JPH01204394A - Thin film el element - Google Patents
Thin film el elementInfo
- Publication number
- JPH01204394A JPH01204394A JP63027540A JP2754088A JPH01204394A JP H01204394 A JPH01204394 A JP H01204394A JP 63027540 A JP63027540 A JP 63027540A JP 2754088 A JP2754088 A JP 2754088A JP H01204394 A JPH01204394 A JP H01204394A
- Authority
- JP
- Japan
- Prior art keywords
- nitride
- film
- emitting layer
- light emitting
- oxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000010409 thin film Substances 0.000 title claims description 11
- 150000004767 nitrides Chemical class 0.000 claims abstract description 20
- 229910052751 metal Inorganic materials 0.000 claims abstract description 11
- 239000010408 film Substances 0.000 claims description 25
- 239000002184 metal Substances 0.000 claims description 4
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 2
- 239000007789 gas Substances 0.000 abstract description 8
- 238000004544 sputter deposition Methods 0.000 abstract description 7
- 239000001301 oxygen Substances 0.000 abstract description 6
- 229910052760 oxygen Inorganic materials 0.000 abstract description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 5
- 230000003647 oxidation Effects 0.000 abstract description 3
- 238000007254 oxidation reaction Methods 0.000 abstract description 3
- 238000002834 transmittance Methods 0.000 abstract description 3
- 230000032683 aging Effects 0.000 abstract description 2
- 238000009413 insulation Methods 0.000 abstract 6
- 230000002542 deteriorative effect Effects 0.000 abstract 1
- 239000000758 substrate Substances 0.000 description 6
- 230000007423 decrease Effects 0.000 description 4
- 230000006866 deterioration Effects 0.000 description 4
- 239000011521 glass Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- PBCFLUZVCVVTBY-UHFFFAOYSA-N tantalum pentoxide Inorganic materials O=[Ta](=O)O[Ta](=O)=O PBCFLUZVCVVTBY-UHFFFAOYSA-N 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- 238000005566 electron beam evaporation Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 239000005132 Calcium sulfide based phosphorescent agent Substances 0.000 description 1
- 239000012190 activator Substances 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- AMGQUBHHOARCQH-UHFFFAOYSA-N indium;oxotin Chemical compound [In].[Sn]=O AMGQUBHHOARCQH-UHFFFAOYSA-N 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- -1 oxygen ions Chemical class 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 238000001552 radio frequency sputter deposition Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
Landscapes
- Electroluminescent Light Sources (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、スペースファクタ、表示品質に優れた平面デ
イスプレィが期待される薄膜ＥＬ素子に係り、特に、輝
度特性に優れた多色表示ＥＬ素子に関する。[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a thin film EL device that is expected to provide a flat display with excellent space factor and display quality, and in particular, to a multicolor display EL device with excellent brightness characteristics. Regarding.
交流電界を印加することによって発光する薄膜ＥＬ素子
は、特開昭５０−１２９８９号及び特開昭５７−１７２
６９２号公報に記載のように、ガラス基板上に形成され
た透明電極上に第一絶縁層、発光層及び第二絶縁層が順
次積層され、さらに、その上部に透明電極と直交するよ
うに、背面電極が形成される。Thin film EL elements that emit light by applying an alternating electric field are disclosed in Japanese Patent Application Laid-Open No. 50-12989 and Japanese Patent Application Laid-open No. 57-172.
As described in Japanese Patent No. 692, a first insulating layer, a light-emitting layer, and a second insulating layer are sequentially laminated on a transparent electrode formed on a glass substrate, and further, on top thereof, so as to be orthogonal to the transparent electrode, A back electrode is formed.
特開昭５０−１２９８９号公報では、絶縁層材料として
、窒化物を用い、発光層材料としてＺｎＳを用いたＥＬ
素子の発光特性や寿命特性の劣化を防ぐことを特徴とし
ている。また、特開昭５７−１７２６９２号公報では、
絶縁材料としてＴａ２Ｏ５を用い、発光層材料としてＺ
ｎＳやＺｎ５ｅ等を用いたＥＬ素子の低駆動電圧化を特
徴とする。JP-A-50-12989 discloses an EL device using nitride as an insulating layer material and ZnS as a light emitting layer material.
It is characterized by preventing deterioration of the light emitting characteristics and life characteristics of the device. Also, in Japanese Patent Application Laid-open No. 57-172692,
Ta2O5 was used as the insulating material, and Z was used as the light emitting layer material.
It is characterized by lower driving voltage for EL elements using nS, Zn5e, etc.
上記従来技術は、発光層にＳｒＳまたはＣａＳを用いた
場合の発光輝度や寿命の点について配慮されておらず、
発光層に付活剤を添加したＳｒＳやＣａＳを用いた場合
、輝度不足や時間の経過とともに輝度が低下していくと
いう問題があった。The above-mentioned conventional technology does not take into consideration the luminance and lifespan when SrS or CaS is used for the light emitting layer.
When SrS or CaS to which an activator is added is used in the light-emitting layer, there are problems such as insufficient brightness and a decrease in brightness over time.
たとえば、ＳｒＳ、または、ＣａＳを母体とする発光層
上に第二絶縁層としてのＴａ２Ｏ５膜をスパッタリング
法で形成する時に、緻密で絶縁特性の優れた絶縁層を得
るために、スパッタリングガスとして、Ａｒと０２の混
合ガスが用いられる。そのため、絶縁層形成過程の初期
に基板が酸素プラズマにさらされ、発光層の表面が酸素
プラズマにさらされ、発光層の表面が酸素イオンによる
衝撃を受けて酸化されＥＬ素子の輝度及び寿命特性を著
しく悪くする原因となっていた。このため、０２プラズ
マを生成しなくとも絶縁特性の優れた窒化物を使用する
必要があった。また、酸化物で発光層をはさんだ場合に
は（０２プラズマを用いずに）エージング中に界面で酸
化が生じ輝度が劣化した。この場合にも、窒化物にする
必要があった。このため、たとえば、５ｉａＮ＋とＴａ
２Ｏ５とを積層した絶縁層膜が試みられたが、密着性が
悪く、健全で信頼性の高いＥＬ素子は実現できなかった
。For example, when forming a Ta2O5 film as a second insulating layer on a light emitting layer based on SrS or CaS by sputtering, Ar is used as the sputtering gas in order to obtain a dense insulating layer with excellent insulating properties. A mixed gas of and 02 is used. Therefore, at the beginning of the insulating layer formation process, the substrate is exposed to oxygen plasma, the surface of the light emitting layer is exposed to oxygen plasma, and the surface of the light emitting layer is bombarded by oxygen ions and oxidized, which affects the brightness and life characteristics of the EL element. This caused a significant deterioration. For this reason, it is necessary to use nitride which has excellent insulating properties even without generating 02 plasma. Furthermore, when the light-emitting layer was sandwiched between oxides (without using 02 plasma), oxidation occurred at the interface during aging, resulting in a decrease in brightness. In this case as well, it was necessary to use nitride. Therefore, for example, 5iaN+ and Ta
An attempt was made to use an insulating layer film in which 2O5 was laminated, but the adhesion was poor and a sound and highly reliable EL element could not be realized.
本発明の目的は、多色表示ＥＬＤ、あるいは、フルカラ
ーＥＬＤに好適な、高輝度で輝度の経時変化のない優れ
た素子を提供することにある。An object of the present invention is to provide an excellent element with high brightness and no change in brightness over time, which is suitable for a multicolor display ELD or a full color ELD.
上記目的は、基板上に形成された透明電極上に第一絶縁
層、発光層、第二絶縁層、及び、背面電極が順次積層さ
れ、この両電極間に交流電界を印加することによってＥ
Ｌ発光を呈する薄膜ＥＬ素子において、ＳｒＳまたはＣ
ａＳを母体とする発光層をサンドイツチ状にはさむ第−
及び第二絶縁層として窒化物が発光層側に接するように
形成し、さらに、窒化物を構成する金属元素と酸化物を
構成する金属元素とが等しい積層絶縁膜にすることによ
り達成される。The above object is achieved by sequentially laminating a first insulating layer, a light emitting layer, a second insulating layer, and a back electrode on a transparent electrode formed on a substrate, and applying an alternating current electric field between these two electrodes.
In a thin film EL device exhibiting L emission, SrS or C
A third layer in which a light-emitting layer containing aS as a matrix is sandwiched between sandwich-like structures.
This is achieved by forming a nitride as the second insulating layer so as to be in contact with the light emitting layer side, and further forming a laminated insulating film in which the metal elements constituting the nitride and the metal elements constituting the oxide are equal.
絶縁層として用いられる窒化物は、ＡｒとＮ２ガス雰囲
気中でスパッタリングして成膜することにより透過率が
高く、しかも、緻密で絶縁特性の優れた膜が得られる。When the nitride used as the insulating layer is formed by sputtering in an Ar and N2 gas atmosphere, a film with high transmittance, denseness, and excellent insulating properties can be obtained.
従って、ＳｒＳ、または、ＣａＳを母体とする発光層に
対して、酸素プラズマによる酸化防止ができ、素子の輝
度劣化を防止することができる。Therefore, the light-emitting layer containing SrS or CaS as a matrix can be prevented from being oxidized by oxygen plasma, and deterioration in the brightness of the device can be prevented.
また、絶縁層として各窒化物を構成する金属元素に等し
く酸化物を構成する金属元素を形成するために密着性が
良く、膜はがれ等もないことを見い出した。さらに、酸
化膜中の酸素は、窒化物を通して発光層中へ拡散し、発
光層を劣化させることもないことが判明した。It has also been found that since the insulating layer is made of a metal element constituting an oxide that is equal to the metal element constituting each nitride, the adhesion is good and there is no peeling of the film. Furthermore, it has been found that oxygen in the oxide film diffuses into the light-emitting layer through the nitride and does not deteriorate the light-emitting layer.
以下本発明の実施例について説明する。まず、第１図は
本発明の構造の一例を示し、その製作法を以下に述べる
。Examples of the present invention will be described below. First, FIG. 1 shows an example of the structure of the present invention, and the manufacturing method thereof will be described below.
第１図に示すように、ガラス基板１上に透明電極である
Ｉ Ｔｏ （Ｉｎｄｉｕｍ Ｔｉｎ ０ｘｉｄｅ） ２
をスパッタリング法、または、電子ビーム蒸着法により
約２Ｏ０ｎｍの厚さに形成する。得られるＩＴＯ膜のシ
ート抵抗は１０Ω／口以下、透過率は８５％以上である
。このＩＴ○膜をフォトリソ技術によつて所望の形状に
パターニングする。この上に、第−絶ｍ層３として、Ｓ
ｉＯ２を１２Ｏｎｍの厚さに、Ａｒと０２ガス雰囲気中
でＲＦスパッタリング法で形成した。さらに、同一バッ
チ内で絶縁層４．５ｉ３１’Ｌ４をＡｒとＮ２混合ガス
雰囲気中でスパッタリング法で２Ｏ０ｎｍ形成した。本
基板を電子ビーム蒸着装置に移し、発光層５としてＳｒ
Ｓ：Ｃｅ、または、ＣａＳ：Ｅｕ膜をマスク蒸着した。As shown in FIG. 1, a transparent electrode of I To (Indium Tin Oxide) 2 is placed on a glass substrate 1.
is formed to a thickness of about 200 nm by sputtering or electron beam evaporation. The resulting ITO film has a sheet resistance of 10 Ω/hole or less and a transmittance of 85% or more. This IT○ film is patterned into a desired shape by photolithography. On top of this, as the m-th layer 3, S
iO2 was formed to a thickness of 12 Onm by RF sputtering in an Ar and O2 gas atmosphere. Furthermore, in the same batch, an insulating layer 4.5i31'L4 was formed to a thickness of 200 nm by sputtering in an Ar and N2 mixed gas atmosphere. This substrate was transferred to an electron beam evaporation device, and the light emitting layer 5 was made of Sr.
A S:Ce or CaS:Eu film was deposited using a mask.
蒸着時の基板温度は４５０℃とし膜厚は１１０００ｎと
した。次に発光層５上に第一絶縁層３，４と同一条件で
第二絶縁層６を発光層５に接する上面に５ｉａＮａ膜を
２Ｏ０ｎｍ、さらに、その上部にＳｉＯ２膜７を１２Ｏ
ｎｍ形成した。The substrate temperature during vapor deposition was 450° C., and the film thickness was 11000 nm. Next, a second insulating layer 6 is placed on the light-emitting layer 5 under the same conditions as the first insulating layers 3 and 4, and a 5iaNa film of 2O0 nm is placed on the upper surface in contact with the light-emitting layer 5, and a SiO2 film 7 of 120nm is added on top of the second insulating layer 6.
nm was formed.
さらに、背面電極８としてＡＭをストライブ状のマスク
を用いてＩＴ○電極２と直交方向に約２Ｏ０ｎｍの厚さ
に蒸着した。この後、作製した素子を湿気から保護する
ため、第１図に示していないが乾燥した空気雰囲気中で
背面電極８上にガラス板を設置し周囲を樹脂で封止した
。Further, as a back electrode 8, AM was deposited to a thickness of about 200 nm in a direction perpendicular to the IT○ electrode 2 using a striped mask. Thereafter, in order to protect the fabricated element from moisture, a glass plate was placed on the back electrode 8 in a dry air atmosphere, although not shown in FIG. 1, and the surrounding area was sealed with resin.
また、第１図の実施例に準じて、発光層５に接する両面
にＡ Ｑ Ｎ ／ Ａ Ｑ ２Ｏ３膜、Ｔ ａ Ｎ ／
Ｔａ２ｅ５、Ｔ ｉ Ｎ ／ Ｔ ｉ ２Ｏ ａの積
層膜を用いたＥＬ素子についても実施した。いずれの場
合も、膜はがれの現象は見られなかった。Further, in accordance with the embodiment shown in FIG. 1, A Q N / A Q 2O3 film and T a N /
Experiments were also conducted on EL devices using laminated films of Ta2e5 and TiN/Ti2Oa. In either case, no phenomenon of film peeling was observed.
第２図は、従来の素子構造を示すが、この素子の絶縁膜
９，１０はＴａ２Ｏ５膜を使用しており、膜形成時のス
パッタリングガスにはＡｒと０２の混合ガスを用いた。FIG. 2 shows a conventional element structure, in which the insulating films 9 and 10 are Ta2O5 films, and a mixed gas of Ar and 02 is used as the sputtering gas during film formation.
本素子を作製後５ Ｋ Ｈｚの正弦波の電圧印加状態で
ＥＬ輝度の連続測定を行った。その結果、第３図に示す
ように、輝度は時間の経過とともに低下して行くが、第
１図に示す本発明の素子構成を用いれば、輝度は電圧印
加直後に若干低下する現象が見られるが、その後の低下
現象は認められず安定な輝度特性を示すことが判明した
。従って、本実施例によれば、発光層の酸化防止ができ
、高輝度、長寿命のＥＬ素子を提供することができる。After manufacturing this device, EL luminance was continuously measured while applying a 5 KHz sine wave voltage. As a result, as shown in FIG. 3, the brightness decreases over time, but if the device configuration of the present invention shown in FIG. However, no subsequent decrease phenomenon was observed, and it was found that stable luminance characteristics were exhibited. Therefore, according to this embodiment, the oxidation of the light emitting layer can be prevented, and an EL element with high brightness and long life can be provided.
一方、従来技術のＳ ｉ ３Ｎ４／ Ｔ ａ ２Ｏ５絶
縁膜を用いたＥＬ素子も作製したが、この場合は窒化物
を形成する金属元素と酸化物を形成する金属元素とが等
しくないことから密着性の向上がなく膜はがれを起こす
ことが判明した。On the other hand, an EL device using the conventional Si 3N4/Ta 2O5 insulating film was also fabricated, but in this case, the adhesion was poor because the metal elements forming the nitride and the metal elements forming the oxide were not equal. It was found that the film did not improve and the film peeled off.
□ 本発明によれば、輝度の経時変化を防止でき、長寿
命、高輝度の薄膜ＥＬ素子が得られる。□ According to the present invention, it is possible to prevent luminance from changing over time, and a thin film EL element with a long life and high luminance can be obtained.
第１図は本発明の一実施例の薄膜ＥＬ素子の断面図、第
２図は従来の薄膜ＥＬ素子の断面図、第３図は従来の薄
膜ＥＬ素子の輝度の劣化を示す図である。FIG. 1 is a sectional view of a thin film EL device according to an embodiment of the present invention, FIG. 2 is a sectional view of a conventional thin film EL device, and FIG. 3 is a diagram showing deterioration in brightness of a conventional thin film EL device.
Claims (2)
に、二つの絶縁層にサンドイツチ状にはさまれた発光層
を設けた薄膜ＥＬ素子において、前記絶縁層は窒化物と
酸化膜の積層膜であり、かつ、窒化膜は前記発光層側に
形成され、さらに前記窒化膜を構成する金属元素と前記
酸化物を構成する金属元素が同じものであることを特徴
とする薄膜ＥＬ素子。1. In a thin film EL device, a light-emitting layer is provided between a pair of electrodes, at least one of which is a transparent electrode, and is sandwiched between two insulating layers in a sandwich-like pattern, and the insulating layer is a laminated film of a nitride and an oxide film. A thin film EL device characterized in that the nitride film is formed on the light emitting layer side, and the metal element constituting the nitride film and the metal element constituting the oxide are the same.
／ＳｉＯ＿２，ＴａＮ／Ｔａ＿２Ｏ＿５，ＴｉＮ／Ｔｉ
＿２Ｏ＿３のうちから選んだ少くも一種であることを特
徴とする薄膜ＥＬ素子。2. In claim 1, the insulating layer is AlN/Al_2O_3, Si_3N_4.
/SiO_2, TaN/Ta_2O_5, TiN/Ti
A thin film EL device characterized in that it is at least one type selected from _2O_3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63027540A JPH01204394A (en) | 1988-02-10 | 1988-02-10 | Thin film el element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63027540A JPH01204394A (en) | 1988-02-10 | 1988-02-10 | Thin film el element |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01204394A true JPH01204394A (en) | 1989-08-16 |
Family
ID=12223920
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63027540A Pending JPH01204394A (en) | 1988-02-10 | 1988-02-10 | Thin film el element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01204394A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02215080A (en) * | 1989-02-14 | 1990-08-28 | Yamaha Corp | Thin film el element |
-
1988
- 1988-02-10 JP JP63027540A patent/JPH01204394A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02215080A (en) * | 1989-02-14 | 1990-08-28 | Yamaha Corp | Thin film el element |
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