JP2001085157A - Electronic device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a dense film at low temperature and prevent penetration of moisture, oxygen, or the like from the outside by forming a protecting film by ECR plasma sputtering method. SOLUTION: A protecting film 7 is formed by ECR plasma sputtering method. An organic EL element is composed of a substrate 1, an anode 2, an organic thin film layer 3, a hole transport layer 4, a light-emitting layer 5, a cathode 6, and the protecting film 7. Penetration of hydrogen, oxygen, or the like from the outside is prevented without breaking the EL element including the cathode 6 and others. Preferably, the organic EL element has a pair of electrodes and at least one organic thin film layer interposed between them, and the protecting film for protecting at least part of the outer surface. An electronic device whose part of the outer surface is protected with silicon nitride-oxide SiON has a pair of electrodes arranged on the substrate and at least one organic thin layer interposed between the electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a protective film used for sealing and protecting various electronic devices, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In general, electronic devices are susceptible to external environment such as moisture and heat, so some kind of sealing is applied. Highly reliable sealing technology has become indispensable, and various studies have been conducted.

[0003] The materials used are also changing from conventional inorganic materials to organic / inorganic hybrid systems utilizing the diversity of organic materials, and are affected by the external environment such as moisture, heat and stress. It is becoming an issue how to suppress the deterioration of organic matter which is liable to occur.

An organic electroluminescent element has recently attracted attention as a device using such an organic material.

[0005] An electroluminescence element is a light-emitting device utilizing electroluminescence of a solid fluorescent substance.
Until now, an inorganic electroluminescence element using an inorganic material as a light emitter has been put to practical use and applied to a backlight of a liquid crystal display, a flat display, and the like. Further, recently, an organic electroluminescence device using an organic material as a light emitting body has begun to be put into practical use.

Here, a conventional organic electroluminescent device will be described with reference to FIG.

FIG. 5 is a cross-sectional view of a main part of a conventional organic electroluminescence device.

In FIG. 5, 1 is a substrate, 2 is an anode, 3 is an organic thin film layer, 4 is a hole transport layer, 5 is a light emitting layer, and 6 is a cathode.

As shown in FIG. 5, a conventional organic electroluminescence element comprises a transparent or translucent substrate 1 made of glass or the like, and a transparent substrate made of ITO or the like formed on the substrate 1 by sputtering or resistance heating evaporation. 2 made of a transparent conductive film, and N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-diphenyl- formed on the anode 2 by resistance heating evaporation or the like. A hole transport layer 4 made of 4,4′-diamine (hereinafter abbreviated as TPD) and 8-hydroxyquinoline aluminum (8-Hy) formed on the hole transport layer 4 by a resistance heating evaporation method or the like;
droxyquinoline Aluminum, hereinafter referred to as Alq _3. ) And a cathode 6 made of a metal film or the like formed on the luminescent layer 5 by a resistance heating evaporation method or the like.

When a DC voltage or a DC current is applied with the anode 2 of the organic electroluminescent device having the above structure as a positive electrode and the cathode 6 as a negative electrode, the anode 2 is applied to the light emitting layer 5 via the hole transport layer 4. Holes are injected, and electrons are injected from the cathode 6 into the light emitting layer 5. Light emitting layer 5
In such a case, recombination of holes and electrons occurs, and a light emission phenomenon occurs when the exciton generated thereby shifts from the excited state to the ground state. The emission wavelength can be changed by changing the layer structure of the organic thin film layer 3 and the material used for the light emitting layer 5.

In order to improve the light-emitting characteristics of such an organic electroluminescence device, there have hitherto been 1) an improvement in the structure of an organic thin film layer such as a light-emitting layer and a hole transport layer, and an improvement in an organic material used for the same, or 2). Improvement of materials used for the anode and the cathode has been studied.

For example, in the case of 2), an Mg-Ag alloy described in US Pat. No. 4,885,211 is used for the purpose of lowering the barrier between the cathode and the light emitting layer so that electrons can be easily injected into the light emitting layer. The work function is small, such as the Al-Li alloy described in JP-A-5-121172,
In addition, materials having high electric conductivity have been proposed, and such materials are widely used even today.

However, since these alloy materials have high activity and are chemically unstable, corrosion and oxidation are caused by reaction with moisture and oxygen in the air. Such corrosion and oxidation of the cathode remarkably grow a non-light-emitting portion called a dark spot (DS) existing in the light-emitting layer, and cause deterioration of characteristics of the organic electroluminescence element over time. .

In addition to the cathode, not only the cathode but also the organic material used for the organic thin film layer such as the light emitting layer and the hole transport layer generally undergoes a structural change due to reaction with moisture or oxygen. It causes growth.

The present inventors have studied the growth of dark spots from various viewpoints. As a result, for example, 10 ⁻⁴ To
It has been discovered that even a very small amount of water, such as that present in a vacuum of about rr, promotes the growth of dark spots. Therefore, in order to completely eliminate the growth of dark spots and increase the durability and reliability of the organic electroluminescence device, it is necessary to prevent the reaction between the material used for the cathode and the organic thin film layer with moisture and oxygen. The entire electroluminescent element needs to be sealed.

The sealing of the organic electroluminescent element has been mainly studied by two methods. One is to form a protective film on the outer surface of the organic electroluminescent element by using a vacuum film forming technique such as a vapor deposition method, and the other is to apply a shielding material such as a glass cap to the organic electroluminescent element. It seals to the element.

The former method of forming a protective film and sealing an organic electroluminescent element is disclosed in, for example, Japanese Patent Application Laid-Open No. 6-96858, GeO, SiO, AlF _3.
And the like are disclosed on an outer surface of an organic electroluminescent element by an ion plating method.

Japanese Patent Application Laid-Open No. Hei 10-261487 discloses a method of forming a Si ₃ N ₄ or a diamond-like carbon film on the outer surface of an organic electroluminescence device by an ECR plasma CVD method.

Further, Japanese Patent Application Laid-Open No. 7-212455 discloses a method for forming a protective film comprising a water-absorbing substance having a water absorption of 1% or more and a moisture-proof substance having a water absorption of 0.1% or less.

As a method of sealing the organic electroluminescence element by sealing the latter shielding material, a glass plate is provided outside the back electrode and the back electrode is used as already used in the inorganic electroluminescence element. After a protective film made of an insulating inorganic compound is formed, as described in Japanese Patent Application Laid-Open No. 5-89959, a method of encapsulating silicone oil between the glass and a glass plate, and then using an electrically insulating glass or an electrically insulating airtight fluid. Shielding method, and furthermore, JP-A-6-176867 and JP-A-9-14
No. 8066 discloses a method of enclosing a desiccant in a sealed airtight container.

As described above, various techniques have been tried for sealing the organic electroluminescent element. However, in order to make use of the thinness which is a great feature of the organic electroluminescent element, sealing is performed only with a thin protective film. Is preferred.

[0022]

Heretofore, a protective film of a general electronic device has been formed by sputtering using a sputtering method.
O ₂ and Al ₂ O ₃ have been used. However, since the organic electroluminescence element does not have heat resistance, a film forming method such as a normal sputtering method which raises the temperature during film formation is not suitable.

As other protective film forming methods, an evaporation method, an electron beam evaporation method, an ion plating method, and the like can be considered. The evaporation method has a porous film quality, and the electron beam evaporation method and the ion plating method have a temperature. There is a problem such as an increase, and a method for forming a protective film suitable for an organic electroluminescence device has not been established at present.

Therefore, for example, Japanese Patent Application Laid-Open No. 6-96858.
In the formation of the protective film using the ion plating method described in Japanese Patent Application Laid-Open Publication No. H11-157, it is difficult to increase the thickness of the protective film due to the temperature during film formation and the film stress after film formation. Spot growth could not be suppressed.

Further, in the formation of a protective film using the ECR plasma CVD method described in JP-A-10-261487, it is necessary to use a gas such as SiH ₄ as a raw material, and the manufacturing method is complicated. Invite. Further, there is a problem that a material for which gas is difficult to obtain cannot be formed into a film.

Also, the sealing with the shielding material, which has been conventionally attempted, has not yet completely suppressed the growth of dark spots, although the sealing material has been improved.

The present invention solves the above-mentioned problems, and can form a film at a low temperature on an electronic device such as an organic electroluminescence element, and is dense and capable of preventing invasion of moisture, oxygen and the like from the outside. An object of the present invention is to provide an electronic device having a protective film formed thereon and a method for manufacturing the same.

[0028]

According to the method of manufacturing an electronic device of the present invention, the formation of a protective film is performed by ECR (electron).
By performing the method by a cyclotron resonance plasma sputtering method, a dense film can be formed at a low temperature, and thus, intrusion of moisture, oxygen, and the like from the outside can be prevented.

In the electronic device of the present invention, by protecting at least a part of the outer surface of the electronic device with silicon nitride oxide, the invasion of moisture and oxygen from the outside can be prevented without breaking the device by stress. Becomes possible.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a method for manufacturing an electronic device protected by at least one protective film.
CR (electron cyclotron res
once) by a plasma sputtering method, it is possible to form a dense film at a low temperature, and it is possible to prevent moisture, oxygen and the like from entering from the outside. It has an effect that a high device can be obtained.

According to a second aspect of the present invention, in the method for manufacturing an electronic device according to the first aspect, at least one protective film is formed by an ECR plasma sputtering method. Has a pair of electrodes arranged on the substrate, and a laminate in which at least one organic thin film layer is sandwiched therebetween,
At least a part of the outer surface of the organic electroluminescent element is to be protected by a protective film, and a dense film can be formed without destroying the organic electroluminescent element by heat. Because it becomes possible to prevent intrusion of oxygen etc.,
This has the effect of providing a highly reliable organic electroluminescent element in which the growth of dark spots is suppressed.

According to a third aspect of the present invention, there is provided an electronic device which functions electrically, wherein at least a part of an outer surface of the electronic device is protected by silicon nitride oxide (SiON). In addition, since the stress of the protective film can be reduced and the thickness can be increased, a highly reliable device can be obtained.

According to a fourth aspect of the present invention, in the third aspect, an electronic device in which at least a part of the outer surface of the device is protected by silicon nitride oxide (SiON) is a pair of electronic devices arranged on a substrate. And an organic electroluminescence element having at least one organic thin film layer sandwiched between the electrodes, and a thick film without destroying the element portion due to the stress of the protective film. Has the effect that a highly reliable organic electroluminescence element in which dark spot growth is suppressed can be obtained.

According to a fifth aspect of the present invention, there is provided an electronic device which functions electrically, wherein at least a part of an outer surface of the electronic device is protected by silicon nitride oxide (SiON) formed by an ECR plasma sputtering method. It is possible to form a dense film without destroying the device due to a rise in temperature during film formation, and to obtain a highly reliable electronic device because the film can be made thicker. It has the action of:

According to a sixth aspect of the present invention, in the fifth aspect, at least a portion of the outer surface of the device is protected by silicon nitride oxide (SiON) formed by ECR plasma sputtering. An electronic device characterized by being an organic electroluminescence element having a pair of electrodes disposed on a substrate and a laminate in which at least one organic thin film layer is sandwiched therebetween. A dense film can be formed without destruction of the organic electroluminescent element due to the temperature rise during film formation, and a thicker film can be formed, so that a highly reliable organic electroluminescent element with suppressed dark spot growth can be obtained. Has the effect of being able to.

According to the ECR plasma sputtering method described in the above claim, it is possible to form a film at a low temperature.
The protective film can be formed not only on the organic electroluminescence element but also on any device, such as a device whose characteristics are degraded by heat.

Further, the silicon nitride oxide (SiON) described in the above claims has a smaller stress than SiO ₂ or SiN, so that the influence on the device can be suppressed low. Further, since its moisture permeability is superior to that of SiO ₂ , it is most suitable for encapsulating devices that require high moisture resistance.

As the substrate described in the above claims, transparent or translucent glass, PET (polyethylene terephthalate), polycarbonate, amorphous polyolefin and the like are used. Further, a flexible substrate or a flexible substrate using these materials as a thin film may be used.

As the anode, ITO, ATO (Sb-doped SnO ₂ ), AZO (Al-doped Zn
O) and the like.

The organic thin-film layer has a single-layer structure of only a light-emitting layer, a two-layer structure of a hole-transport layer and a light-emitting layer, or a two-layer structure of a light-emitting layer and an electron-transport layer, or a hole-transport layer, a light-emitting layer, and an electron. Any structure of the three-layer structure of the transport layer may be used. However, in the case of such a two-layer structure or a three-layer structure, they are stacked so that the hole transport layer and the anode or the electron transport layer and the cathode are in contact with each other.

The light emitting layer is preferably made of a phosphor having a fluorescent property in the visible region and having a good film-forming property, such as Alq ₃ or Be-benzoquinolinol (BeB).
In addition to the q _2), 2,5-bis (5,7-di -t- pentyl-2-benzoxazolyl) -1,3,4-thiadiazole, 4,4'-bis (5,7 Bentyl-2-benzoxazolyl) stilbene, 4,4'-bis [5,7
-Di- (2-methyl-2-butyl) -2-benzoxazolyl] stilbene, 2,5-bis (5,7-di-t-
Bentyl-2-benzoxazolyl) thiofin, 2,
5-bis ([5-α, α-dimethylbenzyl] -2-benzoxazolyl) thiophene, 2,5-bis [5,7
-Di- (2-methyl-2-butyl) -2-benzoxazolyl] -3,4-diphenylthiophene, 2,5-bis (5-methyl-2-benzooxazolyl) thiophene, 4,4 '-Bis (2-benzoxazolyl) biphenyl, 5-methyl-2- [2- [4- (5-methyl-
Benzoxazoles such as 2-benzoxazolyl) phenyl] vinyl] benzoxazolyl and 2- [2- (4-chlorophenyl) vinyl] naphtho [1,2-d] oxazole; 2,2 ′-(p Benzothiazoles such as -phenylenedivinylene) -bisbenzothiazole;
A fluorescent whitening agent such as a benzimidazole type such as 2- [2- [4- (2-benzimidazolyl) phenyl] vinyl] benzimidazole and 2- [2- (4-carboxyphenyl) vinyl] benzimidazole; 8-quinolinol) aluminum, bis (8-quinolinol)
Magnesium, bis (benzo [f] -8-quinolinol) zinc, bis (2-methyl-8-quinolinolate) aluminum oxide, tris (8-quinolinol) indium, tris (5-methyl-8-quinolinol) aluminum, 8- Quinolinol lithium, tris (5-chloro-8-quinolinol) gallium, bis (5-chloro-8-quinolinol) calcium, poly [zinc (")-
Bis- (8-hydroxy-5-quinolinonyl) methane], 8-hydroxyquinoline-based metal complexes, metal-chelated oxinoid compounds such as dilithium epindridione, 1,4-bis (2-methylstyryl) benzene,
1,4- (3-methylstyryl) benzene, 1,4-bis (4-methylstyryl) benzene, distyrylbenzene, 1,4-bis (2-ethylstyryl) benzene,
1,4-bis (3-ethylstyryl) benzene, 1,4
Styrylbenzene compounds such as -bis (2-methylstyryl) 2-methylbenzene, 2,5-bis (4-methylstyryl) pyrazine, 2,5-bis (4-ethylstyryl) pyrazine, 2,5- Bis [2- (1-naphthyl)
Vinyl] pyrazine, 2,5-bis (4-methoxystyryl) pyrazine, 2,5-bis [2- (4-biphenyl)
Distilpyrazine derivatives such as vinyl] pyrazine and 2,5-bis [2- (1-pyrenyl) vinyl] pyrazine;
A naphthalimide derivative, a perylene derivative, an oxadiazole derivative, an aldazine derivative, a cyclopentadiene derivative, a styrylamine derivative, a coumarin derivative, an aromatic dimethylidin derivative, or the like is used. Further, anthracene, salicylate, pyrene, coronene and the like are also used.

As the hole transporting layer, those having high hole mobility, high transparency and good film forming property are preferable, and in addition to TPD, porphine, tetraphenylporphine copper, phthalocyanine, copper phthalocyanine, titanium phthalocyanine oxide, etc. Porphyrin compound, 1,1-bis {4- (di-P-tolylamino) phenyl} cyclohexane, 4,4 ′, 4 ″ -trimethyltriphenylamine, N, N, N ′, N′-tetrakis ( P-tolyl)-
P-phenylenediamine, 1- (N, N-di-P-tolylamino) naphthalene, 4,4′-bis (dimethylamino) -2-2-2′-dimethyltriphenylmethane, N,
N, N ', N'-tetraphenyl-4,4'-diaminobiphenyl, N, N'-diphenyl-N, N'-di-m
-Tolyl-4, N, N-diphenyl-N, N'-bis (3-methylphenyl) -1,1'-4,4'-diamine, 4'-diaminobiphenyl, N-phenylcarbazole and the like Aromatic tertiary amines, 4-di-P-tolylaminostilbene, 4- (di-P-tolylamino) -4 ′
Stilbene compounds such as-[4- (di-P-tolylamino) styryl] stilbene, triazole derivatives, oxazizazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, , Annealed amine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styryl anthracene derivatives, fluorenone derivatives, hydrazone derivatives, silazane derivatives, polysilane aniline copolymers, high molecular oligomers, styrylamine compounds Organic materials such as aromatic dimethylidin compounds and poly-3-methylthiophene are used. Further, a polymer-dispersed hole transport layer in which a low molecular weight organic material for a hole transport layer is dispersed in a polymer such as polycarbonate is also used.

As the electron transporting layer, a joxadiazole derivative such as 1,3-bis (4-tert-butylphenyl-1,3,4-oxadiazolyl) phenylene (OXD-7) or an anthraquinodimethane derivative And diphenylquinone derivatives.

As the cathode, a metal or an alloy having a low work function is used, such as a metal such as Al, In, Mg, and Ti; a Mg alloy such as a Mg—Ag alloy and a Mg—In alloy; and an Al—Li alloy. An alloy, an Al-Sr alloy, an Al alloy such as an Al-Ba alloy, or the like is used.

An embodiment of the present invention will be described below.

(Embodiment 1) A method for forming a protective film according to an embodiment of the present invention will be described.

The film forming method using plasma generates excited species.
Is easy and the process temperature can be reduced.
It is used for film formation. Among them, ECR Plasmas
The sputtering method uses electron cyclotron resonance (ECR)
Low gas pressure (≪10 ^-FourTorr)
The solid target is ionized by this plasma.
To form a film.

FIG. 1 is a schematic view of a microwave branch-coupling type ECR sputtering apparatus used for the ECR plasma sputtering method. The microwave (2.45 GHz) generated by the magnetron is branched and then supplied to the plasma chamber through a quartz window. In addition, the plasma chamber has an EC with respect to a microwave frequency of 2.45 GHz.
A magnetic field of 875 G is applied by an external coil so that the R condition is satisfied, and plasma is generated by introducing Ar, O ₂ , N _{2, and the} like into this plasma chamber. A target such as Si is placed at the outlet of the plasma, and RF voltage is applied to perform sputtering.

Next, the formation of a protective film on the organic electroluminescence element will be described with reference to FIG.

FIG. 2 is a cross-sectional view of a main part of an organic electroluminescence element according to an embodiment of the present invention.

In FIG. 2, reference numeral 7 denotes a protective film, which was formed by ECR plasma sputtering.

The substrate 1, the anode 2, the organic thin film layer 3, the hole transport layer 4, the light emitting layer 5, and the cathode 6 are the same as those of the conventional organic electroluminescence device shown in the prior art. Therefore, the same reference numerals are given and the description is omitted.

As shown in FIG. 2, at least a part of the outer surface of the organic electroluminescence device according to the present embodiment is protected by a protective film formed by ECR plasma sputtering.

The difference between the organic electroluminescent element of the present embodiment and the conventional example is that of the ECR.
That is, the protective film was formed by the plasma sputtering method. This makes it possible to form a dense film for preventing intrusion of moisture, oxygen and the like from the outside without destroying the organic electroluminescence element including the cathode 6.

The operation of the organic electroluminescent device according to the present embodiment having the above-described configuration is the same as that of the conventional example, and the description is omitted.

As described above, according to the present embodiment, in an organic electroluminescence element having a pair of electrodes disposed on a substrate and a laminate in which at least one organic thin film layer is sandwiched therebetween, By protecting at least a part of the outer surface with a protective film formed by the ECR plasma sputtering method, it is possible to prevent the invasion of moisture, oxygen, etc. from the outside, and to reduce the reliability of the dark spot growth. It is possible to obtain a high organic electroluminescence element.

In this embodiment, the case where the organic thin film layer has a two-layer structure including the hole transport layer and the light emitting layer has been described, but the structure is not particularly limited as described above. is not.

In the present embodiment, the case of sealing with only the protective film has been described. However, the present invention is not particularly limited to this case. There is no problem with the combination.

Embodiment 2 Next, an organic electroluminescence device according to an embodiment of the present invention will be described.

FIG. 3 is a cross-sectional view of a main part of an organic electroluminescence element according to an embodiment of the present invention.

In FIG. 3, reference numeral 8 denotes a protective film made of SiON formed by ECR plasma sputtering.
A substrate 1, an anode 2, an organic thin film layer 3, a hole transport layer 4,
Since the light emitting layer 5 and the cathode 6 are the same as those in the conventional example, the same reference numerals are given and the description is omitted.

As shown in FIG. 3, at least a part of the outer surface of the organic electroluminescence device according to the present embodiment is protected by SiON formed by ECR plasma sputtering.

The difference between the organic electroluminescent element of the present embodiment and the conventional example is that of the ECR.
SiON is formed as a protective film by a plasma sputtering method, and this SiON is a thick film. As a result, a dense film can be formed without destruction of the organic electroluminescence element such as the cathode 6 due to a rise in temperature during film formation, and a thick film can be formed. A high organic electroluminescence element can be obtained.

In this embodiment, the case where the organic thin film layer has a two-layer structure including the hole transport layer and the light emitting layer has been described, but the structure is not particularly limited as described above. is not.

In the present embodiment, the case of sealing with only a protective film has been described. However, the present invention is not particularly limited to this embodiment. There is no problem with the combination.

[0066]

(Example 1) After forming an ITO film having a thickness of 160 nm on a glass substrate by a sputtering method,
Resist material (TOPR-80, OFPR-80) on TO film
0) was applied by spin coating to form a resist film having a thickness of 10 μm, and the resist film was patterned into a predetermined shape by masking, exposing, and developing. Next, this glass substrate is immersed in 50% hydrochloric acid at 60 ° C. to etch a portion of the ITO film where the resist film is not formed.
The resist film was also removed to obtain a glass substrate on which an anode made of an ITO film having a predetermined pattern was formed.

Next, the glass substrate was subjected to ultrasonic cleaning with a detergent (Semico Clean, manufactured by Furuuchi Chemical Co., Ltd.) for 5 minutes, ultrasonic cleaning with pure water for 10 minutes, ammonia water 1
(Volume ratio), ultrasonic cleaning with a mixed solution of hydrogen peroxide solution 1 and water 5 for 5 minutes, and ultrasonic cleaning with pure water at 70 ° C. for 5 minutes, followed by glass blowing with a nitrogen blower. The water adhered to the substrate was removed, and the substrate was further heated to 250 ° C. and dried.

Next, the surface of the glass substrate on the anode side was 2 ×
TPD was formed to a thickness of about 50 nm as a hole transport layer in a resistance heating evaporation apparatus in which the degree of vacuum was reduced to 10 ⁻⁶ Torr or less.

Next, similarly, in a resistance heating vapor deposition apparatus, Alq ₃ was formed in a thickness of about 60 nm as a light emitting layer on the hole transport layer. The deposition rates of TPD and Alq ₃ were both 0.2 nm / s.

Next, in the same manner, a cathode was formed in a thickness of 150 nm on the light emitting layer using an Al-Li alloy containing 15 at% Li as an evaporation source in a resistance heating evaporation apparatus.

An ECR plasma sputtering method was used to deposit Si over the organic electroluminescent element.
O ₂ and SiN were formed as protective films.

The film formation conditions were microwave power (mi).
(crower power) = 300 W, RF power = 100 W, gas flow rate (Ar) = 16 sccm, Flo
wRate Ratio O ₂ / (N ₂ + O ₂ ) = 0 (S
iN), 1 (SiO ₂ ). The film thickness at that time was 0.5 μm.

Similarly, germanium monoxide (GeO), which can be formed into a film by a vacuum deposition method, is formed on the organic electroluminescence device having the same structure up to the cathode, in a thickness of 0.5%.
μm formed element and SiO ₂ by electron beam evaporation
Was formed in a thickness of 0.5 μm.

The dark spots on the light-emitting surface of the above four types of organic electroluminescent elements immediately after encapsulation were measured at 60 ° C.
The dark spot after storage for 500 hours in a 90% RH environment was compared.

As a result, as shown in Table 1, the effect of suppressing the dark spot growth was as follows: SiN (ECR)> SiO
₂ (ECR) ≫SiO ₂ (electron beam deposition)> GeO (deposition).

[0076]

[Table 1]

As described above, even when the same material (SiO ₂ ) is used as the protective film, the effect is different due to the difference in the formation method. This is because the protective film formed by the ECR plasma sputtering method forms a denser film than that formed by another vapor deposition method and the like, thereby suppressing invasion of moisture and oxygen from the outside to the element portion. It is considered that

(Example 2) An organic electroluminescent device was produced in the same manner as in Example 1, and a protective film was formed thereon by ECR plasma sputtering. At that time, Flow Rate Ratio O ₂
/ (N ₂ + O ₂ ) to change SiO ₂ to SiON,
The composition of the film was changed up to SiN, and the film thickness for each film formation and the growth of dark spots at 60 ° C. and 90% RH were evaluated. Note that the film thickness that can be formed is a film thickness in a range that does not damage the element, and cracks and the like occur if the film is formed more than that. In addition, other film formation conditions are as follows:
All are the same as in the first embodiment.

First, the film thickness that can be formed is shown in FIG. Thus, the Flow Rate Ratio O ₂ / (N ₂ +
When O ₂ ) is 0.036 to 0.08, the film thickness that can be formed is the thickest, 3 μm, and in other regions, the film thickness that can be formed becomes thinner as the partial pressure of N ₂ and O ₂ increases. .
This is believed to be because the stress of the SiON compared to SiO ₂ and SiN is small.

Next, each Flow Rate Ratio
Table 2 shows the thickness of the protective film that can be formed of O ₂ / (N ₂ + O ₂ ) and the dark spot size of the protective film after storage at 60 ° C. and 90% RH for 500 hours.

[0081]

[Table 2]

As described above, the film itself has the best moisture permeability in the case of SiN, and in the following order of SiON and SiO _2. Considering the film thickness that can be formed, SiON is the most effective for the protective film of the organic electroluminescence element. It became clear that there was.

[0083]

As described above, according to the present invention, by forming a protective film of an electronic device such as an organic electroluminescence element by an ECR plasma sputtering method, device deterioration due to a temperature rise during film formation can be prevented. In addition, since a dense film can be formed, a highly reliable electronic device can be provided.

Further, according to the present invention, an electronic device such as an organic electroluminescence element
By providing protection with a protective film made of N, it is possible to increase the thickness of the device without breaking the device due to stress, and to suppress the invasion of moisture, oxygen, and the like from the outside, thereby providing a highly reliable electronic device. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a microwave branch-coupling type ECR sputtering apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of an organic electroluminescence element according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a main part of the organic electroluminescence element according to one embodiment of the present invention.

FIG. 4 is a view showing film thicknesses of SiO ₂ , SiON, and SiN that can be formed by ECR plasma sputtering.

FIG. 5 is a cross-sectional view of a main part of a conventional organic electroluminescence element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Organic thin film layer 4 Hole transport layer 5 Light emitting layer 6 Cathode 7 Protective film 8 SiON protective film

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Akira Gyutoku Inventor 4-1-2-6 Minojima, Hakata-ku, Fukuoka City, Fukuoka Prefecture Inside Kyushu Matsushita Electric Co., Ltd. (72) Shintaro Hara 4-1-1 Minojima, Hakata-ku, Fukuoka City, Fukuoka Prefecture No. 62 Kyushu Matsushita Electric Industrial Co., Ltd. (72) Inventor Hiroshi Nakajima 1-17-12 Toyohama, Nishi-ku, Fukuoka City, Fukuoka Prefecture (72) Inventor Takadai 2-2-1, Tsutsui, Onojo City, Fukuoka Prefecture 2nd Oka Building No.306 (72) Inventor, Katsunori Muraoka Fukuoka Prefecture, Nakagawa-cho, Nakagawa-cho, Fukuoka, Japan 3K007 AB00 AB12 AB13 BB00 BB01 CA01 CB01 DA00 DB03 EB00 FA00 FA01 FA02 FA03 5G435 AA07 AA13 BB05 FF08 GG25 KK10

Claims (6)

[Claims] 1. A method for manufacturing an electronic device protected by at least one protective film, wherein the protective film is formed by ECR (electron cyclotron).
(Resonance) A method for manufacturing an electronic device, wherein the method is performed by a plasma sputtering method. 2. A method for manufacturing an electronic device, wherein at least one protective film is formed by an ECR plasma sputtering method, wherein the electronic device includes a pair of electrodes disposed on a substrate and a pair of electrodes disposed between the pair of electrodes. A laminate in which at least one organic thin film layer is sandwiched,
2. The method according to claim 1, wherein at least a part of the outer surface is an organic electroluminescent element protected by a protective film. 3. An electronic device that functions electrically, comprising:
An electronic device, wherein at least a part of an outer surface thereof is protected by silicon nitride oxide (SiON). 4. An electronic device in which at least a part of an outer surface of the device is protected by silicon nitride oxide (SiON), wherein at least one organic thin film layer is sandwiched between a pair of electrodes disposed on a substrate. The electronic device according to claim 3, wherein the organic device is an organic electroluminescence element having a laminated body. 5. An electronic device that functions electrically, comprising:
At least a portion of the outer surface of the silicon nitride oxide (S
An electronic device protected by iON). 6. An electronic device according to claim 1, wherein at least a part of said device outer surface is protected by silicon nitride oxide (SiON) formed by ECR plasma sputtering. 6. The electronic device according to claim 5, wherein the organic device is an organic electroluminescent element having an electrode and a laminate in which at least one organic thin film layer is sandwiched therebetween.