JP2004014236A - Manufacturing method of organic el element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a passive matrix drive organic EL element capable of making an upper electrode separated in high definition, without causing degradation of function of an organic EL luminous layer. <P>SOLUTION: The manufacturing method of the organic EL luminous layer comprises a process of evenly forming an upper electrode on a substrate equipped with a lower electrode with a line pattern and the organic EL luminous layer, a process of forming a passivation layer patterned on the upper electrode, and a process of separating the upper electrode into a line pattern extended in a crossing direction with the line pattern of the lower electrode by carrying out a dry etching with the passivation layer as a mask. <P>COPYRIGHT: (C)2004,JPO

Description

【００３０】
上部電極４が複数の材料から成る積層体である場合には、それぞれの材料に対して、前述のエッチングガスを用いるドライエッチングを実施して上部電極４を分離する。
【００３１】
以上のようにして上部電極４を分離した際には、有機ＥＬ発光層３が露出し、その一部がエッチングガスにさらされる恐れがある。しかしながら、有機ＥＬ発光層３に対するエッチングガスの影響は局所的であり、かつ影響を受ける部分は発光する部分ではない。このため、有機ＥＬ素子としての特性はほとんど悪影響を受けることがない。
【００３２】
最後に、有機ＥＬ発光層３の露出部分およびパッシベーション層５の上面に、第２パッシベーション層７を形成する。第２パッシベーション層７を形成するために好ましい材料は、Ａｌ_２Ｏ_３、ＡｌＮ、ＳｉＯ_２、Ｓｉ_３Ｎ_４、Ｔａ_２Ｏ_５、ＺｒＯ_２またはＴｉＯ_２を含み、パッシベーション層５と同一であっても異なっていてもよい。。第２パッシベーション層７は、スパッタ法（ＲＦマグネトロンスパッタ、ＥＣＲスパッタ、および対向ターゲットスパッタ法を含む）、ＣＶＤ法、または電子ビーム蒸着法により形成することができる。第２パッシベーション層７は、１００〜２０００ｎｍ、好ましくは２００〜１０００ｎｍの厚さを有して形成される。
【００３３】
この工程により、有機ＥＬ発光層３は再び完全に覆われるため、後の工程において塗布（ディップ、スピンコート、キャストなど）またはウェットエッチングなどのウェットプロセスを用いても、有機ＥＬ発光層３の特性劣化を発生させることがない。
【００３４】
本発明の方法により上部電極の分離を行った後に、さらに加工を行うことにより、多数の有機ＥＬ素子をマトリクス上に配列したＥＬディスプレイを作製することができる。
【００３５】
トップエミッション方式の有機ＥＬディスプレイの一例を図３に示す。基板２１の上に、下部陽極２２、有機発光層２３、上部透明陰極２４およびパッシベーション層２５からなる有機ＥＬ素子が形成される。ここで、上部透明陰極２４の分離を、本発明の方法を用いて実施する。下部陽極２２および上部透明電極２４は、互いに直交するラインパターンに形成される。一方、透明基板３２の上に、所望される色変換フィルター層を形成する。図３においては、青色、緑色および赤色の色変換フィルター層が形成されており、青色変換フィルター層は青色カラーフィルター層２６Ｂから構成され、および緑色および赤色変換フィルター層は、それぞれカラーフィルター層２６Ｇおよび２６Ｒと色変換層２７Ｇおよび２７Ｒとの積層体で構成されている。また、各色変換フィルター層の間にはブラックマスク３３が形成されている。次に、それら色変換フィルター層およびブラックマスク３３上に保護層２８を形成し、さらに上記の層を覆うようにカラーフィルタ保護用パッシベーション層２９を形成して、色変換フィルターが得られる。次に有機ＥＬ素子と色変換フィルターとを、それらの間に充填剤層３０を形成しながら位置合わせをして貼り合わせ、最後に周辺部分を封止樹脂３１を用いて封止して、有機ＥＬディスプレイが得られる。
【００３６】
ボトムエミッション方式の有機ＥＬディスプレイの一例を図４に示す。透明基板３２の上に、所望される色変換フィルター層を形成する。本実施態様においても、青色（２６Ｂ）、緑色（２６Ｇ，２７Ｇ）および赤色（２６Ｒ，２７Ｒ）の色変換フィルター層が形成されており、その構成はトップエミッション方式の場合と同等である。また、各色変換フィルター層の間にはブラックマスク３３が形成されている。次に、それら色変換フィルター層およびブラックマスク３３上に保護層２８を形成し、さらに上記の層を覆うようにカラーフィルタ保護用パッシベーション層２９が形成する。そして、その上に透明電極３４、有機発光層２３、上部電極３６およびパッシベーション層３５からなる有機ＥＬ素子を形成する。ここで、パッシベーション層３５は、有機ＥＬ発光層２３以下の全ての層を覆うように形成され、また上部透明電極３６の分離を本発明の方法により実施する。透明電極３４および上部電極３６は、互いに直交するラインパターンに形成される。最後に、充填剤３０、封止樹脂３１および封止基板３７を用いて全体を封止して有機ＥＬディスプレイが得られる。
【００３７】
【実施例】
（実施例１）
ガラス基板１の上に、幅３００μｍ、間隔３０μｍのラインパターンを有し、厚さ１００ｎｍのＡｌおよび厚さ２００ｎｍのＩＺＯ（ＩｎＺｎＯ）からなる下部電極（陽極）２を形成した。Ａｌは有機発光層からの発光を反射して効率よく光を放出することおよび電気抵抗を低減することに有効である。また、仕事関数の大きい材料であるＩＺＯは、有機ＥＬ発光層に対してホールを効率よく注入することに有用である。
【００３８】
前記下部陽極２を形成した基板１を抵抗加熱蒸着装置内に装着し、正孔注入層、正孔輸送層、有機発光層、電子注入層を真空を破らずに順次成膜して有機ＥＬ発光層３を形成した。成膜に際して真空槽内圧を１×１０^−４Ｐａまで減圧した。正孔注入層は銅フタロシアニン（ＣｕＰｃ）を１００ｎｍ積層した。正孔輸送層は４，４’−ビス［Ｎ−（１−ナフチル）−Ｎ−フェニルアミノ］ビフェニル（α−ＮＰＤ）を２０ｎｍ積層した。有機発光層は４，４’−ビス（２，２−ジフェニルビニル）ビフェニル（ＤＰＶＢｉ）を３０ｎｍ積層した。電子注入層はアルミニウムトリス（８−キノリノラート）（Ａｌｑ）を２０ｎｍ積層した。
【００３９】
この後、真空を破ることなく、電子注入に必要な仕事関数の小さな金属Ｍｇ／Ａｇを共蒸着法にて膜厚２ｎｍに製膜し、その上にＩＺＯ膜をスパッタリング法で膜厚２００ｎｍに製膜することにより、上部透明電極（陰極）４を形成した。
【００４０】
上部電極４の上に、パッシベーション層５として、スパッタ法にてＳｉＯ_２膜を３００ｎｍ堆積させた。パッシベーション層５の上に厚さ１．５μｍのレジスト６を塗布した。そして、レジスト６を慣用の方法によりパターニングして、幅３０μｍ、間隔１００μｍのラインパターン状の開口部を形成した。
【００４１】
この基板を、ＲＩＥ装置内に配置し、エッチングガスとしてＣＨＦ_３／Ｏ_２を用いるドライエッチングを行った。装置内圧力を２Ｐａとし、ＣＨＦ_３のガス流量を８０ｓｃｃｍとし、Ｏ_２のガス流量を５０ｓｃｃｍとした。ＲＩＥ装置に３０分間にわたって０．１Ｗ／ｃｍ^２の電力を印加して、パッシベーション層５のパターニングを実施した。
【００４２】
ＲＩＥ装置内を排気してＣＨＦ_３を除去し、流量５０ｓｃｃｍのＯ_２ガスを導入し、装置内圧力４Ｐａ、印加電力０．１Ｗ／ｃｍ^２の条件にて、レジスト６をＯ_２アッシングにより除去した。
【００４３】
そして、Ｏ_２ガスの排気後に、圧力０．４Ｐａ（３ｍＴｏｒｒ）のＨＩ／Ａｒ（１：１）をエッチングガスとして用い、３０分間にわたって３．７５Ｗ／ｃｍ^２の電力を印加して、ＩＺＯのパターニングを実施した。これにより、パッシベーション層５に覆われていない部分のＩＺＯが除去され、Ｍｇ／Ａｇが露出する。
【００４４】
ＨＩガスを排気除去した後に、流量５０ｓｃｃｍのＡｒガスを導入し、装置内圧力４Ｐａ、印加電力０．１Ｗ／ｃｍ^２の条件にてドライエッチングを行い、露出しているＭｇ／Ａｇを除去して、上部電極４の分離を実施した。上部電極４は幅１００μｍ、間隔３０μｍの下部電極２のラインパターンと直交する方向に延びるラインパターン状となり、パッシベーション層５は、幅１００μｍ、間隔３０μｍ、厚さ３００ｎｍのラインパターン状になった。
【００４５】
さらに、基板をＲＩＥ装置と真空で連結されたスパッタ装置内に装着し、第２パッシベーション層７としてＳｉＯ_２膜を６００ｎｍ堆積させ、有機ＥＬ素子を得た。
【００４６】
一方、透明（ガラス）基板上に青色フィルター材料（富士ハントエレクトロニクステクノロジー製：カラーモザイクＣＢ−７００１）をスピンコート法にて塗布後，フォトリソグラフ法によりパターニングを実施し，膜厚１０μｍのラインパターンとした。
【００４７】
同様のカラーフィルター材料系で赤、緑のカラーフィルター層６Ｇおよび６Ｒを上記透明基板上にスピンコート法にて塗布後、フォトリソグラフ法によりパターニングを実施し、膜厚１．５μｍのラインパターンとした。
【００４８】
緑色蛍光色素としてクマリン６（０．７重量部）を溶剤のプロピレングリコールモノエチルアセテート（ＰＧＭＥＡ）１２０重量部へ溶解させた。光重合性樹脂の「Ｖ２５９ＰＡ／Ｐ５」（商品名、新日鐵化成工業株式会社）１００重量部を加えて溶解させ、塗布液を得た。この塗布溶液を、透明基板上の緑色カラーフィルター層上にスピンコート法を用いて塗布し、フォトリソグラフ法により、パターニングを実施し、膜厚１０μｍのラインパターンとした。
【００４９】
赤色蛍光色素としてクマリン６（０．６重量部）、ローダミン６Ｇ（０．３重量部）、ベーシックバイオレット１１（０．３重量部）を溶剤のプロピレングリコールモノエチルアセテート（ＰＧＭＥＡ）１２０重量部へ溶解させた。光重合性樹脂の「Ｖ２５９ＰＡ／Ｐ５」（商品名、新日鐵化成工業株式会社）１００重量部を加えて溶解させ、塗布液を得た。この塗布溶液を、基板の赤色カラーフィルター層上に、スピンコート法を用いて塗布し、フォトリソグラフ法により、パターニングを実施し，膜厚１０μｍのラインパターンとした。
【００５０】
各色の色変換フィルター層の間に、ブラックマスク（厚さ１．５μｍ）を形成した。熱伝導率の高いブラックマスクとして、色変換フィルター層壁面に、まず格子状のパターン形成が可能なマスクを用いたスパッタ法にて膜厚５００ｎｍの酸化クロム層を形成した。次いで、同様のマスクを用い、スパッタ法にて、ＳｉＮ膜を、Ｒ，Ｇ，Ｂの各サブピクセルの周辺に、同膜厚になるように形成した。画素のピッチは０．３×０．３ｍｍで、各色のサブピクセルの形状は、０．１×０．３ｍｍである。
【００５１】
色変換フィルター層の上面に、ＺＰＮ１１００（日本ＺＥＯＮ製）を、色変換フィルター層表面からの厚さが３μｍになるようにスピンコート法にて塗布し、保護層を形成した。そして、カラーフィルタ保護用パッシベーション層２９として、スパッタ法にてＳｉＯＮ_ｘ膜を３００ｎｍ堆積させ、色変換フィルター基板を得た。
【００５２】
こうして得られた下部電極、有機ＥＬ発光層、上部電極およびパッシベーション層を形成した基板と色変換フィルター基板とをＵＶ硬化型の封止樹脂１１で貼り合わせて、有機ＥＬディスプレイを得た。このとき、両基板の間の空間にはシリコーンゲル等の材料を充填剤層１０として充填した。
【００５３】
【発明の効果】
本発明のようにドライエッチングにより高精細に分離した上部電極を作成することが可能となる。さらに、エッチング溶液を用いないので有機ＥＬ発光層がエッチング溶液に接触して、その機能を低下させる恐れもない。
【図面の簡単な説明】
【図１】本発明の有機ＥＬ素子の作製方法の工程を示す概略図である。
【図２】従来の絶縁隔壁を用いる有機ＥＬ素子の作製方法を示す概略図である。
【図３】本発明の方法を利用して作製することができるトップエミッション方式の有機ＥＬディスプレイを示す概略図である。
【図４】本発明の方法を利用して作製することができるボトムエミッション方式の有機ＥＬディスプレイを示す概略図である。
【符号の説明】
１、２１，５１　　基板
２、２２、５２　　下部電極
３、２３、５３　　有機ＥＬ発光層
４、２４、５４　　上部電極
５、３５　　パッシベーション層
６　　ワイヤ
７　　第２パッシベーション層
２６Ｒ、２６Ｇ、２６Ｂ　　カラーフィルター層（赤色、緑色、青色）
２７Ｒ、２７Ｇ　　色変換層（赤色、緑色）
２８　　保護層
２９　　カラーフィルタ保護用パッシベーション層
３０　　充填剤層
３１　　封止樹脂
３２　　透明基板
３３　　ブラックマスク
３４　　透明電極
３６　　上部電極
３７　　封止基板
５５　　陰極隔壁[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing an organic EL device, and more particularly to a method for separating an upper electrode of a passive matrix driven organic EL device.
[0002]
[Prior art]
In recent years, the application of organic electroluminescent elements (hereinafter, referred to as organic EL elements) to various flat panel displays has been actively studied. The organic EL element has a structure in which at least a lower electrode, an organic EL light emitting layer, and an upper electrode are stacked on a substrate. When the organic EL element is driven in a passive matrix, the lower electrode and the upper electrode are generally formed in a line pattern extending in a direction orthogonal to each other.
[0003]
When forming an upper electrode having a line pattern, a wet process generally used in the field of semiconductors cannot be used. This is because the etchant invades the organic EL light emitting layer and lowers its function. Therefore, conventionally, as shown in FIG. 2, first, a lower electrode 52 having a line pattern is formed on a substrate 51, an inversely tapered insulating partition 55 is formed on the lower electrode 52, and then an organic EL light emitting layer is formed. A method is used in which a cathode having a line pattern (extending in a direction orthogonal to the lower anode 52) is formed by laminating the upper electrode 53 and the upper electrode 54.
[0004]
Another method for manufacturing a cathode having a line pattern is to form a cathode by stacking electrode materials by sputtering or vapor deposition using a metal mask having an opening corresponding to the line pattern to be manufactured.
[0005]
Japanese Patent Application Laid-Open No. 2000-68054 proposes a method for forming an electrode using a resin wire as a mask.
[0006]
[Problems to be solved by the invention]
However, in the method using the insulating partition, it is necessary to form the insulating partition before forming the organic EL light emitting layer and the upper electrode, and the number of steps is increased as compared with the method using the metal mask. On the other hand, when fabricating a high-resolution separated upper electrode using a metal mask, it is necessary to make the metal mask thinner, which causes the line pattern to be blurred due to deflection due to radiant heat during vapor deposition or the metal mask itself. However, there is a problem that the strength of the steel is reduced. Also, when manufacturing a high-resolution separated upper electrode in a method using a resin wire, it is necessary to make the resin wire thin, and the line pattern is blurred due to bending due to radiant heat at the time of vapor deposition, There is a problem that the strength of the wire itself is reduced.
[0007]
Therefore, there is a strong demand for a method capable of producing a finely separated upper electrode without deteriorating the function of the organic EL light emitting layer.
[0008]
[Means for Solving the Problems]
The method for manufacturing an organic EL device according to the first embodiment of the present invention includes a step of uniformly forming an upper electrode on a substrate provided with a lower electrode having a line pattern and an organic EL light emitting layer; Forming a patterned passivation layer thereon and performing dry etching using the passivation layer as a mask to separate the upper electrode into a line pattern extending in a direction orthogonal to the line pattern of the lower electrode. It is characterized by having.
[0009]
Here, the dry etching may be reactive ion etching or physical etching. The step of forming the patterned passivation layer may include dry etching (preferably reactive ion etching) using a resist as a mask.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
The method for manufacturing an organic EL device according to the present invention includes a step of uniformly forming an upper electrode on a substrate provided with a lower electrode having a line pattern and an organic EL light emitting layer, and a step of forming a passivation layer patterned on the upper electrode. And a step of performing dry etching using the passivation layer as a mask to separate the upper electrode into a line pattern extending in a direction orthogonal to a line pattern of the lower electrode. .
[0011]
Hereinafter, a method for manufacturing the organic EL device of the present invention will be described with reference to FIGS. FIG. 1A is a cross-sectional view showing a lower anode 2 having a line pattern, an organic EL light emitting layer 3, and an upper cathode 4 uniformly formed on a substrate 1. FIG. As the substrate 1, any material known in the art such as glass, plastic, and silicon can be used. When light emitted from the organic EL light emitting layer 3 is extracted outside through the substrate 1 (bottom emission method), the substrate 1 is required to be transparent.
[0012]
The lower electrode 2 formed on the substrate 1 is formed in a line pattern having an appropriate interval. Patterning of the lower electrode 2 can be performed using a normal wet process. When light emitted from the organic EL light emitting layer 3 is extracted from the upper electrode 4 side (top emission method), it is preferable that the lower anode 2 reflects light from the organic EL light emitting layer 3. When light emitted from the organic EL light emitting layer 3 is extracted from the substrate 1 side (bottom emission method), it is essential that the lower electrode is transparent.
[0013]
When the lower electrode 2 is used as an anode, the lower electrode is formed of a material having a large work function in order to improve hole injection properties. Suitable materials include transparent conductive oxides such as ITO or IZO. Because these materials are transparent, they are particularly useful for bottom emission systems. In the case of employing the top emission method, it is preferable that a reflective metal layer (for example, Al) is provided between the lower electrode 2 and the substrate 1 to impart reflectivity.
[0014]
When the lower electrode 2 is used as a cathode, the lower electrode is formed of a material having a small work function in order to impart electron injection properties. Suitable materials include alkali metals such as lithium and sodium; alkaline earth metals such as potassium, calcium, magnesium and strontium; electron-injecting metals such as fluorides thereof; and alloys or compounds with other metals. Including. Since these materials are opaque, when the bottom emission method is adopted, an ultrathin film (10 nm or less) of these materials or an ultrathin film (10 nm) of a two-layer structure of these materials and a metal (for example, Al) capable of transmitting light is used. It is preferable that a transparent conductive film such as ITO or IZO is formed between the ultrathin film and the substrate 1. When employing the top emission method, it is preferable to provide a reflective metal layer (for example, Al or the like) between the lower electrode 2 and the substrate 1 to provide reflectivity as in the case of the anode.
[0015]
An organic EL light emitting layer 3 is provided on the lower anode 2. The organic EL light emitting layer 3 includes at least an organic light emitting layer containing an organic light emitting material, and may be provided with a hole injection layer, a hole transport layer, or an electron injection layer as needed. The configuration of an exemplary organic EL light emitting layer 3 is shown below (including both electrodes for clarity).
(1) anode / organic light emitting layer / cathode (2) anode / hole injection layer / organic light emitting layer / cathode (3) anode / organic light emitting layer / electron injection layer / cathode (4) anode / hole injection layer / organic Light emitting layer / electron injection layer / cathode (5) anode / hole injection layer / hole transport layer / organic light emitting layer / electron injection layer / cathode (6) anode / hole injection layer / hole transport layer / organic light emitting layer / Electron transport layer / electron injection layer / cathode
Known materials are used for the materials of each layer constituting the organic EL light emitting layer 3. For example, in order to obtain blue to blue-green light emission as the organic light emitting layer, for example, a fluorescent whitening agent such as a benzothiazole type, a benzimidazole type, a benzoxazole type, a metal chelated oxonium compound, a styrylbenzene type compound, an aromatic compound Dimethylidin compounds are preferably used.
[0017]
On the organic EL light emitting layer 3, the upper electrode 4 is formed uniformly. In the case of forming a top emission type device, the upper electrode needs to be transparent for light emission from the organic EL light emitting layer 3. On the other hand, when a bottom emission type element is formed, it is preferable to reflect light from the organic EL light emitting layer 3.
[0018]
The transparent and reflective anodes and cathodes can be appropriately formed using the materials described for the lower electrode 2. However, a material having a large work function is in contact with the organic EL light emitting layer 3 in the case of the anode, and a material having a small work function is in contact with the organic EL light emitting layer 3 in the case of the cathode.
[0019]
Next, as shown in FIG. 1B, a passivation layer 5 is formed so as to cover the organic EL light emitting layer 3 and the upper cathode 4. Preferred materials for forming the passivation layer 5 _comprises Al ₂ O _{3, AlN,} and _{SiO 2, Si 3 N 4,} Ta 2 O 5, ZrO 2 or TiO _2. The passivation layer 5 can be formed by a sputtering method (including RF magnetron sputtering, ECR sputtering, and facing target sputtering method), a CVD method, or an electron beam evaporation method. The passivation layer 5 is formed to have a thickness of 50 to 1000 nm, preferably 100 to 500 nm. When the upper electrode 4 is separated by non-selective dry etching as described later, it is necessary to make the passivation layer 5 thicker, and the passivation layer 5 having a thickness of 200 to 10000 nm, preferably 200 to 500 nm is formed. Used. At this stage, since the organic EL light emitting layer 3 is covered with the passivation layer 5, it is possible to use a wet process in the next step of patterning the resist 6.
[0020]
Next, as shown in FIG. 1C, a resist 6 is uniformly applied on the passivation layer 5. The resist 6 may be a positive type or a negative type, and is formed of a material suitable for dry etching of a passivation layer described later. Exposure and development (patterning) of the resist 6 are performed to form an opening exposing the passivation layer 5 as shown in FIG. The opening is formed in a line pattern extending in a direction orthogonal to the line pattern of the lower anode 2. Although FIG. 1D shows the case of one opening, it goes without saying that a plurality of openings may be provided. Although the case where the side wall of the opening is vertical is illustrated, the side wall may be processed into a tapered shape.
[0021]
Next, dry etching of the passivation layer 5 is performed using the resist 6 as a mask. Dry etching includes sputter etching, ion beam etching (milling), reactive ion etching (including RIE, RF and magnetron), reactive ion beam etching, ECR plasma etching, plasma separation type microwave plasma etching or high density plasma etching. (Including inductively coupled and helicon waves) and the like, and can be performed using any of the physical etching, chemical etching, and physicochemical etching techniques known in the art. The use of reactive ion etching is preferred in terms of etching rate, selectivity, and fidelity to the pattern. In the case of performing dry etching, it is preferable to cool the substrate in order to prevent the material of the organic EL light emitting layer 3 from being deteriorated by the applied heat.
[0022]
When the passivation layer 5 is SiO ₂ , the gases that can be used for RIE are halogenated hydrocarbons (CF ₄ , CHF ₃ , CCl ₂ F ₂ , C ₂ F ₄ , C ₂ F ₆ , C ₃ F ₈ , C ₄ F _8), HF, is selected from NF 3, SF _6, and the group consisting of XeF _2. The above gases may be used in combination, or may be used as a mixture with O ₂ , H ₂ , Ar, C ₂ H _4, or the like. When the passivation layer 5 is Al ₂ O ₃ , the etching gas is selected from the group consisting of BCl ₃ , CCl ₄ / Ar, and Cl ₂ / Ar. When the passivation layer 5 is Si ₃ N ₄ , gases that can be used for dry etching include halogenated hydrocarbons (CF ₄ , CHF ₃ , CCl ₂ F ₂ , CBrF ₃ , C ₂ F ₄ , C ₂ F _6). , C ₃ F ₈ , C ₄ F ₈ ), NF ₃ , SF ₆ , and XeF ₂ . The above-mentioned halogenated hydrocarbons may be used as a mixture with O ₂ , H _{2 and the} like. When the passivation layer 5 is Ta ₂ O ₅ , CF ₄ can be used as an etching gas. When RIE is used, the thickness of the resist 6 is 1 to 3 μm.
[0023]
Physical etching (such as sputter etching) using a non-reactive gas such as Ar, He, or Xe may be used. In this case, since the etching selectivity between the resist 6 and the passivation layer 5 becomes low, it is necessary to make the resist 6 thick, and preferably to have a thickness twice or more (for example, 400 nm or more) the passivation layer. .
[0024]
Next, as shown in FIG. 1E, the resist 6 is removed. Since the organic EL light emitting layer is exposed after the upper electrode 4 is separated, it is preferable to remove the resist before the upper electrode 4 is separated. The removal of the resist 6 can be performed by oxygen ashing well known in the art.
[0025]
Next, as shown in FIG. 1F, the upper cathode 4 is separated by dry etching using the patterned passivation layer 5 as a mask. Dry etching in this step is also performed by sputter etching, ion beam etching (milling), reactive ion etching (including RIE, RF, and magnetron), reactive ion beam etching, ECR plasma etching, plasma separation type microwave plasma etching, or It can be performed using any of the physical etching, chemical etching, and physicochemical etching methods known in the art, such as high-density plasma etching (including inductively coupled and helicon waves). The use of chemical ion etching is preferred in terms of etching rate, selectivity, and fidelity to the pattern. In the case of performing dry etching, it is preferable to cool the substrate in order to prevent the material of the organic EL light emitting layer 3 from being deteriorated by the applied heat.
[0026]
When the material of the upper electrode 4 is IZO or ITO, a chlorine-based gas (such as Cl ₂ ) / H ₂ , CH ₄ / He, CH ₄ / H ₂ , HI / Ar, CF ₄ , or CH ₃ OH / Ar , Can be used as an etching gas. When the material of the upper electrode 4 is Al, BCl ₃ , BCl ₃ / Cl ₂ / He, BCl ₃ / CF ₄ / O ₂ , CCl ₄ , CCl ₄ / Ar, CCl ₄ / He, or SiCl ₄ is used. It can be used as an etching gas. When the material of the upper electrode 4 is Mo, CBrF ₃ , CCl ₂ F ₂ , CCl ₄ / O ₂ , CF ₄ , CF ₄ / O ₂ , NF ₃ , SF ₆ , or the like may be used as an etching gas. it can.
[0027]
When the upper electrode 4 is formed of Ag or Mg, dry etching can be performed by physical etching such as sputter etching or ion beam etching using a non-reactive gas such as Ar, He, or Xe. In this case, since both the upper electrode 4 and the passivation layer 5 are non-selectively etched, the passivation layer 5 needs to be thickened as described above.
[0028]
In carrying out the method of the present invention, it is preferable to select a material so that the etching gas for separating the upper electrode 4 does not etch the passivation layer 5. The combinations of such materials are shown below.
[0029]
[Table 1]

[0030]
When the upper electrode 4 is a laminate made of a plurality of materials, dry etching using the above-described etching gas is performed on each material to separate the upper electrode 4.
[0031]
When the upper electrode 4 is separated as described above, the organic EL light emitting layer 3 is exposed, and a part of the light emitting layer 3 may be exposed to an etching gas. However, the influence of the etching gas on the organic EL light emitting layer 3 is local, and the affected part is not a light emitting part. Therefore, the characteristics as the organic EL element are hardly adversely affected.
[0032]
Finally, a second passivation layer 7 is formed on the exposed portion of the organic EL light emitting layer 3 and on the upper surface of the passivation layer 5. Preferred materials for forming the second passivation layer 7 include Al ₂ O ₃ , AlN, SiO ₂ , Si ₃ N ₄ , Ta ₂ O ₅ , ZrO ₂ or TiO ₂ and are the same as the passivation layer 5. May also be different. . The second passivation layer 7 can be formed by a sputtering method (including an RF magnetron sputtering, an ECR sputtering, and a facing target sputtering method), a CVD method, or an electron beam evaporation method. The second passivation layer 7 is formed to have a thickness of 100 to 2000 nm, preferably 200 to 1000 nm.
[0033]
By this step, the organic EL light emitting layer 3 is completely covered again. Therefore, even if a wet process such as coating (dip, spin coating, casting, etc.) or wet etching is used in a later step, the characteristics of the organic EL light emitting layer 3 can be obtained. No degradation occurs.
[0034]
By further processing after separating the upper electrode by the method of the present invention, an EL display in which a large number of organic EL elements are arranged in a matrix can be manufactured.
[0035]
FIG. 3 shows an example of a top emission type organic EL display. On a substrate 21, an organic EL element including a lower anode 22, an organic light emitting layer 23, an upper transparent cathode 24, and a passivation layer 25 is formed. Here, the separation of the upper transparent cathode 24 is performed using the method of the present invention. The lower anode 22 and the upper transparent electrode 24 are formed in line patterns orthogonal to each other. On the other hand, a desired color conversion filter layer is formed on the transparent substrate 32. In FIG. 3, blue, green, and red color conversion filter layers are formed, the blue conversion filter layer is formed of a blue color filter layer 26B, and the green and red conversion filter layers are respectively color filter layers 26G and 26G. 26R and a layered structure of the color conversion layers 27G and 27R. A black mask 33 is formed between the color conversion filter layers. Next, a protective layer 28 is formed on the color conversion filter layer and the black mask 33, and a passivation layer 29 for protecting the color filter is formed so as to cover the above-mentioned layers, thereby obtaining a color conversion filter. Next, the organic EL element and the color conversion filter are aligned and adhered while forming the filler layer 30 therebetween, and finally, the peripheral portion is sealed with the sealing resin 31 so that An EL display is obtained.
[0036]
FIG. 4 shows an example of a bottom emission type organic EL display. A desired color conversion filter layer is formed on the transparent substrate 32. Also in the present embodiment, blue (26B), green (26G, 27G) and red (26R, 27R) color conversion filter layers are formed, and the configuration is the same as that of the top emission type. A black mask 33 is formed between the color conversion filter layers. Next, a protective layer 28 is formed on the color conversion filter layer and the black mask 33, and a passivation layer 29 for protecting the color filter is formed so as to cover the above layers. Then, an organic EL element including the transparent electrode 34, the organic light emitting layer 23, the upper electrode 36, and the passivation layer 35 is formed thereon. Here, the passivation layer 35 is formed so as to cover all the layers below the organic EL light emitting layer 23, and the upper transparent electrode 36 is separated by the method of the present invention. The transparent electrode 34 and the upper electrode 36 are formed in line patterns orthogonal to each other. Finally, the entire structure is sealed using the filler 30, the sealing resin 31, and the sealing substrate 37 to obtain an organic EL display.
[0037]
【Example】
(Example 1)
A lower electrode (anode) 2 having a line pattern having a width of 300 μm and an interval of 30 μm and made of Al having a thickness of 100 nm and IZO (InZnO) having a thickness of 200 nm was formed on a glass substrate 1. Al is effective in efficiently emitting light by reflecting light emitted from the organic light emitting layer and reducing electric resistance. In addition, IZO, which is a material having a large work function, is useful for efficiently injecting holes into the organic EL light emitting layer.
[0038]
The substrate 1 on which the lower anode 2 is formed is mounted in a resistance heating vapor deposition apparatus, and a hole injection layer, a hole transport layer, an organic light emitting layer, and an electron injection layer are sequentially formed without breaking vacuum to form an organic EL light emitting device. Layer 3 was formed. During film formation, the internal pressure of the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa. The hole injection layer was formed by laminating copper phthalocyanine (CuPc) to a thickness of 100 nm. As the hole transport layer, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α-NPD) was laminated to a thickness of 20 nm. The organic luminescent layer was formed by laminating 4,4′-bis (2,2-diphenylvinyl) biphenyl (DPVBi) to a thickness of 30 nm. As the electron injection layer, aluminum tris (8-quinolinolate) (Alq) was laminated to a thickness of 20 nm.
[0039]
Thereafter, without breaking vacuum, a metal Mg / Ag having a small work function required for electron injection is formed to a thickness of 2 nm by co-evaporation, and an IZO film is formed thereon by sputtering to a thickness of 200 nm. By forming a film, an upper transparent electrode (cathode) 4 was formed.
[0040]
A 300 nm SiO ₂ film was deposited as a passivation layer 5 on the upper electrode 4 by a sputtering method. A 1.5 μm-thick resist 6 was applied on the passivation layer 5. The resist 6 was patterned by a conventional method to form a line pattern opening having a width of 30 μm and an interval of 100 μm.
[0041]
This substrate was placed in an RIE apparatus and dry-etched using CHF ₃ / O ₂ as an etching gas. The pressure in the apparatus was 2 Pa, the gas flow rate of CHF ₃ was 80 sccm, and the gas flow rate of O ₂ was 50 sccm. The power of 0.1 W / cm ² was applied to the RIE device for 30 minutes to pattern the passivation layer 5.
[0042]
The inside of the RIE apparatus was evacuated to remove CHF ₃ , O ₂ gas at a flow rate of 50 sccm was introduced, and the resist 6 was removed by O ₂ ashing under the conditions of an apparatus pressure of 4 Pa and an applied power of 0.1 W / cm ² . .
[0043]
Then, after exhausting the O ₂ gas, using HI / Ar (1: 1) at a pressure of 0.4 Pa (3 mTorr) as an etching gas, applying a power of 3.75 W / cm ² for 30 minutes to pattern the IZO Was carried out. As a result, the portion of IZO that is not covered by the passivation layer 5 is removed, and the Mg / Ag is exposed.
[0044]
After exhausting and removing the HI gas, Ar gas at a flow rate of 50 sccm was introduced, dry etching was performed under the conditions of a pressure inside the apparatus of 4 Pa and an applied power of 0.1 W / cm ² to remove exposed Mg / Ag. Then, the upper electrode 4 was separated. The upper electrode 4 had a line pattern extending in a direction perpendicular to the line pattern of the lower electrode 2 having a width of 100 μm and a spacing of 30 μm, and the passivation layer 5 had a line pattern having a width of 100 μm, a spacing of 30 μm, and a thickness of 300 nm.
[0045]
Further, the substrate was mounted in a sputtering apparatus connected to the RIE apparatus by vacuum, and a 600 nm SiO ₂ film was deposited as the second passivation layer 7 to obtain an organic EL device.
[0046]
On the other hand, after a blue filter material (Fuji Hunt Electronics Technology: Color Mosaic CB-7001) is applied on a transparent (glass) substrate by spin coating, patterning is performed by photolithography, and a line pattern having a film thickness of 10 μm is formed. did.
[0047]
After applying the red and green color filter layers 6G and 6R on the transparent substrate by a spin coating method using the same color filter material system, patterning was performed by a photolithographic method to form a line pattern having a film thickness of 1.5 μm. .
[0048]
Coumarin 6 (0.7 parts by weight) as a green fluorescent dye was dissolved in 120 parts by weight of a solvent, propylene glycol monoethyl acetate (PGMEA). 100 parts by weight of a photopolymerizable resin “V259PA / P5” (trade name, Nippon Steel Chemical Co., Ltd.) was added and dissolved to obtain a coating solution. This coating solution was applied on a green color filter layer on a transparent substrate by a spin coating method, and was patterned by a photolithographic method to form a line pattern having a film thickness of 10 μm.
[0049]
Coumarin 6 (0.6 parts by weight), Rhodamine 6G (0.3 parts by weight), and Basic Violet 11 (0.3 parts by weight) as red fluorescent dyes are dissolved in 120 parts by weight of propylene glycol monoethyl acetate (PGMEA) as a solvent. I let it. 100 parts by weight of a photopolymerizable resin “V259PA / P5” (trade name, Nippon Steel Chemical Co., Ltd.) was added and dissolved to obtain a coating solution. This coating solution was applied on the red color filter layer of the substrate by spin coating, and was patterned by photolithography to form a line pattern having a film thickness of 10 μm.
[0050]
A black mask (1.5 μm in thickness) was formed between the color conversion filter layers for each color. First, as a black mask having high thermal conductivity, a chromium oxide layer having a thickness of 500 nm was formed on the wall surface of the color conversion filter layer by a sputtering method using a mask capable of forming a lattice pattern. Next, an SiN film was formed around the R, G, and B sub-pixels to have the same thickness by a sputtering method using the same mask. The pixel pitch is 0.3 × 0.3 mm, and the shape of each color sub-pixel is 0.1 × 0.3 mm.
[0051]
On the upper surface of the color conversion filter layer, ZPN1100 (manufactured by ZEON Japan) was applied by spin coating so that the thickness from the surface of the color conversion filter layer became 3 μm, to form a protective layer. Then, as a passivation layer 29 for protecting the color filter, a 300 nm SiON _x film was deposited by a sputtering method to obtain a color conversion filter substrate.
[0052]
The substrate on which the lower electrode, the organic EL light emitting layer, the upper electrode, and the passivation layer thus obtained were formed and the color conversion filter substrate were bonded with a UV-curable sealing resin 11 to obtain an organic EL display. At this time, the space between the two substrates was filled with a material such as silicone gel as the filler layer 10.
[0053]
【The invention's effect】
As in the present invention, it is possible to form an upper electrode separated with high definition by dry etching. Further, since no etching solution is used, there is no danger that the organic EL light emitting layer comes into contact with the etching solution and deteriorates its function.
[Brief description of the drawings]
FIG. 1 is a schematic view showing steps of a method for manufacturing an organic EL device of the present invention.
FIG. 2 is a schematic view illustrating a method for manufacturing an organic EL element using a conventional insulating partition.
FIG. 3 is a schematic view showing a top emission type organic EL display which can be manufactured by utilizing the method of the present invention.
FIG. 4 is a schematic view showing a bottom emission type organic EL display which can be manufactured by utilizing the method of the present invention.
[Explanation of symbols]
1, 21, 51 Substrate 2, 22, 52 Lower electrode 3, 23, 53 Organic EL light emitting layer 4, 24, 54 Upper electrode 5, 35 Passivation layer 6 Wire 7 Second passivation layer 26R, 26G, 26B Color filter layer ( Red, green, blue)
27R, 27G color conversion layer (red, green)
Reference Signs List 28 protection layer 29 color filter protection passivation layer 30 filler layer 31 sealing resin 32 transparent substrate 33 black mask 34 transparent electrode 36 upper electrode 37 sealing substrate 55 cathode partition

Claims (4)

A step of uniformly forming an upper electrode on a substrate provided with a lower electrode having a line pattern and an organic EL light emitting layer;
Forming a patterned passivation layer on the top electrode;
Separating the upper electrode into a line pattern extending in a direction perpendicular to the line pattern of the lower electrode by performing dry etching using the passivation layer as a mask. . 2. The method according to claim 1, wherein the dry etching is reactive ion etching or physical etching. 2. The method according to claim 1, wherein the step of forming the patterned passivation layer includes dry etching using a resist as a mask. 4. The method according to claim 3, wherein the dry etching using the resist as a mask is reactive ion etching or physical etching.

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