JPH034482A - Method and device for manufacturing thin film electroluminescence element - Google Patents

Abstract

PURPOSE:To prevent lowering of luminance of a thin film electroluminescence element by introducing two kinds of specific mixing gases into a reactor while preventing them from making contact with the injection opening of a nozzle, and then mixing them together, and accelerating their vapor phase growth chemically so as to form a film. CONSTITUTION:A mixed gas containing an organic zinc compound and dicyclopentadienilmangan is introduced into a reactor 21 from the same nozzle 23, while a mixed gas containing metylmercaptan as an organic sulfur compound and ethylmercaptan is introduced but is prevented from making contact with the injection opening 24a of the nozzle 24. After the gases are introduced into the reactor 21, they are mixed together so that their chemical vapor phase growth is accelerated to form a film. Dispersion in the amount of Mn doped in the ZnS film is thereby prevented and is uniformed so high luminance is stably obtained.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a thin film electroluminescent device (hereinafter abbreviated as "IIT film EL device") that emits light by applying a voltage between electrodes, and particularly relates to The body layer is a film made of zinc sulfide doped with manganese (hereinafter referred to as ZnS: Mn
The present invention relates to a method for manufacturing an EL element (abbreviated as a film) and an apparatus therefor.

[Prior Art] In recent years, high-brightness thin-film EL devices have been attracting attention instead of distributed EL devices.

Conventionally, the light-emitting layer of such an EL element has been formed by EB evaporation, sputtering, etc., but in EB evaporation, (1) cluster-like substances fly out from the evaporation crucible, and 1. Defects of ~10 μm occur. (
2) Defects such as pinholes occur in the film. (3) Since the evaporation source is a point, there are drawbacks such as film unevenness, and in the sputtering method, 1) the ZnS:Mn film (light-emitting layer) is damaged by target secondary electrons. (2
) Sputtering gas mixes into the film. (3) There were drawbacks such as the composition of the target surface changing during sputtering.

In addition, a method has been proposed in which a film is formed by the so-called MOCVD method, which involves vapor phase growth of a raw material gas containing an organic zinc compound, an organic manganese compound, and one or more organic sulfur compounds such as dimethyl sulfur, diethyl sulfur, and hydrogen sulfide.
JP-A-62-98596).

However, when using dimethyl sulfide or diethyl sulfide, film formation cannot be performed at a substrate temperature of 500°C or lower; the temperature must be set at 500°C or higher, but this has the disadvantage of slow film formation speed. It was unavoidable that it would react with organic zinc compounds such as diethyl sulfur and produce powder, which would adversely affect film quality.

The present applicant has filed an application for a thin film EL element formed by MOCVD method (Japanese Patent Application No. 63-12
No. 8291).

[Object of the Invention] However, in the conventional method of introducing a mixed gas containing an organozinc compound, dicyclopentadienylmanganese, and methyl mercaptan or ethyl mercaptan as an organosulfur compound into a reactor from the same nozzle, for example, several tens of
When a film was formed on a large cm square substrate, the film thickness was not uniform, and the amount of Mn doping in particular varied, making it impossible to obtain the desired luminance. The film was formed using a shower-type nozzle, but when the aforementioned mixed gas was introduced into the reactor from the same nozzle, a black film was deposited on the back of the nozzle plate, resulting in a decrease in the amount of Mn doped. It has been found that this reduces the luminance of the thin film EL device. When the cause of this was investigated, it was discovered that cyclopentadienylmanganese and an organic sulfur compound reacted to form a black film that was thought to be a compound such as MnS.

The present invention has been made based on this new knowledge, and an object of the present invention is to provide a method and apparatus for manufacturing a thin film EL element that is particularly suitable for large substrates and that can prevent reduction in luminance.

[Means for Solving the Problems] The present invention provides a thin film E in which a pair of electrodes are provided on both surfaces of a light emitting layer, with a dielectric layer interposed on at least one surface thereof.
In the method for manufacturing the L element, the luminescent layer is prepared by introducing a mixed gas containing an organozinc compound and dicyclopentadienylmanganese into the reactor from the same nozzle, and on the other hand, '4itl! l
A mixed gas containing methyl mercaptan or ethyl mercaptan as a sulfur compound is introduced into the reactor and mixed without contacting the mixed gas above the nozzle outlet, thereby causing chemical vapor phase growth. It is characterized by having a membrane.

In addition, an apparatus for carrying out this method has a plurality of ejection ports for introducing a mixed gas containing an organic zinc compound and dicyclopentadienyl manganese when forming a luminescent layer by MOCVD. A configuration in which a nozzle and a nozzle having a plurality of ejection ports for introducing a mixed gas containing methyl mercaptan or ethyl mercaptan as an organic sulfur compound into the reactor are arranged in close proximity to each other; A plurality of nozzles for introducing a mixed gas containing methyl mercaptan or ethyl mercaptan as an organic sulfur compound into the reactor into a nozzle having a plurality of ejection ports for introducing a mixed gas containing dicyclopentadienylmanganese into the reactor. It is characterized by a structure in which a thin tube is inserted therethrough to form a jetting port different from the plurality of jetting ports.

[Function] When dicyclopentadienylmanganese (hereinafter abbreviated as DCPM) and methyl mercaptan or ethyl mercaptan as an organic sulfur compound are introduced into the reactor from the same nozzle, they react within the nozzle to form a black film. Although it is not possible to precisely control the amount of Mn doped, such problems can be solved by preventing the mixed gas from coming into contact with the nozzle outlet.

In addition, doping of Mn into ZnS is performed by substituting Mn with Zn mainly at lattice points in the Zn crystal lattice, so it is necessary to introduce the organic zinc compound and DCPM into the same nozzle and supply the mixed gas to the reactor. DCPM particles are uniformly dispersed in the organozinc compound particles in the nozzle,
As a result, the Mn doping of the substrate and the formed light emitting layer ZnS:Mn film is also uniform and has a 9-way angle, making it possible to obtain stable luminance.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

1 and 2 are schematic diagrams of main parts of an apparatus for producing a light-emitting layer of a thin film EL device according to the present invention, FIG. 3 is a schematic diagram of the entire device, and FIG. FIG. 3 is a cross-sectional view showing an EL element.

A Sn0w film is formed on a 1 m long transparent substrate 1 made of alkali-free glass or the like by CVD using heated vapor containing an organic tin compound and a fluorine compound as a raw material, and then etched to form a striped transparent electrode 2.

Next, using a plasma CVD apparatus (not shown), first, S
A SiO□ film 3 is formed using iH4 gas and N20 gas as raw materials, and then a Si3N film 4 is formed using the same apparatus using SiH4 gas and N2 gas as raw materials to form a first dielectric layer 5 consisting of two layers.

(Light-emitting layer formation) The substrate 1 in this process is placed in a reactor 21 of the MOCVD equipment shown in FIG. 3, held by a holder 22, and the reaction pressure is 3.
Diethylzinc (hereinafter abbreviated as DEZ) as an organic zinc compound under the conditions of 4 days orr and a substrate temperature of 600°C.
A mixed gas containing DEZ and DCPM is discharged through a nozzle 23 having the same plurality of jet ports 23a as shown in FIG.
．． 2X10″″’ mol/sin SDCPM with carrier gas flow rate! ill but a small amount, for example 6.5
XIO"'-' mol/win was introduced into the reactor, and methyl mercaptan gas as an organic sulfur compound was introduced into the nozzle 2.
Zn doped with Mn was introduced into the reactor at 1.1
Form an S film (ZnS:Mn film) to a desired thickness, and form a light emitting layer 6.
shall be.

After that, a Si3N4 film 7.5i02 film 8 is sequentially formed on the other side by the above-mentioned CVD method to form the second dielectric layer 9, and a back electrode 1° made of AI or the like is placed on this layer to cross the transparent electrode 2. The thin film EL element is formed in a stripe shape as shown in FIG.

In the thin-film EL device thus obtained, the light-emitting layer 6 was uniformly doped with Mn in the desired amount (for example, 1 wt%), so there was no variation in luminance and stable high-luminance characteristics were obtained. .

As shown in Figure 2, thin film EL was produced using the same method and equipment as in Example 1, except that the nozzle part of the MOCVD equipment was changed.
This is to obtain the element.

The nozzle 23 forms a plurality of ejection ports 23a for introducing a mixed gas containing an organic zinc compound and DCPM into the reactor, and also contains gases such as methyl mercaptan or ethyl mercaptan. A plurality of thin tubes 25 for introducing a gas containing a yellow compound into the reactor are inserted into the nozzle 23 to form a spout 25a different from the spout 23a.

In this way, the mixed gas containing the organic zinc compound and DCPM comes into contact with each other in the nozzle 23 to disperse Mn and is introduced into the reactor, but the organic sulfur compound does not come into contact with the organic sulfur compound in the nozzle and is introduced into the reactor. Therefore, a black film (compounds such as MnS @13) will not form and adhere to the inside of the nozzle (
, a light emitter layer is formed in which ZnS is uniformly doped with a desired amount of Mn.

Although the present invention has been described above using preferred embodiments, the present invention is not limited to these embodiments, and various applications are possible.

Regarding the nozzle for forming the ZnS:Mn film which is the light emitting layer by the MOCVD method, the D
It is preferable that the nozzle for introducing CPM and the organic zinc compound has a wide area as in Example 1, and the mixed gas is introduced into the reactor through a large number of ejection ports, since the mixed gas can be uniformly supplied onto the substrate. As for the nozzle for introducing the sulfur compound, as in Example 1, the number of pipes can be increased or decreased depending on the size of the substrate using a nozzle in which a vibrator is provided with multiple jetting ports.
DCP by inserting multiple thin tubes into the nozzle as in Example 2
By providing a different jet port from the one where M and the organic zinc compound are introduced, the arrangement of the jet ports can be freely distributed.
It is preferable to form a uniform light-emitting layer, but it is also possible to introduce the mixed gas in the opposite direction to that in Example 2.
Since the organic sulfur compound tends to fill around the substrate and the number of ejection ports can be reduced compared to the number of ejection ports for the organic zinc compound and DCPM, it is better to use the structure as in Example 2.

Regarding the ZnS:Mn film of the light emitting layer, a thin film EL element having similar characteristics can be obtained by using dimethylzinc instead of diethylzinc as the organozinc compound.

Regarding the dielectric layer, if both the first and second dielectrics have a two-layer structure of a 5i02 film and a Si3N4 film, pinholes and
It is preferable to fill the clusters with each other because the dielectric strength is improved, but either layer may be used, or other dielectric layers such as Ti0□, ^1.0. In addition, it is preferable in terms of insulation to have a structure in which a first dielectric layer and a second dielectric layer are provided to sandwich the light emitting layer. It is also possible to do so.

[Effects of the Invention] According to the present invention, since a mixed gas is introduced into the reactor from a nozzle that grows a plurality of ejection ports, it is possible to uniformly form a light-emitting layer ZnS:Mn film on a large-area substrate. At the same time, D
A mixed gas containing CPM and an organic zinc compound is introduced into the reactor from the same nozzle, and these mixed gases and a mixed gas containing methyl mercaptan or ethyl mercaptan are not brought into contact with each other up to the spout of the nozzle, but after being introduced into the reactor. By mixing, it is possible to eliminate variations in the amount of On doped into the ZnS film and make it uniform, thereby making it possible to stably obtain a thin film EL element with high luminance.

[Brief explanation of drawings]

1 and 2 are schematic diagrams of main parts of an apparatus for manufacturing a light-emitting layer of a thin film EL device of the present invention, FIG. 3 is a schematic diagram of the entire device, and FIG. 4 is a diagram of a thin film obtained by the present invention. FIG. 3 is a cross-sectional view showing an EL element. 6... Luminous layer 20-Mo CVD device 2
1...Reactor 23.24...Nozzle 2
3a, 24a... spout 25... thin tube first
Figure 2

Claims (3)

[Claims] (1) In a method for manufacturing a thin film EL device in which a pair of electrodes are provided on both surfaces of a light emitting layer with a dielectric layer interposed on at least one surface, the light emitting layer contains an organic zinc compound and a dielectric layer. A mixed gas containing cyclopentadienylmanganese is introduced into the reactor through the same nozzle, while a mixed gas containing methyl mercaptan or ethyl mercaptan as an organic sulfur compound is not brought into contact with the mixed gas up to the outlet of the nozzle. , by mixing after introduction into the reactor,
A method for manufacturing a thin film EL device, characterized in that the film is formed by chemical vapor phase growth. (2) The light emitting layer is formed by MOCVD in a thin film EL device manufacturing apparatus in which a pair of electrodes are provided on both surfaces of the light emitting layer, with a dielectric layer interposed on at least one surface. For introducing a mixed gas containing an organic zinc compound and dicyclopentadienylmanganese into the reactor, a nozzle having multiple jetting ports and a mixed gas containing methyl mercaptan or ethyl mercaptan as an organic sulfur compound are used. 1. An apparatus for manufacturing a thin film EL element, characterized in that nozzles having a plurality of ejection ports are disposed in close proximity to each other. (3) The light emitting layer is formed by MOCVD in a thin film EL device manufacturing apparatus in which a pair of electrodes are provided on both surfaces of the light emitting layer, with a dielectric layer interposed on at least one surface. At this time, a mixed gas containing methyl mercaptan or ethyl mercaptan as an organic sulfur compound is introduced into the reactor through a nozzle having multiple jetting ports for introducing a mixed gas containing an organic zinc compound and dicyclopentadienyl manganese into the reactor. 1. An apparatus for producing a thin film EL element, characterized in that a plurality of thin tubes are inserted through the thin film EL device to form a jetting port different from the plurality of jetting ports.