 90°C, and the Zn
The house 15 is also heated to about 300° C. using an attached heater wire to evaporate the material onto the 12 surfaces of the substrate 12 to be vaporized at a deposition rate of 3 persons/minute. In addition, Zn house 15 is shown in Figure 5 (a
) or a structure similar to the conventional house shown in FIG. 5(b) is used, and heating is performed using a heater wire 71 (heating zone).

When evaporating S using the house (container) shown in Fig. 2, if it is difficult to maintain the temperature at a low temperature of approximately 90°C using only the heater wire 22, cooling water may be flowed through the vibrator 23 to lower the temperature. It is also possible to adjust.

After the deposition is completed to the desired film thickness, the heating by the heater wires of the Zn house 15 and the S house 20 is stopped, and cooling water is immediately flowed into the vibrator 23 of the S house 20 to quickly fill the S house. 20 is lowered to room temperature.

The cooling liquid flowing through the vibrator 23 may be another liquid cooled to below zero degrees, such as alcohol cooled with dry ice.

If the S house 20 is rapidly cooled in this way,
The problem of excess S being deposited in the high vapor pressure evaporation material after warehousing is stopped is alleviated, and the composition of the ZnS compound can be controlled relatively accurately to improve its crystal quality.

In addition, although S was explained above as an example of a high vapor pressure vapor deposition material, the same effect can be obtained even if it is applied to other high vapor pressure vapor deposition materials.

〔Effect of the invention〕

As is clear from the above description, the vacuum evaporation method and apparatus according to the present invention are useful for forming a high-quality light-emitting layer of a thin-film BL element, and contribute to improving the performance of EL display devices. be.

[Brief explanation of the drawing]

Fig. 1 shows a vacuum evaporation device using the MSD method according to the present invention, Fig. 2 shows a container (house) according to the invention, Fig. 3 is a structural diagram of a thin film EL panel, and Fig. 4 shows a vacuum evaporation device using the conventional MSD method. Applied vacuum evaporation equipment, 5th
The figure shows a conventional container (house). In the figure, 11 is a vacuum deposition chamber, 12 is a substrate to be evaporated, 13 is a substrate heater, 14 is a vacuum exhaust port, 15 is a Zn house, 16.20 is an S house 17, 21 is an alumina crucible, and 18 is a Ta one. Boat, 7L 22 indicates a heater wire (heating zone), 23 indicates a pipe (cooling zone). / ? To, Yuto Esu T, Hat Suning Min Wakami (Hazuotto Z) Fig. 2 Fig. 3 Conventional cqMSD Tsuji 11 Hanging Toku Raku Leather Autumn 1 Fig. 4 Gi Reverse Bundle Simple Melting Elephant (Hefs) Figure 5

Claims (2)

[Claims] (1) A high vapor pressure evaporation material is stored in a container provided with a heating zone and a cooling zone, a low vapor pressure evaporation material is stored in a container provided with only a heating zone, and the heating zones of both containers are operated. A compound having a composition consisting of the high vapor pressure evaporation material and the low vapor pressure evaporation material is evaporated, and then, immediately after the completion of evaporation, the cooling zone is operated to cool the high vapor pressure evaporation material. Vacuum deposition method. (2) A vacuum evaporation apparatus characterized by comprising a evaporation material storage container wrapped around a heater and a cooling pipe.