JP2002173307A - H2s cracking cell, method of manufacturing sulfide using the same, method of manufacturing inorganic el element and inorganic el element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin film forming apparatus, which has excellent composition controllability for sulfur and in which sulfur is stably supplied efficiently with excellent controllability, and a method for manufacturing a sulfide, particularly a sulfide based phosphor using the same. SOLUTION: The thin film forming apparatus, in which sulfur element is supplied from a H2S cracking cell provided at least with an inlet for hydrogen sulfide stream, a heating apparatus for the hydrogen sulfide stream and an absorption apparatus for a gaseous species consisting of hydrogen, is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an H ₂ S cracking cell for supplying sulfur and a method for producing sulfide using the same, and in particular, to reduce impurities in the light emitting layer and to provide excellent control of sulfur composition. A method for producing an inorganic EL device having excellent light-emitting properties and an inorganic E obtained by the method for producing an inorganic EL device
It relates to the L element.

[0002]

2. Description of the Related Art In recent years, thin film EL devices have been studied as small, large, and lightweight flat displays.

FIG. 3 shows the structure of a typical double insulating thin film EL device as a thin film EL device. In FIG. 3, the substrate 1
The lower electrode 5 having a predetermined pattern is formed thereon, and the first insulating layer 2 is formed on the lower electrode 5. A light emitting layer 3 and a second insulating layer 4 are sequentially formed on the first insulating layer 2, and an upper layer is formed on the second insulating layer 4 so as to form a matrix with the lower electrode 5. Electrode 6
Are formed in a predetermined pattern.

As the phosphor, a monochrome thin film EL using a phosphor thin film made of manganese-doped zinc sulfide emitting yellow-orange light is used.
Displays are already in practical use. Further, colorization is indispensable for a display for a personal computer, a TV, and other displays. A thin-film EL display using a sulfide phosphor thin film is excellent in reliability and environmental resistance, and development of a phosphor for EL that emits light in three primary colors of red, green, and blue is underway. For example, a blue light emitting phosphor is SrS: Ce or ZnS: Tm using SrS as a base material and Ce as a light emitting center, ZnS: Sm, CaS: Eu as a red light emitting phosphor, and ZnS: as a green light emitting phosphor. Tb, CaS: Ce and the like are known and research is being continued.

However, these phosphor thin films which emit light in the three primary colors of red, green and blue have problems in light emission luminance, efficiency and color purity, and color EL panels have not yet been put to practical use. In particular, blue is represented by using SrS: Ce,
Although relatively high luminance has been obtained, the luminance of blue for full-color display is insufficient, and the chromaticity has shifted to the green side. Therefore, development of a better blue light-emitting layer is desired.

The lack of luminance and the shift of chromaticity to the green side are caused by poor crystallinity of the SrS: Ce light emitting layer, sulfur loss,
Alternatively, it is attributed to the occurrence of defects due to Sr loss and the mixing of impurities.

[0007] As an example of a method for producing a high-purity, high-quality sulfide phosphor thin film, which solves the problem of poor crystallinity of the SrS: Ce light-emitting layer and the problem of sulfur removal, a sulfide having a composition to be formed is used. There are a method of forming the phosphor at a high temperature of 600 ° C. or higher and a method of annealing at a high temperature of 600 ° C. or higher. Further, as shown in page 593 of IDW 97 proceeding, page 13 of IEICE Technical Report EID97-57 (1997-10), and JP-A-8-45664, H ₂ S
A method of reacting sulfur by introducing gas or S gas, a method of forming a thin film as shown in J. Appl. Phys. 78, 1995, p. 428, and annealing in a sulfur atmosphere, and a method of further using SID95 DIGEST. 720
In the method shown on the page, SrS and Z
A method of co-evaporating nS and obtaining SrS by utilizing re-evaporation of ZnS, and a method of eliminating sulfur composition deviation by a method for compensating S from ZnS with addition of Zn has been attempted. I have.

However, in the above-mentioned method, the supply of sulfur element, that is, sulfur gas or Zn used for sulfur compensation is used.
S easily agglomerates at room temperature, and attaches to and damages equipment for synthesizing thin films and sulfides. In particular,
Contamination of the apparatus, generation of so-called dust such as particles, and reduction of the degree of vacuum in a vacuum apparatus and deposition on a vacuum pump cause a failure of the pump. On the other hand, H ₂ S gas is a gas even at room temperature, and does not damage the apparatus. Therefore, it is often used for producing thin films and synthesizing sulfide materials.

On the other hand, annealing at high temperature, high-temperature synthesis, etc.
When the sulfurization reaction is promoted using an H ₂ S atmosphere at a high temperature,
The atmosphere becomes a strong reducing atmosphere. In a strong reducing atmosphere, the apparatus must be made of a reduction-resistant material in order to reduce damage to the synthesis apparatus. In addition, for example, when synthesizing a thin film, a base material serving as a substrate is exposed to a strong reducing atmosphere. A base that cannot withstand a reducing atmosphere diffuses as an impurity in the thin film, or loses the function of the base and cannot be used for a thin film element.

[0010]

As described above [0008], when the supply of elemental sulfur, when used H ₂ S in the reaction of the sulfide, H ₂
There is a need for a method of reducing the strong reducing property of S and supplying only sulfur efficiently and with good controllability. When manufacturing an EL device using a sulfide thin film, particularly a sulfide-based phosphor such as a SrS: Ce thin film, a manufacturing method is required in which the controllability of sulfur in the sulfide thin film is enhanced in order to improve the emission characteristics. It has been.

An object of the present invention is to provide an H2S cracking cell capable of reducing the strong reducing ability of H ₂ S and efficiently and stably supplying only sulfur with good controllability, and production of a sulfide using the same. Is to provide a way. In addition, if such an H2S cracking cell is used for sulfide synthesis, it is possible to synthesize a sulfide material exhibiting purity and high characteristics that has not been obtained until now. Further, by using the present invention for an inorganic EL device using a sulfide thin film, a method for manufacturing an EL device having high emission characteristics and an excellent EL device can be provided.

[0012]

This and other objects are achieved by any one of the following constitutions (1) to (16). (1) An H2S cracking cell comprising an inlet for a hydrogen sulfide stream, an apparatus for thermally decomposing the hydrogen sulfide stream, and an apparatus for absorbing a gas species consisting only of H element. (2) The heating temperature of the heating device is 400 ° C. to 1200 ° C.
The H2S cracking cell according to (1), wherein (3) The H2S cracking cell according to (1) or (2), wherein the gas type absorbing device consisting only of the H element is a heated metal or a metal hydrogen alloy. (4) The H2S cracking cell according to (3), wherein the temperature of the heated metal or metal-hydrogen alloy is 600 ° C to 800 ° C. (5) The H2S cracking cell according to (3) or (4), wherein the heated metal is tantalum. (6) A method for producing a sulfide while supplying a sulfur element, wherein the hydrogen sulfide gas is heated and decomposed to generate H.
A method for forming a sulfide, comprising absorbing and removing a gas species consisting only of an element and supplying the sulfur element as a sulfur source. (7) The temperature of the thermal decomposition of the hydrogen sulfide gas stream is 400 ° C. or more.
The method for producing a sulfide according to (6), wherein the temperature is 1200 ° C. (8) The method for producing a sulfide according to (6) or (7), wherein the gas species is absorbed and removed by using a heated metal or a metal-hydrogen alloy. (9) The temperature of the heated metal is 600 ° C. to 800 ° C.
The method for producing a sulfide according to (8), wherein (10) The method for producing a sulfide according to (8) or (9), wherein the heated metal is tantalum. (11) A method for manufacturing an inorganic EL device in which a sulfide-based thin-film phosphor is formed on a substrate while supplying a sulfur element, wherein a hydrogen sulfide gas stream is heated and decomposed to absorb and remove gas species consisting of generated hydrogen. And supplying the sulfur element as a sulfur source. (12) The temperature of the thermal decomposition of the hydrogen sulfide gas stream is 400 ° C.
(11) The method for producing an inorganic EL device according to (11), wherein the temperature is from -1200 ° C. (13) The method for producing an inorganic EL device according to (11) or (12), wherein the gas species is absorbed and removed by using a heated metal or a metal-hydrogen alloy. (14) The temperature of the heated metal is from 600 ° C to 800 ° C.
The method for producing an inorganic EL device according to (13), wherein the temperature is ° C. (15) The method for producing an inorganic EL device according to (13) or (14), wherein the heated metal is tantalum. (16) An inorganic EL device obtained by the production method according to any one of (11) to (15).

[0013]

Embodiments of the present invention will be described below in detail.

FIG. 1 shows the H of the present invention._TwoS cracking cell
Show. H_TwoS cracking cell is H _TwoTo decompose S
Heating device and the gas species decomposed by this device
It has a device to absorb and remove gas species consisting only of elements
You. H_TwoAt the top of the S inlet 16, H_TwoFor decomposing S
The heating device 17 has H among the decomposed gas species.
A device 18 for absorbing and removing gas species consisting only of elements is provided.
Have been killed.

FIG. 2 shows a thin film forming apparatus provided with an H2S cracking cell according to the present invention. This thin film forming apparatus is composed of an inlet for a hydrogen sulfide flow, a heating device for the hydrogen sulfide flow, and a device for absorbing a gas species of hydrogen.
Equipped with a ₂ S cracking cell.

The heating device for decomposing H ₂ S may be any device having a predetermined heat capacity, reactivity, etc., and examples thereof include a tungsten wire heater, a tantalum wire heater, a sheath heater, and a carbon heater. The heating temperature by the heating device is 400 ° C to 1200 ° C, preferably 60 ° C.
The temperature may be 0 ° C to 1000 ° C. Temperature control accuracy is 9
It is ± 1 ° C at 00 ° C, and preferably about ± 0.5 ° C.

Here, H ₂ S is decomposed and decomposed into gas species such as H ₂ , H, H radical, H ion, S, S ₂ , S ₃ , S radical, and S ion. If the substrate temperature is too high,
If the temperature is too low, a problem arises that the gas decomposition efficiency deteriorates. For this reason, the above-mentioned temperature range is preferable.

A device for absorbing and removing gas species provided above a heating device for decomposing H ₂ S uses a hydrogen storage material. As the hydrogen storage material, it is preferable to use a hydrogen storage metal. All metals have hydrogen storage properties and can be used in principle, but metals with high hydrogen storage capacity are preferred. Specifically, Ti, Zr, V, Nb, rare earth metals, Ta, Hf, Pd metals, TaV2, TiFe, PdPt, TiCr
2, alloys of LaNi5, TiCo and LaCo5 are preferred. Further, a mixture, a compound, and an alloy of a plurality of these may be used. Of these, Ta metal is most preferably used. This is because Ta is stable at high temperatures and easy to process. These occlude hydrogen and become a metal-hydrogen alloy. So, of course,
A metal hydrogen alloy not saturated with hydrogen may be used.

The hydrogen storage metal is preferably used after being heated. The heating method is tungsten wire heater,
What is necessary is just to heat using a tantalum wire heater, a sheath heater, a carbon heater, etc. Alternatively, an electric current may be applied to the hydrogen storage metal itself to serve also as a heater. The heating temperature is
The optimum temperature is determined in advance according to the characteristics of the hydrogen storage metal. As an example, when Ta is used, the heating temperature is 400 ° C to 1000 ° C, preferably 600 ° C to 8 ° C.
The temperature may be set to 00 ° C. Temperature control accuracy is ± 750 at 750 ° C
The temperature is 1 ° C, preferably about ± 0.5 ° C. If the temperature is too high, the hydrogen-absorbing metal is greatly deteriorated, and particularly when used as a heater, the life of the heater is shortened. If the temperature is too low, sufficient hydrogen absorption cannot be performed.

A device for absorbing and removing a gas species provided above a heating device for decomposing H ₂ S is to absorb and remove a gas species consisting only of the H element among the decomposed gas species. Increases the concentration of the gas species consisting only of the S element. Note that the gas species consisting only of the H element referred to in this specification includes all of H ₂ , H, H radicals, H ions, atomic H, and the like. H ₂ S is used for synthesizing sulfide.
Although used as a reaction source, it becomes a strongly reducing gas. However, according to the present invention, by decomposing H ₂ S gas and removing gas species consisting only of reducing H element,
It is effective for the S reaction by efficiently supplying a gas containing sulfur.
In particular, in applications where the reducibility of H ₂ S has been a problem, for example, avoidance of reduction damage to a synthesis device,
When synthesizing a thin film, it is effective when producing a sulfide thin film on a base that cannot withstand a reducing atmosphere.

The method for producing a sulfide according to the present invention is characterized in that the above-mentioned H ₂ S cracking cell is used as a sulfur element supply method for supplementing a sulfur source and a sulfur deficiency. According to the production method of the present invention, the strong reducing property of H ₂ S can be reduced, and only sulfur can be efficiently and stably supplied with good controllability. The present invention as a sulfur source in various sulfide synthesis, for example, sulfide powder raw materials, sulfide pellets for producing vapor-deposited films, gas atmosphere firing furnaces such as targets for forming sputtered films, and synthesis furnaces for sulfide single crystal materials. It is preferable to use a production method using an H ₂ S cracking cell. Further, the production of sulfides, E
It is particularly preferable for a method for manufacturing an L element.

The sulfide is preferably an alkaline earth metal sulfide, a transition metal sulfide, a rare earth sulfide, a chalcopyrite compound, an alkaline earth thiogalade, an alkaline earth thioaluminate, or an alkaline earth thioinlate. Of these, semiconductor materials, luminous materials, and fluorescent materials, in particular, require high-purity and high-characteristic compounds. Therefore, the production method of the present invention is particularly preferable.

Further, the method for producing a sulfide of the present invention is based on the existing film forming methods such as EB (electron beam) evaporation, resistance heating evaporation, multi-source evaporation, reactive evaporation, MBE, sputtering, laser ablation, and CVD. H
_This is a manufacturing method combining ₂ S cracking cells,
Suitable for sulfide production.

In the thin film production process, the H ₂ S cracking cell decomposes the H ₂ S gas and removes the gas species consisting of only the reducing H element, thereby efficiently converting the sulfur-containing gas species into a vacuum. Can be introduced. In addition to avoiding reduction damage to the vacuum device, the sulfur element can be effectively introduced into the thin film during the film formation, and a high-quality and high-performance sulfide thin film can be manufactured. It is also effective when a sulfide thin film is formed on a base that cannot withstand a reducing atmosphere at a high temperature. Further, in general, when obtaining a high-quality, high-crystalline sulfide thin film, it is necessary to raise the process temperature such as high substrate temperature or annealing at a high temperature. Thus, the sulfur atmosphere can be created while avoiding the above, so that the process temperature for producing the sulfide thin film can be reduced.

Further, the present invention shows an unprecedented excellent effect as a method for producing a phosphor thin film for an EL element. For example, when applied to an EL element using a SrS: Ce phosphor thin film that is a blue light emitting material, it exhibits high light emitting characteristics.

When forming a SrS: Ce phosphor thin film in the following, H _{2 of} the present invention is used as a sulfur element supply source for sulfuration.
The manufacturing method by EB (electron beam) vapor deposition using a cracking cell of S will be described in more detail.

SrS is used as a base material of the phosphor, and a luminescence center is added. It is possible to uniformly add an emission center of several mol% or less to SrS, and to evaporate pellets, powders, compacts, solids, and the like using the same.

The emission center may be added with a certain amount of a transition metal or a rare earth. For example, rare earth metals such as Ce and Eu or Cr, Fe, Co, Ni, Cu, Bi, Ag and the like are added to the raw material in the form of metal, fluoride or sulfide.
Since the amount of addition differs depending on the raw material and the thin film to be formed, the composition of the raw material is adjusted so as to be an appropriate addition amount.

The evaporation source is EB (electron beam)
May be used. The evaporation rate of the material varies depending on the composition of the film to be formed, but is about 1 to 50 nm / sec.

The substrate temperature during the deposition is 150 ° C. to 800
° C, preferably 350 ° C to 650 ° C, more preferably 400 ° C to 600 ° C. If the substrate temperature is too low, the crystallinity of SrS does not increase. If the substrate temperature is too high, the unevenness of the surface of the thin film of the base material becomes severe, pinholes are generated in the thin film, and a problem of current leakage occurs in the EL element. For this reason, the above-mentioned temperature range is preferable.

When an SrS: Ce thin film is to be obtained as a light-emitting layer, the composition of the thin film becomes SrS when the vapor deposition is performed using a pellet obtained by adding Ce to SrS without compensation for the sulfur component.
If S / Sr <1, instead of / Sr = 1, a stoichiometric shortage of sulfur will occur. Thus, in the present invention, H ₂ S is introduced into the H ₂ S cracking cell for the base material to compensate for the sulfur component.

[0032] In the present invention, H ₂ S, which is introduced into H ₂ S cracking cell is sulfur compensation source SrS film. That is, the hydrogen component in H ₂ S is removed from the H ₂ S cracking cell to the substrate surface, and the high-concentration sulfur component, that is,
S, S2, S3, S radicals and S ions are supplied as sulfur sources. When H ₂ S is supplied as it is, when the temperature of the substrate is high, a reducing gas such as H ₂ is generated, and the underlying substrate, the underlying electrode, the sulfide thin film itself, etc. forming the thin film are reduced or hydrogenated, receive damage. In the present invention, since a reducing hydrogen component can be minimized and a sulfur source can be supplied, a high-quality SrS thin film is formed on the substrate surface.
At this time, only sulfur component from the H ₂ S cracking cell,
Although it flies and diffuses and re-evaporates on the substrate surface, it supplies a sulfur component to SrS during surface diffusion or while flying. Therefore, a SrS thin film free from sulfur deficiency can be obtained.

According to the present invention, not only can the SrS composition be controlled, but also the crystallinity of SrS can be improved. S of SrS thin film
Since the ratio of r and S is 1: 1, the crystallinity is increased, and at the same time, the sulfur component is supplied in an atmosphere having no reducing or hydrogenating properties, and each element is located at a stable crystal site. Defects due to Sr, S, Ce added as a luminescence center, etc. are less likely to occur, and a highly crystalline thin film can be obtained. E
Since L is a light emission phenomenon under a high electric field, it is necessary to increase the crystallinity of the base material in order to obtain a high-luminance phosphor thin film. According to the present invention, the source of elemental sulfur is H
Only used ₂ S cracking cell, easily allowing high crystallinity.

In the light emitting layer, in order to increase the luminance, it is necessary to add a light emitting center to a highly crystalline base material in a form containing no defect. For example, taking Ce in SrS as an example, C
e has a trivalent and tetravalent electronic state, and needs to be added as Ce ³⁺ which emits Ce. The SrS host material crystal has a NaCl-type crystal structure, and when Ce is added,
Substitution at the position of r and doping. At this time, Sr
^{Since 2+} and Ce ³⁺ have different ion valences, vacancies are generated at the Sr position, and furthermore, Ce ^{4+ in which} Ce does not contribute to light emission.
Doping in the form.

Here, in the present invention, S, S ₂ , S ₃ , S radicals, S ions and the like supplied from the H ₂ S cracking cell have excellent controllability as compared with other sulfur source supply methods. Show. In the SrS compound crystal, the ratio of Ce ³⁺ and Ce ⁴⁺ generation changes according to the amount of Sr vacancies. That is, in the SrS: Ce phosphor, it is preferable to control the Sr vacancies in order to improve the emission characteristics. For that purpose, it is effective to increase the controllability of the amount of S in the compound crystal.
Therefore, when a phosphor is produced using the H ₂ S cracking cell of the present invention, it is possible to produce a phosphor having excellent emission characteristics than ever before.

As described above, according to the present invention, it is possible to form a sulfide thin film while reducing the strong reducing ability of H ₂ S and supplying only the sulfur component efficiently and controllably and stably.

The formed sulfide fluorescent thin film is preferably a highly crystalline thin film, and although it depends on the material to be formed, particularly has a NaCl type crystal structure and has a (100) or (111) orientation. It is preferably a crystalline thin film.
The evaluation of the crystallinity can be performed by, for example, X-ray diffraction. In order to increase the crystallinity, the substrate temperature should be as high as possible. Also, in a vacuum after forming a thin film, in N2, Ar
Annealing in medium, in sulfur vapor, in H ₂ S, in air, or of course in an atmosphere using a H ₂ S cracking cell is also effective.

The thickness of the light emitting layer is not particularly limited, but if it is too thick, the driving voltage increases, and if it is too thin, the luminous efficiency decreases. Specifically, although it depends on the fluorescent material, it is preferably 100 to 2000 nm, particularly 300 to 15 nm.
It is about 00 nm.

The pressure during the deposition is preferably 1.33 × 10 ^-4 in order to introduce H ₂ S into the H ₂ S cracking cell.
~ 1.33 × 10 ^-1 Pa (1 × 10 ^{-6 -1} × 10 ^-3 Torr)
It is.

The substrate may be moved or rotated at the time of vapor deposition, if necessary. By moving and rotating the substrate, the film composition becomes uniform and the variation in film thickness is reduced.

When the substrate is rotated, the number of rotations of the substrate is preferably 10 times / min or more, more preferably 1 / min.
It is about 0 to 50 times / min, especially about 10 to 30 times / min. If the number of rotations of the substrate is too high, problems such as sealing properties tend to occur when the substrate is introduced into the vacuum chamber. Also,
If it is too slow, composition unevenness occurs in the film thickness direction in the tank, and the characteristics of the produced light emitting layer deteriorate. As a rotating means for rotating the substrate, a motor, a power source such as a hydraulic rotating device, and a power transmission device combining a gear, a belt, a pulley, etc.
It can be constituted by a known rotating device using a reduction gear or the like.

The heating means for heating the substrate has a predetermined heat capacity,
Any material having reactivity or the like may be used, and examples thereof include a tantalum wire heater, a sheath heater, and a carbon heater. The heating temperature by the heating means is preferably 100 to 1
About 400 ° C, temperature control accuracy is ± 1 at 1000 ° C
° C, preferably about ± 0.5 ° C.

FIG. 2 shows a thin film forming apparatus using the H2S cracking cell of the present invention. In the figure, a substrate 12 on which a light emitting layer is formed and an EB evaporation source 15 serving as a strontium sulfide evaporation source are arranged in a vacuum layer 11. The vacuum chamber 11 has an exhaust port 11a, and the inside of the vacuum chamber 11 can be set to a predetermined degree of vacuum by exhausting from the exhaust port.

In the vacuum chamber, H_TwoS cracking cell 1
Through 4, H_TwoS is introduced. H _TwoS cracking
Is placed inside the vacuum chamber and H_TwoThe factor for decomposing S
Absorbs heaters used in thermal equipment and H-based gas species
Heat for heating the hydrogen storage metal in the collecting and removing device
And temperature controller to supply power to
The control device is provided outside the vacuum chamber.

The substrate 12 is fixed to a substrate holder 12a, and a fixed shaft 12b of the substrate holder 12a is rotatably fixed from the outside while maintaining the degree of vacuum in the vacuum chamber 11 by rotating shaft fixing means (not shown). I have. And
Rotation means (not shown) enables rotation at a predetermined rotation number as required. Also, the substrate holder 1
2a is a heating means 1 composed of a heater wire or the like.
3 is closely attached and fixed, and heats the substrate to a desired temperature;
It can be held.

The EB (electron beam) evaporation source 15 serving as SrS evaporation means has a "crucible" 50 in which strontium sulfide 15a to which a luminescent center is added is stored, and an electron gun 51 having a built-in filament 51a for electron emission. . An AC power supply 52 and a bias power supply 53 are connected to the electron gun 51.

Using such an apparatus, the SrS vapor evaporated from the EB evaporation source 15 and the sulfur-based gas supplied from the H ₂ S cracking cell are deposited and combined on the substrate 12 to form a light emitting layer. . At that time, if necessary, the substrate 1
By rotating 2, the composition and the film thickness distribution of the deposited light emitting layer can be made more uniform.

As described above, according to the method for producing a sulfide using the H ₂ S cracking cell of the present invention, a phosphor thin film which emits light with high luminance can be easily formed.

In order to obtain an inorganic EL device by using the manufacturing method of the present invention, for example, a structure as shown in FIG. 3 may be used. Further, between the substrate 1, the lower electrode 5, the upper electrode 6, the thick-film insulating layer 2, and the thin-film insulating layer 4, a layer for improving the adhesion, a layer for relaxing the stress, and preventing a reaction. An intermediate layer such as a layer may be provided. The surface of the thick film may be polished or a flattening layer may be used to improve the flatness.

The material used for the substrate is a thick film forming temperature,
A substrate having a heat-resistant temperature or a melting point of not less than 600 ° C., preferably not less than 700 ° C., especially not less than 800 ° C. which can withstand the formation temperature of the EL fluorescent layer and the annealing temperature of the EL element is used to form the EL element formed thereon. It is not particularly limited as long as it can maintain a predetermined strength. Specifically, alumina (Al ₂ O ₃ ), forsterite (2MgO.SiO ₂ ), steatite (MgO.Si)
O ₂ ), mullite (3Al ₂ O ₃ .2SiO ₂ ), beryllia (BeO), aluminum nitride (AlN), silicon nitride (SiN), ceramic substrate such as silicon carbide (SiC + BeO), heat-resistant glass substrate such as crystallized glass Can be mentioned. Each of these heat-resistant temperatures is 10
It is about 00 ° C or more. Among these, an alumina substrate and crystallized glass are particularly preferable, and when thermal conductivity is required, beryllia, aluminum nitride, silicon carbide and the like are preferable.

In addition, a metal substrate made of titanium, stainless steel, inconel, iron, or the like, such as quartz or thermally oxidized silicon wafer, can also be used. When a conductive substrate such as a metal is used, a structure in which a thick film having an electrode inside is formed on the substrate is preferable.

As the dielectric thick film material (first insulating layer), a known dielectric thick film material can be used. Further, a material having a relatively large dielectric constant is preferable.

For example, materials such as lead titanate, lead niobate, and barium titanate can be used.

The resistivity of the dielectric thick film is 10 ⁸ Ω · c
m or more, particularly about 10 ¹⁰ to 10 ¹⁸ Ω · cm. Further, it is preferable that the material has a relatively high dielectric constant, and the dielectric constant ε thereof is preferably ε = 100 to 1000.
It is about 0. The film thickness is preferably from 5 to 50 μm, particularly preferably from 10 to 30 μm.

The method for forming the insulating layer thick film is not particularly limited, and a method in which a film having a thickness of 10 to 50 μm can be obtained relatively easily is preferable, but a sol-gel method, a printing and baking method and the like are preferable.

In the case of the printing and baking method, the particle size of the material is appropriately adjusted and mixed with a binder to obtain a paste having an appropriate viscosity. This paste is formed on a substrate by a screen printing method and dried. The green sheet is fired at an appropriate temperature to obtain a thick film.

As a constituent material of the thin film insulating layer (second insulating layer), for example, silicon oxide (SiO ₂ ), silicon nitride (SiN), tantalum oxide (Ta ₂ O ₅ ), strontium titanate (SrTiO ₃ ), Yttrium oxide (Y ₂
O ₃ ), barium titanate (BaTiO ₃ ), lead titanate (PbTiO ₃ ), PZT, zirconia (ZrO ₂ ), silicon oxynitride (SiON), alumina (A
l ₂ O _3), lead niobate, PMN-PT based material and can be exemplified these multilayer or mixed thin film, as a method of forming an insulating layer with these materials, vapor deposition, sputtering, CVD An existing method such as a sol-gel method or a printing and baking method may be used. In this case, the thickness of the insulating layer is preferably 50 to 1000 nm, particularly 100 to 500 nm.
It is about nm.

The electrode (lower electrode) is formed on the substrate side or in the first dielectric. At the time of forming the thick film, the electrode layer exposed further to the high temperature of the heat treatment together with the light emitting layer is made of a commonly used metal such as palladium, rhodium, iridium, rhenium, ruthenium, platinum, tantalum, nickel, chromium, titanium, etc. An electrode may be used.

Further, the other electrode layer serving as the upper electrode usually needs a transparent electrode having a light-transmitting property in a predetermined emission wavelength range in order to extract light emission from the side opposite to the substrate. The transparent electrode may be used as the lower electrode because the emitted light can be extracted from the substrate side if the substrate is transparent. In this case, it is particularly preferable to use a transparent electrode such as ZnO or ITO. ITO usually contains In ₂ O ₃ and SnO in a stoichiometric composition, but the amount of O may slightly deviate from this. The mixing ratio of SnO ₂ to In ₂ O ₃ is 1-2.
0 wt%, more preferably 5 to 12 wt%. Also, IZ
The mixing ratio of ZnO to In ₂ O _{3 in} O is usually 12
About 32% by weight.

As a method for forming an electrode layer from these materials, existing methods such as a vapor deposition method, a sputtering method, a CVD method, a sol-gel method, and a printing and baking method may be used. In particular, an electrode is formed inside a substrate. When fabricating a structure having a thick film having the same, the same method as that for the dielectric thick film is preferable.

The preferred resistivity of the electrode layer is 1 Ω · cm or less, particularly 0.003 to 0.1 Ω · cm, in order to efficiently apply an electric field to the light emitting layer. The thickness of the electrode layer depends on the material to be formed, but is preferably from 50 to 200.
0 nm, especially about 100 to 1000 nm.

As described above, the method for producing a sulfide according to the present invention is described as follows.
Although the description has been given of the case where the present invention is applied to the L element, the present invention can be applied to other types of elements and displays as long as the element can use the light emitting layer of the present invention.

[0063]

EXAMPLES Hereinafter, the present invention will be described in more detail by showing specific examples of the present invention. Embodiment 1 FIG. 1 shows a vapor deposition apparatus which is an example of the thin film forming apparatus of the present invention. The H ₂ S cracking cell composed of absorber of hydrogen introduction portion and the alumina container and tungsten heater H ₂ thermal decomposition apparatus and a tantalum wire S of H ₂ S and the heater and the hydrogen storage material as the sulfur source Evaporated from an EB source 15 containing SrS pellets provided with 0.16 mol% of Ce,
A SrS: Ce layer was formed on the substrate heated to 0 ° C. and rotated. The evaporation rate of the evaporation source was adjusted to 1 nm / sec.

As a result of composition analysis of the SrS: Ce thin film by X-ray fluorescence analysis, Sr: S: Ce = 48.1 in atomic ratio.
4: 51.75: 0.11. X-ray diffraction revealed that the film was a (100) -oriented crystal thin film having a NaCl-type crystal structure.

Further, an EL device having the structure shown in FIG. 3 using this light emitting layer was manufactured.

The same material is used for both the substrate and the thick insulating layer.
Using a TiO ₃ based dielectric material having a dielectric constant of 5000,
A Pd electrode was used as a lower electrode. For production, a sheet of a substrate was prepared, and a lower electrode and a thick film insulating layer were screen-printed thereon to form a green sheet, which was simultaneously fired. The surface was polished to obtain a substrate having a thick first insulating layer having a thickness of 30 μm.

On this, a phosphor thin film (light emitting layer) of 1000 nm was formed in the same manner as described above.

Further, a second insulating layer thin film was formed on the phosphor thin film. The second insulating layer film, using a Ta ₂ O _5, to form the Ta ₂ O ₅ film having a thickness of 200 nm. On the second insulating layer thin film, an ITO oxide target was used by RF magnetron sputtering at a substrate temperature of 250 ° C. and a film thickness of 200
An ITO transparent electrode having a thickness of nm was formed to complete an inorganic EL device.

By applying an electric field of 1 KHz and a pulse width of 50 μS to the electrode, an emission luminance of 1000 cd / m ² was obtained with good reproducibility.

For comparison, the conventional manufacturing method Sr
S: H ₂ S at 500 ° C. substrate temperature using Ce pellets
In the light emitting layer formed without introducing the gas and using the H ₂ S cracking cell of the present invention, the light emitting layer had a value of 150 cd / m ² or less, and some of the light emitting layers could not be measured. In the case of the unmeasurable one, the conductivity of the Pd electrode of the lower electrode was lost. That is, it is considered that the introduction of the H ₂ S gas caused a reaction by hydrogenation of the underlying Pd electrode or reduction of the BaTiO ₃ thick film.

The effects of the present invention are clear from the above embodiments. It can be seen that the H ₂ S cracking cell of the present invention is an effective sulfur source for sulfide synthesis. In particular, it can be seen that when used for the production of a phosphor thin film made of a sulfide, the shortage of sulfur and the contamination of impurities of the sulfide, which is the base material of the phosphor thin film, are solved, and a light emitting layer with high luminance can be obtained. An EL element using such a thin film has excellent light-emitting properties, and in particular,
When a multicolor EL element or a full-color EL element is formed, a light-emitting layer can be manufactured with high reproducibility, and has a large practical value.

[0072]

As described above, the H ₂ S cracking cell according to the present invention is excellent as an effective sulfur source for synthesizing sulfide. Since a sulfide thin film in which sulfur deficiency and contamination of impurities are suppressed can be obtained, it is possible to provide a method for manufacturing a light-emitting layer excellent in light emission luminance, efficiency, and degree of coloration, and a method for manufacturing an EL element.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration example of an H ₂ S cracking cell of the present invention.

FIG. 2 is a schematic view showing a configuration example of a thin film forming apparatus of the present invention.

FIG. 3 is a partial cross-sectional view illustrating a configuration example of an inorganic EL element that can be manufactured by the method of the present invention.

[Explanation of symbols]

Reference Signs List 1 substrate 2 first insulating layer (dielectric layer) 3 phosphor thin film (light emitting layer) 4 second insulating layer (dielectric layer) 5 lower electrode 6 upper electrode (transparent electrode) 11 vacuum chamber 12 substrate 13 heating means 14 H ₂ S cracking cell 15 EB evaporation source 16 H ₂ S inlet 17 Heating device for decomposing H ₂ S 18 Device for absorbing and removing H-based gas

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 33/10 H05B 33/10 33/14 33/14 Z F term (Reference) 3K007 AB02 AB04 AB18 BA06 CB01 DA05 DB01 DB02 DC04 EA02 EC01 EC04 FA01 4H001 CA01 CF01 XA16 XA38 YA58 4K029 BA51 BC07 BD00 CA02 DB21

Claims (16)

[Claims] 1. An H2S cracking cell comprising an inlet for a hydrogen sulfide stream, an apparatus for thermally decomposing the hydrogen sulfide stream, and an apparatus for absorbing a gas species consisting only of H element. 2. A heating temperature of the heating device is 400 ° C. to 1 ° C.
The H2S cracking cell according to claim 1, which is at 200C. 3. The H2S cracking cell according to claim 1, wherein the gas type absorbing device consisting only of the H element is a heated metal or a metal hydrogen alloy. 4. The H2S cracking cell according to claim 3, wherein the temperature of the heated metal or metal-hydrogen alloy is between 600 ° C. and 800 ° C. 5. The H2S cracking cell according to claim 3, wherein the heated metal is tantalum. 6. A production method for producing a sulfide while supplying a sulfur element, wherein the hydrogen sulfide gas stream is heated and decomposed to absorb and remove a gas species consisting only of the generated H element, and the sulfur element is used as a sulfur source. A method for forming a sulfide, characterized in that: 7. The thermal decomposition temperature of the hydrogen sulfide gas stream is 4
The method for producing a sulfide according to claim 6, wherein the temperature is from 00C to 1200C. 8. The method for producing a sulfide according to claim 6, wherein the gas species is absorbed and removed by using a heated metal or a metal-hydrogen alloy. 9. The temperature of the heated metal is from 600 ° C.
The method for producing a sulfide according to claim 8, wherein the temperature is 800 ° C. 10. The method for producing a sulfide according to claim 8, wherein the heated metal is tantalum. 11. A method for manufacturing an inorganic EL device in which a sulfide-based thin film phosphor is formed on a substrate while supplying a sulfur element, wherein a hydrogen sulfide gas stream is thermally decomposed to absorb a gas species consisting of generated hydrogen. A method for producing an inorganic EL device, comprising removing the sulfur element and supplying the sulfur element as a sulfur source. 12. The method according to claim 1, wherein the temperature of the thermal decomposition of the hydrogen sulfide gas stream is 400 ° C. to 1200 ° C.
2. The method for producing an inorganic EL device according to item 1. 13. The method according to claim 11, wherein the gas species is absorbed and removed by using a heated metal or a metal hydrogen alloy. 14. The temperature of the heated metal is 600 ° C.
The method for producing an inorganic EL device according to claim 13, wherein the temperature is -800C. 15. The inorganic E according to claim 13, wherein the heated metal is tantalum.
Manufacturing method of L element. 16. An inorganic EL device obtained by the method according to claim 11. Description: